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DB ADAMS JJ LYNCH† BH ANDERSON LR FELL‡ GN HINCH§ RK MUNRO¶ 《Australian veterinary journal》1990,67(12):443-445
Three-year-old, non-lactating and non-pregnant Merino ewes, raised on pasture under a program of strategic treatment with anthelmintic and found to be extremely resistant to "trickle" infection with Haemonchus contortus, were given single-dose infections with either H. contortus or Trichostrongylus colubriformis or both species together. The purpose was to ascertain the intensity of protective immunity against the 2 parasites in sheep with immunity acquired from a presumably slight exposure to infection. To provide a criterion, some infected ewes were immunosuppressed with corticosteroid, dexamethasone. Untreated ewes were extremely resistant to challenge infection with either 15,000 or 150,000 H. contortus or 15,000 T. colubriformis. Surprisingly, when mixed infection was given, egg counts for H. contortus were significantly elevated compared with infection by that species alone. Antibody to antigens from infective larval and adult H. contortus was measured in serum by enzyme-linked-immunosorbent assay (ELISA) during the course of infection. Serum titres against larval antigens were significantly depressed when infections with either H. contortus or T. colubriformis were permitted by immunosuppression with dexamethasone, whereas those against adult antigen were depressed when infection with T. colubriformis was permitted. 相似文献
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PE Bennemann GN Diehl E Milbradt RM Vidor HCC Fries I Wentz ML Bernardi FP Bortolozzo 《Reproduction in domestic animals》2005,40(6):507-510
This study evaluated the reproductive performance of gilts inseminated at three intervals before ovulation (0-12, 13-23, 24-30 h) with sperm doses (SD) stored for 0-48 and 96-120 h. A total of 218 PIC Camborough 22 gilts were inseminated once with SD of 1.5 x 10(9) sperms. Pregnant gilts (n = 166) were slaughtered 30.8 +/- 3.7 days after artificial insemination. The number of corpora lutea (CL) and total embryos (TE) was counted. Pregnancy rates (PR) were analysed by chi-square test. TE and embryonic survival (ES), obtained as the ratio between viable embryos and CL, were analysed by GLM procedure (SAS) and mean values were compared by Tukey's test. Pregnancy rate was similar among artificial insemination-ovulation (AIOV) intervals when semen was stored for 0-48 h. However, the lowest PR was observed in the 24-30 h AIOV interval with storage time (ST) of 96-120 h (p < 0.05). There was a significant effect of the interaction between ST and AIOV (p < 0.05) on TE and ES variables. Total embryos and ES did not differ (p > 0.05) among AIOV intervals in ST of 0-48 h. However, gilts inseminated at 24-30 h AIOV interval with ST of 96-120 h showed a reduction of 6.7 embryos (p < 0.05) compared with gilts in the same interval inseminated with semen stored for 0-48 h. ES for the 24-30 h AIOV interval and ST of 96-120 h was lower than that observed in the other groups (p < 0.05). 相似文献
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Zamoto A Tsuji M Wei Q Cho SH Shin EH Kim TS Leonova GN Hagiwara K Asakawa M Kariwa H Takashima I Ishihara C 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2004,66(7):785-792
We previously reported that small wild rodents in Japan harbor two types of novel Babesia microti-like parasites (designated as Hobetsu and Kobe types), but not the type commonly found in the northeastern United States (U.S. type) where human babesiosis is endemic. To determine whether these new types of parasites are distributed in places surrounding Japan, an epizootiologic survey was undertaken in three geographically distant areas in northeastern Eurasia; South Korea, Vladivostok in Russia, and Xinjiang in China. Blood samples were collected from a total of 387 animals comprising 24 species. DNAs extracted from the samples were tested by nested PCR targeting babesial nuclear small-subunit rRNA gene (rDNA), which revealed that small rodents harboring B. microti exist in all three survey areas. Sequence analysis showed that all PCR-positive samples had rDNA sequences virtually identical to that of U.S.-type B. microti. However, when beta-tubulin gene sequences were compared, evident geographic variations were seen. By use of primers specific for each of the beta-tubulin genes of Kobe-, Hobetsu-, and U.S.-type parasites, a type-specific PCR was developed. Parasite with Hobetsu- or Kobe-type sequence was not detected from any of the three survey areas. These findings suggest that U.S.-type B. microti is widely distributed among small wild mammals in temperate zones of not only North America, but also Eurasia, whereas that Hobetsu- and Kobe-type parasites may be uniquely distributed in Japan. 相似文献
