3,564 research outputs found

    Perceived Barriers to Participation in a Supplemental Nutrition Program Among Low-Income Women on the US/Mexico Border

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    The benefits of supplemental nutrition programs have been well established. In order to gain an insight into perceived barriers to participation in such programs on the US/Mexico border, unstructured qualitative interviews were conducted with former participants of the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC). The main barrier to program participation was a lack of time. Other barriers to participation included confusion about program eligibility and the perceived stigma associated with receiving assistance from WIC. Generally, participants felt that WIC was a beneficial program and would recommend it to others. Expanded hours of operation that address the needs of working mothers were recommended in order to increase the recruitment and retention of program participants

    Discovery of Multiply Imaged Galaxies behind the Cluster and Lensed Quasar SDSS J1004+4112

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    We have identified three multiply imaged galaxies in Hubble Space Telescope images of the redshift z=0.68 cluster responsible for the large-separation quadruply lensed quasar, SDSS J1004+4112. Spectroscopic redshifts have been secured for two of these systems using the Keck I 10m telescope. The most distant lensed galaxy, at z=3.332, forms at least four images, and an Einstein ring encompassing 3.1 times more area than the Einstein ring of the lensed QSO images at z=1.74, due to the greater source distance. For a second multiply imaged galaxy, we identify Ly_alpha emission at a redshift of z=2.74. The cluster mass profile can be constrained from near the center of the brightest cluster galaxy, where we observe both a radial arc and the fifth image of the lensed quasar, to the Einstein radius of the highest redshift galaxy, ~110 kpc. Our preliminary modeling indicates that the mass approximates an elliptical body, with an average projected logarithmic gradient of ~-0.5. The system is potentially useful for a direct measurement of world models in a previously untested redshift range.Comment: 5 pages, 3 figures. Accepted by ApJL. High resolution version of the paper can be found at: http://wise-obs.tau.ac.il/~kerens/papers.htm

    Theory of dynamic crack branching in brittle materials

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    The problem of dynamic symmetric branching of an initial single brittle crack propagating at a given speed under plane loading conditions is studied within a continuum mechanics approach. Griffith's energy criterion and the principle of local symmetry are used to determine the cracks paths. The bifurcation is predicted at a given critical speed and at a specific branching angle: both correlated very well with experiments. The curvature of the subsequent branches is also studied: the sign of TT, with TT being the non singular stress at the initial crack tip, separates branches paths that diverge from or converge to the initial path, a feature that may be tested in future experiments. The model rests on a scenario of crack branching with some reasonable assumptions based on general considerations and in exact dynamic results for anti-plane branching. It is argued that it is possible to use a static analysis of the crack bifurcation for plane loading as a good approximation to the dynamical case. The results are interesting since they explain within a continuum mechanics approach the main features of the branching instabilities of fast cracks in brittle materials, i.e. critical speeds, branching angle and the geometry of subsequent branches paths.Comment: 41 pages, 15 figures. Accepted to International Journal of Fractur

    Parity Violation in Neutron Resonances of Palladium

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    Parity violation in p-wave neutron resonances of the palladium isotopes 104, 105, 106, and 108 has been measured by transmission of a longitudinally polarized neutron beam through a natural palladium target. The measurements were performed at the pulsed spallation neutron source of Los Alamos Neutron Science Center. The rms weak interaction matrix elements and the corresponding spreading widths were determined for 104 Pd, 105 Pd, and 106 P

    Neutron Resonance Spectroscopy of 103Rh from 30 eV to 2 keV

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    Neutron resonances in 103Rh have been measured for neutron energies from 30 to 2000 eV using the time-of-flight method and the (n,γ) reaction. The rhodium resonance spectroscopy is essential for the analysis of parity violation measurements recently performed on neutron resonances in 103Rh. Neutron scattering and radiative widths were determined, and orbital angular momentum assignments made with a Bayesian analysis. The s-wave and p-wave strength functions and average level spacings were determined

    Parity Violation in Neutron Resonances of 103Rh

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    Parity nonconservation (PNC) was studied in p-wave neutron resonances of 103Rh in the neutron energy range 30 to 490 eV. The helicity dependence of the neutron total cross section of rhodium was determined by capture measurements with the time-of-flight method at the Manuel Lujan Neutron Scattering Center at the Los Alamos National Laboratory. A total of 32 p-wave resonances were studied and statistically significant longitudinal asymmetries were observed for resonances at En=44.5, 110.8, 321.6, and 432.9 eV. A statistical analysis treating the PNC matrix elements as random variables yields a weak spreading widthΓw=(1.42-0.59+1.21)×10-7eV

    Neutron Resonance Spectroscopy of 104Pd, 105Pd, and 110Pd

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    We have measured neutron resonances in the palladium isotopes 104, 105, and 110 for neutron energies from 1 to 2100 eV. Many new p-wave resonances have been observed. Their neutron widths and, in several cases, the radiative widths were measured. The average level spacings and the s-wave and p-wave neutron strength functions were determined. The time-of-flight method was used for both neutron total cross section measurements and total (n,γ) reaction yield measurements at the pulsed spallation neutron source of Los Alamos Neutron Science Center. Well established resonance spectroscopy for these isotopes is essential for the analysis of parity violation data that were recently measured in palladium

    Social cognition in adults with autism spectrum disorders: Validation of the Edinburgh Social Cognition Test (ESCoT).

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    Objective: Many existing tests of social cognition are not appropriate for clinical use, due to their length, complexity or uncertainty in what they are assessing. The Edinburgh Social Cognition Test (ESCoT) is a new test of social cognition that assesses affective and cognitive Theory of Mind as well as inter- and intrapersonal understanding of social norms using animated interactions.Method: To support the development of the ESCoT as a clinical tool, we derived cut-off scores from a neurotypical population (n = 236) and sought to validate the ESCoT in a sample of Autism Spectrum Disorder (ASD; n = 19) adults and neurotypical controls (NC; n = 38) matched on age and education. The ESCoT was administered alongside established tests and questionnaire measures of ASD, empathy, systemizing traits and intelligence.Results: Performance on the subtests of the ESCoT and ESCoT total scores correlated with performance on traditional tests, demonstrating convergent validity. ASD adults performed poorer on all measures of social cognition. Unlike the ESCoT, performance on the established tests was predicted by verbal comprehension abilities. Using a ROC curve analysis, we showed that the ESCoT was more effective than existing tests at differentiating ASD adults from NC. Furthermore, a total of 42.11% of ASD adults were impaired on the ESCoT compared to 0% of NC adults.Conclusions: Overall these results demonstrate that the ESCoT is a useful test for clinical assessment and can aid in the detection of potential difficulties in ToM and social norm understanding

    Emerging Pattern of Rabies Deaths and Increased Viral Infectivity

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    Most human rabies deaths in the United States can be attributed to unrecognized exposures to rabies viruses associated with bats, particularly those associated with two infrequently encountered bat species (Lasionycteris noctivagans and Pipistrellus subflavus). These human rabies cases tend to cluster in the southeastern and northwestern United States. In these regions, most rabies deaths associated with bats in nonhuman terrestrial mammals are also associated with virus variants specific to these two bat species rather than more common bat species; outside of these regions, more common bat rabies viruses contribute to most transmissions. The preponderance of rabies deaths connected with the two uncommon L. noctivagans and P. subflavus bat rabies viruses is best explained by their evolution of increased viral infectivity
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