655 research outputs found
Fermi surface, possible unconventional fermions, and unusually robust resistive critical fields in the chiral-structured superconductor AuBe
The noncentrosymmetric superconductor (NCS) AuBe is investigated using a
variety of thermodynamic and resistive probes in magnetic fields of up to 65~T
and temperatures down to 0.3~K. Despite the polycrystalline nature of the
samples, the observation of a complex series of de Haas-van Alphen (dHvA)
oscillations has allowed the calculated bandstructure for AuBe to be validated.
This permits a variety of BCS parameters describing the superconductivity to be
estimated, despite the complexity of the measured Fermi surface. In addition,
AuBe displays a nonstandard field dependence of the phase of dHvA oscillations
associated with a band thought to host unconventional fermions in this chiral
lattice. This result demonstrates the power of the dHvA effect to establish the
properties of a single band despite the presence of other electronic bands with
a larger density of states, even in polycrystalline samples. In common with
several other NCSs, we find that the resistive upper critical field exceeds
that measured by heat capacity and magnetization by a considerable factor. We
suggest that our data exclude mechanisms for such an effect associated with
disorder, implying that topologically protected superconducting surface states
may be involved
Physical activity screening to recruit inactive randomized controlled trial participants: how much is too much?
Citation: Vandelanotte, C., Stanton, R., Rebar, A. L., Van Itallie, A. K., Caperchione, C. M., Duncan, M. J., . . . Kolt, G. S. (2015). Physical activity screening to recruit inactive randomized controlled trial participants: how much is too much? Trials, 16, 3. doi:10.1186/s13063-015-0976-7Screening physical activity levels is common in trials to increase physical activity in inactive populations. Commonly applied single-item screening tools might not always be effective in identifying those who are inactive. We applied the more extensive Active Australia Survey to identify inactive people among those who had initially been misclassified as too active using a single-item measure. Those enrolled after the Active Australia Survey screening had significantly higher physical activity levels at subsequent baseline assessment. Thus, more extensive screening measures might result in the inclusion of participants who would otherwise be excluded, possibly introducing unwanted bias
Automatic evaluation stimuli - the most frequently used words to describe physical activity and the pleasantness of physical activity
Physical activity is partially regulated by non-conscious processes including automatic evaluations - the spontaneous affective reactions we have to physical activity that lead us to approach or avoid physical activity opportunities. A sound understanding of which words best represent the concepts of physical activity and pleasantness (as associated with physical activity) is needed to improve the measurement of automatic evaluations and related constructs (e.g., automatic self-schemas, attentional biases). The first aim of this study was to establish population-level evidence of the most common word stimuli for physical activity and pleasantness. Given that response latency measures have been applied to assess automatic evaluations of physical activity and exercise, the second aim was to determine whether people use the same behavior and pleasant descriptors for physical activity and exercise. Australian adults (N = 1,318; 54.3% women; 48.9% aged 55 years or older) were randomly assigned to one of two groups, through a computer-generated 1:1 ratio allocation, to be asked to list either five behaviors and pleasant descriptors of physical activity (n = 686) or of exercise (n = 632). The words were independently coded twice as to whether they were novel words or the same as another (i.e., same stem or same meaning). Intercoder reliability varied between moderate and strong (agreement = 50.1 to 97.8%; κ = 0.48 to 0.82). A list of the 20 most common behavior and pleasantness words were established based on how many people reported them, weighted by the ranking (1-5) people gave them. The words people described as physical activity were mostly the same as those people used to describe exercise. The most common behavior words were 'walking,' 'running,' 'swimming,' 'bike riding,' and 'gardening'; and the most common pleasant descriptor words were 'relaxing,' 'happiness,' 'enjoyment,' 'exhilarating,' 'exhausting,' and 'good.' These sets of stimuli can be utilized as resources for response latency measurement tasks of automatic evaluations and for tools to enhance automatic evaluations of physical activity in evaluative conditioning tasks.Amanda L. Rebar, Stephanie Schoeppe, Stephanie J. Alley, Camille E. Short, James A. Dimmock, Ben Jackson, David E. Conroy, Ryan E. Rhodes and Corneel Vandelanott
The effect of men's body attitudes and motivation for gym attendance
The current study integrates men's body attitudes with implicitly and explicitly measured motivation to investigate the role of these factors in predicting gym attendance. Male participants (N = 99) who regularly attended a gym were recruited to participate in an online questionnaire. Participants completed implicit and explicit measures of motivation, explicitly-measured men's body attitudes, and reported the average number of gym visits per week. Attitudes related to body fat and explicitly-measured autonomous motivation significantly predicted typical gym attendance. Implicitly-measured motivation significantly and negatively predicted gym attendance. Results indicate some support for a dual-systems account of gym attendance. Men's body attitudes and autonomous motivation influences gym attendance; however, implicitly-measured motivation showed antagonistic effects. While individuals may explicitly state their autonomous motivation for gym attendance, attendance may be influenced at the explicit level. Health and fitness professionals may improve gym attendance by focusing on people's reasons for attending a gym, facilitating autonomous motivation in clients, and minimising the influence of controlled reasons for exercise
The subjective experience of habit captured by self-report indexes may lead to inaccuracies in the measurement of habitual action
Commentary on Gardner, B. (2014). A review and analysis of the use of ‘habit’ inunderstanding, predicting and influencing health-related behaviour
Making the link between critical appraisal, thinking and analysis