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A. I. Fokina E. V. Dabakh L. I. Domracheva S. G. Skugoreva E. I. Lyalina T. Ya. Ashikhmina Yu. N. Zykova K. A. Leonova 《Eurasian Soil Science》2018,51(5):550-560
The comprehensive diagnostics of the state of soils in the impact zone of thermal power station (TPS-5) in the city of Kirov was performed on the basis of the soil chemical analyses and the study of biota response to the loads at different organization levels. The chemical analyses attested to a satisfactory state of the soils. However, the use of soil cyanobacteria and bird’s-foot trefoil (Lótus corniculátus) as test objects showed the toxicity of studied soil samples. The toxicity of the samples was judged from the bioindication effects of cyanophytization and melanization of soil microbial complexes. The obtained results demonstrated that at relatively low concentrations of total and mobile heavy metal compounds in the soil samples, their amount released into the tested soil water (1: 4) extract exceeded the limit allowable for normal functioning of living organisms. For the first time, the express cyanobacterial tetrazole-topographic method of biotesting was applied in the geoecological study to estimate the toxicity of the soil samples. The results obtained with the help of traditional and express methods proved to be comparable. The express-method was sufficiently sensitive and efficient. It allowed the determination of the samples' toxicity in five hours, i.e., four to five times faster than the traditional technique. An inverse relationship between the number of viable cells of cyanobacteria (as judged from the inclusion of formazan crystals) and the concentration of lead ions in the tested soil extracts was found. This finding can be considered a prerequisite for further study and application of the express method in the practice of geoecological monitoring. Our study demonstrated the necessity of a comprehensive approach for the assessment of the real ecological state of soils in the investigated impact zone of the thermal power station. 相似文献
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The effect of high NaCl concentrations on accumulation of biomass and change in content of sodium and potassium ions in 17
accessions of nine species of Aegilops L. is studied. Three salt-tolerant accessions (Ae. tauschii k-677 and 674 and Ae. cylindrica k-676) containing the D genome and having a high K/Na ratio are identified. 相似文献
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I. N. Leonova L. I. Laikova O. M. Popova O. Unger A. Börner M. S. Röder 《Euphytica》2007,155(1-2):79-86
Advanced backcross QTL analysis was used to identify QTLs for seedling and adult plant resistance to leaf rust in introgression lines derived from a cross between the spring wheat cultivar ‘Saratovskaya 29’ and a synthetic allopolyploid wheat (T. timopheevii/T. tauschii). F2 mapping populations involving two backcross selections (‘BC5’ and ‘BC9’ lines) were genotyped with microsatellite markers. Two significant QTL for adult plant resistance were identified in line ‘BC5’: one on chromosome 2B, but originating from chromosome 2G, explained 31% of the trait variance. The other, derived from T. tauschii and mapped to the short arm of chromosome 2D explained 19% of the trait variance. In the second line, one major seedling and adult plant resistance QTL was identified on chromosome 2B. Both QTL co-located to the same marker interval. Such introgression lines, resulting from the reconstruction of common wheat genome, are of interest both as initial material for breeding and improvement of current cultivars, and as a resource for the study of the interaction and transformation of genomes. 相似文献
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Microsatellite monitoring of recombination around the Vrn-B1 locus of wheat during early backcross breeding 总被引：1，自引：0，他引：1
The length of chromosomal segments retained around the Vrn‐B1 gene controlling sensitivity to vernalization in wheat (Triticum aestivum L.) was studied in the first and third backcrosses by using microsatellite markers. Eleven polymorphic markers located on chromosome 5B were used for microsatellite analysis. It was shown in the first backcross that plants with a donor segment around the gene of interest not longer than 50% of chromosome 5B could be selected. When selection is not molecular‐marker assisted, the length of the chromosomal donor segment with the target gene may reach 94% of chromosome 5B even in plants of the third backcross generation. The considerable length differences in the 5B microsatellite loci between the winter and spring lines of wheat studied indicate that these markers are promising in marker‐assisted backcrossing or marker‐assisted selection for the Vrn‐B1 gene using different combinations of Spring and Winter genotypes. 相似文献