Determination of sex from the clavicle and scapula in a Guatemalan contemporary rural indigenous population

The clavicle has been described as a useful bone for the metric determination of sex of human skeletal remains in a contemporary, predominantly white, North American forensic sample. In this article, measurements of clavicle and scapula are provided for a contemporary Guatemalan rural indigenous sample of forensic origin. Maximum length and circumference at midshaft of the clavicle, and height and width of the glenoid fossa of the scapula, were measured in 35 female and 62 male clavicles, and in 38 female and 65 male scapulae. Discriminant function analysis was used to study sexual dimorphism in this population with a classification purpose. Leave-one-out method (jackknife) matrices produced classification success rates ranging from 85.6% to 94.8%. A comparison with the North American forensic sample showed low percentages of correctly sexed Guatemalan male clavicles, ranging from 29.4% to 54.9%. The choice of an appropriate standard for the metric determination of sex is a crucial step in forensic anthropology.     

Stature estimation from long bone lengths in a Thai population

The estimation of stature is a very important step in developing a biological profile for forensic identification. However, little previous work has been done on stature estimation among modern Thai people, despite a growing number of forensic cases in Thailand in recent years. The current study was carried out on a sample of 200 skeletons from a northern Thai population (132 males and 68 females), ranging in age from 19 to 94 years. The maximum lengths of six long bones (humerus, radius, ulna, femur, tibia and fibula) were measured and stature reconstruction formulae generated using linear regression. These equations were then tested on a holdout sample of 15 females and 15 males. Results reveal that the three lower limb bones are the most accurate estimators of stature among the males, with the fibula equation producing the lowest standard error of the estimate (SE=4.89cm), followed by the femur (SE=5.06cm). Results for females were mixed. The femur produced the lowest standard error among the females (SE=5.21cm), followed by the radius (SE=5.63cm). However, when tested against the holdout sample (n=30), the femur equations were considerably more accurate, with a mean absolute error of 3.5cm and a median absolute error of 2.4cm. Females exhibited a higher standard error of the estimate than reported in many previous studies. This higher error may be the result of a recent secular trend in stature affecting the females of our sample somewhat more than the males.     

Determination of sex from femora

The determination of sex from bones or bone fragments considerably contributes to identifying unknown bodies or skeletal remains. Due to temporal change and regional differences anthropometric standards have to be constantly renewed. The present study provides measurements of femoral dimensions in a contemporary German population and analyses sexual dimorphism by discriminant analysis. Maximum length (male: 46.4+/-2.4 cm, female: 43.4+/-2.4 cm), maximum midshaft diameter (male: 3.1+/-0.2 cm, female: 2.8+/-0.2 cm), condylar width (male: 8.4+/-1.0 cm, female: 7.7+/-0.5 cm), vertical head diameter (male: 4.9+/-0.3 cm, female: 4.4+/-0.3 cm), head circumference (male: 15.7+/-0.8 cm, female: 13.8+/-1.0 cm) and transverse head diameter (male: 4.9+/-0.3 cm, female: 4.3+/-0.3 cm) were measured in 170 femora, 100 from male (age: 16-92 years, mean: 60.8 years; body height: 153-190 cm, mean: 171 cm) and 70 from female (age: 20-96 years, mean: 72 years; body height: 146-175 cm, mean: 161 cm) individuals. In the discriminant analysis (leave-one-out-method) 67.7% of cases could be grouped correctly with the maximum length alone, 72.4% with the maximum midshaft diameter, 81.4% with the condylar width, 86.8% with the vertical head diameter, 87.7% with the head circumference and 89.6% with the transverse head diameter. The stepwise procedure with all head measurements showed that the results for the transverse head diameter could not be improved. With all measurements subjected to stepwise procedure 91.7% of cases could be classified correctly combining midshaft diameter and head circumference (D=3.012xmidshaft diameter in cm+0.780xhead circumference in cm 20.569).     

Estimation of sex from hand and handprint dimensions in a Western Australian population

A number of recent studies have demonstrated that sex can be estimated with a high degree of expected accuracy through the analysis of anthropometric measurements of the hand. Presently, however, the majority of previous related research has been focused on a limited range of global populations. The aim of the present study, therefore, is to evaluate the accuracy of using anthropometric hand measurements for the estimation of sex in a contemporary adult Western Australian population; we also assess if sex can be accurately estimated from the measurement of handprints. The study sample comprises a total of 91 male and 110 female individuals; documented mean age for the males is 38 years (range 19-68) and for the female sample it is 36 years (range 18-63). A total of six linear measurements are taken from each hand and its corresponding print. Measurement data is analysed using basic univariate statistics and a series of direct and stepwise discriminant function analyses are performed to assess the sex classification potential of the hand and handprint variables. All six hand and handprint measurements are sexually dimorphic and sex explains 28.4-61.7% of the sample variance. The breadth and length of the hand contribute most significantly to sex discrimination; cross-validated sex classification accuracies range between 82.6 and 96.5% with a sex bias of ≤5%. We conclude that anthropometric measurements of the hand and handprint can be used to classify sex with a high degree of expected accuracy in a Western Australian population.     

