529 research outputs found

    The impact of parent-created motivational climate on adolescent athletes' perceptions of physical self-concept

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    This is a preliminary version of this article. The official published version can be obtained from the link below.Grounded in expectancy-value model (Eccles, 1993) and achievement goal theory (Nicholls, 1989), this study examined the perceived parental climate and its impact on athletes' perceptions of competence and ability. Hierarchical regression analyses with a sample of 237 British adolescent athletes revealed that mothers and fathers' task- and ego-involving climate predicted their son's physical self-concept; the father in particular is the strongest influence in shaping a son's physical self-concept positively and negatively. It was also found that the self-concept of the young adolescent athlete is more strongly affected by the perceived parental-created motivational climate (both task and ego) than the older adolescent athlete's self-concept. These findings support the expectancy-value model assumptions related to the role of parents as important socializing agents, the existence of gender-stereotyping, and the heavy reliance younger children place on parents' feedback

    A Narrative Review of Intensive Group Tobacco Treatment: Clinical, Research, and US Policy Recommendations

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    Clinical practice guidelines recommend comprehensive treatment for tobacco dependence including pharmacotherapies and behavioral interventions. Group counseling may deliver unique treatment aspects not available with other modalities. This manuscript provides a narrative review of group treatment outcomes from real-world practice settings and complements recent meta-analyses of randomized controlled trials (RCTs). Our primary goals were to determine whether group treatments delivered in these settings have yielded similar quit rates compared to individual treatment and to provide recommendations for best practices and policy. Methods: Group treatment was defined as occurring in a clinical or workplace setting (ie, not provided as part of a research study), led by a professionally trained clinician, and offered weekly over several weeks. English language PubMed articles from January 2000 to July 2017 were searched to identify studies that included outcomes from both group and individual treatment offered in real-world settings. Additional data sources meeting our criteria were also included. Reports not using pharmacotherapy and research studies (eg, RCTs) were excluded. The primary outcome was short-term, carbon monoxide (CO)-validated point prevalence abstinence (4-week postquit date). Results: The review included data from 11 observational studies. In all cases, group treatment(s) had higher 4-week CO-validated quit rates (range: 35.5%-67.3%) than individual treatment(s) (range: 18.6%-53.3%). Conclusions: Best practice group treatments for tobacco dependence are generalizable from research to clinical settings and likely to be at least as effective as intensive individual treatment. The added advantages of efficiency and cost-effectiveness can be significant. Group treatment is feasible in various settings with good results. Implications: A major barrier to achieving high rates of tobacco abstinence is under-utilization of evidence-based treatment interventions. This review demonstrates the effectiveness and utility of group treatment for tobacco dependence. Based on the available data described in this narrative review in conjunction with existing RCT data, group treatment for tobacco dependence should be established and available in all behavioral health and medical settings. Group tobacco treatment is now one of the mandated reimbursable tobacco treatment formats within the US health care system, creating enormous opportunities for widespread clinical reach. Finally, comprehensive worksite group programs can further extend impact

    Theory of Coexistence of Superconductivity and Ferroelectricity : A Dynamical Symmetry Model

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    We propose and investigate a model for the coexistence of Superconductivity (SC) and Ferroelectricity (FE) based on the dynamical symmetries su(2)su(2) for the pseudo-spin SC sector, h(4)h(4) for the displaced oscillator FE sector, and su(2)h(4)su(2) \otimes h(4) for the composite system. We assume a minimal symmetry-allowed coupling, and simplify the hamiltonian using a double mean field approximation (DMFA). A variational coherent state (VCS) trial wave-function is used for the ground state: the energy, and the relevant order parameters for SC and FE are obtained. For positive sign of the SC-FE coupling coefficient, a non-zero value of either order parameter can suppress the other (FE polarization suppresses SC and vice versa). This gives some support to "Matthias' Conjecture" [1964], that SC and FE tend to be mutually exclusive. For such a Ferroelectric Superconductor we predict: a) the SC gap Δ\Delta (and TcT_c ) will increase with increasing applied pressure when pressure quenches FE as in many ferroelectrics, and b) the FE polarization will increase with increaesing magnetic field up to HcH_c . The last result is equivalent to the prediction of a new type of Magneto-Electric Effect in a coexistent SC-FE material. Some discussion will be given of the relation of these results to the cuprate superconductors.Comment: 46 page

