The isolation of spermatozoa from sexual assault swabs using proteinase K

The most common examination in sexual offences is the identification of spermatozoa in aqueous extracts from swabs. Using Proteinase K with sodium dodecyl sulphate, it is possible to digest all the cellular material apart from the spermatozoa, resulting in a quick and effective method of their isolation. Spermatozoa were detected in 18 extracts using this treatment when the normal method had failed to reveal all but one of them.     

A continuous model for interpreting the positions of bands in DNA locus-specific work.

A simple but rigorous approach is offered for evaluating the evidential value of single locus DNA autoradiographs. This approach does not use a binning technique and it does not treat alleles as discrete variables. Instead, the allele distribution is considered to be continuous. The variation between two comparable bands is assessed using previously determined experimental parameters. The Bayesian treatment leads to an expression of the "quality of a match".     

Postmortem stability of DNA

High-molecular-weight DNA was recovered postmortem in sufficient quantities from various human organ tissues as well as from blood, although not all organs were equally well suitable. Good DNA stability was found in brain cortex, lymph nodes and psoas muscle over a period of three weeks postmortem. Spleen and kidney showed good DNA stability up to five days postmortem but after longer periods, rapid degradation was observed. Yields of DNA from blood were not consistent because of the non homogeneity of samples. Blood clots were rich with DNA. Generally, the amount of degraded DNA correlated directly with the duration of the postmortem period. However in some cases, DNA degradation was already prominent after a short period. However in some cases, DNA degradation was already prominent after a short period. Case histories showed that high environmental temperature at the site of death and/or infectious diseases prior to death were the main factors for rapid autolysis. Gradual disappearance to complete loss of the long fragments (15-23 kb) was observed in DNA fingerprinting using the minisatellite probe 33.15. No extra-bands were noted, thus excluding erroneous conclusions. However, evidentiary value of older samples was lower.     

Vitamin D binding protein (Gc) subtypes by isoelectric focusing and immunoblotting

The polymorphism of the human vitamin D binding protein (Gc system) was investigated in a total of 149 sera from unrelated healthy Egyptians residing in Tanta City, Gharbiya Governorate, Nile Delta of Egypt, using isoelectric focusing (IEF) in thin-layer polyacrylamide gel followed by immunoblotting. The estimated gene frequencies were Gc1s = 0.540, Gc1f = 0.242 and Gc2 = 0.218.     

How Social and Mass Media Relate to Youth’s Self-Sexualization: Taking a Cross-National Perspective on Rewarded Appearance Ideals

Although media exposure has been related to cognitive preoccupation with appearance, research rarely investigated adolescents’ behavioral self-sexualization. To address this gap, the present study among 12- to 16-year-olds (N?=?1527; 50.2% girls) in Austria, Belgium, Spain, and South-Korea (1) investigates whether different types of media use relate to self-sexualization, (2) explores the explanatory value of rewarded appearance ideals, and (3) considers culture and gender as moderating factors. Despite cultural variation, a general trend of increasing self-sexualization with social media use and magazine reading appeared across the countries. Moreover, women’s magazine reading and rewards were related to self-sexualization among all the girls across the countries, which suggests that girls may be more vulnerable to the examined effects. Overall, this study provides a better understanding of the unique contribution of specific media genres to youth’s self-sexualization and points at the importance of social media use in girls’ and boys’ engagement in sexualizing appearance behaviors across four countries.     

An Examination of Reciprocal Associations Between Social Preference,Popularity, and Friendship during Early Adolescence

Getting along with peers becomes increasingly important to health and well-being during early adolescence (10–14 years). Young adolescents may succeed with peers when they are well-liked by and popular among the larger peer group (or at the group-level of social complexity). They might also fare well with peers when they are able to form numerous mutual and high quality friendships (at the dyadic-level of social complexity). Theory emphasizes the interrelatedness of different types of peer experiences, but few longitudinal studies have examined the interplay among and between group- and dyadic-level peer experiences in the same study. As a result, it is not known whether group-level peer experiences are predictors of dyadic-level peer experiences, and/or vice versa. To address this limitation, this study examined the prospective and reciprocal relations between four indices of peer experiences, preference (or being highly liked and not disliked by peers), popularity (or having a reputation as popular), friendship quantity (or having many mutual friends), and friendship or relationship quality, during early adolescence. Participants were 271 adolescents (49% girls; M_age?=?11.52 years) who completed peer nominations of preference and popularity, a self-report measure of friendship quality, and nominated friends at two waves (Wave 1: November, Grade 6; Wave 2: October, Grade 7). Structural equation modeling indicated that friendship quantity predicted increases in preference and popularity and that friendship quality predicted increases in friendship quantity. Initial popularity was associated with decreases in preference. The importance of these findings for future research is discussed along with study limitations.     

The Efficacy of a Universal School-Based Prevention Program for Eating Disorders among German Adolescents: Results from a Randomized-Controlled Trial

Disordered eating is highly prevalent during adolescence and has a detrimental effect on further development. Effective prevention programs are needed to prevent unhealthy developmental trajectories. This study evaluated the efficacy of the POPS-program (POtsdam Prevention at Schools), a universal school-based eating disorder prevention program for adolescents. In a cluster-randomized design, we compared the intervention group receiving the prevention program to a waiting control group. Outcomes included indicators of disordered eating and relevant risk factors for eating disorders (body dissatisfaction, internalization of the thin ideal, perceived media pressure, perfectionism, emotional element of exercise, social comparison, and perceived teasing). Questionnaires were administered at the start of the intervention, 3 and 12 months post intervention. At baseline, 1112 adolescents aged 10 to 16 years participated (49% girls; 51% intervention group). Intention-to-treat analyses with the complete data set and per-protocol analyses as a completer analysis were performed. The intervention group showed a more favorable course compared to the control group regarding all observed risk factors for eating disorders except for perceived teasing. Effect sizes were small but comparable to other primary prevention programs. At 1-year follow-up, a small but significant effect on disordered eating was observed. Results of the per-protocol analyses were mostly confirmed by the intention-to-treat analyses. Results were promising for both genders although girls benefited more regarding disordered eating and internalization of the thin ideal. Further studies are warranted examining successful program elements and whether gender-specific programs are needed.     

Long-Term Risks and Possible Benefits Associated with Late Adolescent Romantic Relationship Quality

Adolescent romantic relationships have the potential to affect psychological functioning well into adulthood. This study assessed adolescent romantic relationship qualities as long-term predictors of psychological functioning utilizing a longitudinal multi-method, multi-informant study of 80 participants (59% female; 54% Caucasian, 35% African American, 11% mixed or other race) assessed at age 17 along with their romantic partners and at ages 25–27. Controlling for gender, family income, and baseline mental health, partner-reported hostile conflict at age 17 predicted relative increases in internalizing behaviors from age 17 to 27. In contrast, observed teen support with their partner during a help-seeking task at age 17 predicted relative decreases in externalizing behaviors over time. The results are interpreted as suggesting qualities that may help determine whether adolescent romances have positive vs. negative long-term psychological health implications.