bluuebunny/crossref_metadata_2025_split huggingface dataset:
Elastoplastic response and failure assessment of steel alloys: Empirical and computational analyses
Authors: Farahani Behzad V. , Belinha Jorge , Tavares Paulo J. , Moreira Pedro M.G.P. 
Published: August 2018

AbstractThis work aims to study material nonlinearity related to a dual‐phase Steel (DP600) specimen loaded under a tension. Experiment is performed, and then captured data are processed by 3D digital image correlation (DIC). It deals with two analyses; firstly, elastoplastic response of material due to tension up to material plastification. Then, the problem is modelled using FEM, considering an isotropic von Mises criterion/hardening behaviour. To obtain comparable numerical results, model is solved using meshless methods. Besides strain fields, load/displacement response is evaluated, and numerical formulations are validated with experimental solution. Second, failure phenomenon due to plasticity is studied since material undergoes its failure. The empirical results rely on DIC, and then, damage model is resolved using Gurson‐Tvergaard‐Needleman (GTN) criterion. As a result, the engineering stress/strain curves are reported. Comparisons are made between DIC and GTN damage model. Promising computational results are verified by DIC results implying that supportive strategy is proficient.
A global meta‐analysis of marine predator nitrogen stable isotopes: Relationships between trophic structure and environmental conditions
Authors: Pethybridge Heidi , Choy C. Anela , Logan John M. , Allain Valerie , Lorrain Anne , Bodin Nathalie , Somes Christopher J. , Young Jock , Ménard Frederic , Langlais Clothilde , Duffy Leanne , Hobday Alistair J. , Kuhnert Petra , Fry Brian , Menkes Christophe , Olson Robert J. 
Published: August 2018

AbstractAimWe examined potential environmental drivers of broad‐scale spatial patterns in the trophic structure of marine ecosystems as represented by nitrogen stable isotopes in globally distributed marine predators. Additionally, we assessed the effects of spatial scale on the predictive capabilities of environmental variables.LocationGlobal oceans.Time period2000 to 2015.Major taxa studiedTunas: Thunnus albacares, Thunnus obesus, Thunnus alalunga.MethodsWe undertook a global compilation and meta‐analysis of the bulk nitrogen stable isotope ratios (δ15N values) of three tuna species (n = 4,281). After adjusting for regional variations in baseline δ15N values using a global ocean biogeochemistry model, generalized additive mixed models were employed to infer global‐scale oceanographic controls of trophic structure, using cosmopolitan tuna species as a model.ResultsFor the three tuna species, variation in trophic position estimated using bulk δ15N values was largely explained by geographical location and the corresponding oxygen minimum layer depth. Tuna trophic positions declined in areas with reduced oxygen at depth. Food‐chain length, as captured by maximum trophic position, was longer in areas of the western Pacific Ocean and shorter in the northern Atlantic and eastern Pacific Oceans. Trophic adaptability of the tuna predators, as indicated by intraspecific variability, was highest in the western and central Pacific Ocean and lowest in the northern Atlantic Ocean. Our analysis demonstrated that while tunas share similar functional trophic roles, deeper‐foraging tuna species had higher trophic positions globally. The predictive capacity of environmental variables decreased at finer (regional) spatial scales.Main conclusionsOur work suggests that habitat compression resulting from the predicted global expansion of oxygen minimum zones with ocean warming will impact the trophic structure of marine food webs and the corresponding foraging habits of marine predators. Spatial scale analyses highlighted the importance of representing differences in regional ecological dynamics in global‐scale trophic and ecosystem models.
Latitudinal variation in seagrass herbivory: Global patterns and explanatory mechanisms
Authors: Vergés Adriana , Doropoulos Christopher , Czarnik Rob , McMahon Kathryn , Llonch Nil , Poore Alistair G. B. 
Published: August 2018

