Neutrinos from Stellar Collapse: Comparison of signatures in water and heavy water detectors

Signatures of neutrino and antineutrino signals from stellar collapse in heavy water detectors are contrasted with those in water detectors. The effects of mixing, especially due to the highly dense matter in the supernova core, are studied. The mixing parameters used are those sets allowed by current understanding of available neutrino data: from solar, atmospheric and laboratory neutrino experiments. Signals at a heavy water detector, especially the dominant charged current reactions on deuteron, are very sensitive to some of these sets of allowed mixing parameters. Theoretical uncertainties on supernova neutrino spectra notwithstanding, a combination of supernova measurements with water and heavy water detectors may be able to distinguish many of these mixing possibilities and thus help in ruling out many of them.Comment: 36 pages Latex file, with 13 postscript figures; important improvements in the analysis and more detailed presentation of results. To appear in Phys. Rev.

Neutrino oscillation probabilities: Sensitivity to parameters

We study in detail the sensitivity of neutrino oscillation probabilities to the fundamental neutrino parameters and their possible determination through experiments. The first part of the paper is devoted to the broad theme of isolating regions in the neutrino (and anti-neutrino) energy and propagation length that are sensitive to the oscillation parameters. Such a study is relevant to neutrinos both from the Earth's atmosphere or from a neutrino factory. For completeness we discuss the sensitivity, however small, to the parameters involved in a three-generation framework, and to the Earth matter density profile. We then study processes relevant to atmospheric neutrinos which are sensitive to and allow precision measurements of the mixing angle theta_23 and mass-squared difference delta_32 apart from the mixing angle theta_13. Crucial to this analysis is charge identification; detectors having this capability can isolate these matter effects. In particular, we address the issue of using matter effects to determine whether the mixing angle theta_23 is maximal, and, if not, to explore how well its octant can be determined. When realistic detector resolutions are included, we find that deviations of about 15% (20%) from a maximal value of sin^2 theta_23=1/2 can be measured at 95% (99%) CL provided theta_13 is non-zero, sin^2 theta_13 >= 0.015, and the neutrino mass ordering is normal, with fairly large exposures of 1000 kton-years.Comment: 37 pages Latex file, 30 eps figure files; minor typos fixe

Reunion of Vicious Walkers: Results from ϵ\epsilon-Expansion -

The anomalous exponent, $\eta_{p}$, for the decay of the reunion probability of $p$ vicious walkers, each of length $N$, in $d$ $(=2-\epsilon)$ dimensions, is shown to come from the multiplicative renormalization constant of a $p$ directed polymer partition function. Using renormalization group(RG) we evaluate $\eta_{p}$ to $O(\epsilon^2)$. The survival probability exponent is $\eta_{p}/2$. For $p=2$, our RG is exact and $\eta_p$ stops at $O(\epsilon)$. For $d=2$, the log corrections are also determined. The number of walkers that are sure to reunite is 2 and has no $\epsilon$ expansion.Comment: No of pages: 11, 1figure on request, Revtex3,IP/BBSR/929

Facet joint tropism and degenerative spondylolisthesis – a study from the AOSAP (AOSpine Asia Pacific) Research Collaboration

Electronic Poster Presentations: P02INTRODUCTION: The role of facet joint (FJ) tropism (i.e. asymmetry between facet joint orientations) in L4-L5 degenerative spondylolisthesis (dSpl) remains inconclusive, particularly in Asian population, which possibly attributed to nonstandardised definitions of tropism. Thus, this study aimed to examine the role of FJ tropism in relation to L4-L5 dSpl in the Asia-Pacific ..

Feasibility of community DOT providers for tuberculosis treatment in HIV infected individuals - A pilot study

Background: This paper summarises our experiences about the role of community DOT providers in management of TB treatment in HIV infected persons in a mainly rural population of Tamilnadu. Objectives: To evaluate the feasibility of employing Community DOT providers for the treatment of tuberculosis in HIV infected persons, to study patients’ acceptance of Community DOT providers in the closely-knit village communities and to find out the attitude and awareness of DOT Providers on TB and DOT. Method: A total of 62 tuberculosis patients (58 males and 4 females) with HIV infection attending the Government Hospital for Thoracic Medicine, Tambaram and Chennai between July 1999 and July 2002 were selected for this study. Patients were given all the doses under supervision (clinic-based DOT) during the initial intensive phase and through Community DOT providers in the continuation phase. Data was collected both from the patients and their DOT providers about their views on DOT, advantages of DOTS, drug intake, treatment adherence, problems faced by the patients and their DOT Providers in addition to the level of awareness of Community DOT Providers on tuberculosis and DOTS. Results: Regarding treatment adherence, 95% of 62 patients had taken >75% of drugs and 39% had taken 100% drugs. DOT was appreciated both by the patients and their DOTS Providers since it is cost-effective and patient-friendly. Conclusions: Community contribution to TB care even among HIV infected population is feasible, affordable and costeffective. There is a need for greater health education and training on tuberculosis and DOTS for community DOT Providers

Long term follow up of HIV-infected patients with tuberculosis treated with 6-month intermittent short course chemotherapy

Background . Tuberculosis occurs in 60%–70% of HIVpositive persons in India. The outcome of HIV-positive patients treated with 6-month intermittent short course antituberculosis regimens in India is not well described. Methods . This was a prospective observational feasibility study of 71 patients with HIV and tuberculosis who were treated with category I regimen of the Revised National Tuberculosis Control Programme (ethambutol, isoniazid, rifampicin and pyrazinamide thrice weekly for the initial 2 months followed by rifampicin and isoniazid thrice weekly for the next 4 months). Sputum was examined by smear and culture for Mycobacterium tuberculosis every month up to 24 months. Chest X-ray, CD4 cell count and viral load were done prior to and at the end of treatment. None of the patients received antiretroviral therapy. Results . We present here the treatment response of patients with sputum culture-positive pulmonary tuberculosis to category I regimen. By efficacy analysis, among 43 patients treated with category I regimen, sputum smear conversion was observed in 79% and culture conversion in 82% at the second month. A favourable response was seen in 72% of patients. The mean (SD) CD4% fell from 12.6 (5.9) to 8.9 (4.9) (p<0.001) with no significant change in mean (SD) CD4 cell count (169 [126] to 174 [158]; ns) at the end of treatment. Viral load change from 1.8x105 at baseline to 1.3x105 at the end of treatment was not statistically significant. Thirty-one patients, who completed the full course of treatment, were declared cured and were followed up for 24 months. Twelve had recurrent tuberculosis (39%); 16 of 43 (37%) patients had died by the end of 24 months, twothirds due to causes other than tuberculosis. Conclusion . Though the early bacteriological response to intermittent short course antituberculosis regimen was satisfactory, the overall outcome was adversely affected by the high mortality (during and after completion of treatment) and recurrence rate among HIV-infected patients with tuberculosis. Immune status deteriorated in spite of antituberculosis treatment, highlighting the need for antiretroviral treatment in addition to antituberculosis treatment to improve the long term outcome. The results of this pilot study need to be confirmed by larger studies