bluuebunny/crossref_metadata_2025_split huggingface dataset:
Flood regime typology for floodplain ecosystem management as applied to the unregulated Cosumnes River of California, United States
Authors: Whipple Alison A. , Viers Joshua H. , Dahlke Helen E. 
Published: December 2016

AbstractFloods, with their inherent spatiotemporal variability, drive floodplain physical and ecological processes. This research identifies a flood regime typology and approach for flood regime characterization, using unsupervised cluster analysis of flood events defined by ecologically meaningful metrics, including magnitude, timing, duration, and rate of change as applied to the unregulated lowland alluvial Cosumnes River of California, United States. Flood events, isolated from the 107‐year daily flow record, account for approximately two‐thirds of the annual flow volume. Our analysis suggests six flood types best capture the range of flood event variability. Two types are distinguished primarily by high peak flows, another by later season timing and long duration, two by small magnitudes separated by timing, and the last by later peak flow within the flood event. The flood regime was also evaluated through inter‐ and intra‐annual frequency of the identified flood types, their relationship to water year conditions, and their long‐term trends. This revealed, for example, year‐to‐year variability in flood types, associations between wet years and high peak magnitude types and between dry years and the low magnitude, late season flood type, and increasing and decreasing contribution to total annual flow in the highest two peak magnitude classes, respectively. This research focuses needed attention on floodplains, flood hydrology, ecological implications, and the utility of extending flow regime classification typically used for environmental flow targets. The approach is broadly applicable and extensible to other systems, where findings can be used to understand physical processes, assess change, and improve management strategies.
Dissimilarity in the riparian arthropod communities along surface water permanence gradients in aridland streams
Authors: Moody Eric K. , Sabo John L. 
Published: December 2016

AbstractThe riparian areas around streams and rivers are often thought of as distinct habitats with unique species. Research on riparian zones has traditionally focused on those bordering perennial waterways; thus, we know much less about riparian species supported by intermittent and ephemeral streams. As nonperennial streams make up the vast majority of stream channels in many landscapes, we aimed to investigate how surface water permanence affects riparian communities. We focus on riparian ground‐dwelling arthropods, a group that often depends on resources derived from surface and/or ground water. We sampled riparian ground‐dwelling arthropods along surface water permanence gradients in 3 replicated stream channels in southeastern Arizona to assess patterns in diversity and community similarity. We found that alpha diversity did not differ between reach types, but high species turnover led to significant community dissimilarity among perennial, intermittent, and ephemeral riparian zones. Further, intermittent and ephemeral riparian zones harbored more unique species not found at other reach types than did perennial reaches. These patterns were strongest during the dry season, when intermittent and ephemeral reaches are most likely to lack surface water. Our results suggest not only that the riparian zones of nonperennial streams host equivalent arthropod diversity to their perennial counterparts but also that these communities have little overlap with those at perennial reaches. As a result, intermittent and ephemeral stream channels should receive greater consideration than they currently do in efforts to conserve regional biodiversity.
Pinus contorta invasions increase wildfire fuel loads and may create a positive feedback with fire
Authors: Taylor Kimberley T. , Maxwell Bruce D. , McWethy David B. , Pauchard Aníbal , Nuñez Martín A. , Whitlock Cathy 
Published: December 2016

