277 research outputs found

    The centre of rotation of the shoulder complex and the effect of normalisation

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    AbstractShoulder motions consist of a composite movement of three joints and one pseudo-joint, which together dictate the humerothoracic motion. The purpose of this work was to quantify the location of the centre of rotation (CoR) of the shoulder complex as a whole. Dynamic motion of 12 participants was recorded using optical motion tracking during coronal, scapular and sagittal plane elevation. The instantaneous CoR was found for each angle of elevation using helical axes projected onto the three planes of motion. The location of an average CoR for each plane was evaluated using digitised and anthropometric measures for normalisation. When conducting motion in the coronal, scapular, and sagittal planes, respectively, the coefficients for locating the CoRs of the shoulder complex are −61%, −61%, and −65% of the anterior–posterior dimension – the vector between the midpoint of the incisura jugularis and the xiphoid process and the midpoint of the seventh cervical vertebra and the eighth thoracic vertebra; 0%, −1%, and −2% of the superior–inferior dimension – the vector between the midpoint of the acromioclavicular joints and the midpoint of the anterior superior iliac spines; and 57%, 57%, and 78% of the medial–lateral dimension −0.129 times the height of the participant. Knowing the location of the CoR of the shoulder complex as a whole enables improved participant positioning for evaluation and rehabilitation activities that involve movement of the hand with a fixed radius, such as those that employ isokinetic dynamometers

    Nano-scale mechanisms explain the stiffening and strengthening of ligament tissue with increasing strain rate

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    Ligament failure is a major societal burden causing disability and pain. Failure is caused by trauma at high loading rates. At the macroscopic level increasing strain rates cause an increase in failure stress and modulus, but the mechanism for this strain rate dependency is not known. Here we investigate the nano scale mechanical property changes of human ligament using mechanical testing combined with synchrotron X-ray diffraction. With increasing strain rate, we observe a significant increase in fibril modulus and a reduction of fibril to tissue strain ratio, revealing that tissue-level stiffening is mainly due to the stiffening of collagen fibrils. Further, we show that the reduction in fibril deformation at higher strain rates is due to reduced molecular strain and fibrillar gaps, and is associated with rapid disruption of matrix-fibril bonding. This reduction in number of interfibrillar cross-links explains the changes in fibril strain; this is verified through computational modelling

    Bayesian jackknife tests with a small number of subsets: application to HERA 21 cm power spectrum upper limits

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    We present a Bayesian jackknife test for assessing the probability that a data set contains biased subsets, and, if so, which of the subsets are likely to be biased. The test can be used to assess the presence and likely source of statistical tension between different measurements of the same quantities in an automated manner. Under certain broadly applicable assumptions, the test is analytically tractable. We also provide an open-source code, CHIBORG, that performs both analytic and numerical computations of the test on general Gaussian-distributed data. After exploring the information theoretical aspects of the test and its performance with an array of simulations, we apply it to data from the Hydrogen Epoch of Reionization Array (HERA) to assess whether different sub-seasons of observing can justifiably be combined to produce a deeper 21 cm power spectrum upper limit. We find that, with a handful of exceptions, the HERA data in question are statistically consistent and this decision is justified. We conclude by pointing out the wide applicability of this test, including to CMB experiments and the H0 tension

    Disease consequences of higher adiposity uncoupled from its adverse metabolic effects using Mendelian randomisation

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    Background:Some individuals living with obesity may be relatively metabolically healthy, whilst others suffer from multiple conditions that may be linked to adverse metabolic effects or other factors. The extent to which the adverse metabolic component of obesity contributes to disease compared to the non-metabolic components is often uncertain. We aimed to use Mendelian randomisation (MR) and specific genetic variants to separately test the causal roles of higher adiposity with and without its adverse metabolic effects on diseases.Methods:We selected 37 chronic diseases associated with obesity and genetic variants associated with different aspects of excess weight. These genetic variants included those associated with metabolically ‘favourable adiposity’ (FA) and ‘unfavourable adiposity’ (UFA) that are both associated with higher adiposity but with opposite effects on metabolic risk. We used these variants and two sample MR to test the effects on the chronic diseases.Results:MR identified two sets of diseases. First, 11 conditions where the metabolic effect of higher adiposity is the likely primary cause of the disease. Here, MR with the FA and UFA genetics showed opposing effects on risk of disease: coronary artery disease, peripheral artery disease, hypertension, stroke, type 2 diabetes, polycystic ovary syndrome, heart failure, atrial fibrillation, chronic kidney disease, renal cancer, and gout. Second, 9 conditions where the non-metabolic effects of excess weight (e.g. mechanical effect) are likely a cause. Here, MR with the FA genetics, despite leading to lower metabolic risk, and MR with the UFA genetics, both indicated higher disease risk: osteoarthritis, rheumatoid arthritis, osteoporosis, gastro-oesophageal reflux disease, gallstones, adult-onset asthma, psoriasis, deep vein thrombosis, and venous thromboembolism.Conclusions:Our results assist in understanding the consequences of higher adiposity uncoupled from its adverse metabolic effects, including the risks to individuals with high body mass index who may be relatively metabolically healthy.Funding:Diabetes UK, UK Medical Research Council, World Cancer Research Fund, National Cancer Institute

