bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cannibalism amplifies the spread of vertically transmitted pathogens
Authors: Sadeh Asaf , Rosenheim Jay A. 
Published: May 2016

AbstractCannibalism is a widespread behavior. Abundant empirical evidence demonstrates that cannibals incur a risk of contracting pathogenic infections when they consume infected conspecifics. However, current theory suggests that cannibalism generally impedes disease spread, because each victim is usually consumed by a single cannibal, such that cannibalism does not function as a spreading process. Consequently, cannibalism cannot be the only mode of transmission of most parasites. We develop simple, but general epidemiological models to analyze the interaction of cannibalism and vertical transmission. We show that cannibalism increases the prevalence of vertically transmitted pathogens whenever the host population density is not solely regulated by cannibalism. This mechanism, combined with additional, recently published, theoretical mechanisms, presents a strong case for the role of cannibalism in the spread of infectious diseases across a wide range of parasite–host systems.
Adaptation services of floodplains and wetlands under transformational climate change
Authors: Colloff Matthew J. , Lavorel Sandra , Wise Russell M. , Dunlop Michael , Overton Ian C. , Williams Kristen J. 
Published: May 2016

AbstractAdaptation services are the ecosystem processes and services that benefit people by increasing their ability to adapt to change. Benefits may accrue from existing but newly used services where ecosystems persist or from novel services supplied following ecosystem transformation. Ecosystem properties that enable persistence or transformation are important adaptation services because they support future options. The adaptation services approach can be applied to decisions on trade‐offs between currently valued services and benefits from maintaining future options. For example, ecosystem functions and services of floodplains depend on river flows. In those regions of the world where climate change projections are for hotter, drier conditions, floods will be less frequent and floodplains will either persist, though with modified structure and function, or transform to terrestrial (flood‐independent) ecosystems. Many currently valued ecosystem services will reduce in supply or become unavailable, but new options are provided by adaptation services. We present a case study from the Murray–Darling Basin, Australia, for operationalizing the adaptation services concept for floodplains and wetlands. We found large changes in flow and flood regimes are likely under a scenario of +1.6°C by 2030, even with additional water restored to rivers under the proposed Murray–Darling Basin Plan. We predict major changes to floodplain ecosystems, including contraction of riparian forests and woodlands and expansion of terrestrial, drought‐tolerant vegetation communities. Examples of adaptation services under this scenario include substitution of irrigated agriculture with dryland cropping and floodplain grazing; mitigation of damage from rarer, extreme floods; and increased tourism, recreational, and cultural values derived from fewer, smaller wetlands that can be maintained with environmental flows. Management for adaptation services will require decisions on where intervention can enable ecosystem persistence and where transformation is inevitable. New ways of managing water that include consideration of the increasing importance of adaptation services requires major changes to decision‐making that better account for landscape heterogeneity and large‐scale change rather than attempting to maintain ecosystems in fixed states.
Limited carbon and biodiversity co‐benefits for tropical forest mammals and birds
Authors: Beaudrot Lydia , Kroetz Kailin , Alvarez‐Loayza Patricia , Amaral Ieda , Breuer Thomas , Fletcher Christine , Jansen Patrick A. , Kenfack David , Lima Marcela Guimarães Moreira , Marshall Andrew R. , Martin Emanuel H. , Ndoundou‐Hockemba Mireille , O'Brien Timothy , Razafimahaimodison Jean Claude , Romero‐Saltos Hugo , Rovero Francesco , Roy Cisquet Hector , Sheil Douglas , Silva Carlos E.F. , Spironello Wilson Roberto , Valencia Renato , Zvoleff Alex , Ahumada Jorge , Andelman Sandy 
Published: May 2016

