317 research outputs found

    Quantum Cournot equilibrium for the Hotelling-Smithies model of product choice

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    This paper demonstrates the quantization of a spatial Cournot duopoly model with product choice, a two stage game focusing on non-cooperation in locations and quantities. With quantization, the players can access a continuous set of strategies, using continuous variable quantum mechanical approach. The presence of quantum entanglement in the initial state identifies a quantity equilibrium for every location pair choice with any transport cost. Also higher profit is obtained by the firms at Nash equilibrium. Adoption of quantum strategies rewards us by the existence of a larger quantum strategic space at equilibrium.Comment: 13 pages, 6 tables, 8 figure

    eNavigate: A Survey On Effective and Efficient User Website Navigation

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    Web Structure Improvement has attracted much attention now days. The large websites such as E-commerce, universities etc. have lots of pages visited by users daily. The users needed to be navigated effectively and efficiently throughout the website. Each user has its own set of target pages where the stay time is larger than that of other pages. While making website structure improvements the web master must consider the set of target pages of the users. The users’ web log must be maintained at the server side which further has to be divided into session and mini sessions. These mini sessions provides the inputs to extract the target pages of a specific user. The improvement in website must be done under some circumstances. The newly added links must satisfy some criteria such as how many number of links can be added. Previous literature provides some meaningful considerations about static and dynamic websites. The effective website structure improvements along with the set of target pages can be efficiently designed with static and informative websites while it’s difficult to consider the target pages in dynamic one. The structure optimization can be done with minimization or maximization strategies. Here in this survey paper we studied some previously published journals to get better knowledge about the web structure improvements for effective user navigation

    A clinical profile of liver function tests in COVID-19 patients at tertiary care centre from north India

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    Background: The coronavirus is a large group of virus, which spread rapidly as an epidemic in china and was named initially as 2019 novel corona virus and subsequently named as Coronavirus disease 2019 (COVID-19) by World Health Organization (WHO). Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to a dramatic loss of human life globally and manifests a variety of clinical symptoms varying from fever, cough, headache, myalgias, nausea, vomiting to more severe pneumonia, ARDS, septic shock and multiorgan failure. SARS-CoV-2, primarily affect respiratory system but COVID-19 patients also have varying levels of liver injuries or liver dysfunction. This retrospective study was designed to analyze the clinical features, liver function and duration of hospital stay with confirmed cases of covid-19 in a tertiary care centre.Methods: We conducted a cross-sectional study in the Isolation ward, Level -2 Covid Hospital, Government Medical College, Kannauj, Uttar Pradesh (India), from April to June 2021. A detailed history and examination was carried out as per the pre-designed proforma. The liver function test included alanine transaminase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and total bilirubin. Patients were considered with abnormal LFTs when any value of these tests was higher than upper limit of normal.Results: One hundred and ten patients with covid-19 were enrolled during the study period. There were 74 males (67.2%) and 36 (32.7%) females.  The mean age of study population was 49.07±12.05 years. In present study, the mean value of serum bilirubin, SGPT, SGOT and ALP were 0.85±0.47 mg/dl, 74.6±66.9 IU/L, 48.45±36.86 IU/L and 229.25±69.79 IU/L, respectively. In present study, the abnormal liver function was seen in 67.2 % cases with COVID-19 patients. The mean duration of hospital stay among normal LFT and abnormal LFT patients group were 13.33±2.12 and 17.10±2.07 days, respectively.Conclusions: The present study highlighted that abnormal liver function was observed in 67.2% cases with COVID-19 patients. Further research should focus on the cause of liver injury in covid 19 and on treatment and outcome

    Tetraspanin (TSP-17) Protects Dopaminergic Neurons against 6-OHDA-Induced Neurodegeneration in <i>C. elegans</i>

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    Parkinson's disease (PD), the second most prevalent neurodegenerative disease after Alzheimer's disease, is linked to the gradual loss of dopaminergic neurons in the substantia nigra. Disease loci causing hereditary forms of PD are known, but most cases are attributable to a combination of genetic and environmental risk factors. Increased incidence of PD is associated with rural living and pesticide exposure, and dopaminergic neurodegeneration can be triggered by neurotoxins such as 6-hydroxydopamine (6-OHDA). In C. elegans, this drug is taken up by the presynaptic dopamine reuptake transporter (DAT-1) and causes selective death of the eight dopaminergic neurons of the adult hermaphrodite. Using a forward genetic approach to find genes that protect against 6-OHDA-mediated neurodegeneration, we identified tsp-17, which encodes a member of the tetraspanin family of membrane proteins. We show that TSP-17 is expressed in dopaminergic neurons and provide genetic, pharmacological and biochemical evidence that it inhibits DAT-1, thus leading to increased 6-OHDA uptake in tsp-17 loss-of-function mutants. TSP-17 also protects against toxicity conferred by excessive intracellular dopamine. We provide genetic and biochemical evidence that TSP-17 acts partly via the DOP-2 dopamine receptor to negatively regulate DAT-1. tsp-17 mutants also have subtle behavioral phenotypes, some of which are conferred by aberrant dopamine signaling. Incubating mutant worms in liquid medium leads to swimming-induced paralysis. In the L1 larval stage, this phenotype is linked to lethality and cannot be rescued by a dop-3 null mutant. In contrast, mild paralysis occurring in the L4 larval stage is suppressed by dop-3, suggesting defects in dopaminergic signaling. In summary, we show that TSP-17 protects against neurodegeneration and has a role in modulating behaviors linked to dopamine signaling

