ALBERT

Description: Perceptual biases explain the origin and evolution of female preference in many species. Some responses that mediate mate choice, however, may have never been used in nonmating contexts. In the fiddler crab, Uca mjoebergi , mate-searching females prefer faster wave rates and leading wave; however, it remains unclear whether such responses evolved in a mating context (i.e., the preference has effect on the fitness of the female and her offspring that arise from mating with a particular male) or a nonmating contexts (i.e., a female obtains direct benefits through selecting the male with a more detectable trait). Here, we compared the preferences of mate-searching with those of ovigerous females that are searching for a burrow and do not concern about male “quality.” Results showed that as both mate-searching and ovigerous females preferentially approached robotic males with faster wave rates. This suggests that wave rate increases detectability/locatability of males, but the mating preference for this trait is unlikely to evolve in the mating context (although it may currently function in mate choice), as it does not provide fitness-related benefit to females or her offspring. Wave leadership, in contract, was attractive to mate-searching females, but not ovigerous females, suggesting that female preference for leadership evolves because wave leadership conveys information about male quality. We provide not only an empirical evidence of sensory biases (in terms of the preference for faster wave), but the first experimental evidence that mating context can be the only selection force that mediates the evolution of male sexual traits and female preference (in terms of the preference for leading wave). We experimentally investigated the origin of female preference of banana fiddler crabs. We showed that ovigerous females, who are unable to mate and should not concern about male quality, preferred males with fast wave rate, suggesting the preference for wave rate originated from perceptual bias, while these females had no preference for leading waves, suggesting leading wave evolves under mating context, conveying information about male quality.

Description: Host–parasite coevolution stems from reciprocal selection on host resistance and parasite infectivity, and can generate some of the strongest selective pressures known in nature. It is widely seen as a major driver of diversification, the most extreme case being parallel speciation in hosts and their associated parasites. Here, we report on endoparasitic nematodes, most likely members of the mermithid family, infecting different Timema stick insect species throughout California. The nematodes develop in the hemolymph of their insect host and kill it upon emergence, completely impeding host reproduction. Given the direct exposure of the endoparasites to the host's immune system in the hemolymph, and the consequences of infection on host fitness, we predicted that divergence among hosts may drive parallel divergence in the endoparasites. Our phylogenetic analyses suggested the presence of two differentiated endoparasite lineages. However, independently of whether the two lineages were considered separately or jointly, we found a complete lack of codivergence between the endoparasitic nematodes and their hosts in spite of extensive genetic variation among hosts and among parasites. Instead, there was strong isolation by distance among the endoparasitic nematodes, indicating that geography plays a more important role than host-related adaptations in driving parasite diversification in this system. The accumulating evidence for lack of codiversification between parasites and their hosts at macroevolutionary scales contrasts with the overwhelming evidence for coevolution within populations, and calls for studies linking micro- versus macroevolutionary dynamics in host–parasite interactions. We report on endoparasitic nematodes infecting different Timema stick insect species throughout California, and tested whether divergence among hosts may drive parallel divergence in the endoparasites. We found a complete lack of codivergence between the endoparasitic nematodes and their hosts. The accumulating evidence for lack of codiversification between parasites and their hosts at macroevolutionary scales contrasts with the overwhelming evidence for coevolution within populations and calls for studies linking micro- versus macroevolutionary dynamics in host–parasite interactions.

Description: Habitat degradation not only disrupts habitat-forming species, but alters the sensory landscape within which most species must balance behavioural activities against predation risk. Rapidly developing a cautious behavioural phenotype, a condition known as neophobia, is advantageous when entering a novel risky habitat. Many aquatic organisms rely on damage-released conspecific cues (i.e. alarm cues) as an indicator of impending danger and use them to assess general risk and develop neophobia. This study tested whether settlement-stage damselfish associated with degraded coral reef habitats were able to use alarm cues as an indicator of risk and, in turn, develop a neophobic response at the end of their larval phase. Our results indicate that fish in live coral habitats that were exposed to alarm cues developed neophobia, and, in situ , were found to be more cautious, more closely associated with their coral shelters and survived four-times better than non-neophobic control fish. In contrast, fish that settled onto degraded coral habitats did not exhibit neophobia and consequently suffered much greater mortality on the reef, regardless of their history of exposure to alarm cues. Our results show that habitat degradation alters the efficacy of alarm cues with phenotypic and survival consequences for newly settled recruits.

Description: Waterborne diseases have emerged as global health problems and their rapid and sensitive detection in environmental water samples is of great importance. Bacterial identification and enumeration in water samples is significant as it helps to maintain safe drinking water for public consumption. Culture-based methods are laborious, time-consuming, and yield false-positive results, whereas viable but nonculturable (VBNCs) microorganisms cannot be recovered. Hence, numerous methods have been developed for rapid detection and quantification of waterborne pathogenic bacteria in water. These rapid methods can be classified into nucleic acid-based, immunology-based, and biosensor-based detection methods. This review summarizes the principle and current state of rapid methods for the monitoring and detection of waterborne bacterial pathogens. Rapid methods outlined are polymerase chain reaction (PCR), digital droplet PCR, real-time PCR, multiplex PCR, DNA microarray, Next-generation sequencing (pyrosequencing, Illumina technology and genomics), and fluorescence in situ hybridization that are categorized as nucleic acid-based methods. Enzyme-linked immunosorbent assay (ELISA) and immunofluorescence are classified into immunology-based methods. Optical, electrochemical, and mass-based biosensors are grouped into biosensor-based methods. Overall, these methods are sensitive, specific, time-effective, and important in prevention and diagnosis of waterborne bacterial diseases. Waterborne diseases pose constant threats to public health. Therefore, public healthcare needs rapid, sensitive, and accurate detection of pathogens for the diagnosis and treatment.

Description: The main mechanism of toxicity of organophosphate (OP) and carbamate (CB) insecticides is their irreversible binding and inhibition of acetylcholinestrase (AChE), encoded by ace 1 (acetylcholinestrase gene 1), leading to eventual death of insects. Mutations in AChE may significantly reduce insects susceptibility to these pesticides. Bombyx mori is an important beneficial insect, and no OP- or CB-resistant strains have been generated. In this study, wild-type ace 1 ( wace 1) and mutant ace 1 ( mace 1) were introduced into Bm N cells, confirmed by screening and identification. The expression of wace 1 and mace 1 in the cells was confirmed by Western blot and their expression levels were about 21-fold higher than the endogenous ace 1 level. The activities of AChE in wace 1 and mace 1 transgenic cells were 10.6 and 20.2% higher compared to control cells, respectively. mace 1 transgenic cells had higher remaining activity than wace 1 transgenic cells under the treatment of physostigmine (a reversible cholinesterase inhibitor) and phoxim (an OP acaricide). The results showed that ace 1 transgene can significantly improve ace 1 expression, and ace 1 mutation at a specific site can reduce the sensitivity to AChE inhibitors. Our study provides a new direction for the exploration of the relationship between AChE mutations and drug resistance.

Description: Testicular germ cell tumors (TGCTs) are frequent solid malignant tumors and cause of death in men between 20–40 years of age. Genetic and environmental factors play an important role in the origin and development of TGCTs. Although the majority of TGCTs are responsive to chemotherapy, about 20% of patient presents incomplete response or tumors relapse. In addition, the current treatments cause acute toxicity and several chronic collateral effects, including sterility. The present mini-review collectively summarize the most recent findings on the new discovered molecular biomarkers such as tyrosine kinases, HMGAs, Aurora B kinase, and GPR30 receptor predictive of TGCTs and as emerging new possible molecular targets for therapeutic strategies. This article is protected by copyright. All rights reserved

Description: ABSTRACT Atrogin-1, an E3 ligase present in skeletal, cardiac and smooth muscle, down-regulates myocardin protein during skeletal muscle differentiation. Myocardin, the master regulator of smooth muscle cell (SMC) differentiation, induces expression of smooth muscle marker genes through its association with serum response factor (SRF), which binds to the CArG box in the promoter. Myocardin undergoes ubiquitylation and proteasomal degradation. Evidence suggests that proteasomal degradation of myocardin is critical for myocardin to exert its transcriptional activity, but there is no report about the E3 ligase responsible for myocardin ubiquitylation and subsequent transactivation. Here, we showed that overexpression of atrogin-1 increased contractility of cultured SMCs and mouse aortic tissues in organ culture. Overexpression of dominant-negative myocardin attenuated the increase in SMC contractility induced by atrogin-1. Atrogin-1 overexpression increased expression of the SM contractile markers while downregulated expression of myocardin protein but not mRNA. Atrogin-1 also ubiquitylated myocardin for proteasomal degradation in vascular SMCs. Deletion studies showed that atrogin-1 directly interacted with myocardin through its amino acids 284-345. Immunostaining studies showed nuclear localization of atrogin-1, myocardin and the Rpt6 subunit of the 26S proteasome. Atrogin-1 overexpression not only resulted in degradation of myocardin but also increased recruitment of RNA Polymerase II onto the promoters of myocardin target genes. In summary, our results have revealed the roles for atrogin-1 in the regulation of smooth muscle contractility through enhancement of myocardin ubiquitylation/degradation and its transcriptional activity. This article is protected by copyright. All rights reserved

Description: No abstract is available for this article.

Description: Three storm-scale ensemble prediction models (AROME-EPS, COSMO-DE-EPS, and MOGREPS-UK) were combined over Western Europe to create two convection-allowing, multi-model ensemble prediction systems (EPSs) with the goal of improving ensemble spread-skill relationships and probabilistic forecasting ability. A shared, uniform grid of _2.2 km resolution was used, containing two regions where model domains overlapped (AROME-EPS/COSMODE-EPS and AROME-EPS/MOGREPS-UK).Verification was conducted over a fivemonth period spanning two years using near-surface observations of wind, temperature, relative humidity and precipitation. Bias correction was also applied to each model in order to remove systematic error and to better assess the added value of the multi-model ensembles. Analyses of EPS errors and ensemble scores are presented, including comparisons between individual EPS and multi-model scores. Verification results show that the multi-model ensembles exhibit generally lower RMSE, increased spread, and improved ROC, ROCA, and Brier scores than the individual EPSs. In addition, a case study was selected to highlight discrepancies in precipitation frequency bias between the AROME-EPS and COSMODE-EPS models, attributable to differences in distribution and intensity of precipitation. When combined as a multi-model EPS, the sixhour precipitation accumulation forecast for this case study matched the observations better than the individual EPS forecasts. Together, these results highlight the potential advantage of using multiple models with differing dynamics and physics parameterizations when developing a convection-allowing EPS.

