4,939 research outputs found

    Ecological design to shape new urbanities

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    courtesy of the publisher for "Conservation Biology" - reviews are Open Access

    Impact of vertical vibrations on human rhythmic jumping

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    This is the final version. Available from Elsevier via the DOI in this record. This paper investigates the human ability to perform rhythmic jumping on a vertically vibrating platform by analysing kinetics and kinematics. Ten test subjects participated, performing jumping on both non-vibrating and vibrating platforms. Vibration frequencies of 2.0, 2.4, and 2.8 Hz were used, with a vibration level of 2 m/s2. The frequency of jumping matched the vibration frequency, and for the first time, the jumps were timed relative to the platform’s position in the vibration cycle. A metronome prompted landings at four target positions: (i) reference position and on the way down (mid-down), (ii)lowest position (trough), (iii)reference position and on the way up (mid-up), and (iv)highest position (peak), at each frequency. The study compared the achievement of the target frequency of jumping between non-vibrating and vibrating platform conditions for each frequency. Results showed the worst performance when the target frequency was 2.8 Hz on the non-vibrating platform, confirming the difficulty of faster jumping on non-vibrating surfaces. The discrete relative phase analysis revealed a preference for landing at the trough and mid-up positions on the vibrating platform, particularly at 2.8 Hz. The preferred timing of jumps corresponded to greater toe clearance and impact ratio, but shorter contact duration compared to the non-vibrating platform. These findings hold promise for improving human-structure interaction models for assembly structures used in sports and musical events.University of Exete

    Occupational lung diseases among former goldminers in two labour sending areas

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    Objectives. To compare and contrast the prevalence of pneumoconiosis in two groups of former migrant mineworkers in southern Africa, and to examine the effectiveness of the South African compensation system for occupational lung diseases.Design. Comparison of two cross-sectional studies and follow-up data on compensation results.Setting. The village of Thamaga, Botswana and the rural area of Libode, Eastern Cape, South Africa.Subjects. Two hundred and thirty-four former underground mineworkers in Thamaga, and 238 in Libode. Main outcome measures. Prevalence and severity of pneumoconiosis, prevalence of radiological signs of tuberculosis (TB), Medical Bureau for Occupational Diseases (MBOD) certification committee decisions, and compensation results.Results. Prevalence of pneumoconiosis ≥ 2/ 1 was 15.4% in Libode and 13.6% in Thamaga. Significantly more Libode than Thamaga subjects (51.1% versus 29.0%) reported past TB treatment Radiological signs of pulmonary TB were also more prevalent in Libode (33.3% v. 23.9%). Twenty-six per cent of Libode men and 16.1% of Thamaga men were certified with compensable disease. Libode payments were finalised within 30 months, whereas Thamaga cases only began receiving payments 52 months after medical  examination, with 11 cases still pending 66 months after medical examination.Conclusion. There was a high prevalence of pneumoconiosis in both study groups. Many men were eligible for compensation but were previously uncompensated. The higher rate of compensable disease in the Libode group may relate to the higher prevalence of TB, as well as more active follow-up by the study group, including a large number of appeals. Socio-political changes in South Africa between 1994 and 1996 may also have influenced compensation results

    A survey of hospice day services in the United Kingdom & Republic of Ireland: How did hospices offer social support to palliative care patients, pre-pandemic?

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    Introduction: Social support is described by patients and other stakeholders to be a valuable component of palliative day care. Less is known about the range of hospice services that have been used in practice that facilitate social support. An online survey aimed to gain an overview of all hospice day services that facilitated social support for adults outside of their own homes. Methods:An online survey was distributed via email to people involved in managing hospice day services. Questions were asked on hospice characteristics, including staff and volunteer roles. Respondents were asked to identify services they felt offered social support to patients. Data collection took place between August 2017 and May 2018. Results: Responses were received from 103 hospices in the UK and ROI (response rate 49.5%). Results provide an overview of hospice day and outpatient services that offer social support to patients. These are: multi-component interventions, activity groups, formal support groups, befriending, and informal social activities. Multi-component interventions, such as palliative day care, were the most commonly reported. Their stated aims tend to focus on clinical aspects, but many survey respondents considered these multicomponent interventions to be the ‘most social’ service at their hospice. The survey also identified a huge variety of activity groups, as well as formal therapeutic support groups. Informal ‘social-only’ activities were present, but less common. Over a third of all the services were described as ‘drop in’. Most responding hospices did not routinely use patient reported outcome measures in their ‘most social’ services. Conclusions: The survey documents hospice activity in facilitating social support to be diverse and evolving. At the time of data collection, many hospices offered multiple different services by which a patient might obtain social support outside of their own home and in the presence of other patients

    Feedback Stabilization of a Class of Diagonal Infinite-Dimensional Systems with Delay Boundary Control

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    This paper studies the boundary feedback stabilization of a class of diagonal infinite-dimensional boundary control systems. In the studied setting, the boundary control input is subject to a constant delay while the open loop system might exhibit a finite number of unstable modes. The proposed control design strategy consists in two main steps. First, a finite-dimensional subsystem is obtained by truncation of the original Infinite-Dimensional System (IDS) via modal decomposition. It includes the unstable components of the infinite-dimensional system and allows the design of a finite-dimensional delay controller by means of the Artstein transformation and the pole-shifting theorem. Second, it is shown via the selection of an adequate Lyapunov function that 1) the finite-dimensional delay controller successfully stabilizes the original infinite-dimensional system; 2) the closed-loop system is exponentially Input-to-State Stable (ISS) with respect to distributed disturbances. Finally, the obtained ISS property is used to derive a small gain condition ensuring the stability of an IDS-ODE interconnection.Comment: Preprin

