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The Majorana Collaboration is operating an array of high purity Ge detectors to search for neutrinoless double-ß decay in ^{76}Ge. The Majorana Demonstrator comprises 44.1 kg of Ge detectors (29.7 kg enriched in ^{76}Ge) split between two modules contained in a low background shield at the Sanford Underground Research Facility in Lead, South Dakota. Here we present results from data taken during construction, commissioning, and the start of full operations. We achieve unprecedented energy resolution of 2.5 keV FWHM at Q_{ßß} and a very low background with no observed candidate events in 9.95 kg yr of enriched Ge exposure, resulting in a lower limit on the half-life of 1.9×10^{25} yr (90% C.L.). This result constrains the effective Majorana neutrino mass to below 240-520 meV, depending on the matrix elements used. In our experimental configuration with the lowest background, the background is 4.0_{-2.5}^{+3.1} counts/(FWHM t yr).
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INTRODUCTION: Traumatic brain injury is a leading cause of disability in bicycle riders. Preventive measures including bicycle helmet laws have been highlighted; however, its protective role has always been debated. The aim of this study was to determine the utility of bicycle helmets in prevention of intra-cranial hemorrhage. We hypothesized that bicycle helmets are protective and prevent the development of intra-cranial hemorrhage. METHODS: We performed a 4-year (2009-2012) retrospective cohort analysis of all the patients who presented with traumatic brain injury due to bicycle injuries to our level 1 trauma center. We compared helmeted and non-helmeted bicycle riders for differences in the patterns of injury, need for intensive care unit admissions and mortality. RESULTS: A total of 864 patients were reviewed of which, 709 patients (helmeted = 300, non-helmeted = 409) were included. Non-helmeted bicycle riders were more likely to be young (p < 0.001) males (p = 0.01). There was no difference in the median ISS between the two groups (p = 0.3). Non-helmeted riders were more likely to have a skull fracture (p = 0.01) and a scalp laceration (p = 0.01) compared to the helmeted riders. There was no difference in intra-cranial hemorrhage between the two groups (p = 0.1). Wearing a bicycle helmet was not independently associated (p = 0.1) with development of intra-cranial hemorrhage. CONCLUSION: Bicycle helmets may have a protective effect against external head injury but its protective role for intra-cranial hemorrhage is questionable. Further studies assessing the protective role of helmets for intra-cranial hemorrhage are warranted.
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Young broiler chicks were more sensitive to copper toxicity when they were fed diets deficient or marginal in calcium content. Growth rate was depressed and liver copper concentration was increased under these conditions. Chicks fed a casein-gelatin diet were more sensitive to copper toxicity than those fed a corn-soybean meal diet. Addition of phytic acid to the casein-gelatin basal diet enhanced copper toxicity as evidenced by effects on growth rate and liver copper content. Measurements of intestinal and biliary copper content suggested that the influence of calcium on copper toxicity was mediated via intestinal absorption rather than through influences on copper excretion.
