bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dispersal in dendritic networks: Ecological consequences on the spatial distribution of population densities
Authors: Altermatt Florian , Fronhofer Emanuel A. 
Published: June 2017

AbstractUnderstanding the consequences of spatial structure on ecological dynamics is a central theme in ecology. Recently, research has recognised the relevance of river and river‐analogue network structures, because these systems are not only highly diverse but also rapidly changing due to habitat modifications or species invasions.Much of the previous work on ecological and evolutionary dynamics in metapopulations and metacommunities in dendritic river networks has been either using comparative approaches or was purely theoretical. However, the use of microcosm experiments provides the unique opportunity to study large‐scale questions in a causal and experimental framework.We conducted replicated microcosm experiments, in which we manipulated the spatially explicit network configuration of a landscape and addressed how linear versus dendritic connectivity affects population dynamics, specifically the spatial distribution of population densities, and movement behaviour of the protist model organismTetrahymena pyriformis. We tracked population densities and individual‐level movement behaviour of thousands of individuals over time.At the end of the experiment, we found more variable population densities between patches in dendritic networks compared to linear networks, as predicted by theory. Specifically, in dendritic networks, population densities were higher at nodes that connected to headwaters compared to the headwaters themselves and to more central nodes in the network. These differences follow theoretical predictions and emerged from the different network topologies per se. These differences in population densities emerged despite weakly density‐dependent movement.We show that differences in network structure alone can cause characteristic spatial variation in population densities. While such differences have been postulated by theoretical work and are the underlying precondition for differential dispersal evolution in heterogeneous networks, our results may be the first experimental demonstration thereof. Furthermore, these population‐level dynamics may affect extinction risks and can upscale to previously shown metacommunity level diversity dynamics. Given that many species in natural river systems exhibit strong spatiotemporal patterns in population densities, our work suggests that abundance patterns should not only be addressed from a local environmental perspective, but may be the outcome of processes that are inherently driven by the respective habitat network structure.
Increased Arctic sea ice drift alters adult female polar bear movements and energetics
Authors: Durner George M. , Douglas David C. , Albeke Shannon E. , Whiteman John P. , Amstrup Steven C. , Richardson Evan , Wilson Ryan R. , Ben‐David Merav 
Published: June 2017

AbstractRecent reductions in thickness and extent have increased drift rates of Arctic sea ice. Increased ice drift could significantly affect the movements and the energy balance of polar bears (Ursus maritimus) which forage, nearly exclusively, on this substrate. We used radio‐tracking and ice drift data to quantify the influence of increased drift on bear movements, and we modeled the consequences for energy demands of adult females in the Beaufort and Chukchi seas during two periods with different sea ice characteristics. Westward and northward drift of the sea ice used by polar bears in both regions increased between 1987–1998 and 1999–2013. To remain within their home ranges, polar bears responded to the higher westward ice drift with greater eastward movements, while their movements north in the spring and south in fall were frequently aided by ice motion. To compensate for more rapid westward ice drift in recent years, polar bears covered greater daily distances either by increasing their time spent active (7.6%–9.6%) or by increasing their travel speed (8.5%–8.9%). This increased their calculated annual energy expenditure by 1.8%–3.6% (depending on region and reproductive status), a cost that could be met by capturing an additional 1–3 seals/year. Polar bears selected similar habitats in both periods, indicating that faster drift did not alter habitat preferences. Compounding reduced foraging opportunities that result from habitat loss; changes in ice drift, and associated activity increases, likely exacerbate the physiological stress experienced by polar bears in a warming Arctic.
Widespread production of nonmicrobial greenhouse gases in soils
Authors: Wang Bin , Lerdau Manuel , He Yongli 
Published: June 2017

AbstractCarbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) are the three most important greenhouse gases (GHGs), and all show large uncertainties in their atmospheric budgets. Soils of natural and managed ecosystems play an extremely important role in modulating their atmospheric abundance. Mechanisms underlying the exchange of these GHGs at the soil–atmosphere interface are often assumed to be exclusively microbe‐mediated (M‐GHGs). We argue that it is a widespread phenomenon for soil systems to produce GHGs through nonmicrobial pathways (NM‐GHGs) based on a review of the available evidence accumulated over the past half century. We find that five categories of mechanistic process, including photodegradation, thermal degradation, reactive oxidative species (ROS) oxidation, extracellular oxidative metabolism (EXOMET), and inorganic chemical reactions, can be identified as accounting for their production. These pathways are intricately coupled among themselves and with M‐GHGs production and are subject to strong influences from regional and global change agents including, among others, climate warming, solar radiation, and alterations of atmospheric components. Preliminary estimates have suggested that NM‐GHGs could play key roles in contributing to budgets of GHGs in the arid regions, whereas their global importance would be enhanced with accelerated global environmental changes. Therefore, more research should be undertaken, with a differentiation between NM‐GHGs and M‐GHGs, to further elucidate the underlying mechanisms, to investigate the impacts of various global change agents, and to quantify their contributions to regional and global GHGs budgets. These efforts will contribute to a more complete understanding of global carbon and nitrogen cycling and a reduction in the uncertainty of carbon‐climate feedbacks in the Earth system.
Tree‐ring analysis and modeling approaches yield contrary response of circumboreal forest productivity to climate change
Authors: Tei Shunsuke , Sugimoto Atsuko , Yonenobu Hitoshi , Matsuura Yojiro , Osawa Akira , Sato Hisashi , Fujinuma Junichi , Maximov Trofim 
Published: June 2017

