801 research outputs found

    Ultrasonographic-based predictive factors influencing successful return to racing after superficial digital flexor tendon injuries in flat racehorses: a retrospective cohort study in 469 Thoroughbred racehorses in Hong Kong

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    Background: Superficial digital flexor tendon (SDFT) injury is an important health and welfare concern in racehorses. It is generally diagnosed with ultrasonography, predictive ultrasonographic features have not been reported. Objectives: To determine ultrasonographic features of forelimb SDFT injury at initial presentation in Thoroughbred racehorses, that could predict a successful return to racing (completing > or = 5 races). Study Design: Retrospective cohort study. Methods: Digitised ultrasonographic images of 469 horses with forelimb SDFT injuries from the Hong Kong Jockey Club (2003-2014) were evaluated, using a previously validated ultrasonographic scoring system. Six ultrasonographic parameters were evaluated (type and extent of the injury, location, echogenicity, cross-sectional area and longitudinal fiber pattern of the maximal injury zone (MIZ)), as well as horse signalment, retirement date and number of races before and after injury. Data was analysed by generalized linear regression with significance at P<0.05. Results: Cases were divided in two groups: 1) For cases of SDFT tendonitis with core lesions, cross-sectional area at the MIZ was the most significant factor determining a successful return to racing (p=0.03). If the lesion was or > or = 50% this decreased to 11-16%. 2) For cases of SDFT tendonitis without a core lesion, longitudinal fiber pattern at the MIZ best predicted a successful return to racing (P=0.002); if the affected longitudinal fiber pattern was or = 75% this decreased to 14%. Main Limitations: Prognostic information may not be applicable to other breeds/disciplines. Conclusions: This is the first study to describe ultrasonographic features of forelimb SDFT injuries at initial presentation that were predictive of successful return to racing. The outcomes will assist with early, evidence-based decisions on prognosis in Thoroughbred racehorses

    Nonequilibrium dynamics of random field Ising spin chains: exact results via real space RG

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    Non-equilibrium dynamics of classical random Ising spin chains are studied using asymptotically exact real space renormalization group. Specifically the random field Ising model with and without an applied field (and the Ising spin glass (SG) in a field), in the universal regime of a large Imry Ma length so that coarsening of domains after a quench occurs over large scales. Two types of domain walls diffuse in opposite Sinai random potentials and mutually annihilate. The domain walls converge rapidly to a set of system-specific time-dependent positions {\it independent of the initial conditions}. We obtain the time dependent energy, magnetization and domain size distribution (statistically independent). The equilibrium limits agree with known exact results. We obtain exact scaling forms for two-point equal time correlation and two-time autocorrelations. We also compute the persistence properties of a single spin, of local magnetization, and of domains. The analogous quantities for the spin glass are obtained. We compute the two-point two-time correlation which can be measured by experiments on spin-glass like systems. Thermal fluctuations are found to be dominated by rare events; all moments of truncated correlations are computed. The response to a small field applied after waiting time twt_w, as measured in aging experiments, and the fluctuation-dissipation ratio X(t,tw)X(t,t_w) are computed. For (ttw)twα^(t-t_w) \sim t_w^{\hat{\alpha}}, α^<1\hat{\alpha} <1, it equals its equilibrium value X=1, though time translational invariance fails. It exhibits for ttwtwt-t_w \sim t_w aging regime with non-trivial X=X(t/tw)1X=X(t/t_w) \neq 1, different from mean field.Comment: 55 pages, 9 figures, revte

    On the application of population-based structural health monitoring in aerospace engineering

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    One of the major obstacles to the widespread uptake of data-based Structural Health Monitoring so far, has been the lack of damage-state data for the (mostly high-value) structures of interest. To address this issue, a methodology for sharing data and models between structures has been developed–Population-Based Structural Health Monitoring (PBSHM). PBSHM works on the principle that, if populations of structures are sufficiently similar, or share sections which can be considered similar, then data and models can be shared between them for use in diagnostic inference. The PBSHM methodology therefore relies on two key components: firstly, identifying whether structures are sufficiently similar for successful transfer of diagnostics; this is achieved by the use of an abstract representation of structures. Secondly, machine learning techniques are exploited to effectively transfer information between the structures in a way that improves damage detection and classification across the whole population. Although PBSHM has been conceived to deal with large and general classes of structures, much of the detailed developments presented so far have concerned bridges; the aim of this paper is to provide similarly detailed discussions in the aerospace context. The overview here will examine data transfer between aircraft components, as well as illustrating how one might construct an abstract representation of a full aircraft

