Versterking van het diergezondheidsmanagement in de varkenshouderij: belemmeringen en oplossingsinrichtingen

This report presents barriers and possible solutions to strengthen the animal health management on pig farms

Chapter 3: One Health, One Medicine

In recognition that the health of humans, animals, and the environment is linked, One Health seeks to increase communication and collaboration across the disciplines in order to promote, improve, and defend the health of all species on the planet. This strategy may seem simple, but unfortunately it will not be easy to implement. The explosion of medical knowledge in the 20th century led to academic, governmental, and industrial silos of specialization; these silos fostered a compartmentalized approach to health and disease. Building bridges across these silos will require leadership, joint educational programs, financial support, and other strategies that promote transdisciplinary efforts. Before the 20th century, physicians typically worked with veterinary medical colleagues and others to improve the health of humans and animals. This chapter will describe the historical developments in medicine and veterinary medicine leading to the current status quo. It will provide examples of why the status quo is problematic and will highlight the challenges in changing the present paradigm. It will conclude with recommendations on how to implement a One Health approach in the future

Nieuwe wegen naar ontwikkelingsgericht werken : handelingsperspectieven voor de overheid rond duurzame ontwikkeling en maatschappelijke acceptatie van veehouderij

In samenwerking met de vier reconstructie-provincies Overijssel, Gelderland, Noord-Brabant en Limburg heeft Wageningen UR een onderzoek uitgevoerd naar mogelijkheden voor overheden om bij de vergunningverlening voor veehouderijbedrijven meer ontwikkelingsgericht te werken. Deze benadering is een aanvulling op de (huidige) praktijk waarin aanvragen vooral getoetst worden aan normen en maten, zoals bijvoorbeeld de grootte van het bouwblok. Belangrijkste conclusie is dat ontwikkelingsgericht werken inderdaad mogelijkheden biedt voor overheden om duurzaamheid en innovatie in de veehouderij te stimuleren. Tot nu toe werd vooral gestuurd op bouwblokken en milieunormen (o.a. stank en ammoniak), maar deze aanpak blijkt te star en te weinig stimulerend voor een duurzame en innovatieve veehouderij. In de nieuwe, ontwikkelingsgerichte werkwijze moet de economische ontwikkeling van veehouderijbedrijven hand in hand gaan met ontwikkelingen in duurzaamheid en met een dialoog met de directe omgeving. De vier provincies zijn eensgezind over deze gewenste richting, maar verschillen in hun aanpak

Uitroeiing van schurft op varkensbedrijven

De Projectgroep “Vrijwaring Schurft” heeft van het Programmateam “Diergezondheid in Beweging” de opdracht gekregen om, indien mogelijk, een haalbaar en controleerbaar schurftvrij-programma voor de Nederlandse varkenshouderij te ontwikkelen. De volgende onderzoeksvragen zijn hierbij beantwoord: 1 - Is het mogelijk een ELISA te ontwikkelen voor het aantonen van antilichamen in het bloed tegen de schurftmijt van het varken (Sarcoptes scabiei var. suis), die op het laboratorium routinematig kan worden toegepast? 2- Is het mogelijk om met schurft besmette varkensbedrijven door middel van een tweemalige ivermectine-behandeling van alle aanwezige varkens, aangevuld met hygiënische maatregelen maar zonder ontschurfting van de omgeving, vrij te krijgen van schurft? 3 - Kan een bedrijf dat eenmaal schurftvrij is door middel van uitsluitend hygiënische maatregelen gedurende tenminste één jaar schurftvrij blijven? 4 - Wat is het ingeschatte economische effect van uitroeiing van schurft op praktijkbedrijven

Universal Artifacts Affect the Branching of Phylogenetic Trees, Not Universal Scaling Laws