Description: The impact of assimilating lower–tropospheric lidar temperature profiles into a numerical weather prediction (NWP) model was investigated. The profiles were measured with the Temperature Rotational Raman Lidar (TRRL) of the University of Hohenheim on 24 April 2013. The day showed the development of a typical daytime planetary boundary layer (PBL) with no optically thick clouds. The Weather Research and Forecasting model was operated with 57 vertical levels covering Central Europe with 3 km horizontal resolution. Three different experiments were carried out with a rapid update cycle with hourly three–dimensional variational data assimilation. The impact run (ALL_DA) was performed with the assimilation of conventional data and the additional assimilation of TRRL profiles between 0900 and 1800 UTC in a height range from about 500 m to 3000 m above ground level with a vertical resolution of about 100 m. In CONV_DA and NO_DA, only conventional data and no data were assimilated, respectively. To consider the representativeness of the TRRL profiles, an observation error of 0.7 K was used for all heights. The assimilation was performed using the radiosonde operator. The TRRL data assimilation corrected the temperature profiles towards the lidar data. In the mean, the boundary layer height was improved by 60 m in ALL_DA compared to the TRRL data and the temperature gradient in the entrainment layer by 0.19 K (100 m) − 1 . While ALL_DA showed a root mean square error (RMSE) of 0.6 K compared to the TRRL data, the RMSE of CONV_DA was twice as large. Compared to data from radiosondes launched at the TRRL site, ALL_DA showed a significantly smaller RMSE than CONV_DA in two out of four times radiosonde data were available. We conclude that the assimilation of TRRL data has great potential to close the critical gap of missing temperature observations in the lower troposphere.

Description: Peroxidases (POXs) make up a large superfamily of enzymes that act in a wide range of biological mechanisms, including maintaining appropriate redox balances within cells, among other actions. In this study, we cloned a sequence that encodes a POX protein, SaPOX, from wheat aphids, Sitobion avenae . Amino acid sequence alignment showed the SaPOX sequence was conserved with POXs from other insect species. SaPOX mRNA accumulations were present in all nymphal and adult stages, at higher levels during the first and second instar, and lower during later stages in the life cycle. Ingestion of dsRNA specific to POX led to reduced SaPOX mRNA accumulation. Sitobion avenae nymphs continuously exposed to dietary dsPOX via an artificial diet led to reduced survival rate and ecdysis index. We infer that POX is important to maintain the growth and development of S. avenae .

Description: Earlier reports have established that chitin isolates from each body part of an insect cuticle can exhibit diverse physicochemical properties. But it is still unknown if the gender of the insect can influence characteristics of chitin isolates from different body parts. The present study addresses this question. As a result, important physicochemical differences in the chitin samples from different body parts of Melolontha sp. were recorded on the basis of sex. The chitin samples were extracted from eight different body parts (antennae, head, eyes, thorax, abdomen, elytra, hindwings, and legs) of female and male. The most remarkable variations in the chitin isolates from female and male body parts were recorded in chitin content, crystallinity, thermal stability, and surface morphology. And also it was wondered these chitin isolates from different body parts of female and male could find different applications. To check this hypothesis, the chitin samples from female and male were interacted with bovine serum albumin (BSA) protein and important variations were observed.

Description: Cholesterol is an important component for cell physiology. It regulates the fluidity of cell membranes and determines the physical and biochemical properties of proteins. In the central nervous system, cholesterol controls synapse formation and function and supports the saltatory conduction of action potential. In recent years, the role of cholesterol in the brain has caught the attention of several research groups since a breakdown of cholesterol metabolism has been associated with different neurodevelopmental and neurodegenerative diseases, and interestingly also with psychiatric conditions. The aim of this review is to summarize the current knowledge about the connection between cholesterol dysregulation and various neurologic and psychiatric disorders based on clinical and preclinical studies. This article is protected by copyright. All rights reserved

Description: Ebullition is an important pathway for methane emission from inland waters. However, the mechanisms controlling methane bubble formation and release in aquatic sediments remain unclear. A laboratory incubation experiment was conducted to investigate the dynamics of methane bubble formation, storage and release in response to hydrostatic head drops in three different types of natural sediment. Homogenized clayey, silty and sandy sediments (initially quasi-uniform through the depth of the columns) were incubated in chambers for three weeks. We observed three distinct stages of methane bubble formation and release: Stage I – formation of micro bubbles, displacing mobile water from sediment pores with negligible ebullition; Stage II – formation of large bubbles, displacing the surrounding sediment with concurrent increasing in ebullition; Stage III – formation of conduits, with relatively steady ebullition. The maximum depth-averaged volumetric gas content at steady state varied from 18.8% in clayey to 12.0% in silty and 13.2% in sandy sediment. Gas storage in the sediment columns showed a strong vertical stratification: most of the free gas was stored in an upper layer, whose thickness varied with sediment grain size. The magnitude of individual ebullition episodes was linearly correlated to hydrostatic head drop and decreased from clayey to sandy to silty sediment, and was in excess of that estimated from expansion alone indicating the release of porewater methane. These findings combined with a hydrodynamic model capable of determining dominant sediment type and depositional zones could help resolve spatial heterogeneities in methane ebullition at medium to larger scales in inland waters.

Description: Research on the subterranean CO 2 dynamics has focused individually on either surface soils or bedrock cavities, neglecting the interaction of both systems as a whole. In this regard, the vadose-zone contains CO 2 -enriched air ( ca. 5% by volume) in the first meters, and its exchange with the atmosphere can represent from 10 to 90% of total ecosystem CO 2 emissions. Despite its importance, to date still lacking are reliable and robust databases of vadose-zone CO 2 contents that would improve knowledge of seasonal-annual above-belowground CO 2 balances. Here we study two and a half years of vadose-zone CO 2 dynamics in a semi-arid ecosystem. The experimental design includes an integrative approach to continuously measure CO 2 in: vertical and horizontal soil profiles, following gradients from surface to deep horizons and from areas of net biological CO 2 production (under plants) to areas of lowest CO 2 production (bare soil), as well as a bedrock borehole representing karst cavities and ecosystem-scale exchanges. We found that CO 2 followed similar seasonal patterns for the different layers, with the maximum seasonal values of CO 2 delayed with depth (deeper more delayed). However, the behavior of CO 2 transport differed markedly among layers. Advective transport driven by wind induced CO 2 emission both in surface soil and bedrock, but with negligible effect on subsurface soil, which appear to act as a buffer impeding rapid CO 2 exchanges. Our study provides the first evidence of enrichment of CO 2 under plant, hypothesizing that CO 2 -rich air could come from root zone or by transport from deepest layers through cracks and fissures.

Description: ABSTRACT Delta progradation and sediment flux of the Pearl River Delta (PRD), southern China, during the Holocene are presented based on analyses of borehole data on the delta plain. Results indicate that the delta prograded into the drowned valley because of early Holocene inundation from 9 to 6 cal ka BP, as sea-level rise decelerated. The sea level reached its present level at about 6 cal ka BP and, as a consequence, a large portion of the drowned valley was covered by the estuary, with more than 160 rock islands and platforms. The scattered landmasses promoted active deposition and acted as deposition nuclei during deltaic evolution. Consequently, apart from exhibiting a general tendency towards progression, PRD development occurred less regularly over time and space because of deposition around island boundaries. During the last 2 ka, mainly because of significantly increased human activities, which have trapped sediments in the encircled tidal flats along the front of delta plains, the shoreline has advanced rapidly. Estimated sediment fluxes for the three periods (9–6, 6–2 and 2–0 cal ka BP), based on the sediment volume analysis, were 17–25, 22–30 and 44–58 million t a −1 , respectively.

Description: Watershed managers are challenged by the need for predictive temperature models with sufficient accuracy and geographic breadth for practical use. We described thermal regimes of New England rivers and streams based on a reduced set of metrics for the May to September growing season (July or August median temperature, diurnal rate of change, and magnitude and timing of growing season maximum) chosen through principal component analysis of 78 candidate metrics. We then developed and assessed spatial statistical models for each of these metrics, incorporating spatial autocorrelation based on both distance along the flow network and Euclidean distance between points. Calculation of spatial autocorrelation based on travel or retention time in place of network distance yielded tighter-fitting Torgegrams with less scatter but did not improve overall model prediction accuracy. We predicted monthly median July or August stream temperatures as a function of median air temperature, estimated urban heat island effect, shaded solar radiation, main channel slope, watershed storage (percent lake and wetland area), percent coarse-grained surficial deposits, and presence or maximum depth of a lake immediately upstream, with an overall root-mean-square prediction error of 1.4 and 1.5 ○ C, respectively. Growing season maximum water temperature varied as a function of air temperature, local channel slope, shaded August solar radiation, imperviousness, and watershed storage. Predictive models for July or August daily range, maximum daily rate of change, and timing of growing season maximum were statistically significant but explained a much lower proportion of variance than the above models (5-14% of total) . This article is protected by copyright. All rights reserved.

Description: Spontaneous counter-current imbibition into a finite porous medium is an important physical mechanism for many applications, included but not limited to irrigation, CO 2 storage and oil recovery. Symmetry considerations that are often valid in fractured porous media allow us to study the process in a one-dimensional domain. In 1D, the onset of imbibition can be captured by self-similar solutions and the imbibed volume scales with . At later times, the imbibition rate decreases and the finite size of the medium has to be taken into account. This requires numerical solutions. Here, we present a new approach to approximate the whole imbibition process semi-analytically. While the onset is captured by a semi-analytical solution. We also provide an a priori estimate of the time until which the imbibed volume scales with . This time is significantly longer than the time it takes until the imbibition front reaches the model boundary. The remainder of the imbibition process is obtained from a self-similarity solution. We test our approach against numerical solutions that employ parametrizations relevant for oil recovery and CO 2 sequestration. We show that this concept improves common first order approaches that heavily underestimate early-time behaviour and note that it can be readily included into dual porosity models. This article is protected by copyright. All rights reserved.

Description: Water extraction for anthropogenic use has become a major flux in the hydrological cycle. With increasing demand for water and challenges supplying it in the face of climate change, there is a pressing need to better understand connections between human populations, climate, water extraction, water use, and its impacts. To understand these connections, we collected and analyzed stable isotopic ratios of more than 800 urban tap water samples in a series of semiannual water surveys (spring and fall, 2013 to 2015) across the Salt Lake Valley (SLV) of northern Utah. Consistent with previous work, we found that mean tap water had a lower 2 H and 18 O concentration than local precipitation, highlighting the importance of nearby montane winter precipitation as source water for the region. However, we observed strong and structured spatiotemporal variation in tap water isotopic compositions across the region which we attribute to complex distribution systems, varying water management practices and multiple sources used across the valley. Water from different sources was not used uniformly throughout the area and we identified significant correlation between water source and demographic parameters including population and income. Isotopic mass balance indicated significant inter- and intra-annual variability in water losses within the distribution network due to evaporation from surface water resources supplying the SLV. Our results demonstrate the effectiveness of isotopes as an indicator of water management strategies and climate impacts within regional urban water systems, with potential utility for monitoring, regulation, forensic and a range of water resource research. This article is protected by copyright. All rights reserved.

Description: Cellular responses of Fe-limited Microcystis aeruginosa were investigated under nutrient-depleted and -replete conditions. Cellular growth, Fe quota and Fe uptake kinetics were examined in chemostat systems using nutrient-replete Fraquil * (where all nutrients except for Fe are present at sufficient level to achieve optimal growth) and nutrient-deplete Fraquil * (where some nutrients in addition to Fe are potentially growth-limiting factors). For both nutrient conditions, cellular Fe quota increased with increasing dilution rate in a manner consistent with Droop theory. However, the Fe quota in nutrient-deplete Fraquil * was determined to be lower, indicating lower cellular Fe requirement in the nutrient-depleted condition. Short-term Fe uptake assays indicated that cells acclimated in nutrient-replete conditions adjust to various degrees of Fe stress by solely increasing maximum Fe uptake rate, consistent with expected negative feedback regulation. In contrast, the maximum Fe uptake rate decreased with increasing degree of Fe limitation in the nutrient-depleted chemostat (particularly nitrate and molybdenum in this study). This non-negative feedback regulation is likely associated with lower Fe requirement for specific functions (e.g., intracellular nitrate reduction). Cellular affinity for Fe uptake and cellular size were independent of degree of Fe stress for both nutrient conditions.

