bluuebunny/crossref_metadata_2025_split huggingface dataset:
From facilitative to competitive interactions between woody plants and plants with crassulacean acid metabolism (CAM): The role of hydraulic descent
Authors: Yu Kailiang , D'Odorico Paolo 
Published: October 2016

AbstractWoody plants may facilitate the establishment of seedlings with crassulacean acid metabolism (CAM) by ameliorating the abiotic environment through an increase in soil water availability. Because of the low transpiration rate in shallow‐rooted CAM plants and the consequently high soil water contents in the shallow soil, deep‐rooted trees in tree–CAM associations could perform hydraulic descent transporting water from wetter shallow soil to drier deep soil in arid environments. It remains unclear, however, whether a high rate of hydraulic descent can turn the facilitation of CAM plants by woody plants into competition. In this study, we develop a mechanistic model to investigate the facilitation of shallow‐rooted CAM plants by deep‐rooted woody plants in the access to soil water resources along a rainfall gradient. The model results show that in the case of low‐to‐moderate root overlap woody plants could facilitate CAM plants in access to soil water; this effect is mainly induced by the reduction in evaporation from the soil surface due to shading. Both shading and hydraulic descent decrease (or hydraulic lift increases) along a rainfall gradient, thereby favoring facilitation. Investment in deep roots by woody plants is usually thought to increase niche differentiation with shallow‐rooted plants, thereby reducing the competition and promoting species coexistence. This study indicates that deep root development could also favor competition through the mechanism of hydraulic descent, thereby changing our understanding of the role of root depth in niche differentiation between shallow and deep‐rooted plants.
Some like it hot: effect of environment on population dynamics of a small tropical seabird in the Caribbean region
Authors: Precheur Carine , Barbraud Christophe , Martail Fred , Mian Maurice , Nicolas Jean‐Claude , Brithmer Ronald , Belfan David , Conde Béatrice , Bretagnolle Vincent 
Published: October 2016

AbstractAn understanding of how environmental changes affect life history traits and population dynamics is essential for predicting the effects of climate change, managing ecosystems, and determining how species and habitats can best be preserved. This applies particularly to seabirds, which, as top marine predators, are often considered as indicators of marine ecosystem changes. Most studies have so far been conducted in polar or temperate regions. However, important changes in the functioning of tropical marine ecosystems have been reported, but the responses of top predators remain poorly known. This study focused on a tropical seabird, Audubon's shearwaterPuffinus lherminieri, analyzing the relationships between climate change and the survival of adults, nesting success, and population dynamics. The population studied breeds in Martinique, in the south of the Caribbean region, which is strongly influenced by the Amazon and Orinoco rivers. A data set for the period 1995 to 2014 was used to estimate the survival by age classes and breeding success and to determine which climate variables most affected demographic parameters. The population dynamics were modeled to predict the future population growth rates in response to climate change. The annual adult survival rate increased over the last 20 years, currently standing at 94% for adult birds more than 6 years old. Adult survival increased with sea surface temperature (SST) during the nonbreeding season as well as with Amazon River discharge, although the latter with a lag of 1 year. The effect ofSSTwas explained by the positive relationship betweenSSTand chlorophylladuring years of high discharge from the Amazon and Orinoco. The population decreased between 1995 and 2007 at a rate of 3% per year and then increased between 2008 and 2014 at a rate of 7% per year. The increase in adult survival observed should continue as temperatures increase in the future, and the population models predicted a stable or increasing population over the next 50 years (λ = 1.018). These results contrast with the negative effect of increasingSSTon seabird populations found in temperate and polar regions, emphasizing the need to study the impact of climate change on tropical seabirds.
Noninvasive unmanned aerial vehicle provides estimates of the energetic cost of reproduction in humpback whales
Authors: Christiansen Fredrik , Dujon Antoine M. , Sprogis Kate R. , Arnould John P. Y. , Bejder Lars 
Published: October 2016