AbstractAimThe aim was to quantify latitudinal patterns in seagrass–herbivore interactions in the context of a warming climate.Location: We carried out a global meta‐analysis combined with a field experiment across 1,700 km and 12° of latitude in Western Australia.Time period: 1984–2014.Major taxa studied: Seagrasses.MethodsWe first synthesized the global literature on herbivore exclusion experiments in seagrasses to test whether differences in herbivore impacts are related to latitude and sea surface temperature. We then quantified leaf production and consumption rates in the field at nine meadows of the seagrass Amphibolis antarctica across 1,700 km, from tropical to temperate latitudes. Seagrass biomass and nutritional traits (nitrogen, C:N, phenolics) were also measured.ResultsOur meta‐analysis showed that herbivores had a similar net impact on seagrasses across 37° of absolute latitude, and there was little variation in herbivore exclusion effects at different temperatures. In the field, rates of both production and consumption of seagrass were greatest in the tropics and decreased with latitude. Seagrass nutritional quality was lowest in the tropics, where fish removed c. 30% of primary production. Consumption of the more nutritious temperate seagrasses was lower overall but also highly variable and dominated by invertebrates.Main conclusionsIn tropical latitudes, faster growth rates compensated for greater consumption of A. antarctica by herbivores. This resulted in similar net impacts of herbivores across latitudes, because higher latitude plants grew more slowly but also suffered less herbivory. This match between consumption and production rates might explain the global patterns derived from the literature, which show little latitudinal variation in the effects of consumers on seagrasses. As ocean temperatures continue to rise and overall herbivory levels are expected to increase in temperate regions, the survival of seagrass meadows in higher latitudes will depend on the ability of plants to increase growth at compensatory rates.
The influence of pesticide use on amphibian chytrid fungal infections varies with host life stage across broad spatial scales
Authors: Rumschlag Samantha L. , Rohr Jason R. 
Published: August 2018

AbstractAimWidespread pesticides might influence pathogen distributions across landscapes via effects on host–pathogen interactions. Empirical research supports two hypotheses regarding effects of pesticides on amphibians and the aquatic fungal pathogen Batrachochytrium dendrobatidis (Bd): (a) pesticides can be toxic to Bd, reducing infection risk of aquatic larval amphibians; and, (b) exposure to pesticides early in amphibian development can increase disease risk after metamorphosis. The aim of this research is to evaluate whether these patterns from laboratory experiments are consistent across host species and occur in the field at broad spatial scales.LocationContiguous U.S.A.Time period1998–2009.Major taxa studiedAmphibian hosts and Bd.MethodsOur data included 3,946 individuals evaluated for Bd infection across 49 amphibian species, which resulted in 155 estimates of Bd prevalence in populations. We used multimodel inference to examine associations between Bd infection prevalence in amphibian populations and (a) total pesticide use, (b) pesticide use by type (herbicide, insecticide or fungicide), and (c) the most commonly used pesticide compounds across life stages, controlling for several factors documented to affect the distribution of Bd.ResultsConsistent with laboratory findings, our results indicate that use of multiple herbicide compounds is most closely associated with low infection risk in the aquatic larval stage but high risk in the terrestrial post‐metamorphic stage when controlling for insecticide and fungicide use. We caution against assuming that insecticides and fungicides do not influence Bd distributions, because use of herbicides, insecticides and fungicides are all correlated positively.Main conclusionsThe effects that pesticides can have on disease distributions are complex and should be considered strongly at broad scales and across host species, especially in environments in which use and exposure are widespread. Accurate predictions of disease distributions may lead to more effective management strategies to limit disease spread.
Cold and dark captivity: Drivers of amphibian longevity
Authors: Stark Gavin , Meiri Shai 
Published: August 2018

AbstractAimLongevity is a critical life‐history trait of organisms. Multiple abiotic and biotic factors are thought to exert different selection pressures, resulting in a great variation in species longevity. We examined factors that, according to evolutionary theories of senescence, are thought to be related to extrinsic and intrinsic mortality rates, and thus shape the variation in longevity among amphibians.LocationWorld‐wide.Time periodPresent.Major taxa studiedAmphibia.MethodsWe collected literature data on the maximum longevities of 527 amphibian species. Correcting for phylogeny and sample size, we modelled the relationship between amphibian longevity and body size. We also examined the effects of chemical protection, activity period, microhabitat preferences and annual temperature on amphibian longevity.ResultsIn general, members of larger amphibian species live longer. Body size, however, explained less of the variation in amphibian longevity than it does in mammals and birds. Nocturnal amphibians, species that use poison for defence and those inhabiting cold regions live longer, but microhabitat preferences had little effect.Main conclusionsOur results supported predictions of evolutionary theories of senescence. Large amphibians living in colder environments probably experience slower growth and metabolic rates, reducing intrinsic drivers of mortality and increasing longevity. Moreover, species that reduce extrinsic mortality pressures via chemical protection and nocturnality have increased longevity. Sampling captive animals and sampling more individuals of a species increases the chances of finding older individuals and should be corrected for when studying maximum longevity.
Polypharmacy is associated with frailty in Japanese community‐dwelling older adults
Authors: Yuki Atsumu , Otsuka Rei , Tange Chikako , Nishita Yukiko , Tomida Makiko , Ando Fujiko , Shimokata Hiroshi 
Published: August 2018