Description: Carbon-to-chlorophyll a ratios (C:Chl a ; weight : weight) were analyzed for 7578 coastal seawater samples collected from Danish waters from 1990 to 2014. The aim was to identify the seasonal and spatial dynamics relative to nutrient richness and to study the effect of reduced nitrogen loadings over time. C:Chl a values were lowest during winter, about 15 across all stations. During the spring, C:Chl a increased to summer values between 20 and 96, depending on the annual mean of total nitrogen concentration. An inter-annual sinusoidal model with monthly time steps described the seasonal C:Chl a pattern well. The amplitudes of the model varied inversely with the annual mean of total nitrogen. Data also showed that a reduction in nitrogen loadings to the area by ∼ 40% over the past 24 yr, resulted in a statistically significant increase in mean annual C:Chl a values of 0.8 ± 0.2 yr −1 . The patterns derived from this large data set can be used to predict C:Chl a values for temperate coastal phytoplankton. Use of the empirical relationships derived from the data set improves predictions of C:Chl a values and thereby, e.g., carbon based food-web calculations and carbon-based ecosystem models, which often are validated using chlorophyll measurements.

Description: The study of cellular senescence and proliferative lifespan is becoming increasingly important because of the promises of autologous cell therapy, the need for model systems for tissue disease and the implication of senescent cell phenotypes in organismal disease states such as sarcopenia, diabetes and various cancers, among others. Here, we explain the concepts of proliferative cellular lifespan and cellular senescence, and we present factors that have been shown to mediate cellular lifespan positively or negatively. We review much recent literature and present potential molecular mechanisms by which lifespan mediation occurs, drawing from the fields of telomere biology, metabolism, NAD + and sirtuin biology, growth factor signaling and oxygen and antioxidants. We conclude that cellular lifespan and senescence are complex concepts that are governed by multiple independent and interdependent pathways, and that greater understanding of these pathways, their interactions and their convergence upon specific cellular phenotypes may lead to viable therapies for tissue regeneration and treatment of age-related pathologies, which are caused by or exacerbated by senescent cells in vivo. Replicative cellular lifespan is regulated by myriad cellular factors and processes, including telomeres, oxygen, DNA damage signaling, growth factors and metabolism. In this review, we will explain some of the molecular means by which these and other factors mediate cellular lifespan.

Description: Uncoupling proteins (UCPs) regulate mitochondrial function, and thus cellular metabolism. Angiotensin-converting enzyme (ACE) is the central component of endocrine and local tissue renin–angiotensin systems (RAS), which also regulate diverse aspects of whole-body metabolism and mitochondrial function (partly through altering mitochondrial UCP expression). We show that ACE expression also appears to be regulated by mitochondrial UCPs. In genetic analysis of two unrelated populations ( healthy young UK men and Scandinavian diabetic patients ) serum ACE (sACE) activity was significantly higher amongst UCP3-55C (rather than T) and UCP2 I (rather than D) allele carriers. RNA interference against UCP2 in human umbilical vein endothelial cells reduced UCP2 mRNA sixfold ( P  〈 0·01) whilst increasing ACE expression within a physiological range (〈1·8-fold at 48 h; P  〈 0·01). Our findings suggest novel hypotheses. Firstly, cellular feedback regulation may occur between UCPs and ACE. Secondly, cellular UCP regulation of sACE suggests a novel means of crosstalk between (and mutual regulation of) cellular and endocrine metabolism. This might partly explain the reduced risk of developing diabetes and metabolic syndrome with RAS antagonists and offer insight into the origins of cardiovascular disease in which UCPs and ACE both play a role. Uncoupling proteins (UCPs) regulate mitochondrial function, and thus cellular metabolism. Angiotensin-converting enzyme (ACE) is the central component of endocrine and local tissue renin–angiotensin systems, which also regulate diverse aspects of whole-body metabolism and mitochondrial function. We demonstrate that ACE expression appears to be regulated by mitochondrial UCPs.

Description: Positive transcription elongation factor (P-TEFb) plays an important role in host cell and viral gene expression. Many viruses, including Herpes Simplex Virus 1, have evolved strategies to hijack this key factor via their own regulatory proteins. The central role of P-TEFb in viral life cycles raises the possibility that Cdk9 inhibitors might be useful antiviral agents. See article “P-TEFb goes viral” by Justyna Zaborowska, Nur F. Isa and Shona Murphy in this issue.

Description: Tumors are often viewed as unique entities with specific behaviors. However, tumors are a mixture of differentially evolved subpopulations of cells in constant Darwinian evolution, selecting the fittest clone and allowing it to outgrow the rest. As in the natural environment, the niche defines the properties the fittest clones must possess. Therefore, there can be multiple fit clones because of the various microenvironments inside a single tumor. Hypoxia is considered to be a major feature of the tumor microenvironment and is a potential contributor to the cancer stem cell (CSC) phenotype and its enhanced tumorigenicity. The acidic microenvironment around hypoxic cells is accompanied by the activation of a subset of proteases that contribute to metastasis. Because of aberrant angiogenesis and the inaccessibility of their locations, hypoxic cells are less likely to accumulate therapeutic concentrations of chemotherapeutics that can lead to therapeutic resistance. Therefore, the targeting of the hypoxic CSC niche in combination with chemotherapy may provide a promising strategy for eradicating CSCs. In this review, we examine the cancer stem cell hypothesis and its relationship to the microenvironment, specifically to hypoxia and the subsequent metabolic switch and how they shape tumor behavior. Tumors are a mixture of differentially evolved subpopulations of cells in constant evolution. As in the natural environment, the niche defines the properties the fittest clones must possess. Therefore, there can be multiple fit clones because of the various microenvironments inside a single tumor. Hypoxia is considered to be a major feature of the tumor microenvironment and is a potential contributor to the cancer stem cell phenotype and its enhanced tumorigenicity.

Description: The tendency of ectotherms to get larger in the cold (Bergmann clines) has potentially great implications for individual performance and food web dynamics. The mechanistic drivers of this trend are not well understood, however. One fundamental question is to which extent variation in body size is attributed to variation in cell size, which again is related to genome size. In this study, we analyzed body and genome size in four species of marine calanoid copepods, Calanus finmarchicus , C. glacialis , C. hyperboreus and Paraeuchaeta norvegica , with populations from both south Norwegian fjords and the High Arctic. The Calanus species showed typical interspecific Bergmann clines, and we assessed whether they also displayed similar intraspecific variations—and if correlation between genome size and body size differed between species. There were considerable inter- as well as intraspecific variations in body size and genome size, with the northernmost populations having the largest values of both variables within each species. Positive intraspecific relationships suggest a functional link between body and genome size, although its adaptiveness has not been settled. Impact of additional drivers like phylogeny or specific adaptations, however, was suggested by striking divergences in body size – genome size ratios among species. Thus, C. glacialis and C. hyperboreus , had fairly similar genome size despite very different body size, while P. norvegica, of similar body size as C. hyperboreus, had the largest genome sizes ever recorded from copepods. The inter- and intraspecific latitudinal body size clines suggest that climate change may have major impact on body size composition of keystone species in marine planktonic food webs. Four calanoid copepods with populations from arctic and temperate waters, followed Bergmann clines in body size and with correspondingly larger genomes in northern populations, suggesting that body size at least partly is determined by cell size. Interspecific differences were more complex, pointing to phylogeny and life history traits as additional determinant of body size variation among species.

Description: This paper reports on a first attempt of using the virtual velocity approach to assess sediment mobility and transport in two wide and complex gravel-bed rivers of northern Italy. Displacement length and virtual velocity of spray-painted tracers were measured in the field. Also, the thickness of the sediment active layer during floods was measured using scour chains and post-flood morphological changes as documented by repeated survey of channel cross-sections. The effects of 8 and 7 floods were studied on the Tagliamento and Brenta rivers, where 259 and 277 spray-painted areas were surveyed, respectively. In the Tagliamento Rivers 36 % of the spray-painted areas experienced partial transport, whereas in the Brenta this accounted for 20%. Full removal/gravel deposition was whereas observed on 37 % and 26 % of these areas on the Tagliamento and Brenta rivers, respectively. The mean displacement length of particles, the thickness of the active layer and the extent of partial transport are well correlated with the dimensionless shear stress. The virtual velocity approach allowed calculation of bed material transport over a wide range of flood magnitudes. Annual coarse sediment transport was calculated up to 150 for the Tagliamento, and 30 × 10 3  m 3  yr -1 for the Brenta. The outcomes of this work highlight the relevance of partial transport condition, as it could represent more than 70% of the total bed material transported during low-magnitude floods, and up to 40% for near-bankfull events. Results confirm that bed material load tends to be overestimated by traditional formulas. This article is protected by copyright. All rights reserved.

Description: Bacteria are essential for many ecosystem services but our understanding of factors controlling their functioning is incomplete. While biodiversity has been identified as an important driver of ecosystem processes in macrobiotic communities, we know much less about bacterial communities. Due to the high diversity of bacterial communities, high functional redundancy is commonly proposed as explanation for a lack of clear effects of diversity. The generality of this claim has, however, been questioned. We present the results of an outdoor dilution-to-extinction experiment with four lake bacterial communities. The consequences of changes in bacterial diversity in terms of effective number of species, phylogenetic diversity and functional diversity were studied for (i) bacterial abundance, (ii) temporal stability of abundance, (iii) nitrogen concentration, and (iv) multifunctionality. We observed a richness gradient ranging from 15 to 280 operational taxonomic units. Individual relationships between diversity and functioning ranged from negative to positive depending on lake, diversity dimension and aspect of functioning. Only between phylogenetic diversity and abundance did we find a statistically consistent positive relationship across lakes. A literature review of 24 peer-reviewed studies that used dilution-to-extinction to manipulate bacterial diversity corroborated our findings: about 25% found positive relationships. Combined, these results suggest that bacteria-driven community functioning is relatively resistant to reductions in diversity. This article is protected by copyright. All rights reserved.

Description: As the prospect for more frequent and severe extreme weather events gains scientific support, many nations are evaluating mitigation and adaptation options. Insurance and home retrofits could reduce household welfare losses due to flood events. Yet, even after disasters, households often fail to take risk mitigation actions. This paper presents the first randomized field experiment that tests the effect of information provision on household uptake of flood insurance and home retrofits. A sample of 364 flood-prone households in Bangkok was randomly split into treatment and control groups. The treatment group received practical details on home retrofits and flood insurance as well as social information regarding the insurance purchase decisions of peers. Results indicate that the information intervention increased insurance purchases by about five percentage points, while no effect was detected for home retrofits. This effect is nearly equal to the increase in uptake that the national insurance program in Thailand has achieved through all other means since its establishment in 2012. If scaled up to include all uninsured, flood-prone households in Bangkok, nearly 70,000 additional households could be insured. The results suggest that well-designed information interventions could increase uptake of flood insurance, without additional premium subsidies or mandates. This article is protected by copyright. All rights reserved.