The superficial resemblance of phylogenetic trees to other branching structures allows searching for macroevolutionary patterns. However, such trees are just statistical inferences of particular historical events. Recent meta-analyses report finding regularities in the branching pattern of phylogenetic trees. But is this supported by evidence, or are such regularities just methodological artifacts? If so, is there any signal in a phylogeny?In order to evaluate the impact of polytomies and imbalance on tree shape, the distribution of all binary and polytomic trees of up to 7 taxa was assessed in tree-shape space. The relationship between the proportion of outgroups and the amount of imbalance introduced with them was assessed applying four different tree-building methods to 100 combinations from a set of 10 ingroup and 9 outgroup species, and performing covariance analyses. The relevance of this analysis was explored taking 61 published phylogenies, based on nucleic acid sequences and involving various taxa, taxonomic levels, and tree-building methods.All methods of phylogenetic inference are quite sensitive to the artifacts introduced by outgroups. However, published phylogenies appear to be subject to a rather effective, albeit rather intuitive control against such artifacts. The data and methods used to build phylogenetic trees are varied, so any meta-analysis is subject to pitfalls due to their uneven intrinsic merits, which translate into artifacts in tree shape. The binary branching pattern is an imposition of methods, and seldom reflects true relationships in intraspecific analyses, yielding artifactual polytomies in short trees. Above the species level, the departure of real trees from simplistic random models is caused at least by two natural factors--uneven speciation and extinction rates; and artifacts such as choice of taxa included in the analysis, and imbalance introduced by outgroups and basal paraphyletic taxa. This artifactual imbalance accounts for tree shape convergence of large trees.There is no evidence for any universal scaling in the tree of life. Instead, there is a need for improved methods of tree analysis that can be used to discriminate the noise due to outgroups from the phylogenetic signal within the taxon of interest, and to evaluate realistic models of evolution, correcting the retrospective perspective and explicitly recognizing extinction as a driving force. Artifacts are pervasive, and can only be overcome through understanding the structure and biological meaning of phylogenetic trees. Catalan Abstract in Translation S1

The TolC Protein of Legionella pneumophila Plays a Major Role in Multi-Drug Resistance and the Early Steps of Host Invasion

Pneumonia associated with Iegionnaires's disease is initiated in humans after inhalation of contaminated aerosols. In the environment, Legionella pneumophila is thought to survive and multiply as an intracellular parasite within free-living amoeba. In the genome of L. pneumophila Lens, we identified a unique gene, tolC, encoding a protein that is highly homologous to the outer membrane protein TolC of Escherichia coli. Deletion of tolC by allelic exchange in L. pneumophila caused increased sensitivity to various drugs. The complementation of the tolC mutation in trans restored drug resistance, indicating that TolC is involved in multi-drug efflux machinery. In addition, deletion of tolC caused a significant attenuation of virulence towards both amoebae and macrophages. Thus, the TolC protein appears to play a crucial role in virulence which could be mediated by its involvement in efflux pump mechanisms. These findings will be helpful in unraveling the pathogenic mechanisms of L. pneumophila as well as in developing new therapeutic agents affecting the efflux of toxic compounds

Systematic Evaluation of the Descriptive and Predictive Performance of Paediatric Morphine Population Models

Purpose: A framework for the evaluation of paediatric population models is proposed and applied to two different paediatric population pharmacokinetic models for morphine. One covariate model was based on a systematic covariate analysis, the other on fixed allometric scaling principles. Methods: The six evaluation criteria in the framework were 1) number of parameters and condition number, 2) numerical diagnostics, 3) prediction-based diagnostics, 4) η-shrinkage, 5) simulation-based diagnostics, 6) diagnostics of individual and population parameter estimates versus covariates, including measurements of bias and precision of the population values compared to the observed individual values. The framework entails both an internal and external model evaluation procedure. Results: The application of the framework to the two models resulted in the detection of overparameterization and misleading diagnostics based on individual predictions caused by high shrinkage. The diagnostic of individual and population parameter estimates versus covariates proved to be highly informative in assessing obtained covariate relationships. Based on the framework, the systematic covariate model proved to be superior over the fixed allometric model in terms of predictive performance. Conclusions: The proposed framework is suitable for the evaluation of paediatric (covariate) models and should be applied to corroborate the descriptive and predictive properties of these models

Tracking Membrane Protein Association in Model Membranes

Membrane proteins are essential in the exchange processes of cells. In spite of great breakthrough in soluble proteins studies, membrane proteins structures, functions and interactions are still a challenge because of the difficulties related to their hydrophobic properties. Most of the experiments are performed with detergent-solubilized membrane proteins. However widely used micellar systems are far from the biological two-dimensions membrane. The development of new biomimetic membrane systems is fundamental to tackle this issue