SO(10): a possible Scenario for new Physics in the Neutrino Sector and Baryogenesis

The implications on neutrino physics and on the dynamical generation of the baryonic asymmetry of a class of $SO(10)$ non-supersymmetric models are discussed.Comment: 4 pages, LaTex (requires espcrc2.sty which is appended). Contribution to the Proceedings of Trends in Astroparticle Physic

Ethylacetate fraction of Anthocleista vogelii Planch demonstrates antiobesity activities in preclinical models

Purpose: To assess the anti-obesity effect of liquid chromatography mass spectrometry (LCMS) profiled ethylacetate fraction (EF) of Anthocleista vogelii Planch on pancreatic lipase activity in vitro, and on obesity-related hormones in high-fat diet (HFD)-induced obese rats. Methods: Chromatographic analysis of EF to identify bioactive compounds was performed using LCMS electrospray ionization mass spectrometry (ESI-MS) positive mode. Thirty Sprague–Dawley rats were divided into 5 groups (n = 6). Group 1 was fed normal pellet diet, while groups 2 - 5 were fed high-fat diet (HFD) for 14 weeks. The rats were treated for 4 weeks from week 10 with 125 mg/kg of EF (group 3), 250 mg/kg of EF (group 4) or 100 mg/kg of orlistat (group 5). Results: Seven alkaloids were identified in EF, namely, 10-hydroxycamtothecin, moschamindole, camptothecin, moschamine, N6-cis-p-coumaroylserotonin, sinomenine and desacetylcolchicine. The EF of A. vogelii exhibited inhibitory activity against pancreatic lipase with half-maximal inhibitory concentration (IC50) of 8.76 ± 0.110 µg/mL. Rats treated with EF (125 and 250 mg/kg) of A. vogelii showed significantly (p < 0.05) decreased feed intake, body weight, leptin and insulin, when compared to HFD controls. Cortisol, serotonin and noradrenaline were significantly (p < 0.05) increased, but changes in thyroid hormones levels in EF-treated rats were not significant (p > 0.05) when compared to HFD controls. Conclusion: The EF of A. vogelii demonstrate anti-obesity activities by inhibiting pancreatic lipase, elevating serotonin and noradrenaline, and increasing leptin sensitivity, leading consequently to decreased body weight of rats. However, the clinical use of EF of A. vogelii as an antiobesity herbal remedy requires further studies on its mechanisms of action

The trace left by signature-change-induced compactification

Recently, it has been shown that an infinite succession of classical signature changes (''signature oscillations'') can compactify and stabilize internal dimensions, and simultaneously leads, after a coarse graining type of average procedure, to an effective (''physical'') space-time geometry displaying the usual Lorentzian metric signature. Here, we consider a minimally coupled scalar field on such an oscillating background and study its effective dynamics. It turns out that the resulting field equation in four dimensions contains a coupling to some non-metric structure, the imprint of the ''microscopic'' signature oscillations on the effective properties of matter. In a multidimensional FRW model, this structure is identical to a massive scalar field evolving in its homogeneous mode.Comment: 15 pages, LaTeX, no figure

Antidiabetic activities of chloroform fraction of Anthocleista vogelii Planch root bark in rats with diet- and alloxan-induced obesity-diabetes

ETHNOPHARMACOLOGICAL RELEVANCE: Anthocleista vogelii Planch is a medicinal plant traditionally used in West Africa for the management and treatment of diabetes mellitus. AIM OF THE STUDY: To determine the antidiabetic activities of chloroform fraction (CF) of Anthocleista vogelii Planch root bark in rats with diet- and alloxan-induced obesity-diabetes. MATERIALS AND METHODS: Inhibitory activities of CF against α-amylase and α-glucosidase activities were determined in vitro. Three weeks old rats were fed with high-fat diet for 9 weeks to induce obesity prior to further induction of diabetes using alloxan (150 mg/kg body weight, i.p.). Blood glucose levels and body weight were measured every 7 days throughout the experiment. Glucose tolerance was assessed in normal and CF-treated rats on day 21. Terminal blood samples were collected from sacrificed animals for the measurement of serum insulin levels. Pancreases were excised from treated and untreated animals for histopathological examination. RESULTS: LCMS/MS chromatographic profile of CF via positive and negative modes revealed 13 and 23 compounds respectively. Further analysis revealed quebrachitol (QCT), loganin, sweroside, oleoside 11-methyl ester and ferulic acid, which have been previously reported for their antidiabetic activities, as constituents of CF. CF inhibited activities of α-amylase (IC50 = 51.60 ± 0.92 µg/ml) and α-glucosidase (IC50 = 5.86 ± 0.97 µg/ml) in a dose-dependent manner. Treatment of animals with obesity-diabetes with 100 and 200 mg/kg CF significantly improved glucose tolerance (P < 0.001) and enhanced serum insulin levels (P < 0.05) compared to diabetic control rats. CONCLUSIONS: Antidiabetic activities of CF might be mediated via inhibition of α-amylase and α-glucosidase activities, elevation of serum insulin concentration, and enhancement of insulin and leptin sensitivity in obesity-diabetes rats. This study further substantiates the traditional use of A. vogelii in the management and treatment of diabetes in Africa and encourages further studies to investigate its mechanism of action

Testing for sexually transmitted infections in general practice: cross-sectional study

