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41.
This study was conducted to determine the effect of immunization with inhibin DNA vaccine delivered by attenuated Salmonella choleraesuis on ovarian responses and fertility in cross‐bred buffaloes. A total of 134 cross‐bred buffaloes were divided into four groups: groups T1 (n = 34), T2 (n = 35) and T3 (n = 31) were nasal immunized twice a day with 10 ml of 1 × 1010 CFU/ml of the C501 (pVAX‐asd‐IS) vaccine for 5, 3 and 1 day, respectively. Group C (n = 34) was nasal immunized with 10 ml PBS for 5 days. All animals were immunized twice with an interval of 14 days and administered with 200 μg of a GnRH analogue on day 28, 0.5 mg PGF on day 35 and 200 μg of the same GnRH analogue on day 37. TAI was performed at 18 and 24 hr after the second GnRH treatment. Fourteen days after primary immunization, C501 (pVAX‐asd‐IS) elicited significant immune responses, and anti‐inhibin IgG antibody titres in group T1 were significantly higher (< .01) than groups T3 and C. After the second GnRH treatment, the growth speed of the dominant follicles in group T1 was significantly faster (< .05) than groups T3 and C. The number and diameter of large follicles (≥10 mm) as well as ovulatory follicles in group T1 were the greatest in all groups, resulting in a greater conception rate in buffaloes with positive anti‐inhibin antibodies. These results demonstrate that immunization with the C501 (pVAX‐asd‐IS) vaccine, coupled with the Ovsynch protocol, could be used as an alternative approach to improve reproductive performance in cross‐bred buffaloes.  相似文献   
42.
Single crystals of a one-component plasma were observed by optical Bragg diffraction. The plasmas contained 10(5) to 10(6) single-positive beryllium-9 ions (9Be+) at particle densities of 10(8) to 10(9) per cubic centimeter. In approximately spherical plasmas, single body-centered cubic (bcc) crystals or, in some cases, two or more bcc crystals having fixed orientations with respect to each other were observed. In some oblate plasmas, a mixture of bcc and face-centered cubic ordering was seen. Knowledge of the properties of one-component plasma crystals is required for models of white dwarfs and neutron stars, which are believed to contain matter in that form.  相似文献   
43.
The concentrations of the hydrogen radicals OH and HO2 in the middle and upper troposphere were measured simultaneously with those of NO, O3, CO, H2O, CH4, non-methane hydrocarbons, and with the ultraviolet and visible radiation field. The data allow a direct examination of the processes that produce O3 in this region of the atmosphere. Comparison of the measured concentrations of OH and HO2 with calculations based on their production from water vapor, ozone, and methane demonstrate that these sources are insufficient to explain the observed radical concentrations in the upper troposphere. The photolysis of carbonyl and peroxide compounds transported to this region from the lower troposphere may provide the source of HOx required to sustain the measured abundances of these radical species. The mechanism by which NO affects the production of O3 is also illustrated by the measurements. In the upper tropospheric air masses sampled, the production rate for ozone (determined from the measured concentrations of HO2 and NO) is calculated to be about 1 part per billion by volume each day. This production rate is faster than previously thought and implies that anthropogenic activities that add NO to the upper troposphere, such as biomass burning and aviation, will lead to production of more O3 than expected.  相似文献   
44.
The atmospheric residence time for methyl bromide (CH3Br) has been estimated as 0.8 +/- 0.1 years from its empirical spatial variability relative to C2H6, C2Cl4, CHCl3, and CH3Cl. This evaluation of the atmospheric residence time, based on Junge's 1963 general proposal, provides an estimate for CH3Br that is independent of source and sink estimates. Methyl bromide from combined natural and anthropogenic sources furnishes about half of the bromine that enters the stratosphere, where it plays an important role in ozone destruction. This residence time is consistent with the 0.7-year value recently calculated for CH3Br from the combined strength estimates for its known significant sinks.  相似文献   
45.
A commercially available absorbed ELISA for the diagnosis of Johne's disease (JD) (paratuberculosis) in cattle, the Johne's Absorbed EIA, was compared with the conventional complement-fixation test (CFT) used in Australia. Stored plasma from 3 Victorian dairy herds with a history of JD, sera from specimens submitted from animals showing clinical signs of JD and sera from the US National Repository for Paratuberculosis Specimens were used to determine the sensitivity of each test. The EIA detected 48.8% of 43 Australian animals with subclinical JD, while the CFT detected only 12 (21.4%) of 56 subclinically affected cattle. Of 150 subclinically infected US cattle, the EIA detected 47.3% and the CFT detected 52.0%. The EIA detected 59.7% of animals which at the time of sampling were shedding Mycobacterium paratuberculosis in their faeces, but showed no clinical signs of JD, while the CFT detected 57.3%. The EIA correctly identified 88.2% of 136 histologically confirmed clinical cases, and the CFT detected 83.4%. The specificity of each test was determined by testing sera collected at slaughter from animals residing in a known JD-free area of Australia, and from samples from the US National Repository of Paratuberculosis Specimens collected from certified-free herds in Wisconsin. The EIA was found to have a specificity of 99.8% when 998 Australian animals were used as the test population, and 99.0% when 196 US animals were used. The specificity of the CFT using Australian samples was 96.9% and 95.2% using American samples.  相似文献   
46.
