bluuebunny/crossref_metadata_2025_split huggingface dataset:
Persistence of balsam fir and black spruce populations in the mixedwood and coniferous bioclimatic domain of eastern North America
Authors: Messaoud Yassine , Goudiaby Venceslas , Bergeron Yves 
Published: April 2019

AbstractThe boreal ecocline (ca 49°N) between the southern mixedwood (dominated by balsam fir) and the northern coniferous bioclimatic domain (dominated by black spruce) may be explained by a northward decrease of balsam fir regeneration, explaining the gradual shift to black spruce dominance. 7,010 sample plots, with absence of major disturbances, were provided by the Quebec Ministry of Forest, Fauna, and Parks. The regeneration (sapling abundance) of balsam fir and black spruce were compared within and between the two bioclimatic domains, accounting for parental trees, main soil type (clay and till) and climate conditions, reflected by summer growing degree‐days above 5°C (GDD_5), total summer precipitation (May–August; PP_MA). Parental trees and soil type determined balsam fir and black spruce regeneration. Balsam fir and black spruce, respectively, showed higher regeneration in the mixedwood and the coniferous bioclimatic domains. Overall, higher regeneration was obtained on till for balsam fir, and on clay soils for black spruce. GDD_5 and PP_MA were beneficial for balsam fir regeneration on clay and till soils, respectively, while they were detrimental for black spruce regeneration. At a population level, balsam fir required at least 28% of parental tree basal area in the mixedwood, and 38% in the coniferous bioclimatic domains to maintain a regeneration at least equal to the mean regeneration of the whole study area. However, black spruce required 82% and 79% of parental trees basal area in the mixedwood and the coniferous domains, respectively. The northern limit of the mixedwood bioclimatic domain was attributed to a gradual decrease toward the north of balsam fir regeneration most likely due to cooler temperatures, shorter growing seasons, and decrease of the parental trees further north of this northern limit. However, balsam fir still persists above this northern limit, owing to a patchy occurrence of small parental trees populations, and good establishment substrates.
“Balancing” balancing selection? Assortative mating at the major histocompatibility complex despite molecular signatures of balancing selection
Authors: Slade Joel W. G. , Watson Matthew J. , MacDougall‐Shackleton Elizabeth A. 
Published: April 2019

AbstractIn vertebrate animals, genes of the major histocompatibility complex (MHC) determine the set of pathogens to which an individual's adaptive immune system can respond. MHC genes are extraordinarily polymorphic, often showing elevated nonsynonymous relative to synonymous sequence variation and sharing presumably ancient polymorphisms between lineages. These patterns likely reflect pathogen‐mediated balancing selection, for example, rare‐allele or heterozygote advantage. Such selection is often reinforced by disassortative mating at MHC. We characterized exon 2 of MHC class II, corresponding to the hypervariable peptide‐binding region, in song sparrows (Melospiza melodia). We compared nonsynonymous to synonymous sequence variation in order to identify positively selected sites; assessed evidence for trans‐species polymorphisms indicating ancient balancing selection; and compared MHC similarity of socially mated pairs to expectations under random mating. Six codons showed elevated ratios of nonsynonymous to synonymous variation, consistent with balancing selection, and we characterized several alleles similar to those occurring in at least four other avian families. Despite this evidence for historical balancing selection, mated pairs were significantly more similar at MHC than were randomly generated pairings. Nonrandom mating at MHC thus appears to partially counteract, not reinforce, pathogen‐mediated balancing selection in this system. We suggest that in systems where individual fitness does not increase monotonically with MHC diversity, assortative mating may help to avoid excessive offspring heterozygosity that could otherwise arise from long‐standing balancing selection.
Plant selection initiates alternative successional trajectories in the soil microbial community after disturbance
Authors: Duhamel Marie , Wan Joe , Bogar Laura M. , Segnitz R. Max , Duncritts Nora C. , Peay Kabir G. 
Published: April 2019

