bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tuning of the Seebeck Coefficient and the Electrical and Thermal Conductivity of Hybrid Materials Based on Polypyrrole and Bismuth Nanowires
Authors: Hnida Katarzyna E. , Pilarczyk Kacper , Knutelski Marcin , Marzec Mateusz , Gajewska Marta , Kosonowski Artur , Chlebda Damian , Lis Bartłomiej , Przybylski Marek 
Published: April 2018

AbstractThe growing demand for clean energy catalyzes the development of new devices capable of generating electricity from renewable energy resources. One of the possible approaches focuses on the use of thermoelectric materials (TE), which may utilize waste heat, water, and solar thermal energy to generate electrical power. An improvement of the performance of such devices may be achieved through the development of composites made of an organic matrix filled with nanostructured thermoelectric materials working in a synergetic way. The first step towards such designs requires a better understanding of the fundamental interactions between available materials. In this paper, this matter is investigated and the questions regarding the change of electrical and thermal properties of nanocomposites based on low‐conductive polypyrrole enriched with bismuth nanowires of well‐defined geometry and morphology is answered. It is clearly demonstrated that the electrical conductivity and the Seebeck coefficient may be tuned either simultaneously or separately within particular Bi NWs content ranges, and that both parameters may be increased at the same time.
An Effective Heterogeneous Catalyst of [BMIM]3PMo12O40 for Selective Sugar Epimerization
Authors: Bayu Asep , Yoshida Akihiro , Karnjanakom Surachai , Zuo Zhijun , Hao Xiaogang , Abudula Abuliti , Guan Guoqing 
Published: April 2018

AbstractThe development of heterogeneous catalysts for the epimerization of sugars has received much less attention than that for the isomerization of sugars. To date, molybdates are the most effective catalysts for the epimerization of sugars, although they lack stability toward hydrolysis of their active sites in water. To solve the issue of the formation of a highly water‐soluble heteropolyblue (PMored) for phosphomolybdates (PMos) in aqueous reaction systems, herein, a 1‐butyl‐3‐methylimidazolium phosphomolybdate ([BMIM]3PMo12O40) was synthesized through an ion‐exchange method. This catalyst was effective and selective for the C2‐epimerization of sugars under mild reaction conditions (<100 °C; 1–2 h) with good water‐tolerant properties. The reaction was confirmed to occur in a heterogeneous manner and no leaching of PMored was detected by means of UV/Vis spectroscopy. Moreover, the catalyst can be simply separated by filtration and reused for at least eight cycles without a drop in catalytic activity. XRD, FTIR, and X‐ray photoelectron spectroscopy measurements indicate that the catalyst is stable under the reaction conditions. In a comparison of the catalytic activity and surface wettability with those of other PMo salts, that is, 1‐ethyl‐3‐methylimidazolium phosphomolybdate ([EMIM]3PMo12O40), 1‐hexyl‐3‐methylimidazolium ([HexMIM]3PMo12O40), [choline]3PMo12O40, and cetyltrimethylammonium phosphomolybdate ([CTA]3PMo12O40), it is found that [BMIM]3PMo12O40 has more appropriate hydrophobic–hydrophilic balance, which should be responsible for better catalytic activity and stability.
The paradoxical nexus between corporate social responsibility and sustainable financial performance: Evidence from the international construction business
Authors: Lu Weisheng , Ye Meng , Chau K.W. , Flanagan Roger 
Published: April 2018

AbstractThe aim of the research is to substantiate the hypothesis of a paradoxical dynamic link between corporate social responsibility (CSR) and its material implications including sustainable corporate financial performance (CFP). By analysing a panel of 67 international construction companies from 2006 to 2015, we found that CSR programs can be detrimental to CFP in the short term but conducive to improving it in the long term. The findings of this research indicate that, in the international construction business, the impact of CSR on CFP is not immediate and unchanging, and it takes time to materialize CSR for sustainable development. A significant practical use of this research is to provide evidence for the assertion that business stakeholders should be relieved from short‐termism in assuming social responsibility. Further research is recommended to test this support in a more general business setting towards developing a general theory on CSR and sustainable development.
Diel movement of brown trout,Salmo trutta, is reduced in dense populations with high site fidelity
Authors: Slavík Ondřej , Horký Pavel , Maciak Matúš , Horká Petra , Langrová Iva 
Published: April 2018

