Beyond Manpower Planning: ROA's Labour Market Model and its Forecasts to 2002

This paper describes the forecasting model of the Research Centre for Education and the Labour Market (ROA), which has been developed for making forecasts about developments of the labour market position of different types of education with respect to the Dutch labour market. Every two years, ROA compiles forecasts of changes in the labour market in the medium term, differentiated by a large number of economic sectors, occupational classes and types of education to illustrate the meaning of the information. The paper aims particularly to describe the objectives, the basic principles, the theoretical foundations and the structure of ROA''s forecasting approach and the major labour market indicators in more detail. The forecast labour market developments for the types of education up to the year 2002 will also be presented. Due to the low level of aggregation used, these forecasts provide very useful information for people who are involved in decisions about educational investments.education, training and the labour market;

VARIwise: a general-purpose adaptive control simulation framework for spatially and temporally varied irrigation at sub-field scale

Irrigation control strategies may be used to improve the site-specific irrigation of cotton via lateral move and centre pivot irrigation machines. A simulation framework ‘VARIwise’ has been created to aid the development, evaluation and management of spatially and temporally varied site-specific irrigation control strategies. VARIwise accommodates sub-field scale variations in all input parameters using a 1 m2 cell size, and permits application of differing control strategies within the field, as well as differing irrigation amounts down to this scale. In this paper the motivation and objectives for the creation of VARIwise are discussed, the structure of the software is outlined and an example of the use and utility of VARIwise is presented. Three irrigation control strategies have been simulated in VARIwise using a cotton model with a range of input parameters including spatially variable soil properties, non-uniform irrigation application, three weather profiles and two crop varieties. The simulated yield and water use efficiency were affected by the combination of input parameters and the control strategy implemented

Alice in prognoseland Over de zin van arbeidsmarktprognoses

In 1995 bracht het ROA prognoses naar buiten die erop wezen dat zich de komende jaren een opmerkelijke omslag op de arbeidsmarkt voor hoger opgeleiden zou voltrekken. Op grond van de ervaringen van de laatste twee decennia was destijds het beeld ontstaan van grote groepen afgestudeerden van met name de universiteiten die grote moeite hadden om een baan te vinden en vaak werk kregen waarvoor geen academische opleiding vereist was. Door op systematische wijze vraag- en aanbodontwikkelingen per opleidingstype naast elkaar te zetten, liet De arbeidsmarkt naar opleiding en beroep tot 2000 echter zien, dat voor een groot aantal opleidingen in het hoger onderwijs in de periode tot 2000 een einde zou komen aan dit sombere perspectief voor afgestudeerden. Ook in latere prognosestudies tot 2002, 2004 en 2007 worden weer aanwijzingen gevonden voor gunstige arbeidsmarktperspectieven voor hoger opgeleiden.education, training and the labour market;

Does Self-directedness in Learning and Careers Predict the Employability of Low-Qualified Employees?

Employability has become a key element in sustaining successful vocational careers. The role of self-directedness is considered paramount in maintaining one's employability. However, it also requires certain competences on part of employees to invest in learning and career development. This study examines the influence of self-directedness in learning and career of low-qualified employees on their employability. In a follow-up study of 284 low-qualified employees, we find that higher levels of self-directedness in learning and career of employees corresponds with higher chance to be promoted to higher-level job positions (vertical job mobility). However, no relationship was found between different formats of self-directedness and job retention or horizontal job mobility of lower qualified personnel.</p

Angiotensin-converting enzyme insertion/deletion polymorphism does not influence the restenosis rate after coronary stent implantation

Background. Experimental studies have shown an activation of the angiotensin-converting enzyme (ACE) system as a response to endothelial injury. Recent publications have elucidated the hypothesis that the ACE gene polymorphism may influence the level of late luminal loss after coronary stent implantation. It is still unclear whether the polymorphism of the angiotensin gene is a major predictor of the extent of neointimal hyperplasia. In this multicenter study, we therefore tested the relationship between the ACE gene polymorphism and the restenosis rate after coronary stent implantation. Methods: As a substudy of the optimization with intracoronary, ultrasound (ICUS) to reduce stent restenosis (OPTICUS) study, we analyzed ACE serum levels and the ACE gene polymorphism in 154 patients at 9 different centers. All patients underwent elective coronary stent implantation in a stenosis of a major coronary vessel. Balloon inflations were repeated until a satisfactory result was achieved in on-line quantitative coronary angiography or ICUS fulfilling the OPTICUS study criteria. After follow-up of 6 months, all patients underwent reangiography tinder identical projections as the baseline procedure. A blinded quantitative analysis of the initial procedure as well as the follow-up examinations were performed by an independent core laboratory. ACE gene polymorphism and ACE serum activity were measured at the 6-month follow-up in a double-blinded setting. Results: With respect to the ACE gene polymorphism, there were three subgroups: DID genotype (48 patients), ID (83 patients) and 11 (23 patients). The subgroups did not differ in regard to age, gender, extent of coronary artery disease, stenosis length, initial degree of stenosis or degree of stenosis after stent implantation. In all, 39 patients (25.3%) had significant restenosis: 12 DD patients (25.0%), 18 ID patients (21.7%) and 9 II patients (39.1%) (odds ratio 2.164, 95% confidence interval 0.853-5.493). We obtained the following results for ACE serum levels: 0.53 mumol/l/s in the DD subgroup, 0.29 mumol/l/s in the ID

Light sensitivity in a vertebrate mechanoreceptor?

Using immunohistochemistry and Western blot analysis we demonstrate that melanopsin is localised in cells around the central pore of lateral line neuromasts in the African clawed frog, Xenopus laevis. Since melanopsin is a known photoreceptor pigment with diverse functions in vertebrates, we suggest that the lateral line of Xenopus laevis, which is primarily a mechanorecptor, may also be light sensitive. Potential functions of such photosensitivity are discussed, including its role in mediating locomotor responses following dermal illumination

Modeling subsurface transport in extensive glaciofluvial and littoral sediments to remediate a municipal drinking water aquifer

Few studies have been carried out that cover the entire transport process of pesticides, from application at the soil surface, through subsurface transport, to contamination of drinking water in esker aquifers. In formerly glaciated regions, such as Scandinavia, many of the most important groundwater resources are situated in glaciofluvial eskers. The purpose of the present study was to model and identify significant processes that govern subsurface transport of pesticides in extensive glaciofluvial and littoral sediments. To simulate the transport processes, we coupled a vadose zone model at soil profile scale to a regional groundwater flow model. The model was applied to a municipal drinking-water aquifer, contaminated with the pesticide-metabolite BAM (2,6-dichlorobenzoamide). At regional scale, with the combination of a ten-meter-deep vadose zone and coarse texture, the observed concentrations could be described by the model without assuming preferential flow. A sensitivity analysis revealed that hydraulic conductivity in the aquifer and infiltration rate accounted for almost half of the model uncertainty. The calibrated model was applied to optimize the location of extraction wells for remediation, which were used to validate the predictive modeling. Running a worst-case scenario, the model showed that the establishment of two remediation wells would clean the aquifer in four years, compared to nine years without them. Further development of the model would require additional field measurements in order to improve the description of macrodispersion in deep, sandy vadose zones. We also suggest that future research should focus on characterization of the variability of hydraulic conductivity and its effect on contaminant transport in eskers