986 research outputs found

    Acoustical-Mode-Driven Electron-Phonon Coupling in Transition-Metal Diborides

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    We show that the electron-phonon coupling in the transition-metal diborides NbB2 and TaB2 is dominated by the longitudinal acoustical (LA) mode, in contrast to the optical E_{2g} mode dominated coupling in MgB2. Our ab initio results, described in terms of phonon dispersion, linewidth, and partial electron-phonon coupling along Gamma to A, also show that (i) NbB2 and TaB2 have a relatively weak electron-phonon coupling, (ii) the E_{2g} linewidth is an order of magnitude larger in MgB2 than in NbB2 or TaB2, (iii) the E_{2g} frequency in NbB2 and TaB2 is considerably higher than in MgB2, and (iv) the LA frequency at A for TaB2 is almost half of that of MgB2 or NbB2.Comment: 4 pages, 4 figures, and 1 tabl

    Prevalence of non-alcoholic fatty liver disease (NAFLD) in patients with type 2 diabetes mellitus and its correlation with coronary artery disease (CAD)

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    Background: Non-alcoholic fatty liver disease (NAFLD) is a common association of Type 2 diabetes mellitus and diabetes mellitus is a leading risk factor for coronary artery disease (CAD). This study aims at estimating the prevalence of NAFLD by ultrasonography and to correlate NAFLD with CAD in a group of patients with Type 2 DM.Methods: Consecutive patients of Type 2 diabetes fulfilling the inclusion criteria were recruited. Clinical and biochemical parameters were recorded. NAFLD was diagnosed by ultrasonography.Results: The prevalence of NAFLD was 41.2% in the study group (n=114) and was higher in females. Prevalence of NAFLD in the younger age group was significantly higher than that in the older age group. Elevated liver enzymes, elevated HbA1C, duration of diabetes, obesity, acanthosis nigricans and metabolic syndrome were all significantly associated with NAFLD. CAD was significantly higher in the NAFLD subgroup (72.46%) compared to the non-NAFLD subgroup (52.63%) (p=0.001). Using binary logistic regression analysis, it was found that NAFLD is an independent predictor of CAD (p=0.002).Conclusions: NAFLD is extremely common in people with Type 2 diabetes and is associated with a higher prevalence of CAD.NAFLD is an independent risk factor for development of CAD. Thus, identification of NAFLD in diabetics might help in predicting the risk of CAD and to adopt the necessary preventive strategy.

    Significance of APTT as early predictor of bleeding in comparison to thrombocytopenia in dengue virus infection

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    Background: Dengue is a systemic viral infection transmitted by mosquitoes such as Aedes aegypti or Aedes albopictus. Dengue Fever (DF) is characterized by fever, headache, muscle or joint pain, and rash. The spectrum of dengue virus infection spreads from an undifferentiated fever and dengue fever (DF) to dengue haemorrhagic fever (DHF) with shock. Factors responsible for bleeding manifestations in dengue are vasculopathy, thrombocytopenia, coagulopathy, and disseminated intravascular coagulation (DIC). Coagulopathy results in derangement of activated partial thromboplastin time (APTT) which is an indicator of impending bleeding risk.Methods: A prospective study was conducted from June to December in 2017 in R L Jalappa Hospital. Patients aged above 18 years with febrile thrombocytopenia who are positive for dengue virus serology (NS1Ag and/ or IgM) were included in the study. Serial daily monitoring of platelet count and analysis of APTT levels were done. APTT was considered abnormal if it was more than 33.8s. Patients were followed up for evidence of leaking and bleeding manifestations.Results: Out of 170 patients 28.1% patients had bleeding manifestations. Bleeding signs were seen on clinical examination in 52.37% of patients. capillary leak was found in the form of Pleural effusion in 35.3%, Ascites in 41.2% and Periorbital edema in 31.2% of patients. Elevated APTT levels were seen in 110(64.7%) patients. Among patients with abnormal APTT platelet transfusion was done in 78.9% of patients, and among those with normal APTT levels platelet transfusion was done in 21.1% of patients.Conclusions: Our study showed significant correlation between bleeding manifestations and prolonged APTT levels as well as thrombocytopenia with abnormal APTT levels. Study concluded that 21.1% of platelet transfusions could have been prevented considering prolonged APTT as a predictor of bleeding manifestation, thus saving the resources and reactions due to platelet concentrate transfusion

