956 research outputs found

    Piloted simulation study of an ILS approach of a twin-pusher business/commuter turboprop aircraft configuration

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    A six-degree-of-freedom nonlinear simulation of a twin-pusher, turboprop business/commuter aircraft configuration representative of the Cessna ATPTB (Advanced turboprop test bed) was developed for use in piloted studies with the Langley General Aviation Simulator. The math models developed are provided, simulation predictions are compared with with Cessna flight-test data for validation purposes, and results of a handling quality study during simulated ILS (instrument landing system) approaches and missed approaches are presented. Simulated flight trajectories, task performance measures, and pilot evaluations are presented for the ILS approach and missed-approach tasks conducted with the vehicle in the presence of moderate turbulence, varying horizontal winds and engine-out conditions. Six test subjects consisting of two research pilots, a Cessna test pilot, and three general aviation pilots participated in the study. This effort was undertaken in cooperation with the Cessna Aircraft Company

    What challenges did junior doctors face while working during the COVID-19 pandemic? A qualitative study.

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    Objectives This paper reports findings exploring junior doctors’ experiences of working during the COVID-19 pandemic in the UK.Design Qualitative study using in-depth interviews with 15 junior doctors. Interviews were audio-recorded, transcribed, anonymised and imported into NVivo V.12 to facilitate data management. Data were analysed using reflexive thematic analysis.Setting National Health Service (NHS) England.Participants A purposive sample of 12 female and 3 male junior doctors who indicated severe depression and/or anxiety on the DASS-21 questionnaire or high suicidality on Paykel’s measure were recruited. These doctors self-identified as having lived experience of distress due to their working conditions.Results We report three major themes. First, the challenges of working during the COVID-19 pandemic, which were both personal and organisational. Personal challenges were characterised by helplessness and included the trauma of seeing many patients dying, fears about safety and being powerless to switch off. Work-related challenges revolved around change and uncertainty and included increasing workloads, decreasing staff numbers and negative impacts on relationships with colleagues and patients. The second theme was strategies for coping with the impact of COVID-19 on work, which were also both personal and organisational. Personal coping strategies, which appeared limited in their usefulness, were problem and emotion focused. Several participants appeared to have moved from coping towards learnt helplessness. Some organisations reacted to COVID-19 collaboratively and flexibly. Third, participants reported a positive impact of the COVID-19 pandemic on working practices, which included simplified new ways of working—such as consistent teams and longer rotations—as well as increased camaraderie and support.Conclusions The trauma that junior doctors experienced while working during COVID-19 led to powerlessness and a reduction in the benefit of individual coping strategies. This may have resulted in feelings of resignation. We recommend that, postpandemic, junior doctors are assigned to consistent teams and offered ongoing support

    Sunburns and Sun Protection Behaviors among Male Hispanic Outdoor Day Laborers

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    Individuals who work outside are at increased risk for skin cancer due to excessive exposure to ultraviolet (UV) radiation. Little is known about UV exposures and sun safety practices of outdoor day laborers, who are disproportionately Hispanic. This study identified the correlates of sunburn and sun protection behaviors in a sample of male, Hispanic day laborers (n = 175). More than half of the participants (54.9%) experienced one or more sunburns when working during the past summer, and 62.9% reported having one or more symptoms of heat illness. The frequency of engaging in sun protection behaviors was suboptimal, including sunglasses use (M = 2.68, SD = 1.71), staying in the shade (M = 2.30, SD = 0.94), wearing sunscreen (M = 2.10, SD = 1.39), and wearing a wide-brimmed hat (M = 1.75, SD = 1.32), based on a 5-point scale (1 = never; 5 = always). Lower education level, higher levels of skin sensitivity to the sun, any symptom of heat illness, fewer barriers to wearing a wide-brimmed hat, and not wearing a wide-brimmed hat were associated with a greater number of sunburns. Factors associated with each sun protection behavior varied. Implications and directions for future research are discussed

    Pediatric Patient-Reported Outcome Instruments for Research to Support Medical Product Labeling: Report of the ISPOR Good Research Practices for the Assessment of Patient-Reported Outcomes in Children and Adolescents Task Force

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    Pediatric Patient-Reported Outcome Instruments for Research to Support Medical Product Labeling: Report of the ISPOR Good Research Practices for the Assessment of Patient-Reported Outcomes in Children and Adolescents Task Force Abstract. Patient-reported outcome (PRO) instruments for children and adolescents are often included in clinical trials with the intention of collecting data to support claims in a medical product label. The purpose of the current task force report is to recommend good practices for pediatric PRO research that is conducted to inform regulatory decision making and support claims made in medical product labeling. The recommendations are based on the consensus of an interdisciplinary group of researchers who were assembled for a task force associated with the International Society for Pharmacoeconomics and Outcomes Research (ISPOR). In those areas in which supporting evidence is limited or in which general principles may not apply to every situation, this task force report identifies factors to consider when making decisions about the design and use of pediatric PRO instruments, while highlighting issues that require further research. Five good research practices are discussed: 1) Consider developmental differences and determine age-based criteria for PRO administration: Four age groups are discussed on the basis of previous research

