bluuebunny/crossref_metadata_2025_split huggingface dataset:
Empirical test on the relative climatic sensitivity between individuals of narrowly and broadly distributed species
Authors: Lacher Iara , Schwartz Mark W. 
Published: April 2016

AbstractClimate change is already influencing global ecology, exacerbating human‐induced biodiversity loss with potentially devastating results. A first step to addressing climate change impacts on conservation is to better understand how and to what extent species will be affected. Species with smaller geographic distributions are commonly perceived to be at highest risk of extinction. However, estimates of species vulnerability are frequently based on simplifying assumptions regarding climatic tolerance, usually arrived at through the use of models that associate mean spatial or temporal climate values with species distributions. Model estimated climatic tolerances may be improved by incorporating either finer spatial or temporal resolutions and/or additional distribution‐limiting factors like dispersal, habitat connectivity, and species interactions. However, the underlying assumption that species‐level climatic reflect individual tolerances can skew vulnerability estimates toward over‐or underestimation. We use empirically derived fitness reaction norms of biomass and seed pod count to estimate the relative sensitivity of individuals of broadly distributed (BD) and narrowly distributed (ND) species across temperature and water gradients. Temperature and water treatments were based on local climate station data and IPCC projections of climatic change. On the basis of fitness reaction norms, we infer relative vulnerability to examine the assumption that ND species are relatively more vulnerable to climatic change than BD species. Study species included the BD Mimulus guttatus and Clarkia purpurea and the ND Mimulus nudatus and Clarkia gracilis ssp. tracyi. Compared to M. nudatus (ND), individuals of M. guttatus (BD) exhibited biomass responses that were significantly more sensitive to temperature and seed pod count responses that were significantly more sensitive to water and temperature. Conversely, compared to C. purpurea (BD), C. gracilis ssp. tracyi (ND) individuals exhibited biomass and seed pod count responses that were significantly more sensitive to temperature. In addition, we measured unexpected positive responses from both Clarkia species to increases in temperature. Our results support the idea that, when examined at a local scale, the size of a species' geographic distribution does not necessarily correlate to climate change vulnerability.
Contact heterogeneities in feral swine: implications for disease management and future research
Authors: Pepin Kim M. , Davis Amy J. , Beasley James , Boughton Raoul , Campbell Tyler , Cooper Susan M. , Gaston Wes , Hartley Steve , Kilgo John C. , Wisely Samantha M. , Wyckoff Christy , VerCauteren Kurt C. 
Published: April 2016

AbstractContact rates vary widely among individuals in socially structured wildlife populations. Understanding the interplay of factors responsible for this variation is essential for planning effective disease management. Feral swine (Sus scrofa) are a socially structured species which pose an increasing threat to livestock and human health, and little is known about contact structure. We analyzed 11 GPS data sets from across the United States to understand the interplay of ecological and demographic factors on variation in co‐location rates, a proxy for contact rates. Between‐sounder contact rates strongly depended on the distance among home ranges (less contact among sounders separated by >2 km; negligible between sounders separated by >6 km), but other factors causing high clustering between groups of sounders also seemed apparent. Our results provide spatial parameters for targeted management actions, identify data gaps that could lead to improved management and provide insight on experimental design for quantitating contact rates and structure.
Major drivers of invasion risks throughout the world
Authors: Bellard C. , Leroy B. , Thuiller W. , Rysman J.‐F. , Courchamp F. 
Published: April 2016

