Evaluating the accuracy and precision of cranial morphological traits for sex determination

Sex determination is a key analysis that forensic anthropologists perform in order to construct a biological profile of human remains. The techniques used in forensic investigations must meet the Mohan or Daubert criteria, for admissibility in a court of law. In this study, the precision and accuracy of 21 morphological characteristics of the skull were tested on a modern sample of 50 adult crania of European White ancestry. The following craniofacial features are identified as high-quality traits, defined by intraobserver error or=80%: mastoid size, supraorbital ridge size, general size and architecture, rugosity of the zygomatic extension, size and shape of the nasal aperture, and gonial angle. Ninety-six percent accuracy and 92% precision were achieved using 20 traits in combination. Fisher's exact probability tests revealed no significant differences (p=0.05) in the levels of precision or accuracy between age categories. Sex-related bias in accuracy was found for the following cranial features: ramus symphysis (p=0.009), zygomatic extension (p=0.0016), and occipital markings (p=0.0013). These traits demonstrated a greater tendency to be scored male than female.     

Metric assessment of the "mastoid triangle" for sex determination: a validation study

Recently, a metric approach to skeletal sex determination was published by Paiva and Segre which is based on the summation of two triangular areas defined by three distinct craniometric landmarks: Porion, Mastoidale, and Asterion. According to the authors, values for the total triangle > or =1447.40 mm(2) are characteristic for male crania, while values < or =1260.36 mm(2) are indicative of female skulls (95% confidence). In order to evaluate the method's validity, two sex- and age-documented samples of different provenience were analyzed (N=197). The results show that while the indicated measurements display significant sex differences, the technique is of little practical meaning where a single individual must be independently classified. It is hypothesized that differences in the expression of sexual dimorphism as well as a population-specific variability of the asterion location undermine the value of the mastoid triangle as a sex determinant.     

Morphometrics of the hyoid bone for human sex determination from digital photographs

The identification of unknown remains is very important. When unknown remains are found, anthropologists first determine their sex and age. The sex of most skeletons is determined by their shape. In the hyoid bone, the shape is sex related, so it can be used forensically to determine the sex. This study focused on sex-based morphometry of the hyoid bone in Koreans using digital photographs. Hyoid bones from 52 males and 33 females were examined. For each subject, we took 34 measurements from photographs using a computer program, and the data were analyzed statistically using SPSS 11.0. Twenty-one of 34 measurements had significant sex differences (p<0.05). The discriminant functions based on three measurements (X(1)-X(3)) were as follows: The accuracy of discriminant functions is 88.2% in both groups, so these can be used to distinguish males from females in a statistically significant manner.     

Can electronic monitoring reduce crime for moderate to high-risk offenders?

Electronic monitoring (EM) of offenders has been in use for just over two decades and motives for using it remain diverse. Some agencies that use EM attempt to deliver humane and affordable sanctions while others seek to relieve jail crowding or to avoid the construction of new jails. Nonetheless, all EM programs aim to suppress the criminal behavior of offenders being monitored and its advocates have always hoped EM could be instrumental in reducing long-term recidivism. This review investigates the history of EM and the extent to which EM empirically affects criminal behavior in moderate to high-risk populations. All available recidivism studies that included at least one comparison group between the first impact study in 1986 and 2002 were considered for the review. Although variants such as GPS tracking and continuous testing for alcohol in perspiration have recently emerged, no studies of these technologies were found that met the review’s inclusion criteria. Studies are examined and combined for meta-analysis where appropriate. Given its continued and widespread use and the dearth of reliable information about its effects, the authors conclude that applications of EM as a tool for reducing crime are not supported by existing data. Properly controlled experiments would be required to draw stronger conclusions about the effects of EM.     

Evaluation of Purkait's triangle method for determining sexual dimorphism

The identification of sex from the skeleton is an important demographic assessment in medicolegal investigations. Rama Purkait developed a method for estimating sex using measurements from a triangle defined by three points on the proximal end of the femur using skeletal material from Bhopal, India. This method was tested with measurements on 200 Indo-European and African American adult femora from the Terry collection using discriminant function analysis to determine if Purkait's method was valuable for determining sex in Americans. A side-by-side analysis was conducted of Purkait's "triangle method" and the maximum diameter of the femoral head to determine their relative value in assessing sexual dimorphism. In the study sample a single variable from Purkait's method provided 85.5% prediction accuracy, similar to 87% for the head diameter. Combining threshold values for a single variable from Purkait's method and the femoral head diameter raised the predictability to greater than 90% for both sexes.     

浅论媒介与女性形象的互动关系

对女性问题研究的主要目的,是消除性别误解,树立正确的性别印象。这就需要用"性别误解"这一概念取代"性别歧视",目的在于变性别等级为性别差异。广告和影视作品中流露的"性别误解",强化或改变了受众的性别印象,而受众的性别印象又是媒介表达的动力和来源。在这个过程中,媒介起了强大的作用,因此也承担着主要的责任。性别误解不仅仅是女性自身发展的障碍,也阻碍了整个人类社会的发展。大众传媒可以作为一支独立的力量,促进女性性别误解的改变,进而促进社会的和谐发展。     

An investigation into the differentiating characteristics between car key burglars and regular burglars

Car key burglary has recently become the focus of empirical investigation as offenders, no longer able to steal vehicles without first obtaining their keys, resort to "burgling" target properties. Research surrounding the modus operandi of these offenses is beginning to emerge; however, little attention has been paid to investigating the characteristics of car key burglary offenders. Challenging the assumption that car key burglary offenses are perpetrated by regular burglars, this study aims to differentiate between offenders. Logistic regression analysis of 110 car key and 110 regular burglary offenders revealed that car key burglars are more likely to have previous vehicle theft convictions and are also more likely to be detected on information supplied to the police than regular burglars. Regular burglars are more likely to have previous shoplifting convictions. It was concluded that car key burglars are a distinct sample of offenders and the implications of these findings are discussed.     

Humeral and femoral head diameters in recent white American skeletons

Osteologists often rely on single measurements, such as humeral and femoral head diameters, to estimate sex, especially when skeletons are incomplete. Measurements of 237 Bass Donated Collection skeletons provide a means of distinguishing white American females from males based on a modern sample: humeral head, female mean 42.1 mm, male mean 49.0 mm; and femoral head, female mean 42.2 mm, male mean 48.4 mm. Probabilities that bones at 1-mm increments came from females (p(f)) are estimated (p(m) = 1 - p(f)). An overrepresentation of one sex in the skeletons that are examined influences the probability that a bone of a certain size is from a female or male. So, probabilities are also estimated for samples consisting of an unequal number of males and females. Sample composition has its greatest effect when one sex dominates the remains that are the subject of investigation.     

Sex determination from the talus of Koreans by discriminant function analysis

The aims of this study were to investigate the sex discriminating potential of the talus in Koreans and compare this with other analyses in different populations. Statistical analyses were performed using data from nine measurements acquired from 140 tali (70 men, 70 women). The talus of Koreans is dimorphic between sexes in all measurements (p < 0.01). Discriminant function equations were generated by univariate, multivariate, and stepwise methods with a range of accuracy from 67.1 to 87.1%. Stepwise equations of other populations did not discriminate the sex of the Korean sample as accurately as each equation's own accuracies. The variables with high accuracy in this study are useful for sex determination of Koreans on the basis of confirmation of population specificity.