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  • 1
    Publication Date: 2018-04-01
    Print ISSN: 0031-3203
    Electronic ISSN: 1873-5142
    Topics: Computer Science
    Published by Elsevier
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  • 2
    Publication Date: 2018-01-01
    Print ISSN: 0031-3203
    Electronic ISSN: 1873-5142
    Topics: Computer Science
    Published by Elsevier
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  • 3
    Publication Date: 2018
    Description: 〈p〉Publication date: November 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Comptes Rendus Geoscience, Volume 350, Issue 7〈/p〉 〈p〉Author(s): Ilias Fountoulakis, Christos S. Zerefos, Alkiviadis F. Bais, John Kapsomenakis, Maria-Elissavet Koukouli, Nozomu Ohkawara, Vitali Fioletov, Hugo De Backer, Kaisa Lakkala, Tomi Karppinen, Ann R. Webb〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Spectral UV records of solar irradiance at stations over Europe, Canada, and Japan were used to study long-term trends at 307.5 nm for a 25-year period, from 1992 to 2016. Ground-based measurements of total ozone, as well as satellite measurements of the Aerosol Index, the Total Cloud Cover and the surface reflectivity were also used in order to attribute the estimated changes of the UV to the corresponding changes of these factors. The present study shows that over the Northern Hemisphere, the long-term changes in UV-B radiation reaching the Earth's surface vary significantly over different locations, and that the main drivers of these variations are changes in aerosols and total ozone. At high latitudes, part of the observed changes may also be attributed to changes in the surface reflectivity. Over Japan, the UV-B irradiance at 307.5 nm has increased significantly by ∼3%/decade during the past 25 years, possibly due to the corresponding significant decrease of its absorption by aerosols. It was found that the greatest part of this increase took place before the mid-2000s. The only European station, over which UV radiation increases significantly, is that of Thessaloniki, Greece. Analysis of the clear-sky irradiance for the particular station shows increasing irradiance at 307.5 nm by ∼3.5%/decade during the entire period of study, with an increasing rate of change during the last decade, possibly again due to the decreasing absorption by aerosols.〈/p〉〈/div〉
    Print ISSN: 1631-0713
    Electronic ISSN: 1778-7025
    Topics: Geography , Geosciences
    Published by Elsevier
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  • 4
    Publication Date: 2018
    Description: 〈p〉Publication date: Available online 1 November 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Complexity〈/p〉 〈p〉Author(s): Robert J. Kunsch, Erich Novak, Daniel Rudolf〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We compute the integral of a function or the expectation of a random variable with minimal cost and use, for our new algorithm and for upper bounds of the complexity, i.i.d. samples. Under certain assumptions it is possible to select a sample size based on a variance estimation, or – more generally – based on an estimation of a (central absolute) 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si1.gif"〉〈mi〉p〈/mi〉〈/math〉-moment. That way one can guarantee a small absolute error with high probability, the problem is thus called solvable. The expected cost of the method depends on the 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si1.gif"〉〈mi〉p〈/mi〉〈/math〉-moment of the random variable, which can be arbitrarily large. In order to prove the optimality of our algorithm we also provide lower bounds. These bounds apply not only to methods based on i.i.d. samples but also to general randomized algorithms. They show that – up to constants – the cost of the algorithm is optimal in terms of accuracy, confidence level, and norm of the particular input random variable. Since the considered classes of random variables or integrands are very large, the worst case cost would be infinite. Nevertheless one can define adaptive stopping rules such that for each input the expected cost is finite. We contrast these positive results with examples of integration problems that are not solvable.〈/p〉〈/div〉
    Print ISSN: 0885-064X
    Electronic ISSN: 1090-2708
    Topics: Computer Science , Mathematics
    Published by Elsevier
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  • 5
    Publication Date: 2018
    Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 84〈/p〉 〈p〉Author(s): Xing-Wei Xiang, Jin-Xing Xiao, Yu-Fang Zhou, Bin Zheng, Zheng-Shun Wen〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The black seabream (〈em〉Sparus macrocephlus〈/em〉) is an economically pivotal aquaculture species cultured in China and Southeast Asian countries. To understand the molecular immune mechanisms underlying the response to 〈em〉Vibrio parahaemolyticus〈/em〉, a comparative gene transcription analysis were performed with utilized fresh livers of 〈em〉V. parahaemolyticus〈/em〉-immunized 〈em〉Sparus macrocephlus〈/em〉 with a control group through RNA-Seq technology. A total of 256663 contigs were obtained after excluded the low-quality sequences and assembly. The average length of contigs collected from this research is 1066.93 bp. Furthermore, blast analysis indicates 30747 contigs were annotated based on homology with matches in the NT, NR, gene, and string databases. A gene ontology analysis was employed to classify 21598 genes according to three major functional categories: molecular function, cellular component, and biological process. A total of 14470 genes were discovered in 303 KEGG pathways. RSEM and EdgeR were introduced to estimate 3841 genes significantly different expressed (False Discovery Rate〈0.001) which includes 4072 up-regulated genes and 3771 down-regulated genes. A significant enrichment analysis of these differentially expressed genes and isogenes were conducted to reveal the major immune-related pathways which refer to the toll-like receptor, complement, coagulation cascades, and chemokine signaling pathways. In addition, 92175 potential simple sequence repeats (SSRs) and 121912 candidate single nucleotide polymorphisms (SNPs) were detected and identified sequencely in the 〈em〉Sparus macrocephlus〈/em〉 liver transcriptome. This research characterized a gene expression pattern for normal and the 〈em〉V. parahaemolyticus〈/em〉 -immunized 〈em〉Sparus macrocephlus〈/em〉 for the first time and not only sheds new light on the molecular mechanisms underlying the host-〈em〉V. parahaemolyticus〈/em〉 interaction but contribute to facilitate future studies on 〈em〉Sparus macrocephlus〈/em〉 gene expression and functional genomics.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 1050-4648
    Electronic ISSN: 1095-9947
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Published by Elsevier
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  • 6
    Publication Date: 2018
    Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 84〈/p〉 〈p〉Author(s): Yi-Hong Chen, Jian-Guo He〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The shrimp aquaculture industry is plagued by disease. Due to the lack of deep understanding of the relationship between innate immune mechanism and environmental adaptation mechanism, it is difficult to prevent and control the diseases of shrimp. The shrimp innate immune system has received much recent attention, and the functions of the humoral immune response and the cellular immune response have been preliminarily characterized. The role of environmental stress in shrimp disease has also been investigated recently, attempting to clarify the interactions among the innate immune response, the environmental stress response, and disease. Both the innate immune response and the environmental stress response have a complex relationship with shrimp diseases. Although these systems are important safeguards, allowing shrimp to adapt to adverse environments and resist infection, some pathogens, such as white spot syndrome virus, hijack these host systems. As shrimp lack an adaptive immune system, immunization therapy cannot be used to prevent and control shrimp disease. However, shrimp diseases can be controlled using ecological techniques. These techniques, which are based on the innate immune response and the environmental stress response, significantly reduce the impact of shrimp diseases. The object of this review is to summarize the recent research on shrimp environmental adaptation mechanisms, innate immune response mechanisms, and the relationship between these systems. We also suggest some directions for future research.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 1050-4648
    Electronic ISSN: 1095-9947
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
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  • 7
    Publication Date: 2018
    Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 84〈/p〉 〈p〉Author(s): Yinnan Mu, Shimin Zhou, Ning Ding, Jingqun Ao, Xinhua Chen〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Chemokines are a superfamily of structurally related chemotactic cytokines exerting significant roles in regulating cell migration and activation. Currently, five subgroups of fish specific CXC chemokines, named CXCL_F1-CXCL_F5, have been identified in teleost fish. However, understanding of the functions of these fish specific CXC chemokines is still limited. Here, a new member of fish specific CXC chemokines, 〈em〉Lc〈/em〉CXCL_F6, was cloned from large yellow croaker 〈em〉Larimichthys crocea〈/em〉. Its open reading frame (ORF) is 369 nucleotides long, encoding a peptide of 122 amino acids (aa). The deduced 〈em〉Lc〈/em〉CXCL_F6 protein contains a 19-aa signal peptide and a 103-aa mature polypeptide, which has four conserved cysteine residues (C〈sup〉28〈/sup〉, C〈sup〉30〈/sup〉, C〈sup〉56〈/sup〉, and C〈sup〉72〈/sup〉), as found in other known CXC chemokines. Phylogenetic analysis showed 〈em〉Lc〈/em〉CXCL_F6 formed a separate clade with sequences from other fish species, tentatively named CXCL_F6, distinct from the clades formed by fish CXCL_F1-5 and mammalian CXC chemokines. The 〈em〉Lc〈/em〉CXCL_F6 transcripts were constitutively expressed in all examined tissues and significantly up-regulated in the spleen and head kidney tissues by poly (I:C) and 〈em〉Vibrio alginolyticus〈/em〉. Its transcripts were also detected in primary head kidney leukocytes (HKLs), peripheral blood leucocytes (PBLs), and large yellow croaker head kidney (LYCK) cell line, and significantly up-regulated by poly(I:C), lipopolysaccharide (LPS), and peptidoglycan (PGN) in HKLs. Recombinant 〈em〉Lc〈/em〉CXCL_F6 protein (r〈em〉Lc〈/em〉CXCL_F6) could not only chemotactically attract monocytes/macrophages and lymphocytes from PBLs, but also enhance NO release and expression of proinflammatory cytokines (TNF-α, IL-1β, and CXCL8) in monocytes/macrophages. These results indicate that 〈em〉Lc〈/em〉CXCL_F6 plays a role in mediating the inflammatory response.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 1050-4648
    Electronic ISSN: 1095-9947
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
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  • 8
    Publication Date: 2018
    Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Technological Forecasting and Social Change, Volume 138〈/p〉 〈p〉Author(s): Jae-Woong Min, Nicholas S. Vonortas, YoungJun Kim〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This study explores the factors that contribute to the commercialization of technologies transferred from universities and public research institutes (U&PRIs) to companies. We take a step further than the established literature focusing on technology transfer to examine factors that also affect the chances of the successful commercialization of the transferred technologies through an empirical analysis of 669 technology transfer cases in Korea. The study shows that the intensity of market competition is a key factor in moderating the effects of partnership and absorptive capacity on the successful commercialization of transferred technologies. While collaboration with U&PRIs exerts a positive effect on commercialization success, this effect is weakened by the intensity of market competition. The intensity of market competition boosts the importance of company absorptive capacity for the commercialization success of the transferred technology. We conclude that strategic management of the absorptive capacities of companies and their partnership with U&PRIs are necessary ingredients of the success of technology transfer in concordance with the intensity of competition that the company faces in the market.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0040-1625
    Electronic ISSN: 1873-5509
    Topics: Geography , Sociology , Technology
    Published by Elsevier
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  • 9
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    Elsevier
    Publication Date: 2018
    Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Computers in Industry, Volume 104〈/p〉 〈p〉Author(s): Jacques Bahi, Wiem Elghazel, Christophe Guyeux, Mourad Hakem, Kamal Medjaher, Noureddine Zerhouni〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Monitoring activities in industry may require the use of wireless sensor networks, for instance due to difficult access or hostile environment. But it is well known that this type of networks has various limitations like the amount of disposable energy. Indeed, once a sensor node exhausts its resources, it will be dropped from the network, stopping so to forward information about maybe relevant features towards the sink. This will result in broken links and data loss which impacts the diagnostic accuracy at the sink level. It is therefore important to keep the network's monitoring service as long as possible by preserving the energy held by the nodes. As packet transfer consumes the highest amount of energy comparing to other activities in the network, various topologies are usually implemented in wireless sensor networks to increase the network lifetime. In this paper, we emphasize that it is more difficult to perform a good diagnostic when data are gathered by a wireless sensor network instead of a wired one, due to broken links and data loss on the one hand, and deployed network topologies on the other hand. Three strategies are considered to reduce packet transfers: (1) sensor nodes send directly their data to the sink, (2) nodes are divided by clusters, and the cluster heads send the average of their clusters directly to the sink, and (3) averaged data are sent from cluster heads to cluster heads in a hop-by-hop mode, leading to an avalanche of averages. Their impact on the diagnostic accuracy is then evaluated. We show that the use of random forests is relevant for diagnostics when data are aggregated through the network and when sensors stop to transmit their values when their batteries are emptied. This relevance is discussed qualitatively and evaluated numerically by comparing the random forests performance to state-of-the-art PHM approaches, namely: basic bagging of decision trees, support vector machine, multinomial naive Bayes, AdaBoost, and Gradient Boosting. Finally, a way to couple the two best methods, namely the random forests and the gradient boosting, is proposed by finding the best hyperparameters of the former by using the latter.〈/p〉〈/div〉
    Print ISSN: 0166-3615
    Electronic ISSN: 1872-6194
    Topics: Computer Science , Technology
    Published by Elsevier
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  • 10
    Publication Date: 2018
    Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Marine Policy, Volume 99〈/p〉 〈p〉Author(s): Pablo Quero García, Javier García Sanabria, Juan Adolfo Chica Ruiz〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In recent years the European Union has firmly committed itself to energy from oceans as a means of decarbonising the European energy system. Despite a favourable political landscape, the development of offshore renewables still faces economic and technological barriers, which are coupled with the inherent difficulties of an increasingly industrialised marine environment, such as complex evolving regulation, lack of knowledge regarding the possible environmental impact of such an activity, as well as spatial conflicts with other traditional and emerging uses. Most of the coastal Member States have adopted Maritime Spatial Planning (MSP) as a fundamental tool for integrated and sustainable management of human activities in the marine environment. MSP is capable of definitively driving the use of offshore renewable facilities. Its proper application supports decision making, simplifies and accelerates the process of obtaining permits, improves compatibility of uses, integrates stakeholders in planning, prevents environmental deterioration of sensitive areas, enhances the availability of information and promotes cross-border co-operation. This paper aims to evaluate the influence of maritime spatial planning processes on the advance of blue energy within the framework of the European Union. The results show positive relationships between MSP and the development of offshore renewable energy in countries such as Germany, the Netherlands and the United Kingdom.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0308597X1830304X-fx1.jpg" width="477" alt="fx1" title="fx1"〉〈/figure〉〈/p〉〈/div〉
    Print ISSN: 0308-597X
    Electronic ISSN: 1872-9460
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Political Science , Law
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  • 11
    Publication Date: 2018
    Description: 〈p〉Publication date: 1 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Ocean & Coastal Management, Volume 167〈/p〉 〈p〉Author(s): Uxío Labarta, M〈sup〉a〈/sup〉 José Fernández-Reiriz〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉The mussels industry with a production that accounts for more than twenty five percent of the fresh product landings from the sea, and the full-time employment of more than 8000 people, is by far the largest productive activity of the Galician sea.〈/p〉 〈p〉In the 1980s was noticed an increase in productivity related to processes of innovation in the industry of mussel. Together with it, the first organizational forms of the Galician-based production sector was constituted, with a spatial and administrative reordering for mussel rafts and crops. A new reality of the sector was maintained in both the marketing guidelines and the fact of initiating a vertical integration between the mussel industry and the commercialization. Everything was accompanied by changes in markets and strong tensions: derived from red tides that limit the operating cycle and even its profitability and also from the conflicts between the producing and transforming organizations, added to the competition in the markets of other countries, mainly Chile.〈/p〉 〈p〉The reality of mussel culture and markets leads to a reformulation in the industry, with strategies for territorial diversification of suppliers, new technological improvements in production and even organizational, economic, and bioecological innovations.〈/p〉 〈/div〉 〈/div〉
    Print ISSN: 0964-5691
    Electronic ISSN: 1873-524X
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Geography
    Published by Elsevier
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  • 12
    Publication Date: 2018
    Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Marine Policy, Volume 99〈/p〉 〈p〉Author(s): Bong-Tae Kim, Christopher L. Brown, Do-Hoon Kim〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We assess the vulnerability to climate change of Korean aquaculture based on predicted changes in seawater temperature and salinity in adjacent sea areas of the Korean Peninsula according to representative concentration pathways (RCP) scenarios. Unlike previous studies that have been conducted mostly on a national scale, we classify 14 farming species in major production regions of the Republic of Korea, and assess their vulnerability for each region, using the indicator-based method and the Intergovernmental Panel on Climate Change's definition of vulnerability in order to overcome limitations in developing specific adaptation strategies within a country. First, for each exposure, sensitivity, and adaptive capacity, specific and proper indicators are selected. Subsequently, these indicators are estimated and weighted to analyze vulnerability to climate change. The results show that the absolute level of vulnerability is high in a long-term period of RCP8.5 in which exposure becomes severe, whereas the relative vulnerability is similar among farming species and regions. Specifically, vulnerability is at the highest level in seaweed, such as laver and sea mustard, while fish, shrimp, and abalone are relatively less vulnerable to climate change.〈/p〉〈/div〉
    Print ISSN: 0308-597X
    Electronic ISSN: 1872-9460
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Political Science , Law
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  • 13
    Publication Date: 2018
    Description: 〈p〉Publication date: December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Transport Geography, Volume 73〈/p〉 〈p〉Author(s): Chengxi Liu, Yusak O. Susilo, Dimas B.E. Dharmowijoyo〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The activity space of an individual is defined as the activity-travel environment which a traveller is using for his or her activities (Axhausen et al., 2002). It is limited by this individual's ability and resources, such as available time for travel as well as his or her anchor points. However, most existing studies have focused on single individual activity space, ignoring the fact that individuals' activities often interact with that of his or her family members'. In this paper a multivariate model is proposed where the correlation between travel time of fathers and mothers, and the correlation between the activity space and travel time are modelled explicitly. The estimated correlations from these joint distributions provide insights into both the intra-household interactions in daily travel and the intrinsic relationships of the hidden limits in the dimensions of space and time. The travel time limits are modelled using a stochastic frontier model component, which can estimate an unobserved upper or lower limit for travel time expenditure. This limit usually refers to the maximum travel time budget or minimum travel time need, which denotes the maximum or minimum amount of travel time that an individual is willing or able to allocate per day. The concept of the confidence ellipse is used as a measure of activity space constructed from the multi-day travel diary data. It is hypothesised that the unobserved travel time limits and activity space sizes of fathers and mothers are correlated with each other, due to a similar spatial knowledge and accessibility to various facilities. The daily variations in the travel time expenditure of parents are also assumed to be correlated because of daily household task allocation and joint household travel. Data collected from a three-week household travel diary in the Bandung Metropolitan Area in Indonesia are used for estimation in this study. The estimated frontier model component shows that neither parent has reached their maximum travel time budget and/or minimum travel time need that they inherently must spend. Compared with other attributes, the perceived accessibility attributes play the most important role in influencing the activity space limits. For households with fully employed fathers, a trade-off mechanism is found in travel time expenditure between parents, which is likely due to the redistribution of household tasks. On the other hand, for households with fathers who are not fully employed, a complementary effect is found, arising from the joint travel among household members. The travel time budget and activity space limits of fathers are positively correlated with those of mothers. These findings call for the formulation of transport policies that consider the household as a unit, especially in developing countries such as Indonesia, to fulfil the mobility needs of different market segments, e.g., households with fully employed fathers and those with fathers who are not fully employed.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0966-6923
    Electronic ISSN: 1873-1236
    Topics: Architecture, Civil Engineering, Surveying , Geography
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  • 14
    Publication Date: 2018
    Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Biology and Biochemistry, Volume 128〈/p〉 〈p〉Author(s): J.M. Kranabetter〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Forest floor carbon (C) sequestration has been negatively correlated with manganese (Mn) availability, possibly due to reduced efficacy of Mn-peridoxase enzymes produced by Agaricomycete fungi. I examined a soil C and Mn dataset from a podzolization gradient, along with fungal sporocarp Mn concentrations, to potentially corroborate this finding. An inverse power relationship between soil C and soil Mn content across temperate rainforests was confirmed, which provides further evidence of a Mn bottleneck in C turnover. Average Mn concentrations of saprotrophic sporocarps were greater than those of ectomycorrhizal fungi, and displayed a similar inverse correlation with increasing soil C. The absence or limited effectiveness of select saprotrophic fungi across Mn-depleted forest soils may be one mechanism behind impeded turnover of recalcitrant organic matter.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0038-0717
    Electronic ISSN: 1879-3428
