bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polyradical PROXYL/TEMPO‐Derived Amides: Synthesis, Physicochemical Studies, DFT Calculations, and Antimicrobial Activity
Authors: Poprac Patrik , Poliak Peter , Kavala Miroslav , Barbieriková Zuzana , Zalibera Michal , Fronc Marek , Švorc Ľubomír , Vihonská Zuzana , Olejníková Petra , Lušpai Karol , Lukeš Vladimír , Brezová Vlasta , Szolcsányi Peter 
Published: October 2017

AbstractA series of polynitroxide amides possessing 2,2,5,5‐tetramethyl‐1‐pyrrolidinyloxy (PROXYL) and/or 2,2,6,6‐tetramethyl‐1‐piperidinyloxy (TEMPO) units connected through various bridges were synthesized and their properties were analyzed. EPR spectroscopy provided detailed insight into their paramagnetic character and related properties. A thorough examination of the EPR spectra of dinitroxides in organic solvents provided valuable information on the intramolecular motions, thermodynamics, and spin‐exchange mechanisms. Analysis of low‐temperature X‐ and Q‐band EPR spectra of the dissolved dinitroxides provided spin–spin distances that were comparable with the theoretical values obtained by DFT. Cyclic voltammetry investigations revealed (quasi)reversible electrochemical behavior for PROXYL‐derived biradicals, whereas significant loss of the reversibility was found for TEMPO‐containing bi‐ and polyradicals. The inhibitory activities of the nitroxides against model bacteria, yeasts, and filamentous fungi were assessed.
Ecotypic differences in the phenology of the tundra species Eriophorum vaginatum reflect sites of origin
Authors: Parker Thomas C. , Tang Jianwu , Clark Mahalia B. , Moody Michael M. , Fetcher Ned 
Published: October 2017

AbstractEriophorum vaginatum is a tussock‐forming sedge that contributes significantly to the structure and primary productivity of moist acidic tussock tundra. Locally adapted populations (ecotypes) have been identified across the geographical distribution of E. vaginatum; however, little is known about how their growth and phenology differ over the course of a growing season. The growing season is short in the Arctic and therefore exerts a strong selection pressure on tundra species. This raises the hypothesis that the phenology of arctic species may be poorly adapted if the timing and length of the growing season change. Mature E. vaginatum tussocks from across a latitudinal gradient (65–70°N) were transplanted into a common garden at a central location (Toolik Lake, 68°38′N, 149°36′W) where half were warmed using open‐top chambers. Over two growing seasons (2015 and 2016), leaf length was measured weekly to track growth rates, timing of senescence, and biomass accumulation. Growth rates were similar across ecotypes and between years and were not affected by warming. However, southern populations accumulated significantly more biomass, largely because they started to senesce later. In 2016, peak biomass and senescence of most populations occurred later than in 2015, probably induced by colder weather at the beginning of the growing season in 2016, which caused a delayed start to growth. The finish was delayed as well. Differences in phenology between populations were largely retained between years, suggesting that the amount of time that these ecotypes grow has been selected by the length of the growing seasons at their respective home sites. As potential growing seasons lengthen, E. vaginatum may be unable to respond appropriately as a result of genetic control and may have reduced fitness in the rapidly warming Arctic tundra.
Multilocus genetic analyses and spatial modeling reveal complex population structure and history in a widespread resident North American passerine (Perisoreus canadensis)
Authors: Dohms Kimberly M. , Graham Brendan A. , Burg Theresa M. 
Published: October 2017

