bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modified hypoosmotic swelling test for the assessment of boar and bull sperm sensitivity to cryopreservation
Authors: Přinosilová Petra , Kopecká Věra , Hlavicová Jaroslava , Kunetková Monika 
Published: December 2014

Routine methods for the evaluation of sperm quality are not sufficiently useful to determine the sensitivity of sperm cells to cold shock. The aim of our preliminary study was to determine whether the sperm plasma membrane integrity evaluated by modified hypoosmotic swelling test based on simple hypoosmotic swelling test (HOS test) and eosin-nigrosin staining could be helpful in predicting the degree of boar sperm survivability during semen cryopreservation. Ejaculates collected from 24 boars and 20 bulls were used in the experiment. Fresh ejaculates were evaluated by routine sperm analysis and a modified HOS test, and subsequently frozen. Sperm cryosurvivability was defined as the percentage of motile spermatozoa that survived the freezing process. A higher percentage of sperm was recovered after the thawing of semen with a higher percentage of HOS-positive and eosin-negative sperm (P < 0.01). Both indicators were found to be correlated (r = 0.707 and r = 0.705, respectively; P < 0.01). Moreover, the percentage of HOS-positive and eosin-negative sperm was similar to the percentage of viable sperm after thawing as determined by traditional eosin-nigrosin staining in boars (50.90 ± 9.88% and 49.31 ± 11.63%, respectively) and bulls (55.91 ± 10.34% and 55.63 ± 6.64%, respectively) and both indicators showed a positive correlation (r = 0.558 and r = 0.504, respectively; P < 0.05). In conclusion, based on the obtained results, we can assume that the modified HOS test can detect differences in sperm membrane resistance which allows assessment of semen quality from the perspective of its further use, e.g. cryopreservation.
Force chains as the link between particle and bulk friction angles in granular material
Authors: Booth Adam M. , Hurley Ryan , Lamb Michael P. , Andrade José E. 
Published: December 2014

AbstractFrom sediment transport in rivers to landslides, predictions of granular motion rely on a Mohr‐Coulomb failure criterion parameterized by a friction angle. Measured friction angles are generally large for single grains, smaller for large numbers of grains, and no theory exists for intermediate numbers of grains. We propose that a continuum of friction angles exists between single‐grain and bulk friction angles due to grain‐to‐grain force chains. Physical experiments, probabilistic modeling, and discrete element modeling demonstrate that friction angles decrease by up to 15° as the number of potentially mobile grains increases from 1 to ~20. Decreased stability occurs as longer force chains more effectively dislodge downslope “keystone” grains, implying that bulk friction angles are set by the statistics of single‐grain friction angles. Both angles are distinct from and generally larger than grain contact‐point friction, with implications for a variety of sediment transport processes involving small clusters of grains.
Organic iodine in Antarctic sea ice: A comparison between winter in the Weddell Sea and summer in the Amundsen Sea
Authors: Granfors Anna , Ahnoff Martin , Mills Matthew M. , Abrahamsson Katarina 
Published: December 2014

AbstractRecent studies have recognized sea ice as a source of reactive iodine to the Antarctic boundary layer. Volatile iodinated compounds (iodocarbons) are released from sea ice, and they have been suggested to contribute to the formation of iodine oxide (IO), which takes part in tropospheric ozone destruction in the polar spring. We measured iodocarbons (CH3I, CH2ClI, CH2BrI, and CH2I2) in sea ice, snow, brine, and air during two expeditions to Antarctica, OSO 10/11 to the Amundsen Sea during austral summer and ANT XXIX/6 to the Weddell Sea in austral winter. These are the first reported measurements of iodocarbons from the Antarctic winter. Iodocarbons were enriched in sea ice in relation to seawater in both summer and winter. During summer, the positive relationship to chlorophyll a biomass indicated a biological origin. We suggest that CH3I is formed biotically in sea ice during both summer and winter. For CH2ClI, CH2BrI, and CH2I2, an additional abiotic source at the snow/ice interface in winter is suggested. Elevated air concentrations of CH3I and CH2ClI during winter indicate that they are enriched in lower troposphere and may take part in the formation of IO at polar sunrise.
Species‐specific transpiration responses to intermediate disturbance in a northern hardwood forest
Authors: Matheny Ashley M. , Bohrer Gil , Vogel Christoph S. , Morin Timothy H. , He Lingli , Frasson Renato Prata de Moraes , Mirfenderesgi Golnazalsadat , Schäfer Karina V. R. , Gough Christopher M. , Ivanov Valeriy Y. , Curtis Peter S. 
Published: December 2014