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
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  • 15
    Publication Date: 2018
    Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Biology and Biochemistry, Volume 128〈/p〉 〈p〉Author(s): Charles R. Warren〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Phospholipids are isolated from crude lipid extracts by silica solid phase extraction (SPE), but for soils we don't know if phospholipids are the only fatty acid-based lipids present in the polar lipid fraction. Lipids extracted from three soils were fractionated with a silica SPE protocol commonly used for soils, with “neutrals” eluted by chloroform, “glycolipids” eluted by acetone, and “phospholipids” eluted by methanol. Fatty acid-based lipids were identified and quantified by liquid chromatography-mass spectrometry. Phospholipids were recovered in the methanol fraction, but this fraction also included betaine lipids. In two soils the methanol fraction was 3–6% betaine lipid while in one soil betaine lipids accounted for 48% of lipids in the methanol fraction. Clearly the fraction obtained by eluting lipids from silica with methanol is not purely phospholipid but can contain significant amounts of other polar lipids.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0038-0717
    Electronic ISSN: 1879-3428
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
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  • 16
    Publication Date: 2018
    Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Remote Sensing of Environment, Volume 220〈/p〉 〈p〉Author(s): Xiyu Chen, Lin Liu, Annett Bartsch〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Microwave remote sensing, both active or passive, can provide useful information about the freeze/thaw (F/T) state of soil near the surface. Here we apply an edge detection algorithm on time series of indicators derived from measurements of SMAP L-band radiometer and ASCAT C-band scatterometer to detect the freeze/thaw onsets of surface soil. Comparing these results against the onsets derived from in situ measurements in Alaska, we demonstrate that this algorithm is an effective approach to detect onsets of the soil F/T transition. More specifically, our results show that the thawing onsets estimated from the SMAP data occurred 5 to 13 days earlier than the onsets estimated from the in situ measurements, which is likely due to the influence of snowmelt on the radiometer signal. The thawing onsets estimated from the ASCAT data were about 6 days later than the in situ onsets. Our estimated freezing onsets from each microwave remote sensing dataset were close to the in situ onsets (1–5 days). We also compare our estimated onsets with those from the SMAP Level 3 F/T product and the mean biases for thawing and freezing onsets are 1 ± 2 and 1 ± 3 days, respectively. Furthermore, we illustrate the complementary nature of the SMAP and ASCAT measurements and the potential for combining these two to differentiate snowmelt from soil thawing events.〈/p〉〈/div〉
    Print ISSN: 0034-4257
    Electronic ISSN: 1879-0704
    Topics: Architecture, Civil Engineering, Surveying , Geography
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  • 17
    Publication Date: 2018
    Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Remote Sensing of Environment, Volume 220〈/p〉 〈p〉Author(s): Mathilde Cancet, David Griffin, Madeleine Cahill, Bertrand Chapron, Johnny Johannessen, Craig Donlon〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉Australia's marginal seas include a wide range of ocean current regimes ranging from tide-dominated in the North-West where the continental shelf is wide, to boundary current- and eddy-dominated in the South-East, where the shelf is narrow. Here, we take the opportunity to test the GlobCurrent surface ocean current products against in-situ observations in these two contrasting regimes. Observations by Acoustic Doppler Current Profiler (ADCP) instruments of Australia's Integrated Marine Observing System (IMOS) and drifting buoys of the Global Drifting Programme (GDP) are used.〈/p〉 〈p〉The monthly-timescale variability of the GlobCurrent alongshore current component is in moderately good agreement with the observations on the continental shelf in the South-East but neither the shorter period variability nor the long-term mean are representative of the ADCP observations. While the observed tidal currents are negligibly small, the wind-driven signals are not. But these are evidently too transient to be adequately sampled by altimetry. The inclusion of an Ekman component does not represent these signals because the interaction of the Ekman transport with the coastal boundary condition is not included. Similarly, the error of the time-mean velocity, which is the dominant error, is because that product is not designed to represent the highly anisotropic nature of the sea level gradients over the continental shelf nor the constraints on the flow field that are imposed by the topography. We thus conclude that the GlobCurrent product needs improvements before it can be described as very suitable for applications on this, and probably other, narrow continental shelf. Off the continental shelf, in contrast, the GlobCurrent products compare quite well with the trajectories of drifting buoys, confirming that the products are quite suitable for blue-water applications.〈/p〉 〈p〉In contrast to the South-East, the tides are very strong in the North-West region of Australia. The sub-tidal variability is weak, in both relative and absolute senses. Consequently, the removal of the tidal signal from the sea level observations needs to be very complete for the residual error to be smaller than the true sub-tidal signal. Transient wind forced signals are also occasionally large so this step of the de-aliasing also needs to be very accurate. Unfortunately, it appears that more work is required before accurate estimates of sub-tidal variability are available from GlobCurrent: the magnitude of the GlobCurrent estimates of sub-tidal current variability far exceed the magnitude of, and are uncorrelated with, the detided ADCP data.〈/p〉 〈/div〉 〈/div〉
    Print ISSN: 0034-4257
    Electronic ISSN: 1879-0704
    Topics: Architecture, Civil Engineering, Surveying , Geography
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  • 18
    Publication Date: 2018
    Description: 〈p〉Publication date: 1 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Geoderma, Volume 337〈/p〉 〈p〉Author(s): R. Calvelo Pereira, M. Camps Arbestain, F.M. Kelliher, B.K.G. Theng, S.R. McNally, F. Macías, F. Guitián〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We have investigated the effect of supercritical drying (SD) on the porosity and the BET-N〈sub〉2〈/sub〉 specific surface area (SSA) of five allophane-rich and three non-allophanic topsoils. The contribution of organic matter (OM) and short-range ordered (SRO) constituents to the nanoscale porosity (〈100 nm size) and SSA was also evaluated following chemical treatments to oxidise OM and then remove the SRO phase. The average pore volume and SSA of the soils, measured after SD, are greater than the values obtained after air drying. For soils that are rich in SRO constituents, oxidation of OM leads to an increase in SSA. This observation is attributed to the unblocking of pore necks previously covered by OM, while the subsequent removal of SRO constituents causes a sharp decrease in SSA. The SRO constituents containing oxalate-extractable Al, are the major contributors to the SSA of the inorganic fraction. Besides confirming that SD can help preserve the nanoscale porosity of allophane-rich soils, the results highlight the contribution of SRO constituents to the SSA of soils and their ability to accumulate OM.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0016-7061
    Electronic ISSN: 1872-6259
    Topics: Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
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  • 19
    Publication Date: 2018
    Description: 〈p〉Publication date: Available online 30 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Technological Forecasting and Social Change〈/p〉 〈p〉Author(s): Sonal Choudhary, Rakesh Nayak, Sushma Kumari, Homagni Choudhury〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Drawing on theories of acculturation and information diffusion, this paper examines whether social media usage, intergroup contacts and information dissemination influence the cultural adaptation of three ethnic groups, and its implications on sustainable consumption behaviour. Twenty-four semi-structured interviews containing multiple dimensions of social media uses, acculturation, food consumption behaviour, and information diffusion were administered to a sample of Indians (living in the home country), British Indians (living in the host country for more than 10 years) and White British (natives of Britain) users of social media. Our findings suggest that there is a clear link between the integrated strategy of acculturation and information diffusion on social media, which influences acculturation to sustainable food consumption behaviour among social media users. Managerial implications of this research finding are that intervention in information diffusion aids acculturation through the social media, which serves to infuse social media and sustainability strategist with knowledge to best influence the consumers in developing sustainable food consumption behaviour. This research also identifies opportunities to expand this academic research and contribute further to the theories of remote acculturation on which limited research has been done.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0040-1625
    Electronic ISSN: 1873-5509
    Topics: Geography , Sociology , Technology
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  • 20
    Publication Date: 2018
    Description: 〈p〉Publication date: March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil and Tillage Research, Volume 186〈/p〉 〈p〉Author(s): Márcio R. Nunes, Eloy A. Pauletto, José E. Denardin, Luis E.A. S. Suzuki, Harold M. van Es〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Tillage and no-tillage result in different soil mechanical responses which in turn may affect crop growth. Better understanding of soil compressive behavior, therefore, is relevant for the assessment of tillage practices in agricultural systems. We studied the change in soil compressive properties and their relationship with soil physical attributes and plant growth through a chisel tillage chronosequence in a Nitisol where soil was untilled after chiseling for 24 months, 18 months, 12 months, 6 months, and zero months, and was under continuous (12-year) NT. The effects were measured for three soil depth layers: 0 to 7-cm, 7 to 17-cm and 20 to 30-cm. Mechanical chiseling was found to reduce both the degree of compactness and the pre-compression pressure compared to continuous NT, but made the soil more susceptible to new compaction. The effects of chisel tillage generally persisted for a period of 12–24 months. The degree of compactness and soil pre-compression pressure were found to be strongly correlated, and were strongly correlated with other soil physical attributes (soil penetration resistance, soil macroporosity, and soil aggregate stability). They were negatively correlated with root length, root density, and root volume, as well as stalk diameter, linking soil structure indicators to plant growth. Our results also showed that soil compressive parameter values can be estimated based on other soil physical properties that influence plant growth. These findings have potential for studies of crop response to soil structure and soil compaction and could be used to aid in choosing optimal soil management practices, in order to reduce the risk of soil compaction, linking soil compressive behavior and soil physical conditions to plant growth.〈/p〉〈/div〉
    Print ISSN: 0167-1987
    Electronic ISSN: 1879-3444
    Topics: Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
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  • 21
    Publication Date: 2018
    Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Computational Physics, Volume 379〈/p〉 〈p〉Author(s): Takashi Shiroto, Naofumi Ohnishi, Yasuhiko Sentoku〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉For more than half a century, most of the plasma scientists have encountered a violation of the conservation laws of charge, momentum, and energy whenever they have numerically solved the first-principle equations of kinetic plasmas, such as the relativistic Vlasov–Maxwell system. This fatal problem is brought by the fact that both the Vlasov and Maxwell equations are indirectly associated with the conservation laws by means of some mathematical manipulations. Here we propose a quadratic conservative scheme, which can strictly maintain the conservation laws by discretizing the relativistic Vlasov–Maxwell system. A discrete product rule and summation-by-parts are the key players in the construction of the quadratic conservative scheme. Numerical experiments of the relativistic two-stream instability and relativistic Weibel instability prove the validity of our computational theory, and the proposed strategy will open the doors to the first-principle studies of mesoscopic and macroscopic plasma physics.〈/p〉〈/div〉
    Print ISSN: 0021-9991
    Electronic ISSN: 1090-2716
    Topics: Computer Science , Physics
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  • 22
    Publication Date: 2018
    Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hydrology, Volume 568〈/p〉 〈p〉Author(s): E.A. Zakharova, I.N. Krylenko, A.V. Kouraev〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Due to the rapid decline of 〈em〉in situ〈/em〉 observations on river discharge in Arctic regions, evaluation of the continental freshwater input to the Arctic Ocean has become problematic and necessitates the development of alternative approaches based on remote sensing. Radar altimetric satellites have demonstrated high potential for estimation of river water discharge. Compared to polar orbiting altimeters, non-polar orbit satellites have an advantage in temporal sampling. Their greatest drawback, however, is spatial coverage: observations do not cover the low reaches of most parts of Arctic rivers. In this study of the Lena River, we demonstrate a way to overcome this limitation by using a combination of 〈em〉in situ〈/em〉 observations from tributaries and satellite observations in the middle river reaches. The water discharge as well as monthly and annual water flow were evaluated using three virtual stations. Direct combination of the water level from these virtual stations was not possible because of the difference in seasonal amplitude. However, the combination of altimetric discharge from the three independently processed tracks significantly improves the flow retrievals. The accuracy of the monthly water flow estimates at the river outlet is 23%. It increases with the integration time giving 7% for annual flow.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0022-1694
    Electronic ISSN: 1879-2707
    Topics: Architecture, Civil Engineering, Surveying , Geography , Geosciences
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  • 23
    Publication Date: 2018
    Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hydrology, Volume 568〈/p〉 〈p〉Author(s): Weihua Wu, Mingzhao Sun, Xiang Ji, Shuyi Qu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉To determine the influence of the Mesozoic Yanshanian orogeny in East Asia on contemporaneous Sr isotopic evolution of seawater, we systematically investigated the weathering profile, riverbed sediment and stream water in mono-lithological small granitic watersheds of the Jiuhua Mountains, Anhui, eastern China. Analysis based on 190 samples from 1 to 2 samplings per month during an entire hydrological year, spanning July 2014 to June 2015, shows that the intra-annual change of Sr concentration is 10–70%, but 〈sup〉87〈/sup〉Sr/〈sup〉86〈/sup〉Sr ratios only exhibit a slight change (0.709148–0.710427). This result indicates that using single sampling data to evaluate the influence of chemical weathering on the 〈sup〉87〈/sup〉Sr/〈sup〉86〈/sup〉Sr ratio evolution of seawater may cause some deviations. The 〈sup〉87〈/sup〉Sr/〈sup〉86〈/sup〉Sr ratio in the small granitic watersheds of the Jiuhua Mountains is 0.709148–0.710427 with an average of 0.710021, which is significantly higher than the lowest value (0.7068, ∼160 Ma) of seawater in the Phanerozoic. During and after this period, the East Asian continent experienced a strong tectonic event — Yanshanian orogeny and formed widespread Jurassic–Cretaceous igneous rocks, such as the Jiuhua Mountains granite in the Yangtze Block. The Yanshanian granites in several main tectonic units in China exhibit high radiogenic Sr characteristics. Combined with the evidence of enhanced chemical weathering during Late Jurassic-Early Cretaceous, the notable increase of the seawater 〈sup〉87〈/sup〉Sr/〈sup〉86〈/sup〉Sr ratio after 160 Ma may be related to the Yanshanian orogeny in East Asia.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0022169418308412-ga1.jpg" width="245" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0022-1694
    Electronic ISSN: 1879-2707
    Topics: Architecture, Civil Engineering, Surveying , Geography , Geosciences
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  • 24
    Publication Date: 2018
    Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 84〈/p〉 〈p〉Author(s): Jinghua Chen, Lu Zhang, Ning Yang, Mengyu Tian, Qiang Fu, Fenghua Tan, Chao Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Galectins are a family of galactoside-binding proteins with an affinity for β-galactosides, involved in mediating fundamental processes including development, inflammation, cell migration and apoptosis. Galectin-4 is a member of tendem-repeat galectins, plays vital roles in intestinal epithelial barrier. Here, one galectin-4 gene was captured in turbot (〈em〉Sm〈/em〉Lgals4) contains a 1197 bp open reading frame (ORF). In comparison to other species, 〈em〉Sm〈/em〉Lgals4 showed the highest similarity and identity both to large yellow croaker. The genomic structure analysis showed that 〈em〉Sm〈/em〉Lgals4 had conserved exons in the CRD domains compared to other vertebrate species. The syntenic analysis revealed that galectin-4 had the same neighboring genes across all the selected species, which suggested the synteny encompassing galectin-4 region during vertebrate evolution. Subsequently, 〈em〉Sm〈/em〉Lgals4 was widely expressed in all the examined tissues, with the highest expression level in intestine and the lowest expression level in skin. In addition, 〈em〉Sm〈/em〉Lgals4 was significantly down-regulated in intestine following both Gram-negative bacteria 〈em〉Vibrio anguillarum〈/em〉, and Gram-positive bacteria 〈em〉Streptococcus iniae〈/em〉 immersion challenge. Finally, the 〈em〉rSm〈/em〉Lgals4 showed strong binding ability to all the examined microbial ligands. Taken together, our results suggested 〈em〉Sm〈/em〉Lgals4 plays vital roles in fish intestinal immune responses against infection, but the detailed roles of galectin-4 in teleost are still lacking, further studies are needed to be carried out to characterize whether galectin-4 plays similar roles in teleost intestinal immunity.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 1050-4648
    Electronic ISSN: 1095-9947
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
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  • 25
    Publication Date: 2018
    Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 84〈/p〉 〈p〉Author(s): Yanxiu Mo, Yunpeng Fan, Wen Fu, Wenting Xu, Shujuan Chen, Yuanhui Wen, Shaojun Liu, Liangyue Peng, Yamei Xiao〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Previous research has indicated that the small compound, SP600125, could induce polyploidy of fish cells, and has established a stable tetraploid cell line from diploid fish cells. In order to explore how fish cells maintain homeostasis under SP600125-stress 〈em〉in vitro〈/em〉, this study investigates impacts of SP600125-stress on intracellular pathways, as well as on regulation of the cellular homeostasis feedback in fish cells. Transcriptomes are obtained from the SP600125-treated cells. Compared with unigenes expressed in control group (crucial carp fin cells), a total of 2670 and 1846 unigenes are significantly upregulated and downregulated in these cells, respectively. Differentially expressed genes are found, which are involved in innate defense, inflammatory pathways and cell adhesion molecules-related pathways. The SP600125-stress enhances cell-mediated immunity, characterized by significantly increasing expression of multiple immune genes. These enhanced immune genes include the pro-inflammatory cytokines (IL-1β, TNF-ɑ, IL-6R), the adaptor signal transducers (STAT, IκBɑ), and the integrins (ɑ2β1, ɑMβ2). Furthermore, mitochondria are contributed to the cellular homeostasis regulation upon the SP600125-stress. The results show that acute inflammation is an adaptive and controlled response to the SP600125-stress, which is beneficial for alleviating toxicity by SP600125. They provide a potential way of breeding fish polyploidy induced by SP600125 in the future research.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 1050-4648
    Electronic ISSN: 1095-9947
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
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  • 26
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    Elsevier
    In: Geoforum
    Publication Date: 2018
    Description: 〈p〉Publication date: December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Geoforum, Volume 97〈/p〉 〈p〉Author(s): Rebecca Sandover, Samuel Kinsley, Stephen Hinchliffe〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Geographers and other social scientists have for some time been interested in how scientific and environmental controversies emerge and become public or collective issues. Social media are now key platforms through which these issues are publically raised and through which groups or publics can organise themselves. As media that generate data and traces of networking activity, these platforms also provide an opportunity for scholars to study the character and constitution of those groupings. In this paper we lay out a method for studying these ‘issue publics’: emergent groupings involved in publicising an issue. We focus on the controversy surrounding the state-sanctioned cull of wild badgers in England as a contested means of disease management in cattle. We analyse two overlapping groupings to demonstrate how online issue publics function in a variety of ways – from the ‘echo chambers’ of online sharing of information, to the marshalling of agreements on strategies for action, to more dialogic patterns of debate. We demonstrate the ways in which digital media platforms are themselves performative in the formation of issue publics and that, while this creates issues, we should not retreat into debates around the ‘proper object’ of research but rather engage with the productive complications of mapping social media data into knowledge (Whatmore, 2009). In turn, we argue that online issue publics are not homogeneous and that the lines of heterogeneity are neither simple or to be expected and merit study as a means to understand the suite of processes and novel contexts involved in the emergence of a public.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0016-7185
    Electronic ISSN: 1872-9398
    Topics: Geography , Economics
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  • 27
    Publication Date: 2018
    Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 84〈/p〉 〈p〉Author(s): Maciej Woźny, Kazimierz Obremski, Piotr Hliwa, Piotr Gomułka, Rafał Różyński, Paweł Wojtacha, Maciej Florczyk, Helmut Segner, Paweł Brzuzan〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉To investigate the effects of feed contamination with zearalenone (ZEN) at the current European Commission (EC) guidance value (2 mg⋅kg〈sup〉−1〈/sup〉 feed) on the growth and health of rainbow trout, we performed a long-term feeding trial under aquaculture conditions. It started with the external feeding of the fish larvae, and continued for 96 weeks, at which point the fish had reached market size. To assess the growth of fish and their feeding efficiency throughout this period, the fish were regularly weighed and measured, and their feed consumption was monitored. Additionally, to investigate potential health effects, after 72 weeks of the exposure to ZEN, the fishes' blood was analyzed for major hematological and biochemical indices, and their head kidney, spleen, and liver were examined for morphological, histopathological, cytological, and molecular changes. Finally, to gain insight into the metabolism and distribution of ZEN in fish, the content of free and glucuronidated forms of ZEN and its major metabolites was measured in the intestine, liver, and muscles of the exposed fish. The feed-borne exposure of rainbow trout to ZEN at a dose of 2 mg⋅kg〈sup〉−1〈/sup〉 feed resulted in higher feeding efficiency and growth rate, most probably due to the anabolic properties of the ZEN metabolite. Importantly for the consumers of fish, despite absorption and metabolism of ZEN in the digestive system of the fish that had been exposed for 72 weeks, the residuals of ZEN were not transferred to the fishes’ muscles, which rules out a potential risk to human health related to the consumption of fish meat. However, the increased growth of fish fed with the contaminated feed may come at some cost, as the exposure to ZEN was associated with modulation of key components of the adaptive and innate immune systems. Moreover, the trunk kidney of ZEN-fed fish showed massive inflammation that was likely caused by pathogen infection. These findings raise concerns about fish health under the current recommended EC guidance values.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 1050-4648
