UV-Visible spectroscopic effect on Haemoglobin & DNA degradation: A forensic approach.

In forensic casework, sample degradation is a largely an unsolved problem that exists due to poor preservation protocols. In Indian subcontinent, the forensic blood stains are commonly exposed to different ecological conditions for months before they are collected and transferred to the forensic laboratory for analysis. Under such conditions, the question of haemoglobin (Hb) & nucleic acid stability is of utmost importance. The biological evidence, especially the blood sample that underwent extreme conditions should further be retained in an appropriate storage facility until processed for the forensic serology/DNA testing. The present study provides the spectroscopic approach of analyzing Hb and DNA degradation of forensic blood samples preserved under varied conditions (tabulated and graphically). These samples were further subjected to and DNA analysis to assess the quality of sample based on different preservation conditions. At last, this study suggests the effective and appropriate preservation protocol of sample soon after its collection.

Secular trends in cranial chord variables: a study of changes in sexual dimorphism of the North Indian population during 1954-2011.

Background: Sex estimation of fragmentary remains is a critical problem which is further aggravated by the changing pattern of sexual dimorphism due to temporal/secular changes. Previously cranial chord variables were examined only to deduce cranial abnormalities and hominin evolution. In forensic anthropological literature to date, no studies have examined the importance of cranial chord variables in sex determination and neither have secular changes been reported in those measurements to date.Aim: The present study aims to examine the sexual dimorphism and temporal changes in chord measurements in the Indian population and to provide updated sex discriminant formulae.Subjects and methods: A total of 483 (contemporary: n = 158; sub-recent: n = 325) adult crania (18-70 years) from two temporally distinct North Indian populations were included in the study. Seven chord variables were measured and data were subjected to discriminant function analysis using SPSS 16.00.Results: Analysis of the data using the t-test demonstrated significant sexual and population variations over time. Univariate discriminant analysis revealed the glabella-bregma chord as the best variable in both populations (78.5 and 74.5% accuracy in the contemporary and sub-recent populations, respectively). Using multivariate analysis classification accuracy reached 86.1% in the contemporary sample.Conclusion: It is concluded that Indian crania are going through secular changes as the contemporary population has larger chord dimensions than their predecessors and chord variables can be applied for sex estimation in the Indian population.

Significance of temporal changes on sexual dimorphism of cranial measurements of Indian population.

Revision of discriminant function formulae has always been advocated by anthropologist to take into account the changing pattern of sexual dimorphism due to temporal/secular changes. The present study aims to track temporal changes in cranial measurements of temporally distinct North Indian population and providing updated sex discriminating formulae. A total of 483 adult (20-65 years) crania representing contemporary and sub-recent populations collected from two medical colleges in North India. A total of 11 variables were measured to observe the changes in cranial dimension over time. Analysis of data demonstrated significant sexual and population (contemporary vs sub-recent sample) variations over time. The contemporary males and females exhibited larger cranial dimensions but it expressed less dimorphism than their predecessors. A trend toward brachycephalization was also observed in contemporary females. Maximum cranial length (84%) and biauricular breadth (79%) represent the most dimorphic variables for contemporary and sub-recent sample, respectively. The possible causes of such variations are discussed.

Temporal variations in basicranium dimorphism of North Indians.

In recent years, several investigations have documented notable secular changes in human skull morphology. The present study is the next link in the series, addressing its possible effects in the cranial base in North Indian populations. The present study aims to examine the sexual dimorphism in cranial base of two temporally different samples of North Indian population to provide updated population specific osteometric standards. The contemporary and the subrecent samples are comprised of 158 (M 110; F 48) and 325 adult crania (M 206; F 119), respectively. Five variables of cranial base were measured, and data were subjected to discriminant function analysis using SPSS 16.0. The t-tests between the two temporally different samples showed significant sexual dimorphism and population variation. Contemporary females showed comparatively greater dimensions than subrecent. Contemporary population exhibited less sexual dimorphism than subrecent population. Factors associated with the changes in sexual dimorphism are likely to be a consequence of improved nutrition and population admixture in last 50 years. The accuracy of sex prediction ranged from 48.1 to 70.0 % in contemporary sample and 60.9 % to 77.2 % in subrecent sample. Overall, these findings support the conclusion that sexual dimorphism shows variation within few decades, so sex discriminating osteometric standards must be updated regularly.

Sexual dimorphism in ulna: an osteometric study from India.

Determination of sex constitutes the most important element during the identification process of human skeletal remains. Several sex-specific features of human skeleton have been exploited for sex determination with varying reliability. This study aims to obtain sexual dimorphic standards for ulnae of the north Indian population. Eight measurements were obtained on a sample of 106 ulnae (males--80, females--26) in the age range of 25-65 years. The sexual dimorphism index and demarking points were calculated for all the variables. The data were then subjected to stepwise and direct discriminant function analysis. The best discriminator of sex was the maximum length (84.9%) followed by radial notch width (84%). In stepwise analysis, these two variables were selected and provided an accuracy of 88.7% (M-87.5%, F-92.3%). The proximal end provided a classification rate of 81.1% (M-80%, F-84.6%) with selection of the notch length and olecranon width.

