522 research outputs found

    Changes In Jump Performance And Dynamic Balance At High Terrestrial Altitude

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    The purpose of this study was to examine the effects of altitude on dynamic balance and jump performance of a controlled landing during a 12-day high altitude trek. Following a two-legged jump, time to stabilization (5% of body mass for 0.5 s), maximum power, and jump height were measured in 11 participants using a portable force platform at sea level (BL), 3619 m (C1), and 5140 m (C3). Jump performance significantly decreased at C1 and C3 compared to BL (P=0.001). There were no significant differences found in time to stabilization and maximum power with increasing altitude. The present findings indicate that jump performance is significantly decreased with increasing altitude. However, dynamic balance and jump power remain unaffected

    An interdisciplinary examination of attentional focus strategies used during running gait retraining

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    The aim was to investigate the biomechanical, physiological and perceptual responses to different motor learning strategies derived to elicit a flatter foot contact. Twenty‐eight, rearfoot‐striking recreational runners (age 24.9±2.8 years; body mass 78.8±13.6 kg; height 1.79±0.09 m) were matched by age, mass and height and assigned to one verbal cue group: internal focus of attention (IF), external focus of attention (EF) and a clinically derived condition (CLIN) incorporating an IF followed by an EF statement. Participants completed two treadmill runs at 10 km.h‐1 for six minutes each: normal running (control) followed by the experimental condition (IF, EF or CLIN). Lower limb kinematics, oxygen consumption (V̇02 )and central and peripheral ratings of perceived exertion (RPE) were recorded for each run. Compared to the control condition, foot angle was reduced in the IF (difference=5.86°, d=2.58) and CLIN (difference=3.00°, d=1.31) conditions, but unchanged in the EF (difference=0.33°, d=0.14) condition, whilst greater knee flexion at initial contact in the EF and CLIN conditions was observed (difference=‐5.19°, d=1.97; difference=‐3.66°, d=1.39, respectively). A higher V̇02 was observed in the CLIN condition (difference=‐4.56 ml.kg‐1.min‐1, d=2.29), but unchanged in the IF (difference = ‐1.87 ml.kg‐1.min‐1, d=0.94) and EF conditions (difference=‐0.37 ml.kg‐1.min‐1, d=0.19). All experimental conditions increased central and peripheral RPE (difference=‐1.08, d=0.54 and difference=‐2.39, d=1.33 respectively). Providing gait retraining instructions using an internally directed focus of attention was the most effective way to target specific changes in running kinematics, with no detrimental effect on physiological responses. Yet, perceptual effort responses increased regardless of the type of cue provided

    UK-Wide Surveillance of Neurological and Neuropsychiatric Complications of COVID-19: The First 153 Patients

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    Background: Increasingly neurological complications of COVID-19 are identified, mostly in small series. Larger studies have been limited by both geography and specialty. Consequently, the breadth of complications is not represented. Comprehensive characterization of clinical syndromes is critical to rationally select and evaluate potential therapies. / Methods: During the exponential pandemic phase, we developed coordinated online portals for rapid notification across the spectrum of major UK neuroscience bodies, representing neurology, stroke, psychiatry, and intensive care. Evidence of infection and clinical case definitions were applied prospectively. Cases were compared to overall Government Public Health COVID-19 reporting. / Findings: Within three weeks, 153 cases were notified, both geographically and temporally representative of overall COVID-19 Public Health reports. Median (range) age was 71 (23-94) years. 77 (62%) had a cerebrovascular event: 57 (74%) ischemic strokes, nine (12%) intracerebral hemorrhages, and one CNS vasculitis. The second most common group were 39 (31%) who had altered mental status, including 16 (41%) with encephalopathy of whom seven (44%) had encephalitis. The remaining 23 (59%) had a psychiatric diagnosis of whom 21 (92%) were new diagnoses; including ten (43%) with psychosis, six (26%) neurocognitive (dementia-like) syndrome, and 4 (17%) an affective disorder. Cerebrovascular events predominated in older patients. Conversely, altered mental status, whilst present in all ages, had disproportionate representation in the young. / Interpretation: This is the first nationwide, cross-specialty surveillance study of acute complications of COVID-19 in the nervous system. Alteration in mental status was common, reflecting encephalopathy/encephalitis and primary psychiatric diagnoses, often in young patients. These data provide valuable and timely information urgently needed by clinicians, researchers, and funders to inform immediate steps in COVID-19 neuroscience research and health policy throughout the areas of neurology and neuropsychiatry

