1,835 research outputs found
Dairy farmers can change: results of a five-year national mastitis control program in The Netherlands
Over the years, much effort has been put into mastitis control programs. To further improve such programs, we need to understand farmers’ knowledge, attitude and behavior regarding udder health, and the way this can be influenced by mastitis control programs. This study aimed to explore the effect of a Dutch national mastitis control program on farmers’ knowledge, attitude and behavior regarding mastitis. In this study, 204 randomly selected dairy farmers completed a survey on attitude, knowledge and behavior regarding mastitis before the start of the national mastitis control program (2004) and in the final year of the program (2009). Statistical analyses show that, compared to 2004, the attitude, knowledge and behavior of the participating farmers changed significantly. Farmers’ satisfaction level and problem level of BMSCC changed; farmers were satisfied with on average 156,000 cells/ml in 2004 compared to 150,000 cells/ml in 2009, and perceived a problem at 285,000 cells/ml in 2004 compared to 271,000 cells/ml in 2009. More farmers perceived that they had sufficient knowledge about the control of mastitis (34% in 2004 vs. 53% in 2009), and they focused more often on udder health characteristics when selecting bulls (46% vs. 61%). Specific mastitis control measures have increased significantly during the program. The use of milking gloves increased from 15% to 46%, the use of a standardized mastitis treatment protocol increased from 7% to 34% and cubicles are cleaned more often (2.28 vs. 2.51 times/day)
Seroprevalence of bluetongue serotype 8 in cattle in the Netherlands in spring 2007, and its consequences
A cross-sectional study was carried out in spring 2007, at the end of the first bluetongue outbreak season, to determine the geographical spread of bluetongue virus serotype 8 (BTV-8) infection in cattle in the Netherlands and the consequences for some production parameters. Blood samples from cattle submitted to the laboratory of the Dutch Animal Health Service for other voluntary and obligatory health programmes were tested serologically for BTV-8. in total, 37,073 samples were tested and 659 (1.78 per cent) were seropositive. The samples came from 5436 herds, of which 45 per cent of herds had only one sample submitted from them. The prevalence was highest in the south of the country, where the outbreak had started, and decreased towards the north. in 340 herds more than 50 per cent of cattle were tested, of which 156 herds were located in infected compartments, and in 37 of these herds (10.9 per cent) at least one positive cow was detected. The average within-herd prevalence in the 37 herds was 39.3 per cent: 2.2 per cent in I I dairy herds, 68.4 per cent in 20 small-scale herds and 14 per cent in four suckler cow herds. The prevalence differed significantly between herd types but did not show a geographical trend. The average net return for milk production amounted to is an element of 2417/cow/year and it decreased significantly on average by is an element of 48/ cow/year in the bluetongue-infected dairy herds during the bluetongue period. on the small-scale farms, the incidence of mortality increased by 3.2 (95 per cent confidence interval [a] 1.2 to 9.1) times in the infected herds during the bluetongue period, but the voluntary culling rate decreased by a factor of 2.3 (95 per cent Cl 1.1 to 4.8)
Isolation and characterisation of microsatellite loci for two species of Spinturnicid wing mites (Spinturnix myoti and Spinturnix bechsteini)
To investigate the potential for host-parasite coadaptation between bats and their wing mites, we developed microsatellite loci for two species of Spinturnix mites. For Spinturnix myoti, parasite of Myotis myotis, we were able to develop nine polymorphic loci and screened them in 100 mites from five bat colonies. For S. bechsteini, parasite of M. bechsteinii, we developed five polymorphic loci, which were also screened in 100 mites from five bat colonies. In both species, all markers were highly polymorphic (22-46 and 6-23 alleles per locus respectively). The majority of markers for both species exhibited departure from Hardy-Weinberg proportions (8 of 9 and 3 of 5, respectively). One marker pair in S. myoti showed evidence for linkage disequilibrium. As the observed departures from Hardy-Weinberg proportions are most likely a consequence of the biology of the mites, the described microsatellite loci should be useful in studying population genetics and host-parasite dynamics of Spinturnix myoti and Spinturnix bechsteini in relation to their bat hosts
The effect of host social system on parasite population genetic structure: comparative population genetics of two ectoparasitic mites and their bat hosts.
BACKGROUND: The population genetic structure of a parasite, and consequently its ability to adapt to a given host, is strongly linked to its own life history as well as the life history of its host. While the effects of parasite life history on their population genetic structure have received some attention, the effect of host social system has remained largely unstudied. In this study, we investigated the population genetic structure of two closely related parasitic mite species (Spinturnix myoti and Spinturnix bechsteini) with very similar life histories. Their respective hosts, the greater mouse-eared bat (Myotis myotis) and the Bechstein's bat (Myotis bechsteinii) have social systems that differ in several substantial features, such as group size, mating system and dispersal patterns.
RESULTS: We found that the two mite species have strongly differing population genetic structures. In S. myoti we found high levels of genetic diversity and very little pairwise differentiation, whereas in S. bechsteini we observed much less diversity, strongly differentiated populations and strong temporal turnover. These differences are likely to be the result of the differences in genetic drift and dispersal opportunities afforded to the two parasites by the different social systems of their hosts.