AbstractAn animal's body condition will affect its survival and reproductive success, which influences population dynamics. Despite its importance, relatively little is known about the body condition of large whales and its relationship to reproduction. We assessed the body condition of humpback whales (Megaptera novaeangliae) at a breeding/resting ground from aerial photographs recorded using an unmanned aerial vehicle (UAV). Photogrammetry methods were used to measure the surface area of individual whales, which was used as an index for body condition. Repeated measurements of the same individuals were not possible; hence, this study represents a cross‐sectional sample of the population. Intraseasonal changes in the body condition of four reproductive classes (calves, immature, mature, and lactating) were investigated to infer the relative energetic cost that each class faces during the breeding season. To better understand the costs of reproduction, we investigated the relationship between female body condition (FBC) and the linear growth and body condition of their dependent calves (CBC). We documented a linear decline in the body condition of mature whales (0.027 m2/d; n = 20) and lactating females (0.032 m2/d; n = 31) throughout the breeding season, while there was no change in body condition of immature whales (n = 51) and calves (n = 32). The significant decline in mature and lactating female's body condition implies substantial energetic costs for these reproductive classes. In support of this, we found a positive linear relationship between FBC and CBC. This suggests that females in poorer body condition may not have sufficient energy stores to invest as much energy into their offspring as better conditioned females without jeopardizing their own body condition and survival probability. Measurement precision was investigated from repeated measurements of the same animals both from the same and different photographs, and by looking at residual errors in relation to the positioning of the whales in the photographs. The resulting errors were included in a sensitivity analysis to demonstrate that model parameters were robust to measurement errors. Our findings provide strong support for the use of UAVs as a noninvasive tool to measure the body condition of whales and other mammals.
The consequences of four land‐use scenarios for forest ecosystems and the services they provide
Authors: Thompson Jonathan R. , Lambert Kathleen F. , Foster David R. , Broadbent Eben N. , Blumstein Meghan , Almeyda Zambrano Angelica M. , Fan Yuanchao 
Published: October 2016

AbstractAnticipating landscape‐ to regional‐scale impacts of land use on ecosystems and the services they provide is a central challenge for scientists, policymakers, and resource managers. Working with a panel of practitioners and regional experts, we developed and analyzed four plausible but divergent land‐use scenarios that depict the future of Massachusetts from 2010 to 2060 to address two questions: (1) “How do the magnitude and spatial distribution of ecosystem service provisioning vary under the different land‐use regimes?” and (2) “What are the synergies and trade‐offs among direct human uses, ecosystem services, and habitat quality?” Each scenario specifies the detailed prescriptions for the major uses of the forests, including conversion to residential and commercial development, clearing new farmland, shifting silvicultural practices, and designating forests protected from development. We simulated the land‐use scenarios and their interactions with anticipated climate change by coupling statistical models of land use to the LANDIS‐II landscape model and then evaluated the outcomes in terms of the magnitude and spatial distribution of (1) direct human uses of the landscape (residential and commercial development, agricultural, timber harvest), (2) ecosystem services (carbon storage, flood regulation, nutrient retention), and (3) habitat quality (forest tree species composition, interior forest habitat). Across all scenarios, conflicts occurred between dispersed residential development and the supply of ecosystem services and habitat quality. In all but the scenario that envisioned a significant agricultural expansion, forest growth resulted in net increases in aboveground carbon storage, despite the concomitant forest clearing and harvesting. One scenario, called Forests as Infrastructure, showed the potential for synergies between increased forest harvest volume through the sustainable practices that encouraged the maintenance of economically and ecologically important tree species, and carbon storage. This scenario also showed trade‐offs between development density and water quantity and quality at the watershed scale. The process of integrated scenario analysis led to important insights for land managers and policymakers in a populated forested region where there are tensions among development, forest harvesting, and land conservation. More broadly, the results emphasize the need to consider the consequences of contrasting land‐use regimes that result from the interactions between human decisions and spatially heterogeneous landscape dynamics.
Stage‐dependent effects of browsing by snowshoe hares on successional dynamics in a boreal forest ecosystem
Authors: Olnes Justin , Kielland Knut 
Published: October 2016