Description: The need to understand potential climate impacts and feedbacks in Arctic regions has prompted recent interest in modeling of permafrost dynamics in a warming climate. A new fine-scale integrated surface/subsurface thermal hydrology modeling capability is described and demonstrated in proof-of-concept simulations. The new modeling capability combines a surface energy balance model with recently developed three-dimensional subsurface thermal hydrology models and new models for nonisothermal surface water flows and snow distribution in the microtopography. Surface water flows are modeled using the diffusion wave equation extended to include energy transport and phase change of ponded water. Variation of snow depth in the microtopography, physically the result of wind scour, is modeled phenomenologically with a diffusion wave equation. The multiple surface and subsurface processes are implemented by leveraging highly parallel community software. Fully integrated thermal hydrology simulations on the tilted open book catchment, an important test case for integrated surface/subsurface flow modeling, are presented. Fine-scale 100-year projections of the integrated permafrost thermal hydrological system on an ice wedge polygon at Barrow Alaska in a warming climate are also presented. These simulations demonstrate the feasibility of microtopography-resolving, process-rich simulations as a tool to help understand possible future evolution of the carbon-rich Arctic tundra in a warming climate. This article is protected by copyright. All rights reserved.

Description: The annual North Atlantic spring bloom influences the ecology and biogeochemistry of the Atlantic Ocean. Diatoms dominate the peak of the bloom and significantly impact productivity and export of organic carbon from the bloom. Despite their key role in a yearly event with global impacts, the genetic diversity and population structure of diatoms that comprise the bloom are unknown. Here, we investigated the population genetics of the diatom Thalassiosira gravida sampled during the 2008 North Atlantic Bloom Experiment using newly developed microsatellite markers. High levels of genetic diversity (clonal diversity: 0.970; expected heterozygosity: 0.884) were observed across all water samples and did not change during the bloom. Four genetically distinct populations were identified ( F ST : 0.036–0.093) but were not associated with different water masses, depths, or time points during the bloom. Instead, all four populations co-existed within individual water samples, spanning different water masses, stages of the bloom, and depths of over 300 m. The co-existence of multiple, genetically distinct populations during the bloom event suggested large-scale admixture, with populations originating via transport from disparate locations combined with potential overwintering capacity in the water column or sediments. The pattern of co-existence suggests that the open ocean may serve as a gene pool that harbors different populations that are then available for selection to act upon, which may contribute to the ecological and biogeochemical success of diatoms and influence their long-term evolutionary survival.

Description: Eukaryotic gene expression is extensively controlled at the level of mRNA stability and the mechanisms underlying this regulation are markedly different from their archaeal and bacterial counterparts. We propose that two such mechanisms, nonsense-mediated decay (NMD) and motif-specific transcript destabilization by CCCH-type zinc finger RNA-binding proteins, originated as a part of cellular defense against RNA pathogens. These branches of the mRNA turnover pathway might have been used by primeval eukaryotes alongside RNA interference to distinguish their own messages from those of RNA viruses and retrotransposable elements. We further hypothesize that the subsequent advent of “professional” innate and adaptive immunity systems allowed NMD and the motif-triggered mechanisms to be efficiently repurposed for regulation of endogenous cellular transcripts. This scenario explains the rapid emergence of archetypical mRNA destabilization pathways in eukaryotes and argues that other aspects of post-transcriptional gene regulation in this lineage might have been derived through a similar exaptation route. mRNA turnover in eukaryotes is remarkably different from its prokaryotic counterparts and possible reasons underlying this divergence remain unclear. Here we propose that eukaryotic mRNA destabilization pathways evolved as a part of host defense against RNA pathogens and were subsequently repurposed for post-transcriptional regulation of cell-encoded genes.

Description: ABSTRACT Abstract: The level of storminess in Ireland during the winter of 2013/2014 was exceptional, the effects of which cost the Irish state in excess of €260 Million in infrastructure repair and insurance claims. In Ireland, a lack of coastal process data from monitoring programmes means that the response of protective barrier coasts to such events remains largely un-investigated. This study addresses this issue through an examination of the geomorphic impacts of recent storms, including those that occurred during the winter 2013/2014, on a breached barrier on the southwest coast of Ireland. Data from a two-year terrestrial laser scanning (TLS) monitoring campaign shows that the W2013/2014 events caused a major (〉50 m) dune recession at Rossbehy, Co. Kerry. Results from a simple linear regression analysis indicate storm duration plays an important role in the removal of foredunes at the study site. Given the fact that the frequency of intense storms in the vicinity of Ireland is forecast increase within the next century, a scientific understanding of barrier response to such events is critical to inform sound management practices. This article is protected by copyright. All rights reserved.

Description: Despite covering only approximately 138,000 km 2 , mangroves are globally important carbon sinks with carbon density values 3-4 times that of terrestrial forests. A key challenge in evaluating the carbon benefits from mangrove forest conservation is the lack of rigorous spatially resolved estimates of mangrove sediment carbon stocks; most mangrove carbon is stored belowground. Previous work has focused on detailed estimations of carbon stores over relatively small areas, which has obvious limitations in terms of generality and scope of application. Most studies have focused only on quantifying the top 1m of belowground carbon (BGC). Carbon stored at depths beyond 1m, and the effects of mangrove species, location and environmental context on these stores, is poorly studied. This study investigated these variables at two sites (Gazi and Vanga in the south of Kenya) and used the data to produce a country-specific BGC predictive model for Kenya and map BGC store estimates throughout Kenya at spatial scales relevant for climate change research, forest management and REDD+ (Reduced Emissions from Deforestation and Degradation). The results revealed that mangrove species was the most reliable predictor of BGC; Rhizophora muronata had the highest mean BGC with 1485.5t C ha −1 . Applying the species-based predictive model to a base map of species distribution in Kenya for the year 2010 with a 2.5m 2 resolution, produced an estimate of 69.41 Mt C (± 9.15 95% C.I.) for BGC in Kenyan mangroves. When applied to a 1992 mangrove distribution map, the BGC estimate was 75.65 Mt C (± 12.21 95% C.I.); an 8.3% loss in BGC stores between 1992 and 2010 in Kenya. The country level mangrove map provides a valuable tool for assessing carbon stocks and visualising the distribution of BGC. Estimates at the 2.5m 2 resolution provide sufficient detail for highlighting and prioritising areas for mangrove conservation and restoration. This article is protected by copyright. All rights reserved.

Description: Photodynamic therapy (PDT) is a non-thermal technique for inducing tumour damage following administration of a light-activated photosensitizing drug (PS). In a previous work we found that PDT induces cytoskeleton changes in HB4a-Ras cells (human mammary breast carcinoma HB4a cells transfected with the RAS oncogene). In the present work we have studied the migratory and invasive features and the expression of proteins related to these processes on HB4a-Ras cells after 3 successive cycles of PDT using different PSs: 5-aminolevulinic acid (ALA), Verteporfin (Verte), m -tetrahydroxyphenylchlorin ( m -THPC) and Merocyanine 540 (MC). A slight (1.25- to -2 fold) degree of resistance was acquired in cell populations subjected to the three successive PDT treatments. However, complete cell killing was achieved after a light dose increase. Regardless of the PS employed, all the PDT-treated populations had shorter stress fibres than the untreated control HB4a-Ras cells, and the number of dorsal stress fibres was decreased in the PDT-treated populations. E-Cadherin distribution, which was already aberrant in HB4a-Ras cells, became even more diffuse in the PDT-treated populations, though its expression was increased in some of them. The strong migratory and invasive ability of HB4a-Ras cells in vitro was impaired in all the PDT-treated populations, with a behaviour that was similar to the parental non-tumoral HB4a cells. MMP-2 and MMP-9 metalloproteinase activities were also impaired in the PDT-treated populations. The evidence presented herein suggests that the cells surviving PDT would be less metastatic than the initial population. These findings encourage the use of PDT in combination with other treatments such as intraoperative or post-surgery therapeutic procedures. This article is protected by copyright. All rights reserved

Description: ABSTRACT Nestin (+) -cardiomyocytes were identified in the ischemically damaged human/rodent heart, albeit the cellular source and signaling events implicated in the appearance of the intermediate filament protein remained undefined. Expression of the enhanced green fluorescent protein (EGFP) driven by the second intron of the nestin gene identified a subpopulation of EGFP/nestin (+) cells that differentiated to a vascular phenotype in the peri-infarct/infarct region of post-MI mice albeit the transgene was not detected in nestin (+) -cardiomyocytes. α-MHC-driven expression of the reporter mCherry was detected in troponin-T (+) - and nestin (+) -cardiomyocytes in the peri-infarct/infarct region of post-MI mice. However, the cell cycle re-entry of nestin/mCherry (+) -cardiomyocytes was not observed. Nestin staining was identified in a paucity of neonatal rat ventricular cardiomyocytes (NNVM). Exposure to phorbol 12, 13-dibutyrate (PDBu) induced NNVM hypertrophy but did not promote nestin expression or Brdu incorporation. PDBu treatment of NNVMs phosphorylated p38 MAPK and HSP27 and HSP27 phosphorylation was abrogated by the p38 MAPK inhibitor SB203580. PDBu/SB203580 co-treatment significantly increased the percentage of NNVMs that expressed nestin and incorporated Brdu. In the heart of embryonic 10.5 day mice, nestin was detected in cycling troponin-T (+) -cardiomyocytes. Nestin was also detected in embryonic rat ventricular cardiomyocytes and depletion of the intermediate filament protein attenuated cell cycle re-entry. Thus, nestin expressed by pre-existing cardiomyocytes following ischemic damage recapitulated in part an embryonic phenotype and may provide the requisite phenotype to initiate cell cycle re-entry. However, the overt activation of the p38 MAPK pathway post-MI may in part limit the appearance and inhibit the cell cycle re-entry of nestin (+) -cardiomyocytes. This article is protected by copyright. All rights reserved

Description: Oceanic and atmospheric global numerical models represent explicitly the large-scale dynamics while the smaller-scale processes are not resolved so that their effects in the large-scale dynamics are included through subgrid-scale parameterizations. These parameterizations represent small-scale effects as a function of the resolved variables. In this work, data assimilation principles are used not only to estimate the parameters of subgrid-scale parameterizations but also to uncover the functional dependencies of subgrid-scale processes as a function of large-scale variables. Two data assimilation methods based on the ensemble transform Kalman filter (ETKF) are evaluated in the two-scale Lorenz ’96 system scenario. The first method is an online estimation that uses the ETKF with an augmented space state composed of the model large-scale variables and a set of unknown global parameters from the parameterization. The second method is an offline estimation that uses the ETKF to estimate an augmented space state composed of the large-scale variables and by a space dependent model error term. Then a polynomial regression is used to fit the estimated model error as a function of the large-scale model variables in order to develop a parameterization of small-scale dynamics. The online estimation shows a good performance when the parameter-state relationship is assumed to be quadratic polynomial function. The offline estimation captures better some of the highly nonlinear functional dependencies found in the subgrid-scale processes. The nonlinear and nonlocal dependence found in an experiment with shear-generated small-scale dynamics is also recovered by the offline estimation method. Therefore, the combination of these two methods could be a useful tool for the estimation of the functional form of subgrid-scale parameterizations.

