6,621 research outputs found

    Mild acetabular dysplasia and risk of osteoarthritis of the hip : a case-control study

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    Objective To determine whether mild variation in acetabular depth (AD) and shape is a risk factor for osteoarthritis (OA) of the hip. Methods The unaffected contralateral hip of patients with unilateral hip OA was compared with hips of asymptomatic controls without hip OA, derived from the Nottingham Genetics Osteoarthritis and Lifestyle case–control study. Standardised anteroposterior x-rays of the pelvis were used to measure centre edge (CE) angle and AD. Cut-off points for narrow CE angle and shallow AD were calculated from the control group (mean −1.96×SD). The relative risk of hip OA associated with each feature was estimated using OR and 95% CI and adjusted risks were calculated by logistic regression. Results In controls, both the CE angle and the AD were lower in the left hip than in the right hip. The CE angle related to age in both hips, and AD of the right hip was lower in men than in women. The contralateral unaffected hip in patients with unilateral hip OA had a decreased CE angle and AD compared with controls, irrespective of side. The lowest tertile of the CE angle in contralateral hips was associated with an eightfold risk of OA (aOR 8.06, 95% CI 4.87 to 13.35) and the lowest tertile of AD was associated with a 2.5-fold risk of OA (aOR 2.53, 95% CI 1.28 to 5.00). Significant increases in the risk of OA were also found as the CE angle and AD decreased

    Adaptation of a mouse Doppler echocardiograph system for assessing cardiac function and thermal performance in a juvenile salmonid

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    Measures of cardiac performance are pertinent to the study of thermal physiology and exercise in teleosts, particularly as they pertain to migration success. Increased heart rate, stroke volume and cardiac output have previously been linked to improved swimming performance and increased upper thermal tolerance in anadromous salmonids. To assess thermal performance in fishes, it has become commonplace to measure the response of maximum heart rate to warming using electrocardiograms. However, electrocardiograms do not provide insight into the hemodynamic characteristics of heart function that can impact whole-animal performance. Doppler echocardiography is a popular tool used to examine live animal processes, including real-time cardiac function. This method allows for nonsurgical measurements of blood flow velocity through the heart and has been used to detect abnormalities in cardiovascular function, particularly in mammals. Here, we show how a mouse Doppler echocardiograph system can be adapted for use in a juvenile salmonid over a range of temperatures and timeframes. Using this compact, noninvasive system, we measured maximum heart rate, atrioventricular (AV) blood flow velocity, the early flow-atrial flow ratio and stroke distance in juvenile Atlantic salmon (Salmo salar) during acute warming. Using histologically determined measures of AV valve area, we show how stroke distance measurements obtained with this system can be used to calculate ventricular inflow volume and approximate cardiac output. Further, we show how this Doppler system can be used to determine cardiorespiratory thresholds for thermal performance, which are increasingly being used to predict the consequences that warming water temperatures will have on migratory fishes

    Bootstrap Technique to Study Correlation Between Neutron Skin Thickness and the Slope of Symmetry Energy in Atomic Nuclei

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    We examine the proposed correlation between the neutron skin thickness and the slope of the symmetry energy for two doubly-magic nuclei (Sn-100 and Sn-132) and find that a statistically significant correlation appears to exist for Sn-132 whilst no such correlation appears to exist for Sn-100. Additionally, we present a new statistical tool based on random sampling to assess the confidence interval of Pearson's and Spearman's correlation coefficients in order to examine the aforementioned correlation. These estimators are then used to quantify the statistical correlations among the neutron skin thickness of atomic nuclei and the slope of the symmetry energy in the infinite nuclear medium.Peer reviewe

    Blaming Bill Gates AGAIN! Misuse, overuse and misunderstanding of performance data in sport

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    Recently in Sport, Education and Society, Williams and Manley (2014) argued against the heavy reliance on technology in professional Rugby Union and elite sport in general. In summary, technology is presented as an elitist, ‘gold standard’ villain that management and coaches use to exert control and by which players lose autonomy, identity, motivation, social interactions and expertise. In this article we suggest that the sociological interpretations and implications offered by Williams and Manley may be somewhat limited when viewed in isolation. In doing so, we identify some core methodological issues in Williams and Manley’s study and critically consider important arguments for utilising technology; notably, to inform coach decision making and generate player empowerment. Secondly, we present a different, yet perhaps equally concerning, practice-oriented interpretation of the same results but from alternative coaching and expertise literature. Accordingly, we suggest that Williams and Manley have perhaps raised their alarm prematurely, inappropriately and on somewhat shaky foundations. We also hope to stimulate others to consider contrary positions, or at least to think about this topic in greater detail. More specifically, we encourage coaches and academics to think carefully about what technology is employed, how and why, and then the means by which these decisions are discussed with and, preferably, sold to players. Certainly, technology can significantly enhance coach decision making and practice, while also helping players to optimise their focus, empowerment and independence in knowing how to achieve their personal and collective goals

    DRAM:A three-dimensional analytical model for the mobilisation of root reinforcement in direct shear conditions