    Effective Lagrangian Approach to the Theory of Eta Photoproduction in the N(1535)N^{*}(1535) Region

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    We investigate eta photoproduction in the N(1535)N^{*}(1535) resonance region within the effective Lagrangian approach (ELA), wherein leading contributions to the amplitude at the tree level are taken into account. These include the nucleon Born terms and the leading tt-channel vector meson exchanges as the non-resonant pieces. In addition, we consider five resonance contributions in the ss- and uu- channel; besides the dominant N(1535)N^{*}(1535), these are: N(1440),N(1520),N(1650)N^{*}(1440),N^{*}(1520),N^{*}(1650) and N(1710)N^{*}(1710). The amplitudes for the π\pi^\circ and the η\eta photoproduction near threshold have significant differences, even as they share common contributions, such as those of the nucleon Born terms. Among these differences, the contribution to the η\eta photoproduction of the ss-channel excitation of the N(1535)N^{*}(1535) is the most significant. We find the off-shell properties of the spin-3/2 resonances to be important in determining the background contributions. Fitting our effective amplitude to the available data base allows us to extract the quantity χΓηA1/2/ΓT\sqrt{\chi \Gamma_\eta} A_{1/2}/\Gamma_T, characteristic of the photoexcitation of the N(1535)N^{*}(1535) resonance and its decay into the η\eta-nucleon channel, of interest to precise tests of hadron models. At the photon point, we determine it to be (2.2±0.2)×101GeV1(2.2\pm 0.2)\times 10^{-1} GeV^{-1} from the old data base, and (2.2±0.1)×101GeV1(2.2\pm 0.1) \times 10^{-1} GeV^{-1} from a combination of old data base and new Bates data. We obtain the helicity amplitude for N(1535)γpN^{*}(1535)\rightarrow \gamma p to be A1/2=(97±7)×103GeV1/2A_{1/2}=(97\pm 7)\times 10^{-3} GeV^{-1/2} from the old data base, and A1/2=(97±6)×103GeV1/2A_{1/2}=(97\pm 6)\times 10^{-3} GeV^{-1/2} from the combination of the old data base and new Bates data, compared with the results of the analysis of pion photoproduction yielding 74±1174\pm 11, in the same units.Comment: 43 pages, RevTeX, 9 figures available upon request, to appear in Phys. Rev.

    Study of the B^0 Semileptonic Decay Spectrum at the Upsilon(4S) Resonance

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    We have made a first measurement of the lepton momentum spectrum in a sample of events enriched in neutral B's through a partial reconstruction of B0 --> D*- l+ nu. This spectrum, measured with 2.38 fb**-1 of data collected at the Upsilon(4S) resonance by the CLEO II detector, is compared directly to the inclusive lepton spectrum from all Upsilon(4S) events in the same data set. These two spectra are consistent with having the same shape above 1.5 GeV/c. From the two spectra and two other CLEO measurements, we obtain the B0 and B+ semileptonic branching fractions, b0 and b+, their ratio, and the production ratio f+-/f00 of B+ and B0 pairs at the Upsilon(4S). We report b+/b0=0.950 (+0.117-0.080) +- 0.091, b0 = (10.78 +- 0.60 +- 0.69)%, and b+ = (10.25 +- 0.57 +- 0.65)%. b+/b0 is equivalent to the ratio of charged to neutral B lifetimes, tau+/tau0.Comment: 14 page, postscript file also available at http://w4.lns.cornell.edu/public/CLN

    Measurement of the B0-anti-B0-Oscillation Frequency with Inclusive Dilepton Events

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    The B0B^0-Bˉ0\bar B^0 oscillation frequency has been measured with a sample of 23 million \B\bar B pairs collected with the BABAR detector at the PEP-II asymmetric B Factory at SLAC. In this sample, we select events in which both B mesons decay semileptonically and use the charge of the leptons to identify the flavor of each B meson. A simultaneous fit to the decay time difference distributions for opposite- and same-sign dilepton events gives Δmd=0.493±0.012(stat)±0.009(syst)\Delta m_d = 0.493 \pm 0.012{(stat)}\pm 0.009{(syst)} ps1^{-1}.Comment: 7 pages, 1 figure, submitted to Physical Review Letter

