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991.
Zusammenfassung Junge Rosenköpfchen,Agapornis roseicollis, verlassen durchschnittlich mit 42 Lebenstagen zum erstenmal die Nisthöhlen und werden danach noch etwa zwei Wochen vorwiegend vom Vater gefüttert. Fütterungen treten gelegentlich auch zwischen Geschwistern auf. Die Jungvögel haben mit den Eltern und Geschwistern bis Anfang des vierten Lebensmonats Kraulkontakte. Noch im Jugendkleid, zumeist im Alter von 65 bis 90 Tagen, verpaaren sich Rosenköpfchen mit einem anderen Jungvogel, bevorzugt aus einer anderen Familie und anderen Geschlechts. Diese Jugendpaare bleiben stabil bis über die Geschlechtsreife hinaus. Bestimmte soziale Verhaltensweisen (Sexualverhalten, Kraulen, Kontaktsitzen) werden nur mit dem Partner ausgeführt.
Socialization of the Peach-faced Lovebird,Agapornis roseicollis
Summary Young Peach-faced Lovebirds, leave their nest-box on an average with 42 days of age. They are still fed for about another two weeks, mainly by the father. Feeding interactions sometimes also occur between siblings. The young undergo allopreening interactions with parents and siblings until the beginning of the fourth month of life. While still in juvenile plumage, usually between 65 und 90 days of life, they form a pair-bond with another young bird, preferably from another family and the other sex. These pairs remain stable beyond sexual maturation. Several social behaviour patterns (sexual behaviour, allopreening, contact sitting) are restricted to the mate.相似文献
992.
Gisela Segond von Banchet Peter K Petrow Rolf Bräuer Hans-Georg Schaible 《Arthritis research & therapy》2000,2(5):424-15
This study describes the upregulation of neurokinin 1 and bradykinin 2 receptors in dorsal root ganglion (DRG) neurons in
the course of antigen-induced arthritis (AIA) in the rat knee. In the acute phase of AIA, which was characterized by pronounced
hyperalgesia, there was a substantial bilateral increase in the proportion of lumbar DRG neurons that express neurokinin 1
receptors (activated by substance P) and bradykinin 2 receptors. In the chronic phase the upregulation of bradykinin 2 receptors
persisted on the side of inflammation. The increase in the receptor expression is relevant for the generation of acute and
chronic inflammatory pain. 相似文献
993.
Investigations for the race analysis of P. hordei (location Cologne, W.-Germany) showed, that most of the resistant genotypes in the International differential set with Pa1 to Pa8 were ineffective for that purpose. Out of 80 selected barley genotypes with different degree of resistance against the field-collection RG 1975 hosts with a strongly differentiating effect were chosen. This was done using three parameters: mean resistance x?w, its standard deviation x?w and the range z. They were calculated from evaluating the reaction types of 80 barley genotypes infected with 116 single-pustule lines of barley brown rust. Eight hosts with strongly differentiating reactions towards the 116 rust lines were composed into a differential set, which could characterize the heterogeneity of the Cologne P. hordei-population essentially better and more precisely than the International differential set. 相似文献
994.
The effects of different social living conditions on estrogen excretion and on the ovarian cycle of saddle back tamarins were investigated. Urinary estrogens were monitored as indices of ovarian cyclicity in groups of adult females living under the following experimental conditions: (1) five parous females, each living with an adult castrated male (in one of the females plasma estradiol and progesterone were also measured); (2) five adult daughters living with their families. Each daughter was then removed from her family and paired with a vasectomized male. After pairing, scent marks collected from the family were introduced daily to one of the daughters and her mate. Scent exposure was then discontinued and hormone excretion measured for several weeks. The remaining four daughters were not exposed to family scent. The females living with castrated males showed urinary estrogen cycles of an average length of 17.5 ± 1.0 days. The plasma estrogen cycle was of the same length. The females studied under condition 2 showed low, noncycling estrogen levels while living in their families. They responded to pairing with an increase in the level of urinary estrogens, and four out of five showed regular estrogen cyclicity. The fifth female exposed to family scent marks after pairing also showed an increase in urinary estrogens. However, as long as scent transfer was maintained, no cycle was observed. Estrogen excretion increased again, and cyclicity commenced when scent transfer was discontinued. It is concluded that ovarian estrogen production is suppressed and cyclicity does not occur as long as daughters live in their families. Release from suppression and perhaps stimulation by the male cause a rapid increase in estrogen levels and the onset of cyclicity. Chemical stimuli produced by the family, perhaps particularly by the mother, may be involved in reproductive suppression. 相似文献
995.