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    Roots can stabilise slopes against shallow landslides by mobilising their mechanical strength. Existing analytical models are highly simplified and typically focus on the ultimate limit state only, thus providing little insight into the underlying mechanism of reinforcement mobilisation. A new analytical model (‘DRAM’) was therefore developed to predict mechanical root reinforcement as a function of direct shear displacements. This model accounts for elasto-plastic root behaviour, three-dimensional root orientations, root failure through breakage or slippage, and a dynamically changing shear zone thickness. Comparison to two independent experimental direct shear data sets showed that the model was able to accurately predict the gradual mobilisation of root strength, the magnitude of peak root reinforcement, as well as the presence of significant root reinforcement at large shear displacements, associated with a relatively large quantity of roots slipping out of the surrounding soil. Because the newly developed model more closely resembles the underlying physics of the mobilisation of root reinforcement in direct shear while still being easy to use, it will be a useful tool for the engineering industry, in terms of quantifying root reinforcement distribution for limit analyses at the ultimate limit state, as well as for directing future research into the drivers of mechanical root reinforcement.</p

    Chlamydia trachomatis Pgp3 antibody persists and correlates with self-reported infection and behavioural risks in a blinded cohort study

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    Chlamydia trachomatis (Ct) serological studies in populations could help monitor changes in lifetime cumulative risk of infection. We developed a double-antigen sandwich ELISA based on the Ct-specific Pgp3 antigen, then tested blind stored sera from over 800 participants in a New Zealand birth cohort from Dunedin at ages 26, 32 and 38. The double-antigen sandwich ELISA was more sensitive than our previously characterised indirect Pgp3 ELISA. Pgp3 antibody was detected more often in women compared to men and correlated with increasing numbers of sexual partners, self-reported Ct, and younger age at sexual debut in both women and men. At age 26, 24.1% (99/411) of women were Pgp3 seropositive, as were 79.5% (35/44) of those reporting Ct infection; Pgp3 antibody persisted to age 38 in 96.5% (83/86). In men at age 26, the figures were 10.7% (47/442) and 25.0% (6/24), respectively, with high (83.9%) antibody persistence to age 38. At age 38, among those Pgp3 seropositive, 63.3% of women and 83.1% of men had not reported Ct infection. Thus, Ct-specific Pgp3 antibody was detected in most women reporting Ct infection and correlated with risk of infection in those who did not, with most infections remaining undetected. As this antibody persisted for at least twelve years in 96% of these women, serology could be used to evaluate Ct prevention programmes among women

    Genetic Manipulation of Sainfoin Leaf Tannins

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    An isogenic population of sainfoin (Onobrychis viciifolia Scop.) plants was developed by two methods; regeneration after long term tissue culture and plant transformation with an antisense chalcone synthase gene. Tannin (proanthocyanidin) content could be dramatically increased in untransformed callus by long term culture, but was not significantly altered in regenerating plantlets. Some of the mature transgenic plants had dramatically reduced levels of leaf tannin. The antisense gene was eliminated from all transgenic plants later in development

    Supporting public involvement in interview and other panels: a systematic review.

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    BACKGROUND: Members of the public are increasingly being invited to become members of a variety of different panels and boards. OBJECTIVE: This study aimed to systematically search the literature to identify studies relating to support or training provided to members of the public who are asked to be members of an interview panel. SEARCH STRATEGY: A systematic search for published and unpublished studies was carried out from June to September 2015. The search methods included electronic database searching, reference list screening, citation searching and scrutinizing online sources. INCLUSION CRITERIA: We included studies of any design including published and unpublished documents which outlined preparation or guidance relating to public participants who were members of interview panels or representatives on other types of panels or committees. DATA SYNTHESIS: Results were synthesised via narrative methods. MAIN RESULTS: Thirty-six documents were included in the review. Scrutiny of this literature highlighted ten areas which require consideration when including members of the public on interview panels: financial resources; clarity of role; role in the interview process; role in evaluation; training; orientation/induction; information needs; terminology; support; and other public representative needs such as timing, accessibility and support with information technology. DISCUSSION AND CONCLUSIONS: The results of the review emphasize a range of elements that need to be fully considered when planning the involvement of public participants on interview panels. It highlights potential issues relating to the degree of involvement of public representatives in evaluating/grading decisions and the need for preparation and on-going support

    Strike point splitting induced by the application of magnetic perturbations on MAST

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    Divertor strike point splitting induced by resonant magnetic perturbations (RMPs) has been observed on MAST for a variety of RMP configurations in a plasma scenario with Ip=750kA where those configurations all have similar resonant components. Complementary measurements have been obtained with divertor Langmuir probes and an infrared camera. Clear splitting consistently appears in this scenario only in the even configuration of the perturbation coils, similarly to the density pump-out. These results present a challenge for models of plasma response to RMPs.Comment: 9 pages, 4 figures, submitted to the proceedings of the 20th Conference on Plasma Surface Interactions, to be published in the Journal of Nuclear Material

    Gull plumages are, and are not, what they appear to human vision

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    Clear correlations between human and bird visual assessments of color have been documented, and are often assumed, despite fundamental differences in human and avian visual physiology and morphology. Analyses of plumage colors with avian perceptual models have shown widespread hidden inter-sexual and inter-specific color variation among passerines perceived as monochromatic to humans, highlighting the uncertainty of human vision to predict potentially relevant variation in color. Herein, we use reflectance data from 13 Larus gull species as an exemplar data set to study concordance between human vision and avian visual modeling of feather colors near, or below, the human threshold for discrimination. We found little evidence among gulls for sexual dichromatism hidden from human vision, but did find inter-specific color variation among gulls that is not seen by humans. Neither of these results were predictable a priori, and we reassert that reflectance measurements of actual feather colors, analyzed with avian relevant visual models, represent best practice when studying bird coloration
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