Maria A. Hendriks

Characterization and biocompatibility of epoxy-crosslinked dermal sheep collagens

Dermal sheep collagen (DSC), which was crosslinked with 1, 4-butanediol diglycidyl ether (BD) by using four different conditions, was characterized and its biocompatibility was evaluated after subcutaneous implantation in rats. Crosslinking at pH 9.0 (BD90) or with successive epoxy and carbodiimide steps (BD45EN) resulted in a large increase in the shrinkage temperature (T(s)) in combination with a clear reduction in amines. Crosslinking at pH 4.5 (BD45) increased the T(s) of the material but hardly reduced the number of amines. Acylation (BD45HAc) showed the largest reduction in amines in combination with the lowest T(s). An evaluation of the implants showed that BD45, BD90, and BD45EN were biocompatible. A high influx of polymorphonuclear cells and macrophages was observed for BD45HAc, but this subsided at day 5. At week 6 the BD45 had completely degraded and BD45HAc was remarkably reduced in size, while BD45EN showed a clear size reduction of the outer DSC bundles; BD90 showed none of these features. This agreed with the observed degree of macrophage accumulation and giant cell formation. None of the materials calcified. For the purpose of soft tissue replacement, BD90 was defined as the material of choice because it combined biocompatibility, low cellular ingrowth, low biodegradation, and the absence of calcification with fibroblast ingrowth and new collagen formation.

School leadership effects revisited: a review of empirical studies guided by indirect-effect models

Fourteen leadership effect studies that used indirect-effect models were quantitatively analysed to explore the most promising mediating variables. The results indicate that total effect sizes based on indirect-effect studies appear to be low, quite comparable to the results of some meta-analyses of direct-effect studies. As the earlier indirect-effect studies tended to include a broad range of mainly school organisational conditions as intermediary variables, more recent studies focus more sharply on instructional conditions. The results of the conceptual analysis and the quantitative research synthesis would seem to support conceptualising educational leadership as a detached and ‘lean’ kind of meta-control, which would make maximum use of the available substitutes and self-organisation offered by the school staff and school organisational structural provisions. The coupling of conceptual analysis and systematic review of studies driven by indirect-effect models provides a new perspective on leadership effectiveness

Results from School Leadership Effectiveness Studies (2005–2010)

In this chapter an overview is presented of recent studies in which the impact of school leadership on student achievement was investigated. The technique of meta-analysis was used to synthesize the results of 25 studies published between 2005 and 2010. In the meta-analysis both studies exploiting direct and indirect models of school leadership were examined. Next, the conceptual content of the school leadership measures and intermediary variables used in the studies was analyzed.

Guidelines for the Quality Assurance of Vocational Education and Training in EU Countries

This chapter contains guidelines for the quality assurance of vocational education and training (VET) in Europe. The guidelines are based on research into quality assurance within case study institutions providing healthcare VET in six EU countries: Denmark, Estonia, Germany, United Kingdom (England), Italy and the Netherlands. This research was undertaken by the EU-funded ‘From Review to Improvement’ (REVIMP) project team.

School size effects: review and conceptual analysis

In this chapter, a review of international review studies on school size effects is presented. Next, ingredients of a more contextualized and tentative causal mediation model of school size effects are discussed. The chapter is completed by a short overview of school size effects as found in international comparative assessment studies and by a synthesis of Dutch empirical studies that have addressed school size effects, in terms of achievement and attainment outcomes, costs, social outcomes, and good teaching practice.

Research Synthesis of Studies Published Between 1990 and 2012

In this chapter, the results of a research synthesis of the effects on school size on various outcome variables are presented. The present review built on an earlier “quick scan” on the impact of secondary school size on achievement, social cohesion, school safety, and involvement conducted for the Dutch Ministry of Education and Sciences in 2008 (Hendriks et al. 2008). It focuses on a broader set of outcome variables, and includes studies that investigated the effects of school size in primary education as well. Studies that provided information about economies of school size were included as well.

The influence of school size, leadership, evaluation, and time on student outcomes Four reviews and meta-analyses

School effectiveness research addresses the question why and how some schools are more effective than others when the differences in achievement cannot be attributed to student intake and educational background characteristics. A main aim is to identify and investigate those malleable conditions at different levels –classroom, school and above school– that can directly or indirectly explain the differences in the learning outcomes of students. As from the early phases of school effectiveness research there was a great interest in reviews and later also meta-analyses that compile the start-of the art knowledge and show evidence on factors that are associated with better student achievement. The dissertation builds on these previous reviews and meta-analyses and it consists of four reviews and meta-analyses of effectiveness enhancing factors at school and/or classroom level: school size, school leadership, evaluation and assessment and time and homework. Depending on the data available in the primary studies, different methods for review and meta-analysis were applied. The meta-analyses yielded small positive significant effects for school leadership, evaluation and learning time and homework. The meta-analyses did not indicate a significant effect of assessment on student learning. For school size it was found that the impact of size varied with the type if outcome variable considered. Effects of smaller schools appeared to be stronger when social cohesion and participation were the outcome variables, while for safety and attendance the available evidence favoring small schools appeared to be less convincing. School size did not seem to matter for academic achievement. The results of this dissertation study further validate the consensus that consists of the ‘factors that work’ in education. At the same it also draws the attention to the divergence in the magnitudes in mean effect sizes that various meta-analyses yield when the same effectiveness enhancing factor is considered and provides insight into the many methodological and conceptual challenges in meta-analysis and school effectiveness research.

The Factors that Matter for Quality Assurance Across Six Countries

In this chapter the results of the transnational analysis are presented. First, the contexts of Quality Assurance in (I)VET in the six project countries are described. Next, the case study results for all six countries are compared as a basis for drawing conclusions about which overall factors matter for review activities in Quality Assurance. The final section (10.4) includes some general conclusions.