Regionale kennisarrangementen: verslag van quickscan en kennisdag 2009

In veel regio’s zijn burgers, bestuurders en ondernemers actief betrokken bij de ontwikkeling van hun omgeving. In het kader van gebiedsplannen wordt gewerkt aan doelen op het terrein van landschap, natuur, landbouw en plattelandsontwikkeling. Hierbij komen uiteenlopende (kennis)vragen naar boven. De kennisvragen worden vaak ad hoc gesteld en men weet vaak niet waar men terecht kan. In een aantal regio’s in Nederland wordt dit verschijnsel onderkend en groeit het besef dat het zoeken naar de antwoorden op deze kennisvragen een serieuze bijdrage levert aan gebiedsontwikkeling. Hier wordt een verbinding met onderwijs en onderzoek gemaakt. Omdat ook bij de kennisinstellingen steeds vaker wordt gezocht naar manieren om meer praktijkgerichte werken, ontstaan er samenwerkingsverbanden. Deze verbindingen tussen regio en onderwijs en onderzoek rond kennisvragen, noemen we een regionaal kennisarrangemen

Biophysical interactions in tropical agroforestry systems

sequential systems, simultaneous systems Abstract. The rate and extent to which biophysical resources are captured and utilized by the components of an agroforestry system are determined by the nature and intensity of interac-tions between the components. The net effect of these interactions is often determined by the influence of the tree component on the other component(s) and/or on the overall system, and is expressed in terms of such quantifiable responses as soil fertility changes, microclimate modification, resource (water, nutrients, and light) availability and utilization, pest and disease incidence, and allelopathy. The paper reviews such manifestations of biophysical interactions in major simultaneous (e.g., hedgerow intercropping and trees on croplands) and sequential (e.g., planted tree fallows) agroforestry systems. In hedgerow intercropping (HI), the hedge/crop interactions are dominated by soil fertility improvement and competition for growth resources. Higher crop yields in HI than in sole cropping are noted mostly in inherently fertile soils in humid and subhumid tropics, and are caused by large fertility improvement relative to the effects of competition. But, yield increases are rare in semiarid tropics and infertile acid soils because fertility improvement does not offse

Degradation of haloaromatic compounds

An ever increasing number of halogenated organic compounds has been produced by industry in the last few decades. These compounds are employed as biocides, for synthetic polymers, as solvents, and as synthetic intermediates. Production figures are often incomplete, and total production has frequently to be extrapolated from estimates for individual countries. Compounds of this type as a rule are highly persistent against biodegradation and belong, as "recalcitrant" chemicals, to the class of so-called xenobiotics. This term is used to characterise chemical substances which have no or limited structural analogy to natural compounds for which degradation pathways have evolved over billions of years. Xenobiotics frequently have some common features. e.g. high octanol/water partitioning coefficients and low water solubility which makes for a high accumulation ratio in the biosphere (bioaccumulation potential). Recalcitrant compounds therefore are found accumulated in mammals, especially in fat tissue, animal milk supplies and also in human milk. Highly sophisticated analytical techniques have been developed for the detection of organochlorines at the trace and ultratrace level

Initial non-operative management of uncomplicated appendicitis in children: a protocol for a multicentre randomised controlled trial (APAC trial)

