Renormalization group flows in a Lifshitz-like four fermi model

We study renormalization group flows in the Lifshitz-like $N$-flavour four fermi model discussed in 0905.2928. In the large-$N$ limit, a nontrivial flow occurs in only one of all possible marginal couplings and one relevant coupling, which provides the scale for Lorentz invariance violations. We discuss in detail the phase diagram and RG flows in the space of couplings, which includes the Lifshitz fixed point, the free field fixed point and a new fixed point characterized by $z=1$ scaling and a violation of Lorentz invariance, which cannot be tuned away by adjusting a parameter. In the broken symmetry phase, the model flows from the $z=3$ Lifshitz-like fixed point in the ultraviolet to this new fixed point in the infrared. However, in a modified version of the present model, which has an effective ultraviolet cut-off much smaller than the Lorentz invariance violating scale, the infrared behaviour is governed by an approximately Lorentz invariant theory, similar to the low energy limit of the usual relativistic Nambu$-$Jona-Lasinio model. Such a modified model could be realized by a supersymmetric version of the present model.Comment: 30 pages, 2 figure

A new (k,n) verifiable secret image sharing scheme (VSISS)

AbstractIn this paper, a new (k,n) verifiable secret image sharing scheme (VSISS) is proposed in which third order LFSR (linear-feedback shift register)-based public key cryptosystem is applied for the cheating prevention and preview before decryption. In the proposed scheme the secret image is first partitioned into several non-overlapping blocks of k pixels. Every k pixel is then used to form m=⌈k/4⌉+1 pixels of one encrypted share. The original secret image can be reconstructed by gathering any k or more encrypted shared images. The experimental results show that the proposed VSISS is an efficient and safe method

A cross sectional study on the prevalence of diabetes mellitus among adult population in a peri-urban area of West Tripura, India

Background: Diabetes mellitus, a major lifestyle disease is undoubtedly the most challenging public health problem of 21st century with a worldwide prevalence of 387 million (8.3%).  The objective of this study was to get an estimate of the prevalence of diabetes mellitus and associated factors in a sample of adult population in a peri-urban area of West Tripura.Methods: In a cross-sectional study, prevalence of diabetes mellitus was found among adult population of a peri-urban area (Dukli) of west Tripura from April 2016 to May 2016. Multistage random sampling was followed to include 76 participants. Taking house as a sampling unit, every 5th house was chosen for this study. From every selected house, one adult participant was chosen by simple random sampling until desired sample size was attained. Collected data was compiled and analyzed with the help of statistical package for social sciences (SPSS 16.0.). Chi-square, Fischer exact test was applied to find out association.Results: The mean age of the study participants was 42.21±17.65 years, comprised of 23.7% male and 76.3% female. The prevalence of diabetes mellitus was 17.1% among study participants. Diabetes was found highest in 39-58-year age group (37.5%). Males were more affected with diabetes mellitus (22.2%) compared to females (15.5%). The study also revealed a significant association of diabetes mellitus with family history of diabetes mellitus (p value 0.00).Conclusions: Present study showed very high prevalence of diabetes mellitus among adult population. Healthy lifestyle measures might reduce burden of diabetes mellitus which could be evaluated in future research

A cross-sectional study on morbidity pattern of elderly population residing in a rural area of Tripura

Background: The elderly is one of the most vulnerable and high-risk groups in terms of health and their health seeking behaviour is crucial in any society. A major component of the burden of illness for the elderly derives from prevalent chronic disease. The objective of study aims to find out morbidity pattern of elderly population aged 60 years and above.Methods: A community based cross-sectional study was done in rural areas of Madhupur, Sepahijala district, Tripura from August 2015-January 2016. A total of 260 (elderly aged 60 years and above) study participants were selected by simple random sampling.Results: Majority (52.7%) were between 60-70 years of age, least (1.5%) was in 90-100 years age group. Most of the study population (84.6%) were Hindu and female were more than male (51.9 % vs 48.1%). Majority (38.8%) of them were suffering from two (2) morbidities and 8.1% of study population had 4 and more morbidities. Non-specific generalized weakness was the most common (62.7%) morbidity, followed by gastrointestinal problems (56%) found in geriatric population. Musculoskeletal problems (low back pain, joint pain, osteoarthritis) were 45% followed by anaemia (42%) and impaired vision (36%). Increasing age group and non-smoke tobacco habit among the elderly population was associated with number of morbidities (≥ 3 morbidities/ person) per person (p <0.05).Conclusions: The study showed high prevalence of morbidities among elderly population. Non-specific generalized weakness was one of the most important problems in this age group. We have to find out the underlying cause of this non-specific generalized weakness by further clinical examination and laboratory investigations in future research