AbstractAn increasing body of studies of widely distributed, high latitude species shows a variety of refugial locations and population genetic patterns. We examined the effects of glaciations and dispersal barriers on the population genetic patterns of a widely distributed, high latitude, resident corvid, the gray jay (Perisoreus canadensis), using the highly variable mitochondrial DNA (mtDNA) control region and microsatellite markers combined with species distribution modeling. We sequenced 914 bp of mtDNA control region for 375 individuals from 37 populations and screened seven loci for 402 individuals from 27 populations across the gray jay range. We used species distribution modeling and a range of phylogeographic analyses (haplotype diversity, ΦST, SAMOVA, FST, Bayesian clustering analyses) to examine evolutionary history and population genetic structure. MtDNA and microsatellite markers revealed significant genetic differentiation among populations with high concordance between markers. Paleodistribution models supported at least five potential areas of suitable gray jay habitat during the last glacial maximum and revealed distributions similar to the gray jay's contemporary during the last interglacial. Colonization from and prolonged isolation in multiple refugia is evident. Historical climatic fluctuations, the presence of multiple dispersal barriers, and highly restricted gene flow appear to be responsible for strong genetic diversification and differentiation in gray jays.
Ad hoc instrumentation methods in ecological studies produce highly biased temperature measurements
Authors: Terando Adam J. , Youngsteadt Elsa , Meineke Emily K. , Prado Sara G. 
Published: October 2017

AbstractIn light of global climate change, ecological studies increasingly address effects of temperature on organisms and ecosystems. To measure air temperature at biologically relevant scales in the field, ecologists often use small, portable temperature sensors. Sensors must be shielded from solar radiation to provide accurate temperature measurements, but our review of 18 years of ecological literature indicates that shielding practices vary across studies (when reported at all), and that ecologists often invent and construct ad hoc radiation shields without testing their efficacy. We performed two field experiments to examine the accuracy of temperature observations from three commonly used portable data loggers (HOBOPro,HOBOPendant, andiButton hygrochron) housed in manufactured Gill shields or ad hoc, custom‐fabricated shields constructed from everyday materials such as plastic cups. We installed this sensor array (five replicates of 11 sensor‐shield combinations) at weather stations located in open and forested sites.HOBOPro sensors with Gill shields were the most accurate devices, with a mean absolute error of 0.2°C relative to weather stations at each site. Error in ad hoc shield treatments ranged from 0.8 to 3.0°C, with the largest errors at the open site. We then deployed one replicate of each sensor‐shield combination at five sites that varied in the amount of urban impervious surface cover, which presents a further shielding challenge. Bias in sensors paired with ad hoc shields increased by up to 0.7°C for every 10% increase in impervious surface. Our results indicate that, due to variable shielding practices, the ecological literature likely includes highly biased temperature data that cannot be compared directly across studies. If left unaddressed, these errors will hinder efforts to predict biological responses to climate change. We call for greater standardization in how temperature data are recorded in the field, handled in analyses, and reported in publications.
Have bird distributions shifted along an elevational gradient on a tropical mountain?
Authors: Campos‐Cerqueira Marconi , Arendt Wayne J. , Wunderle Joseph M. , Aide T. Mitchell 
Published: October 2017

AbstractAn upward shift in elevation is one of the most conspicuous species responses to climate change. Nevertheless, downward shifts and, apparently, the absences of response have also been recently reported. Given the growing evidence of multiple responses of species distributions due to climate change and the paucity of studies in the tropics, we evaluated the response of a montane bird community to climate change, without the confounding effects of land‐use change. To test for elevational shifts, we compared the distribution of 21 avian species in 1998 and 2015 using occupancy models. The historical data set was based on point counts, whereas the contemporary data set was based on acoustic monitoring. We detected a similar number of species in historical (36) and contemporary data sets (33). We show an overall pattern of no significant change in range limits for most species, although there was a significant shift in the range limit of eight species (38%). Elevation limits shifted mostly upward, and this pattern was more common for upper than lower limits. Our results highlight the variability of species responses to climate change and illustrate how acoustic monitoring provides an easy and powerful way to monitor animal populations along elevational gradients.
Genetic implications of bottleneck effects of differing severities on genetic diversity in naturally recovering populations: An example from Hawaiian coot and Hawaiian gallinule
Authors: Sonsthagen Sarah A. , Wilson Robert E. , Underwood Jared G. 
Published: October 2017

