Stress-symptoms and well-being in children and adolescents: factor structure, measurement invariance, and validity of English, French, German, Russian, Spanish, and Ukrainian language versions of the SSKJ scales.

OBJECTIVE: The present cross-cultural study examined the factor structure, measurement invariance, and convergent validity of the Stress-Symptom and Well-Being Scales from the Stress and Coping Questionnaire for Children and Adolescents (SSKJ), originally in German, across gender and for five newly developed language versions: English, French, Russian, Spanish, and Ukrainian. DESIGN: Children and adolescents (N = 5,227) from Germany, France, Russia, the Dominican Republic, Ukraine, and several English-speaking countries participated in the survey study. MAIN OUTCOME MEASURES: The SSKJ Stress-Symptom and Well-Being Scales capture stress symptomatology and well-being with five subscales: Somatic Symptoms, Anger, Sadness, Anxiety, and Well-Being. The Strengths and Difficulties Questionnaire (SDQ) was used for validation. RESULTS: The factorial structure (five factors) was confirmed. In multi-group comparisons, confirmatory factor analyses showed partial metric invariance across the different languages. Regarding gender, results showed scalar invariance for all languages, except for Spanish. Gender differences were shown with girls scoring higher on somatic symptoms, sadness, anxiety (German-, French-, Russian-speaking samples), anger (French), and well-being (German, Ukrainian). Correlations with indicators of mental health and behavioral problems demonstrated convergent validity. CONCLUSION: The SSKJ Stress-Symptom and Well-Being Scales showed psychometric evidence for equivalence across the different languages and gender. Thus, this instrument is a useful tool for cross-cultural research in children and adolescents.

Polytraumatization in young male refugees from the Middle East and its association with internalizing and externalizing symptoms.

BACKGROUND: Young Middle Eastern male refugees are currently among the most vulnerable groups in Europe. Most of them have experienced potentially traumatic events (PTEs) such as rape, torture, or violent assaults. Compared to their peers, young refugees suffer more from internalizing and externalizing symptoms, especially when unaccompanied. Little is known about the cumulative impact of experiencing different types of PTEs on mental health outcomes (polytraumatization) of young male refugees from the Middle East. We investigated (1) whether there is a dose-response relationship between multiple PTE types experienced and mental health outcomes, (2) whether individual types of PTEs are particularly important, and (3) to what extent these are differentially associated with mental health outcomes among unaccompanied or accompanied peers. METHODS: In total, 151 young Middle Eastern male refugees in Germany (Mage = 16.81 years, SDage = 2.01) answered questionnaires on PTEs, mental health, and post-migration stress. RESULTS: Hierarchical regression analyses revealed, while controlling for age, duration of stay, unaccompanied status, and post-migration stress, (1) a dose-effect between PTE types on both internalizing and externalizing symptoms. Moreover, (2) regarding internalizing symptoms, violent family separation and experiencing life-threatening medical problems were particularly crucial. The latter was driven by unaccompanied refugees, who also reported higher levels of substance use. CONCLUSIONS: The results extend findings from the literature and suggest that not only may greater polytraumatization be related to greater depression among refugees, but also to a range of other mental health outcomes from the internalizing and externalizing symptom domains. Furthermore, the results highlight the mental health risks that unaccompanied and accompanied refugee adolescents face after exposure to PTEs, and provide information for practitioners as well as researchers about event types that may be particularly relevant.

The Influence of Sample Size on Parameter Estimates in Three-Level Random-Effects Models.

In educational psychology, observational units are oftentimes nested within superordinate groups. Researchers need to account for hierarchy in the data by means of multilevel modeling, but especially in three-level longitudinal models, it is often unclear which sample size is necessary for reliable parameter estimation. To address this question, we generated a population dataset based on a study in the field of educational psychology, consisting of 3000 classrooms (level-3) with 55000 students (level-2) measured at 5 occasions (level-1), including predictors on each level and interaction effects. Drawing from this data, we realized 1000 random samples each for various sample and missing value conditions and compared analysis results with the true population parameters. We found that sampling at least 15 level-2 units each in 35 level-3 units results in unbiased fixed effects estimates, whereas higher-level random effects variance estimates require larger samples. Overall, increasing the level-2 sample size most strongly improves estimation soundness. We further discuss how data characteristics influence parameter estimation and provide specific sample size recommendations.

Auxotrophy to Xeno-DNA: an exploration of combinatorial mechanisms for a high-fidelity biosafety system for synthetic biology applications.

BACKGROUND: Biosafety is a key aspect in the international Genetically Engineered Machine (iGEM) competition, which offers student teams an amazing opportunity to pursue their own research projects in the field of Synthetic Biology. iGEM projects often involve the creation of genetically engineered bacterial strains. To minimize the risks associated with bacterial release, a variety of biosafety systems were constructed, either to prevent survival of bacteria outside the lab or to hinder horizontal or vertical gene transfer. MAIN BODY: Physical containment methods such as bioreactors or microencapsulation are considered the first safety level. Additionally, various systems involving auxotrophies for both natural and synthetic compounds have been utilized by iGEM teams in recent years. Combinatorial systems comprising multiple auxotrophies have been shown to reduced escape frequencies below the detection limit. Furthermore, a number of natural toxin-antitoxin systems can be deployed to kill cells under certain conditions. Additionally, parts of naturally occurring toxin-antitoxin systems can be used for the construction of 'kill switches' controlled by synthetic regulatory modules, allowing control of cell survival. Kill switches prevent cell survival but do not completely degrade nucleic acids. To avoid horizontal gene transfer, multiple mechanisms to cleave nucleic acids can be employed, resulting in 'self-destruction' of cells. Changes in light or temperature conditions are powerful regulators of gene expression and could serve as triggers for kill switches or self-destruction systems. Xenobiology-based containment uses applications of Xeno-DNA, recoded codons and non-canonical amino acids to nullify the genetic information of constructed cells for wild type organisms. A 'minimal genome' approach brings the opportunity to reduce the genome of a cell to only genes necessary for survival under lab conditions. Such cells are unlikely to survive in the natural environment and are thus considered safe hosts. If suitable for the desired application, a shift to cell-free systems based on Xeno-DNA may represent the ultimate biosafety system. CONCLUSION: Here we describe different containment approaches in synthetic biology, ranging from auxotrophies to minimal genomes, which can be combined to significantly improve reliability. Since the iGEM competition greatly increases the number of people involved in synthetic biology, we will focus especially on biosafety systems developed and applied in the context of the iGEM competition.