64 research outputs found

    Comparative metabolomics of erythroid lineage and Plasmodium life stages reveal novel host and parasite metabolism

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    Malaria, caused by the Apicomplexan parasite Plasmodium is a deadly disease which poses a huge health and economic burden over many populations in the world, mostly in sub-Saharan Africa and Asia. To design new intervention strategies and to improve upon existing drugs against malaria, it is important to understand the biochemistry of the Plasmodium parasite and its interaction with the host. We used metabolomics to dissect the biology of the reticulocyte preferring rodent malaria parasite Plasmodium berghei and showed that metabolic reserves in the reticulocytes can aid in survival of malaria parasites when their metabolism is genetically or chemically disrupted, pointing towards a direct role of host cell metabolism in parasite survival. These results have implications for currently used ways of intermediation in malaria infections which target only parasite metabolism against the human malaria parasites, Plasmodium vivax which prefers to infect reticulocytes and Plasmodium falciparum which is capable of infecting all erythrocytes. We also used metabolomics to show the biochemical differences between the asexual and sexual stages of P. berghei parasites and our data gave additional insights into the preparatory phase of the gametocyte stage at the metabolic level with the discovery of a phosphagen system which plays a role in gametogenesis. Targeted metabolomics of P. berghei life stages using isotopic labelling showed that TCA cycle metabolism is predominant in the mosquito stages. Discovery of a reductive arm of TCA metabolism in reticulocytes pointed towards the existence of rudimentary mitochondria in young erythrocytes. Another surprising discovery was the presence of up regulated γ-Aminobutyric acid (GABA) metabolism in the ookinete stage in P. berghei which may act as an energy source during the ookinete to oocyst transition in the mosquito. This pathway presented novel candidates for transmission blocking

    Extremely fast (a,b)-trees at all contention levels

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    Many concurrent dictionary implementations are designed and evaluated with only low-contention workloads in mind. This thesis presents several concurrent linearizable (a,b)-tree implementations with the overarching goal of performing well on both low- and high-contention workloads, and especially update-heavy workloads. The OCC-ABtree uses optimistic concurrency control to achieve state-of-the-art low-contention performance. However, under high-contention, cache coherence traffic begins to affect its performance. This is addressed by replacing its test-and-compare-and-swap locks with MCS queue locks. The resulting MCS-ABtree scales well under both low- and high-contention workloads. This thesis also introduces two coalescing-based trees, the CoMCS-ABtree and the CoPub-ABtree, that achieve substantially better performance under high-contention by reordering and coalescing concurrent inserts and deletes. Comparing these algorithms against the state of the art in concurrent search trees, we find that the fastest algorithm, the CoPub-ABtree, outperforms the next fastest competitor by up to 2x. This thesis then describes persistent versions of the four trees, whose implementations use fewer sfence instructions than a leading competitor (the FPTree). The persistent trees are proved to be strictly linearizable. Experimentally, the persistent trees are only slightly slower than their volatile counterparts, suggesting that they have great use as in-memory databases that need to be able to recover after a crash

    GESTURE RECOGNITION SYSTEM

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    In this paper, the hand gesture of a person is recognised and it identifies which hand of the person is raised. The skin colour is taken to recognise hands and face and the dark background is taken so that the skin detection may become easier. The hands and face are differentiated on the basis of area and centroid. Camera is the only input device used in this algorithm. No other input device is used to differentiate hands from the remaining body. This algorithm can be used both on the captured images and real time images

    GSM Controlled Automatic Irrigation System

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    Volume 7 Issue 8 (August 201

    Host reticulocytes provide metabolic reservoirs that can be exploited by malaria parasites

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    Human malaria parasites proliferate in different erythroid cell types during infection. Whilst Plasmodium vivax exhibits a strong preference for immature reticulocytes, the more pathogenic P. falciparum primarily infects mature erythrocytes. In order to assess if these two cell types offer different growth conditions and relate them to parasite preference, we compared the metabolomes of human and rodent reticulocytes with those of their mature erythrocyte counterparts. Reticulocytes were found to have a more complex, enriched metabolic profile than mature erythrocytes and a higher level of metabolic overlap between reticulocyte resident parasite stages and their host cell. This redundancy was assessed by generating a panel of mutants of the rodent malaria parasite P. berghei with defects in intermediary carbon metabolism (ICM) and pyrimidine biosynthesis known to be important for P. falciparum growth and survival in vitro in mature erythrocytes. P. berghei ICM mutants (pbpepc-, phosphoenolpyruvate carboxylase and pbmdh-, malate dehydrogenase) multiplied in reticulocytes and committed to sexual development like wild type parasites. However, P. berghei pyrimidine biosynthesis mutants (pboprt-, orotate phosphoribosyltransferase and pbompdc-, orotidine 5′-monophosphate decarboxylase) were restricted to growth in the youngest forms of reticulocytes and had a severe slow growth phenotype in part resulting from reduced merozoite production. The pbpepc-, pboprt- and pbompdc- mutants retained virulence in mice implying that malaria parasites can partially salvage pyrimidines but failed to complete differentiation to various stages in mosquitoes. These findings suggest that species-specific differences in Plasmodium host cell tropism result in marked differences in the necessity for parasite intrinsic metabolism. These data have implications for drug design when targeting mature erythrocyte or reticulocyte resident parasites