AbstractThe conservation of tropical forest carbon stocks offers the opportunity to curb climate change by reducing greenhouse gas emissions from deforestation and simultaneously conserve biodiversity. However, there has been considerable debate about the extent to which carbon stock conservation will provide benefits to biodiversity in part because whether forests that contain high carbon density in their aboveground biomass also contain high animal diversity is unknown. Here, we empirically examined medium to large bodied ground‐dwelling mammal and bird (hereafter “wildlife”) diversity and carbon stock levels within the tropics using camera trap and vegetation data from a pantropical network of sites. Specifically, we tested whether tropical forests that stored more carbon contained higher wildlife species richness, taxonomic diversity, and trait diversity. We found that carbon stocks were not a significant predictor for any of these three measures of diversity, which suggests that benefits for wildlife diversity will not be maximized unless wildlife diversity is explicitly taken into account; prioritizing carbon stocks alone will not necessarily meet biodiversity conservation goals. We recommend conservation planning that considers both objectives because there is the potential for more wildlife diversity and carbon stock conservation to be achieved for the same total budget if both objectives are pursued in tandem rather than independently. Tropical forests with low elevation variability and low tree density supported significantly higher wildlife diversity. These tropical forest characteristics may provide more affordable proxies of wildlife diversity for future multi‐objective conservation planning when fine scale data on wildlife are lacking.
Convergence of detrital stoichiometry predicts thresholds of nutrient‐stimulated breakdown in streams
Authors: Manning David W. P. , Rosemond Amy D. , Gulis Vladislav , Benstead Jonathan P. , Kominoski John S. , Maerz John C. 
Published: May 2016

AbstractNutrient enrichment of detritus‐based streams increases detrital resource quality for consumers and stimulates breakdown rates of particulate organic carbon (C). The relative importance of dissolved inorganic nitrogen (N) vs. phosphorus (P) for detrital quality and their effects on microbial‐ vs. detritivore‐mediated detrital breakdown are poorly understood. We tested effects of experimental N and P additions on detrital stoichiometry (C:N, C:P) and total and microbial breakdown (i.e., with and without detritivorous shredders, respectively) of five detritus types (four leaf litter species and wood) with different initial C : nutrient content. We enriched five headwater streams continuously for two years at different relative availabilities of N and P and compared breakdown rates and detrital stoichiometry to pretreatment conditions. Total breakdown rates increased with nutrient enrichment and were predicted by altered detrital stoichiometry. Streamwater N and P, fungal biomass, and their interactions affected stoichiometry of detritus. Streamwater N and P decreased detrital C:N, whereas streamwater P had stronger negative effects on detrital C:P. Nutrient addition and fungal biomass reduced C:N by 70% and C:P by 83% on average after conditioning, compared to only 26% for C:N and 10% for C:P under pretreatment conditions. Detritus with lowest initial nutrient content changed the most and had greatest increases in total breakdown rates. Detrital stoichiometry was reduced and differences among detritus types were homogenized by nutrient enrichment. With enrichment, detrital nutrient content approached detritivore nutritional requirements and stimulated greater detritivore vs. microbial litter breakdown. We used breakpoint regression to estimate values of detrital stoichiometry that can potentially be used to indicate elevated breakdown rates. Breakpoint ratios for total breakdown were 41 (C:N) and 1518 (C:P), coinciding with total breakdown rates that were ~1.9 times higher when C:N or C:P fell below these breakpoints. Microbial and shredder‐mediated breakdown rates both increased when C:N and C:P were reduced, suggesting that detrital stoichiometry is useful for predicting litter breakdown dominated by either microbial or shredder activity. Our results show strong effects of nutrient enrichment on detrital stoichiometry and offer a robust link between a potential holistic nutrient loading metric (decreased and homogenized detrital stoichiometry) and increased C loss from stream ecosystems.
Ecological similarity is related to phylogenetic distance between species in a cross‐niche field transplant experiment
Authors: Anacker Brian L. , Strauss Sharon Y. 
Published: May 2016

