678 research outputs found

    Spectral Representation of Thermal OTO Correlators

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    We study the spectral representation of finite temperature, out of time ordered (OTO) correlators on the multi-time-fold generalised Schwinger-Keldysh contour. We write the contour-ordered correlators as a sum over time-order permutations acting on a funda- mental array of Wightman correlators. We decompose this Wightman array in a basis of column vectors, which provide a natural generalisation of the familiar retarded-advanced basis in the finite temperature Schwinger-Keldysh formalism. The coefficients of this de- composition take the form of generalised spectral functions, which are Fourier transforms of nested and double commutators. Our construction extends a variety of classical results on spectral functions in the SK formalism at finite temperature to the OTO case.Comment: 19 pages+appendices, references adde

    Joint Spectrum Sensing and Resource Allocation for OFDM-based Transmission with a Cognitive Relay

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    In this paper, we investigate the joint spectrum sensing and resource allocation problem to maximize throughput capacity of an OFDM-based cognitive radio link with a cognitive relay. By applying a cognitive relay that uses decode and forward (D&F), we achieve more reliable communications, generating less interference (by needing less transmit power) and more diversity gain. In order to account for imperfections in spectrum sensing, the proposed schemes jointly modify energy detector thresholds and allocates transmit powers to all cognitive radio (CR) subcarriers, while simultaneously assigning subcarrier pairs for secondary users (SU) and the cognitive relay. This problem is cast as a constrained optimization problem with constraints on (1) interference introduced by the SU and the cognitive relay to the PUs; (2) miss-detection and false alarm probabilities and (3) subcarrier pairing for transmission on the SU transmitter and the cognitive relay and (4) minimum Quality of Service (QoS) for each CR subcarrier. We propose one optimal and two sub-optimal schemes all of which are compared to other schemes in the literature. Simulation results show that the proposed schemes achieve significantly higher throughput than other schemes in the literature for different relay situations.Comment: EAI Endorsed Transactions on Wireless Spectrum 14(1): e4 Published 13th Apr 201

    Impact of Three Different Mutations in Ehrlichia chaffeensis in Altering the Global Gene Expression Patterns

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    Citation: Kondethimmanahalli, C., & Ganta, R. (2018). Impact of Three Different Mutations in Ehrlichia chaffeensis in Altering the Global Gene Expression Patterns. Scientific Reports, 8(1). https://doi.org/10.1038/s41598-018-24471-3The rickettsial pathogen Ehrlichia chaffeensis causes a tick-borne disease, human monocytic ehrlichiosis. Mutations within certain genomic locations of the pathogen aid in understanding the pathogenesis and in developing attenuated vaccines. Our previous studies demonstrated that mutations in different genomic sites in E. chaffeensis caused variable impacts on their growth and attenuation in vertebrate and tick hosts. Here, we assessed the effect of three mutations on transcriptional changes using RNA deep-sequencing technology. RNA sequencing aided in detecting 66–80% of the transcripts of wildtype and mutant E. chaffeensis. Mutation in an antiporter gene (ECH_0379) causing attenuated growth in vertebrate hosts resulted in the down regulation of many transcribed genes. Similarly, a mutation downstream to the ECH_0490 coding sequence resulted in minimal impact on the pathogen’s in vivo growth, but caused major changes in its transcriptome. This mutation caused enhanced expression of several host stress response genes. Even though the ECH_0660 gene mutation caused the pathogen’s rapid clearance in vertebrate hosts and aids in generating a protective response, there was minimal impact on the transcriptome. The transcriptomic data offer novel insights about the impact of mutations on global gene expression and how they may contribute to the pathogen’s resistance and/or clearance from the host

    A Genetic Algorithm Based Optimization Framework To Visualize, Evaluate, And Modify 3D Space Configurations In Desktop VR

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    This paper presents the design and implementation of a Desktop VR (Virtual Reality) framework for generating and evaluating Pareto-optimal alternate 3D spatial configurations using GA (genetic algorithms). The 3-tier framework involves the generation of the Pareto-optimal plans using GA which are subsequently visualized first using a Java-based 2D Interface and finally in the form of a 3D VR scene. The search spaces (function domains) are extremely large in today’s multifaceted interior design situations, and the optimization procedure involves conflicting objective functions, and limitations in the form of constraint functions. The interior space allocation problem is formulated and implemented as the ‘‘optimal configuration of artifacts’’. When using GAs, a group of Pareto-optimal solutions (Pareto set) are available for the planners and decision-makers, wherefrom one solution ought to be picked. Therefore, this study applies a tool to not only visually evaluate the plans, but also to interact with those plans to develop them further if needed. Besides enabling the optimal spatial configuration of the scene elements, this framework also facilitates evaluation and interaction via the 3D VR worlds. The framework aids the proactive exploration, analysis, and finalization of design aspects such as color, size, lighting, etc. of the various elements prior to the actual construction. The results demonstrate the robust performance of the GA and the final 3D VR environment with dynamic interactive capabilities. This final interface facilitates ‘‘GA-Compliant’’ transformations and scene modifications thereby facilitating the exploration and examination of alternative scene configurations

