bluuebunny/crossref_metadata_2025 huggingface dataset:
WHY DO CHARTER SCHOOLS FAIL? AN ANALYSIS OF CHARTER SCHOOL SURVIVAL IN NEW JERSEY
Authors: Schwenkenberg Julia , VanderHoff James
Published: May 2014

Charter school competition can only work as a policy to improve public education if schools that do not contribute to this goal are allowed to fail. We estimate survival regressions to assess the effects of various factors on the probability of school failure. We find that students' test scores are the most important determinant of survival: a one standard deviation increase reduces the probability of failure by 76%. Higher expenditures per student and a longer wait list result in smaller, but significant, reductions. Enrollment, average performance in the host district, and student demographics do not significantly affect school survival. (JEL I21, H75)
Urinary biomarkers of acute kidney injury in deceased organ donors – kidney injury molecule‐1 as an adjunct to predicting outcome
Authors: Field Melanie , Dronavalli Vamsi , Mistry Punam , Drayson Mark , Ready Andrew , Cobbold Mark , Inston Nicholas
Published: May 2014

Background

Deceased kidney donors are increasingly “marginal,” and many have risk factors for acute kidney injury (AKI) that may impact on subsequent renal transplant outcome. Despite this, determining the presence of AKI at the time of deceased organ donation remains difficult.

Methods

Urine samples from 182 brainstem dead multi‐organ donors (all of whom donated hearts that were transplanted) were analyzed for a Luminex™ panel of biomarkers linked with AKI. This included KIM‐1, NGAL, IFN‐γ, TNF‐α, cystatin C, Fractalkine and vascular endothelial growth factor. Levels were correlated to early renal transplant outcomes, most specifically delayed graft function.

Results

Donor urinary KIM‐1 levels were significantly higher in donors whose kidneys displayed aberrant early function (p = 0.011). Fractalkine levels showed a trend toward elevation in such donors but uncorrected this did not attain significance. No correlation occurred with the remaining biomarkers.

Conclusions

KIM‐1 appears to show promise as a marker for AKI in deceased cardiac organ donors. The availability of a lateral flow device (Renastick™) for KIM‐1 that also demonstrates higher urinary KIM‐1 levels in donors whose kidneys show aberrant initial function (p = 0.03), makes KIM‐1 a potential indicator of AKI that may merit further evaluation for its application at the donor bedside.
Epicardial fat thickness: threshold values and lifestyle association in male adolescents
Authors: Cena H. , Fonte M. L. , Casali P. M. , Maffoni S. , Roggi C. , Biino G.
Published: May 2014

Background

Obese adolescents with high proportion of visceral fat are at higher risk of developing the metabolic syndrome.

Objectives

The study aims to investigate if echocardiographic epicardial fat thickness (EF) could be predictive of visceral obesity (VO) early in life and to provide EF threshold values specific for male adolescents. Further aim was to investigate the association between EF, lifestyle and metabolic disease familiarity.

Methods

Anthropometric data were collected from 102 normal weight and overweight, healthy male adolescents (mean age: 14.91 ±  1.98 years); bioelectrical impedance analysis and transthoracic echocardiogram were performed in the same sample. Each participant fulfilled a validated self‐administered lifestyle questionnaire.

Results

We found higher EF values in sedentary adolescents (P < 0.05), in those who never eat fruit and vegetables (P < 0.05), and in those with overweight mothers (P < 0.05). The strongest independent predictor of EF was waist circumference (P < 0.0001). Using the waist to height ratio as a marker of VO, logistic regression analysis revealed that 1 mm EF gain is responsible for seven times higher VO risk (P < 0.0001). Receiver Operating Characteristic (ROC) analysis showed that the optimal cut‐off for EF thickness associated to youth VO is 3.2 mm.

Conclusion

Ultrasonography EF measurement might be a second‐level assessment tool, useful to detect early cardiometabolic damage stage.
The influence of job characteristics and self‐directed learning orientation on workplace learning
Authors: Raemdonck Isabel , Gijbels David , van Groen Willemijn
Published: May 2014

Given the increasing importance of learning at work, we set out to examine the factors which influence workplace learning behaviour. The study investigated the influence of the job characteristics fromKarasek'sJobDemandControlSupport model and the personal characteristic self‐directed learning orientation on workplace learning. A total of 837 workers, aged between 18 and 65, from different sectors and with different educational levels completed a paper questionnaire. Analysis revealed that job demands and self‐directed learning orientation constitute significant and positive predictors of workplace learning behaviour. The study can help organizations to create job structures that promote workplace learning.
Learning, intention to transfer and transfer in executive education
Authors: Culpin Victoria , Eichenberg Timm , Hayward Ian , Abraham Priya
Published: May 2014

