199 research outputs found

    Effect of sand on knee load during a single-leg jump task: Implications for injury prevention and rehabilitation programs

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    The purpose of the study was to determine potential differences in landing strategies and subsequent joint loads at the knee (knee abduction moment [KAM], anterior-posterior [AP] tibial translation, and total knee shear force) when jumping onto sand and firm ground from both a level surface and a 30-cm height. Firm ground would act as the control for the study. Seventeen subjects (age: 23.6 ± 3.7 years; body mass: 67.7 ± 10.3 kg; height: 168.5 ± 7.4 cm) performed 3 single-leg jumps on their dominant leg for each of the 4 conditions tested (ground level, sand level, ground height, and sand height). A repeated-measures design investigated the effect of sand on KAM, AP tibial translation, and total knee shear force. Data were analyzed using magnitude-based inferences and presented as percentage change with 90% confidence limits. Results indicated that sand had a clear beneficial effect on KAM, which was possibly moderate during a drop jump (30 cm) and possibly small from a level jump. Sand also had a possibly moderate beneficial effect on AP tibial translation from a level jump. The effect of sand on total knee shear force was unclear. These results suggest that sand may provide a safer alternative to firm ground when performing jump tasks commonly used in anterior cruciate ligament and patellofemoral joint injury prevention and rehabilitation programs. Sand may also allow for an accelerated rehabilitation program because jumping activities could potentially be implemented more safely at an earlier stage in the process

    Chemogenetics—A Transformational and Translational Platform

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    Neurologic disorders are frequently a result of inappropriate electrical and/or chemical signaling of neurons and glia. Ultimate remediation would necessitate reprogramming these signals. Historically, correcting neuronal and glial signaling is accomplished via drug therapy/administration, although they frequently fail to effectively and fully treat the underlying disorder. Developments in basic research have produced several new classes of potential therapeutics to directly and precisely control neuron activity at the single-cell level. We review one such technology, Designer Receptors Exclusively Activated by Designer Drugs, and suggest its potential as a powerful tool for augmenting neuronal and glial signaling and activity for basic and translational applications

    Mapping the Evolution of Optically-Generated Rotational Wavepackets in a Room Temperature Ensemble of D2_2

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    A coherent superposition of rotational states in D2_2 has been excited by nonresonant ultrafast (12 femtosecond) intense (2 ×\times 1014^{14} Wcm2^{-2}) 800 nm laser pulses leading to impulsive dynamic alignment. Field-free evolution of this rotational wavepacket has been mapped to high temporal resolution by a time-delayed pulse, initiating rapid double ionization, which is highly sensitive to the angle of orientation of the molecular axis with respect to the polarization direction, θ\theta. The detailed fractional revivals of the neutral D2_2 wavepacket as a function of θ\theta and evolution time have been observed and modelled theoretically.Comment: 4 pages, 3 figures. Accepted for publication in Phys. Rev. A. Full reference to follow.

    Atomic excitation during recollision-free ultrafast multi-electron tunnel ionization

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    Modern intense ultrafast pulsed lasers generate an electric field of sufficient strength to permit tunnel ionization of the valence electrons in atoms. This process is usually treated as a rapid succession of isolated events, in which the states of the remaining electrons are neglected. Such electronic interactions are predicted to be weak, the exception being recollision excitation and ionization caused by linearly-polarized radiation. In contrast, it has recently been suggested that intense field ionization may be accompanied by a two-stage `shake-up' reaction. Here we report a unique combination of experimental techniques that enables us to accurately measure the tunnel ionization probability for argon exposed to 50 femtosecond laser pulses. Most significantly for the current study, this measurement is independent of the optical focal geometry, equivalent to a homogenous electric field. Furthermore, circularly-polarized radiation negates recollision. The present measurements indicate that tunnel ionization results in simultaneous excitation of one or more remaining electrons through shake-up. From an atomic physics standpoint, it may be possible to induce ionization from specific states, and will influence the development of coherent attosecond XUV radiation sources. Such pulses have vital scientific and economic potential in areas such as high-resolution imaging of in-vivo cells and nanoscale XUV lithography.Comment: 17 pages, 4 figures, original format as accepted by Nature Physic

    Terminology and Classification of Muscle Injuries in Sport: The Munich Consensus Statement

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    Objective: To provide a clear terminology and classification of muscle injuries in order to facilitate effective communication among medical practitioners and development of systematic treatment strategies. Methods: Thirty native English-speaking scientists and team doctors of national and first division professional sports teams were asked to complete a questionnaire on muscle injuries to evaluate the currently used terminology of athletic muscle injury. In addition, a consensus meeting of international sports medicine experts was established to develop practical and scientific definitions of muscle injuries as well as a new and comprehensive classification system. Results: The response rate of the survey was 63%. The responses confirmed the marked variability in the use of the terminology relating to muscle injury, with the most obvious inconsistencies for the term strain. In the consensus meeting, practical and systematic terms were defined and established. In addition, a new comprehensive classification system was developed, which differentiates between four types: functional muscle disorders (type 1: overexertion-related and type 2: neuromuscular muscle disorders) describing disorders without macroscopic evidence of fibre tear and structural muscle injuries (type 3: partial tears and type 4: (sub)total tears/tendinous avulsions) with macroscopic evidence of fibre tear, that is, structural damage. Subclassifications are presented for each type. Conclusions: A consistent English terminology as well as a comprehensive classification system for athletic muscle injuries which is proven in the daily practice are presented. This will help to improve clarity of communication for diagnostic and therapeutic purposes and can serve as the basis for future comparative studies to address the continued lack of systematic information on muscle injuries in the literature. What are the new things: Consensus definitions of the terminology which is used in the field of muscle injuries as well as a new comprehensive classification system which clearly defines types of athletic muscle injuries

    Increasing condom use in heterosexual men: development of a theory-based interactive digital intervention

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    Increasing condom use to prevent sexually transmitted infections is a key public health goal. Interventions are more likely to be effective if they are theory- and evidence-based. The Behaviour Change Wheel (BCW) provides a framework for intervention development. To provide an example of how the BCW was used to develop an intervention to increase condom use in heterosexual men (the MenSS website), the steps of the BCW intervention development process were followed, incorporating evidence from the research literature and views of experts and the target population. Capability (e.g. knowledge) and motivation (e.g. beliefs about pleasure) were identified as important targets of the intervention. We devised ways to address each intervention target, including selecting interactive features and behaviour change techniques. The BCW provides a useful framework for integrating sources of evidence to inform intervention content and deciding which influences on behaviour to target

    Rethinking irrigation modernisation: Realising multiple objectives through the integration of fisheries

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    Irrigation has been, and will remain, instrumental in addressing water security (Sustainable Development Goal (SDG) 6), food insecurity (SDG 2) and poverty (SDG 1) goals. However, the global context in which irrigation takes place is changing rapidly. A call for healthier and more sustainable food systems is placing new demands on how irrigation is developed and managed. Growing pressures from competing water uses in the domestic and industrial sectors, as well increasing environmental awareness, mean irrigation is increasingly called on to perform better, delivering acceptable returns on investment and simultaneously improving food security, rural livelihoods and nutrition, as well as supporting environmental conservation. Better integration of fisheries (including aquaculture) in irrigation planning, investment and management can contribute to the modernisation of irrigation and the achievement of the multiple objectives that it is called on to deliver. A framework illustrating how fisheries can be better integrated with irrigation, and how the two can complement each other across a range of scales, from scheme to catchment and, ultimately, national level, is presented
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