AbstractIntermediate disturbances shape forest structure and composition, which may in turn alter carbon, nitrogen, and water cycling. We used a large‐scale experiment in a forest in northern lower Michigan where we prescribed an intermediate disturbance by stem girdling all canopy‐dominant early successional trees to simulate an accelerated age‐related senescence associated with natural succession. Using 3 years of eddy covariance and sap flux measurements in the disturbed area and an adjacent control plot, we analyzed disturbance‐induced changes to plot level and species‐specific transpiration and stomatal conductance. We found transpiration to be ~15% lower in disturbed plots than in unmanipulated control plots. However, species‐specific responses to changes in microclimate varied. While red oak and white pine showed increases in stomatal conductance during postdisturbance (62.5 and 132.2%, respectively), red maple reduced stomatal conductance by 36.8%. We used the hysteresis between sap flux and vapor pressure deficit to quantify diurnal hydraulic stress incurred by each species in both plots. Red oak, a ring porous anisohydric species, demonstrated the largest mean relative hysteresis, while red maple, bigtooth aspen, and paper birch, all diffuse porous species, had the lowest relative hysteresis. We employed the Penman‐Monteith model for LE to demonstrate that these species‐specific responses to disturbance are not well captured using current modeling strategies and that accounting for changes to leaf area index and plot microclimate are insufficient to fully describe the effects of disturbance on transpiration.
Gut microbiota are related to Parkinson's disease and clinical phenotype
Authors: Scheperjans Filip , Aho Velma , Pereira Pedro A. B. , Koskinen Kaisa , Paulin Lars , Pekkonen Eero , Haapaniemi Elena , Kaakkola Seppo , Eerola‐Rautio Johanna , Pohja Marjatta , Kinnunen Esko , Murros Kari , Auvinen Petri 
Published: December 2014

AbstractIn the course of Parkinson's disease (PD), the enteric nervous system (ENS) and parasympathetic nerves are amongst the structures earliest and most frequently affected by alpha‐synuclein pathology. Accordingly, gastrointestinal dysfunction, in particular constipation, is an important non‐motor symptom in PD and often precedes the onset of motor symptoms by years. Recent research has shown that intestinal microbiota interact with the autonomic and central nervous system via diverse pathways including the ENS and vagal nerve. The gut microbiome in PD has not been previously investigated. We compared the fecal microbiomes of 72 PD patients and 72 control subjects by pyrosequencing the V1–V3 regions of the bacterial 16S ribosomal RNA gene. Associations between clinical parameters and microbiota were analyzed using generalized linear models, taking into account potential confounders. On average, the abundance of Prevotellaceae in feces of PD patients was reduced by 77.6% as compared with controls. Relative abundance of Prevotellaceae of 6.5% or less had 86.1% sensitivity and 38.9% specificity for PD. A logistic regression classifier based on the abundance of four bacterial families and the severity of constipation identified PD patients with 66.7% sensitivity and 90.3% specificity. The relative abundance of Enterobacteriaceae was positively associated with the severity of postural instability and gait difficulty. These findings suggest that the intestinal microbiome is altered in PD and is related to motor phenotype. Further studies are warranted to elucidate the temporal and causal relationships between gut microbiota and PD and the suitability of the microbiome as a biomarker. © 2014 International Parkinson and Movement Disorder Society
Multiresolution calculation of ionic liquids
Authors: Kirchner Barbara , Hollóczki Oldamur , Canongia Lopes José Nuno , Pádua Agílio A. H. 
Published: December 2014