The main aim of this study was to understand the relationship between self‐reported ‘intention’ to transfer and self‐reported ‘actual’ transfer within a population of middle and senior executives on an executive education programme. A secondary objective was to consider the relationship between these qualitative self‐reports of intent and actual transfer and a quantitative measure of knowledge and skill acquisition immediately post programme. The focus is on ‘what’ is transferred as well as changes in behaviour rather than on identifying and measuring the strength of factors associated with the act of transfer. Practical tools as well as frameworks and ideas designed to foster a change of mindset were mentioned most frequently in terms of both transfer and intention to transfer, thus there was found to be a similar relationship between those aspects of a leadership development programme that participants have already transferred back in to the workplace and those they intend to transfer. In consideration of the secondary objective, the themes that received the largest number of nominations for transfer of learning were also comparable to the skills that gained the highest learning change scores on the questionnaire. It is postulated that the types of learning material used in the executive development programme adhere to four basic principles of learning: active engagement, limited but some prior knowledge, clear applicability back in to the workplace and the opportunity for repeated practice. The implications for programme design to maximize transfer of learning for middle and senior executives, focusing on these four principles, are discussed, along with the importance of executives autonomy in their working environment to facilitate the transfer (or intention to transfer) learning.
Anti‐Toll‐like receptor 2 and 4 antibodies suppress inflammatory response in mice
Authors: Komai‐Koma Mousa , Li Dong , Wang Eryi , Vaughan Diane , Xu Damo
Published: May 2014

Toll‐like receptors (TLRs) 2 and 4 recognize different endogenous and exogenous agonists and play a distinct role in infection and inflammation. However, their ultimate effect in a given infectious and inflammatory disease is less understood. We produced polyclonal anti‐murine TLR2 and TLR4 antibodies and investigated their effect on cutaneous leishmaniasis and inflammatory arthritis. Administration of these antibodies to susceptible BALB/c mice, infected in the footpad with Leishmania major, reduced footpad swelling but not the parasite load compared with mice treated with control IgG. The antibodies synergistically reduced leishmanial‐specific T‐cell proliferation, T helper type 1 and type 2 cytokine production, specific IgG1 and IgG2a antibody synthesis, and T‐cell receptor and co‐stimulatory molecule expression on dendritic cells in infected mice. We then tested the effect of these antibodies on collagen‐induced arthritis (CIA) in DBA/1 mice, a classic model of chronic inflammation. Both antibodies markedly suppressed the development of clinical parameters with concomitant reduction of pro‐inflammatory cytokine production. These data therefore suggest that anti‐TLR2 and 4 antibodies may have a synergistic therapeutic effect on inflammatory disease in vivo.
Analysis and design of peer‐assisted video‐on‐demand services
Authors: Romero Pablo , Robledo Franco , Rodríguez‐Bocca Pablo , Rostagnol Claudia
Published: May 2014

We propose a deterministic fluid model to understand the trade‐offs in the design of peer‐assisted video‐on‐demand (VoD) services. There are three entities in this model: peers (or end users), seeders (altruistic users that own one or several complete video items), and cache servers that store and forward videos with a limited capacity. Peers join the network, download one or multiple concurrent video streams (possibly different video items), and abort the system when they wish. Peers are assumed to cooperate in a BitTorrent‐based fashion, governed by tit‐for‐tat and fair availability. The issue is to minimize the expected downloading times, choosing the set of video items that should be stored in each cache server. We first prove that the deterministic model is globally stable, and find closed expressions for the expected waiting times. Then, we introduce a combinatorial optimization problem (COP), whose nature is similar to the multiknapsack problem (where the items are videos, and knapsacks are related with the storage of cache servers). The problem turns out to be NP‐complete. Therefore, we heuristically address the problem following a GRASP (greedy randomized adaptive search procedure) methodology. Finally, we simulate the new caching methodology with real‐life traces taken from YouTube logs. The results suggest that the peer‐to‐peer philosophy is both stable and cost‐effective for on‐demand streaming purposes.
Migrate small, sound big: functional constraints on body size promote tracheal elongation in cranes
Authors: Jones M. R. , Witt C. C.
Published: May 2014

Organismal traits often represent the outcome of opposing selection pressures. Although social or sexual selection can cause the evolution of traits that constrain function or survival (e.g. ornamental feathers), it is unclear how the strength and direction of selection respond to ecological shifts that increase the severity of the constraint. For example, reduced body size might evolve by natural selection to enhance flight performance in migratory birds, but social or sexual selection favouring large body size may provide a countervailing force. Tracheal elongation is a potential outcome of these opposing pressures because it allows birds to convey an auditory signal of exaggerated body size. We predicted that the evolution of migration in cranes has coincided with a reduction in body size and a concomitant intensification of social or sexual selection for apparent large body size via tracheal elongation. We used a phylogenetic comparative approach to examine the relationships among migration distance, body mass and trachea length in cranes. As predicted, we found that migration distance correlated negatively with body size and positively with proportional trachea length. This result was consistent with our hypothesis that evolutionary reductions in body size led to intensified selection for trachea length. The most likely ultimate causes of intensified positive selection on trachea length are the direct benefits of conveying a large body size in intraspecific contests for mates and territories. We conclude that the strength of social or sexual selection on crane body size is linked to the degree of functional constraint.
‘Prudent habitat choice’: a novel mechanism of size‐assortative mating
Authors: Taborsky B. , Guyer L. , Demus P.
Published: May 2014