AbstractThe evolutionary trajectory of populations through time is influenced by the interplay of forces (biological, evolutionary, and anthropogenic) acting on the standing genetic variation. We used microsatellite and mitochondrial loci to examine the influence of population declines, of varying severity, on genetic diversity within two Hawaiian endemic waterbirds, the Hawaiian coot and Hawaiian gallinule, by comparing historical (samples collected in the late 1800s and early 1900s) and modern (collected in 2012–2013) populations. Population declines simultaneously experienced by Hawaiian coots and Hawaiian gallinules differentially shaped the evolutionary trajectory of these two populations. Within Hawaiian coot, large reductions (between −38.4% and −51.4%) in mitochondrial diversity were observed, although minimal differences were observed in the distribution of allelic and haplotypic frequencies between sampled time periods. Conversely, for Hawaiian gallinule, allelic frequencies were strongly differentiated between time periods, signatures of a genetic bottleneck were detected, and biases in means of the effective population size were observed at microsatellite loci. The strength of the decline appears to have had a greater influence on genetic diversity within Hawaiian gallinule than Hawaiian coot, coincident with the reduction in census size. These species exhibit similar life history characteristics and generation times; therefore, we hypothesize that differences in behavior and colonization history are likely playing a large role in how allelic and haplotypic frequencies are being shaped through time. Furthermore, differences in patterns of genetic diversity within Hawaiian coot and Hawaiian gallinule highlight the influence of demographic and evolutionary processes in shaping how species respond genetically to ecological stressors.
Advancing ecohydrology in the changing tropics: Perspectives from early career scientists
Authors: Wright Cynthia , Kagawa‐Viviani Aurora , Gerlein‐Safdi Cynthia , Mosquera Giovanny M. , Poca María , Tseng Han , Chun Kwok Pan 
Published: October 2017

AbstractTropical ecosystems offer a unique setting for understanding ecohydrological processes, but to date, such investigations have been limited. The purpose of this paper is to highlight the importance of studying these processes—specifically, how they are being affected by the transformative changes taking place in the tropics—and to offer an agenda for future research. At present, the ongoing loss of native ecosystems is largely due to agricultural expansion, but parallel processes of afforestation are also taking place, leading to shifts in ecohydrological fluxes. Similarly, shifts in water availability due to climate change will affect both water and carbon fluxes in tropical ecosystems. A number of methods exist that can help us better understand how changes in land use and climate affect ecohydrological processes; these include stable isotopes, remote sensing, and process‐based models. Still, our knowledge of the underlying physical mechanisms, especially those that determine the effects of scale on ecosystem processes, remains incomplete. We assert that development of a knowledge base concerning the effects of transformative change on ecological, hydrological, and biogeochemical processes at different spatio‐temporal scales is an urgent need for tropical regions and should serve as a compass for emerging ecohydrologists. To reach this goal, we advocate a research agenda that expands the number and diversity of ecosystems targeted for ecohydrological investigations and connects researchers across the tropics. We believe that the use of big data and open source software—already an important integrative tool/skill for the young ecohydrologist—will be key in expanding research capabilities.
Habitat characteristics of the hoary marmot: assessing distribution limitations in Montana
Authors: Turnock B. Y. , Litt A. R. , Vore J. M. , Hammond C. A. M. 
Published: October 2017