Background: Primary care is an important provider of sexual health care in England. We sought to explore the extent of testing for chlamydia and HIV in general practice and its relation to associated measures of sexual health in two contrasting geographical settings.Methods: We analysed chlamydia and HIV testing data from 64 general practices and one genitourinary medicine (GUM) clinic in Brent (from mid-2003 to mid-2006) and 143 general practices and two GUM clinics in Avon (2004). We examined associations between practice testing status, practice characteristics and hypothesised markers of population need (area level teenage conception rates and Index of Multiple Deprivation, IMD scores).Results: No HIV or chlamydia testing was done in 19% (12/64) of general practices in Brent, compared to 2.1% (3/143) in Avon. In Brent, the mean age of general practitioners (GPs) in Brent practices that tested for chlamydia or HIV was lower than in those that had not conducted testing. Practices where no HIV testing was done had slightly higher local teenage conception rates (median 23.5 vs. 17.4/1000 women aged 15-44, p = 0.07) and served more deprived areas (median IMD score 27.1 vs. 21.8, p = 0.05). Mean yearly chlamydia and HIV testing rates, in practices that did test were 33.2 and 0.6 (per 1000 patients aged 15-44 years) in Brent, and 34.1 and 10.3 in Avon, respectively. In Brent practices only 20% of chlamydia tests were conducted in patients aged under 25 years, compared with 39% in Avon.Conclusions: There are substantial geographical differences in the intensity of chlamydia and HIV testing in general practice. Interventions to facilitate sexually transmitted infection and HIV testing in general practice are needed to improve access to effective sexual health care. The use of routinely-collected laboratory, practice-level and demographic data for monitoring sexual health service provision and informing service planning should be more widely evaluated

Chaotic Inflationary Universe on Brane

The chaotic inflationary model of the early universe, proposed by Linde is explored in the brane world considering matter described by a minimally coupled self interacting scalar field. We obtain cosmological solutions which admit evolution of a universe either from a singularity or without a singularity. It is found that a very weakly coupled self-interacting scalar field is necessary for a quartic type potential in the brane world model compared to that necessary in general relativity. In the brane world sufficient inflation may be obtained even with an initial scalar field having value less than the Planck scale. It is found that if the universe is kinetic energy dominated to begin with, it transits to an inflationary stage subsequently.Comment: 13 pages, no fig., accepted in Physical Review

Is CP Violation Observable in Long Baseline Neutrino Oscillation Experiments ?

We have studied CP violation originated by the phase of the neutrino mixing matrix in the long baseline neutrino oscillation experiments. The direct measurements of CP violation is the difference of the transition probabilities between CP-conjugate channels. In those experiments, the CP violating effect is not suppressed if the highest neutrino mass scale is taken to be 1\sim 5 \eV, which is appropriate for the cosmological hot dark matter. Assuming the hierarchy for the neutrino masses, the upper bounds of CP violation have been caluculated for three cases, in which mixings are constrained by the recent short baseline ones. The calculated upper bounds are larger than $10^{-2}$, which will be observable in the long baseline accelerator experiments. The matter effect, which is not CP invariant, has been also estimated in those experiments.Comment: 28 pages, LaTex file, 6 figures included using epsfig Matter effect is estimated(Figs.3(a) (b)). Physical parameters are change

Electron transport through a mesoscopic metal-CDW-metal junction

In this work we study the transport properties of a finite Peierls-Fr\"ohlich dielectric with a charge density wave of the commensurate type. We show that at low temperatures this problem can be mapped onto a problem of fractional charge transport through a finite-length correlated dielectric, recently studied by Ponomarenko and Nagaosa [Phys. Rev. Lett {\bf 81}, 2304 (1998)]. The temperature dependence of conductance of the charge density wave junction is presented for a wide range of temperatures.Comment: Latex, Revtex 3.0, 7 pages, 2 EPS figures (uses epfs

Brane Inflation and Cosmic String Tension in Superstring Theory

In a simple reanalysis of the KKLMMT scenario, we argue that the slow roll condition in the D3-anti-D3-brane inflationary scenario in superstring theory requires no more than a moderate tuning. The cosmic string tension is very sensitive to the conformal coupling: with less fine-tuning, the cosmic string tension (as well as the ratio of tensor to scalar perturbation mode) increases rapidly and can easily saturate the present observational bound. In a multi-throat brane inflationary scenario, this feature substantially improves the chance of detecting and measuring the properties of the cosmic strings as a window to the superstring theory and our pre-inflationary universe.Comment: Combined bounds from WMAP and SDSS Lyman alpha experiments are added for analysis, changes are added to the tabl

Kaluza-Klein Type Robertson Walker Cosmological Model With Dynamical Cosmological Term Λ\Lambda

In this paper we have analyzed the Kaluza-Klein type Robertson Walker (RW) cosmological models by considering three different forms of variable $\Lambda$: $\Lambda\sim(\frac{\dot{a}}{a})^2$,$\Lambda\sim(\frac{\ddot{a}} {a})$ and $\Lambda \sim \rho$. It is found that, the connecting free parameters of the models with cosmic matter and vacuum energy density parameters are equivalent, in the context of higher dimensional space time. The expression for the look back time, luminosity distance and angular diameter distance are also derived. This work has thus generalized to higher dimensions the well-known results in four dimensional space time. It is found that there may be significant difference in principle at least, from the analogous situation in four dimensional space time.Comment: 16 pages, no figur