AbstractThe movement of individuals within preferred areas is reduced by a high availability of food and information about its distribution, while high number of competitors promotes increased movement. Experienced animals use information about social and physical environment to improve resources exploitation, tended to maintain positions within the preferred areas and reuse the environment that is often referred to as site fidelity. In this study, radio‐telemetry was used to observe the movements of 98 adult brown trout,Salmo trutta, in oligotrophic streams with different population densities; to determine subpopulation site fidelity, 5,195 conspecifics from 14 subpopulations were individually tagged during spring and autumn. During a 7‐year‐long field study, we tested the hypothesis that brown trout individuals from subpopulations with high site fidelity would display lower movement. The hypothesis was supported, and reduced movement was further related to high subpopulation density in association with high slope indicating the physical environment‐influenced movement. The probability of contact between individuals increased with subpopulation site fidelity and subpopulation density. No influence of food abundance on brown trout movement was found. Furthermore, increased body size predicted higher movement (and vice versa). The least movement occurred during the day and during the full moons. Our study tended to show that individuals reused preferred areas and needed less movement to exploit available resources.
Timber harvest as the predominant disturbance regime in northeastern U.S. forests: effects of harvest intensification
Authors: Brown Michelle L. , Canham Charles D. , Murphy Lora , Donovan Therese M. 
Published: April 2018

AbstractHarvesting is the leading cause of adult tree mortality in forests of the northeastern United States. While current rates of timber harvest are generally sustainable, there is considerable pressure to increase the contribution of forest biomass to meet renewable energy goals. We estimated current harvest regimes for different forest types and regions across the U.S. states of New York, Vermont, New Hampshire, and Maine using data from the U.S. Forest Inventory and Analysis Program. We implemented the harvest regimes inSORTIE‐ND, an individual‐based model of forest dynamics, and simulated the effects of current harvest regimes and five additional harvest scenarios that varied by harvest frequency and intensity over 150 yr. The best statistical model for the harvest regime described the annual probability of harvest as a function of forest type/region, total plot basal area, and distance to the nearest improved road. Forests were predicted to increase in adult aboveground biomass in all harvest scenarios in all forest type and region combinations. The magnitude of the increase, however, varied dramatically—increasing from 3% to 120% above current landscape averages as harvest frequency and intensity decreased. The variation can be largely explained by the disproportionately high harvest rates estimated for Maine as compared with the rest of the region. Despite steady biomass accumulation across the landscape, stands that exhibited old‐growth characteristics (defined as ≥300 metric tons of biomass/hectare) were rare (8% or less of stands). Intensified harvest regimes had little effect on species composition due to widespread partial harvesting in all scenarios, resulting in dominance by late‐successional species over time. Our analyses indicate that forest biomass can represent a sustainable, if small, component of renewable energy portfolios in the region, although there are tradeoffs between carbon sequestration in forest biomass and sustainable feedstock supply. Integrating harvest regimes into a disturbance theory framework is critical to understanding the dynamics of forested landscapes, especially given the predominance of logging as a disturbance agent and the increasing pressure to meet renewable energy needs.
Understanding biological effectiveness before scaling up range‐wide restoration investments for Gunnison sage‐grouse
Authors: Doherty Kevin E. , Hennig Jacob D. , Dinkins Jonathan B. , Griffin Kathleen A. , Cook Avery A. , Maestas Jeremy D. , Naugle David E. , Beck Jeffrey L. 
Published: April 2018

AbstractImperiled species recovery is a high‐stakes endeavor where uncertainty surrounding effectiveness of conservation actions can be an impediment to implementation at necessary scales, especially where habitat restoration is required. Gunnison sage‐grouse (Centrocercus minimus) represents one such species in need of large‐scale habitat restoration. It is a federally threatened sagebrush (Artemisia spp.) obligate bird with a limited range in Colorado and Utah. Threats to recovery of Gunnison sage‐grouse include conifer expansion into sagebrush along with additional habitat loss and degradation attributed to human development and agricultural conversion. Recovery of Gunnison sage‐grouse and other sensitive species can be aided by spatial tools that forecast plausible outcomes of conservation actions. We illustrate this by using a novel framework for predicting outcomes of proactive tree removal and subsequent sagebrush restoration for the Gunnison sage‐grouse. To assess threats on Gunnison sage‐grouse lek presence, we developed a spatially explicit breeding habitat model to compare active lek and random pseudo‐absence locations from 2015. Models identified land cover, climatic, and abiotic variables at landscape‐level scales (0.56 and 4 km) most important for predicting breeding habitat. Our model correctly differentiated between lek and pseudo‐absence locations 94% of the time. All but one of the active leks (n = 94) were in areas with >0.65 probability of lek occurrence. Using this probability value as a threshold, we predicted 15% of the current grouse range as high‐quality breeding habitat. Simulated removal of trees in areas with ≤30% tree canopy cover (0.56‐km scale) increased extent of high‐quality habitat fourfold (59%). Hypothetical restoration of sagebrush cover in the same areas increased habitat quality an additional 11%. Our breeding habitat model indicated that targeted tree removal and sagebrush restoration have potential to improve Gunnison sage‐grouse breeding habitat. While our habitat treatment scenarios were not meant to be prescriptive, they highlight that considerable uplift in Gunnison sage‐grouse breeding habitat may be possible across much of its range with cooperation from multiple stakeholders and illustrates the utility of this approach for predicting biological return on investment.
Leaf‐level trade‐offs between drought avoidance and desiccation recovery drive elevation stratification in arid oaks
Authors: Fallon Beth , Cavender‐Bares Jeannine 
Published: April 2018