AbstractIn this paper, we investigate how climate, land use, habitat characteristics, and socioeconomic activities contribute to predict the current potential distributions of the “100 among the world's worst invasive alien species”. We calculated the predictive power of each of the 41 variables for the 95 species including a large number of plants, vertebrates and invertebrates. We then calibrated the species distribution models with a set of appropriate variables for each invasive alien species to predict the potential distribution of these species and identify the major regions of origin of the invasive alien species. We found that climate variables were primarily predictors of the distribution of the global invaders studied. In addition, the habitat characteristics were also important predictors following by the socioeconomic variables such as the nearest distance to airports, seaports and human population density. We show that the potential areas at the highest risk of invasions from these species are located in Western Europe, Eastern United States, Central America, the eastern coast of Australia, and some Indonesian islands. We argue that these potential hotspots of invasions should be monitored in priority to prevent new invasions from these species. This study provides evidence of the importance of considering both habitat characteristics, socioeconomic and climate change factors for the current and future predictions of biological invasions.
The implications of mid‐latitude climate extremes for North American migratory bird populations
Authors: La Sorte Frank A. , Hochachka Wesley M. , Farnsworth Andrew , Dhondt André A. , Sheldon Daniel 
Published: April 2016

AbstractMid‐latitude climate extremes are projected to increase in frequency under global climate change. How this may affect migratory bird populations is not well understood. The mid‐latitudes of North America experienced an extreme warming event during March 2012 that advanced the spring phenology of ecological productivity, resulting in lower levels of productivity during the summer. Here, we test the predictions that: (1) short‐distance migratory birds, due to geographic proximity and more flexible migratory behavior, should advance their spring migration phenology; and (2) breeding populations, due to lower summer productivity, should have reduced occurrences. We used occurrence data for 353 bird species from the eBird database to calculate weekly occurrence anomalies for 2012 relative to the 2010–2014 average. We identified species having unusually large positive occurrence anomalies during March 2012 and species having unusually large negative occurrence anomalies during July–August 2012. For each category, we summarized migration strategies, geographic distributions, and annual associations with temperature and ecological productivity. Short‐distance migrants whose winter and breeding ranges intersect the mid‐latitudes advanced their spring migration phenology during March (n = 21). Long‐distance migrants whose winter and breeding distributions were weakly associated with the mid‐latitudes had lower occurrences during the summer (n = 32). Five species were shared between the two categories. Within species’ winter ranges, temperature and ecological productivity were higher than expected during March; within species’ breeding ranges, ecological productivity was lower than expected during the summer. These differences were strongest for the 21 short‐distance migrants. Following our expectations, mid‐latitude climate extremes and associated ecological consequences broadly affected avian migration and breeding activities within the region. Our findings suggest short‐distance migrants are more flexible and resilient, whereas populations of long‐distance migrants are at a distinct disadvantage, which may intensify if the frequency of these events increases.
Could the lateral transfer of nutrients by outbreaking insects lead to consequential landscape‐scale effects?
Authors: Landry Jean‐Sébastien , Parrott Lael 
Published: April 2016

AbstractThe processes that transfer nutrients laterally over large distances are limited within terrestrial ecosystems. Here, we present the hypothesis that outbreaking insects can sometimes transport consequential amounts of embodied nutrients over long distances, thereby connecting ecological dynamics across space and leading to potential emergent effects at the landscape scale that have not been specifically addressed heretofore. Based on previously published data on insect population density, individual body mass, and nutrient content, we present initial quantitative estimates of nitrogen and phosphorus fluxes for various outbreaking insect species in different ecosystems. The results suggest that during the phases of major population change within an outbreak cycle, this process may transfer, over a given area, amounts of nutrients that exceed annual input from contemporaneous levels of atmospheric deposition, particularly for phosphorus. In addition, the relative strength of the process was likely even higher in the preindustrial era, especially for nitrogen, due to a weaker anthropogenic influence on atmospheric deposition at that time. The values we have found are comparable to the results from previous studies on 2‐D nutrient fluxes by other animals and that have been considered consequential for ecosystem processes. We further illustrate the implications of the process for the spatial distribution of nutrients and resulting ecological complexity and argue that the process is inherently scale dependent, contrary to vertical fluxes like atmospheric deposition. Moreover, we provide suggestions for future studies, both empirical and theoretical, that would better quantify the strength of the process and assess its implications. Given that the productivity of most natural terrestrial ecosystems depends primarily on locally recycled nutrients and that spatial source–sink nutrient dynamics has been shown to have important ecological consequences, the long‐distance lateral transfer of nutrients by outbreaking insects appears like a relevant landscape‐level process worthwhile of more specific attention.
Genetic co‐structuring in host‐parasite systems: Empirical data from raccoons and raccoon ticks
Authors: Dharmarajan Guha , Beasley James C. , Beatty William S. , Olson Zachary H. , Fike Jennifer A. , Rhodes Olin E. 
Published: April 2016