Juvenile sex offenders: a complex population

Individuals who engage in sexual offending behavior represent a heterogeneous population. Recent research has found some success in categorizing sexual offenders based on a number of variables, particularly the type of victim. For example, differences have been found between those offenders who victimize adults when compared with those who victimize children. However, the research in this area has been conducted predominantly with adult samples. As the adult sex offender literature has progressed, it has become evident that risk assessment, treatment effectiveness, and risk management are dependent on such offender characteristics. Unfortunately, the relevance to juveniles of characteristics deemed to be important with adult sex offenders is limited due to the complexity of developmental processes, particularly with respect to mental disorders and personality formation. As such, the formulation and implementation of treatment and risk management strategies that will be effective with juvenile sex offenders are challenging. The goal of this paper is to review some of the complexities inherent in the juvenile sex offender population by focusing on specific areas of complication, including: classification systems, comorbid paraphilias and other mental illnesses, and maladaptive personality traits.     

Determination of sex and race from the subpubic angle in Ugandan subjects

The accurate determination of sex and race are important tools to forensic and physical anthropologists. In this study, the sex and race of 205 adult Ugandans were determined from the antero-posterior radiographs of the pelvis by measuring their subpubic angles. The angle ranged from 50 to 140 degrees with a mean of 93.86 degrees and standard deviation (SD) of 21.12 degrees for males and 75 to 155 degrees with a mean of 116.11 degrees (SD, 17.79 degrees) for females. The angle was significantly wider in women than men (P < 0.05), as indeed has previously been shown in other population groups studied. Using the demarking point method, 31.82% of Ugandan men and 10.53% of Ugandan women could be accurately sexed. However, more Malawians of both sexes previously studied had lower values for the angle and could be more accurately sexed. This study has also documented regional and racial variability of this angle among different population groups previously documented. Using the watershed subpubic angle derived from the means of this study and those of previously documented studies, 63% of Ugandans and 71% of Malawians could be accurately assigned to the black race. This method is recommended to physical and forensic anthropologists in the developing world.     

A novel fluorescent quadruplex STR typing system and the allele frequency distributions in a Thai population

We have previously reported a new triplex amplification and typing system by silver staining for three short tandem repeat (STR) loci, 9q2h2 (D2S3020), D15S233, and D14S299 without "microvariant" alleles such as .1, .2, and, .3 alleles in the Japanese population. In the present study, we established a new quadruplex system with an additional locus D7S809 using primer sets labeled with fluorescent multi-color dyes. Using this system, we genotyped 183 Thai people, found only one "microvariant" allele (allele 20.2) at D7S809, and calculated allele frequencies and some statistical properties at these four STR loci. From these allele frequencies at four STR loci, we performed three statistical analyses including a homozygosity test, a likelihood ratio test, and an exact test for Hardy-Weinberg equilibrium (HWE). Deviations from HWE (p < 0.05) were observed only in the two tests at the locus D7S809. In the present study, we compared the allele frequencies at these four loci in the Thai population to those in the Japanese population described previously. Consequently, all observed heterozygosities and power of discrimination (PD) at those loci in the Thai population were higher than 0.8 and 0.9, respectively, and all statistical values for discriminating power in the Thai population were slightly higher than those in the Japanese population. The combined paternity exclusion rate (combined PE) in the Thai population (0.978) was almost the same as that in the Japanese population (0.971). Therefore, this novel PCR amplification and typing system for four STR loci would be a convenient and informative DNA profiling system in the forensic field.     

