The age at death assessment in a multi-ethnic sample of pelvic bones using nature-inspired data mining methods

Recently published studies showed that age assessment methods are population specific. Authors analyse the senescence changes in pubic symphysis and sacro-pelvic surface of a pelvic bone using data mining methods. The multi-ethnic data set consists of 956 adult individuals ranging from 19 to 100 years of age derived from 9 different populations with known age and sex. The results show that accurate and reliable age assessment is possible to three age classes (less than 30, 30-60, 60 and more). The study confirms that population specificity of the methods exists and the variable "sex" is not important in age classification.     

Variability of the pattern of aging on the human skeleton: evidence from bone indicators and implications on age at death estimation

Age at death assessment of adult skeletons is one of the most difficult problems in forensic and physical anthropology. Two fundamental sources of error are described: the complex variability in the process of skeletal aging and methodological bias. Taking into account these limits, we developed a new scoring system for the auricular surface of the ilium and the pubic symphysis. In order to address a large variability, we examine reference samples from Europe, North America, Africa, and Asia. Data were processed using Bayesian prediction in order to classify specimens in age range categories. Results show that combining indicators do not perform better than the auricular surface used as a single indicator. Morphological changes with aging are variable between Asian, African, and European populations, confirming the necessity to use population-specific standards. Bayesian prediction produces reliable classification and is applicable for subjects over 50 years old, a real methodological improvement.     

Suicide by Medication Overdose in Prison: A Study of Three Cases

Suicide is one of the principal causes of mortality in a prison environment. Although suicide by medication overdose is less frequent than suicide by hanging, self‐strangulation, or vein cutting, it raises questions as to how the medications are obtained, particularly in view of the specific organization of the medication circuit in prisons. We present three cases of suicide by medication overdose involving different therapeutic classes with different distribution circuits and review the regulatory requirements and the measures that could be taken to prevent such suicides.     

An Evaluation of Statistical Methods for the Determination of Age of Death Using Dental Root Translucency and Periodontosis

Abstract: Lamendin and colleagues (1992) proposed to assess age‐at‐death from root translucency and periodontosis. Several teeth from the same individual were included in their study. In our work, we evaluate the reliability of their formulas without introducing this bias. Our sample was constituted of 214 individuals (114 males and 100 women) selected from the Terry collection (U.S.A.). The R² between age and both indicators is equal to 0.33 and 0.08 (p < 0.001). Based on linear regression, the mean of standard error for individual age prediction was equal to 13.67 years, and the mean interval length is equal to 53.89 years. Multinomial logistic regression and Bayesian approach failed to give satisfactory results when classifying the individuals in age categories. Therefore, the use of root translucency and periodontosis may lead to incorrect age‐at‐death assessment, and it is thus necessary to complement this approach with other techniques to assess age‐at‐death.     

Estimation of age at death from the pubic symphysis and the auricular surface of the ilium using a smoothing procedure

We discuss here the estimation of age at death from two indicators (pubic symphysis and the sacro-pelvic surface of the ilium) based on four different osteological series from Portugal, Great-Britain, South Africa or USA (European origin). These samples and the scoring system of the two indicators were used by Schmitt et al. (2002), applying the methodology proposed by Lucy et al. (1996). In the present work, the same data was processed using a modification of the empirical method proposed by Lucy et al. (2002). The various probability distributions are estimated from training data by using kernel density procedures and Jackknife methodology. Bayes's theorem is then used to produce the posterior distribution from which point and interval estimates may be made. This statistical approach reduces the bias of the estimates to less than 70% of what was obtained by the initial method. This reduction going up to 52% if knowledge of sex of the individual is available, and produces an age for all the individuals that improves age at death assessment.     

Aging process variability on the human skeleton: artificial network as an appropriate tool for age at death assessment

Adult age-at-death assessment is one of the most difficult problem encountered in paleoanthropology. Many procedures have been proposed using either skeletal remains or dental records, but most show systematic bias. Data processing of current methods are a source of error because they neglect that process of biological ageing is very variable between individuals and populations. The aim of this study is to test the potentiality of artificial neural networks (ANN) as a prediction tool. ANN have been used for a wide variety of applications where statistical methods are traditionally employed. But it performs better to solve linearly non separable patterns. We applied this technique after observation of several features' aging changes of the pubic symphysis and the auricular surface of the ilium. Although we failed to reduce the size of the intermediate class (30-59 years), the neural network identifies, with better reliability than previous works, the youngest (20-29 years) and the oldest (above 60 years) individuals.