636 research outputs found

    Absolute differential positronium-formation cross sections

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    The first absolute experimental determinations of the differential cross-sections for the formation of ground-state positronium are presented for He, Ar, H2 and CO2 near 0○. Results are compared with available theories. The ratio of the differential and integrated cross-sections for the targets exposes the higher propensity for forward-emission of positronium formed from He and H2

    History on trial: evaluating learning outcomes through audit and accreditation in a national standards environment

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    This paper uses a trial audit of history programs undertaken in 2011-2012 to explore issues surrounding the attainment of Threshold Learning Outcomes (TLOs) in an emerging Australian national standards environment for the discipline of history. The audit sought to ascertain whether an accreditation process managed by the discipline under the auspices of the Australian Historical Association (AHA) could be based on a limited-intervention, “light-touch” approach to assessing attainment of the TLOs. The results of the audit show that successful proof of TLO attainment would only be possible with more active intervention into existing history majors and courses. Assessments across all levels of history teaching would have to be designed, undertaken, and marked using a rubric matched to the TLOs. It proved unrealistic to expect students to demonstrate acquisition of the TLOs from existing teaching and assessment practices. The failure of the “light-touch” audit process indicates that demonstrating student attainment under a national standards regime would require fundamental redevelopment of the curriculum. With standards-based approaches to teaching and learning emerging as international phenomena, this case study resonates beyond Australia and the discipline under investigation.Sean Brawley, Jennifer Clark, Chris Dixon, Lisa Ford, Erik Nielsen, Shawn Ross, Stuart Upto

    Resonant scattering of positronium as a quasifree electron

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    In order to clarify the physics underlying the observations of the electronlike behavior of positronium (Ps) and its resonant scattering from CO2, we have measured the Ps+N2 total cross section and found it also to exhibit significant structure. Analysis of the resonances reveals that Ps is distorted in the collisions and classical trajectory Monte Carlo calculations indicate that the electron is on average closer to the target than the positron, which may in turn bind resonantly to the ensuing temporary negative ion. This description of the nature of Ps resonances agrees with long-standing theoretical predictions

    The Effects of Ketone Supplementation on Recovery in Collegiate Male Soccer Players: Pilot Trial

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    Complete Break Up of Ortho Positronium (Ps)- Hydrogenic ion System

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    The dynamics of the complete breakup process in an Ortho Ps - He+ system including electron loss to the continuum (ELC) is studied where both the projectile and the target get ionized. The process is essentially a four body problem and the present model takes account of the two centre effect on the electron ejected from the Ps atom which is crucial for a proper description of the ELC phenomena. The calculations are performed in the framework of Coulomb Distorted Eikonal Approximation. The exchange effect between the target and the projectile electron is taken into account in a consistent manner. The proper asymptotic 3-body boundary condition for this ionization process is also satisfied in the present model. A distinct broad ELC peak is noted in the fully differential cross sections (5DCS) for the Ps electron corroborating qualitatively the experiment for the Ps - He system. Both the dynamics of the ELC from the Ps and the ejected electron from the target He+ in the FDCS are studied using coplanar geometry. Interesting features are noted in the FDCS for both the electrons belonging to the target and the projectile.Comment: 14 pages,7 figure

    Efficacy of Online Training for Improving Camp Staff Competency

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    Preparing competent staff is a critical issue within the camp community. This quasi-experimental study examined the effectiveness of an online course for improving staff competency in camp healthcare practices among college-aged camp staff and a comparison group (N = 55). We hypothesized that working in camp would increase competency test scores due to opportunities for staff to experientially apply knowledge learned online. Hierarchical linear modeling was used to analyse the cross-level effects of a between-individuals factor (assignment to experimental or comparison group) and within-individual effects of time (pre-test, post-test #1, and post-test #2) on online course test scores. At post-test #2, the difference in average test scores between groups was ~30 points, with the treatment group scoring lower on average than the comparison group. Factors that may have influenced these findings are explored, including fatigue and the limited durability of online learning. Recommendations for research and practice are discussed

    Cohesion, team mental models, and collective efficacy: Towards an integrated framework of team dynamics in sport

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    A nomological network on team dynamics in sports consisting of a multi-framework perspective is introduced and tested. The aim was to explore the interrelationship among cohesion, team mental models (TMM), collective-efficacy (CE), and perceived performance potential (PPP). Three hundred and forty college-aged soccer players representing 17 different teams (8 female and 9 male) participated in the study. They responded to surveys on team cohesion, TMM, CE and PPP. Results are congruent with the theoretical conceptualization of a parsimonious view of team dynamics in sports. Specifically, cohesion was found to be an exogenous variable predicting both TMM and CE beliefs. TMM and CE were correlated and predicted PPP, which in turn accounted for 59% of the variance of objective performance scores as measured by teams’ season record. From a theoretical standpoint, findings resulted in a parsimonious view of team dynamics, which may represent an initial step towards clarifying the epistemological roots and nomological network of various team-level properties. From an applied standpoint, results suggest that team expertise starts with the establishment of team cohesion. Following the establishment of cohesiveness, teammates are able to advance team-related schemas and a collective sense of confidence. Limitations and key directions for future research are outlined

    Better Together: Expanding Rural Partnerships to Support Families

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    Chronic shortages of health, social service, and mental health professionals in rural areas necessitate creative partnerships in support of families. Cooperative extension professionals in Family and Consumer Sciences and community health nurses are introduced as trusted professionals in rural communities who can bring critical skills to human services teams. Multidisciplinary prevention programs offer particularly good contexts for county extension educators and community health nurses to work in collaboration with social workers. The case of grandparents raising grandchildren illustrates the critical roles that can be filled by professionals in these two fields to extend the reach of family support programs
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