291 research outputs found

    The impact of body armor on physical performance of law enforcement personnel: A systematic review

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    Abstract Background The law enforcement officer profession requires performance of arduous occupational tasks while carrying an external load, consisting of, at minimum, a chest rig, a communication system, weaponry, handcuffs, personal protective equipment and a torch. The aim of this systematic review of the literature was to identify and critically appraise the methodological quality of published studies that have investigated the impacts of body armour on task performance and to synthesize and report key findings from these studies to inform law enforcement organizations. Methods Several literature databases (Medline, CINAHL, SPORTDiscus, EMBAS) were searched using key search words and terms to identify appropriate studies. Studies meeting the inclusion criteria were critically evaluated using the Downs and Black protocol with inter-rater agreement determined by Cohen’s Kappa. Results Sixteen articles were retained for evaluation with a mean Downs and Black score of 73.2 ± 6.8% (k = 0.841). Based on the research quality and findings across the included studies, this review determined that while effects of body armour on marksmanship and physiological responses have not yet been adequately ascertained, body armour does have significant physical performance and biomechanical impacts on the wearer, including: a) increased ratings of perceived exertion and increased time to complete functional tasks, b) decreased work capability (indicated by deterioration in fitness test scores), c) decreased balance and stability, and d) increased ground reaction forces. Conclusions Given the physical performance and biomechanical impacts on the wearer, body armour should be carefully selected, with consideration of the physical fitness of the wearers and the degree to which the armour systems can be ergonomically optimized for the specific population in question

    That Landscape Painting in your Bathroom

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    Pages 93-9

    Assessing the probative value of DNA evidence: guidance for judges, lawyers, forensic scientists and expert witnesses

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    Practical guidance for judges, lawyers, forensic scientists and expert witnesses on the logical analysis of DNA profiles, and their probative value in criminal proceedings. Explains technical aspects of DNA profiling and how this information should be presented and interpreted in criminal trials

    Electronic properties of sculpturenes

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    We investigate the electronic properties of sculpturenes, formed by sculpting selected shapes from bilayer graphene, boron nitride or graphene-boron nitride hetero-bilayers and allowing the shapes to spontaneously reconstruct. The simplest sculpturenes are periodic nanotubes, containing lines of non-hexagonal rings. More complex sculpturenes formed from shapes with non-trivial topologies, connectivities and materials combinations may also be constructed. Results are presented for the reconstructed geometries, electronic densities of states and current-voltage relations of these new structures

    Sculpting molecular structures from bilayer graphene and other materials

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    We demonstrate a technique for creating unique forms of pure sp(2)-bonded carbon and unprecedented heteromolecules. These new structures, which we refer to as sculpturenes, are formed by sculpting selected shapes from bilayer graphene, heterobilayers, or multilayered materials and allowing the shapes to spontaneously reconstruct. The simplest sculpturene is topologically equivalent to a torus, with dimensions comparable to those of fullerenes. The topology of these new molecular structures is stable against atomic-scale defects. We demonstrate that sculpturenes can form the basic building blocks of hollow, multiconnected structures, with potential applications to nanofluidics and nanoelectronics

    Sensing single molecules with carbon-boronnitride nanotubes

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    We investigate the molecular sensing properties of carbon nanotube-boron nitride-carbon nanotube (CNT-BN-CNT) junctions. We demonstrate that the electrical conductance of such a junction changes in response to the binding of an analyte molecule to the region of BN. The change in conductance depends on the length of the BN spacer and the position of the analyte and therefore we propose a method of statistically analysing conductance data. We demonstrate the ability to discriminate between analytes, by computing the conductance changes due to three analytes (benzene, thiol-capped oligoyne and a pyridyl-capped oligoyne) binding to junctions with five different lengths of BN spacer

    Perthes' disease of the hip: socioeconomic inequalities and the urban environment.

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    INTRODUCTION: Perthes' disease is a puzzling childhood hip disorder for which the aetiology is unknown. It is known to be associated with socioeconomic deprivation. Urban environments have also been implicated as a risk factor, however socioeconomic deprivation often occurs within urban environments and it is unclear if this association is the result of confounding. The objective of the current work was to gain a greater understanding of the influence of the urban/rural environment in Perthes' disease. METHODS: This was a descriptive observational study using the Scottish Morbidity Record, based in Scotland, UK using data from 2000-2010. A total of 443 patients with a discharge diagnosis of Perthes' disease were included. Socioeconomic deprivation was determined using the Scottish Index of Multiple Deprivation, and exposure to the 'urban environment' was recorded based on the Scottish Urban-Rural Classification. RESULTS: There was a strong association with socioeconomic deprivation, with rates among the most deprived quintile more than twice those of the most affluent (RR 2.1 (95% CI 1.5 to 2.9)). Urban areas had a greater rate of Perthes' disease discharges (RR 1.8 (95% CI 1.1 to 3.2)), though this was a reflection of greater deprivation in urban areas. Stratification for socioeconomic deprivation revealed similar discharge rates in urban and rural environments, suggesting that the aetiological determinants were not independently associated with urban environments. CONCLUSIONS: The occurrence of Perthes' disease within urban environments is high, yet this appears to be a reflection of higher socioeconomic deprivation exposure. Disease rates appear equivalent in similarly deprived urban and non-urban areas, suggesting that the determinant is not a consequence of the urban environment
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