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The validity of the method in which Total Body Score (TBS) and Accumulated Degree-Days (ADD) are used to estimate the postmortem interval (PMI) is examined. TBS and ADD were recorded for 232 days in northern South Africa, which has temperatures between 17 and 28 ºC in summer and 6 and 20 ºC in winter. Winter temperatures rarely go below 0 ºC. Thirty pig carcasses, which weighed between 38 and 91 kg, were used. TBS was scored using the modified method of Megyesi et al. [1]. Temperature was acquired from an on site data logger and the weather station bureau; differences between these two sources were not statistically significant.Using Loglinear Random-effects Maximum Likelihood Regression, an r 2 value for ADD (0.6227) was produced and linear regression formulae to estimate PMI from ADD with a 95% prediction interval were developed. The data of 16 additional pigs that were placed a year later were then used to validate the accuracy of this method. The actual PMI and ADD were compared to the estimated PMI and ADD produced by the developed formulae as well as the estimated PMIs within the 95% prediction interval. A validation of the study produced poor results as only one pig of 16 fell within the 95% interval when using the formulae, showing that ADD has limited use in the prediction of PMI in a South African setting.

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Pattern-expressions of morphoscopic cranial traits vary across populations with classification accuracies being highly dependent on the reference collection to which unknown skulls are compared. Despite recent developments in population-specific standards for South Africans, researchers have not addressed the accuracy of morphological methods. Several studies demonstrate differences in sexual dimorphism between South Africans and North Americans, warranting a need to re-evaluate sex estimation methods in South Africa. The purpose of this study was to test the reliability and accuracy of the Walker (2008) method and to examine patterns of sexual dimorphism among South Africans.A total of 245 modern black and white South African male and female crania from the Pretoria Bone Collection, University of Pretoria, were scored using the Walker (2008) methodology. Cohen's Kappa was used to evaluate reliability of the method and percent correct assessed validity of the method. Logistic regression was utilised to create modified population-specific formulae.Inter-and intra-observer agreement was moderate to excellent (0.60-0.90), except for the mental eminence (0.40). The percent correct results for sex were 80% or higher for combinations of glabella, mastoid and menton and between 68% and 73% for menton, mastoid, orbital and nuchal margin using logistic equations 2 of Walker (2008). White males had the highest (94-97%) and white females had the lowest (31-62%) percent correct.The low accuracies obtained when using Walker (2008) emphasized the need for population-specific sex estimation models. Modified formulae for South Africans were created, yielding higher classification rates (84-93%) than when North American standards were employed.

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