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  • 1
    Publication Date: 2019-11-01
    Electronic ISSN: 2542-5196
    Topics: Medicine , Natural Sciences in General
    Published by Elsevier
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  • 2
  • 3
  • 4
    Publication Date: 2019-11-01
    Electronic ISSN: 2542-5196
    Topics: Medicine , Natural Sciences in General
    Published by Elsevier
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  • 5
    Publication Date: 2019-12-01
    Print ISSN: 0038-0806
    Topics: Architecture, Civil Engineering, Surveying , Geosciences
    Published by Elsevier
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  • 6
    Publication Date: 2019
    Description: 〈p〉Publication date: October–December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Mutation Research/Reviews in Mutation Research, Volume 782〈/p〉 〈p〉Author(s): Yuxiao Liao, Zhao Peng, Liangkai Chen, Liegang Liu, Qinghua Wu, Wei Yang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Mycotoxins, produced by fungi, are secondary metabolites causing adverse, toxic and pathological effects on human and animals. Studies about the association between mycotoxins and microRNAs (miRNAs) were developed since miRNAs have been demonstrated to play a critical role in many developmental processes for regulating messenger RNA (mRNA). As published studies showed, dozens of miRNAs were influenced by mycotoxins, indicating that miRNAs can play important roles in the occurrence and development of mycotoxicosis. Besides, a hypothesis called competing endogenous RNA (ceRNA) was reported to indirectly modulate the expression of mRNA 〈em〉via〈/em〉 miRNA response elements (MREs) to consequently regulate cell functions. As a result, four common miRNAs were focused to predict the corresponding ceRNAs based on their own characteristics and the effects of mycotoxins on them, in hope of providing potential ways or directions of miRNAs regulation for mycotoxicosis, and expanding the research field about mycotoxicosis from ceRNA.〈/p〉〈/div〉
    Print ISSN: 1383-5742
    Electronic ISSN: 1388-2139
    Topics: Biology , Medicine
    Published by Elsevier
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  • 7
    Publication Date: 2019
    Description: 〈p〉Publication date: October–December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Mutation Research/Reviews in Mutation Research, Volume 782〈/p〉 〈p〉Author(s): Yanan Xu, Qian Zhang, Liang Tan, Xubiao Xie, Yong Zhao〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Niemann–Pick C disease (NPC) is a rare autosomal recessive disorder characterized by severe neurodegeneration of central nervous system. Linkage studies in multiplex NPC families and genetic complementation research revealed two disease genes, 〈em〉NPC1 and NPC2,〈/em〉 both of which are important transporters for cholesterol trafficking. NPC2 executes cholesterol-transport function through protein-protein interaction with NPC1 as well as through protein-membrane interaction directly with membrane of late endosome and lysosome. In addition, NPC2 may play many other roles as indicated by its widely expressing pattern in different cells and presenting in numerous secretory fluids, although it biological significance is less studied today. About 50 clinical cases have been reported documenting over twenty different mutations of 〈em〉NPC2〈/em〉 in NPC patients so far. In this review, we will mainly summarize the molecular characteristics and biological significance of NPC2, highlighting its vital roles in NPC disease.〈/p〉〈/div〉
    Print ISSN: 1383-5742
    Electronic ISSN: 1388-2139
    Topics: Biology , Medicine
    Published by Elsevier
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  • 8
    Publication Date: 2019
    Description: 〈p〉Publication date: 15 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Bioorganic & Medicinal Chemistry, Volume 27, Issue 16〈/p〉 〈p〉Author(s): Tao Li, Jing Li, Yang Yang, Yilin Han, Dirong Wu, Tao Xiao, Yang Wang, Ting Liu, Yonglong Zhao, Yongjun Li, Zeqin Dai, Xiaozhong Fu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The deficiency of nucleos(t)ide analogues (NAs) as anti-hepatitis B virus (HBV) drugs in clinical use is attributable to their insufficient enrichment in liver and non-target organ toxicity. We aimed to develop potent anti-HBV adefovir derivatives with hepatotrophic properties and reduced nephrotoxicity. A series of adefovir mono 〈span〉l〈/span〉-amino acids, mono cholic acid-drug conjugates were designed and synthesized, and their antiviral activity and uptake in rat primary hepatocytes and Na〈sup〉+〈/sup〉-dependent taurocholate co-transporting polypeptide (NTCP)-HEK293 cells were evaluated. We isolated compound 〈strong〉6c〈/strong〉 as the optimal molecular candidate, with the highest antiviral activity (EC〈sub〉50〈/sub〉 0.42 μmol/L, SI 1063.07) and highest cellular uptake in primary hepatocytes and NTCP-HEK293 cells. In-depth mechanistic studies demonstrated that 〈strong〉6c〈/strong〉 exhibited a lower toxicity in HK-2 cells when compared to adefovir dipivoxil (ADV). This is because 〈strong〉6c〈/strong〉 cannot be transported by the human renal organic anion transporter 1 (hOAT1). Furthermore, pharmacokinetic characterization and tissue distribution of 〈strong〉6c〈/strong〉 indicates it has favorable druggability and pharmacokinetic properties. Further docking studies suggested compounds with ursodeoxycholic acid and 〈span〉l〈/span〉-amino acid groups are better at binding to NTCP due to their hydrophilic properties, indicating that 〈strong〉6c〈/strong〉 is a potential candidate as an anti-HBV therapy and therefore merits further investigation.〈/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-S0968089619309034-ga1.jpg" width="327" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0968-0896
    Electronic ISSN: 1464-3391
    Topics: Chemistry and Pharmacology , Medicine
    Published by Elsevier
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  • 9
    Publication Date: 2019
    Description: 〈p〉Publication date: 1 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Bioorganic & Medicinal Chemistry, Volume 27, Issue 17〈/p〉 〈p〉Author(s): Bo Hou, Ze Liu, Xiao-Bei Yang, Wen-Fei Zhu, Jin-Yu Li, Liu Yang, Fu-Cai Reng, Yong-Feng Lv, Jiang-Miao Hu, Guo-Yang Liao, Jun Zhou〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The stems of 〈em〉Dryopteris crassirhizoma〈/em〉, one of the main components of Lianhua-Qingwen Formula (LQF) was traditionally used for heat-clearing and detoxifying. Dryocrassin 〈strong〉ABBA〈/strong〉 is a key antiviral component in the herbal medicine while the compound is hard to get in large amounts with the features of homologous compounds, polyphenol groups, and low contents. Therefore, the present work aims to seek influenza H7N9 virus inhibitors from natural source by synthesis of dryocrassin 〈strong〉ABBA〈/strong〉 and its analogues. As a result, total synthesis of the compound was achieved in nine steps with an over-all yield of 4.6%. Neuraminidases (NAs) inhibitory activities of the synthesized product and its analogues were evaluated afterward. Comparing with the positive control, OSV (9.6 μM), it was very exciting that dryocrassin 〈strong〉ABBA〈/strong〉 and its analogues (〈strong〉b5〈/strong〉 and 〈strong〉e2〈/strong〉) showed better NAs inhibitory activity against Anhui H7N9 with IC〈sub〉50〈/sub〉 values of 3.6 μM, 2.5 μM and 1.6 μM. For the highly resistant Shanghai N9, these compounds can also show medium inhibitory activities. Docking results indicated the direct interaction of synthesized 3 hits with the key K294 by hydrogen bonds, but no direct interaction of OSV with the key K294 was observed in Shanghai N9. This study suggested that dryocrassin 〈strong〉ABBA〈/strong〉 and its analogues especially 〈strong〉AB〈/strong〉, which consisted of polyphenol groups may have beneficial effects on treating avian influenza H7N9 virus.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉Total synthesis of dryocrassin ABBA and analogue structures with potential inhibitory activity against drug-resistant neuraminidases.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0968089619308879-ga1.jpg" width="278" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉 〈/div〉
    Print ISSN: 0968-0896
    Electronic ISSN: 1464-3391
    Topics: Chemistry and Pharmacology , Medicine
    Published by Elsevier
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  • 10
    Publication Date: 2019
    Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics, Volume 1867, Issue 9〈/p〉 〈p〉Author(s): 〈/p〉
    Print ISSN: 1570-9639
    Electronic ISSN: 1878-1454
    Topics: Biology , Chemistry and Pharmacology , Medicine , Physics
    Published by Elsevier
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  • 11
    Publication Date: 2019
    Description: 〈p〉Publication date: Available online 8 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Biochimica et Biophysica Acta (BBA) - Biomembranes〈/p〉 〈p〉Author(s): Deo R. Singh, Christopher King, Matt Salotto, Kalina Hristova〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉EGFR is a receptor tyrosine kinase that plays a critical role in cell proliferation, differentiation, survival and migration. Its activating ligand, EGF, has long been believed to stabilize the EGFR dimer. Two research studies aimed at quantitative measurements of EGFR dimerization, however, have led to contradicting conclusions and have questioned this view. Given the controversy, here we sought to measure the dimerization of EGFR in the absence and in the presence of saturating EGF concentrations, and to tease out the effect of ligand on dimer stability, using a FRET-based quantitative method. Our measurements show that the dissociation constant is decreased ~150 times due to ligand binding, indicative of significant dimer stabilization. In addition, our measurements demonstrate that EGF binding induces a conformational change in the EGFR dimer.〈/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-S0005273619301476-ga1.jpg" width="265" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0005-2736
    Electronic ISSN: 1879-2642
    Topics: Biology , Chemistry and Pharmacology , Medicine , Physics
    Published by Elsevier
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  • 12
    Publication Date: 2019
    Description: 〈p〉Publication date: November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Carbon, Volume 153〈/p〉 〈p〉Author(s): Ayoub H. Jaafar, N.T. Kemp〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This paper reports on the first optically tunable graphene oxide memristor device. Modulation of resistive switching memory by light opens the route to new optoelectronic devices that can be switched optically and read electronically. Applications include integrated circuits with memory elements switchable by light and optically reconfigurable and tunable synaptic circuits for neuromorphic computing and brain-inspired, artificial intelligence systems. In this report, planar and vertical structured optical resistive switching memristors based on graphene oxide are reported. The device is switchable by either optical or electronic means, or by a combination of both. In addition the devices exhibit a unique wavelength dependence that produces reversible and irreversible properties depending on whether the irradiation is long or short wavelength light, respectively. For long wavelength light, the reversible photoconductance effect permits short-term dynamic modulation of the resistive switching properties of the light, which has application as short-term memory in neuromorphic computing. In contrast, short wavelength light induces both the reversible photoconductance effect and an irreversible change in the memristance due to reduction of the graphene oxide. This has important application in the fabrication of cloned neural networks with factory defined weights, enabling the fast replication of artificial intelligent chips with pre-trained information.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0008622319306943-fx1.jpg" width="485" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉
    Print ISSN: 0008-6223
    Electronic ISSN: 1873-3891
    Topics: Chemistry and Pharmacology , Geosciences
    Published by Elsevier
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  • 13
    Publication Date: 2019
    Description: 〈p〉Publication date: Available online 8 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics〈/p〉 〈p〉Author(s): Martina Paumann-Page, Rupert Tscheliessnig, Benjamin Sevcnikar, Romy-Sophie Katz, Irene Schwartz, Stefan Hofbauer, Vera Pfanzagl, Paul G. Furtmüller, Christian Obinger〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Human peroxidasin 1 is a multidomain peroxidase situated in the basement membrane. The iron enzyme with covalently bound heme oxidizes bromide to hypobromous acid which facilitates the formation of distinct sulfilimine cross-links in the collagen IV network and therefore contributes to its mechanical stability. Additional to the catalytically active peroxidase domain peroxidasin comprises a leucine rich repeat domain, four Ig domains and a C-terminal von Willebrand factor type C module (VWC). Peroxidasin has been shown to form homotrimers involving two redox-sensitive cysteine residues and to undergo posttranslational C-terminal proteolytic cleavage. The present study on several recombinantly produced truncated peroxidasin variants showed that the VWC is not required for trimer formation whereas the alpha-helical linker region located between the peroxidase domain and the VWC is crucial for trimerization. Our data furthermore implies that peroxidasin oligomerization occurs intracellularly before C-terminal cleavage. For the first time we present overall solution structures of monomeric and trimeric truncated peroxidasin variants which were determined by rotary shadowing combined with transmission electron microscopy and by small-angle X-ray scattering (SAXS). A triangular arrangement of the peroxidase domains to each other within the homotrimer was revealed and this structure was confirmed by a model of trimeric peroxidase domains. Our SAXS data showed that the Ig domains are highly flexible and interact with the peroxidase domain and that within the homotrimer each alpha-helical linker region interacts with the respective adjacent peroxidase domain. The implications of our findings on the structure-function relationship of peroxidasin are discussed.〈/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-S1570963919301219-ga1.jpg" width="240" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉
    Print ISSN: 1570-9639
    Electronic ISSN: 1878-1454
    Topics: Biology , Chemistry and Pharmacology , Medicine , Physics
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  • 14
    Publication Date: 2019
    Description: 〈p〉Publication date: November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Carbon, Volume 153〈/p〉 〈p〉Author(s): C.M. Ramos-Castillo, M.E. Cifuentes-Quintal, E. Martínez-Guerra, R. de Coss〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Energy gap engineering in graphene nanostructures is one of the most important topics towards development of graphene-based electronics. In this work, based on the density functional theory, the role of the edge magnetism on the size dependence of Kohn-Sham gap and fundamental energy gap for 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.svg"〉〈mrow〉〈msub〉〈mrow〉〈mtext〉C〈/mtext〉〈/mrow〉〈mrow〉〈mn〉6〈/mn〉〈mtext〉nn〈/mtext〉〈/mrow〉〈/msub〉〈msub〉〈mrow〉〈mtext〉H〈/mtext〉〈/mrow〉〈mrow〉〈mn〉6〈/mn〉〈mtext〉n〈/mtext〉〈/mrow〉〈/msub〉〈/mrow〉〈/math〉 (〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si2.svg"〉〈mrow〉〈mtext〉n〈/mtext〉〈mo linebreak="badbreak"〉=〈/mo〉〈mn〉2〈/mn〉〈mo linebreak="goodbreak" linebreakstyle="after"〉−〈/mo〉〈mn〉16〈/mn〉〈/mrow〉〈/math〉) hexagonal graphene quantum dots (GQDs) with zigzag edges is studied. We found a transition from a nonmagnetic to an antiferromagnetic state at a certain critical diameter (〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si3.svg"〉〈mrow〉〈mo〉∼〈/mo〉〈/mrow〉〈/math〉 3 nm), characterized by the opening of a Kohn-Sham gap as a consequence of the exchange interaction between localized edge states. Furthermore, the fundamental gap is obtained from the difference between the calculated vertical ionization and electron affinity energies. Such approximation includes relaxation in the exchange correlation potential when the electron is added to the system, which might be useful for GQDs transport properties interpretation. We found a scaling rule for the fundamental gap dependence on quantum dot size, providing a practical way to predict this property for large GQDs with zigzag edges, which currently in most demanding approaches, such as GW, is unfeasible.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0008622319306876-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉
    Print ISSN: 0008-6223
    Electronic ISSN: 1873-3891
    Topics: Chemistry and Pharmacology , Geosciences
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  • 15
    Publication Date: 2019
    Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 The International Journal of Biochemistry & Cell Biology, Volume 114〈/p〉 〈p〉Author(s): Deep Pooja, Anusha Gunukula, Nitin Gupta, David J. Adams, Hitesh Kulhari〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The biggest challenge in delivering anticancer agents is the ability to direct these molecules specifically to cancer cells. With this in mind, modern research is focussing on improving the precision of cancer drug delivery by incorporating a ligand that has the ability to specifically recognize cancer cells. Peptides are emerging as a new tool in drug and gene delivery. Peptide-drug conjugates, peptide-modified drug delivery systems, and peptide-coupled imaging agents have been shown to increase on-site delivery. This has allowed better tumor mass contouring in imaging and increased therapeutic efficacy of chemotherapies, reducing adverse effects. Benefits of peptide ligands include their small size, easy and affordable production, high specificity and remarkable flexibility regarding their sequence and conjugation possibilities. Bombesin (Bn) receptors have shown great promise for tumor targeting due to their increased expression in a variety of human cancers, including prostate, breast, small cell lung, and pancreatic cells. This review discusses the overexpression of Bn receptors in different cancers and various approaches to target these receptors for therapeutic and diagnostic interventions in human malignancies.〈/p〉〈/div〉
    Print ISSN: 1357-2725
    Electronic ISSN: 1878-5875
    Topics: Biology , Chemistry and Pharmacology , Medicine
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  • 16
    Publication Date: 2019
    Description: 〈p〉Publication date: November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Marine Systems, Volume 199〈/p〉 〈p〉Author(s): Peisheng Huang, Kerry Trayler, Benya Wang, Amina Saeed, Carolyn E. Oldham, Brendan Busch, Matthew R. Hipsey〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Effective short- and long-term estuarine water quality management decisions require a holistic view of estuarine response to multiple stressors that may be achieved through the integration of numerical modelling and observed data. Such an approach has been developed for the Swan-Canning Estuary system, a eutrophic urban estuary in Western Australia under threat from nutrient enrichment and a drying climate. Numerical modelling was integrated with long-term monitoring to develop the system Swan-Canning Estuary Virtual Observatory (SCEVO), which has been used to facilitate water quality management and streamline prediction workflows of hindcast, forecast, and environmental response functions. The system is based on a validated 3D water quality model, integrated within a data management system and related environmental models. A machine-learning method to improve the patchy and time-lagged catchment inputs is also highlighted. This work has identified that the key challenge associated with estuarine water quality prediction is the capability to (1) simulate internal physical and biogeochemical processes at suitable spatial resolution to resolve the gradients along the freshwater-ocean continuum; and (2) transition from using routine monitoring data as the basis for management decisions to using a diverse and integrated set of data streams as the basis for real-time operational decisions. Recommendations for high-frequency monitoring to support water quality modelling and dynamic integration between numerical and observed data for improved forecasting are discussed.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0924-7963
    Electronic ISSN: 1879-1573
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Geosciences , Physics
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  • 17
    Publication Date: 2019
    Description: 〈p〉Publication date: November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Marine Systems, Volume 199〈/p〉 〈p〉Author(s): Arseny A. Kubryakov, Alexander S. Mikaelyan, Sergey V. Stanichny〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉Bio-Argo measurements of the backscattering coefficient (〈em〉bbp〈/em〉) were used to investigate the time-depth evolution of coccolithophore blooms in the Black Sea. Five years of Bio-Argo data obtained in 2014–2018 revealed two distinct peaks of 〈em〉bbp〈/em〉 corresponding to the winter and early summer coccolithophore blooms. The latter started in the upper mixed layer (UML) in April–May and was characterized by the highest coccolithophore concentrations. During the most extensive summer bloom in 2017, its estimates reach 10 × 10〈sup〉6〈/sup〉 cells l〈sup〉−1〈/sup〉. The summer blooms occupied the UML (0–10 m) and a seasonal thermocline (10–30 m). The lower boundary of the bloom was related to the position of isopycnal 1014 kg m〈sup〉−3〈/sup〉, which deepens in May–July due to summer heating. Consequently, the coccolithophore bloom deepened to 20–30 m and terminated rapidly in July. Bloom termination was accompanied by a significant rise in light attenuation (〈em〉kd〈/em〉) in the sea basin. This peak was attributed to the release of dissolved organic carbon (DOC), which was possibly related to viral lysis and the exudation of lipids from coccolithophore cells. Data on the 〈em〉kd〈/em〉 was used to estimate the seasonal variability in DOC in the Black Sea. Maximal estimated values of DOC were observed at 15–35 m depth in June-August and coincided with the early summer coccolithophore bloom termination.〈/p〉 〈p〉The winter coccolithophore bloom started in October–November in the UML. The maximum 〈em〉bbp〈/em〉 was observed in January. High values of 〈em〉bbp〈/em〉 were observed down to a depth of 60 m during the maximal deepening of the mixed layer. The winter blooms were distinctly observed in MODIS satellite images, where they were characterized by high reflectance and relatively low chlorophyll concentrations. The estimated coccolithophore concentration in winter was lower than that in summer, but column-averaged 〈em〉bbp〈/em〉 values were comparable. The winter coccolithophore bloom reached a peak within one month after the autumn peak of chlorophyll A, indicating the possible importance of the nutrients recycled after the diatom autumn bloom. In contrast to summer, the maximum DOC observed at the surface preceded the winter coccolithophore bloom, and the mass DOC production was probably attributed to the excretion and lysis of the non-calcified phytoplankton cells.〈/p〉 〈/div〉 〈/div〉
    Print ISSN: 0924-7963
    Electronic ISSN: 1879-1573
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Geosciences , Physics
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  • 18
    Publication Date: 2019
