555 research outputs found

    Management Options of Colonoscopic Splenic Injury

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    Injury to the spleen during routine colonoscopy is an extremely rare injury. Diagnosis and management of the injury has evolved with technological advances and experience gained in the management of splenic injuries sustained in trauma. Of the 37 reported cases of colonoscopic splenic injury, 12 had a history of prior surgery or a disease process suggesting the presence of adhesions. Only 6 had noted difficulty during the procedure, and 31 patients experienced pain, shock, or hemoglobin drop as the indication of splenic injury. Since 1989, 21/24 (87.5%) patients have been diagnosed initially using computed tomography or ultrasonography. Overall, only 27.8% have retained their spleens. None have experienced as long a delay as our patient, nor have any had an attempt at percutaneous control of the injury. This report presents an unusual case of a rare complication of colonoscopy and the unsuccessful use of one nonoperative technique, and reviews the experience reported in the world literature, including current day management options

    Big Data in Science and Healthcare: A Review of Recent Literature and Perspectives

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    Objectives: As technology continues to evolve and rise in various industries, such as healthcare, science, education, and gaming, a sophisticated concept known as Big Data is surfacing. The concept of analytics aims to understand data. We set out to portray and discuss perspectives of the evolving use of Big Data in science and healthcare and, to examine some of the opportunities and challenges. Methods: A literature review was conducted to highlight the implications associated with the use of Big Data in scientific research and healthcare innovations, both on a large and small scale. Results: Scientists and health-care providers may learn from one another when it comes to understanding the value of Big Data and analytics. Small data, derived by patients and consumers, also requires analytics to become actionable. Connectivism provides a framework for the use of Big Data and analytics in the areas of science and healthcare. This theory assists individuals to recognize and synthesize how human connections are driving the increase in data. Despite the volume and velocity of Big Data, it is truly about technology connecting humans and assisting them to construct knowledge in new ways. Concluding Thoughts: The concept of Big Data and associated analytics are to be taken seriously when approaching the use of vast volumes of both structured and unstructured data in science and health-care. Future exploration of issues surrounding data privacy, confidentiality, and education are needed. A greater focus on data from social media, the quantified self-movement, and the application of analytics to small data would also be useful

    The internal magnetic field in superconducting ferromagnets

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    We have measured the nonlinear response to the ac magnetic field in the superconducting weak ferromagnet Ru-1222, at different regimes of sample cooling which provides unambiguous evidence of the interplay of the domain structure and the vorticity in the superconducting state. This is {\em direct} proof of coexistence of ferromagnetic and superconductive order parameters in high-TcT_c ruthenocuprates.Comment: 9 pages, 6 figure

    Stratifying quotient stacks and moduli stacks

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    Recent results in geometric invariant theory (GIT) for non-reductive linear algebraic group actions allow us to stratify quotient stacks of the form [X/H], where X is a projective scheme and H is a linear algebraic group with internally graded unipotent radical acting linearly on X, in such a way that each stratum [S/H] has a geometric quotient S/H. This leads to stratifications of moduli stacks (for example, sheaves over a projective scheme) such that each stratum has a coarse moduli space.Comment: 25 pages, submitted to the Proceedings of the Abel Symposium 201

    Free-form optics for Fresnel-lens-based photovoltaic concentrators

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    The Concentrated Photovoltaics (CPV) promise relies upon the use of high-efficiency triple-junction solar cells (with proven efficiencies of over 44%) and upon high-performance optics that allow for high concentration concurrent with relaxed manufacturing tolerances (all key elements for low-cost mass production). Additionally, uniform illumination is highly desirable for efficiency and reliability reasons. All of these features have to be achieved with inexpensive optics containing only a few (in general no more than 2) optical elements. In this paper we show that the degrees of freedom using free-forms allow the introduction of multiple functionalities required for CPV with just 2 optical elements, one of which is a Fresnel lens

    Factive and nonfactive mental state attribution

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    Factive mental states, such as knowing or being aware, can only link an agent to the truth; by contrast, nonfactive states, such as believing or thinking, can link an agent to either truths or falsehoods. Researchers of mental state attribution often draw a sharp line between the capacity to attribute accurate states of mind and the capacity to attribute inaccurate or “reality-incongruent” states of mind, such as false belief. This article argues that the contrast that really matters for mental state attribution does not divide accurate from inaccurate states, but factive from nonfactive ones

    An application of the SMS method for imaging designs.

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    The Simultaneous Multiple Surface (SMS) method in planar geometry (2D) is applied to imaging designs, generating lenses that compare well with aplanatic designs. When the merit function utilizes image quality over the entire field (not just paraxial), the SMS strategy is superior. In fact, the traditional aplanatic approach is actually a particular case of the SMS strateg

    Managed Aquifer Recharge as a Tool to Enhance Sustainable Groundwater Management in California

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    A growing population and an increased demand for water resources have resulted in a global trend of groundwater depletion. Arid and semi-arid climates are particularly susceptible, often relying on groundwater to support large population centers or irrigated agriculture in the absence of sufficient surface water resources. In an effort to increase the security of groundwater resources, managed aquifer recharge (MAR) programs have been developed and implemented globally. MAR is the approach of intentionally harvesting and infiltrating water to recharge depleted aquifer storage. California is a prime example of this growing problem, with three cities that have over a million residents and an agricultural industry that was valued at 47 billion dollars in 2015. The present-day groundwater overdraft of over 100 km3 (since 1962) indicates a clear disparity between surface water supply and water demand within the state. In the face of groundwater overdraft and the anticipated effects of climate change, many new MAR projects are being constructed or investigated throughout California, adding to those that have existed for decades. Some common MAR types utilized in California include injection wells, infiltration basins (also known as spreading basins, percolation basins, or recharge basins), and low-impact development. An emerging MAR type that is actively being investigated is the winter flooding of agricultural fields using existing irrigation infrastructure and excess surface water resources, known as agricultural MAR. California therefore provides an excellent case study to look at the historical use and performance of MAR, ongoing and emerging challenges, novel MAR applications, and the potential for expansion of MAR. Effective MAR projects are an essential tool for increasing groundwater security, both in California and on a global scale. This chapter aims to provide an overview of the most common MAR types and applications within the State of California and neighboring semi-arid regions

    Measures on Banach Manifolds and Supersymmetric Quantum Field Theory

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    We show how to construct measures on Banach manifolds associated to supersymmetric quantum field theories. These measures are mathematically well-defined objects inspired by the formal path integrals appearing in the physics literature on quantum field theory. We give three concrete examples of our construction. The first example is a family μPs,t\mu_P^{s,t} of measures on a space of functions on the two-torus, parametrized by a polynomial PP (the Wess-Zumino-Landau-Ginzburg model). The second is a family \mu_\cG^{s,t} of measures on a space \cG of maps from ¶1\P^1 to a Lie group (the Wess-Zumino-Novikov-Witten model). Finally we study a family μM,Gs,t\mu_{M,G}^{s,t} of measures on the product of a space of connection s on the trivial principal bundle with structure group GG on a three-dimensional manifold MM with a space of \fg-valued three-forms on M.M. We show that these measures are positive, and that the measures \mu_\cG^{s,t} are Borel probability measures. As an application we show that formulas arising from expectations in the measures \mu_\cG^{s,1} reproduce formulas discovered by Frenkel and Zhu in the theory of vertex operator algebras. We conjecture that a similar computation for the measures μM,SU(2)s,t,\mu_{M,SU(2)}^{s,t}, where MM is a homology three-sphere, will yield the Casson invariant of M.M.Comment: Minor correction
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