CHIKUNDA

for Karl-Albrecht and Siglinde von Maltzahn     

A new method for the evaluation of matches in non-recombining genomes: application to Y-chromosomal short tandem repeat (STR) haplotypes in European males

A 9-locus microsatellite framework (minimal haplotype), previously developed for forensic purposes so as to facilitate stain analysis, personal identification and kinship testing, has been adopted for the establishment of a large reference database of male European Y-chromosomal haplotypes. The extent of population stratification pertaining to this database, an issue crucial for its practical forensic application, was assessed through analysis of molecular variance (AMOVA) of the 20 regional samples included. Despite the notion of some significant haplotype frequency differences, which were found to correlate with known demographic and historic features of Europeans, AMOVA generally revealed a high level of genetic homogeneity among the populations analyzed. Owing to their high diversity, however, accurate frequency estimation is difficult for Y-STR haplotypes when realistic (i.e. moderately sized) datasets are being used. As expected, strong pair-wise and higher order allelic associations were found to exist between all markers studied, implying that haplotype frequencies cannot be estimated as products of allele frequencies. A new extrapolation method was therefore developed which treats haplotype frequencies as random variables and generates estimates of the underlying distribution functions on the basis of closely related haplotypes. This approach, termed frequency 'surveying', is based upon standard population genetics theory and can in principle be applied to any combination of markers located on the Y-chromosome or in the mitochondrial genome. Application of the method to the quality assured reference Y-STR haplotype database described herein will prove very useful for the evaluation of positive trace-donor matches in forensic casework.     

Relative improvement over chance (RIOC) and phi as measures of predictive efficiency and strength of association in 2×2 tables

In a 2×2 table, phi measures the strength of the relationship and relative improvement over chance (RIOC) measures the predictive efficiency. A simplified formula for RIOC is derived. From the linkage between RIOC and the adjusted standardized residual, the variance of RIOC is calculated, thereby allowing its statistical significance to be tested. A disadvantage of phi is that its maximum value can be less than 1. A corrected phi correlation, obtained by dividing phi by the maximum possible phi, is shown to be mathematically identical to RIOC. Hence, there is a linkage between the percentage of correct predictions and the percentage of variance explained. RIOC is unchanged even when the social costs and benefits of the different outcomes are differentially weighted. RIOC is also mathematically identical to a corrected kappa calculated in a similar fashion to the corrected phi. Therefore, RIQC has distinct advantages over phi and kappa.     

Deaths associated with electric shock injuries in children and adults: A 10-year retrospective examination in Şanlıurfa,Southeast Turkey (2012–2022)

Electric shock injuries (EIs) have high rates of morbidity and mortality in both children and adults. The aim of this study was to examine autopsy cases resulting from EIs and to compare pediatric and adult groups with respect to sociodemographic data, clinical characteristics, location of the incident, electricity entry–exit wound characteristics, current direction, pathological effects of the electric shocks on the body, and cause of death. A total of 8075 autopsies conducted between 2012 and 2022 were retrospectively examined. Şanliurfa is a city in the southeast of Turkey with the highest birth rate in the country. Of 123 cases of death resulting from EIs in Şanliurfa, 58 (47.2%) were children (age < 18 years). In the majority of children (81%), a low-voltage injury resulted from a domestic appliance while the children were playing at home in a rural area. In the vast majority of adults, a high-voltage injury (HVI) resulted from a workplace accident due to working with HVI materials in an area outside the home. The manner of death was accidental in all the electric shock injuries. The electricity entry and exit wounds formed as a result of EIs had similar characteristics in both children and adults, with no significant difference identified. In the province of Şanliurfa, Turkey, which borders Syria and where the main occupation is agricultural activities, there is a need to increase electrical safety precautions within the home, educate parents, and increase electrical safety conditions and worker education in the workplace.     

An unusual case of a triple suicide pact at the time of the COVID-19 pandemic

In December 2020, the World Health Organization (WHO) declared SARS-CoV2 a global pandemic. Home confinement, low social contacts, and fear of virus transmission played a major role as risk factors for suicides during the following period. Suicide pacts, in particular, showed a different pattern. A rare case of a triple suicide pact among members of the same family nucleus is presented. The victims were an elderly, severely ill woman and her adult children (a son and daughter), linked by a morbid relationship. The last time the family was seen alive was 40 days before the discovery. All corpses presented decompositional changes. After a full autopsy, the cause of death was determined to be a lethal intake of morphine for the mother and acute blood loss due to self-stabbing at the neck for the siblings. The younger woman was under the effects of a large amount of heparin. Toxicological analysis was positive for opioids and alcohol in both siblings. Suicide pacts have rarely been described during the COVID-19 pandemic. In the few cases reported, the victims were more often relatives than people in a romantic relationship. The involvement of three people is unusual, as is the use of different suicide methods among the victims. In the presented case, the elderly mother's imminent death from terminal cancer, her concern over dying in a nondomestic environment, and the siblings' fear of being alone likely led to the conception of the suicide pact. Social isolation and economic difficulties also played a contributing role.     