Description: Large-eddy simulation of a nocturnal stratocumulus-topped boundary layer in a continental mid-latitude environment has been performed to examine the sensitivity of the cloud to a number of different environmental parameters. The simulations showed that the stratocumulus cloud was strongly affected by the presence of an overlying free tropospheric cirrus cloud (FTC), in agreement with previous studies of marine nighttime stratocumulus. When introducing an FTC with an optical thickness of 2, stratocumulus liquid water path decreased by 30%. Enhancing the optical thickness of the FTC to 8 further decreased the liquid water path by almost 10%. The presence of an FTC decreased the cloud-top radiative cooling which decreased the turbulent mixing in the boundary layer so that the liquid water content and cloud depth were reduced. The sensitivity of the stratocumulus cloud to an overlying FTC was found to be affected by the moisture content in the free troposphere. When a clear positive or negative moisture gradient above the inversion was imposed, and an overlying FTC with an optical thickness of 8 was introduced, the stratocumulus cloud LWP decreased by more than 40%. Furthermore, the effect of changes in free tropospheric moisture content and an overlying FTC on the stratocumulus cloud properties was found to be non-linear, the combined response was in general weaker than the two responses added together. The modeled response to changes in cloud condensation nuclei (CCN) concentrations was found to be non-significant, unless the CCN concentrations were so low that drizzle was induced (r 50 cm −3 ).

Description: ABSTRACT The specification of model parameters in numerical weather prediction (NWP) models has great influence on model performance. However, how to specify model parameters properly is not a trivial task because a typical NWP model like the Weather Research and Forecasting (WRF) model contains many model parameters and many model outputs. This paper presents the results of an investigation into the sensitivities of different WRF model outputs to the specification of its model parameters. Using a global sensitivity analysis method, the sensitivities are evaluated for surface meteorological variables such as precipitation, surface air temperature, humidity and wind speed, as well as for atmospheric variables such as total precipitable water, cloud cover, boundary layer height and outgoing longwave radiation at the top of the atmosphere, all simulated by the WRF model using different model parameters. The goal of this study is to identify the parameters that exert most influence on the skill of short-range meteorological forecasts. The study was performed over the Greater Beijing Region of China. A total of 23 adjustable parameters from seven different physical parameterization schemes were considered. The results indicate that parameter sensitivities vary with different model outputs. However, some of the 23 model parameters considered are shown to be sensitive to all model outputs evaluated, while other parameters may be sensitive to a particular output. The sensitivity results from this research are a basis for further optimizations of the WRF model parameters.

Description: Soma to germline inheritance of extrachromosomal genetic information. Non-Mendelian transgenerational inheritance is a growingly recognized phenomenon, yet still elusive in its molecular nature . On pages 726–733 of this issue, Corrado Spadafora proposes a model, whereby extrachromosomal genetic information released form somatic cells can cross the Weismann barrier and become internalized in epididymal spermatozoa, which thereafter mediate the acquisition of new traits in the offspring at fertilization. The sperm endogenous reverse transcriptase (RT) plays a key role in developmental control. Sperm cells therefore act as recipients, and at the same time transgenerational vectors, of somatically derived genetic information, which they pass to the next generation in a non chromosomally-integrated form, yet with the potential to modify the fate of the developing embryos.

Description: Forest ecosystems play an important role in the global cycling of mercury (Hg). In this study, we characterized the Hg cycling at a remote evergreen broadleaf (EB) forest site in southwest China (Mt. Ailao). The annual Hg input via litterfall is estimated to be 75.0 ± 24.2 µg m -2 yr -1 at Mt. Ailao. Such a quantity is up to one order of magnitude greater than those observed at remote temperate/boreal (T/B) forest sites. Production of litter biomass is found to be the most influential factor causing the high Hg input to the EB forest. Given their large areal coverage, Hg deposition through litterfall in EB forests is appropriately 9 ± 5 Mg yr -1 in China and 1086 ± 775 Mg yr -1 globally. The observed wet Hg deposition at Mt. Ailao is 4.9 ± 4.5 µg m -2 yr -1 , falling in the lower range of those observed at 49 T/B forest sites in North America and Europe. Given the data, the Hg deposition flux through litterfall is approximately 15 times higher than the wet Hg deposition at Mt. Ailao. Steady Hg accumulation in decomposing litter biomass and Hg uptake from the environment were observed during a 25-month litter decomposition. The size of the Hg pool in the organic horizon of EB forest floors is estimated to be up to 2-10 times the typical pool size in T/B forests. This study highlights the importance of EB forest ecosystems in global Hg cycling, which requires further assessment when more data become available in tropical forests.

Description: Salt marshes provide numerous valuable ecological services. In particular, nitrogen (N) removal in salt marsh sediments alleviates N loading to the coastal ocean. N removal reduces the threat of eutrophication caused by increased N inputs from anthropogenic sources. It is unclear, however, whether chronic nutrient over-enrichment alters the capacity of salt marshes to remove anthropogenic N. To assess the effect of nutrient enrichment on N cycling in salt marsh sediments, we examined important N cycle pathways in experimental fertilization plots in a New England salt marsh. We determined rates of nitrification, denitrification, and dissimilatory nitrate reduction to ammonium (DNRA) using sediment slurry incubations with 15 N labeled ammonium or nitrate tracers under oxic headspace (20% oxygen / 80% helium). Nitrification and denitrification rates were more than ten-fold higher in fertilized plots compared to control plots. By contrast, DNRA, which retains N in the system, was high in control plots but not detected in fertilized plots. The relative contribution of DNRA to total nitrate reduction largely depends on the carbon/nitrate ratio in the sediment. These results suggest that long-term fertilization shifts N cycling in salt marsh sediments from predominantly retention to removal.

Description: Beet Armyworm, Spodoptera exigua is a herbivorous moth and a serious pest of many economically important plants, which are used as food sources. Because of rigorous standards of food quality, usage of synthetic insecticides in crop protection, against pests, is limited. Solanaceae plant extracts may be a relatively cheap source of efficient natural insecticides that can limit usage of synthetic substances. Their biological activity is not fully known. In particular, ultrastructural studies, using transmission electron microscopy, are not usual. In the present article we describe the effects of sublethal concentrations of tomato and potato leaf extracts against S. exigua . Acute lethal effects were not observed. Both extracts exerted similar effects within midgut and fat body cells. Midgut cells were not significantly altered while fat body cells showed prominent swelling of nuclear envelope and endoplasmic reticulum, vacuolization of mitochondria and fusion of fat droplets. These changes were much more intensive within groups exposed to potato than tomato extracts at highest concentration at least. Light microscopy was used to observe and document developmental alterations of S. exigua exposed to potato and tomato leaf extracts. Potato leaf extracts significantly decreased hatching success and caused morphological malformations of imagoes. Among them, malformations of wings were the most prominent. Interestingly, these effects were not observed within populations exposed to tomato extracts at highest concentration at least.

Description: In this study, two full-length cDNA sequences ( Cmace1 and Cmace2 ) encoding putative acetylcholinesterases (AChEs) were cloned and characterized from the rice leaffolder, Cnaphalocrocis medinalis , an important lepidopteran rice pest in Asia. Cmace1 encodes a CmAChE1 consisting of 689 amino acid residues, while Cmace2 encodes a 639 amino acids CmAChE2. The two CmAChEs both have N-terminal signal peptides and conserved motifs including the catalytic triad, choline-binding sites, oxianion hole, acyl pocket, peripheral anionic subsite, and the characteristic FGESAG motif and conserved 14 aromatic amino acids. Phylogenetic analysis showed that Cmace1 and Cmace2 are clustered into distinct clusters that are completely diverged from each other. Reverse-transcription quantitative PCR analysis revealed that Cmace1 and Cmace2 were predominately expressed in the larval brain and at the fifth-instar larvae stage, and the transcription levels of Cmace1 were significantly higher than those of Cmace2 in all the tested samples. Recombinant CmAChE1 and CmAChE2 were heterologously expressed in baculovirus system. Using acetylthiocholine iodide (ATChI) as substrate, the Michaelis constant ( K m ) values of rCmAChE1 and rCmAChE2 were 39.81 ± 6.49 and 68.29 ± 6.72 μmol/l, respectively; and the maximum velocity ( V max ) values of the two rCmAChEs were 0.60 ± 0.02 and 0.31 ± 0.06 μmol/min/mg protein, respectively. Inhibition assay indicated that rCmAChE1 was more sensitive to the organophosphate insecticides chlorpyrifos and triazophos than rCmAChE2. This study is the first report of molecular cloning and biochemical characterization of two acetylcholinesterase genes/enzymes in C. medinalis .

Description: In Gryllus bimaculatus, the size of the caecum decreases in the latter half of each instar to a stable minimal size with a steady minimal rate of digestive enzyme secretion until feeding resumes after ecdysis. The higher the percent protein in the newly ingested food, the faster and larger the caecum grows, and as a consequent the higher the secretion rate of trypsin and amylase. When hard boiled eggs (40% protein) are eaten the caecum is 2× larger, the trypsin secretion is almost 3× greater, and amylase 2.5× greater then when fed the same amount of apples (1.5% protein). Only dietary protein increases amylase secretion, whereas dietary carbohydrates have no effect on amylase secretion. The minimal caecal size and secretion rate must be supported by utilization of hemolymph amino acids, but the growth of the caecum and increasing enzymes secretions after the molt depend upon an amino acid source in the lumen. This simple regulation of digestive enzyme secretion is ideal for animals that must stop feeding in order to molt. This basic control system does not preclude additional regulation mechanisms, such as prandal, which is also indicated for G. bimaculatus, or even paramonal regulation.

Description: The degree of ecological specialization plays a crucial role in shaping the structure and functioning of communities. However, comparing specialization within and among groups of organisms is complicated due to methodological issues but also by conceptual and terminological inconsistencies. Environmental predictability has been considered a key determinant of specialization though empirical evidence is still limited. Fungi and their insect consumers provide a poorly studied but promising system to measure host specialization and test the predictability hypothesis. In this study we systematically sampled mushrooms in North European boreal forest, and reared total samples of fungivores colonizing the fruitbodies. Due to the unpredictable nature of mushrooms as a resource, low levels of host specialization can be predicted for these insects which have indeed widely been considered polyphagous. Contrary to expectations, majority of the studied fungus gnats were found not to exploit their host taxa indiscriminately. Not only were some mushroom taxa never colonised, but also the infestation rate of acceptable hosts differed in most of these fungivores. Gnat species themselves formed continua with respect to the estimates of the degree of specialization, derived from parametric individual-based analyses of presence-absence data. In most cases, host use was best explained by models in which the hosts were classified at genus level, with limited support to specialization to particular host species, families or orders. Indeed, most of the common fungivores appeared to preferentially use various species from one or a few mushroom genera while occasionally feeding on members of other host taxa. This pattern has likely evolved as a compromise between selective forces stemming from host unpredictability, and taxon-specific chemical profiles of the mushrooms. Our study highlights the multidimensional nature of ecological specialization: a high number of acceptable hosts does not preclude considerable discrimination among members of the available resource pool. Such situations can only be revealed by individual-based analyses capable of capturing differences in partner-to-partner interaction intensities. This article is protected by copyright. All rights reserved.