    Sources of work-related psychological distress experienced by UK-wide foundation and junior doctors: a qualitative study

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    Objectives: This paper reports findings exploring work cultures, contexts and conditions associated with psychological distress in foundation and junior doctors. Design: Qualitative study using in-depth interviews with 21 junior doctor participants. The interviews were audio-recorded, transcribed, anonymised and imported into NVivo V.11 to facilitate data management. Data were analysed using a thematic analysis employing the constant comparative method. Setting: NHS in England. Participants: A purposive sample of 16 female and five male junior doctor junior doctor participants who self-identified as having stress, distress, anxiety, depression and suicidal thoughts, or having attempted to kill themselves. Results: Analysis reported four key themes: (1) workload and working conditions; (2) toxic work cultures—including abuse and bullying, sexism and racism, culture of blaming and shaming; (3) lack of support; (4) stigma and a perceived need to appear invulnerable. Conclusion: This study highlights the need for future solutions and interventions targeted at improving work cultures and conditions. There needs to be greater recognition of the components and cumulative effects of potentially toxic workplaces and stressors intrinsic to the work of junior doctors, such as the stress of managing high workloads and lack of access to clinical and emotional support. A cultural shift is needed within medicine to more supportive and compassionate leadership and work environments, and a zero-tolerance approach to bullying, harassment and discrimination

    Transition from Persistent to Anti-Persistent Correlations in Postural Sway Indicates Velocity-Based Control

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    The displacement of the center-of-pressure (COP) during quiet stance has often been accounted for by the control of COP position dynamics. In this paper, we discuss the conclusions drawn from previous analyses of COP dynamics using fractal-related methods. On the basis of some methodological clarification and the analysis of experimental data using stabilogram diffusion analysis, detrended fluctuation analysis, and an improved version of spectral analysis, we show that COP velocity is typically bounded between upper and lower limits. We argue that the hypothesis of an intermittent velocity-based control of posture is more relevant than position-based control. A simple model for COP velocity dynamics, based on a bounded correlated random walk, reproduces the main statistical signatures evidenced in the experimental series. The implications of these results are discussed

    Isolation and Characterization of New Leptospira Genotypes from Patients in Mayotte (Indian Ocean)

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    Leptospirosis has been recognized as an increasing public health problem affecting poor people from developing countries and tropical regions. However, the epidemiology of leptospirosis remains poorly understood in remote parts of the world. In this study of patients from the island of Mayotte, we isolated 22 strains from the blood of patients during the acute phase of illness. The pathogenic Leptospira strains were characterized by serology and various molecular typing methods. Based on serological data, serogroup Mini appears to be the dominant cause of leptospirosis in Mayotte. Further molecular characterization of these isolates allowed the identification of 10 pathogenic Leptospira genotypes that could correspond to previously unknown serovars. Further progress in our understanding of the epidemiology of Leptospira circulating genotypes in highly endemic regions should contribute to the development of novel strategies for the diagnosis and prevention of this neglected emerging disease

    Phase 1 Study of Two Merozoite Surface Protein 1 (MSP1(42)) Vaccines for Plasmodium falciparum Malaria

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    OBJECTIVES: To assess the safety and immunogenicity of two vaccines, MSP1(42)-FVO/Alhydrogel and MSP1(42)-3D7/Alhydrogel, targeting blood-stage Plasmodium falciparum parasites. DESIGN: A Phase 1 open-label, dose-escalating study. SETTING: Quintiles Phase 1 Services, Lenexa, Kansas between July 2004 and November 2005. PARTICIPANTS: Sixty healthy malaria-naïve volunteers 18–48 y of age. INTERVENTIONS: The C-terminal 42-kDa region of merozoite surface protein 1 (MSP1(42)) corresponding to the two allelic forms present in FVO and 3D7 P. falciparum lines were expressed in Escherichia coli, refolded, purified, and formulated on Alhydrogel (aluminum hydroxide). For each vaccine, volunteers in each of three dose cohorts (5, 20, and 80 μg) were vaccinated at 0, 28, and 180 d. Volunteers were followed for 1 y. OUTCOME MEASURES: The safety of MSP1(42)-FVO/Alhydrogel and MSP1(42)-3D7/Alhydrogel was assessed. The antibody response to each vaccine was measured by reactivity to homologous and heterologous MSP1(42), MSP1(19), and MSP1(33) recombinant proteins and recognition of FVO and 3D7 parasites. RESULTS: Anti-MSP1(42) antibodies were detected by ELISA in 20/27 (74%) and 22/27 (81%) volunteers receiving three vaccinations of MSP1(42)-FVO/Alhydrogel or MSP1(42)-3D7/Alhydrogel, respectively. Regardless of the vaccine, the antibodies were cross-reactive to both MSP1(42)-FVO and MSP1(42)-3D7 proteins. The majority of the antibody response targeted the C-terminal 19-kDa domain of MSP1(42), although low-level antibodies to the N-terminal 33-kDa domain of MSP1(42) were also detected. Immunofluorescence microscopy of sera from the volunteers demonstrated reactivity with both FVO and 3D7 P. falciparum schizonts and free merozoites. Minimal in vitro growth inhibition of FVO or 3D7 parasites by purified IgG from the sera of the vaccinees was observed. CONCLUSIONS: The MSP1(42)/Alhydrogel vaccines were safe and well tolerated but not sufficiently immunogenic to generate a biologic effect in vitro. Addition of immunostimulants to the Alhydrogel formulation to elicit higher vaccine-induced responses in humans may be required for an effective vaccine