INTRODUCTION: Based on epidemiological, immunological and pathology data, the idea that appendicitis is not necessarily a progressive disease is gaining ground. Two types are distinguished: simple and complicated appendicitis. Non-operative treatment (NOT) of children with simple appendicitis has been investigated in several small studies. So far, it is deemed safe. However, its effectiveness and effect on quality of life (QoL) have yet to be established in an adequately powered randomised trial. In this article, we provide the study protocol for the APAC (Antibiotics versus Primary Appendectomy in Children) trial. METHODS AND ANALYSIS: This multicentre, non-inferiority, randomised controlled trial randomises children aged 7-17 years with imaging-confirmed simple appendicitis between appendectomy and NOT. Patients are recruited in 15 hospitals. The intended sample size, based on the primary outcome, rate of complications and a non-inferiority margin of 5%, is 334 patients.NOT consists of intravenous antibiotics for 48-72 hours, daily blood tests and ultrasound follow-up. If the patient meets the predefined discharge criteria, antibiotic treatment is continued orally at home. Primary outcome is the rate of complications at 1-year follow-up. An independent adjudication committee will assess all complications and their relation to the allocated treatment. Secondary outcomes include, but are not limited to, delayed appendectomies, QoL, pain and (in)direct costs.The primary outcome will be analysed both according to the intention-to-treat principle and the per-protocol principle, and is presented with a one-sided 97.5% CI. We will use multiple logistic and linear regression for binary and continuous outcomes, respectively, to adjust for stratification factors. ETHICS AND DISSEMINATION: The protocol has been approved by the Medical Ethics Review Committee of the Academic Medical Center, Amsterdam. Data monitoring is performed by an independent institute and a Data Safety Monitoring Board has been assigned. Results will be presented in peer-reviewed academic journals and at (international) conferences. TRIAL REGISTRATION NUMBER: NCT02848820; NTR5977; Pre-results

The influence of clan structure on the genetic variation in a single Ghanaian village

Socioeconomic and cultural factors are thought to have an important role in influencing human population genetic structure. To explain such population structure differences, most studies analyse genetic differences among widely dispersed human populations. In contrast, we have studied the genetic structure of an ethnic group occupying a single village in north-eastern Ghana. We found a markedly skewed male population substructure because of an almost complete lack of male gene flow among Bimoba clans in this village. We also observed a deep male substructure within one of the clans in this village. Among all males, we observed only three Y-single-nucleotide polymorphism (SNP) haplogroups: E1b1a*-M2, E1b1a7a*-U174 and E1b1a8a*-U209, P277, P278. In contrast to the marked Y-chromosomal substructure, mitochondrial DNA HVS-1 sequence variation and autosomal short-tandem repeats variation patterns indicate high genetic diversities and a virtually random female-mediated gene flow among clans. On the extreme micro-geographical scale of this single Bimoba village, correspondence between the Y-chromosome lineages and clan membership could be due to the combined effects of the strict patrilocal and patrilineal structure. If translated to larger geographic scales, our results would imply that the extent of variation in uniparentally inherited genetic markers, which are typically associated with historical migration on a continental scale, could equally likely be the result of many small and different cumulative effects of social factors such as clan membership that act at a local scale. Such local scale effects should therefore be considered in genetic studies, especially those that use uniparental markers, before making inferences about human history at large

Case-Based Knowledge and Ethics Education: Improving Learning and Transfer Through Emotionally Rich Cases

Case-based instruction is a stable feature of ethics education, however, little is known about the attributes of the cases that make them effective. Emotions are an inherent part of ethical decision-making and one source of information actively stored in case-based knowledge, making them an attribute of cases that likely facilitates case-based learning. Emotions also make cases more realistic, an essential component for effective case-based instruction. The purpose of this study was to investigate the influence of emotional case content, and complementary socio-relational case content, on case-based knowledge acquisition and transfer on future ethical decision-making tasks. Study findings suggest that emotional case content stimulates retention of cases and facilitates transfer of ethical decision-making principles demonstrated in cases

Kinetic constraints on the In-situ remediation of soils contaminated with organic chemicals.

Cleanup of contaminated soils to comply with soil quality limits currently receives much interest.In-situ remediation of contaminated soils relies on the ability of the techniques employed to enhance the rate of release of contaminants from the soil-sorbed and nonaqueous phase liquid (NAPL) phases into the aqueous or gaseous phases from which they can be more readily removed and treated. Contaminant concentrations in these “environmentally mobile” forms usually decline over time so that the economic efficiency and the overall success of remediation technologies are subject to the “law of diminishing returns”. In this paper we consider the “state of the art” in our understanding of NAPL dissolution and transport, desorption of soilsorbed contaminants and fluid flow in porous media. The extent to which these processes may constrain the success of bioremediation, pump-and-treat remediation and soil venting in relation to established soil quality limits is addressed. Finally, we suggest directions for future research and comment on legislative considerations