AbstractInvasive plant species that have the potential to alter fire regimes have significant impacts on native ecosystems. Concern that pine invasions in the Southern Hemisphere will increase fire activity and severity and subsequently promote further pine invasion prompted us to examine the potential for feedbacks between Pinus contorta invasions and fire in Patagonia and New Zealand. We determined how fuel loads and fire effects were altered by P. contorta invasion. We also examined post‐fire plant communities across invasion gradients at a subset of sites to assess how invasion alters the post‐fire vegetation trajectory. We found that fuel loads and soil heating during simulated fire increase with increasing P. contorta invasion age or density at all sites. However, P. contorta density did not always increase post‐fire. In the largest fire, P. contorta density only increased significantly post‐fire where the pre‐fire P. contorta density was above an invasion threshold. Below this threshold, P. contorta did not dominate after fire and plant communities responded to fire in a similar manner as uninvaded communities. The positive feedback observed at high densities is caused by the accumulation of fuel that in turn results in greater soil heating during fires and high P. contorta density post‐fire. Therefore, a positive feedback may form between P. contorta invasions and fire, but only above an invasion density threshold. These results suggest that management of pine invasions before they reach the invasion density threshold is important for reducing fire risk and preventing a transition to an alternate ecosystem state dominated by pines and novel understory plant communities.
The basis function approach for modeling autocorrelation in ecological data
Authors: Hefley Trevor J. , Broms Kristin M. , Brost Brian M. , Buderman Frances E. , Kay Shannon L. , Scharf Henry R. , Tipton John R. , Williams Perry J. , Hooten Mevin B. 
Published: December 2016

AbstractAnalyzing ecological data often requires modeling the autocorrelation created by spatial and temporal processes. Many seemingly disparate statistical methods used to account for autocorrelation can be expressed as regression models that include basis functions. Basis functions also enable ecologists to modify a wide range of existing ecological models in order to account for autocorrelation, which can improve inference and predictive accuracy. Furthermore, understanding the properties of basis functions is essential for evaluating the fit of spatial or time‐series models, detecting a hidden form of collinearity, and analyzing large data sets. We present important concepts and properties related to basis functions and illustrate several tools and techniques ecologists can use when modeling autocorrelation in ecological data.
Dopant‐Free Hole‐Transport Material with a Tetraphenylethene Core for Efficient Perovskite Solar Cells
Authors: Zhu Hongwei , Zhang Fei , Liu Xicheng , Sun Mengna , Han Jianlei , You Jing , Wang Shirong , Xiao Yin , Li Xianggao 
Published: December 2016

AbstractA hole‐transport material (HTM), 1,1,2,2‐tetrakis[4‐(3,6‐di‐tert‐butyl‐9H‐carbazol‐9‐yl)phenyl]ethene (TTBCPE), was prepared straightforwardly and employed in the fabrication of perovskite solar cells (PSCs). The investigated HTM with tetraphenylethene as the core and tert‐butylcarbazole as terminal units was synthesized in two steps from commercially available and cheap raw materials. The devices based on TTBCPE without the use of any dopants and additives exhibited a power conversion efficiency (PCE) of 12.65 %, which is comparable to 14.46 % obtained by using devices based on 2,2′,7,7′‐tetrakis(N,N′‐di‐p‐methoxyphenylamino)‐9,9′‐spirobifluorene (p‐doped spiro‐OMeTAD). Importantly, the device based on TTBCPE showed a higher stability than devices based on doped spiro‐OMeTAD if stored under ambient conditions. In this regard, this easily synthesized and dopant‐free system paves a new way to develop low‐cost HTMs.
Probabilistic development of shear strength model for reinforced concrete squat walls
Authors: Ning Chao‐Lie , Li Bing 
Published: December 2016

SummaryIn order to reconcile the larger scatter and avoid the biased estimate from deterministic predictions for the shear strength of reinforced concrete (RC) squat structural walls, a probabilistic shear strength model is developed in this paper based on the strut‐and‐tie model and the generalized likelihood uncertainty estimation (GLUE) method. The strut‐and‐tie model is used to derive an appropriate function form for the probabilistic shear strength model, where four unknown model parameters (e.g. k1, k2, k3 and k4) are defined carefully to guarantee them having a clear physical‐based meaning so that the corresponding prior distribution ranges can be specified reasonably. Then, the GLUE method is adopted to estimate the posterior cumulative distribution of k1, k2, k3 and k4 with an available experimental database. Furthermore, to demonstrate the stability of the estimated posterior cumulative distribution, the sensitivity of three major aspects in GLUE method is investigated. Finally, based on the estimated cumulative distribution of k1, k2, k3 and k4, the developed probabilistic shear strength model is simplified as a mean prediction model and a standard deviation prediction model for facilitate using in engineering practice. Therefore, with the developed probabilistic shear strength model, not only can the squat structural walls be designed in confidence, but the accuracy of those deterministic predictions can be evaluated in a probabilistic manner. Copyright © 2016 John Wiley & Sons, Ltd.
The mechanisms of nickel toxicity in aquatic environments: An adverse outcome pathway analysis
Authors: Brix Kevin V. , Schlekat Christian E. , Garman Emily R. 
Published: December 2016