    Electronic ISSN: 1095-9947
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
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  • 28
    Publication Date: 2018
    Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Transportation Research Part F: Traffic Psychology and Behaviour, Volume 60〈/p〉 〈p〉Author(s): Jennifer Howcroft, Frank Knoefel, Bruce Wallace, Rafik Goubran, Michelle M. Porter, Shawn Marshall〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Naturalistic in-car driving informatics provides opportunities to identify links between driving behaviours and cognitive and physical health status. The coefficient of variation was used to evaluate deceleration event variability (1) for differences between 171 older adult drivers grouped based on physical and cognitive scores and (2) for changes that aligned with longitudinal health changes in 62 older adult drivers. Differences in older adult physical and cognitive health status were related to deceleration event variability. Greater deceleration event variability was identified in individuals with better cognitive health, with two exceptions. There were also deceleration events subsets where individuals with poorer physical health status exhibited greater variability in deceleration patterns than those with better health status. CoV-measured deceleration event variability did significantly decrease for individuals with longitudinal cognitive health decline and for individuals with longitudinal physical health declines (velocity signal only) for decelerations subsets and CoV increased for individuals with longitudinal physical health decline for acceleration and jerk signals for event deceleration subsets. These findings suggest that worse cognitive health may limit older adult driver’s ability to adapt deceleration patterns when needed, resulting in lower CoV-measured variability. However, particularly in situations that require less adaptation to deceleration patterns, worse physical health may induce unnecessary variability during deceleration events. Further investigation is warranted to determine whether differences in variability relate to successful braking collision avoidance behaviours.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 1369-8478
    Electronic ISSN: 1873-5517
    Topics: Geography , Psychology
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  • 29
    Publication Date: 2018
    Description: 〈p〉Publication date: 5 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science, Volume 217〈/p〉 〈p〉Author(s): Chao Chen, Jiaoqi Fu, Shuai Zhang, Xin Zhao〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉As a dynamic belt between land and oceans, coastline provides rich information on land-ocean interactions. Sensitive to climate and anthropogenic influences, the changing coastline affects intertidal mudflat resources and the coastal environment. In this study, the greenness and wetness components of the tasseled cap transformation (TCT) were used to extract coastline information. Due to the high total suspended sediment content that leads to the failure of traditional method, sea-waterbody information extraction was initially carried out by TCT. After considering the characteristics of coastline in remote sensing images and coastline morphology in the natural world, the coastline with shorter length was eliminated and the intermittent coastline was connected based on the coordinate geometry description (such as length, distance, and direction). Finally, the results of the coastline information extraction were superimposed on the original images to evaluate accuracy. The experimental results indicated that the proposed method was more effective in clearly delineating the land-ocean boundary. The producer's accuracy and user's accuracy were 0.95 and 0.91, respectively, and the length extraction error was −2.16%. Therefore, the proposed method was more successful for coastline information extraction in the area with high sediment concentration.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0272-7714
    Electronic ISSN: 1096-0015
    Topics: Biology , Geography , Geosciences
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  • 30
    Publication Date: 2018
    Description: 〈p〉Publication date: December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Transportation Research Part D: Transport and Environment, Volume 65〈/p〉 〈p〉Author(s): Michel André, Anaïs Pasquier, Marion Carteret〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Low emission zones are frequently envisaged as a means of decreasing air pollution in city centres. In the present study, we used video monitoring to characterize the in-use local vehicle fleet at several points in the Île-de-France region (which includes the city of Paris), enabling accurate description of the type of engine and vehicle age and emission standard, which together determine their pollutant emission levels. Local vehicle fleets differed from French national estimates, as further confirmed by a Regional Mobility Survey. Both approaches (video monitoring and mobility survey) demonstrated geographical differences in the proportions of diesel and of recent vehicles. Economically advantaged areas, with lower rates of polluting and diesel-fuelled vehicles, are thus further advantaged as regards air quality and less affected by driving restrictions. Simulation of pollutant emissions demonstrated the sensitivity of the estimates to local fleet composition. They also raised the important contributions of traffic outside the city centre, of heavy vehicles and cold starts. Knowledge of the local vehicle fleet is thus important for designing low emission zones that will be effective in terms of air pollution and equitable in terms of geographical areas.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 1361-9209
    Electronic ISSN: 1879-2340
    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography
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  • 31
    Publication Date: 2018
    Description: 〈p〉Publication date: December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Transportation Research Part C: Emerging Technologies, Volume 97〈/p〉 〈p〉Author(s): Alexandros Angelopoulos, Damianos Gavalas, Charalampos Konstantopoulos, Damianos Kypriadis, Grammati Pantziou〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The asymmetric demand-offer problem represents a major challenge for one-way vehicle sharing systems (VSS) affecting their economic viability as it necessitates the engagement of considerable human (and financial) resources in relocating vehicles to satisfy customer demand. In this paper, we propose a novel approach which involves user-based vehicle relocations to address supply-and-demand mismatches; in our approach, VSS users are offered price incentives so as to accept picking up their vehicle from an oversupplied station and/or to drop it off to an under-supplied station. The system incentivizes users based on the priorities of vehicle relocations among stations, taking into account the fluctuating demand for vehicles and parking places at different stations over time. A graph-theoretic approach is employed for modeling the problem of allocating vehicles to users in a way that maximizes the profit of the system taking into account the budget the VSS can afford to spend for rewarding users, as well as the users’ strategic behavior. We present two different schemes for incentivizing users to act in favour of the system. Both schemes consider budget constraints and are truthful and budget-feasible. We have extensively evaluated our approach through simulations which demonstrated significant gain with respect to the number of completed trips and system revenue. We have also validated our approach through pilot trials conducted in a free-floating e-motorbike sharing system in the framework of an EU-funded research project.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0968-090X
    Electronic ISSN: 1879-2359
    Topics: Architecture, Civil Engineering, Surveying , Geography
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  • 32
    Publication Date: 2018
    Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Transportation Research Part F: Traffic Psychology and Behaviour, Volume 60〈/p〉 〈p〉Author(s): Jing Shi, Meiyu Liu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Inappropriate lane changing behaviour increases a driver’s risk of being involved in a crash and the injury severity levels. It is hypothesized in this study that differentiated per-lane speed limit freeways could reduce inappropriate lane changing behaviours. A driving simulator experiment was conducted to investigate drivers’ lane changing behaviour and the corresponding workload levels when different speed limit values are assigned to different lanes. Participants (〈em〉N〈/em〉 = 36) experienced three different test scenarios with different speed limit configurations. Lane changing behaviours are compared in regards to five measures describing lane changing behaviour. Meanwhile, task workload indexes were developed to evaluate key aspects of drivers’ subjective experience of the test. The results reveal that the speed limit configurations have a considerable impact on lane changing behaviour as well as on the corresponding driving workload levels. This applies especially to the scenario with both different maximum and minimum speed limits for adjacent lanes, with drivers behaving differently than they did in other situations. Lane changes were found to be less frequent and have shorter durations, and drivers tended to avoid the dangerous behaviour of “rolling on the lane edge”, therefore these compensatory safety-prone driving strategies suggest an enhanced driving safety level in association with the differentiated per-lane speed limit scenarios. The findings could provide important references for traffic management of freeways.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 1369-8478
    Electronic ISSN: 1873-5517
    Topics: Geography , Psychology
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  • 33
    Publication Date: 2018
    Description: 〈p〉Publication date: December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Transportation Research Part B: Methodological, Volume 118〈/p〉 〈p〉Author(s): Qian-Wen Guo, Shumin Chen, Paul Schonfeld, Zhongfei Li〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We address optimal rail transit investment issues considering time-inconsistent preferences and population uncertainty. Instead of adopting the typical real options approach which assumes that authorities possess a constant discount rate over time, we propose an extension of real options analysis by modeling authorities’ intertemporal choices with a quasi-hyperbolic discount function. Depending on the assumption about the strategies guiding the behaviors of future authorities, we consider three types of authorities, namely time-consistent authority, naïve authority and sophisticated authority, of which the latter two are time-inconsistent. First, an optimal transit investment timing model is proposed. Then, solutions for the above three types of authorities are derived and compared. We demonstrate the performance of the proposed model by conducting numerical tests and applying it to Dalian, China. Main findings include: (1) an authority with time-inconsistent preferences makes decisions earlier than a standard, time-consistent authority; (2) the sophisticated authority invests earlier than the naïve authority. Other implications of considering time-inconsistent preferences are also identified.〈/p〉〈/div〉
    Print ISSN: 0191-2615
    Electronic ISSN: 1879-2367
    Topics: Architecture, Civil Engineering, Surveying , Geography , Economics
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  • 34
    Publication Date: 2018
    Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Geomorphology, Volume 327〈/p〉 〈p〉Author(s): Fei Yan, Qiuwen Zhang, Song Ye, Bo Ren〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Landslides, which could cause huge losses of lives or property damages, result from several different environmental factors whose influences on landslides are very complex. Therefore, it is essential to understand the relationships between these environmental factors and landslides. Thus, the integration of the analytical hierarchy process (AHP) with the normalized frequency ratio (NFR) is evaluated for landslide susceptibility analyses. However, in addition to these complex relationships, the randomness and fuzziness always affect landslide susceptibility mapping. This study introduces the cloud model (CM) to improve the integrated AHP-NFR method, and proposes a novel hybrid AHP-NFR-CM method for landslide susceptibility analyses, which can better address issues of the randomness and fuzziness. Firstly, ten environmental parameters are selected as landslide impact factors, and their values for all the landslides identified in the study area are obtained through the remote sensing (RS) and geographical information system (GIS) technologies. The AHP method is used to obtain the weight of each landslide impact factor, and the NFR method is used to obtain the weight of each subclass in each landslide impact factor, which can reflect the relationship between the landslide impact factor and landslide occurrence. After applying an appropriate compositional operation between the weights of the landslide impact factors and the weights of the subclasses of the impact factors, a landslide susceptibility index (LSI) for each grid divided via the attribution-based spatial information multi-grid method (ASIMG) can be computed. To solve the inevitable issues of randomness and fuzziness in landslide susceptibility analyses, a cloud model that uses three numerical features (expectation, entropy and hyper-entropy) to represent the intension of the concept, is adopted to improve the methods of AHP and NFR. The relative importance of two landslide impact factors is scaled with the cloud model rather than the Saaty criteria. Pair-wise comparison matrixes of landslide impact factors given by each expert are described by the normal cloud model, and the floating cloud model is used to aggregate all experts' judgments. The weight of each landslide impact factor is also expressed with the cloud model rather than a certain value. In improving the NFR, the weight of each subclass of each landslide impact factor is expressed with the cloud model rather than a certain value. In the improvement of the landslide susceptibility results, the domain of landslide risk assessment results is also displayed with the cloud model instead of a series of definite intervals. As the study area examined is large, several grids would need to be divided, meaning that it would take a considerable amount time to subject the entire study area to landslide susceptibility mapping. Thus, we propose a new attribute-based spatial information multi-grid (ASIMG) division method and introduce grid-computing technology to improve the calculation efficiency during the process. Finally, the proposed hybrid AHP-NFR-CM-ASIMG approach is validated and applied in the study area. It's concluded that the new integration of AHP and NFR methods with the cloud model can consider both randomness and fuzziness and therefore can increase the robustness of landslide susceptibility analyses, while the ASIMG technology can enhance the calculation efficiency in regional landslide susceptibility mapping.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0169-555X
    Electronic ISSN: 1872-695X
    Topics: Geography , Geosciences
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  • 35
    Publication Date: 2018
    Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hydrology, Volume 568〈/p〉 〈p〉Author(s): Shanshan Deng, Junqiang Xia, Meirong Zhou, Fenfen Lin〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Recent significant channel evolution in the Jingjiang Reach has raised much attention, particularly the remarkable bank erosion. A coupled model for simulating bed deformation and bank erosion has been proposed in this study, which focuses on the erosion of the bank with a composite structure in the Lower Jingjiang Reach. In order to cover three contributing processes that may interact with each other, the proposed model integrates a one-dimensional morphodynamic module with a two-dimensional module of ground water flow and a bank erosion module for the cantilever failure of a composite riverbank. Model performance was evaluated through a detailed simulation of channel evolution along a 150.8-km subreach in the Jingjiang Reach over the 2005 hydrological year. Satisfying results were obtained from the simulation, showing relatively close agreement between the calculations and measurements in terms of hydrological data at the outlet section, bank erosion sites, longitudinal channel profile and typical cross-sectional profiles. In addition, investigations into temporal changes in bank soil properties and critical overhanging width at cantilever failure demonstrate that there was a seasonal variation in the volumetric water content of bank soil, which increased during the rising and flood periods and then decreased during the recession period, showing an impact on the occurrence timing of cantilever failures. The tensile strength and critical overhanging width had an inverse relationship with the water content, whereas the critical width sharply increased and then decreased during high flows affected by a rapid change in river stage. The temporal distribution of cantilever failure events indicates that cantilever failure primarily occurred in the flood and recession periods. The effects of bed roughness, water content variation and secondary flow on bank erosion were also discussed.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0022-1694
    Electronic ISSN: 1879-2707
    Topics: Architecture, Civil Engineering, Surveying , Geography , Geosciences
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  • 36
    Publication Date: 2018
    Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hydrology, Volume 568〈/p〉 〈p〉Author(s): M. Esteves, C. Legout, O. Navratil, O. Evrard〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉In mountainous catchments, soil erosion and sediment transport are highly variable throughout time and their quantification remains a major challenge for the scientific community. Understanding the temporal patterns and the main controls of sediment yields in these environments requires a long term monitoring of rainfall, runoff and sediment flux. This paper analyses this type of data collected during 7 years (2007–2014), at the outlet of the Galabre River, a 20 km〈sup〉2〈/sup〉 watershed, in south eastern France, representative of meso-scale Mediterranean mountainous catchments.〈/p〉 〈p〉This study is based on a hybrid approach using continuous turbidity records and automated total suspended solid sampling to quantify the instantaneous suspended sediment concentrations (SSC), sediment fluxes, event loads and yields. The total suspended sediment yield was 4661 Mg km〈sup〉−2〈/sup〉 and was observed during flood events. The two crucial periods for suspended sediment transport at the outlet were June and November/December (63% of the total). The analysis of suspended sediment transport dynamics observed during 236 flood events highlighted their intermittency and did not show any clear relationship between rainfall, discharge and SSC. The most efficient floods were characterised by counter-clockwise hysteresis relationships between SSC and discharges. The floods with complex hysteresis were the more productive in the long term, during this measuring period exceeding a decade. Nevertheless, the current research outlines the need to obtain medium-term (five years) continuous time series to assess the range of variations of suspended sediment fluxes and to outline clearly the seasonality of suspended sediment yields. Results suggest the occurrence of a temporal dis-connectivity in meso-scale catchments over short time-scales between the meteorological forcing and the sediment yields estimated at the outlet. These findings have important methodological impacts for modelling and operational implications for watershed management.〈/p〉 〈/div〉 〈/div〉
    Print ISSN: 0022-1694
    Electronic ISSN: 1879-2707
    Topics: Architecture, Civil Engineering, Surveying , Geography , Geosciences
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  • 37
    Publication Date: 2018
    Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Computers & Geosciences, Volume 122〈/p〉 〈p〉Author(s): Hassan Talebi, Ute Mueller, Raimon Tolosana-Delgado〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Ore deposits usually consist of ore materials with different discrete (e.g. rock and alteration types) and continuous (e.g. geochemical and mineral composition) features. Financial feasibility studies are highly dependent on the modelling of these features and their associated joint uncertainties. Few geostatistical techniques have been developed for the joint modelling of high-dimensional mixed data (continuous and categorical) or constrained data, such as compositional data. The compositional nature of the mineral and geochemical data induces several challenges for multivariate geostatistical techniques, because such data carry relative information and are known for spurious statistical and spatial correlation effects. This paper investigates the application of the direct sampling algorithm for joint modelling of compositional and categorical data. In some mining projects the amount of available data may be enormous in some parts of the deposit and if the density of measurements is sufficient, multivariate geospatial patterns can be derived from that data and be simulated (without model inference) at other undersampled areas of the deposit with similar characteristics. In this context, the direct sampling multiple-point simulation method can be implemented for this reconstruction process. The compositional nature of the data is addressed via implementing an isometric log-ratio transformation. The approach is illustrated through two case studies, one synthetic and one real. The accuracy of the results is checked against a set of validation data, revealing the potential of the proposed methodology for joint modelling of compositional and categorical information. The direct sampling technique can be considered as a smart move to assess the future risk and uncertainty of a resource by making use of all the information hidden within the early data.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0098-3004
    Electronic ISSN: 1873-7803
    Topics: Geosciences , Computer Science
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  • 38
    Publication Date: 2018
    Description: 〈p〉Publication date: 1 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Geoderma, Volume 337〈/p〉 〈p〉Author(s): Hongfei Liu, Yang Wu, Zemin Ai, Jiaoyang Zhang, Chao Zhang, Sha Xue, Guobin Liu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉DOM is the most bioavailable organic pool in the soil. The restoration of vegetation on abandoned cropland has a major impact on the concentration and composition of the DOM and thus affects the biodegradability of the soil DOM. Understanding the response of the microbial degradation of the DOM to temperature is important to maintain soil bioavailable organic matter in the field. We conducted a laboratory DOM solution incubation experiment to examine the temporal dynamics of DOM concentrations at temperatures of 4 °C (low), 20 °C (medium), and 35 °C (high) for four types of land uses: sloped cropland, grassland, shrub land, and woodland. Ultraviolet–visible and fluorescence spectroscopy were used to determine the structural complexity of the DOM. The conversion of the sloped cropland to shrub land and woodland significantly increased contents of DOC, DON, and recalcitrant substances in DOM soilution, such as humic-like material and fulvic acid, and stabilised the DOC pool, and reduced the decomposition of the DOC at 20 °C and 35 °C. The conversion of the sloped cropland to woodland dramatically reduced TDN decomposition. The DON loss after 60-day incubation significantly correlated with the initial content of tryptophan-like material. The biodegradability of the DON was higher and more sensitive to temperature than that of the DOC. Rising temperature initially promotes the decomposition of tryptophan-like material, and later promotes the degradation of more recalcitrant substances, such as humic-like material and fulvic acid, which enhanced the decomposition of the DOC and DON. The results suggest that the conversion of sloped cropland to shrubland and woodland not only promoted the accumulation of DOC, TDN, and recalcitrant substances in DOM solution, and decreased their biodegradability but also decreased the temperature sensitivity of the decomposition of the DOC and DON. Therefore, shrubland and woodland were the optimal choices for revegetation in the Loess Plateau of China.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0016706117316403-ga1.jpg" width="301" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0016-7061
    Electronic ISSN: 1872-6259
    Topics: Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
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  • 39