AbstractHerbivores transform landscapes and affect succession via selective foraging that alters vegetation composition. In the boreal forest, mammalian herbivores, mainly moose, facilitate a shift toward the dominance of heavily defended species over time, such as white spruce. The effects of moose herbivory are intensified by the browsing of snowshoe hares. However, unlike moose, snowshoe hares also browse seedlings of white spruce. We quantified herbivory by snowshoe hares on white spruce along the Tanana River, interior Alaska, and assessed the effects on white spruce demography via two different herbivore exclosure experiments. We hypothesized that both experiments would show reduced plant density and height growth in the presence of hares. We found evidence of extensive browsing of white spruce seedlings by snowshoe hares, which negatively affected white spruce establishment along the Tanana River floodplain. Previous research has indicated that hares facilitate floodplain succession in the forward direction. However, hare herbivory can also retard succession by depressing white spruce establishment and increase the time individual trees spend in the understory. This stage‐dependent effect on successional dynamics via a unique temporal variation in snowshoe hare herbivory may contribute to alternative successional trajectories in the boreal forest.
Global associations between birds and vane‐dwelling feather mites
Authors: Doña Jorge , Proctor Heather , Mironov Sergey , Serrano David , Jovani Roger 
Published: October 2016

AbstractUnderstanding host–symbiont networks is a major question in evolutionary ecology. Birds host a great diversity of endo‐ and ectosymbiotic organisms, with feather mites (Arachnida: Acariformes: Analgoidea, Pterolichoidea) being among the most diverse of avian symbionts. A global approach to the ecology and evolution of bird–feather‐mite associations has been hampered because of the absence of a centralized data repository. Here we present the most extensive data set of associations between feather mites and birds. Data include 12 036 records of 1887 feather mite species located on the flight feathers of 2234 bird species from 147 countries. Feather mites typically located inside quills, on the skin, or on downy body feathers are not included. Data were extracted from 493 published sources dating from 1882 to 2015. Data exploration shows that although most continents and bird families are represented, most bird species remain unexplored for feather mites. Nevertheless, this is the most comprehensive data set available for enabling global macroecological analyses of feather mites and their hosts, such as ecological network analyses. This metadata file outlines the structure of these data and provides primary references for all records used.
Cascading effects of predation risk determine how marine predators become terrestrial prey on an oceanic island
Authors: Thomsen Sarah K. , Green David J. 
Published: October 2016

AbstractApex predators can suppress the foraging activity of mesopredators, which may then result in cascading benefits for the prey of those mesopredators. We studied the interactions between a top predator, the Barn Owl (Tyto alba), and their primary prey, an island endemic deer mouse (Peromyscus maniculatus elusus), which in turn consumes the eggs of seabirds nesting on Santa Barbara Island in California. Scripps's Murrelets (Synthliboramphus scrippsi), a threatened nocturnal seabird, arrive annually to breed on this island, and whose first egg is particularly vulnerable to predation by mice. We took advantage of naturally occurring extreme variations in the density of mice and owls on the island over 3 years and predicted that (1) mouse foraging would decrease with increasing predation risk from owls and moonlight and (2) these decreases in foraging would reduce predation on murrelet eggs. We measured the giving up densities of mice with experimental foraging stations and found that mice were sensitive to predation risk and foraged less when owls were more abundant and less during the full moon compared to the new moon. We also monitored the fates of 151 murrelet eggs, and found that murrelet egg predation declined as owl abundance increased, and was lower during the full moon compared to the new moon. Moreover, high owl abundance suppressed egg predation even when mice were extremely abundant. We conclude that there is a behaviorally mediated cascade such that owls on the island had a positive indirect effect on murrelet egg survival. Our study adds to the wider recognition of the strength of risk effects to structure food webs, as well as highlighting the complex ways that marine and terrestrial food webs can intersect.
Cardiogenic shock in intensive care units: evolution of prevalence, patient profile, management and outcomes, 1997–2012
Authors: Puymirat Etienne , Fagon Jean Yves , Aegerter Philippe , Diehl Jean Luc , Monnier Alexandra , Hauw‐Berlemont Caroline , Boissier Florence , Chatellier Gilles , Guidet Bertrand , Danchin Nicolas , Aissaoui Nadia ,   on behalf of the Collège des Utilisateurs de Bases de données en Réanimation (CUB‐Réa Group [Intensive Care Database User Group])
Published: October 2016