    Autoimmune hemolytic anemia occurred prior to evident nephropathy in a patient with chronic hepatitis C virus infection: case report

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    BACKGROUND: Renal involvement in patients with chronic hepatitis C virus infection has been suggested to be due to a variety of immunological processes. However, the precise mechanism by which the kidneys are damaged in these patients is still unclear. CASE PRESENTATION: A 66 year old man presented with the sudden onset of autoimmune hemolytic anemia. Concomitant with a worsening of hemolysis, his initially mild proteinuria and hemoglobinuria progressed. On admission, laboratory tests revealed that he was positive for hepatitis C virus in his blood, though his liver function tests were all normal. The patient displayed cryoglobulinemia and hypocomplementemia with cold activation, and exhibited a biological false positive of syphilic test. Renal biopsy specimens showed signs of immune complex type nephropathy with hemosiderin deposition in the tubular epithelial cells. CONCLUSIONS: The renal histological findings in this case are consistent with the deposition of immune complexes and hemolytic products, which might have occurred as a result of the patient's underlying autoimmune imbalance, autoimmune hemolytic anemia, and chronic hepatitis C virus infection

    UK-Wide Surveillance of Neurological and Neuropsychiatric Complications of COVID-19: The First 153 Patients

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    Background: Increasingly neurological complications of COVID-19 are identified, mostly in small series. Larger studies have been limited by both geography and specialty.Consequently, the breadth of complications is not represented. Comprehensive characterization of clinical syndromes is critical to rationally select and evaluate potential therapies.Methods: During the exponential pandemic phase, we developed coordinated online portals for rapid notification across the spectrum of major UK neuroscience bodies, representing neurology, stroke, psychiatry, and intensive care. Evidence of infection and clinical case definitions were applied prospectively. Cases were compared to overall Government Public Health COVID-19 reporting.Findings: Within three weeks, 153 cases were notified, both geographically and temporally representative of overall COVID-19 Public Health reports. Median (range) age was 71 (23-94) years. 77 (62%) had a cerebrovascular event: 57 (74%) ischemic strokes, nine (12%) intracerebral hemorrhages, and one CNS vasculitis.The second most common group were 39 (31%) who had altered mental status, including 16 (41%) with encephalopathy of whom seven (44%) had encephalitis. The remaining 23 (59%) had a psychiatric diagnosis of whom 21 (92%) were new diagnoses; including ten (43%) with psychosis, six (26%) neurocognitive (dementia-like) syndrome, and 4 (17%) an affective disorder. Cerebrovascular events predominated in older patients. Conversely, altered mental status, whilst present in all ages, had disproportionate representation in the young.Interpretation: This is the first nationwide, cross-specialty surveillance study of acute complications of COVID-19 in the nervous system. Alteration in mental status was common, reflecting encephalopathy/encephalitis and primary psychiatric diagnoses, often in young patients.These data provide valuable and timely information urgently needed by clinicians, researchers, and funders to inform immediate steps in COVID-19 neuroscience research and health policy throughout the areas of neurology and neuropsychiatry

    Self-assembly, Self-organization, Nanotechnology and vitalism

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    International audienceOver the past decades, self-assembly has attracted a lot of research attention and transformed the relations between chemistry, materials science and biology. The paper explores the impact of the current interest in self-assembly techniques on the traditional debate over the nature of life. The first section describes three different research programs of self-assembly in nanotechnology in order to characterize their metaphysical implications: -1- Hybridization ( using the building blocks of living systems for making devices and machines) ; -2- Biomimetics (making artifacts mimicking nature); -3- Integration (a composite of the two previous strategies). The second section focused on the elusive boundary between selfassembly and self-organization tries to map out the various positions adopted by the promoters of self-assembly on the issue of vitalism
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