Assortative mating, an ubiquitous form of nonrandom mating, strongly impacts Darwinian fitness and can drive biological diversification. Despite its ecological and evolutionary importance, the behavioural processes underlying assortative mating are often unknown, and in particular, mechanisms not involving mate choice have been largely ignored so far. Here, we propose that assortative mating can arise from ‘prudent habitat choice’, a general mechanism that acts under natural selection, and that it can occur despite a complete mixing of phenotypes. We show that in the cichlid Eretmodus cyanostictus size‐assortative mating ensues, because individuals of weaker competitive ability ignore high‐quality but strongly competed habitat patches. Previous studies showed that in E. cyanostictus, size‐based mate preferences are absent. By field and laboratory experiments, here we showed that (i) habitat quality and body size are correlated in this species; (ii) territories with more stone cover are preferred by both sexes in the absence of competition; and (iii) smaller fish prudently occupy vacant territories of worse quality than do larger fish. Prudent habitat choice is likely to be a widespread mechanism of assortative mating, as both preferences for and dominance‐based access to high‐quality habitats are generic phenomena in animals.
Three‐dimensional cellular distribution in polymeric scaffolds for bone regeneration: a microCT analysis compared to SEM, CLSM and DNA content
Authors: PARRILLI A. , PAGANI S. , MALTARELLO M. C. , SANTI S. , SALERNO A. , NETTI P. A. , GIARDINO R. , RIMONDINI L. , FINI M.
Published: May 2014

In orthopaedic surgery the tissues damaged by injury or disease could be replaced using constructs based on biocompatible materials, cells and growth factors. Scaffold design, porosity and early colonization are key components for the implant success. From biological point of view, attention may be also given to the number, type and size of seeded cells, as well as the seeding technique and cell morphological and volumetric alterations. This paper describes the use of the microCT approach (to date used principally for mineralized matrix quantification) to observe construct colonization in terms of cell localization, and make a direct comparison of the microtomographic sections with scanning electron microscopy images and confocal laser scanning microscope analysis. Briefly, polycaprolactone scaffolds were seeded at different cell densities with MG63 osteoblastic‐like cells. Two different endpoints, 1 and 2 weeks, were selected for the three‐dimensional colonization and proliferation analysis of the cells. By observing all images obtained, in addition to a more extensive distribution of cells on scaffolds surfaces than in the deeper layers, cell volume increased at 2 weeks compared to 1 week after seeding. Combining the cell number quantification by deoxyribonucleic acid analysis and the single cell volume changes by confocal laser scanning microscope, we validated the microCT segmentation method by finding no statistical differences in the evaluation of the cell volume fraction of the scaffold. Furthermore, the morphological results of this study suggest that an effective scaffold colonization requires a precise balance between different factors, such as number, type and size of seeded cells in addition to scaffold porosity.
Seascape continuity plays an important role in determining patterns of spatial genetic structure in a coral reef fish
Authors: D'Aloia C. C. , Bogdanowicz S. M. , Harrison R. G. , Buston P. M.
Published: May 2014

Detecting patterns of spatial genetic structure (SGS) can help identify intrinsic and extrinsic barriers to gene flow within metapopulations. For marine organisms such as coral reef fishes, identifying these barriers is critical to predicting evolutionary dynamics and demarcating evolutionarily significant units for conservation. In this study, we adopted an alternative hypothesis‐testing framework to identify the patterns and predictors of SGS in the Caribbean reef fish Elacatinus lori. First, genetic structure was estimated using nuclear microsatellites and mitochondrial cytochrome b sequences. Next, clustering and network analyses were applied to visualize patterns of SGS. Finally, logistic regressions and linear mixed models were used to identify the predictors of SGS. Both sets of markers revealed low global structure: mitochondrial ΦST = 0.12, microsatellite FST = 0.0056. However, there was high variability among pairwise estimates, ranging from no differentiation between sites on contiguous reef (ΦST = 0) to strong differentiation between sites separated by ocean expanses ≥ 20 km (maximum ΦST = 0.65). Genetic clustering and statistical analyses provided additional support for the hypothesis that seascape discontinuity, represented by oceanic breaks between patches of reef habitat, is a key predictor of SGS in E. lori. Notably, the estimated patterns and predictors of SGS were consistent between both sets of markers. Combined with previous studies of dispersal in E. lori, these results suggest that the interaction between seascape continuity and the dispersal kernel plays an important role in determining genetic connectivity within metapopulations.
Assessing the efficacy of candidate mosquito repellents against the background of an attractive source that mimics a human host
Authors: MENGER D. J. , VAN LOON J. J. A. , TAKKEN W.
Published: May 2014

Mosquito repellents are used around the globe to protect against nuisance biting and disease‐transmitting mosquitoes. Recently, there has been renewed interest in the development of repellents as tools to control the transmission of mosquito‐borne diseases. We present a new bioassay for the accurate assessment of candidate repellent compounds, using a synthetic odour that mimics the odour blend released by human skin. Using DEET (N,N‐diethyl‐meta‐toluamide) and PMD (p‐menthane‐3,8‐diol) as reference compounds, nine candidate repellents were tested, of which five showed significant repellency to the malaria mosquito Anopheles gambiae sensu stricto (Diptera: Culicidae). These included: 2‐nonanone; 6‐methyl‐5‐hepten‐2‐one; linalool; δ‐decalactone, and δ‐undecalactone. The lactones were also tested on the yellow fever mosquito Aedes aegypti (Stegomyia aegypti) (Diptera: Culicidae), against which they showed similar degrees of repellency. We conclude that the lactones are highly promising repellents, particularly because these compounds are pleasant‐smelling, natural products that are also present in human food sources.
Using plants to elucidate the mechanisms of cytonuclear co‐evolution
Authors: Sloan Daniel B.
Published: May 2014