    Publication Date: 2018
    Description: 〈p〉Publication date: 15 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Agricultural and Forest Meteorology, Volume 264〈/p〉 〈p〉Author(s): Antonio D. del Campo, María González-Sanchis, Alberto García-Prats, Carlos J. Ceacero, Cristina Lull〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Marginal semi-arid forests in areas currently affected by climate change are a challenge to forest management, which has to focus on key functional traits that can effectively contribute to resistance under extreme drought. We studied the effects of thinning in a marginal forest by quantifying functional responses relating to growth, carbon and water fluxes. Two experimental plots were established, one thinned in 2012 and the other one left as a control. The environmental conditions varied substantially during the 4-year study period, although dry years predominated. There were signs of dieback in the control with a decreasing inter-annual trend in LAI, as opposed to the treated plots, where LAI by the end of the study almost reached pre-thinning levels. Sap flow and transpiration were greatly enhanced by the treatment, with thinned trees transpiring 22.4 l tree〈sup〉−1〈/sup〉 day〈sup〉−1〈/sup〉 in the growing season, about twice the control figures. The seasonal patterns of transpiration and soil moisture were uncoupled, indicating a contribution of deep groundwater to the former flux. In the control, limitations to water and carbon dynamics (canopy conductance) occurred at soil moisture values below 16%, whereas in the thinned trees these limitations appeared when soil moisture dropped below 10%. Overall, oaks’ transpiration was enhanced with thinning to the point that stand-water use surpassed that of the control by the second half of the study period, averaging 24% of gross rainfall in both plots. Soil evaporation increased from 12 to 20% of gross rainfall after treatment in the overall period. The treatment had a profound watering effect in this marginal forest, led by fewer trees using the same amount of water as those in the untreated overstocked plot. This research may provide guidelines for ecohydrology-oriented silviculture in stands experiencing tree encroachment and transformation into shrublands that are more prone to global change-induced disturbances.〈/p〉〈/div〉
    Print ISSN: 0168-1923
    Electronic ISSN: 1873-2240
    Topics: Geography , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Physics
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  • 40
    Publication Date: 2018
    Description: 〈p〉Publication date: December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Transport Geography, Volume 73〈/p〉 〈p〉Author(s): Amparo Moyano, Borja Moya-Gómez, Javier Gutiérrez〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Accessibility by high-speed rail (HSR) depends not only on station-to-station travel time, but also on access and egress times, which can be determining factors in total journey travel time. However, studies focusing on accessibility analyses of access/egress times to/from stations are less extended in the literature and centre mainly on the influence of access times to stations on HSR accessibility levels on a regional scale. This paper's aim is to evaluate the importance of access and egress times to/from HSR stations in an urban context. We carry out a spatiotemporal accessibility analysis that considers the temporal variations of both taxi and public transport travel times. General Transit Feed Specification (GTFS) files for public transport and TomTom Speed Profiles data for cars are used to measure access/egress times. These kinds of data allow for the calculation of travel times from/to HSR stations through network analysis GIS tools at different times of the day, and thus a spatiotemporal accessibility measure can be obtained. This accessibility measure is complemented by a mass factors representing the activity ‘hotspots’ in the visited city throughout the workday, which is derived from Twitter data, while population is considered for city of residence. This method was applied to the two largest metropolitan areas in Spain: Madrid and Barcelona, where the influence of access/egress times acquires a higher relevance for rail-based trips. The results obtained show that access and egress times vary significantly during the day, depending on the levels of traffic congestion and the frequency of public transport services, which are always more favourable for taxis. In addition, weighted average access and egress times at the home end are higher than those at the activity end since population tends to show more dispersed spatial patterns than activities. Another interesting finding is that the first and last mile of the HSR trip usually account for a high percentage increase in travel time (about 35% for taxis and 55% for public transport, respectively). These results have important policy implications. The paper suggests that HSR accessibility can be improved also by improving local transport services, scheduling coordination and land use policies.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0966-6923
    Electronic ISSN: 1873-1236
    Topics: Architecture, Civil Engineering, Surveying , Geography
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  • 41
    Publication Date: 2018
    Description: 〈p〉Publication date: 15 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Agricultural and Forest Meteorology, Volume 264〈/p〉 〈p〉Author(s): Ren Li, Lin Zhao, Tonghua Wu, Qinxue Wang, Yongjian Ding, Jimin Yao, Xiaodong Wu, Guojie Hu, Yao Xiao, Yizhen Du, Xiaofan Zhu, Yanhui Qin, Shuhua Yang, Rui Bai, Erji Du, Guangyue Liu, Defu Zou, Yongping Qiao, Jianzong Shi〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Soil thermal conductivity (〈em〉λ〈/em〉) is one of the essential parameters relating to heat exchange, and it also plays a key role in verifying soil thermal hydrodynamics in permafrost regions. In this paper, the characteristic of in situ 〈em〉λ〈/em〉 was analyzed based on data measured from June 2004 to December 2008 at Tanggula district on the Qinghai–Tibet Plateau. The result showed that diurnal 〈em〉λ〈/em〉 strongly influenced by variation of soil moisture content. The daily 〈em〉λ〈/em〉 exhibited distinct seasonal variation; on average, the largest value of 〈em〉λ〈/em〉 occurred in summer, followed by the autumn and spring season, while the smallest value occurred in winter. As a whole, 〈em〉λ〈/em〉 values in the unfrozen state were larger than those in the frozen state. Unsaturated soil and the huge difference in soil moisture content between the unfrozen state and initial freeze resulted in the lower 〈em〉λ〈/em〉 in the frozen state. For the study area, the critical value of local soil saturation degree was about 0.37, the corresponding critical soil moisture content was about 0.195 m〈sup〉3〈/sup〉 m〈sup〉−3〈/sup〉. And soil moisture content was the main factor controlling in situ 〈em〉λ〈/em〉. Finally, an empirically-derived model was proposed for predicting daily 〈em〉λ〈/em〉, and which showed good performance in the study area.〈/p〉〈/div〉
    Print ISSN: 0168-1923
    Electronic ISSN: 1873-2240
    Topics: Geography , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Physics
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  • 42
    Publication Date: 2018
    Description: 〈p〉Publication date: 15 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Agricultural and Forest Meteorology, Volume 264〈/p〉 〈p〉Author(s): Baoqing Zhang, Amir AghaKouchak, Yuting Yang, Jiahua Wei, Guangqian Wang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Different categories of droughts (e.g., meteorological, agricultural, hydrological), and their multi-scalar features often make description of drought onset, persistence, and termination challenging and often subjective. Here we show that a water-energy balance based indicator, named Standardized Moisture Anomaly Index (SZI), better captures multiple categories of droughts and their multi-scalar features. We globally evaluate and compare the performance of SZI with existing drought indicators that use potential evapotranspiration (PET) as a measure of atmospheric water demand including the Standardized Precipitation Evapotranspiration Index (SPEI) and self-calibrated Palmer Drought Severity Index (scPDSI). We show that while 〈em〉PET〈/em〉 is a good indicator for characterizing the climate aridity, using it as a measure of atmospheric water demand for drought analysis leads to misrepresentation of droughts, especially over water-limited (non-humid) regions where the actual evapotranspiration is primarily dominated by water availability rather than energy (or PET). The main advantage of SZI is that, instead of PET, it uses a variable termed climatically appropriate precipitation for existing conditions (〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si2.gif" overflow="scroll"〉〈mover accent="true"〉〈mi〉P〈/mi〉〈mo〉ˆ〈/mo〉〈/mover〉〈/math〉) as the atmospheric water demand metric. Investigating droughts over 32 large basins across the globe, we show that the SZI can better represent meteorological, hydrological, and agricultural droughts compared to SPEI (especially in non-humid basins; 18 out of 32 basins) and scPDSI at multiple time scales. Given that SZI is physically more reasonable in reflecting surface water-energy balance over both humid and non-humid regions, it enables better characterization of different types of droughts in different climatic regions.〈/p〉〈/div〉
    Print ISSN: 0168-1923
    Electronic ISSN: 1873-2240
    Topics: Geography , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Physics
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  • 43
    Publication Date: 2018
    Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Geomorphology, Volume 327〈/p〉 〈p〉Author(s): Chenge An, Gary Parker, Marwan A. Hassan, Xudong Fu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Massive bed degradation (20 m in 7 years) has been observed in the Shi‑ting River, Sichuan Province, China, since the 2008 Wenchuan Ms. 8.0 earthquake. The reason for the massive bed degradation has not been well understood. A hypothesis has been proposed that relates bed degradation to the augmentation of sand supply after the earthquake. The effect of sand on gravel mobility (〈em〉magic sand〈/em〉 effect) has long been observed in laboratory experiments. In this paper, we study whether the augmentation of sand supply and its 〈em〉magic sand〈/em〉 effect can lead to the observed massive degradation at decadal scales. A one-dimensional river morphodynamic model is implemented to study the problem in general at field scale and in context of the gravel-bed Shi‑ting River. Sediment transport is calculated with the Wilcock and Crowe (2003) relation, in which the 〈em〉magic sand〈/em〉 effect is explicitly embedded in terms of a function relating reference Shields number to the surface sand fraction. We find that the augmentation of gravel supply leads to bed aggradation, whereas the augmentation of sand supply can indeed lead to bed degradation and surface fining. The magnitude and timescale of bed degradation are not sensitive to the sand supply rate but are sensitive to the flood intermittency factor〈sub〉,〈/sub〉 i.e., the fraction of time the river is in flood. However, an unrealistic flood intermittency factor (≥0.3) would be required in order to match the observed timescale of bed degradation, thus indicating that the 〈em〉magic sand〈/em〉 effect might not be the governing reason for massive bed degradation in the Shi‑ting River, and by implication in gravel-bed rivers in general. Our simulation results also indicate that despite the fact that 〈em〉magic sand〈/em〉 effects are not explicitly included in most sediment transport relations, they are at least partly built in via the hiding function that is contained in most sediment transport relations for gravel-sand mixtures. While here we use the Shi‑ting River as an example, our results have applicability to gravel-bed rivers subjected to augmentation in sand supply in general.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0169-555X
    Electronic ISSN: 1872-695X
    Topics: Geography , Geosciences
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  • 44
    Publication Date: 2018
    Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Geomorphology, Volume 327〈/p〉 〈p〉Author(s): Hakan Tanyas, Mauro Rossi, Massimiliano Alvioli, Cees J. van Westen, Ivan Marchesini〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Rapid assessment of spatial distribution of earthquake-induced landslides could provide valuable information in the emergency response phase. Previous studies proposed global analyses with the aim of predicting earthquake-induced landslide distributions in near real-time. However, in all those studies, mapping units are constituted by pixels, which do not reflect homogeneously distributed physical property for a given terrain unit and whose size do not match the resolution of existing thematic data at global scale. Moreover, none of the existing analyses considers sampling balance between different inventories or categorizing the inventories to construct a training set with higher statistical representativeness. We develop an improved global statistical method to address these drawbacks. We use slope units, which are terrain partitions attributed to similar hydrological and geomorphological conditions and to processes that shape natural landscapes. A set of 25 earthquake-induced landslide-events are selected and categorized based on the similarity between causal factors to determine the most relevant training set to make a prediction for a given landslide-event. As a result, we develop a specific model for each category. We sample an equal number of landslide points from each inventory to overcome the dominance of some inventories with large landslide population. We use seven independent thematic variables for both categorizing the inventories and modeling, based on logistic regression. The results show that categorizing landslide-events introduces a remarkable improvement in the modeling performance of many events. The categorization of existing inventories can be applied within any statistical, global approach to earthquake-induced landslide events. The proposed categorization approach and the classification performance can be further improved with the acquisition of new inventory maps.〈/p〉〈/div〉 〈/div〉
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    Topics: Geography , Geosciences
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  • 45
    Publication Date: 2018
    Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 84〈/p〉 〈p〉Author(s): Xin Cai, Chengbin Gao, Huanhuan Song, Ning Yang, Qiang Fu, Fenghua Tan, Chao Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Cathepsin Z (CTSZ) is a lysosomal cysteine protease of the papain superfamily. It participates in the host immune defense via phagocytosis, signal transduction, cell-cell communication, proliferation, and migration of immune cells such as monocytes, macrophages, and dendritic cells. In this study, we reported the identification of 〈em〉Sm〈/em〉CTSZ, a CTSZ homolog from turbot (〈em〉Scophthalmus maximus〈/em〉 L.). 〈em〉Sm〈/em〉CTSZ was 317 residues in length and contains a Pept-C1 domain. In multiple species comparison, 〈em〉Sm〈/em〉CTSZ shared 65–93% overall sequence identities with the CTSZ counterparts from human, rat, and several fish species. In the phylogenetic analysis, 〈em〉Sm〈/em〉CTSZ showed the closest relationship to 〈em〉Cynoglossus semilaevis〈/em〉. The syntenic analysis revealed the similar neighboring genes of CTSZ across all the selected species, which suggested the synteny encompassing CTSZ region during vertebrate evolution. Subsequently, 〈em〉Sm〈/em〉CTSZ was constitutively expressed in various tissues, with the lowest and highest levels in brain and intestine respectively. In addition, 〈em〉Sm〈/em〉CTSZ was significantly up-regulated in intestine following both Gram-negative bacteria 〈em〉Vibrio anguillarum〈/em〉, and Gram-positive bacteria 〈em〉Streptococcus iniae〈/em〉 immersion challenge. Finally, the 〈em〉rSm〈/em〉CTSZ showed strong binding ability to all the examined microbial ligands, and the agglutination effect to different bacteria. Taken together, these results indicated 〈em〉Sm〈/em〉CTSZ could play important roles in mucosal immune response in the event of bacterial infection in teleost. However, the knowledge of CTSZ are still limited in teleost species, further studies should be carried out to better characterize its detailed roles in teleost mucosal immunity.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 1050-4648
    Electronic ISSN: 1095-9947
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
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  • 46
    Publication Date: 2018
    Description: 〈p〉Publication date: Available online 14 August 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Computational Physics〈/p〉 〈p〉Author(s): Mehdi Samiee, Mohsen Zayernouri, Mark M. Meerschaert〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We present the stability and error analysis of the unified Petrov–Galerkin spectral method, developed in [1], for linear fractional partial differential equations with two-sided derivatives and constant coefficients in any (〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"〉〈mn〉1〈/mn〉〈mo〉+〈/mo〉〈mi〉d〈/mi〉〈/math〉)-dimensional space-time hypercube, 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si2.gif" overflow="scroll"〉〈mi〉d〈/mi〉〈mo〉=〈/mo〉〈mn〉1〈/mn〉〈mo〉,〈/mo〉〈mn〉2〈/mn〉〈mo〉,〈/mo〉〈mn〉3〈/mn〉〈mo〉,〈/mo〉〈mo〉⋯〈/mo〉〈/math〉, subject to homogeneous Dirichlet initial/boundary conditions. Specifically, we prove the existence and uniqueness of the weak form and perform the corresponding stability and error analysis of the proposed method. Finally, we perform several numerical simulations to compare the theoretical and computational rates of convergence.〈/p〉〈/div〉
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  • 47
    Publication Date: 2018
    Description: 〈p〉Publication date: 1 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Computational Physics, Volume 376〈/p〉 〈p〉Author(s): Giovanni Soligo, Alessio Roccon, Alfredo Soldati〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this work, we propose and test the validity of a modified Phase Field Method (PFM), which is specifically developed for large scale simulations of turbulent flows with large and deformable surfactant-laden droplets. The time evolution of the phase field, 〈em〉ϕ〈/em〉, and of the surfactant concentration field, 〈em〉ψ〈/em〉, are obtained from two Cahn–Hilliard-like equations together with a two-order-parameter Time-Dependent Ginzburg–Landau (TDGL) free energy functional. The modifications introduced circumvent existing limitations of current approaches based on PFM and improve the well-posedness of the model. The effect of surfactant on surface tension is modeled via an Equation Of State (EOS), further improving the flexibility of the approach. This method can efficiently handle topological changes, i.e. breakup and coalescence, and describe adsorption/desorption of surfactant. The capabilities of the proposed approach are tested in this paper against previous experimental results on the effects of surfactant on the deformation of a single droplet and on the interactions between two droplets. Finally, to appreciate the performances of the model on a large scale complex simulation, a qualitative analysis of the behavior of surfactant-laden droplets in a turbulent channel flow is presented and discussed.〈/p〉〈/div〉
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  • 48
    Publication Date: 2018
    Description: 〈p〉Publication date: 1 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Computational Physics, Volume 376〈/p〉 〈p〉Author(s): Sergii V. Siryk〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We provide a careful Fourier analysis of the Guermond–Pasquetti mass lumping correction technique (Guermond and Pasquetti, 2013 [11]) applied to pure transport and convection–diffusion problems. In particular, it is found that increasing the number of corrections reduces the accuracy for problems with diffusion; however all the corrected schemes are more accurate than the consistent Galerkin formulation in this case. For the pure transport problems the situation is the opposite. We also investigate the differences between two numerical solutions – the consistent solution and the corrected ones, and show that increasing the number of corrections makes solutions of the corrected schemes closer to the consistent solution in all cases.〈/p〉〈/div〉
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  • 49
    Publication Date: 2018
    Description: 〈p〉Publication date: 15 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Computational Physics, Volume 377〈/p〉 〈p〉Author(s): Adam S. Jermyn〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Tensors are a natural way to express correlations among many physical variables, but storing tensors in a computer naively requires memory which scales exponentially in the rank of the tensor. This is not optimal, as the required memory is actually set not by the rank but by the mutual information amongst the variables in question. Representations such as the tensor tree perform near-optimally when the tree decomposition is chosen to reflect the correlation structure in question, but making such a choice is non-trivial and good heuristics remain highly context-specific. In this work I present two new algorithms for choosing efficient tree decompositions, independent of the physical context of the tensor. The first is a brute-force algorithm which produces optimal decompositions up to truncation error but is generally impractical for high-rank tensors, as the number of possible choices grows exponentially in rank. The second is a greedy algorithm, and while it is not optimal it performs extremely well in numerical experiments while having runtime which makes it practical even for tensors of very high rank.〈/p〉〈/div〉
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  • 50
    Publication Date: 2018
    Description: 〈p〉Publication date: 15 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Computational Physics, Volume 377〈/p〉 〈p〉Author(s): Lam H. Nguyen, Dominik Schillinger〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We describe a local iterative corrector scheme that significantly improves the accuracy of the multiscale finite element method (MsFEM). Our technique is based on the definition of a local corrector problem for each multiscale basis function that is driven by the residual of the previous multiscale solution. Each corrector problem results in a local corrector solution that improves the accuracy of the corresponding multiscale basis function at element interfaces. We cast the strategy of residual-driven correction in an iterative scheme that is straightforward to implement and, due to the locality of corrector problems, well-suited for parallel computing. We show that the iterative scheme converges to the best possible fine-mesh solution. Finally, we illustrate the effectiveness of our approach with multiscale benchmarks characterized by missing scale separation, including the microCT-based stress analysis of a vertebra with trabecular microstructure.〈/p〉〈/div〉
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  • 51
    Publication Date: 2018
    Description: 〈p〉Publication date: 15 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Computational Physics, Volume 377〈/p〉 〈p〉Author(s): Brody Bassett, Brian Kiedrowski〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The meshless local Petrov–Galerkin (MLPG) method is applied to the steady-state and 〈em〉k〈/em〉-eigenvalue neutron transport equations, which are discretized in energy using the multigroup approximation and in angle using the discrete ordinates approximation. To prevent oscillations in the neutron flux, the MLPG transport equation is stabilized by the streamline upwind Petrov–Galerkin (SUPG) method. Global neutron conservation is enforced by using moving least squares basis and weight functions and appropriate SUPG parameters. The cross sections in the transport equation are approximated in accordance with global particle balance and without constraint on their spatial dependence or the location of the basis and weight functions. The equations for the strong-form meshless collocation approach are derived for comparison to the MLPG equations. The method of manufactured solutions is used to verify the resulting MLPG method in one, two and three dimensions. Results for realistic problems, including two-dimensional pincells, a reflected ellipsoid and a three-dimensional problem with voids, are verified by comparison to Monte Carlo simulations.〈/p〉〈/div〉
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  • 52
    Publication Date: 2018
    Description: 〈p〉Publication date: Available online 28 May 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Computational Physics〈/p〉 〈p〉Author(s): Frederic Gibou, David Hyde, Ron Fedkiw〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We present a review on numerical methods for simulating multiphase and free surface flows. We focus in particular on numerical methods that seek to preserve the discontinuous nature of the solutions across the interface between phases. We provide a discussion on the Ghost-Fluid and Voronoi Interface methods, on the treatment of surface tension forces that avoid stringent time step restrictions, on adaptive grid refinement techniques for improved efficiency and on parallel computing approaches. We present the results of some simulations obtained with these treatments in two and three spatial dimensions. We also provide a discussion of Machine Learning and Deep Learning techniques in the context of multiphase flows and propose several future potential research thrusts for using deep learning to enhance the study and simulation of multiphase flows.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈/p〉〈/div〉 〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0021999118303371-gr001.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉
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  • 53
    Publication Date: 2018
    Description: 〈p〉Publication date: Available online 26 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Computational Physics〈/p〉 〈p〉Author(s): Xiaodong Liu, Jiguang Sun〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Inverse scattering has been an active research area for the past thirty years. While very successful in many cases, progress has lagged when only 〈em〉limited-aperture〈/em〉 measurement is available. In this paper, we perform some elementary study to recover data that can not be measured directly. In particular, we aim at recovering the 〈em〉full-aperture〈/em〉 far field data from 〈em〉limited-aperture〈/em〉 measurement. Due to the reciprocity relation, the multi-static response matrix (MSR) has a symmetric structure. Using the Green's formula and single layer potential, we propose two schemes to recover 〈em〉full-aperture〈/em〉 MSR. The recovered data is tested by a recently proposed direct sampling method and the factorization method. Numerical results show that it is possible to, at least, partially recover the missing data and consequently improve the reconstruction of the scatterer.〈/p〉〈/div〉
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  • 54
    Publication Date: 2018
    Description: 〈p〉Publication date: 15 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Computational Physics, Volume 377〈/p〉 〈p〉Author(s): D. Reiser, J. Romazanov, Ch. Linsmeier〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The problem of constructing Monte-Carlo solutions of drift-diffusion systems corresponding to Fokker–Planck equations with sources and sinks is revisited. Firstly, a compact formalism is introduced for the specific problem of stationary solutions. This leads to identification of the dwell time as the key quantity to characterize the system and to obtain a proper normalization for statistical analysis of numerical results. Secondly, the question of appropriate track length estimators for drift-diffusion systems is discussed for a 1D model system. It is found that a simple track length estimator can be given only for pure drift motion without diffusion. The stochastic nature of the diffusive part cannot be appropriately described by the path length of simulation particles. Further analysis of the usual situation with inhomogeneous drift and diffusion coefficients leads to an error estimate based on particle trajectories. The result for limits in grid cell size and time step used for the construction of Monte-Carlo trajectories resembles the Courant-Friedrichs-Lewy and von Neumann conditions for explicit methods.〈/p〉〈/div〉
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  • 55
    Publication Date: 2018
    Description: 〈p〉Publication date: 1 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Computational Physics, Volume 376〈/p〉 〈p〉Author(s): Dinshaw S. Balsara, Roger Käppeli〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉The time-dependent equations of computational electrodynamics (CED) are evolved consistent with the divergence constraints on the electric displacement and magnetic induction vector fields. Respecting these constraints has proved to be very useful in the classic finite-difference time-domain (FDTD) schemes. As a result, there has been a recent effort to design finite volume time domain (FVTD) and discontinuous Galerkin time domain (DGTD) schemes that satisfy the same constraints and, nevertheless, draw on recent advances in higher order Godunov methods. This paper catalogues the first step in the design of globally constraint-preserving DGTD schemes. The algorithms presented here are based on a novel DG-like method that is applied to a Yee-type staggering of the electromagnetic field variables in the faces of the mesh. The other two novel building blocks of the method include constraint-preserving reconstruction of the electromagnetic fields and multidimensional Riemann solvers; both of which have been developed in recent years by the first author.〈/p〉 〈p〉The resulting DGTD scheme is linear, at least when limiters are not applied to the DG scheme. As a result, it is possible to carry out a von Neumann stability analysis of the entire suite of DGTD schemes for CED at orders of accuracy ranging from second to fourth. The analysis requires some simplifications in order to make it analytically tractable, however, it proves to be extremely instructive. A von Neumann stability analysis is a necessary precursor to the design of a full DGTD scheme for CED. It gives us the maximal CFL numbers that can be sustained by the DGTD schemes presented here at all orders. It also enables us to understand the wave propagation characteristics of the schemes in various directions on a Cartesian mesh. We find that constraint-preserving DGTD schemes permit CFL numbers that are competitive with conventional DG schemes. However, like conventional DG schemes, the CFL of DGTD schemes decreases with increasing order. To counteract that, we also present constraint-preserving PNPM schemes for CED. We find that the third and fourth order constraint-preserving DGTD and P1PM schemes have some extremely attractive properties when it comes to low-dispersion, low-dissipation propagation of electromagnetic waves in multidimensions. Numerical accuracy tests are also provided to support the von Neumann stability analysis. We expect these methods to play a role in those problems of engineering CED where exceptional precision must be achieved at any cost.〈/p〉 〈/div〉
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  • 56
    Publication Date: 2018
    Description: 〈p〉Publication date: 15 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Computational Physics, Volume 377〈/p〉 〈p〉Author(s): Yinghe Qi, Jiacai Lu, Ruben Scardovelli, Stéphane Zaleski, Grétar Tryggvason〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In spite of considerable progress, computing curvature in Volume of Fluid (VOF) methods continues to be a challenge. The goal is to develop a function or a subroutine that returns the curvature in computational cells containing an interface separating two immiscible fluids, given the volume fraction in the cell and the adjacent cells. Currently, the most accurate approach is to fit a curve (2D), or a surface (3D), matching the volume fractions and finding the curvature by differentiation. Here, a different approach is examined. A synthetic data set, relating curvature to volume fractions, is generated using well-defined shapes where the curvature and volume fractions are easily found and then machine learning is used to fit the data (training). The resulting function is used to find the curvature for shapes not used for the training and implemented into a code to track moving interfaces. The results suggest that using machine learning to generate the relationship is a viable approach that results in reasonably accurate predictions.〈/p〉〈/div〉
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  • 57
    Publication Date: 2018
    Description: 〈p〉Publication date: 1 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Computational Physics, Volume 376〈/p〉 〈p〉Author(s): Mani Razi, Robert M. Kirby, Akil Narayan〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this paper, we introduce a novel approach for the construction of multi-fidelity surrogate models with “discrete” fidelity levels. The notion of a discrete level of fidelity is in contrast to a mathematical model, for which the notion of refinement towards a high-fidelity model is relevant to sending a discretization parameter toward zero in a continuous way. Our notion of discrete fidelity levels encompasses cases for which there is no notion of convergence in terms of a fidelity parameter that can be sent to zero or infinity. The particular choice of how levels of fidelity are defined in this framework paves the way for using models that may have no apparent physical or mathematical relationship to the target high-fidelity model. However, our approach requires that models can produce results with a common set of parameters in the target model. Hence, fidelity level in this work is not directly representative of the degree of similarity of a low-fidelity model to a target high-fidelity model. In particular, we show that our approach is applicable to competitive ecological systems with different numbers of species, discrete-state Markov chains with a different number of states, polymer networks with a different number of connections, and nano-particle plasmonic arrays with a different number of scatterers. The results of this study demonstrate that our procedure boasts computational efficiency and accuracy for a wide variety of models and engineering systems.〈/p〉〈/div〉
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  • 58
    Publication Date: 2018
    Description: 〈p〉Publication date: 1 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Computational Physics, Volume 376〈/p〉 〈p〉Author(s): Hasan Almanasreh〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this work we will treat the spurious eigenvalues obstacle that appears in the computation of the radial Dirac eigenvalue problem using numerical methods. The treatment of the spurious solution is based on applying Petrov–Galerkin finite element method. The significance of this work is the employment of just continuous basis functions, thus the need of a continuous function which has a continuous first derivative as a basis, as in [2], [3], is no longer required. The Petrov–Galerkin finite element method for the Dirac eigenvalue problem strongly depends on a stability parameter, 〈em〉τ〈/em〉, that controls the size of the diffusion terms added to the finite element formulation for the problem. The mesh-dependent parameter 〈em〉τ〈/em〉 is derived based on the given problem with the particular basis functions.〈/p〉〈/div〉
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  • 59
    Publication Date: 2018
    Description: 〈p〉Publication date: 1 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Computational Physics, Volume 376〈/p〉 〈p〉Author(s): S.B. Adrian, F.P. Andriulli, T.F. Eibert〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We present a Calderón preconditioner for the electric field integral equation (EFIE), which does not require a barycentric refinement of the mesh and which yields a Hermitian, positive definite (HPD) system matrix allowing for the usage of the conjugate gradient (CG) solver. The resulting discrete equation system is immune to the low-frequency and the dense-discretization breakdown and, in contrast to existing Calderón preconditioners, no second discretization of the EFIE operator with Buffa–Christiansen (BC) functions is necessary. This preconditioner is obtained by leveraging on spectral equivalences between (scalar) integral operators, namely the single layer and the hypersingular operator known from electrostatics, on the one hand, and the Laplace–Beltrami operator on the other hand. Since our approach incorporates Helmholtz projectors, there is no search for global loops necessary and thus our method remains stable on multiply connected geometries. The numerical results demonstrate the effectiveness of this approach for both canonical and realistic (multi-scale) problems.〈/p〉〈/div〉
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  • 60
    Publication Date: 2018
    Description: 〈p〉Publication date: Available online 21 February 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Computational Physics〈/p〉 〈p〉Author(s): Mehdi Samiee, Mohsen Zayernouri, Mark M. Meerschaert〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We develop a unified Petrov–Galerkin spectral method for a class of fractional partial differential equations with two-sided derivatives and constant coefficients of the form 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"〉〈mmultiscripts〉〈mrow〉〈mi mathvariant="script"〉D〈/mi〉〈/mrow〉〈mrow〉〈mi〉t〈/mi〉〈/mrow〉〈none〉〈/none〉〈none〉〈/none〉〈mrow〉〈mn〉2〈/mn〉〈mi〉τ〈/mi〉〈/mrow〉〈mprescripts〉〈/mprescripts〉〈mrow〉〈mn〉0〈/mn〉〈/mrow〉〈none〉〈/none〉〈/mmultiscripts〉〈mi〉u〈/mi〉〈mo〉+〈/mo〉〈msubsup〉〈mrow〉〈mo〉∑〈/mo〉〈/mrow〉〈mrow〉〈mi〉i〈/mi〉〈mo〉=〈/mo〉〈mn〉1〈/mn〉〈/mrow〉〈mrow〉〈mi〉d〈/mi〉〈/mrow〉〈/msubsup〉〈mo stretchy="false"〉[〈/mo〉〈msub〉〈mrow〉〈msub〉〈mrow〉〈mi〉c〈/mi〉〈/mrow〉〈mrow〉〈msub〉〈mrow〉〈mi〉l〈/mi〉〈/mrow〉〈mrow〉〈mi〉i〈/mi〉〈/mrow〉〈/msub〉〈/mrow〉〈/msub〉〈/mrow〉〈mrow〉〈msub〉〈mrow〉〈mi〉a〈/mi〉〈/mrow〉〈mrow〉〈mi〉i〈/mi〉〈/mrow〉〈/msub〉〈/mrow〉〈/msub〉〈msubsup〉〈mrow〉〈mi mathvariant="script"〉D〈/mi〉〈/mrow〉〈mrow〉〈msub〉〈mrow〉〈mi〉x〈/mi〉〈/mrow〉〈mrow〉〈mi〉i〈/mi〉〈/mrow〉〈/msub〉〈/mrow〉〈mrow〉〈mn〉2〈/mn〉〈msub〉〈mrow〉〈mi〉μ〈/mi〉〈/mrow〉〈mrow〉〈mi〉i〈/mi〉〈/mrow〉〈/msub〉〈/mrow〉〈/msubsup〉〈mi〉u〈/mi〉〈mo〉+〈/mo〉〈msub〉〈mrow〉〈msub〉〈mrow〉〈mi〉c〈/mi〉〈/mrow〉〈mrow〉〈msub〉〈mrow〉〈mi〉r〈/mi〉〈/mrow〉〈mrow〉〈mi〉i〈/mi〉〈/mrow〉〈/msub〉〈/mrow〉〈/msub〉〈/mrow〉〈mrow〉〈msub〉〈mrow〉〈mi〉x〈/mi〉〈/mrow〉〈mrow〉〈mi〉i〈/mi〉〈/mrow〉〈/msub〉〈/mrow〉〈/msub〉〈msubsup〉〈mrow〉〈mi mathvariant="script"〉D〈/mi〉〈/mrow〉〈mrow〉〈msub〉〈mrow〉〈mi〉b〈/mi〉〈/mrow〉〈mrow〉〈mi〉i〈/mi〉〈/mrow〉〈/msub〉〈/mrow〉〈mrow〉〈mn〉2〈/mn〉〈msub〉〈mrow〉〈mi〉μ〈/mi〉〈/mrow〉〈mrow〉〈mi〉i〈/mi〉〈/mrow〉〈/msub〉〈/mrow〉〈/msubsup〉〈mi〉u〈/mi〉〈mo stretchy="false"〉]〈/mo〉〈mo〉+〈/mo〉〈mi〉γ〈/mi〉〈mspace width="0.2em"〉〈/mspace〉〈mspace width="0.2em"〉〈/mspace〉〈mi〉u〈/mi〉〈mo〉=〈/mo〉〈msubsup〉〈mrow〉〈mo〉∑〈/mo〉〈/mrow〉〈mrow〉〈mi〉j〈/mi〉〈mo〉=〈/mo〉〈mn〉1〈/mn〉〈/mrow〉〈mrow〉〈mi〉d〈/mi〉〈/mrow〉〈/msubsup〉〈mo stretchy="false"〉[〈/mo〉〈msub〉〈mrow〉〈msub〉〈mrow〉〈mi〉κ〈/mi〉〈/mrow〉〈mrow〉〈msub〉〈mrow〉〈mi〉l〈/mi〉〈/mrow〉〈mrow〉〈mi〉j〈/mi〉〈/mrow〉〈/msub〉〈/mrow〉〈/msub〉〈/mrow〉〈mrow〉〈msub〉〈mrow〉〈mi〉a〈/mi〉〈/mrow〉〈mrow〉〈mi〉j〈/mi〉〈/mrow〉〈/msub〉〈/mrow〉〈/msub〉〈msubsup〉〈mrow〉〈mi mathvariant="script"〉D〈/mi〉〈/mrow〉〈mrow〉〈msub〉〈mrow〉〈mi〉x〈/mi〉〈/mrow〉〈mrow〉〈mi〉j〈/mi〉〈/mrow〉〈/msub〉〈/mrow〉〈mrow〉〈mn〉2〈/mn〉〈msub〉〈mrow〉〈mi〉ν〈/mi〉〈/mrow〉〈mrow〉〈mi〉j〈/mi〉〈/mrow〉〈/msub〉〈/mrow〉〈/msubsup〉〈mi〉u〈/mi〉〈mo〉+〈/mo〉〈msub〉〈mrow〉〈msub〉〈mrow〉〈mi〉κ〈/mi〉〈/mrow〉〈mrow〉〈msub〉〈mrow〉〈mi〉r〈/mi〉〈/mrow〉〈mrow〉〈mi〉j〈/mi〉〈/mrow〉〈/msub〉〈/mrow〉〈/msub〉〈/mrow〉〈mrow〉〈msub〉〈mrow〉〈mi〉x〈/mi〉〈/mrow〉〈mrow〉〈mi〉j〈/mi〉〈/mrow〉〈/msub〉〈/mrow〉〈/msub〉〈msubsup〉〈mrow〉〈mi mathvariant="script"〉D〈/mi〉〈/mrow〉〈mrow〉〈msub〉〈mrow〉〈mi〉b〈/mi〉〈/mrow〉〈mrow〉〈mi〉j〈/mi〉〈/mrow〉〈/msub〉〈/mrow〉〈mrow〉〈mn〉2〈/mn〉〈msub〉〈mrow〉〈mi〉ν〈/mi〉〈/mrow〉〈mrow〉〈mi〉j〈/mi〉〈/mrow〉〈/msub〉〈/mrow〉〈/msubsup〉〈mi〉u〈/mi〉〈mo stretchy="false"〉]〈/mo〉〈mo〉+〈/mo〉〈mi〉f〈/mi〉〈/math〉, where 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si2.gif" overflow="scroll"〉〈mn〉2〈/mn〉〈mi〉τ〈/mi〉〈mo〉∈〈/mo〉〈mo stretchy="false"〉(〈/mo〉〈mn〉0〈/mn〉〈mo〉,〈/mo〉〈mn〉2〈/mn〉〈mo stretchy="false"〉)〈/mo〉〈/math〉, 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si3.gif" overflow="scroll"〉〈mn〉2〈/mn〉〈mi〉τ〈/mi〉〈mo〉≠〈/mo〉〈mn〉1〈/mn〉〈/math〉, 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si4.gif" overflow="scroll"〉〈mn〉2〈/mn〉〈msub〉〈mrow〉〈mi〉μ〈/mi〉〈/mrow〉〈mrow〉〈mi〉i〈/mi〉〈/mrow〉〈/msub〉〈mo〉∈〈/mo〉〈mo stretchy="false"〉(〈/mo〉〈mn〉0〈/mn〉〈mo〉,〈/mo〉〈mn〉1〈/mn〉〈mo stretchy="false"〉)〈/mo〉〈/math〉 and 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si5.gif" overflow="scroll"〉〈mn〉2〈/mn〉〈msub〉〈mrow〉〈mi〉ν〈/mi〉〈/mrow〉〈mrow〉〈mi〉j〈/mi〉〈/mrow〉〈/msub〉〈mo〉∈〈/mo〉〈mo stretchy="false"〉(〈/mo〉〈mn〉1〈/mn〉〈mo〉,〈/mo〉〈mn〉2〈/mn〉〈mo stretchy="false"〉)〈/mo〉〈/math〉, in a (〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si6.gif" overflow="scroll"〉〈mn〉1〈/mn〉〈mo〉+〈/mo〉〈mi〉d〈/mi〉〈/math〉)-dimensional 〈em〉space–time〈/em〉 hypercube, 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si7.gif" overflow="scroll"〉〈mi〉d〈/mi〉〈mo〉=〈/mo〉〈mn〉1〈/mn〉〈mo〉,〈/mo〉〈mn〉2〈/mn〉〈mo〉,〈/mo〉〈mn〉3〈/mn〉〈mo〉,〈/mo〉〈mo〉⋯〈/mo〉〈/math〉, subject to homogeneous Dirichlet initial/boundary conditions. We employ the eigenfunctions of the fractional Sturm–Liouville eigen-problems of the first kind in [1], called 〈em〉Jacobi poly-fractonomial〈/em〉s, as temporal bases, and the eigen-functions of the boundary-value problem of the second kind as temporal test functions. Next, we construct our spatial basis/test functions using Legendre polynomials, yielding mass matrices being independent of the spatial fractional orders (〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si8.gif" overflow="scroll"〉〈msub〉〈mrow〉〈mi〉μ〈/mi〉〈/mrow〉〈mrow〉〈mi〉i〈/mi〉〈/mrow〉〈/msub〉〈mo〉,〈/mo〉〈mspace width="0.2em"〉〈/mspace〉〈msub〉〈mrow〉〈mi〉ν〈/mi〉〈/mrow〉〈mrow〉〈mi〉j〈/mi〉〈/mrow〉〈/msub〉〈mo〉,〈/mo〉〈mspace width="0.2em"〉〈/mspace〉〈mi〉i〈/mi〉〈mo〉,〈/mo〉〈mspace width="0.2em"〉〈/mspace〉〈mi〉j〈/mi〉〈mo〉=〈/mo〉〈mn〉1〈/mn〉〈mo〉,〈/mo〉〈mn〉2〈/mn〉〈mo〉,〈/mo〉〈mo〉⋯〈/mo〉〈mo〉,〈/mo〉〈mi〉d〈/mi〉〈/math〉). Furthermore, we formulate a novel unified fast linear solver for the resulting high-dimensional linear system based on the solution of generalized eigen-problem of spatial mass matrices with respect to the corresponding stiffness matrices, hence, making the complexity of the problem optimal, i.e., 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si9.gif" overflow="scroll"〉〈mi mathvariant="script"〉O〈/mi〉〈mo stretchy="false"〉(〈/mo〉〈msup〉〈mrow〉〈mi〉N〈/mi〉〈/mrow〉〈mrow〉〈mi〉d〈/mi〉〈mo〉+〈/mo〉〈mn〉2〈/mn〉〈/mrow〉〈/msup〉〈mo stretchy="false"〉)〈/mo〉〈/math〉. We carry out several numerical test cases to examine the CPU time and convergence rate of the method. The corresponding stability and error analysis of the Petrov–Galerkin method are carried out in [2].〈/p〉〈/div〉
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  • 61
    Publication Date: 2018
    Description: 〈p〉Publication date: 1 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Computational Physics, Volume 376〈/p〉 〈p〉Author(s): Ruilian Du, Yubin Yan, Zongqi Liang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A new high-order finite difference scheme to approximate the Caputo fractional derivative 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"〉〈mfrac〉〈mrow〉〈mn〉1〈/mn〉〈/mrow〉〈mrow〉〈mn〉2〈/mn〉〈/mrow〉〈/mfrac〉〈mo stretchy="true" maxsize="2.4ex" minsize="2.4ex"〉(〈/mo〉〈mspace width="0.2em"〉〈/mspace〉〈mmultiscripts〉〈mrow〉〈mi〉D〈/mi〉〈/mrow〉〈mrow〉〈mi〉t〈/mi〉〈/mrow〉〈mrow〉〈mi〉α〈/mi〉〈/mrow〉〈mprescripts〉〈/mprescripts〉〈mrow〉〈mn〉0〈/mn〉〈/mrow〉〈mrow〉〈mi〉C〈/mi〉〈/mrow〉〈/mmultiscripts〉〈mi〉f〈/mi〉〈mo stretchy="false"〉(〈/mo〉〈msub〉〈mrow〉〈mi〉t〈/mi〉〈/mrow〉〈mrow〉〈mi〉k〈/mi〉〈/mrow〉〈/msub〉〈mo stretchy="false"〉)〈/mo〉〈mo〉+〈/mo〉〈mspace width="0.2em"〉〈/mspace〉〈mmultiscripts〉〈mrow〉〈mi〉D〈/mi〉〈/mrow〉〈mrow〉〈mi〉t〈/mi〉〈/mrow〉〈mrow〉〈mi〉α〈/mi〉〈/mrow〉〈mprescripts〉〈/mprescripts〉〈mrow〉〈mn〉0〈/mn〉〈/mrow〉〈mrow〉〈mi〉C〈/mi〉〈/mrow〉〈/mmultiscripts〉〈mi〉f〈/mi〉〈mo stretchy="false"〉(〈/mo〉〈msub〉〈mrow〉〈mi〉t〈/mi〉〈/mrow〉〈mrow〉〈mi〉k〈/mi〉〈mo〉−〈/mo〉〈mn〉1〈/mn〉〈/mrow〉〈/msub〉〈mo stretchy="false"〉)〈/mo〉〈mo stretchy="true" maxsize="2.4ex" minsize="2.4ex"〉)〈/mo〉〈/math〉, 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si2.gif" overflow="scroll"〉〈mi〉k〈/mi〉〈mo〉=〈/mo〉〈mn〉1〈/mn〉〈mo〉,〈/mo〉〈mn〉2〈/mn〉〈mo〉,〈/mo〉〈mo〉…〈/mo〉〈mo〉,〈/mo〉〈mi〉N〈/mi〉〈/math〉, with the convergence order 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si160.gif" overflow="scroll"〉〈mi〉O〈/mi〉〈mo stretchy="false"〉(〈/mo〉〈mi mathvariant="normal"〉Δ〈/mi〉〈msup〉〈mrow〉〈mi〉t〈/mi〉〈/mrow〉〈mrow〉〈mn〉4〈/mn〉〈mo〉−〈/mo〉〈mi〉α〈/mi〉〈/mrow〉〈/msup〉〈mo stretchy="false"〉)〈/mo〉〈/math〉, 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si4.gif" overflow="scroll"〉〈mi〉α〈/mi〉〈mo〉∈〈/mo〉〈mo stretchy="false"〉(〈/mo〉〈mn〉1〈/mn〉〈mo〉,〈/mo〉〈mn〉2〈/mn〉〈mo stretchy="false"〉)〈/mo〉〈/math〉 is obtained when 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si123.gif" overflow="scroll"〉〈msup〉〈mrow〉〈mi〉f〈/mi〉〈/mrow〉〈mrow〉〈mo〉‴〈/mo〉〈/mrow〉〈/msup〉〈mo stretchy="false"〉(〈/mo〉〈msub〉〈mrow〉〈mi〉t〈/mi〉〈/mrow〉〈mrow〉〈mn〉0〈/mn〉〈/mrow〉〈/msub〉〈mo stretchy="false"〉)〈/mo〉〈mo〉=〈/mo〉〈mn〉0〈/mn〉〈/math〉, where Δ〈em〉t〈/em〉 denotes the time step size. Based on this scheme we introduce a finite difference method for solving fractional diffusion wave equation with the convergence order 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si6.gif" overflow="scroll"〉〈mi〉O〈/mi〉〈mo stretchy="false"〉(〈/mo〉〈mi mathvariant="normal"〉Δ〈/mi〉〈msup〉〈mrow〉〈mi〉t〈/mi〉〈/mrow〉〈mrow〉〈mn〉4〈/mn〉〈mo〉−〈/mo〉〈mi〉α〈/mi〉〈/mrow〉〈/msup〉〈mo〉+〈/mo〉〈msup〉〈mrow〉〈mi〉h〈/mi〉〈/mrow〉〈mrow〉〈mn〉2〈/mn〉〈/mrow〉〈/msup〉〈mo stretchy="false"〉)〈/mo〉〈/math〉, where 〈em〉h〈/em〉 denotes the space step size. Numerical examples are given to show that the numerical results are consistent with the theoretical results.〈/p〉〈/div〉
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  • 62
    Publication Date: 2018
    Description: 〈p〉Publication date: 15 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Computational Physics, Volume 377〈/p〉 〈p〉Author(s): Jie Du, Yang Yang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Local discontinuous Galerkin (LDG) methods are popular for convection-diffusion equations. In LDG methods, we introduce an auxiliary variable 〈em〉p〈/em〉 to represent the derivative of the primary variable 〈em〉u〈/em〉, and solve them on the same mesh. It is well known that the maximum-principle-preserving (MPP) LDG method is only available up to second-order accuracy. Recently, we introduced a new algorithm, and solve 〈em〉u〈/em〉 and 〈em〉p〈/em〉 on different meshes, and obtained stability and optimal error estimates. In this paper, we will continue this approach and construct MPP third-order LDG methods for convection-diffusion equations on overlapping meshes. The new algorithm is more flexible and does not increase any computational cost. Numerical evidence will be given to demonstrate the accuracy and good performance of the third-order MPP LDG method.〈/p〉〈/div〉
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  • 63
    Publication Date: 2018
    Description: 〈p〉Publication date: 1 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Computational Physics, Volume 376〈/p〉 〈p〉Author(s): Yunchang Seol, Yu-Hau Tseng, Yongsam Kim, Ming-Chih Lai〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this paper, a two-dimensional immersed boundary method is developed to simulate the dynamics of Newtonian vesicle in viscoelastic Oldroyd-B fluid under shear flow. The viscoelasticity effect of extra stress is well incorporated into the immersed boundary formulation using the indicator function. Our numerical methodology is first validated in comparison with theoretical results in purely Newtonian fluid, and then a series of numerical experiments is conducted to study the effects of different dimensionless parameters on the vesicle motions. Although the tank-treading (TT) motion of Newtonian vesicle in Oldroyd-B fluid under shear flow can be observed just like in Newtonian fluid, it is surprising to find that the stationary inclination angle can be negative without the transition to tumbling (TB) motion. Moreover, the inertia effect plays a significant role that is able to turn the vesicle back to positive inclination angle through TT-TB-TT transition as the Reynolds number increases. To the best of our knowledge, this is the first numerical work for the detailed investigations of Newtonian vesicle dynamics suspended in viscoelastic Oldroyd-B fluid. We believe that our numerical results can be used to motivate further studies in theory and experiments for such coupling vesicle problems.〈/p〉〈/div〉
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  • 64
    Publication Date: 2018
    Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Forest Ecology and Management, Volume 433〈/p〉 〈p〉Author(s): Matthew E. Hane, Andrew J. Kroll, Aaron Springford, Jack Giovanini, Mike Rochelle, Edward B. Arnett〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Structural enrichment in commercial tree plantations is a potential tool to increase snag numbers but relatively little information is available about how species, size, and spatial distribution of created snags are associated with longevity of these structures. We created 1197 snags in 31 harvest units from 1997 to 1999 in the Cascade and Coast Ranges, Oregon, USA, by topping live trees with harvesting equipment. We used an experimental design to distribute created snags at three densities and as either single or clumped created snags. We fit Weibull and log-logistic Accelerated Failure Time models and found that the median failure time was insensitive to the choice of distribution. We found a small positive effect of diameter at breast height (DBH) and a slight negative effect of increasing distance between created snags on survival. Assuming Weibull and log-logistic distributions at mean observed values of DBH and distance between snags, median survival times for Douglas-fir (〈em〉Pseudotsuga menziesii〈/em〉) were 21.0 (95% confidence interval: 19.3, 22.8) years and 21.2 (19.7, 22.8) years, respectively. For western hemlock (〈em〉Tsuga heterophylla〈/em〉), median survival times were 13.0 (11.9, 14.2) years and 12.5 (11.4, 13.7) years, respectively. Although the two failure distributions had similar median failure times, the log-logistic implies a higher survival probability over time for snags that remained standing at the end of the study period. Created snags can be a useful supplement for harvest units rotated at ∼45 years and Douglas-fir will be available for longer as standing structures. For example, under the log-logistic model, a predicted 5% of Douglas-fir snags are retained to rotation age, so that 40 snags per hectare would be required at harvest to maintain 2 snags per hectare through stand rotation. Snags created from western hemlock will provide an early rotation pulse but are unlikely to last longer than 20 years. Our results suggest that longevity can be increased by maximizing the snag size within the safety constraints of harvesting equipment. Scattering of snags may have a slightly negative effect on snag survival but this outcome should be weighed against potential ecological benefits of variation in snag distributions.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0378-1127