Description: Prey at risk of predation may experience stress and respond physiologically by altering their metabolic rates. Theory predicts that such physiological changes should alter prey nutrient demands from N-rich to C-rich macronutrients and shift the balance between maintenance and growth/reproduction. Theory further suggests that for ectotherms, temperature stands to exacerbate this stress. Yet, the interactive effects of predation stress and temperature stress on diet, metabolism, and survival of ectotherms are not well known. This knowledge gap was addressed with a laboratory study in which wild juvenile grasshoppers were collected, assigned to one of three groups, and raised at three different temperatures. All grasshoppers had access to equal quantities of two diets composed of opposite carbohydrate:protein ratios. Half of the individuals in each temperature group were exposed to predation risk cues from spider predators, while the other half were kept in risk free conditions. Grasshoppers consumed more carbohydrates when exposed to predation risk, but consumption favored greater protein intake as temperature increased. Moreover, the difference in carbohydrate intake between risk cue and risk free treatments diminished as temperature increased. Furthermore, variability between individual consumption patterns both within and between treatments decreased markedly as temperature increased, suggesting that higher temperatures promote more consistent individual consumption behaviors. Grasshoppers grew faster and larger as temperature increased, which translated into higher survival rates at higher temperatures. Warmer grasshoppers also did not alter their metabolic rates in response to predation risk cues, in contrast to colder grasshoppers. Digestive efficiency increased with temperature as well, further indicating that lower temperatures were much more stressful than higher temperatures for grasshoppers. The study shows that physiological responses of ectothermic herbivores to predation stress are highly plastic and temperature dependent, with higher temperatures promoting increased protein intake, growth, development, survival, and digestive efficiency relative to colder temperatures. These findings help to reconcile why dietary responses (proportion of protein vs. carbohydrate intake) to predation stress may vary among different prey taxa studied previously. This article is protected by copyright. All rights reserved.

Description: Contradictory evidence from biogeomorphological studies has increased the debate on the extent of lichen contribution to differential rock surface weathering in both natural and cultural settings. This study, undertaken in Côa Valley Archaeological Park, aimed at evaluating the effect of rock surface orientation on the weathering ability of dominant lichens. Hyphal penetration and oxalate formation at the lichen-rock interface were evaluated as proxies of physical and chemical weathering, respectively. A new protocol of pixel-based supervised image classification for the analysis of periodic acid-Schiff stained cross-sections of colonized schist revealed that hyphal spread of individual species was not influenced by surface orientation. However, hyphal spread was significantly higher in species dominant on north-west facing surfaces. An apparently opposite effect was noticed in terms of calcium oxalate accumulation at the lichen-rock interface, detected by Raman spectroscopy and complementary X-ray microdiffraction on south-east facing surfaces only. These results suggest that lichen-induced physical weathering may be most severe on north-west facing surfaces by means of an indirect effect of surface orientation on species abundance, and thus dependent on the species, whereas lichen-induced chemical weathering is apparently higher on south-east facing surfaces and dependent on micro-environmental conditions, giving only weak support to the hypothesis that lichens are responsible for the currently observed pattern of rock-art distribution in Côa Valley. Assumptions about the drivers of open-air rock-art distribution patterns elsewhere should also consider the micro-environmental controls of lichen-induced weathering, to avoid biased measures of lichen contribution to rock-art deterioration. This article is protected by copyright. All rights reserved.

Description: Steep genetic clines resulting from recent secondary contact between previously isolated taxa can either gradually erode over time or be stabilized by factors such as ecological selection or selection against hybrids. We used patterns of variation in 30 nuclear and two mitochondrial SNPs to examine the factors that could be involved in stabilizing clines across a hybrid zone between two subspecies of the Atlantic killifish, Fundulus heteroclitus . Increased heterozygote deficit and cytonuclear disequilibrium in populations near the center of the mtDNA cline suggest that some form of reproductive isolation such as assortative mating or selection against hybrids may be acting in this hybrid zone. However, only a small number of loci exhibited these signatures, suggesting locus-specific, rather than genomewide, factors. Fourteen of the 32 loci surveyed had cline widths inconsistent with neutral expectations, with two SNPs in the mitochondrial genome exhibiting the steepest clines. Seven of the 12 putatively non-neutral nuclear clines were for SNPs in genes related to oxidative metabolism. Among these putatively non-neutral nuclear clines, SNPs in two nuclear-encoded mitochondrial genes (SLC25A3 and HDDC2), as well as SNPs in the myoglobin, 40S ribosomal protein S17, and actin-binding LIM protein genes, had clines that were coincident and concordant with the mitochondrial clines. When hybrid index was calculated using this subset of loci, the frequency distribution of hybrid indices for a population located at the mtDNA cline center was non-unimodal, suggesting selection against advanced-generation hybrids, possibly due to effects on processes involved in oxidative metabolism. Using patterns of genetic variation in 30 nuclear and two mitochondrial SNPs, we detected elevated heterozygote deficit and cytonuclear disequilibrium in populations near the centre of the mtDNA cline which connects the subspecies of the Atlantic killifish, Fundulus heteroclitus . Furthermore, when hybrid index was calculated using a subset of non-neutral markers, the distribution of hybrid indices deviated from unimodality. These findings suggest that selection against advanced-generation hybrids is responsible for stabilizing the steep genetic clines observed across this hybrid zone.

Description: Despite recent advances in high-throughput sequencing, difficulties are often encountered when developing microsatellites for species with large and complex genomes. This probably reflects the close association in many species of microsatellites with cryptic repetitive elements. We therefore developed a novel approach for isolating polymorphic microsatellites from the club-legged grasshopper ( Gomphocerus sibiricus ), an emerging quantitative genetic and behavioral model system. Whole genome shotgun Illumina MiSeq sequencing was used to generate over three million 300 bp paired-end reads, of which 67.75% were grouped into 40,548 clusters within RepeatExplorer. Annotations of the top 468 clusters, which represent 60.5% of the reads, revealed homology to satellite DNA and a variety of transposable elements. Evaluating 96 primer pairs in eight wild-caught individuals, we found that primers mined from singleton reads were six times more likely to amplify a single polymorphic microsatellite locus than primers mined from clusters. Our study provides experimental evidence in support of the notion that microsatellites associated with repetitive elements are less likely to successfully amplify. It also reveals how advances in high-throughput sequencing and graph-based repetitive DNA analysis can be leveraged to isolate polymorphic microsatellites from complex genomes. High throughput sequencing and graph-based cluster analysis of repetitive elements facilitates microsatellite development from a highly complex genome.

Description: Biogeochemical teleconnection links seemingly unrelated chemical/biological anomalies that are geographically separated by large distances. Bronselaer et al propose a new mechanism for an interhemispheric teleconnection of air-sea carbon dioxide fluxes in which the upwelling of the Southern Ocean triggers a series of perturbations leading to the alteration of the carbon uptake in the North Atlantic. The westerly wind over the Southern Ocean has a unique role in the climate system. It energizes the strongest ocean current, Antarctic Circumpolar Current, and it lifts up the carbon- and nutrient-rich deep waters all the way to the surface. It is an end point of the ocean's deep overturning circulation and associated biological carbon storage, where the excess carbon from accumulated decomposition of organic material is finally released back into the atmosphere. It is well established that the Southern Ocean upwelling regionally modulates the de-gassing of carbon dioxide there. However, its global-scale implication is not yet fully understood. What happens to the carbon uptake in the other parts of the oceans? In this volume of Global Biogeochemical Cycles, Bronselaer et al describes the chain of events that link the increased Southern Ocean wind to the ocean carbon uptake in the northern high latitudes. The authors conducted a set of computational experiments, showing that the Southern Ocean is a starting point of the oceanic teleconnection, where the excess nutrient is transported equatorward through the shallow overturning circulation. The stream of macro-nutrient then fertilizes the low-latitude productivity that eventually shifts the carbonate chemistry of the high latitude surface waters. This is an intriguing case of oceanic teleconnection, linking seemingly unrelated biogeochemical anomalies that are geographically separated by large distances. The surprising conclusion is that a stronger Southern Ocean wind increases the de-gassing of carbon dioxide in both northern and southern high latitudes. This happens because more carbon is upwelling into the northern high latitudes due to the increased low-latitude biological pump, approximately doubling the de-gassing intensity relative to the Southern Ocean response alone. There may be more surprises from the Southern Ocean.

Description: The most popular practice for analyzing nonstationarity of flood series is to use a fixed single-type probability distribution incorporated with the time-varying moments. However, the type of probability distribution could be both complex because of distinct flood populations and time-varying under changing environments. To allow the investigation of this complex nature, the time-varying two-component mixture distributions (TTMD) method is proposed in this study by considering the time variations of not only the moments of its component distributions but also the weighting coefficients. Having identified the existence of mixed flood populations based on circular statistics, the proposed TTMD was applied to model the annual maximum flood series (AMFS) of two stations in the Weihe River basin (WRB), with the model parameters calibrated by the meta-heuristic maximum likelihood (MHML) method. The performance of TTMD was evaluated by different diagnostic plots and indexes and compared with stationary single-type distributions, stationary mixture distributions and time-varying single-type distributions. The results highlighted the advantages of TTMD with physically-based covariates for both stations. Besides, the optimal TTMD models were considered to be capable of settling the issue of nonstationarity and capturing the mixed flood populations satisfactorily. This article is protected by copyright. All rights reserved.

Description: While the effects of land use change in urban areas have been widely examined, the combined effects of climate and land use change on the quality of urban and urbanizing streams have received much less attention. We describe a modeling framework that is applicable to the evaluation of potential changes in urban water quality and associated hydrologic changes in response to ongoing climate and landscape alteration. The grid-based spatially distributed model, DHSVM-WQ, is an outgrowth of the Distributed Hydrology-Soil-Vegetation Model (DHSVM) that incorporates modules for assessing hydrology and water quality in urbanized watersheds at a high spatial and temporal resolution. DHSVM-WQ simulates surface runoff quality and in-stream processes that control the transport of nonpoint-source (NPS) pollutants into urban streams. We configure DHSVM-WQ for three partially urbanized catchments in the Puget Sound region to evaluate the water quality responses to current conditions and projected changes in climate and/or land use over the next century. Here we focus on total suspended solids (TSS) and total phosphorus (TP) from nonpoint sources (runoff), as well as stream temperature. The projection of future land use is characterized by a combination of densification in existing urban or partially urban areas, and expansion of the urban footprint. The climate change scenarios consist of individual and concurrent changes in temperature and precipitation. Future precipitation is projected to increase in winter and decrease in summer, while future temperature is projected to increase throughout the year. Our results show that urbanization has a much greater effect than climate change on both the magnitude and seasonal variability of streamflow, TSS and TP loads largely due to substantially increased streamflow, and particularly winter flow peaks. Water temperature is more sensitive to climate warming scenarios than to urbanization and precipitation changes. Future urbanization and climate change together are predicted to significantly increase annual mean streamflow (up to 55%), water temperature (up to 1.9 °C), TSS load (up to 182%), and TP load (up to 74%). This article is protected by copyright. All rights reserved.

