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991.
本文对得自不同地区的四株0139菌株做了毒力、免疫力及交叉免疫力试验;四个地区0139菌株免疫小鼠后血清IgG、肠液sIgA抗体滴度的比较以及01群霍乱与0139型霍乱的交叉保护力试验。结果表明:01群霍乱与0139型霍乱无交叉免疫力。01群霍乱菌苗对0139型霍乱弧菌基本无保护作用;四株菌株的自身毒力基本相同。3#株免疫力高于其它株,用3#株免疫后能抵抗2#、3#及5#株的感染。四株菌株免疫小鼠 相似文献
992.
Stephen F. Norton 《Environmental Biology of Fishes》1995,44(1-3):61-78
Synopsis One of the major goals of an ecomorphological analysis is to correlate patterns of interspecific differences in morphology with patterns of interspecific differences in ecology. Information derived from functional morphological studies may provide a mechanistic framework supporting the correlation, but the move from a correlational relationship to a causal relationship requires experimental evidence that the interspecific morphological differences create performance differences and therefore ecological differences. The goal of this study was to examine ecomorphological relationships in the diets of cottid fishes (Scorpaeniformes: Cottidae) from the northeastern Pacific by using functional classifications of predators (based on their mode of attack) and of prey (based on their anti-predator defenses). The proposed ecomorphological relationships were tested by examining capture success among the cottids in attacks on prey with different escape abilities. As predicted on functional morphological grounds, both multivariate and univariate analyses indicated that the gravimetric importance of elusive prey (i.e. fishes, shrimp, mysids, and octopods) was greater in cottid species with a larger relative mouth size. Supporting a causal link between morphology and ecology, performance tests indicated that larger-mouthed cottids had significantly higher capture success on Heptacarpus shrimp than did smaller-mouthed species. As predicted, there were no differences in capture success among predators regardless of their attack style or ecomorphological patterns in attack on crabs (Cancer and Petrolisthes spp.) when the crabs were presented on a sand surface (i.e. easy prey). Several difficulties still exist when trying to apply a functional group approach to ecomorphology. These include the behavioral plasticity of the predators, the confounding factor of evolutionary history in identifying correlated ecomorphological features, multiple morphological solutions to common functional problems, the limitations of traditional dietary studies during extremes of prey abundance, and an inadequate understanding of the anti- predator defenses of most prey, including modifications that occur during ontogeny or in different habitats. 相似文献
993.
Akiyoshi Utsunomiya Daniel Elío-Calvo Armando Alberto Benitez Reyes Ernesto Sanzetenea Castro Enrique Rodríguez Carolina Tress Jenny I. Zamora de Corzo Erika Hannover Akemi Kai Kazumichi Tamura Naomi Higa 《Microbiology and immunology》1995,39(11):845-851
A total of 1,234 fecal samples from diarrhea cases were examined for etiological bacterial agents at medical facilities in La Paz and Sucre, Bolivia. Eighty strains of Shigella spp., 39 strains of Salmonella spp., 29 strains of Vibrio cholerae, and 222 strains of enteropathogenic Escherichia coli (139 EPEC, 55 ETEC, 29 EIEC, and 1 EHEC) were isolated. With regard to the serovars of Shigella, S. flexneri 2a, 3a, and 1b were predominant. In the case of Salmonella, S. enteritidis was the most common, followed by S. typhi, S. poona, and S. paratyphi B. Out of 29 cholera strains, 25 belonged to biovar El Tor, serovar Ogawa while the remaining 4 were serovar Inaba. Among 55 strains of ETEC serotypes, 5 showed ST producers but none showed LT producers. Likewise, among 55 strains of enterohemorrhagic serotypes, only one strain (O157:H7) produced verocytotoxin (VT 2). The results of drug sensitivity tests revealed the predominance of Shigella, EPEC, and ETEC strains resistant to aminobenzil-penicillin (ABPC) and trimethoprim. Since diarrheal patients in Bolivia are treated mainly with ABPC or sulfamethoxazole/trimethoprim (SXT) and rarely with gentamicin, kanamycin, or other drugs, it is possible that ABPC- and SXT-resistant strains will increase and persist in the near future. 相似文献
994.
Peripheral blood was collected from 13 captive seals (12 harbor seals and 1 gray seal) of various ages to study different immunological and hematological parameters. In vitro mitogenic reactivity of blood lymphocytes was measured by means of a microculture lymphocyte transformation test (LTT). After stimulation with different doses of the mitogens concanavalin A (Con A) and pokeweed mitogen (PWM), all examined seals showed significant proliferative responses to each mitogen. Furthermore, mitogenic reactivity significantly decreased with animal age suggesting this parameter of seal lymphocyte function is age-related. The present experiments support that the LTT is a suitable tool to monitor the functional capacity of seal lymphocytes. By means of the erythrocyte-rosette (E:-rosette) test it was demonstrated that a subpopulation of mononuclear seal bloosd leucocytes formed rosettes with sheep red blood cells (Srbc). This observation indicates that the phenomenon probably represents a marker for T lymphocytes in the seal as in several other mammalian species. Furthermore, the percentage of Srbc rosette-forming cells decreased with the age of the animals. Total blood leucocyte counts and differential leucocyte counts were determined by light microscopy. The number of leucocytes varied considerably among individual animals. Parallel to a significant decline of the percentage of lymphocytes with age, a corresponding increase in the percentage of neutrophils was demonstrated. In all of the seals, the percentages of monocytes and eosinophils were found to be low with only minor individual variation. The LTT and the E-rosette test are suggested as potential tools to elucidate immunological disorders in the seal. 相似文献
995.