    Heparin binding domain in vitronectin is required for oligomerization and thus enhances integrin mediated cell adhesion and spreading

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    AbstractVitronectin is a multi-functional protein found predominantly as a monomer in blood and as an oligomer in the extracellular matrix. We have dissected the minimal regions of vitronectin protein needed for effective integrin dependent cell adhesion and spreading. A fragment of vitronectin containing the RGD integrin binding site showed similar binding affinity as that of full vitronectin protein to purified integrin αvÎČ3 but had diminished cell adhesion and spreading function in vivo. We demonstrate that the oligomeric state of the protein is responsible for this effect. We provide compelling evidence for the involvement of the heparin binding domain of vitronectin in the oligomerization process and show that such oligomerization reinforces the activity of vitronectin in cell adhesion and spreading.Structured summaryMINT-7905703: Vn (uniprotkb:P04004) and Vn (uniprotkb:P04004) bind (MI:0407) by molecular sieving (MI:0071

    A Study on Serum Prolactin Levels in CKD Patients and it’s Correlation with Coronary Artery Heart Disease

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    BACKGROUND: In CKD patient’s prolactin clearance & production are altered; this causes Hyperprolactinemia in CKD patients. CKD is associated with increased risk of CAHD.Emerging evidence suggests that prolactin plays a major role in atherosclerotic process. OBJECTIVES: 1. To study the occurrence of Hyperprolactinemia in CKD patients. 2. To study the links between hyperprolactinemia in CKD patients & occurrence of CAHD in them. METHODOLOGY: We conducted an observational study in 50 CKD patients. Fasting serum prolactin levels were measured in them; Incidence of CAHD was evaluated in them using ECG & ECHO. RESULTS: In our study among the 50 CKD patients, 28 patients had Hyperprolactinemia which is about 56% of the study population. Statistical analysis using T test showed significant association to exist between Hyperprolactinemia & CKD. In our study among the 28 CKD patients with Hyperprolactinemia 17 patients were diagnosed to have CAHD; this is about 60.7%. Statistical analysis using Chi Square test showed significant association to exist between Hyperprolactinemia in CKD patients & Occurence of CAHD among them. CONCLUSION: Serum prolactin levels are increased in patients with CKD. This hyperprolactinemia in CKD patients is associated with increased risk of CAHD in them

    Cognitive development in children with chronic protein energy malnutrition

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    <p>Abstract</p> <p>Background</p> <p>Malnutrition is associated with both structural and functional pathology of the brain. A wide range of cognitive deficits has been reported in malnourished children. Effect of chronic protein energy malnutrition (PEM) causing stunting and wasting in children could also affect the ongoing development of higher cognitive processes during childhood (>5 years of age). The present study examined the effect of stunted growth on the rate of development of cognitive processes using neuropsychological measures.</p> <p>Methods</p> <p>Twenty children identified as malnourished and twenty as adequately nourished in the age groups of 5–7 years and 8–10 years were examined. NIMHANS neuropsychological battery for children sensitive to the effects of brain dysfunction and age related improvement was employed. The battery consisted of tests of motor speed, attention, visuospatial ability, executive functions, comprehension and learning and memory</p> <p>Results</p> <p>Development of cognitive processes appeared to be governed by both age and nutritional status. Malnourished children performed poor on tests of attention, working memory, learning and memory and visuospatial ability except on the test of motor speed and coordination. Age related improvement was not observed on tests of design fluency, working memory, visual construction, learning and memory in malnourished children. However, age related improvement was observed on tests of attention, visual perception, and verbal comprehension in malnourished children even though the performance was deficient as compared to the performance level of adequately nourished children.</p> <p>Conclusion</p> <p>Chronic protein energy malnutrition (stunting) affects the ongoing development of higher cognitive processes during childhood years rather than merely showing a generalized cognitive impairment. Stunting could result in slowing in the age related improvement in certain and not all higher order cognitive processes and may also result in long lasting cognitive impairments.</p

    Growth Patterns of Neuropsychological Functions in Indian Children

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    We investigated age-related differences in neuropsychological performance in 400 Indian school children (5–15 years of age). Functions of motor speed, attention, executive functions, visuospatial functions, comprehension, learning, and memory were examined. Growth curve analysis was performed. Different growth models fitted different cognitive functions. Neuropsychological task performance improved slowly between 5 and 7 years, moderately between 8 and 12 years and slowly between 13 and 15 years of age. The overall growth patterns of neuropsychological functions in Indian children have been discussed with the findings reported on American children. The present work describes non-linear, heterogeneous, and protracted age trends of neuropsychological functions in Indian children and adolescents
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