154 research outputs found

    Electromagnetic ion-cyclotron instability in the presence of a parallel electric field with general loss-cone distribution function - particle aspect analysis

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    International audienceThe effect of parallel electric field on the growth rate, parallel and perpendicular resonant energy and marginal stability of the electromagnetic ion-cyclotron (EMIC) wave with general loss-cone distribution function in a low ? homogeneous plasma is investigated by particle aspect approach. The effect of the steepness of the loss-cone distribution is investigated on the electromagnetic ion-cyclotron wave. The whole plasma is considered to consist of resonant and non-resonant particles. It is assumed that resonant particles participate in the energy exchange with the wave, whereas non-resonant particles support the oscillatory motion of the wave. The wave is assumed to propagate parallel to the static magnetic field. The effect of the parallel electric field with the general distribution function is to control the growth rate of the EMIC waves, whereas the effect of steep loss-cone distribution is to enhance the growth rate and perpendicular heating of the ions. This study is relevant to the analysis of ion conics in the presence of an EMIC wave in the auroral acceleration region of the Earth's magnetoplasma

    Beam effect on electromagnetic ion-cyclotron waves with general loss ? cone distribution function in an anisotropic plasma-particle aspect analysis

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    International audienceThe effect of upgoing ion beam and temperature anisotropy on the dispersion relation, growth rate, parallel and perpendicular resonant energies, and marginal instability of the electromagnetic ion cyclotron (EMIC) waves, with general loss-cone distribution function, in a low ? homogeneous plasma, is discussed by investigating the trajectories of the charged particles. The whole plasma is considered to consist of resonant and non-resonant particles. The resonant particles participate in an energy exchange with the waves, whereas the non-resonant particles support the oscillatory motion of the waves. The effects of the steepness of the loss-cone distribution, ion beam velocity, with thermal anisotropy on resonant energy transferred, and the growth rate of the EMIC waves are discussed. It is found that the effect of the upgoing ion beam is to reduce the energy of transversely heated ions, whereas the thermal anisotropy acts as a source of free energy for the EMIC waves and enhances the growth rate. It is found that the EMIC wave emissions occur by extracting energy of perpendicularly heated ions in the presence of an upflowing ion beam and a steep loss-cone distribution function in the anisotropic magnetoplasma. The effect of the steepness of the loss-cone is also to enhance the growth rate of the EMIC waves. The results are interpreted for EMIC emissions in the auroral acceleration region

    Demographic study of congenital talipes equinovarus deformity in central India

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    Background: Congenital idiopathic clubfoot is the most common birth defect of the musculoskeletal system affecting 1 in every 1000 live births each year. Aim of our study was to determine the demographic variables, risk factors associated with CTEV in central India.Methods: A retrospective study was conducted from January 2019 to August 2020 using data of 200 patients with CTEV registered at department of orthopaedics, Netaji Subhash Chandra Bose medical college, Jabalpur, Madhya Pradesh, India were included in our study.Results; Out of total of 200 patients, 167 patients belong to age group <1 year (83.5%) with range from 10 days -7 years. Males were twice (65%) likely affected and (53.5%) clubfoot cases had both feet affected. Right side was more affected in unilateral cases. 189 patients (94.5%) were idiopathic, whereas 11 patients (5.5%) were non-idiopathic. there were 58 (29%) children out of 200, born of consanguineous marriage of parents. Risk factors like anemia, jaundice, asphyxia, obstructed labor, history of miscarriage had positive correlation with clubfoot. CTEV patients of low birth weight <2.5 kg associated with maternal risk factors like smoking, alcohol, anemia.Conclusions: Demographic study is useful tool for determining birth prevalence and risk factors associated with CTEV. There are significantly higher proportion of consanguinity in clubfoot patients. Cultural differences may lead to differences in our findings with respect to the previous studies. These preliminary findings will help in the future for similar studies in central India as well as in the general Indian population

    Medicinal and Phamacological Potential of Nigella sativa: A Review

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    Herbs are vital source of drugs from the ancient time holding the scenario of the Indian system of medicine. Nigella sativa commonly known as karayal is an annual flowering plant, native to southwest Asia. Seeds and their oil have a long history of folklore usage in various systems of medicines and are used in food as well as medicine. The present paper enumerates the medicinal, pharmacological, traditional value and folk remedies of this herb, which may help the researchers to set their minds for approaching the utility, efficacy and potency of Nigella sativa

