- S.M. Bierman (1)
- R.J. Bijlsma (1)
- C. Bravo De Rueda Cabrera (1)
- C.J.G. Damme van (1)
- M. Dickey-Collas (1)
- M.J.L. Dols (1)
- A.J. Krift van der (1)
- H.M.J. Overzee van (1)
- I. Pennock (1)
- A. Punt (1)
- H.N. Siebel (1)
- S.V. Tribuhl (1)
- M.J.M. Warmerdam (1)
- R.A. Woutersen (1)
Foot-and-mouth disease virus : the role of infection routes and species differences in the transmission of FMDV
Bravo De Rueda Cabrera, C. - \ 2015
Wageningen University. Promotor(en): Mart de Jong, co-promotor(en): Aldo Dekker; Phaedra Eble. - Wageningen : Wageningen University - ISBN 9789462573284 - 137
mond- en klauwzeervirus - mond- en klauwzeer - infectieziekten - ziekteoverdracht - ziektebestrijding - infectiebestrijding - soortverschillen - epidemiologie - diergeneeskunde - foot-and-mouth disease virus - foot and mouth disease - infectious diseases - disease transmission - disease control - infection control - species differences - epidemiology - veterinary science
ÁFoot-and-mouth disease is a contagious viral disease of cloven-hoofed animals (e.g. cattle, sheep, pigs) and can cause severe economic losses to the farm animal industries. The aim of this thesis was to quantify underlying mechanisms regarding transmission of FMDV. With data from past animal experiments we identified the factors which are associated with the amount of virus shed by infected animals and thus may be of importance for transmission of the virus. In an experimental study, the contribution of the environment on the transmission of FMDV was investigated by using a new mathematical model in which the contribution of the environment on transmission was incorporated. Roughly 44% of the transmission of FMDV occurred through the environment that was contaminated with se-excretions from FMDV infected animals. The role of the different species on the transmission of FMDV was investigated with a transmission study of FMDV between infected sheep and naïve cattle. Sheep were found to be less infectious than cattle but similarly susceptible. Using a so-called next-generation matrix, transmission of FMDV in mixed cattle-sheep populations (with different proportions of cattle and different proportions of vaccinated animals) was quantified and the effects of different vaccination strategies against FMDV were analysed. In mixed populations of cattle and sheep, transmission of FMDV is higher when more cattle are present. In populations with more than 14% cattle, targeting vaccination to cattle only can be sufficient to control FMDV.
The results of this thesis show that transmission of FMDV can occur via a contaminated environment, (without animal presence) and that sheep seem to play a limited role in the transmission of FMDV. These results can be used to improve the control measures to prevent and control FMDV in different animal populations.
Norwegian Sea Herring Stock Discrimination phase I (NORDISI)
Overzee, H.M.J. van; Dickey-Collas, M. ; Pennock, I. ; Tribuhl, S.V. ; Bierman, S.M. ; Damme, C.J.G. van; Warmerdam, M.J.M. - \ 2009
IJmuiden : IMARES (Report / MARES Wageningen UR no. C142/09) - 28
visserij - haringen - morfometrie - soortverschillen - monitoring - zeevisserij - biologische monitoring - fisheries - herrings - morphometrics - species differences - marine fisheries - biomonitoring
There is growing concern among fishermen about the migration of North Sea herring into the Norwegian Sea. The Pelagic Freezer-trawler Association therefore commissioned IMARES to develop a technique to monitor possible catches of North Sea herring in the Norwegian Sea. This technique will use morphometric (shape) differences in herring to distinguish between Norwegian Sea spawning herring and North Sea herring. The results show that the model is able to distinguish Norwegian spring spawning herring from North Sea autumn or winter spawning herring. Overall we can conclude that even though we still have to overcome some methodological problems we are confident that this research constitutes a first step towards developing a technique to monitor catches of herring from the Norwegian Sea for Norwegian Spring spawning or other herring.
Physiologically based biokinetic (PBBK) models to characterize dose dependent effects, species differences, and interindividual human variation and detoxification of estragole
Punt, A. - \ 2009
Wageningen University. Promotor(en): Ivonne Rietjens; Peter van Bladeren, co-promotor(en): B. Schilter. - [S.l.] : s.n. - ISBN 9789085853718 - 251
toxiciteit - soortverschillen - metabolische detoxificatie - etherische oliën - risicoschatting - carcinogenese - toxicity - species differences - metabolic detoxification - essential oils - risk assessment - carcinogenesis - cum laude
cum laude graduation (with distinction)
Translationele toxicologie: de mens als proefdier?
