New detection method for atrazine pesticides with the optical waveguide Mach-Zehnder immunosensor

Concentrations of analytes can be determined within a few minutes using on-line analysis of the immunobinding kinetics in a solid phase immunoassay. This approach has been applied to the detection of atrazine. Atrazine is detected, at concentrations around the European Community limit (0.1 ¿g/l) by a competitive assay. To this end, the two channels of a Mach-Zehnder waveguide sensor are used simultaneously in a difference measurement. The advantage of this way of measuring is discussed with the atrazine measurements

'Dierziekten zijn niet langer een louter agrarische zaak'

Een onbekende ziekte veroorzaakt veel meer maatschappelijke onrust dan een bekende. Risico’s waar we aan gewend zijn, zoals salmonella en roken, worden doorgaans onderschat, terwijl nieuwe bedreigingen zoals exotische dierziektes door hun onbekendheid veel meer angst oproepen. Dat zegt Ron Bergevoet, onderzoeker bij LEI Wageningen U

GTA: Groupware task analysis Modeling complexity

The task analysis methods discussed in this presentation stem from Human-Computer Interaction (HCI) and Ethnography (as applied for the design of Computer Supported Cooperative Work CSCW), different disciplines that often are considered conflicting approaches when applied to the same design problems. Both approaches have their strength and weakness, and an integration of them does add value to the early stages of design of cooperation technology. In order to develop an integrated method for groupware task analysis (GTA) a conceptual framework is presented that allows a systematic perspective on complex work phenomena. The framework features a triple focus, considering (a) people, (b) work, and (c) the situation. Integrating various task-modeling approaches requires vehicles for making design information explicit, for which an object oriented formalism will be suggested. GTA consists of a method and framework that have been developed during practical design exercises. Examples from some of these cases will illustrate our approach

Food supply chain consequences of new responses to livestock epidemics

This article studies supply chain consequences from applying the new-more socially acceptable -strategy of emergency vaccination instead of the large-scale killing of healthy animals for controlling livestock epidemics. We consider an outbreak of foot and mouth disease in a densely populated livestock area of the Netherlands. From an epidemiological perspective, simulation results show that emergency vaccination significantly reduces the size of an epidemic, both in terms of the length of an outbreak and in the number of animals killed. However, in a worst-case situation, not destroying the vaccinated animals after the end of the epidemic leads to additional consequential losses for food supply chains involved of about Euro 200 million. A business case illustrates that the exact size of these losses depends on specific supply volumes and marketing strategies. Calculations provide a basis for addressing cost sharing issues and loss reducing opportunities of new responses to livestock epidemics.livestock epidemics, financial impact, consumer acceptance, Food Consumption/Nutrition/Food Safety,

A Bayesian Belief Network to Infer Incentive Mechanisms to Reduce Antibiotic Use in Livestock Production

Efficient policy intervention to reduce antibiotic use in livestock production requires knowledge about the rationale underlying antibiotic usage. Animal health status and management quality are considered the two most important factors that influence farmers’ decision-making concerning antibiotic use. Information on these two factors is therefore crucial in designing incentive mechanisms. In this paper, a Bayesian belief network (BBN) is built to represent the knowledge on how these factors can directly and indirectly determine antibiotic use and the possible impact on economic incentives. Since both factors are not directly observable (i.e. latent), they are inferred from measurable variables (i.e. manifest variables) which are influenced by these factors. Using farm accounting data and registration data on antibiotic use and veterinary services in specialized finisher pig production farms, a confirmatory factor analysis was carried out to construct these factors. The BBN is then parameterized through regression analysis on the constructed factors and manifest variables. Using the BBN, possible incentive mechanisms through prices and management training are discussed.Livestock Production/Industries,

Antibioticagebruik op melkvee-, varkens- en pluimveebedrijven in Nederland : gebruik in 2007 in vergelijking met voorgaande jaren

De overheid en andere belanghebbenden willen meer inzicht in het gebruik van antibiotica in de veehouderij. Antibioticagebruik bij voedselproducerende dieren draagt namelijk bij aan resistentieontwikkeling en vormt daarmee een risico voor de volksgezondheid. Om die reden verplicht de Europese commissie lidstaten tot bewaking van antimicrobiële resistentie en is ook gebruiksmonitoring van evident belang. Dit rapport brengt het antibioticagebruik in Nederland en in andere landen in beeld. Ook wordt inzicht gegeven in mogelijke oorzaken

State of the Animal: monitoring animal welfare and health in The Netherlands (0-measurement) : summary, full report is available in Dutch (report 323)

25 measuring points summarise the results of policy measures for animal welfare and health in The Netherland

Assessing Food Safety Concepts on the Dairy Farm: The Case of Chemical Hazards

Adaptive conjoint analysis was used to elicit farmers' and experts' preferences for attributes of improving food safety with respect to chemical hazards on the dairy farm. Groups of respondents were determined by cluster analysis based on similar farmers' and experts' perceptions of food safety improvement. Results show differences in priority of the more important attributes. However, respondents in all groups valued "identification of treated cows" as one of the most important attributes. The results provide the processing industry and extension service with a better understanding of aspects that may form farmers' perceptions of improving food safety, and thus help to define the message for targeting different farmer groups.food safety, dairy farm, conjoint analysis, cluster analysis, Food Consumption/Nutrition/Food Safety,

Benodigde destructiecapaciteit bij de bestrijding van besmettelijke dierziekten in Nederland

In deze notitie tracht men de omvang te bepalen van het aan te bieden destructiemateriaal op enig moment in de toekomst als gevolg van een dierziektebestrijding. Belangrijk is niet zozeer de totale hoeveelheid, maar de maximale hoeveelheid per week die moet worden verwerkt. Resultaten zijn geven voor Afrikaanse varkenspest, aviaire influenza en mond en klauwzee

Vaccination against Foot-and-Mouth Disease : differentiating strategies and their epidemiological and economic consequences

The effectiveness of different control strategies against Foot-and-Mouth Disease (FMD) were investigated using epidemiological and economic models. A quick and large-scale vaccination within a radius of at least 2km is as effective as preemptive 1-km ring culling to mitigate FMD epidemics. Control measures should primarily target cattle farms. After the epidemic, most seropositive animals are expected on sheep farms and vaccinated cattle farms. An effective end-screening strategy should focus on these farms. Market acceptance by trade partners of products of vaccinated animals can limit the economic consequences of outbreaks of FMD.De effectiviteit van bestrijdingstrategieën tegen Mond-en-Klauwzeer (MKZ) is onderzochtmet behulp van epidemiologische en economische modellen. Het blijkt dat snelle en op grote schaal toegepaste vaccinatie in een straal van 2 km rond geïnfecteerde bedrijven net zo effectief is als ruimen in een straal van 1 km rond geïnfecteerde bedrijven bij het bestrijden van MKZ-uitbraken. Controlemaatregelen moeten vooral worden gericht op rundveebedrijven. Na de epidemie zijn de meeste seropositieve dieren te verwachten. De eindscreening zal zich op schapenbedrijven en gevaccineerde rundveebedrijven moeten richten. Acceptatie door internationale handelspartners van producten van gevaccineerde dieren kan de economische gevolgen van een uitbraak van MKZ beperken