Landscape Ecology - Several case studies investigated the role of ecosystem services in participatory planning processes. However, no systematic study exists that cuts across a large number of... 相似文献
Cattle were immunized with vaccines containing modified-live or inactivated bovine respiratory syncytial virus (BRSV) and serum antibody responses were analyzed. Compared with preinculation values, at Day 14 after two biweekly immunizations with modified-live or inactivated vaccines there were significant increases in BRSV-specific titers in the sera of cattle that received both types of vaccines, as determined by a whole cell ELISA. Using a blocking ELISA and radioimmune precipitation it was determined that there was recognition of the fusion (F) protein by antibodies from cattle that received both types of BRSV antigens: however, virus neutralization assays revealed that only cattle that received modified live virus, either in monovalent or polyvalent vaccines, developed neutralizing antibodies to BRSV after two immunizations. These results indicate that inactivation of BRSV can lead to a dissociation between serological recognition of the F protein and virus neutralization in vaccinated cattle. 相似文献
Two serological tests (indirect immunofluorescence and enzyme-linked immunosorbent assay) were developed for the detection of fetal antibody to Chlamydia psittaci. Fetal blood and thoracic fluid from 126 field cases of suspected ovine chlamydial abortion were examined using both tests. Placenta and fetal tissues (lung, liver, and kidney) from the same animals were also examined by the following conventional diagnostic methods: isolation in McCoy cells, detection of chlamydial lipopolysaccharide (LPS), modified Ziehl-Nielsen staining, and direct fluorescent antibody staining of chlamydia in frozen cryostat sections. Seventy cases were positive by fetal serology, and of these, 68 were also positive by isolation and/or LPS detection. The remaining 56 cases had negative fetal serology, and of these, 39 were positive by isolation and/or LPS detection. Results indicate that fetal serology, although less sensitive than either isolation in McCoy cells or detection of chlamydial LPS antigen, may be of particular use when placenta is not available. 相似文献
A strain of Yersinia enterocolitica of O serogroup 6,30 isolated from the liver of an aborted ovine fetus was inoculated intravenously into a group of pregnant ewes at about 90 days gestation and produced placentitis with abortion or delivery of infected lambs about 50 days later. Y. enterocolitica of the same serogroup was recovered from the necrotic placental cotyledons and most other fetal tissues and could be isolated from vaginal discharges of the ewes for a least 2 weeks after abortion. Histological changes were consistent with an acute bacterial necrotizing placentitis and systemic infection of the fetus. Subsequent pregnancies in the ewes proceeded to term without evidence of infection. 相似文献
Pulmonary lesions associated with Corynebacterium ovis were analyzed with an indirect immunoperoxidase staining technique using monoclonal antibodies. The predominant cells in abscess walls and surrounding lung parenchyma were large macrophages which expressed major histocompatibility complex (MHC) class II molecules on their surfaces. T lymphocytes were prominent in the same sites in the naturally occurring lesions, and SBU-T4-positive ("helper/inducer") cells were the major subset of lymphocytes (mean T4/T8 ratio = 3.5). B lymphocytes and granulocytes comprised minor populations of infiltrating cells. These results implicate activated macrophages and MHC class II-restricted T lymphocytes in the pathogenesis of established C. ovis infections in sheep. 相似文献
1. The fear levels of broilers arriving from slaughter at 4 commercial processing plants were assessed using tonic immobility (TI) tests. The relative effects of selected variables were also examined.
2. Neither the position of the birds on the lorry, nor their sex, nor the ambient temperature nor the identity of the experimeter exerted any significant effects on tonic immobility reactions.
3. Although the longest and shortest immobility responses followed transportation in the fixed crates and metal modules respectively, system comparisons may be confounded by variations in the birds’ genetic and/or experiential backgrounds.
4. Both journey duration and waiting time before transport bore an unambiguous and positive linear relationship with mean TI duration. The duration of transit was the major factor determining fear levels following both commercial and simulated journeys. 相似文献