AbstractMany aspects of parasite biology critically depend on their hosts, and understanding how host‐parasite populations are co‐structured can help improve our understanding of the ecology of parasites, their hosts, and host‐parasite interactions. This study utilized genetic data collected from raccoons (Procyon lotor), and a specialist parasite, the raccoon tick (Ixodes texanus), to test for genetic co‐structuring of host‐parasite populations at both landscape and host scales. At the landscape scale, our analyses revealed a significant correlation between genetic and geographic distance matrices (i.e., isolation by distance) in ticks, but not their hosts. While there are several mechanisms that could lead to a stronger pattern of isolation by distance in tick vs. raccoon datasets, our analyses suggest that at least one reason for the above pattern is the substantial increase in statistical power (due to the ≈8‐fold increase in sample size) afforded by sampling parasites. Host‐scale analyses indicated higher relatedness between ticks sampled from related vs. unrelated raccoons trapped within the same habitat patch, a pattern likely driven by increased contact rates between related hosts. By utilizing fine‐scale genetic data from both parasites and hosts, our analyses help improve our understanding of epidemiology and host ecology.
Estimating competition coefficients in tree communities: a hierarchical Bayesian approach to neighborhood analysis
Authors: Tatsumi Shinichi , Owari Toshiaki , Mori Akira S. 
Published: April 2016

AbstractQuantifying the strength of competition and understanding how it translates into consequences at the community level are among the key aims of plant ecology. Neighborhood analysis based on the neighborhood competition index has been widely used to estimate species‐specific competition coefficients in tree communities. These estimates, however, could not be estimated for rare species with small sample sizes using the conventional species‐by‐species approach. Here, we develop a new modeling framework for neighborhood analysis in which the competition coefficient is assumed to have a hierarchical parameter structure. Using actual tree census data consisting of 38 species, we demonstrate that the hierarchical model enables us to estimate competition coefficients for all species, including rare ones, within a community. The hierarchical models were selected over the models based on the species‐by‐species approach as a result of model selection, in either cases where we assumed the competitive strength is determined by niche difference or competitive ability difference. Our results suggest that the hierarchical approaches can serve as a useful alternative to species‐by‐species approach for estimating competition coefficients in tree communities.
Variation in metapopulation dynamics of a wetland mammal: The effect of hydrology
Authors: van der Merwe Jorista , Hellgren Eric C. , Schauber Eric M. 
Published: April 2016

AbstractKey factors affecting metapopulation dynamics of animals include patch size, isolation, and patch quality. For wetland‐associated species, hydrology can affect patch availability, connectivity, and potentially habitat quality; and therefore drive metapopulation dynamics. Wetlands occurring on natural river floodplains typically have more dynamic hydrology than anthropogenic wetlands. Our overall objective was to assess the multiyear spatial and temporal variation in occupancy and turnover rates of a semi‐aquatic small mammal at two hydrologically distinct wetland complexes. We live‐trapped marsh rice rats (Oryzomys palustris) for 3 yr and >50 000 trap nights at nine wetland patches on the Mississippi River floodplain and 14 patches at a reclaimed surface mine in southern Illinois. We used dynamic occupancy modeling to estimate initial occupancy, detection, colonization, and extinction rates at each complex. Catch per unit effort (rice rats captured/1000 trap nights) was markedly higher at the floodplain site (28.1) than the mining site (8.1). We found no evidence that temperature, rainfall, or trapping effort affected detection probability. Probability of initial occupancy was similar between sites and positively related to patch size. Patch colonization probability at both sites was related negatively to total rainfall 3 weeks prior to trapping, and varied across years differently at each site. We found interacting effects of site and rainfall on extinction probability: extinction increased with total rainfall 3 months prior to trapping but markedly more at the floodplain site than at the mining site. These site‐specific patterns of colonization and extinction are consistent with the rice rat metapopulation in the floodplain exhibiting a habitat‐tracking dynamic (occupancy dynamics driven by fluctuating quality), whereas the mineland complex behaved more as a classic metapopulation (stochastic colonization & extinction). Our study supports previous work demonstrating metapopulation dynamics in wetland systems being driven by changes in patch quality (via hydrology) rather than solely area and isolation.
Host community composition and defensive symbionts determine trematode parasite abundance in host communities
Authors: Hopkins Skylar R. , Ocampo Jancarla M. , Wojdak Jeremy M. , Belden Lisa K. 
Published: April 2016