AbstractBecause interactions between plants and microbial organisms can influence species diversity and rates of nutrient cycling, how plants shape microbial communities is fundamental to understanding the structure of ecosystems. Despite this, the spatial and temporal scales over which plants influence microbial communities is poorly understood, particularly whether past abiotic or biotic legacies strongly constrain microbial community development. We examined biogeochemical cycling and microbial community structure in a coastal landscape where historical patterns of vegetation transition after a large fire in 1995 are well known, allowing us to account for past abiotic and biotic conditions. We found that alternative states in microbial community structure and ecosystem processes emerged under different plant species, regardless of past conditions. Greenhouse studies further demonstrated that these differences arise from direct plant selection of microbes, with selection stronger in roots compared with soils, especially for bacteria. Correlation of microbial community structure with seedling growth rates was also stronger for fungi compared to bacteria. Despite these effects, minimal overlap between seedling and field microbial communities indicates that the effects of initial plant selection are not stable; rather, plant selection initiated alternative successional trajectories after the fire. Using data from a guild where we have abundant natural history information, ectomycorrhizal fungi, we show that greenhouse communities are dominated by ruderal taxa that are also common in the field after the fire and that these ruderal fungi strongly alter spatial patterns in plant–soil feedback, enabling invasion and transformation of soils previously occupied by heterospecific plants, thus potentially acting as keystone mutualists.
Soil organic matter determines the distribution and abundance of nematodes on alluvial fans in Death Valley, California
Authors: Treonis Amy M. , Sutton Kelsey A. , Unangst Samantha K. , Wren Julia E. , Dragan Emma S. , McQueen J. Parr 
Published: April 2019

AbstractDeath Valley, located within the Mojave Desert of the United States, is one of the most extreme terrestrial environments on Earth. We studied free‐living soil nematode abundance and community structure in soil samples collected from alluvial fans in Death Valley between 2013 and 2018. Our objective was to establish the distribution and abundance of soil nematodes on alluvial fans with respect to soil properties, vegetation, and channels that reflect past and future water flows. The study period spanned an extreme drought for the region but also included a 2016 superbloom of spring annual plants that followed a strong El Niño event. We found that nematode communities were dominated by bacterial‐feeding species and had higher densities under shrub canopies than in adjacent interplant soils. Nematode abundance was similar between areas on alluvial fans that were channelized by past water flows and adjacent desert pavement and does not appear to be linked to how water distributes on the fans following rainfall events. Nematode abundance increased during the superbloom in soils around annual plants. Across the study period, soil organic matter content was the only soil variable measured that was significantly and positively correlated to nematode abundance. Overall, nematodes in this extreme environment are adapted to drought, but they are highly dependent on the growth and distribution of both perennial and annual plants to supply the soil organic matter that their microbial food sources rely upon.
Use, selection, and home range properties: complex patterns of individual habitat utilization
Authors: Ofstad Endre Grüner , Herfindal Ivar , Solberg Erling J. , Heim Morten , Rolandsen Christer Moe , Sæther Bernt‐Erik 
Published: April 2019

AbstractIndividual patterns of habitat use emerge from behavioral decisions driven by interactions between landscape characteristics and individual traits. Individual traits, such as age and sex, influence the net gain of using habitats and associated resources, and thus the relationship between size and composition of the home range. However, the pathways from individual variation in home range size and composition to habitat selection are rarely fully explored. We investigated how habitat selection in moose (Alces alces) was a result of individual traits and home range characteristics, that is, we described the pathway from home range to habitat selection. The study was conducted at two spatial scales during two contrasting seasons. Home range size and composition varied with sex, with season, and to some extent with age. Males had larger home range size, and the composition of their home ranges changed more with home range size than for females. The general trend was that moose used habitats according to availability more in winter than in summer, that is, a weaker habitat selection in winter than in summer. Sex and age explained little of the variation in habitat selection, but sex had a pronounced effect on the relationship between home range size and composition. Because habitat availability (i.e., home range composition) is a component of habitat selection, it suggests that varying habitat use partly compensates for sex‐specific differences in home range composition, which in turn results from home range settlement. Hence, although males and females showed similar habitat selection, they differed in the underlying mechanisms generating the pattern of habitat selection. These complex interactions between individual traits and environmental variation have consequences for how we understand the relationships between landscape characteristics, individual behavior, and fitness.
Pathogenic modification of plants enhances long‐distance dispersal of nonpersistently transmitted viruses to new hosts
Authors: Donnelly Ruairí , Cunniffe Nik J. , Carr John P. , Gilligan Christopher A. 
Published: April 2019