The presence of both cytoplasmic and nuclear genomes within eukaryotic cells raises fascinating questions about co‐evolution between genomic compartments that experience fundamentally different mutation rates and modes of inheritance. The highly mutagenic environments found in the mitochondria of some eukaryotes have generated interest in the role that mitochondrial mutation accumulation plays in phenomena such as intracellular gene transfer, compensatory evolution in the nucleus and the evolution of reproductive isolation. Although plant systems have played an important historical role in the study of cytonuclear co‐evolution, they remain underutilized in many respects. In particular, the enormous natural variation in DNA substitution rates, gene content and genome architecture in plant mitochondria – much of which has even been found within a single genus – provides opportunities to resolve longstanding evolutionary questions about the consequences of mitochondrial mutation accumulation. This review summarizes some of the classic questions about cytonuclear co‐evolution that could be addressed by taking advantage of the variation in plants and highlights a recent analysis of the effect of mitochondrial mutation accumulation on rates of molecular evolution in the nucleus.
Mallard duck (Anas platyrhynchos)‐mediated dispersal of Lemnaceae: a contributing factor in the spread of invasive Lemna minuta?
Authors: Coughlan N. E. , Kelly T. C. , Jansen M. A. K.
Published: May 2014

Our ability to predict and manage the spread of alien, invasive plants is limited by a lack of understanding of dispersal potential. Invasive Lemna minuta has spread within a few decennia throughout Europe. However, the mechanism by which the species continues to spread remains a matter of speculation. In this study, hypothesised epizoochorous transport of L. minuta propagules by mallard ducks was investigated. Landolt (Biosystematic investigations in the family of duckweeds (Lemnaceae) (Vol. 2), The family of Lemnaceae – a monographic study (Vol. 1), 1986, Veröffentlichungen des Geobotanischen Institutes Der Eidg. Techniasche Hochschule, Stiftung Rübel, Zürich, Switzerland) referred to desiccation as the key limitation of the “colonization capability” of Lemnaceae. Therefore, we analysed retention of viability in L. minuta kept outside the liquid growth medium. Our data show prolonged viability of L. minuta fronds inserted between the feathers of a mallard duck. Consistently, the relative humidity between feathers ranged between 65% and 90%. Taking together evidence of entanglement and retention of L. minuta between the feathers of live ducks, with retention of viability, we consider it likely that mallards contribute to L. minuta dispersal. These data have implications for the management strategy of this invasive species.
A retrospective study of volume doubling time in surgically resected non‐small cell lung cancer
Authors: Mackintosh John A. , Marshall Henry M. , Yang Ian A. , Bowman Rayleen V. , Fong Kwun M.
Published: May 2014

Background and objective

Volume doubling time (VDT) contributes to the evaluation of the indeterminate pulmonary nodule, an increasingly frequent problem given the rising use of computed tomography (CT). We aimed to correlate patient and tumour characteristics with VDT and growth rates of primary non‐small cell lung cancers (NSCLC).

Methods

Surgically treated NSCLC, which underwent two or more CT scans separated by 25 or more days were studied. Tumour volume was measured using semi‐automated volumetric software. VDT and growth rate (1/VDT) were correlated with patient and tumour characteristics.

Results

Thirty‐six adenocarcinomas (AC), six squamous cell carcinoma (SCC), two large cell and two carcinoids in 46 patients had 109 eligible scans. Median VDT was 191 days (range −9435 to 2256 days); median growth rate was 0.0038 (range −0.0086 to 0.0186). Median growth rate of AC was significantly slower than SCC (0.0034 vs 0.0103, P = 0.037). Nine AC had VDT >400 days, three of which developed distant metastases. Median growth rate of AC was faster in smokers compared with never‐smokers (0.0052 vs 0.0014, P = 0.02). Growth rate was not related to symptoms at diagnosis (P = 0.16). Less differentiated tumours tended to grow faster than more differentiated (P = 0.0038). Growth curves of 12 multi‐imaged tumours conformed best with the exponential model of growth.

Conclusions

NSCLC growth rate appears to be highly variable and related to histological subtype and smoking history, but not the presence of symptoms at diagnosis. Significant growth may be detected in as little as 2 months in NSCLC in smokers. Relatively slow‐growing AC can metastasize.
An open, self‐controlled study on the efficacy of topical indoxacarb for eliminating fleas and clinical signs of flea‐allergy dermatitis in client‐owned dogs in Queensland, Australia
Authors: Fisara Petr , Sargent Roger M. , Shipstone Michael , von Berky Andrew , von Berky Janet
Published: May 2014

Background

Canine flea‐allergy dermatitis (FAD), a hypersensitivity response to antigenic material in the saliva of feeding fleas, occurs worldwide and remains a common presentation in companion animal veterinary practice despite widespread availability of effective systemic and topical flea‐control products.

Hypothesis/Objectives

To evaluate the clinical response in dogs with FAD treated topically with indoxacarb, a novel oxadiazine insecticide.

