Abstract. This paper focuses on the longitudinal relationships between foster children’s mental health problems and parental stress across a 1-year interval with three measurements. A sample of 94 foster children and a comparison group of 157 biological children and their families participated in this study. The age of the children was between 2 and 7 years. At the initial assessment, the foster children had been in their foster families since 2–24 months. Based on Child Behavior Checklist (CBCL) scores, the results indicated increased internalizing and externalizing mental health problems in the foster children group. Both mental health scores remained rather stable across the longitudinal assessments in foster as well as in biological children. Internalizing as well as externalizing scores were substantially correlated with parental stress in both samples. Moreover, changes in mental health scores were associated with changes in parental stress. However, cross-lagged panel analyses showed no clear pattern of temporal relationships between children’s mental health scores and parental stress. Implications as well as strengths and limitations of the current study are addressed in the Discussion section.

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.

BackgroundBiosafety 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 bodyPhysical 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.ConclusionHere 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.

Abstract. This study investigated whether foster parents’ reports of their dyadic coping competencies differ from biological parents, whether there are differences with regard to the temporal associations between maternal and paternal dyadic coping in the two samples, and whether parental dyadic coping competencies predict future mental health problems in children. A total of 94 foster children and 157 children living in their biological families, both samples aged 2–7 years, as well as their (foster) parents were assessed three times over a 12-month period. The mothers’ and fathers’ dyadic coping competencies were assessed using the Dyadic Coping Inventory (DCI). Child psychopathology was assessed using the Child Behavior Checklist (CBCL) and a standardized clinical interview (Kinder-DIPS), both mainly based on maternal report. Foster parents reported better dyadic coping competencies across the three assessments than did biological parents. There were no significant differences with regard to the temporal associations between mothers’ and fathers’ report over time between the two samples. Cross-lagged panel models yielded a high within person stability across the three assessments for both, mothers and fathers (actor effects), as well as some significant interpersonal effects primarily from paternal to maternal dyadic coping (partner effects). In contrast to the expectation, mothers’ and fathers’ dyadic coping did not predict child mental health problems at the third assessment. The results make an important contribution to the research on dyadic coping and on how child mental health problems affect parental dyadic coping competencies and vice versa.