23,159 research outputs found

    New observables for multiple-parton interactions measurements using Z + jets process at the LHC

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    Multiple-parton interactions play a vital role in hadron-hadron collisions. This paper presents a study of the multiple-parton interactions with simulated Z + jets events in proton-proton collisions at a centre-of-mass energy of 13 TeV. The events are simulated with POWHEG followed by hadronization and parton-showering using PYTHIA 8. The events with dimuon invariant mass in the range of 60--120 GeV are selected for the analysis. The charged particle jets, having minimum transverse momentum of 5 GeV and absolute pseudo-rapidity less than 2, are used to construct the observables for measurements of the multiple-parton interactions. The proposed observables and phase-space region presented in this paper found to have enhanced sensitivity to multiple-parton interactions. The increased sensitivity to MPI will be lead to precise constraints on the parameters of the MPI models.Comment: 17 pages, 7 figures, Accepted for publication in Physical Review

    Malignant peripheral nerve sheath tumor of the cervical vagus nerve in a neurofibromatosis type 1 patient - An unusual presentation

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    Malignant peripheral nerve sheath tumors (MPNST’S) of the head and neck comprise 2% to 6% of head and neck sarcomas. These tumors may arise as sporadic variants or in patients with neurofibromatosis (NF). Development of these MPNST’s is one of the serious complications of neurofibromatosis type 1(NF1). To our knowledge there are only two reported cases of MPNST’s arising in the cervical vagal nerve, occurring in NF1 patients. We present here an NF1 patient who developed an MPNST of the cervical vagus nerve and presented only with a cervical swelling and hoarseness

    Undifferentiated Carcinoma of Larynx of Nasopharyngeal Type

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    Undifferentiated carcinoma of nasopharyngeal type arising in the larynx is unusual. This type of carcinoma-which occurs almost exclusively in nasopharynx-is very infrequent in the larynx (0.2%). Till date only 17 cases are reported in the medical literature. We present the clinical and histopathological findings along with the management of one additional case of undifferentiated carcinoma of nasopharyngeal type in the larynx which was managed successfully with radiotherapy

    Sequential item pricing for unlimited supply

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    We investigate the extent to which price updates can increase the revenue of a seller with little prior information on demand. We study prior-free revenue maximization for a seller with unlimited supply of n item types facing m myopic buyers present for k < log n days. For the static (k = 1) case, Balcan et al. [2] show that one random item price (the same on each item) yields revenue within a \Theta(log m + log n) factor of optimum and this factor is tight. We define the hereditary maximizers property of buyer valuations (satisfied by any multi-unit or gross substitutes valuation) that is sufficient for a significant improvement of the approximation factor in the dynamic (k > 1) setting. Our main result is a non-increasing, randomized, schedule of k equal item prices with expected revenue within a O((log m + log n) / k) factor of optimum for private valuations with hereditary maximizers. This factor is almost tight: we show that any pricing scheme over k days has a revenue approximation factor of at least (log m + log n) / (3k). We obtain analogous matching lower and upper bounds of \Theta((log n) / k) if all valuations have the same maximum. We expect our upper bound technique to be of broader interest; for example, it can significantly improve the result of Akhlaghpour et al. [1]. We also initiate the study of revenue maximization given allocative externalities (i.e. influences) between buyers with combinatorial valuations. We provide a rather general model of positive influence of others' ownership of items on a buyer's valuation. For affine, submodular externalities and valuations with hereditary maximizers we present an influence-and-exploit (Hartline et al. [13]) marketing strategy based on our algorithm for private valuations. This strategy preserves our approximation factor, despite an affine increase (due to externalities) in the optimum revenue.Comment: 18 pages, 1 figur

    A New Simulation Metric to Determine Safe Environments and Controllers for Systems with Unknown Dynamics

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    We consider the problem of extracting safe environments and controllers for reach-avoid objectives for systems with known state and control spaces, but unknown dynamics. In a given environment, a common approach is to synthesize a controller from an abstraction or a model of the system (potentially learned from data). However, in many situations, the relationship between the dynamics of the model and the \textit{actual system} is not known; and hence it is difficult to provide safety guarantees for the system. In such cases, the Standard Simulation Metric (SSM), defined as the worst-case norm distance between the model and the system output trajectories, can be used to modify a reach-avoid specification for the system into a more stringent specification for the abstraction. Nevertheless, the obtained distance, and hence the modified specification, can be quite conservative. This limits the set of environments for which a safe controller can be obtained. We propose SPEC, a specification-centric simulation metric, which overcomes these limitations by computing the distance using only the trajectories that violate the specification for the system. We show that modifying a reach-avoid specification with SPEC allows us to synthesize a safe controller for a larger set of environments compared to SSM. We also propose a probabilistic method to compute SPEC for a general class of systems. Case studies using simulators for quadrotors and autonomous cars illustrate the advantages of the proposed metric for determining safe environment sets and controllers.Comment: 22nd ACM International Conference on Hybrid Systems: Computation and Control (2019

    An Assessment of Knowledge and Practices Regarding Tuberculosis in the Context of RNTCP Among Non Allopathic Practitioners in Gwalior District

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    Introduction: India has the highest TB burden accounting for one-fifth of the global incidence with an estimated 1.98 million cases. Non- allopathic practitioners are the major service providers especially in rural and peri-urban areas, treating not just patients of diarrhea, respiratory infections and abdominal Pain but also of tuberculosis. Objectives: To assess the knowledge of sign and symptoms of TB and its management as per the RNTCP guidelines and to assess the practicing pattern regarding tuberculosis. Material & Methods: The present was carried out among the registered non allopathic practitioners providing their services in Gwalior District during the study period. A total of 150 non allopathic practitioners of various methods from both government and private sectors were interviewed using a pre-designed, pre-tested semi-structured questionnaire. The information was collected on the General profile of the participant, knowledge about signs and symptoms of TB and its management, practices commonly adopted in the management and their views on involvement of non allopathic practitioners in RNTCP programme. Result: The average score of government practitioners was 7.3 compared to 4.6 by private practitioners. There was a statistically significant difference between the two group on issue related to the management of TB patients as per the RNTCP guidelines. Government practitioners relied mostly on sputum examination for diagnosis and follow up compared to private practitioners who chose other modalities like X-ray, blood examination for this work. Conclusion: There is a gap in knowledge and practices of practitioners of both the sectors. Some serious efforts were required to upgrade the knowledge of non allopathic practitioners if the government is serious about controlling tuberculosis in India
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