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161.
162.
In this study, we have analyzed 23 PCV2 ORF2 sequences recovered from wild boar population in Romania. The PCV2 sequences were originated from different geographical regions in Romania, and collected between 2008 and 2009 during the classical swine fever virus (CSFV) surveillance campaign. Complete open reading frame 2 (ORF2) nucleotide sequences were obtained and compared with sequences mainly from European and Asian isolates. The Romanian sequences were identified as belonging to previously described clusters 2a and 2b, with high degree of heterogeneity (PCV2 ORF2 nucleotide homology ranged between 90.1% and 100%). Interestingly, for cluster 2a, the majority of the sequences (8 from a total number of 9) clustered mainly with the Asian isolates (especially China, but also India and South Korea), with three exceptions from Europe previously reported in Germany, Belgium and The Netherlands.  相似文献   
163.
We conducted a two-part study in the native home areas of four cattle breeds, Abigar, Gurage, Horro and Sheko, in south-western Ethiopia. The first part of the study investigated livestock keeper knowledge about trypanosomosis and trypanotolerance. For each breed 60 livestock keepers were interviewed, resulting in a total of 240 interviews. The second part of the study focused on biological evidence for trypanotolerance. Blood samples of about 100 head of cattle per breed were collected during peak trypanosomosis challenge period and analyzed for packed cell volume (PCV) and parasitaemia. In addition individual body measurements of the sampled animals were taken and the keepers provided some information regarding their animals. Livestock keeper interviews revealed that trypanosomosis was considered a major problem in all areas (95-100%). Almost all Abigar livestock keepers knew how trypanosomosis is transmitted, whereas only 34-52% of the keepers of the other breeds had that knowledge. Most Sheko keepers (75%) knew of trypanotolerance and claimed to have trypanotolerant animals in their own herds. Among the other three breeds the knowledge of trypanotolerance was much less (8-18%). A majority of the keepers were interested in purchasing trypanotolerant animals. PCV was highest among Horro (26.2) and Sheko (25.1) cattle whereas Abigar had the lowest PCV (20.0). Sheko were least infected by trypanosomes (6%) and had the lowest number of trypanocidal treatments per year (1 treatment/animal and year). Abigar cattle were most infected (23%) followed by Gurage (20%) and Horro (17%). Gurage had by far the highest number of treatments per animal and year (24). There were large differences between the number of cattle perceived by the keepers to be infected, and the number detected from blood sampled, among Abigar, Gurage and Horro. Sheko livestock keepers were better at correctly diagnosing trypanosomosis in their animals. It is concluded that Sheko cattle have higher trypanotolerance attributes of the breeds investigated and a better use of this breed could improve cattle health and household welfare in tsetse-infested areas.  相似文献   
164.
165.
The immune responsiveness of mice (without prior natural exposure) and mares (with naturally acquired antibodies) was determined following vaccination with Actinobacillus equuli outer membrane proteins (OMPs) and/or recombinant A. equuli toxin (rAqx). Mice were vaccinated subcutaneously on days 0 and 21 with one of three doses (5, 25 or 50μg) of A. equuli OMPs, rAqx or both, together with Freund's incomplete adjuvant (FIA). Antibodies against formalin-killed whole bacterial cells (WBCs), OMPs and Aqx were determined on days 0, 21 and 42. Mares were vaccinated subcutaneously on days 0 and 21 with 100μg OMPs, 100μg rAqx or a combination of 50μg of each antigen, together with FIA. Antibodies against WBCs, OMPs and Aqx were determined at 7day intervals for the first 42days, as well as on days 56, 70, 154 and 238. Vaccination of mice stimulated an apparent dose response to OMPs and Aqx. Antibodies against OMPs and Aqx were enhanced following vaccination of mares that had naturally acquired pre-existing antibodies. There was no evidence of interference with antibody responses to the individual antigens when OMPs and rAqx were combined prior to vaccination.  相似文献   
166.
Results for multielement analysis of lunar soil and of seven rocks returned by Apollo 11 are presented. Sixty-six elements were determined with spark source mass spectrography and neutron activation. U. S. Geological Survey standard W-1 was used as a comparative stanadard. Results indicate an apparent uniformity of composition among the samples. Comparison with solar, meteoritic, and terrestrial abundances reveals depletiozt of volatile elements and enrichment of the rare earths titaniunm, zirconium, yttriuntm, and hafnium. Althouglh there is an overall similarity of the lunar material to basaltic achondrites amid basalts, the differences suggest detailed geochemical processes to the history of this material.  相似文献   
167.