Abstract

Current ecological risk assessment and water quality regulations for nickel (Ni) use mechanistically based, predictive tools such as biotic ligand models (BLMs). However, despite many detailed studies, the precise mechanism(s) of Ni toxicity to aquatic organisms remains elusive. This uncertainty in the mechanism(s) of action for Ni has led to concern over the use of tools like the BLM in some regulatory settings. To address this knowledge gap, the authors used an adverse outcome pathway (AOP) analysis, the first AOP for a metal, to identify multiple potential mechanisms of Ni toxicity and their interactions with freshwater aquatic organisms. The analysis considered potential mechanisms of action based on data from a wide range of organisms in aquatic and terrestrial environments on the premise that molecular initiating events for an essential metal would potentially be conserved across taxa. Through this analysis the authors identified 5 potential molecular initiating events by which Ni may exert toxicity on aquatic organisms: disruption of Ca2+ homeostasis, disruption of Mg2+ homeostasis, disruption of Fe2+/3+ homeostasis, reactive oxygen species–induced oxidative damage, and an allergic-type response of respiratory epithelia. At the organ level of biological organization, these 5 potential molecular initiating events collapse into 3 potential pathways: reduced Ca2+ availability to support formation of exoskeleton, shell, and bone for growth; impaired respiration; and cytotoxicity and tumor formation. At the level of the whole organism, the organ-level responses contribute to potential reductions in growth and reproduction and/or alterations in energy metabolism, with several potential feedback loops between each of the pathways. Overall, the present AOP analysis provides a robust framework for future directed studies on the mechanisms of Ni toxicity and for developing AOPs for other metals. Environ Toxicol Chem 2017;36:1128–1137. © 2016 SETAC
Value‐added probiotic development by high‐solid fermentation of sweet potato with Saccharomyces boulardii
Authors: Campbell Carmen , Nanjundaswamy Ananda K. , Njiti Victor , Xia Qun , Chukwuma Franklin 
Published: December 2016

AbstractControlled fermentation of Sweet potato (Ipomoea batatas) var. Beauregard by yeast, Saccharomyces boulardii (MAY 796) to enhance the nutritional value of sweet potato was investigated. An average 8.00 × 1010 Colony Forming Units (CFU)/g of viable cells were obtained over 5‐day high‐solid fermentation. Yeast cell viability did not change significantly over time at 4°C whereas the number of viable yeast cells reduced significantly at room temperature (25°C), which was approximately 40% in 12 months. Overall, the controlled fermentation of sweet potato by MAY 796 enhanced protein, crude fiber, neutral detergent fiber, acid detergent fiber, amino acid, and fatty acid levels. Development of value‐added sweet potato has a great potential in animal feed and human nutrition. S. boulardii‐ fermented sweet potato has great potential as probiotic‐enriched animal feed and/or functional food for human nutrition.
Strength varying laws of rock soaked with supercritical CO2drilling fluid and the prediction of safe mud weight window
Authors: Sun Baojiang , Zhang Hongkun 
Published: December 2016

