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B. Karmakar

Bio: B. Karmakar is an academic researcher from Indian Statistical Institute. The author has contributed to research in topics: Population & Dermatoglyphics. The author has an hindex of 10, co-authored 34 publications receiving 274 citations.

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TL;DR: The results strongly suggest that the two categories of dermatoglyphic variables provide similar possibilities to discriminate between the sexes in populations.
Abstract: Summary Five different endogamous populations who encompass the main social rank in the caste hierarchy of West Bengal were analysed for this report. The present approach is to compare the pattern of sex differences/similarities exhibited by two different sets of dermatoglyphic traits. Cluster and discriminant analysis and Mantel test of matrix correlations were performed. The nature of variation between sexes within population groups and two types of variable sets has a good similarity in all five populations. These results strongly suggest that the two categories of dermatoglyphic variables provide similar possibilities to discriminate between the sexes in populations.

10 citations

Journal ArticleDOI
01 Dec 2012
TL;DR: The results of palmar traits reveal homogeneity which also presents a common picture obtained in the earlier studies, perhaps due to the possible role of environmental (prenatal) factors in the realization of dermatoglyphics between finger and palm.
Abstract: Quantitative finger and palmar dermatoglyphics of 218 individuals (170 males and 48 females) belonging to the Muzeina Bedouins from South Sinai Peninsula. They are characterized with a high degree of consanguinity, a small isolate nomadic tribe. 22 quantitative dermatoglyphic traits (12 finger and 10 palms) were considered in the present study. Except PII (non-significant sex difference), the results of significant sex differences of finger ridge counts (TFRC), MLI are similar with the earlier studies in various populations. However, the results of palmar traits reveal homogeneity which also presents a common picture obtained in the earlier studies, perhaps due to the possible role of environmental (prenatal) factors in the realization of dermatoglyphics between finger and palm. The development of palmar dermatoglyphics has a relatively longer growth period compared with fingers (Cummins 1929). Thus, the palmar dermatoglyphic pattern of affinities corresponds better than fingers to the ethno-historic background of the populations (Reddy et al. 1988, Karmakar et al. 1989, 2002, 2008, 2010).

10 citations

Journal ArticleDOI
TL;DR: The results of bivariate variance decomposition analysis strongly suggest the existence of common genetic factors simultaneously affecting HOC and VEC; 41.8% of the two traits' total residual variance was attributable to the effect of these common Genetic factors.
Abstract: The substantial involvement of genetic factors in the determination of head-size and head-shape traits has been firmly established. However, there has been a lack of agreement on a number of specific issues concerning the pattern of inheritance of craniofacial features. In this study we examined some of these issues in a large, ethnically homogeneous sample of Indian pedigrees. The data included 1,263 individuals belonging to 373 nuclear families. Eleven raw head-size traits and two synthetic phenotypes, interpreted as horizontal and vertical head-size components (HOC and VEC, respectively), were used in the analysis. To establish the pattern of inheritance of head traits, we carried out univariate and bivariate analyses. Maximum heritability estimates ranged from 0.41 to 0.83 for the studied head-size phenotypes. The portion of the total residual variance attributable to putative additive genetic factors was 68.3% and 70.3% for HOC and VEC, respectively, and common familial factor effects were found to be nonsignificant. The extent of genetic influences did not differ significantly with respect to sex or between HOC and VEC. The results of bivariate variance decomposition analysis strongly suggest the existence of common genetic factors simultaneously affecting HOC and VEC; 41.8% of the two traits' total residual variance was attributable to the effect of these common genetic factors.

10 citations

Journal ArticleDOI
TL;DR: The results support the idea postulated by several previous authors that FA provides a measure of developmental instability in man and the contribution of heredity on these asymmetric variables is not unimportant but that of the common environment is very substantial.
Abstract: To understand the genetics of Fluctuating Asymmetry (FA) and Directional Asymmetry (DA), the present study comprised 14 bilateral morphometric traits from 200 Vaidya families including 824 individuals (of two generations) from North 24 Parganas, West Bengal. The statistical analysis included: Regression analysis to remove the age effect, Familial correlation, Heritability estimation, Principal Component Analysis and Segregation Analysis (SA) using genetic model test. The obtained results revealed little effect of genetic factor and considerable amount of environmental influence on anthropometric asymmetry. The results support the idea postulated by several previous authors that FA provides a measure of developmental instability in man. The contribution of heredity on these asymmetric variables is not unimportant but that of the common environment is very substantial. The magnitude of heritability of DA traits is slightly higher than that of FA traits. Five principal factors were detected from these asymmetric traits (three factors are on asymmetry on length, head, and breadth; while last two factors represent the asymmetry of diameters). SA did not suggest any evidence of major gene contribution. But the involvement of minor genes or polygenes could not be discarded. As the study on SA of asymmetry in man is limited, similar other studies are needed to confirm the result of the present study.Am. J. Hum. Biol. 19:399–408, 2007. © 2007 Wiley-Liss, Inc.