Ionic liquids—which are special solvents composed entirely of ions—are difficult albeit interesting to study for several reasons. Owing to the many possible cation and anion combinations that form ionic liquids, common properties are hard to classify for them, which makes the theoretical investigation crucial for ionic liquids. The system size, the amount of possible isomers including cation–anion orientation and coordination, as well as the rotation of the side chain(s) prevent the use of high‐level electronic structure methods, and density functional theory is the method of choice. Dispersion forces—although they are small compared to electrostatics—play a major role in ionic liquids; therefore, methods that describe such kind of interplay are preferred. Between the cation and the anion, there is a sizable charge transfer, which has important consequences for molecular dynamics simulations and force field development. Already based on the first generation of force fields important discoveries were made, namely that ionic liquids are nanostructured. Moreover, it was possible to predict that their distillation is possible. Throughout the construction of these force fields, transferability was taken into account which allowed them to describe homologous series. For studying reactions in ionic liquid (IL) media, continuum models were found to improve the results. Ab initio molecular dynamics (AIMD) and quantum mechanics (QM)/molecular mechanics (MM) approaches are well suited for spontaneous events. In case of very large systems, such as cellulose in ionic liquids, coarse‐grained methods are providing insight and are applied more frequently. This makes ionic liquids real multiscalar systems. WIREs Comput Mol Sci 2015, 5:202–214. doi: 10.1002/wcms.1212This article is categorized under:

Structure and Mechanism > Computational Materials Science
Electronic Structure Theory > Density Functional Theory
Molecular and Statistical Mechanics > Molecular Dynamics and Monte-Carlo Methods
Maximum Marginal Likelihood Estimation of a Monotonic Polynomial Generalized Partial Credit Model with Applications to Multiple Group Analysis
Authors: Falk Carl F. , Cai Li 
Published: December 2014

AbstractWe present a semi-parametric approach to estimating item response functions (IRF) useful when the true IRF does not strictly follow commonly used functions. Our approach replaces the linear predictor of the generalized partial credit model with a monotonic polynomial. The model includes the regular generalized partial credit model at the lowest order polynomial. Our approach extends Liang’s (A semi-parametric approach to estimate IRFs, Unpublished doctoral dissertation, 2007) method for dichotomous item responses to the case of polytomous data. Furthermore, item parameter estimation is implemented with maximum marginal likelihood using the Bock–Aitkin EM algorithm, thereby facilitating multiple group analyses useful in operational settings. Our approach is demonstrated on both educational and psychological data. We present simulation results comparing our approach to more standard IRF estimation approaches and other non-parametric and semi-parametric alternatives.
Analysis of Multiple Partially Ordered Responses to Belief Items with Don’t Know Option
Authors: Ip Edward H. , Chen Shyh-Huei , Quandt Sara A. 
Published: December 2014

AbstractUnderstanding beliefs, values, and preferences of patients is a tenet of contemporary health sciences. This application was motivated by the analysis of multiple partially ordered set (poset) responses from an inventory on layman beliefs about diabetes. The partially ordered set arises because of two features in the data—first, the response options contain a Don’t Know (DK) option, and second, there were two consecutive occasions of measurement. As predicted by the common sense model of illness, beliefs about diabetes were not necessarily stable across the two measurement occasions. Instead of analyzing the two occasions separately, we studied the joint responses across the occasions as a poset response. Few analytic methods exist for data structures other than ordered or nominal categories. Poset responses are routinely collapsed and then analyzed as either rank ordered or nominal data, leading to the loss of nuanced information that might be present within poset categories. In this paper we developed a general class of item response models for analyzing the poset data collected from the Common Sense Model of Diabetes Inventory. The inferential object of interest is the latent trait that indicates congruence of belief with the biomedical model. To apply an item response model to the poset diabetes inventory, we proved that a simple coding algorithm circumvents the requirement of writing new codes such that standard IRT software could be directly used for the purpose of item estimation and individual scoring. Simulation experiments were used to examine parameter recovery for the proposed poset model.
Buoyancy-induced turbulence in a tilted pipe
Authors: Hallez Yannick , Magnaudet Jacques 
Published: December 2014