AimThe association between polypharmacy and the development of frailty is unknown. The present study assessed the longitudinal relationship between polypharmacy and frailty risk in Japanese community‐dwelling older adults.MethodsParticipants included 299 non‐frail older Japanese adults aged 65–81 years who participated in both baseline and follow‐up examinations of a longitudinal study of aging (mean duration 6.2 years). At baseline examination, all prescribed and non‐prescribed medications used during the previous 2 weeks were confirmed and coded by physicians. Frailty was diagnosed according to frailty criteria, and included shrinking, exhaustion, low activity, low grip strength and low gait speed. The relationship between frailty and the number of medications was assessed using multiple logistic regression analysis. The logistic regression model was used to control for potential confounders, including age at baseline, sex, body fat, total physical activity, education, employment, current smoking and number of comorbidities.ResultsThe percentage of participants who developed frailty during follow up was 5.1% in those taking five or fewer medications, and 22.5% in those taking six or more medications. The fully adjusted odds ratio for frailty among participants taking six or more medications was 5.55 (95% confidence interval 2.17–14.22).ConclusionsPolypharmacy appears to be a significant risk factor for the development of frailty in older Japanese adults. Geriatr Gerontol Int 2018; 18: 1497–1500.
Higher Education institutional governance reforms in the Netherlands, Portugal and Italy: A policy translation perspective addressing the homogeneous/heterogeneous dilemma
Authors: Donina Davide , Hasanefendic Sandra 
Published: August 2018

AbstractThis paper addresses the homogeneous/heterogeneous dilemma regarding formal arrangements of university central governance structures. Most topical studies argue that these structures are becoming homogeneous across countries and prove it by adopting purposive sampling techniques. Yet, other scholars stress heterogeneity within countries. This paper aims to clarify this dilemma through a multi‐level analysis that simultaneously considers three levels of embeddedness (i.e., supranational, national and institutional), by employing a policy translation perspective, which can accommodate both homogeneity and heterogeneity. The national sample comprises three countries (the Netherlands, Portugal and Italy). The institutional sample is comprehensive and encompasses all public universities within each country. The study discloses heterogeneity in how countries responded to supranational policy pressures as well as heterogeneous responses at the institutional level even when unitary laws are applied. Relying on these findings, we stress the importance of adopting comprehensive (rather than purposive) sampling to infer about international and/or national homogeneity because studies that generalise results based on one/few case studies per country could be biased by the sample selection criteria. In addition, the research implications of our analysis on steering‐at‐a‐distance and on the relation between the grade of cogency of the national laws and homogeneous/heterogeneous reform outcomes are discussed.
From activism to secrecy: Contemporary experiences of living with HIV in London in people diagnosed from 1986 to 2014
Authors: Rai Tanvi , Bruton Jane , Day Sophie , Ward Helen 
Published: August 2018