    Description: 〈p〉Publication date: November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Marine Systems, Volume 199〈/p〉 〈p〉Author(s): Yuanyi Li, Huan Feng, Haiwen Zhang, Jian Sun, Dekui Yuan, Lei Guo, Jing Nie, Jinglong Du〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The time required for water exchange characterizes the hydrodynamic condition of a water body, which is related to its self-purification ability. In this study, a numerical model based on a three-dimensional hydrodynamic model is established and implemented to calculate the age of water. Using the model, the spatial distribution and seasonal variation of the age of the water discharged into the New York/New Jersey (NY/NJ) Harbor from the Passaic River and the Hackensack River are calculated. The hydrodynamic conditions and the characteristics of water exchange in the harbor are analyzed from the perspective of age. The results indicate that the monthly-averaged age at the entrance of the NY/NJ Harbor is approximately 26 days and 40 days during the wet season and the dry season, respectively. River discharge has a significant impact on the spatial distribution of water age in the NY/NJ Harbor. Generally, high river discharge results in better water exchange and flushes contaminants out of the harbor quickly. However, discharges from several rivers flowing into the harbor interact and interfere with one another. Such interactions can improve or inhibit water and contaminant flushing from the harbor. The analysis of age variations and residual flows indicates that the Kill van Kull is one of the key channels controlling the contaminant transport and water quality in the Newark Bay. This study demonstrates the advantages of using water age to study the water exchange and physical self-purification ability of this complex harbor.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0924-7963
    Electronic ISSN: 1879-1573
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Geosciences , Physics
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  • 19
    Publication Date: 2019
    Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Contaminant Hydrology, Volume 226〈/p〉 〈p〉Author(s): Mehrdad Bastani, Thomas Harter〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉Nitrate in drinking water may cause serious health problems for consumers. Agricultural activities are known to be the main source of groundwater nitrate contaminating rural domestic and urban public water supply wells in farming regions. Management practices have been proposed to reduce the amount of nitrate in groundwater, including improved nutrient management practices and “pump and fertilize” with nitrate-affected irrigation wells. Here, we evaluate the feasibility and long-term impacts of agricultural managed aquifer recharge (Ag-MAR) in the source area of public water supply wells. A numerical model of nitrate fate and transport was developed for the Modesto basin, part of California's Central Valley aquifer system. The basin is representative of semi-arid agricultural regions around the world with a diversity of crop types, overlying an unconsolidated sedimentary aquifer system. A local public supply well in an economically disadvantaged community surrounded by farmland was the focus of this study. Model scenarios implemented include business as usual, alternative low-impact crops, and Ag-MAR in the source area of the public supply well. Alternative nutrient management and recharge practices act as remediation tools in the area between farmland and the public supply well. Improved agricultural source area management practices are shown to be an effective tool to maintain or even enhance groundwater quality in the targeted supply well while remediating ambient groundwater.〈/p〉 〈p〉Best results are obtained when lowering nitrate load while also increasing recharge in the source area simultaneously. This scenario reduced nitrate in the supply well's drinking water by 80% relative to the business as usual scenario. It also remediated ambient groundwater used by domestic wells between the source area farmlands and the supply well and showed 60% more reduction of nitrate after 60 years of application. Increasing recharge led to shorter initial response time (five years) and showed the most sustainable impact. Our analysis further suggests that Ag-MAR in a highly discontinuous, wide-spread pattern leads to slow water quality response and may not yield sufficient water quality improvements.〈/p〉 〈/div〉 〈/div〉
    Print ISSN: 0169-7722
    Electronic ISSN: 1873-6009
    Topics: Geography , Geosciences
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  • 20
    Publication Date: 2019
    Description: 〈p〉Publication date: Available online 8 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Contaminant Hydrology〈/p〉 〈p〉Author(s): Héloïse A.A. Thouement, Tomasz Kuder, Timo J. Heimovaara, Boris M. Van Breukelen〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Back-diffusion of chlorinated ethenes (CEs) from low-permeability layers (LPLs) causes contaminant persistence long after the primary spill zones have disappeared. Naturally occurring degradation in LPLs lowers remediation time frames, but its assessment through sediment sampling is prohibitive in conventional remediation projects. Scenario simulations were performed with a reactive transport model (PHT3D in FloPy) accounting for isotope effects associated with degradation, sorption, and diffusion, to evaluate the potential of CSIA data from aquifers in assessing degradation in aquitards. The model simulated a trichloroethylene (TCE) DNAPL and its pollution plume within an aquifer-aquitard-aquifer system. Sequential reductive dechlorination to ethene and sorption were uniform in the aquitard and did not occur in the aquifer. After 10 years of loading the aquitard through diffusion from the plume, subsequent source removal triggered release of TCE by back-diffusion. In the upper aquifer, during the loading phase, δ〈sup〉13〈/sup〉C-TCE was slightly enriched (up to 2‰) due to diffusion effects stimulated by degradation in the aquitard. In the upper aquifer, during the release phase, (i) source removal triggered a huge δ〈sup〉13〈/sup〉C increase especially for higher CEs, (ii) moreover, downstream decreasing isotope ratios (caused by downgradient later onset of the release phase) with temporal increasing isotope ratios reflect aquitard degradation (as opposed to downstream increasing and temporally constant isotope ratios in reactive aquifers), and (iii) the carbon isotope mass balance (CIMB) enriched up to 4‰ as lower CEs (more depleted, less sorbing) have been transported deeper into the aquitard. Thus, enriched CIMB does not indicate oxidative transformation in this system. The CIMB enrichment enhanced with more sorption and lower aquitard thickness. Thin aquitards are quicker flushed from lower CEs leading to faster CIMB enrichment over time. CIMB enrichment is smaller or nearly absent when daughter products accumulate. Aquifer CSIA patterns indicative of aquitard degradation were similar in case of linear decreasing rate constants but contrasted with previous simulations assuming a thin bioactive zone. The Rayleigh equation systematically underestimates the extent of TCE degradation in aquifer samples especially during the loading phase and for conditions leading to long remediation time frames (low groundwater flow velocity, thicker aquitards, strong sorption in the aquitard). The Rayleigh equation provides a good and useful picture on aquitard degradation during the release phase throughout the sensitivity analysis. This modelling study provides a framework on how aquifer CSIA data can inform on the occurrence of aquitard degradation and its pitfalls.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0169-7722
    Electronic ISSN: 1873-6009
    Topics: Geography , Geosciences
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  • 21
    Publication Date: 2019
    Description: 〈p〉Publication date: 1 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Continental Shelf Research, Volume 184〈/p〉 〈p〉Author(s): Israel Medina-Gómez, Ana Aguilar Trujillo, Ismael Marino-Tapia, Giuliana Cruz, Jorge Herrera-Silveira, Cecilia Enriquez〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Inorganic nutrients and phytoplankton (chlorophyll-〈em〉a〈/em〉 concentration and community variables) were studied under a hydrologic scenario defined by a joint topographic-hydrodynamic upwelling event and an algal bloom in the southeast Gulf of Mexico. To do so three oceanographic cruises (GOMEX series) were undertaken throughout the Yucatan shelf during: September 11th-21st of 2010, September 23rd-October 3 〈sup〉rd〈/sup〉 of 2011, and November 29th-December 9th〈sup〉,〈/sup〉 2012 (named as GOMEX-1, GOMEX-2 and GOMEX-3, respectively). We aim to assess the spatial inorganic nutrients and Chl-a patterns corresponding to each cruise to explore potential biochemical consequences of the temporal variability of the vertical inflow in the eastern shelf boundary (Cape Catoche: CC) and further spatial propagation of water featuring this hydrographic signature onto a shallow shelf, marked also by a high algal bloom incidence. This framework allows tackling the implications of the interplay between coastal variability and oceanographic processes on the phytoplankton biomass and community parameters. The spatial pattern of surficial Chl-a, as well as sub-surface maxima of ≈10 mgm〈sup〉−3〈/sup〉 concurrent with the 22.5 °C isotherm over the southeastern shelf area of CC supports the fact that vertical nutrients supply is removed from the euphotic layer through phytoplankton uptake. This scenario indicates a biochemical setting consistent with rapid transfer of external resources advected from deep levels, capable not only to enhance phytoplankton growth, but also to change its species composition. Vertical mixing conditions associated with N-NW winds (locally known as “nortes”) and a lack of upwelling scenario during GOMEX-3 in 2012 lead to relatively more homogeneous nitrate spatial distribution with overall high concentrations in deep, oceanic areas subject to nutrients entrainment. The distribution of specific richness among diatoms and dinoflagellates and relative abundance within such groups, as well as Chl-〈em〉a〈/em〉 concentrations are considered normal with regards to what has been observed in other studies for the Gulf of Mexico. The potential implications of large-scale, inter-annual climatic processes (e.g., El Niño-Southern Oscillation) on marine resources relevant to regional primary productivity variability (changes in the phytoplankton community) are discussed.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0278-4343
    Electronic ISSN: 1873-6955
    Topics: Geosciences
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  • 22
    Publication Date: 2019
    Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Petroleum Science and Engineering, Volume 181〈/p〉 〈p〉Author(s): Shuai Zhao, Wanfen Pu, Mikhail A. Varfolomeev, Chengdong Yuan, Shan Qin, Liangliang Wang, Dmitrii A. Emelianov, Artashes A. Khachatrian〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Because the thermal release correlates directly with the success of in-situ combustion (ISC) technology, this research performs a series of investigations concerning thermal behavior and kinetics of heavy crude oil during combustion using high pressure differential scanning calorimetry (HP-DSC) and accelerating rate calorimetry (ARC). The results obtained from HP-DSC profiles indicated that for oil alone and its mixtures with quartz sand/crushed core, the peak temperature was lowered, and the heat flow increased with increasing oxygen partial pressure. The heat enthalpy of low temperature oxidation (LTO) was higher than that of high temperature oxidation (HTO) under oxygen partial pressures of 0.5, 1 and 1.5 MPa, and the increase in heat enthalpy of LTO with oxygen partial pressure was more pronounced than that of HTO. Unlike the crushed core, the addition of quartz sand delayed exothermic oxidation reactions. Compared with oil only and oil + quartz sand, the LTO and HTO peak temperatures of oil + crushed core were considerably lowered, and the effect of crushed core on increasing heat release for LTO at oxygen partial pressure of 1.5 MPa was more prominent. It was observed that the heat enthalpy of LTO and HTO increased quasi-linearly with the oxygen partial pressure in both the presence and absence of quartz sand/crushed core. ISC might be considered as an appropriate candidate for Jiqi block, based on exothermic continuity of the ARC curves, with the near-wellbore zone of target block heated to 180 °C where the exothermic oxidation activity is notably intensified. The kinetic results showed that the LTO and HTO intervals were divided into 6 and 2 subintervals, respectively, which facilitated more precise modelling of the ISC process.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0920-4105
    Electronic ISSN: 1873-4715
    Topics: Chemistry and Pharmacology , Geosciences , Process Engineering, Biotechnology, Nutrition Technology
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  • 23
    Publication Date: 2019
    Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Petroleum Science and Engineering, Volume 181〈/p〉 〈p〉Author(s): Zan Chen, Menglu Lin, Shuhua Wang, Shengnan Chen, Linsong Cheng〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Studies have shown that the gas huff and puff injection potentially perform better than the continuous gas flooding in enhancing the hydrocarbon recovery in the liquid rich tight reservoirs. During the fracturing stimulation, only part of the induced hydraulic fractures is propped because proppants cannot be carried to the fracture tips. Moreover, some secondary and tertiary fractures may be too narrow to accommodate any proppants. The conductivity of the unpropped fractures is highly dependent on the variation of the in-situ pressure and may be open and close periodically during the huff-n-puff cycles. In this study, the stress-dependent fracture conductivity and its impact on the produced gas huff-n-puff performance are investigated in a liquid rich tight reservoir, considering the existence of the large amount of the unpropped fractures. The experimental data of stress-dependent fracture conductivity is employed first to simulate the dynamic conductivity during the depletion and the gas huff and puff cycles. A reservoir model is then constructed and history-matched based on the reservoir fluid samples and the field production data collected from the Montney liquid rich tight reservoir in Western Canada. Performance of the produced gas huff-n-puff is examined in the targeted reservoir and results show that contributions of the unpropped fractures cannot be ignored, which leads to 7.8% more condensate (i.e., oil) production and 2.8% higher in barrel of oil equivalent (BOE), compared to the case with propped fractures only. The effects of complex fracture geometry and the cluster completion are also investigated and results show that the unpropped fracture contributions towards the condensate production and BOE are even more pronounced in the complicated scenarios. The condensate oil and BOE are 42.0% and 22.9% higher in complex fracture geometry case and 12.4% and 5.6% higher in the fractures with multiple clusters than those scenarios with propped fractures only. This paper provides a better understanding on the potential performance of enhanced hydrocarbons recovery in liquid rich tight gas reservoirs via gas huff-n-puff operations.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0920-4105
    Electronic ISSN: 1873-4715
    Topics: Chemistry and Pharmacology , Geosciences , Process Engineering, Biotechnology, Nutrition Technology
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  • 24
    Publication Date: 2019
    Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Petroleum Science and Engineering, Volume 181〈/p〉 〈p〉Author(s): Abdelrahman Elkhateeb, Reza Rezaee, Ali Kadkhodaie〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉Traditionally, prediction of facies and permeability for a reservoir rock was one of many challenges in the industry that necessitates advanced and sophisticated evaluation for effective reservoir description. Three wells have been studied in the Perth Basin in Western Australia across the shaly sand of the Irwin River Coal Measures Formation, which contain a comprehensive suite of advanced and conventional logs. Due to the reservoir heterogeneity and the clay distribution, it is very challenging to resolve the effective pore volume, the reservoir facies and how the high permeability zones are distributed within the formation.〈/p〉 〈p〉In this paper, a new technique has been successfully tested on the Shaly Sand by integrating the nuclear magnetic resonance (NMR) and the conventional density log. The method allows the establishment of high-resolution facies classification for the reservoir using an Equivalent Flow Zone Indicator Index (EFZI). The studied core facies have been integrated with the EFZI into a new workflow to distribute facies on a larger scale in the uncored wells.〈/p〉 〈p〉Four hydraulic flow units (HFU) have been defined from one cored well using Flow Zone Indicator approach, with each has a unique FZI value and different permeability model based on core measurements. The EFZI-based high-resolution facies have been validated at several formation depths using the core thin sections to ensure the best calibration will be obtained for facies log, hence the permeability log-to-core match.〈/p〉 〈p〉The methodology will help running an advanced petrophysical analysis for the zone of interest and will reduce the parameters uncertainty. Application of this methodology in the uncored wells has shown very encouraging results, which is believed it can be used in the absence of any core data to resolve the rock typing from the well logs.〈/p〉 〈/div〉 〈/div〉
    Print ISSN: 0920-4105
    Electronic ISSN: 1873-4715
    Topics: Chemistry and Pharmacology , Geosciences , Process Engineering, Biotechnology, Nutrition Technology
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  • 25
    Publication Date: 2019
    Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Petroleum Science and Engineering, Volume 181〈/p〉 〈p〉Author(s): Atousa Heydari, Kiana Peyvandi〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this work, the stainless steel mesh was used to study the effect of metallic porous media on the formation of methane hydrate and some parameters such as induction time, the kinetics growth and the mole of gas consumed have been investigated at a temperature of 3 °C (276.15 K) and a pressure of 760 psi (5.24Mpa). The metallic porous media was able to show better results on the methane hydrate formation relative to the silica gel. Hence the induction time and, eventually, the total time of the hydrate formation process decreased by about 60%. The kinetics growth and the amount of gas consumed increased significantly. Also, the effect of two types of anionic and nonionic surfactants as kinetics promoters studied in this porous media. The result of adding SDS and SDBS at a concentration near the CMC designated that the induction time lasted nearly zero and the total time of the process by SDBS was minimal. It should be noted that the non-ionic surfactant SPAN 80 could not have a positive effect on this porous media. In general, therefore, the results of this research attempts to show that the stainless steel mesh with SDBS possessed high potential in obtaining the industrial purpose of gas hydrate growth and also was significant in the field of energy storage and transport.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0920410519306473-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉
    Print ISSN: 0920-4105
    Electronic ISSN: 1873-4715
    Topics: Chemistry and Pharmacology , Geosciences , Process Engineering, Biotechnology, Nutrition Technology
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  • 26
    Publication Date: 2019
    Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Petroleum Science and Engineering, Volume 181〈/p〉 〈p〉Author(s): Shuaishuai Jiang, Xuehua Chen, Yingkai Qi, Wei Jiang, Jie Zhang, Zhenhua He〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The frequency-dependent attenuation and velocity dispersion of seismic responses are closely related to hydrocarbon reservoirs. To further investigate the characteristics of seismic responses caused by pore fluid-bearing reservoirs, the role of gas saturation is analyzed in seismic responses of sand reservoirs characterized by the patchy saturation model. To this end, a novel wave extrapolation method is developed based on the diffusive-viscous wave equation (DVWE) as well as a scheme for an extended local Rytov Fourier (ELRF) approximation within the extrapolation depth interval. Our proposed method considers the presence of fluid mixtures in the porous media, resulting in seismic attenuation and dispersion by the mechanism generally known as wave-induced fluid flow (WIFF). This method enables an accommodation for the lateral variations in slowness, diffusion coefficient and viscosity. Subsequently, the extrapolation is adopted to model the synthetic seismic data of a distributary channel model. During this modeling, a gas-water saturated sand reservoir embedded into one of the channels was used to comparatively analyze the distinct features on its seismic synthetic data. We exhibited the numerical simulation results using the proposed wave extrapolation method here and the traditional acoustic wave equation (AWE) method. A comparison of the simulation results, demonstrates that our proposed numerical method can depict the seismic dispersion and frequency-dependent attenuation as well as the phase delay effects associated with gas-water-saturated sand reservoirs. Furthermore, we compare the seismic responses by changing the gas saturations of the sand reservoir. The gas saturation of the reservoir has significant effects on the seismic characteristics of the numerical modeling data. The numerical modeling method improves our understanding of the mechanisms of seismic frequency-dependent characteristics associated with gas saturations and potentially contributes to better insights into gas reservoir indicators derived from seismic field data.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0920-4105
    Electronic ISSN: 1873-4715
    Topics: Chemistry and Pharmacology , Geosciences , Process Engineering, Biotechnology, Nutrition Technology
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  • 27
    Publication Date: 2019
    Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Ocean Modelling, Volume 140〈/p〉 〈p〉Author(s): Oleg Druzhinin, Yuliya Troitskaya, Wu-ting Tsai, Po-chen Chen〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The present study is concerned with direct numerical simulation (DNS) of turbulent air flow over a waved water surface. Three-dimensional, turbulent Couette flow is considered in DNS as a model of a constant-flux layer in the marine atmospheric surface layer. Two-dimensional stationary waves at the water surface are prescribed and assumed to be unaffected by the air-flow. We consider capillary-gravity water surface waves and are interested in the influence of “parasitic” capillary ripples riding on the carrier, energy-containing waves, on the properties of the air-flow. The surface waves are prescribed and considered to be stationary, the capillaries being in phase with the carrier wave. The surface elevations spectra are also prescribed and mimicking stationary capillaries riding on Stokes waves observed in a 2D numerical simulation of water-surface capillary-gravity waves by Hung & Tsai (2009). The bulk air velocity and the carrier water surface waves lengths are considered in our DNS in the range of 3 to 5 m/s and 3 to 7 cm, respectively. Under these conditions, the capillaries are found to be submerged within the viscous sublayer of the atmospheric boundary layer. Our DNS results show that although the flow fields are characterized by instantaneous separations of the boundary layer, the ensemble (wave-phase) averaged flow fields are non-separating and well predicted by a quasilinear theoretical model. We find also that capillaries mitigate the development of coherent (horse-shoe) vortex structures as compared to the no-ripples flow-case. We further use DNS results and quasilinear model formulation to parameterize the water surface roughness height in terms of critical layer thickness and the amplitude of a dominant, energy-containing harmonic of the water surface elevation spectrum.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 1463-5003
