Walter Steurbaut

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Chitosan, a hydrophilic biopolymer industrially obtained by N-deacetylation of chitin, can be applied as an antimicrobial agent. The current review of 129 references describes the biological activity of several chitosan derivatives and the modes of action that have been postulated in the literature. It highlights the applications of chitosan as an(More)
BACKGROUND Indoor Residual Spraying (IRS), insecticide-treated nets (ITNs) and long-lasting insecticidal nets (LLINs) are key components in malaria prevention and control strategy. However, the development of resistance by mosquitoes to insecticides recommended for IRS and/or ITNs/LLINs would affect insecticide-based malaria vector control. We assessed the(More)
Pesticides are widely used in food production to increase food security despite the fact that they can have negative health effects on consumers. Pesticide residues have been found in various fruits and vegetables; both raw and processed. One of the most common routes of pesticide exposure in consumers is via food consumption. Most foods are consumed after(More)
Chitosan, the N-deacetylated derivative of chitin, is a potential biopolysaccharide owing to its specific structure and properties. In this paper, we report on the synthesis of 24 new chitosan derivatives, N-alkyl chitosans (NAC) and N-benzyl chitosans (NBC), that are soluble in dilute aqueous acetic acid. The different derivatives were synthesized by(More)
With the potential advent of genetically modified herbicide-resistant (GMHR) crops in the European Union, changes in patterns of herbicide use are predicted. Broad-spectrum, non-selective herbicides used with GMHR crops are expected to substitute for a set of currently used herbicides, which might alter the agro-environmental footprint from crop production.(More)
In 1997 the Flemish Environmental Agency (FEA) started a monitoring program "Pesticides in Rain in Flanders, Belgium". The original purpose of the monitoring program was to examine the possible occurrence of dichlorvos in rainwater and subsequent deposition. However, it was thought necessary from the beginning to monitor a wide range of pesticides. During(More)
Novel N,O-acyl chitosan (NOAC) derivatives were synthesized to examine their fungicidal activity against the gray mould fungus Botrytis cinerea (Leotiales: Sclerotiniaceae) and the rice leaf blast fungus Pyricularia oryzae (Teleomorph: Magnaporth grisea). The fungicidal activity was evaluated by the radial growth bioassay. NOAC derivatives were more active(More)
The formation of a spray is the result of interaction between the nozzle type and the spray liquid. When adjuvants lower the surface tension, a shift to a finer spray quality might be expected. Increases in viscosity might cause coarser sprays. The spray pressure, nozzle type and spray liquid determine spray performance. Adjuvants that cause droplets of oil(More)
Groundwater and surface water is at risk of contamination from the use of some agricultural pesticides. In many circumstances pesticide contamination of water resources is more likely to result from point sources than from diffuse sources following approved application to crops in the field. Such point sources include areas on farms where pesticides are(More)
The PPR Panel was asked to deliver a scientific opinion on the science behind the development of a risk assessment of plant protection products on bees (Apis mellifera, Bombus spp. and solitary bees). Specific protection goals options were suggested based on the ecosystem services approach. The different routes of exposure were analysed in detail for(More)