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Methods for isolation of human serum thyroxine-binding globulin are presented and evaluated; the preparation of Korcek and Tabachnik (1974) using bioselective adsorption (affinity) chromatography, ion-exchange chromatography on DEAE-Sephadex and preparative polyacrylamide gel electrophoresis, is considered to be the most satisfactory.  相似文献   

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Current understanding of genetic variation in lions (Panthera leo) is inadequate to guide many management decisions necessary for conservation of the species. We studied sequence variation in the mitochondrial cytochrome-b (cyt-b) gene of 75 lions and nuclear variation at 11 microsatellite loci of 480 lions across 8 range states (Cameroon, Uganda, Kenya, Zambia, Zimbabwe, South Africa, Botswana, and Namibia) and 13 Lion Conservation Units (LCUs) plus two other unassigned sites (Cameroon and Zimbabwe). A total of 11 cyt-b haplotypes were found, whose variation follows an isolation-by-distance model. In combination with previously known sequences, the haplotypes document the close relationship, derived position, and limited variability of Asian and West and Central African lions relative to other extant lions. Both phylogenetic analyses and substitution networks identify two clades in Eastern and Southern Africa—one restricted to Namibia and South Africa and the other more widespread across the region. However, these analyses are equivocal on which of these is closest to the ancestor of modern lions. Microsatellite analyses showed high levels of variation within and among populations, subdivision among most LCUs, and evidence of isolation by distance. While rates of gene flow are generally low, admixture among lions in northern Botswana, Caprivi Strip (Namibia) and Zambia is apparent from STRUCTURE analyses. Conservation management plans should incorporate information on genetic variability and gene flow in delimiting management units and in guiding translocations of lions to minimize inbreeding and to control problem animals.  相似文献   

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Background

Leptospirosis is a worldwide zoonotic and recognized neglected infectious disease. It has been observed that only a proportion of individuals exposed to pathogenic species of Leptospira become infected and develop clinically evident disease. Moreover, little information is available in subsequent reinfections. In the present study, we determine if a first infection with leptospirosis protects against subsequent reinfection, and investigate which of the host genetic factors are involved in the susceptibility and resistance to leptospirosis.

Methodology and Findings

We conducted, in 2011, a retrospective hospital-based case-control study in the São Miguel Island population (Azores archipelago). In order to determine the seropositivity against pathogenic Leptospira after the first episode of leptospirosis, we performed a serological evaluation in 97 unrelated participants diagnosed with leptospirosis between 1992 and 2011. The results revealed that 46.4% of the 97 participants have circulating anti-Leptospira antibodies, and from these participants 35.6% maintained the seroprevalence for the same serogroup. Moreover, three of them were reinfected with unrelated Leptospira serovars. The genetic study was carried out by adding a control group composed of 470 unrelated healthy blood donors, also from São Miguel Island. Twenty five SNPs among twelve innate immune genes – IL1α, IL1β, IL6, IL10, IL12RB1, TLR2, TLR4, TLR9, CD14, CISH, LTA and TNF – were genotyped, as well as HLA class I (–A and –B) genes. Association analysis indicates that genotypes -511GG (OR = 1.6, 95%CI 1.01-2.56, p = 0.04) in IL1β, +1196CG (OR = 2.0, 95%CI 1.26-3.27, p = 0.003) in IL12RB1, -292TA (OR = 1.8, 95% CI 1.06–2.1, p = 0.03) and +3415CG (OR = 1.8, 95% CI 1.08–3.08, p = 0.02), both in CISH confer susceptibility to pathogenic Leptospira.

Conclusion

The present study suggests some degree of long-term protection against leptospires with an attenuation of symptoms in case of reinfection. Moreover, our data supports the genetic influence of IL1β, IL12RB1 and CISH genes and the susceptibility to leptospirosis infection.  相似文献   

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J. R. Steffan 《BioControl》1958,3(3):275-280
Summary In this paper,Brachymeria multicolor (Kieff.) and the new speciesB. tibialis, both reared fromAnomis flava f. in Madagascar, are described. The former, still bred from a Pierid, has no economical value, while the latter, which attacks many others Noctuids and Pyralids, seems very effective againstAnomis on cotton.   相似文献   

