352 research outputs found

    Prognostic potential of body composition indices in detecting risk of musculoskeletal injury in army officer cadet profiles.

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    OBJECTIVES: High values in most of the body composition indices have been related to musculoskeletal injuries, but limited data exists on the accuracy of these diagnoses when detecting musculoskeletal injuries in military populations. METHODS: The suitability of body fat percentage, body mass index, fat mass index and fat free mass index to identify injury risk was examined in a group of army officer recruits. All body composition diagnoses were measured in 268 male army officer recruits prior to the commencement of basic combat training. Musculoskeletal injury was identified using codes from the International Classification of Diseases. The area under the curve, in the receiver operating characteristic curve, was used to quantify the overall ability to discriminate between those who were injured and those who were not. RESULTS: The statistics indicated that all indices, apart from body mass index, had a significant possibility to detect musculoskeletal injury potential (p 22, for fat mass index >6.5 and for fat free mass index <16.5. CONCLUSION: Body mass index values can not similarly detect the possibility of occurrence of musculoskeletal injuries in army officer recruits, just as other body composition diagnoses related to fat mass or/and free fat mass. However, the cut off-points related to the overall diagnostic performance of each body composition index should be used with caution and in accordance with the aims of each experimental setting

    Neutralizing antibody response during acute and chronic hepatitis C virus infection

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    Little is known about the role of Abs in determining the outcome of hepatitis C virus (HCV) infection. By using infectious retroviral pseudotypes bearing HCV glycoproteins, we measured neutralizing Ab (nAb) responses during acute and chronic HCV infection. In seven acutely infected health care workers, only two developed a nAb response that failed to associate with viral clearance. In contrast, the majority of chronically infected patients had nAbs. To determine the kinetics of strain-specific and crossreactive nAb emergence, we studied patient H, the source of the prototype genotype 1a H77 HCV strain. An early weak nAb response, specific for the autologous virus, was detected at seroconversion. However, neutralization of heterologous viruses was detected only between 33 and 111 weeks of infection. We also examined the development of nAbs in 10 chimpanzees infected with H77 clonal virus. No nAb responses were detected in three animals that cleared virus, whereas strain-specific nAbs were detected in six of the seven chronically infected animals after approximately 50 weeks of infection. The delayed appearance of high titer crossreactive nAbs in chronically infected patients suggests that selective mechanism(s) may operate to prevent the appearance of these Abs during acute infection. The long-term persistence of these nAbs in chronically infected patients may regulate viral replication

    Developing a framework for the analysis of power through depotentia

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    Stakeholder participation in tourism policy-making is usually perceived as providing a means of empowerment. However participatory processes drawing upon stakeholders from traditionally empowered backgrounds may provide the means of removing empowerment from stakeholders. Such an outcome would be in contradiction to the claims that participatory processes improve both inclusivity and sustainability. In order to form an understanding of the sources through which empowerment may be removed, an analytical perspective has been developed deriving from Lukes�s views of power dating from 1974. This perspective considers the concept of depotentia as the removal of �power to� without speculating upon the underlying intent and also provides for the multidimensionality of power to be examined within a single study. The application of this analytical perspective has been tested upon findings of the government-commissioned report of the Countryside and Community Research Unit in 2005. The survey and report investigated the progress of Local Access Forums in England created in response to the Countryside and Rights of Way Act 2000. Consideration of the data from this perspective permits the classification of individual sources of depotentia which can each be addressed and potentially enable stakeholder groups to reverse loss of empowerment where it has occurred

    Rapid counting and spectral sorting of live coral larvae using large-particle flow cytometry

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    Research with coral embryos and larvae often requires laborious manual counting and sorting of individual specimens, usually via microscopy. Because many coral species spawn only once per year during a narrow temporal window, sample processing is a time-limiting step for research on the early life-history stages of corals. Flow cytometry, an automated technique for measuring and sorting particles, cells, and cell-clusters, is a potential solution to this bottleneck. Yet most flow cytometers do not accommodate live organisms of the size of most coral embryos (> 250 µm), and sample processing is often destructive. Here we tested the ability of a large-particle flow cytometer with a gentle pneumatic sorting mechanism to process and spectrally sort live and preserved Montipora capitata coral embryos and larvae. Average survival rates of mechanically-sorted larvae were over 90% and were comparable to those achieved by careful hand-sorting. Preserved eggs and embryos remained intact throughout the sorting process and were successfully sorted based on real-time size and fluorescence detection. In-line bright-field microscopy images were captured for each sample object as it passed through the flow-cell, enabling the identification of early-stage embryos (2-cell to morula stage). Samples were counted and sorted at an average rate of 4 s larva−1 and as high as 0.2 s larva−1 for high-density samples. Results presented here suggest that large-particle flow cytometry has the potential to significantly increase efficiency and accuracy of data collection and sample processing during time-limited coral spawning events, facilitating larger-scale and higher-replication studies with an expanded number of species