    Electronic ISSN: 1463-5011
    Topics: Geography , Geosciences , Physics
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  • 28
    Publication Date: 2019
    Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Dynamics and Earthquake Engineering, Volume 125〈/p〉 〈p〉Author(s): Ahmet Hilmi Deringöl, Esra Mete Güneyisi〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This study investigates the influence of the friction pendulum bearing (FPB) isolator characteristics on the nonlinear response of the buildings under various seismic excitations. To represent a wide range of assessment, 3, 6, and 9-storey steel framed buildings with twenty seven different isolation models of FPB were studied by identifying the local and global deformations. Three important parameters such as isolation period T (as 2, 2.5, and 3 s), effective damping ratio ß (as 0.05, 0.15, 0.25), and yield strength ratio Fy/W (as 0.025, 0.05, and 0.10) were used in the modelling of FPB. Two-dimensional model of the base-isolated steel frames were created and the nonlinear time history analysis was performed through a number of earthquake ground motions. The behaviour of the isolated frames was measured by the variation of isolator displacement, roof drift ratio, relative displacement, interstorey drift ratio, absolute acceleration, base shear, base moment, hysteretic curve, and dissipated energy. The benefits obtained through the adoption of the base isolation system were discussed. It was found that the seismic response of the base-isolated frames could be estimated accurately by adjusting the proper isolation period, yield strength ratio, and effective damping ratio for the case studied structures.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0267-7261
    Electronic ISSN: 1879-341X
    Topics: Architecture, Civil Engineering, Surveying , Geosciences , Physics
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  • 29
    Publication Date: 2019
    Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Dynamics and Earthquake Engineering, Volume 125〈/p〉 〈p〉Author(s): Jinbao Yao, Rutao Zhao, Nan Zhang, Dujuan Yang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉An in-filled trench barrier is usually used to reduce the damages from train-induced environmental vibrations. To find the vibration isolation effect of an in-filled trench barrier, this paper analyses the reflection coefficients and transmission coefficients of the Rayleigh wave at the interface between in-filled trenches and the soil. In our calculation formulas of ground vibrations, a single point and a single frequency excitation, as well as multi-point and multi-frequency excitation, are simultaneously derived in a soil-in-filled-trench system.〈/p〉 〈p〉Using these formulas and a numerical analysis, the effects of an in-filled trench barrier on the environmental vibrations induced by running trains are analyzed. The results show that the reflection coefficients increase, while the transmission coefficients decrease, with the density and elastic modulus of the in-filled material. The vibration isolation effect is clearly better than that without trenches. In a certain width range, the transmission coefficient and vertical acceleration levels decrease with the increase of trench width. The influences of the transmission coefficient and the vibration isolation effects are not clear with the trenches’ depth variation. The vertical vibrations of the ground pick-up point are all smaller than those without in-filled trenches.〈/p〉 〈/div〉 〈/div〉
    Print ISSN: 0267-7261
    Electronic ISSN: 1879-341X
    Topics: Architecture, Civil Engineering, Surveying , Geosciences , Physics
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  • 30
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    Elsevier
    Publication Date: 2019
    Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Dynamics and Earthquake Engineering, Volume 124〈/p〉 〈p〉Author(s): 〈/p〉
    Print ISSN: 0267-7261
    Electronic ISSN: 1879-341X
    Topics: Architecture, Civil Engineering, Surveying , Geosciences , Physics
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  • 31
    Publication Date: 2019
    Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Dynamics and Earthquake Engineering, Volume 125〈/p〉 〈p〉Author(s): Benshun Shao, Stephen A. Mahin, Victor Zayas〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉By interpreting the seismic responses of two seismically isolated low-rise case-study buildings probabilistically using FEMA P695 methodology, the study indicates for the design of seismically isolated structures, providing isolator capacities equal to risk-targeted maximum considered earthquake (MCE〈sub〉R〈/sub〉) demand does not achieve targeted levels of reliability specified in ASCE 7–16. To do so, isolation system capacities beyond average MCE〈sub〉R〈/sub〉 demand are required. The minimum required capacities for using three types of enhanced isolation system (isolator without displacement restraint, isolator combined with external hard-stopping mechanism, and isolator with internal stiffening behavior at large horizontal displacement) are calculated with nonlinear response history analysis following probabilistic framework for different design risk categories numerically. The results indicate that isolator displacement capacities ranging from 1.5 to 2.60 times the average MCE〈sub〉R〈/sub〉 demand and isolation system shear capacities ranging from 1.5 to 5 times the average MCE〈sub〉R〈/sub〉 demand are required, depending on seismic risk categories and isolation system types. The use of an isolator with internal stiffening behavior is an efficient option to provide the required capacities for achieving reliability goals, especially for high risk-category design.〈/p〉〈/div〉 〈/div〉
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    Electronic ISSN: 1879-341X
    Topics: Architecture, Civil Engineering, Surveying , Geosciences , Physics
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  • 32
    Publication Date: 2019
    Description: 〈p〉Publication date: Available online 8 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Quaternary International〈/p〉 〈p〉Author(s): Brian F. Codding, Adrian R. Whitaker, Nathan E. Stevens〈/p〉
    Print ISSN: 1040-6182
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    Topics: Geography , Geosciences
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  • 33
    Publication Date: 2019
    Description: 〈p〉Publication date: 15 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Quaternary Science Reviews, Volume 218〈/p〉 〈p〉Author(s): Athanassios Athanassiou, Alexandra A.E. van der Geer, George A. Lyras〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The Eastern Mediterranean islands, most of which belong to the Aegean archipelago, have a complex biogeographic history, which puts its stamp on their fauna and flora. A now extinct but most important faunal component, in terms of geographic spread and taxonomic diversity, are the elephants. The Eastern Mediterranean islands are particularly rich in Pleistocene endemic elephant localities, which preserve samples of extinct endemic populations. These were either descendants of the European straight-tusked elephant 〈em〉Palaeoloxodon antiquus〈/em〉 or the Southern mammoth, 〈em〉Mammuthus meridionalis〈/em〉. Their presence, history and palaeobiogeography has been documented only for Cyprus, Crete, Kasos, Rhodes, Tilos, Kýthera, Naxos, and Delos. For six other islands only anecdotal references exist in the literature: Kálymnos, Astypálaia, Milos, Sériphos, Kýthnos and Paros. Here, we provide an update on previously published specimens and taxa, describe previously undescribed specimens that were relocated in museum collections, as well as recently excavated specimens, and put these in the context of island palaeobiogeography. We conclude that dwarf elephants, endemic to their palaeo-island, lived on the islands of palaeo-Cyclades, Astypálaia, Crete, Kasos–Kárpathos–Saría, Tilos, Rhodes and Cyprus, whereas the elephants from Kephallenía, Kálymnos and Kýthera are indistinguishable on the species level from mainland 〈em〉Palaeoloxodon antiquus〈/em〉. Elephant fossils of unresolved taxonomic status are reported from five present-day islands. The Eastern Mediterranean endemic elephants likely derived from separate and independent colonisation events from the mainland. No island supported more than one proboscidean species at any time. We found that isolation had no effect on the degree of dwarfism, but that there exists a threshold of about 6–10 km distance between the island and the mainland, below which no dwarfism evolved, likely as a result of genetic contact with the mainland population. We also found that although island area is correlated with the degree of dwarfism in elephants, other factors, such as the level of interspecific competition, may limit this degree.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0277-3791
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  • 34
    Publication Date: 2019
    Description: 〈p〉Publication date: Available online 8 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Quaternary International〈/p〉 〈p〉Author(s): Xiaolin Ren, Duowen Mo, Michael Storozum, Ximena Lemoine, Yanyan Yu, Wanfa Gu, Xingshan Lei, Jiaqiang Zhang, Jianqing Lü, Tristram R. Kidder〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Archaeologists have focused on the social conditions surrounding the development of urbanism around the world, however the environmental impact of these ancient cities remains unclear. In this paper, we present palynological data from the early Bronze Age city of Dongzhao, Henan Province, China. Our data indicate that vegetation change and the development of early urban settlements are closely linked, with the advent of urban development significantly accelerating deforestation and altering the composition of local vegetation communities. The pollen record from Dongzhao provides new evidence to support the claim that urban expansion, coupled with a drying climate and the expansion of agriculture, dramatically reconfigured the landscapes of Bronze Age China.〈/p〉〈/div〉 〈/div〉
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  • 35
    Publication Date: 2019
    Description: 〈p〉Publication date: 15 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Precambrian Research, Volume 332〈/p〉 〈p〉Author(s): Farzaneh Shakerardakani, Xian-Hua Li, Xiao-Xiao Ling, Jiao Li, Guo-Qiang Tang, Yu Liu, Behzad Monfaredi〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉High-precision secondary-ion mass spectrometry (SIMS) U–Pb and Hf–O isotopic microanalyses of zircons from the central Sanandaj–Sirjan metamorphic zone (SSMZ) of the Zagros orogen, Iran, provide evidence of the presence of 2.7 Ga xenocrystic zircons, suggesting that the SSMZ records Neoarchean crustal components that have not previously been reported in Iran. The two amphibolite samples analyzed from the Muteh–Golpaygan metamorphic complex during this study include one sample (GQ-10) that yielded xenocrystic zircons with ages clustered around 〈em〉ca〈/em〉 2.7 Ga. The second sample (GC-15) contains zircons that show two distinct xenocrystic zircon domains with ages of (i) 〈em〉ca〈/em〉 2.7 and 2.5 Ga, and (ii) 〈em〉ca〈/em〉 52 Ma. The 〈em〉ca〈/em〉 2.7 Ga zircons and zircon domains have homogeneous, mantle-like δ〈sup〉18〈/sup〉O values with a mean of 6.10 ± 0.69‰. They have εHf(t) values that vary between +0.2 to +6.8 with T〈sub〉DM〈/sub〉〈sup〉C〈/sup〉 ages of 3.1–2.7 Ga, suggesting they crystallized from granitoid melts derived from juvenile components. However, the younger 〈em〉ca〈/em〉 2.5 Ga zircons yield an average δ〈sup〉18〈/sup〉O value of 6.17 ± 0.24‰ and have evolved Hf isotopic compositions (εHf(t) −0.8 to −3.4; T〈sub〉DM〈/sub〉〈sup〉C〈/sup〉 = 3.2–3.1 Ga), indicating that the older crust in this region underwent more intense later reworking than is the case for crustal material formed at 〈em〉ca〈/em〉 2.7 Ga. These data provide evidence of Neoarchean basement rocks in this region, indicating that the SSMZ records ancient crustal growth events. The youngest 〈em〉ca〈/em〉 52 Ma xenocrystic zircons within these samples most likely reflect the late Paleocene–Eocene magmatic ‘flare-up’ within Iran. These zircons have slightly elevated δ〈sup〉18〈/sup〉O values (7.69 ± 0.21‰) and negative Hf isotopic compositions (εHf(t) −8.3 to −12.1; T〈sub〉DM〈/sub〉〈sup〉C〈/sup〉 = 1.9–1.6 Ga), suggesting intensive crustal reworking at 〈em〉ca〈/em〉 50 Ma.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0301-9268
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  • 36
    Publication Date: 2019
    Description: 〈p〉Publication date: 15 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Precambrian Research, Volume 332〈/p〉 〈p〉Author(s): Kelsey G. Lamothe, Paul F. Hoffman, J. Wilder Greenman, Galen P. Halverson〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The Islay carbon isotope anomaly is a late Tonian negative δ〈sup〉13〈/sup〉C excursion that has been documented in marine carbonates globally. It has in the past been thought to be causally linked to the onset of Cryogenian glaciation ca. 717 Ma. However, recent work suggests that this anomaly is instead closer to ca. 739–735 Ma and that it may be one of two distinct late Tonian carbon isotope anomalies. Here we present the litho- and chemo-stratigraphy of the late Tonian Ugab Subgroup of the Otavi/Swakop Group in northwestern Namibia. Carbon isotope data from two separate outcrop belts, the Summas Mountains and the Vrede Domes, indicate that the Ugab Subgroup strata exposed in the former inlier are older than those of the latter, with only approximately 100 m of stratigraphic overlap. We use detailed measured sections to develop a sequence stratigraphic framework for the Ugab Subgroup in each outcrop belt, and correlate strata across the two exposures to construct a composite carbonate δ〈sup〉13〈/sup〉C record for the late Tonian in Namibia. This carbon isotope profile of the Ugab Subgroup shows two separate pre-Sturtian negative anomalies, consistent with findings in northern Canada, Svalbard, Scotland, and Ethiopia. Our results are an important contribution to the pre-Cryogenian carbon isotope record, as these data may serve as the first definitive documentation of both anomalies within a single basin.〈/p〉〈/div〉 〈/div〉
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  • 37
    Publication Date: 2019
    Description: 〈p〉Publication date: 15 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Precambrian Research, Volume 332〈/p〉 〈p〉Author(s): V.S. Shatsky, Q. Wang, S.Yu. Skuzovatov, A.L. Ragozin〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉To clarify the tectonic-thermal evolution of the Anabar tectonic province in the central Siberian Craton, we performed an isotope-geochemical study of 20 xenoliths from the Udachnaya, Zarnitsa, and Komsomolskaya kimberlite pipes to represent different crustal levels. Most mafic granulites have Proterozoic Nd model ages and geochemical characteristics close to those of intraplate basalts, whereas some mafic and intermediate granulites with Archean model ages exhibit geochemical features of supra-subduction ophiolitic basalts. Analysis of U-Pb ages and hafnium isotopic composition of zircon indicates that the main tectonic-thermal events modified the crust at 2.7 and 1.9–1.8 Ga, which is consistent with ages of mantle depletion events from previous studies. All zircons have Archean Hf model ages (〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si2.svg"〉〈mrow〉〈msubsup〉〈mi〉T〈/mi〉〈mrow〉〈mi mathvariant="italic"〉DM〈/mi〉〈/mrow〉〈mi〉C〈/mi〉〈/msubsup〉〈mspace width=".25em"〉〈/mspace〉〈mn〉3.6〈/mn〉〈mo linebreak="badbreak" linebreakstyle="after"〉-〈/mo〉〈/mrow〉〈/math〉3.2 Ga). Overall, thermal events with ages of 2.9–2.8, 2.7, 2.4, 1.97 and 1.8 Ga have remarkable influence on the studied zircons. Tectono-thermal events at 2.4 1.97, 1.9 and 1.8 Ga with no addition of juvenile material are recorded by zircons from xenoliths of mafic and intermediate granulites and metadiorites. A compilation of isotope-geochemical data demonstrates that instead of age-stratified, the crust of the Anabar tectonic province consists of variably reworked Paleoarchean rocks and juvenile Proterozoic rocks at all crustal levels. Hence the crust and mantle of the Siberian Craton has been coupled since the Paleoarchean.〈/p〉〈/div〉 〈/div〉
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  • 38
    Publication Date: 2019
    Description: 〈p〉Publication date: Available online 8 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Precambrian Research〈/p〉 〈p〉Author(s): B.R. Choudhary, R.E. Ernst, Y-G. Xu, D.A.D. Evans, M. de Kock, J.G. Meert, A. Ruiz, G.A. Lima〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉1110 Ma Large Igneous Province (LIP) fragments in the Kalahari craton, southern Africa (Umkondo LIP); Dronning Maud Land, Antarctica; Bundelkhand portion of Indian craton (Mahoba dolerite dykes); Congo craton (Huila-Epembe dolerite dykes); and Amazonia (Rincon del Tigre-Huanchaca LIP) have been reconstructed as a single LIP with plume centre beneath the NW part of the Kalahari Craton. This paper offers the best estimates for the paleoposition of the〈/p〉 〈p〉Indian and Amazonian cratons along with conjoined Kalahari-SF/Congo reconstruction. This 1110 Ma mafic magmatism is dominantly tholeiitic, ranging from basalt to andesitic basalt in composition, generated over a range of mantle melting depths [(Gd/Yb)N =1.2 to 2.3], exhibit low to high contamination with crustal components (negative Nb anomalies, eNd (0 to -12), and elevated Th/Yb). The data fall into two Groups based on TiO2 content, with Group 1 (low Ti) of andesitic basalt composition, and Group 2 (high Ti) exhibiting a basaltic affinity. Group 1 magmas were generated in the spinel lherzolite field followed by significant contamination likely during passage through metasomatised lithospheric mantle in crustal magma chambers. A greater melting depth reaching into the garnet lherzolite field is proposed for the Group 2 magmas. The majority of Group 2 units are located in the Kalahari and Congo cratons, and this reflects onset of deeper melting closer to the interpreted plume axis in our reconstruction.〈/p〉 〈/div〉 〈/div〉
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  • 39
    Publication Date: 2019
    Description: 〈p〉Publication date: November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Computers & Geosciences, Volume 132〈/p〉 〈p〉Author(s): T. Carlotto, P.L.B. Chaffe〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Streamflow recession analysis is crucial for understanding how catchments release water in periods of drought and therefore is important for water resources planning and management. Despite there being several theories on how to model recession curves, few studies compare the different approaches to that problem. In this work, we developed the Master Recession Curve Parameterization tool (MRCPtool), which brings together a set of automated methods for the analysis of recession periods based only on streamflow data. The methods include: (i) hydrograph separation using numerical filters; (ii) automatic extraction of recession periods; (iii) creation of the MRC with the matching strip method; (iv) creation of the MRC for different flow classes defined from the flow duration curve; (v) analysis of flow recession rates 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" altimg="si1.svg"〉〈mrow〉〈mo〉(〈/mo〉〈mo linebreak="goodbreak" linebreakstyle="after"〉−〈/mo〉〈mi〉d〈/mi〉〈mi〉Q〈/mi〉〈mo〉∕〈/mo〉〈mi〉d〈/mi〉〈mi〉t〈/mi〉〈mo〉)〈/mo〉〈/mrow〉〈/math〉 as a function of flow 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" altimg="si2.svg"〉〈mrow〉〈mo〉(〈/mo〉〈mi〉Q〈/mi〉〈mo〉)〈/mo〉〈/mrow〉〈/math〉 and (vi) creation of the MRC from simulated recession curves with different analytical approaches, including linear and nonlinear models. The MRCPtool contains a graphical user interface developed in MATLAB software that facilitates the analysis of streamflow datasets. Finally, we present an example application of the MRCPtool using a streamflow dataset of 44 years. The MRCPtool is an open source tool that can be downloaded from the site: 〈a href="http://www.labhidro.ufsc.br/static/software/MRCPtool.rar" target="_blank"〉http://www.labhidro.ufsc.br/static/software/MRCPtool.rar〈/a〉.〈/p〉〈/div〉
    Print ISSN: 0098-3004
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    Topics: Geosciences , Computer Science
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  • 40
    Publication Date: 2019
    Description: 〈p〉Publication date: Available online 8 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Precambrian Research〈/p〉 〈p〉Author(s): Vladimir N. Sergeev, J. William Schopf, Anatoliy B. Kudryavtsev〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉Subtidal cherts from phosphorite-bearing basal strata of the Early Cambrian Shabakta (Dzhylandy) Formation, Tamda Group of the Maly Karatau Range of South Kazakhstan, contain a diverse assemblage of acanthomorph acritarchs and other well-preserved organic-walled microfossils. Acanthomorphs of the Shabakta lowermost layers are taxonomically essentially identical to those of many similarly aged Early Cambrian organic-walled compression-preserved and permineralized microbiotas preserved in rocks deposited in relatively open marine settings and are biostratigraphically correlative with acanthomorph-containing microfloral assemblages of the Vergale and Rausve Horizons (Regional Stages) of the East European Platform as well as with other assemblages known worldwide from the upper Atdabanian (Series 2 of the International Union of Geological Sciences [IUGS]). Although lower Atdabanian deposits of the Talsy (Lükati) horizon are missing from the Maly Karatau succession studied here, Nemakit-Daldynian through Tommotian (the IUGS Terranovian) microbiotas both of the Shabakta-underlying Berkuta Member of the Kyrshabakta Formation and phosphoritic Chulaktau Formation are comparable to those of the pre-trilobite Rovno and Lontova Horizons (Regional Stages) of the East European Platform. Thus, the phosphatized and chert-permineralized Shabakta assemblages date from of the Early Cambrian part of the Precambrian-Cambrian phosphogenic event, an interpretation supported also by associated small shelly fossils.〈/p〉 〈p〉The studies reported here of the Shabakta microfossils – based on the use of optical microscopy, confocal laser scanning microscopy (CLSM) and Raman spectroscopy – provide information in three dimensions at high spatial resolution about their organismal morphology, cellular anatomy, kerogenous composition, taphonomy, and mode and fidelity of preservation. The combined use of CLSM and Raman, techniques introduced to Precambrian paleobiology only rather recently, is shown to reveal morphological characters of taxonomic, biostratigraphic and palaeoenvironmental significance.〈/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-S0301926818306260-ga1.jpg" width="274" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉
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  • 41
    Publication Date: 2019