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Many invasive alien plants drive changes in native community composition, structure and diversity. They alter soil nutrient regimes of native communities and affect native plant recovery outcomes following their removal. We assessed whether Eucalyptus grandis invasion and removal alters the soil physico‐chemical properties and native vegetation recovery in the Eastern Cape Province, South Africa. We collected samples from topsoil in E. grandis invaded sites (canopy cover > 75%), cleared sites (eight years ago) and native sites (canopy cover > 80%) and quantified soil moisture, concentrations of soil macro elements (N, C and P), pH and exchangeable cations (K, Ca, Mg, Na) as well as measured soil water repellency using the Water Droplet Penetration Time and infiltration. We conducted vegetation surveys in plots measuring 10 × 10 m. Invasion by E. grandis had varying effects on soil physico‐chemical properties, causing increase in soil pH and P, while decreasing total N and C. The removal of E. grandis also showed varying effects on soil physico‐chemical properties, but seems to have further triggered the loss of some soil nutrients (especially soil P). Soil water repellency (a measure of soil compaction) has improved in cleared sites to non‐repellent soils compared to repellent soils in invaded site. Eucalyptus grandis reduced species richness of the invaded sites. The presence of native species on cleared sites indicates a positive trajectory towards vegetation recovery. We conclude that E. grandis invasion and removal trigger varying effects on soil properties (both increases and decreases). For soil and vegetation restoration of cleared sites to be effective, active restoration techniques such as soil transfer, nutrient manipulation and native plant seeding should be considered.  相似文献   

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This paper examines how the 19th-century British naturalist Alfred Russel Wallace used biogeographical mapping practices to draw a boundary line between Malay and Papuan groups in the colonial East Indies in the 1850s. Instead of looking for a continuous gradient of variation between Malays and Papuans, Wallace chose to look for a sharp discontinuity between them. While Wallace’s “human biogeography” paralleled his similar project to map plant and animal distributions in the same region, he invoked distinctive “mental and moral” features as more decisive than physical ones. By following Wallace in the field, we can see his field mapping practices in action – how he conquered the problem of local particularity in the case of human variation. His experiences on the periphery of expanding European empires, far from metropolitan centers, shaped Wallace’s observations in the field. Taking his cues from colonial racial categories and his experiences collaborating with local people in the field, Wallace constructed the boundary line between the Malay and Papuan races during several years of work in the field criss-crossing the archipelago as a scientific collector. This effort to map a boundary line in the field was a bold example of using the practices of survey science to raise the status of field work by combining fact gathering with higher-level generalizing, although the response back in the metropole was less than enthusiastic. Upon his return to Britain in the 1860s, Wallace found that appreciation for observational facts he had gathered in the field was not accompanied by agreement with his theoretical interpretations and methods for doing human biogeography.  相似文献   

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STW 5 (Iberogast®) is a fixed combination of nine medicinal plant extracts effective in the treatment of functional dyspepsia and irritable bowel syndrome. The effects of STW 5, a combination of Iberis amara fresh plant extract, and other eight plant extracts as well as single extract components including extracts from Menthae piperitae folium, Matricariae flos and Liquiritiae radix, were assayed in guinea pig ileum with or without stimulation with acetylcholine or histamine, in order to find a possible effect on the contractility of intestinal smooth muscle.STW 5 decreased acetylcholine- and histamine-induced contraction of guinea pig ileum. This was also true for extracts of Menthae piperitae folium, Matricariae flos and L. radix. Extract from I. amara, however, showed no spasmolytic action; in contrary, it increased the basal resting tone and contraction of atonic ileal segments. This was also true when STW 5 was employed.A spasmolytic action of STW 5 could also be observed in duodenum, jejunum and colon.These data are the first to show not only the spasmolytic effects of STW 5 and its component extracts in intestinal muscle but also the tonicising effects of STW 5 through its component Iberis amara extract in relaxed intestinal muscle. Thus, pharmacological evidence suggests a dual-action principle and may explain, at least in part, the clinically observed therapeutic efficacy of STW 5 (Iberogast®) in both hypotonic and spastic dysmotility symptoms of functional dyspepsia and irritable bowel syndrome.  相似文献   

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A new genus, Neoanabrolepis gen. n. with the type species N. valentinae sp. n., parasitoid of the soft scale Asterolecanium sp. on bamboo in Vietnam, is described in the tribe Habrolepidini Hoffer.  相似文献   

