Field dependent nilpotent symmetry for gauge theories

We construct the field dependent mixed BRST (combination of BRST and anti-BRST) transformations for pure gauge theories. These are shown to be an exact nilpotent symmetry of both the effective action as well as the generating functional for certain choices of the field dependent parameters. We show that the Jacobian contributions for path integral measure in the definition of generating functional arising from BRST and anti-BRST part compensate each other. The field dependent mixed BRST transformations are also considered in field/antifield formulation to show that the solutions of quantum master equation remain invariant under these. Our results are supported by several explicit examples.Comment: 25 pages, No figures, Revte

Study of incidence of antiphospholipid antibody syndrome and low vitamin D levels as an etiological factor in recurrent pregnanc loss and their correlation

Background: Recurrent pregnancy loss is a heterogeneous reproductive problem, with multiple etiologies. Objective of this study was to study the incidence of APLA syndrome and low vitamin d levels in RPL and correlation between APLA syndrome and low vitamin D levels.Methods: This was an observational study conducted on 110 women seen in outpatient department/inpatient department of our institution from 1st August 2015 to 31st July 2016 who were known cases of RPL who fitted our inclusion and exclusion criteria.Results: It was found that majority of the RPL patients were in the age group of 30-34 years (42.72%) and they contributed to 43% of the abortions. 77.4% abortions occurred in the gestational age of 6-8 weeks. 21.81% patients were APLA positive. 23.63% patients had  low vitamin D levels. Out of the 21.81% patients who were APLA positive (50%) also had a low vitamin D level which was found to be statistically significant.Conclusions: There appears to be some correlation between APLA syndrome and low vitamin D levels, so both have to be treated simultaneously. Properly investigating women for APLA syndrome and vitamin D deficiency would select a treatable group of women with RPL

Dynamical complexities in a tri-trophic hybrid food chain model with Holling type II and Crowley–Martin functional responses

We study how predator behavior influences community dynamics of predatorprey systems. It turns out that predator behavior plays a dominant role in community dynamics. The hybrid model studied in this paper reveals that period-doubling and period-doubling reversals can generate short-term recurrent chaos (STRC), which mimics chaotic dynamics observed in natural populations. STRC manifests itself when deterministic changes in a system parameter interrupt chaotic behavior at unpredictable intervals. Numerical results reinforce an earlier suggestion that period-doubling reversals could control chaotic dynamics in ecological models. In ecological terms, the prey and intermediate predator populations may go to extinction in the event of a catastrophe. The top predator is always a survivor. In contrast to this, this is not the case when the constituent populations are interacting through Holling type II functional response. Even this top predator can go to extinction in the event of such catastrophes

Effect of Cross-Section-Change Induced Advective Flow on the Primary Dendrite Array Morphology of Hypoeutectic Pb-Sb Alloys During Directional Solidification

The morphology and distribution of primary dendrites have been examined in Pb-2.2, 5.8 and 10.8 wt. pct. Sb alloy samples directionally solidified (DSed) in ampoules shaped like an hour-glass to examine the influence of cross-section change induced advective flow on the cellular/dendritic interface. This sample design increases the advective flow of the melt towards the array tips, as the liquid-solid interface enters the neck of the ampoule, and then decreases it as the interface exits the neck. The warm solute-rich melt flowing towards the growth front suppresses the extent of side-branching, decreases the primary dendrite spacing, and increases the primary dendrite trunk diameter as observed in the Pb-5.8 and 10.8 Sb alloys. The flow appears to suppress the formation of cells. A cellular interface growing in the Pb-2.2Sb alloy became planar as the solidification front entered the neck, becoming cellular again as it exited the neck

Effects of Gamma Radiation on the concentration of 5 Hydroxy L Tryptophan and 5 Hydroxytryptamine in presence of Radioprotector in Sprague Dawley Rats

