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101.
102.
Molecular phylogenetics of Stenodermatini bat genera: congruence of data from nuclear and mitochondrial DNA 总被引:2,自引:1,他引:1
Van den Bussche RA; Baker RJ; Wichman HA; Hamilton MJ 《Molecular biology and evolution》1993,10(5):944-959
Within the tribe Stenodermatini the systematics of the complex of species
allied with the genus Artibeus has generated several alternative
phylogenetic hypotheses. The most recent treatment recognized four genera
(Artibeus, Dermanura, Enchisthenes, and Koopmania) and suggested that the
most recent common ancestor of these four genera would include the common
ancestor of all other currently recognized Stenodermatini genera except
Sturnira. To test this hypothesis, we examined an EcoRI-defined nuclear
satellite DNA repeat and 402 bp of DNA sequence variation from the
mitochondrial cytochrome b gene. Phylogenetic conclusions based on Southern
blot analyses, in situ hybridization, and mitochondrial DNA sequence data
indicate that Enchisthenes is not closely related to Dermanura, Artibeus,
or Koopmania and that Dermanura, Artibeus, and Koopmania shared a common
ancestor after diverging from the remainder of the Stenodermatini. If our
conclusions are correct, then justification for recognizing Dermanura and
Koopmania as generically distinct from Artibeus must be based on the
magnitude of difference that distinguishes each rather than on the
conclusion that to place them as congeneric with Artibeus creates a
paraphyletic taxon.
相似文献
103.
104.
S.D. HA S.D. PILLAI S.C. RICKE 《Journal of Rapid Methods and Automation in Microbiology》1995,4(1):77-85
The present study was designed to evaluate cycloheximide as a potential media amendment to prevent fungal overgrowth on selective media for salmonellae enumeration. The objectives were to determine the effect of cycloheximide on Salmonella spp growth rates and to determine the effect of cycloheximide addition on Salmonella enumeration in selective media. The bacteria tested included two strains of Salmonella typhimurium (NO/NA and LT2) and one strain of Salmonella arizonae. All strains were grown in tryptic soy broth containing cycloheximide to determine the effect of cycloheximide on bacterial specific growth rates. The growth rate of all strains grown in tryptic soy broth were not significantly influenced by addition of cycloheximide at concentrations up to 1,000 mg/L. Growth rates of S. typhimurium NO/NA in minimal media were significantly decreased by addition of cycloheximide aerobically (300 mg/L) and anaerobically (600 mg/L). However, S. typhimurium NO/NA populations on brilliant green agar, MacConkey agar, and from selenite cysteine broth and tetrathionate broth were not affected by cycloheximide additions at concentrations up to 1,000 mg/L. Cycloheximide has potential as a fungistat additive for salmonellae selective media. 相似文献
105.
Bud formation capacity of callus formed from thin epidermal cell loyers excised from floral branches of Nicotiana tabacum cv. Wise. 38. Subepidermal cells of thin tissue pieces with a few cell layers were capable of forming eitber buds, roots, (lowers or non-organ ogenetic callus. To determine wheiher this calltjs is able to dirferentiate into organs, we transferred it to media inducing eitber flowers, or buds, or roots. In this paper, we study ibe capacity of lbe callus to form buds. In 50% of the cases, the explants (being maintained for I day to 2 years in callus media) can still express the capacity to form buds. This percentage increased with increased agar concentration of the culture media. At the histological level, non-organogenetic callus is characterized by the absence of tracheid differentiation, whereas in the organogenetic callus, iracheids were induced after their transfer into a ‘Bud medium’ and indicate an organogenetic differentiation pattern. 相似文献
106.
107.
Many mainland populations of kiwi are declining because stoats (Mustela erminea) kill most of their chicks. Stoats are often trapped during conservation programmes, but the long-term effectiveness of trapping has not been measured. During continuous trapping of mammalian predators in the 9800?ha Whangarei Kiwi Sanctuary, the survival of brown kiwi (Apteryx mantelli) chicks declined over time. Following the use of sodium fluoroacetate (1080) to kill rats (Rattus spp.) and possums (Trichosurus vulpecula) and likely secondary poisoning of stoats, chick survival at Riponui increased from 5% to 56%, and the 62% chick survival at Rarewarewa was better than the 20% recorded in a trapped-only area nearby. We suggest that untrappable stoats accumulate in areas subjected to continuous predator trapping. Conservation managers should build into their long-term pest control programmes a periodic pulse of an alternative tool to kill pests that, for whatever reason, actively avoid the primary control tool. 相似文献
108.
Nova E Montecinos F Brunet JE Lagos R Monasterio O 《Archives of biochemistry and biophysics》2007,465(2):315-319
FtsZ (Filamentous temperature sensitivity Z) cell division protein from Escherichia coli binds the fluorescence probe DAPI. Bundling of FtsZ was facilitated in the presence of DAPI, and the polymers in solution remained polymerized longer time than the protofilaments formed in the absence of DAPI. DAPI decreased both the maximal velocity of the GTPase activity and the Michaelis-Menten constant for GTP, indicating that behaves like an uncompetitive inhibitor of the GTPase activity favoring the GTP form of FtsZ in the polymers. The results presented in this work support a cooperative polymerization mechanism in which the binding of DAPI favors protofilament lateral interactions and the stability of the resulting polymers. 相似文献
109.
Amiodarone (AM) is an effective anti-arrhythmic drug. We investigated the role of mast cells and macrophages on AM induced pulmonary fibrosis and the action of atorvastatin on this fibrosis. Rats were allocated into four groups; negative control (1), positive control (2), 30 mg/kg body weight/day AM (3) and AM + 10 mg/kg/day atorvastatin (4). Lungs were harvested and prepared for histology and immunohistochemistry. Hematoxylin and eosin stained sections of group 3 exhibited disorganized lung architecture. We found cellular debris in the lumen of both intrapulmonary bronchi and bronchioles with partial disruption of the thickened epithelial lining and mononuclear cellular infiltration into the lamina propria. We also observed thickening of the epithelial lining and the smooth muscle layer. Congested, dilated and thickened blood capillaries and thickened inter-alveolar septa were observed with mononuclear cellular infiltrates in the lung of group 3. Most alveoli were collapsed, but some dilated ones were detected. In some alveoli, type ?? pneumocytes were increased, while type I cells were decreased. We observed significant increases in the amount of collagen in the thickened inter-alveolar septa, around bronchioles and around blood capillaries in sections from group 3. We found a significant increase in mast cells and alveolar macrophages in group 3 compared to group 1. Mast cells and macrophages appear to play important roles in AM induced pulmonary fibrosis. Atorvastatin appears to attenuate this condition. 相似文献
110.
甲基纤维素辐射降解及工艺研究 总被引:3,自引:0,他引:3
介绍了^60Co γ-射线对甲基纤维素的辐射降解作用,初步研究了辐射剂量、剂量率对甲基纤维素粘的影响。评价了甲基纤维素辐照后的贮存稳定性,并对辐射降解工艺进行了探讨。 相似文献