    Description: 〈p〉Publication date: December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Marine and Petroleum Geology, Volume 110〈/p〉 〈p〉Author(s): Walid A. Makled, Ahmed A. Abd El Ghany, Soheir I. Soliman〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Productivity, redox conditions and sedimentation rate constrain the enrichments of organic matters and under suitable conditions they can trigger larger enrichments. These parameters are tracked in the subsurface Miocene sediments in four wells on east to west transect across north Sinai. These wells are Abu Roda-1, Misfaq-1, Teffah-1 and Einab-1. The Miocene sections cover the Aquitanian, Burdigalian, Langhian, Serravalian and Tortonian. The tracking is based on the proxies of planktonic and benthic foraminifera that offer many solutions in the application of the equations used to calculate these parameters. The first of these parameters is the sedimentation rate which is calculated for different time segments based on the planktonic foraminifera bioevents. The sedimentation rates are correlated throughout the basin. The second parameter is the water depth that is obtained from conversion of the scores of component 1 resulted during the routine statistical analysis of the benthic foraminifera by cluster and principal component analyses. These analyses are used also in assessment of redox condition and eutrophication. The sedimentation rates and water paleobathymetry alongside the measured C〈sub〉org〈/sub〉 are used to calculate the paleoproductivity and to determine four stratigraphic sequences (Seq1, Seq2, Seq3 and Seq4). The tracking of these parameters reveal higher productivity levels in the Seq1 (Aquitanian and Burdigalian) accompanied with dysoxic and mesotrophic conditions, however the lower sedimentation rates are not optimum to stimulate enough burial efficiency that reduced values of C〈sub〉org〈/sub〉. In the younger sequences (Seq2-4), the higher sedimentation rates increase the burial efficiency and values of C〈sub〉org〈/sub〉 despite the lower paleoproductivity and oxic oligotrphic conditions.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0264-8172
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  • 42
    Publication Date: 2019
    Description: 〈p〉Publication date: December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Marine and Petroleum Geology, Volume 110〈/p〉 〈p〉Author(s): Marwa Yousef, Mohamed Yousef, Adel Sehim〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉High-quality three-dimensional (3D) seismic reflection and borehole data are used to characterize in detail the structural style and evolution of inversion structures in Horus oil field. This field lies in the central part of Alamein Basin, northern Western Desert of Egypt, in the hanging-wall of a major Jurassic-Early Cretaceous normal fault. This fault delineates the northwestern margin of the basin and extends in an ENE-WSW direction, bounding a half-graben trough in its hanging-wall. This trough had continued subsidence during Early Cretaceous time with depositional thickening of the Lower Cretaceous Alam el Bueib Formation. Fault displacement had ceased near the top of Barremian level. Aptian-Lower Senonian seismically traced levels show a major NE-plunging asymmetrical anticline overlying the Jurassic-Barremian half-graben. This anticline is sub-parallel to the inherited Jurassic rifting fault. At shallower Cretaceous levels, this fault is replaced by a set of WNW-ESE-trending en echelon faults of considerable displacements, which probably indicates a strike-slip component of deformation. These faults display normal separation on all displaced stratigraphic levels and tip upwards in the upper part of the Upper Cretaceous succession. This marks a considerable change in the tectonic mode of the area. NW-SE extensional faults were developed perpendicular to the fold axis, dissecting the anticline into several blocks entrapping hydrocarbons. Detailed seismic structural analysis of growth strata indicates that the fold initiated in Early Senonian time was associated with the inversion of the earlier Jurassic-Barremian half-graben. This basin inversion is attributed to the Syrian-Arc event that dominated North Africa during the Late Cretaceous time and continued through to the Early Miocene. Low fold amplitude coupled with normal displacements on the deep-seated ENE-WSW-trending Jurassic-Barremian fault indicate a mild phase of positive inversion. The Upper Senonian-Eocene stratigraphic sequences increased in thickness in the back-troughs that were associated with basin inversion.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0264817219303198-fx1.jpg" width="57" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉
    Print ISSN: 0264-8172
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  • 43
    Publication Date: 2019
    Description: 〈p〉Publication date: 1 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Geoderma, Volume 353〈/p〉 〈p〉Author(s): Jingzhe Wang, Jianli Ding, Danlin Yu, Xuankai Ma, Zipeng Zhang, Xiangyu Ge, Dexiong Teng, Xiaohang Li, Jing Liang, Ivan Lizaga, Xiangyue Chen, Lin Yuan, Yahui Guo〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Soil salinization is one of the most important causes for land degradation and desertification and is an important threat to land management, farming activities, water quality, and sustainable development in arid and semi-arid areas. Soil salinization is often characterized with significant spatiotemporal dynamics. The salt-affected soil is predominant in the Ebinur Lake region in the Northwestern China. However, detailed local soil salinity information is ambiguous at the best due to limited monitoring techniques. Nowadays, the availability of Multi-Spectral Instrument (MSI) onboard Sentinel-2, offers unprecedented perspectives for the monitoring and mapping of soil salinity. The use of MSI data is an innovative attempt for salinity detection in arid land. We hypothesize that field observations and MSI data and MSI data-derived spectral indices using the partial least square regression (PLSR) approach will yield fairly accurate regional salinity map. Based on electrical conductivity of 1:5 soil:water extract (EC) of 72 ground-truth measurements (out of 116 sample sites) and various spectral parameters, such as satellite band reflectance, published satellite salinity indices, red-edge indices, newly constructed two-band indices, and three-band indices from MSI data, we built a few inversion models in an attempt to produce the regional salinity maps. Different algorithms including Pearson correlation coefficient method (PCC), variable importance in projection (VIP), Gray relational analysis (GRA), and random forest (RF) were applied for variable selection. The results suggest that both the newly proposed normalized difference index (NDI) [(B12 − B7) / (B12 + B7)] and three-band index (TBI4) [(B12 − B3) / (B3 − B11)] show a better correlation with validation data and could be applied to estimate the soil salinity in the Ebinur Lake region. The established models were validated using the remaining 44 independent ground-based measurements. The RF-PLSR model performed the best across the five models with R〈sup〉2〈/sup〉〈sub〉V〈/sub〉, RMSE〈sub〉V〈/sub〉, and RPD of 0.92, 7.58 dS m〈sup〉−1〈/sup〉, and 2.36, respectively. The result from this model was then used to map the soil salinity over the study area. Our analyses suggest that soil salinization changes quite significantly in different seasons. Specifically, soil salinity in the dry season was higher than in the wet season, mostly in the lake area and nearby shores. We contend that the results from the study will be useful for soil salinization monitoring and land reclamation in arid or semi-arid regions outside the current study area.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0016-7061
    Electronic ISSN: 1872-6259
    Topics: Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
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  • 44
    Publication Date: 2019
    Description: 〈p〉Publication date: December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Marine and Petroleum Geology, Volume 110〈/p〉 〈p〉Author(s): Shuheng Du, Yapu Zhao, Jun Jin, Gen Kou, Yongmin Shi, Xianfu Huang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Perthite is a special type of skeleton mineral in tight oil sandstone which cannot be ignored. However, few attention was paid to the secondary pores in perthite and their contributions in tight oil reservoir. This study reveals the perthite's significance in unconventional oil flow characterizes comprehensively and quantitativel by combining the Field Emission Scanning Electron Microscope (FE-SEM) with high resolution, Energy Dispersive Spectrometer (EDS) analysis, high precision image processing, comprehensive parameters construction and calculation. Typical perthite samples of Chang 7 tight oil reservoir of Ordos basin were selected for this study. Our results demonstrate that the growth of K-feldspar and Na-feldspar in perthite is complementary. The mixing process of the two types of stripes promotes each other rather than inhibiting each other. As to the development of secondary pores of perthite, there are clear differences in the area and number of pores, medium differences in the porosity, radius and perimeter, and small differences in other parameters. The more regular and uniform growth of Na-feldspar, the more likely the perthite is to form regular and normalized secondary pore. At least 56.7% of the secondary pore of perthite contributes to oil flow in the process of oil migration or development, and its scientific significance cannot be ignored. The conclusion could provide the geological basis for the effective development of the unconventional hydrocarbon reservoirs.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0264-8172
    Electronic ISSN: 1873-4073
    Topics: Geosciences
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  • 45
    Publication Date: 2019
    Description: 〈p〉Publication date: Available online 9 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Geochemistry〈/p〉 〈p〉Author(s): Yu Zhang, Xianghong Meng, Duoyun Wang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The Ordos Basin is a large interior continental sedimentary basin in western China; its Mesozoic evolution was controlled by surrounding orogenic belts. To constrain the evolution of the southern Ordos Basin, four samples from the southern Ordos Basin were analyzed for U-Pb ages. Similar detrital zircon U-Pb age patterns of the samples suggest no provenance change occurred during the Middle Triassic. Detrital zircons from the samples are divided into three major groups based on their U-Pb ages: 360-250 Ma, 2000-1600 Ma and 2800-2200 Ma. The first group of zircons is consistent with Paleozoic igneous zircons from the northern margin of the North China Craton (NCC). Detrital zircons of the second and third groups are likely derived from the basement of the NCC northern margin. In the Middle Triassic, detritus from the Qinling Orogenic belt may only have reached the piedmont deep depression. The absence of the Qilian Mountain source suggests that the Ordos Basin may not have been connected with the Hexi Corridor Basin in the Middle Triassic. Combining our results with those of previous studies, we suggest that the southern borderline of the Ordos Basin may not have reached the Qinling Orogenic Belt. The northern margin of the NCC, the Qinling Orogenic Belt and the pre-Middle Triassic sedimentary rocks of the eastern NCC provided sources for the Southern Ordos Basin in the Late Triassic. The rapid uplift of the Qinling Orogenic belt occurred in the Late Triassic. This event was response to collision between the NCC and the South China Block. The deposition and evolution of the Ordos Basin were controlled by the Indosinian movement. The change in source areas for the Southern Ordos Basin was closely related to the development and evolution of the Qinling Orogenic Belt. The Qinling Orogenic Belt shows good coupling with the sedimentation and structures of the Southern Ordos Basin.〈/p〉〈/div〉
    Print ISSN: 0009-2819
    Electronic ISSN: 1611-5864
    Topics: Chemistry and Pharmacology , Geosciences
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  • 46
    Publication Date: 2019
    Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Applied Geophysics, Volume 169〈/p〉 〈p〉Author(s): Zhiqu Lu, Glenn V. Wilson, Mark W. Shankle〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉For soil exploration in the vadose zone, a high-frequency multi-channel analysis of surface waves (HF-MASW) method with three enhanced techniques has been developed. In this paper, we apply this enhanced HF-MASW method to re-process field testing data that were collected over the past several years on five different sites. These sites are selected for their different soil properties and data acquisition configurations. The derived overtone images, extracted dispersion curves, and inverted soil profiles of these soil sites are shown and discussed. Penetration tests were conducted and comparisons are made between the soil profiles taken from the HF-MASW tests and those from the penetration tests. One of the objectives of the paper is to determine the optimal data acquisition parameters, including the source parameters and sensor array geometric configuration through the discussions of these case studies. Practical concerns of the HF-MASW method and lessons learnt from these tests are addressed. Recommendations for data acquisition, signal processing, and inversion are provided.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0926-9851
    Electronic ISSN: 1879-1859
    Topics: Geosciences , Physics
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  • 47
    Publication Date: 2019
    Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Free Radical Biology and Medicine, Volume 141〈/p〉 〈p〉Author(s): Chao Wang, Yuan Yuan, Jie Wu, Yuanlin Zhao, Xing Gao, Yihua Chen, Chao Sun, Liming Xiao, Pengfei Zheng, Peizhen Hu, Zengshan Li, Zhe Wang, Jing Ye, Lijun Zhang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉While cardiac hypertrophy and heart failure are accompanied by significant alterations in energy metabolism, more than 50–70% of energy is obtained from fatty acid β-oxidation (FAO) in adult hearts under physiological conditions. Plin5 is involved in the metabolism of lipid droplets (LDs) and is highly abundant in oxidative tissues including heart, liver and skeletal muscle. Plin5 protects the storage of triglyceride (TG) in LDs by inhibiting lipolysis, thereby suppressing excess FAO and preventing excessive oxidative stress in the heart. In this study, we investigated the roles of Plin5 in cardiac hypertrophy and heart failure in mice treated with transverse aortic constriction (TAC). The results indicated that Plin5 deficiency aggravated myocardial hypertrophy in the TAC-treated mice and exacerbated the TAC-induced heart failure. We also found that Plin5 deficiency reduced the cardiac lipid accumulation and upregulated the levels of PPARα and PGC-1α, which stimulate mitochondrial proliferation. Moreover, Plin5 deficiency aggravated the TAC-induced oxidative stress. We consistently found that Plin5 knockdown disrupted TG storage and elevated FAO and lipolysis in H9C2 rat cardiomyocytes. In addition, Plin5 knockdown also provoked mitochondrial proliferation and lipotoxic injury in H9C2 cells. In conclusion, Plin5 deficiency increases myocardial lipolysis, elevates FAO and oxidative burden, and thereby exacerbates cardiac hypertrophy and heart failure in TAC-treated mice.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S089158491930471X-fx1.jpg" width="336" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉
    Print ISSN: 0891-5849
    Electronic ISSN: 1873-4596
    Topics: Biology , Chemistry and Pharmacology , Medicine
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  • 48
    Publication Date: 2019
    Description: 〈p〉Publication date: 15 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Lithos, Volumes 346–347〈/p〉 〈p〉Author(s): Rohit Pandey, Ashutosh Pandey, N.V. Chalapathi Rao, B. Belyatsky, A.K. Choudhary, B. Lehmann, Dinesh Pandit, Prashant Dhote〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We present petrology, geochemistry and radiogenic isotope (Sr and Nd) data of thirteen post-Deccan lamprophyre dykes in the Narmada rift zone from the Chhotaudepur alkaline province of the Deccan Large Igneous Province (DLIP). Mineralogically, these dykes show affinity towards alkaline (sannaite and camptonite) as well as ultramafic (damtjernite) varieties of lamprophyres. Their major oxides and certain trace element ratios increase with increasing silica content highlighting the strong influence of fractionation processes. Their Nb/U and Ce/Pb ratios are similar to the mantle array defined by MORBs and OIBs and suggests an uncontaminated nature. Major oxide (K〈sub〉2〈/sub〉O, Na〈sub〉2〈/sub〉O, SiO〈sub〉2〈/sub〉 and TiO〈sub〉2〈/sub〉) contents show geochemical similarity towards shoshonitic volcanic series, whereas elevated Zr/Hf and Nb/La coupled with suppressed Rb/Nb and Zr/b display their affinity towards HIMU-type intraplate basalts. Their radiogenic initial 〈sup〉87〈/sup〉Sr/〈sup〉86〈/sup〉Sr (0.706034–0.710582) and sub-chondritic initial ɛNd (−8.6 to 2.1) are akin to those of the (i) ca. 65 Ma Ambadongar carbonatite, NW India, and (ii) ca. 65 Ma orangeites from Bastar Craton, central India, highlighting an enriched lithospheric mantle source. REE inversion modeling suggests ~3% enrichment of an undepleted mantle followed by small degrees of melting of this enriched mantle source are sufficient- as in the case of ocean island basalts (OIB)- to reproduce their observed REE concentrations. Their T〈sub〉DM〈/sub〉 Nd model ages (564–961 Ma) are consistent with widespread convergent margin-related magmatism during the amalgamation of the Rodinia supercontinent. We propose that enriched lithospheric mantle developed during the Neoproterozoic was metasomatized by small-volume CO〈sub〉2〈/sub〉-rich melts imparting a HIMU-type geochemical character during Late Cretaceous, when the mantle plume (viz., Réunion) responsible for the flood basalt eruption, impinged at the base of the NW Indian lithosphere. From the presence of F-rich apatite and high K/Rb in mica, we infer the (i) presence of F-phlogopite in their source regions, and (ii) that the depth of post-Deccan lithosphere-asthenosphere boundary (LAB) beneath NW India was at least ~100 km at ca. 65 Ma.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0024-4937
    Electronic ISSN: 1872-6143
    Topics: Geosciences
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  • 49
    Publication Date: 2019
    Description: 〈p〉Publication date: 15 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Lithos, Volumes 346–347〈/p〉 〈p〉Author(s): Babita Rani Choudhary, M. Santosh, Benedetto De Vivo, Gajananrao Jadhav, E.V.S.S.K. Babu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Silicate melt inclusions (MI) trapped in minerals provide direct tools to evaluate source characteristics and magma evolution including magma chamber processes. Here we present results from the study of MIs in basalts from the Western Ghats region of the Deccan Large Igneous Province (LIP) in India. The MIs in plagioclase and clinopyroxene phenocrysts were analyzed. The MIs exhibit post-entrapment modification by in situ crystal fractionation, chemical interaction with the host phenocryst (plagioclase or clinopyroxene), degassing/decrepitation, and crystallization of daughter minerals during cooling. The MIs display variable silica (SiO〈sub〉2〈/sub〉 41–68 wt%), low potassium, and high Fe〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉Ti contents, corresponding to differentiation of basaltic to andesitic magma. Our data indicate H〈sub〉2〈/sub〉O content of about 2 wt% which is consistent with recent evidence for elevated primary H〈sub〉2〈/sub〉O content in the Deccan and other LIPs, corresponding to elevated H〈sub〉2〈/sub〉O in the lithospheric mantle and plumes passing through the mid-mantle inheriting the hydrous nature.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0024-4937
    Electronic ISSN: 1872-6143
    Topics: Geosciences
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  • 50
    Publication Date: 2019
    Description: 〈p〉Publication date: 1 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Crystal Growth, Volume 523〈/p〉 〈p〉Author(s): Yuichiro Hayashi, Takeshi Mitani, Naoyoshi Komatsu, Tomohisa Kato, Hajime Okumura〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We investigated the surface roughening in 4H-SiC solution growth from the following two aspects: the roughening of the seed surface before seeding and the roughening caused by the adhesion of SiC particles during growth. First, we investigated the morphological changes of the seed surface before and after the melt-back process. The seed surface just before seeding was covered with macrosteps and 6H-SiC hillocks with a height of several micrometers. This surface roughening was caused by condensation of droplets of vaporized solvent on the seed surface. We found that the 6H-SiC hillocks were the origins of trench defects. The melt-back process completely removed the hillocks and produced a smooth surface adequate for successive bulk growth. Second, we investigated surface roughening caused by the formation of SiC particles. The adhesion of SiC particles on the growth surface introduced trench defects and polytype inclusions. The adhesion of SiC particles was suppressed by controlling the distribution of carbon supersaturation in the solvent.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0022-0248
    Electronic ISSN: 1873-5002
    Topics: Chemistry and Pharmacology , Geosciences , Physics
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  • 51
    Publication Date: 2019
    Description: 〈p〉Publication date: 15 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Lithos, Volumes 346–347〈/p〉 〈p〉Author(s): Rosana Silveira Resende, Carlos Alberto Tello Sáenz, Luiz Augusto Stuani Pereira, Elton Luiz Dantas〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Understanding the chemical etching effects in the crystalline structure of zircon grains is crucial to know their chemical composition, morphology and isotopic geochemistry. After chemical etching, the zircon grain can be classified as homogeneous heterogeneous, hybrid and anomalous depending on the surface fission-track density observed under an optical microscope. The complementary techniques such as optical microscopy, micro-Raman spectroscopy, scanning electron microscopy (imaging by cathodoluminescence and secondary electrons) and electron microprobe, were employed to characterize the zircon grain surfaces from Igneous, Metamorphic and Sedimentary rocks before and after chemical etching, except for Raman spectroscopy. Measurements of U-Pb age are concordant in areas on the grain surface with uniform fission-track density. The chemical and isotopic analyses show that the etching is capable of revealing the different layer imperfections of the zircon crystalline structure, which can be inherent in its crystallization or acquired during its geological history. Therefore, identification of crystallographic preserved areas on the zircon surface, which are associated with uniform fission-track density, helps to get highly concordant U-Pb ages. In general, the results showed that the U-Pb system depends significantly on the amorphization degree of the zircon crystalline structure, which in most cases can only be revealed by etching.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0024-4937
    Electronic ISSN: 1872-6143
    Topics: Geosciences
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  • 52
    Publication Date: 2019
    Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Applied Geophysics, Volume 169〈/p〉 〈p〉Author(s): Rakoto Heritiana A., Rajaomahefasoa Riva, Razafiarisera Ralay, Razafindrakoto Boni〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉Multiple electrical geophysical survey techniques were used to evaluate the flaky graphite reserves found along the east coast of Madagascar. Self-potential (SP) combined with induced polarization (IP) and electrical resistivity tomography (ERT) methods were applied and provide information about the graphite ore spatial distribution. Unlike conventional geophysical survey methods that use SP and electromagnetic (EM) methods for exploration of this type of metal, the addition of IP and ERT offers a geoelectrical map and section which indicate correlations with the graphite content.〈/p〉 〈p〉The obtained SP map enabled us to delineate the mineralized area whereas the geoelectrical sections obtained from ERT and IP provide additional information on the vertical extent of the mineral of interest, in this case flake-graphite. We overlaid the graphite content, as measured on samples, on the SP map in order to verify the effectiveness of the geophysical methodology. Good correlation between negative SP anomalies and positive indication of graphite content confirms that the methods used in this study (SP, ERT and IP) are sensitive for delineation of the mineralized zone and consequent evaluation of the ore reserve. Resistivity and chargeability obtained from the inversion of the ERT/IP data are low and high, respectively, within the saturated zone inside SP-anomalous zones.〈/p〉 〈p〉The principal ore body is located in the lateritic zone composed of clay-rich formations derived from the weathering of gneiss and migmatite rocks. Negative SP anomalies, along with low electrical resistivity and high chargeability values, are found mainly in areas where the graphitic content exceeds 5%.〈/p〉 〈/div〉 〈/div〉