AbstractAimTo address the paucity of data on the characteristics, outcome and temporal trends in mortality of cardiogenic shock (CS) patients admitted to intensive care units (ICUs) we examined key features, variations in mortality from CS, and predictors of death in ICU patients over the past 15 years.Methods and resultsFrom the 1997–2012 database of the Collège des Utilisateurs de Bases de données en Réanimation (CUB‐Réa) that prospectively collects data from ICUs in the greater Paris area, we determined temporal trends in the incidence of CS, patient outcomes [Crude and Simplified Acute Physiology Score (SAPS)‐II Standardized Mortality] and predictors of in‐ICU mortality. Of the 316 905 ICU admissions, 19 416 (6.1%) exhibited CS, with incidence increasing from 4.1% to 7.7% (P < 0.001). Over time, the age of admitted patients decreased by 2.7 years [95% confidence interval (CI), −2.0 to −3.4] and SAPS‐II increased by 5.8% (95% CI 4.8–6.8) from 58.7 ± 25.3 to 64.5 ± 23.3 (P < 0.001). Crude in‐ICU mortality declined from 50% to 45% (−5.6%; 95% CI −7.7 to −3.5) as SAPS‐II Standardized ICU mortality rates decreased from 56.5% to 44.2% (P < 0.001). A more recent time‐period was an independent correlate of decreased mortality in multivariate analyses. The decrease in mortality rate was more marked in patients with decompensated heart failure, cardiac arrest, or acute myocardial infarction.ConclusionsPatients with CS represent a greater proportion of patients admitted to ICUs over the past 15 years, having become younger but more critically ill. Although their mortality has decreased, suggesting improved overall patient management, it remains particularly high, warranting further research specifically focused on this population.
Antigen presentation by B cells guides programing of memory CD4+ T‐cell responses to a TLR4‐agonist containing vaccine in mice
Authors: Dubois Cauwelaert Natasha , Baldwin Susan L. , Orr Mark T. , Desbien Anthony L. , Gage Emily , Hofmeyer Kimberly A. , Coler Rhea N. 
Published: October 2016

The contribution of B cells to immunity against many infectious diseases is unquestionably important and well characterized. Here, we sought to determine the role of B cells in the induction of T‐helper 1 (TH1) CD4+ T cells upon vaccination with a tuberculosis (TB) antigen combined with a TLR4 agonist. We used B‐cell deficient mice (μMT−/−), tetramer‐positive CD4+ T cells, markers of memory “precursor” effector cells (MPECs), and T‐cell adoptive transfers and demonstrated that the early antigen‐specific cytokine‐producing TH1 responses are unaffected in the absence of B cells, however MPEC induction is strongly impaired resulting in a deficiency of the memory TH1 response in μMT−/− mice. We further show that antigen‐presentation by B cells is necessary for their role in MPEC generation using B‐cell adoptive transfers from wt or MHC class II knock‐out mice into μMT−/− mice. Our study challenges the view that B‐cell deficiency exclusively alters the TH1 response at memory time‐points. Collectively, our results provide new insights on the multifaceted roles of B cells that will have a high impact on vaccine development against several pathogens including those requiring TH1 cell‐mediated immunity.
Effects of influent organic loading rates and electrode locations on the electrogenesis capacity of constructed wetland‐microbial fuel cell systems
Authors: Xu Dan , Xiao En‐Rong , Xu Peng , Zhou Yin , Zhou Qiao‐Hong , Xu Dong , Wu Zhen‐Bin 
Published: October 2016

