26 research outputs found

    Meson Masses and Mixing Angles in 2+1 Flavor Polyakov Quark Meson Sigma Model and Symmetry Restoration Effects

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    The meson masses and mixing angles have been calculated for the scalar and pseudoscalar sector in the framework of the generalized 2+1 flavor Polyakov loop augmented quark meson linear sigma model. We have given the results for two different forms of the effective Polyakov loop potential. The comparison of results with the existing calculations in the bare 2+1 quark meson linear sigma model, shows that the restoration of chiral symmetry becomes sharper due to the influence of the Polyakov loop potential. We find that inclusion of the Polyakov loop in quark meson linear sigma model together with the presence of axial anomaly, triggers an early and significant melting of the strange condensate. We have examined how the inclusion of the Polyakov loop qualitatively and quantitatively affects the convergence in the masses of the chiral partners in pseudoscalar (π\pi, η\eta, η\eta', KK) and scalar (σ\sigma, a0a_0, f0f_0,κ\kappa) meson nonets as the temperature is varied on the reduced temperature scale. The role of UA(1)U_A(1) anomaly in determining the isoscalar masses and mixing angles for the pseudoscalar (η\eta and η\eta') and scalar (σ\sigma and f0f_0)meson complex, has also been investigated in the Polyakov quark meson linear sigma model. The interplay of chiral symmetry restoration effects and the setting up of UA(1)U_A(1) restoration trend has been discussed and analyzed in the framework of the presented model calculations.Comment: 15 pages, 8 figures, 4 table

    Effects of quarks on the formation and evolution of Z(3) walls and strings in relativistic heavy-ion collisions

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    We investigate the effects of explicit breaking of Z(3) symmetry due to the presence of dynamical quarks on the formation and evolution of Z(3) walls and associated QGP strings within Polyakov loop model. We carry out numerical simulations of the first order quark-hadron phase transition via bubble nucleation (which may be appropriate, for example, at finite baryon chemical potential) in the context of relativistic heavy-ion collision experiments. Using appropriate shifting of the order parameter in the Polyakov loop effective potential, we calculate the bubble profiles using bounce technique, for the true vacuum as well as for the metastable Z(3) vacua, and estimate the associated nucleation probabilities. These different bubbles are then nucleated and evolved and resulting formation and dynamics of Z(3) walls and QGP strings is studied. We discuss various implications of the existence of these Z(3) interfaces and the QGP strings, especially in view of the effects of the explicit breaking of the Z(3) symmetry on the formation and dynamical evolution of these objects.Comment: 17 pages, 9 figures, PDFLate

    High Rates of All-cause and Gastroenteritis-related Hospitalization Morbidity and Mortality among HIV-exposed Indian Infants

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    <p>Abstract</p> <p>Background</p> <p>HIV-infected and HIV-exposed, uninfected infants experience a high burden of infectious morbidity and mortality. Hospitalization is an important metric for morbidity and is associated with high mortality, yet, little is known about rates and causes of hospitalization among these infants in the first 12 months of life.</p> <p>Methods</p> <p>Using data from a prevention of mother-to-child transmission (PMTCT) trial (India SWEN), where HIV-exposed breastfed infants were given extended nevirapine, we measured 12-month infant all-cause and cause-specific hospitalization rates and hospitalization risk factors.</p> <p>Results</p> <p>Among 737 HIV-exposed Indian infants, 93 (13%) were HIV-infected, 15 (16%) were on HAART, and 260 (35%) were hospitalized 381 times by 12 months of life. Fifty-six percent of the hospitalizations were attributed to infections; gastroenteritis was most common accounting for 31% of infectious hospitalizations. Gastrointestinal-related hospitalizations steadily increased over time, peaking around 9 months. The 12-month all-cause hospitalization, gastroenteritis-related hospitalization, and in-hospital mortality rates were 906/1000 PY, 229/1000 PY, and 35/1000 PY respectively among HIV-infected infants and 497/1000 PY, 107/1000 PY, and 3/1000 PY respectively among HIV-exposed, uninfected infants. Advanced maternal age, infant HIV infection, gestational age, and male sex were associated with higher all-cause hospitalization risk while shorter duration of breastfeeding and abrupt weaning were associated with gastroenteritis-related hospitalization.</p> <p>Conclusions</p> <p>HIV-exposed Indian infants experience high rates of all-cause and infectious hospitalization (particularly gastroenteritis) and in-hospital mortality. HIV-infected infants are nearly 2-fold more likely to experience hospitalization and 10-fold more likely to die compared to HIV-exposed, uninfected infants. The combination of scaling up HIV PMTCT programs and implementing proven health measures against infections could significantly reduce hospitalization morbidity and mortality among HIV-exposed Indian infants.</p

