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201.
C. J. Reading S. T. Buckland † G. M. McGowan ‡ G. Jayasinghe § S. Gorzula ¶ D. Balharry 《Journal of Biogeography》1996,23(5):657-667
Abstract. During 1992 two questionnaire surveys, aimed at farmers and sections of the general public, were conducted to determine the distribution and status of the adder ( Vipera berus L.) in Scotland. In total, 94% of the Scottish mainland and inner isles were covered by the two surveys. The adder appears to be widespread throughout Scotland, although it is absent from much of the Central Valley, the Outer Hebrides and Northern Isles, and from much of the mountainous region between Inverness and Glasgow.
The distribution of the adder in Scotland was compared with the distributions of different habitat types defined in the ITE Land Class survey. Adders were strongly associated with areas of heterogeneous land use and negatively associated with intensively arable areas and rugged mountainous areas. Strong evidence was found to suggest that perceived adder abundance had declined during the last 10 years. Although the evidence suggesting that the distribution of adders in Scotland had changed was less strong, the results of the Farm Survey did indicate that it had contracted. The perceived change in status of the adder in Scotland during the last 10 years was compared with the observed changes in land use over the same period. 相似文献
The distribution of the adder in Scotland was compared with the distributions of different habitat types defined in the ITE Land Class survey. Adders were strongly associated with areas of heterogeneous land use and negatively associated with intensively arable areas and rugged mountainous areas. Strong evidence was found to suggest that perceived adder abundance had declined during the last 10 years. Although the evidence suggesting that the distribution of adders in Scotland had changed was less strong, the results of the Farm Survey did indicate that it had contracted. The perceived change in status of the adder in Scotland during the last 10 years was compared with the observed changes in land use over the same period. 相似文献
202.
AAM Coelho-Castelo AP Trombone RS Rosada RR Santos Jr VLD Bonato A Sartori CL Silva 《Genetic vaccines and therapy》2006,4(1):1-10
In order to assess a new strategy of DNA vaccine for a more complete understanding of its action in immune response, it is important to determine the in vivo biodistribution fate and antigen expression. In previous studies, our group focused on the prophylactic and therapeutic use of a plasmid DNA encoding the Mycobacterium leprae 65-kDa heat shock protein (Hsp65) and achieved an efficient immune response induction as well as protection against virulent M. tuberculosis challenge. In the present study, we examined in vivo tissue distribution of naked DNA-Hsp65 vaccine, the Hsp65 message, genome integration and methylation status of plasmid DNA. The DNA-Hsp65 was detectable in several tissue types, indicating that DNA-Hsp65 disseminates widely throughout the body. The biodistribution was dose-dependent. In contrast, RT-PCR detected the Hsp65 message for at least 15 days in muscle or liver tissue from immunized mice. We also analyzed the methylation status and integration of the injected plasmid DNA into the host cellular genome. The bacterial methylation pattern persisted for at least 6 months, indicating that the plasmid DNA-Hsp65 does not replicate in mammalian tissue, and Southern blot analysis showed that plasmid DNA was not integrated. These results have important implications for the use of DNA-Hsp65 vaccine in a clinical setting and open new perspectives for DNA vaccines and new considerations about the inoculation site and delivery system. 相似文献
203.
204.
