579 research outputs found

    Second Order Corrections to QED Coupling at Low Temperature

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    We calculate the second order corrections to vacuum polarization tensor of photons at low temperatures, i.e; T ≤1010\le 10^{10} K (T<<meT << m_e). The thermal contributions to the QED coupling constant are evaluated at temperatures below the electron mass that is T<meT< m_e . Renormalization of QED at these temperatures has explicitly been checked. The electromagnetic properties of such a thermal medium are modified. Parameters like electric permittivity and magnetic permeability of such a medium are no more constant and become functions of temperature.Comment: 8 latex pages and 1 figure (to appear in IJMP

    The impact of mobility models on the performance of mobile Ad Hoc network routing protocol

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    A mobility model represents nodes distribution and movement over the network. Several research works have shown that a selection of mobility model can affect the outcome of routing performance simulation in Mobile Ad Hoc Networks. Thus, a routing protocol may only be effective in a particular mobility model or scenario but performs inferiorly in another. As a result, analyses of routing protocol performance are often based on inadequate information leading to inaccurate argument and conclusion. In this paper, three different mobility models have been selected, where each of them is highly distinctive in terms of nodes movement behavior. In addition, a new measurement technique called probability of route connectivity is introduced. The technique is used to quantify the success rate of route established by a routing protocol. Extensive simulation runs are done and results are compared between each mobility model

    Antidepressant activity of aqueous extract of Momordica charantia leaves

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    Background: Depression is a common debilitating illness contributing to increase in morbidity and mortality worldwide. 20% of all depressed patients are refractory to treatment with available antidepressants at adequate doses. Momordica charantia commonly known as Karela is widely used in Indian cuisine. This study was carried out to evaluate its lesser known Antidepressant activity. The objective of this study is to evaluate the Antidepressant activity of Aqueous extract of Momordica charantia leaves.Methods: This study was done in Department of Pharmacology, JNMC, AMU. Tail Suspension test and 5-Hydroxytrytophan induced Head Potentiation was evaluated in Swiss Albino mice. Forced swim test, Learned Helplessness test and Spontaneous motor activity was noted in Albino Wistar rats respectively at doses of AEMC (Aqueous extract of Momordica charantia leaves) 100mg/kg, 200mg/kg and 300mg/kg.Results: AEMC at all three doses 100mg/kg, 200mg/kg and 300mg/kg exhibited antidepressant activity by significantly decreasing the immobility time in Tail Suspension test and except 100mg/kg. In forced swim test psychostimulant activity of AEMC was ruled out in Spontaneous motor activity. Number of Escape failures was decreased in Learned Helplessness test at doses of AEMC 200mg/kg and 300 mg/kg. Increase in Head twitches was seen only with AEMC 300mg/kg in 5-Hydroxytrytophan induced Head Potentiation in mice.Conclusions: Aqueous Extract of Momordica Charantia leaves exhibits Antidepressant activity in animal models of Depression
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