    Electronic ISSN: 1872-7042
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
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  • 65
    Publication Date: 2018
    Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Forest Ecology and Management, Volume 433〈/p〉 〈p〉Author(s): Hilman T. Sukma, Julian Di Stefano, Matthew Swan, Holly Sitters〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Enhanced understanding of relationships between functional diversity (FD) and environmental gradients is crucial given accelerating rates of land-cover change and disturbance worldwide. Functional diversity measures the abundance, range and distribution of traits in a community, and links species diversity with ecosystem function. Several studies have related bird or invertebrate FD to environmental gradients, but information on the responses of mammal FD to vegetation structural diversity at scales of management relevance is scarce. We addressed this knowledge gap by examining responses of ground-dwelling mammal FD to vegetation structural complexity in wet (high-productivity) and dry (low-productivity) eucalypt forest in the Otway Ranges, southeast Australia. In dry forest, we expected a positive relationship between FD and vegetation structural complexity because more resources should enable species with a greater diversity of traits to co-exist. We expected negative correlations in wet forest, where competitive dominance may drive a decrease in FD as structural complexity increases. Ground-dwelling mammals were surveyed using camera traps, and we used five traits to construct four FD indices (richness, evenness, divergence, and dispersion). Six vegetation structure variables were used to calculate two indices of vegetation structure, and we used linear mixed models to relate functional diversity and species richness to vegetation structural complexity (the total abundance of structural attributes) and heterogeneity (the level of contrast or patchiness in structure), in wet and dry forest. Camera traps detected ten native ground-dwelling mammal species. All FD indices were positively correlated with vegetation structural complexity, but only functional dispersion responded to structural heterogeneity. Contrary to expectations, relationships between FD and structural complexity were consistent in both forest types, and we suggest that low levels of functional niche occupancy prevented competitive dominance in wet forest. Species richness did not respond to any predictor variables, and is unlikely to be a useful surrogate of ground-dwelling mammal FD. Our results indicate that forest managers may sustain ecosystem functions performed by ground-dwelling mammals by conserving structurally complex vegetation.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0378-1127
    Electronic ISSN: 1872-7042
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
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  • 66
    Publication Date: 2018
    Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Remote Sensing of Environment, Volume 220〈/p〉 〈p〉Author(s): F.J.A. van Ruitenbeek, H.M.A. van der Werff, W.H. Bakker, F.D. van der Meer, K.A.A. Hein〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉A novel method is presented to measure rock microstructure in hyperspectral mineral maps of rock specimens. Shape parameters were calculated from rock objects in segmented mineral maps. Object area, object perimeter, object hull perimeter and fitted ellipses were used to calculate shape parameters such as compactness, convexity and a cookie-cutter parameter. Shape parameters were used to describe a variety of microstructures and microstructural elements. The parameters were tested on microstructures in artificial imagery and subsequently applied to hyperspectral mineral maps of rocks.〈/p〉 〈p〉Analyses of parameters calculated on artificial imagery showed that object shapes could be measured by the flattening of fitted ellipses as a measure of sphericity and elongation, together with the cookie-cutter parameters that measured angularity. Compactness and convexity could differentiate between euhedral, subhedral and anhedral crystal shapes. Aphanitic, phaneritic and porphyritic igneous microstructures could be identified and differentiated by homogeneity and relative object size parameters. The degree of sorting of sedimentary rocks was measured by the distribution of object sizes and statistical parameters describing the distribution. Orientation of single objects was measured by the angle between the major axis of a fitted ellipse and the vertical of the image. Preferred orientations in the rock microstructure were determined by calculation of a standardized resultant of orientation vectors and a mean angle. Layering and banding of the rock was identified by the length of major axes of fitted ellipses relative to the image dimension.〈/p〉 〈p〉The shape parameters calculated on objects in segmented hyperspectral mineral maps of rock specimens were able to discriminate between sedimentary and volcanic microstructures using the size distribution of mineral objects, the presence of a preferred orientation of the rock and a layered microstructure. The volcanic microstructures could be differentiated by the size distribution of amygdales, phenocrysts and xenocrysts in the rock. Shape parameters could be used to differentiate between xenocrysts and phenocrysts, the latter being more elongated in the studied samples.〈/p〉 〈p〉The study shows that object shape parameters can be used to measure microstructure and microstructural elements in mineral maps, and subsequently discriminate between different rock types and microstructures. The expression of microstructure into numeric parameters is a first step towards quantification of microstructures in mineral maps of rocks. Further development of the methodology could contribute to the creation of unbiased classification scheme of rocks, improved statistical modeling of compositional rock parameters such as mineral ore grades, and the automated recognition of microstructures in large image databases of rocks and drill-core.〈/p〉 〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S003442571830484X-ga1.jpg" width="314" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0034-4257
    Electronic ISSN: 1879-0704
    Topics: Architecture, Civil Engineering, Surveying , Geography
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  • 67
    Publication Date: 2018
    Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Forest Ecology and Management, Volume 433〈/p〉 〈p〉Author(s): Gustavo Mariano Rezende, Daniel Luis Mascia Vieira〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Forest regeneration in abandoned pastures in Amazonia has been well studied, but active restoration of non-resilient pastures has not. In this work, we evaluated large-scale active restoration of intensively used pastures in southern Amazonia, where the highest deforestation rates are observed. With the construction of the Jirau Dam in the Madeira river (state of Rondônia, Brazil), a 3000-ha forest buffer zone has been established. This area was previously covered by African pasture grasses for cattle ranching. Eight mixed-species planting sites with variable grass management and ranging from 6 to 60 months post-planting were measured three times over 2.5 years. We also tested a gradient of restoration intensity in an experimental planting: (i) no intervention (control), (ii) harrowing and herbicides to control grasses, and (iii) harrowing and herbicides plus tree planting. Our goals were to understand the initial trajectory of actively restored sites, the role of harrowing and herbicide application in triggering natural regeneration, and the role of seedling planting on the initial vegetation structure. All tree species ≥30 cm in height were sampled in five circular 10-m-radius plots per site. Plant cover was also monitored using the step-point method. At 18 months, stem density ranged from 2500 to 14,490 ind·ha〈sup〉−1〈/sup〉, demonstrating that density increased suddenly in most sites through colonization, although this was highly variable. Tree cover reached 81% in five years, virtually eliminating grass cover after 36 months. Recruits contributed more to basal area than planted seedlings. Although 17 species, on average, were planted in restoration sites, the number of species at the sites steadily increased over time, at a rate of 7 species·yr〈sup〉−1〈/sup〉 per 1570 m〈sup〉2〈/sup〉. 〈em〉Cecropia〈/em〉 spp. and 〈em〉Trema micrantha〈/em〉 recruits had the highest stem densities and basal areas. Harrowing and grass control were enough to trigger succession in sites where natural regeneration was not taking place, shifting these sites to the highly resilient route of early secondary forest succession in the Amazon. Future restoration efforts should use a combination of methods, first evaluating the potential for natural regeneration and then gradually eliminating barriers.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0378-1127
    Electronic ISSN: 1872-7042
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
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  • 68
    Publication Date: 2018
    Description: 〈p〉Publication date: 15 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Agricultural and Forest Meteorology, Volume 264〈/p〉 〈p〉Author(s): Ravshan Eshonkulov, Arne Poyda, Joachim Ingwersen, Alim Pulatov, Thilo Streck〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Turbulent fluxes at the land surface measured by the Eddy Covariance (EC) technique are typically considerably less than the difference between net radiation and ground heat flux. This is known as the energy balance closure (EBC) problem. It is crucial for validating land surface models as it provokes substantial uncertainty to the magnitude and partitioning of energy fluxes. The gap in the energy balance calls for searching for additional energy terms in the soil-plant-atmosphere system. To evaluate the contribution of these minor storage terms to the measured EBC, we conducted an experimental study to evaluate the contribution of these minor storage terms to measured EBC in the Kraichgau region in southwest Germany over two consecutive growing seasons (2015 and 2016). The measured and calculated minor storage terms comprised the enthalpy change in the plant canopy (〈em〉S〈sub〉c〈/sub〉〈/em〉), the air enthalpy change (〈em〉S〈sub〉a〈/sub〉〈/em〉), the energy consumption and release by photosynthesis and respiration (〈em〉S〈sub〉p〈/sub〉〈/em〉), and the atmospheric moisture change (〈em〉S〈sub〉q〈/sub〉〈/em〉). Furthermore, the soil heat storage (〈em〉S〈sub〉g〈/sub〉〈/em〉) was determined at different locations within the EC footprint and compared to the single point measurements of 〈em〉S〈sub〉g〈/sub〉〈/em〉 at the EC station. Calorimetric and harmonic analysis were performed to compute ground heat flux. 〈em〉S〈sub〉p〈/sub〉〈/em〉 had the strongest effect in improving EBC due to the high net CO〈sub〉2〈/sub〉 uptake during the productive phase of plant growth. In 2015, all minor storage terms together increased EBC by 5.0% on average, with a maximum value of 7.4% in May, while the improvement in 2016 was 6.8% on average and 8.4% in May. Ground heat flux computed with the harmonic analysis based on plate data narrowed the EBC by 3% more than the calorimetric method. In summary, a better EBC can be achieved by considering minor storage terms and applying a harmonic analysis to ground heat flux data. Regarding future research, we recommend to focus on year-round measurements of energy terms because energy stored during the growing season might be lost from the system during the rest of the year. Nonetheless, the significant contribution of minor energy terms to EBC indicates that turbulent energy fluxes are most likely overestimated when all the missing energy is assumed to be turbulent–the typical approach when fluxes are corrected by the Bowen ratio post-closure method for instance.〈/p〉〈/div〉
    Print ISSN: 0168-1923
    Electronic ISSN: 1873-2240
    Topics: Geography , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Physics
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  • 69
    Publication Date: 2018
    Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Computers & Geosciences, Volume 122〈/p〉 〈p〉Author(s): Seth Goodman, Ariel BenYishay, Zhonghui Lv, Daniel Runfola〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Interdisciplinary use of geospatial data requires the integration of data from a breadth of sources, and frequently involves the harmonization of different methods of sampling, measurement, and technical data types. These integrative efforts are often inhibited by fundamental geocomputational challenges, including a lack of memory efficient or parallel processing approaches to traditional methods such as zonal statistics. GeoQuery (〈a href="http://geoquery.org/" target="_blank"〉geoquery.org〈/a〉) is a dynamic web application which utilizes a High Performance Computing cluster and novel parallel geospatial data processing methods to overcome these challenges. Through an online interface, GeoQuery users can request geospatial data - which spans categories including geophysical, environmental and social measurements - to be aggregated to user-selected units of analysis (e.g., subnational administrative boundaries). Once a request has been processed, users are provided with permanent links to access their customized data and documentation. Datasets made available through GeoQuery are reviewed, prepared, and provisioned by geospatial data specialists, with processing routines tailored for each dataset. The code used and steps taken while preparing datasets and processing user requests are publicly available, ensuring transparency and replicability of all data and processes. By mediating the complexities of working with geospatial data, GeoQuery reduces the barriers to entry and the related costs of incorporating geospatial data into research across disciplines. This paper presents the technology and methods used by GeoQuery to process and manage geospatial data and user requests.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0098-3004
    Electronic ISSN: 1873-7803
    Topics: Geosciences , Computer Science
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  • 70
    Publication Date: 2018
    Description: 〈p〉Publication date: February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Computers & Geosciences, Volume 123〈/p〉 〈p〉Author(s): Pouyan Pirnia, François Duhaime, Yannic Ethier, Jean-Sébastien Dubé〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The thermal, mechanical and hydrodynamic behaviour of porous media in geoscience applications is usually modelled through the finite-element (FEM) or finite-difference methods. These continuum models tend to perform poorly when modelling phenomena that are essentially dependent on behaviour at the particle scale or phenomena that are not accurately described by partial differential equations (PDE), such as internal erosion and filtration. The discrete nature of granular materials can be modelled through the discrete-element method (DEM). However, in some instances, DEM models would benefit from an interface with continuum models to solve coupled PDEs or to model phenomena that occur at a different scale. This paper introduces ICY, an interface between COMSOL Multiphysics, a commercial finite-element engine, and YADE, an open-source discrete-element code. The interface is centred on a JAVA class. It was verified using the simple example of a sphere falling in water according to Stokes’ law. For this example, the drag force was calculated in COMSOL and body forces (gravity, buoyancy and drag) on the sphere were summed in YADE. The paper also presents an application example for the interface based on the modelling of internal erosion tests.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0098300417313213-fx1.jpg" width="334" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉
    Print ISSN: 0098-3004
    Electronic ISSN: 1873-7803
    Topics: Geosciences , Computer Science
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  • 71
    Publication Date: 2018
    Description: 〈p〉Publication date: December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 ISPRS Journal of Photogrammetry and Remote Sensing, Volume 146〈/p〉 〈p〉Author(s): Jean-François Tremblay, Martin Béland〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Terrestrial laser scanning (TLS) often makes use of multiple scans in forests to allow for a complete view of a given area. Combining measurements from multiple locations requires accurate co-registration of the scans to a common reference coordinate system, which currently relies on markers, an often cumbersome process in forests. Existing algorithms for achieving marker-free registration of TLS scans in forests promise to significantly decrease field work time, but are not yet operational and their results have not been validated against traditional methods. Here we present a new implementation of an existing approach which runs in parallel mode and is able to process TLS data acquired over large forest areas. To validate our algorithm, point cloud registration matrices (translation and rotation) derived from our algorithm were compared to those obtained using reflective markers in multiple forest types. The results show that our approach can be used operationally in forests with relatively clear understory, and it provides accuracy similar to that obtained from using reflective markers. Furthermore, we identified factors that can lead to this approach falling short of providing acceptable results in terms of accuracy.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0924-2716
    Electronic ISSN: 1872-8235
    Topics: Architecture, Civil Engineering, Surveying , Geography
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  • 72
    Publication Date: 2018
    Description: 〈p〉Publication date: 1 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Geoderma, Volume 337〈/p〉 〈p〉Author(s): Yang Ou, Alain N. Rousseau, Lixia Wang, Baixing Yan, Thiago Gumiere, Hui Zhu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In China, most riparian wetlands have undergone degradation and shrinkage, due to severe droughts or low hydrological connectivity. There are considerable studies focusing on the impact of water level on wetland vegetation; however, changes in the soil components, such as the microbial community, of wetlands following flooding remains unclear. Here, we verified the effects of an extreme flooding event on the soil physicochemical conditions, enzyme activities and soil microbial composition. Overall, we observed that the flooding event impacted the soil properties and modified the enzyme activities. Also, the flooding affected more the biomass than the composition of the soil microbial community. We observed that after the flooding event, manganese (Mn) replaced total nitrogen (TN) as one of the major governing factors of soil enzyme activities. Soil organic carbon (SOC), and pH were also correlated with soil enzyme activities before and after the flooding event. Soil conductivity (EC), C/N ratio, and iron (Fe) contents had a large influence on microbial communities. Nevertheless, the soil C/N ratio was the dominant governing factor of the microbial structure. Therefore, edaphic factors were remarkably related to microbial organisms as flooding was deemed a key driving factor to the linkage between them. The antecedent long-term drought provoked by human disturbance, and subsequent flooding (i.e., re-inundating) may thus damage the soil dynamics of riparian wetlands, and hence, altering the carbon storage capacity. The results of this study suggest that rehabilitating hydrological connectivity and promoting primary succession of vegetation could become effective practices for improving the soil ecosystem of riparian wetlands.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0016-7061
    Electronic ISSN: 1872-6259
    Topics: Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
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  • 73
    Publication Date: 2018
    Description: 〈p〉Publication date: 15 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Agricultural and Forest Meteorology, Volume 264〈/p〉 〈p〉Author(s): Adrià Barbeta, J. Julio Camarero, Gabriel Sangüesa-Barreda, Lena Muffler, Josep Peñuelas〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The performance and persistence of rear-edge tree populations are relevant issues for conserving biodiversity because these stands harbor high intraspecific biodiversity and play a key role during periods of climate change. The occurrence of these populations is associated with the influence of heterogeneous topography, creating suitable refugia with regionally rare environmental conditions. Climate is changing at a global-scale, but little is known about the long-term impact on local climatic singularities and the associated taxa. We analyzed tree-ring growth chronologies of the two species (〈em〉Fagus sylvatica〈/em〉 and 〈em〉Quercus ilex〈/em〉) forming the evergreen-deciduous forest ecotone, constitutive of the rear-edge of 〈em〉F. sylvatica〈/em〉 distribution. The study area is a coastal range with frequent fog immersion, which has been hypothesized to favor the persistence of 〈em〉F. sylvatica〈/em〉 in Mediterranean peninsulas. We analyzed the long-term effect of fog on tree growth along a topographical gradient and the sensitivity of growth to rainfall and temperature. The annual number of foggy days has decreased by 62% over the last four decades, concomitant with increasing temperatures. Fog frequency was a relevant factor determining tree growth; fog during summer had positive effects on 〈em〉F. sylvatica〈/em〉 growth mainly through a temperature buffering effect. The positive effect of fog on the growth of 〈em〉Q. ilex〈/em〉, however, was likely caused by a collinearity with rainfall. 〈em〉Q. ilex〈/em〉 growth was less sensitive to climate than 〈em〉F. sylvatica〈/em〉, but growth of both species was enhanced by a positive early-summer water balance. Our results indicate that a decrease in fog frequency and an increase in temperature may generally benefit 〈em〉Q. ilex〈/em〉 in this forest ecotone. Although future changes in rainfall and temperature matter most for the fate of rear-edge tree populations, local climatic singularities such as fog should also be considered. Those can have complementary effects that can swing the balance in ecotones and rear-edge tree populations such as those studied here.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0168192318303447-ga1.jpg" width="269" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉
    Print ISSN: 0168-1923
    Electronic ISSN: 1873-2240
    Topics: Geography , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Physics
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  • 74
    Publication Date: 2018
    Description: 〈p〉Publication date: December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Dynamics of Atmospheres and Oceans, Volume 84〈/p〉 〈p〉Author(s): A. Lugo-Fernández〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The Loop Current (LC) intrusion into the Gulf of Mexico is analyzed using steady, 2-D nonlinear shallow water equations expressed in Cartesian and natural coordinates. The model suggests that the LC moves with constant relative vorticity along isopleths of the Bernoulli function B such that its surface area (A) has a steady dA/dt and frontal velocity. The intrusion is envisioned as an initial transport imbalance that creates volume storage within the Gulf. Because of the advection of relative vorticity, the intruding inflow splits into a northward flow on the west and a southward flow on the east. The storage creates a sea level difference across the LC that induces a northward force due to Coriolis. This force reinforces the northward flow but opposes the southward flow, helping store water inside the Gulf. This sea level difference is in addition to the one in the B field. The storage implies loss of kinetic energy, which creates a speed shear across the LC and gives rise to the small speed of the LC front. The relative vorticity equation in natural coordinates reveals three aspects of the LC: (1) a velocity difference across the LC, (2) a parabolic shape of the sea surface; and (3) a negative curvature of the LC meaning the velocity changes direction anticyclonically along the B-contours.〈/p〉〈/div〉
    Print ISSN: 0377-0265
    Electronic ISSN: 1872-6879
    Topics: Geography , Geosciences , Physics
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  • 75
    Publication Date: 2018