    Disease consequences of higher adiposity uncoupled from its adverse metabolic effects using Mendelian randomisation

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    Background:Some individuals living with obesity may be relatively metabolically healthy, whilst others suffer from multiple conditions that may be linked to adverse metabolic effects or other factors. The extent to which the adverse metabolic component of obesity contributes to disease compared to the non-metabolic components is often uncertain. We aimed to use Mendelian randomisation (MR) and specific genetic variants to separately test the causal roles of higher adiposity with and without its adverse metabolic effects on diseases.Methods:We selected 37 chronic diseases associated with obesity and genetic variants associated with different aspects of excess weight. These genetic variants included those associated with metabolically ‘favourable adiposity’ (FA) and ‘unfavourable adiposity’ (UFA) that are both associated with higher adiposity but with opposite effects on metabolic risk. We used these variants and two sample MR to test the effects on the chronic diseases.Results:MR identified two sets of diseases. First, 11 conditions where the metabolic effect of higher adiposity is the likely primary cause of the disease. Here, MR with the FA and UFA genetics showed opposing effects on risk of disease: coronary artery disease, peripheral artery disease, hypertension, stroke, type 2 diabetes, polycystic ovary syndrome, heart failure, atrial fibrillation, chronic kidney disease, renal cancer, and gout. Second, 9 conditions where the non-metabolic effects of excess weight (e.g. mechanical effect) are likely a cause. Here, MR with the FA genetics, despite leading to lower metabolic risk, and MR with the UFA genetics, both indicated higher disease risk: osteoarthritis, rheumatoid arthritis, osteoporosis, gastro-oesophageal reflux disease, gallstones, adult-onset asthma, psoriasis, deep vein thrombosis, and venous thromboembolism.Conclusions:Our results assist in understanding the consequences of higher adiposity uncoupled from its adverse metabolic effects, including the risks to individuals with high body mass index who may be relatively metabolically healthy.Funding:Diabetes UK, UK Medical Research Council, World Cancer Research Fund, National Cancer Institute

    Policy and public communication methods among U.S. state prisons during the first year of the COVID-19 pandemic

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    Background: Throughout the first year of the COVID-19 pandemic, our research team monitored and documented policy changes in United States (U.S.) prison systems. Data sources included prison websites and official prison social media accounts. Over 2500 data sources relevant to the COVID-19 pandemic in U.S. prisons were located and summarized in to five different categories: 1) prevention, 2) case identification and intervention, 3) movement, 4) social communication and connection, and 5) programming, recreation, and privileges. Results: All state prison systems reportedly enacted multiple policies intended to limit the spread of COVID-19 during the pandemic. Document analysis revealed that the most commonly released policies were restrictions on social contacts and privileges, basic preventive measures (e.g., distribution of masks), and basic case identification measures (e.g., verbal screening and temperature checks). Utilization of social media for policy communication varied significantly across states, though relevant data was more often released on Facebook than Twitter. Conclusions: Together, our work provides foundational knowledge on the wide breadth of policies that were reportedly enacted in the first year of the pandemic that may be used as a base for quantitative work on policy effectiveness and examinations of implementation

    Influenza classification from short reads with VAPOR facilitates robust mapping pipelines and zoonotic strain detection for routine surveillance applications

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    Motivation: Influenza viruses represent a global public health burden due to annual epidemics and pandemic potential. Due to a rapidly evolving RNA genome, inter-species transmission, intra-host variation, and noise in short-read data, reads can be lost during mapping, and de novo assembly can be time consuming and result in misassembly. We assessed read loss during mapping, and designed a graph-based classifier, VAPOR, for selecting mapping references, assembly validation, and detection of strains of non-human origin. Results: Standard human reference viruses were insufficient for mapping diverse influenza samples in simulation. VAPOR retrieved references for 257 real whole genome sequencing (WGS) samples with a mean of >99.8% identity to assemblies, and increased the proportion of mapped reads by up to 13.3% compared to standard references. VAPOR has the potential to improve the robustness of bioinformatics pipelines for surveillance and could be adapted to other RNA viruses

    Monitoring Chemical Pollution in Europe’s Seas: Programmes, practices and priorities for research

