Structural, elastic, and electronic properties of newly discovered Li2PtSi3 superconductor: Effect of transition metals

First-principles calculations within the density functional theory (DFT) with GGA-PBE exchange-correlation scheme have been employed to predict the structural, the elastic and the electronic properties of newly discovered lithium silicide superconductor, Li2PtSi3, for the first time. All the theoretical results are compared with those calculated recently for isostructural Li2IrSi3. The present study sheds light on the effect of replacement of transition metal element Ir with Pt on different mechanical, electronic, and superconducting properties. The effect of spin-orbit coupling on electronic band structure was found to be insignificant for Li2PtSi3. The difference in superconducting transition temperatures of Li2PtSi3 and Li2IrSi3 arises primarily due to the difference in electronic energy density of states at the Fermi level. Somewhat reduced Debye temperature in Li2PtSi3 plays a minor role. We have discussed the implications of the theoretical results in details in this study.Comment: Submitted for publicatio

Characterization of pathogenic mutations in 21-hydroxylase gene of Pakistani patients with congenital adrenal hyperplasia and their family members--a preliminary report

Objective: To characterize specific mutations within the 21-hydroxylase gene (CYP21-B) using ARMS-PCR assay in patients with congenital adrenal hyperplasia (CAH) and to compare it with that reported in other populations. Subjects and Methods: Five families, having an index case with CAH diagnosed on the basis of clinical and biochemical findings volunteered to give blood samples for analysis. A strategy, based on ARMS-PCR (Amplified Refractory Mutation System) was employed for the detection of mutations in 21-hydroxylase gene. The products of ARMS-PCR were resolved on agarose gels and the PCR products were visualized over ultra violet illumination. Results: Twenty-six specimens were analyzed for common point mutations in the 21-hydroxlase genes at the nucleotide positions 659, 1004 and 1688. Seven samples belonged to index cases with CAH. Of these 7, the assigned sex was male in 5 and female in 2 cases. However, genotypic sex was 3 males and 4 females. The mean age was 8 months in 5 cases while the median 17-OH Progesterone levels was 273.2 ng/ml. Vomiting, precocious puberty and ambiguous genitalia were the presenting features in 2, 1 and 4 cases respectively. Analysis for mutation at 659, 100 and 1688 was performed on 7 index cases and the family members of 5 index cases. The mutation analysis for the family members of index case 6 and 7 was not performed due to non-availability of their blood specimens. Index case No. 1, 4 and 7 showed homozygosity for splice mutations at nucleotide position 659, intron 2 with a sequence change of A to G, while the index case No. 2 and 6 showed heterozygosity for the same mutation. No mutation was found at 659, 1004 or 1688 in index case No. 3 and 4 at the analyzed nucleotide position. Nineteen family members of Case Nos. 1-5 were also analyzed for the same mutations. (Family No. 1, 2, 3, 4 and 5 included 3, 2, 7, 4 and 5 members respectively). These included 8 males and 11 females. All were asymptomatic. Both the parents of index case 1 and 4 were heterozygous at 659 while the father of index case No. 2 was heterozygous at 659 and mother was normal. Conculsion: Our results demonstrated the A to G transition at nucleotide 659 causing aberrant splicing, reported for some other populations as the most commonly identified point mutations. All cases were appropriately assigned to paternal or maternal chromosomes

Associations between personality traits and body weight status with energy intake of adolescents in Hulu Langat district, Malaysia

Introduction: Personality traits are divided into five basic dimensions: extraversion, neuroticism, conscientiousness, agreeableness and openness. These influence our attitudes and behaviours. Studies show that differences in personality traits may influence the dietary intake. Methods: A cross-sectional study aimed at determining the association between personality traits and body weight status with energy intake was conducted among adolescents in Hulu Langat district of Selangor. Height, weight and waist circumference were measured and respondents completed a pre-tested self-administered questionnaire. Personality traits were assessed using the Malay version of USM Personality (USMaP-i). A single 24-h dietary recall was used to assess dietary intake. Results: A total of 430 adolescents aged 13-16 years (46% male and 54% female) was recruited. Female respondents tended to be more neurotic and agreeable compared to male respondents. A majority of the respondents (67%) were in the normal weight category, 26.7% were overweight and obese, while 19.0% had a high risk of developing abdominal obesity with a mean waist circumference of 72.65 ± 10.93cm. Males significantly had a higher intake of energy (1425±583 kcal), compared to females (1232±462 kcal). Conscientiousness trait (r=-0.158, p<0.01), BMI-for-age (r=-0.147, p<0.01) and waist circumference (r=-0.108, p<0.05) were inversely related to the energy intake of the respondents. Conclusion: Leaner adolescents and individuals with low conscientiousness were significantly consuming more energy than their counterparts. Understanding the personality traits that may regulate caloric intake is essential in order to develop effective interventions towards modifying obesity inducing eating patterns

Conservation Laws in a First Order Dynamical System of Vortices

Gauge invariant conservation laws for the linear and angular momenta are studied in a certain 2+1 dimensional first order dynamical model of vortices in superconductivity. In analogy with fluid vortices it is possible to express the linear and angular momenta as low moments of vorticity. The conservation laws are compared with those obtained in the moduli space approximation for vortex dynamics.Comment: LaTex file, 16 page