AbstractCircumboreal forest ecosystems are exposed to a larger magnitude of warming in comparison with the global average, as a result of warming‐induced environmental changes. However, it is not clear how tree growth in these ecosystems responds to these changes. In this study, we investigated the sensitivity of forest productivity to climate change using ring width indices (RWI) from a tree‐ring width dataset accessed from the International Tree‐Ring Data Bank and gridded climate datasets from the Climate Research Unit. A negative relationship of RWI with summer temperature and recent reductions in RWI were typically observed in continental dry regions, such as inner Alaska and Canada, southern Europe, and the southern part of eastern Siberia. We then developed a multiple regression model with regional meteorological parameters to predict RWI, and then applied to these models to predict how tree growth will respond to twenty‐first‐century climate change (RCP8.5 scenario). The projections showed a spatial variation and future continuous reduction in tree growth in those continental dry regions. The spatial variation, however, could not be reproduced by a dynamic global vegetation model (DGVM). The DGVM projected a generally positive trend in future tree growth all over the circumboreal region. These results indicate that DGVMs may overestimate future wood net primary productivity (NPP) in continental dry regions such as these; this seems to be common feature of current DGVMs. DGVMs should be able to express the negative effect of warming on tree growth, so that they simulate the observed recent reduction in tree growth in continental dry regions.
Decreased plant productivity resulting from plant group removal experiment constrains soil microbial functional diversity
Authors: Zhang Ximei , Johnston Eric R. , Barberán Albert , Ren Yi , Lü Xiaotao , Han Xingguo 
Published: June 2017

AbstractAnthropogenic environmental changes are accelerating the rate of biodiversity loss on Earth. Plant diversity loss is predicted to reduce soil microbial diversity primarily due to the decreased variety of carbon/energy resources. However, this intuitive hypothesis is supported by sparse empirical evidence, and most underlying mechanisms remain underexplored or obscure altogether. We constructed four diversity gradients (0–3) in a five‐year plant functional group removal experiment in a steppe ecosystem in Inner Mongolia, China, and quantified microbial taxonomic and functional diversity with shotgun metagenome sequencing. The treatments had little effect on microbial taxonomic diversity, but were found to decrease functional gene diversity. However, the observed decrease in functional gene diversity was more attributable to a loss in plant productivity, rather than to the loss of any individual plant functional group per se. Reduced productivity limited fresh plant resources supplied to microorganisms, and thus, intensified the pressure of ecological filtering, favoring genes responsible for energy production/conversion, material transport/metabolism and amino acid recycling, and accordingly disfavored many genes with other functions. Furthermore, microbial respiration was correlated with the variation in functional composition but not taxonomic composition. Overall, the amount of carbon/energy resources driving microbial gene diversity was identified to be the critical linkage between above‐ and belowground communities, contrary to the traditional framework of linking plant clade/taxonomic diversity to microbial taxonomic diversity.
Legacy effects of individual crops affect N2O emissions accounting within crop rotations
Authors: Adler Paul R. , Spatari Sabrina , D'Ottone Federico , Vazquez Daniel , Peterson Lisa , Del Grosso Stephen J. , Baethgen Walter E. , Parton William J. 
Published: June 2017