AbstractDrilling with supercritical CO2(SC‐CO2) is an important new technology in petroleum engineering. The technology has many unique advantages for increasing the penetration rate and reducing formation damage, but it is a disadvantage for the wellbore stability. Therefore, an experimental technique has been developed to determine the safe mud weight window for drilling with SC‐CO2. More specifically, a special experimental apparatus has been designed to mimic thein situtemperature and pressure conditions during drilling operations. Different experiments were conducted using core samples soaked in SC‐CO2and water‐based and oil‐based drilling fluids, respectively. Once the experimental measurements regressed, an empirical correlation, including time, temperature and pressure factors, was obtained to describe the compressive strength of the SC‐CO2‐soaked core samples. Further modifications were then made to the formulations used to calculate the densities of the drilling fluids at the corresponding burst and collapse pressure, respectively. In addition, the effects of dynamic cohesion, internal friction angle, and tensile strength on the wellbore stability were determined. Compared to the conventional water‐based and oil‐based drilling fluids, the SC‐CO2drilling fluid performs better with respect to wellbore stability and has a wider safe mud weight window. © 2016 Society of Chemical Industry and John Wiley & Sons, Ltd.
Cortico‐limbic connectivity in MAOA‐L carriers is vulnerable to acute tryptophan depletion
Authors: Eisner Patrick , Klasen Martin , Wolf Dhana , Zerres Klaus , Eggermann Thomas , Eisert Albrecht , Zvyagintsev Mikhail , Sarkheil Pegah , Mathiak Krystyna A. , Zepf Florian , Mathiak Klaus 
Published: December 2016

AbstractIntroductionA gene–environment interaction between expression genotypes of the monoamine oxidase A (MAOA) and adverse childhood experience increases the risk of antisocial behavior. However, the neural underpinnings of this interaction remain uninvestigated. A cortico‐limbic circuit involving the prefrontal cortex (PFC) and the amygdala is central to the suppression of aggressive impulses and is modulated by serotonin (5‐HT). MAOA genotypes may modulate the vulnerability of this circuit and increase the risk for emotion regulation deficits after specific life events. Acute tryptophan depletion (ATD) challenges 5‐HT regulation and may identify vulnerable neuronal circuits, contributing to the gene–environment interaction.MethodsFunctional magnetic resonance imaging measured the resting‐state state activity in 64 healthy males in a double‐blind, placebo‐controlled study. Cortical maps of amygdala correlation identified the impact of ATD and its interaction with low‐ (MAOA‐L) and high‐expression variants (MAOA‐H) of MAOA on cortico‐limbic connectivity.ResultsAcross all Regions of Interest (ROIs) exhibiting an ATD effect on cortico‐limbic connectivity, MAOA‐L carriers were more susceptible to ATD than MAOA‐H carriers. In particular, the MAOA‐L group exhibited a larger reduction of amygdala connectivity with the right prefrontal cortex and a larger increase of amygdala connectivity with the insula and dorsal PCC.ConclusionMAOA‐L carriers were more susceptable to a central 5‐HT challenge in cortico‐limbic networks. Such vulnerability of the cortical serotonergic system may contribute to the emergence of antisocial behavior after systemic challenges, observed as gene–environment interaction. Hum Brain Mapp 38:1622–1635, 2017. © 2016 Wiley Periodicals, Inc.
The hippocampus influences assimilation and accommodation of schemata that are not hippocampus‐dependent
Authors: Armelin Anna , Heinemann Uwe , de Hoz Livia 
Published: December 2016

ABSTRACTLearning is facilitated when information can be incorporated into an already learned set of rules or ‘mental schema’. The location of a new restaurant, for example, is learned more easily if the neighbourhood's general layout is already known. This type of information is processed by the hippocampus and stored as a schema in the cortex, but it is not known whether the hippocampus can also map new stimuli to cortical schemata that are hippocampus‐independent, such as odour classification. Using a hippocampus‐independent odour‐rule task we found that animals without a functional hippocampus learnt which odours did not fit the rule faster than sham animals, which persistently applied the rule to all odours. Conversely, when non‐fitting odours were linked to a new rule sham animals were faster to link these odours to the new rule. The hippocampus, thus, regulates the association of stimuli with existing schemata even when the schemata are hippocampus‐independent. © 2016 Wiley Periodicals, Inc.
The sorting receptor SorCS3 is a stronger regulator of glutamate receptor functions compared to GABAergic mechanisms in the hippocampus
Authors: Christiansen Gitte B. , Andersen Katrine H. , Riis Sarah , Nykjaer Anders , Bolcho Ulrik , Jensen Morten S. , Holm Mai Marie 
Published: December 2016

