587 research outputs found
Rekenen aan Afrikaanse paardenpest
In de computer van Aline de Koeijer bij het CVI is Nederland regelmatig een rampgebied. Ze analyseert de uitbraken van verschillende dierziektes. In opdracht van LNV probeert ze onder andere het verloop van een uitbraak van drie opkomende dierziekten te voorspellen: riftdalkoorts, de Afrikaanse paardenpest en Krim-Congo hemorragische koort
Review on the epidemiology and dynamics of BSE epidemics
The paper describes how the comprehensive surveillance of bovine spongiform encephalopathy (BSE) and studies carried out on these data has enhanced our knowledge of the epidemiology of BSE. Around 7 000 BSE cases were detected through the screening of about 50 million cattle with rapid tests in Europe. It confirmed that the clinical surveillance had a poor capacity to detect cases, and also showed the discrepancy of this passive surveillance efficiency between regions and production types (dairy/beef). Other risk factors for BSE were being in a dairy herd (three times more than beef), having a young age at first calving (for dairy cattle), being autumn-born (dairy and beef), and being in a herd with a very high milk yield. These findings focus the risk on the feeding regimen of calves/heifers. Several epidemiological studies across countries suggest that the feedborne source related to meat and bone meal (MBM) is the only substantiated route of infection ¿ even after the feed ban ¿, while it is not possible to exclude maternal transmission or milk replacers as a source of some infections. In most European countries, the average age of the cases is increasing over time and the prevalence decreasing, which reflects the effectiveness of control measures. Consistent results on the trend of the epidemic were obtained using back-calculation modelling, the R0 approach and Age-Period-Cohort models. Furthermore, active surveillance also resulted in the finding of atypical cases. These are distinct from previously found BSE and classified in two different forms based on biochemical characteristics; their prevalence is very low (36 cases up to 1st September 2007), affected animals were old and some of them displayed clinical signs. The origin and possibility of natural transmission is unknown
Spread and Control of Rift Valley Fever virus after accidental introduction in the Netherlands: a modelling study.
Rift Valley Fever (RVF) is a zoonotic vector-borne infection and causes a potentially severe disease in both humans and young animals. The Ministry of Economic Affairs, Agriculture and Innovation (EL&I) is interested in the risk of an outbreak of Rift Valley Fever virus (RVFV) for the Netherlands, and more knowledge is needed about the risk of introduction of the virus, the risk of spread (transmission) of the virus in the country once introduced, and the methods for control and surveillance. For this purpose, a mathematical model was developed to study (1) the probability of a RVF outbreak at different days of introduction during the year, (2) the probability of persistence of the infection during the entire year, and (3) outbreak size and duration at different days of introduction during the year
Lean Management & Six Sigma in internal service units within academic hospitals: investigating the impact on people and performance
Natuuraanleg op landbouwgrond: belangstelling gemeten
Sinds een aantal jaren neemt particuliere natuuraanleg deels de plaats in van grondaankopen door de overheid. De deelname van particulieren aan natuuraanleg blijft echter achter bij de verwachtingen. Ook blijkt de belangstelling bij particuliere grondeigenaren onvoldoende om het beleidsdoel van 42.770 ha in 2018 te realiseren
Natuurbeheer nog zwakke inkomenspeiler
In Natuurbalans 2002 is het effect van agrarisch natuurbeheer op de vitaliteit van de landbouw geanalyseerd. De gedachte hierbij is dat een vitaal platteland gebaat is bij een rendabele landbouw
Development of nature-oriented dairy farm systems with an optimization model: the case of ‘Farming for Nature’ in ‘de Langstraat’, the Netherlands
‘Farming for Nature’, a relatively new policy instrument being tried out in the Netherlands, is evaluated. The concept has been designed to allow dairy farmers to improve nature conservation on their farms. Under the scheme, no manure, fertilizer, or feed – concentrates or roughage - may be imported into farm systems from external sources. The feasibility of such a self-sustaining system and the conditions required for it to deliver the desired results, are explored with a farm-based linear programming model known as FIONA (Farm based Integrated Optimization Model for Nature and Agriculture). The model is explained and applied to ‘de Langstraat’, a region in southern Netherlands. The results show that levels of production under the ‘Farming for Nature’ regime are dependent upon soil fertility and the proportion of land that is suitable for growing arable crops. If all available land on a dairy farm in the scheme is arable land, then high production levels of up to 7,500 kg milk per hectare can be realized. If only 30% of the farm area is suitable for arable crops, then only lower production levels, of about 6,600 kg milk per hectare can be realized. The scheme has positive ecological effects. Both nature and cultural landscape values may benefit significantly from the concept. Improvement in ecological terms however, carries a price in terms of agricultural income. An average dairy farm adopting the concept of ‘Farming for Nature’ experiences an income loss of approximately € 840 per hectare in the short-run (5-10 years). More important is the observation that the scale of such farms in the short-run might be too small to earn an attractive income for its workers, even when fully compensated according to European Union regulations.nature management, dairy farming system, linear programming, farm-economics, Farm Management, Land Economics/Use,
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