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981.
We monitored nine butterfly communities with varying degrees of human disturbance by conducting a census twice a month during 1980 by the line transect method in and around Tsukuba City, central Japan. We analyzed the biodiversity and community structures using the generalist/specialist concept. The site (community) order based on decreasing human disturbance was positively correlated with butterfly species diversity (H′), species richness (the total number of species), and the number of specialist species in a community, but not with the number of generalist species. The number of generalist species was rather constant, irrespective of the degree of human disturbance. Thus, both the butterfly species diversity and species richness were more dependent on the specialists than the generalists. Our analyses also showed that the generalist species were distributed widely over the communities, and they maintained high population densities, resulting in high rank status in abundance in a community, with more spatial variation in density per species. Specialist species showed the opposite trends. These results demonstrate that the generalist/specialist concept is a powerful tool applicable to analyse the biodiversity and structure of natural communities. 相似文献
982.
One hundred and thirty carcasses of the red fox were collected in Tochigi Prefecture, by the Tochigi Prefectural Museum, from 1981 to 1991. The young/adult ratio of the sample was 1.60, which suggests that the hunting pressure has been relatively low in this area. Six percent of the animals were 5 years or older which compares to those taken in Hokkaido, but is higher than those in Europe and North America. The sex ratio for all specimens had a tendency towards male bias (0.587), but this bias was higher for the adult (0.605) than for the young (0.576). Among young (0 year-old) foxes, more individuals were killed on roads than by trapping or shooting (P<0.02, chisquare test). This mortality pattern was caused by high mortality of young males (P<0.02). The proportions of adults killed by the three mortality factors were similar, though only one of the 14 foxes older than 4 years old was shot, probably due to age-linked activity patterns. Most road-kills of young foxes occurred in May when juveniles began exploiting and in November when sub-adults began dispersal. The ratios of road-kills for the whole sample and for adults alone were 42% and 34%, respectively. These high rates of road-kills suggest that the mortality pattern in Tochigi has been affected by factors characteristic of urban environments. 相似文献
983.
Daniel W. Armstrong Russell Seguin Masahiko Saburi Janos H. Fendler 《Journal of molecular evolution》1979,13(2):103-113
Summary Alanyl, [14C]-alanyl, phenylalanyl, and methionyl adenylates have been synthesized in high yields and relatively good purities. Elemental analysis1H nmr and ir spectra have been utilized for the characterization of these extremely labile compounds. The present synthesis, which uses readily available N-tert-butoxycarbonyl amino acids, is compared with previous methods. 相似文献
984.
An ecological study was carried out on the fungal flora in the human lung of 159 autopsy cases. Fungi were isolated from 129 cases (81.1%). Filamentous fungi consisting of 918 strains were isolated from 113 cases, and the dominant genera were Aspergillus and Penicillium. Yeasts were isolated from 58 cases, and the dominant genus appeared to be Candida.With morbid anatomical study, the incidence of the fungus isolation was examined from various points of view. It was concluded that even a healthy respiratory parenchyma of the human lung cannot be assumed as aseptic. However, only a few numbers of a few genera of air-born fungi were isolated.Special stress was laid on the exposure of the respiratory parenchyma of the human lung to air-born fungi in connection with the pathogenesis of opportunistic fungus infections. 相似文献
985.
Bacteria, yeasts, and molds which grew in a medium containing a synthetic lignin — a dehydrogenation polymer (DHP) of coniferyl alcohol — as a sole carbon source, were isolated from soil. One fungus, Fusarium solani M-13-1, was found to degrade the DHP most vigorously among the isolated organisms. It was shake-cultured in a medium containing dehydrodiconiferyl alcohol (DHCA) (I), an important lignin model compound, and the following six metabolic products were isolated and identified: 1) Phenylcoumaran--aldehydic (II) and -carboxylic compounds, 2) phenylcoumaran--aldehydic compound (IV), formed by release of a 2-carbon fragment from the phenylcoumaran--carboxylic compound, 3) 5-acetylvanillyl alcohol (V), formed by cleavage of the coumaran ring and reduction of the -aldehyde group, 4) 5-carboxyvanillyl alcohol (VI), formed by subsequent oxidation of the acetyl group, and 5) the -ether of DHCA (VII), considered to be a by-product. A degradation pathway for DHCA was proposed on the basis of these metabolic products.Non-Standard Abbreviations DHP
dehydrogenation polymer
- DHCA
dehydrodiconiferyl alcohol
- DDQ
dichlorodicyano-p-benzoquinone
- DDHQ
dichlorodicyano-p-hydroquinone
- Ar
aromatic
- TLC
thin layer chromatography
- GC-MS
gas chromatography-mass spectrometry 相似文献
986.