AbstractHost species vary in their propensity to become infected by and transmit parasites, and this variation in host competency can influence parasite transmission within host communities. Host competency is often attributed to morphological, physiological, and behavioral defenses of hosts, but hosts commonly have an additional, lesser studied form of protection: defensive symbionts. For instance, snails are facultatively defended by ectosymbiotic oligochaete worms (Chaetogaster limnaei) that consume free‐living trematode parasites, bacteria protect amphibians from the fungus that causes chytridiomycosis, and ants protect plants from herbivores. In addition to reducing infection on their hosts, defensive symbionts may influence parasite transmission to other hosts by redirecting parasites toward other hosts and/or removing parasites from the system. We explored these possibilities by examining the relative roles of community composition and the presence of defensive symbionts (C. limnaei) in determining trematode infection intensity among second intermediate host communities composed of snails (Helisoma trivolvis) and tadpoles (Rana catesbeiana). Parasites were dramatically more successful at infecting snails than tadpoles, which led to more total parasites in host communities where snails were present. In addition, defensive symbionts substantially reduced snail infection intensity and thus reduced the total number of parasites in communities containing symbiont‐defended snail hosts. Neither host community composition nor the presence of defensive symbionts on snails influenced individual tadpole infection in our experiments. Therefore, in our experiments, second intermediate host community structure did not influence individual host tadpole infection risk, but did influence total parasite transmission.
Specialization of oribatid mites to forest microhabitats—the enigmatic role of litter
Authors: Wehner Katja , Norton Roy A. , Blüthgen Nico , Heethoff Michael 
Published: April 2016

AbstractThe degree of ecological specialization influences the biological performance of species in their natural environment and affects the coexistence of different taxa. However, on a small scale, the diversity of microarthropods that coexist in forest soils and leaf litter seems inordinately high, a situation known as the “enigma of soil animal species diversity”. Since recent studies point to the importance of small‐scale heterogeneity to explain this phenomenon, we use interaction networks between microhabitats and their inhabitants to resolve and quantify the community structure (species composition, richness, and diversity) of oribatid mites (Oribatida) in five discrete, patchy substrates—dead wood, lichens, mosses, sod, and tree bark—and in the general leaf litter. Since oribatid mites are ubiquitous in all these microhabitats in temperate forests, the analysis of their community structure in the light of generalization and specialization might help us understand the ecological role of litter. We investigated whether litter acts as a specific microhabitat with the intrinsic characteristics that enable the “enigmatic” high diversity of oribatid mites (Habitat‐Hypothesis), if litter acts as a source from which oribatid mite species more or less randomly invade different associated microhabitat‐patches (Source‐Hypothesis), or if litter only connects patchily distributed microhabitats with specific species compositions (Connector‐Hypothesis). In total, 25,162 adult oribatid mite individuals were analyzed, most belonging to the derived group Brachypylina. Species richness, density, and diversity differed among microhabitats with highest values found in mosses and dead wood and lowest on tree bark. In general, specialization of oribatid mite species was low—highest on tree bark and in grass sod—but differed slightly among oribatid mite taxa (Enarthronota, Mixonomata, Nothrina, Brachypylina). The Connector‐ and Habitat‐Hypotheses can explain the distribution of most oribatid mite species but the Source‐Hypothesis explains the distribution patterns for only a few species.
Probability of actuating a seismic shutoff device
Authors: Malhotra Praveen K. 
Published: April 2016

