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981.
Accurate identification of the bovine pathogen Tritrichomonas foetus is sometimes complicated by the presence of other trichomonadid protozoa in clinical samples. A highly specific and reproducible approach for differentiating 3 common types of bovine trichomonadid protozoa found in the bovine preputial cavity, T. foetus, Pentatrichomonas hominis, and a Tetratrichomonas species, was developed using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis. Universal trichomonadid protozoa primers, TFR1 and TFR2, were used to amplify the 5.85 rRNA gene and internal transcribed spacer regions (ITSRs), and the products were digested with the restriction enzyme HpyCH4IV. Restriction fragment length polymorphism analysis was performed on 55 trichomonad isolates from bovine preputial washing and scraping samples. The RFLP results correlated 100% with 5.85 rRNA gene and ITSR sequence resultsand PCR results with primers specific for T. foetus. The results of this study demonstrate that PCR and RFLP analysis can be used in lieu of DNA sequencing to identify the specific trichomonadid protozoa isolated from the bovine preputial cavity.  相似文献   
982.
We generated mice lacking Cks2, one of two mammalian homologs of the yeast Cdk1-binding proteins, Suc1 and Cks1, and found them to be viable but sterile in both sexes. Sterility is due to failure of both male and female germ cells to progress past the first meiotic metaphase. The chromosomal events up through the end of prophase I are normal in both CKS2-/- males and females, suggesting that the phenotype is due directly to failure to enter anaphase and not a consequence of a checkpoint-mediated metaphase I arrest.  相似文献   
983.
A list of often-discussed resistance management tactics is critically reviewed. Alteration of insecticides across generations, non-persistent formulations, and the use of pesticides conferring only low magnitudes of resistance seem to be among the most promising tactics for general use in resistance management. Justifying the first two choices usually requires little more than data on product persistence in terms of toxic effect on susceptible individuals under field conditions. The last tactic requires additional information on resistance ratios for resistant and susceptible genotypes under field exposure. The efficacy of pesticide mixtures is highly dependent on equal persistence of both compounds used in the mixture. The number of genes involved in resistance and the fitness disadvantages they may confer in the absence of use appear to be of relatively little significance in choosing management tactics.  相似文献   
984.
The aim of this experiment was to evaluate the significance of neonatal environment on feed efficiency. For that purpose, rabbits from a line selected for residual feed intake (RFI) during 10 generations (G10 kits) were cross‐fostered with non‐selected control does (i.e., G0 line), and reciprocally. In parallel, sibs were fostered by mothers from their original line. Nine hundred animals were raised in individual (N = 456) or collective (N = 320) cages. Traits analysed in this study were body weight at 32 days and at 63 days, average daily gain (ADG), feed intake between weaning and 63 days (FI), feed conversion ratio (FCR) and RFI. The maternal environment offered by does from the line selected for RFI deteriorated the FCR of the kits, independently of their line of origin, during fattening (+0.08 ± 0.02) compared to FCR of kits nursed by G0 does. The line, the type of housing and the batch were significant effects for all the measured traits: G10 kits were lighter than their G0 counterparts at 32 days (?82.9 ± 9 g, p < 0.0001) and at 63 days (?161 ± 16 g, p < 0.0001). They also had a lower ADG (?2.36 ± 0.36 g/day, p < 0.0001), RFI (?521 ± 24 g/day, p < 0.0001) and a lower FI (?855 ± 31 g, p < 0.0001), resulting in a more desirable feed efficiency (FCR: ?0.35 ± 0.02). There was no significant difference in the contrast of G10 and G0 performances between collective and individual/digestive cages (p > 0.22): ?2.35 g/day versus 2.94 g/day for ADG, ?0.39 versus ?0.40 for FCR, ?577 g versus ?565 g for RFI and ?879 g versus ?859 g for FI, respectively). Thus, no genotype‐by‐environment (housing) interaction is expected at the commercial level, that is, no re‐ranking of the animals due to collective housing.  相似文献   
985.
Rates of degradation of polycyclic aromatic hydrocarbons (PAH) were examined after addition of crude oil enriched with anthracene, fluoranthene, benz(a)anthracene, and benzo(a)pyrene to coastal sediments in a laboratory (20°) flowing seawater system. Three types of sediment (fine sand, medium sand, and marsh sediment) with and without the benthic polychaete worm, Capitella capitata, were used. After extraction from the sediment, PAH concentrations were measured by liquid chromatography with fluorescent detection. Microbial degradation was studied by incubating sediments with radioactive PAH and measuring subsequent production of 14C02. Concentrations of the four PAH decreased significantly with time in fine and medium sized sands. PAH levels also decreased in marsh sediment but trends were not significant (P < 0.05). C. capitata stimulated PAH degradation. Microbial degradation was more rapid in upper surfaces than in lower layers of the sediments.  相似文献   
986.
987.
988.
Data from focused studies and comprehensive surveys suggest that developing or enhancing non-technical (professional) skills will result in a more satisfied and successful veterinary student or veterinary graduate. The College of Veterinary Medicine at Washington State University has devoted considerable time, effort, and resources to augmenting the non-technical aspects of its curriculum while maintaining the traditional strengths of its DVM program. Here we summarize pertinent research and best-practice recommendations from a variety of sources and outline the steps that have been taken, with the underlying rationales, to integrate the teaching and modeling of non-technical (professional) competence throughout a four-year course of veterinary study.  相似文献   
989.
990.
Two natural calcium-rich bentonites used for the removal of wine proteins, originating from Greece and Turkey, were studied by X-ray diffraction, thermal analysis, and solid state NMR, before and after activation by solid Na(2)CO(3). Exchange of Ca(2+) by Na(+) mainly occurs for cations located at the edge of layers and only weakly for interlayer cations. This Na(2)CO(3) activation process leads to an increased efficiency in the adsorption process of bovine serum albumin (BSA) used as a model protein for both bentonites. A direct correlation is observed between the extent of Ca(2+)/Na(+) exchange, the strength of adsorption of BSA, and the extent of unfolding of BSA backbone.  相似文献   
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