    Physics and Applications of Laser Diode Chaos

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    An overview of chaos in laser diodes is provided which surveys experimental achievements in the area and explains the theory behind the phenomenon. The fundamental physics underpinning this behaviour and also the opportunities for harnessing laser diode chaos for potential applications are discussed. The availability and ease of operation of laser diodes, in a wide range of configurations, make them a convenient test-bed for exploring basic aspects of nonlinear and chaotic dynamics. It also makes them attractive for practical tasks, such as chaos-based secure communications and random number generation. Avenues for future research and development of chaotic laser diodes are also identified.Comment: Published in Nature Photonic

    Free Energy Simulations of a GTPase: GTP and GDP Binding to Archaeal Initiation Factor 2

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    International audienceArchaeal initiation factor 2 (aIF2) is a protein involved in the initiation of protein biosynthesis. In its GTP-bound, "ON" conformation, aIF2 binds an initiator tRNA and carries it to the ribosome. In its GDP-bound, "OFF" conformation, it dissociates from tRNA. To understand the specific binding of GTP and GDP and its dependence on the ON or OFF conformational state of aIF2, molecular dynamics free energy simulations (MDFE) are a tool of choice. However, the validity of the computed free energies depends on the simulation model, including the force field and the boundary conditions, and on the extent of conformational sampling in the simulations. aIF2 and other GTPases present specific difficulties; in particular, the nucleotide ligand coordinates a divalent Mg(2+) ion, which can polarize the electronic distribution of its environment. Thus, a force field with an explicit treatment of electronic polarizability could be necessary, rather than a simpler, fixed charge force field. Here, we begin by comparing a fixed charge force field to quantum chemical calculations and experiment for Mg(2+):phosphate binding in solution, with the force field giving large errors. Next, we consider GTP and GDP bound to aIF2 and we compare two fixed charge force fields to the recent, polarizable, AMOEBA force field, extended here in a simple, approximate manner to include GTP. We focus on a quantity that approximates the free energy to change GTP into GDP. Despite the errors seen for Mg(2+):phosphate binding in solution, we observe a substantial cancellation of errors when we compare the free energy change in the protein to that in solution, or when we compare the protein ON and OFF states. Finally, we have used the fixed charge force field to perform MDFE simulations and alchemically transform GTP into GDP in the protein and in solution. With a total of about 200 ns of molecular dynamics, we obtain good convergence and a reasonable statistical uncertainty, comparable to the force field uncertainty, and somewhat lower than the predicted GTP/GDP binding free energy differences. The sign and magnitudes of the differences can thus be interpreted at a semiquantitative level, and are found to be consistent with the experimental binding preferences of ON- and OFF-aIF2

    Deleterious variants in CRLS1 lead to cardiolipin deficiency and cause an autosomal recessive multi-system mitochondrial disease

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    Mitochondrial diseases are a group of inherited diseases with highly varied and complex clinical presentations. Here, we report four individuals, including two siblings, affected by a progressive mitochondrial encephalopathy with biallelic variants in the cardiolipin biosynthesis gene CRLS1. Three affected individuals had a similar infantile presentation comprising progressive encephalopathy, bull’s eye maculopathy, auditory neuropathy, diabetes insipidus, autonomic instability, cardiac defects and early death. The fourth affected individual presented with chronic encephalopathy with neurodevelopmental regression, congenital nystagmus with decreased vision, sensorineural hearing loss, failure to thrive and acquired microcephaly. Using patient-derived fibroblasts, we characterized cardiolipin synthase 1 (CRLS1) dysfunction that impaired mitochondrial morphology and biogenesis, providing functional evidence that the CRLS1 variants cause mitochondrial disease. Lipid profiling in fibroblasts from two patients further confirmed the functional defect demonstrating reduced cardiolipin levels, altered acyl-chain composition and significantly increased levels of phosphatidylglycerol, the substrate of CRLS1. Proteomic profiling of patient cells and mouse Crls1 knockout cell lines identified both endoplasmic reticular and mitochondrial stress responses, and key features that distinguish between varying degrees of cardiolipin insufficiency. These findings support that deleterious variants in CRLS1 cause an autosomal recessive mitochondrial disease, presenting as a severe encephalopathy with multi-systemic involvement. Furthermore, we identify key signatures in cardiolipin and proteome profiles across various degrees of cardiolipin loss, facilitating the use of omics technologies to guide future diagnosis of mitochondrial diseases.Richard G. Lee ... Janice Fletcher ... et al

    Sensitivity of the Cherenkov Telescope Array to TeV photon emission from the Large Magellanic Cloud

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    A deep survey of the Large Magellanic Cloud at ∼0.1-100 TeV photon energies with the Cherenkov Telescope Array is planned. We assess the detection prospects based on a model for the emission of the galaxy, comprising the four known TeV emitters, mock populations of sources, and interstellar emission on galactic scales. We also assess the detectability of 30 Doradus and SN 1987A, and the constraints that can be derived on the nature of dark matter. The survey will allow for fine spectral studies of N 157B, N 132D, LMC P3, and 30 Doradus C, and half a dozen other sources should be revealed, mainly pulsar-powered objects. The remnant from SN 1987A could be detected if it produces cosmic-ray nuclei with a flat power-law spectrum at high energies, or with a steeper index 2.3-2.4 pending a flux increase by a factor of &gt;3-4 over ∼2015-2035. Large-scale interstellar emission remains mostly out of reach of the survey if its &gt;10 GeV spectrum has a soft photon index ∼2.7, but degree-scale 0.1-10 TeV pion-decay emission could be detected if the cosmic-ray spectrum hardens above &gt;100 GeV. The 30 Doradus star-forming region is detectable if acceleration efficiency is on the order of 1−10 per cent of the mechanical luminosity and diffusion is suppressed by two orders of magnitude within &lt;100 pc. Finally, the survey could probe the canonical velocity-averaged cross-section for self-annihilation of weakly interacting massive particles for cuspy Navarro-Frenk-White profiles
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