A technique for thoracic duct-portal vein anastomosis in the dog     

J S Loubser  B J Meyer  C R Jansen  J B Fichardt  J S Le Roux 《The Onderstepoort journal of veterinary research》1966,33(1):239-241

  相似文献   

The antigenicity of Clostridium botulinum type C toxin administered per os     

B C Jansen  P C Knoetze  F Visser 《The Onderstepoort journal of veterinary research》1970,37(3):169-171

  相似文献   

Comment on "Lévy walks evolve through interaction between movement and environmental complexity"     

Jansen VA  Mashanova A  Petrovskii S 《Science (New York, N.Y.)》2012,335(6071):918; author reply 918

de Jager et al. (Reports, 24 June 2011, p. 1551) concluded that mussels Lévy walk. We confronted a larger model set with these data and found that mussels do not Lévy walk: Their movement is best described by a composite Brownian walk. This shows how model selection based on an impoverished set of candidate models can lead to incorrect inferences.  相似文献   

The Role of Communication in Improving Udder Health     

Jolanda Jansen  Theo J.G.M. Lam 《Veterinary Clinics of North America: Food Animal Practice》2012

  相似文献   

Monitoring and identification of residues of anabolic preparations in slaughtered cattle by HPLC with diode array detection     

E. H. J. M. Jansen  H. van Blitterswijk  R. W. Stephany 《The Veterinary quarterly》2013,33(2):60-65

Summary

The new combination of isocratic high performance liquid chromatography (HPLC) with on line UV spectrum detection via a diode array configuration has been applied to the detection and identification of anabolics present in application sites of cattle.

Combination of the characteristic retention time in the HPLC chromatogram and a comparison of the full spectrum between 190–400 nm of the anabolic components with that of a standard resulted in a very reliable identification. By means of this method 117 samples of application sites were investigated for the presence of anabolic residues. Of the xenobiotic anabolics, 19‐nortestosterone (NT) was found most frequently (in 96 cases), whereas diethylstilbestrol (DES) was found in only 11 cases.

In all samples the identification of NT and DES was confirmed by high resolution gas chromatography‐mass spectrometry (GCMS).  相似文献   

Effective control for diethylstilbestrol in cattle in the Netherlands     

E. H. J. M. Jansen  R. W. Stephany 《The Veterinary quarterly》2013,33(1):35-38

Summary

In the period from August 1981 to April 1983, 10243 random samples of urine from slaughtered cattle were inspected for the presence of the stilbene derivatives diethylstilbestrol (DES), dienestrol (DE), and hexestrol (HEX). Fast screening of all samples was performed by radioimmunoassay (RIA) with prior clean‐up column chromatography. In this screening, 216 samples were indicated for confirmatory analyses by combined high performance liquid chromatography‐gas chromatography‐mass spectrometry (HPLC‐GCMS) on account of an immunochemical response equivalent to 1 μg/ 1 DES or more. The presence of DES was confirmed in 184 samples, DE in 5 samples and HEX in 14 samples. In the remaining 13 samples no stilbene derivative could be confirmed.

From the results in 1984, after the introduction of the Meat Inspection Act, it is concluded that the use of stilbene derivatives in cattle in the Netherlands has dropped almost to zero. Of 4558 samples investigated, only 6 (0.13%) were indicated as ‘stilbene’ positive. The presence of DES was confirmed in 2 samples and DE in 4 samples.  相似文献   

Rapid NK-cell activation in chicken after infection with infectious bronchitis virus M41     

L. Vervelde  M.G.R. Matthijs  D.A. van Haarlem  J.J. de Wit  C.A. Jansen 《Veterinary immunology and immunopathology》2013,151(3-4):337-341

Natural killer (NK) cells are cytotoxic lymphocytes and play an important role in the early defence against viruses. In this study we focussed on NK cell and interferon (IFN) responses after infection with infectious bronchitis virus (IBV). Based on surface expression of CD107+, enhanced activation of lung NK cells was observed at 1 dpi, whereas in blood prolonged NK-cell activation was found. IFN-α and IFN-β mRNA and proteins were not rapidly induced whereas IFN-γ production in lung, measured by Elispot assay, increased over time at 2 and 4 dpi. In contrast, IFN-γ production in blood was highest at 1 dpi and decreased over time down to levels comparable to uninfected birds at 4 dpi. Collectively, infection with IBV-M41 resulted in activation of NK cells in the lung and blood and rapid production of IFN-γ and not IFN-α and IFN-β compared to uninfected birds.  相似文献   

Agronomic evaluation and identification of potential cowpea (Vigna unguiculata L. Walp) genotypes in South Africa     

Abe Shegro Gerrano  Willem S. Jansen van Rensburg  Funso R. Kutu 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2019,69(4):295-303

