Heteroplasmy in hair: differences among hair and blood from the same individuals are still a matter of debate

The analysis of mitochondrial DNA (mtDNA) is a useful tool in forensic cases when sample contents too little or degraded nuclear DNA to genotype by autosomal short tandem repeat (STR) loci, but it is especially useful when the only forensic evidence is a hair shaft. Several authors have related differences in mtDNA from different tissues within the same individual, with high frequency of heteroplasmic variants in hair, as also in some other tissues. Is still a matter of debate how the differences influence the interpretation forensic protocols. One difference between two samples supposed to be originated from the same individual are related to an inconclusive result, but depending on the tissue and the position of the difference it should have a different interpretation, based on mutation-rate heterogeneity of mtDNA. In order to investigate it differences in the mtDNA control region from hair shafts and blood in our population, sequences from the hypervariable regions 1 and 2 (HV1 and HV2) from 100 Brazilian unrelated individuals were compared. The frequency of point heteroplasmy observed in hair was 10.5% by sequencing. Our study confirms the results related by other authors that concluded that small differences within tissues should be interpreted with caution especially when analyzing hair samples.     

Amphetamine, cocaine and cannabinoids use among truck drivers on the roads in the State of Sao Paulo, Brazil

Lysergic acid diethylamide (LSD) is a potent hallucinogen, active at very low dosage and its determination in body fluids in a forensic context may present some difficulties, even more so in hair. A dedicated liquid chromatography-electrospray-tandem mass spectrometry (LC-ES-MS/MS) assay in hair was used to document the case of a 24-year-old man found dead after a party. Briefly, after a decontamination step, a 50mg sample of the victim's pubic hair was cut into small pieces (<1mm length), and incubated overnight in 3mL of phosphate buffer pH 5 at room temperature. After a liquid-liquid extraction (dichloromethane/ether), the extract was analyzed using a LC-ES-MS/MS method exhibiting a limit of quantification of 0.5pg/mg for LSD. A LSD concentration of 0.66pg/mg of pubic hair was observed. However, this result remains difficult to interpret owing to the concomitant LSD presence in the victim's post mortem blood and urine, the lack of previously reported LSD concentrations in hair, and the absence of data about LSD incorporation and stability in pubic hair.     

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.     

Chinese Economic Statecraft and U.S. Hegemony in Latin America: An Empirical Analysis, 2003–2014

If one interprets China's sizable rise in Latin America as an unprecedented phenomenon, it follows that the concurrent story of declining U.S. influence in the region is an event hastily acknowledged at best and ignored at worst. In this article, we ask whether Chinese economic statecraft in Latin America is related to the declining U.S. hegemonic influence in the region and explore how. To do so we analyze foreign direct investments, bank loans, and international trade from 2003 to 2014, when China became a major player in the region. We use data from 21 Latin American countries, and find that an inversely proportional relationship exists between the investments made by Chinese state‐owned enterprises (SOEs), bank loans, manufacturing exports, and the U.S. hegemonic influence exerted in the region. In other words, Beijing has filled the void left by a diminished U.S. presence in the latter's own backyard.     

Gender and Negotiation in the Small: Are Women (Perceived to Be) More Cooperative than Men?

We surveyed research by experimental economists that examines gender differences in negotiation in the context of two simple, two-player games. Our purpose is to uncover empirical regularities in the results that might be useful to teachers or practitioners of negotiation. In the dictator game, one player unilaterally determines the division of a fixed amount of money. In the ultimatum game, one player offers a division and the other must accept or reject that offer; if rejected, both players receive a zero payoff. The results have shown that, on balance, women tend to be more egalitarian than men, to expect and ask for less in the negotiation. Women also seem to be more responsive to the context of a negotiation and are less likely to fail to reach an agreement than men. These differences are small, however, in comparison with differences in expectations about what women and men will do. We conclude that stereotyping is alive and well in negotiations and that this can help or hinder negotiation outcomes, depending on the context.     

Y chromosome SNP analysis in a Portuguese population sample using a multiplex PCR and minisequencing strategy

The study of single nucleotide polymorphisms (SNPs) located on the Y chromosome specific region Y-SNPs (92R7, M70, M22, Tat, P25, SRY10831, M173, M213 and M9) was used to characterize a population sample from Central Portugal, in order to investigate the frequency distribution of the male lineages and to compare the observed results with those obtained in other Portuguese regions.The genotyping strategy was according to the described by Brion et al. [M. Brion, et al., Int. J. Legal Med. 119 (2004) 10-15].In this population sample from Central Portugal a typical Western European haplogroup composition was found. The majority of samples (almost 70%) were assigned inside haplogroup R. As for other Iberian populations, the most frequent haplogroup was R1b-P25 (52.2%), followed by F(xK)-M213 (15.2%), E-B-SRY10831.1, R1(xR1a,b)-M173 and R1a-SRY10831.2 (each of them with a 8.7% frequency), K2-M70 (4.3%) and L-M22 (2.2%). When comparing our sample with other samples from Portugal, no significant differences were found.