A search for double beta decays of tin isotopes with enhanced sensitivity

A search for the various double beta decay modes of 124Sn and 112Sn has been performed on 75 kg.days of data. New half-life limits for excited states in 124Sn have been obtained including a lower limit for the decay into the first excited 2+ state of 124Te of T_half > 0.87e20 yrs (90% CL) and into the first excited 0+ state of T_half > 1.08e20 yrs (90% CL). Ground state and excited state transitions of 112Sn have also been experimentally explored. A limit for the 2 neutrino double electron capture of T_half > 1.8e19 yrs (90% CL) is obtained. The non-observation of de-excitation gammas from the 0+ at 1888.5keV results in a lower half-life limit on the 0 neutrino double electron capture decay of 112Sn of T_half > 0.8e19 yrs (90% CL), despite a possible resonant enhancement of the decay rate due to degenerated states.Comment: 6 pages, 7 figures, updated analysis and tex

Spatial Distribution of Flying Southern Pine Beetle (Coleoptera:Scolytidae) and the Predator ThanasUnus dubius (Coleoptera:Cleridae)

Spatial dispersion patterns of flying southern pine beetles, Dendroctonus frontalis Zimm., and the clerid predator Thanasimus dubius (F.) were determined within 3 natural infestations of southern pine beetle (SPB) in eastern Texas using grids of sticky traps. There was significant positive association of the 2 insects throughout the trapping grids, although aerial population densities of the clerid were inversely related to aerial densities of SPB. Aggregation patterns were quantified using the index of patchiness (lP) and the regressions of mean crowding (m) on mean density (m). Both methods showed a highly clumped pattern for both beetle species. SPB density in the infestations was positively associated with the daily rate of tree attack by the beetles, but the degree of population aggregation in the infestations was inversely related to the daily rate of tree attack. Although densities of the two species did not follow the same trends among the 3 infestations, the degree of aggregation did (i.e., SPB was most highly aggregated in the location where T. dubius was most highly aggregated) and Lloyd\u27s index of interspecific patchiness indicated overlapping aggregate distributions. A kairomonal response mechanism for T. dubius, and SPB co-aggregation within infestations is hypothesized

Enhancing education activities for health care trainees and professionals using audience response systems: a systematic review

Introduction: This review examines the effect of incorporating clickers within practice-based education sessions on educational outcomes of health care trainees and professionals. Methods: A systematic literature review was conducted on primary research studies published up until August 2014. Studies were identified by database searching (Ovid MEDLINE, EMBASE, CINAHL, Scopus, Web of Science, and PsychInfo), citation searching, and reference list checking. Studies were restricted to those evaluating the use of clickers as part of the provision of postgraduate education or continuing education programs and were evaluated according to Kirkpatrick's four levels of training evaluation (reaction, learning, behavior, and results). Results: Seventeen studies met the eligibility criteria. Twelve studies assessed learner and/or speaker reactions, with feedback overwhelmingly positive in all studies. Reported learner benefits included increased attentiveness, engagement, and enjoyment of presentations. Speakers reported that using clickers engaged the audience and assisted in assessing audience comprehension. Eight studies assessed learning outcomes. Higher level evidence obtained from four randomized studies demonstrated significant improvements in knowledge with the use of clickers compared with traditional didactic presentations, but no differences when clickers were compared with an interactive lecture with integrated questions. No studies adequately assessed higher level educational outcomes (behavior and results). Conclusion: Although the use of clickers improves learning environment and learner satisfaction, the limited high-quality data for improvements in learning and behavior outcomes make it uncertain whether the acceptance and implementation of clickers within routine practice-based education programs are warranted at this stage.Luke E. Grzeskowiak, Alice E. Thomas, Josephine To, Adam J. Phillips, Emily Reev

Applying the integrated trans-contextual model to mathematics activities in the classroom and homework behavior and attainment

The aim of the present study was to test hypotheses of the trans-contextual model. We predicted relations between perceived autonomy support, autonomous motivation toward mathematics learning activities in an educational context, autonomous motivation toward mathematics homework in an out-of-school context, social-cognitive variables and intentions for future engagement in mathematics homework, and mathematics homework outcomes. Secondary school students completed measures of perceived autonomy support from teachers and autonomous motivation for in-class mathematics activities; measures of autonomous motivation, social-cognitive variables, and intentions for out-of-school mathematics homework; and follow-up measures of students' mathematics homework outcomes: self-reported homework engagement and actual homework grades. Perceived autonomy support was related to autonomous motivation toward in-class mathematics activities. There were trans-contextual effects of autonomous motivation across educational and out-of-school contexts, and relations between out-of-school autonomous motivation, intentions, and mathematics homework outcomes. Findings support trans-contextual effects of autonomous motivation toward mathematics activities across educational and out-of-school contexts and homework outcomes

Scaling behaviour near jamming in random sequential adsorption

For the random Sequential adsorption model, we introduce the ‘availability’ as a new variable corresponding to the number of available locations in which an adsorbate can be accommodated. We investigate the relation of the availability to the coverage of the adsorbent surface over time. Power law scaling between the two is obtained both through numerical simulations and analytical techniques for both one- and two- dimensional random sequential adsorption, as well as in the case of competitive random sequential adsorption in one dimension