In champagne tasting, gaseous CO(2) and volatile organic compounds progressively invade the headspace above glasses, thus progressively modifying the chemical space perceived by the consumer. In this study, a novel, rapid, and nonintrusive method aimed to simultaneously determine the content in gaseous CO(2) and ethanol above a glass poured with champagne, using a micro-gas chromatography technique coupled with a thermal conductivity detector, was presented. The simultaneous quantification of CO(2) and ethanol in the headspace of a champagne glass was monitored, in real tasting conditions, all along the first 15 min following pouring, depending on whether or not the glass shows effervescence. Both CO(2) and ethanol were found to be enhanced by the presence of ascending bubbles, thus confirming the close link between rising bubbles and the release of gaseous CO(2) and volatile organic compounds.  相似文献   
168.
Botrytis cinerea infection of grape berries leads to changes in the chemical composition of grape and the corresponding wine and, thus, affects wine quality. The metabolic effect of Botrytis infection in Champagne base wine was investigated through a (1)H NMR-based metabolomic approach. Isoleucine, leucine, threonine, valine, arginine, proline, glutamine, γ-aminobutyric acid (GABA), succinate, malate, citrate, tartarate, fructose, glucose, oligosaccharides, amino acid derivatives, 2,3-butanediol, acetate, glycerol, tyrosine, 2-phenylethanol, trigonelline, and phenylpropanoids in a grape must and wine were identified by (1)H NMR spectroscopy and contributed to metabolic differentiations between healthy and botrytized wines by using multivariate statistical analysis such as principal component analysis (PCA). Lowered levels of glycerol, 2,3-butanediol, succinate, tyrosine, valine derivative, and phenylpropanoids but higher levels of oligosaccharides in the botrytized wines were main discriminant metabolites, demonstrating that Botrytis infection of grape caused the fermentative retardation during alcoholic fermentation because the main metabolites responsible for the differentiation are fermentative products. Moreover, higher levels of several oligosaccharides in the botrytized wines also indicated the less fermentative behavior of yeast in the botrytized wines. This study highlights a metabolomic approach for better understanding of the comprehensive metabolic influences of Botrytis infection of grape berries in Champagne wines.  相似文献   
169.
Distinct extractable organic matter (EOM) fractions have been used to assess the capacity of soils to supply nitrogen (N). However, substantial uncertainty exists on their role in the N cycle and their functional dependency on soil properties. We therefore examined the variation in mineralizable N and its relationship with EOM fractions, soil physical and chemical properties across 98 agricultural soils with contrasting inherent properties and management histories. Mineralizable N was determined by aerobic incubation at 20 °C and optimum moisture content for 20 weeks. We used multivariate statistical modelling to account for multi-collinearity, an issue generally overlooked in studies evaluating the predictive value of EOM fractions. Mineralization of N was primarily related to the size of OM pools and fractions present; they explained 78% of the variation in mineralizable N whereas other soil variables could explain maximally 8%. Both total and extractable OM expressed the same soil characteristic from a mineralization perspective; they were positively related to mineralizable N and explained a similar percentage of the variation in mineralizable N. Inclusion of mineralizable N in fertilizer recommendation systems should be based on at least one OM variable. The most appropriate EOM fraction can only be identified when the underlying mechanisms are known; regression techniques are not suitable for this purpose. Combination of single EOM fractions is not likely to improve the prediction of mineralizable N due to high multi-collinearity. Inclusion of texture-related soil variables or variables reflecting soil organic matter quality may be neglected due to their limited power to improve the prediction of mineralizable N.  相似文献   
170.
The extreme toxicity of organomercury compounds that are found in the environment has focused attention on the mechanisms of action of bacterial remediating enzymes. We describe facile room-temperature protolytic cleavage by a thiol of the Hg-C bond in mercury-alkyl compounds that emulate the structure and function of the organomercurial lyase MerB. Specifically, the tris(2-mercapto-1-t-butylimidazolyl)hydroborato ligand [Tm(Bu(t))], which features three sulfur donors, has been used to synthesize [Tm(Bu(t))]HgR alkyl compounds (R = methyl or ethyl) that react with phenylthiol (PhSH) to yield [Tm(Bu(t))]HgSPh and RH. Although [Tm(Bu(t))]HgR compounds exist as linear two-coordinate complexes in the solid state, 1H nuclear magnetic resonance spectroscopy indicates that the complexes exist in rapid equilibrium with their higher-coordinate [kappa2-Tm(Bu(t))]HgR and [kappa3-Tm(Bu(t))]HgR isomers in solution. Facile access to a higher-coordinate species is proposed to account for the exceptional reactivity of [Tm(Bu(t))]HgR relative to that of other two-coordinate mercury-alkyl compounds.  相似文献   
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