6,692 research outputs found

    Conservative management of a grade V injury to an ectopic pelvic kidney following blunt trauma to the lower abdomen: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Ectopic pelvic kidneys represent an anatomic variant that remains clinically asymptomatic in most patients. While there is some literature to suggest that ectopic kidneys may be more predisposed to blunt trauma injuries, there are few examples to guide the management of these injuries. To our knowledge, we present the first case of a grade V renal injury to an ectopic pelvic kidney managed successfully with conservative measures.</p> <p>Case Presentation</p> <p>We present a case of grade V renal injury to an ectopic pelvic kidney in a 21 year-old African-American male. The clinical and radiographic findings are presented, along with the patient's conservative hospital course.</p> <p>Conclusion</p> <p>We suggest that management of grade V renal injuries to ectopic pelvic kidneys can be treated similarly to that of kidneys in normal anatomic position. Conservative measures may be considered in properly selected patients.</p

    Partial Covering Arrays: Algorithms and Asymptotics

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    A covering array CA(N;t,k,v)\mathsf{CA}(N;t,k,v) is an N×kN\times k array with entries in {1,2,,v}\{1, 2, \ldots , v\}, for which every N×tN\times t subarray contains each tt-tuple of {1,2,,v}t\{1, 2, \ldots , v\}^t among its rows. Covering arrays find application in interaction testing, including software and hardware testing, advanced materials development, and biological systems. A central question is to determine or bound CAN(t,k,v)\mathsf{CAN}(t,k,v), the minimum number NN of rows of a CA(N;t,k,v)\mathsf{CA}(N;t,k,v). The well known bound CAN(t,k,v)=O((t1)vtlogk)\mathsf{CAN}(t,k,v)=O((t-1)v^t\log k) is not too far from being asymptotically optimal. Sensible relaxations of the covering requirement arise when (1) the set {1,2,,v}t\{1, 2, \ldots , v\}^t need only be contained among the rows of at least (1ϵ)(kt)(1-\epsilon)\binom{k}{t} of the N×tN\times t subarrays and (2) the rows of every N×tN\times t subarray need only contain a (large) subset of {1,2,,v}t\{1, 2, \ldots , v\}^t. In this paper, using probabilistic methods, significant improvements on the covering array upper bound are established for both relaxations, and for the conjunction of the two. In each case, a randomized algorithm constructs such arrays in expected polynomial time

    On the Core of Dynamic Cooperative Games

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    We consider dynamic cooperative games, where the worth of coalitions varies over time according to the history of allocations. When defining the core of a dynamic game, we allow the possibility for coalitions to deviate at any time and thereby to give rise to a new environment. A coalition that considers a deviation needs to take the consequences into account because from the deviation point on, the game is no longer played with the original set of players. The deviating coalition becomes the new grand coalition which, in turn, induces a new dynamic game. The stage games of the new dynamical game depend on all previous allocation including those that have materialized from the deviating time on. We define three types of core solutions: fair core, stable core and credible core. We characterize the first two in case where the instantaneous game depends on the last allocation (rather than on the whole history of allocations) and the third in the general case. The analysis and the results resembles to a great extent the theory of non-cooperative dynamic games.Comment: 25 page

    Understanding consumer demand for new transport technologies and services, and implications for the future of mobility

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    The transport sector is witnessing unprecedented levels of disruption. Privately owned cars that operate on internal combustion engines have been the dominant modes of passenger transport for much of the last century. However, recent advances in transport technologies and services, such as the development of autonomous vehicles, the emergence of shared mobility services, and the commercialization of alternative fuel vehicle technologies, promise to revolutionise how humans travel. The implications are profound: some have predicted the end of private car dependent Western societies, others have portended greater suburbanization than has ever been observed before. If transport systems are to fulfil current and future needs of different subpopulations, and satisfy short and long-term societal objectives, it is imperative that we comprehend the many factors that shape individual behaviour. This chapter introduces the technologies and services most likely to disrupt prevailing practices in the transport sector. We review past studies that have examined current and future demand for these new technologies and services, and their likely short and long-term impacts on extant mobility patterns. We conclude with a summary of what these new technologies and services might mean for the future of mobility.Comment: 15 pages, 0 figures, book chapte

    Evaluation of two interaction techniques for visualization of dynamic graphs

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    Several techniques for visualization of dynamic graphs are based on different spatial arrangements of a temporal sequence of node-link diagrams. Many studies in the literature have investigated the importance of maintaining the user's mental map across this temporal sequence, but usually each layout is considered as a static graph drawing and the effect of user interaction is disregarded. We conducted a task-based controlled experiment to assess the effectiveness of two basic interaction techniques: the adjustment of the layout stability and the highlighting of adjacent nodes and edges. We found that generally both interaction techniques increase accuracy, sometimes at the cost of longer completion times, and that the highlighting outclasses the stability adjustment for many tasks except the most complex ones.Comment: Appears in the Proceedings of the 24th International Symposium on Graph Drawing and Network Visualization (GD 2016

    Rational land and housing bubbles in infinite-horizon economies

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    URL des Documents de travail : http://ces.univ-paris1.fr/cesdp/cesdp2016.htmlDocuments de travail du Centre d'Economie de la Sorbonne 2016.27 - ISSN : 1955-611XThis paper considers rational land and housing bubbles in an infinite-horizon general equilibrium model. Their demands rest on two different grounds: the land is an input to produce while the house may be consumed. Our work differs from the existing literature in two respects. First, dividends on both these long-lived assets are endogenous and their sequences are computed. Second, we introduce and study different concepts of bubbles, including individual and strong bubbles

    Heterotic type IIA duality with fluxes - towards the complete story

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    In this paper we study the heterotic type IIA duality when fluxes are turned on. We show that many of the known fluxes are dual to each other and claim that certain fluxes on the heterotic side require that the type IIA picture is lifted to M or even F-theory compactifications with geometric fluxes.Comment: 31 pages, references adde
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