    Ultrasonographic-based predictive factors influencing successful return to racing after superficial digital flexor tendon injuries in flat racehorses: a retrospective cohort study in 469 Thoroughbred racehorses in Hong Kong

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    Background: Superficial digital flexor tendon (SDFT) injury is an important health and welfare concern in racehorses. It is generally diagnosed with ultrasonography, predictive ultrasonographic features have not been reported. Objectives: To determine ultrasonographic features of forelimb SDFT injury at initial presentation in Thoroughbred racehorses, that could predict a successful return to racing (completing > or = 5 races). Study Design: Retrospective cohort study. Methods: Digitised ultrasonographic images of 469 horses with forelimb SDFT injuries from the Hong Kong Jockey Club (2003-2014) were evaluated, using a previously validated ultrasonographic scoring system. Six ultrasonographic parameters were evaluated (type and extent of the injury, location, echogenicity, cross-sectional area and longitudinal fiber pattern of the maximal injury zone (MIZ)), as well as horse signalment, retirement date and number of races before and after injury. Data was analysed by generalized linear regression with significance at P<0.05. Results: Cases were divided in two groups: 1) For cases of SDFT tendonitis with core lesions, cross-sectional area at the MIZ was the most significant factor determining a successful return to racing (p=0.03). If the lesion was or > or = 50% this decreased to 11-16%. 2) For cases of SDFT tendonitis without a core lesion, longitudinal fiber pattern at the MIZ best predicted a successful return to racing (P=0.002); if the affected longitudinal fiber pattern was or = 75% this decreased to 14%. Main Limitations: Prognostic information may not be applicable to other breeds/disciplines. Conclusions: This is the first study to describe ultrasonographic features of forelimb SDFT injuries at initial presentation that were predictive of successful return to racing. The outcomes will assist with early, evidence-based decisions on prognosis in Thoroughbred racehorses

    The emergence of the cortisol circadian rhythm in monozygotic and dizygotic twin infants: the twin-pair synchrony

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    OBJECTIVE: Studies on the influence of genetic factors on the ontogeny of cortisol circadian rhythm in infants are lacking. This study evaluated the influence of twinning and the heritability on the age of emergence of salivary cortisol rhythm. DESIGN AND SUBJECTS: A longitudinal study was performed using salivary samples obtained during morning and night, at 2, 4, 8, 12, 16, 20 and 24 weeks of postnatal life in 34 infants, 10 monozygotic (MZ) and 7 dizygotic (DZ) twin pairs. Salivary cortisol was determined by radioimmunoassay (RIA). Zigosity was verified by DNA analysis of at least 13 short tandem repeat polymorphisms. Difference of the emergence of cortisol circadian rhythm, within each twin pair, the intraclass correlation coefficient and the heritability index (h(2)) were calculated. RESULTS: The mean (± SEM) age of emergence of salivary cortisol circadian rhythm was similar in MZ and DZ (7·8 ± 1·0 vs 7·4 ± 1·3 weeks). Seven pairs showed coincidence of the emergence of cortisol rhythm. Ten pairs were not coincident; among them the within-pair difference of emergence of salivary circadian rhythm was similar in both MZ and DZ groups. The intraclass correlation coefficients were rMZ = 0·60, P = 0·02; and rDZ = 0·65, P = 0·03, respectively. The heritability index (h(2)) was 0·21 (ns). CONCLUSIONS: Salivary circadian rhythm appeared at the same postnatal age in MZ and DZ twin infants. Although several physiological aspects might be involved, the heritability index, obtained in the present study, suggests less genetic than environmental impact on the age of the onset of the cortisol circadian rhythm. Our data also indicated that each twin-pair show synchrony because they probably shared prenatal and postnatal environmental synchronizers

