242 research outputs found

    New Prospects in Fixed Target Searches for Dark Forces with the SeaQuest Experiment at Fermilab

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    An intense, 120 GeV proton beam incident on an extremely long, iron target generates enormous numbers of light-mass particles that also decay within that target. If one of these particles decays to a final state with a hidden gauge boson, or if such a particle is produced as a result of the initial collision, then that weakly interacting, hidden-sector particle may traverse the remainder of the target and be detected downstream through its possible decay to an e+ee^+e^-, μ+μ\mu^+\mu^-, or π+π\pi^+\pi^- final state. These conditions can be realized through an extension of the SeaQuest experiment at Fermilab, and in this initial investigation we consider how it can serve as an ultrasensitive probe of hidden vector gauge forces, both Abelian and non-Abelian. A light, weakly coupled hidden sector may well explain the dark matter established through astrophysical observations, and the proposed search can provide tangible evidence for its existence --- or, alternatively, constrain a "sea" of possibilities.Comment: 14 pages, 8 figures; improved sensitivity analysis and cross-checks; small shifts in the expected limits; conclusions unchanged; refs. adde

    Linearly Polarized Wide-Band Microstrip Antenna

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    Managing Security in the Built Environment – A Review of Environmental Crime Prevention Strategies

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    The practice of urban planning and building design largely follow traditional methods while transforming the structure and quality of life in the built environment. The process of managing cities requires updates and integration of new technologies and research efforts. In this context, development of smart, sustainable, energy efficient, healthy, safe and secure built environment is a priority that is shaping modern cities all over the world. Though management of Indian cities tries to address these issues to a certain extent, it can be said that, as compared to many developed countries, aspects of safety and security have not been the top priority of our planners and designers. Research on Environmental Criminology and Environmental Psychology clearly indicates the important role and benefits of crime prevention through appropriate design of the built environment. In this context, this paper highlights the role of crime prevention strategies and the relevance of environmental criminology in current building practices for addressing security concerns in India

    Carcinomatous Meningitis: The Natural History of Successfully Treated Metastatic Bladder Cancer

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    Carcinomatous meningitis due to bladder cancer is a rare entity reported only in case reports. Optimal therapy is thus poorly defined with earlier cases reporting an unsuccessful outcome. Here we report a case of late carcinomatous meningitis secondary to transitional cell carcinoma (TCC) of the bladder occurring in a patient in complete remission. He was successfully treated with intrathecal methotrexate and whole brain irradiation and experienced prolonged survival after treatment. With modern chemotherapy increasing complete remissions and survival rates in patients with TCC, more and more patients are being reported with carcinomatous meningitis. We raise the question of whether central nervous system prophylaxis should be considered in patients with TCC achieving a complete remission to chemotherapy in the metastatic setting

    Dispersive wave runup on non-uniform shores

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    Historically the finite volume methods have been developed for the numerical integration of conservation laws. In this study we present some recent results on the application of such schemes to dispersive PDEs. Namely, we solve numerically a representative of Boussinesq type equations in view of important applications to the coastal hydrodynamics. Numerical results of the runup of a moderate wave onto a non-uniform beach are presented along with great lines of the employed numerical method (see D. Dutykh et al. (2011) for more details).Comment: 8 pages, 6 figures, 18 references. This preprint is submitted to FVCA6 conference proceedings. Other author papers can be downloaded at http://www.lama.univ-savoie.fr/~dutykh

    Adaptive Evolutionary Clustering

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    In many practical applications of clustering, the objects to be clustered evolve over time, and a clustering result is desired at each time step. In such applications, evolutionary clustering typically outperforms traditional static clustering by producing clustering results that reflect long-term trends while being robust to short-term variations. Several evolutionary clustering algorithms have recently been proposed, often by adding a temporal smoothness penalty to the cost function of a static clustering method. In this paper, we introduce a different approach to evolutionary clustering by accurately tracking the time-varying proximities between objects followed by static clustering. We present an evolutionary clustering framework that adaptively estimates the optimal smoothing parameter using shrinkage estimation, a statistical approach that improves a naive estimate using additional information. The proposed framework can be used to extend a variety of static clustering algorithms, including hierarchical, k-means, and spectral clustering, into evolutionary clustering algorithms. Experiments on synthetic and real data sets indicate that the proposed framework outperforms static clustering and existing evolutionary clustering algorithms in many scenarios.Comment: To appear in Data Mining and Knowledge Discovery, MATLAB toolbox available at http://tbayes.eecs.umich.edu/xukevin/affec

    What has finite element analysis taught us about diabetic foot disease and its management?:a systematic review

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    Over the past two decades finite element (FE) analysis has become a popular tool for researchers seeking to simulate the biomechanics of the healthy and diabetic foot. The primary aims of these simulations have been to improve our understanding of the foot's complicated mechanical loading in health and disease and to inform interventions designed to prevent plantar ulceration, a major complication of diabetes. This article provides a systematic review and summary of the findings from FE analysis-based computational simulations of the diabetic foot.A systematic literature search was carried out and 31 relevant articles were identified covering three primary themes: methodological aspects relevant to modelling the diabetic foot; investigations of the pathomechanics of the diabetic foot; and simulation-based design of interventions to reduce ulceration risk.Methodological studies illustrated appropriate use of FE analysis for simulation of foot mechanics, incorporating nonlinear tissue mechanics, contact and rigid body movements. FE studies of pathomechanics have provided estimates of internal soft tissue stresses, and suggest that such stresses may often be considerably larger than those measured at the plantar surface and are proportionally greater in the diabetic foot compared to controls. FE analysis allowed evaluation of insole performance and development of new insole designs, footwear and corrective surgery to effectively provide intervention strategies. The technique also presents the opportunity to simulate the effect of changes associated with the diabetic foot on non-mechanical factors such as blood supply to local tissues.While significant advancement in diabetic foot research has been made possible by the use of FE analysis, translational utility of this powerful tool for routine clinical care at the patient level requires adoption of cost-effective (both in terms of labour and computation) and reliable approaches with clear clinical validity for decision making

    The T2K ND280 Off-Axis Pi-Zero Detector

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    The Pi-Zero detector (P{\O}D) is one of the subdetectors that makes up the off-axis near detector for the Tokai-to-Kamioka (T2K) long baseline neutrino experiment. The primary goal for the P{\O}D is to measure the relevant cross sections for neutrino interactions that generate pi-zero's, especially the cross section for neutral current pi-zero interactions, which are one of the dominant sources of background to the electron neutrino appearance signal in T2K. The P{\O}D is composed of layers of plastic scintillator alternating with water bags and brass sheets or lead sheets and is one of the first detectors to use Multi-Pixel Photon Counters (MPPCs) on a large scale.Comment: 17 pages, submitted to NIM
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