595 research outputs found

    Exact Haldane mapping for all SS and super universality in spin chains

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    The low energy dynamics of the anti-ferromagnetic Heisenberg spin SS chain in the semiclassical limit S→∞S\to\infty is known to map onto the O(3) nonlinear σ\sigma model with a θ\theta term in 1+1 dimension. Guided by the underlying dual symmetry of the spin chain, as well as the recently established topological significance of "dangling edge spins," we report an {\em exact} mapping onto the O(3) model that avoids the conventional large SS approximation altogether. Our new methodology demonstrates all the super universal features of the θ\theta angle concept that previously arose in the theory of the quantum Hall effect. It explains why Haldane's original ideas remarkably yield the correct answer in spite of the fundamental complications that generally exist in the idea of semiclassical expansions

    Some characteristics of the larval breeding sites of Anopheles culicifacies species B and E in Sri Lanka

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    Background & objectives : Anopheles culicifacies Giles, the major malaria vector in Sri Lanka, existsas a species complex comprising two sympatric sibling species— species B and E. Species E is reportedto be the major vector of Plasmodium vivax and P. falciparum parasites in Sri Lanka, whilst speciesB is a poor or nonvector as in India. Knowledge of the breeding habits of the two sibling species canhelp in designing optimal vector control strategies. Hence, a survey was conducted in Sri Lanka tostudy the preferential breeding habitats of An. culicifacies species B and E.Methods: Immature forms of An. culicifacies were collected from identified breeding sites in malariousdistricts. Collected larvae were typed for their sibling species status based on mitotic Y-chromosomestructure. Data was analysed using Statistical Package for Social Science version 10.0.Results: An. culicifacies immature forms were found in 23 collection sites. Among these samples19 were found to have species E and four to have species B. All species B larvae were collected fromTonigala village in the Puttalam district. None of the 23 sites was found to have both species B and E.Species E, the major vector of malaria, appears to breed in variety of breeding sites which can be of anindication of its adaptive variation to exploit breeding sites with varying limnological characteristics.Interpretation & conclusion: The present findings have to be taken into account when formulatingmore effective larval control measures. They also show the need for a detailed study of possibledifferent preferences for larval breeding sites between species B and E

    Gender and innovation processes in integrated fish agri-food systems in Bangladesh and the Philippines: Insights from the CGIAR Research Program on FISH

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    This FISH report provides insights on the interactions between gender norms, agency, and innovation in fish agri-food systems

    An Elastic Scheduling Algorithm For Resource Co-Allocation Based on System Generated Predictions With Priority

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    Resource Co-Allocation is basically used to execute multiple site jobs in a large scale computing environments with secure, faultless and in transparent manner. To be precise we are actually allocating multiple resources for different jobs taking into account the time parameter. Here we make use of the Scheduling queue and Resource Co-Allocation to reduce the Turn-around time with an advanced concept of System Generated Prediction based on Priority. In existing works we are scheduling the resource co-allocation request from user runtime estimation. As user runtime estimations are usually very imprecise that is not clear. In proposed work we are scheduling the resource co-allocation request based on system generated predictions through Discovery service & Priority (fairness and user experience) through topological sorting technique. The system generated predictions are better parameters than user runtime estimates for Resource co-Allocation scheduling, because System generated predictions reduce the scheduling time through proxy ser based discovery service technique. The proposed work consider priorities like advanced reservation, system Generated Predictions, Negotiation, Co-scheduling, policy (SLA, Price, Trust) for resource Co-Allocation. The system generated predictions are better than user runtime estimates for Resource co- Allocation scheduling, using the experimental data’s we proved this concept. End User doesn’t want the grid and resource knowledge only submit job to the portal. This proposed portal will take care of all knowledge about the resource collocation automatically with fast and efficient manner