    Genes Suggest Ancestral Colour Polymorphisms Are Shared across Morphologically Cryptic Species in Arctic Bumblebees

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    email Suzanne orcd idCopyright: © 2015 Williams et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

    Expression of homothorax and extradenticle mRNA in the legs of the crustacean Parhyale hawaiensis: evidence for a reversal of gene expression regulation in the pancrustacean lineage

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    In Drosophila leg development, the extradenticle (exd) gene is expressed ubiquitously and its co-factor homothorax (hth) is restricted to the proximal leg portion. This condition is conserved in other insect species but is reversed in chelicerates and myriapods. As the region of co-expression does not differ in the two groups and transcripts from both are necessary for function, this difference in expression is likely to be functionally neutral. Here, we report the expression patterns of exd and hth in a crustacean, the amphipod shrimp Parhyale hawaiensis. The patterns in P. hawaiensis are similar to the insect patterns, supporting the close relationship between crustaceans and insects in the taxon Tetraconata. However, mRNA expression of exd in P. hawaiensis is weak in the distal leg parts, thus being intermediate between the complete lack of distal exd expression in chelicerates and myriapods and the strong distal exd expression in insects. Our data suggest that the reversal of the gene expression regulation of hth and exd occurred in the pancrustacean lineage

    Industry in Motion: Using Smart Phones to Explore the Spatial Network of the Garment Industry in New York City

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    Industrial agglomerations have long been thought to offer economic and social benefits to firms and people that are only captured by location within their specified geographies. Using the case study of New York City’s garment industry along with data acquired from cell phones and social media, this study set out to understand the discrete activities underpinning the economic dynamics of an industrial agglomeration. Over a two week period, data was collected by employing the geo-locative capabilities of Foursquare, a social media application, to record every movement of fashion workers employed at fashion design firms located both inside and outside the geographical boundaries of New York City’s Garment District. This unique method of studying worker activity exposed the day-to-day dynamics of an industrial district with a precision thus far undocumented in literature. Our work suggests that having access to the cluster provides almost the same agglomeration economies as residing within its borders.Rockefeller Foundatio

    Role of P-selectin in platelet sequestration in pulmonary capillaries during endotoxemia

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    Background: There is growing evidence that platelets accumulate in the lung and contribute to the pathogenesis of acute lung injury during endotoxemia. The aims of the present study were to localize platelet sequestration in the pulmonary microcirculation and to investigate the role of P-selectin as a molecular mechanism of platelet endothelial cell interaction. Methods: We used in vivo fluorescence microscopy to quantify the kinetics of fluorescently labeled erythrocytes and platelets in alveolar capillary networks in rabbit lungs. Results: Six hours after onset of endotoxin infusion we observed a massive rolling along and firm adherence of platelets to lung capillary endothelial cells whereas under control conditions no platelet sequestration was detected. P-selectin was expressed on the surface of separated platelets which were incubated with endotoxin and in lung tissue. Pretreatment of platelets with fucoidin, a P-selectin antagonist, significantly attenuated the endotoxin-induced platelet rolling and adherence. In contrast, intravenous infusion of fucoidin in endotoxin-treated rabbits did not inhibit platelet sequestration in pulmonary capillaries. Conclusion: We conclude that platelets accumulate in alveolar capillaries following endotoxemia. P-selectin expressed on the surface of platelets seems to play an important role in mediating this platelet-endothelial cell interaction. Copyright (c) 2006 S. Karger AG, Basel

    Vascular disease and vascular risk factors in relation to motor features and cognition in early Parkinson's disease

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    OBJECTIVE: The purpose of this study was to examine the relationship between vascular disease (and vascular risk factors), cognition and motor phenotype in Parkinson's disease (PD). METHODS: Recently diagnosed PD cases were enrolled in a multicenter prospective observational longitudinal cohort study. Montreal cognitive assessment (normal >23, mild cognitive impairment 22 to 23 or lower but without functional impairment, and dementia 21 or less with functional impairment) and Movement Disorder Society Unified PD Rating Scale part 3 (UPDRS 3) scores were analyzed in relation to a history of vascular events and risk factors. RESULTS: In 1759 PD cases, mean age 67.5 (standard deviation 9.3) years, mean disease duration 1.3 (standard deviation 0.9) years, 65.2% were men, 4.7% had a history of prior stroke or transient ischemic attack, and 12.5% had cardiac disease (angina, myocardial infarction, heart failure). In cases without a history of vascular disease, hypertension was recorded in 30.4%, high cholesterol 27.3%, obesity 20.7%, diabetes 7.2%, and cigarette smoking in 4.6%. Patients with prior stroke or transient ischemic attack were more likely to have cognitive impairment (42% vs 25%) and postural instability gait difficulty (53.5% vs 39.5%), but these findings were not significant after adjustment for age, sex, and disease duration (P = .075). The presence of more than 2 vascular risks was associated with worse UPDRS 3 motor scores (beta coefficient 4.05, 95% confidence interval 1.48, 6.61, p = .002) and with cognitive impairment (ordinal odds ratio 2.24, 95% confidence interval 1.34, 3.74, p = .002). In 842 patients (47.8%) with structural brain imaging, white matter leukoaraiosis, but not lacunar or territorial infarction, was associated with impaired cognition (p = .006) and postural instability gait difficulty (p = .010). CONCLUSION: Vascular comorbidity is significantly associated with cognitive and gait impairment in patients with early PD, which may have prognostic and treatment implications. © 2016 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society
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