The result of variation of 5-hydroxy-L-tryptophan (HT) and S-hydroxytryptamine (S-HT) in different tissues of control and gamma-irradiated Sprague Dawley rats with and without a radioprotector Beeta-amino-ethylisothiuronium bromide hydrobromide (AET) combination e.g. (HT + AET) have been studied. The retention of HT, in the tissues studied, decreased after lethal dose (10.5 Gy) but for 5-HT, no such trend was observed after incorporation of HT + AET. A slight tendency of both metabolites to come back to control level was also observed for Sprague Dawley rats. In urine, concentration of HT was less compared to 5-HT with a lethal dose (10.5 Gy). After incorporation of HT + AET the turnover rate of HT and 5-HT were found to be maximum when it was injected through intraperitoneal route

Chemical Radioprotectors

Protection of biological systems against radiation damage is of paramount importance during accidental and unavoidable exposure to radiation. Several physico-chemical and biological factors collectively contribute to the damage caused by radiation and are, therefore, targets for developing radioprotectors. Work on the development of chemicals capable of protecting biological systemsfrom radiation damage was initiated nearly six decades ago with cysteine being the first molecule to be reported. Chemicals capable of scavenging free radicals, inducing oxygen depletion,antioxidants and modulators of immune response have been some of the radioprotectors extensively investigated with limited success. Mechanism of action of some chemical radioprotectors and their combinations have been elucidated, while further understanding is required in many instances. The present review elaborates on structure-activity relationship of some of the chemical radioprotectors, their evaluation, and assessment, limitation, and future prospects

Some aspects of animal behavior and community dynamics

We simulate the dynamical behavior of a few two - dimensional predator - prey systems in two - dimensional parameter spaces to gain insight into how functional responses affect community dynamics. The insight gained helps us design three dimensional systems. We construct models for a few ecosystems with three species and study them using computer simulations. The models have been developed by linking food chains which have both kinds of predators: specialist as well as generalist. The linking functions are weakly non-linear. The three dimensional model ecosystems have sexually reproducing top - predators. We perform extensive simulations to figure out dynamics of dynamical possibilities caused by changes in animal behavior. The animals change the foraging strategies and behave differently in different environments. At the end of the paper, we examine how diseases can govern transitions in meandering of dynamical models in bounded volume of their phase spaces

A systematic review of current knowledge of HIV epidemiology and of sexual behaviour in Nepal

OBJECTIVE: To systematically review information on HIV epidemiology and on sexual behaviour in Nepal with a view to identifying gaps in current knowledge. METHODS: Systematic review covering electronic databases, web-based information, personal contact with experts and hand searching of key journals. RESULTS: HIV-1 seroprevalence has been rising rapidly in association with high-risk behaviours, with current levels of 40% amongst the nation's injecting drug users and approaching 20% amongst Kathmandu's female commercial sex workers (FCSWs). HIV seroprevalence remains low in the general population (0.29% of 15–49 year olds). There are significant methodological limitations in many of the seroprevalence studies identified, and these estimates need to be treated with caution. There are extensive migration patterns both within the country and internationally which provide the potential for considerable sexual networking. However, studies of sexual behaviour have focused on FCSWs and the extent of sexual networks within the general population is largely unknown. CONCLUSIONS: Whilst some of the ingredients are present for an explosive HIV epidemic in Nepal, crucial knowledge on sexual behaviour in the general population is missing. Research on sexual networking is urgently required to guide HIV control in Nepal. There is also a need for further good-quality epidemiological studies of HIV seroprevalence

Andreev Scattering and the Kondo Effect

We examine the properties of an infinite-$U$ Anderson impurity coupled to both normal and superconducting metals. Both the cases of a quantum dot and a quantum point contact containing an impurity are considered; for the latter, we study both one and two-channel impurities. Using a generalization of the noncrossing approximation which incorporates multiple Andreev reflection, we compute the impurity spectral function and the linear-response conductance of these devices. We find generically that the Kondo resonance develops structure at energies corresponding to the superconducting gap, and that the magnitude of the resonance at the Fermi energy is altered. This leads to observable changes in the zero-bias conductance as compared to the case with no superconductivity.Comment: 8 pages, 7 figures; expanded version to appear in PR