AbstractUruguay is pursuing renewable energy production pathways using feedstocks from its agricultural sector to supply transportation fuels, among them ethanol produced from commercial technologies that use sweet and grain sorghum. However, the environmental performance of the fuel is not known. We investigate the life cycle environmental and cost performance of these two major agricultural crops used to produce ethanol that have begun commercial production and are poised to grow to meet national energy targets for replacing gasoline. Using both attributional and consequential life cycle assessment (LCA) frameworks for system boundaries to quantify the carbon intensity, and engineering cost analysis to estimate the unit production cost of ethanol from grain and sweet sorghum, we determined abatement costs. We found 1) an accounting error in estimating N2O emissions for a specific crop in multiple crop rotations when using Intergovernmental Panel on Climate Change(IPCC) Tier 1 methods within an attributional LCA framework, due to N legacy effects; 2) choice of baseline and crop identity in multiple crop rotations evaluated within the consequential LCA framework both affect the global warming intensity (GWI) of ethanol; and 3) although abatement costs for ethanol from grain sorghum are positive and from sweet sorghum they are negative, both grain and sweet sorghum pathways have a high potential for reducing transport fuel GWI by more than 50% relative to gasoline, and are within the ranges targeted by the US renewable transportation fuel policies.
Frequency of, and factors associated with, hepatitis B virus reactivation in hepatitis C patients treated with all‐oral direct‐acting antivirals: Analysis of a Japanese prospective cohort
Authors: Doi Akira , Sakamori Ryotaro , Tahata Yuki , Urabe Ayako , Morishita Naoki , Yamada Ryoko , Furuta Kunimaro , Kodama Takahiro , Hikita Hayato , Yakushijin Takayuki , Ohkawa Kazuyoshi , Kaneko Akira , Imai Yasuharu , Tatsumi Tomohide , Takehara Tetsuo 
Published: June 2017

AimSeveral case reports have shown that hepatitis B virus (HBV) reactivation developed in hepatitis C patients with a current or previous HBV infection during direct‐acting antiviral (DAA) treatment, which led to severe hepatitis or death in some cases. However, its precise frequency and risk factors are not entirely clear. We analyzed a prospective cohort.MethodsWe analyzed HBV reactivation in 461 consecutive hepatitis C patients who received 12 weeks of ledipasvir/sofosbuvir for genotype 1 or sofosbuvir plus ribavirin for genotype 2 at multiple centers.ResultsBy the examination of the preserved sera at baseline, 159 patients (34%) were identified as seropositive for HBV core antibody (anti‐HBc) and were included in the subsequent analysis; 4 patients were positive for HBV surface antigen (HBsAg), and the others were negative. Serum HBV DNA was undetectable or was detectable but <20 IU/mL at baseline for all patients. Serial measurement of HBV DNA at 4 weeks and 12 weeks in the preserved serum samples was available in 147 patients and identified HBV reactivation (defined as the appearance of serum HBV DNA ≥20 IU/mL) in 2 HBsAg‐positive and 3 HBsAg‐negative patients. No patient developed HBV‐associated hepatitis. Patients who developed HBV reactivation had significantly lower anti‐HBs titers and higher serum alanine transferase levels before treatment.ConclusionHepatitis B virus reactivation during direct‐acting antiviral therapies occurs in 3.4% (5/147) of patients who are positive for anti‐HBc. A low titer of anti‐HBs and a high serum alanine transferase level prior to treatment are associated with reactivation in this patient group.
Junior doctors’ attitudes to opioids for refractory breathlessness in patients with advanced chronic obstructive pulmonary disease
Authors: Smallwood Natasha , Gaffney Nicole , Gorelik Alexandra , Irving Louis , Le Brian , Philip Jennifer 
Published: June 2017

AbstractBackgroundRefractory breathlessness is a common, distressing symptom in patients with advanced chronic obstructive pulmonary disease (COPD). The judicious, off‐licence prescription of opioids, together with other management strategies, can improve breathlessness, however, internationally there is profound reluctance to prescribe opioids for breathlessness in COPD.AimsTo understand Australian junior doctors’ knowledge and attitudes regarding the management of refractory breathlessness and the role of opioids in COPD.MethodsAll junior doctors undertaking basic training in internal medicine in Victoria were invited to complete an online survey. Knowledge, willingness, and experience prescribing opioids to COPD patients with refractory breathlessness, were examined.ResultsOf the 243 responses received, most trainees (193, 86.5%) believed opioids have a role in treating refractory breathlessness in stable COPD outpatients, with 143 (64.1%) recommending morphine as first‐line treatment for refractory breathlessness. One quarter (55, 24.7%) reported having themselves initiated an opioid and 102 (45.7%) had prescribed an opioid under senior supervision for management of breathlessness in COPD. Concern regarding adverse opioid effects was low, with 58 (26.0%) having no concerns prescribing an opioid to COPD patients.ConclusionThis is the first study of doctors to demonstrate high awareness, confidence, willingness and experience in prescribing opioids for the off‐licence indication of refractory breathlessness in COPD. These findings differ significantly from attitudes reported overseas and are unexpected given the doctors surveyed were recently qualified. The low awareness of possible adverse events and limited insight regarding knowledge gaps is concerning and highlights the significant need for greater education in palliative care.
Registered Nurses’ and nurse assistants’ responses to older persons’ expressions of emotional needs in home care
Authors: Höglander Jessica , Eklund Jakob Håkansson , Eide Hilde , Holmström Inger K , Sundler Annelie J 
Published: June 2017