    Print ISSN: 0926-9851
    Electronic ISSN: 1879-1859
    Topics: Geosciences , Physics
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  • 53
    Publication Date: 2019
    Description: 〈p〉Publication date: Available online 7 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Experimental Cell Research〈/p〉 〈p〉Author(s): Rong Jiang, Yan Liao, Fuhuang Yang, Yusi Cheng, Xiaoniu Dai, Jie Chao〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Endothelial-mesenchymal transition (EndoMT) is a key step during lung fibrosis. Studies have shown that bone marrow mesenchymal stem cells (BMSCs) may act as therapeutic candidates for lung fibrosis. However, the effects of BMSCs on EndoMT induced by SiO〈sub〉2〈/sub〉 have not been elucidated, and means to label and track grafted cells have been lacking. The current study explored whether BMSCs prevented pulmonary fibrosis by targeting EndoMT, as well as analyzed the distribution of BMSCs labeled with superparamagnetic iron oxide (SPIO) nanoparticles during treatment. TIE2-GFP mice, human umbilical vein endothelial cells (HUVECs), and BMSCs labeled with SPIO nanoparticles were used to explore the distributions and therapeutic effects of BMSCs in vivo and in vitro. We found that BMSCs reversed lung fibrosis by targeting EndoMT in vivo. Furthermore, we show that BMSCs labeled with SPIO nanoparticles could be used to track stem cells reliably in the lungs for 14 days. Conditioned medium from BMSCs attenuated the increased functional changes and reversed the SiO〈sub〉2〈/sub〉-induced upregulation of ER stress and autophagy markers irrespective of whether they were nanoparticle labeled or not. Our findings identify novel methods to track labeled BMSCs with therapeutic potential.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0014-4827
    Electronic ISSN: 1090-2422
    Topics: Biology , Medicine
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  • 54
    Publication Date: 2019
    Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Biochimica et Biophysica Acta (BBA) - Gene Regulatory Mechanisms, Volume 1862, Issue 8〈/p〉 〈p〉Author(s): Ruifan Wu, Guanqun Guo, Zhen Bi, Youhua Liu, Yuanling Zhao, Nana Chen, Fengqin Wang, Yizhen Wang, Xinxia Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉〈em〉N〈/em〉〈sup〉6〈/sup〉-methyladenosine (m〈sup〉6〈/sup〉A), the most abundant internal mRNA modification in eukaryotes, plays a vital role in regulating adipogenesis. However, its underlying mechanism remains largely unknown. Here, we reveal that deletion of m〈sup〉6〈/sup〉A demethylase FTO in porcine and mouse preadipocytes inhibits adipogenesis through JAK2-STAT3-C/EBPβ signaling. Mechanistically, FTO deficiency suppresses JAK2 expression and STAT3 phosphorylation, leading to attenuated transcription of C/EBPβ, which is essential for the early stage of adipocyte differentiation. Using dual-luciferase assay, we validate that knockdown of FTO reduces expression of JAK2 in an m〈sup〉6〈/sup〉A-dependent manner. Furthermore, we find that m〈sup〉6〈/sup〉A “reader” protein YTHDF2 directly targets m〈sup〉6〈/sup〉A-modified transcripts of JAK2 and accelerates mRNA decay, which results in decreased JAK2 expression and inactivated JAK2-STAT3-C/EBPβ signaling, thereby inhibiting adipogenesis. Collectively, our results provide a novel insight into the molecular mechanism of m〈sup〉6〈/sup〉A methylation in post-transcriptional regulation of JAK2-STAT3-C/EBPβ signaling axis and highlight the crucial role of m〈sup〉6〈/sup〉A modification and its modulators in adipogenesis.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 1874-9399
    Electronic ISSN: 1876-4320
    Topics: Biology , Chemistry and Pharmacology , Medicine
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  • 55
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    Unknown
    Elsevier
    Publication Date: 2019
    Description: 〈p〉Publication date: 1 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Biochimica et Biophysica Acta (BBA) - Biomembranes, Volume 1861, Issue 8〈/p〉 〈p〉Author(s): 〈/p〉
    Print ISSN: 0005-2736
    Electronic ISSN: 1879-2642
    Topics: Biology , Chemistry and Pharmacology , Medicine , Physics
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  • 56
    Publication Date: 2019
    Description: 〈p〉Publication date: 1 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Biochimica et Biophysica Acta (BBA) - Molecular Basis of Disease, Volume 1865, Issue 10〈/p〉 〈p〉Author(s): Tomonaga Ichikawa, Shingo Nakahata, Masahiro Fujii, Hidekatsu Iha, Kazuya Shimoda, Kazuhiro Morishita〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉N-myc downstream-regulated gene 2 (NDRG2) is a candidate tumor suppressor that is frequently downregulated in adult T-cell leukemia/lymphoma (ATLL) and functions to negatively regulate several cellular signaling pathways as PP2A recruiter. To clarify the molecular mechanisms of suppression of NDRG2 expression, we initially determined the expression pattern of NDRG2 in various types of T-cells and ATLL cells. NDRG2 expression was significantly upregulated in HTLV-1/Tax-immortalized T-cells, which was mediated by NF-κB activation through Tax expression. On the other hand, NDRG2 expression was suppressed in HTLV-1-infected cell lines and various types of ATLL cells, which was dependent on the DNA methylation of the NDRG2 promoter. We found that the expression of enhancer of zeste homolog 2 (EZH2), a member of the polycomb family, is increased in ATLL, and that EZH2 directly binds to the NDRG2 promoter and induces DNA methylation of the NDRG2 promoter. Since the expression of EZH2 were anti-parallelly regulated with the NDRG2 expression, EZH2 might be one of the most important regulators of the downregulation of NDRG2, contributing to enhanced activation of signaling pathways during ATLL development.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0925-4439
    Electronic ISSN: 1879-260X
    Topics: Biology , Chemistry and Pharmacology , Medicine , Physics
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  • 57
    Publication Date: 2019
    Description: 〈p〉Publication date: 1 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Biochimica et Biophysica Acta (BBA) - Biomembranes, Volume 1861, Issue 9〈/p〉 〈p〉Author(s): Mariafrancesca Scalise, Michele Galluccio, Lorena Pochini, Jessica Cosco, Miriam Trotta, Manuele Rebsamen, Giulio Superti-Furga, Cesare Indiveri〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The lysosomal amino acid transporter SLC38A9 is referred to as transceptor, i.e. a transporter with a receptor function. The protein is responsible for coupling amino acid transport across the lysosomal membrane according to the substrate availability to mTORC1 signal transduction. This process allows cells to sense amino acid level responding to growth stimuli in physiological and pathological conditions triggering mTOR regulation. The main substrates underlying this function are glutamine and arginine. The functional and kinetic characterization of glutamine and arginine transport was performed using human SLC38A9 produced in 〈em〉E. coli〈/em〉, purified by affinity chromatography and reconstituted in liposomes. A cooperative behaviour for the wild type protein was revealed for both the substrates. A novel Na〈sup〉+〈/sup〉 binding site, namely T453, was described by combined approaches of bioinformatics, site-directed mutagenesis and transport assay. Stimulation by cholesterol of glutamine and arginine transport was observed. The biological function of SLC38A9 relies on the interaction between its N-terminus and components of the mTOR complex; a deletion mutant of the N-terminus tail was produced and transport of glutamine was assayed revealing that this portion does not play any role in the intrinsic transport function of the human SLC38A9. Different features for glutamine and arginine transport were revealed: human SLC38A9 is competent for glutamine efflux, while that of arginine is negligible. In line with these results, imposed ∆pH stimulated glutamine, not arginine transport. Arginine plays, on the contrary, a modulatory function and is able to stimulate glutamine efflux. Interestingly, reciprocal inhibition experiments also supported by bioinformatics, suggested that glutamine and arginine may bind to different sites in the human SLC38A9 transporter.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉Proteoliposome reconstitution of hSLC38A9 WT and mutants.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0005273619301567-ga1.jpg" width="301" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0005-2736
    Electronic ISSN: 1879-2642
    Topics: Biology , Chemistry and Pharmacology , Medicine , Physics
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  • 58
    Publication Date: 2019
    Description: 〈p〉Publication date: Available online 8 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Computer Methods and Programs in Biomedicine〈/p〉 〈p〉Author(s): Alae Ammour, Ibtissame Aouraghe, Ghizlane Khaissidi, Mostapha Mrabti, Ghita Aboulem, Faouzi Belhacen〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Parkinson's disease (PD) is the second most common neurodegenerative disease affecting significant portion of elderly population. One of the most frequent hallmarks and the first manifestation of PD is deterioration of handwriting. Since the diagnosis of Parkinson's disease is difficult, researchers have worked to develop a support tool based on algorithms to separate healthy controls from PD patients. On-line handwriting analysis is one of the methods that can be used to diagnose PD. In this study, we aimed to analyze the Arabic Handwriting of 28 Parkinson's disease patients and 28 healthy controls (HCs) who were the same age and have the same intellectual level. We focused on copying an Arabic text task. For each participant we have calculated 1482 features. Based on the most relevant features selected by the Pearson's coefficient correlation, the Hierarchical Ascendant Classification (HAC) was applied and generated 3 clusters of writers. The characterization of these clusters was carried out by using the quantitative and qualitative parameters. The obtained results show that the combination of these two aspects can discriminate at best PD patients from HCs.〈/p〉〈/div〉
    Print ISSN: 0169-2607
    Electronic ISSN: 1872-7565
    Topics: Biology , Medicine
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  • 59
    facet.materialart.
    Unknown
    Elsevier
    Publication Date: 2019
    Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Biochimica et Biophysica Acta (BBA) - General Subjects, Volume 1863, Issue 9〈/p〉 〈p〉Author(s): 〈/p〉
    Print ISSN: 0304-4165
    Electronic ISSN: 1872-8006
    Topics: Biology , Chemistry and Pharmacology , Medicine , Physics
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  • 60
    Publication Date: 2019
    Description: 〈p〉Publication date: 1 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Biochimica et Biophysica Acta (BBA) - Biomembranes, Volume 1861, Issue 9〈/p〉 〈p〉Author(s): Oumaima Et-Thakafy, Fanny Guyomarc'h, Christelle Lopez〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The biological membrane surrounding milk fat globules (MFGM) exhibits lateral phase separation of lipids, interpreted as gel or liquid-ordered phase sphingomyelin-rich (milk SM) domains dispersed in a fluid continuous lipid phase. The objective of this study was to investigate whether changes in the phase state of milk SM-rich domains induced by temperature (T 〈 Tm or T 〉 Tm) or cholesterol affected the Young modulus of the lipid membrane. Supported lipid bilayers composed of MFGM polar lipids, milk SM or milk SM/cholesterol (50:50 mol) were investigated at 20 °C and 50 °C using atomic force microscopy (AFM) and force spectroscopy. At 20 °C, gel-phase SM-rich domains and the surrounding fluid phase of the MFGM polar lipids exhibited Young modulus values of 10–20 MPa and 4–6 MPa, respectively. Upon heating at 50 °C, the milk SM-rich domains in MFGM bilayers as well as pure milk SM bilayers melted, leading to the formation of a homogeneous membrane with similar Young modulus values to that of a fluid phase (0–5 MPa). Upon addition of cholesterol to the milk SM to reach 50:50 mol%, membranes in the liquid-ordered phase exhibited Young modulus values of a few MPa, at either 20 or 50 °C. This indicated that the presence of cholesterol fluidized milk SM membranes and that the Young modulus was weakly affected by the temperature. These results open perspectives for the development of milk polar lipid based vesicles with modulated mechanical properties.〈/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-S0005273619301555-ga1.jpg" width="317" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0005-2736
    Electronic ISSN: 1879-2642
    Topics: Biology , Chemistry and Pharmacology , Medicine , Physics
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  • 61
    Publication Date: 2019
    Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Advances in Water Resources, Volume 131〈/p〉 〈p〉Author(s): Shaokun He, Shenglian Guo, Kebing Chen, Lele Deng, Zhen Liao, Feng Xiong, Jiabo Yin〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The optimal impoundment operation of cascade reservoirs can dramatically improve the utilization of water resources. However, their complex non-convexity and computational costs pose challenges to optimal hydroelectricity output and limit further development of joint operation within larger-scale cascade reservoirs. In recent decades, parallel dynamic programming (PDP) has emerged as a means of alleviating the ‘curse of dimensionality’ in the mid-long term reservoir operation with more involved computing processors. But it still can't effectively solve the daily impoundment operation of more than three reservoirs. Here, we propose a novel method called importance sampling-PDP (IS-PDP) algorithm in which the merits of PDP are integrated with importance sampling and successive approximation strategy. Importance sampling is first used to construct the state vectors of each period by introducing ‘Manhattan distance’ in the discrete state space. Then the PDP recursive equation is used to find an improved solution during the iteration. The IS-PDP method is tested to optimize hydropower output for the joint operation of an 11-reservoir system located in the upper Yangtze River basin of China after establishing impoundment operation by advancing impoundment timings and rising water levels. We find that our methodology could effectively deal with the ‘curse of dimensionality’ for such mega reservoir systems and make better use of water resources in comparison to the Standard Operation Policy (SOP). Given its computational efficiency and robust convergence, the methodology is an attractive alternative for non-convex operation of large-scale cascade reservoirs.〈/p〉〈/div〉
    Print ISSN: 0309-1708
    Electronic ISSN: 1872-9657
    Topics: Geography , Geosciences
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  • 62
    Publication Date: 2019
    Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Biomass and Bioenergy, Volume 127〈/p〉 〈p〉Author(s): Shuping Zhang, Shuguang Zhu, Houlei Zhang, Xinzhi Liu, Huiyan Zhang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Effect of combined pretreatment on the mechanism of pyrolysis behavior and pyrolysis products (bio-oil, non-condensable gas and char) of rice husk was investigated using thermogravimetric analyzer (TGA) and laboratory-scale fixed-bed reactor. A coupling method combining iso-conversional method and model-fitting method was used to obtain the pyrolysis kinetic parameter. Pyrolysis kinetics results indicated that activation energy (〈em〉E〈/em〉) gradually increased with the increase of conversion rate (〈em〉α〈/em〉), which was due to the differences in thermal stability of biomass components. Acid washing pretreatment slightly increased the average activation energy (〈em〉E〈/em〉〈sub〉a〈/sub〉), and then subsequent torrefaction process further increased it. The entire pyrolysis reaction process of all the rice husk samples can be described by the reaction-order model. In addition, a laboratory-scale fixed-bed reactor was used to investigate the yields and detailed characteristics of pyrolysis products. The results suggested that phenols and sugars contents in bio-oil increased, while that of small-molecule components with high thermal instability decreased, which was favor for the storage and subsequent utilization of bio-oil. Rice husk char obtained from pyrolysis also has the potential for preparation of silica products. We concluded that combined pretreatment of washing and torrefaction significantly improved the thermochemical utilization potential of rice husk for fuels and chemicals by pyrolysis.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0961953419302429-fx1.jpg" width="307" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉
    Print ISSN: 0961-9534
    Electronic ISSN: 1873-2909
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Process Engineering, Biotechnology, Nutrition Technology
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  • 63
    Publication Date: 2019
    Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Marine Geology, Volume 416〈/p〉 〈p〉Author(s): Pedro Terrinha, Henrique Duarte, Pedro Brito, João Noiva, Carlos Ribeiro, Rachid Omira, Maria Ana Baptista, Miguel Miranda, Vitor Magalhães, Cristina Roque, Tagusdelta cruise team〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The stratigraphy of the Tagus river ebb-tidal delta off Lisbon (Portugal) is investigated using high resolution multichannel seismic reflection profiles with the purpose of searching for sedimentary or erosive features associated with landslides. The Tagus delta is sub-divided in two prograding seismic units of 17 ky to 13 ky and 13 ky to Present based on the calibration of seismic lines using gravity and box-cores in the Tagus pro-delta. We report the existence of a buried landslide with 11 km of length, 3.5 km of width and a maximum thickness of 20 m that accounted for the collapse of half of the upper unit of the Tagus river delta front in Holocene times. The non-collapsed half of the delta front contains extensive shallow gas of still unknown origin and nature. An estimated age of ~8 ky BP for the Tagus delta landslide is proposed based on stratigraphic correlation. The trigger mechanisms of the newly identified Tagus landslide are discussed as well as of the several landslides also found in the lower delta unit. These findings present a first step towards a future assessment of the susceptibility of the nearby coastal areas and the off-shore infrastructures to hazards related to such large collapses.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0025-3227
    Electronic ISSN: 1872-6151
    Topics: Geosciences
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  • 64
    Publication Date: 2019
    Description: 〈p〉Publication date: 1 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Atmospheric Environment, Volume 214〈/p〉 〈p〉Author(s): Daniela Polag, Frank Keppler〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Methane (CH〈sub〉4〈/sub〉) is a potent greenhouse gas released to the atmosphere by various natural and anthropogenic sources. Numerous studies have been conducted to quantify the major and minor CH〈sub〉4〈/sub〉 sources on spatial and temporal time scales. A minor source of the atmospheric global CH〈sub〉4〈/sub〉 budget is the direct release of CH〈sub〉4〈/sub〉 from the living human body. Based on available data from recent publications, for the first time, CH〈sub〉4〈/sub〉 emissions from human breath and flatus are estimated on a global scale taking into account dominant factors influencing emission, such as age, ethnicity, and gender. Human CH〈sub〉4〈/sub〉 emissions are compared between preindustrial times (1750), present age (2017) and future prediction (2100) using demographic data based on World Population Prospects 2017 of the United Nations (UN 2017). In preindustrial times the global CH〈sub〉4〈/sub〉 release by humans is estimated at 34 ± 28 Gg and then substantially increase by a factor of ten reaching 344 ± 255 Gg by 2017. Emissions are estimated to further increase by almost fourfold to a value of 1221 ± 672 Gg by 2100, even though the rise in population is predicted to only increase by 50%. This nonlinear relationship is related to the predicted change in population structure affecting the number of CH〈sub〉4〈/sub〉 producers. In contrast, for the year 2100 the simplified non-weighted estimation which merely considers the expected increase in population would only account for 612 ± 169 Gg. The discrepancy between the simplified non-weighted and weighted estimations of human CH〈sub〉4〈/sub〉 emissions emphasises the importance of factor-based calculations in order to compile more accurate data.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 1352-2310
    Electronic ISSN: 1873-2844
    Topics: Geosciences , Physics
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  • 65
    Publication Date: 2019
    Description: 〈p〉Publication date: Available online 8 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Palaeogeography, Palaeoclimatology, Palaeoecology〈/p〉 〈p〉Author(s): William J. Freimuth, David J. Varricchio〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We describe the diversity and abundance of insect (specifically hymenopterans and coleopterans) pupation structures in the Upper Cretaceous (Campanian) Two Medicine Formation at the Egg Mountain locality, western Montana, U.S.A., an important dinosaur nesting site. The study interval comprises a massive calcareous siltstone and indurated silty limestone horizons interpreted as the product of cumulative paleosols. A 7 m by 11 m area was quarried with a jackhammer at intervals of 12.5 cm thickness for a 1.5 m thick stratigraphic section. The ichnoassemblage comprises four morphotypes (small, medium, large, and wide) assigned to 〈em〉Fictovichnus sciuttoi〈/em〉, of which three represent wasp (hymenopteran) cocoons while the fourth (wide) type potentially was produced by a coleopteran. Medium and small 〈em〉F. sciuttoi〈/em〉 are dominant while large and wide 〈em〉Fictovichnus〈/em〉 are less common and absent in some sample intervals. Other probable insect traces include partial perforations in cocoons (〈em〉Tombownichnus〈/em〉), isolated burrows, and an enigmatic hemispherical trace. Material is representative of a depauperate 〈em〉Celliforma〈/em〉 ichnofacies. Pervasive cocoons and other traces throughout the sequence suggest persistent soil conditions suitable for insect nesting and pupation, and suggest an absence of sediment pulses of sufficient thickness to prohibit thorough colonization. Peaks in pupation chamber abundance may reflect episodes of reduced sedimentation rates otherwise unseen in the absence of primary bedding structures. Well-drained and friable soil conditions favorable for insect nesting also may help explain the abundance of dinosaur nests and other vertebrate nesting events in associated strata as well as the presence of small terrestrial forms.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0031-0182
    Electronic ISSN: 1872-616X
    Topics: Geosciences , Physics
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  • 66
    facet.materialart.