    Tuberculosis-diabetes mellitus bidirectional screening at a tertiary care centre, South India

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    Supported by the TB Union/MSF Course on Operational Researc

    Composite CDMA - A statistical mechanics analysis

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    Code Division Multiple Access (CDMA) in which the spreading code assignment to users contains a random element has recently become a cornerstone of CDMA research. The random element in the construction is particular attractive as it provides robustness and flexibility in utilising multi-access channels, whilst not making significant sacrifices in terms of transmission power. Random codes are generated from some ensemble, here we consider the possibility of combining two standard paradigms, sparsely and densely spread codes, in a single composite code ensemble. The composite code analysis includes a replica symmetric calculation of performance in the large system limit, and investigation of finite systems through a composite belief propagation algorithm. A variety of codes are examined with a focus on the high multi-access interference regime. In both the large size limit and finite systems we demonstrate scenarios in which the composite code has typical performance exceeding sparse and dense codes at equivalent signal to noise ratio.Comment: 23 pages, 11 figures, Sigma Phi 2008 conference submission - submitted to J.Stat.Mec

    From chaos to disorder: Statistics of the eigenfunctions of microwave cavities

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    We study the statistics of the experimental eigenfunctions of chaotic and disordered microwave billiards in terms of the moments of their spatial distributions, such as the Inverse Participation Ratio (IPR) and density-density auto-correlation. A path from chaos to disorder is described in terms of increasing IPR. In the chaotic, ballistic limit, the data correspond well with universal results from random matrix theory. Deviations from universal distributions are observed due to disorder induced localization, and for the weakly disordered case the data are well-described by including finite conductance and mean free path contributions in the framework of nonlinear sigma models of supersymetry.Comment: 5 pages + 2 JPG figure

    Bounded Temporal Fairness for FIFO Financial Markets

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    Financial exchange operators cater to the needs of their users while simultaneously ensuring compliance with the financial regulations. In this work, we focus on the operators' commitment for fair treatment of all competing participants. We first discuss unbounded temporal fairness and then investigate its implementation and infrastructure requirements for exchanges. We find that these requirements can be fully met only under ideal conditions and argue that unbounded fairness in FIFO markets is unrealistic. To further support this claim, we analyse several real-world incidents and show that subtle implementation inefficiencies and technical optimizations suffice to give unfair advantages to a minority of the participants. We finally introduce, {\epsilon}-fairness, a bounded definition of temporal fairness and discuss how it can be combined with non-continuous market designs to provide equal participant treatment with minimum divergence from the existing market operation

    A special purpose silicon compiler for designing supercomputing VLSI systems

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    Design of general/special purpose supercomputing VLSI systems for numeric algorithm execution involves tackling two important aspects, namely their computational and communication complexities. Development of software tools for designing such systems itself becomes complex. Hence a novel design methodology has to be developed. For designing such complex systems a special purpose silicon compiler is needed in which: the computational and communicational structures of different numeric algorithms should be taken into account to simplify the silicon compiler design, the approach is macrocell based, and the software tools at different levels (algorithm down to the VLSI circuit layout) should get integrated. In this paper a special purpose silicon (SPS) compiler based on PACUBE macrocell VLSI arrays for designing supercomputing VLSI systems is presented. It is shown that turn-around time and silicon real estate get reduced over the silicon compilers based on PLA's, SLA's, and gate arrays. The first two silicon compiler characteristics mentioned above enable the SPS compiler to perform systolic mapping (at the macrocell level) of algorithms whose computational structures are of GIPOP (generalized inner product outer product) form. Direct systolic mapping on PLA's, SLA's, and gate arrays is very difficult as they are micro-cell based. A novel GIPOP processor is under development using this special purpose silicon compiler
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