The enzymatic activity of 70 feline and canineMicrosporum canis isolates was determined by the Api-Zym® test. The liquid phase of cultures, inoculated into Tryptic Soy Broth, was used to examine 19 enzymes. Considerable differences were observed among the extracellular enzymatic patterns. All the isolates produced alkaline phosphatase and beta-glucosidase, while lipase (C14), trypsin, chymotrypsin, beta-glucuronidase, and alpha-fucosidase activity was never revealed. Esterase (C4) activity was present in 57 samples (81%), esterase lipase (C8) in 31 (44%), leucine arylamidase in 35 (50%), valine arylamidase and cystine arylamidase in 7 (10%), acid phosphatase in 64 (91%), naphthol-AS-BI-phosphohydrolase in 60 (86%), alpha-galactosidase in 5 (7%), beta-galactosidase in 6 (8%), alpha-glucosidase in 25 (36%), N-acetyl-beta-glucosaminidase in 41 (58%), and alpha-mannosidase in 51 (73%). The beta-galactosidase activity ofM. canis has not been reported previously. Remarkable variations of intensity for each enzymatic activity were also detected. It is believed that these results could provide basic data for further investigations on the pathogenic role of enzymes secreted byM. canis. 相似文献
996.
C. Hagger C. Stricker R. C. Elston G. Stranzinger 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1995,90(1):120-123
Data on egg weight from experimental crosses with two inbred lines of chickens suggested evidence for segregation of a single dominant major gene. Because the data could not be transformed to satisfy normality and homoscedasticity conditions, the non-parametric test of Elston and the graphical approach used by Stolk et al. were applied. Due to a bad fit of the backcross B2 (P2×F1) and the F2 groups, both methods reject the hypothesis of a dominant major gene as the the only cause of the differences in egg weight between the six genetic groups involved. 相似文献
997.
L. Samsøe-Petersen 《BioControl》1995,40(1):95-104
Effects of 67 herbicides — several of which were mixtures — and plant growth regulators on adult females of the rove beetle,Aleochara bilineata, were investigated in the laboratory. The pesticides were tested in concentrations equivalent to the highest recommended
dosages for practical use. Mortality, egg production and hatch of the eggs were measured.
Most herbicides had no serious effect on any of the parameters recorded. Among the urea herbicides, however, several showed
adverse effects on egg production and/or hatch of the eggs laid. The strongest effect was exerted by methabenzthiazuron that
impeded hatch of the eggs completely. Bromoxynil, pyridate and haloxyfod reduced survival, egg production and/or egg hatch
to some degree, while carbaryl, which is also used as a plant growth regulator, killed all the beetles immediately. The usefulness
of dose-response-studies and the importance of measuring sublethal effects are stressed, and the choice of herbicides showing
no toxic effects is recommended.
Résumé Des expériences ont été faites au laboratoire pour tester les effets de 67 herbicides — dont plusieurs étaient des mélanges — et régulateurs de croissance des plantes sur les femelles adultes d'Aleochara bilineata. Les pesticides ont été testés à des concentrations équivalant aux dosages les plus élevés recommandés pour l'usage agricole. La mortalité, la production et l'éclosion des oeufs ont été mesurés. La plupart des herbicides n'ont pas d'effet important sur aucun des paramètres retenus. Parmi les herbicides à base d'urée cependant, plusieurs montrent des effets négatifs sur la production d'oeufs et/ou l'éclosion des oeufs. L'effet le plus fort a été provoqué par le métabenzthiazuron qui empêchait complètement l'éclosion des oeufs. Le bromoxynil, le pyridate et l'haloxyfop réduisaient la survie, la production d'œufs et/ou, jusqu'à un certain point, l'éclosion des œufs. Le carbaryl par contre, qui est aussi employé comme régulateur de croissance des plantes, tuait immédiatement tous les staphylins. L'utilité des études dose-réponse et l'importance de mesurer les effets sublétaux sont soulignés; le choix des herbicides ne montrant pas d'effet toxiques est recommandé.相似文献
998.
999.
The presence of conflicts in the allocation of resources among the different functions of an organism is a fundamental postulate of modern ecology. It is assumed that reproduction occurs at a cost because it monopolizes resources that could be used for other functions (e.g., growth). These conflicts may be particularly evident under stressful conditions, such as under low water or nutrient availability, or under severe climatic conditions. There we may expect to find strong negative relationships between an organism's growth and reproduction. We studied a population of Pinus banksiana (Pinaceae) at the northern limit of the species distribution, in subarctic Québec (Canada) where Pinus banksiana occupies nutrient-poor, sandy terraces along the Great Whale river. Serotinous cones of Pinus banksiana produced between 1969 and 1992 were sampled to estimate interannual variations in several variables representing reproduction, and to relate these to climate and tree growth. Climate appears to influence each developmental stage involved in the production of viable seeds, from the time of cone initiation to that of seed maturation. In general, reproductive variables are positively related to high temperatures during the three growing seasons required for seed production; growth is also positively correlated to summer temperatures. Consequently, investment in maturing seeds is positively associated with growth. Thus, both reproduction and growth covary with climate: during relatively warm and long growing seasons, resource allocation to both functions increases. Under these conditions, no trade-off is apparent. 相似文献
1000.