    Unknown
    Elsevier
    Publication Date: 2019
    Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Geodynamics, Volume 129〈/p〉 〈p〉Author(s): 〈/p〉
    Print ISSN: 0264-3707
    Electronic ISSN: 1879-1670
    Topics: Geosciences , Physics
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  • 67
    Publication Date: 2019
    Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Petroleum Science and Engineering, Volume 181〈/p〉 〈p〉Author(s): Jingyi Zhu, Zhaozhong Yang, Xiaogang Li, Zhichao Song, Ziwei Liu, Shiyi Xie〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Liquid foam is an alternative to water-based fracturing fluid due to its great proppant suspension ability. In this work, theoretical and experimental investigations on the settling behavior of the proppants in viscoelastic foams were analyzed on bubble scale. Settling trajectory was captured over time by optical microscope to calculate proppant settling velocity. At room temperature, proppants kept suspended well, but noticeable changes in proppant position could be observed at 70 °C. We concluded that the sedimentation of the proppants at high temperature was divided into three stages, that were drainage-dominated, structure-dominated and fluid-dominated regimes. For the large proppants, quick settling velocity was seen at first due to fast drainage rate. Then bubble pressure force and network force served as drag force exerting on the proppants when the proppants stretched or squeezed the liquid films. During this regime, bubble distribution, the existence of nodes, the length and the orientation of Plateau border leaded to the fluctuation in settling velocity. Lastly, the proppants would also flow freely along Plateau border over time, and the properties of the foam fluid such as viscosity and elasticity provided the drag force to prevent the proppants from settling. It's more likely for small proppants to change to this stage called fluid-dominated regime, but elasticity also guaranteed their low settling velocity. Moreover, in the existence of proppants, the analysis into drainage rate and bubble structure demonstrated the high stability of viscoelastic foams. These results helped understand the sedimentation of proppants in wet foams and broadened the application of viscoelastic foams in hydraulic fracturing.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0920-4105
    Electronic ISSN: 1873-4715
    Topics: Chemistry and Pharmacology , Geosciences , Process Engineering, Biotechnology, Nutrition Technology
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  • 68
    facet.materialart.
    Unknown
    Elsevier
    Publication Date: 2019
    Description: 〈p〉Publication date: July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Ocean Modelling, Volume 139〈/p〉 〈p〉Author(s): 〈/p〉
    Print ISSN: 1463-5003
    Electronic ISSN: 1463-5011
    Topics: Geography , Geosciences , Physics
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  • 69
    Publication Date: 2019
    Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Petroleum Science and Engineering, Volume 181〈/p〉 〈p〉Author(s): Zhong-Zhen Chen, Hong-Ze Gang, Jin-Feng Liu, Bo-Zhong Mu, Shi-Zhong Yang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A thermal-stable and salt-tolerant biobased zwitterionic surfactant 〈em〉N, N〈/em〉-Dimethyl-〈em〉N〈/em〉-[2-hydroxy-3-sulfo-propyl]-〈em〉N〈/em〉′-phenyloctadecanoyl-1, 3-diaminopropane (SPODP) was successfully obtained from modification of oleic acids which can be regenerated from waste cooking oils, and its structure was characterized using GC-MS, ESI-MS and 〈sup〉1〈/sup〉H NMR approaches. The biobased zwitterionic surfactant demonstrated a strong interfacial activity at high salinity and high temperature conditions at a very low surfactant dosage in formation brine. The ultralow interfacial tension (≤10〈sup〉−3〈/sup〉 mN/m) between crude oil and brine was reached at 0.5 g/L in brine with a wide range compatibility of NaCl up to saturation, Ca〈sup〉2+〈/sup〉 up to 500 mg/L, and temperature up to 95 °C. Meanwhile, it also exhibited strong wetting ability and resistance against adsorption on sands. All the results from this study suggest that the biobased zwitterionic surfactant is promising over varieties of traditional surfactants in applications in alkali free systems in enhanced oil recovery (EOR).〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0920-4105
    Electronic ISSN: 1873-4715
    Topics: Chemistry and Pharmacology , Geosciences , Process Engineering, Biotechnology, Nutrition Technology
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  • 70
    Publication Date: 2019
    Description: 〈p〉Publication date: Available online 6 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Ore Geology Reviews〈/p〉 〈p〉Author(s): Henrik Kalliomäki, Thomas Wagner, Tobias Fusswinkel, Dina Schultze〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Orogenic style gold mineralizations in the Archean Hattu schist belt (E Finland) are present in all major host rock lithologies including epiclastic sedimentary rocks, volcanic rocks, and felsic intrusives. The gold deposits are related to extensive quartz-dominated vein networks and the gold mineralization occurs as dissemination in altered wall rocks and within hydrothermal quartz veins. The quartz-dominated veins frequently contain calcite, which is also present within the country rocks. We analyze and compare the major and trace element chemistry of these calcites and test whether they carry the signatures of the origin of hydrothermal fluids associated with the gold deposits or record fluid interaction with the local wall rocks. The calcites show textural growth and chemical zoning, considerable chemical variations within samples and the chemical data do show some overlap between the samples. All calcites contain dominantly Ca with other elements being typically below 2 wt.%, and they are accordingly classified as rather pure calcites. Amongst minor elements, both Mg and Fe show larger variations than Mn. The concentrations of most trace elements analyzed are relatively low, except for Sr and Y, which can attain values up to 1 wt.% and 200 ppm, respectively. Some of the trace elements or trace element ratios in hydrothermal calcite, including Sr, Y, Mn, (La/Lu)〈sub〉N〈/sub〉 and ∑REE, show correlations with the respective host rock lithologies. This indicates that interaction between hydrothermal fluids and adjacent and diverse host rocks has strongly affected the trace element chemistry of calcite. Chemically variable growth zones in large calcite crystals and distinct grain populations within individual samples cannot be readily explained by host rock control, but instead they are interpreted to reflect changes in fluid composition over time. The hydrothermal calcites have chondrite-normalized REE patterns that are mostly HREE enriched relative to LREE, with very few exceptions that show unfractionated flat or LREE enriched (relative to the HREE) patterns. The REE patterns of the calcites are very different from those of their immediate host rocks, suggesting that they are inherited from the hydrothermal fluid(s) from which they precipitated. The HREE enrichment relative to the LREE visible in the patterns resembles the REE patterns of calcites from hydrothermal vein type deposits of metamorphic origin elsewhere and contrasts with the REE patterns of calcites from magmatic-hydrothermal environments. The REE patterns of the hydrothermal calcites in the Hattu schist belt deposits would therefore be compatible with formation from a fluid system that is essentially derived from metamorphic sources, in agreement with conclusions drawn from the fluid inclusion chemistry.〈/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-S0169136818309636-ga1.jpg" width="86" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0169-1368
    Electronic ISSN: 1872-7360
    Topics: Geosciences
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  • 71
    Publication Date: 2019
    Description: 〈p〉Publication date: Available online 6 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Deep Sea Research Part II: Topical Studies in Oceanography〈/p〉 〈p〉Author(s): Stacey A. McCormack, Jessica Melbourne-Thomas, Rowan Trebilco, Julia L. Blanchard, Andrew Constable〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In recent years, there has been a shift away from the long-standing paradigm in which a short, krill-dominated food chain was considered to be the central element in Southern Ocean food webs. Instead, there is now increasing recognition that alternative energy pathways through mid-trophic level groups (mesopelagic fish and squid) may be equally (if not more) important than the krill pathway in many regions. Ecosystem models are a valuable tool to synthesise existing data on the structure of marine food webs and to visualise and quantify alternative energy pathways. In this study we develop a static mass balance food web model for the southern Kerguelen Axis region (Prydz Bay and Princess Elizabeth Trough) to evaluate the importance of alternative energy pathways through mid-trophic level groups, including fish, squid and krill, in maintaining energy flow to top predators within East Antarctica. Our model reveals several major trophic pathways distinct from, and equally important to the Antarctic krill (〈em〉Euphausia superba〈/em〉) pathway. Using simple scenarios of reductions in krill biomass, we investigate how the system might switch to a state dominated by fish and squid pathways with the response of krill-reliant predators strongly dependent on their ability to switch to other prey sources. We conclude by discussing what these findings might suggest for the future vulnerability of East Antarctic food webs and the implications for future modelling work in the region.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0967-0645
    Electronic ISSN: 1879-0100
    Topics: Biology , Geosciences , Physics
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  • 72
    Publication Date: 2019
    Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Ore Geology Reviews, Volume 111〈/p〉 〈p〉Author(s): Wenyuan Liu, Nigel J. Cook, Cristiana L. Ciobanu, Sarah E. Gilbert〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Enargite, Cu〈sub〉3〈/sub〉AsS〈sub〉4〈/sub〉, is a relatively common sulphide mineral and is considered diagnostic for deposits of intermediate- to high-sulphidation type. Analysis of enargite-bearing samples from deposits in the Zijinshan porphyry – high-sulphidation epithermal Cu-Au orefield, southeastern China, provides evidence for the diversity of trace elements that may be hosted within enargite and their range of concentrations. Enargite is shown to host Sb, Te, Sn, Zn and Ge at concentrations up to several thousand ppm. The mineral also incorporates measurable concentrations of Mo, Cd, Bi, Pb, Fe, Se, Ag, Au W, Ga and In. Element mapping (electron probe microanalysis and laser ablation inductively coupled plasma mass spectrometry) provides evidence for grain-scale heterogeneity in enargite in the form of oscillatory, grain-scale compositional zonation with respect to Sb, Sn, Te and several other trace elements. Element mapping also clearly shows an inverse correlation between the concentrations of As and Te, and between As and Sn. Incorporation of Sn and Te into the enargite structure is achieved by substitution of Sn〈sup〉4+〈/sup〉 and Te〈sup〉4+〈/sup〉 for As〈sup〉5+〈/sup〉. Charge balance is maintained by incorporation of Fe〈sup〉2+〈/sup〉, Zn〈sup〉2+〈/sup〉 and other divalent cations (potentially including Cu〈sup〉2+〈/sup〉) into the Cu〈sup〉+〈/sup〉 site. The complex intra-grain zoning results from evolving fluids, multiple phases of growth – in turn leading to an overprinting of primary distribution patterns. Observed patterns are also influenced by equilibrium partitioning between enargite and co-existing minerals. Nevertheless, trace element signatures in enargite from different parts of the Zijinshan ore system show notable differences. Enargite from the high-sulphidation stage typically shows a marked enrichment in Te and Sn whereas enargite from intermediate-sulphidation stage is relatively depleted in Te and Sn, and comparatively enriched in Sb and Se. These differences represent a potential vector for exploration within porphyry – high-sulphidation epithermal systems. Furthermore, the presence of Te-rich enargite may be a prospective guide to high Au-grade mineralization. The notable concentrations of precious metals (Au, Ag) and critical elements (notably Te and Ge) within enargite make this mineral of particular interest from the perspective of potential recovery of these economically important elements. The observed grain-scale zoning and inherent variability within any given sample emphasize that spot analysis of trace elements alone without consideration of such heterogeneity may provide quantitative data of limited use and potentially, lead to misleading interpretations.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉 〈p〉LA-ICP-MS element maps of zoned enargite from the Zijinshan high-sulphidation Cu-Au deposit reveal often spectacular grain-scale zonation that track changes in fluid composition. Enargite also concentrates several elements of interest, including Ag, Au, Te and Ge, relative to associated minerals.〈/p〉 〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0169136819303750-ga1.jpg" width="292" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉 〈/div〉 〈/div〉
    Print ISSN: 0169-1368
    Electronic ISSN: 1872-7360
    Topics: Geosciences
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  • 73
    Publication Date: 2019
    Description: 〈p〉Publication date: November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Carbon, Volume 153〈/p〉 〈p〉Author(s): A-Young Kim, Ryanda Enggar Anugrah Ardhi, Guicheng Liu, Ji Young Kim, Hyun-Jin Shin, Dongjin Byun, Joong Kee Lee〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A hierarchical hollow SnO/SnO〈sub〉2〈/sub〉 heterostructure anode surrounded by a dual carbon layer (DCL@SnO/SnO〈sub〉2〈/sub〉), inner (host) and outer carbon layers, was successfully designed 〈em〉via〈/em〉 a simple hydrothermal method with a single Sn precursor to achieving high-performance Li-ion batteries (LIBs) and Li-ion capacitors (LICs). The carbon nanotube (CNT)-based inner carbon host and an ultrathin outer amorphous carbon layer introduced at the SnO/SnO〈sub〉2〈/sub〉 heterostructure had good elasticity and high electrical properties to prevent volume change and ensure fast Li-ion transport during cycling, respectively. Meanwhile, the SnO/SnO〈sub〉2〈/sub〉 heterostructure comprising p-type SnO and n-type SnO〈sub〉2〈/sub〉 facilitated further fast interfacial Li-ion transfer within the p–n SnO/SnO〈sub〉2〈/sub〉 heterojunction anode 〈em〉via〈/em〉 the acceleration effect induced by the built-in electric field (BEF). The resulting half cells LIBs consisting DCL@SnO/SnO〈sub〉2〈/sub〉 anode shows a high reversible specific capacity of 902.1 mAh g〈sup〉−1〈/sup〉 after 500 cycles at a current density of 1400 mA g〈sup〉−1〈/sup〉. The specific capacity of 347.04 mAh g〈sup〉−1〈/sup〉 was still maintained even at a high current density of 10 000 mA g〈sup〉−1〈/sup〉. Moreover, the maximum energy and power density of 125 W kg〈sup〉−1〈/sup〉 and 200 Wh kg〈sup〉−1〈/sup〉, respectively, were achieved from the half cells LIC comprising DCL@SnO/SnO〈sub〉2〈/sub〉 anode (LIC-DCL@SnO/SnO〈sub〉2〈/sub〉).〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉A hierarchical hollow SnO/SnO〈sub〉2〈/sub〉 heterostructure anode surrounded by a dual carbon layer (DCL@SnO/SnO〈sub〉2〈/sub〉) is prepared by a simple hydrothermal method using a single Sn precursor. The CNT-based inner carbon host layer is equipped by a nanotail CNT to form a tadpole-like structure. The ultrathin elastic amorphous outer carbon layer buffers the cyclic volume change of the SnO/SnO〈sub〉2〈/sub〉 heterostructure, while its natural properties could realize the formation of thin, instead of thick, solid-electrolyte interphase (SEI) layer to enhance e〈sup〉−〈/sup〉/Li〈sup〉+〈/sup〉 reversibility and transport kinetics during charge charge–discharge cycles. The p–n heterojunction created from SnO/SnO〈sub〉2〈/sub〉 heterostructure facilitates the creation of the built-in electric field (BEF) to promote e〈sup〉−〈/sup〉/Li〈sup〉+〈/sup〉 transport rate during charge–discharge cycling and to maintain a reversible high capacity at a high current density.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0008622319306888-fx1.jpg" width="288" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉
    Print ISSN: 0008-6223
    Electronic ISSN: 1873-3891
    Topics: Chemistry and Pharmacology , Geosciences
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  • 74
    Publication Date: 2019
    Description: 〈p〉Publication date: November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Carbon, Volume 153〈/p〉 〈p〉Author(s): Chen Han, Xiaoguang Duan, Mingjie Zhang, Wenzhao Fu, Xuezhi Duan, Wenjie Ma, Shaomin Liu, Shaobin Wang, Xinggui Zhou〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Nanocarbon-catalyzed advanced oxidation processes for wastewater remediation are green and state-of-the-art methods, nevertheless, the origins of carbocatalysis remain unresolved. In this study, carbon nanotubes (CNTs) are employed as typical metal-free catalysts for catalytic peroxymonosulfate (PMS) activation and phenol oxidation. The surface chemistry and electronic properties of CNTs are deliberately tailored by liquid acid oxidation and subsequent thermal treatment. It is unveiled that the electron-rich carbon surface and carbonyl groups can affect organic adsorption capacity of the carbocatalysts and modulate persulfate activation in different catalytic manners. Furthermore, the relationship between the surface chemistry (oxygen functionality and electron density) and carbocatalysis is established, which is decisive to regulate the radical/nonradical pathways in the catalytic oxidation for water purification. This study provides new insights to carbon-catalyzed persulfate activation with manipulated reaction pathways and redox potentials.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0008622319306839-fx1.jpg" width="260" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉
    Print ISSN: 0008-6223
    Electronic ISSN: 1873-3891
    Topics: Chemistry and Pharmacology , Geosciences
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  • 75
    Publication Date: 2019
    Description: 〈p〉Publication date: 15 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Volcanology and Geothermal Research, Volume 384〈/p〉 〈p〉Author(s): Chiou Ting Tan, Benoît Taisne, Jurgen Neuberg, Ahmad Basuki〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Magma opening new fluid pathways through the crust can generate migrating seismic sources following the trail of the magma. By using Seismic Amplitude Ratio Analysis (SARA), it is possible to detect this seismic migration simply from the amplitudes of continuous data recorded at different stations in a network, without having to do any picking of seismic phases. In this study, we present a modified method – Red-flag SARA, which adapts SARA for real-time monitoring. Red-flag SARA provides a quantitative tool to analyse amplitude ratios between stations in a network and detect temporal changes in these ratios. Since such changes imply seismic source location variations, Red-flag SARA is a handy tool during seismic crises to quickly answer the question of whether seismic activity, and therefore magma, is migrating or not. We tested Red-flag SARA on synthetic data and validated it using real data from two volcanoes – Piton de la Fournaise, Reunion Island, and Gede, Indonesia, for three scenarios: 1) magma migration ending as intrusion, 2) migration leading to eruption and 3) a burst of seismicity with no magma migration.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0377-0273
    Electronic ISSN: 1872-6097
    Topics: Geosciences
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  • 76
    Publication Date: 2019
    Description: 〈p〉Publication date: 1 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Palaeogeography, Palaeoclimatology, Palaeoecology, Volume 533〈/p〉 〈p〉Author(s): Wenhui Wang, Linna Zhang, Hao Liu, Xin Deng, Jingqiang Tan〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This study presents a new analysis of three species of the Ordovician graptolite genus 〈em〉Azygograptus〈/em〉 Nicholson & Lapworth from the Wenxiakou section in the Zhongxiang area of Hubei Province. The paleogeographic occurrences of the genus within South China were plotted on an up-to-date paleogeographic map based on a revised data set of graptolite occurrences from 68 localities compiled by the online Geobiodiversity Database (GBDB). The paleogeographic distribution of 〈em〉Azygograptus〈/em〉 follows a nearshore-offshore trend, and the taxonomic diversity of 〈em〉Azygograptus〈/em〉 is higher in nearshore high-energy environments than in offshore low-energy environments. However, graptolites also gathered in deeper-water environments surrounding oldlands partly due to the high-nutrient inputs and rapid deposition. 〈em〉Azygograptus〈/em〉 is found not only in high-latitude cold-water regions as endemic taxa but also in low-latitude regions. Oceanic circulation may account for the rapid dispersal of 〈em〉Azygograptus〈/em〉 from high-latitude regions, such as Britain and Scandinavia, to low-latitude regions, such as South China, eventually resulting in their observed paleogeographic distribution.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0031-0182
    Electronic ISSN: 1872-616X
    Topics: Geosciences , Physics
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  • 77
    Publication Date: 2019
    Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Marine Geology, Volume 416〈/p〉 〈p〉Author(s): Manli Zhang, Changsong Lin, Min He, Zhongtao Zhang, Hao Li, Xuan Feng, Hongxun Tian, Hanyao Liu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The early-stage shelf-margin prism in the Pearl River Mouth Basin (PRMB), northern South China Sea, formed from the Late Oligocene to Early Miocene, comprises a set of shelf-edge delta and slope fan wedges of the Zhuhai Formation and records the development of the continental slope in response to the interaction of sea-level change, tectonic subsidence and sediment supply. Based on integrated analysis of seismic, well logging and core data, the stratigraphic architecture, depositional systems and controlling processes are documented. The Zhuhai Formation is a composite sequence bounded by regional unconformity, and can be further divided into five sequences (CS3-1-CS3-5). The depositional genetic units (transgression, ascending normal regression and descending forced regression) are identified within sequences based on variation in shelf edge trajectories. The shelf deltaic clinoforms are characterized by oblique-tangential reflections in seismic profiles with a thickness of 100–150 m. In contrast, the shelf-margin delta and slope clinoforms generally are 300–1200 m thick and mainly display as sigmoid or sigmoid-tangential seismic reflections. The delta deposits usually consist of thick beds of delta front deposits and prodelta slump and deformed sediments, and are associated with sandy slope fan systems. Eleven delta complexes are distinguished by tracking the distribution of the deltaic clinoforms in each sequence, and these deltaic deposits tend to extend along their strike direction which may be related to the reworking of strong waves and coastal currents. Slope fan systems consist mainly of turbidite channel fills, frontal splay and debris flow deposits, and generally develop along the slope in CS3-3-CS3-5, which may be triggered by steep shelf margin slope and fault activity. The stratigraphic pattern of the shelf margin prism and depositional evolution of the deltaic systems from the Late Oligocene to Early Miocene were controlled by the interaction of sea level changes, sediment supply and tectonic subsidence. The ascending trajectory from the CS3-1 (30 Ma) to the top of the CS3-5 indicates that the relative sea level continued to rise generally but the shelf margin prograded basinward rapidly due to the great amount of sediment supply and lower subsidence rate. Tectonic uplift of the source area and strengthened physical erosion during this period may be the reason for the large sediment supply.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0025-3227
