bluuebunny/crossref_metadata_2025_split huggingface dataset:
To cross or not to cross: modeling wildlife road crossings as a binary response variable with contextual predictors
Authors: Siers Shane R. , Reed Robert N. , Savidge Julie A. 
Published: June 2016

AbstractRoads are significant barriers to landscape‐scale movements of individuals or populations of many wildlife taxa. The decision by an animal near a road to either cross or not cross may be influenced by characteristics of the road, environmental conditions, traits of the individual animal, and other aspects of the context within which the decision is made. We considered such factors in a mixed‐effects logistic regression model describing the nightly road crossing probabilities of invasive nocturnal Brown Treesnakes (Boiga irregularis) through short‐term radiotracking of 691 snakes within close proximity to 50 road segments across the island of Guam. All measures of road magnitude (traffic volume, gap width, surface type, etc.) were significantly negatively correlated with crossing probabilities. Snake body size was the only intrinsic factor associated with crossing rates, with larger snakes crossing roads more frequently. Humidity was the only environmental variable affecting crossing rate. The distance of the snake from the road at the start of nightly movement trials was the most significant predictor of crossings. The presence of snake traps with live mouse lures during a portion of the trials indicated that localized prey cues reduced the probability of a snake crossing the road away from the traps, suggesting that a snake's decision to cross roads is influenced by local foraging opportunities. Per capita road crossing rates of Brown Treesnakes were very low, and comparisons to historical records suggest that crossing rates have declined in the 60+ yr since introduction to Guam. We report a simplified model that will allow managers to predict road crossing rates based on snake, road, and contextual characteristics. Road crossing simulations based on actual snake size distributions demonstrate that populations with size distributions skewed toward larger snakes will result in a higher number of road crossings. Our method of modeling per capita road crossing probabilities as a binary response variable, influenced by contextual factors, may be useful for describing or predicting road crossings by individuals of other taxa provided that appropriate spatial and temporal resolution can be achieved and that potentially influential covariate data can be obtained.
Social information use by competitors: Resolving the enigma of species coexistence in animals?
Authors: Parejo Deseada , Avilés Jesús M. 
Published: June 2016

AbstractThe competitive exclusion principle states that species limited by the same factors cannot share the same environment. Challenging this paradigm, empirical studies often report competitors' coexistence in natural communities, which has long puzzled evolutionary ecologists. Theoretical studies on animal communities have conferred a prime role to the negative effects of interactions in explaining coexistence, but largely neglected the potential positive side of interactions. Here, we propose that living close to a competitor could have beneficial aspects because competitors may provide fitness‐enhancing social information, which under some circumstances may counter the negative effects of competition, thus promoting coexistence. We use conceptual models and discuss factors influencing social information use and their influence on the outcome of competitors' interaction in terms of coexistence probability. Finally, we discuss ecological and evolutionary implications of these processes and suggest exciting avenues for future research on animal communities.
Differential impacts from an extreme cold spell on subtropical vs. tropical specialist bees in southern Florida
Authors: Downing Jason , Borrero Haydee , Liu Hong 
Published: June 2016

AbstractGradual warming and changes in extreme weather patterns associated with human induced climate change are altering the range distributions of species. However, species responses to climate change are predicted to be more strongly affected by extreme events than by changes in mean values. As a result, measuring species' responses to extreme events in addition to the mean changes in climate are necessary to predict species range limits under future conditions. This study examines the impacts of a cold spell in southern Florida on native and an introduced oil‐collecting bees by examining the bees' interactions with two native plants species. Our results provide evidence of differential impacts from an extreme cold event on a native, subtropical bee vs. an introduced, tropical bee. Specifically, the cold spell had little impact on the abundance of the native bee, while the abundance of the introduced, tropical bee was negatively impacted. Our findings demonstrate that extreme cold spells are important climate change‐related phenomena that can have strong impacts on tropical species distributions and abundances, especially at the threshold of their thermal tolerances. Our approach also provided a rare opportunity to examine these impacts on multiple interacting species, which provides a more realistic assessment of the potential impacts of climate change.
Vegetation productivity responds to sub‐annual climate conditions across semiarid biomes
Authors: Barnes Mallory L. , Moran M. Susan , Scott Russell L. , Kolb Thomas E. , Ponce‐Campos Guillermo E. , Moore David J. P. , Ross Morgan A. , Mitra Bhaskar , Dore Sabina 
Published: June 2016