    THERMAL ANALYSIS OF AUTOMOTIVE CYLINDER HEAD MADE BY ALUMINIUM METAL MATRIX COMPOSITE REINFORCED WITH NANO ALUMINA

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    Metal Matrix Nano Composites (MMNC’s) have been developed to meet the demand for lighter materials with significant improvements in mechanical and physical properties like high strength, excellent wear resistance, good thermal conductivity, low thermal expansion coefficient with particulate reinforcements. Aluminium based nano composites (AA356 – nano Al2O3) with three different percentage (1%, 1.5%, 2.5% Wt) of nano – alumina particulate reinforcement (~40 nm) were fabricated using in-situ stir casting technique. Mechanical properties characterization which strongly depends on microstructural properties of reinforcement revealed that the presence of nano – alumina particulates lead to simultaneous increase in hardness, UTS, wear behaviour. The results revealed that UTS, Hardness, Wear behaviour increases with the increase in the percentage of reinforcement of nano – Al2O3 whereas the thermal conductivity drops with increasing percentage of reinforcement when compared to the base alloy AA356. An attempt is made in the present study to review the opportunities of using such a MMNC developed in automotive brake drum replacing the current system using cast iron

    Dynamic Race Prediction in Linear Time

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    Writing reliable concurrent software remains a huge challenge for today's programmers. Programmers rarely reason about their code by explicitly considering different possible inter-leavings of its execution. We consider the problem of detecting data races from individual executions in a sound manner. The classical approach to solving this problem has been to use Lamport's happens-before (HB) relation. Until now HB remains the only approach that runs in linear time. Previous efforts in improving over HB such as causally-precedes (CP) and maximal causal models fall short due to the fact that they are not implementable efficiently and hence have to compromise on their race detecting ability by limiting their techniques to bounded sized fragments of the execution. We present a new relation weak-causally-precedes (WCP) that is provably better than CP in terms of being able to detect more races, while still remaining sound. Moreover it admits a linear time algorithm which works on the entire execution without having to fragment it.Comment: 22 pages, 8 figures, 1 algorithm, 1 tabl

    Relationship of Platelet Distribution Width and White Blood Cell Count on admission with ST-segment resolution in patients with ST-segment elevation myocardial infarction thrombolysed with streptokinase

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    BACKGROUND AND OBJECTIVES : There is an alarming rise in the incidence of coronary artery heart disease, STsegment Elevation Myocardial Infarction (STEMI) being one among them. ST segment resolution (STR) in an electrocardiogram is one of the most effective way to analyse the reperfusion after thrombolysis.. Here in our study, we try to analyse the relationship between ST-segment resolution (which predicts the success of thrombolysis) and two parameters – 1. Platelet Distribution Width (PDW) and 2. White blood cell count WBC-count) on admission in patients with STEMI. MATERIALS AND METHODOLOGY : We studied 100 patients admitted to Coimbatore Medical College Hospital with STEMI who are treated with streptokinase. Blood samples are taken for PDW and WBC-count on admission. A repeat electrocardiogram is taken 60 minutes after thrombolysis and the ST-segment resolution is calculated. More than 50% resolution is considered as successful thrombolysis. Patients are divided into groups as PDW more than and less than 12.85 and WBC-count more than and less than 12650 cells per microlitre. RESULTS : PDW and ST segment resolution with a p value of <0.001 and WBC-count and ST segment resolution with a p valute of <0.001 were found to be statistically significant. CONCLUSION : PDW and WBC-count can be used to prognosticate and risk stratify patients with STEMI thrombolysed with streptokinase

    General topological features and instanton vacuum in quantum Hall and spin liquids

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    We introduce the concept of super universality in quantum Hall and spin liquids which has emerged from previous studies. It states that all the fundamental features of the quantum Hall effect are generically displayed as general topological features of the θ\theta parameter in nonlinear sigma models in two dimensions. To establish super universality in spin liquids we revisit the mapping by Haldane who argued that the anti ferromagnetic Heisenberg spin ss chain is effectively described by the O(3) nonlinear sigma model with a θ\theta term. By combining the path integral representation for the dimerized spin s=1/2s=1/2 chain with renormalization group decimation techniques we generalise the Haldane approach to include a more complicated theory, the fermionic rotor chain, involving four different renormalization group parameters. We show how the renormalization group calculation technique can be used to lay the bridge between the fermionic rotor chain and the sigma model. As an integral and fundamental aspect of the mapping we establish the topological significance of the dangling spin at the edge of the chain which is in all respects identical to the massless chiral edge excitations in quantum Hall liquids. We consider various different geometries of the spin chain and show that for each of the different geometries correspond to a topologically equivalent quantum Hall liquid.Comment: Title changed, Section 2 and Appendix expanded, an error in the expression for theta correcte
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