AbstractUnderstanding the extent to which climate limitations drive elevation stratification among species is integral to predicting the impacts of climate change. Zonation patterns of species within mountains have been well documented, and shifts in these patterns have been correlated with recent warming. However, the physiological mechanisms that explain these zonation patterns are not well understood. We used a system of broadly sympatric oak species within semi‐arid mountains to (1) investigate the extent to which species elevation ranges correlate with climate, (2) test for associations of cold and drought resistances with upper and lower elevation limits, and for trade‐offs between resistance mechanisms with elevation, and (3) examine the extent to which species‐wide climatic ranges predict traits that drive local community assembly along an elevation gradient. We found that aridity gradients but not winter minimum temperatures predict oak stratification. Species differed in drought resistance, demonstrating a trade‐off between drought avoidance and drought recovery. At lower elevations, species avoided drought stress during the dry season through leaf abscission; at upper elevations, they maintained transpiration but recovered from daily desiccation via higher leaf water storage capacity, rather than tolerating desiccation via lower turgor loss points. Freezing resistance, measured as stem electrolyte leakage, was not correlated with elevation differences. Taken together, these results indicate that elevation stratification is linked to drought resistance rather than freezing resistance. We also found evidence of niche partitioning among closely related oaks linked to contrasting leaf phenology. The functional, phenological, and physiological traits important for elevation stratification were correlated with species’ range‐wide mean annual precipitation and precipitation seasonality, but not aridity. Our findings indicate that drought resistance along a leaf avoidance–recovery trade‐off is integral to species stratification within this semi‐arid montane system. Additionally, the mechanism of stratification acts upon traits and strategies conserved at the species level. Species within this system are likely vulnerable to range retraction under increased drought as a consequence of this phenological avoidance–physiological tolerance trade‐off.
Dissolved oxygen concentration affects δ15N values in oyster tissues: implications for stable isotope ecology
Authors: Patterson Heather K. , Carmichael Ruth H. 
Published: April 2018

AbstractTo investigate the potential effects of physiological stress on stable isotope (SI) ratios in oysters, we transplanted hatchery‐reared oysters to reefs that experienced different concentrations of dissolved oxygen (DO) in Mobile Bay, Alabama, USA, a freshwater dominated estuary that experiences periodic hypoxia. We monitored physical, biological, and chemical parameters of the environment and biological responses in oysters, including growth, survival, and carbon and nitrogen SI ratios in tissues. Oysters at the low DO site (3.66 ± 0.05 mg/L) had ~1 ‰ higher δ15N values in tissue than oysters at the higher DO site (6.00 ± 0.06 mg/L). Oysters grown at the low DO site also had lower survival (25%) and no growth compared to oysters at the higher DO site, which had 96% survival and growth rates up to 38 mm/d. Multivariate and regression statistics related DO concentration to changes in δ15N values in three different oyster tissues (adductor muscle, gut gland, and gill), regardless of similarity in suspended particulate matter and chlorophyll a concentrations (food quantity), C:N (food quality), and SI composition in available foods between sites. The increased δ15N values in oyster tissues under low DO conditions during this study were consistent with known starvation responses in which oysters stop feeding and catabolize tissues. These data indicate that environmental conditions related to physiological stress can affect SI ratios in oysters in a similar manner to changes in diet composition. Small changes in SI ratios, therefore, may be physiologically significant indicators of environmental stress. When analyzing SI ratios for food web dynamics and source tracing, potential for confounding effects of environmental stressors should be considered.
Unsuccessful invaders structure a natural freshwater phytoplankton community
Authors: Buchberger Felicitas , Stockenreiter Maria 
Published: April 2018