ABSTRACTCorrect function of glutamate receptors in the postsynaptic density is crucial to synaptic function and plasticity. SorCS3 (sortilin‐related receptor CNS expressed 3) is a sorting receptor which previously has been shown to interact with the key postsynaptic proteins; PSD‐95 and PICK1. In this study, we employed electrophysiological analyses of acute brain slices combined with immunohistochemistry to define the role of SorCS3 in hippocampal synapses in CA1 and the dentate gyrus. We analyzed a juvenile (P17‐21) and a young adult (P55‐65) group of animals from a Sorcs3 knockout mouse model. We show that the basal synaptic transmission is severely affected in SorCS3‐deficient neurons in CA1, while only slightly reduced in the dentate gyrus. Specifically, input/output curves of CA1 synapses revealed a 20% reduction of fEPSP (field excitatory postsynaptic potential) slopes at the highest stimulation intensity in knockouts of the juvenile group, which developed to a 33% decrease in young adult animals. These impairments may be a result of changes in the postsynaptic AMPA receptors. Interestingly, repetitive afferent stimulation demonstrated that SorCS3‐deficient slices respond with an enhanced synaptic facilitation and reduced synaptic depression. These changes also developed with age. A molecular mechanism underlying this relative increase during repetitive stimulations is compatible with enhanced mobility of postsynaptic AMPA receptors resulting in faster exchange of desensitized receptors in the postsynaptic density. The altered response during repetitive stimulation was characteristic for CA1 but not the dentate gyrus. Immunohistochemical analyses of parvalbumin positive neurons combined with paired‐pulse tests of network inhibition and patch‐clamp recordings only showed minute inhibitory changes in SorCS3‐deficient slices. Our results suggest that SorCS3 serves an important role in the postsynaptic protein network, which is more pronounced in CA1 compared to the dentate gyrus. These data support a role for SorCS3 in controlling proper positioning and mobility of glutamate receptors in the postsynaptic density. © 2016 Wiley Periodicals, Inc.
White matter hyperintensities are associated with disproportionate progressive hippocampal atrophy
Authors: Fiford Cassidy M. , Manning Emily N. , Bartlett Jonathan W. , Cash David M. , Malone Ian B. , Ridgway Gerard R. , Lehmann Manja , Leung Kelvin K. , Sudre Carole H. , Ourselin Sebastien , Biessels Geert Jan , Carmichael Owen T. , Fox Nick C. , Cardoso M. Jorge , Barnes Josephine ,   for the Alzheimer's Disease Neuroimaging Initiative
Published: December 2016

ABSTRACTThis study investigates relationships between white matter hyperintensity (WMH) volume, cerebrospinal fluid (CSF) Alzheimer's disease (AD) pathology markers, and brain and hippocampal volume loss. Subjects included 198 controls, 345 mild cognitive impairment (MCI), and 154 AD subjects with serial volumetric 1.5‐T MRI. CSF Aβ42 and total tau were measured (n = 353). Brain and hippocampal loss were quantified from serial MRI using the boundary shift integral (BSI). Multiple linear regression models assessed the relationships between WMHs and hippocampal and brain atrophy rates. Models were refitted adjusting for (a) concurrent brain/hippocampal atrophy rates and (b) CSF Aβ42 and tau in subjects with CSF data. WMH burden was positively associated with hippocampal atrophy rate in controls (P = 0.002) and MCI subjects (P = 0.03), and with brain atrophy rate in controls (P = 0.03). The associations with hippocampal atrophy rate remained following adjustment for concurrent brain atrophy rate in controls and MCIs, and for CSF biomarkers in controls (P = 0.007). These novel results suggest that vascular damage alongside AD pathology is associated with disproportionately greater hippocampal atrophy in nondemented older adults. © 2016 The Authors Hippocampus Published by Wiley Periodicals, Inc.