AbstractTo determine whether phylogenetic relatedness predicts ecological niche differences and community assembly in the field, we transplanted 16 focal plant species into field niches of species of increasing phylogenetic relatedness, manipulated the presence of plant neighbors, and measured environmental covariates. We found that plant survivorship declined with increasing phylogenetic distance in the presence of neighbors, but with neighbor removal, reached a low point in field niches occupied by species diverged at 63 My, the maximum age of confamilials in our study, and then increased again in the sites of distant relatives. Plant biomass was similarly nonlinear, and niche differences increased with neighbor removal. Competitive response showed a linear decline with relatedness. We compared our experimental results to natural community composition, finding that conspecifics and distant relatives were more likely to co‐occur at smaller spatial scales, as predicted by our measures of performance.
Integrating population dynamics models and distance sampling data: a spatial hierarchical state‐space approach
Authors: Nadeem Khurram , Moore Jeffrey E. , Zhang Ying , Chipman Hugh 
Published: May 2016

AbstractStochastic versions of Gompertz, Ricker, and various other dynamics models play a fundamental role in quantifying strength of density dependence and studying long‐term dynamics of wildlife populations. These models are frequently estimated using time series of abundance estimates that are inevitably subject to observation error and missing data. This issue can be addressed with a state‐space modeling framework that jointly estimates the observed data model and the underlying stochastic population dynamics (SPD) model. In cases where abundance data are from multiple locations with a smaller spatial resolution (e.g., from mark–recapture and distance sampling studies), models are conventionally fitted to spatiallypooledestimates of yearly abundances. Here, we demonstrate that a spatial version of SPD models can be directly estimated from short time series of spatially referenced distance sampling data in a unified hierarchical state‐space modeling framework that also allows for spatial variance (covariance) in population growth. We also show that a full range of likelihood based inference, including estimability diagnostics and model selection, is feasible in this class of models using a data cloning algorithm. We further show through simulation experiments that the hierarchical state‐space framework introduced herein efficiently captures the underlying dynamical parameters and spatial abundance distribution. We apply our methodology by analyzing a time series of line‐transect distance sampling data for fin whales (Balaenoptera physalus) off the U.S. west coast. Although there were only seven surveys conducted during the study time frame, 1991–2014, our analysis detected presence of strong density regulation and provided reliable estimates of fin whale densities. In summary, we show that the integrative framework developed herein allows ecologists to better infer key population characteristics such as presence of density regulation and spatial variability in a population's intrinsic growth potential.
Estimating local biodiversity change: a critique of papers claiming no net loss of local diversity
Authors: Gonzalez Andrew , Cardinale Bradley J. , Allington Ginger R. H. , Byrnes Jarrett , Arthur Endsley K. , Brown Daniel G. , Hooper David U. , Isbell Forest , O'Connor Mary I. , Loreau Michel 
Published: May 2016

AbstractGlobal species extinction rates are orders of magnitude above the background rate documented in the fossil record. However, recent data syntheses have found mixed evidence for patterns of net species loss at local spatial scales. For example, two recent data meta‐analyses have found that species richness is decreasing in some locations and is increasing in others. When these trends are combined, these papers argued there has been no net change in species richness, and suggested this pattern is globally representative of biodiversity change at local scales. Here we reanalyze results of these data syntheses and outline why this conclusion is unfounded. First, we show the datasets collated for these syntheses are spatially biased and not representative of the spatial distribution of species richness or the distribution of many primary drivers of biodiversity change. This casts doubt that their results are representative of global patterns. Second, we argue that detecting the trend in local species richness is very difficult with short time series and can lead to biased estimates of change. Reanalyses of the data detected a signal of study duration on biodiversity change, indicating net biodiversity loss is most apparent in studies of longer duration. Third, estimates of species richness change can be biased if species gains during post‐disturbance recovery are included without also including species losses that occurred during the disturbance. Net species gains or losses should be assessed with respect to common baselines or reference communities. Ultimately, we need a globally coordinated effort to monitor biodiversity so that we can estimate and attribute human impacts as causes of biodiversity change. A combination of technologies will be needed to produce regularly updated global datasets of local biodiversity change to guide future policy. At this time the conclusion that there is no net change in local species richness is not the consensus state of knowledge.
Intraspecific leaf chemistry drives locally accelerated ecosystem function in aquatic and terrestrial communities
Authors: Jackrel Sara L. , Morton Timothy C. , Wootton J. Timothy 
Published: May 2016

