Evaluation of anxiolytic effect of furosemide in Albino rats

Background: Anxiety disorders are the most prevalent class of psychiatric condition. Medications commonly given for treatment can elicit several central nervous system (CNS) side-effects that patients find difficult to tolerate. So there is a need for new pharmacotherapeutic approaches to treat anxiety with greater efficacy and fewer side effects. Hence this study has been taken up to evaluate the anxiolytic effect of furosemide at three different doses (75mg/kg, 150mg/kg and 200mg/kg) in Albino rats.Methods: After obtaining approval from the institutional animal ethical committee 30 Albino rats weighing about 150-200gm were taken and divided into 5 groups of 6 rats each. Group 1: Normal Saline 10ml/kg (control); Group 2: Diazepam 2mg/kg (standard); Group 3: Furosemide 150mg/kg (test group 1); Group 4: Furosemide 200mg/kg (test group 2); Group 5: Furosemide 75mg/kg + Diazepam 1mg/kg (sub threshold dose). The anxiolytic activity of furosemide was tested by elevated plus maze and digital actophotometer models. Data was analysed using one way ANOVA followed by Posthoc Tukey’s test.Results: Furosemide (150mg/kg and 200mg/kg) have shown significant increase in open arm entries (p<0.05) and time spent in open arm (p<0.05) compared to control. Also furosemide (150mg/kg and 200mg/kg) have shown statistically significant decrease in locomotor activity (p<0.05) compared to control in actophotometer model. Potentiation of time spent and number of entries in open arm and decrease in locomotor activity were noticed when sub threshold doses of combination of diazepam and furosemide were used.Conclusions: These results suggest that furosemide possesses significant anxiolytic activity at both the doses. Furosemide given in sub threshold dose potentiates the antianxiety effect of sub threshold dose of diazepam when used in combination. Hence, after further studies, furosemide can be used as an anxiolytic drug

Extragalactic radio sources with sharply inverted spectrum at metre wavelengths

We present the first results of a systematic search for the rare extragalactic radio sources showing an inverted (integrated) spectrum, with spectral index $\alpha \ge +2.0$, a previously unexplored spectral domain. The search is expected to yield strong candidates for $\alpha \ge +2.5$, for which the standard synchrotron self-absorption (characterized by a single power-law energy distribution of relativistic electron population) would not be a plausible explanation, even in an ideal case of a perfectly homogeneous source of incoherent synchrotron radiation. Such sharply inverted spectra, if found, would require alternative explanations, e.g., free-free absorption, or non-standard energy distribution of relativistic electrons which differs from a power-law (e.g., Maxwellian). The search was carried out by comparing two sensitive low-frequency radio surveys made with sub-arcminute resolution, namely, the WISH survey at 352 MHz and TGSS/DR5 at 150 MHz. The overlap region between these two surveys contains 7056 WISH sources classified as `single' and brighter than 100 mJy at 352 MHz. We focus here on the seven of these sources for which we find $\alpha > +2.0$. Two of these are undetected at 150 MHz and are particularly good candidates for $\alpha > +2.5$. Five of the seven sources exhibit a `Gigahertz-Peaked-Spectrum' (GPS).Comment: 8 pages, 2 figures, accepted for publication in MNRA

Hybrid Stars

Recently there have been important developments in the determination of neutron star masses which put severe constraints on the composition and equation of state (EOS) of the neutron star matter. Here we study the effect of quark and nuclear matter mixed phase on mass radius relationship of neutron stars employing recent models from two classes of EOS's and discuss their implications.Comment: 3 pages LaTeX including 2 figures, macros included, Talk presented at the IX International Symposium on Particles, Strings and Cosmology (PASCOS'03), TIFR, Mumbai, India, January 3-8,2003. To appear in their proceeding

Evolution of Coordination in Social Networks: A Numerical Study

Coordination games are important to explain efficient and desirable social behavior. Here we study these games by extensive numerical simulation on networked social structures using an evolutionary approach. We show that local network effects may promote selection of efficient equilibria in both pure and general coordination games and may explain social polarization. These results are put into perspective with respect to known theoretical results. The main insight we obtain is that clustering, and especially community structure in social networks has a positive role in promoting socially efficient outcomes.Comment: preprint submitted to IJMP

Shade Promotes Phototropism through Phytochrome B-Controlled Auxin Production.

