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21.
Ursula Bartecki 《Primates; journal of primatology》1986,27(2):173-184
A study was carried out on the social position of 12 subadult males of a semifreeranging Barbary macaque population during
the non-mating season. The social position was measured in terms of spatial as well as interactive parameters. The subadult
males had social contacts to members of nearly all other age-sex classes but showed clear preferences for same-sexed partners.
Besides this differences were found between 5- and 6-year-old males with respect to their interaction profiles and the preference
for special classes of interaction partners. The terms “peripheral-central” is discussed with reference to the social structures
of macaque societies. The data of the present study indicate that the social position of subadult male Barbary macaques can
not be described by one of these terms exclusively. The results are compared to other studies on Barbary macaques and other
macaque species. It is concluded that in macaque societies subadult males are not obligatorily forced to live at the periphery
or to abide. It is proposed not to postulate stiff social structures but to put more emphasis on the range of variation among
macaque species. 相似文献
22.
Summary In the terminal ganglion of the cricket, Acheta domesticus, the somata of certain interneurones and efferent neurones consistently react to 5-HT immunohistochemistry. There are serially homologous pairs of bilateral interneurones seen in the neuromeres of the 7th to the 10th segment and hindgut neurones with their somata located at the posterior median end of the ganglion. In adult crickets, pairs of large efferent neurones with lateral somata supply specific genital muscles in the 8th and the 9th segment of females. In males, only one pair of these efferent neurones supplies genital muscles of the 9th segment only. These identified 5-HT-immunoreactive neurones are not detected in larval crickets before development of the genital apparatus. 相似文献
23.
Stanley W. Watson Eberhard Bock Frederica W. Valois John B. Waterbury Ursula Schlosser 《Archives of microbiology》1986,144(1):1-7
A new chemolithotrophic nitrite-oxidizing bacterium, for which the name Nitrospira marina is proposed, was isolated from the Gulf of Maine. N. marina is a Gramnegative curved rod which may form spirals with 1 to 12 turns. Cells have a unique periplasmic space and lack intracytoplasmic membranes and carboxysomes. N. marina is an obligate chemolithotroph, but best growth is obtained in a mixotrophic medium. N. marina may be one of the most prevalent nitrite-oxidizing bacteria in some oceanic environments. Type strain is field with American Type Culture Collection (ATCC 43039). 相似文献
24.
In intact, uncoupled type B chloroplasts from spinach, added ATP causes a slow light-induced decline () of chlorophyll a fluorescence at room temperature. Fluorescence spectra were recorded after fast cooling to 77 K and normalized with fluorescein as an internal standard. Related to the fluorescence quenching at room temperature, an increase in Photosystem (PS) I fluorescence (F735) and a decrease in PS II fluorescence (F695) were observed in the low-temperature spectra. The change in the ratio was abolished by the presence of methyl viologen. Fluorescence induction at 77 K of chloroplasts frozen in the quenched state showed lowered variable (Fv) and initial (F0) fluorescence at 690 nm and an increase in F0 at 735 nm. The results are interpreted as indicating an ATP-dependent change of the initial distribution of excitation energy in favor of PS I, which is controlled by the redox state of the electron-transport chain and, according to current theories, is caused by phosphorylation of the light-harvesting complex. 相似文献
25.
STRUCTURAL DIFFERENTIATION OF STACKED AND UNSTACKED CHLOROPLAST MEMBRANES : Freeze-Etch Electron Microscopy of Wild-Type and Mutant Strains of Chlamydomonas 总被引:15,自引:10,他引:5 下载免费PDF全文
Wild-type chloroplast membranes from Chlamydomonas reinhardi exhibit four faces in freeze-etchreplicas: the complementary Bs and Cs faces are found where the membranes are stacked together; the complementary Bu and Cu faces are found in unstacked membranes. The Bs face carries a dense population of regularly spaced particles containing the large, 160 ± 10 A particles that appear to be unique to chloroplast membranes. Under certain growth conditions, membrane stacking does not occur in the ac-5 strain. When isolated, these membranes remain unstacked, exhibit only Bu and Cu faces, and retain the ability to carry out normal photosynthesis. Membrane stacking is also absent in the ac-31 strain, and, when isolated in a low-salt medium, these membranes remain unstacked and exhibit only Bu and Cu faces. When isolated in a high-salt medium, however, they stack normally, and Bs and Cs faces are produced by this in vitro stacking process. We conclude that certain particle distributions in the chloroplast membrane are created as a consequence of the stacking process, and that the ability of membranes to stack can be modified both by gene mutation and by the ionic environment in which the membranes are found. 相似文献
26.
