Analysis of DNA profiles extracted from degraded samples from archival of formalin fixed tissue included in paraffin (FFTIP) and hairs

The possibility of studying DNA extracted from archival of formalin fixed tissue included in paraffin (FFTIP) enables valuable retrospective investigations. However, according to some authors it is difficult to obtain genomic DNA of good quality, since the process of fixation often results in fragmentation of DNA. In order to evaluate the quality and quantity of DNA extracted, necropsy samples of FFTIP (spleen/lung) and hairs, with or without bulbs, were analyzed using three methods of extraction (QIAamp DNA mini, QIAamp DNA micro-kit and phenol–chloroform followed by microcon YM-30). The amount of DNA recovered was quantified by spectrophotometer. The β-actin, amelogenin gene and the profiles of STR were analyzed. Based on experimental results, a general guideline concerning the appropriate extraction method according to the tissue and the quantity of the starting material for the analysis of DNA from FFTIP and hairs could be suggested.     

Stronger core,weaker fringes: the Danish general election 2019

Abstract

The 2015–2019 election period was long; hence, the election campaign had already begun when the Prime Minister called the election for 5 June 2019, just 10 days after the EP election. Nine already established parties, one old yet unrepresented party and three new parties, two of which are (very) opposed to immigration, fielded candidates across the 10 electoral districts for the 175 seats in parliament (excluding the four MPs elected in Greenland and the Faroe Islands). The overlapping EP election, climate and immigration characterised the campaign agenda. One of the new (anti-immigration) parties made it into parliament, and among the established parties, some were (more than) halved, others were (more than) doubled and some remained stable. In particular, the two government (supporting) parties, Liberal Alliance and Danish People’s Party, received a slap in the face from the electorate. While the Prime Minister’s party, the Liberals, did well, the majority shifted to left of centre, which resulted in a minority Social Democratic government headed by Mette Frederiksen, supported by the Red?Green Alliance, Socialist People’s Party and Social Liberals.     

Results of the 2018 Rapid DNA Maturity Assessment

Three commercially available integrated rapid DNA instruments were tested as a part of a rapid DNA maturity assessment in July of 2018. The assessment was conducted with sets of blinded single-source reference samples provided to participants for testing on the individual rapid platforms within their laboratories. The data were returned to the National Institute of Standards and Technology (NIST) for review and analysis. Both FBI-defined automated review (Rapid DNA Analysis) and manual review (Modified Rapid DNA Analysis) of the datasets were conducted to assess the success of genotyping the 20 Combined DNA Index System (CODIS) core STR loci and full profiles generated by the instruments. Genotype results from the multiple platforms, participating laboratories, and STR typing chemistries were combined into a single analysis. The Rapid DNA Analysis resulted in a success rate of 80% for full profiles (85% for the 20 CODIS core loci) with automated analysis. Modified Rapid DNA Analysis resulted in a success rate of 90% for both the CODIS 20 core loci and full profiles (all attempted loci per chemistry). An analysis of the peak height ratios demonstrated that 95% of all heterozygous alleles were above 59% heterozygote balance. For base-pair sizing precision, the precision was below the standard 0.5 bp deviation for both the ANDE 6C System and the RapidHIT 200.     

Artifacts Caused by Leaf-Cutting Ants of the Genus Atta (Hymenoptera: Formicidae): Postmortem Bite Injuries and the Tearing of Clothes

Ants are one of the first insects to find an exposed cadaver and can be present during all stages of decomposition. Although these organisms are not commonly used in postmortem interval estimates, they are to be taken into account on criminal investigations involving human corpses, since they can leave bite marks that can be mistaken for antemortem or perimortem injuries, which could be misleading when ascertaining the occurrence of abuse or physical altercation during a crime. A few studies report the action of ants on human cadavers and even though leaf-cutting ants of the genus Atta are frequently encountered in succession studies that use animal carcasses, there are no records of these fungus-growing species on human corpses. Atta is a genus restricted to the New World, ranging from northern Argentina to southern United States and acts as one of the most conspicuous neotropical herbivores. In this study, we report three cases of violent death that illustrate the impact of ants, especially those of the genus Atta, in a forensic setting. We compare the patterns displayed by postmortem bite injuries caused by leaf-cutter ants and other common species with less robust mandibles. We also present the capability of Atta ants to create artifacts by cutting victim’s clothes in a crime scene, contributing to the knowledge of ant-mediated confounding factors in crime scene investigation.     

Effects of Deviant Peer Association on Adolescent Alcohol Consumption: A Growth Mixture Modeling Analysis

This study examined concurrent and lagged effects of deviant peer association on levels of alcohol use for distinctive trajectories of drinking from ages 14–18 years, while controlling for age, paternal education, community size, and conduct problems. Longitudinal data were available from a secondary data archive of male and female German adolescents (N = 1,619). Conditional latent growth mixture modeling analysis indicated consistent concurrent effects of deviant peer association (specified as time-varying covariate) on alcohol use for the regular users group, but not any of the other drinking trajectory groups. Very few lagged effects of deviant peers association on alcohol use were found, and thus the social influence hypothesis received little empirical support. Overall, findings suggest the need to consider heterogeneity in the study of peer characteristics and alcohol use for both male and female adolescents.

Effects of Pubertal Timing on Communication Behaviors and Stress Reactivity in Young Women During Conflict Discussions with their Mothers

Individuation, a process whereby adolescents gain autonomy from their parents while maintaining emotional relatedness, is displayed by characteristic styles of verbal exchanges. Negotiating this developmental transition is often stressful for adolescents and their parents. This study deals with the association between pubertal timing, communication behaviors, and stress reactivity assessed during young females’ conflict discussions with their mothers. A sample of N = 32 girls (age 9–13, T1) was grouped by pubertal timing. Years later (age 17–22, T2) they were followed up and videotapes of daughter–mother conflict discussions were evaluated. Salivary alpha-amylase was used to assess the stress reactivity. Results revealed that young women who had entered puberty early were higher in striving for control and separation in interactions with their mothers, and displayed higher stress levels. These results pointed to less successful individuation in late adolescence/young adulthood compared to on-time and late maturing age mates.