    Effect of temperature anisotropy on various modes and instabilities for a magnetized non-relativistic bi-Maxwellian plasma

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    Using kinetic theory for homogeneous collisionless magnetized plasmas, we present an extended review of the plasma waves and instabilities and discuss the anisotropic response of generalized relativistic dielectric tensor and Onsager symmetry properties for arbitrary distribution functions. In general, we observe that for such plasmas only those electromagnetic modes whose magnetic field perturbations are perpendicular to the ambient magneticeld, i.e.,B1 \perp B0, are effected by the anisotropy. However, in oblique propagation all modes do show such anisotropic effects. Considering the non-relativistic bi-Maxwellian distribution and studying the relevant components of the general dielectric tensor under appropriate conditions, we derive the dispersion relations for various modes and instabilities. We show that only the electromagnetic R- and L- waves, those derived from them and the O-mode are affected by thermal anisotropies, since they satisfy the required condition B1\perpB0. By contrast, the perpendicularly propagating X-mode and the modes derived from it (the pure transverse X-mode and Bernstein mode) show no such effect. In general, we note that the thermal anisotropy modifies the parallel propagating modes via the parallel acoustic effect, while it modifies the perpendicular propagating modes via the Larmor-radius effect. In oblique propagation for kinetic Alfven waves, the thermal anisotropy affects the kinetic regime more than it affects the inertial regime. The generalized fast mode exhibits two distinct acoustic effects, one in the direction parallel to the ambient magnetic field and the other in the direction perpendicular to it. In the fast-mode instability, the magneto-sonic wave causes suppression of the firehose instability. We discuss all these propagation characteristics and present graphic illustrations

    Pharmacognostic Standardization, Physico- and Phytochemical Evaluation of Amaranthus Spinosus Linn. Root

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    Amaranthus spinosus Linn. (Amaranthaceae) is found throughout India. This tree species has been of interest to researchers because it is a medicinal plant employed in the Indian traditional system of medicine. Pharmacognostic standardization; physico-and phytochemical evaluation of the roots of Amaranthus spinosus was carried out, to determine its macro-and microscopical characters, and also some of its quantitative standards. Microscopical studies were done by using the trinocular microscope. Total ash, water-soluble ash, acid-insoluble ash, sulfated ash values, and alcohol-and water-soluble extractive values were determined for physico-chemical evaluations. A preliminary phytochemical screening was also done to detect different phytoconstituents. Microscopically, the root showed cork, cortex, stellar region, and calcium oxalate crystals. Powder microscopy showed anamalous secondary growth in between the xylem vessels and Calcium Oxalate crystals in the cortex region. Total ash was approximately three times more than acid insoluble and water soluble ash. The ethanol soluble extractive was approximately the same as the water soluble extractive. Thin Layer Chromatography (TLC) of the Petroleum-ether extract using Benzene : Ethyl acetate (6 : 1), showed six spots. In the chloroform extract, using Benzene : Ethyl acetate (4 : 1) nine spots were seen, and in the ethanol extract, using Chloroform: Methanol (93 : 7), only four spots were observed, using Iodine vapor as a viewing medium. Phytochemically, the root exhibited terpenes, alkaloids, glycosides, and sugars. These findings might be useful to supplement information with regard to its identification parameters, which are assumed significant in the way of acceptability of herbal drugs, in the present scenario, which lacks regulatory laws to control the quality of herbal drugs

    Evaluation of 3-(3-chloro-phenyl)-5-(4-pyridyl)-4,5-dihydroisoxazole as a Novel Anti-Inflammatory Drug Candidate

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    BACKGROUND: 3-(3-chloro-phenyl)-5-(4-pyridyl)-4,5-dihydroisoxazole (DIC) is a five-membered heterocyclic compound containing a N-O bond. The anti-inflammatory effects of this compound were studied both in vitro and in vivo. PRINCIPAL FINDINGS: DIC effectively decreased TNF-α and IL-6 release from LPS-stimulated macrophages in a dose dependent manner. DIC diminished the levels of COX-2 with subsequent inhibition of PGE(2) production. DIC also compromised HMGB1 translocation from the nucleus to the cytoplasm. Moreover, DIC prevented the nuclear translocation of NF-κB and inhibited the MAPK pathway. In vivo, DIC inhibited migration of neutrophils to the peritoneal cavity of mice. CONCLUSIONS: This study presents the potential utilization of a synthetic compound, as a lead for the development of novel anti-inflammatory drugs
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