AbstractSpecies that live in ecosystems with extremely different seasonal conditions must balance the constraints of each season to survive. Alpine species that do not migrate seasonally are especially adept at balancing the constraints created by short growing seasons and long, harsh winters. We investigated the habitat characteristics of hoary marmots in western Montana to provide a better understanding about habitat selection at the southern extent of this species’ distribution. Hoary marmots are an alpine obligate of special concern in western Montana; given that climate change is impacting alpine ecosystems at a rapid rate, this species may be especially vulnerable at the southern edge of their range. We conducted occupancy surveys in three study areas along a latitudinal gradient in 2014 and 2015 to assess the importance of specific habitat characteristics to their presence on the landscape. Slope, aspect, and presence of shrubs were all important habitat characteristics. Marmots preferred shallow slopes and southern aspects, similar to findings from other studies on hoary marmots and other marmot species. Our results provide evidence that marmots may strike a balance between the environmental conditions they require during summer and winter. Shallow slopes typically accumulate deeper snow in winter that provide the best insulating snowpack. However, a preference for southern aspects allows for more snow‐free areas in spring, providing a slightly longer growing season than northern aspects. Hoary marmots may be selecting areas with shrubs because shrubs can accumulate deeper snow and the additional insulation can increase subnivian temperatures. Other studies suggest that marmot survival is influenced by snowpack, indicating that marmot distribution may be more closely tied to winter conditions rather than summer conditions. This highlights the difficulty of working on marmots and other alpine obligates, as most studies occur only during the short growing season. Given the current and projected increases in temperature and reduction in snowpack in Montana, areas that provide the winter conditions hoary marmots require may become more limited. Effectively conserving, monitoring, and managing alpine obligates under an uncertain climate future will require a closer look at how winter conditions drive habitat selection and distributions on the landscape.
A Voltage Control Method for a Distributed Line Feeder by means of Multiagent Approach
Authors: KURISU SHINYA , NAGATA TAKESHI 
Published: October 2017

SUMMARYThis paper proposes a method for the coordinated control of power factor by means of a multiagent approach. The proposed multiagent system consists of two types of agent: single feeder agent (F_AG) and bus agent (B_AG). In the proposed system, an F_AG plays as an important role, which decides the power factors of all distributed generators by executing the load flow calculations repeatedly. The voltage control strategies are implemented as the class definition of Java into the system. In order to verify the performance of the proposed method, it has been applied to a typical distribution model system. The simulation results show that the system is able to control very violent fluctuation of the demands and the photovoltaic (PV) generations.
What makes displaced revenge taste sweet: Retributing displaced responsibility or sending a message to the original perpetrator?
Authors: Sjöström Arne , Magraw‐Mickelson Zoe , Gollwitzer Mario 
Published: October 2017

AbstractThe present research investigates the psychological dynamics underlying displaced revenge. We examine (1) the effect of entitativity on displaced revenge tendencies, including potential mediators of this effect, and (2) the conditions under which taking displaced revenge is satisfying for avengers. In three studies, we show that (a) perpetrator group entitativity predicts the tendency to take displaced revenge via perceptions that the vengeful action is effective in delivering a message to the original perpetrator, (b) that displaced revenge is satisfying when the group continues to exist in its original form, but not when the perpetrator has left the group or when the group has dissolved, and (c) that displaced revenge is most satisfying when both the original perpetrator and the target of revenge understand why revenge has been taken. These findings imply that sending a message to the original perpetrator is an important aspect of the psychological dynamics underlying displaced revenge.
Historical land use as a driver of alternative states for stream form and function in forested mountain watersheds of the Southern Rocky Mountains
Authors: Livers Bridget , Wohl Ellen , Jackson Karen J. , Sutfin Nicholas A. 
Published: October 2017

AbstractWe demonstrate how land use can drive mountain streams in the Southern Rockies across a threshold to induce an alternative state of significantly reduced physical complexity of form and reduced ecological function. We evaluate field data from 28 stream reaches in relatively laterally unconfined valleys and unmanaged forest that is either old‐growth forest or naturally disturbed younger forest, and 19 stream reaches in managed forest with past land use. We evaluate potential differences in stream form, as reflected in channel planform, cross‐sectional geometry, and in‐stream wood loads, and stream function, as reflected in pool volume and storage of organic carbon. Field data indicate a threshold of differences in stream form and function between unmanaged and managed stream reaches, regardless of forest stand age, supporting our hypothesis that the legacy effects of past land use result in an alternative state of streams. Because physical complexity that increases stream retentiveness and habitat can maintain aquatic‐riparian ecosystem functions, the alternative physical state of streams in managed watersheds creates a physical template for an alternative ecological state with reduced pool volume, organic carbon storage, and ecosystem productivity. We recommend maintaining riparian forests that can supply large wood to streams as a stream restoration technique in historically forested stream segments. Copyright © 2017 John Wiley & Sons, Ltd.
Bleomycin‐induced chromosomal damage and shortening of telomeres in peripheral blood lymphocytes of incident cancer patients
Authors: Kroupa Michal , Polivkova Zdenka , Rachakonda Sivaramakrishna , Schneiderova Michaela , Vodenkova Sona , Buchler Tomas , Jiraskova Katerina , Urbanova Marketa , Vodickova Ludmila , Hemminki Kari , Kumar Rajiv , Vodicka Pavel 
Published: October 2017