Description: The resolution of a digital elevation model (DEM) is a crucial factor in watershed hydrologic and environmental modeling. DEM resolution can cause significant variability in the representation of surface topography, which further affects quantification of hydrologic connectivity and simulation of hydrologic processes. The objective of this study is to examine the effects of DEM resolution on (1) surface microtopographic characteristics, (2) hydrologic connectivity, and (3) the spatial and temporal variations of hydrologic processes. A puddle-to-puddle (P2P) modeling system was utilized for surface delineation and modeling of the P2P overland flow dynamics, surface runoff, infiltration, and unsaturated flow for nine DEM resolution scenarios of a field plot surface. Comparisons of the nine modeling scenarios demonstrated that coarser DEM resolutions tended to eliminate topographic features, reduce surface depression storage, and strengthen hydrologic connectivity and surface runoff. We found that reduction in maximum depression storage and maximum ponding area was as high as 97.56% and 76.36%, respectively, as the DEM grid size increased from 2 cm to 80 cm. The paired t-test and fractal analysis demonstrated the existence of a threshold DEM resolution (10 cm for the field plot), within which the DEM-based hydrologic modeling was effective and acceptable. The effects of DEM resolution were further evaluated for a larger surface in the Prairie Pothole Region (PPR) subjected to observed rainfall events. It was found that simulations based on coarser resolution DEMs (〉10 m) tended to overestimate ponded areas and underestimate runoff discharge peaks. The simulated peak discharge from the PPR surface reduced by approximately 50% as the DEM resolution changed from 2 m to 90 m. Fractal analysis results elucidated scale dependency of hydrologic and topographic processes. In particular, scale analysis highlighted a unique constant-threshold-power relationship between DEM scale and topographic and hydrologic parameters/variables. Not only does this finding allow one to identify threshold DEM, but also further develop functional relationships for scaling to achieve valid topographic characterization as well as effective and efficient hydrologic modeling. This article is protected by copyright. All rights reserved.

Description: In light of daunting global sustainability challenges such as climate change, biodiversity loss and food security, improving our understanding of the complex dynamics of the Earth system is crucial. However, large knowledge gaps related to the effects of land management persist, in particular those human-induced changes in terrestrial ecosystems that do not result in land cover conversions. Here we review the current state of knowledge of ten common land management activities for their biogeochemical and biophysical impacts, the level of process-understanding and data availability. Our review shows that ca. one tenth of the ice free land surface is under intense human management, half under medium and one fifth under extensive management. Based on our review, we cluster these ten management activities into three groups: (1) management activities for which datasets are available, and for which a good knowledge base exists (cropland harvest and irrigation); (2) management activities for which sufficient knowledge on biogeochemical and biophysical effects exists but robust global datasets are lacking (forest harvest, tree species selection, grazing and mowing harvest, N-fertilization); and (3) land management practices with severe data gaps concomitant with an unsatisfactory level of process understanding (crop species selection, artificial wetland drainage, tillage and fire management and crop residue management, an element of crop harvest). Although we identify multiple impediments to progress, we conclude that the current status of process understanding and data availability is sufficient to advance with incorporating management in e.g. Earth System or Dynamic Vegetation models in order to provide a systematic assessment of their role in the Earth system. This review contributes to a strategic prioritization of research efforts across multiple disciplines, including land system research, ecological research and Earth system modelling. This article is protected by copyright. All rights reserved.

Description: This paper presents a methodology for hydrograph separation in mountain watersheds, which aims at identifying flow sources among ungauged headwater sub-catchments through a combination of observed streamflow and data on natural tracers including isotope and dissolved solids. Daily summer and bi-daily spring season water samples obtained at the outlet of the Juncal River Basin in the Andes of Central Chile were analyzed for all major ions as well as stable water isotopes, δ 18 O and δD. Additionally, various samples from rain, snow, surface streams and exfiltrating subsurface water (springs), were sampled throughout the catchment. A principal component analysis (PCA) was performed in order to address cross-correlation in the tracer dataset, reduce the dimensionality of the problem and to uncover patterns of variability. Potential sources were identified in a two-component U-space that explains 94% of the observed tracer variability at the catchment outlet. Hydrograph separation was performed through an Informative - Bayesian model. Our results indicate that the Juncal Norte Glacier headwater sub-catchment contributed at least 50% of summer flows at the Juncal River Basin outlet during the 2011–12 water year (a hydrologically dry period in the Region), even though it accounts for only 27% of the basin area. Our study confirms the value of combining solute and isotope information for estimating source contributions in complex hydrologic systems, and provides insights regarding experimental design in high-elevation semi-arid catchments. The findings of this study can be useful for evaluating modeling studies of the hydrological consequences of the rapid decrease in glacier cover observed in this region, by providing insights into the origin of river water in basins with little hydrometeorological information.

Description: Although the genetic basis of color variation has been extensively studied in humans and domestic animals, the genetic polymorphisms responsible for different color morphs remain to be elucidated in many wild vertebrate species. For example, hypopigmentation has been observed in numerous marine mammal species but the underlying mutations have not been identified. A particularly compelling candidate gene for explaining color polymorphism is the melanocortin 1 receptor ( MC1R ), which plays a key role in the regulation of pigment production. We therefore used Antarctic fur seals ( Arctocephalus gazella ) as a highly tractable marine mammal system with which to test for an association between nucleotide variation at the MC1R and melanin-based coat color phenotypes. By sequencing 70 wild-type individuals with dark-colored coats and 26 hypopigmented individuals with cream-colored coats, we identified a nonsynonymous mutation that results in the substitution of serine with phenylalanine at an evolutionarily highly conserved structural domain. All of the hypopigmented individuals were homozygous for the allele coding for phenylalanine, consistent with a recessive loss-of-function allele. In order to test for cryptic population structure, which can generate artefactual associations, and to evaluate whether homozygosity at the MC1R could be indicative of low genome-wide heterozygosity, we also genotyped all of the individuals at 50 polymorphic microsatellite loci. We were unable to detect any population structure and also found that wild-type and hypopigmented individuals did not differ significantly in their standardized multilocus heterozygosity. Such a lack of association implies that hypopigmented individuals are unlikely to suffer disproportionately from inbreeding depression, and hence, we have no reason to believe that they are at a selective disadvantage in the wider population. We sequenced the melanocortin 1 receptor ( MC1R ) of 70 wild-type and 26 cream-coloured Antarctic fur seals and identified a recessive loss-of-function mutation clearly associated with cream coat colour. In order to evaluate whether homozygosity at the MC1R could be indicative of low genome-wide heterozygosity, we also genotyped all individuals at 50 polymorphic microsatellite loci and found no difference in standardized multilocus heterozygosity between wild-type and cream-coloured individuals. Such a lack of association implies that hypopigmented individuals are unlikely to suffer disproportionally from inbreeding depression and thus do not appear to be at a selective disadvantage in the wider population.

Description: The average flow of Silver Springs, one of the largest magnitude springs in central Florida, declined 32% from 2000 to 2012. The average groundwater head in the springshed declined 0.14 m, and the spring pool altitude increased 0.24 m during the same period. This paper presents a novel explanation of the spring flow recession curve for Silver Springs using Torricelli model, which uses the groundwater head at a sentinel well, the spring pool altitude, and the net recharge to groundwater. The effective springshed area and net recharge (defined as recharge minus groundwater pumping and evapotranspiration) were estimated based on the observed recession slopes for spring flow, groundwater head, and spring pool altitude. The results show that the effective springshed area continuously declined since 1989, and the net recharge declined since the 1970s with a significant drop in 2002. Subsequent to 2002, the net recharge increased modestly but not to the levels prior to the 1990s. The reduction in net recharge was caused by changes in hydroclimatic conditions including precipitation and temperature, along with groundwater withdrawals, which contributed to the declined spring flow.

Description: Differences in the predicted carbon and water fluxes by different global land models have been quite large and have not decreased over the last two decades. Quantification and attribution of the uncertainties of global land surface models are important for improving the performance of global land surface models, and are the foci of this study. Here we quantified the model errors by comparing the simulated monthly global gross primary productivity (GPP) and latent heat flux (LE) by two global land surface models with the model-data products of global GPP and LE from 1982-2005. By analyzing model parameter sensitivities within their ranges, we identified about 2 to 11 most sensitive model parameters that have strong influences on the simulated GPP or LE by two global land models, and found that the sensitivities of the same parameters are different among the plant functional types (PFT). Using parameter ensemble simulations, we found that 15% to 60% of the model errors were reduced by tuning only a few (〈4) most sensitive parameters for most PFTs, and that the reduction in model errors varied spatially within a PFT or among different PFTs. Our study shows that future model improvement should optimize key model parameters, particularly those parameters relating to leaf area index, maximum carboxylation rate and stomatal conductance. This article is protected by copyright. All rights reserved.

Description: Alkaptonuria (AKU) is an ultra-rare autosomal genetic disorder caused by a defect in the activity of the enzyme homogentisate 1,2-dioxygenase (HGD) that leads to the accumulation of homogentisic acid (HGA) and its oxidized product, benzoquinone acetic acid (BQA), in the connective tissues causing a pigmentation called “ochronosis”. The consequent progressive formation of ochronotic aggregates generate a severe condition of oxidative stress and inflammation in all the affected areas. Experimental evidences have also proved the presence of serum amyloid A (SAA) in several AKU tissues and it allowed classifying AKU as a secondary amyloidosis. Although AKU is a multisystemic disease, the most affected system is the osteoarticular one and articular cartilage is the most damaged tissue. In this work, we have analyzed for the first time the cytoskeleton of AKU chondrocytes by means of immunofluorescence staining. We have shown the presence of SAA within AKU chondrocytes and finally we have demonstrated the co-localization of SAA with three cytoskeletal proteins: actin, vimentin and β-tubulin. Furthermore, in order to observe the ultrastructural features of AKU chondrocytes we have performed TEM analysis, focusing on the Golgi apparatus structure and, to demonstrate that pigmented areas in AKU cartilage are correspondent to areas of oxidation, 4-HNE presence has been evaluated by means of immunofluorescence. This article is protected by copyright. All rights reserved

Description: In this report, we present an analysis of several recycling protocols based on labeling of membrane proteins with specific monoclonal antibodies (mAbs). We analyzed recycling of membrane proteins that are internalized by clathrin-dependent endocytosis, represented by the transferrin receptor, and by clathrin-independent endocytosis, represented by the Major Histocompatibility Class I molecules. Cell surface membrane proteins were labeled with mAbs and recycling of mAb:protein complexes was determined by several approaches. Our study demonstrates that direct and indirect detection of recycled mAb:protein complexes at the cell surface underestimate the recycling pool, especially for clathrin-dependent membrane proteins that are rapidly reinternalized after recycling. Recycling protocols based on the capture of recycled mAb:protein complexes require the use of the Alexa Fluor 488 conjugated secondary antibodies or FITC-conjugated secondary antibodies in combination with inhibitors of endosomal acidification and degradation. Finally, protocols based on the capture of recycled proteins that are labeled with Alexa Fluor 488 conjugated primary antibodies and quenching of fluorescence by the anti-Alexa Fluor 488 displayed the same quantitative assessment of recycling as the antibody-capture protocols. This article is protected by copyright. All rights reserved

Description: Understanding how tropical rainforests respond to elevated atmospheric CO 2 concentration (eCO 2 ) is essential for predicting Earth's carbon, water and energy budgets under future climate change. Here we use long-term (1982-2010) precipitation ( P ) and runoff ( Q ) measurements to infer runoff coefficient ( Q / P ) and evapotranspiration ( E ) trends across 18 unimpaired tropical rainforest catchments. We complement that analysis by using satellite observations coupled with ecosystem process modelling (using both ‘top-down’ and ‘bottom-up’ perspectives) to examine trends in carbon uptake and relate that to the observed changes in Q / P and E . Our results show there have been only minor changes in the satellite-observed canopy leaf area over 1982-2010, suggesting that eCO 2 has not increased vegetation leaf area in tropical rainforests and therefore any plant response to eCO 2 occurs at the leaf-level. Meanwhile, observed Q / P and E also remained relatively constant in the 18 catchments, implying an unchanged hydrological partitioning and thus approximately conserved transpiration under eCO 2 . For the same period, using a ‘top-down’ model based on gas-exchange theory, we predict increases in plant assimilation ( A ) and light-use efficiency ( ε ) at the leaf-level under eCO 2 , the magnitude of which is essentially that of eCO 2 ( i.e ., ~12% over 1982-2010). Simulations from ten state-of-the-art ‘bottom-up’ ecosystem models over the same catchments also show the direct effect of eCO 2 is to mostly increase A and ε with little impact on E . Our findings add to the current limited pool of knowledge regarding the long-term eCO 2 impacts in tropical rainforests.