Deoxyuridine residues in DNA of thymine-requiring Bacillus subtilis strains with defective N-glycosidase activity for uracil-containing DNA. 总被引:3,自引:3,他引:0 下载免费PDF全文
DNA extracted from exponentially growing cells of thymine-requiring Bacillus subtilis strains with defective N-glycosidase activity for deoxyuridine residues in DNA was subjected to the action of N-glycosidase in vitro and analyzed by sedimentation in alkaline sucrose gradients. The sites attacked by N-glycosidase occurred once per 6 X 10(6) to 7 X 10(6) daltons of DNA from cells cultured in the presence of growth-supporting concentrations of thymine. The number of N-glycosidase-susceptible sites increased when the thymine concentration in the medium was lowered. Parallel to this observation, the N-glycosidase-defective mutant cells were less apt to show the detrimental effect due to thymine depletion than were the parental cells. Such sites were not detected in DNA from cells with a normal N-glycosidase activity or with a "wild type" capacity for thymidylate synthesis. The results are interpreted to mean that cells defective for thymidylate synthesis incorporate dUTP in place of TTP in DNA and that the deoxyuridine residues, once incorporated, remain in the DNA in the absence of N-glycosidase activity. 相似文献
987.
Hybrid-heme hemoglobins, alpha(meso)2beta(proto)2 and alpha(proto)2beta(meso)2, were prepared, and the O2 equilibria of their alpha and beta chains were measured separately at the isosbestic points of the partner chains at different pH values and in the presence and absence of inositol hexaphosphate. The Adair equation was extended to distinguish between the O2 saturations of the alpha and beta chains, and the seven equilibrium parameters were obtained by curve fitting to those equations. The results showed that the beta chains have an affinity slightly higher than the alpha chains in the binding of the first O2 molecule. For the second O2 molecule, the molecular species that has been oxygenated on the alpha chain has a higher affinity than that carrying O2 on the beta chain. The slopes of the Hill plots were higher for the alpha chain. The O2 saturation curves for the alpha and beta chains were calculated from the parameters averaged for the hybrids alpha(meso)2beta(proto)2 and alpha(proto)2beta(meso)2 in order to cancel the effects of the heme replacement. The curves showed that the difference in O2 saturation between the two kinds of chains depends on the conditions and on the degree of O2 saturation. It was concluded that the functional difference between the chains is small enough so that it is not required to modify the models already accepted for the cooperativity of hemoglobin. 相似文献
988.
Yushin Fujimura Sumikazu Ishii Masahiko Kawamura Hiroshi Naruse 《Analytical biochemistry》1981,117(1):187-195
Newborn screening for galactosemia (galactose-1-phosphate uridyltransferase deficiency), as well as for other defects in galactose metabolism (galactokinase deficiency and uridine diphosphogalactose 4-epimerase deficiency), requires a method of determining both galactose and galactose 1-phosphate in dried blood. We have developed a sequential quantitative method for the microdetermination of galactose and galactose 1-phosphate that can be applied to 3-mm-diameter disks of dried blood and that can be used with a Technion Autoanalyser II equipped with a fluorometer.Galactose is determined by the fluorescence of NADH following treatment with β-galactose dehydrogenase and with the consequent reduction of NAD. The complete system includes alkaline phosphatase for the hydrolysis of galactose 1-phosphate, so that the total amounts of a galactose and galactose 1-phosphate are determined. For the measurement of galactose alone, alkaline phosphate is omitted from the system. The difference in fluorescence between that from the complete system and that from the alkaline phosphatase-omitted system yields the concentration of galactose 1-phosphate. 相似文献
989.
To investigate the postreceptor mechanism, especially the role of protein kinase C (C-kinase), in luteinizing hormone (LH) release from anterior pituitary cells, dispersed rat anterior pituitary cells were stimulated with luteinizing hormone-releasing hormone (LH-RH), [D-Ser(tBu)]6 des-Gly-NH2(10) ethylamide (Buserelin), 12-0-tetradecanoyl phorbol-13-acetate (TPA) and trifluoperazine (TFP) and the LH released into the medium was determined by radioimmunoassay. LH released by combined stimulation with TPA and either LH-RH or Buserelin was significantly less than that released by LH-RH or Buserelin alone (LH-RH: p less than 0.05; Buserelin: p less than 0.01). It is thought that this paradoxical phenomenon occurred due to desensitization accompanied by down-regulation of LH-RH receptors induced by TPA. This hypothesis was supported by the finding indicating that the binding capacity of LH-RH receptors decreased in a time-course manner during incubation with TPA. The amount of LH released by combined stimulation with TPA and TFP was significantly greater than with TPA alone (P less than 0.01). This suggests that TFP has dual actions, i.e., facilitating and inhibiting LH release. 相似文献
990.
Comparison of DNA sequences required for the function of citrate utilization among different citrate utilization plasmids 总被引:5,自引:4,他引:1 下载免费PDF全文
The relatedness of DNA sequences encoding citrate utilization was examined by hybridization with a cloned DNA fragment from a citrate utilization (Cit) plasmid, pOH30221, and DNA of other Cit plasmids. This revealed that there are at least two groups of Cit plasmids: the Inc W Cit plasmids, which show homology with the probe, and the Inc H1 plasmids, which do not. 相似文献