Gamow-Teller strength distributions and electron capture rates for 55Co and 56Ni

The Gamow-Teller strength (GT) distributions and electron capture rates on 55Co and 56Ni have been calculated using the proton-neutron quasiparticle random phase approximation theory. We calculate these weak interaction mediated rates over a wide temperature (0.01x109 - 30x109 K) and density (10 - 1011 g cm-3) domain. Electron capture process is one of the essential ingredients involved in the complex dynamics of supernova explosion. Our calculations of electron capture rates show differences with the reported shell model diagonalization approach calculations and are comparatively enhanced at presupernova temperatures. We note that the GT strength is fragmented over many final states.Comment: 10 pages, 6 figure

Gamow-Teller transitions from 24Mg and its impact on the electron capture rates in the O + Ne + Mg cores of stars

Electron captures on nuclei play an important role in the collapse of stellar core in the stages leading to a type-II supernova. Recent observations of subluminous Type II-P supernovae (e.g. 2005cs, 2003gd, 1999br) were able to rekindle the interest in 8 - 10 which develop O+Ne+Mg cores. We used the proton-neutron quasiparticle random phase approximation (pn-QRPA) theory to calculate the B(GT) strength for 24Mg \rightarrow 24Na and its associated electron capture rates for incorporation in simulation calculations. The calculated rates, in this letter, have differences with the earlier reported shell model and Fuller, Fowler, Newman (hereafter F2N) rates. We compared Gamow-Teller strength distribution functions and found fairly good agreement with experiment and shell model. However, the GT centroid and the total GT strength, which are useful in the calculation of electron capture rates in the core of massive pre-supernova stars, lead to the enhancement of our rate up to a factor of four compared to the shell model rates at high temperatures and densities.Comment: 13 pages, 3 figure

Estimation of Bovine Tuberculosis Prevalence, Associated Risk Factors, and Public Health Significance in District Dera Ismail Khan

Bovine tuberculosis (bTB) is zoonotic disease of global concern, affecting both animal and human populations. To estimate the prevalence of bovine TB in District Dera Ismail Khan and identify associated risk factors. A total of 138 cattle from different herds were included in the survey, and diagnostic tests, including the tuberculin skin test and Ziehl Neelsen stain, were employed. The results revealed a high prevalence of bovine TB, with an estimated prevalence of 10.87 % in the study area. Prevalence analysis based on Tehsil revealed varying rates: 6.66 % in Dera Ismail Khan, 11.11 % in Kulachi, and 14.81 % in Daraban and Paroa. Paharpur had a prevalence of 7.40 %. The overall district prevalence was 10.87 %. Age-wise prevalence showed no significant difference, with 10 % in calves (\u3c1 year) and 9.33 % in 1-3-year-olds. Prevalence in cattle over 3 years was 13.95 %. Sex-wise prevalence showed no significant difference between male (10 %) and female (12.38 %) cows (p \u3e 0.05). Seasonal prevalence indicated 10 % in spring, 6.06 % in summer, 11.11 % in autumn, and 27.27 % in winter (highest prevalence) (p \u3c 0.05). Overcrowding of animals and inadequate biosecurity measures were significantly associated with higher prevalence rates (p \u3c 0.05). Herd size and presence of co-infections showed no significant correlation with bovine TB prevalence (p \u3e 0.05). This study found a high prevalence of bTB in District Dera Ismail Khan and identified overcrowding of animals and inadequate biosecurity measures as significant risk factors for disease transmission