AbstractNumerical simulation is used to document the statistical structure and better understand energy transfers in a low-Reynolds-number turbulent flow generated by negative axial buoyancy in a long circular tilted pipe under the Boussinesq approximation. The flow is found to exhibit specific features which strikingly contrast with the familiar characteristics of pressure-driven pipe and channel flows. The mean flow, dominated by an axial component exhibiting a uniform shear in the core, also comprises a weak secondary component made of four counter-rotating cells filling the entire cross-section. Within the cross-section, variations of the axial and transverse velocity fluctuations are markedly different, the former reaching its maximum at the edge of the core while the latter two decrease monotonically from the axis to the wall. The negative axial buoyancy component generates long plumes travelling along the pipe, yielding unusually large longitudinal integral length scales. The axial and crosswise mean density variations are shown to be respectively responsible for a quadratic variation of the crosswise shear stress and density flux which both decrease from a maximum on the pipe axis to near-zero values throughout the near-wall region. Although the crosswise buoyancy component is stabilizing everywhere, the crosswise density flux is negative in some peripheral regions, which corresponds to apparent counter-gradient diffusion. Budgets of velocity and density fluctuations variances and of crosswise shear stress and density flux are analysed to explain the above features. A novel two-time algebraic model of the turbulent fluxes is introduced to determine all components of the diffusivity tensor, revealing that they are significantly influenced by axial and crosswise buoyancy effects. The eddy viscosity and eddy diffusivity concepts and the Reynolds analogy are found to work reasonably well within the central part of the section whereas non-local effects cannot be ignored elsewhere.
Timing of positive blood samples does not differentiate pathogens causing healthcare-associated from community-acquired bloodstream infections in children in England: a linked retrospective cohort study
Authors: HENDERSON K. L. , MÜLLER-PEBODY B. , WADE A. , SHARLAND M. , MINAJI M. , JOHNSON A. P. , GILBERT R 
Published: December 2014

SUMMARYPaediatricians recognize that using the time-dependent community-acquired vs. hospital-acquired bloodstream infection (BSI) dichotomy to guide empirical treatment no longer distinguishes between causative pathogens due to the emergence of healthcare-associated BSIs. However, paediatric epidemiological evidence of the aetiology of BSIs in relation to hospital admission in England is lacking. For 12 common BSI-causing pathogens in England, timing of laboratory reports of positive paediatric (3 months to 5 years) bacterial blood isolates were linked to in-patient hospital data and plotted in relation to hospital admission. The majority (88·6%) of linked pathogens were isolated <2 days after hospital admission, including pathogens widely regarded as hospital acquired: Enterococcus spp. (67·2%) and Klebsiella spp. (88·9%). Neisseria meningitidis, Streptococcus pneumoniae, group A streptococcus and Salmonella spp. were unlikely to cause hospital-acquired BSI. Pathogens commonly associated with hospital-acquired BSI are being isolated <2 days after hospital admission alongside pathogens commonly associated with community-acquired BSI. We confirm that timing of blood samples alone does not differentiate between bacterial pathogens. Additional factors including clinical patient characteristics and healthcare contact should be considered to help predict the causative pathogen and guide empirical antibiotic therapy.
Medication decision making and patient outcomes in GP, nurse and pharmacist prescriber consultations
Authors: Weiss Marjorie C. , Platt Jo , Riley Ruth , Chewning Betty , Taylor Gordon , Horrocks Susan , Taylor Andrea 
Published: December 2014

