35 research outputs found

    Ideal operators and relative Godun sets

    Get PDF
    In this paper we study ideals in Banach spaces through ideal operators. We provide characterisation of recently introduced notion of almost isometric ideal which is a version of Principle of Local Reexivity for a subspace of a Banach space. Studying ideals through ideal operators give us better insight in to the properties of these subspaces vis-a-vis properties of the space itself. We provide a few applications of our characterisation theorem.The National Board for Higher Mathematics (NBHM) of India. (No.2/40(2)/2014/R&D-II/6252).peerReviewe

    Decreased GABAB receptor function in the cerebellum and brain stem of hypoxic neonatal rats: Role of glucose, oxygen and epinephrine resuscitation

    Get PDF
    <p>Abstract</p> <p>Background-</p> <p>Hypoxia during the first week of life can induce neuronal death in vulnerable brain regions usually associated with an impairment of cognitive function that can be detected later in life. The neurobiological changes mediated through neurotransmitters and other signaling molecules associated with neonatal hypoxia are an important aspect in establishing a proper neonatal care.</p> <p>Methods-</p> <p>The present study evaluated total GABA, GABA<sub>B </sub>receptor alterations, gene expression changes in GABA<sub>B </sub>receptor and glutamate decarboxylase in the cerebellum and brain stem of hypoxic neonatal rats and the resuscitation groups with glucose, oxygen and epinephrine. Radiolabelled GABA and baclofen were used for receptor studies of GABA and GABA<sub>B </sub>receptors respectively and Real Time PCR analysis using specific probes for GABA<sub>B </sub>receptor and GAD mRNA was done for gene expression studies.</p> <p>Results-</p> <p>The adaptive response of the body to hypoxic stress resulted in a reduction in total GABA and GABA<sub>B </sub>receptors along with decreased GABA<sub>B </sub>receptor and GAD gene expression in the cerebellum and brain stem. Hypoxic rats supplemented with glucose alone and with oxygen showed a reversal of the receptor alterations and changes in GAD. Resuscitation with oxygen alone and epinephrine was less effective in reversing the receptor alterations.</p> <p>Conclusions-</p> <p>Being a source of immediate energy, glucose can reduce the ATP-depletion-induced changes in GABA and oxygenation, which helps in encountering hypoxia. The present study suggests that reduction in the GABA<sub>B </sub>receptors functional regulation during hypoxia plays an important role in central nervous system damage. Resuscitation with glucose alone and glucose and oxygen to hypoxic neonatal rats helps in protecting the brain from severe hypoxic damage.</p

    Carbamoylated Erythropoietin-Induced Cerebral Blood Perfusion and Vascular Gene Regulation.

    Get PDF
    Cerebral hypoperfusion is associated with enhanced cognitive decline and increased risk of neuropsychiatric disorders. Erythropoietin (EPO) is a neurotrophic factor known to improve cognitive function in preclinical and clinical studies of neurodegenerative and psychiatric disorders. However, the clinical application of EPO is limited due to its erythropoietic activity that can adversely elevate hematocrit in non-anemic populations. Carbamoylated erythropoietin (CEPO), a chemically engineered non-erythropoietic derivative of EPO, does not alter hematocrit and maintains neurotrophic and behavioral effects comparable to EPO. Our study aimed to investigate the role of CEPO in cerebral hemodynamics. Magnetic resonance imaging (MRI) analysis indicated increased blood perfusion in the hippocampal and striatal region without altering tight junction integrity. In vitro and in vivo analyses indicated that hippocampal neurotransmission was unaltered and increased cerebral perfusion was likely due to EDRF, CGRP, and NOS-mediated vasodilation. In vitro analysis using human umbilical vein endothelial cells (HUVEC) and hippocampal vascular gene expression analysis showed CEPO to be a non-angiogenic agent which regulates the MEOX2 gene expression. The results from our study demonstrate a novel role of CEPO in modulating cerebral vasodilation and blood perfusion

    The worldwide C3S CORDEX grand ensemble: A major contribution to assess regional climate change in the IPCC AR6 Atlas