    Description: 〈p〉Publication date: October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hydrology: Regional Studies, Volume 19〈/p〉 〈p〉Author(s): José Bandeira Brasil, Eunice Maia de Andrade, Helba Araújo de Queiroz Palácio, Pedro Henrique Augusto Medeiros, Julio Cesar Neves dos Santos〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉 〈h6〉Study region〈/h6〉 〈p〉Iguatu Experimental Basin, located in the semi-arid region of northeastern Brazil.〈/p〉 〈/div〉 〈div〉 〈h6〉Study focus〈/h6〉 〈p〉The aim of this study was to investigate the influence of rainfall characteristics on throughfall, stemflow and interception loss in a deciduous forest of a tropical semi-arid region, from a data series of eight consecutive years. The data were collected from 2010 to 2017, comprising a total of 225 events.〈/p〉 〈/div〉 〈div〉 〈h6〉New hydrological insights for the region〈/h6〉 〈p〉Among the variables used to characterize rainfall, the maximum 30-min intensity (〈em〉I30〈/em〉) best explained the interception losses, which is also well correlated to rainfall depth and event average intensity. The predominant events (67% of the total) are characterised by low rainfall depth, low 〈em〉I30〈/em〉 and higher interception loss (18% of the gross rainfall). In addition, there is a threshold between rainfall characteristics and the interception process: for rainfall and 〈em〉I30〈/em〉 lower than 20 mm and 15 mm/h respectively, and rainfall duration lower than 100 min, interception losses are usually higher than 30%, reaching up to 74%. For the remaining events, interception losses are mostly within the range of 10–20% of rainfall. The data and information on the interception process, presented in this study, helps the comprehension of the overall water balance in dry environments and improve the capacity for parameterization of hydrological models, contributing to a more efficient water and environmental management.〈/p〉 〈/div〉
    Print ISSN: 2214-5818
    Topics: Architecture, Civil Engineering, Surveying , Geography , Geosciences
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  • 76
    Publication Date: 2018
    Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 84〈/p〉 〈p〉Author(s): Zhi Zhou, Zhaoqun Liu, Lingui Wang, Jian Luo, Hailang Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Giant clams are one of the most important animals in coral reef ecosystem, and its growth and reproduction are being threatened by heat stress due to global warming. In the present study, the symbiont density, the crucial enzyme activities and the transcriptome were investigated in the outer mantle of giant clam 〈em〉Tridacna crocea〈/em〉 after the acute exposure of high temperature. The density of symbiotic zooxanthellae decreased significantly during 12–24 h, with the minimum level (7.75 × 10〈sup〉5〈/sup〉 cell cm〈sup〉−2〈/sup〉, 〈em〉p〈/em〉 〈 0.05) at 12 h after heat stress. The activities of superoxide dismutase in the heat stress group was significantly lower than that in the control group at 24 h after heat stress, while no significant change in the activities of catalase was observed during the entire stress process. The activation level of caspase3 began to increase significantly at 12 h (1.22-fold, 〈em〉p〈/em〉 〈 0.05), and reached the highest level at 24 h (1.38-fold, 〈em〉p〈/em〉 〈 0.05) after heat stress. Six paired-end libraries were sequenced in two groups, including the heat stress and control group at 12 h after heat stress. Through the assembling of 187,116,632 paired-end reads with lengths of 2 × 150 bp, a total of 26,676 genes were obtained which derived from giant clam. Bioinformatics analysis revealed 47 significantly upregulated and 88 significantly downregulated genes at 12 h after the treatment. There were 12 overrepresented GO terms for significantly upregulated genes, mostly related to unfolded protein binding and ATP binding, whereas no GO term was overrepresented for significantly downregulated genes. These results collectively suggest high temperature could induce excessive oxidative stress through the repressed antioxidant ability, the apoptosis activated by the unfolded protein response, and further the collapse of the symbiosis between host and symbiont, which has been threatening the growth and reproduction of the giant clam 〈em〉T. crocea〈/em〉.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 1050-4648
    Electronic ISSN: 1095-9947
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
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  • 77
    Publication Date: 2018
    Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 84〈/p〉 〈p〉Author(s): Zhi-qiang Du, Yue Wang, Hong-yu Ma, Xiu-li Shen, Kai Wang, Jie Du, Xiao-dong Yu, Wen-hong Fang, Xin-cang Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Crustins play important roles in defending against bacteria in the innate immunity system of crustaceans. In present study, we identified a crustin gene in 〈em〉Scylla paramamosain〈/em〉, which was named as 〈em〉SpCrus6〈/em〉. The ORF of 〈em〉Sp〈/em〉Crus6 possessed a signal peptide sequence (SPS) at the N-terminus and a WAP domain at the C-terminus. And there were 5 Proline residues, 5 Glycine and 4 Cysteine residues between SPS and WAP domain in 〈em〉Sp〈/em〉Crus6. These features indicated that 〈em〉Sp〈/em〉Crus6 was a new member of crustin family. The 〈em〉SpCrus6〈/em〉 mRNA transcripts were up-regulated obviously after bacteria or virus challenge. These changes showed that 〈em〉SpCrus6〈/em〉 was involved in the antimicrobial and antiviral responses of 〈em〉Scylla paramamosain〈/em〉. Recombinant 〈em〉Sp〈/em〉Crus6 (r〈em〉Sp〈/em〉Crus6) showed strong inhibitory abilities against Gram-positive bacteria (〈em〉Bacillus megaterium〈/em〉, 〈em〉Staphylococcus aureus〈/em〉, and 〈em〉Bacillus subtilis〈/em〉). But the inhibitory abilities against four Gram-negative bacteria (〈em〉Vibrio parahemolyticus〈/em〉, 〈em〉Vibrio alginolyticus〈/em〉, 〈em〉Vibrio harveyi〈/em〉 and 〈em〉Escherichia coli〈/em〉) and two fungi (〈em〉Pichia pastoris〈/em〉 and 〈em〉Candida albicans〈/em〉) were not strong enough. Besides, r〈em〉Sp〈/em〉Crus6 could strongly bind to two Gram-positive bacteria (〈em〉B〈/em〉. 〈em〉subtilis〈/em〉 and 〈em〉B〈/em〉. 〈em〉megaterium〈/em〉) and three Gram-negative bacteria (〈em〉V〈/em〉. 〈em〉alginolyticus〈/em〉, 〈em〉V〈/em〉. 〈em〉parahemolyticus〈/em〉, and 〈em〉V〈/em〉. 〈em〉harveyi〈/em〉). And the binding levels to 〈em〉S. aureus〈/em〉 and two fungi (〈em〉P〈/em〉. 〈em〉pastoris〈/em〉 and 〈em〉C〈/em〉. 〈em〉albicans〈/em〉) were weak. The polysaccharides binding assays’ results showed r〈em〉Sp〈/em〉Crus6 had superior binding activities to LPS, LTA, PGN and 〈em〉β〈/em〉-glucan. Through agglutinating assays, we found r〈em〉Sp〈/em〉Crus6 could agglutinate well three Gram-positive bacteria (〈em〉S〈/em〉. 〈em〉aureus〈/em〉, 〈em〉B〈/em〉. 〈em〉subtilis〈/em〉 and 〈em〉B〈/em〉. 〈em〉megaterium〈/em〉). And the agglutinating activities to Gram-negative bacteria and fungi were not found. In the aspect of antiviral functions, r〈em〉Sp〈/em〉Crus6 could bind specifically to the recombinant envelop protein 26 (rVP26) of white spot syndrome virus (WSSV) but not to recombinant envelop protein 28 (rVP28), whereas GST protein could not bind to rVP26 or rVP28. Besides, r〈em〉Sp〈/em〉Crus6 could suppress WSSV reproduction to some extent. Taken together, 〈em〉Sp〈/em〉Crus6 was a multifunctional immunity effector in the innate immunity defending response of 〈em〉S〈/em〉. 〈em〉paramamosain〈/em〉.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 1050-4648
    Electronic ISSN: 1095-9947
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
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  • 78
    Publication Date: 2018
    Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 84〈/p〉 〈p〉Author(s): Yunkun Li, Jiayu Wu, Dong Li, Anqi Huang, Guixian Bu, Fengyan Meng, Fanli Kong, Xiaohan Cao, Xingfa Han, Xiaofu Pan, Wei Fan, Shiyong Yang, Xianyin Zeng, Xiaogang Du〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉〈em〉Schizothorax prenanti〈/em〉 (〈em〉S. prenanti〈/em〉), an important species of economical fish in Southwest China, is susceptible to 〈em〉Aeromonas hydrophila〈/em〉 (Ah). To understand the immune response to Ah, the transcriptome profiling of spleen of 〈em〉S. prenanti〈/em〉 was analyzed after Ah infection. A total of 6, 213 different expression genes (DEGs) were obtained, including 3, 066 up-regulated DEGs and 3, 147 down-regulated DEGs. These DEGs were annotated by KEGG and GO databases, so that the immune-related DEGs (IRDs) can be identified and classified. Then, the interesting IRDs were screened to build heat map, and the reliability of the transcriptome data was validated by qPCR. In order to clarify the mechanism of signal transduction in the anti-bacterial immunity, the signaling pathway initiated by TLRs was predicted. In this pathway, TLR25 and TLR5 mediate the NF-κB and AP-1 signals via MyD88-dependent pathway. Meanwhile, the type I IFN (IFNα/β) induced by IRF1 and IRF3/7 may play an important role in the anti-bacterial immunity. In conclusion, this study preliminarily provides insights into the mechanism of signal transduction after Ah infection in 〈em〉S. prenanti〈/em〉, which contributes to exploring the complex anti-bacterial immunity.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 1050-4648
    Electronic ISSN: 1095-9947
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
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  • 79
    Publication Date: 2018
    Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 84〈/p〉 〈p〉Author(s): Hongye Jiang, Qing Bian, Weiwei Zeng, Pengli Ren, Hengchang Sun, Zhipeng Lin, Zeli Tang, Xinyi Zhou, Qing Wang, Yingying Wang, Yensheng Wang, Mei X. Wu, Xuerong Li, Xinbing Yu, Yan Huang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Grass carp (〈em〉Ctenopharyngodon idellus〈/em〉) hemorrhagic disease (GCHD), caused by grass carp reovirus (GCRV), has given rise to an enormous loss in grass carp industry during the past years. Up to date, vaccination remained to be the most effective way to protect grass carp from GCHD. Oral vaccination is of major interest due to its advantages of noninvasive, time-saving, and easily-operated. The introduction of oral vaccination has profound impact on aquaculture industry because of its feasibility of extensive application for fish in various size and age. However, the main challenge in developing oral vaccine is that antigens are easily degraded and are easy to induce tolerance. 〈em〉Bacillus subtilis〈/em〉 (〈em〉B. subtilis〈/em〉) spores would be an ideal oral vaccine delivery system for their robust specialty, gene operability, safety and adjuvant property. VP4 protein is the major outer capsid protein encoded by GCRV segment 6 (S6), which plays an important role in viral invasion and replication. In this study, we used 〈em〉B. subtilis〈/em〉 spores as the oral delivery system and successfully constructed the 〈em〉B. subtilis〈/em〉 CotC-VP4 recombinant spores (CotC-VP4 spores) to evaluate its protective efficacy in grass carp. Grass carp orally immunized with CotC-VP4 spores showed a survival rate of 57% and the relative percent survival (RPS) of 47% after the viral challenge. Further, the specific IgM levels in serum and the specific IgZ levels in intestinal mucus were significantly higher in the CotC-VP4 group than those in the Naive group. The immune-related genes including three innate immune-related genes (IL-4/13A, IL-4/13B, CSF1R), four adaptive immune-related genes (BAFF, CD4L, MHC-II, CD8), three inflammation-related genes (IL-1β, TNF-α, TGF-β) and interferon type I (IFN-I) related signaling pathway genes were significantly up-regulated in the CotC-VP4 group. The study demonstrated that the CotC-VP4 spores produced protection in grass carp against GCRV infection, and triggered both innate and adaptive immunity post oral immunization. This work highlighted that 〈em〉Bacillus subtilis〈/em〉 spores were powerful platforms for oral vaccine delivery, and the combination of 〈em〉Bacillus subtilis〈/em〉 spores with GCRV VP4 protein was a promising oral vaccine.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 1050-4648
    Electronic ISSN: 1095-9947
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
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  • 80
    Publication Date: 2018
    Description: 〈p〉Publication date: December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Transportation Research Part C: Emerging Technologies, Volume 97〈/p〉 〈p〉Author(s): Jian Wen, Yu Xin Chen, Neema Nassir, Jinhua Zhao〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉Autonomous vehicles (AVs) represent potentially disruptive and innovative changes to public transportation (PT) systems. However, the exact interplay between AV and PT is understudied in existing research. This paper proposes a systematic approach to the design, simulation, and evaluation of integrated autonomous vehicle and public transportation (AV + PT) systems. Two features distinguish this research from the state of the art in the literature: the first is the transit-oriented AV operation with the purpose of supporting existing PT modes; the second is the explicit modeling of the interaction between demand and supply.〈/p〉 〈p〉We highlight the transit-orientation by identifying the synergistic opportunities between AV and PT, which makes AVs more acceptable to all the stakeholders and respects the social-purpose considerations such as maintaining service availability and ensuring equity. Specifically, AV is designed to serve first-mile connections to rail stations and provide efficient shared mobility in low-density suburban areas. The interaction between demand and supply is modeled using a set of system dynamics equations and solved as a fixed-point problem through an iterative simulation procedure. We develop an agent-based simulation platform of service and a discrete choice model of demand as two subproblems. Using a feedback loop between supply and demand, we capture the interaction between the decisions of the service operator and those of the travelers and model the choices of both parties. Considering uncertainties in demand prediction and stochasticity in simulation, we also evaluate the robustness of our fixed-point solution and demonstrate the convergence of the proposed method empirically.〈/p〉 〈p〉We test our approach in a major European city, simulating scenarios with various fleet sizes, vehicle capacities, fare schemes, and hailing strategies such as in-advance requests. Scenarios are evaluated from the perspectives of passengers, AV operators, PT operators, and urban mobility system. Results show the trade off between the level of service and the operational cost, providing insight for fleet sizing to reach the optimal balance. Our simulated experiments show that encouraging ride-sharing, allowing in-advance requests, and combining fare with transit help enable service integration and encourage sustainable travel. Both the transit-oriented AV operation and the demand-supply interaction are essential components for defining and assessing the roles of the AV technology in our future transportation systems, especially those with ample and robust transit networks.〈/p〉 〈/div〉 〈/div〉
    Print ISSN: 0968-090X
    Electronic ISSN: 1879-2359
    Topics: Architecture, Civil Engineering, Surveying , Geography
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  • 81
    Publication Date: 2018
    Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Transportation Research Part F: Traffic Psychology and Behaviour, Volume 60〈/p〉 〈p〉Author(s): Heejin Jeong, Yili Liu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Driving on horizontal, curved roads requires much research attention because it tends to result in more accidents compared to driving on straight roads. Several studies have found that non-driving-related-task (or secondary-task) sensory modality and horizontal-road geometry (e.g., curvature radius and curve direction) are major factors that affect driving performance and safety on horizontal curves. However, few studies have examined the combined effects of these factors. This paper reports a driving simulation study of the impacts of non-driving-related-task modality (4 levels), road curvature radius (4 levels), and curve direction (2 levels) on driver behaviour. Eye movements, lane-keeping performance, and subjective workload of 24 participants were measured. The results showed that drivers performing non-driving-related tasks using visual stimuli or manual responses on curved roads fixated less frequently and with shorter durations on the road and showed poorer lane-keeping performance compared to other modalities. In addition, when driving on sharper curves with a non-driving-related task, drivers looked at the road more frequently and longer, but their lane-keeping performance was poorer (i.e., higher standard deviations of lane position and of steering wheel angle). Participants reported higher visual demand when performing visual-speech types of tasks compared to auditory-manual types of tasks. The practical implications for driving safety on horizontal, curved roads are discussed.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 1369-8478
    Electronic ISSN: 1873-5517
    Topics: Geography , Psychology
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  • 82
    facet.materialart.
    Unknown
    Elsevier
    Publication Date: 2018
    Description: 〈p〉Publication date: 1 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Ocean & Coastal Management, Volume 166〈/p〉 〈p〉Author(s): 〈/p〉
    Print ISSN: 0964-5691
    Electronic ISSN: 1873-524X
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Geography
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  • 83
    Publication Date: 2018
    Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Marine Policy, Volume 99〈/p〉 〈p〉Author(s): Y.W. Bakker, J. de Koning, J. van Tatenhove〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Between 2010 and 2016, the Orkney Islands Council, Highland Council and Marine Scotland have collaborated to develop a pilot Marine Spatial Plan for the Pentland Firth and Orkney Waters in Scotland. This paper explores the challenges of marine spatial planning processes by looking at the possibilities for fisheries communities to mobilize their social capital – in the form of bonding, bridging or linking – in order to re-position and to empower themselves in these processes. This paper aims to uncover the resilience of local communities that deploy social capital in order to influence MSP processes and safeguard their own interests. For this article ten weeks of qualitative fieldwork in the form of in-depth interviews and participant observation with stakeholders of the pilot marine spatial plan were conducted on the Orkney Islands in Scotland. The strong bonding social capital among fishermen in Orkney has resulted in a resilient community identity which allows for collaboration and self-organization, but also creates a defensive mentality which does not favor linking. Furthermore, a lack of trust in governmental authorities inhibits the mobilization of linking social capital among fishermen, obstructing the ability to access power through cross-scale connections. In response the fisheries community uses bridging social capital outside governance arenas to access networks and mobilize resources to strengthen its socio-economic and political position in support of future linking social capital. Researching this complex interrelation and functioning of social capital uncovers some of the social dimensions and socio-institutional constraints for fisheries engagement with and power in marine spatial planning.〈/p〉〈/div〉
    Print ISSN: 0308-597X
    Electronic ISSN: 1872-9460
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Political Science , Law
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  • 84
    Publication Date: 2018
    Description: 〈p〉Publication date: 1 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Agriculture, Ecosystems & Environment, Volumes 270–271〈/p〉 〈p〉Author(s): Camilla Lemming, Astrid Oberson, Jakob Magid, Sander Bruun, Charlotte Scheutz, Emmanuel Frossard, Lars Stoumann Jensen〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Phosphorus (P) accumulated in soil after surplus P applications can potentially serve as a P source for subsequent crop production. This study investigated residual P availability after long-term surplus P application with different organic waste products. Topsoil samples from a long-term field trial treated with different types of organic wastes were subjected to P characterization, including determination of total P, water-soluble P, and isotopically exchangeable P pools. The waste products were applied for 12 years before sampling, at rates according to crop nitrogen demand and thus typically in excess of crop P requirements. Residual waste P in soil was determined based on the difference between total soil P measured in the different specific waste-treated plots and a balanced reference treatment. After 12 years of surplus P balance (inputs – crop offtake) of 79–598 kg P ha〈sup〉−1〈/sup〉 yr〈sup〉−1〈/sup〉 with waste, significant amounts of P (636–4177 kg ha〈sup〉−1〈/sup〉) had accumulated in the soil as residual P. The average fraction of residual waste P which could be recovered as rapidly exchangeable P (within 1 min) followed the order: composted household waste P (2.1%) 〈 sewage sludge P (5.1%) 〈 cattle manure P (10.9%), indicating that type of waste has an impact on residual P availability after long-term surplus P application. Unaccounted P (surplus P balance – residual P, i.e., P potentially lost from the topsoil) followed the same order, so compost P was better retained in the soil, but with a less clear difference between sewage sludge and cattle manure. For the latter two wastes, approximately half the surplus P balance could not be accounted for in the topsoil and was assumed to be transported down the soil profile. Three years after waste application was terminated, the fraction of rapidly exchangeable residual P had not declined significantly, suggesting sustained availability of residual P in the soil after long-term application of organic waste. Overall, the availability and mobility of residual P after applying composted household waste to soil was significantly lower than that of residual P from sewage sludge and cattle manure.〈/p〉〈/div〉
    Print ISSN: 0167-8809
    Electronic ISSN: 1873-2305
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
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  • 85
    Publication Date: 2018
    Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 84〈/p〉 〈p〉Author(s): Guang-hua Wang, Jing-jing Wang, Bin Yue, Xue Du, He-he Du, Min Zhang, Yong-hua Hu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉High-mobility group box 2 (HMGB2) is a non-histone chromosomal protein that involved diverse functions such as transcriptional regulation and innate immune responses in mammalian. In teleost, very limited studies on HMGB2 proteins have been documented. Black rockfish (〈em〉Sebastes schlegelii〈/em〉) is an economic fish species and cultured worldwide. However, the study of black rockfish about immunology is very scarce. In the present study, a HMGB2 homologue gene (〈em〉SsHMGB2〈/em〉) was identified and characterized in black rockfish. The open reading frame of 〈em〉SsHMGB2〈/em〉 is 648 bp, and the deduced amino acid sequence of 〈em〉SsHMGB2〈/em〉 shares 74.4%–91.2% overall sequence identities with the HMGB2 proteins of several fish species. In silico analysis identified several conserved features, including two basic HMG boxes and an acidic C-terminal tail composed of 24 Asp/Glu residues. Expression of 〈em〉SsHMGB2〈/em〉 occurred in multiple tissues and was upregulated during pathogens infection. Recombinant SsHMGB2 (rSsHMGB2) exhibited apparent binding activities against DNA. 〈em〉In vivo〈/em〉 studies showed that the expressions of multiple immune-related genes in head kidney were significantly enhanced when black rockfish were treated with rSsHMGB2. Furthermore, rSsHMGB2 reduced pathogen dissemination and replication in fish kidney and spleen. Taken together, these results suggest that SsHMGB2 possesses apparent immunoregulatory properties and played a role in fighting bacterial infection.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 1050-4648
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    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
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  • 86
    Publication Date: 2018
    Description: 〈p〉Publication date: December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Transport Geography, Volume 73〈/p〉 〈p〉Author(s): Tingting Tong, T. Edward Yu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This study analyzes the cointegration and causal relationship between transportation and economic growth in the eastern, central and western regions of China using provincial data from 2000 to 2015. Accounting for cross-section dependence and heterogeneity among provinces, a long-run equilibrium relationship is established between freight transportation and economic growth in all three regions. Specifically, the long-run output elasticity coefficient for freight transportation ranges between 0.35 and 0.89 among the three regions, with the highest economic impact in the central region. In addition, a bidirectional Granger causal relationship is identified between freight transportation and economic growth in the less developed central and western regions, while freight transportation leads economic growth in the more affluent eastern region but not the reverse. When considering modes of freight transportations, highways are found to be cointegrated with economic growth, with a long run impact ranging from 0.37 to 0.67 among the three regions. Also, the causality between highway freight and economic growth follows the relationship between overall freight transportation and economy in all three regions; whereas rail freight do not cause economic growth in any of the three regions. Our findings imply that highway freight has become the dominant mode of transportation in terms of supporting regional economic growth. In addition, spatial diversity in economic activity should be taken into consideration in planning regional transportation system in China.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0966-6923
    Electronic ISSN: 1873-1236
    Topics: Architecture, Civil Engineering, Surveying , Geography
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  • 87
    facet.materialart.