    Multilayered feed forward Artificial Neural Network model to predict the average summer-monsoon rainfall in India

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    In the present research, possibility of predicting average summer-monsoon rainfall over India has been analyzed through Artificial Neural Network models. In formulating the Artificial Neural Network based predictive model, three layered networks have been constructed with sigmoid non-linearity. The models under study are different in the number of hidden neurons. After a thorough training and test procedure, neural net with three nodes in the hidden layer is found to be the best predictive model.Comment: 19 pages, 1 table, 3 figure

    Exact Occupation Time Distribution in a Non-Markovian Sequence and Its Relation to Spin Glass Models

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    We compute exactly the distribution of the occupation time in a discrete {\em non-Markovian} toy sequence which appears in various physical contexts such as the diffusion processes and Ising spin glass chains. The non-Markovian property makes the results nontrivial even for this toy sequence. The distribution is shown to have non-Gaussian tails characterized by a nontrivial large deviation function which is computed explicitly. An exact mapping of this sequence to an Ising spin glass chain via a gauge transformation raises an interesting new question for a generic finite sized spin glass model: at a given temperature, what is the distribution (over disorder) of the thermally averaged number of spins that are aligned to their local fields? We show that this distribution remains nontrivial even at infinite temperature and can be computed explicitly in few cases such as in the Sherrington-Kirkpatrick model with Gaussian disorder.Comment: 10 pages Revtex (two-column), 1 eps figure (included

    Anomalous diffusion, Localization, Aging and Sub-aging effects in trap models at very low temperature

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    We study in details the dynamics of the one dimensional symmetric trap model, via a real-space renormalization procedure which becomes exact in the limit of zero temperature. In this limit, the diffusion front in each sample consists in two delta peaks, which are completely out of equilibrium with each other. The statistics of the positions and weights of these delta peaks over the samples allows to obtain explicit results for all observables in the limit T0T \to 0. We first compute disorder averages of one-time observables, such as the diffusion front, the thermal width, the localization parameters, the two-particle correlation function, and the generating function of thermal cumulants of the position. We then study aging and sub-aging effects : our approach reproduces very simply the two different aging exponents and yields explicit forms for scaling functions of the various two-time correlations. We also extend the RSRG method to include systematic corrections to the previous zero temperature procedure via a series expansion in TT. We then consider the generalized trap model with parameter α[0,1]\alpha \in [0,1] and obtain that the large scale effective model at low temperature does not depend on α\alpha in any dimension, so that the only observables sensitive to α\alpha are those that measure the `local persistence', such as the probability to remain exactly in the same trap during a time interval. Finally, we extend our approach at a scaling level for the trap model in d=2d=2 and obtain the two relevant time scales for aging properties.Comment: 33 pages, 3 eps figure

    Ethnicity and consumption: South Asian food shopping patterns in Britain 1947-75

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    Authors' draft version also available on University of Surrey e-print repository. Final version published by Sage and available at http://joc.sagepub.com/This article reviews the literature that explores the relationship between ethnic identities and food consumption, with particular reference to business management studies. It focuses on the food shopping practices of south Asians in Britain in the period 1947 to 1975, to illustrate the need for more historically contextualized studies that can provide a more nuanced exploration of any interconnections between ethnic identity and shopping behaviour. The article draws on a reasonably long-standing interest in ethnicity and consumption in marketing studies, and explores the conceptual use of acculturation within this literature. The arguments put forward are framed by recent interdisciplinary studies of the broader relationship between consumption and identity, which stress the importance of contextualizing any influence of ethnic identifications through a wider consideration of other factors including societal status, gender and age, rather than giving it singular treatment. The article uses a body of empirical research drawn from recent oral histories, to explore how these factors informed everyday shopping practices among south Asians in Britain. It examines some of the shopping and wider food provisioning strategies adopted by early immigrants on arrival in Britain. It considers the interaction between the south Asian population and the changing retail structure, in the context of the development of self-service and the supermarket. Finally, it demonstrates how age, gender and socioeconomic status interacted with ethnic identities to produce variations in shopping patterns
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