AbstractAphids spread the majority of plant viruses through nonpersistent transmission (NPT), whereby virus particles attach transiently to these insects’ probing mouthparts. Virus acquisition from infected plants and inoculation to healthy host plants is favored when aphids briefly probe plant epidermal cells. It is well established that NPT virus infection can alter plant–vector interactions, and, moreover, such pathogen modifications are found in a range of plant and animal systems. In particular, viruses can make plants more attractive to aphids but inhibit aphid settling on infected plants. It is hypothesized that this viral “reprogramming” of plants promotes virus acquisition and encourages dispersal of virus‐bearing aphids to fresh hosts. In contrast, it is hypothesized that virus‐induced biochemical changes encouraging prolonged feeding on infected hosts inhibit NPT. To understand how these virus‐induced modifications affect epidemics, we developed a modeling framework accounting for important but often neglected factors, including feeding behaviors (probing or prolonged feeding) and distinct spatial scales of transmission (as conditioned by wingless or winged aphids). Analysis of our models confirmed that when viruses inhibit aphid settling on infected plants this initially promotes virus transmission. However, initially enhanced transmission is self‐limiting because it decreases vector density. Another important finding is that virus‐induced changes encouraging settling will stimulate birth of winged aphids, which promotes epidemics of NPT viruses over greater distances. Thus our results illustrate how plant virus modifications influence epidemics by altering vector distribution, density, and even vector form. Our insights are important for understanding how pathogens in general propagate through natural plant communities and crops.
Exercise‐induced hypoalgesia is present in people with Parkinson’s disease: Two observational cross‐sectional studies
Authors: Nguy Vanessa , Barry Benjamin K. , Moloney Niamh , Hassett Leanne M. , Canning Colleen G. , Lewis Simon J. G. , Allen Natalie E. 
Published: April 2019

AbstractBackgroundExercise is prescribed for people with Parkinson’s disease to address motor and non‐motor impairments, including pain. Exercise‐induced hypoalgesia (i.e., an immediate reduction in pain sensitivity following exercise) is reported in the general population; however, the immediate response of pain sensitivity to exercise in people with Parkinson’s disease is unknown. The purpose of this study was to investigate if exercise‐induced hypoalgesia is present following isometric and aerobic exercise in people with Parkinson’s disease, and if so, if it varies with the dose of aerobic exercise.MethodsThirty people with idiopathic Parkinson’s disease and pain‐free age‐matched controls completed two observational studies evaluating the response to: (a) right arm isometric exercise; and (b) treadmill walking at low and moderate intensities. Pressure pain thresholds were measured over biceps brachii and quadriceps muscles immediately before and after exercise, with increased thresholds after exercise indicating exercise‐induced hypoalgesia.ResultsPressure pain thresholds increased in the Parkinson’s disease group at all tested sites following all exercise bouts (e.g., isometric exercise, right bicep 29%; aerobic exercise, quadriceps, moderate intensity 8.9%, low intensity 7.1% (p ≤ 0.008)), with no effect of aerobic exercise dose (p = 0.159). Similar results were found in the control group.ConclusionsOverall, people with Parkinson’s disease experienced an exercise‐induced hypoalgesia response similar to that of the control group, the extent of which did not vary between mild and moderate doses of aerobic exercise. Further research is warranted to investigate potential longer term benefits from exercise in the management of pain in this population.SignificanceIsometric and aerobic exercise reduces pain sensitivity in people with Parkinson’s disease. As exercise is important for people with Parkinson’s disease, these results provide assurance that people with Parkinson’s disease and pain can exercise without an immediate increase in pain sensitivity. The reduction in pain sensitivity with both modes and with low and moderate intensities of aerobic exercise suggests that people with Parkinson’s disease can safely choose the mode and intensity of exercise that best suits their needs.
Composite material for high‐temperature thermochemical energy storage using calcium hydroxide and ceramic foam
Authors: Funayama Shigehiko , Takasu Hiroki , Zamengo Massimiliano , Kariya Jun , Kim Seon Tae , Kato Yukitaka 
Published: April 2019