Phototropism is an asymmetric growth response enabling plants to optimally position their organs. In flowering plants, the phototropin (phot) blue light receptors are essential to detect light gradients. In etiolated seedlings, the phototropic response is enhanced by the red/far-red (R/FR)-sensing phytochromes (phy) with a predominant function of phyA. In this study, we analyzed the influence of the phytochromes on phototropism in green (de-etiolated) Arabidopsis seedlings. Our experiments in the laboratory and outdoors revealed that, in open environments (high R/FR ratio), phyB inhibits phototropism. In contrast, under foliar shade, where access to direct sunlight becomes important, the phototropic response was strong. phyB modulates phototropism, depending on the R/FR ratio, by controlling the activity of three basic-helix-loop-helix (bHLH) transcription factors of the PHYTOCHROME INTERACTING FACTORs (PIFs) family. Promotion of phototropism depends on PIF-mediated induction of several members of the YUCCA gene family, leading to auxin production in the cotyledons. Our study identifies PIFs and YUCCAs as novel molecular players promoting phototropism in photoautotrophic, but not etiolated, seedlings. Moreover, our findings reveal fundamental differences in the phytochrome-phototropism crosstalk in etiolated versus green seedlings. We propose that in natural conditions where the light environment is not homogeneous, the uncovered phytochrome-phototropin co-action is important for plants to adapt their growth strategy to optimize photosynthetic light capture

Effect of control procedures on the evolution of entanglement in open quantum systems

The effect of a number of mechanisms designed to suppress decoherence in open quantum systems are studied with respect to their effectiveness at slowing down the loss of entanglement. The effect of photonic band-gap materials and frequency modulation of the system-bath coupling are along expected lines in this regard. However, other control schemes, like resonance fluorescence, achieve quite the contrary: increasing the strength of the control kills entanglement off faster. The effect of dynamic decoupling schemes on two qualitatively different system-bath interactions are studied in depth. Dynamic decoupling control has the expected effect of slowing down the decay of entanglement in a two-qubit system coupled to a harmonic oscillator bath under non-demolition interaction. However, non-trivial phenomena are observed when a Josephson charge qubit, strongly coupled to a random telegraph noise bath, is subject to decoupling pulses. The most striking of these reflects the resonance fluorescence scenario in that an increase in the pulse strength decreases decoherence but also speeds up the sudden death of entanglement. This demonstrates that the behaviour of decoherence and entanglement in time can be qualitatively different in the strong-coupling non-Markovian regime

Dynamical evolution of the Universe in the quark-hadron phase transition and possible nugget formation

We study the dynamics of first-order phase transition in the early Universe when it was $10-50 \mu s$ old with quarks and gluons condensing into hadrons. We look at how the Universe evolved through the phase transition in small as well as large super cooling scenario, specifically exploring the formation of quark nuggets and their possible survival. The nucleation of the hadron phase introduces new distance scales in the Universe, which we estimate along with the hadron fraction, temperature, nucleation time etc. It is of interest to explore whether there is a relic signature of this transition in the form of quark nuggets which might be identified with the recently observed dark objects in our galactic halo and account for the Dark Matter in the Universe at present.Comment: LaTeX file with four postscript figure

How to identify a Strange Star

Contrary to young neutron stars, young strange stars are not subject to the r-mode instability which slows rapidly rotating, hot neutron stars to rotation periods near 10 ms via gravitational wave emission. Young millisecond pulsars are therefore likely to be strange stars rather than neutron stars, or at least to contain significant quantities of quark matter in the interior.Comment: 4 pages, 1 figur

Origin of Complex Quantum Amplitudes and Feynman's Rules

Complex numbers are an intrinsic part of the mathematical formalism of quantum theory, and are perhaps its most mysterious feature. In this paper, we show that the complex nature of the quantum formalism can be derived directly from the assumption that a pair of real numbers is associated with each sequence of measurement outcomes, with the probability of this sequence being a real-valued function of this number pair. By making use of elementary symmetry conditions, and without assuming that these real number pairs have any other algebraic structure, we show that these pairs must be manipulated according to the rules of complex arithmetic. We demonstrate that these complex numbers combine according to Feynman's sum and product rules, with the modulus-squared yielding the probability of a sequence of outcomes.Comment: v2: Clarifications, and minor corrections and modifications. Results unchanged. v3: Minor changes to introduction and conclusio