    IP-10-Mediated T Cell Homing Promotes Cerebral Inflammation over Splenic Immunity to Malaria Infection

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    Plasmodium falciparum malaria causes 660 million clinical cases with over 2 million deaths each year. Acquired host immunity limits the clinical impact of malaria infection and provides protection against parasite replication. Experimental evidence indicates that cell-mediated immune responses also result in detrimental inflammation and contribute to severe disease induction. In both humans and mice, the spleen is a crucial organ involved in blood stage malaria clearance, while organ-specific disease appears to be associated with sequestration of parasitized erythrocytes in vascular beds and subsequent recruitment of inflammatory leukocytes. Using a rodent model of cerebral malaria, we have previously found that the majority of T lymphocytes in intravascular infiltrates of cerebral malaria-affected mice express the chemokine receptor CXCR3. Here we investigated the effect of IP-10 blockade in the development of experimental cerebral malaria and the induction of splenic anti-parasite immunity. We found that specific neutralization of IP-10 over the course of infection and genetic deletion of this chemokine in knockout mice reduces cerebral intravascular inflammation and is sufficient to protect P. berghei ANKA-infected mice from fatality. Furthermore, our results demonstrate that lack of IP-10 during infection significantly reduces peripheral parasitemia. The increased resistance to infection observed in the absence of IP-10-mediated cell trafficking was associated with retention and subsequent expansion of parasite-specific T cells in spleens of infected animals, which appears to be advantageous for the control of parasite burden. Thus, our results demonstrate that modulating homing of cellular immune responses to malaria is critical for reaching a balance between protective immunity and immunopathogenesis

    A Policy-into-Practice Intervention to Increase the Uptake of Evidence-Based Management of Low Back Pain in Primary Care: A Prospective Cohort Study

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    BACKGROUND: Persistent non-specific low back pain (nsLBP) is poorly understood by the general community, by educators, researchers and health professionals, making effective care problematic. This study evaluated the effectiveness of a policy-into-practice intervention developed for primary care physicians (PCPs). METHODS: To encourage PCPs to adopt practical evidence-based approaches and facilitate time-efficient, integrated management of patients with nsLBP, we developed an interdisciplinary evidence-based, practical pain education program (gPEP) based on a contemporary biopsychosocial framework. One hundred and twenty six PCPs from primary care settings in Western Australia were recruited. PCPs participated in a 6.5-hour gPEP. Self-report measures recorded at baseline and at 2 months post-intervention included PCPs' attitudes, beliefs (modified Health Care Providers Pain and Impairment Relationship Scale (HC-PAIRS), evidence-based clinical practices (knowledge and skills regarding nsLBP management: 5-point Likert scale with 1  =  nil and 5  =  excellent) and practice behaviours (recommendations based on a patient vignette; 5-point Likert scale). RESULTS: Ninety one PCPs participated (attendance rate of 72%; post-intervention response rate 88%). PCP-responders adopted more positive, guideline-consistent beliefs, evidenced by clinically significant HC-PAIRS score differences (mean change  =  -5.6±8.2, p<0.0001; 95% confidence interval: -7.6 to -3.6) and significant positive shifts on all measures of clinical knowledge and skills (p<0.0001 for all questions). Self management strategies were recommended more frequently post-intervention. The majority of responders who were guideline-inconsistent for work and bed rest recommendations (82% and 62% respectively) at pre-intervention, gave guideline-consistent responses at post-intervention. CONCLUSION: An interprofessional pain education program set within a framework that aligns health policy and practice, encourages PCPs to adopt more self-reported evidence-based attitudes, beliefs and clinical behaviours in their management of patients with nsLBP. However, further research is required to determine cost effectiveness of this approach when compared with other modes of educational delivery and to examine PCP behaviours in actual clinical practice
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