中国成都汉族及泰国群体D7S2846基因座的遗传多态性

研究STR基因座D7S2 846的遗传多态性 ,为法科学应用提供基础数据。应用PCR及PAG电泳技术 ,对376名中国成都汉族无关个体及 131名泰国无关个体进行了调查。两群体分别检出 8个和 7个等位基因 ,首次获得该基因座基因在两群体中的频率分布。两群体基因型频率分布均符合Hardy Weinberg平衡。家系调查证实了等位基因的传递遵循孟德尔遗传规律。该基因座在两群体中的个人识别能力 (Dp)分别为 0 85 70、 0 86 0 2 ,杂合度 (H )分别为0 6 915、 0 6 870 ,多态性信息含量 (PIC)分别为 0 6 445、 0 6 5 5 3 ,非父排除率 (PE )分别为 0 415 2、 0 40 85。D7S2 846基因座在法医学个人识别及亲子鉴定中具有较高的实用价值。     

Eye colour single nucleotide polymorphisms (SNPs) variants in Thai population

Human eye colour is recognized as one of the visible characterized features that would be valuable for forensic identification by predicting these phenotypes with particular genotypes. Recent gene association study had figured the remarkable variants mainly in OCA2 and HERC2 genes. In this study, eight human eye colour single nucleotide polymorphisms (SNPs) in five pigmentation genes, OCA2 (rs7495174, rs4778241 and rs4778138), HERC2 (rs12913832 and rs1667394), SLC24A4 (rs12896399), SLC45A2 (rs16891982) and TYR (rs1393350) were investigated in 374 Thai samples. The homozygote genotypes were predominantly observed in rs16891982 (GG/0.9920), rs1393350 (GG/0.9973) and rs12913832 (AA/0.9866). The allele frequency comparison with other populations in HapMap had identified the major allele of East Asia and Thai. Furthermore, the analysis of haplotype block of HERC2-OCA2 comprised five SNPs (rs12913832, rs1667394, rs7495174, rs4778241 and rs4778138) presented the most haplotype was AG-GAG (0.5199), which was rarely observed in European population.     

A comparison between neural network and other metric methods to determine sex from the upper femur in a modern French population

Forensic anthropologists are frequently asked to assess partial or badly damaged skeletal remains.One such request led us to compare the predictive accuracy of different mathematical methods using four non-standard measurements of the proximal femur (trochanter–diaphysis distance (TD), greater–lesser trochanter distance (TT), greater trochanter width (TW) and trochanter–head distance (TH)). These measurements were taken on 76 femurs (38 males and 38 females) of French individuals. Intra- and inter-observer trials did not reveal any significant statistical differences. The predictive accuracy of three models built using linear and non-linear modelling techniques was compared: discriminant analysis, logistic regression and neural network. The neural network outperformed discriminant analysis and, to a lesser extent, logistic regression. Indeed, the best results were obtained with a neural network that correctly classified 93.4% of femurs, with similar results in males (92.1%) and females (94.7%). Univariate functions were less accurate (68–88%). Discriminant analysis and logistic regression, both using all four variables, led to slightly better results (88.2% and 89.5%, respectively). In addition, all the models, save the neural network, led to unbalanced results between males and females. In conclusion, the artificial neural network is a powerful classification technique that may improve the accuracy rate of sex determination models for skeletal remains.     

An assessment of the accuracy of discriminant function equations for sex determination of the femur and tibia from a South African population

The purpose of this study is to test the accuracy of seven discriminant function equations that have been derived by Steyn and Is?an for sex determination using measurements of the femur and tibia of South Africans of European descent (SAED). While the validity of some of the discriminant functions has been assessed by the authors who derived them, no previous independent study has been carried out to assess the accuracy of these equations. These equations have not been tested on skeletons located outside of the Gauteng province. A suite of measurements were taken on 272 femora and 256 tibiae obtained from four South African skeletal collections. The validity of each of the previously published equations for the femur was confirmed. However, two functions of the tibia showed low accuracy rates, most likely due to difficulties in recording the distal epiphyseal breadth measurement, and thus were found to be poor assessors of sex.     

Determination of sex from juvenile crania by means of discriminant function analysis

This study provides evidence of craniofacial growth variation between the sexes in juveniles of European descent. Data were collected from lateral cephalometric radiographs belonging to the Michigan Craniofacial Growth Study. The collection consists of longitudinal lateral radiographs that represent individuals 5-16 years of age. Each radiograph was manually traced on hyprint vellum from which eight craniometric points were identified. From these points, 20 craniofacial measurements were recorded and then analyzed by means of a canonical discriminant function analysis. Sex classification equations were then created by applying a backward stepwise procedure to the discriminant functions. The analysis demonstrates the presence of sexually dimorphic differences in craniofacial growth. The neurocranium is the most sexually dimorphic region of the juvenile craniofacial skeleton, until the onset of puberty. Size is the main source of variation with males having taller and longer heads than females. Overall, sex classification in the sample ranges from 78 to 89% accuracy.     

