Computing Sampling Weights in Large-scale Assessments in Education

Sampling weights are a reflection of sampling design; they allow us to draw valid conclusions about population features from sample data. This paper explains the fundamentals of computing sampling weights for large-scale assessments in educational research. The relationship between the nature of complex samples and best practices in developing a set of weights to enable computation of unbiased population estimates is described. Effects of sampling weights on estimates are shown, as well as potential consequences of not using weights when analysing data from complex samples. Illustrative examples are provided in order to make it easy to understand the rationale behind the mathematical foundations

Cytoplasmic islet cell antibodies recognize distinct islet antigens in IDDM but not in stiff man syndrome

Cytoplasmic islet cell antibodies are well-established predictive markers of IDDM. Although target molecules of ICA have been suggested to be gangliosides, human monoclonal ICA of the immunoglobulin G class (MICA 1-6) produced from a patient with newly diagnosed IDDM recognized glutamate decarboxylase as a target antigen. Here we analyzed the possible heterogeneity of target antigens of ICA by subtracting the GAD-specific ICA staining from total ICA staining of sera. This was achieved 1) by preabsorption of ICA+ sera with recombinant GAD65 and/or GAD67 expressed in a baculovirus system and 2) by ICA analysis of sera on mouse pancreas, as GAD antibodies do not stain mouse islets in the immunofluorescence test. We show that 24 of 25 sera from newly diagnosed patients with IDDM recognize islet antigens besides GAD. In contrast, GAD was the only islet antigen recognized by ICA from 7 sera from patients with stiff man syndrome. Two of these sera, however, recognized antigens besides GAD in Purkinje cells. In patients with IDDM, non-GAD ICA were diverse. One group, found in 64% of the sera, stained human and mouse islets, whereas the other group of non-GAD ICA was human specific. Therefore, mouse islets distinguish two groups of non-GAD ICA and lack additional target epitopes of ICA besides GAD. Longitudinal analysis of 6 sera from nondiabetic ICA+ individuals revealed that mouse-reactive ICA may appear closer to clinical onset of IDDM in some individuals

Bekämpfung der Kraut- und Knollenfäule im Ökokartoffelanbau

In dieser Arbeit wird ein zusammenfassender Überblick über Schadbilder und Infektionsketten sowie indirekte und direkte Gegenmaßnahmen gegen die Kraut- und Knollenfäule von Kartoffeln gegeben. Ein Schwerpunkt liegt in der Vermittlung, dass viele Faktoren beachtet werden müssen, um die Schadwirkung in Grenzen zu halten

Emotional abuse of girls in Swaziland:Prevalence, perpetrators, risk and protective factors and health outcomes

Background: Research on emotional child abuse in sub–Saharan Africa is scarce. Few studies thus far have examined prevalence, risk and protective factors for emotional child abuse or the associations between emotional abuse and girls’ health. Methods: A nationally representative two–stage, cluster–sampled, household survey of females aged 13–24 years (n=1244) on childhood abuse victimisation was conducted. Participants completed interviewer–assisted questionnaires. Associations between emotional abuse and putative risk, and protective factors and health outcomes were analyzed using separate logistic regression models accounting for sampling design. Marginal effects of cumulative risk factors for emotional abuse victimisation were examined. Results: Lifetime prevalence of emotional abuse was 28.5% with 58.3% of these girls reporting many abusive incidents. The most common perpetrators were female (27.8%) and male (16.7%) relatives and, more rarely, biological parents. Risk factors associated with emotional abuse were frequent caregiver changes (odds ratio (OR) 1.42, 95% confidence interval (CI) 1.03–1.970, poverty (OR 1.51, 95% CI 1.12–2.03), physical abuse (OR 1.98, 95% CI 1.45–2.71) and sexual abuse (OR 2.22, 95% CI 1.57–3.10) victimisation. Being close to one’s mother was a protective factor (OR 0.88, 95% CI 0.80–0.97). Risk for emotional abuse increased from 13% with no risk factors present to 58.4% –with all four risk factors present. Health outcomes associated with emotional child abuse were suicidal ideation (OR 1.85, 95% CI 1.30–2.63) and feeling depressed (OR 1.89, 95% CI 1.31–2.71). Conclusions: Girls in Swaziland experience high levels of emotional abuse victimisation. Emotional abuse is associated with economic disadvantage, family factors, other types of abuse victimisation and poor mental health. Therefore, a holistic approach to prevention is needed, incorporating poverty reduction and programmes to improve parent– child relationships, reduce the use of harsh criticism, and change parenting social norms