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《新西兰生态学杂志》2011,35(3):220-228
Genetic variation in two translocated populations of North Island saddleback (Philesturnus rufusater) on Kapiti Island and at Zealandia was investigated using five microsatellite loci and compared with the source populations in the Hauraki Gulf. Although the absolute number of alleles in the two populations was low (3 alleles per locus), both populations carried all the alleles found in their immediate source populations, but lacked one rare allele found in only one individual from the original remnant population on Hen Island. Overall heterozygosity was high and inbreeding coefficients were low. Population viability analyses showed that these populations will likely reach carrying capacity by the middle of this decade, and genetic simulations predicted that they should retain between 90% (Kapiti) and 95% (Zealandia) of the heterozygosity of their sources. The difference between the two populations is most likely due to the prolonged post-translocation bottleneck on Kapiti when rats were still present on the island. While our results suggest that additional top-up translocations would be unnecessary and unwarranted at this time, further work on potentially selected loci or inbreeding depression could justify this decision to be revisited.  相似文献   

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Direct reaction of copper(I) chloride with triphenylphosphine (tpp) in molar ratio 2:3 and 1:3, results in the formation of the [(tpp)Cu(μ2-Cl)2Cu(tpp)2] (1) and {[CuCl(tpp)3]·(CH3CN)} (2) complexes. The complexes have been characterized by melting point, FT-IR, UV-Vis spectroscopic data and X-ray crystallography. Complex 1 is di-nuclear. Two μ2-Cl atoms bridge two copper(I) ions with tetrahedral and trigonal geometry respectively. The short copper-copper bond distance of 2.9039(6) ? in case of 1 indicates d10-d10 interaction between metal centers. Thus, our studies were extended here in the determination of the quasi-aromaticity, which results in strong Cu-Cu interactions, using the computational method of nucleus-independent chemical shifts (NICS). The NICS calculated at the inner region of the Cu2Cl2P3 core in complex 1 is shielded up to −6.05 ppm. Complex 2 is mono-nuclear where three phosphorus and one chloride atoms form a tetrahedron around the copper(I) ion. Photolysis of both complexes 1 and 2, results in the formation of triphenylphosphine oxide.The complexes 1 and 2, were tested for their in vitro cytotoxic activity against leiomyosarcoma cells (LMS) and human breast adenocarcinoma cells (MCF-7). The type of LMS cell death caused by the complexes was also evaluated by use of a flow cytometry assay. The results show that at concentration of 5 μΜ of complexes 1 and 2, 34.1% (1) and 19.6 (2)% of LMS cells undergo programmed cell death (apoptosis), while at 10 μΜ, 80.4% (1) and 65.2% (2) of LMS cells undergo apoptosis. The light sensitivity of the complex is discussed in relation with the biological activity.  相似文献   

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Cephalosporins are major antimicrobials used to treat serious infections. However, their effectiveness is being compromised by the emergence of extended-spectrum β-lactamases (ESBLs). A total of 138 enteric bacteria were isolated from 53 faecal samples of pigs collected from different districts of Mizoram, of which 102 (73.91 %) were Escherichia coli, 26 (18.84 %) were Salmonella spp. and 10 (7.25 %) were Klebsiella pneumoniae. Phenotypic confirmatory test (Double Discs Synergy Test) showed that 8 (5.80 %) E. coli isolates were ESBLs producer. PCR analysis confirmed that out of the eight isolate, 7 (5.07 %) harboured bla CTX-M-1 gene and/or bla TEM gene. Of the eight positive isolates, 7 (5.07 %) and 3 (2.17 %) were found to be positive for bla CTX-M-1 gene and bla TEM gene, respectively, of which 3 (2.17 %) isolates were positive for both the genes. Only 4 (2.90 %) E. coli isolates carried bla CTX-M-1 gene alone. Agarose gel electrophoresis showed that all the isolates were carrying plasmids ranging between 0.9 and ~30 kb. Out of the seven isolates positive for bla CTX-M-1 and/or bla TEM , 2 (1.84 %) isolates were confirmed for bla CTX-M-1 gene in their plasmid. Only one E. coli isolate was found to be positive for both the genes in its plasmid. The resistance plasmid could not be transferred to a recipient by in vitro horizontal gene transfer method.  相似文献   

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