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101.
The aim of this work was to examine variation for activity of symbiosis with Rhizobium meliloti in alfalfa, sweet clover and fenugreek. Seed specimens were obtained from the collection of the All-Union Research Institute for Plant Breeding and Rhizobium strains from the All-Union Research Institute for Agricultural Microbiology, both in Leningrad. Sterile methods of vegetative culture were employed. Statistical analysis of data on inter- and intracultivar variation allow one to suppose that in alfalfa and sweet clover, nitrogenase activity and symbiotic efficiency (ability of plants to increase biomass after inoculation) are controlled by different groups of genes. The latter symbiotic property is more strictly controlled by host genotype than the former. Fenugreek appeared to be more variable in its capacity for symbiosis than alfalfa and sweet clover. Differences between genotyyes in symbiotic activity correlate with division into subspecies and are inherited in self-fertile progeny of fenugreek plants. Differences between R. meliloti strains for the efficiency of symbiosis with heterogceic natural fenugreek population are expressed to a lesser degree than with plants of more homogenic cultivar populations. 相似文献
102.
In this paper, habitat models were used to predict potential habitat for endangered species, which is an important question in landscape and conservation planning. Based on logistic regression, we developed habitat distribution models for the burnet moth Zygaena carniolica and the nymphalid butterfly Coenonympha arcania in Northern Bavaria, Germany. The relation between adult occurrence and habitat parameters, including the influence of landscape context, was analyzed on 118 sites. Habitat connectivity analyses were carried out on the basis of (1) habitat suitability maps generated from these models and (2) dispersal data from mark recapture studies. Our results showed that (1) the presence of the burnet depended mainly on the presence of nectar plants and of nutrient-poor dry grasslands in direct vicinity, that of the nymphalid on larger areas of extensively used dry grasslands within 100 m vicinity in combination with small patches of higher shrubs and bushes. (2) Internal as well as external validation indicated the robustness and general applicability of the models. Transferability in time and space indicated their high potential relevance for applications in nature conservation, such as predicting possible effects of land use changes. (3) Habitat connectivity analyses revealed a high degree of habitat connectivity within the study area. Thus, we could show no effects of isolation or habitat size for both species. 相似文献
103.
Mercury in the Aquatic Environment of the Village of Caimito at the Mojana Region,North of Colombia 总被引:1,自引:0,他引:1
Olivero-Verbel Jesus Johnson-Restrepo Boris Mendoza-Marín Claudia Paz-Martinez Ramon Olivero-Verbel Rafael 《Water, air, and soil pollution》2004,159(1):409-420
During May–September 1999, several aquatic environmental samples were collected from the village of Caimito, in the San Jorge River basin area, state of Sucre (Colombia), and analyzed for total mercury (T-Hg). Mean T-Hg concentration in sediments from surrounded marshes was 0.155 ± 0.016 g Hg/g. Low Hg concentrations were found in the phytoplanktivorous fish species Prochilodus magdalenae (0.087 ± 0.01 g Hg/g), while four-fold greater concentrations were found in all the carnivorous species. In average, T-Hg concentrations for fish samples did not exceed the limit consumption level (0.5 g Hg/g). However, risk assessment based on the hazard index suggested that the consumption of 0.1 kg per day of carnivorous fish could increase the risk of mercury poisoning in local population. 相似文献
104.
The pale-headed brush-finch (Atlapetes pallidiceps) is threatened with extinction due to habitat loss, but very little is known about its ecological requirements. We used multiple logistic regression to study habitat selection of this species at landscape, territory, and nest site scales in order to make recommendations about effective management. Habitat selection by the sympatric stripe-headed brush-finch (Buarremon torquatus) was examined with the same methods in order to analyse interspecific resource partitioning and potential competition. The pale-headed brush-finch selected semi-open habitat types with intermediate scrub heights, and avoided forests. Nest sites depended on the presence of vines or bamboo. By contrast, the stripe-headed brush-finch chose dense habitat with low ground cover under tall vegetation and avoided semi-open habitat. The two species had overlapping territories but differed significantly in microhabitat use and the use of vegetation strata. We found no convincing evidence that the stripe-headed brush-finch displaces the pale-headed brush-finch from optimal habitat. The preservation of semi-open scrubland maintained by low-intensity grazing is suggested for future conservation of the pale-headed brush-finch. 相似文献
105.
