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1.
Feline herpesvirus (FHV-1; felid herpesvirus 1 (FeHV-1)) is an alphaherpesvirus of cats closely related to canine herpesvirus-1 and phocine herpesvirus-1. There is only one serotype of the virus and it is relatively homogenous genetically. FeHV-1 is an important cause of acute upper respiratory tract and ocular disease in cats. In addition, its role in more chronic ocular disease and skin lesions is increasingly being recognised. Epidemiologically, FeHV-1 behaves as a typical alphaherpesvirus whereby clinically recovered cats become latently infected carriers which undergo periodic episodes of virus reactivation, particularly after a stress. The primary site of latency is the trigeminal ganglion. Conventional inactivated and modified-live vaccines are available and protect reasonably well against disease but not infection, although viral shedding may be reduced. Genetically engineered vaccines have also been developed, both for FeHV-1 and as vector vaccines for other pathogens, but none is as yet marketed. 相似文献
2.
This article considers the experiences of a Samoan female geographer undertaking community‐based field research in her home country, and identifies some lessons for researchers working in similar circumstances. The paper suggests that ethical behaviour in research is ‘place‐specific’, and there is therefore a need to employ culturally sensitive and ‘location‐specific’ methodologies when undertaking community‐based research fieldwork. For the lead researcher, growing up in Samoa played a significant role in gaining an understanding of a set of robust and effective procedures to evaluate citizens' resilience to climatic and other environmental challenges. Fluency in everyday and more formal local languages, and awareness of local differences, each with multi‐layered connections to local communities, understanding cultural nuances and practising respect for va tapuia [sacred space or relationships] protocols, together facilitated the process of knowledge acquisition and helped to confirm the validity of the conclusions derived from the study. 相似文献
3.
Casparus J. BRINK Anneke POSTMA Etienne SLABBERT Ferdinand POSTMA A. Muthama MUASYA Karin JACOBS 《土壤圈》2020,30(6):778-790
Aspalathus linearis is a commercially important plant species endemic to the Cape Floristic Region of South Africa and is used to produce a herbal tea known as rooibos tea. Symbiotic interactions between A. linearis and soil bacteria play an important role in the survival of Aspalathus plants in the highly nutrient-poor, acidic fynbos soil. The aim of this study was to characterize and compare rhizosphere and bulk soil bacterial communities associated with natural and commercially grown A. linearis, as well as the effect of seasonal changes on these communities. Bacterial communities were characterized using high throughput amplicon sequencing, and their correlations with soil chemical properties were investigated. The N-fixing bacterial community was characterized using terminal restriction fragment length polymorphism and real time quantitative polymerase chain reaction. Actinobacteria, Proteobacteria, and Acidobacteria were the most dominant bacterial phyla detected in this study. Highly similar bacterial communities were associated with natural and commercially grown plants. Significant differences in the bacterial community were observed between rhizosphere and bulk soils collected in the dry season, while no significant differences were detected in the wet season. This study provides insights into bacterial community structure and potential factors shaping bacterial community structure with commercially important A. linearis. 相似文献
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This study was conducted to determine whether young calves with maternal antibodies against bovine herpesvirus type 1 (BHV-1) but without antibodies against glycoprotein E (gE) can produce an active antibody response to gE after a BHV-1 infection. Five calves received at birth colostrum from gE-seronegative cows which had been vaccinated two or three times with an inactivated BHV-1, gE-deleted marker vaccine. After inoculation with a wild-type virulent strain of BHV-1, all the passively immunised gE-negative calves shed virus in large amounts in their nasal secretions. All the calves seroconverted to gE within two to four weeks after inoculation and then had high levels of gE antibodies for at least four months. The development of an active cell-mediated immune response was also detected by in vitro BHV-1-specific interferon-gamma assays. All the calves were latently infected, because one of them re-excreted the virus spontaneously and the other four did so after being treated with dexamethasone. The results showed that under the conditions of this work the gE-negative marker could also distinguish between passively immunised and latently infected calves. 相似文献
6.
This paper presents a method for characterizing the complexity of landscape boundaries by remote sensing. This characterization is supported by a new boundary typology, that takes into account points where three or more landcovers converge (i.e., convergency points or coverts). Landscape boundary richness and diversity indices were proposed and calculated over 19 landscapes in South-East Brazil. Results showed that landscape boundaries, especially convergency points, provided an enrichment in landscape pattern analysis. Landcover boundary diversities were significantly related to landcover shape: elongated riparian units had the highest values for boundary diversity and coverts proportion indices. On the other hand, landscape analysis showed that indices of shape, richness, diversity and coverts proportion provided an additional evaluation of landcover spatial distribution within the landscape. 相似文献
7.