Animals

Twenty‐five client‐owned dogs in Queensland, Australia diagnosed with pre‐existing FAD on the basis of clinical signs, flea‐antigen intradermal and serological tests.

Methods

An open‐label, noncontrolled study, in which all dogs were treated with topical indoxacarb at 4 week intervals, three times over 12 weeks.

Results

Twenty‐four dogs completed the study. Complete resolution of clinical signs of FAD was observed in 21 cases (87.5%), with nearly complete resolution or marked improvement in the remaining three cases. Mean clinical scores (Canine Atopic Dermatitis Extent and Severity Index‐03) were reduced by 93.3% at week 12. Mean owner‐assessed pruritus scores were reduced by 88% by week 12. Mean flea counts reduced by 98.7 and 100% in weeks 8 and 12, respectively.

Conclusions and clinical importance

Topical indoxacarb treatment applied every 4 weeks for 12 weeks, without concomitant antipruritic or ectoparasiticide therapy, completely alleviated flea infestations in all dogs and associated clinical signs of FAD in a high proportion of this population of dogs in a challenging flea‐infestation environment.
Study on Kelvin–Helmholtz Instability With Heat and Mass Transfer
Authors: Kumar Awasthi Mukesh
Published: May 2014

The effect of heat and mass transfer on the Kelvin–Helmholtz instability between liquid and vapor phases of a fluid has been studied using three different theories: a purely irrotational theory based on the dissipation method, a hybrid irrotational-rotational theory, and an inviscid potential flow theory. These new results are compared with previous results from viscous irrotational theory. The stability criterion is given in terms of the critical value of relative velocity. The system is shown to be unstable when the relative velocity is greater than the critical value of relative velocity; otherwise, it is stable. It is observed that heat and mass transfer has a destabilizing effect on the stability of the system while vapor fraction has a stabilizing effect.
Stability Analysis of a Droplet Pinned in Channel Under Gravity
Authors: Hekiri Haider , Hawa Takumi
Published: May 2014

The stability of a two-dimensional, incompressible droplet, with two cylindrical-caps that is held in a channel under gravity, is investigated through the development of an analytical model based on the Young–Laplace relationship. The droplet state is measured by the location of its center of mass, where the center of mass is derived analytically by assuming a circular shape for the droplet cap. The derived analytical expressions are validated through the use of computational fluid dynamics (CFD). When a droplet is suspended under no gravity conditions, there is a critical droplet volume Vcr where asymmetric droplet states appear in addition to the basic symmetric states when the drop volume V > Vcr. When V < Vcr, the symmetric droplet states are stable, and when V > Vcr, the symmetric states are unstable and the asymmetric states are stable. With gravity, the pitchfork bifurcation diagram of the droplet system changes into two separate branches of equilibrium states: The primary branch describes a gradual and stable change of the droplet from a symmetric to asymmetric state as the droplet volume is increased. The secondary branch appears at a modified critical volume Vmcr and describes two additional asymmetric states when V > Vmcr. The large-amplitude states along the secondary branch are stable whereas the small-amplitude states are unstable. There exists a maximum volume on each of the primary and secondary branch where the droplet no longer sustains its weight and where the maximum volume on the primary branch is smaller than the maximum volume on the secondary branch. There is a critical value for the strength of the gravity force, relative to the capillary force, that provides the condition at which a droplet state exists only at the primary branch; the secondary branch is unstable. Analytical solutions show good agreement with CFD results as long as the circular shape assumption of the droplet cap is approximately valid.
Wear Prediction of a Mechanism With Joint Clearance Involving Aleatory and Epistemic Uncertainty
Authors: Sun Dongyang , Chen Guoping , Wang Tiecheng , Sun Rujie
Published: May 2014

In this paper, a dynamic wear model to predict wear volume in a mechanism, involving aleatory and epistemic uncertainty, is established. In this case, harmonic drives are applied to alleviate the impact of clearance for wear of the mechanism. The contact model of a mechanism with clearance that is subjected to harmonic drive is established, with the nonlinear spring-damp model and flexibility of harmonic gear considered. Especially, a slider-crank mechanism with clearance is simulated. The result shows that the cushioning effect of collisions for clearance with application of harmonic drive is superior to that through the flexibility of mechanical parts. Following confidence region method (CRM) for quantification of aleatory and epistemic uncertainty is proposed to analyze the effect of parameter uncertainty for wear volume during the entire time domain, and double-loop Monte Carlo sampling (MCS) approach is improved to propagate uncertainties during the entire time domain. Finally, based on Kriging model, the CRM is used to analyze the effect of parameter uncertainty for wear volume. The result shows that, when both aleatory and epistemic uncertainties are considered, the wear volume boundary is wider and better than that when only aleatory uncertainty is considered. These analyses help to improve the reliability design of system and set a theoretical foundation for the mechanic design and precision analysis of the mechanical system.
Large Eddy Simulation of Transitional Flow in an Idealized Stenotic Blood Vessel: Evaluation of Subgrid Scale Models
Authors: Pal Abhro , Anupindi Kameswararao , Delorme Yann , Ghaisas Niranjan , Shetty Dinesh A. , Frankel Steven H.
Published: May 2014