AbstractDisruption of genomic integrity due to deficient DNA repair capacity and telomere shortening constitute hallmarks of malignant diseases. Incomplete or deficient repair of DNA double‐strand breaks (DSB) is manifested by chromosomal aberrations and their frequency reflects inter‐individual differences of response to exposure to mutagenic compounds. In this study, we investigated chromosomal integrity in peripheral blood lymphocytes (PBL) from newly diagnosed cancer patients, including 47 breast (BC) and 44 colorectal cancer (CRC) patients and 90 matched healthy controls. Mutagen sensitivity was evaluated by measuring chromatid breaks (CTAs) induced by bleomycin and supplemented by the chemiluminescent measurement of γ‐H2AX phosphorylation in 19 cancer patients (11 BC, 8 CRC). Relative telomere length (RTL) was determined in 22 BC, 32 CRC, and 64 controls. We observed statistically significant increased level of CTAs (P = .03) and increased percentage of aberrant cells (ACs) with CTAs (P = .05) in CRC patients compared with controls after bleomycin treatment. No differences were observed between BC cases and corresponding controls. CRC and BC patients with shorter RTL (below median) exhibited significantly higher amount of ACs (P = .02), CTAs (P = .02), and cells with high frequency of CTAs (≥12 CTAs/PBL; P = .03) after bleomycin treatment. No such associations were observed in healthy controls. γ‐H2AX phosphorylation after bleomycin treatment in PBL did not differ between CRC and BC patients. Our results suggest that altered DSB repair measured by sensitivity towards mutagen in PBL occurs particularly in CRC carcinogenesis. Irrespective of cancer type, telomere shortening may be associated with a decreased capacity to repair DSB.
Geochronology, geochemistry, and zircon Hf isotopes of the late Permian–early Triassic Wuma intrusions in the Erguna Block, northeast China: Petrogenesis and implications for tectonic setting and crustal growth
Authors: Gou Jun , Sun De‐You , Hou Xue‐Gang , Yang Dong‐Guang 
Published: October 2017

The Wuma magmatic suite is a group of large granite plutons and small diorite stocks in the Erguna Block, northeast China. These intrusions were emplaced along the Mongol–Okhotsk Suture Zone during the late Permian–early Triassic (253–248 Ma). Significant chemical and isotopic diversity within the granites and diorites suggests variable formation conditions and the involvement of multiple magmatic sources. The granitic intrusions are dominantly characterized by moderate to large, uniform light rare earth element enrichments and variable heavy rare earth element depletions. Zircons from the Wuma granites have εHf(t) values of −6.0 to 0.5 and TDM2 ages of 1.6–1.2 Ga, suggesting that these granitic magmas were generated by partial melting of Mesoproterozoic continental crust. The diorites are compositionally similar to Andean plutonic rocks with moderate light rare earth element and heavy rare earth element fractionations and likely formed by partial melting of a sediment‐metasomatized mantle. The Wuma intrusions belong to the high‐K calc‐alkaline series and are characterized by a significant enrichment in large‐ion lithophile elements (e.g., Rb, Ba, K, and U) and depletion of high‐field strength elements (e.g., Nb, Ta, and Ti). These geochemical characteristics are typical of subduction‐related magmatism, which can be linked to the southward subduction of the Mongol–Okhotsk oceanic plate. Combined with data from published studies, our Hf isotopic analyses indicate 4 main periods of crustal growth beneath the Erguna Block: Mesoarchean (3.0–2.8 Ga), Neoarchean–Paleoproterozoic (2.6–1.8 Ga), Meso‐ to Neoproterozoic (1.6–0.7 Ga), and Phanerozoic (mainly Ordovician and Late Triassic–Early Cretaceous).