1,320 research outputs found

    Isospin Impurity of the 4.57-MeV State in ^6Li

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    The T=1 isospin mixing in the 4.57-MeV (T=0) state in ^6Li is investigated via the α+d→^6Li*→α+d* reaction and found to be less than 1%

    Analytical approximation for the sphere-sphere Coulomb potential

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    A simple analytical expression, which closely approximates the Coulomb potential between two uniformly charged spheres, is presented. This expression can be used in the optical potential semiclassical analyses which require that the interaction be analytic on and near the real r-axis.Comment: 4 pages including 3 figures and 1 tabl

    Psychosocial resilience among left-behind adolescents in rural Thailand: A qualitative exploration

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    When parents migrate, they often leave children behind with relatives. Despite being at higher risk of socio-emotional problems, many left-behind children have good health and social outcomes, suggesting their resilience. We sought to understand how adolescents with internal and international migrant parents build resilience in Thailand. We conducted qualitative interviews with 24 adolescents aged 10–19, and six caregivers, parents and community leaders. Interviews were transcribed, translated and analysed, drawing on techniques from grounded theory. We found that resilience was built in a context where for many families, migration was a financial necessity and the parent–child relationship was mainly phone-based. Adolescents built resilience using three key ‘resources’: warmth (love and understanding), financial support and guidance. Adolescents with insecure parent or caregiver relationships, or with caring responsibilities for relatives, were less likely to have access to these resources. These adolescents sought emotional and financial independence, prioritised friendships and identified role models to obtain key resources and build resilience. The findings indicate practical and psychosocial barriers to building resilience among left-behind adolescents in Thailand. Further work could explore pathways to mental illness in this population, interventions that build peer networks and caregiver–child relationships and the use of technology to support remote parenting

    Decadal Trends in Abundance, Size and Condition of Antarctic Toothfish in McMurdo Sound, Antarctica, 1972-2010

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    We report analyses of a dataset spanning 38 years of near-annual fishing for Antarctic toothfish Dissostichus mawsoni, using a vertical setline through the fast ice of McMurdo Sound, Antarctica, 1972-2010. This constitutes one of the longest biological time series in the Southern Ocean, and certainly the longest for any fish. Fish total length, condition and catch per unit effort (CPUE) were derived from the more than 5500 fish caught. Contrary to expectation, length-frequency was dominated by fish in the upper half of the industrial catch. The discrepancy may be due to biases in the sampling capabilities of vertical (this study) versus benthic (horizontal) fishing gear (industry long lines), related to the fact that only large Antarctic toothfish (more than 100 cm TL) are neutrally buoyant and occur in the water column. Fish length and condition increased from the early 1970s to the early 1990s and then decreased, related to sea ice cover, with lags of 8 months to 5 years, and may ultimately be related to the fishery (which targets large fish) and changes in the Southern Annular Mode through effects on toothfish main prey, Antarctic silverfish Pleuragramma antarcticum. CPUE was constant through 2001 and then decreased dramatically, likely related to the industrial fishery, which began in 1996 and which concentrates effort over the Ross Sea slope, where tagged McMurdo fish have been found. Due to limited prey choices and, therefore, close coupling among mesopredators of the Ross Sea, Antarctic toothfish included, the fishery may be altering the trophic structure of the Ross Sea

    The effect of beta-alanine supplementation on neuromuscular fatigue in elderly (55–92 Years): a double-blind randomized study

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    <p>Abstract</p> <p>Background</p> <p>Ageing is associated with a significant reduction in skeletal muscle carnosine which has been linked with a reduction in the buffering capacity of muscle and in theory, may increase the rate of fatigue during exercise. Supplementing beta-alanine has been shown to significantly increase skeletal muscle carnosine. The purpose of this study, therefore, was to examine the effects of ninety days of beta-alanine supplementation on the physical working capacity at the fatigue threshold (PWC<sub>FT</sub>) in elderly men and women.</p> <p>Methods</p> <p>Using a double-blind placebo controlled design, twenty-six men (n = 9) and women (n = 17) (age ± SD = 72.8 ± 11.1 yrs) were randomly assigned to either beta-alanine (BA: 800 mg × 3 per day; n = 12; CarnoSyn™) or Placebo (PL; n = 14) group. Before (pre) and after (post) the supplementation period, participants performed a discontinuous cycle ergometry test to determine the PWC<sub>FT</sub>.</p> <p>Results</p> <p>Significant increases in PWC<sub>FT </sub>(28.6%) from pre- to post-supplementation were found for the BA treatment group (p < 0.05), but no change was observed with PL treatment. These findings suggest that ninety days of BA supplementation may increase physical working capacity by delaying the onset of neuromuscular fatigue in elderly men and women.</p> <p>Conclusion</p> <p>We suggest that BA supplementation, by improving intracellular pH control, improves muscle endurance in the elderly. This, we believe, could have importance in the prevention of falls, and the maintenance of health and independent living in elderly men and women.</p

    Interference scheme to measure light-induced nonlinearities in Bose-Einstein condensates

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    Light-induced nonlinear terms in the Gross-Pitaevskii equation arise from the stimulated coherent exchange of photons between two atoms. For atoms in an optical dipole trap this effect depends on the spatial profile of the trapping laser beam. Two different laser beams can induce the same trapping potential but very different nonlinearities. We propose a scheme to measure light-induced nonlinearities which is based on this observation.Comment: 2 figure

    Quantized circular motion of a trapped Bose-Einstein condensate: coherent rotation and vortices

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    We study the creation of vortex states in a trapped Bose-Einstein condensate by a rotating force. For a harmonic trapping potential the rotating force induces only a circular motion of the whole condensate around the trap center which does not depend on the interatomic interaction. For the creation of a pure vortex state it is necessary to confine the atoms in an anharmonic trapping potential. The efficiency of the creation can be greatly enhanced by a sinusodial variation of the force's angular velocity. We present analytical and numerical calculations for the case of a quartic trapping potential. The physical mechanism behind the requirement of an anharmonic trapping potential for the creation of pure vortex states is explained. [Changes: new numerical and analytical results are added and the representation is improved.]Comment: 13 Pages, 5 Figures, RevTe
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