388 research outputs found
Aspects of competence-based education as footholds to improve the connectivity between learning in school and in the workplace
Recent developments in competence-based education have motivated institutions of vocational education and training (VET) to improve the links or connectivity between learning in school and learning in the workplace, which has been a problem for decades. In previous research, a theoretical framework describing the underlying aspects of competence-based education was developed. In this study, three aspects of this framework were used to analyse connectivity between learning in school and learning in the workplace. These aspects were: i) authenticity, ii) selfresponsibility, and iii) the role of the teacher as expert and coach. Three stakeholder groups (i.e., students, teachers, and workplace training supervisors) involved in secondary VET programs in the field of life sciences in the Netherlands were questioned on these aspects. Based on their interviews, it is concluded that these aspects provide information about the process of connectivity. Because stakeholder groups hold different conceptions of workplace learning and often do not communicate adequately about mutual responsibilities, the implementation of these aspects of competence-based education has not significantly improved the connectivity situation. Nevertheless, these aspects of competence-based education can guide stakeholder groups in making clearer agreements about mutual responsibilities, which may improve connectivity in the futur
Effects of precipitation uncertainty on discharge calculations for main river basins
This study quantifies the uncertainty in discharge calculations caused by uncertainty in precipitation input for 294 river basins worldwide. Seven global gridded precipitation datasets are compared at river basin scale in terms of mean annual and seasonal precipitation. The representation of seasonality is similar in all datasets, but the uncertainty in mean annual precipitation is large, especially in mountainous, arctic, and small basins. The average precipitation uncertainty in a basin is 30%, but there are strong differences between basins. The effect of this precipitation uncertainty on mean annual and seasonal discharge was assessed using the uncalibrated dynamic global vegetation and hydrology model Lund-Potsdam-Jena managed land (LPJmL), yielding even larger uncertainties in discharge (average 90%). For 95 basins (out of 213 basins for which measurements were available) calibration of model parameters is problematic because the observed discharge falls within the uncertainty of the simulated discharge. A method is presented to account for precipitation uncertainty in discharge simulations
Investigating competence-based VET in The Netherlands: backgrounds, pitfalls and implications
In the Dutch VET system, competence-based education is the leading paradigm for innovation both on systems´ level and on the level of teaching and learning arrangements. This phenomenon was the impetus for organising a scientific conference in October 2002, under the umbrella of the Dutch Educational Research Association (VOR), to bring to the fore a diversity of results of educational research related to competence-based VET. This paper provides an analysis of the competence concept and its popularity and an internationally embedded historical analysis of the development of competence-based education. Moreover, based on the presentations of the October conference, (possible) pitfalls and roads for future development will be sketched
Modelling transmission and control of Mycobacterium avium subspecies paratuberculosis within Irish dairy herds with compact spring calving
Paratuberculosis is a chronic bacterial infection of the intestine in cattle caused by Mycobacterium avium subspecies paratuberculosis (Map). To better understand Map transmission in Irish dairy herds, we adapted the French stochastic individual-based epidemiological simulation model to account for seasonal herd demographics. We investigated the probability of Map persistence over time, the within-herd prevalence over time, and the relative importance of transmission pathways, and assessed the relative effectiveness of test-and-cull control strategies. We investigated the impact on model outputs of calf separation from cows (calves grazed on pasture adjacent to cows vs. were completely separated from cows) and test-and-cull. Test-and-cull scenarios consisted of highly test-positive cows culled within 13 or 4 weeks after detection, and calf born to highly test-positive cows kept vs removed. We simulated a typical Irish dairy herd with on average 82 lactating cows, 112 animals in total. Each scenario was iterated 1000 times to adjust variation caused by stochasticity. Map was introduced in the fully naive herd through the purchase of a moderately infectious primiparous cow. Infection was considered to persist when at least one infected animal remained in the herd or when Map was present in the environment.
The probability of Map persistence 15 years after introduction ranged between 32.2-42.7 % when calves and cows had contact on pasture, and between 18.9-29.4 % when calves and cows were separated on pasture. The most effective control strategy was to cull highly test-positive cows within four weeks of detection (absolute 10 % lower persistence compared to scenarios without control). Removing the offspring of highly test-positive dams did not affect either Map persistence or within-herd prevalence of Map.
Mean prevalence 15 years after Map introduction was highest (63.5 %) when calves and cows had contact on pasture. Mean prevalence was 15 % lower (absolute decrease) when cows were culled within 13 weeks of a high test-positive result, and 28 % lower when culled within 4 weeks.
Around calving, the infection rate was high, with calves being infected in utero or via the general indoor environment (most important transmission routes). For the remainder of the year, the incidence rate was relatively low with most calves being infected on pasture when in contact with cows. Testing and culling was an effective control strategy when it was used prior to the calving period to minimize the number of highly infectious cows present when calves were born
Competence-based education: An example from vocational practice.
First, the existing confusion about competence-based education is described: the behavioristic, generic and holistic approach. The following definition is formulated: Competence-based education is creating opportunities for students and workers, close to their world of experience in a meaningful learning environment (preferable the professional practice) wherein the learner can develop integrated performance-oriented capabilities to handle the problems in practice. The principles described in this article have been formulated by various authors. Central question in this paper is: What are the experiences of the different groups involved with competence-based education, and to what extent do those experiences influence the principles formulated? Most principles are useful, but more attention has to be paid on coaching
Understanding the hydration process of salts:the impact of a nucleation barrier
The solid-state hydration of salts has gained particular interest within the frame of thermochemical energy storage. In this work, the water vapor pressure–temperature (p–T) phase diagram of the following thermochemical salts was constructed by combining equilibrium and nonequilibrium hydration experiments: CuCl2, K2CO3, MgCl2·4H2O, and LiCl. The hydration of CuCl2 and K2CO3 involves a metastable zone of ca. 10 K, and the induction times preceding hydration are well-described by classical homogeneous nucleation theory. It is further shown for K2CO3 (metastable) and MgCl2·4H2O (not metastable) through solubility calculations that the phase transition is not mediated by bulk dissolution. We conclude that the hydration proceeds as a solid–solid phase transition, mobilized by a wetting layer, where the mobility of the wetting layer increases with increasing vapor pressure. In view of heat storage application, the finding of metastability in thermochemical salts reveals the impact of nucleation and growth processes on the thermochemical performance and demonstrates that practical aspects like the output temperature of a thermochemical salt are defined by its metastable zone width (MZW) rather than its equilibrium phase diagram. Manipulation of the MZW by e.g. prenucleation or heterogeneous nucleation is a potential way to raise the output temperature and power on material level in thermochemical applications
DNA immunisation. New histochemical and morphometric data.
Splenic germinal center reactions were measured during primary response to a plasmidic DNA intramuscular injection. Cardiotoxin-pretreated Balb/c mice were immunized with DNA plasmids encodmg or not the SAG1 protein, a membrane antigen of Toxoplasma gondii. Specific anti-SAG1 antibodies were detected on days 16 and 36 after injection of coding plasmids. The results of ELISAs showed that the SAG1-specific antibodies are of the IgG2a class. Morphometric analyses were done on serial immunostained cryosections of spleen and draining or non-draining lymph nodes. This new approach made it possible to evaluate the chronological changes induced by DNA immunisation in the germinal centres (in number and in size). Significant increases in the number of germinal centres were measured in the spleen and only in draining lymph nodes after plasmid injection, the measured changes of the germinal centers appeared to result from the adjuvant stimulatory effect of the plasmidic DNA since both the coding and the noncoding plasmid DNA induced them. No measurable changes were recorded in the T-dependent zone of lymph organs
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