Haladová E Mojžišová J Smrčo P Ondrejková A Vojtek B Prokeš M Petrovová E 《Acta veterinaria Hungarica》2011,59(1):77-86
The objective of the study was to determine the immunostimulatory effect of β-(1,3/1,6)-D-glucan in puppies. The effect exerted on the efficacy of vaccination, especially against canine parvovirus and rabies infection, was studied. The application of vaccine and glucan leads to significant increases in the nonspecific immunological parameters (phagocytic ability of leukocytes, blastogenic response of lymphocytes, metabolic and chemotactic activity of polymorphonuclear cells). The level of antibodies against canine parvovirus (Ab CPV) and rabies infection reached the most statistically significant values on the 28th day after the application of vaccine and a syrup containing β-(1,3/1,6)-D-glucan (Group GV) as compared to the control group (Group V, puppies receiving only vaccine). Dogs without glucan supplementation did not produce such significant levels of antibodies. We can conclude that glucan has relevant immunostimulatory effects in dogs with altered immunity. The glucan product tested in this study (PleraSAN V, PLEURAN, Bratislava, Slovakia) could be used in the small animal clinical practice. 相似文献
106.
Raj VS Fournier G Rakus K Ronsmans M Ouyang P Michel B Delforges C Costes B Farnir F Leroy B Wattiez R Melard C Mast J Lieffrig F Vanderplasschen A 《Veterinary research》2011,42(1):92
ABSTRACT: Cyprinid herpesvirus 3 (CyHV-3) is the aetiological agent of a mortal and highly contagious disease in common and koi carp. The skin is the major portal of entry of CyHV-3 in carp after immersion in water containing the virus. In the present study, we used in vivo bioluminescence imaging to investigate the effect of skin mucus removal and skin epidermis lesion on CyHV-3 entry. Physical treatments inducing removal of the mucus up to complete erosion of the epidermis were applied on a defined area of carp skin just before inoculation by immersion in infectious water. CyHV-3 entry in carp was drastically enhanced on the area of the skin where the mucus was removed with or without associated epidermal lesion. To investigate whether skin mucus inhibits CyHV-3 binding to epidermal cells, tail fins with an intact mucus layer or without mucus were inoculated ex vivo. While electron microscopy examination revealed numerous viral particles bound on the fins inoculated after mucus removal, no particle could be detected after infection of mucus-covered fins. Finally, anti-CyHV-3 neutralising activity of mucus extract was tested in vitro. Incubation of CyHV-3 with mucus extract reduced its infectivity in a dose dependent manner. The present study demonstrates that skin mucus removal and epidermal lesions enhance CyHV-3 entry in carp. It highlights the role of fish skin mucus as an innate immune protection against viral epidermal entry. 相似文献
107.
Mannosidosis in a litter of Persian cats 总被引:1,自引:0,他引:1
T Maenhout J A Kint G Dacremont R Ducatelle J G Leroy J K Hoorens 《The Veterinary record》1988,122(15):351-354
Three kittens in a litter of Persian cats showed, from the age of eight weeks, tremor, ataxia, dysmetria, progressive weakness and emaciation. Cytoplasmic vacuolation was observed in neurons, mesenchymal and epithelial cells of tissues taken post mortem. The alpha-mannosidase activity of brain tissue of one cat tested was 4.8 per cent of control values and the urine of two cats contained large amounts of mannose-rich oligosaccharides. 相似文献
108.
109.
P Marchot E Thiry P Jetteur P Leroy 《Revue d'élevage et de médecine vétérinaire des pays tropicaux》1991,44(4):405-406
Sera from cattle of the Accra Plains in Ghana were screened for bovine type-4 herpesvirus (BHV-4) antibodies by an indirect immunofluorescence test. Among the 176 screened serums, 14% were found positive at a 1/100 dilution. Further studies are necessary for a better understanding of the relationships between BHV-4 or some other agents and necrotic vaginitis associated with poor fertility observed in cattle in this area. 相似文献
110.