AbstractBackgroundSuccesses in biomedicine have transformed HIV from a debilitating and frequently fatal infection to a chronic, manageable condition.ObjectiveTo explore how the contemporary metanarrative of HIV as a chronic condition is understood by patients and how it varies depending on when they were diagnosed.DesignQualitative interviews with 52 people living with HIV who were diagnosed during different phases in the history of the epidemic.Setting and participantsParticipants were recruited from two HIV clinics in London to include four “HIV generations”: generation 1 were those who had been diagnosed pre‐1997 (pre‐ART), generation 2 from 1997 to 2005 (complex ART), generation 3 from 2006 to 2012 (simpler ART) and generation 4 diagnosed in the year before the study (2013‐2014).ResultsParticipants in all HIV generations took their medication as prescribed, attended clinic appointments and were well informed about their immunological biomarkers. While the pre‐treatment generation had been engaged in community endeavours such as activism, public education and use of support groups, those more recently diagnosed had little experience of collective activities and their HIV was essentially a private matter, separate from their social identity. These strategies worked for some; however, those experiencing clinical or social problems related to HIV or wider issues often relied exclusively on their HIV clinic for wider support.ConclusionThe loss of public conversation around HIV, the imperative for patients to take on greater individual responsibility for HIV management and the streamlining of HIV services alongside reductions in ancillary support services may expose some people to suboptimal health outcomes.
Assessment of endothelial function during the loading phase of infliximab in psoriasis: a potential predictor of its drug survival
Authors: Nakao Momoko , Nakamura Kouki , Fukasawa Takemichi , Shida Rino , Ito Arisa , Ichimura Yohei , Takahashi Takehiro , Mitsui Aya , Yoshizaki Ayumi , Shibata Sayaka , Kamata Masahiro , Araki Mayuko , Watanabe Rei , Sato Shinichi , Asano Yoshihide 
Published: August 2018

AbstractBackgroundTumor necrosis factor inhibitors decrease the risk of cardiovascular events in moderate to severe psoriasis, but the association between their effects on endothelial function and those on skin lesions has not been well studied. We investigated the association between infliximab effects on endothelial function during the loading phase and those on skin lesions in patients with psoriasis.MethodsWe evaluated endothelial function with reactive hyperemia‐peripheral arterial tonometry index (RHI) in 15 patients with psoriasis before the first and third infusions of infliximab. Patients were stratified into two groups; those who maintained Psoriasis Area and Severity Index (PASI) 75 response for more than 6 months (defined as responders) and the others (defined as nonresponders).ResultsSix weeks after the initiation of infliximab (before the third infusion), PASI scores were significantly improved compared with baseline, while RHI values were not altered in the whole patient group. However, when the responders and the nonresponders were analyzed separately, RHI values tended to be decreased before the third infusion compared with baseline in the nonresponders, while being unchanged in the responders. Importantly, the difference in ∆RHI reached a statistical significance between the two groups, and the cutoff value (mean − 2 standard deviation of RHI values in the responders) identified the nonresponders with 67% of sensitivity and 100% of specificity.ConclusionsThe decrease in RHI values before the third infusion may serve as a predictor for the long‐term unfavorable effect of infliximab on psoriatic skin lesions.
Model‐Assisted Regression Estimators for Longitudinal Data with Nonignorable Dropout
Authors: Wang Lei , Qi Cuicui , Shao Jun 
Published: August 2018

SummaryEstimation with longitudinalYhaving nonignorable dropout is considered when the joint distribution ofYand covariateXis nonparametric and the dropout propensity conditional on (Y,X) is parametric. We apply the generalised method of moments to estimate the parameters in the nonignorable dropout propensity based on estimating equations constructed using an instrumentZ, which is part ofXrelated toYbut unrelated to the dropout propensity conditioned onYand other covariates. Population means and other parameters in the nonparametric distribution ofYcan be estimated based on inverse propensity weighting with estimated propensity. To improve efficiency, we derive a model‐assisted regression estimator making use of information provided by the covariates and previously observedY‐values in the longitudinal setting. The model‐assisted regression estimator is protected from model misspecification and is asymptotically normal and more efficient when the working models are correct and some other conditions are satisfied. The finite‐sample performance of the estimators is studied through simulation, and an application to the HIV‐CD4 data set is also presented as illustration.
Sintering of ferrous metallic compacts: Chemical reactions that involve interstitial elements
Authors: Gierl‐Mayer Christian , de Oro Calderon Raquel , Danninger Herbert 
Published: August 2018

