189 research outputs found

    Hidden magnetic transitions in thermoelectric layered cobaltite, [Ca2_2CoO3_3]0.62_{0.62}[CoO2_2]

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    A positive muon spin rotation and relaxation (ÎŒ+\mu^+SR) experiment on [Ca2_2CoO3_3]0.62_{0.62}[CoO2_2], ({\sl i.e.}, Ca3_3Co4_4O9_9, a layered thermoelectric cobaltite) indicates the existence of two magnetic transitions at ∌\sim 100 K and 400 - 600 K; the former is a transition from a paramagnetic state to an incommensurate ({\sf IC}) spin density wave ({\sf SDW}) state. The anisotropic behavior of zero-field ÎŒ+\mu^+SR spectra at 5 K suggests that the {\sf IC-SDW} propagates in the aa-bb plane, with oscillating moments directed along the c-axis; also the {\sf IC-SDW} is found to exist not in the [Ca2_2CoO3_3] subsystem but in the [CoO2_2] subsystem. In addition, it is found that the long-range {\sf IC-SDW} order completes below ∌\sim 30 K, whereas the short-range order appears below 100 K. The latter transition is interpreted as a gradual change in the spin state of Co ions %% at temperatures above 400 K. These two magnetic transitions detected by ÎŒ+\mu^+SR are found to correlate closely with the transport properties of [Ca2_2CoO3_3]0.62_{0.62}[CoO2_2].Comment: 7 pages, 8 figures. to be appeared in Phys. Rev.

    Analysis of Exertion-Related Injuries and Fatalities in Laborers in the United States

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    Laborers are particularly vulnerable to exertional injuries and illnesses, as they often engage in heavy physical work for prolonged hours, yet no studies have examined the top causes of catastrophic exertional injuries and fatalities among this population. The purpose of the investigation was to characterize the top causes of exertional injury and fatality within open access, Occupational Safety and Health Administration (OSHA) reportable data. A secondary analysis of OSHA reported injury and fatality data was performed through open access records from OSHA Severe Injury Reports (2015–2022) and OSHA fatality inspection data (2017–2020), respectively. The research team characterized each reported injury and fatality as “exertion-related” or “non-exertion-related. Injury and fatality rates were reported per 100,000 equivalent full-time worker years and included 95% confidence intervals (95% CI). Of 58,648 cases in the OSHA Severe Injury Report database from 2015–2020, 1682 cases (2.9%) were characterized as exertional (0.20 injuries per 100,000 full-time worker years, 95% CI: 0.19, 0.22). Heat-related injuries encompassed 91.9% of the exertional injuries (n = 1546). From the 2017–2022 OSHA fatality inspection database, 89 (1.9%) of 4598 fatalities were characterized as exertion-related (fatality rate: 0.0160 per 100,000 full-time equivalent workers, 95% CI: 0.009, 0.0134). The exertion-related fatalities primarily consisted of heat-related cases (87.6%). Exertion-related injuries and fatalities were most reported in Southeast states, in the construction and excavation industry, and among nonunionized workers. As heat stress continues to be recognized as an occupational health and safety hazard, this analysis further highlights the need for targeted interventions or further evaluation of the impact of heat stress on construction and excavation workers, nonunionized workers, and workers in Southeastern states

    Community structure and ethnic preferences in school friendship networks

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    Recently developed concepts and techniques of analyzing complex systems provide new insight into the structure of social networks. Uncovering recurrent preferences and organizational principles in such networks is a key issue to characterize them. We investigate school friendship networks from the Add Health database. Applying threshold analysis, we find that the friendship networks do not form a single connected component through mutual strong nominations within a school, while under weaker conditions such interconnectedness is present. We extract the networks of overlapping communities at the schools (c-networks) and find that they are scale free and disassortative in contrast to the direct friendship networks, which have an exponential degree distribution and are assortative. Based on the network analysis we study the ethnic preferences in friendship selection. The clique percolation method we use reveals that when in minority, the students tend to build more densely interconnected groups of friends. We also find an asymmetry in the behavior of black minorities in a white majority as compared to that of white minorities in a black majority.Comment: submitted to Physica

    Pharmacist insights into adolescent human papillomavirus vaccination provision in the United States