Three novel constructed wetland‐microbial fuel cells (CW‐MFCs), based on electrode location, were developed for wastewater treatment and sustainable electricity production by embedding a MFC into a CW system. In the three CW‐MFCs, electrodes were placed in different locations, including bottom anode‐rhizosphere cathode CW‐MFC (BA‐RC‐CW‐MFC), rhizosphere anode‐air cathode CW‐MFC (RA‐AC‐CW‐MFC), and bottom anode‐air cathode CW‐MFC (BA‐AC‐CW‐MFC), to investigate the combined effects of organic loading rates (OLRs) and reactor configurations on the electrogenesis capacity of the hybrid system. All the systems operated continuously to treat five types of synthetic wastewater with increasing OLRs: 9.2, 18.4, 27.6, 55.2, and 92.0 g chemical oxygen demand (COD) m−2 d−1. The BA‐RC‐CW‐MFC failed to produce electricity at any OLR, whereas the maximum power densities of 0.79 ± 0.01 and 10.77 ± 0.52 mW m−2 were achieved in the RA‐AC‐CW‐MFC with 18.4 g COD m−2 d−1 influent OLR and in the BA‐AC‐CW‐MFC with 27.6 g COD m−2 d−1 influent OLR, respectively. The coulombic efficiencies of the RA‐AC‐CW‐MFC and BA‐AC‐CW‐MFC decreased gradually with the increase in influent OLRs. © 2016 American Institute of Chemical Engineers Environ Prog, 36: 435–441, 2017
Numerical simulation of imbert biomass gasifier to select the feedstock available in remote areas
Authors: Murugan P.C. , Joseph Sekhar S. 
Published: October 2016

The performance of a gasifier which is designed for a particular feedstock varies whenever the feedstock is changed. Moreover, to implement the biomass gasification technology in remote places, the performance of existing gasifier should be analysed for its dimensional suitability to work with different feedstock which are available in such locations. Even though, the species transport approach is more appropriate to model the gasification processes, it was not used to analyse all the zones of a gasifier. Hence, in this work, a numerical study was carried out with species transport model by considering all the four zones of a gasifier. This model uses gasification reactions with the corresponding pre‐exponential factor and activation energy to check the performance of a biomass gasifier. Different feedstocks such as coconut shell, rice husk, cow dung, rubber wood and rubber seed kernel shell that are commonly available in the selected region were used in this study. The influences of equivalence ratio on the composition and higher heating value of producer gas, and the temperature distribution inside the gasifier were been studied. Both the experimental and numerical studies demonstrate the best performance when the equivalence ratio is close to 0.25. Among the locally available biomasses, the producer gas from rubber seed kernel shell has the calorific value of 6.08 MJ/Nm3 and therefore it can be used as feedstock in gasifier which is designed for woody biomass. © 2016 American Institute of Chemical Engineers Environ Prog, 36: 708–716, 2017
Evaluating the zebrafish embryo toxicity test for pesticide hazard screening
Authors: Glaberman Scott , Padilla Stephanie , Barron Mace G. 
Published: October 2016

Abstract

Given the numerous chemicals used in society, it is critical to develop tools for accurate and efficient evaluation of potential risks to human and ecological receptors. Fish embryo acute toxicity tests are 1 tool that has been shown to be highly predictive of standard, more resource-intensive, juvenile fish acute toxicity tests. However, there is also evidence that fish embryos are less sensitive than juvenile fish for certain types of chemicals, including neurotoxicants. The utility of fish embryos for pesticide hazard assessment was investigated by comparing published zebrafish embryo toxicity data from pesticides with median lethal concentration 50% (LC50) data for juveniles of 3 commonly tested fish species: rainbow trout, bluegill sunfish, and sheepshead minnow. A poor, albeit significant, relationship (r2 = 0.28; p &lt; 0.05) was found between zebrafish embryo and juvenile fish toxicity when pesticides were considered as a single group, but a much better relationship (r2 = 0.64; p &lt; 0.05) when pesticide mode of action was factored into an analysis of covariance. This discrepancy is partly explained by the large number of neurotoxic pesticides in the dataset, supporting previous findings that commonly used fish embryo toxicity test endpoints are particularly insensitive to neurotoxicants. These results indicate that it is still premature to replace juvenile fish toxicity tests with embryo-based tests such as the Organisation for Economic Co-operation and Development Fish Embryo Acute Toxicity Test for routine pesticide hazard assessment, although embryo testing could be used with other screening tools for testing prioritization. Environ Toxicol Chem 2017;36:1221–1226. © 2016 SETAC