    Electronic ISSN: 1872-6151
    Topics: Geosciences
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  • 78
    Publication Date: 2019
    Description: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemical Geology, Volume 524〈/p〉 〈p〉Author(s): Mengxue Li, Haibo Liu, Tianhu Chen, Lin Wei, Can Wang, Wei Hu, Hanlin Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The transformation of Al-substituted goethite in oxidative and reductive atmosphere, which models natural fire, was investigated in detail. Various characterization results indicated that Al-substituted goethite transformed into hematite in an oxidative atmosphere and magnetite followed by zero-valent iron in a reductive atmosphere. Interestingly, the substitution of Al for Fe not only changed the crystal morphology affecting crystal surface reactivity, but also restrained the transformation of goethite into hematite, magnetite and zero-valent iron. In addition, the Al in the goethite was embedded into the crystal structure of thermally formed hematite and magnetite, considerably influencing their surface reactivity. The macroscopic adsorption results indicated that the substitution of Al for Fe increased the adsorption capacity of goethite and the corresponding derivatives except zero-valent iron. For the same Al amount, the adsorption capacity followed an order of goethite 〉 hematite 〉 magnetite, implying a loss of phosphate in goethite-rich soil after experiencing natural fire. However, with increasing in temperature in the reductive atmosphere, Al-magnetite transformed into a mixture of Al-magnetite and zero-valent iron which displayed excellent phosphate adsorption capacities increasing to 1.21–5.96 mg/g. The phosphate adsorption behaviors to thermally formed products were fitted well by surface complexation modeling with five complexation sites, which were more obvious for goethite than for hematite and magnetite. These findings presented in this study represent significant progress toward an understanding of the migration, enrichment and transformation of phosphate in Al-substituted goethite-rich soil in cases experiencing natural fire.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0009-2541
    Electronic ISSN: 1872-6836
    Topics: Chemistry and Pharmacology , Geosciences
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  • 79
    Publication Date: 2019
    Description: 〈p〉Publication date: 5 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Chemical Geology, Volume 524〈/p〉 〈p〉Author(s): Xue-Feng Hu, Jing-Long Zhao, Pei-Feng Zhang, Yong Xue, Bo-Nian An, Fang Huang, Hui-Min Yu, Gan-Lin Zhang, Xiang-Jun Liu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉To probe Fe isotopic signatures of the Quaternary Red Clay (QRC) in subtropical southeastern China, two QRC profiles located in southern Anhui Province, Southeast China, were studied. The whole profiles were generally in a narrow range in δ〈sup〉56〈/sup〉Fe of −0.040 ± 0.061‰—0.117 ± 0.048‰. The Yellow-brown Earth (YBE) and Uniform Red Clay (URC) of the upper profiles were similar in δ〈sup〉56〈/sup〉Fe to the Xiashu Loess along the Yangtze River, Southeast China, and the loess, paleosols and Tertiary red clay in the Chinese Loess Plateaus, Northwest China, as well as the baseline of terrestrial igneous rocks. The slight variation of δ〈sup〉56〈/sup〉Fe from the YBE to the URC suggests that the chemical weathering and rubification on the aerobic surface did not fractionate Fe isotopes significantly. The Reticulate Red Clay (RRC) underlying the YBE and URC fluctuated in δ〈sup〉56〈/sup〉Fe to some extent. The white veins separated from the lower RRC were depleted of Fe oxides and heavier in Fe isotopes, and the red veins, on the contrary, were isotopically lighter in Fe. δ〈sup〉56〈/sup〉Fe of the white veins, 0.345 ± 0.053‰ on average, was significantly higher than the bulk samples, 0.033 ± 0.044‰ on average, and the red veins, −0.021 ± 0.046‰ on average. This suggests that the reticulate textures of the RRC were formed by the reductive removal/re-precipitation of Fe due to the cyclical changes of redoxic conditions. Fe isotopic composition of the QRC was dominantly controlled by the redoxic mobility of Fe, rather than the degree of weathering. δ〈sup〉56〈/sup〉Fe of the profiles was not correlated with the paleoclimatic events, and thus cannot be used as a paleoclimatic proxy. The fractionation of Fe isotopes in the lower RRC, however, indicated the occurrence of over-humid paleoclimate with alternations between drought and wetness in Southern China during the Pleistocene.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0009-2541
    Electronic ISSN: 1872-6836
    Topics: Chemistry and Pharmacology , Geosciences
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  • 80
    Publication Date: 2019
    Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of African Earth Sciences, Volume 158〈/p〉 〈p〉Author(s): Sayed Mosaad, El Sayed El Abd, Alan E. Kehew〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The Middle Eocene carbonate aquifer constitutes the major source of groundwater for the expansion of reclamation projects outside the Nile Valley southeast of Beni-Suef, Egypt. In the past few decades, groundwater abstraction from the Middle Eocene carbonate aquifer has increased, leading to the deterioration of groundwater quality. The current study combines geochemical methods and multivariate statistical analysis to assess the factors controlling the deterioration of groundwater quality in this aquifer. The results show that the total dissolved solids (TDS) varies between 263.7 and 4214 mg/l. The groundwater is dominantly of Na–Ca–Cl SO〈sub〉4〈/sub〉 type. Various plots were used to assess processes such as carbonate and evaporite dissolution, silicates weathering and/or cation exchange controlling groundwater quality. Geochemical modelling with NETPATH indicates that recharge sources and mixing of groundwater within the aquifer result from occasional storms over the eastern watershed. These rainfall events account for ~32% of aquifer recharge, along with infiltration of Nile water in the west, which contributes ~36% of the recharge. The groundwater salinity is controlled by precipitation of calcite, dissolution of dolomite, gypsum and halite and ion exchange along the groundwater flow path. Multivariate statistical analysis highlights that the Ca, Na, Cl and SO4 ions control groundwater salinity within the aquifer through water-rock reactions and mixing of Nile water from the western side of the study area with subsurface recharge from mountainous areas in the eastern portion of the watershed. Integration of hydro-geochemical data and multivariate statistical analysis leads to better understanding of geochemical processes controlling regional groundwater quality in the Middle Eocene carbonate aquifer near Beni-Suef, Egypt and in areas with comparable conditions.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 1464-343X
    Electronic ISSN: 1879-1956
    Topics: Geosciences
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  • 81
    Publication Date: 2019
    Description: 〈p〉Publication date: 15 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Precambrian Research, Volume 332〈/p〉 〈p〉Author(s): Lucía E. Gómez-Peral, María Julia Arrouy, Daniel G. Poiré, Claudia E. Cavarozzi〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The limestones of the Loma Negra Formation provide an excellent opportunity to examine the behaviour of rare earth elements plus yttrium (REY) due to the near-zero diagenetic alteration of the carbonate system. The terrigenous supply to this unit was minimal or scarce in relation to the depth of seawater in which the limestones accumulated. The interpreted palaeoenvironment suggests that limestones could have originated by suspension fall-out in a shallow, open marine ramp. The diagenetic features, composition, and original microtextures are considered good criteria for investigating their REY composition. Burial diagenesis products were limited and limestones largely preserved their original texture and organic matter, as well as their isotope and trace element composition. The study of REY distribution in the Loma Negra Formation in different settings of the Tandilia System revealed systematic chemostratigraphic patterns related to uniform palaeo-redox conditions. The general light rare-earth element depletion, marked positive La, Y, and Gd anomalies, as well as the clear negative Ce anomalies, are further features typically ascribed to oxidizing seawater conditions. From these results, it can be concluded that the Loma Negra Formation documents an oxygenation event that stands out in the overall anoxic Ediacaran ocean. This record may be correlated with the mid-Ediacaran oxygenation event (ca. 580 Ma). This may support the hypothesis that the Clymene Ocean was well oxygenated and connected during the Ediacaran, at least in the southwestern border of Gondwana.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0301-9268
    Electronic ISSN: 1872-7433
    Topics: Geosciences
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  • 82
    Publication Date: 2019
    Description: 〈p〉Publication date: 1 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Geoderma, Volume 353〈/p〉 〈p〉Author(s): Roozbeh Moazenzadeh, Babak Mohammadi〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Root zone temperature is one of the most important soil characteristics, controlling many of the physical, chemical and biological processes in the soil. Temperature varies by soil depth, and exerts a profound impact on plant germination and growth. In this study, the accuracy of two artificial intelligence models including support vector regression (SVR) and elman neural network (ENN) and their hybrids with firefly algorithm (SVR-FA and ENN-FA) and krill herd algorithm (SVR-KHA and ENN-KHA) was assessed in estimating soil temperature (Ts) at 5, 10, 20, 30, 50 and 100 cm depths at Maragheh meteorological station in north-western Iran. The results of the models were evaluated under 5 scenarios with various inputs including the main meteorological parameters measured at the station (air temperature, sunshine hours, relative humidity, wind speed and saturation vapour pressure deficit). Daily Ts data recorded from January 1, 2006 to December 30, 2012 and from January 1, 2013 to December 30, 2015 were used for model training and testing, respectively. The results showed that error rates have decreased from 5 to 10 cm soil depth (root mean square error (RMSE) reduced by 2.97, 4.68 and 3.19% for the best scenarios of SVR, SVR-FA and SVR-KHA models, respectively), whereas error rates have been increasing from 10 to 100 cm soil depths (RMSE increased by 62.4, 80.9 and 73.6% for the best scenarios of SVR, SVR-FA and SVR-KHA models, respectively). For the best scenarios of ENN, ENN-FA and ENN-KHA models, RMSE values decreased by 2.1, 1.6 and 3.1% from 5 to 10 cm depth and increased by 61.1, 84.1 and 81.1% from 10 to 100 cm depth, so that all six models reached their best performance at 10 cm soil depth. Examination of the results in terms of under-estimation or over-estimation of Ts indicated that the lowest and highest differences in performance between under- and over-estimation sets were 0.01 °C (SVR-FA at 5 cm depth) and 1.64 °C (SVR at 100 cm depth) for SVR-based models and 0 °C (ENN at 10 cm depth) and 0.56 °C (ENN at 100 cm depth) for ELM-based models, respectively. According to the results from the best scenarios of SVR, SVR-FA and SVR-KHA models in the under-estimation set at 100 cm depth, all the three models have exhibited a poorer performance over the temperature range 15–25 °C (RMSE increased by 56.7, 47 and 61.3% for SVR, SVR-FA and SVR-KHA, respectively) compared to temperature values outside that range. Exactly the same trend was also observed for ELM-based models, where the mentioned increases in RMSE were about 37.7, 59.4 and 55.5% for ELM, ELM-FA and ELM-KHA, respectively. According to the results, bio-inspired metaheuristic optimisation algorithms based on SVR and ENN which use appropriate meteorological parameters as inputs can have a relatively satisfactory performance in estimating Ts under climatic conditions similar to our study area, especially in lower depths, and can be used as an alternative to direct measurement of this important parameter.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0016-7061
    Electronic ISSN: 1872-6259
    Topics: Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
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  • 83
    Publication Date: 2019
    Description: 〈p〉Publication date: Available online 6 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Marine and Petroleum Geology〈/p〉 〈p〉Author(s): Momotaj Begum, Mahmood Reza Yassin, Hassan Dehghanpour, University of Alberta〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉We evaluated the wettability of organic-rich shale plugs from 6 wells drilled in the Duvernay Formation, which is a self-sourced reservoir. We divided our samples into Upper (UD) and Lower (LD) Duvernay based on the variations in depth and kerogen maturity levels. UD and LD samples belong to oil and gas windows, respectively. We measured and compared spontaneous imbibition of oil and brine into 17 twin plugs with wide range of kerogen maturity level and total organic carbon (TOC) content. We also characterized the shale samples by conducting tight-rock analysis (TRA), x-ray diffraction (XRD), and rock-eval pyrolysis tests to identify the petrophysical properties, mineralogy, and organic-carbon properties, respectively. To investigate the size, abundance, and morphology of pores, we analyzed scanning electron microscopy (SEM) of the shale samples. Finally, we investigated the relationships between the results of spontaneous-imbibition tests and geochemical properties to understand the effect of kerogen maturity level on shale wettability.〈/p〉 〈p〉The results of wettability tests show higher normalized imbibed volume of oil (I〈sub〉o〈/sub〉) compared with that of brine (I〈sub〉w〈/sub〉), suggesting that the uncleaned dry plugs are strongly oil-wet. The positive correlations of TOC content with effective porosity and pressure-decay permeability indicate that a significant fraction of the pore space is within the organic matter, supported by the SEM images. The abundance of organic pores may explain the strong wetting affinity of the shale samples to oil. We observed negative and positive correlations between TOC content and equilibrated I〈sub〉o〈/sub〉 (I〈sub〉o〈/sub〉〈sup〉eq〈/sup〉) of UD and LD samples, respectively. This discrepancy can be explained by the smaller number of organic pores of UD samples with lower thermal maturity (oil window), confirmed by the results of SEM analysis and pore size distribution (N〈sub〉2〈/sub〉 sorption) tests. Furthermore, the free hydrocarbons content (S〈sub〉1〈/sub〉 in rock-eval data) in the form of oil in the UD samples is higher than that in the LD samples. The existence of free hydrocarbons content may reduce the pore space available for oil imbibition, leading to lower I〈sub〉o〈/sub〉〈sup〉eq〈/sup〉 for the UD samples with higher TOC content.〈/p〉 〈/div〉 〈/div〉
    Print ISSN: 0264-8172
    Electronic ISSN: 1873-4073
    Topics: Geosciences
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  • 84
    Publication Date: 2019
    Description: 〈p〉Publication date: 15 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Precambrian Research, Volume 332〈/p〉 〈p〉Author(s): Bruno Becker-Kerber, Fernando Rodrigues da Silva, Kamilla Borges Amorim, Mírian Liza Alves Forancelli Pacheco, Juliana de Moraes Leme〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The arrival of animals with hard parts at the end of the Ediacaran Period was an important evolutionary innovation. Biomineralized structures serve a number of biological functions and pose environmental challenges. Those same hard parts that once played a role in living organisms also affect their postmortem histories. Taphonomic scenarios may create biases that can impact perceptions on the systematic, morphological, biostratigraphic, and paleogeographic patterns in the fossil record. This is well exemplified by the taxonomic controversies regarding 〈em〉Cloudina〈/em〉, the most geographically widespread and abundant shelly fossil of the uppermost Ediacaran. In this study, we discuss new taphonomic data on 〈em〉Cloudina〈/em〉-bearing strata deposits from the Tamengo Formation (Corumbá Group, Brazil) and how influential this taphonomy is on a robust taxonomy of this fossil. Our observations suggest that allochthonous 〈em〉Cloudina〈/em〉 deposits from the Tamengo Formation present evidence of taphonomic influences on the transporting/reworking of fragmentation and disarticulation of 〈em〉Cloudina〈/em〉 tubes. Differences in size distributions between some of the localities have demonstrated that this trait is not reliable for defining or synonymizing species of 〈em〉Cloudina〈/em〉, and these differences probably reflect a myriad of taphonomic and paleobiological phenomena. Moreover, in some outcrops of the Tamengo Formation, shell walls are usually poorly preserved due to plastic deformations and diagenetic dissolution/recrystallization processes, which conceal morphological diagnostic features used in 〈em〉Cloudina〈/em〉 taxonomy. Similar taphonomic biases may be of equal importance to the taxonomy of 〈em〉Cloudina〈/em〉 preserved in other upper Ediacaran carbonates. Hence, earlier claims in favor of the synonymization of 〈em〉Cloudina〈/em〉 species from the Tamengo Formation cannot currently be justified.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0301-9268
    Electronic ISSN: 1872-7433
    Topics: Geosciences
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  • 85
    Publication Date: 2019
    Description: 〈p〉Publication date: Available online 7 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Physics and Chemistry of the Earth, Parts A/B/C〈/p〉 〈p〉Author(s): Maria Isabel Vélez Márquez, Jasmin Raymond, Daniela Blessent, Mikael Philippe〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The terrestrial heat flux density, an essential information to evaluate the deep geothermal resource potential, is rarely defined over urban areas where energy needs are important. In an effort to fill this gap, the subsurface thermal conductivity estimated during two thermal response tests was coupled with undisturbed temperature profile measurements conducted in the same boreholes to infer terrestrial heat flow near the surface. The undisturbed temperature profiles were reproduced with an inverse numerical model of conductive heat transfer, where the optimization of the model bottom boundary condition allows determining the near-surface heat flow. The inverse numerical simulation approach was previously validated by optimizing a steady-state and synthetic temperature profile calculated with Fourier's Law. Data from two thermal response tests in ground heat exchangers of one hundred meters depth were analyzed with inverse numerical simulations provided as examples for the town of Québec City, Canada, and Orléans, France. The temperature profiles measured at the sites and corrected according to the paleoclimate effects of the quaternary glaciations were reproduced with the model. The approach presented offers an alternative to assess heat flow in the preliminary exploration of deep geothermal resources of urban areas, where thermal response tests may be common while deep wells are sparsely distributed over the area to assess heat flow.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 1474-7065
    Electronic ISSN: 1873-5193
    Topics: Geosciences , Physics
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  • 86
    Publication Date: 2019
    Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Geochemistry, Volume 108〈/p〉 〈p〉Author(s): Irina Drozdova, Natalya Alekseeva-Popova, Vladimir Dorofeyev, Jaume Bech, Alla Belyaeva, Núria Roca〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Native plant species growing on contaminated sites in an urban environment successfully develop under strong anthropogenic pressure and thereby may have the potential for phytoremediation. The concentrations of potentially toxic metals were measured in leaves, roots, stems, and inflorescences of fifteen Brassicaceae plant species from the urban park of Botanical Garden of Komarov Botanical Institute. The potential of phytoextraction and phytostabilization of the species was evaluated considering the concentration of Cd, Cu, Ni, Pb, Zn in the plant organs, and the bioconcentration factor (BCF) and the translocation factor (TF). The metal content in plant organs varied with plant species. The study of metal accumulation in plants showed that 〈em〉Brassica campestris〈/em〉 has the potential for the simultaneous phytoextraction of three metals Zn, Cd, and Cu, and 〈em〉Rorippa palustris〈/em〉 – of two metals Zn and Cd. According to received data, species 〈em〉Sinapis arvensis〈/em〉 and 〈em〉Thlaspi arvense〈/em〉 can be considered adequate candidates for soil Zn and Pb phytostabilization and soil conservation.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0883-2927
    Electronic ISSN: 1872-9134
    Topics: Chemistry and Pharmacology , Geosciences
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  • 87
    Publication Date: 2019
    Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Weather and Climate Extremes, Volume 25〈/p〉 〈p〉Author(s): Jeremy Diaz, Maxwell B. Joseph〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Tornadoes are the most violent of all atmospheric storms. In a typical year, the United States experiences hundreds of tornadoes with associated damages on the order of one billion dollars. Community preparation and resilience would benefit from accurate predictions of these economic losses, particularly as populations in tornado-prone areas increase in density and extent. Here, we use a zero-inflated modeling approach and artificial neural networks to predict tornado-induced property damage using publicly available data. We developed a neural network that predicts whether a tornado will cause property damage (out-of-sample accuracy = 0.821 and area under the receiver operating characteristic curve, AUROC, = 0.872). Conditional on a tornado causing damage, another neural network predicts the amount of damage (out-of-sample mean squared error = 0.0918 and 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.svg"〉〈mrow〉〈msup〉〈mrow〉〈mi〉R〈/mi〉〈/mrow〉〈mrow〉〈mn〉2〈/mn〉〈/mrow〉〈/msup〉〈/mrow〉〈/math〉  = 0.432). When used together, these two models function as a zero-inflated log-normal regression with hidden layers. From the best-performing models, we provide static and interactive gridded maps of monthly predicted probabilities of damage and property damages for the year 2019. Two primary weaknesses include (1) model fitting requires log-scale data which leads to large natural-scale residuals and (2) beginning tornado coordinates were utilized rather than tornado paths. Ultimately, this is the first known study to directly model tornado-induced property damages, and all data, code, and tools are publicly available. The predictive capacity of this model along with an interactive interface may provide an opportunity for science-informed tornado disaster planning.〈/p〉〈/div〉 〈/div〉
    Electronic ISSN: 2212-0947
    Topics: Geography , Geosciences
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  • 88
    Publication Date: 2019