Zusammenfassung Es wird über vergleichende Untersuchungen beim Nachweis der ATPase im niederen pH-Bereich unter Verwendung der Ca- und Pb-Methode berichtet. Hierbei zeigt es sich, daß es sich um ATPasen mit unterschiedlichen Eigenschaften handelt. Während die ATPase pH 7,2 keine Abhängigkeit von SH-Gruppen aufweist und Mg.. benötigt, wird die Aktivität der ATPase pH 7,5 (Ca-Methode) durch SH-Gruppen-Blocker gehemmt, es tritt eine Aktivitätsminderung nach Zugabe von Mg.. ins Inkubationsmedium ein. Auch der Einfluß der Fixierung ist bei beiden ATPasen unterschiedlich. Unabhängig hiervon ist hervorzuheben, daß sich auch Unterschiede im Verhalten der ATPase in Abhängigkeit vom untersuchten Organ ergeben. Unsere Ergebnisse unterstützen die Notwendigkeit eines spezifischen, von der Fragestellung bestimmten, Nachweises der ATPase.
Summary The results of comparative studies on the determination of ATP-ase in the low pH range (using the Ca- and the Pb-method) are reported. The findings show that there are ATP-ases of different properties. Whereas ATP-ase pH 7.2 depends not on SH-groups but on the presence of Mg.., the activity of ATP-ase pH 7.5 (Ca-method) is inhibited not only by SH-group blockers but also by the addition of Mg.. to the incubation medium. There is also evidence that fixation has varying effects on ATP-ases. However, it must be emphasized that there are differences in the ATP-ase activity within the various organs investigated. Our results show that the choice of the method for a specific demonstration of ATP-ase depends to a very high degree on the problem under investigation.相似文献
996.
997.
Paula Huber Sebastian Metz Fernando Unrein Gisela Mayora Hugo Sarmento Melina Devercelli 《The ISME journal》2020,14(12):2951
How diversity is structured has been a central goal of microbial ecology. In freshwater ecosystems, selection has been found to be the main driver shaping bacterial communities. However, its relative importance compared with other processes (dispersal, drift, diversification) may depend on spatial heterogeneity and the dispersal rates within a metacommunity. Still, a decrease in the role of selection is expected with increasing dispersal homogenization. Here, we investigate the main ecological processes modulating bacterial assembly in contrasting scenarios of environmental heterogeneity. We carried out a spatiotemporal survey in the floodplain system of the Paraná River. The bacterioplankton metacommunity was studied using both statistical inferences based on phylogenetic and taxa turnover as well as co-occurrence networks. We found that selection was the main process determining community assembly even at both extremes of environmental heterogeneity and homogeneity, challenging the general view that the strength of selection is weakened due to dispersal homogenization. The ecological processes acting on the community also determined the connectedness of bacterial networks associations. Heterogeneous selection promoted more interconnected networks increasing β-diversity. Finally, spatiotemporal heterogeneity was an important factor determining the number and identity of the most highly connected taxa in the system. Integrating all these empirical evidences, we propose a new conceptual model that elucidates how the environmental heterogeneity determines the action of the ecological processes shaping the bacterial metacommunity.Subject terms: Community ecology, Microbial ecology 相似文献
998.
Naturally preserved human soft tissue remains from mediaeval burials (ll-13th century A. D.) were investigated histologically after azocarmine/aniline alcohol (AZAN) or keratin-prekeratin-mucin (KPM) staining. The tissue remnants were in an advanced state of decomposition; they were completely collapsed and had lost their macroscopic characteristics. After rehydration, thin sectioning, and staining, microscopic properties permitted tissue identification, although differential staining of tissue components did not necessarily correspond with the expected results based on fresh tissue. The techniques and results presented in this paper are relevant for both anthropological and forensic purposes. 相似文献
999.
1000.