Strong proximinality and intersection properties of balls in Banach spaces

We investigate a variation of the transitivity problem for proximinality properties of subspaces and intersection properties of balls in Banach spaces. For instance, we prove that if Z⊆Y⊆X, where Z is a finite co-dimensional subspace of X which is strongly proximinal in Y and Y is an M-ideal in X, then Z is strongly proximinal in X. Towards this, we prove that a finite co-dimensional proximinal subspace Y of X is strongly proximinal in X if and only if Y⊥⊥ is strongly proximinal in X**. We also prove that in an abstract L1-space, the notions of strongly subdifferentiable points and quasi-polyhedral points coincide. We also give an example to show that M-ideals need not be ball proximinal. Moreover, we prove that in an L1-predual space, M-ideals are ball proximinal

Ideal operators and relative Godun sets

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

<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_Breceptor alterations, gene expression changes in GABA_Breceptor 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_Breceptors respectively and Real Time PCR analysis using specific probes for GABA_Breceptor 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_Breceptors along with decreased GABA_Breceptor 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_Breceptors 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

CFD Based Unsteady Aerodynamic Modeling For Rotor Aeroelastic Analysis

A Computational Fluid Dynamics (CFD) analysis is developed for 3-D rotor unsteady aerodynamic load prediction. It is then coupled to a rotor structural analysis for predicting aeroelastic blade response, airloads and vibration. The CFD analysis accounts for the elastic deformations using a dynamically deforming mesh system. All the rotor blades are assumed to be identical, therefore to reduce the computational complexity the CFD calculations are performed for a single blade. This accounts for the near wake flow field. But the far wake effects because of the trailed tip vortices from all the blades have to be included separately. This is achieved by the use of the field velocity approach, which is a method for modeling unsteady flows via apparent grid movement. In this method, the induced velocity field caused by the trailed vortex wake is included by modifying the grid time metrics. The CFD method developed is systematically validated for a range of problems starting from simple 2-D model problems to full scale forward flight cases. The CFD analysis shows significant improvements in airloads prediction compared to a table lookup based lifting-line analysis. The CFD analysis is then used to investigate the fundamental mechanisms of rotor vibration. It is found that both the normal forces and pitching moments are dominated by three dimensional aerodynamic effects. The curvature introduced by the blade elasticity appears to play a key role in the generation of the vibratory harmonics in airloads. The pitching moments near the blade tip (85\% outboard) are significantly affected by transonic tip relief effects. The fundamental understanding of rotor vibrations gained from this study is then used to develop generic corrections for improving the accuracy of a lifting line analysis. Finally the CFD analysis developed is coupled with an advanced comprehensive rotor aeroelastic analysis. The coupling procedure is formulated in a way such that there is an exchange of information between the structural model and CFD model every rotor revolution. The coupled CFD/structure scheme is found to considerably improve the prediction of rotor vibratory airloads compared to the baseline rotor aeroelastic analysis which uses a lifting line based aerodynamic model

Study of stratospheric composition using airborne submillimeter radiometry and a chemical transport model

The Airborne Submillimeter Radiometer (ASUR) was deployed aboard the Falcon research aircraft during the SCIAVALUE (SCIAMACHY - Scanning Imaging Absorption Spectrometer for Atmospheric ChartographY - Validation Utilization Experiment), the EUPLEX (European Polar and Lee wave Experiment), and the PAVE (Polar Aura Validation Experiment) campaigns. An impressive array of microwave measurements of O3, N2O, HCl, HNO3 and ClO is amassed during the missions from the tropics to the Arctic in various seasons.Using the data various satellite sensor measurements for different molecules are validated. In addition, a new model, the Bremen Chemical Transport Model (CTMB), is introduced. Evaluation of the Linearized ozone chemistry shows that the ozone profiles simulated with the Linoz model are accurate enough to be used for stratospheric chemistry and transport studies though the simulations show a low bias of about 9% in the middle stratosphere and a high bias of 10-30% in the lower and upper stratosphere, depending on altitude. The simulations for various years suggest that the N2O and NOy calculations depend greatly on the accuracy of the meteorological analyses used in the model. The simulations reveal that the N2O VMRs calculated with the parameterized chemistry are slightly smaller in the lower stratosphere. The inaccuracies in the wind analyses and in the model transport and uncertainties in the chemical reaction rates can be the reasons for the lower values. The N2O-NOy coupled chemistry is in good shape and the transport barriers are reasonably represented in the model. The comparison among the ASUR, the SLIMCAT and the CTMB profiles reveal the upper stratospheric ozone deficit in the SLIMCAT calculations. The comparisons also indicate that the transport process in the models is still to be improved

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

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

High Performance In-Situ Composites Developed from Polypropylene/Nylon 6/Carbon Nanotube Blend Systems

In the present work, microfibrillar composites (MFCs) based on polypropylene (PP) /Nylon 6 (NY) blends, along with multi walled carbon tubes (MWCNT) were prepared by melt processing technique. The blending of the fibre forming polymers was carried out in a twin screw extruder with varying concentrations of MWCNT. The drawing of the extruded strands was accomplished in a stretching unit followed by isotropization by compression moulding at a processing temperature below the melting point of NY. At an optimized fixed composition of PP/NY (70/30 w/w %), the influence of stretch ratio on the properties of nanofiller incorporated MFCs was investigated. The morphology development of the MFC samples was observed using high resolution scanning electron microscopy (HRSEM). The static mechanical studies signify the constructive effect of microfibrils and MWCNTs in reinforcing PP matrix. Dynamic rheological studies support the microfibrils contribution towards the stiffness of the syste

Improved regeneration and de novo bone formation in a diabetic zebrafish model treated with paricalcitol and cinacalcet

Bone changes related to diabetes have been well stablished, but few strategies have been developed to prevent this growing health problem. In our work, we propose to investigate the effects of calcitriol as well as of a vitamin D analog (paricalcitol) and a calcimimetic (cinacalcet), in fin regeneration and de novo mineralization in a zebrafish model of diabetes. Following exposure of diabetic transgenic Tg(ins: nfsb-mCherry) zebrafish to calcitriol, paricalcitol and cinacalcet, caudal fins were amputated to assess their effects on tissue regeneration. Caudal fin mineralized and regenerated areas were quantified by in vivo alizarin red staining. Quantitative real-time PCR was performed using RNA from the vertebral column. Diabetic fish treated with cinacalcet and paricalcitol presented increased regenerated and mineralized areas when compared with non-treated diabetic group, while no significant increase was observed in nondiabetic fish treated with both drugs. Gene expression analysis showed an up-regulation for runt-related transcription factor 2b (runx2b), bone gamma-carboxyglutamic acid-containing protein (bglap), insulin a (insa) and insulin b (insb) and a trend of increase for sp7 transcription factor (sp7) in diabetic groups treated with cinacalcet and paricalcitol. Expression of insra and vdra was up-regulated in both diabetic and nondiabetic fish treated with cinacalcet. In nondiabetic fish treated with paricalcitol and cinacalcet a similar increase in gene expression could be observed but not so pronounced. The increased mineralization and regeneration in diabetic zebrafish treated with cinacalcet and paricalcitol can be explained by increased osteoblastic differentiation and increased insulin expression indicating pro-osteogenic potential of both drugs.European Regional Development Fund (ERDF) through the COMPETE-Operational Competitiveness ProgramFCT-Fundacao para a Ciencia e a Tecnologia [PEst-CCMAR/Multi/04326/2013]info:eu-repo/semantics/publishedVersio