Gagandeep Singh

Detailed computational analysis of queueing-time distributions of the BMAP/G/1 queue using roots

In this paper we present closed-form expressions for the distribution of the virtual (actual) queueing time for the BMAP/R/1 and BMAP/D/1 queues, where ‘R’ represents a class of distributions having rational Laplace–Stieltjes transforms. The closed-form analysis is based on the roots of the underlying characteristic equation. Numerical aspects have been tested for a variety of arrival and service-time distributions and results are matched with those obtained using the matrix-analytic method (MAM). Further, a comparative study of computation time of the proposed method with the MAM has been carried out. Finally, we also present closed-form expressions for the distribution of the virtual (actual) system time. The proposed method is analytically quite simple and easy to implement.

Drug resistance and lecithinase activity of Yersinia enterocolitica isolated from buffalo milk

Two-hundred-and-seven samples of raw buffalo milk and 60 samples of pasteurized buffalo milk were screened for presence of Yersinia enterocolitica. The prevalence of Y. enterocolitica was found to be 24.1% in raw milk, however, no isolation could be made from the pasteurized milk samples. Cold enrichment in trypticase soy broth and alkali treatment methods were followed in this study. The majority of the isolates (62%) were found sensitive to all the antibiotics used and only a few (16%) were resistant to two or more than two antibiotics. The incidence of Y. enterocolitica showed seasonal variations. Incidence was much higher (25-50%) during the winter season as compared to the summer (0-17%). The incidence of lecithinase production was high (40-50%) in Yersinia isolates resistant to one or two antibiotics.

Analysis of ANKKI (rs1800497) and DRD2 (rs1079597, rs1800498) variants in five ethnic groups from Punjab, North-West India

Dopamine D2 receptor (DRD2) is one of the essential neurotransmitters in the brain studied extensively in the field of psychiatric disorders, alcoholic behaviors and Pharmacology. It is also a promising gene for studying the evolutionary and genetic variation among populations. The present study was an attempt to understand the extent of genetic variation among five different ethnic groups (Bania, Brahmin, Jat Sikh, Khatri and Scheduled caste) of Punjab (North West India). A total of 1012 individuals belonging to the above mentioned groups were analyzed for three TaqI Polymorphic loci of DRD2 and ankyrin repeat and kinase domain containing 1 (ANKKI) using the allele frequencies and haplotype frequency distribution pattern. All the three loci were found to be polymorphic among the studied populations. The average heterozygosity for all loci in these ethnic groups was fairly substantial ranging from 0.3936 to 0.4986. The genetic differentiation among the population was observed to be in order of 0.0053.Among of the eight studied haplotypes, only six were shared by all the ethnic groups. TaqID and TaqIB loci were reported to be in significantly higher linkage disequilibrium (LD) in Scheduled Caste only, whereas TaqIA and TaqID showed modest LD in Brahmin, Jat Sikh and Khatri. Multidimensional scaling analysis revealed that the studied ethnic groups formed a close cluster, suggesting similar genetic structure of these populations which are in close proximity with other Indo European speaking North Indian and western Indian population groups. Overall this study highlights the genomic uniformity among the ethnic groups of Punjab (North-West India) owing to their common ancestral history and geographical closeness.

Genetic dissection of five ethnic groups from Punjab, North-West India–A study based on Autosomal Markers

The present study assessed the applicability of Alu insertion elements and Single Nucleotide Polymorphisms (SNPs) in forensic identification and estimated the extent of genetic variation in five major ethnic groups of Punjab, North-West India. A total of 1012 unrelated samples belonging to Banias, Brahmins, Jat Sikhs, Khatris and Scheduled Castes were genotyped for four Alu elements (ACE, APO, PLAT, D1) and six Single Nucleotide Polymorphisms [ESR (PvuII), LPL (PvuII), HTR2A (MspI), DRD2 Taq1A, Taq1B, Taq1D]. Allele frequencies observed heterozygosity and forensic efficacy parameters were determined. The data on the genetic affinity of the studied populations among themselves and with other populations of India was also analysed using a Neighbor-Joining tree and multidimensional scaling plot respectively. All the 10 loci were polymorphic and their average observed heterozygosity ranged from 0.3872 (Banias) to 0.4311 (Scheduled Castes). Allele frequency variation at the 9 out of 10 loci led to statistically significant pairwise differences among the five study population groups. The result from AMOVA, Structure analysis, and Phylogenetic tree suggests that these populations are homogenous. In the multidimensional scaling plot, the present study populations formed a compact cluster clearly separated from other populations, suggesting a unique genetic identity of the Punjab populations as a whole. All these observations suggest that either a recent common origin of these populations or extensive gene flow across the populations that dissolve the original genetic differences. The data generated in this study will be useful for forensic genetics, molecular anthropological and demographic studies.

Associating genetic variation at Perilipin 1, Complement Factor D and Adiponectin loci to the bone health status in North Indian population

Osteoporosis, the most common bone metabolic disease affecting nearly 200 million people worldwide is under the strong influence of genetic components. Simultaneously, adipogenesis and osteogenesis are two highly coordinated processes imperative for the maintenance of bone quality and quantity, where any perturbation leads to pathological conditions of obesity, osteopenia and osteoporosis. To delineate this adipogenic-osteogenic connection, a total of 254 cases (T-score<-1.0 SD) and 250 age, gender and ethnicity matched healthy controls (T-score≥-1.0 SD) were recruited from North India after analyzing bone health status employing quantitative ultrasound (QUS) bone densitometer. The genetic variants of Perilipin 1 (PLIN1), Complement Factor D (CFD) and Adiponectin (ADIPOQ) were genotyped using the PCR-RFLP/ARMS-PCR approach. Subjects with CC+CT (PLIN1 rs2304795) and CC+CG (CFD rs1683563) genotypes conferred nearly 1.54-1.87 fold increased risk towards bone deterioration. Predicted RNA secondary structures of rs2304795 corroborated the risk associated with wild type C allele. G allele carriers at the ADIPOQ locus (rs1501299) were more likely to have a lower bone health (1.57-fold). Haplotype analysis revealed the ADIPOQ variants rs1501299 and rs3774261 in slight linkage disequilibrium (LD), nonetheless G/G haplotype was associated with increased risk. 3-locus and 5-locus gene-gene interaction models revealed a greater likelihood of bone deterioration. In conclusion, certain variants of adipogenic genes might serve as potential biomarkers for determining the genetic predisposition towards bone loss in the North Indian population, further, emphasizing the role of impaired metabolism in bone health.