9 citations

Journal Article
TL;DR: In the present study, non-significant change in the frequency of pattern and more or less same PII have been observed in both sexes, but significant quantitative differences were found between the two samples.
Abstract: In order to investigate the intergenerational change of dermatoglyphics, fingerprints of 400 individuals were collected from an endogamous caste Vaidyas of Barasat, West Bengal. Results were compared with the data of an earlier sample of Banerjee collected in 35 years before on the same community of the same area. As it is generally known that dermatoglyphics is selectively neutral, thus if no other evolutionary forces play a role, we cannot expect any change of dermatoglyphic characters after several years. In the present study, non-significant change in the frequency of pattern and more or less same PII have been observed in both sexes. But significant quantitative differences were found between the two samples. These differences may not be due to the change of intra-uterine environment, rather due to the inter-observer error of these two studies and the small sample size of the earlier study. Because though same methods were used in both studies, inter-observer variation is much possible in ridge counting than pattern type determination.

9 citations


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TL;DR: For the next few weeks the course is going to be exploring a field that’s actually older than classical population genetics, although the approach it’ll be taking to it involves the use of population genetic machinery.
Abstract: So far in this course we have dealt entirely with the evolution of characters that are controlled by simple Mendelian inheritance at a single locus. There are notes on the course website about gametic disequilibrium and how allele frequencies change at two loci simultaneously, but we didn’t discuss them. In every example we’ve considered we’ve imagined that we could understand something about evolution by examining the evolution of a single gene. That’s the domain of classical population genetics. For the next few weeks we’re going to be exploring a field that’s actually older than classical population genetics, although the approach we’ll be taking to it involves the use of population genetic machinery. If you know a little about the history of evolutionary biology, you may know that after the rediscovery of Mendel’s work in 1900 there was a heated debate between the “biometricians” (e.g., Galton and Pearson) and the “Mendelians” (e.g., de Vries, Correns, Bateson, and Morgan). Biometricians asserted that the really important variation in evolution didn’t follow Mendelian rules. Height, weight, skin color, and similar traits seemed to

9,847 citations

Journal ArticleDOI
01 Nov 2016-Thyroid
TL;DR: A systematic review supports a widespread and persistent increase in TC incidence and evidence for over-detection of PTC as the predominant influence includes increased numbers of smaller size tumors and improved or unchanged survival.
Abstract: Background: A large proportion of global increase in thyroid cancer (TC) incidence has been attributed to increased detection of papillary thyroid cancer (PTC). Nonetheless, some reports support a real increase in incidence. This study aimed to perform a systematic review to evaluate the changing trends in TC incidence and summarize potential risk factors predisposing to this trend. Methods: Literature published in the English language between 1980 and August 2014 was searched via PubMed (MEDLINE) and OvidSP (EMBASE). Original studies on changes in TC incidence in defined geographic areas that described clear methods of case selection and population estimates were included. Data on incidence rates and risk factors were collected. Results: Of 4719 manuscripts, 60 studies were included, of which 31 were from Europe, 13 from North America, and the rest from Asia (n = 9), Oceania (n = 4), and South America (n = 3). Fifty-three articles reported a significant increase in incidence (highest was a 10-fold increa...

247 citations

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241 citations

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TL;DR: This foetus into man physical growth from conception to maturity will help people to enjoy a good book with a cup of coffee in the afternoon instead of facing with some malicious virus inside their desktop computer.
Abstract: Thank you for downloading foetus into man physical growth from conception to maturity. As you may know, people have look numerous times for their chosen novels like this foetus into man physical growth from conception to maturity, but end up in infectious downloads. Rather than enjoying a good book with a cup of coffee in the afternoon, instead they are facing with some malicious virus inside their desktop computer.

234 citations