AbstractIn the southwest United States, the current prolonged warm drought is similar to the predicted future climate change scenarios for the region. This study aimed to determine patterns in vegetation response to the early 21st century drought across multiple biomes. We hypothesized that different biomes (forests, shrublands, and grasslands) would have different relative sensitivities to both climate drivers (precipitation and temperature) and legacy effects (previous‐year's productivity). We tested this hypothesis at eight Ameriflux sites in various Southwest biomes using NASA Moderate‐resolution Imaging Spectroradiometer Enhanced Vegetation Index (EVI) from 2001 to 2013. All sites experienced prolonged dry conditions during the study period. The impact of combined precipitation and temperature on Southwest ecosystems at both annual and sub‐annual timescales was tested using Standardized Precipitation Evapotranspiration Index (SPEI). All biomes studied had critical sub‐annual climate periods during which precipitation and temperature influenced production. In forests, annual peak greenness (EVImax) was best predicted by 9‐month SPEI calculated in July (i.e., January–July). In shrublands and grasslands, EVImax was best predicted by SPEI in July through September, with little effect of the previous year's EVImax. Daily gross ecosystem production (GEP) derived from flux tower data yielded further insights into the complex interplay between precipitation and temperature. In forests, GEP was driven by cool‐season precipitation and constrained by warm‐season maximum temperature. GEP in both shrublands and grasslands was driven by summer precipitation and constrained by high daily summer maximum temperatures. In grasslands, there was a negative relationship between temperature and GEP in July, but no relationship in August and September. Consideration of sub‐annual climate conditions and the inclusion of the effect of temperature on the water balance allowed us to generalize the functional responses of vegetation to predicted future climate conditions. We conclude that across biomes, drought conditions during critical sub‐annual climate periods could have a strong negative impact on vegetation production in the southwestern United States.
Burning the legacy? Influence of wildfire reburn on dead wood dynamics in a temperate conifer forest
Authors: Donato Daniel C. , Fontaine Joseph B. , Campbell John L. 
Published: June 2016

AbstractDynamics of dead wood, a key component of forest structure, are not well described for mixed‐severity fire regimes with widely varying fire intervals. A prominent form of such variation is when two stand‐replacing fires occur in rapid succession, commonly termed an early‐seral “reburn.” These events are thought to strongly influence dead wood abundance in a regenerating forest, but this hypothesis has scarcely been tested. We measured dead wood following two overlapping wildfires in conifer‐dominated forests of the Klamath Mountains, Oregon (USA), to assess whether reburning (15‐yr interval, with >90% vegetation mortality) resulted in lower dead wood abundance and altered character relative to once‐burned stands, and how any differences may project through succession. Total dead wood mass (standing + down) following the reburn (169 ± 83 Mg/ha [95%CI]) was 45% lower than after a single fire (309 ± 87 Mg/ha). Lower levels in reburn stands were due to, in roughly equal parts, additional combustion and greater time for decay. Although a single fire in mature forest both consumed and created dead wood (by killing large live trees), a reburn only consumed dead wood (few large live trees to kill). Charred biomass (black carbon generation) was higher in reburned stands by a factor of 2 for logs and 8 for snags. Projecting these stands forward (notwithstanding future disturbances) suggests: (1) the near‐halving of dead‐wood mass in reburn stands will persist for ~50 yr until the recruitment of new material begins, and (2) the reburn signature on dead wood abundance will remain apparent for over a century. These findings demonstrate how a single stochastic variation in disturbance interval can impart lasting influence on dead‐wood succession, reinforcing the notion that many temperate forests exist in a state of dead‐wood disequilibrium governed by site‐specific disturbance history. Accounting for such variation in disturbance impacts is crucial to better understanding forests with complex mixed‐severity disturbance regimes and with increasing stochasticity under climatic change.
Eutrophication triggers contrasting multilevel feedbacks on litter accumulation and decomposition in fens
Authors: Emsens W.‐J. , Aggenbach C. J. S. , Grootjans A. P. , Nfor E. E. , Schoelynck J. , Struyf E. , van Diggelen R. 
Published: June 2016