SummaryAutomatic seismic shutoff devices are used to reduce the risk to gas and liquid distribution systems from earthquakes. In the USA, the gas shutoff devices are tested and certified according to the American Society of Civil Engineers' Standard ASCE 25. During tests, devices are shaken by simple harmonic (sinusoidal) motions of different frequencies and checked for actuation. Because earthquake motions are not sinusoidal, the amplitude of earthquake motions that will actuate these devices is not clearly understood. This paper determines the probability of actuating devices by earthquake motions of different amplitudes. The probability of actuation increases with increase in the resultant peak horizontal ground acceleration (PGA). The probability of actuation is 50% for PGA = 0.23g and 90% for PGA = 0.31g, where g = 9.81 m/s2 = acceleration due to gravity. On a ‘stiff soil’ site in San Francisco, CA, the mean recurrence interval of actuation is 51 years. On a similar site in Boston, MA, the mean recurrence interval of actuation is 3000 years. ASCE 25 compliant devices are actuated by high frequencies in ground motions. There is greater uncertainty in the actuation of these devices by ground motions that are damaging to very flexible systems. Copyright © 2016 John Wiley & Sons, Ltd.
Relaxation base seismic isolator
Authors: Vu Duc Chuan , Politopoulos Ioannis , Diop Sette 
Published: April 2016

SummaryThis paper deals with the use, for seismic applications, of a Maxwell element in parallel with a low damping isolator. The study of the properties of the frequency response function shows that this isolator is capable to reduce the base displacement of isolated structures with no considerable amplification of the non‐isolated modes. This is, also, confirmed by the floor response spectra under earthquake excitations. Hence, the previously mentioned isolator does not present the drawbacks met when base displacement is reduced by increasing damping. Moreover, it seems that its performance is comparable with that of more elaborated and expensive techniques combining passive and semi‐active devices. Copyright © 2016 John Wiley & Sons, Ltd.
Feasibility of a novel classification for parotid gland cytology: A retrospective review of 512 cytology reports taken from 4 United Kingdom general hospitals
Authors: Bajwa Mandeep S. , Rose Samantha J. , Mairembam Priya , Nash Robert , Hotchen David , Godden Daryl , Alam Peyman , Daborn Louise , Spedding Anne V. , Brennan Peter A. 
Published: April 2016

AbstractBackgroundA novel classification for parotid cytology has been previously proposed. The purpose of this study was to assess the feasibility and clinical relevance of this classification.MethodBetween 2010 and 2013, cytology reports from 4 United Kingdom general hospitals were retrospectively classified and compared to histological and clinical outcomes.ResultsBased on the cytology reports of 512 patients, we revised our previous “P” system to a “Sal” (salivary) classification to encompass all cytologic outcomes. The percentage of patients with a final diagnosis of malignancy according to each category heading were: Sal 1 (inadequate) 7.9%; Sal 2I (nonneoplastic) 10%; Sal 2N (benign neoplastic) 1.4%; Sal 3 (atypical) 20.4%; Sal 4 (suspicious) 52.6%; Sal 5P (primary salivary gland malignancy) 71.4%; Sal 5NOS (malignancy not otherwise specified) 100%; and Sal 5M (metastasis) 91.7%.ConclusionBy stratifying the probability of encountering a malignant neoplasm, the classification could guide clinical management decisions. A future prospective study is warranted. © 2016 Wiley Periodicals, Inc. Head Neck 38: 1708–1716, 2016