AbstractResource patchiness influences consumer foraging, movement, and physiology. Fluxes across ecosystem boundaries can extend these effects to otherwise distinct food webs. Intraspecific diversity of these cross‐ecosystem subsidies can have large consequences for recipient systems. Here, we show intraspecific variation in leaf defensive chemistry of riparian trees drives local adaptation among terrestrial and riverine decomposers that consume shed leaf litter. We found extensive geographic structuring of ellagitannins, diarylheptanoids, and flavonoids in red alder trees. Ellagitannins, particularly those with strong oxidative activity, drive aquatic leaf decomposition. Further, spatial variation in these leaf components drives local ecological matching: in experiments using artificial food sources distinguished only by the chemical content of individual trees, we found decomposers both on land and in rivers more quickly consumed locally derived food sources. These results illustrate that terrestrial processes can change the chemistry of cross‐ecosystem subsidies in ways that ultimately alter ecosystem function in donor and recipient systems.
Sediments and flow have mainly independent effects on multitrophic stream communities and ecosystem functions
Authors: Mustonen Kaisa‐Riikka , Mykrä Heikki , Louhi Pauliina , Markkola Annamari , Tolkkinen Mikko , Huusko Ari , Alioravainen Nico , Lehtinen Sirkku , Muotka Timo 
Published: May 2016

AbstractStream ecosystems are affected by multiple abiotic stressors, and species responses to simultaneous stressors may differ from those predicted based on single‐stressor responses. Using 12 semi‐natural stream channels, we examined the individual and interactive effects of flow level (low or high flow) and addition of fine sediments (grain size <2 mm) on key ecosystem processes (leaf breakdown, algal biomass accrual) and benthic macroinvertebrate and fungal communities. Both stressors had mostly independent effects on biological responses, with sand addition being the more influential of the two. Sand addition decreased algal biomass and microbe‐mediated leaf breakdown significantly, whereas invertebrate shredder‐mediated breakdown only responded to flow level. Macroinvertebrate community composition responded significantly to both stressors. Fungal biomass decreased and shredder abundance increased when sand was added; thus, organisms at different trophic levels can exhibit highly variable responses to the same stressor. Terrestrial endophytic fungi were abundant in low‐flow flumes where leaf mass loss was also highest, indicating that terrestrial endophytes may contribute importantly to leaf decomposition in the aquatic environment. Leaf breakdown rates depended on the identity and abundance of the dominant decomposer species, suggesting that the effects of anthropogenic activities on ecosystem processes may be driven by changes in the abundance of a few key species. The few observed interactive effects were all antagonistic (i.e., less than the sum of the individual effects); for example, increased flow stimulated algal biomass accumulation but this effect was largely cancelled by sand. While our finding that sand and stream flow did not have strong synergistic effects can be considered reassuring for management, future experiments should manipulate these and other human stressors in experiments that run for much longer periods, thus focusing on the long‐term impacts of multiple simultaneously operating stressors.
Compensatory dynamics stabilize aggregate community properties in response to multiple types of perturbations
Authors: Brown Bryan L. , Downing Amy L. , Leibold Mathew A. 
Published: May 2016