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    HPV vaccination coverage in the United States (US) falls short of the Healthy People 2020 goal of 80% coverage among 13–15 year-old adolescents. Pharmacies are a promising alternative vaccine delivery site that may increase access to HPV vaccination. Our objective was to assess pharmacists’ insights into HPV vaccination provision to adolescents. We recruited 40 licensed pharmacists in eight states with different pharmacy vaccination laws: Alabama, California, Indiana, Kentucky, Maine, Tennessee, Texas, and Washington. Eligible pharmacists either previously provided or were currently providing HPV, tetanus-diphtheria-pertussis, or meningococcal vaccines to adolescents aged 9–17 years. Pharmacists were administered a semi-structured survey to explore insights into HPV vaccination provision. Forty-five percent of surveyed pharmacies offered HPV vaccination to adolescents. Pharmacists’ reported challenges to providing HPV vaccination were parental consent (28%), tracking and patient recall (17%), perceived stigma of vaccination (17%), and education about or promotion of vaccination (17%). Pharmacists offering HPV vaccination sent patient reminders for vaccines with multiple doses (89%) and utilized telephone reminders (72%). Pharmacists informed patients’ primary care providers of HPV vaccination doses most commonly through fax (72%) and updating electronic medical records (22%). One-third of pharmacists reported vaccination provision using the state immunization information system (IIS). Seventy-five percent reported vaccination rates could be increased at their respective pharmacy. Pharmacies are underutilized, although highly accessible, for HPV vaccination in the US. National efforts should expand educational programs to improve public awareness of in-pharmacy HPV vaccination, and improve the utilization of state IIS for reporting immunization coverage of adolescents by pharmacists

    Melting and Dimensionality of the Vortex Lattice in Underdoped YBa2Cu3O6.60

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    Muon spin rotation measurements of the magnetic field distribution in the vortex state of the oxygen deficient high-Tc superconductor YBa{2}Cu{3}O{6.60} reveal a vortex-lattice melting transition at much lower temperature than that in the fully oxygenated material. The transition is best described by a model in which adjacent layers of ``pancake'' vortices decouple in the liquid phase. Evidence is also found for a pinning-induced crossover from a solid 3D to quasi-2D vortex lattice, similar to that observed in the highly anisotropic superconductor Bi{2+x}Sr{2-x}CaCu{2}O{8+y}.Comment: 8 pages, 4 figures, 5 postscript file

    Modeling and optimization of sensory changes and shelf-life in vacuum-packaged cooked ham treated by E-beam irradiation

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    [EN] The E-beam irradiation of vacuum-packaged RTE cooked ham was carried out to establish the dose required to achieve the food safety objective (FSO) and to minimize changes in selected sensory attributes. Cooked ham was irradiated with doses ranging 1-4 kGy. After the treatment, the microbial inactivation of Listeria monocytogenes, the shelf-life of the product and some sensory attributes (appearance, odor, and flavor) were determined. The inactivation of L monocytogenes was satisfactorily described by a first-order kinetics equation (R2=0.99). The influence of the irradiation dose on appearance, odor, and flavor was modeled through Gompertz (R2=0.99, for appearance) and Activation/Inactivation (R2=0.99, for odor and flavor) equations. A model was also developed to determine the shelf-life of irradiated cooked ham depending on the irradiation dose (R2 > 0.91). The dose that maximized the scores of the sensory attributes was 0.96 kGy resulting in an acceptable sensory quality for 80 days. It is possible to apply up to 2 kGy to ensure microbial safety, while provoking no significant changes in the above mentioned sensory attributes. (C) 2010 Elsevier Ltd. All rights reserved.The authors acknowledge the financial support from the Project CSD2007-00016 (CONSOLIDER-INGENIO 2010) funded by the Spanish Ministry of Science and Innovation.Benedito Fort, JJ.; Cambero, MI.; Ortuño Cases, C.; Cabeza, MC.; Ordoñez, JA.; De La Hoz, L. (2011). Modeling and optimization of sensory changes and shelf-life in vacuum-packaged cooked ham treated by E-beam irradiation. Radiation Physics and Chemistry. 80(3):505-513. https://doi.org/10.1016/j.radphyschem.2010.11.001S50551380

    An Integrated TCGA Pan-Cancer Clinical Data Resource to Drive High-Quality Survival Outcome Analytics

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    For a decade, The Cancer Genome Atlas (TCGA) program collected clinicopathologic annotation data along with multi-platform molecular profiles of more than 11,000 human tumors across 33 different cancer types. TCGA clinical data contain key features representing the democratized nature of the data collection process. To ensure proper use of this large clinical dataset associated with genomic features, we developed a standardized dataset named the TCGA Pan-Cancer Clinical Data Resource (TCGA-CDR), which includes four major clinical outcome endpoints. In addition to detailing major challenges and statistical limitations encountered during the effort of integrating the acquired clinical data, we present a summary that includes endpoint usage recommendations for each cancer type. These TCGA-CDR findings appear to be consistent with cancer genomics studies independent of the TCGA effort and provide opportunities for investigating cancer biology using clinical correlates at an unprecedented scale. Analysis of clinicopathologic annotations for over 11,000 cancer patients in the TCGA program leads to the generation of TCGA Clinical Data Resource, which provides recommendations of clinical outcome endpoint usage for 33 cancer types
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