Intersecting branes and Nambu−-Jona-Lasinio model

We discuss chiral symmetry breaking in the intersecting brane model of Sakai and Sugimoto at weak coupling for a generic value of separation $L$ between the flavour $D8$ and anti-$D8$-branes. For any finite value of the radius $R$ of the circle around which the colour $D4$-branes wrap, a non-local Nambu$-$Jona-Lasinio (NJL) type short-range interaction couples the flavour branes and anti-branes. We argue that chiral symmetry is broken in this model only above a certain critical value of the 4-dimensional 't Hooft coupling and confirm this through numerical calculations of solutions to the gap equation. We also numerically investigate chiral symmetry breaking in the limit $R \to \infty$ keeping $L$ fixed, but find that simple ways of implementing this limit do not lead to a consistent picture of chiral symmetry breaking in the non-compact version of the non-local NJL model.Comment: latex, 25 pages, 7 figures, v2; minor changes, typos corrected and a reference adde

Tachyon condensation and quark mass in modified Sakai-Sugimoto model

This paper continues the investigation of the modified Sakai-Sugimoto model proposed in arXiv:0708.3233. Here we discuss in detail numerical solutions to the classical equations for the brane profile and the tachyon condensate. An ultraviolet cut-off turns out to be essential because the numerical solutions tend to rapidly diverge from the desired asymptotic solutions, beyond a sufficiently large value of the holographic coordinate. The required cut-off is determined by the non-normalizable part of the tachyon and is parametrically far smaller than that dictated by consistency of a description in terms of 10-dimensional bulk gravity. In arXiv:0708.3233 we had argued that the solution in which the tachyon field goes to infinity at the point where the brane and antibrane meet has only one free parameter, which may be taken to be the asymptotic brane-antibrane separation. Here we present numerical evidence in favour of this observation. We also present evidence that the non-normalizable part of the asymptotic tachyon solution, which is identified with quark mass in the QCD-like boundary theory, is determined by this parameter. We show that the normalizable part of the asymptotic tachyon solution determines the quark condensate, but this requires holographic renormalization of the on-shell boundary brane action because of the presence of infinite cut-off dependent terms. Our renormalization scheme gives an exponential dependence on the cut-off to the quark mass. We also discuss meson spectra in detail and show that the pion mass is nonzero and satisfies the Gell-Mann-Oakes-Renner relation when a small quark mass is switched on.Comment: 37 pages + appendices, 12 figures, v2; a clarifying paragraph added at the end of Section 4.1, typos correcte

Multilayered and Chemiresistive Thin and Thick Film Gas Sensors for Air Quality Monitoring

Selective detection of gases such as nitrogen dioxide (NO2), carbon monoxide (CO), carbon dioxide (CO2), and various volatile organic components (VOCs) is necessary for air quality monitoring. Detection of hydrogen (H2) is equally important as it is a flammable gas and poses serious threat of explosion when exposed to oxygen gas. We have studied the sensing characteristics of these gases using thin film deposited by chemical solution deposition as well as relatively thicker films deposited by atmospheric plasma spray (APS) process. The chapter starts with the sensing mechanism of chemiresistive sensors followed by the definition of gas sensing parameters. Subsequently, we have demonstrated selective NO2 sensing characteristics of zinc oxide-graphene (ZnO-G) multilayered thin film followed by CO and H2 sensing characteristics of ZnO thin film and SnO2 thick film. Cross-sensitivity among CO and H2 gases has been addressed through the analysis of conductance transients with the determination of activation energy, Ea, and heat of adsorption, Q. The concepts of reversible and irreversible sensing have also been discussed in relation to CO and H2 gases. CO2 sensing characteristics of LaFe0.8Co0.2O3 (LFCO)-ZnO thin film have been elucidated. Interference from CO has been addressed with principal component analyses and the ascertaining of Ea and Q values. Additionally, the variation of response with temperature for each gas was simulated to determine distinct parameters for the individual gases. Further, VOC sensing characteristics of copper oxide (CuO) thin film and WO3-SnO2 thick film were investigated. Principal component analysis was performed to discriminate the gases in CuO thin film. The interaction of WO3-SnO2 thick film with various VOCs was found to obey the Freundlich adsorption isotherm based on which Ea and Q values were determined

Discovery of Bisamide-heterocycles as Inhibitors of Scavenger Receptor BI (SR-BI)-mediated Lipid Uptake

A new series of potent inhibitors of cellular lipid uptake from HDL particles mediated by scavenger receptor, class B, type I (SR-BI) was identified. The series was identified via a high-throughput screen of the National Institutes of Health Molecular Libraries Small Molecule Repository (NIH MLSMR) that measured the transfer of the fluorescent lipid DiI from HDL particles to CHO cells overexpressing SR-BI. The series is characterized by a linear peptidomimetic scaffold with two adjacent amide groups, as well as an aryl-substituted heterocycle. Analogs of the initial hit were rapidly prepared via Ugi 4-component reaction, and select enantiopure compounds were prepared via a stepwise sequence. Structure–activity relationship (SAR) studies suggest an oxygenated arene is preferred at the western end of the molecule, as well as highly lipophilic substituents on the central and eastern nitrogens. Compound 5e, with (R)-stereochemistry at the central carbon, was designated as probe ML279. Mechanistic studies indicate that ML279 stabilizes the interaction of HDL particles with SR-BI, and its effect is reversible. It shows good potency (IC50 = 17 nM), is non-toxic, plasma stable, and has improved solubility over our alternative probe ML278