CONCLUSIONS: Our results suggest that host social system can strongly influence parasite population structure. As a result, the evolutionary potential of these two parasites with very similar life histories also differs, thereby affecting the risk and evolutionary pressure exerted by each parasite on its host
Synthesis of neural networks for spatio-temporal spike pattern recognition and processing
The advent of large scale neural computational platforms has highlighted the
lack of algorithms for synthesis of neural structures to perform predefined
cognitive tasks. The Neural Engineering Framework offers one such synthesis,
but it is most effective for a spike rate representation of neural information,
and it requires a large number of neurons to implement simple functions. We
describe a neural network synthesis method that generates synaptic connectivity
for neurons which process time-encoded neural signals, and which makes very
sparse use of neurons. The method allows the user to specify, arbitrarily,
neuronal characteristics such as axonal and dendritic delays, and synaptic
transfer functions, and then solves for the optimal input-output relationship
using computed dendritic weights. The method may be used for batch or online
learning and has an extremely fast optimization process. We demonstrate its use
in generating a network to recognize speech which is sparsely encoded as spike
times.Comment: In submission to Frontiers in Neuromorphic Engineerin
Risk and economics of disease introduction into dairy farms
A well closed farming system will enhance the success of disease eradication programs, because introduction or reintroduction of infectious diseases are less likely. The economic implications of a more closed farming system will not always been obvious for farmers. The management decisions need to be made for different parts of the farm and are farm-specific. The objective of the study was to obtain input for and to develop an on-farm decisions support model to calculate the economic consequences of a more closed farming system. The input was based on IBR, since there were numerous data on this disease, but a more closed farming system will prevent introduction of other diseases as well (i.e. Bovine Virus Diarrhoea Virus (BVDV), Leptospira interrogans serovar hardjo (L. hardjo) , and Salmonella enterica subsp. enterica serotype Dublin (S. dublin) ). Direct animal contacts such as purchase of cattle, participating in cattle shows, and cattle that breach or escape and mingle with other cattle were found to be important risk factors for introduction of Bovine Herpesvirus type 1 (BHV1). Furthermore, the use of protective farm clothing was found to be an important preventive factor. The effect of a BHV1 outbreak on milk production was estimated with a random effect model. An outbreak of BHV1 on a BHV1-free farm, caused limited milk production losses of on average 39 kg per cow during the outbreak, but the variability was high (95% CI 1-77 kg). Nine percent of Dutch BHV1-free dairy farms that were also at risk for BVDV, L. hardjo and/or S. dublin had one introduction per year of one of these four diseases. All these results were incorporated in the static, deterministic economic model. The management measures to reduce the probability of introduction of BHV1, the costs of these measures, and the risk reduction of these measures were obtained from other sources. Costs were calculated by using partial budgeting.The model was verified and partly validated and a sensitivity analysis was carried out to obtain insight into the model behaviour. A hypothetical 55-cow dairy farm that refrained from purchasing cattle, provided protective clothing to professional visitors and a temporary worker, and placed a double fence on six ha. of land to prevent over the fence contacts, had to spend Dfl. 4495 in five years. The probability of disease introduction was decreased by 74%. The avoided losses for disease introduction amounted to Dfl. 7033 over five years. The benefit of becoming more closed for this hypothetical farm was Dfl. 2538. The implementation of a more closed system will be profitable for most farms. The profitability will increase when a farm is at risk for more diseases, but will decrease when farms are limited in their facilities to rear replacement heifers or when a large amount of pasture adjoins pasture of other cattle farms.</p
Upholding the World Health Organization: Next steps for the EU
Before the COVID-19 pandemic, the European Union (EU) was neither a strong promoter of global health nor a strong supporter of the World Health Organization (WHO). The Global Health Council Conclusions from 2010 were never comprehensively implemented and quickly forgotten. With the pandemic greatly affecting EU member states, the EU is increasingly interested in upholding multilateral cooperation in the global health field. Therefore, the EU should aim for an upgrading of the EU’s status in WHO, the establishment of a global health unit in the European External Action Service (EEAS), and an overhaul of the formal relationship between the European Commission and WHO. (Autorenreferat
A Review of Control Strategies in Closed-Loop Neuroprosthetic Systems
It has been widely recognized that closed-loop neuroprosthetic systems achieve more favourable outcomes for users then equivalent open-loop devices. Improved performance of tasks, better usability and greater embodiment have all been reported in systems utilizing some form of feedback. However the interdisciplinary work on neuroprosthetic systems can lead to miscommunication due to similarities in well established nomenclature in different fields. Here we present a review of control strategies in existing experimental, investigational and clinical neuroprosthetic systems in order to establish a baseline and promote a common understanding of different feedback modes and closed loop controllers. The first section provides a brief discussion of feedback control and control theory. The second section reviews the control strategies of recent Brain Machine Interfaces, neuromodulatory implants, neuroprosthetic systems and assistive neurorobotic devices. The final section examines the different approaches to feedback in current neuroprosthetic and neurorobotic systems
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