AbstractCompensatory dynamics are an important suite of mechanisms that can stabilize community and ecosystem attributes in systems subject to environmental fluctuations. However, few experimental investigations of compensatory dynamics have addressed these mechanisms in systems of real‐world complexity, and existing evidence relies heavily on correlative analyses, retrospective examination, and experiments in simple systems. We investigated the potential for compensatory dynamics to stabilize plankton communities in plankton mesocosm systems of real‐world complexity. We employed four types of perturbations including two types of nutrient pulses, shading, and acidification. To quantify how communities responded to these perturbations, we used a measure of community‐wide synchrony combined with spectral analysis that allowed us to assess timescale‐specific community dynamics, for example, whether dynamics were synchronous at some timescales but compensatory at others. The 150‐d experiment produced 32‐point time series of all zooplankton taxa in the mesocosms. We then used those time series to evaluate total zooplankton biomass as an aggregate property and to evaluate community dynamics. For three of our four perturbation types, total zooplankton biomass was significantly less variable in systems with environmental variation than in constant environments. For the same three perturbation types, community‐wide synchrony was much lower in fluctuating environments than in the constant environment, particularly at longer timescales (periods ≈ 60 d). Additionally, there were strong negative correlations between population temporal variances and the level of community‐wide synchrony. Taken together, these results strongly imply that compensatory interactions between species stabilized total biomass in response to perturbations. Diversity did not differ significantly across either treatments or perturbation types, thus ruling out several classes of mechanisms driven by changes in diversity. We also used several pieces of secondary evidence to evaluate the particular mechanism behind compensatory responses since a wide variety of mechanisms are hypothesized to produce compensatory dynamics. We concluded that fluctuation dependent endogenous cycles that occur as a consequence of consumer–resource interactions in competitive communities were the most likely explanation for the compensatory dynamics observed in our experiment. As with our previous work, scale‐dependent dynamics were also a key to understanding compensatory dynamics in these experimental communities.
Coaching nutricional para la pérdida de peso
Authors: Giménez Sánchez Jaume , Fleta Sánchez Yolanda , Meya Molina Alba 
Published: May 2016

Introducción: debido a la alta prevalencia de sobrepeso y obesidad se hacen necesarias nuevas estrategias para su prevención y tratamiento. El coaching nutricional (CN) ha emergido en los últimos años y ha demostrado ser efectivo para la pérdida de peso aunque, al ser un concepto innovador, no siempre se utiliza apropiadamente.Objetivo: verificar si el CN, junto con el asesoramiento técnico, es una estrategia efectiva para la disminución de peso en población con sobrepeso u obesidad en comparación con el asesoramiento nutricional por sí solo.Material y métodos: se revisó la bibliografía referente a CN para determinar los parámetros de calidad en cuanto a esta intervención. Se realizó una búsqueda de estudios controlados aleatorizados que aplicaran CN según los parámetros seleccionados y lo compararan con asesoramiento técnico nutricional.Resultados: se analizaron ocho estudios con alta calidad en la intervención de coaching y calidad metodológica media o alta. Seis de ellos indicaron diferencias significativas a favor del grupo que recibió CN.Conclusión: el CN es una estrategia efectiva para bajar de peso. Se necesitan más investigaciones con una definición clara de la metodología utilizada para aportar solidez a este nuevo enfoque.
Performance of a Beryllium Copper Nonmagnetic Drill Collar Alloy
Authors: Dunlevey F. 
Published: May 2016

ABSTRACT
Laboratory characterization and field testing show the advantages of beryllium copper Alloy 25 for use in non-magnetic drill collars, stabilizers, and subs. Beryllium copper is resistant to stress corrosion cracking failures at elevated temperature and pressure in the presence of hydrogen sulfide and dissolved chloride solutions. The alloy is more resistant than stainless steel to galling failure in threaded joints.
Potential of Brass to Remove Inorganic Hg(II) from Aqueous Solution through Amalgamation
Authors: Wenke Axel , Bollen Anne , Richard Jan‐Helge , Biester Harald 
Published: May 2016

ABSTRACT: Brass shavings (CuZn45) were tested for their efficiency to remove Hg(II) from contaminated groundwater through amalgamation. The study was focused on long‐term retention efficiency, the understanding of the amalgamation process and kinetics, and influences of filter surface alteration.Column tests were performed with brass filters (thickness 3 to 9 cm) flushed with 1000 μg/L Hg solution for 8 hours under different flow rates (300 to 600 mL/h). Brass filters consistently removed >98% of Hg from solution independent of filter thickness and flow rate. In a long‐term experiment (filter thickness 2 cm), Hg retention decreased from 96 to 92% within 2000 hours. Batch and column experiments for studying kinetics of Hg removal indicate ~100% Hg removal from solution within only 2 hours. Solid‐phase mercury thermo‐desorption analysis revealed that Hg(0) diffusion into the brass surface controls kinetics of mercury retention. Brass surface alteration could be observed, but did not influence Hg retention.