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121.
New evidence for the systematic significance of acylated spermidines and flavonoids in pollen of Higher Hamamelidae 总被引:1,自引:0,他引:1
Barbara Meurer-Grimes 《Brittonia》1995,47(2):130-142
New distributional recores of hydroxycinnamoyl spermidines (HCS), including novel trisubstituted HCSs and flavonol glycosides,
in pollen of Higher Hamamelidae are presented. The 51 taxa analyzed by HPLC and TLC included members of the families Fagaceae
(Castanoideae, Fagoideae, Quercoideae), Betulaceae, Juglandaceae, Myricaceae, Hamamelidaceae, Rosaceae, and Buxaceae (Simmondsia). The results support generic concepts in the Higher Hamamelidae derived from morphological and chloroplast DNA data and
support a close evolutionary relationship between the Higher Hamamelidae and the Rosidae. 相似文献
122.
Barbara Thöni 《Journal of Ornithology》1997,138(3):315-324
Zusammenfassung Im Frühjahr 1995 (Febr.–Mai) wurden auf der Schwäbischen Alb 7 Kolkrabenpaare beobachtet. Ziel der Untersuchung war es den Aufwand der Altvögel für die Jungenaufzucht zu erfassen. Der Aufwand wurde über die Aktivität der Altvögel am Nest abgeschätzt und bezüglich der Jungenzahl und des Wetters ausgewertet. Paare, die mehrere Junge hatten, sparten beim Hudern Kosten ein, da sie ihre Jungen bis zu einem geringeren Alter hudern mußten und weniger stark von der Temperatur abhängig waren. Bei den Fütterungen verringerte sich die Fütterfrequenz pro Jungvogel mit zunehmender Jungenzahl, die absolute Anzahl an Fütterungen nahm jedoch zu. Der Aufwand für die Nesthygiene war unabhängig von der Jungenzahl. Selbst bei mehreren Jungen blieb Zeit für Komfortverhalten. Jungenaufzucht war also effektiver, wenn mehrere Jungen gleichzeitig aufgezogen wurden.
Parental expenditure for rearing nestlings by ravensCorvus corax
In spring 1995 (Feb.–May) I observed seven pairs of Raven in southern Germany on the Schwäbischen Alb. The aim was to record parental expenditure for rearing nestlings. Expenditure was assessed by recording the activities of the adults at their nest (mainly brooding and feeding the offspring) and was analysed with respect to the number of nestlings per brood and with respect to the weather. Pairs with more than one nestling saved effort by stopping brooding their offspring at a lower nestling age. Also brooding was less dependent on the ambient temperature for pairs with more than one nestling than for pairs with only one nestling. The feeding frequency per nestling has been lower, if there were more nestlings to feed. The total frequency of feeding increased with increasing number of nestlings per brood. The effort for the hygiene of the nest was independent upon the number of offspring per nest. Nevertheless, pairs with more than one nestling spent time for comfort behaviour. Thus, it was more effective to reare more than one nestling at a time.相似文献
123.
Barbara Płytycz 《Immunogenetics》1984,19(1):3-11
The major histocompatibility complex (MHC) zygosity of the field-collected frogs, Rana temporaria, was detected by progeny testing. Groups of sibling tadpoles were grafted with intrafamilial tail-tip allografts and the ratio of rapidly rejected allografts to slowly rejected ones was estimated. Twenty-five percent of parental frogs appeared to be MHC homozygotes. Thus, MHC homozygosity in natural frog populations seems to be considerably higher than in wild mouse populations. 相似文献
124.