Lindy J. Thompson David R. Barber Marc J. Bechard André J. Botha Kerri Wolter Walter Neser Evan R. Buechley Richard Reading Rebecca A. Garbett Pete Hancock Glyn Maude Munir Z. Virani Simon Thomsett Hansoo Lee Darcy Ogada Clive R. Barlow Keith L. Bildstein 《Ibis》2020,162(4):1324-1338
Tracking studies are often used to inform conservation plans and actions. However, species have frequently only been tracked in one or a few localities, whereas space use can be remarkably flexible, especially in long-lived species with advanced learning abilities. We assessed variability in space use in the Critically Endangered Hooded Vulture Necrosyrtes monachus by pooling movement data from three populations across the species’ sub-Saharan range (in South Africa, Botswana, Ethiopia, Kenya, The Gambia and Mozambique). We estimated minimum convex polygons and kernel density estimators (KDEs) and compared monthly home-range sizes between breeding and non-breeding seasons, age-classes and subspecies, accounting for uneven sampling within groups. Mean (± sd) monthly home-range sizes (95% KDEs) for adult Hooded Vultures from southern (12 453 ± 21 188 km2, n = 82) and eastern Africa (3735 ± 3652 km2, n = 24) were 103 and 31 times larger than those of conspecifics from western Africa (121 ± 98 km2, n = 48). This may relate partly to subspecific differences, and individuals with small home-ranges in western Africa and Ethiopia were trapped in urban environments. Regional variation in space use by Hooded Vultures may be linked to flexibility in feeding behaviour (degree of commensalism) which may arise in response to resource availability and persecution in different areas. Age-class also affected monthly home-range sizes, with immature birds generally having larger monthly home-range size estimates than adults. Our results highlight the flexibility of Hooded Vultures in terms of their home-range sizes and suggest that home-range sizes differ between populations and individuals, depending on the extent of human commensalism. Our results also reaffirm the importance of international co-operation in conservation efforts aimed at protecting this wide-ranging, non-migratory species. 相似文献
205.
C. J. Reading 《Journal of Zoology》1984,203(1):95-101
The interaction between Common frogs (Rana temporaria) and Common toads (Bufo bufo) during the breeding season was studied at a small pond on Portland, Dorset. Although the frogs started and finished spawning earlier than the toads there was a period during which interspecific spawning between female toads and male frogs took place. This appears to have resulted from reduced male toad activity caused by the cold breeding season given that spatial, temporal and behavioural species separation did not occur. 相似文献
206.
Relative stability of recombinant versus native peroxidases from Phanerochaete chrysosporium. 总被引:3,自引:0,他引:3
Two types of glycosylated peroxidases are secreted by the white-rot fungus Phanerochaete chrysosporium, lignin peroxidase (LiP) and manganese peroxidase (MnP). The thermal stabilities of recombinant LiPH2, LiPH8, and MnPH4, which were expressed without glycosylation in Escherichia coli, were lower than those of corresponding native peroxidases isolated from P. chrysosporium. Recovery of thermally inactivated recombinant enzyme activities was higher than with that of the thermally inactivated native peroxidases. Removal of N-linked glycans from native LiPH8 and MnPH4 did not affect enzyme activities or thermal stabilities of the enzymes. Although LiPH2, LiPH8, and MnPH4 contained O-linked glycans, only the O-linked glycans from MnPH4 could be removed by O-glycosidase, and the glycan-depleted MnPH4 exhibited essentially the same activity as nondeglycosylated MnPH4, but thermal stability decreased. Periodate-treated MnPH4 exhibited even lower thermal stability than O-glycosidase treated MnPH4. The role of O-linked glycans in protein stability was also evidenced with LiPH2 and LiPH8. Based on these data, we propose that neither N- nor O-linked glycans are likely to have a direct role in enzyme activity of native LiPH2, LiPH8, and MnPH4 and that only O-linked glycans may play a crucial role in protein stability of native peroxidases. 相似文献
207.
We have developed a limiting dilution assay for human bone marrow hematopoietic precursor (granulocytes-macrophages) in microwells. Bone marrow cells were fractionated by discontinuous Percoll gradients and diluted in culture medium containing colony-stimulating factors. They were diluted and cultured in medium containing colony-stimulating factor and 10(-5) M hydrocortisone in microwells over a range of cell densities that allowed calculation of the frequency of growth-inducible precursors. After 10 days, the wells were examined for clonal growth. Clonal proliferation followed the single-hit model of the Poisson distribution. More progenitors were detected in this assay than in simultaneous methylcellulose colony assays or agar cultures. Thymidine suicide experiments led to an increase in the frequency of progenitors detected in this assay, but a decrease in the frequency of methylcellulose colonies. This system may detect additional, less mature progenitors than are detected in semisolid culture systems. 相似文献
208.