In the present study, we performed large eddy simulation (LES) of axisymmetric, and 75% stenosed, eccentric arterial models with steady inflow conditions at a Reynolds number of 1000. The results obtained are compared with the direct numerical simulation (DNS) data (Varghese et al., 2007, “Direct Numerical Simulation of Stenotic Flows. Part 1. Steady Flow,” J. Fluid Mech., 582, pp. 253–280). An inhouse code (WenoHemo) employing high-order numerical methods for spatial and temporal terms, along with a 2nd order accurate ghost point immersed boundary method (IBM) (Mark, and Vanwachem, 2008, “Derivation and Validation of a Novel Implicit Second-Order Accurate Immersed Boundary Method,” J. Comput. Phys., 227(13), pp. 6660–6680) for enforcing boundary conditions on curved geometries is used for simulations. Three subgrid scale (SGS) models, namely, the classical Smagorinsky model (Smagorinsky, 1963, “General Circulation Experiments With the Primitive Equations,” Mon. Weather Rev., 91(10), pp. 99–164), recently developed Vreman model (Vreman, 2004, “An Eddy-Viscosity Subgrid-Scale Model for Turbulent Shear Flow: Algebraic Theory and Applications,” Phys. Fluids, 16(10), pp. 3670–3681), and the Sigma model (Nicoud et al., 2011, “Using Singular Values to Build a Subgrid-Scale Model for Large Eddy Simulations,” Phys. Fluids, 23(8), 085106) are evaluated in the present study. Evaluation of SGS models suggests that the classical constant coefficient Smagorinsky model gives best agreement with the DNS data, whereas the Vreman and Sigma models predict an early transition to turbulence in the poststenotic region. Supplementary simulations are performed using Open source field operation and manipulation (OpenFOAM) (“OpenFOAM,” http://www.openfoam.org/) solver and the results are inline with those obtained with WenoHemo.
A Hole in One (Hundred Forty Characters): A Case Study Examining PGA Tour Golfers’ Twitter Use During the Masters
Authors: Hull Kevin
Published: May 2014

This case study explored how professional golfers participating in the Masters tournament used Twitter during the week of the event. Basing the research in self-presentation theory, the author conducted a content analysis of 895 tweets by 39 golfers. The results suggest that athletes are using Twitter to give fans both a front-stage and a backstage glimpse into their lives, with engaging with fans (front stage) being the most prominent. By balancing between front stage and backstage, the athletes are able to give fans a more intimate view of their life, while also maintaining a public persona that can please sponsors. Limitations and directions for future research are also discussed.
Corporate Consolidation and Content-Management Systems in College Athletics Web Sites: A Case Study of MGoBlue.com
Authors: Dichter Heather L.
Published: May 2014

This historical case study addresses the issues related to the use of content-management systems (CMSs) in the production of a college athletic department Web site. The article considers the factors that influenced a university athletic department to adopt a CMS. Corporate consolidation among CMS providers frequently affected the options available to athletic departments. Using an in-depth interview with the primary individual behind the University of Michigan’s athletic department Web site, MGoBlue.com, this article also explores how the explosion of Web-site content and adoption of a CMS has transformed the workflow in athletic media relations.
The Role of Fan Identification in the Perceived Credibility of Sports Articles
Authors: Sadri Sean R.
Published: May 2014

The current study examined how article source, medium, and fan identification can all affect the credibility of sports articles. An online experiment was conducted, and participants read an article that was indicated to have originated from a mainstream sports Web site, a sports blog, a social-networking site, or a wire service. Analysis revealed that fan-identification level was an important factor in credibility ratings in which highly identified fans found sports articles to be significantly more credible than fans with low identification. Highly identified fans also rated the article as equally credible on all 3 Web sites. However, low-identification fans rated the mainstream sports Web site article as significantly more credible than the other 2. Article medium was not shown to have a significant influence on perceived credibility for either identification group. The implications of fan-identification level on the discrepancies in ratings of perceived credibility are explored.
Fish Oil Supplementation Reduces Markers of Oxidative Stress But Not Muscle Soreness After Eccentric Exercise
Authors: Gray Patrick , Chappell Andrew , Jenkinson Alison McE , Thies Frank , Gray Stuart R.
Published: May 2014

Due to the potential anti-inflammatory properties of fish-derived long chain n-3 fatty acids, it has been suggested that athletes should regularly consume fish oils—although evidence in support of this recommendation is not clear. While fish oils can positively modulate immune function, it remains possible that, due to their high number of double bonds, there may be concurrent increases in lipid peroxidation. The current study aims to investigate the effect of fish oil supplementation on exercise-induced markers of oxidative stress and muscle damage. Twenty males underwent a 6-week double-blind randomized placebo-controlled supplementation trial involving two groups (fish oil or placebo). After supplementation, participants undertook 200 repetitions of eccentric knee contractions. Blood samples were taken presupplementation, postsupplementation, immediately, 24, 48, and 72 hr postexercise and muscle soreness/maximal voluntary contraction (MVC) assessed. There were no differences in creatine kinase, protein carbonyls, endogenous DNA damage, muscle soreness or MVC between groups. Plasma thiobarbituric acid reactive substances (TBARS) were lower (p < .05) at 48 and 72 hr post exercise and H2O2 stimulated DNA damage was lower (p < .05) immediately postexercise in the fish oil, compared with the control group. The current study demonstrates that fish oil supplementation reduces selected markers of oxidative stress after a single bout of eccentric exercise.
The Complexity of Leading in Sport: Examining the Role of Domain Expertise in Assessing Leader Credibility and Prototypicality
Authors: Swanson Steve , Kent Aubrey
Published: May 2014