AbstractThermochemical energy storage using a calcium oxide/calcium hydroxide/water (CaO/Ca(OH)2/H2O) reaction system is a promising technology for thermal energy storage at high‐temperatures (400°C‐600°C). The purpose of this study is to develop a practical composite material by enhancing heat transfer through the reaction bed and mitigating problems of pure CaO/Ca(OH)2 materials, such as formation of centimeter‐scale agglomerates and change in the bulk volume during repetitive reactions. The present study focused on a novel composite material using a silicon carbide/silicon (SiC/Si) foam. In the literature, performance of thermochemical energy storage of the composite using the ceramic foam remains unclear. In this study, we evaluated the performance of the composite material (~63 g) by a 100‐W‐scale packed bed reactor. The volumetric heat output rate (for the first 5 minutes, under maximum hydration pressure) of the composite was 1.3 kW L‐bed−1, which was 1.4 times higher than that previously reported for a bed of pure Ca(OH)2 pellets. The composite material, in which the CaO/Ca(OH)2 samples were subdivided inside pores with a mean diameter of 400 μm, retained high reactivity during cycle reactions, and maintained its bulk volume. Therefore, the composite material developed in this study shows promising application for high‐temperature thermochemical energy storage.
The quantile dependence of commodity futures markets on news sentiment
Authors: Omura Akihiro , Todorova Neda 
Published: April 2019

AbstractFocusing on energy commodities, industrial metals, and gold, this paper examines the degree to which commodity futures returns depend on news sentiment under various market conditions, and the structure of that dependence. We observe an asymmetric market reaction to positive and negative news sentiment, which changes in periods of financial turmoil. The quantile regression analysis shows that news sentiment's influence on the futures returns follows an upward trend at higher percentiles. This structure flattens for positive news during the global financial crisis, while the slope for the negative component steepens in backwardation periods.
Sulfatase 2 promotes generation of a spinal cord astrocyte subtype that stands out through the expression of Olig2
Authors: Ohayon David , Escalas Nathalie , Cochard Philippe , Glise Bruno , Danesin Cathy , Soula Cathy 
Published: April 2019

AbstractGeneration of glial cell diversity in the developing spinal cord is known to depend on spatio‐temporal patterning programs. In particular, expression of the transcription factor Olig2 in neural progenitors of the pMN domain is recognized as critical to their fate choice decision to form oligodendrocyte precursor cells (OPCs) instead of astrocyte precursors (APs). However, generating some confusion, lineage‐tracing studies of Olig2 progenitors in the spinal cord provided evidence that these progenitors also generate some astrocytes. Here, we addressed the role of the heparan sulfate‐editing enzyme Sulf2 in the control of gliogenesis and found an unanticipated function for this enzyme. At initiation of gliogenesis in mouse, Sulf2 is expressed in ventral neural progenitors of the embryonic spinal cord, including in Olig2‐expressing cells of the pMN domain. We found that sulf2 deletion, while not affecting OPC production, impairs generation of a previously unknown Olig2‐expressing pMN‐derived cell subtype that, in contrast to OPCs, does not upregulate Sox10, PDGFRα or Olig1. Instead, these cells activate expression of AP identity genes, including aldh1L1 and fgfr3 and, of note, retain Olig2 expression as they populate the spinal parenchyma at embryonic stages but also as they differentiate into mature astrocytes at postnatal stages. Thus, our study, by revealing the existence of Olig2‐expressing APs that segregate early from pMN cells under the influence of Sulf2, supports the existence of a common source of APs and OPCs in the ventral spinal cord and highlights divergent regulatory mechanism for the development of pMN‐derived OPCs and APs.
Patients’ sun practices, perceptions of skin cancer and their risk of skin cancer in rural Australia
Authors: Sideris Emily , Thomas Susan J. 
Published: April 2019

