2,259 research outputs found

    State-resolved measurements of single-electron capture in slow Ne7+- and Ne8+-helium collisions

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    Single-electron capture in collisions of 9 keV x q Ne8+ and Ne7+ ions with He has been studied using cold-target recoil-ion momentum spectroscopy. With an improved apparatus a longitudinal momentum resolution of 0.07 au has been achieved. This momentum component is directly proportional to the difference in the binding energy of the active electron between the final and the initial state. For the first time state- resolved differential cross sections have been determined with respect to the main quantum number, subshell level and spin state of the captured electron. A comparison with recent theoretical results for energy levels in Be-like Ne is given

    Sleep disorders, sleepiness and traffic safety: a public health menace

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    Sleep disorders are not uncommon and have been widely reported throughout the world. They have a profound impact on industrialized 24-h societies. Consequences of these problems include impaired social and recreational activities, increased human errors, loss of productivity, and elevated risk of accidents. Conditions such as acute and chronic insomnia, sleep loss, excessive sleepiness, shift-work, jet lag, narcolepsy, and sleep apnea warrant public health attention, since residual sleepiness during the day may affect performance of daily activities such as driving a car. Benzodiazepine hypnotics and zopiclone promote sleep, both having residual effects the following day including sleepiness and reduced alertness. In contrast, the non-benzodiazepine hypnotics zolpidem and zaleplon have no significant next-day residual effects when taken as recommended. Research on the effects of wakefulness-promoting drugs on driving ability is limited. Countermeasures for excessive daytime sleepiness have a limited effect. There is a need for a social awareness program to educate the public about the potential consequences of various sleep disorders such as narcolepsy, sleep apnea, shift-work-related sleep loss, and excessive daytime sleepiness in order to reduce the number of sleep-related traffic accidents.Mount Sinai School of Medicine Division of Pulmonary, Critical Care, and Sleep MedicineUniversity of Utrecht Utrecht Institute for Pharmaceutical Sciences Department of PsychopharmacologyUniversity of Toronto, and Sleep and Neuropsychiatry Institute Department of PsychiatryUniversidade Federal de São Paulo (UNIFESP) Departamento de PsicobiologiaUNIFESP, Depto. de PsicobiologiaSciEL

    Hybrid team-based learning in cardiorespiratory physiotherapy in higher education

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    Background: Today’s modern and future cardio-respiratory physiotherapist are, and will be, presented with ubiquitous and uncertain complex problems in professional life. Yet, to date, teaching approaches lacks robust scientific evidence of optimal learning to stimulate student’s active cognitive engagement of higher order skills beyond knowledge and skills transfer and are only focused on graduation. For past two decades, pedagogy recommends use of active learning strategies to enhance authentic student engagement, self-efficacy, and satisfaction. In recent years, team-based learning (TBL) is emerging as a popular student-centred active collaborative learning strategy that promotes individual and team learning in medical and allied health education. Objective: This paper reports on the design and impact of a novel “Hybrid Team-Based learning' (H-TBL) on students’ engagement and perceptions of their learning experience in a Year 2 undergraduate physiotherapy Cohorts. Study Design: A retrospective study. Methods: In 2019, a keynote lecture on Chronic Obstructive Pulmonary Disease (COPD) was taught using novel “hybrid team-based learning' (H-TBL) comprising phases 1-4, delivered in two sessions (COPD1 and 2) to our year two (n=136), undergraduate physiotherapy students. Results: Of 136 students, 82% engaged in Phase 1, 80% attended the Phase 2 and 3 of COPD 2 session and 74% engaged in phase 4. 72% provided their perception on their learning experience. Conclusion: Majority of our students valued the learning experience in H-TBL design. This study confers that H-TBL supports students’ active engagement and self- efficacy. Future randomized studies are mandated to explore the validity and specificity of H-TBL in physiotherapy curriculum

    A multiscale active structural model of the arterial wall accounting for smooth muscle dynamics

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    Arterial wall dynamics arise from the synergy of passive mechano-elastic properties of the vascular tissue and the active contractile behaviour of smooth muscle cells (SMCs) that form the media layer of vessels. We have developed a computational framework that incorporates both these components to account for vascular responses to mechanical and pharmacological stimuli. To validate the proposed framework and demonstrate its potential for testing hypotheses on the pathogenesis of vascular disease, we have employed a number of pharmacological probes that modulate the arterial wall contractile machinery by selectively inhibiting a range of intracellular signalling pathways. Experimental probes used on ring segments from the rabbit central ear artery are: phenylephrine, a selective α1-adrenergic receptor agonist that induces vasoconstriction; cyclopiazonic acid (CPA), a specific inhibitor of sarcoplasmic/endoplasmic reticulum Ca2+-ATPase; and ryanodine, a diterpenoid that modulates Ca2+ release from the sarcoplasmic reticulum. These interventions were able to delineate the role of membrane versus intracellular signalling, previously identified as main factors in smooth muscle contraction and the generation of vessel tone. Each SMC was modelled by a system of nonlinear differential equations that account for intracellular ionic signalling, and in particular Ca2+ dynamics. Cytosolic Ca2+ concentrations formed the catalytic input to a cross-bridge kinetics model. Contractile output from these cellular components forms the input to the finite-element model of the arterial rings under isometric conditions that reproduces the experimental conditions. The model does not account for the role of the endothelium, as the nitric oxide production was suppressed by the action of L-NAME, and also due to the absence of shear stress on the arterial ring, as the experimental set-up did not involve flow. Simulations generated by the integrated model closely matched experimental observations qualitatively, as well as quantitatively within a range of physiological parametric values. The model also illustrated how increased intercellular coupling led to smooth muscle coordination and the genesis of vascular tone

    Effective critical behaviour of diluted Heisenberg-like magnets

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    In agreement with the Harris criterion, asymptotic critical exponents of three-dimensional (3d) Heisenberg-like magnets are not influenced by weak quenched dilution of non-magnetic component. However, often in the experimental studies of corresponding systems concentration- and temperature-dependent exponents are found with values differing from those of the 3d Heisenberg model. In our study, we use the field--theoretical renormalization group approach to explain this observation and to calculate the effective critical exponents of weakly diluted quenched Heisenberg-like magnet. Being non-universal, these exponents change with distance to the critical point TcT_c as observed experimentally. In the asymptotic limit (at TcT_c) they equal to the critical exponents of the pure 3d Heisenberg magnet as predicted by the Harris criterion.Comment: 15 pages, 4 figure
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