    Time-integrated luminosity recorded by the BABAR detector at the PEP-II e+e- collider

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    This article is the Preprint version of the final published artcile which can be accessed at the link below.We describe a measurement of the time-integrated luminosity of the data collected by the BABAR experiment at the PEP-II asymmetric-energy e+e- collider at the ϒ(4S), ϒ(3S), and ϒ(2S) resonances and in a continuum region below each resonance. We measure the time-integrated luminosity by counting e+e-→e+e- and (for the ϒ(4S) only) e+e-→μ+μ- candidate events, allowing additional photons in the final state. We use data-corrected simulation to determine the cross-sections and reconstruction efficiencies for these processes, as well as the major backgrounds. Due to the large cross-sections of e+e-→e+e- and e+e-→μ+μ-, the statistical uncertainties of the measurement are substantially smaller than the systematic uncertainties. The dominant systematic uncertainties are due to observed differences between data and simulation, as well as uncertainties on the cross-sections. For data collected on the ϒ(3S) and ϒ(2S) resonances, an additional uncertainty arises due to ϒ→e+e-X background. For data collected off the ϒ resonances, we estimate an additional uncertainty due to time dependent efficiency variations, which can affect the short off-resonance runs. The relative uncertainties on the luminosities of the on-resonance (off-resonance) samples are 0.43% (0.43%) for the ϒ(4S), 0.58% (0.72%) for the ϒ(3S), and 0.68% (0.88%) for the ϒ(2S).This work is supported by the US Department of Energy and National Science Foundation, the Natural Sciences and Engineering Research Council (Canada), the Commissariat à l’Energie Atomique and Institut National de Physique Nucléaire et de Physiquedes Particules (France), the Bundesministerium für Bildung und Forschung and Deutsche Forschungsgemeinschaft (Germany), the Istituto Nazionale di Fisica Nucleare (Italy), the Foundation for Fundamental Research on Matter (The Netherlands), the Research Council of Norway, the Ministry of Education and Science of the Russian Federation, Ministerio de Ciencia e Innovación (Spain), and the Science and Technology Facilities Council (United Kingdom). Individuals have received support from the Marie-Curie IEF program (European Union) and the A.P. Sloan Foundation (USA)

    Measurement of the Mass Splittings between the bbˉχb,J(1P)b\bar{b}\chi_{b,J}(1P) States

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    We present new measurements of photon energies and branching fractions for the radiative transitions: Upsilon(2S)->gamma+chi_b(J=0,1,2). The masses of the chi_b states are determined from the measured radiative photon energies. The ratio of mass splittings between the chi_b substates, r==(M[J=2]-M[J=1])/(M[J=1]-M[J=0]) with M the chi_b mass, provides information on the nature of the bbbar confining potential. We find r(1P)=0.54+/-0.02+/-0.02. This value is in conflict with the previous world average, but more consistent with the theoretical expectation that r(1P)<r(2P); i.e., that this mass splittings ratio is smaller for the chi_b(1P) triplet than for the chi_b(2P) triplet.Comment: 11 page postscript file, postscript file also available through http://w4.lns.cornell.edu/public/CLN

    Radiative Decay Modes of the D0D^{0} Meson

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    Using data recorded by the CLEO-II detector at CESR we have searched for four radiative decay modes of the D0D^0 meson: D0ϕγD^0\to\phi\gamma, D0ωγD^0\to\omega\gamma, D0KˉγD^0\to\bar{K}^{*}\gamma, and D0ρ0γD^0\to\rho^0\gamma. We obtain 90% CL upper limits on the branching ratios of these modes of 1.9×1041.9\times 10^{-4}, 2.4×1042.4\times 10^{-4}, 7.6×1047.6\times 10^{-4} and 2.4×1042.4\times 10^{-4} respectively.Comment: 15 page postscript file, postscript file also available through http://w4.lns.cornell.edu/public/CLN
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