AimThe aims of this study were twofold: (a) to explore whether specific components of shared decision making were present in consultations involving nurse prescribers (NPs), pharmacist prescribers (PPs) and general practitioners (GPs) and (b) to relate these to self-reported patient outcomes including satisfaction, adherence and patient perceptions of practitioner empathy.BackgroundThere are a range of ways for defining and measuring the process of concordance, or shared decision making as it relates to decisions about medicines. As a result, demonstrating a convincing link between shared decision making and patient benefit is challenging. In the United Kingdom, nurses and pharmacists can now take on a prescribing role, engaging in shared decision making. Given the different professional backgrounds of GPs, NPs and PPs, this study sought to explore the process of shared decision making across these three prescriber groups.MethodsAnalysis of audio-recordings of consultations in primary care in South England between patients and GPs, NPs and PPs. Analysis of patient questionnaires completed post consultation.FindingsA total of 532 consultations were audio-recorded with 20 GPs, 19 NPs and 12 PPs. Prescribing decisions occurred in 421 (79%). Patients were given treatment options in 21% (102/482) of decisions, the prescriber elicited the patient’s treatment preference in 18% (88/482) and the patient expressed a treatment preference in 24% (118/482) of decisions. PPs were more likely to ask for the patient’s preference about their treatment regimen (χ2=6.6,P=0.036, Cramer’sV=0.12) than either NPs or GPs. Of the 275 patient questionnaires, 192(70%) could be matched with a prescribing decision. NP patients had higher satisfaction levels than patients of GPs or PPs. More time describing treatment options was associated with increased satisfaction, adherence and greater perceived practitioner empathy. While defining, measuring and enabling the process of shared decision making remains challenging, it may have patient benefit.
Evaluation and policy learning: The learners' perspective
Authors: Borrás Susana , Højlund Steven 
Published: December 2014

AbstractThis article examines how evaluation induces policy learning – a question largely neglected by the scholarly literature on evaluation and policy learning. Following a learner's perspective, the article attempts to ascertain who the learners are, and what, and how, learners actually learn from evaluations. In so doing, it focuses on what different types of learners actually learn within the context of the evaluation framework (the set of administrative structures defining the evaluation goals and process). Taking the empirical case of threeEUprogramme evaluations, the patterns of policy learning emanating from them are examined. The findings are that only two types of actors involved in the evaluation are actually learning (programme units and external evaluators), that learners learn different things (programme overview, small‐scale programme adjustments, policy change and evaluation methods) and that different learners are in control of different aspects of the evaluation (learning objectives and processes) according to the evaluation framework established by theEuropeanCommission.
The construction of party membership
Authors: Gauja Anika 
Published: December 2014

AbstractWhile the collapse of party membership in the last half‐century has consumed much of the focus of party scholarship, the notion of membership itself is surprisingly under‐theorised. This article presents a tripartite framework for understanding party membership as a constructed concept: from the perspective of the state, the individual and the political party. As organisational mediators and strategic electoral actors, political parties construct varying notions of membership in order to mobilise resources and gain legitimacy, while balancing the participatory demands of citizens with the legal and normative expectations imposed by the state. Using a number of illustrative examples fromEurope and beyond, the article analyses the development of supporters' networks and the extension of participatory opportunities to non‐members. Designed in part to address this membership decline and to offer individuals a different way of engaging with political parties, these initiatives are seen as a crucial step in the evolution of modern parties towards looser, more individualised and amorphous networks of affiliation.
Environmental regulation and technology transfers
Authors: Asano Takao , Matsushima Noriaki 
Published: December 2014

AbstractThis paper analyzes the situation in which a national government introduces environmental regulations. Within the framework of an international duopoly with environmental regulations, an environmental tax imposed by the government in the home country can induce a foreign firm with advanced abatement technology to license it to a domestic firm without this technology. Furthermore, when the domestic firm's production technology is less efficient than that of the foreign firm, the foreign firm may freely reveal its technology to the domestic firm. These improvements through the voluntary transfer of technology imply that environmental regulations have positive impacts on innovation.