Description: The savanna vegetation of Brazil (Cerrado) accounts for 20-25% of the land cover of Brazil and is the second largest ecosystem following Amazonian forest; however, Cerrado mass and energy exchange is still highly uncertain. We used eddy covariance to measure the net ecosystem CO 2 exchange (NEE) of grass-dominated Cerrado ( campo sujo ) over three years. We hypothesized that soil water availability would be a key control over the seasonal and interannual variations in NEE. Multiple regression indicated that gross primary production (GPP) was positively correlated (Pearson's r = 0.69; p 〈 0.001) with soil water content, radiation, and the MODIS-derived Enhanced Vegetation Index (EVI), but negatively correlated with the vapor pressure deficit (VPD), indicating that drier conditions increased water limitations on GPP. Similarly, ecosystem respiration (Reco) was positively correlated (Pearson's r = 0.78; p 〈 0.001) with the EVI, radiation, soil water content, and temperature but slightly negatively correlated with rainfall and the VPD. While the NEE responded rapidly to temporal variations in soil water availability, the grass-dominated Cerrado stand was a net source of CO 2 to the atmosphere during the study period, which was drier compared to the long-term average rainfall. Cumulative NEE was approximately 842 gC m -2 , varying from 357 gC m -2 in 2011 to 242 gC m -2 in 2012. Our results indicate that grass-dominated Cerrado may be an important regional CO 2 source in response to the warming and drying that is expected to occur in the southern Amazon Basin under climate change.

Description: ABSTRACT The Qilianshan [ shan means ‘mountain(s)’ in Chinese] are important for understanding the Quaternary glaciations which occurred along the north-eastern margins of the Tibetan Plateau (TP). Two sets of moraines identified in the Gangshika Valley on the southern slopes of the Qilianshan, and in the Jindonggou Valley on the northern slopes of the Lenglongling Ridge in the eastern Qilianshan, were dated using optically stimulated luminescence (OSL) dating. The D e values of the sediments were determined using single aliquot regeneration (SAR) and ‘global standardized growth curve’ (gSGC) procedures. The gSGC method was first applied to glacial sediment and proved to be adaptable. Based on D e distribution analysis, and a comparison between the ages of coarse-grained (90–125 μm) quartz, we concluded that the minimum age model (MAM) OSL age obtained may be closer to the burial age of the sediments. The first set of moraines in the Gangshika Valley was formed at 18.1 ± 1.8 ka. The second set of moraines in both the Gangshika and the Jindonggou valleys was mainly formed at ∼12.5–10.7 ka, consistent with the Younger Drays chronozone, most probably covering the moraines produced at 14.3 ± 1.4 ka. These results indicate that the glaciers along the Lenglongling Ridge were sensitive to abrupt decreases in temperature.

Description: ABSTRACT A depositional sequence bounded by upper and lower erosion surfaces covering a 35-km × 20-km area within the northern embayment of the Early Pleistocene Central North Sea is dated close to the Jaramillo Normal sub-chron at approximately 1.0–1.1 Ma. The basal surface cuts shallow marine clays of the upper Nordland Group and is characterized by furrow incisions, mega-scale glacial lineation textures and bedforms that are all orientated NNW–SSE. The sequence comprises a suite of distinctive bedforms, including a chaotic deposit up to 60 m thick, a series of moulded and lineated depositional bodies and some more complex bedforms, with lithologies shown by petrophysical data to be dominated by overconsolidated clays and thin sand layers. This sequence is considered to represent deposition from the advance and subsequent decay of a marine-terminating ice-sheet. The upper surface of the sequence coincides with the so-called ‘Crenulate Reflection’ and is characterized by a fluvial channel system, representing final retreat of the ice-sheet, which was followed by shallow marine conditions and deposition of the Aberdeen Ground Formation. It is considered that the Aberdeen Ground Formation comprises at least two main sequences spanning the Early to Middle Pleistocene.

Description: ABSTRACT Spheroidal weathering, one of the important rock weathering styles, has been attributed to chemical weathering by the water from joint surfaces, and mechanical aspects of the weathering have not been well addressed. We made an investigation on spheroidal weathering of Miocene granite porphyry with well-developed columnar joints and found that this spheroidal weathering proceeds through chemical processes and accompanying mechanical processes. The investigation of the textures, physical properties, mineralogy, and chemistry of the porphyry revealed the presence of a brown band on the surface margins of corestones, representing the oxidation of pyrite and chlorite, and the precipitation of iron hydroxides, and the consequent generation of micro-cracks within the band. During weathering, oxidation progresses inwards from joints that surround the rindlets, including both high-angle columnar and low-angle planar joints, and causes rounding of the unweathered interior portion of the rock. Microscopic observations of the brown band embedded with fluorescent resin show that pores are first filled with iron hydroxides, and that micro-cracks then form parallel to the oxidation front in the outer portion of the brown band. Iron hydroxide precipitation increases the P-wave velocity in the brown band, while micro-crack formation decreases the tensile strength of the rock. Where the brown band has thickened to ~6 cm, the micro-cracks are connected to one another to create continuous cracks, which separate the rindlets from the corestone. Micro-crack formation parallel to the corestone surface may be attributed to compressive stresses generated by small amounts of volumetric expansion due to the precipitation of iron hydroxides in the brown band. Earth surface is under oxidizing environments so that precipitation of iron hydroxides commonly occurs; the spheroidal weathering in this paper is a typical example of the combination of chemical and mechanical processes under such environments. This article is protected by copyright. All rights reserved.

Description: No abstract is available for this article.

Description: No abstract is available for this article.

Description: ABSTRACT Cultivated fields have been shown to be the dominant sources of sediment in almost all investigated UK catchments, typically contributing 85 to 95% of sediment inputs. As a result, most catchment management strategies are directed towards mitigating these sediment inputs. However, in many regions of the UK such as the Nene basin there is a paucity of sediment provenance data. This study used the 137 Cs inventories of lake and floodplain cores as well as the 137 Cs activities of present day sediment to determine sediment provenance. Sediment yields were also reconstructed in a small lake catchment. This article is protected by copyright. All rights reserved. Low 137 Cs inventories were present in the lake and floodplain cores in comparison to the reference inventory and inventories in cores from other UK catchments. 137 Cs activities in the present day sediments were low; falling close to those found in the channel bank catchment samples. It was estimated that 60 to 100% of the sediment in the Nene originated from channel banks. This article is protected by copyright. All rights reserved. Pre 1963 sediment yields were approximately 11.2 t km −2 yr −1 and post 1963 was approximately 11.9 t km −2 yr −1 . The lack of increased sediment yield post 1963 and low sediment yield is unusual for a UK catchment (where a yield of 28 to 51 t km −2 yr −1 is typical for a lowland agricultural catchment), but is explained by the low predicted contribution of sediment from agricultural topsoils. The high channel bank contribution is likely caused by the river being starved of sediment from topsoils, increasing its capacity to entrain bank material. This article is protected by copyright. All rights reserved. The good agreement between the results derived using cores and recently transported sediments, highlight the reliability of 137 Cs when tracing sediment sources. However, care should be taken to assess the potential impacts of sediment particle size, sediment focusing in lakes and the possible remobilisation of 137 Cs from sedimentary deposits. This article is protected by copyright. All rights reserved.

Description: ABSTRACT Reporting uncertainty in environmental measurements and estimates is important for cross comparison and inter-comparison of sites and other spatial units. One such measure is the load of large in-stream wood in river systems. In this paper we propose the use of the Weibull distribution to describe the central tendency and variability of wood loads along a river reach. We illustrate the link between the average wood load and the central tendency or scale parameter of the Weibull distribution. The shape of the Weibull distribution is strongly related to the ability of rivers to transport and rearrange the wood in a reach. We use six Victorian rivers to test the fit of the Weibull distribution, showing that the Weibull is a useful and flexible distribution that provides common reporting metrics useful for future studies. Using a common reporting metrics provides a stronger tool for comparisons of wood loads between rivers and with reaches. This article is protected by copyright. All rights reserved.

Description: Fire plays an important role in structuring vegetation in fire-prone regions worldwide. Progress has been made towards documenting the effects of individual fire events and fire regimes on vegetation structure; less is known of how different fire history attributes (e.g., time-since-fire, fire frequency) interact to affect vegetation. Using the temperate eucalypt ‘foothill’ forests of south-eastern Australia as a case-study system, we examine two hypotheses about such interactions: 1) that post-fire vegetation succession (e.g., time-since-fire effects) is influenced by other fire regime attributes, and 2) that the severity of the most recent fire overrides the effect of preceding fires on vegetation structure. Empirical data on vegetation structure were collected from 540 sites distributed across central and eastern Victoria, Australia. Linear mixed models were used to examine these hypotheses, and determine the relative influence of fire and environmental attributes on vegetation structure. Fire history measures, particularly time-since-fire, affected several vegetation attributes including ground and canopy strata; others such as low and sub-canopy vegetation were more strongly influenced by environmental characteristics like rainfall. There was little support for the hypothesis that post-fire succession is influenced by fire history attributes other than time-since-fire: only canopy regeneration was influenced by another variable (‘fire type’, representing severity). Our capacity to detect an overriding effect of the severity of the most recent fire was limited by a consistently weak effect of preceding fires on vegetation structure. Overall, results suggest the primary way that fire affects vegetation structure in foothill forests is via attributes of the most recent fire, both its severity and time since its occurrence: other attributes of fire regimes (e.g., fire interval, frequency) have less influence. The strong effect of environmental drivers such as rainfall and topography on many structural features show that foothill forest vegetation is also influenced by factors outside human control. While fire is amenable to human management, results suggest that at broad scales, structural attributes of these forests are relatively resilient to the effects of current fire regimes. Nonetheless, the potential for more frequent severe fires at short intervals, associated with a changing climate and/or fire management, warrant further consideration. This article is protected by copyright. All rights reserved.