Dispas M Schynts F Lemaire M Letellier C Vanopdenbosch E Thiry E Kerkhofs P 《The Veterinary record》2003,153(7):209-212
During a field trial to evaluate the efficacy of repeated vaccinations with bovine herpesvirus type 1 (BHV-1) marker vaccines, a glycoprotein E (gE)-negative BHV-1 strain was isolated from the nasal secretions of two cows, eight months after vaccination with a gE-negative live-attenuated vaccine, initially given intranasally, then intramuscularly. The strain isolated was characterised using immunofluorescence, restriction analysis and PCR. All the techniques used identified the isolated virus as a gE-negative BHV-1 phenotypically and genotypically identical to the Za strain used as a control. 相似文献
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9.
DNA sequences coding for the F18 fimbriae and AIDA adhesin are localised on the same plasmid in Escherichia coli isolates from piglets 总被引:3,自引:0,他引:3
The adhesin-involved-in-diffuse-adherence (AIDA) afimbrial adhesin is produced by human, but not by animal, Escherichia coli, with the exception of German porcine verotoxigenic Escherichia coli (VTEC) [Clin. Diagn. Lab. Immunol. 8 (2001) 143]. Presence and localisation of DNA sequences (aidA) coding for and production of an AIDA adhesin were investigated in a collection of Belgian VTEC and non-VTEC E. coli isolated from piglets at weaning time. The 174 isolates were also studied by colony hybridisation for the presence of DNA sequences coding for the Stx2e verocytotoxin and the F18 fimbrial adhesin (fed): 71 were Stx2+F18+AIDA+, 26 were F18+AIDA+, 12 were AIDA+, two were Stx2+AIDA+, and one was Stx2+ only. Fifty-four of the 58 (F18+)AIDA+ isolates tested positive in a western blotting assay with an immune serum raised against the AIDA protein. Hybridisation with the AIDA gene probe on plasmid DNA profiles identified a probe-positive plasmid band in the 10 AIDA+ and in 24 of the 25 F18+AIDA+ isolates studied. Moreover in F18+AIDA+ isolates, only one plasmid band hybridised with both F18 and AIDA probes. These results confirm the presence of aidA-related genes in not only VTEC, but also non-VTEC, isolates from piglets and the production of an antigenically AIDA-related protein by the majority of probe-positive E. coli. Moreover the plasmid DNA hybridisation results suggest a localisation on the same plasmid of the aidA- and fed-related DNA sequences. 相似文献
10.
Adaptations of glucose metabolism in multiparous sows: effects of pregnancy and feeding level 总被引:3,自引:0,他引:3
This experiment was undertaken to determine whether pregnancy affects glucose metabolism and insulin sensitivity in sows fed at different levels. Four replicates of six multiparous Large White sows were involved. In each replicate, four sows were inseminated on the first postweaning estrus (pregnant group) and the two remaining were kept nonpregnant. Half of the sows of each group were fed 2.5 kg/d (low level) and the others 4 kg/d (high level) of the same standard pregnancy diet. Jugular catheters were implanted 2 to 3 d after estrus. Plasma concentrations of glucose, insulin, and FFA were determined before and during the 4 h following the morning meal at 10, 30, 59, 87, 93, 101, and 110 d of gestation and at equivalent periods for the nonpregnant sows. Intravenous glucose tolerance tests were performed at 33, 71, 85, 96, and 108 d by i.v. injection of 0.5 g glucose/kg BW. Compared with the glycemia before the meal, all the sows showed hyperglycemia 30 min after the initiation of the meal and hypoglycemia thereafter, with a minimum reached at approximately 75 min. Insulinemia increased from 20 min after food access, reached a maximum at 40 min, and returned to the basal level after 180 min. The higher feeding level increased plasma insulin and lowered plasma glucose levels. Glycemia and insulinemia profiles changed from 87 d onward in the pregnant sows. The peak of glucose induced by the meal was higher, and the subsequent period of hypoglycemia almost disappeared. The area under the insulin curve was unchanged, but insulin secretion was delayed. The glucose tolerance tests showed that between d 85 and 108 the half-life of injected glucose increased and insulin secretion was delayed in the pregnant sows. Compared to the following stages, plasma FFA were high before and after the meal at 10 d, which most likely was a residual effect from the previous gestation/lactation cycle. They were lower from 30 to 101 d in the pregnant and nonpregnant sows. At 110 d, fasting FFA were high again in the pregnant sows only, very likely in relation to the preparation for lactation. This experiment showed that insulin sensitivity decreases after 85 d of pregnancy in multiparous sows. 相似文献