    Description: 〈p〉Publication date: Available online 6 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Solid Earth Sciences〈/p〉 〈p〉Author(s): C.C. Mgbolu, I.I. Obiadi, C.M. Obiadi, C.M. Okolo, P.E. Irumhe〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Field geological and geophysical (Vertical Electrical Sounding VES) survey data were used in investigating groundwater potentials, aquifer characteristics and vulnerability in parts of Ndokwa area, Niger Delta, Nigeria. Data from twenty-one (21) representative VES survey points using Schlumberger configuration were acquired, processed and interpreted. Pumping test data and litho-log data from existing boreholes in the area were used to constrain interpretation and correlation of the VES results. The results revealed five to six geo-electric layers/units across the study area. The subsurface lithology is predominantly sandstone intercalated, in some cases, with clay, sandy clay, and clayey sand. Results also revealed the average depth to aquifer as 71.91 m (10.33–173.97 m); average aquifer thickness as 42.52 m (4.7–149.7 m) and average aquifer resistivity value as 1289 Ωm (470.84–2697.7 Ωm). Average overburden thickness was estimated to be 28.53 m (4.28–62.44 m). Aquifer characteristics derived from the VES results gave average calculated aquifer transmissivity value as 1162.31 m〈sup〉2〈/sup〉/day (129.54–4181.31 m〈sup〉2〈/sup〉/day), and average calculated aquifer hydraulic conductivity as 27.28 m/day (25.69–28.92 m/day). Longitudinal conductance values range of 0.006–0.137 were recorded from geo-electric field survey data in the area, indicating dominance of sand and sparse distribution of clay; and suggesting that the Aquifer Protective Capacity APC of the overburden above the aquifers in the study area is mostly poor to weak and prone to contamination from infiltration. The DRASTIC model was applied to ascertain the DRASTIC Index and compute aquifer vulnerability distribution of the area; and it revealed that the study area is characterised by low – moderate – high vulnerability at different locations. Topsoil corrosivity studies showed that topsoil in the area is practically non-corrosive to slightly corrosive. The results of this study have implications for groundwater resources development and management in the study area.〈/p〉〈/div〉 〈/div〉
    Electronic ISSN: 2451-912X
    Topics: Geosciences
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  • 89
    Publication Date: 2019
    Description: 〈p〉Publication date: Available online 5 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soils and Foundations〈/p〉 〈p〉Author(s): Toshihiro Noda, Tomohiro Toyoda〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Most soil–water coupled analyses of saturated soil are based on the 〈strong〉〈em〉u〈/em〉〈/strong〉–〈em〉p〈/em〉 formulation, where a set of equations is reduced by assuming that the acceleration of the fluid phase relative to that of the solid phase is less than that of the solid phase. Therefore, this analysis cannot be used for a coupled analysis with dynamic water flow in highly permeable soil. This study aims to present a soil–water coupled finite deformation analysis method based on full formulation, or 〈strong〉〈em〉u〈/em〉〈/strong〉–〈strong〉〈em〉w〈/em〉〈/strong〉–〈em〉p〈/em〉 formulation. This method differs from conventional methods in the following ways: (1) the governing equations explicitly include the equation of motion for the fluid phase, (2) a relative convective term is used to describe a change in the relative configuration between the two phases, and (3) the moving/inclined discharge boundary is directly implemented to the discretized governing equations. Herein, one/two dimensional seepage and plane-strain deformation analysis results are reported. In the seepage analysis, accelerating permeation of pore water is obtained and the undrained constraint condition is verified. In the deformation analysis, dynamic migration in a high permeable soil specimen, i.e., wave propagation and rotational flow of pore water, is observed.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0038-0806
    Topics: Architecture, Civil Engineering, Surveying , Geosciences
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  • 90
    Publication Date: 2019
    Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 92〈/p〉 〈p〉Author(s): Yang Hu, Wei-Chao Chen, Yu-Feng Shen, Bin Zhu, Gao-Xue Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Viral diseases in aquaculture were challenging because there are few preventative measures and/or treatments. Our previous study indicated that imidazole arctigenin derivatives possessed antiviral activities against infectious hematopoietic necrosis virus (IHNV). Based on the structure-activity relationship in that study, a new imidazole arctigenin derivative, 4-(8-(2-ethylimidazole)octyloxy)-arctigenin (EOA), was designed, synthesized and its anti-IHNV activity was evaluated. By comparing inhibitory concentration at half-maximal activity (IC〈sub〉50〈/sub〉), we found that EOA (IC〈sub〉50〈/sub〉 = 0.56 mg/L) possessed a higher antiviral activity than those imidazole arctigenin derivatives in our previous study. Besides, EOA could significantly decrease cytopathic effect (CPE) and viral titer induced by IHNV in epithelioma papulosum cyprinid (EPC) cells. In addition, EOA significantly inhibited apoptosis induced by IHNV in EPC cells. Further data verified that EOA inhibited IHNV replication in rainbow trout, with reducing 32.0% mortality of IHNV-infected fish. The results suggested that EOA was more stable with a prolonged inhibitory half-life in the early stage of virus infection (1–4 days). Consistent with above results, EOA repressed IHNV glycoprotein gene expression in virus sensitive tissues (kidney and spleen) in the early stage of virus infection. Moreover, histopathological evaluation showed that tissues from the spleen and kidney of fish infected with IHNV exhibited pathological changes. But there were no lesions in any of the tissues from the control group and EOA-treaten group. In accordance with the histopathological assay, EOA could elicited anti-inflammation response in non-viral infected rainbow trout by down-regulating the expression of cytokine genes (〈em〉IL-8〈/em〉, 〈em〉IL-12p40〈/em〉, and 〈em〉TNF-α〈/em〉). Altogether, EOA was expected to be a therapeutic agent against IHNV infection in the field of aquaculture.〈/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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  • 91
    Publication Date: 2019
    Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Hydrology: Regional Studies, Volume 24〈/p〉 〈p〉Author(s): Johnson U. Kitheka〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉 〈h6〉Study region〈/h6〉 〈p〉This study was undertaken in the Athi-Sabaki river basin in Kenya in East Africa.〈/p〉 〈/div〉 〈div〉 〈h6〉Study focus〈/h6〉 〈p〉The study focused on the determination of the influence of streamflow variability on salt fluxes. This involved monitoring of river discharge and river salinity in the period between 2012 and 2018.〈/p〉 〈/div〉 〈div〉 〈h6〉New hydrological insights〈/h6〉 〈p〉: This study demonstrates that Athi-Sabaki river discharges significant quantity of salt to the sea. There are significant seasonal and inter-annual variations in salt fluxes that are due to variations in river discharge and rainfall in the basin. The relationship between streamflow variations and variations of salinity in the river was inverse with highest salinity concentrations and fluxes occurring during low flow conditions. The river salinity and TDS concentrations decreased with an increase in river discharge due to dilution effect and flushing of salt from the river. The highly polluted sub-basins draining through the City of Nairobi exhibited relatively higher salinity and salt fluxes as compared to non-polluted ones draining rural areas. The total salt flux in the basin ranged between 29 × 10〈sup〉3〈/sup〉 and 261 × 10〈sup〉3〈/sup〉 tons year〈sup〉−1〈/sup〉. The relatively high salinity and salt fluxes were attributed to the discharge of wastewaters, seepage of groundwater and irrigation return flows. The study calls for water pollution control, sustainable irrigation and landuse practices in the basin.〈/p〉 〈/div〉
    Print ISSN: 2214-5818
    Topics: Architecture, Civil Engineering, Surveying , Geography , Geosciences
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  • 92
    Publication Date: 2019
    Description: 〈p〉Publication date: Available online 5 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soils and Foundations〈/p〉 〈p〉Author(s): Yiqun Tang, Siqi Xiao, Yangjie Zhan〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉More and more excavation projects are being performed near existing buildings and structures due to large-scale urban construction, in which the excavation unavoidably causes settlement and potential danger to the surrounding construction and buildings. For linear traffic facilities parallel to the excavation, the settlement profile parallel to the excavation, namely, the settlement along the traffic line, should also be considered. Moreover, the precise control of the differential settlement along the traffic lines also plays a very important role. Thus, it is necessary to establish a quick prediction model, which is able to consider both vertical and parallel settlement profiles, using the basic information on the excavation. Based on the large amount of field data, the characteristics of the settlement profiles are analyzed. A simplified empirical method is proposed; it is established based on the Rayleigh and Gauss distribution functions for predicting the ground settlement along railways induced by an excavation. Meanwhile, back-propagation neural networks are also used to predict the settlement behavior. A comparison between the predicted results and the monitoring data is given to verify the feasibility of the proposed method. A good agreement indicates that the proposed method can be employed to predict the settlement along railways due to an adjacent excavation.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0038-0806
    Topics: Architecture, Civil Engineering, Surveying , Geosciences
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  • 93
    Publication Date: 2019
    Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 92〈/p〉 〈p〉Author(s): Junjun He, Haiying Liang, Jiaping Zhu, Xiaochen Fang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Antibacterial peptides (AMPs) constitute an important part of the body's innate immune system and are responsible for a wide range of inhibitory effects against pathogens such as bacteria, fungi, and viruses. In this study, multi-step high performance liquid chromatography (HPLC), combined with Mass Spectrometry (MS), was used to isolate and identify proteins with antibacterial activity from the serum of 〈em〉Pinctada fucata martensii〈/em〉 (〈em〉P.f. Martensii〈/em〉) and obtain a component named 〈em〉P.f. Martensii〈/em〉 antimicrobial peptide-1 (PmAMP-1). 〈em〉PmAMP-1〈/em〉 cDNA was cloned and sequenced by rapid amplification of cDNA ends (RACE) and mRNA expression of was analyzed by quantitative real-time PCR (qRT-PCR). From the results of this study, full-length 〈em〉PmAMP-1 c〈/em〉DNA was shown to be 700 base pairs (bp) long with an open reading frame (ORF) of 294 bp, encoding 97 amino acids with a predicted structure that is mostly α-helices. 〈em〉PmAMP-〈/em〉1 mRNA was constitutively expressed in all tested tissues including the adductor muscle, mantle, hepatopancreas, gill, gonads and hemocytes. The highest level of 〈em〉PmAMP-〈/em〉1 transcription was observed at 8 h and 2 h after bacterial challenge in hemocytes and adductor muscle (p 〈 0.01), respectively. Furthermore, PmAMP-1 caused significant morphological alterations in 〈em〉E. coli,〈/em〉 as shown by transmission electron microscopy (TEM). The results from this study provide a valuable base for further exploration of molluscan innate immunity and immune 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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  • 94
    Publication Date: 2019
    Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Magnetic Resonance, Volume 305〈/p〉 〈p〉Author(s): A. Gallo, W.T. Franks, J.R. Lewandowski〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We present a suite of two-receiver solid-state NMR experiments for backbone and side chain resonance assignment. The experiments rely on either dipolar coupling or scalar coupling for polarization transfer and are devised to acquire a 〈sup〉1〈/sup〉H–detected 3D experiment AND a nested 〈sup〉13〈/sup〉C–detected 2D from a shared excitation pulse. In order to compensate for the lower sensitivity of detection on 〈sup〉13〈/sup〉C nucleus, 2D rows are signal averaged during 3D planes. The 3D dual receiver experiments do not suffer from any appreciable signal loss compared to their single receiver versions and require no extra optimization. The resulting data is higher in information content with no additional experiment time. The approach is expected to become widespread as multiple receivers become standard for new NMR spectrometers.〈/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-S1090780719301302-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉
    Print ISSN: 1090-7807
    Electronic ISSN: 1096-0856
    Topics: Medicine , Physics
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  • 95
    Publication Date: 2019
    Description: 〈p〉Publication date: August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Magnetic Resonance, Volume 305〈/p〉 〈p〉Author(s): Ibrahim A. Elabyad, M. Terekhov, M.R. Stefanescu, D. Lohr, M. Fischer, L.M. Schreiber〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The design, simulation, assembly and testing of a novel dedicated antisymmetric transmit/receive (Tx/Rx) coil array to demonstrate the feasibility of cardiac magnetic resonance imaging (cMRI) in pigs at 7 T was described. The novel antisymmetric array is composed of eight elements based on mirrored and reversed loop orientations to generate varying 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.svg"〉〈mrow〉〈msubsup〉〈mi〉B〈/mi〉〈mrow〉〈mn〉1〈/mn〉〈/mrow〉〈mo〉+〈/mo〉〈/msubsup〉〈/mrow〉〈/math〉 field harmonics for RF shimming. The central four loop elements formed together a pair of antisymmetric L-shaped channels to allow good decoupling between all neighboring elements of the entire array. The antisymmetric array was compared to a standard symmetric rectilinear loop array with an identical housing dimension. Both arrays were driven in the parallel transmit (pTx) mode forming an 8-channel transmit and 16-channel receive (8Tx/16Rx) coil array, where the same posterior array was combined with both anterior arrays. The hardware and imaging performance of the dedicated cardiac arrays were validated and compared by means of electromagnetic (EM) simulations, bench-top measurements, phantom, and 〈em〉ex-vivo〈/em〉 MRI experiments with 46 kg female pig. Combined signal-to-noise ratio (SNR), geometry factor (g-factor), noise correlation maps, and high resolution 〈em〉ex-vivo〈/em〉 cardiac images were acquired with an in-plane resolution of 0.3 mm × 0.3 mm using both arrays. The novel antisymmetric array enhanced the SNR within the heart by about two times and demonstrated good decoupling and improved control of the 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.svg"〉〈mrow〉〈msubsup〉〈mi〉B〈/mi〉〈mrow〉〈mn〉1〈/mn〉〈/mrow〉〈mo〉+〈/mo〉〈/msubsup〉〈/mrow〉〈/math〉 field distributions for RF shimming compared to the standard coil array. Parallel imaging with acceleration factor (R) up to 4 was possible using the novel antisymmetric coil array while maintaining the mean g-factor within the heart region of 1.13.〈/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-S1090780719301284-ga1.jpg" width="356" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉
    Print ISSN: 1090-7807
    Electronic ISSN: 1096-0856
    Topics: Medicine , Physics
    Published by Elsevier
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  • 96
    Publication Date: 2019
    Description: 〈p〉Publication date: Available online 6 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Experimental Cell Research〈/p〉 〈p〉Author(s): Yan Zhang, Hongyan Wang, Tao Yin, Yue Liu, Wenchao Zhou, Xinbin Fan, Liang Wu, Chao Song, Jin Shao, Tieyi Yang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Transmembrane protein 18 (〈em〉Tmem18〈/em〉) is an obesity-associated gene essential for adipogenesis; however, its function in the osteogenic differentiation of bone marrow–derived mesenchymal stem cells (BMSCs) is still unclear. In this study, we found that 〈em〉Tmem18〈/em〉 was significantly downregulated in rat BMSCs after osteogenic induction. TMEM18 overexpression remarkably downregulated osteo-specific genes including alkaline phosphatase (〈em〉Alp〈/em〉), Runt˗related transcription factor 2 (〈em〉Runx2〈/em〉), osteocalcin (〈em〉Ocn〈/em〉), and osteopontin (〈em〉Opn〈/em〉), and reduced the number of mineral deposits and ALP activity 〈em〉in vitro〈/em〉, whereas knockdown of 〈em〉Tmem18〈/em〉 yielded the opposite results. 〈em〉In vivo〈/em〉 assays also indicated that TMEM18 knockdown BMSCs have an increased bone formation potential in a rat model of calvarial defects. Analyses of the mechanism suggested that TMEM18 overexpression decreased β-catenin expression, whereas the TMEM18 knockdown enhanced β-catenin expression and promoted its nuclear translocation. The positive effects on osteogenic differentiation of rat BMSCs owing to the TMEM18 knockdown were attenuated by β-catenin downregulation. Taken together, these results indicate that TMEM18 plays an inhibitory role in osteogenic differentiation of BMSCs via inactivation of β-catenin.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0014-4827
    Electronic ISSN: 1090-2422
    Topics: Biology , Medicine
    Published by Elsevier
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  • 97
    Publication Date: 2019
    Description: 〈p〉Publication date: Available online 5 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Experimental Cell Research〈/p〉 〈p〉Author(s): Olaf Strømme, Katarzyna M. Psonka-Antonczyk, Bjørn Torger Stokke, Anders Sundan, Carl-Jørgen Arum, Gaute Brede〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Multiple myeloma is an incurable cancer of antibody-producing plasma cells. Hepatocyte growth factor (HGF), a cytokine aberrantly expressed in half of myeloma patients, is involved in myeloma pathogenesis by enhancing myeloma growth and invasiveness, and may play a role in myeloma bone disease by inhibiting osteoblastogenesis. In this study, we investigated whether extracellular vesicles (EVs) may play a role in HGF signaling between myeloma cells and osteoblast-like target cells. EVs from the HGF-positive cell line JJN-3 and the HGF-negative cell line INA-6, and from bone marrow plasma and primary human myeloma cells, were isolated using sequential centrifugation techniques and the presence of HGF on the EV-surface was investigated with ELISA. EVs from both cell lines were added to an established bioassay where HGF is known to induce interleukin-11 secretion in osteoblast-like cells. Our results show that HGF was bound to the surface of JJN-3-derived EVs, while INA-6-derived EVs were negative for HGF. Only JJN-3-derived EVs induced IL-11 secretion in osteoblast-like recipient cells. When osteoblast-like cells were preincubated with a specific HGF-receptor (c-Met) inhibitor, no induction of interleukin-11 was observed. Downstream c-Met phosphorylation was demonstrated by immunoblotting. EVs isolated from bone marrow plasma and primary myeloma cells were HGF-positive for a subset of myeloma patients. Taken together, this work shows for the first time that HGF bound on the surface of myeloma-derived EVs can effectuate HGF/c-Met signaling in osteoblast-like cells. Myeloma-derived EVs may play a role in myeloma bone disease by induction of the osteoclast-activating cytokine interleukin-11 in osteoblasts.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0014482719303313-fx1.jpg" width="280" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉
    Print ISSN: 0014-4827
    Electronic ISSN: 1090-2422
    Topics: Biology , Medicine
    Published by Elsevier
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  • 98
    Publication Date: 2019
    Description: 〈p〉Publication date: Available online 5 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Experimental Cell Research〈/p〉 〈p〉Author(s): Kepeng Ou, Sonja Mertsch, Sofia Theodoropoulou, Jiahui Wu, Jian Liu, David A. Copland, Stefan Schrader, Lei Liu, Andrew D. Dick〈/p〉
    Print ISSN: 0014-4827
    Electronic ISSN: 1090-2422
    Topics: Biology , Medicine
    Published by Elsevier
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  • 99
    Publication Date: 2019
    Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Biomaterials, Volume 218〈/p〉 〈p〉Author(s): Yuwei Liu, Biao Kuang, Benjamin B. Rothrauff, Rocky S. Tuan, Hang Lin〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Mesenchymal stem cells (MSCs) embedded in their secreted extracellular matrix (mECM) constitute an exogenous scaffold-free construct capable of generating different types of tissues. Whether MSC-mECM constructs can recapitulate endochondral ossification (ECO), a developmental process during 〈em〉in vivo〈/em〉 skeletogenesis, remains unknown. In this study, MSC-mECM constructs are shown to result in robust bone formation both 〈em〉in vitro〈/em〉 and 〈em〉in vivo〈/em〉 through the process of endochondral ossification when sequentially exposed to chondrogenic and osteogenic cues. Of interest, a novel trypsin pre-treatment was introduced to change cell morphology, which allowed MSC-mECM constructs to undergo the N-cadherin-mediated developmental condensation process and subsequent chondrogenesis. Furthermore, bone formation by MSC-mECM constructs were significantly enhanced by the ECO protocol, as compared to conventional 〈em〉in vitro〈/em〉 culture in osteogenic medium alone. This was designed to promote direct bone formation as seen in intramembranous ossification (IMO). The developmentally informed method reported in this study represents a robust and efficacious approach for stem-cell based bone generation, which is superior to the conventional osteogenic induction procedure.〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0142-9612
    Electronic ISSN: 1878-5905
    Topics: Biology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Medicine
    Published by Elsevier
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  • 100
    Publication Date: 2019
    Description: 〈p〉Publication date: Available online 5 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Bioorganic & Medicinal Chemistry Letters〈/p〉 〈p〉Author(s): Gyeong Han Jeong, Jae-Hyeon Cho, Tae Hoon Kim〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Convenient structure modification of (+)-catechin (〈strong〉1〈/strong〉) induced by nonthermal dielectric barrier discharge (DBD) plasma treatment afforded three novel methylene-linked flavan-3-ol oligomers, methylenetetracatechin (〈strong〉2〈/strong〉), methylenetricatechin (〈strong〉3〈/strong〉), and methylenedicatechin (〈strong〉4〈/strong〉), together with two known catechin dimers, 〈em〉bis〈/em〉 8,8′-catechinylmethane (〈strong〉5〈/strong〉) and 〈em〉bis〈/em〉 6,8′-catechinylmethane (〈strong〉6〈/strong〉). The structures of the three new catechin oligomers 〈strong〉2〈/strong〉–〈strong〉4〈/strong〉 with methylene bridges were elucidated by detailed 1D- and 2D-NMR analysis, and the absolute configurations were established by the observation of circular dichroism (CD). The novel products 〈strong〉2〈/strong〉 and 〈strong〉3〈/strong〉 showed significantly enhanced anti-adipogenic capacities against both pancreatic lipase and differentiation of 3T3-L1 preadipocytes compared to the parent (+)-catechin.〈/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-S0960894X19304536-ga1.jpg" width="500" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉
    Print ISSN: 0960-894X
    Electronic ISSN: 1464-3405
    Topics: Chemistry and Pharmacology , Medicine
    Published by Elsevier
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