Chick embryo chorioallantoic membrane, infected with the Blacksburg strain of Newcastle disease virus, was examined with an electron microscope to investigate the sequence of viral-induced host cell alterations. These were evident mostly in the endodermal epithelial cells lining the allantoic sac and were divided arbitrarily into three stages. Stage 1 was characterized by commencement of cell hypertrophy and hyperplasia and presence of fewer cytoplasmic inclusion bodies normally found in the cells; in stage 2, juxtanuclear nucleocapsid-glycogen aggregates appeared, and there were increased numbers of microvilli; stage 3 was characterized by increased cytoplasmic density and evidence of viral assembly and release. The morphological features of viral assembly and the virion are also described. 相似文献
27.
Zusammenfassung Das Fungicid Captan erwies sich bei 37 Stämmen von Chlorella als ein wirksamer Wachstumshemmstoff. Nur 3 Chlorella-Stämme besitzen eine gewisse Captanresistenz. Das Merkmal Captanresistenz scheint in der Gattung Chlorella nicht artspezifisch verteilt zu sein.Bei Scenedesmus acutus f. alternans Hortob. und Scenedesmus armatus (Chod.) Smith wird Captan noch in einer Dosis von 50 mg/l vertragen, ohne daß Anzeichen einer Hemmwirkung zu erkennen sind.
Differential action of captan on the growth of some strains of Chlorella and Scenedesmus
Summary The fungicide captan was found to inhibit strongly the photoautotrophic growth of 37 Chlorella strains. Only 3 strains are fairly resistant to captan. In the genus Chlorella resistance to captan does not seem to be species specific.Two strains of Scenedesmus (Scenedesmus acutus f. alternans Hortob. and Scenedesmus armatus (Chod.) Smith) tolerate captan up to 50 mg/l without being inhibited at all.相似文献
28.
Zusammenfassung 19 Patienten, die nach einer Nierentransplantation mit Imuran behandelt wurden, wiesen eine erhöhte Anzahl Chromosomenabnormitäten im Vergleich zu 30 gesunden Kontrollpersonen der gleichen Altersklasse auf. Keine signifikant erhöhte Anzahl an Chromosomenabnormitäten fand sich jedoch bei 7 Patienten, die vor und unter der Imuran-behandlung untersucht wurden. Es wird vermutet, daß die Chromosomenabnormitäten bei den 19 mit Imuran behandelten Patienten wahrscheinlich nicht durch Imuran, sondern durch die Urämie entstanden sind.
Summary 19 patients treated with Imuran after a renal transplantation showed a high frequency of chromosome abnormalities, compared with 30 healthy control persons in the same age range. No significantly higher frequency of chromosome abnormalities was, however, found in 7 patients examined before and during treatment with Imuran. It is suggested that the chromosome abnormalities found in the 19 patients treated with Imuran were probably not due to Imuran but to Uremia.相似文献
29.
Ursula Seelemann 《Oecologia》1968,1(4):356-368
Zusammenfassung Je höher marine Gastropoden ins Supralitoral vordringen, umso größer wird ihre Salinitätstoleranz. Das äußert sich im Überleben auf extremen Salinitäten, in der Waschstumsgeschwindigkeit und in der Fortpflanzungsrate.Die toleranz wird bei den drei großen Gastropodengruppen—Opisthobranchier (Limapontia depressa)—Prosobranchier (Assiminea grayana)—Pulmonaten (Ovatella myosotis)—im niedrigsalzigen Bereich durch Entwicklung einer Hypertonieregulation und bei hoher Salinität durch Poikilosmotie ermöglicht. Während adulte Schnecken des Supralitorals große Schwankungen im Salzgehalt ertragen, sind die Eier dagegen sehr empfindlich; Embryonen entwickeln sich bevorzugt bei Salinitäten, bei denen die Gelege von den Adulten produziet wurden.
The emigration of Gastropods from the seaII. Studies on Limatpontia capitata, L. depressa und Assiminea grayana
Summary The higher marine Gastropods live on the shore the more their salinity tolerance increases. This is expressed in the animals' survival, their growth rate, and their reproduction rate on extreme salinity concentrations. In all the three gastropod groups—Opisthobranchia (Limapontia depressa), Prosobranchia (Assiminea grayana), Pulmonata (Ovatella myosotis)—a more or less effective hyperosmotic regulation has evolved which enables the animals to live with low salinity concentrations in their surrounding. In high salinities they are poikilosmotic. Adult supralittoral Gastopods can stand considerable salinity changes. The eggs are more delicate: The embryos develop best when the eggs stay on the salinity where they were produced even if the concentrations are extremely high or low.相似文献
30.