AbstractAimThis study aims to explore nurse assistants’ and Registered Nurses’ responses to older persons’ expressions of emotional needs during home care visits.BackgroundCommunication is a central aspect of care. Older persons might express different emotions and needs during home care visits and such expressions can be challenging to respond to. Little is known about communication in home care or nursing staff responses to older persons’ expressed emotional needs.DesignDescriptive, cross‐sectional design on nursing staff responses to older persons’ negative emotions in home care.MethodsCollected data consisted of audio recordings of home care visits between older persons and nursing staff. Data were collected between August 2014–November 2015. The nursing staff responses to older persons’ negative emotions in the communication were analysed with the Verona Coding Definitions of Emotional Sequences (VR‐CoDES).ResultsThe nursing staff most often give non‐explicit responses, providing space for further disclosure of older persons’ expressed negative emotions. Such responses were more frequent if the nursing staff had elicited the older persons’ expressions of a negative emotion than if such expressions were elicited by the older persons themselves. Most frequent types of responses were backchannel, active invitation or information advice.ConclusionThe nursing staff responses were mainly non‐explicit responses providing space for older persons to tell more about their experiences. Such responses can be discussed in terms of person‐centred communication and is important for the comfort of emotional concerns.
The association between the physical environment and the well‐being of older people in residential care facilities: A multilevel analysis
Authors: Nordin Susanna , McKee Kevin , Wijk Helle , Elf Marie 
Published: June 2017

AbstractAimsTo investigate the associations between the quality of the physical environment and the psychological and social well‐being of older people living in residential care facilities.BackgroundMany older people in care facilities have cognitive and physical frailties and are at risk of experiencing low levels of well‐being. High‐quality physical environments can support older people as frailty increases and promote their well‐being. Although the importance of the physical environment for residents’ well‐being is recognized, more research is needed.DesignA cross‐sectional survey of 20 care facilities from each of which 10 residents were sampled. As the individual resident data were nested in the facilities, a multilevel analysis was conducted.MethodsData were collected during 2013 and 2014. The care facilities were purposely sampled to ensure a high level of variation in their physical characteristics. Residents’ demographic and health data were collected via medical records and interviews. Residents’ well‐being and perceived quality of care were assessed via questionnaires and interviews. Environmental quality was assessed with a structured observational instrument.ResultsMultilevel analysis indicated that cognitive support in the physical environment was associated with residents’ social well‐being, after controlling for independence and perceived care quality. However, no significant association was found between the physical environment and residents’ psychological well‐being.ConclusionOur study demonstrates the role of the physical environment for enhancing the social well‐being of frail older people. Professionals and practitioners involved in the design of care facilities have a responsibility to ensure that such facilities meet high‐quality specifications.
“They just said inappropriate contact.” What do service users hear when staff talk about sex and relationships?
Authors: Grace Nici , Greenhill Beth , Withers Paul 
Published: June 2017

BackgroundResearch into how people with intellectual disabilities (ID) pursue intimate relationships in care settings presents some contradictory findings; despite increasingly liberal staff views, service users experience significant restrictions. This study attempts to explore this gap within a secure hospital, examining service user's representations of staff discourses about sexuality and intimate relationships.MethodSemi‐structured interviews with eight service users with intellectual disability were analysed using critical discourse analysis.ResultsAnalysis enabled construction of 11 themes falling into three categories. Dominant discourses appeared to maintain the integrity of the institution, enable staff to occupy a position of power and demonstrate service users’ responses to perceived control.ConclusionsDiscourses around sex appear to serve the interests of staff and the hospital, while being restrictive and often incomprehensible to service users. Implications for service development, and future research directions, are considered in the context of “Transforming Care.”
Agency, social and healthcare supports for adults with intellectual disability at the end of life in out‐of‐home, non‐institutional community residences in Western nations: A literature review
Authors: Moro Teresa T. , Savage Teresa A. , Gehlert Sarah 
Published: June 2017

BackgroundThe nature and quality of end‐of‐life care received by adults with intellectual disabilities in out‐of‐home, non‐institutional community agency residences in Western nations is not well understood.MethodA range of databases and search engines were used to locate conceptual, clinical and research articles from relevant peer‐reviewed journals.ResultsThe present authors present a literature review of the agency, social and healthcare supports that impact end‐of‐life care for adults with intellectual disabilities. More information is needed about where people with intellectual disabilities are living at the very end of life and where they die.ConclusionsThe support needs for adults with intellectual disabilities will change over time, particularly at the end of life. There are some areas, such as removing barriers to providing services, staff training, partnerships between agencies and palliative care providers, and advocacy, where further research may help to improve the end‐of‐life care for adults with intellectual disabilities.