Y-chromosome STR system, Y-PLEX 12, for forensic casework: development and validation

The Y-PLEX 12 system, developed for use in human identification, enables simultaneous amplification of eleven polymorphic short tandem repeat (STR) loci, namely DYS392, DYS390, DYS385 a/b, DYS393, DYS389I, DYS391, DYS389II, DYS 19, DYS439 and DYS438, residing on the Y chromosome and Amelogenin. Amelogenin provides results for gender identification and serves as internal control for PCR. The validation studies were performed according to the DNA Advisory Board's (DAB) Quality Assurance Standards. The minimal sensitivity of the Y-PLEX 12 system was 0.1 ng of male DNA. The mean stutter values ranged between 3.76-15.72%. A full male profile was observed in mixture samples containing 0.5 ng of male DNA and up to 400 ng of female DNA. Amelogenin did not adversely affect the amplification of Y-STRs in mixture samples containing male and female DNA. The primers for the Y-STR loci present in Y-PLEX 12 are specific for human DNA and some higher primates. None of the primate samples tested provided a complete profile at all 11 Y-STR loci amplified with the Y-PLEX 12 system. Y-PLEX 12 is a sensitive, valid, reliable, and robust multiplex system for forensic analysis, and it can be used in human forensic and male lineage identification cases.     

Use of thermal drone in detection and assessment of larval mass temperature in decomposed rabbit carcasses

Manual ground searches and cadaver dogs are traditional methods for locating remains, but they can be time- and resource-intensive, resulting in the decomposition of bodies and delay in victim identification. Therefore, thermal imaging has been proposed as a potentially useful tool for detecting remains based on their temperature. This study investigated the potential of a novel search technique of thermal drones to detect surface remains through the detection of maggot mass temperatures. Two trials were carried out at Selangor, Malaysia, each utilizing 12 healthy male Oryctolagus cuniculus European white rabbits and DJI Matrice 300 RTK drone China, equipped with a thermal camera; Zenmuse H20T to record the thermal imaging footage of the carcasses at various heights (15, 30, 60–100 m) for 14 days for each trial. Our results demonstrated that the larval masses and corresponding heat emissions were at their largest during the active decay stage; therefore, all the carcasses were observable in thermal images on day 5 and remained until day 7. Statistical analyses showed that (1) no statistically significant differences in thermal images between clothed and unclothed subjects (p > 0.05); (2) 15 m above ground level was proven to be the optimal height, as it showed the greatest contrast between the carcass heat signature and the background (p < 0.005). Our data suggested the potential window of detection of thermal signatures was detectable up to 7 days post-deposition. This could be an important guideline for the search and recovery teams for operational implementation in this tropical region.     

Les étudiants et la fonction publique: une etude des perceptions,des valeurs professionnelles et de I'attrait cornparatif

Sommaire. Cette communication donne les résultats dune enquête entreprise en 1973 par ses auteurs à l'occasion de laquelle ils distribuèrent un questionnaire comprenant quarante-trois questions à 323 étudiants de deux universités et trois cégeps de la province de Québec. Les opinions exprimées par ces répon-dants indiquent qu'une trés grande majorité des étudiants préfèrent orienter leur future carrière vers le secteur privé plutôt que vers le secteur public. 11s conçoi-vent le travail dans le secteur privé comme étant créateur, captivant et comme demandant de l'initiative. Par opposition ils ont tendance à considérer que le travail dans la fonction public requiert peu d'initiatives et est routinier. Nos conclusions confirment des études antérieures suivant lesquelles les anté cédants socio-économiques des personnes questionnées déterminent leurs perceptions et leurs attitudes vis-à-vis de I'emploi. Nous avons trouvé que les étudiants des couches socio-économiques inférieures avaient une opinion plus favorable de l'emploi dans le secteur public que leurs collégues plus favorisés. Les femmes éftaient plus favorable au service public que les hommes. Les étudiants des collèges avaient une nieilleure opinion de la fonction publique que leurs anînéks des universit.és. La fonction publique fédérale a un peu plus de prestige que la fonction publique québécoise bien que les étudiants ne soient pas -plus tentés de traveler pour le gouvernement fédéral que pour le gouvernement provincial. Abstract. This paper reports the results of a survey done by the authors in 1973. A close-ended questionnaire of forty-three items was administered to 323 students of two universities and three cégeps in the province of Québec. The attitudes expressed by our sample indicate that an overwhelming majority of students prefer the private sector as opposed to the public service, for future employment. The nature of work in the private sector is perceived to be challenging, captivating, and requiring initiative. Work in the public sector is generally looked upon as routine and requiring little initiative. Our findings support the conclusions of previous studies that the socioeconomic background of the respondents determines the nature of their perceptions and attitudes towards employment. We found that the students of lower socioeconomic status were more favorably inclined towards public service than those with higher status. Women were more attracted to public service than men. The cégep students had a better image of the public service than did their seniors in the universities. The federal Public Service projects a slightly better image than the Fonction Publiqué Québécoise. However, the students are not more attracted to work for the federal government than the provincial government.     

