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51.
Miya Hamai Toshisada Nishida Hiroyuki Takasaki Linda A. Turner 《Primates; journal of primatology》1992,33(2):151-162
Two cases of within-group infanticide and cannibalism were observed among the M Group chimpanzees of the Mahale Mountains,
Tanzania. In both cases, victimized infants were male, 5 – 6 months of age, and in good health when killed. Four to five years
have passed since the mothers of the victims immigrated into M Group as nulliparous immigrants. In one case the 2nd-ranking
male was observed to detach the infant from the mother's belly. Both infants were finally killed by the alpha male after several
adult males scrambled for the bodies. There was no evidence that the mothers had mated with males other than those of M Group.
Nor was there evidence that the mothers had restrictive mating relationships with some of the M Group adult males. What little
evidence is available shows that the mothers had mated mostly with adolescent and other immature males during their conception
cycles. However, at least in one case, the mother began to mate more with adult males rather than with immature males after
the infanticide. It is proposed that the function of within-group male infanticide can be explained by the male-male competition
hypothesis developed for hanuman langurs and other nonhuman primates. 相似文献
52.
An annual average of 163 Kuril seals was found dead in two years in salmon trap nets along the coastal waters of the Nemuro Peninsula and adjacent areas. The seal-caused damage to the total salmon catch at the salmon trap nets was concentrated in some of them, particularly No. 27, where seals killed or injured 5.1% of the catch in 1982, and 1.8% in 1983. Based on the proportion of Kuril seals among the dead seals in the trap nets, it was estimated that Kuril seals damaged 4.7% of the total salmon catch at No. 27 in 1982, and 1.7% in 1983. Not all seals that entered the trap net drowned; some killed or damaged salmon, and then escaped. 相似文献
53.
5′-Nucleotidase (EC 3.1.3.5) was solubilized from rod membranes with Ammonyx LO and purified by chromatographic methods. A highly sensitive radioassay was developed. The purified enzyme behaved as a homogeneous protein of 75,000 daltons in sodium dodecyl sulfate-polyacrylamide gel electrophoresis and as a protein of 79,000 in gel filtration. Thus, the enzyme does not contain subunits. The Km values obtained were 1.3 μm for 5′-AMP and 2.3 μm for 5′-GMP. The enzyme was inhibited by concanavalin A, wheat germ agglutinin, and Ricinus communis agglutinin. Rabbit muscle G-actin formed a complex with the enzyme and inhibited its activity. The catalytic site of the enzyme was localized on the internal surface of the disk which, in terms of membrane sidedness, corresponds to the cell surface. A soluble 5′-nucleotidase was extracted from rod membranes with Tris buffer (pH 8.0) containing EGTA in the dark; less enzyme was extracted if the membranes had been exposed to light or incubated with Ca2+. The extracted enzyme was partially purified. The enzyme was unstable and lost 50% of its activity in 3 days at 3 °C. The Km values were 1.3 μm for 5′-AMP and 2.3 μm for 5′-GMP. The enzyme was inhibited by G-actin. A role for the soluble enzyme in the regulation of 5′-GMP in the rod outer segment was suggested. 相似文献
54.
Shigeo Yamamoto Miki Yokogawa Kyomi Wakamatsu Hiroyuki Kataoka Masami Makita 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1982,233(1):29-38
A gas chromatographic method was developed for the determination of monoacetylputrescine, monoacetylcadaverine, N1-acetylspermidine and N5-acetylspermidine in human urine. The amines were isolated from urine by silica gel column chromatography. 1, 10-Diaminodecane was used as internal standard. The amines were reacted with ethyl chloroformate in aqueous medium to four ethyloxycarbonyl derivatives prior to application to gas chromatography using a flame ionization detector. Separation and determination of the derivatives were carried out on a Uniport HP column (1.0 m) impregnated with 0.5% SP-1000 under temperature-programmed conditions. The monoacetylpolyamines could be measured accurately at the nanomole level. The method was used for the determination of the monoacetylpolyamines in urine of healthy volunteers. The values obtained were in the range of the published data. 相似文献
55.
Multiple Molecular Forms of Acetylcholine Receptors in Cultured Skeletal Muscle Cells: Subcellular Localization and Characterization 总被引:1,自引:0,他引:1
Abstract: Skeletal muscle cells of newborn rats, cultured in the absence of neuronal influence, were found to contain two types of cell surface acetylcholine receptors as demonstrated by isoelectric focusing. The isoelectric points of the two types of receptors were indistinguishable from those of junctional and extrajunctional types of receptors in mature animals. The cultured cells had two classes of intracellular α-bungarotoxin (αBT) binding components; one had the same sedimentation coefficient as that of surface receptors (9S), and the other had much smaller apparent molecular weights. Only a single major component was detected by isoelectric focusing analysis of the 9s intracellular aBT binding component, with a PI value close to that of the extra junctional receptor. These results suggest that the junctional and extrajunctional types of receptors may be synthesized through a common precursor. 相似文献
56.
Mitsumasa Haruna Makiko Kato Kazuo Ito Toshiaki Nikai Hisayoshi Sugihara Hiroyuki Muratat 《Phytochemistry》1981,20(11):2583-2584
Angeloylcumambrin-B, a new antimicrobial guaianolide sesquiterpene lactone, was isolated from Chrysanthemum ornatum and the structure was determined by a combination of chemical and physical methods. 相似文献
57.
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59.
From leaves and twigs of Ixora chinensis, two new iridoid glucosides, ixoroside (1) and ixoside (7,8-dehydroforsythide) (2) along with known geniposidic acid (3) have been isolated and their structures have been established. 相似文献
60.