    Unknown
    Elsevier
    Publication Date: 2018
    Description: 〈p〉Publication date: 15 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Remote Sensing of Environment, Volume 219〈/p〉 〈p〉Author(s): 〈/p〉
    Print ISSN: 0034-4257
    Electronic ISSN: 1879-0704
    Topics: Architecture, Civil Engineering, Surveying , Geography
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  • 88
    Publication Date: 2018
    Description: 〈p〉Publication date: December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 ISPRS Journal of Photogrammetry and Remote Sensing, Volume 146〈/p〉 〈p〉Author(s): Yumin Tan, Shuai Wang, Bo Xu, Jiabin Zhang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉With the advent of unmanned aerial vehicle (UAV)-based photogrammetry and structure from motion (SFM) software, it is possible to obtain high-density point clouds of which the accuracy can meet the requirements of river bank monitoring. Ground filtering, i.e., removing the points belonging to above-ground objects, is an important process of digital terrain model (DTM) generation which is essential to river bank monitoring. Progressive morphological filter (PM) is a widely-adopted ground filtering algorithm and performs well with LiDAR data. However, it may incorrectly classify vegetation points as ground points when used to filter UAV-based photogrammetric point clouds because ground points beneath vegetation cannot be captured with the digital camera on-board UAV. In this study, we propose the improved progressive morphological filter (IPM) algorithm to improve the accuracy of ground filtering on UAV-based photogrammetric point clouds by introducing visible-band difference vegetation index (VDVI) to PM. The proposed IPM is subsequently evaluated along with the original PM algorithm and four other widely-used ground filtering algorithms in four test sites along the Yangtze River. The results show that IPM improves the overall accuracy from PM in all the four test sites, and produces the best results among the six ground filtering algorithms in three out of the four sites. IPM proves to be an effective ground filtering algorithm for UAV-based photogrammetric point clouds in river bank monitoring.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0924-2716
    Electronic ISSN: 1872-8235
    Topics: Architecture, Civil Engineering, Surveying , Geography
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  • 89
    Publication Date: 2018
    Description: 〈p〉Publication date: 1 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Computational Physics, Volume 378〈/p〉 〈p〉Author(s): Oscar P. Bruno, Martín Maas〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This paper introduces a fast algorithm, applicable throughout the electromagnetic spectrum, for the numerical solution of problems of scattering by periodic surfaces in two-dimensional space. The proposed algorithm remains highly accurate and efficient for challenging configurations including randomly rough surfaces, deep corrugations, large periods, near grazing incidences, and, importantly, Wood-anomaly resonant frequencies. The proposed approach is based on use of certain “shifted equivalent sources” which enable FFT acceleration of a Wood-anomaly-capable quasi-periodic Green function introduced recently (Bruno and Delourme (2014) [4]). The Green-function strategy additionally incorporates an exponentially convergent shifted version of the classical 〈em〉spectral〈/em〉 series for the Green function. While the computing-cost asymptotics depend on the asymptotic configuration assumed, the computing costs rise at most linearly with the size of the problem for a number of important rough-surface cases we consider. In practice, single-core runs in computing times ranging from a fraction of a second to a few seconds suffice for the proposed algorithm to produce highly-accurate solutions in some of the most challenging contexts arising in applications.〈/p〉〈/div〉
    Print ISSN: 0021-9991
    Electronic ISSN: 1090-2716
    Topics: Computer Science , Physics
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  • 90
    Publication Date: 2018
    Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Computational Physics, Volume 379〈/p〉 〈p〉Author(s): Denis S. Grebenkov, Sergey D. Traytak〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The generalized method of separation of variables (GMSV) is applied to solve boundary value problems for the Laplace operator in three-dimensional domains with disconnected spherical boundaries (e.g., an arbitrary configuration of non-overlapping partially reactive spherical sinks or obstacles). We consider both exterior and interior problems and all most common boundary conditions: Dirichlet, Neumann, Robin, and conjugate one. Using the translational addition theorems for solid harmonics to switch between the local spherical coordinates, we obtain a semi-analytical expression of the Green function as a linear combination of partial solutions whose coefficients are fixed by boundary conditions. Although the numerical computation of the coefficients involves series truncation and solution of a system of linear algebraic equations, the use of the solid harmonics as basis functions naturally adapted to the intrinsic symmetries of the problem makes the GMSV particularly efficient, especially for exterior problems. The obtained Green function is the key ingredient to solve boundary value problems and to determine various characteristics of stationary diffusion such as reaction rate, escape probability, harmonic measure, residence time, and mean first passage time, to name but a few. The relevant aspects of the numerical implementation and potential applications in chemical physics, heat transfer, electrostatics, and hydrodynamics are discussed.〈/p〉〈/div〉
    Print ISSN: 0021-9991
    Electronic ISSN: 1090-2716
    Topics: Computer Science , Physics
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  • 91
    Publication Date: 2018
    Description: 〈p〉Publication date: Available online 31 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Geoderma〈/p〉 〈p〉Author(s): Talita R. Ferreira, Luiz F. Pires, Dorthe Wildenschild, André M. Brinatti, Jaqueline A.R. Borges, André C. Auler, Aline M.H. dos Reis〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The hierarchical organization of aggregates in soil is responsible for the presence of inter and intra-aggregate pores. This research aimed to investigate effects of soil surface liming, considering lime rates of 0, 10 and 15 t ha〈sup〉−1〈/sup〉, on the intra-aggregate porous system of soil aggregates with equivalent diameters of 2–4 and 1–2 mm, from 0 to 10 (A) and 10 to 20 cm (B) soil layers. These aggregates were selected by the wet sieving method carried out for determination of the mean weight diameter. Synchrotron-based computed microtomography (μCT) of aggregates was analyzed in terms of porosity, connectivity, tortuosity, and fractal dimension. Additionally, X-ray fluorescence was used to evaluate the elemental composition of the soil aggregates. All liming effects were concentrated at layer A, where calcium percentage was elevated in aggregates from 1–2 mm class as compared to those from 2–4 mm class. Accordingly, the physical parameters studied were generally more affected in the case of smaller aggregates (1–2 mm). Liming decreased total porosity, increased tortuosity of pores, and decreased fractal dimension for 1–2 mm aggregates, which was in line with the fact that larger pores were replaced by smaller ones in 1–2 mm aggregates, as found 〈em〉via〈/em〉 both quantitative and qualitative analyses. On the other hand, liming did not affect pore connectivity under any of the circumstances.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0016-7061
    Electronic ISSN: 1872-6259
    Topics: Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
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  • 92
    Publication Date: 2018
    Description: 〈p〉Publication date: 15 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Computational Physics, Volume 377〈/p〉 〈p〉Author(s): Samar Chehade, Audrey Kamta Djakou, Michel Darmon, Gilles Lebeau〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Non Destructive Examination (NDE) of industrial structures requires the modeling of specimen geometry echoes generated by the surfaces (entry, backwall …) of inspected blocks. For that purpose, the study of plane wave diffraction by a wedge is of great interest. The work presented here is preliminary research to model the case of an elastic wave diffracted by a wedge in the future, for which there exist various modeling approaches but the numerical aspects have only been developed for wedge angles lower than 〈em〉π〈/em〉. The spectral functions method has previously been introduced to solve the 2D diffraction problem of an immersed elastic wedge for angles lower than 〈em〉π〈/em〉. As a first step, the spectral functions method has been developed here for the diffraction on an acoustic wave by a stress-free wedge, in 2D and for any wedge angle, before studying the elastic wave diffraction from a wedge. In this method, the solution to the diffraction problem is expressed in terms of two unknown functions called the spectral functions. These functions are computed semi-analytically, meaning that they are the sum of two terms. One of them is determined exactly and the other is approached numerically, using a collocation method. A successful numerical validation of the method for all wedge angles is proposed, by comparison with the GTD (Geometrical Theory of Diffraction) solution derived from the exact Sommerfeld integral.〈/p〉〈/div〉
    Print ISSN: 0021-9991
    Electronic ISSN: 1090-2716
    Topics: Computer Science , Physics
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  • 93
    Publication Date: 2018
    Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hydrology, Volume 568〈/p〉 〈p〉Author(s): Jian Zhang, Chunling Zhang, Wanli Shi, Yicheng Fu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The water resources-water environment carrying capacity (WR-WECC) is an important indicator for judging the regional macro-control ability of water resources. The nature-based solutions (NBS) concept is related closely to sustainability, harmonious and green development, resources rational exploitation, coupled human and environment, and ecological protection priority. Participatory water management has necessitated the formation of village water resources committees and/or village environmental committees; while in the case of water management, a participatory approach has resulted in the formation of community water association, domestic water committees, cooperative societies, and various water user groups. The WR-WECC evaluation goal is to find the most appropriate water resources development and utilization to maximize benefits and system efficiency while minimizing costs and trade‐offs. To realize the development and utilization of water resources, water ecological conservation, and water environment protection in Yuetang District, we constructed a dynamic evaluation index system including water resources, water environment and water ecological characteristics, applying the principal component analysis (PCA) method to evaluate the temporal scale variation tendency of WR-WECC, and explore a deep-seated reason based on NBS. The WR-WECC evaluation index system covered 16 indexes belonging to three subsystems of water resource, socioeconomic, and eco-environmental systems. We used Statistical Product and Service Solutions (SPSS) 19.0 software and adopted the improved PCA to integrate the urban economic-social-ecological development of the Xiangjiang (a tributary of the Yangtze River) River Basin. We applied the evaluation index system to analyse the trend variability of WR-WECC of Yuetang District from 2005 to 2015 based on NBS. The WR-WECC of Yuetang District was affected mainly by the urban sewage treatment rate, the water use amount per ten thousand Yuan gross domestic product (GDP), and per capita water resources. In addition to minor fluctuations in 2007 and 2011, the WR-WECC in Yuetang District was generally on the rise year by year and was related to socioeconomic development level, regional water environment comprehensive management, and awareness of water ecological protection. The WR-WECC of the Yuetang District in 2013–2015 was in a Class I (excellent) condition. The temporal variations analysis based on NBS was proposed through a combination of economic-social-ecological values provided by nature-based development and utilization patterns. Based on the relationship among regional water resources, economic society, and eco-environment protection, the paper supplied a WR-WECC improvement strategy that was suitable for the development and utilization of water resources in a water-rich area in south China.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0022-1694
    Electronic ISSN: 1879-2707
    Topics: Architecture, Civil Engineering, Surveying , Geography , Geosciences
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  • 94
    Publication Date: 2018
    Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hydrology, Volume 568〈/p〉 〈p〉Author(s): Klodian Gradeci, Nathalie Labonnote, Edvard Sivertsen, Berit Time〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This study employs a systematic literature review to investigate how insurance data can be applied in the analysis of Surface Water Flood events. The study firstly identifies the variables expressing insurance data and those explaining them, together with their interrelationships. Damage variables may be expressed as either monetary-based or number of claims-based. Explaining variables may be subdivided into four categories: meteorological, geographic, demographic and property/building-based. Most of the common and under-researched combinations of these variables and their expression are discussed. Secondly, a comparative analysis is presented of current models, highlighting their differences and similarities. The study demonstrates that the scope and approach of the models varies in relation to scale, the coverage and period of incorporated insurance claims, and the methods used for model development and validation. Thirdly, the study proposes a generic and adaptable framework, constructed from an aggregation of information contained in relevant literature, to define a workflow for model development and future deployment. The study concludes with a discussion of the challenges facing model development and opportunities for deployment.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0022-1694
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    Topics: Architecture, Civil Engineering, Surveying , Geography , Geosciences
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  • 95
    Publication Date: 2018
    Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Transportation Research Part F: Traffic Psychology and Behaviour, Volume 60〈/p〉 〈p〉Author(s): Frederik Naujoks, Katharina Wiedemann, Nadja Schömig, Sebastian Hergeth, Andreas Keinath〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In most levels of vehicle automation, drivers will not be merely occupants or passengers of automated vehicles. Especially in lower levels of automation, where the driver is still required to serve as a fallback level (SAE L3) or even as a supervisor (SAE L2), there is a need to communicate relevant system states (e.g., that the automated driving system works reliably or that there is a need for manual intervention) via the Human-Machine Interface (HMI). However, there are currently no agreed-upon guidelines that apply specifically to HMIs for automated driving. In this paper, we summarize design recommendations for visual-auditory and visual-vibrotactile HMIs derived from empirical research, applicable standards and design guidelines pertaining to in-vehicle interfaces. On this basis, we derive an initial set of principles and criteria for guiding the development and design of automated vehicle HMIs. A heuristic evaluation methodology consisting of an itemized checklist evaluation that can be used to verify that basic HMI requirements formulated in the guidelines are met is also presented. The heuristic evaluation involves an inspection of the HMI during typical use cases, judging their compliance with the proposed guidelines and documentation of identified instances of non-compliance. Taken together, the combination of the proposed guidelines and the heuristic evaluation methodology form the basis for both design and validation recommendations of automated vehicle HMIs, that can serve the industry in the important evolution of automation within vehicles.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 1369-8478
    Electronic ISSN: 1873-5517
    Topics: Geography , Psychology
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  • 96
    Publication Date: 2018
    Description: 〈p〉Publication date: December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Transportation Research Part D: Transport and Environment, Volume 65〈/p〉 〈p〉Author(s): Laura Minet, Jonathan Stokes, James Scott, Junshi Xu, Scott Weichenthal, Marianne Hatzopoulou〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This study was motivated by an interest in capturing the factors affecting the exposure of cyclists to ambient Ultrafine Particles (UFP), Black Carbon (BC), and noise (LA〈sub〉eq〈/sub〉) across the entire bicycle network of the City of Toronto. Measurements were conducted along 270 km of unique roads, and we developed land use regression models and exposure surfaces. Median UFP, BC and noise levels recorded were 19,848 part/cm〈sup〉3〈/sup〉, 1224 ng/m〈sup〉3〈/sup〉, and 72.9 dB respectively. The average UFP and BC exposures along the biking routes (18,900 part/cm〈sup〉3〈/sup〉 and 1130 ng/m〈sup〉3〈/sup〉) were higher than the average levels measured at a fixed station located in downtown Toronto (13,300 part/cm〈sup〉3〈/sup〉 and 809 ng/m〈sup〉3〈/sup〉). The highest UFP and BC levels were experienced on dedicated bicycle tracks (30,000 part/cm〈sup〉3〈/sup〉 and 1600 ng/m〈sup〉3〈/sup〉 as median concentrations), while the highest noise levels occurred on major roads (median of 74 dB). In contrast, median levels on trails were 13,200 part/cm〈sup〉3〈/sup〉, 535 ng/m〈sup〉3〈/sup〉 and 70.2 dB, for UFP, BC, and noise. The exposure surfaces developed for the air pollutants and noise were intersected with the planned extensions to the bicycle network in the City of Toronto to evaluate the distributions of exposures expected across the future cycling network. We observe that the mean and median UFP, BC, and noise levels across planned facilities are equal to or significantly higher than the levels across the current network.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1361920918301925-ga1.jpg" width="269" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉
    Print ISSN: 1361-9209
    Electronic ISSN: 1879-2340
    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography
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  • 97
    Publication Date: 2018
    Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Transportation Research Part F: Traffic Psychology and Behaviour, Volume 60〈/p〉 〈p〉Author(s): Bharat Kumar Pathivada, Vedagiri Perumal〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Intersections are important node points in the road network, ensuring safe and efficient way of maneuvering the traffic. The Ministry of Road Transport and Highways (MORTH) reported in year 2016 that the highest number of road accidents in India happened at intersections accounting for nearly thirty seven percent (37%) of the total crashes that took place. Even though traffic signals are considered to be the most effective way of controlling the traffic, more than 4300 lost their lives at signalized intersections in India. One of the main contributing factor in traffic signal related crashes is the presence of dilemma zone, where a driver becomes indecisive whether to pass or stop at the intersection on the yellow onset. Significant amount of research has been done on the dilemma driver behavior under homogeneous traffic conditions, however little or no research has been found on mixed traffic conditions, where vehicles do vary in physical and dynamic characteristics. The main motive of this study is to investigate the factors influencing the driver behavior in dilemma zone at signalized approaches in India under mixed traffic conditions. Field data was collected at five signalized approaches using video capturing technique to investigate the driver behavior. Frame by frame manual extraction resulted in 1054 driver responses at the yellow onset and binary logistic regression model is developed to represent the observed behavior. Distance from stop line, vehicle’s approach speed and type of intersection were found to be important factors in drivers stop/go decisions. Vehicle type, which is a characteristic of mixed traffic conditions is found to have a significant impact on the driver’s decision at the onset of yellow. The insights from this study findings can be used to enhance the safety and performance of signalized intersections in developing countries.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 1369-8478
    Electronic ISSN: 1873-5517
    Topics: Geography , Psychology
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  • 98
    Publication Date: 2018
    Description: 〈p〉Publication date: December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Transportation Research Part C: Emerging Technologies, Volume 97〈/p〉 〈p〉Author(s): Yong-Xian Huang, Rui Jiang, HM Zhang, Mao-Bin Hu, Jun-Fang Tian, Bin Jia, Zi-You Gao〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉To investigate the car-following behavior under high speed driving conditions, we performed a set of 11-car-platoon experiments on Hefei airport highway. The formation and growth of oscillations have been analyzed and compared with that in low speed situations. It was found that there is considerable heterogeneity for the same driver over different runs of the experiment. This intra-driver heterogeneity was quantitatively depicted by a new index and incorporated in an enhanced two-dimensional intelligent driver model. Using both the new high-speed and the previous low-speed experimental data, the new and three existing models were calibrated. Simulation results show that the enhanced model outperforms the three existing car-following models that do not take into account this intra-driver heterogeneity in reproducing the essential features of the traffic in the experiments.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0968-090X
    Electronic ISSN: 1879-2359
    Topics: Architecture, Civil Engineering, Surveying , Geography
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  • 99
    Publication Date: 2018
    Description: 〈p〉Publication date: Available online 30 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Transportation Research Part A: Policy and Practice〈/p〉 〈p〉Author(s): Samantha J. Leger, Jennifer L. Dean, Sara Edge, Jeffrey M. Casello〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The predominance of automobile dependency in North America is associated with a host of negative health and environmental impacts and has sparked the promotion of low-carbon and active modes of transportation. Encompassing both priorities, electric-bicycles have become a popular mode of transportation in some parts of the world. While multiple studies have suggested older adult populations may be most likely to benefit from e-bike technology, few studies have exclusively focused on this demographic to identify the factors that may promote or inhibit e-bike adoption amongst this group. This study explores the potential for e-bikes to support independent mobility and active aging among the older adult population in Canada’s auto-dependent context. Guided by a conceptual framework for older adult mobility, this study used qualitative methods to gather perceptual and experiential data from 17 community stakeholders and 37 older adults in the Region of Waterloo, Ontario. The findings highlight the importance of cycling life histories, social connection and physical limitations to adopting cycling later in life. Specific individual and structural factors were discussed in relation to e-bike adoption including facilitators such as increased convenience, reduced physical exertion, reduced reliance on a vehicle and fun. Barriers included cycling infrastructure and road safety, regulation, and stigmatization barriers. E-bikes as a more convenient and supportive mode of transit for older adults is discussed alongside the importance of e-bikes as a replacement for traditional bicycles in a subset of this population.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0965-8564
    Electronic ISSN: 1879-2375
    Topics: Architecture, Civil Engineering, Surveying , Geography
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  • 100
    Publication Date: 2018
    Description: 〈p〉Publication date: January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hydrology, Volume 568〈/p〉 〈p〉Author(s): G.W. Ma, H.D. Wang, L.F. Fan, Y. Chen〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A unified pipe-network-based numerical manifold method (NMM) is developed to simulate immiscible two-phase flow in a geological medium. Both heterogeneous and non-heterogeneous geological media can be discretized as numerical pipe networks, which have high efficiency and accuracy in simulating fluid and mass transfer in fractured rock masses. A manifold element method is developed to solve the governing equations of immiscible two-phase flow in pipes. The developed NMM can simulate moving and deforming of two-phase flow interface. A grid-based front-tracking method updates the marker points constructing the fluid interface explicitly in each time step. The effectiveness of the NMM is verified through analytical and finite element analysis. Parametric studies are conducted by simulating immiscible two-phase flows with various fluid properties in homogeneous and inhomogeneous geological conditions. The results show that the developed method can efficiently simulate the moving interface of two-phase flow in geological media, including effects such as “viscous fingering”, a noteworthy phenomenon in enhanced oil recovery. When the mobility of the driving fluid is larger than that of the driven fluid, the inhomogeneity of the medium can cause the fluid interface to roughen, which increases over time during the process of two-phase flow. For the inverse situation, although the fluid interface remains rough, the roughness variation throughout the process is not prominent.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0022-1694
    Electronic ISSN: 1879-2707
    Topics: Architecture, Civil Engineering, Surveying , Geography , Geosciences
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