The way in which leaders in sport organizations are evaluated by their employees is dependent upon perceived levels of credibility and implicit theories of leadership. Leader knowledge and expertise play significant roles in this process, yet both have been treated as comprehensive constructs irrespective of specific knowledge domains. Drawing from the education literature, this research looks to disentangle the global perspective used by the credibility and prototypicality literatures. It is proposed that employees in sport organizations expect managers to possess domain-specific expertise which is separate from the functional area requirement. Two different samples including professional sport employees and sport management students were used, with confirmatory factor and conjoint analyses used to test the research hypotheses. The results support the notion that distinct psychological processes exist within sport organizations, and that sport domain knowledge and expertise are distinct constructs which play important roles in the perception of leaders within this context.
Interdependence, Mutuality, and Collective Action in Sport
Authors: Cunningham George B.
Published: May 2014

In this paper, from the Dr. Earle F. Zeigler Award Lecture presented in Austin, Texas, the author proposes that all persons have an obligation to ensure sport is inclusive and socially just. Works from a variety of disciplines, including religion, sociology, and social psychology, support the thesis. The author calls for collective action among sport management academicians, coalesced around teaching, research, and service to promote change. The final sections address potential counter narratives and provide an overview of the outcomes associated with an inclusive and socially just sport environment.
Chloride Sensing by WNK1 Involves Inhibition of Autophosphorylation
Authors: Piala Alexander T. , Moon Thomas M. , Akella Radha , He Haixia , Cobb Melanie H. , Goldsmith Elizabeth J.
Published: May 2014

Structural analysis reveals how chloride inhibits the activation of a kinase implicated in hypertension.
Planar Cell Polarity Goes Perpendicular
Authors: VanHook Annalisa M.
Published: May 2014

The planar cell polarity pathway influences the apicobasal distribution of a cell fate determinant.
Surotomycin Demonstrates Low
In Vitro
Frequency of Resistance and Rapid Bactericidal Activity in Clostridium difficile, Enterococcus faecalis, and Enterococcus faecium
Authors: Mascio Carmela T. M. , Chesnel Laurent , Thorne Grace , Silverman Jared A.
Published: May 2014

Surotomycin (CB-183,315) is an orally administered, minimally absorbed, selective bactericidal cyclic lipopeptide in phase 3 development for the treatment of
Clostridium difficile
-associated diarrhea. The aim of this study was to evaluate the emergence of resistance in
C. difficile
(ATCC 700057 and three recent clinical isolates from the restriction endonuclease analysis groups BI, BK, and K), vancomycin-susceptible (VS)
Enterococcus faecalis
(ATCC 49452), vancomycin-resistant (VR)
E. faecalis
(ATCC 700802), VS
Enterococcus faecium
(ATCC 6569), and VR
E. faecium
(ATCC 51559) under anaerobic conditions. The rate of spontaneous resistance was below the limit of detection (<10
−8
to <10
−9
) for surotomycin at 16 and 32× the MIC for all isolates tested. Under selective pressure by serial passage,
C. difficile
grew in a maximum of 4 μg/ml surotomycin (final MICs of 2 to 8 μg/ml [4- to 16-fold higher than those of the naive control]) at day 15, with the exception of the
C. difficile
BK strain, which grew in 16 to 32 μg/ml (final MICs of 8 to 32 μg/ml [16- to 64-fold higher than those of the naive control]). Enterococci remained relatively unchanged over 15 days, growing in a maximum of 8 μg/ml surotomycin (final MICs of 2 to 16 μg/ml [8- to 64-fold higher than those of the naive control]). Of the isolates tested, no cross-resistance to vancomycin, rifampin, ampicillin, metronidazole, or moxifloxacin was observed. Surotomycin at 20× MIC demonstrated equally rapid bactericidal activity (≥3-log-unit reduction in CFU/ml in ≤8 h) against naive and reduced-susceptibility isolates of
C. difficile
, VS
Enterococcus
(VSE), and VR
Enterococcus
(VRE), except for
C. difficile
BK (2.6-log-unit reductions for both). These results suggest that emergence of resistance to surotomycin against
C. difficile
,
E. faecalis
, and
E. faecium
is likely to be rare.
Screening for Inhibition of Vibrio cholerae VipA-VipB Interaction Identifies Small-Molecule Compounds Active against Type VI Secretion
Authors: Sun Kun , Bröms Jeanette , Lavander Moa , Gurram Bharat Kumar , Enquist Per-Anders , Andersson C. David , Elofsson Mikael , Sjöstedt Anders
Published: May 2014