AbstractEutrophication is a major threat for the persistence of nutrient‐poor fens, as multilevel feedbacks on decomposition rates could trigger carbon loss and increase nutrient cycling. Here, we experimentally investigate the effects of macronutrient (NPK) enrichment on litter quality of six species of sedge (Carex sp.), which we relate to litter decomposition rates in a nutrient‐poor and nutrient‐rich environment. Our research focused on four levels: we examined how eutrophication alters (1) fresh litter production (“productivity shift”), (2) litter stoichiometry within the same species (“intraspecific shift”), (3) overall litter stoichiometry of the vegetation under the prediction that low‐competitive species are outcompeted by fast‐growing competitors (“interspecific shift”), and (4) litter decomposition rates due to an altered external environment (e.g., shifts in microbial activity; “exogenous shift”). Eutrophication triggered a strong increase in fresh litter production. Moreover, individuals of the same species produced litter with lower C:N and C:P ratios, higher K contents, and lower lignin, Ca and Mg contents (intraspecific shift), which increased litter decomposability. In addition, species typical for eutrophic conditions produced more easily degradable litter than did species typical for nutrient‐poor conditions (interspecific shift). However, the effects of nutrient loading of the external environment (exogenous shift) were contradictory. Here, interactions between litter type and ambient nutrient level indicate that the (exogenous) effects of eutrophication on litter decomposition rates are strongly dependent of litter quality. Moreover, parameters of litter quality only correlated with decomposition rates for litter incubated in nutrient‐poor environments, but not in eutrophic environments. This suggests that rates of litter decomposition can be uncoupled from litter stoichiometry under eutrophic conditions. In conclusion, our results show that eutrophication affects litter accumulation and ‐decomposition at multiple levels, in which stimulatory and inhibitory effects interact. The cumulative effect of these interactions ultimately determine whether peatlands remain sinks or become sources of carbon under eutrophic conditions.
Consequences of toxic secondary compounds in nectar for mutualist bees and antagonist butterflies
Authors: Jones Patricia L. , Agrawal Anurag A. 
Published: June 2016

AbstractAttraction of mutualists and defense against antagonists are critical challenges for most organisms and can be especially acute for plants with pollinating and non‐pollinating flower visitors. Secondary compounds in flowers have been hypothesized to adaptively mediate attraction of mutualists and defense against antagonists, but this hypothesis has rarely been tested. The tissues of milkweeds (Asclepias spp.) contain toxic cardenolides that have long been studied as chemical defenses against herbivores. Milkweed nectar also contains cardenolides, and we have examined the impact of manipulating cardenolides in nectar on the foraging choices of two flower visitors: generalist bumble bees, Bombus impatiens, which are mutualistic pollinators, and specialist monarch butterflies, Danaus plexippus, which are herbivores as larvae and ineffective pollinators as adults. Although individual bumble bees in single foraging bouts showed no avoidance of cardenolides at the highest natural concentrations reported for milkweeds, a pattern of deterrence did arise when entire colonies were allowed to forage for several days. Monarch butterflies were not deterred by the presence of cardenolides in nectar when foraging from flowers, but laid fewer eggs on plants paired with cardenolide‐laced flowers compared to controls. Thus, although deterrence of bumble bees by cardenolides may only occur after extensive foraging, a primary effect of nectar cardenolides appears to be reduction of monarch butterfly oviposition.
Stream drying drives microbial ammonia oxidation and first‐flush nitrate export
Authors: Merbt Stephanie N. , Proia Lorenzo , Prosser James I. , Martí Eugènia , Casamayor Emilio O. , von Schiller Daniel 
Published: June 2016