AbstractFor sintering of ferrous metallic compacts, the chemical reactions with the atmosphere are of special interest. This is due to the very large specific surface of the compacts that makes them highly reactive with the atmosphere, much more than cast and wrought metals. Within this paper, the interactions of interstitial elements with the metallic matrix and the surrounding atmosphere are described. The main reaction partners are interstitial elements that may emerge from the starting powders or from the surrounding atmosphere. The oxidation/reduction and decarburization phenomena have been studied by thermoanalytical techniques both for mixed and prealloyed systems. The reaction mechanisms are discussed as well as their impacts on the sintering processes and the resulting properties. Oxygen transfer reactions (“Internal gettering”) and formation of methane are observed for systems with widely varying oxygen affinity of the components. The results presented show that controlling the interactions of the interstitial elements with the metallic components is crucial for successful sintering of advanced PM alloy steels.
High‐energy density of Pb0.97La0.02(Zr0.50Sn0.45Ti0.05)O3 antiferroelectric ceramics prepared by sol‐gel method with low‐cost dibutyltin oxide
Authors: Dan Yu , Xu Haojie , Zhang Yangyang , Zou Kailun , Zhang Qingfeng , Lu Yinmei , Chang Gang , Zhang Qi , He Yunbin 
Published: August 2018

AbstractLead lanthanum zirconate stannate titanate (PbLa(ZrSnTi)O3) antiferroelectric (AFE) ceramics are widely used in dielectric capacitors due to their superior energy‐storage capacity. Generally, these ceramics can be synthesized by solid‐state reaction and sol‐gel methods. Ceramics prepared using the sol‐gel method have a purer phase than those prepared using the solid‐state reaction method because the sol‐gel method can avoid the segregation of Sn. However, because the commonly used raw material tin acetate is very expensive, the preparation of PbLa(ZrSnTi)O3 AFE ceramics via the sol‐gel method is not cost‐effective, which prevents the use of sol‐gel method for manufacturing PbLa(ZrSnTi)O3 in a large scale. In this work, low‐cost dibutyltin oxide instead of expensive tin acetate is used to synthesize Pb0.97La0.02(Zr0.50Sn0.45Ti0.05)O3 (PLZST) nanopowders, and single‐phase powders with a perovskite structure and average grain size of 200 nm are obtained at a calcination temperature of 580°C. In addition, dense PLZST AFE ceramics with a pure perovskite structure are obtained by sintering the PLZST nanopowders at temperatures as low as 1100°C. The sintered PLZST ceramics exhibit a room‐temperature recoverable energy‐storage density as high as 1.93 J/cm3 with an efficiency of 75%, which varies only slightly in the temperature range of 20‐120°C. The high energy‐storage density (>1.9 J/cm3) over a wide temperature range illustrates that the sol‐gel‐derived PLZST ceramics with low‐cost dibutyltin oxide are quite promising for manufacturing pulse power capacitors.
Professional and family caregivers’ attitudes towards involuntary treatment in community‐dwelling people with dementia
Authors: Mengelers Angela M. H. J. , Bleijlevens Michel H. C. , Verbeek Hilde , Capezuti Elizabeth , Tan Frans E. S. , Hamers Jan P. H. 
Published: August 2018

AbstractAimsThe aim of this study was to gain insight into professional and family caregivers’ attitudes towards involuntary treatment in community‐dwelling people with dementia (PwD).BackgroundThe number of PwD with complex care needs living at home is increasing rapidly. In some situations, caregivers provide care against the will of PwD, referred to as involuntary treatment, which includes non‐consensual care, psychotropic medication and physical restraints.DesignA cross‐sectional study.MethodsA total of 228 professional (nursing staff, general practitioners (GPs) and other healthcare professionals such as physical therapists and psychologists) and 77 family caregivers of PwD completed the Maastricht Attitude Questionnaire—Home Care. This questionnaire measures attitudes towards involuntary treatment and perceived restrictiveness of and experienced discomfort in using involuntary treatment. Data were collected in the Netherlands between June and November 2016.ResultsFamily caregivers and GPs had more positive attitudes towards involuntary treatment than nursing staff and other healthcare professionals, indicating that they are more accepting of involuntary treatment. A more positive attitude was associated with higher perceived caregiver burden and being a family caregiver. Family caregivers and GPs found the use of involuntary treatment less restrictive and indicated feeling more comfortable when using these measures.ConclusionIt is important to account for the differences in attitudes and foster dialogue among professional and family caregivers to find common ground about alternatives to involuntary treatment. These results will inform the development of an intervention that aims to prevent involuntary treatment in home care.