    GESTURE RECOGNITION SYSTEM

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    Abstract: In this paper, the hand gesture of a person is recognised and it identifies which hand of the person is raised. The skin colour is taken to recognise hands and face and the dark background is taken so that the skin detection may become easier. The hands and face are differentiated on the basis of area and centroid. Camera is the only input device used in this algorithm. No other input device is used to differentiate hands from the remaining body. This algorithm can be used both on the captured images and real time images

    Certifying the quantum Fisher information from a given set of mean values: a semidefinite programming approach

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    We introduce a semidefinite programming algorithm to find the minimal quantum Fisher information compatible with an arbitrary dataset of mean values. This certification task allows one to quantify the resource content of a quantum system for metrology applications without complete knowledge of the quantum state. We implement the algorithm to study quantum spin ensembles. We first focus on Dicke states, where our findings challenge and complement previous results in the literature. We then investigate states generated during the one-axis twisting dynamics, where in particular we find that the metrological power of the so-called multi-headed cat states can be certified using simple collective spin observables, such as fourth-order moments for small systems, and parity measurements for arbitrary system sizes.Comment: 25 pages, 10 figure

    Enhancing quantum state tomography via resource-efficient attention-based neural networks

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    Resource-efficient quantum state tomography is one of the key ingredients of future quantum technologies. In this work, we propose a new tomography protocol combining standard quantum state reconstruction methods with an attention-based neural network architecture. We show how the proposed protocol is able to improve the averaged fidelity reconstruction over linear inversion and maximum-likelihood estimation in the finite-statistics regime, reducing at least by an order of magnitude the amount of necessary training data. We demonstrate the potential use of our protocol in physically relevant scenarios, in particular, to certify metrological resources in the form of many-body entanglement generated during the spin squeezing protocols. This could be implemented with the current quantum simulator platforms, such as trapped ions, and ultra-cold atoms in optical lattices

    Determinants of Intravascular Resistance in Indian Diabetic Nephropathy Patients: A Hospital-Based Study

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    Aims and Objectives. Metabolic dysregulation has failed to explain clinical variability of patients with diabetic nephropathy and hence a renewed interest emerged in haemodynamic factors as determinant of progression and development of diabetic nephropathy. We therefore studied for various factors which can correlate with raised renal vascular resistance in diabetic nephropathy. Material and Methods. Renal vascular resistance was measured in patients with established and incipient diabetic nephropathy and compared with controls using noninvasive color Doppler examinations of intrarenal vasculature. Results. Renal vascular resistance correlated with age, duration of disease, GFR, serum creatinine, and stage of retinopathy. Renal vascular resistance was significantly reduced in patients on treatment with RAAS inhibitors and insulin, than those on OHA and antihypertensives other than RAAS inhibitors. Conclusion. The study implies that renal vascular resistance may help identify diabetics at high risk of developing nephropathy, and these set of patients could be candidates for RAAS inhibition and early insulin therapy even in patients without albuminuria

    Greedy Algorithms for Finding Entanglement Swap Paths in Quantum Networks

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    The entanglement swap primitive facilitates the establishment of shared entanglement between non-adjacent nodes in a quantum network. This shared entanglement can subsequently be used for executing quantum communication protocols. The fundamental problem in quantum networks is to determine a path for entanglement swapping in response to demands for entanglement sharing between pairs of nodes. We investigate variants of this problem in this work. We propose a framework of Greedy algorithms that can be tweaked towards optimizing on various objective functions. In conjunction with a novel Spatial and Temporal (split across multiple paths) splitting approach to entanglement routing, we use this framework, which we call GST, to investigate the scenario when the demands are specified in terms of a starting time and a deadline. Considering the fragile nature of quantum memory, "bursty"demands are natural, and therefore the setting is important. We study the algorithm for maximizing the number of satisfied demands and the number of entangled pairs shared. We report empirical results on the performance against these objective functions, and compare with a naive algorithm that involves neither temporal and spatial splitting of the demands, nor the greedy approach to scheduling the demands
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