Validating TrueAllele® Interpretation of DNA Mixtures Containing up to Ten Unknown Contributors

Most DNA evidence is a mixture of two or more people. Cybergenetics TrueAllele^® system uses Bayesian computing to separate genotypes from mixture data and compare genotypes to calculate likelihood ratio (LR) match statistics. This validation study examined the reliability of TrueAllele computing on laboratory-generated DNA mixtures containing up to ten unknown contributors. Using log(LR) match information, the study measured sensitivity, specificity, and reproducibility. These reliability metrics were assessed under different conditions, including varying the number of assumed contributors, statistical sampling duration, and setting known genotypes. The main determiner of match information and variability was how much DNA a person contributed to a mixture. Observed contributor number based on data peaks gave better results than the number known from experimental design. The study found that TrueAllele is a reliable method for analyzing DNA mixtures containing up to ten unknown contributors.     

Utility of the Y-STR typing systems Y-PLEX 6 and Y-PLEX 5 in forensic casework and 11 Y-STR haplotype database for three major population groups in the United States

The Y-PLEX 6 and Y-PLEX 5 systems enable analysis for 11 Y-STR loci. We present here the utility of these systems in forensic casework. A total of 188 samples, including 127 evidence samples, were analyzed using either or both of the systems. The evidence sample types included fingernail scrapings, sperm or seminal fluid, epithelial cells, blood and other tissues. The Y-STR typing systems provided useful probative results in difficult cases. A reference database for Caucasian (n = 517), African American (n = 535), and Hispanic (n = 245) population groups within the United States was generated for estimating the haplotype frequency in forensic casework. Among the individuals profiled, 311 Caucasians, 412 African Americans, and 194 Hispanics provided unique profiles in their respective population datasets. This is the first report describing the haplotype database for the set of 11 Y-STR loci recommended by the Scientific Working Group on DNA Analysis Methods (SWGDAM). Linkage analysis reveals that the frequencies from forensically important autosomal loci can be multiplied with the Y-STR haplotype frequency. The results from Y-PLEX systems have been accepted in courts in the United States.     

Improving psychosocial well-being of child laborers and young people who are engaged in low-income economic activities in Istanbul,Turkey

Child laborers are typically subjected to multiple and chronic traumatic experiences. With no parents or caregivers to act as a buffer zone against stressors, they grow up in chaotic and unpredictable work environments. Child laborers are more at risk of developing a range of psychological, emotional, and behavioral problems. The authors established an 8-month psychosocial support program for child laborers and young people attending a vocational training center one day a week. The authors found that anxiety and depression moderately correlated with negative self-concept, somatization, and hostility. Toward the end of the 8-month program, participants reported improved psychological and emotional well-being. The provision of a safe and mediated psychosocial program enhanced the emotional and mental well-being of vulnerable children and young people.