Bacteroides nodosus involved in several outbreaks of ovine footrot over a number of years were subjected to DNA restriction endonuclease analysis. Individual isolates were found to have characteristic Bam HI profiles which permitted their accurate identification and differentiation from other isolates. Bam HI profiles of B. nodosus isolates were used in epidemiological investigations involving consecutive outbreaks of footrot on individual and neighbouring farms. The relationship of given isolates to a common source could be established by this means. Restriction endonuclease analysis provides an additional epidemiological tool in ovine footrot investigations as it accurately identifies interstrain differences in a manner not possible by conventional bacteriological and serological means.  相似文献   
47.
48.
Objective To evaluate the usefulness of the gamma-interferon assay in the diagnosis of caprine tuberculosis in comparison with a single intradermal tuberculin test, and to obtain a group of animals free from this infection in a herd with a high prevalence.
Design An immunological study involving four serial comparative gamma-interferon and single intradermal tuberculin tests.
Animals A herd of 87 goats of Guadarrama breed.
Procedure Serial testing and segregation of animals.
Results We found that the number of infections detected by the gamma-interferon test was considerably greater than the number detected by the single intradermal tuberculin test. A group of 10 animals was negative to both tests in two consecutive rounds and three kids were negative in the last round of testing.
Conclusions Gamma-interferon assay is appropriate for diagnosis and eradication of tuberculosis in goats. This test is able to detect early Mycobacterium bovis infection. Avian reactors with simultaneous increased reaction to bovine PPD in the gamma-interferon assay (designated as avianB reactors) should be considered test positive for M bovis . By serial testing with the gamma-interferon and the single intradermal tuberculin tests, and a policy of segregation of kids at birth, it is possible to achieve a group of animals test negative for tuberculosis from a herd of goats with high immunoreactivity to this infection.  相似文献   
49.
The objectives of this study were to determine the non‐specific aerobic and anaerobic bacterial causes of endometritis causing repeat breeding of cycling Iraqi buffalo cows at Nineveh province, validate diagnostic criteria for endometritis and to evaluate the treatment efficiency of using systemic or intra‐uterine infusion of antibiotics for the treatment of endometritis. Data were collected from 60 buffalo cows with history of repeat breeding in different herds. All buffaloes were subjected to detailed clinical examination including external inspection, vaginoscopy and transrectal palpation of the cervix, uterus and ovaries. Swabs for bacteriology and biopsies for histopathology were collected from the uterine lumen from each cow. Character, odour and estimation of polymorphonuclear cells (PMN) of the vaginal mucus were scored. Blood samples were collected from cows for creatine kinase (CK) and aspartate aminotransferase (AST) measurement. Treatment conducted using oxytetracycline with tylosin in local intrauterine infusion or systemically with hormonal treatment. The most pre‐disposing factor for uterine infection was retained placenta (13.3%). The most prevalent bacteria in uterine lumen were E. coli (23%), Archanobacterium pyogenes (13%) and Staphylococcus aureus (10%) were mostly isolated from buffaloes with repeat breeding. Vaginal mucus character score was associated with the bacterial growth density score. The difference in PMN was highly significant (p < 0.01) in animals with repeat breeding than control groups. In addition, PMNs was significantly (p < 0.01) correlated r = 0.894 with the character of vaginal discharge. High level of PMNs observed in buffaloes infected with A. pyogenes. Buffalo cows with endometritis had higher CK (321.47 ± 39.06 vs 162.01 ± 16.41 U/l) and AST (133.93 ± 12.43 vs 97.01 ± 6.86 U/l) activities (p < 0.05) than control‐heifers, but no significant difference was observed between buffalo cows with endometritis in CK (321.47 ± 39.06 vs 208.33 ± 5.84) and AST (133.93 ± 12.43 vs 156.17 ± 9.65) activities than control‐pluriparious. It could be concluded that A. pyogenes was the only non‐specific uterine pathogen directly associated with severe endometrial lesions. Vaginoscopy examination combined with palpation of uterus increase the accuracy of diagnosing endometritis and cytogenic examination of uterine discharge is more reliable method of establishing the presence or absence of uterine inflammation in buffalo cows. Animals with repeat breeding (endometritis) showed clinical cure and improved pregnancy in all treatment groups with no significant difference. The use of oestradiol in repeat breeder cases has no effect in improving neither clinical cure rate nor pregnancy rate.  相似文献   
50.
A heterologous in vitro system, using zona‐intact sheep oocytes, was used to evaluate the relationship between sperm factors of Iberian red deer thawed epididymal sperm and the percentage of cleaved oocytes. Epididymal spermatozoa were recovered from six males, diluted with freezing extender and cryopreserved. After thawing sperm motility (SM) and acrosome and membrane integrities were evaluated. Again, these parameters were assessed after incubation in freezing extender at 37°C for 2 h. After cryopreservation the values for SM and acrosome and membrane integrities were high (~80, 80 and 70% respectively). However, these values significantly decreased after incubation (~59, 62 and 47% respectively). Red deer thawed epididymal sperm fertilized zona‐intact sheep oocytes, although the percentage of cleaved oocytes was low (~22%). No relationship was found between sperm parameters assessed after thawing and the percentage of cleaved oocytes. Likewise, any sperm parameter evaluated after incubation was assessed in relation to the percentage of cleaved oocytes. However, acrosome and membrane integrities were near to significance (p = 0.06 and p = 0.09 respectively). Then, we conducted a reduced model with these two variables and both were related to the percentage of cleaved oocytes (p = 0.02 and p = 0.04 respectively). Thus, acrosome and membrane integrities were related to the percentage of cleaved oocytes negatively and positively respectively. It was concluded that the classical parameters assessed in deer thawed sperm samples can be good predictors of the ability to fertilize zona‐intact sheep oocytes.  相似文献   
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