Cultivar development of cowpea with increased grain yield depends on evaluation and selection of genetically unique and complementary breeding lines. The objective of this study was to evaluate cowpea collections using agronomic traits to select promising parents to develop breeding population. Twenty-two cowpea genotypes were field evaluated using a randomised complete block design with three replications in two locations in South Africa. Analysis of variance revealed significant genotypic (G) and locations (L) differences for all agronomic traits evaluated. Significant differences were also observed for most of the traits due to G X L, G X Year (Y), L X Y and G X L X Y interactions effects. The genotypes tested at two locations showed considerable genetic variation for the following agronomic traits that varied for number of leaves (NL) (20.08–179.78), leaf length (LL) (12.36–67.72 cm), leaf width (LW) (4.78–22.02 cm), number of branches (NB) (6.81–13.85), number of pods per plant (NPPP) (14.33–54.04), number of seeds per pod (NSPP) (11.7286.28), pod diameter (PD) (5.75–22.73 mm), plant height (PH) (6.57–233.71 cm), pod length (PL) (3.94–100.92 mm), hundred seed weight (HSWt) (8.11–49.52 g) and grain yield (GY) (0.10-1.48 t ha^?1). Grain yield was significant and positively correlated with all of the traits except leaf length. The principal component analysis (PCA) identified four principal components (PCs) contributing to 73.62% of the total explained variation amongst the tested genotypes. The selected cowpea genotypes for most of agronomic characteristics are useful and candidate genetic resources for the development of breeding population in cowpea breeding and enhanced production and productivity for food and nutrition in the country.  相似文献   

Simulation of over-exploitation of ornamental fish and its consequences for the functional structure of assemblages of Amazonian streams     

Danilo G. R. Castanho  Cláudia P. de Deus  Jansen Zuanon  Sergio Santorelli  Rafael P. Leitão  Fabrício B. Teresa 《Ecology of Freshwater Fish》2020,29(4):533-541

The consequences of over-exploitation may seriously impair the integrity and functioning of ecosystems. When loss of species is accompanied by the loss of ecological processes, the effects are no longer just taxonomic and may affect the stability of the environments. Ornamental fishing is one of the main economic activities of the middle Negro River. Such activity is directed to a small number of species and has the Cardinal Tetra (Paracheirodon axelrodi) as the main target species. Given the potential effects this pressure and the lack of information on its consequences, the present study analysed, through simulations, the possible effects of depletion of ornamental fish populations on the functional structure of fish assemblages, represented by functional diversity (FD) and functional redundancy (FR) indexes. We sampled 13 streams exploited by the ornamental fishery, where we collected 4,286 specimens of 110 species, of which 22 were targeted as ornamental fishing. We found that the ornamental species corresponded, on average, to 27.8% of the species and 33.3% of the FD of the assemblages. In a scenario of complete exclusion of ornamental species, local communities would lose 24.6% of the FD and reduce up to 12% of the FR. With these results, it is possible to infer that the local extinction of exploited species would cause negative impacts on the multifunctionality and the resilience of the streams ecosystems. In this way, we emphasise the need for proper management of the ornamental fisheries aiming to the sustainability of the activity and to the conservation of ecosystem functionality.  相似文献   

The addition of lysolecithin to broiler diets improves growth performance across fat levels and sources: a meta-analysis of 33 trials     

A. L. Wealleans  M. Jansen  M. di Benedetto 《British poultry science》2020,61(1):51-56

ABSTRACT

1. This study aimed to quantify the effect of fat type (including unsaturated to saturated ratio (U:S)) and increasing doses of lysolecithin-based products on nutrient availability and growth performance in broiler chickens.

2. A total of 33 separate experimental reports were collated according to predetermined selection criteria to provide 16 performance trials with ‘on top’ application, and 17 performance trials using reformulated diets, where the contribution of the lysolecithin was taken into account. Data on average daily gain (ADG) and body weight corrected FCR (FCRc) were analysed using the REML method with trial as a random effect.

3. Across the constituent trials, average added dietary fat and oil inclusion was 4.42% (min 1.15%, max 7.00%), with varied U:S ratio (min 0.94, avg 2.50, max 7.65), reflecting diverse fat sources. Overall, neither bird growth performance nor response to lysolecithin supplementation were significantly affected by the U:S ratio of the diets.

4. In performance trials where lysolecithin was added ‘on top’ of existing formulations, FCRc was significantly reduced by lysolecithin at 250 g/t inclusion compared to the control, with 125 g/t returning an intermediate value. In reformulated trials, FCRc was not significantly affected, suggesting lysolecithin supplementation at 125 and 250 g/t could recover average dietary energy reductions of 57.88 and 73.11 kcal/kg feed, respectively.

5. In conclusion, this study showed that the addition of lysolecithin at levels of 125 g/t and above to broiler diets consistently improved feed efficiency across a range of basal dietary ingredients and fat sources.  相似文献