    Get PDF
    peer reviewedAbstract The collaboration between the Coordinated Regional Climate Downscaling Experiment (CORDEX) and the Earth System Grid Federation (ESGF) provides open access to an unprecedented ensemble of Regional Climate Model (RCM) simulations, across the 14 CORDEX continental-scale domains, with global coverage. These simulations have been used as a new line of evidence to assess regional climate projections in the latest contribution of the Working Group I (WGI) to the IPCC Sixth Assessment Report (AR6), particularly in the regional chapters and the Atlas. Here, we present the work done in the framework of the Copernicus Climate Change Service (C3S) to assemble a consistent worldwide CORDEX grand ensemble, aligned with the deadlines and activities of IPCC AR6. This work addressed the uneven and heterogeneous availability of CORDEX ESGF data by supporting publication in CORDEX domains with few archived simulations and performing quality control. It also addressed the lack of comprehensive documentation by compiling information from all contributing regional models, allowing for an informed use of data. In addition to presenting the worldwide CORDEX dataset, we assess here its consistency for precipitation and temperature by comparing climate change signals in regions with overlapping CORDEX domains, obtaining overall coincident regional climate change signals. The C3S CORDEX dataset has been used for the assessment of regional climate change in the IPCC AR6 (and for the interactive Atlas) and is available through the Copernicus Climate Data Store (CDS)

    Effect Of Vitamin D3 And Curcumin Supplementation

    No full text
    The present study was designed to investigate the protective effect of curcumin and vitamin D3 in the functional regulation of glutamatergic NMDA and AMPA receptors in streptozotocin (STZ) induced diabetic rats. Alterations in glutamatergic neurotransmission in the brain were evaluated by analyzing the glutamate content, glutamate receptors - NMDA and AMPA receptors binding parameters and gene expression, GAD and GLAST gene expression. Immunohistochemistry studies using confocal microscope were carried out to confirm receptor density and gene expression results of NMDA and AMPA receptors. The role of glutamatergic receptors in pancreas was studied using the following parameters; glutamate content, GLAST expression, glutamate receptors - NMDA and AMPA receptor binding and gene expression. Increasing evidence in both experimental and clinical studies suggests that oxidative stress plays a major role in the pathogenesis of diabetes. In the present study SOD assay and GPx gene expression were done to evaluate the activity of antioxidant enzymes in the brain regions and pancreas. NeuroD1 and Pdx1 gene expression were performed in pancreas of experimental rats to evaluate pancreatic islet survival. Gene expression profiles of caspase 8, Bax, and Akt in brain regions and pancreas were studied to understand the possible mechanism behind curcumin and vitamin D3 mediated neuroprotection and islet survival. Gene expression studies of vitamin D3 receptor localisation in the pancreas was done to understand the mechanism of vitamin D3 in insulin secretion. Curcumin and vitamin D3 mediated insulin secretion via Ca2+ release were studied using confocal microscope.Cochin University of Science and TechnologyDepartment of Biotechnology Cochin University of Science and Technolog

    Improved sub-threshold slope in short channel vertical MOSFETs using FILOX oxidation

    No full text
    This paper investigates the origins of sub-threshold slope degradation in vertical MOSFETs (v-MOSFETs) due to dry etching of the polysilicon surround gate. Control v-MOSFETs exhibit a degradation of sub-threshold slope as the channel length is reduced from 250 to 100 nm, with 100 nm transistors having a value of 125 mV/dec and a DIBL of 210 mV/V. The effect of the polysilicon gate etch is investigated using a frame-gate architecture in which the polysilicon gate overlaps the side of the pillar, thereby protecting the channel from etch damage. This device shows no degradation of short channel effects when the channel length is scaled and exhibits a near-ideal sub-threshold slope of 76 mV/dec and a DIBL of 33 mV/V at a channel length of 100 nm. Gated diode measurements unambiguously demonstrate that this improved sub-threshold slope is due to the elimination of etch damage at the top and bottom of the pillar created during polysilicon gate etch. An alternative method of eliminating dry etch damage is then investigated by optimizing the Fillet Local Oxidation (FILOX). These devices give a sub-threshold slope of 81 mV/dec and a DIBL of 25 mV/V at a channel length of 100 nm. The improved immunity to dry etch damage is due to the creation of a thick protective oxide at the top and bottom of the pillar during the FILOX proces
    corecore