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    This report has been produced by the Marine Board Working Group on Existing and Emerging Chemical Pollutants (WGPOL) first convened in 2008 and tasked to examine the assessment and monitoring of existing and emerging chemicals in the European marine and coastal environment. The Working Group considered (i) existing monitoring/assessment frameworks; (ii) current monitoring practices; and (iii) new and emerging chemicals of concern and the mechanisms used to include them in current monitoring programmes. The primary conclusions and recommendations of this position paper are: 1. Fully implement state of the art environmental risk assessment procedures (combining exposure and effect assessment) to evaluate the full impact of chemical substances on the different compartments of coastal and open sea systems. 2. Further improve the coordination, cooperation and harmonization between existing monitoring efforts and those under development, to avoid duplication of effort, loss of expertise and a reduced willingness to fulfil the obligations towards regional conventions. 3. Ensure that the development and implementation of monitoring programmes for the assessment of chemicals in marine and coastal environment are based on a science-based and dynamic process. 4. Apply more resources targeted at developing appropriate approaches, tools and practices (education and training) to improve the acquisition and management of monitoring data. In addition to the above main recommendations, two further recommendations have been identified on the basis of two specific case studies which form part of this paper and which focus on the release, effects and monitoring of (i) hydrophobic and insoluble chemicals in the marine environment from merchant shipping; and (ii) chemicals released by the offshore oil-industry in the North Sea. These case studies highlighted the need to: 5. Develop a consistent, pan-European or regional (legal) framework/regulation which covers the activities of the oil and gas industry at sea. At the same time, more information and research is needed on the release and the effects of chemicals arising from offshore oil and gas activities. 6. Develop and apply state-of-the-art environmental risk assessment procedures (combining exposure and effect assessments, including on human health) to evaluate the impact of noxious liquid substances listed under MARPOL Annex II on the different compartments in coastal and open sea ecosystems

    A Novel 2D Folding Technique for Enhancing Fermi Surface Signatures in the Momentum Density: Application to Compton Scattering Data from an Al-3at%Li Disordered Alloy

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    We present a novel technique for enhancing Fermi surface (FS) signatures in the 2D distribution obtained after the 3D momentum density in a crystal is projected along a specific direction in momentum space. These results are useful for investigating fermiology via high resolution Compton scattering and positron annihilation spectroscopies. We focus on the particular case of the (110) projection in an fcc crystal where the standard approach based on the use of the Lock-Crisp-West (LCW) folding theorem fails to give a clear FS image due to the strong overlap with FS images obtained through projection from higher Brillouin zones. We show how these superposed FS images can be disentangled by using a selected set of reciprocal lattice vectors in the folding process. The applicability of our partial folding scheme is illustrated by considering Compton spectra from an Al-3at%Li disordered alloy single crystal. For this purpose, high resolution Compton profiles along nine directions in the (110) plane were measured. Corresponding highly accurate theoretical profiles in Al-3at%Li were computed within the local density approximation (LDA)-based Korringa-Kohn-Rostoker coherent potential approximation (KKR-CPA) first-principles framework. A good level of overall accord between theory and experiment is obtained, some expected discrepancies reflecting electron correlation effects notwithstanding, and the partial folding scheme is shown to yield a clear FS image in the (110) plane in Al-3%Li.Comment: 24 pages, 8 figures, to appear in Phys. Rev.

    Post-traumatic growth amongst UK armed forces personnel who were deployed to Afghanistan and the role of combat injury, mental health and pain: the ADVANCE cohort study.

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    BACKGROUND: Post-traumatic growth (PTG) is a positive psychological consequence of trauma. The aims of this study were to investigate whether combat injury was associated with deployment-related PTG in a cohort of UK military personnel who were deployed to Afghanistan, and whether post-traumatic stress disorder (PTSD), depression and pain mediate this relationship. METHODS: 521 physically injured (n = 138 amputation; n = 383 non-amputation injury) and 514 frequency-matched uninjured personnel completed questionnaires including the deployment-related Post-Traumatic Growth Inventory (DPTGI). DPTGI scores were categorised into tertiles of: no/low (score 0-20), moderate (score 21-34) or a large (35-63) degree of deployment-related PTG. Analysis was completed using generalised structural equation modelling. RESULTS: A large degree of PTG was reported by 28.0% (n = 140) of the uninjured group, 36.9% (n = 196) of the overall injured group, 45.4% (n = 62) of amputee and 34.1% (n = 134) of the non-amputee injured subgroups. Combat injury had a direct effect on reporting a large degree of PTG [Relative risk ratio (RRR) 1.59 (95% confidence interval (CI) 1.17-2.17)] compared to sustaining no injury. Amputation injuries also had a significant direct effect [RRR 2.18 (95% CI 1.24-3.75)], but non-amputation injuries did not [RRR 1.35 (95% CI 0.92-1.93)]. PTSD, depression and pain partially mediate this relationship, though mediation differed depending on the injury subtype. PTSD had a curvilinear relationship with PTG, whilst depression had a negative association and pain had a positive association. CONCLUSIONS: Combat injury, in particular injury resulting in traumatic amputation, is associated with reporting a large degree of PTG
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