4,002 research outputs found

    Determination of the resistivity anisotropy of SrRuO3_{3} by measuring the planar Hall effect

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    We have measured the planar Hall effect in epitaxial thin films of the itinerant ferromagnet SrRuO3 patterned with their current paths at different angles relative to the crystallographic axes. Based on the results, we have determined that SrRuO3 exhibits small resistivity anisotropy in the entire temperature range of our measurements (between 2 to 300 K); namely, both above and below its Curie temperature (~150 K). It means that in addition to anisotropy related to magnetism, the resistivity anisotropy of SrRuO3 has an intrinsic, nonmagnetic source. We have found that the two sources of anisotropy have competing effects

    Quaternion algebras with the same subfields

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    G. Prasad and A. Rapinchuk asked if two quaternion division F -algebras that have the same subfields are necessarily isomorphic. The answer is known to be "no" for some very large fields. We prove that the answer is "yes" if F is an extension of a global field K so that F /K is unirational and has zero unramified Brauer group. We also prove a similar result for Pfister forms and give an application to tractable fields

    Plasma Cortisol in Men – Relationship With Atherosclerosis of Retinal Arteries

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    The production of cortisol increases in acute stress but the effects of chronic stress on plasma cortisol are still controversial. Stress on the other hand plays a role in coronary artery disease (CAD) and carotid atherosclerosis. Since there is no data about plasma cortisol and atherosclerosis of the retinal arteries, the purpose of this study was to explore the relationship between plasma cortisol in 101 adult males with the degree of their retinal vessels atherosclerosis. The results were compared with those in 47 matched apparently healthy men with no retinal vessels changes. The atherosclerotic changes of retinal vessels were determined by direct ophthalmoscopy and graded (1–4) according to Scheie. Morning plasma cortisol levels were determined by radioimmunoassay using commercial kits. The results were compared by using chi-square test. No association between morning plasma cortisol concentrations and retinal vessels atherosclerosis could be found. The results of this study do not support a role for physiological levels of plasma cortisol in the development of atherosclerosis, at least of the retinal arteries, in men

    The overlapping burden of the three leading causes of disability and death in sub-Saharan African children

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    Despite substantial declines since 2000, lower respiratory infections (LRIs), diarrhoeal diseases, and malaria remain among the leading causes of nonfatal and fatal disease burden for children under 5 years of age (under 5), primarily in sub-Saharan Africa (SSA). The spatial burden of each of these diseases has been estimated subnationally across SSA, yet no prior analyses have examined the pattern of their combined burden. Here we synthesise subnational estimates of the burden of LRIs, diarrhoea, and malaria in children under-5 from 2000 to 2017 for 43 sub-Saharan countries. Some units faced a relatively equal burden from each of the three diseases, while others had one or two dominant sources of unit-level burden, with no consistent pattern geographically across the entire subcontinent. Using a subnational counterfactual analysis, we show that nearly 300 million DALYs could have been averted since 2000 by raising all units to their national average. Our findings are directly relevant for decision-makers in determining which and targeting where the most appropriate interventions are for increasing child survival

    Intellectual Property in Medical Imaging and Informatics: The Independent Inventor’s Perspective

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    While innovation and new product development is traditionally thought of as the exclusive domain of industry and academia, a large number of innovations in medicine and information technology have come from independent inventors, which account for almost 30% of new patents issued in the U.S. today. A large number of economic, political, and legal challenges exist within the current marketplace that serves as relative impediments to independent invention. This article explores the existing challenges facing the independent inventor and offers a number of recommendations and resources to facilitate independent inventors in their quest for innovation and entrepreneurship. The concept of “outsourcing innovation” is discussed as an alternative to the existing model of industry sponsored research and development (R&D), with the goal of combining the unique attributes and strengths of independent inventors and industry sponsors

    Refinement of primary Si in hypereutectic Al-Si alloys by intensive melt shearing

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    Hypereutectic Al-Si based alloys are gaining popularity for applications where a combination of light weight and high wear resistance is required. The high wear resistance arising from the hard primary Si particles comes at the price of extremely poor machine tool life. To minimize machining problems while exploiting outstanding wear resistance, the primary Si particles must be controlled to a uniform small size and uniform spatial distribution. The current industrial means of refining primary Si chemically by the addition of phosphorous suffers from a number of problems. In the present paper an alternative, physical means of refining primary Si by intensive shearing of the melt prior to casting is investigated. Al-15wt%Si alloy has been solidified under varying casting conditions (cooling rate) and the resulting microstructures have been studied using microscopy and quantitative image analysis. Primary Si particles were finer, more compact in shape and more numerous with increasing cooling rate. Intensive melt shearing led to greater refinement and more enhanced nucleation of primary Si than was achieved by adding phosphorous. The mechanism of enhanced nucleation is discussed.EPSRC (grant EP/H026177/1)

    Financial stability evaluation of banks of the Russian Federation

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    In this paper we propose the model for evaluating financial stability of the Russian Federation banks by using discriminatory analysis. The statistical significance of the model was established. Critical value of the resulting was measured. The result of this research can be used in the area of banking
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