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21.
A. H. Coetzer 《Hydrobiologia》1987,144(3):193-210
Paramesochra mielkei sp.n. is described and figured from the interstices of subtidal sandy sediments off the SW Dutch coast. Kunz' (1981) phylogenetic scheme of the Paramesochridae Lang, 1948 is re-examined and it is suggested that the family comprises two phyletic lines which originated early in paramesochrid evolution. Translation into Linnean hierarchies implies the establishment of two new sub-families. Within the primitive Diarthrodellinae subfam. n., Tisbisoma Bozic, 1964 is ancestral to Diarthrodella Klie, 1949 s.l. and Rossopsyllus Soyer, 1975. Remanea Klie, 1929 is transferred to the Paramesochrinae subfam. n. which comprises the genera of both the Scottopsyllus- and the Paramesochra-group. The aberrant genus Caligopsyllus Kunz, 1975, standing close to Apodopsyllus, is removed from the Paramesochra-group. P. brevifurca Galhano, 1970 is splitted into two subspecies and replaced in the genus Paramesochra. An attempt is made to assess the phyletic interrelationships of the Paramesochra-species and the resulting cladogram splits the genus into four species-groups. P. mielkei sp.n. is referred to the dubia-group and seems to be closely related to P. borealis Geddes, 1981. Finally, an amended diagnosis and a revised key to the species of the genus Paramesochra are presented. 相似文献
22.
Enhancement of Stimulation-Evoked Catecholamine Release from Cultured Bovine Adrenal Chromaffin Cells by Forskolin 总被引:16,自引:9,他引:7
Katsuya Morita Toshihiro Dohi Shigeo Kitayama Yutaka Koyama Akira Tsujimoto 《Journal of neurochemistry》1987,48(1):243-247
Acetylcholine (ACh) increased cyclic AMP levels in cultured bovine chromaffin cells with a peak effect at 1 min after the addition. Pretreatment with forskolin (0.3 microM) enhanced the ACh-evoked cyclic AMP increase. The catecholamine (CA) release induced by ACh was enhanced by forskolin, but forskolin alone did not enhance the CA release. The effect of forskolin increased dose-dependently up to 1 microM, but decreased at higher concentrations. Dibutyryl cyclic AMP (DBcAMP) also enhanced ACh-evoked CA release, but the effect was less potent than that of forskolin. Forskolin enhanced both [3H]norepinephrine ([3H]NE) and endogenous CA release evoked by 30 mM K+ from cells that were preloaded with [3H]NE. The effects of forskolin were substantial when CA release was evoked with low concentrations of ACh or excess K+, but decreased with higher concentrations of the stimulants. Forskolin also enhanced the CA release induced by ionomycin and veratrine, or by caffeine in Ca2+-free medium. The potentiation by forskolin of the ACh-evoked CA release was manifest in low Ca2+ concentrations in the medium, but decreased when Ca2+ concentration was increased. These results suggest that cyclic AMP may play a role in the modulation of CA release from chromaffin cells. 相似文献
23.
本文报告了福建厦门地区寄生于鸭鹅类的膜壳科绦虫计5属9种。实验阐明了5种绦虫的生活史,其中有三种生活史为我国首次报告。厦门地区有5种嵌水甲壳类可作膜壳绦虫的中间宿主。其中短角异剑水蚤(Apocyclops royi)是矛形剑带绦虫和片形皱缘绦虫的审间宿主,不等异介虫(Heterocypris anomala)为新发现的棘盘双睾绦虫的中间宿主,介虫(Cyprinotus sp.)为新发现的美丽膜壳绦虫的中间宿主。 相似文献
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Synopsis The caloric density of stomach contents in juvenile chinook salmon,Oncorhynchus tshawytscha, was not affected by gastric evacuation, suggesting a constant caloric density of stomach contents during evacuation. Differences in the caloric density of prey consumed did affect caloric density of stomach contents over a 24-h period. Consumption of the amphipodCorophium sp. was associated with reduced caloric densities of stomach contents. During periods whenCorophium contributed more than 4% of the stomach contents, average caloric density declined from 5.56 to 5.33 kcal g–1. Despite this difference, estimates of daily energy intake of juvenile chinook salmon were only 3%, greater when developed from the mean caloric density of stomach contents excludingCorophium. 相似文献
26.
Anaerobic degradation of phenol by pure cultures of newly isolated denitrifying pseudomonads 总被引:33,自引:0,他引:33
From various oxic or anoxic habitats several strains of bacteria were isolated which in the absence of molecular oxygen oxidized phenol to CO2 with nitrate as the terminal electron acceptor. All strains grew in defined mineral salts medium; two of them were further characterized. The bacteria were facultatively anaerobic Gramnegative rods; metabolism was strictly oxidative with molecular oxygen, nitrate, or nitrite as electron acceptor. The isolates were tentatively identified as pseudomonads. Besides phenol many other benzene derivatives like cresols or aromatic acids were anaerobically oxidized in the presence of nitrate. While benzoate or 4-hydroxybenzoate was degraded both anaerobically and aerobically, phenol was oxidized under anaerobic conditions only. Reduced alicyclic compounds were not degraded. Preliminary evidence is presented that the first reaction in anaerobic phenol oxidation is phenol carboxylation to 4-hydroxybenzoate. 相似文献
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