Woutersen, R.A. - \ 2009
Wageningen : Wageningen Universiteit - ISBN 9789085852759 - 28
toxicologie - soortverschillen - risicoschatting - alternatieven voor dierproeven - ethiek - toxicology - species differences - risk assessment - animal testing alternatives - ethics
Thema van de rede: men kan zich de vraag stellen of het mogelijk is de veiligheid van mensen, die op een of andere manier aan een chemisch stof, nieuw voedingsingrediënt of een nieuw geneesmiddel worden blootgesteld, te garanderen zonder dat dit product in dierproeven op veiligheid is onderzocht. Vooralsnog moet deze vraag met nee worden beantwoord, maar het kan wel efficiënter en met minder gebruik van proefdieren
Over de herkenning en het voorkomen van bosklauwtjesmos (Hypnum andoi) in Nederland
Siebel, H.N. ; Bijlsma, R.J. - \ 2003
Buxbaumiella 65 (2003). - ISSN 0166-5405 - p. 58 - 64.
mossen - classificatie - soortverschillen - groeiplaatsen - veluwe - mosses - classification - species differences - sites
Hypnum andoi can be recognized as a species in the Netherlands. The differences with Hypnum cupressiforme are discussed. Generally, the two species are easily recognized in the field. We propose to use the average maximum cell length rather than mean cell length for distinguishing the species microscopically. Hypnum andoi is a rather common species in sheltered places in old oak and beech forest on sandy soils and occurs only on tree trunks and dead wood. Mixed colonies of the two species are common, especially in the central part of the Netherlands (Veluwe area).
Effects of plant species on nitrogen mineralization in grassland ecosystems
Krift, A.J. van der - \ 2000
Agricultural University. Promotor(en): Frank Berendse; P.J. Kuikman. - S.l. : S.n. - ISBN 9789058083203 - 131
stikstof - mineralisatie - bodemvruchtbaarheid - voedingsstoffen - decompositie - voedingsstoffenbeschikbaarheid - graslanden - grassen - wortels - wortelexudaten - soortverschillen - nitrogen - mineralization - soil fertility - nutrients - decomposition - nutrient availability - grasslands - grasses - roots - root exudates - species differences
<p>In many ecosystems, the nutrient supply is an important factor that determines plant species composition. Plant species have developed different characteristics, which make them successful competitors in either nutrient-poor or more fertile environments. These plant characteristics could, in turn, have important consequences for soil fertility. The research described in this thesis set out to investigate different plant characteristics of species from habitats that differ in nitrogen availability, to assess their possible consequences for soil nitrogen mineralization. Compared to species from nutrient-poor habitats, species from fertile habitats were expected to stimulate the N mineralization because they produce larger quantities of rhizodeposits and litter, which decompose better.</p><p>Overall, the results described in this thesis support this hypothesis. Plant species from high fertility habitats increased soil N mineralization more than species from low fertility habitats. Living plants of species from high fertility habitats produced more root biomass and consequently more rhizodeposits. Moreover, species from high fertility habitats had a shorter root lifespan than low fertility species. As a result, they added greater amounts of dead roots to the soil, but the decomposability of these dead roots was not related to the fertility of the habitat that they preferred. The effect of N availability on the plant characteristics studied was striking. When N supply decreased, root biomass declined, especially for the species from high fertility habitats, and as a result the rhizodeposition decreased. Moreover, for all species lower N supplies had a negative effect on rhizodeposit and dead root decomposition. Living plants stimulated dead root decomposition but the degree of stimulation depended on the C:N ratio of the decomposing roots. Overall, the differences in stimulation or inhibition of the N mineralization as a result of different levels of soil fertility seemed to be greater in species from high fertility habitats than in species from low fertility habitats.</p><p><strong>Keywords:</strong> decomposition, nitrogen mineralization, perennial grasses, rhizodeposition, root lifespan, soil fertility.</p>
Vergelijkend onderzoek op ratten en kuikens over de identiteit van het kunstmatige antirachitische vitamine (bestraald ergosterol) en het natuurlijke vitamine D uit kabeljauw-levertraan
Dols, M.J.L. - \ 1935
Wageningen University. Promotor(en): G. Grijns. - Nijmegen : Centrale Drukkerij - 139
vitamine d - ratten - vleeskuikens - soortverschillen - vitamin d - rats - broilers - species differences
Cod liver oil 2% sufficed to protect chickens against rickets, but irradiated ergosterol equivalent in rat units of vitamin D, equivalent to 20 % cod liver oil, was not sufficient. No single fact pointed to the presence of another factor in cod liver oil being indispensable besides vitamin D to protect chickens against rickets.
Unsaponifiable matter from cod liver oil, irradiated cholesterol or concentrate from tunny liver oil, all in rat units of vitamin D equivalent to 2 % cod liver oil were within limits of experimental error equally protective against rickets in chickens. Crystalline irradiated ergosterol was not identical with vitamin D from cod liver oil. The provitamin D in cholesterol, activated antirachitically by ultraviolet irradiation, was not ergosterol. Requirement of vitamin D by chickens from the 1st till the 75th day, either as cod liver oil or as tunny liver oil concentrate or of irradiated cholesterol was 250 IU per 100 g ration, about 80 IU daily per chicken.
To find rickets in chickens, radiography sometimes yields more information than examination of the skeleton post mortem. The average ash content of the tibiae was not a reliable comparison of the antirachitic efficiency of vitamin D preparations in chickens.