A study of sexual dimorphism in the femur among North Indians.

Determination of sex of unknown skeleton remains is the most important step in the identification process. Racial and regional differences in the populations create and maintain specificity in their dimorphic characteristics. Moreover, considering continued secular changes in the population structure, constant revision of osteometric standards becomes mandatory. In an effort to establish osteometric standards for the femur of contemporary North Indian populations, 122 adult femora of known sex (M: 94; F: 28) were collected in the Department of Forensic Medicine, IMS, BHU, Varanasi. Eight standard parameters were measured and analyzed by discriminant function analysis using SPSS 16. The accuracy of sex prediction ranged from 70.5% to 83.6% with single variables. In stepwise analysis, epicondylar breadth, proximal breadth, and antero-posterior diameter of the lateral condyle were found to be the most discriminating variables providing an accuracy of 90.2%. The results clearly indicate the importance of the ends of femur in the determination of sex.

Sex estimation from the mastoid process among North Indians.

Determination of sex from fragmentary crania is a critical problem in forensic anthropology. Osteometric analysis of mastoid can serve forensic anthropologists better in sex identification by virtue of the noticeable dimorphic characteristics. The present study aims to develop population-specific, sex-differentiating anthropometric standards for the mastoid process of North Indian skulls. Eight parameters of the mastoid region were measured on 138 adult crania (M/F 104:34, 22-65 years) and analyzed using SPSS 16.0. All parameters showed significant sexual dimorphism (p < 0.000). In stepwise analysis, asterion-mastoidale and mastoid breadth have provided an accuracy of 87%. Receiver operating characteristic curves were obtained for each variable to observe their overall performance in sex determination. Posterior end of incisura mastoidea-depression of suprameatal triangle was found to be the best variable with maximum area under curve and highest predictive accuracy (82.6%).

Sex determination using mandibular ramus flexure: a preliminary study on Indian population.

Determination of sex by morphological assessment has been one of the oldest approaches in forensic anthropology. Loth and Henneberg(6) introduced a morphological trait "Mandibular Ramus Flexure" for sex identification with a high accuracy of 99% in African Blacks. However, the population specificity of sexually dimorphic features is well known. The purpose of this study is to test the reliability of this trait in Indian population. A total number of 112 adult mandibles (88 males and 24 females) were studied from the Department of Forensic Medicine, Institute of Medical Sciences, Banaras Hindu University, India. The mandibles were scored according to the original method by two observers in three different sessions. This was done to test inter and intra-observer errors in identifying the trait. The result shows that this trait can be used to diagnose sex with an average accuracy of upto 82%. Though, inter and intra-observer errors were present but could be minimized with extended practice. So, the trait has the potential to be relied upon as a single morphological trait for determination of sex in Indian population.

An osteometric study of northern Indian populations for sexual dimorphism in craniofacial region.

Sex identification is an initial crucial objective in the revelation of the complete identity of the human skeleton as it also renders significantly clearer guidance towards age and stature estimation. Population specific standards are of great practical relevance in the present era of increasing population intermixing. Size differences and robusticity are the two well-elaborated pillars holding most of the dimorphic burdens of the skull. This study is designed to explore dimorphic characteristics of the craniofacial region to establish anthropometric standards for contemporary North Indian populations, which have not been available so far. One hundred and twelve adult crania of known age (23-65 years) and sex (M:F; 82:30) were collected in the Department of Forensic Medicine, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India. Ten standard metric parameters of craniofacial region were measured and subjected to stepwise and direct discriminant function analysis employing SPSS 16.00. Bizygomatic breadth emerged as the single best parameter in stepwise analysis, providing an average accuracy of 85.5%.

Mandibular ramus: an indicator for sex in fragmentary mandible.

Mandible is the hardest and most durable bone of the skull exhibiting a high degree of sexual dimorphism. Especially ramus of mandible is subjected to greater stress than any other bone of the skull because of the process of mastication. This study has been performed to establish the osteometric standards for practical use in forensic context over Indian population using mandibular ramus. The sample consists of 116 mandibles of Northern Indian population (M:F; 92:24, mean age 37.4 years), collected from the Department of Forensic Medicine, IMS, BHU, Varanasi. Osteometric informations about five metric parameters (coronoid height, projective height, condylar height, and maximum breadth and minimum breadth of ramus) were taken with sliding calipers. These parameters were subjected to different discriminant function analysis using SPSS 16.0. All parameters showed significant sexual dimorphism (p < 0.001 in all cases) with an overall accuracy of 80.2%, and coronoid height was the single best parameter providing an accuracy of 74.1%.