AbstractStream microbial communities and associated processes are influenced by environmental fluctuations that may ultimately dictate nutrient export. Discharge fluctuations caused by intermittent stream flow are increasing worldwide in response to global change. We examined the impact of flow cessation and drying on in‐stream nitrogen cycling. We determined archaeal (AOA) and bacterial ammonia oxidizer (AOB) abundance and ammonia oxidation activity in surface and deep sediments from different sites along the Fuirosos stream (Spain) subjected to contrasting hydrological conditions (i.e., running water, isolated pools, and dry streambeds). AOA were more abundant than AOB, with no major changes across hydrological conditions or sediment layers. However, ammonia oxidation activity and sediment nitrate content increased with the degree of stream drying, especially in surface sediments. Upscaling of our results shows that ammonia oxidation in dry streambeds can contribute considerably (~50%) to the high nitrate export typically observed in intermittent streams during first‐flush events following flow reconnection. Our study illustrates how the dry channels of intermittent streams can be potential hotspots of ammonia oxidation. Consequently, shifts in the duration, spatial extent and severity of intermittent flow can play a decisive role in shaping nitrogen cycling and export along fluvial networks in response to global change.
Development and validation of a novel microwave assisted extraction method for fish lipids
Authors: Costa Débora dos Santos Venâncio , Bragagnolo Neura 
Published: June 2016

A novel microwave assisted extraction (MAE) method for fish lipids was optimized by means of a central composite design and validated using a fish tissue standard reference material (SRM, 1946, NIST). Scanning electron microscopy showed that MAE caused total disruption of the fish tissue, thus lipid migration to the extraction solvent was more efficient and faster in comparison to the Folch method. The lipid content of the SRM obtained by MAE (10.1 ± 0.2 g/100 g) was similar to that declared on the certificate (10.2 ± 0.5 g/100 g). The use of microwave energy did not alter the fatty acid composition of the fish nor formed lipid oxidation derived compounds at higher levels than in the Folch method. The MAE method was applied to fishes with different lipid contents, tilapia, pacu, and hake. MAE is a fast and robust technique with low solvent consumption when compared to the Folch method.Practical applications: MAE presented the following advantages over the Folch method: the lipids can be extracted from up to 12 samples simultaneously, it reduces the extraction time by up to 90%, produces less residues, reduces solvent consumption proportionaly to the mass used by up to 25%, and contributes to a reduction in toxicity in the environment by substituting chloroform with ethyl acetate.The MAE method was applied to fishes with different lipid contents, tilapia, pacu, and hake.
Recurrent laryngeal nerve injury in thyroid surgery: Clinical pathways and resources consumption
Authors: Ferrari Cesare Carlo , Rausei Stefano , Amico Francesco , Boni Luigi , Chiang Feng‐Yu , Wu Che‐Wei , Kim Hoon Yub , Dionigi Gianlorenzo 
Published: June 2016

AbstractBackgroundThe impact of recurrent laryngeal nerve (RLN) injury management in thyroid surgery seems to be relevant to patients, National Healthcare System (NHS), and society.MethodsWe studied resource consumption in the management of patients with RLN injury versus noninjured patients investigating 3 perspectives (patients, NHS, and society) in 5 clinical pathways.ResultsDirect medical costs supported by the NHS range from a minimum of euro (€) 79.46 to a maximum of € 3261.95. From the patient's perspective, the direct medical costs supported by the patient increased from a minimum of € 3.60 to a maximum of € 499.45. Productivity losses were accounted in € 156 per day per patient. From the NHS perspective, the percentage increase ranged from 43.25% to 98.14%. From the patient's perspective, it ranged from 51.52% to 80.60%.ConclusionThe analysis shows a significant economic impact of RLN injury management, which varies depending on the damage, duration, and severity. © 2016 Wiley Periodicals, Inc. Head Neck 38: 1708–1716, 2016
Determinants of Liquidity (Re)Allocation and the Decision to Cross‐List or Cross‐Delist
Authors: Füss Roland , Hommel Ulrich , Plagge Jan‐Carl 
Published: June 2016