Nursing has become an all-graduate profession; as such, student nurses must develop their skills of critical analysis. The need to develop critical analytical thinking has been identified as the single most important skill in undergraduate education and reaching the academic requirements of level six study. In degree-level healthcare programmes, students are frequently asked to complete a structured critical appraisal of research. This paper examines how critical appraisal activities can be an opportunity for students to develop transferable critical thinking skills. Critical appraisal teaches objectivity, reflection, logic and discipline, which encourage students to think critically in both theory and practice.N/
Physical activity and mental health; it is more than just a prescription
Most mental health and physical activity research describes unidirectional causes of physical activity on mental health, and as a result, a strong evidence base is being established for the effectiveness of physical activity as a treatment for mental health issues. Given that the efficacy of physical activity prescriptions are entirely reliant on individuals’ behavioral engagement, the aim of this special issue is to draw attention to translational evidence relevant to mental health and physical activity. This issue encompasses findings from a wide array of study designs (e.g., reviews, qualitative investigations, correlations studies, trial descriptions, pilot trial findings) of populations from high, middle, and low-income countries with clinical and non-clinical mental health issues. The evidence illustrates that people with mental health issues have unique facilitators and barriers to physical activity that are not accounted for within behavior change theories or interventions for the general population. Within this issue, you will find evidence of how mental health issues impact physical activity behavior change processes as well as examples of how context and person factors may moderate physical activity intervention efficacy amongst these populations. Informed by this evidence, we are calling for future research to investigate acceptability, maintenance, scalability, and generalizability of physical activity interventions for people with mental health issues. This future research will need to account for the unique barriers and facilitators of the population, be theoretically sound, apply to unique contexts, and adapt to dynamic change processes (including engagement and maintenance). © 2017 Elsevier Lt
Testing a model of successful aging in a cohort of masters swimmers
Geard, DE ORCiD: 0000-0002-4292-9278; Rebar, A ORCiD: 0000-0003-3164-993XDue to their high physical functioning, masters athletes are regularly proposed to exemplify successful aging. However, successful aging research on masters athletes has never been undertaken using a multidimensional successful aging model. To determine the best model for future successful aging research on masters athletes, we had masters swimmers (N = 169, M age = 57.4 years, 61% women) self-report subjective successful aging, and physical, psychological, cognitive, and social functioning. Using this data we tested one hypothesized and three alternative successful aging models. The hypothesized model fit the data best (-2LL = 2052.32, AIC = 1717) with physical (β = 0.31, SE = 0.11), psychological (β = 0.25, SE = 0.11), and social (β = 1.20, SE = 0.63) functioning factors significantly loading onto a higher order successful aging latent factor. Successful aging should be conceptualized as a multidimensional phenomenon in future masters athlete research. © 2018 Human Kinetics, Inc
ADAM17-dependent proteolysis of L-selectin promotes early clonal expansion of cytotoxic T cells
L-selectin on T-cells is best known as an adhesion molecule that supports recruitment of blood-borne naïve and central memory cells into lymph nodes. Proteolytic shedding of the ectodomain is thought to redirect activated T-cells from lymph nodes to sites of infection. However, we have shown that activated T-cells re-express L-selectin before lymph node egress and use L-selectin to locate to virus-infected tissues. Therefore, we considered other roles for L-selectin proteolysis during T cell activation. In this study, we used T cells expressing cleavable or non-cleavable L-selectin and determined the impact of L-selectin proteolysis on T cell activation in virus-infected mice. We confirm an essential and non-redundant role for ADAM17 in TCR-induced proteolysis of L-selectin in mouse and human T cells and show that L-selectin cleavage does not regulate T cell activation measured by CD69 or TCR internalisation. Following virus infection of mice, L-selectin proteolysis promoted early clonal expansion of cytotoxic T cells resulting in an 8-fold increase over T cells unable to cleave L-selectin. T cells unable to cleave L-selectin showed delayed proliferation in vitro which correlated with lower CD25 expression. Based on these results, we propose that ADAM17-dependent proteolysis of L-selectin should be considered a regulator of T-cell activation at sites of immune activity
Effects of a 12-Week Cycling Intervention on Successful Aging Measures in Mid-Aged Adults
Purpose: To compare the effect of 12-weeks of cycling training and competition versus recreational cycling on successful aging across physical, psychological, cognitive, and social functioning domains in mid-aged adults. Methods: Recreational cyclists were randomly assigned to an intervention (n = 13, M age = 47.18 years) and comparison (n = 13, M age = 46.91 years) group. Analysis of Covariance was used on self-reported pre-post data to determine changes across time and differences between groups on outcomes. Results: The intervention group scored higher on the role limitation due to physical problems measure of physical functioning (p = .045) and the social activity measure of social functioning (p = .008) with large effect sizes (ηp2 > .14). The remaining physical, psychological, cognitive, and social functioning measures were not significantly different (p > .05) between groups with small to medium effect sizes (ηp2 > .01 to ≤ .06). Conclusion: Cycling training and competition promotes better physical and social functioning than recreational cycling. This finding indicates that an intervention that incorporates the training and competition aspects of sport may promote positive outcomes that are above and beyond those that can be gained from participation in recreational physical activity. Objective measurements on larger samples across a broader range of sports are required to confirm and extend these findings
- …