AbstractIssue addressedSkin cancer affects nearly one in three Australians. As a preventable disease there have been many public awareness campaigns targeting skin cancer knowledge and sun protection in Australia in the last 30 years to increase knowledge of the disease and how to prevent it. Despite higher incidence and mortality of skin cancer in regional Australia and adults over 65 years though, little research exists examining this high‐risk population's skin cancer knowledge and sun behaviours, with most previous research conducted in urban Australia or overseas. This study aimed to examine adults’ skin cancer knowledge, sun behaviours and demographic factors in a regional Australian town.MethodsCross‐sectional study design was utilised. Adult patients of a Mudgee General Practice (n = 179, 18‐89 years) completed a survey based on their skin cancer knowledge and sun behaviours. Chi‐squared tests were used to analyse responses.ResultsPoor non‐melanoma skin cancer awareness, risky sun behaviours and inadequate sun protection behaviours were found. Males and those at greatest current risk of skin cancer in Australia, those over 60 years, had the poorest skin cancer knowledge and were least likely to recognise skin cancer or use some sun protection measures.ConclusionsGreater non‐melanoma skin cancer and sun protection education and research is needed, particularly targeting older and male Australians.So what?The findings suggest rural men and older Australians would benefit from more targeted campaigns and education to increase their skin cancer awareness and use of sun protection in order to minimise future skin cancer.
Upregulation of CBP by PLY can cause permeability of blood‐brain barrier to increase meningitis
Authors: Chen Jia‐Quan , Li Nan‐Nan , Wang Bo‐Wen , Liu Xiu‐Fang , Liu Jia‐Lin , Chang Qing 
Published: April 2019

AbstractBackgroundStreptococcus pneumoniae causes many human diseases including bacterial meningitis. Previous study proposed that pneumolysin (PLY), a cytotoxin from pneumococcus, is related to the infection across blood‐brain barrier (BBB). However, the mechanism of how PLY break through BBB remains elusive. The present study showed that PLY can increase the permeability of BBB both in vitro and in vivo in our experiments.ResultsFurther we found out that PLY leads to the high expression of CERB‐binding protein (CBP) which can lead to releasing of tumor necrosis factor α then enhance apoptosis of cells which is a significant factor leading to permeabilization of BBB.ConclusionOur findings demonstrate that CBP plays an important role in the pneumococcus infection in the brain and could be a potential therapeutic target against pneumococcal meningitis.
Synergistic effects of hormone therapy drugs and usnic acid on hormone receptor‐positive breast and prostate cancer cells
Authors: Guney Eskiler Gamze , Eryilmaz Isil Ezgi , Yurdacan Beste , Egeli Unal , Cecener Gulsah , Tunca Berrin 
Published: April 2019

AbstractThe aim of this study was to investigate the combined effects of usnic acid (UA) and Tamoxifen (Tam) or Enzalutamide (Enz) on hormone receptor‐positive breast and prostate cancer (BC and PC), respectively. The antiproliferative and apoptotic effects of Tam or Enz alone and in combination with UA on MCF7 and LNCaP cancer cells were detected. The results of the WST‐1 assay indicated that UA was a promising anticancer compound that significantly enhanced the effectiveness of hormone therapy drugs compared with each drug alone (combination index < 1). In addition, the combination of UA with Tam or Enz remarkably induced more cell cycle arrest at the G0/G1 phase and apoptosis than only drug‐treated cells (P < 0.01). Consequently, our findings suggest that the combination of UA with Tam or Enz may be a potential therapeutic approach for the treatment of BC and PC and further studies are required to exploit the potential mechanisms of synergistic effects.