AbstractSpecies invasion dynamics are a core topic in ecology and the effects of species invasions on ecosystems are well described. However, the knowledge about the mechanisms during the invasion process itself is limited. Many interactions between invaders and resident species occur during the invasion process. These interactions influence individual species abundance and subsequently community composition. Even though invaders are often unsuccessful, the very short interactions with the resident species can influence species abundances and therefore community composition. The prominent effects of unsuccessful invaders on community composition were already predicted in a theoretical model. To empirically test the effect of such unsuccessful invaders on a resident phytoplankton community, we conducted a mesocosm experiment in a mesotrophic freshwater pond. Six freshwater algae belonging to three taxonomic groups (chlorophyta, cyanobacteria, and bacillariophyta) were added as potential invader species to the natural phytoplankton community of the pond (as single species or as combination of two species of the same taxonomic group). After nine days, the invasion success and the impact on the natural phytoplankton community were estimated. Results show that although all invaders were unsuccessful, they had lasting effects on the resident community. In all communities exposed to invasion, biodiversity (H′) was maintained. In contrast, in control communities, the diversity at the end of the experiment was lower compared to the initial community. Furthermore, communities exposed to invasion were less similar to control communities without invasion than to the other invaded communities. Differences were found in taxonomic group composition as well as in species composition. Additionally, we found evidence for synergistic effects between the combined added species. Our results give clear evidence of strong transient effects of unsuccessful invaders on freshwater phytoplankton community composition.
Mechanisms of surviving burial: Dune grass interspecific differences drive resource allocation after sand deposition
Authors: Brown Joseph K. , Zinnert Julie C. 
Published: April 2018

AbstractSand dunes are important geomorphic formations of coastal ecosystems that are critical in protecting human populations that live in coastal areas. Dune formation is driven by ecomorphodynamic interactions between vegetation and sediment deposition. While there has been extensive research on responses of dune grasses to sand burial, there is a knowledge gap in understanding mechanisms of acclimation between similar, coexistent, dune‐building grasses such as Ammophila breviligulata (C3), Spartina patens (C4), and Uniola paniculata (C4). Our goal was to determine how physiological mechanisms of acclimation to sand burial vary between species. We hypothesize that (1) in the presence of burial, resource allocation will be predicated on photosynthetic pathway and that we will be able to characterize the C3 species as a root allocator and the C4 species as leaf allocators. We also hypothesize that (2) despite similarities between these species in habitat, growth form, and life history, leaf, root, and whole plant traits will vary between species when burial is not present. Furthermore, when burial is present, the existing variability in physiological strategy will drive species‐specific mechanisms of survival. In a greenhouse experiment, we exposed three dune grass species to different burial treatments: 0 cm (control) and a one‐time 25‐cm burial to mimic sediment deposition during a storm. At the conclusion of our study, we collected a suite of physiological and morphological functional traits. Results showed that Ammophila decreased allocation to aboveground biomass to maintain root biomass, preserving photosynthesis by allocating nitrogen (N) into light‐exposed leaves. Conversely, Uniola and Spartina decreased allocation to belowground production to increase elongation and maintain aboveground biomass. Interestingly, we found that species were functionally distinct when burial was absent; however, all species became more similar when treated with burial. In the presence of burial, species utilized functional traits of rapid growth strategy, although mechanisms of change were interspecifically variable.
Do novel ecosystems provide habitat value for wildlife? Revisiting the physiognomy vs. floristics debate
Authors: Kennedy Patricia L. , Fontaine Joseph B. , Hobbs Richard J. , Johnson Tracey N. , Boyle Rafeena , Lueders Andrea S. 
Published: April 2018

AbstractAlthough novel ecosystems are increasing globally, their utility for biodiversity conservation is poorly understood. Native fauna are predicted to use novel ecosystems when those ecosystems provide structure and resources similar to the native habitat. We modified existing terminology on wildlife functional groups to develop a conceptual model that illustrates fundamental differences in how native wildlife respond to novel ecosystems: novel ecosystem avoiders, novel ecosystem utilizers, and novel ecosystem flourishers. We postulate that species membership in these functional groups is related to the relative importance habitat physiognomy and floristics play in habitat selection cues. An excellent opportunity to test this conceptual model exists with birds in historic and novel ecosystems. A long‐standing, equivocal literature investigating relative contribution of physiognomy vs. floristics to avian abundance and community diversity in native ecosystems exists. Using data from grassland and woodland biomes in western North America (Oregon, USA) and Western Australia, respectively, we evaluated use of habitats by indigenous bird species in relation to physiognomy and floristics. Our two case studies represent two extremes on the novelty spectrum: (1) urban gardens in the metropolitan region of Perth, Western Australia, which are designed ecosystems that vary in the percentage of native plantings; and (2) the Zumwalt Prairie in northeastern Oregon where native grassland plants still dominate the ecosystem but non‐native plants are present and available for use as breeding sites. Using an information‐theoretic perspective, we asked whether habitat use based on occurrence (Perth gardens) or breeding success (Oregon grassland) was best explained by physiognomy, floristics, or both. Using these two case studies, our evidence shows that species or guilds within a community will not respond equally to novelty as predicted. We found strong evidence for only one taxon showing sensitivity to floristics and two to physiognomy. All taxa considered were either grouped as novel ecosystem avoiders or utilizers; no flourishers were identified. These results suggest novel ecosystems providing appropriate physiognomy can provision suitable habitat for some taxa.