Discriminant function analysis for sex assessment in pelvic girdle bones: sample from the contemporary Mexican population

Sex assessment of skeletal remains plays an important role in forensic anthropology. The pelvic bones are the most studied part of the postcranial skeleton for the assessment of sex. It is evident that a population-specific approach improves rates of accuracy within the group. The present study proposes a discriminant function method for the sex assessment of skeletal remains from a contemporary Mexican population. A total of 146 adult human pelvic bones (61 females and 85 males) from the skeletal series pertaining to the National Autonomous University of Mexico were evaluated. Twenty-four direct metrical parameters of coxal and sacral bones were measured and subsequently, sides and sex differences were evaluated, applying a stepwise discriminant function analysis. Coxal and sacra functions achieved accuracies of 99% and 87%, respectively. These analyses follow a population-specific approach; nevertheless, we consider that our results are applicable to any other Hispanic samples for purposes of forensic human identification.     

Metric determination of sex from the humerus in a Guatemalan forensic sample

The absence of population-specific standards for sex, age and stature estimation for rural Guatemala is problematic for the forensic analysis of skeletal remains recovered from clandestine graves attributed to the recent armed conflict in that country. In order to increase the reliability of the forensic analyses being undertaken in Guatemala, standards for metric determination of sex were developed. Data was collected on several bones; the results for the humerus are presented here. A sample of 118 complete humeri (68 male and 50 female) was studied; maximum length, maximum diameter of the head, circumference at midshaft, maximum diameter at midshaft, minimum diameter at midshaft and epicondylar breadth were measured and subjected to discriminant function analysis. The classification accuracies for the univariate functions range from 76.8% for the maximum diameter at midshaft to 95.5% for the maximum diameter of the head. The classification accuracy for the stepwise procedure was 98.2%.     

Learning to pass: sex offenders' strategies for establishing a viable identity in the prison general population

This article endeavors to illustrate the realities of prison life for sex offenders and the means by which they attempt to establish viable identities and acquire a survivable niche in the prison general population, particularly when established identities and protective niches are put at risk by entry into a sex offender treatment program. Qualitative data was collected by repeatedly interviewing a cohort of sex offenders for 6 months as they completed a basic sex offender treatment program. The findings indicate a need to include consideration of treatment context in understanding the limits of treatment gain in prison-based programs.     

Higher failures of amelogenin sex test in an Indian population group

The human sex test in forensic multiplexes is based on the amelogenin gene on both the X and Y chromosomes commonly used in sex genotyping. In this study of 338 male individuals in a Malaysian population comprising Malays, Chinese and Indians, using the AmpFlSTR Profiler Plus kit, the amelogenin test gave a significant proportion of null alleles in the Indian ethnic group (3.6% frequency) and 0.88% frequency in the Malay ethnic group due to a deletion of the gene on the Y chromosome. This sex test also failed in a forensic casework sample. Failure of the amelogenin test highlights the need for more reliable sex determination than is offered by the amelogenin locus in the Malay and Indian populations. The gender of the Indian-Malay amelogenin nulls was confirmed by the presence of three Y-STR alleles (DYS438, DYS390 and DYS439). For the Indian ethnic group, one of the Y-STR forms a stable haplotype with the amelogenin null. The amelogenin-deletion individuals also showed a null with a male-specific minisatellite MSY1, indicating that a very large deletion was involved that included the amelogenin and the MSY1 loci on the short arm of the Y chromosomes (Yp).     

Assessment of public attitudes towards sex offenders in an Australian population

Public attitudes towards sex offenders are believed to play a key role in the development of legislation and public policy designed to manage the risks posed by known sex offenders who live in the community. There have, however, been few previous attempts to validate methods by which public attitudes can be measured. The current study aims to address this issue by establishing the factor structure of the Community Attitudes Towards Sex Offenders (CATSO) scale with an Australian community sample and examine the extent to which demographic variables and support for sex offender management policies influence these attitudes. A sample of 552 participants recruited through online social media sites completed the CATSO as well as a number of items developed by the researchers designed to assess individuals' support for specific sex offender policies. Results of an exploratory factor analysis suggested the presence of four distinct factors which were labelled ‘social tendencies’, ‘treatment and punishment’, ‘crime characteristics’ and ‘sexual behaviour’. Individuals with higher levels of educational attainment rated sex offenders less negatively than those with lower educational attainment, while those who reported being supportive of community notification reported more negative attitudes towards sex offenders.