    Spatial Distribution, Diversity Mapping, and Gap Analysis of Wild <i>Vigna</i> Species Conserved in India’s National Genebank

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    The genus Vigna has several crop species that could be used to feasibly address nutritional security challenges in the subtropical and tropical regions of the world, particularly in climate-changing scenarios. Wild taxa of Vigna are a source of economically important traits and need to be studied. Out of the 34 wild Vigna species reported in India, 928 indigenous accessions belonging to 19 wild Vigna are conserved in India’s National Genebank (INGB) housed at the National Bureau of Plant Genetic Resources, New Delhi. Geospatial mapping has identified diversity-rich areas and the Western Ghats region exhibits the highest Shannon diversity values (H = 1.65–3.0). Using the complementarity procedure, six diversity hotspots were identified for the 34 wild Vigna, and these require utmost priority for exploration and germplasm collection. Due to the meagre amount of information available for wild Vigna, the BioClim model was used to successfully predict the Idukki district of Kerala as a suitable site for germplasm-collecting expeditions. Coastal areas identified as rich in twelve wild taxa, V. bourneae, V. dalzelliana, V. marina, V. sublobata, V. subramaniana, V. vexillata, V. stipulacea, V. trilobata, and V. trinervia, require immediate attention to protect hotspots as well as to collect accessions from these areas for ex situ conservation. A hotspot in the protected forest of Anshi National Park and Bhagwan Mahavira Wildlife Sanctuary was identified as an ideal spot for possible in situ conservation of V. konkanensis, V silvestris, and V. sublobata. The 15 wild Vigna species do not have representation in the INGB, and 11 Vigna species have been identified as endemic species to India. Priority needs to be given to these species for focussed exploration and germplasm collection. This paper discusses the future focus on explorations to be carried out for the collection of the germplasm of wild Vigna species

    Growth patterns among HIV-exposed infants receiving nevirapine prophylaxis in Pune, India

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    Abstract Background India has among the highest rates of infant malnutrition. Few studies investigating the growth patterns of HIV-exposed infants in India or the impact of timing of HIV infection on growth in settings such as India exist. Methods We used data from the Six Week Extended Nevirapine (SWEN) trial to compare the growth patterns of HIV-infected and HIV-exposed but uninfected infants accounting for timing of HIV infection, and to identify risk factors for stunting, underweight and wasting. Growth and timing of HIV infection were assessed at weeks 1, 2, 4, 6, 10, 14 weeks and 6, 9, 12 months of life. Random effects multivariable logistic regression method was used to assess factors associated with stunting, underweight and wasting. Results Among 737 HIV-exposed infants, 93 (13%) were HIV-infected by 12 months of age. Among HIV-infected and uninfected infants, baseline prevalence of stunting (48% vs. 46%), underweight (27% vs. 26%) and wasting (7% vs. 11%) was similar (p>0.29), but by 12 months stunting and underweight, but not wasting, were significantly higher in HIV-infected infants (80% vs. 56%, 52% vs. 29%, p Conclusion Baseline stunting and underweight was high in both HIV-infected and uninfected infants; growth indices diverged early and were impacted by timing of infection and SWEN prophylaxis. Early growth monitoring of all HIV-exposed infants is an important low-cost strategy for improving health and survival outcomes of these infants. Trial Registration NCT00061321</p