G. Mauff K. Bender Carolyn M. Giles S. Goldmann W. Opferkuch Barbara Wachauf 《Human genetics》1984,65(4):362-372
Summary Ten families with 82 members were investigated for C4A- and B polymorphism in a blind trial. Phenotyping was done on neuraminidase treated sera by immunofixation and simulataneously by hemolytic overlay electrophoresis. In addition Rg, Ch, BF, C2, HLA-A, B, C, DR, and GLO were determined. After decoding the samples the reliability of blind typing was found to be 84.4% according to segregation patters. Inconsistencies occurred mostly when A 4, A 2, or A 92 were present. The detection of silent A*Q0 and B*Q0 alleles was more critical than that of difficult allotypes. The quantitation of the C4A/B ratio by densitometry of stained gels or by conventional immunochemical measurements of serum C4 level could not substantially improve the identification of A*Q0 or B*Q0. C4 dependent activity in radial diffusion hemolysis showed satisfactory correspondence with the number of expressed C4B alleles. At least three haplotypes with two C4A genes (duplicated A genes) were observed as ascertained from offspring analysis in accordance with the MHC segregation pattern. Individuals with the duplicated C4A gene (C4A*3. A*2. in the absence of any other expressed A allele or together with C4A*92) showed only partial inhibition of Rodgers antisera. Partial inhibition of Chido antisera was seen in individuals with C4B 2 (in the absence of other B allotypes). The findings support the hypothesis of at least two structural C4 loci. The also demonstrate the inconsistency of quantitative data in the recognition of silent alleles. 相似文献
125.
James C. Willey Clementh E. Moser Jr. Curtis C. Harris 《Cell biology and toxicology》1984,1(1):145-154
The effects of aplysiatoxin and debromoaplysiatoxin on the clonal growth rate, cross-linked envelope formation and plasminogen activator secretion of normal human bronchial epithelial cells were studied. Neither compound was mitogenic over a wide range of concentrations (10–13 to 10–7M). Both aplysiatoxin and debromoaplysiatoxin inhibited clonal growth rate with 50% inhibitory concentrations of 3 × 10–11M and 10–10M, respectively. Both compounds induced the formation of cross-linked envelopes and increased plasminogen activator secretion with equal potency. These data are similar to those previously obtained with 12-0-tetradecanoylphorbol-13-acetate and teleocidin B and suggest that aplysiatoxin and debromoaplysiatoxin induce terminal squamous differentiation in normal human bronchial epithelial cells.Abbreviations TPA
12-0-tetradecanoylphorbol-13-acetate
- NHBE
Normal Human bronchial epithelial
- ID50
50% inhibitory concentration (dose)
- PA
Plasminogen activator
- CLE
Cross-linked envelope
- LHC
Laboratory of Human Carcinogenesis 相似文献
126.
When LETS protein positive and negative cells were co-cultured, the positive cells remained as positive and the negative cells remained as negative. Apparently the transformed cells do not secrete factors which are sufficient to influence the distribution of surface LETS protein on normal cells. 相似文献
127.
Summary Histochemical techniques applied at the ultrastructural level have established the periplasmic space as the site of cell bound alkaline phosphatase activity inAnabaena cylindrica andCoccochloris peniocytis. For localization of activity unfixed cells were reacted with calcium nitrate, which acts as the initial capture reagent. After this deposition, the cells were suspended in 2% lead nitrate to convert the calcium phosphate to more electron dense lead phosphate. The majority of cell bound activity appeared to be associated with layer 3 of the cell wall. InA. cylindrica a secondary site of cell bound activity appeared to be in the sheath. Placement in a phosphate free medium caused a substantial increase in the enzyme activity ofA. cylindrica while the activity present in log phase cells ofC. peniocytis was similar to that found in phosphate starved cells.C. peniocytis also secretes the enzyme into the surrounding medium. 相似文献
128.
129.
Head movements of different species of walking beetles elicited by rotating stripe patterns have been investigated. They are of the usual type in contrast to an inverted nystagmus reported forTenebrio molitor in similar experimental situations. Reexamination of theTenebrio records revealed that the sign of the stimulus was interchanged by a mistake while plotting the results. Thus, the head nystagmus inTenebrio is also of the usual type, consisting of a smooth pursuit head movement followed by a faster returning phase. 相似文献
130.