The type VI secretion system (T6SS) is the most prevalent bacterial secretion system and an important virulence mechanism utilized by Gram-negative bacteria, either to target eukaryotic cells or to combat other microbes. The components show much variability, but some appear essential for the function, and two homologues, denoted VipA and VipB in
Vibrio cholerae
, have been identified in all T6SSs described so far. Secretion is dependent on binding of an α-helical region of VipA to VipB, and in the absence of this binding, both components are degraded within minutes and secretion is ceased. The aim of the study was to investigate if this interaction could be blocked, and we hypothesized that such inhibition would lead to abrogation of T6S. A library of 9,600 small-molecule compounds was screened for their ability to block the binding of VipA-VipB in a bacterial two-hybrid system (B2H). After excluding compounds that showed cytotoxicity toward eukaryotic cells, that inhibited growth of
Vibrio
, or that inhibited an unrelated B2H interaction, 34 compounds were further investigated for effects on the T6SS-dependent secretion of hemolysin-coregulated protein (Hcp) or of phospholipase A
1
activity. Two compounds, KS100 and KS200, showed intermediate or strong effects in both assays. Analogues were obtained, and compounds with potent inhibitory effects in the assays and desirable physicochemical properties as predicted by
in silico
analysis were identified. Since the compounds specifically target a virulence mechanism without affecting bacterial replication, they have the potential to mitigate the virulence with minimal risk for development of resistance.
Linezolid-Induced Lactic Acidosis in Two Liver Transplant Patients with the Mitochondrial DNA A2706G Polymorphism
Authors: Del Pozo J. L. , Fernández-Ros N. , Sáez E. , Herrero J. I. , Yuste J. R. , Banales J. M.
Published: May 2014

Mitochondrial toxicity has been recently suggested to be the underlying mechanism of long-term linezolid-associated toxicity in patients with 16S rRNA genetic polymorphisms. Here, we report for the first time two cases of lactic acidosis due to long-term linezolid exposure in liver transplant recipients who presented an A2706G mitochondrial DNA polymorphism.
Effector CD8+T Cells Are Generated in Response to an Immunodominant Epitope in Type III Effector YopE during Primary Yersinia pseudotuberculosis Infection
Authors: Zhang Yue , Mena Patricio , Romanov Galina , Bliska James B.
Published: May 2014

YopE is a virulence factor that is secreted into host cells infected byYersiniaspecies. The YopE C-terminal domain has GTPase-activating protein (GAP) activity. The YopE N-terminal domain contains an epitope that is an immunodominant CD8+T cell antigen during primary infection of C57BL/6 mice withYersinia pseudotuberculosis. The characteristics of the CD8+T cells generated in response to the epitope, which comprises YopE amino acid residues 69 to 77 (YopE69–77), and the features of YopE that are important for antigenicity during primary infection, are unknown. Following intravenous infection of naïve C57BL/6 mice with ayopEGAP mutant (the R144A mutant), flow cytometry analysis of splenocytes by tetramer and intracellular cytokine staining over a time course showed that YopE69–77-specific CD8+T cells producing gamma interferon (IFN-γ) and tumor necrosis factor alpha (TNF-α) were generated by day 7, with a peak at day 14. In addition, ∼80% of YopE69–77-specific CD8+T cells were positive for KLRG1, a memory phenotype marker, at day 21. To determine if residues that regulate YopE activity by ubiquitination or membrane localization affect the antigenicity of YopE69–77, mice were infected with ayopEubiquitination or membrane localization mutant (the R62K or L55N I59N L63N mutant, respectively). These mutants elicited YopE69–77-specific CD8+T cells producing IFN-γ and TNF-α with kinetics and magnitudes similar to those of the parental R144A strain, indicating that primary infection primes effector CD8+T cells independently of the ubiquitination or membrane localization of YopE. Additionally, at day 7, there was an unexpected positive correlation between the numbers of YopE69–77-specific CD8+T cells and CD11b+cells, but not between the numbers of YopE69–77-specific CD8+T cells and bacterial cells, in spleens, suggesting that the innate immune response contributes to the immunodominance of YopE69–77.
Phenotypic Differences of Cryptococcus Molecular Types and Their Implications for Virulence in a Drosophila Model of Infection
Authors: Thompson George R. , Albert Nathaniel , Hodge Greg , Wilson Machelle D. , Sykes Jane E. , Bays Derek J. , Firacative Carolina , Meyer Wieland , Kontoyiannis Dimitrios P.
Published: May 2014

Compared toCryptococcus neoformans, little is known about the virulence of the molecular types inCryptococcus gattii. We comparedin vitrovirulence factor production and survival data using aDrosophilamodel of infection to further characterize the phenotypic features of different cryptococcal molecular types. Forty-nine different isolates were inoculated into wild-type flies and followed for survival.In vitro, isolates were assessed for growth at 30 and 37°C, melanin production, capsule size, resistance to H2O2, and antifungal susceptibility. A mediator model was used to assess molecular type and virulence characteristics as predictors of survival in the fly model. VGIII was the most virulent molecular type in flies (P< 0.001). At 30°C, VGIII isolates grew most rapidly; at 37°C, VNI isolates grew best.C. gattiicapsules were larger than those ofC. neoformans(P< 0.001). Mediator model analysis found a strong correlation ofDrosophilasurvival with molecular type and with growth at 30°C. We found molecular-type-specific differences inC. gattiiin growth at different temperatures, melanin production, capsule size, ability to resist hydrogen peroxide, and antifungal susceptibility, while growth at 30°C and the VGIII molecular type were strongly associated with virulence in aDrosophilamodel of infection.