Knowledge of child abuse and neglect in nursing students: Assessment and perspectives

Misdiagnosis of child abuse and neglect can delay early treatment. Some authors have pointed out that nurses can miss child abuse and neglect diagnoses due to a lack of knowledge. It is unclear whether the lack of knowledge is due to students' insufficient preparation in nursing school and/or a deficiency in continuing education. An 18-item questionnaire was administered to final-year nursing students to assess their degree of knowledge on child abuse and neglect and to evaluate if the lack of knowledge was due to insufficient teaching/training during nursing school. The students were also asked to evaluate themselves by assigning a score to their knowledge. A statistical comparison was performed to define whether sufficient/insufficient results were associated with the following variables: sex, pediatric or general nursing student, attending pediatric lectures, training in pediatric wards/ambulatories, and attending specific lectures on child abuse and neglect. The study population comprised 175 students (154 females, 20 males, 1 unknown). Exactly 66.3% of the participants had ≤9/18 correct answers. Of all students, 77.7% self-evaluated their level of knowledge as ≤5/10. The comparisons yielded statistically significant differences between the groups with sufficient objective knowledge and those unrelated to training in pediatric wards/ambulatories or pediatric nursing students. Overall, there was little objective knowledge on the subject, which may be related to insufficient teaching/training in nursing schools. Useful corrective strategies include further teaching on child abuse and neglect, preferably using a practical approach. Further, common teaching/training programs should be conducted by both pediatric and general nursing schools.     

A systematic approach to improve downstream single-cell analysis for the DEPArray™ technology

Most commercially available STR amplification kits have never been fully validated for low template DNA analysis, highlighting the need for testing different PCR kits and conditions for improving single-cell profiling. Here, current strategies rely mainly on adjusting PCR cycle number and analytical threshold settings, with a strong preference for using 30 amplification cycles and thresholds at 30–150 RFU for allele detection. This study aimed to (1) determine appropriate conditions for obtaining informative profiles utilizing a dilution series, and (2) test the outcome on single cells using the DEPArray™ technology. Four routinely applied forensic STR kits were compared by using three different amplification volumes and DNA dilutions down to 3.0 pg, while two well-performing kits were used for single/pooled leucocyte and sperm cell genotyping. Besides reduced costs, the results demonstrate that a 50%–75% PCR volume reduction was beneficial for peak height evaluation. However, this was counteracted by an increased artifact generation in diluted DNA volumes. Regarding profile completeness, the advantage of volume reduction was only prominent in samples processed with Fusion 6C. For single and pooled cells, ESIFast and NGMDetect provided a solid basis for consensus profiling regarding locus failure, although locus dropouts were generally observed as stochastic events. Amplification volume of 12.5 μL was confirmed as appropriate in terms of peak heights and stutter frequencies, with increased stutter peaks being the main artifact in single-cell profiles. Limitations associated with these analyses are discussed, providing a solid foundation for further studies on low template DNA.     

The Prediction of Young Homicide and Violent Offenders

Aim was to investigate a range of potentially modifiable risk factors for boys in late childhood for later violence and homicide convictions. Boys from the Pittsburgh Youth Study (N = 1,517) were measured through self-reports and official records in late childhood (ages 11–13) on a large number of potentially modifiable risk factors, and were followed up in juvenile and adult criminal records in terms of violence and homicide. Predictors of conviction for homicide largely overlapped with predictors of conviction for violence. Twenty three out of 28 possible risk factors significantly predicted later violence convictions. Regression analysis identified four significant modifiable risk factors in late childhood for any violent offenders: physical abuse, parental stress, bad friends and low school motivation. The higher the number of early risk factors, the higher the probability of later conviction for violent offenses including homicide. The discussion focus on single-, and multi-modal interventions in late childhood to reduce later violence and possibly homicide.     

Psychopathy and affect consciousness in young criminal offenders

A key characteristic of psychopathy is the individual's problematic relation to certain affects, particularly shame. Previous research has studied relations between expressed shame and psychopathy. In this study, the author analyzes potential associations between psychopathy and consciousness of feelings (i.e., participants' ability to recognize and tolerate the feeling and describe how they believe it is expressed in their posture and verbal expressions). Psychopathy is assessed with the Psychopathy Checklist: Screening Version, and affect consciousness is assessed with a semistructured interview. Additionally, risk for criminal behavior, moral reasoning, cognitive distortions, and attachment style in the participants was assessed. The participants are 47 adolescent boys who were treated at juvenile delinquency homes. The results indicate that boys with higher ratings of psychopathy had lower consciousness of shame feelings and lower empathy scores. The results in combination with qualitative analyses of the interview answers are interpreted as indicating that consciousness of shame is specifically problematic for psychopathic adolescents.