AbstractThis paper examines the factors influencing the liquidity allocation between local and foreign dual listings. Based on a comprehensive data set covering the period between 2001 and 2011, empirical results suggest that the fraction of trading in the foreign listing decreases with a higher degree of stock market integration measured as the stock price correlation with the world market. Furthermore, the analysis of individual cross‐listings reveals that both an improvement of a country's state of economic development and a better regulatory environment significantly affect the allocation of trading. While an improvement in economic development increases both local and foreign liquidity, a strengthening of regulatory standards leads to a decrease in trading volumes at foreign exchanges. Finally, the liquidity share in the foreign listing is found to decrease over time, a trend that turns out to be driven by developing rather than by developed markets. Copyright © 2016 John Wiley & Sons, Ltd.
Wide‐field time‐gated photoluminescence microscopy for fast ultrahigh‐sensitivity imaging of photoluminescent probes
Authors: Razali Wan A. W. , Sreenivasan Varun K. A. , Bradac Carlo , Connor Mark , Goldys Ewa M. , Zvyagin Andrei V. 
Published: June 2016

Fluorescence microscopy is a fundamental technique for the life sciences, where biocompatible and photostable photoluminescence probes in combination with fast and sensitive imaging systems are continually transforming this field. A wide‐field time‐gated photoluminescence microscopy system customised for ultrasensitive imaging of unique nanoruby probes with long photoluminescence lifetime is described. The detection sensitivity derived from the long photoluminescence lifetime of the nanoruby makes it possible to discriminate signals from unwanted autofluorescence background and laser backscatter by employing a time‐gated image acquisition mode. This mode enabled several‐fold improvement of the photoluminescence imaging contrast of discrete nanorubies dispersed on a coverslip. It enabled recovery of the photoluminescence signal emanating from discrete nanorubies when covered by a layer of an organic fluorescent dye, which were otherwise invisible without the use of spectral filtering approaches. Time‐gated imaging also facilitated high sensitivity detection of nanorubies in a biological environment of cultured cells. Finally, we monitor the binding kinetics of nanorubies to a functionalised substrate, which exemplified a real‐time assay in biological fluids.
3D‐pseudo colour images of nanorubies immersed in a highly fluorescent dye solution. Nanoruby photoluminescence is subdued by that of the dye in continuous excitation/imaging (left), however it can be recovered by time‐gated imaging (right). At the bottom is schematic diagram of nanoruby assay in a biological fluid.magnified image3D‐pseudo colour images of nanorubies immersed in a highly fluorescent dye solution. Nanoruby photoluminescence is subdued by that of the dye in continuous excitation/imaging (left), however it can be recovered by time‐gated imaging (right). At the bottom is schematic diagram of nanoruby assay in a biological fluid.
Increase of forage dryness induces differentiated anatomical response in the sheep rumen compartments
Authors: Scocco Paola , Mercati Francesca , Tardella Federico Maria , Catorci Andrea 
Published: June 2016

ABSTRACTThe aim of this study was to investigate how the Surface Enlargement Factor (SEF) and the epithelial keratinization degree of sheep rumen change in response to phytomass production, and to forage fiber and water content during the pasture vegetative cycle. The study used eighteen sheep nourished with dry hay and cereals during the winter season and with fresh hay during the pasture vegetative cycle. We collected samples from rumen indicative regions for two consecutive years characterized by different rainfall and pasture productivity values. We evaluated the densities (D) of rumen papillae to estimate the rumen SEF, and the keratinization percentage of the epithelial lining; these parameters showed differentiated modifications in the four ruminal analyzed compartments in response to pasture seasonal conditions. In addition, we performed Canonical Redundancy Analysis (RDA) on the “keratinization and SEF” matrix constrained by phytomass, water, and crude fiber contents of pasture at different time in the two considered years to highlight how rumen features answer to pasture conditions. Atrium (A) and ventral sac (VS) keratinization showed a strict positive correlation to crude fiber, while SEF of VS was positively related to phytomass and forage water content. The degree of keratinization of the rumen VS epithelium proved to be a useful parameter for evaluating anatomical variations in the short term period related to pasture features; in addition, its monitoring could be carried out through biopsy, thus avoiding the killing of animals. The study also leads to the application of the 3Rs (Replacement; Reduction; and Refinement). Microsc. Res. Tech. 79:738–743, 2016. © 2016 Wiley Periodicals, Inc.