    Climate geoengineering: issues of path-dependence and socio-technical lock-in

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    As academic and policy interest in climate geoengineering grows, the potential irreversibility of technological developments in this domain has been raised as a pressing concern. The literature on socio-technical lock-in and path dependence is illuminating in helping to situate current concerns about climate geoengineering and irreversibility in the context of academic understandings of historical socio-technical development and persistence. This literature provides a wealth of material illustrating the pervasiveness of positive feedbacks of various types (from the discursive to the material) leading to complex socio-technical entanglements which may resist change and become inflexible even in the light of evidence of negative impacts. With regard to climate geoengineering, there are concerns that geoengineering technologies might contribute so-called ‘carbon lock-in’, or become irreversibly ‘locked-in’ themselves. In particular, the scale of infrastructures that geoengineering interventions would require, and the issue of the so-called ‘termination effect’ have been discussed in these terms. Despite the emergent and somewhat ill-defined nature of the field, some authors also suggest that the extant framings of geoengineering in academic and policy literatures may already demonstrate features recognizable as forms of cognitive lock-in, likely to have profound implications for future developments in this area. While the concepts of path-dependence and lock-in are the subject of ongoing academic critique, by drawing analytical attention to these pervasive processes of positive feedback and entanglement, this literature is highly relevant to current debates around geoengineering

    An organizing center in a planar model of neuronal excitability

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    The paper studies the excitability properties of a generalized FitzHugh-Nagumo model. The model differs from the purely competitive FitzHugh-Nagumo model in that it accounts for the effect of cooperative gating variables such as activation of calcium currents. Excitability is explored by unfolding a pitchfork bifurcation that is shown to organize five different types of excitability. In addition to the three classical types of neuronal excitability, two novel types are described and distinctly associated to the presence of cooperative variables

    An agenda for ethics and justice in adaptation to climate change

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    As experts predict that at least some irreversible climate change will occur with potentially disastrous effects on the lives and well-being of vulnerable communities around the world, it is paramount to ensure that these communities are resilient and have adaptive capacity to withstand the consequences. Adaptation and resilience planning present several ethical issues that need to be resolved if we are to achieve successful adaptation and resilience to climate change, taking into consideration vulnerabilities and inequalities in terms of power, income, gender, age, sexuality, race, culture, religion, and spatiality. Sustainable adaptation and resilience planning that addresses these ethical issues requires interdisciplinary dialogues between the natural sciences, social sciences, and philosophy, in order to integrate empirical insights on socioeconomic inequality and climate vulnerability with ethical analysis of the underlying causes and consequences of injustice in adaptation and resilience. In this paper, we set out an interdisciplinary research agenda for the inclusion of ethics and justice theories in adaptation and resilience planning, particularly into the Sixth Assessment Report of the International Panel on Climate Change (IPCC AR6). We present six core discussions that we believe should be an integral part of these interdisciplinary dialogues on adaptation and resilience as part of IPCC AR6, especially Chapters 2 (“Terrestial and freshwater ecosystems and their services”), 6 (“Cities, settlements and key infrastructure”), 7 (“Health, wellbeing and the changing structure of communities”), 8 (“Poverty, livelihoods and sustainable development”), 16 “Key risks across sectors and regions”), 17 (“Decision-making options for managing risk”), and 18 (“Climate resilient development pathways”).: (i) Where does ‘justice’ feature in resilience and adaptation planning and what does it require in that regard?; (ii) How can it be ensured that adaptation and resilience strategies protect and take into consideration and represent the interest of the most vulnerable women and men, and communities?; (iii) How can different forms of knowledge be integrated within adaptation and resilience planning?; (iv) What trade-offs need to be made when focusing on resilience and adaptation and how can they be resolved?; (v) What roles and responsibilities do different actors have to build resilience and achieve adaptation?; (vi) Finally, what does the focus on ethics imply for the practice of adaptation and resilience planning

    Is bioelectrical impedance accurate for use in large epidemiological studies?

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    Percentage of body fat is strongly associated with the risk of several chronic diseases but its accurate measurement is difficult. Bioelectrical impedance analysis (BIA) is a relatively simple, quick and non-invasive technique, to measure body composition. It measures body fat accurately in controlled clinical conditions but its performance in the field is inconsistent. In large epidemiologic studies simpler surrogate techniques such as body mass index (BMI), waist circumference, and waist-hip ratio are frequently used instead of BIA to measure body fatness. We reviewed the rationale, theory, and technique of recently developed systems such as foot (or hand)-to-foot BIA measurement, and the elements that could influence its results in large epidemiologic studies. BIA results are influenced by factors such as the environment, ethnicity, phase of menstrual cycle, and underlying medical conditions. We concluded that BIA measurements validated for specific ethnic groups, populations and conditions can accurately measure body fat in those populations, but not others and suggest that for large epdiemiological studies with diverse populations BIA may not be the appropriate choice for body composition measurement unless specific calibration equations are developed for different groups participating in the study

    Water Contamination Reduces the Tolerance of Coral Larvae to Thermal Stress

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    Coral reefs are highly susceptible to climate change, with elevated sea surface temperatures (SST) posing one of the main threats to coral survival. Successful recruitment of new colonies is important for the recovery of degraded reefs following mortality events. Coral larvae require relatively uncontaminated substratum on which to metamorphose into sessile polyps, and the increasing pollution of coastal waters therefore constitutes an additional threat to reef resilience. Here we develop and analyse a model of larval metamorphosis success for two common coral species to quantify the interactive effects of water pollution (copper contamination) and SST. We identify thresholds of temperature and pollution that prevent larval metamorphosis, and evaluate synergistic interactions between these stressors. Our analyses show that halving the concentration of Cu can protect corals from the negative effects of a 2–3°C increase in SST. These results demonstrate that effective mitigation of local impacts can reduce negative effects of global stressors
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