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91.
Mating patterns and reproductive success in the bushy-tailed woodrat (Neotoma cinerea), as revealed by DNA fingerprinting 总被引:1,自引:0,他引:1
The mating patterns and reproductive success of the bushy-tailed woodrat (Neotoma cinerea) were investigated over a 3-year period (1992–1994) using DNA fingerprinting. Paternity was determined by genetic analysis
of 58 juveniles of known maternity from 35 litters. Analysis of DNA fingerprints revealed that all offspring within a litter
were fathered by a single male; the statistical probability of detecting multiple males mating with a female was high, indicating
that multiple paternity would have been detected had it occurred. However, individual males did not father more than one litter
from a given female either within or between years. At least 75% of females and 57% of males successfully produced offspring
each year. The finding that all littermates are first-order relatives may contribute to the high level of female cooperation
in this species.
Received: 28 May 1997 / Accepted after revision: 22 March 1998 相似文献
92.
93.
1. The HGPRT (Hypoxanthine‐Guanine‐Phospho‐Ribosyl‐Transferase) assay with Chinese Hamster V79 cells was used to measure the mutagenic effects of UV irradiation, potassium dichromate and nickel chloride. The agents were tested separately and in the combinations of UV plus nickel and dichromate plus nickel. 2. UV, Cr(VI) and Ni(II) were confirmed to be mutagenic in the V79 cell assay. The combination of UV(5J/m2) and Ni(II) (0.5 mM) caused a mutation rate 11.2 times above that corresponding to the sum of the individual mutation rates of these agents. The combined action of Cr(VI) (0.1 mM) and Ni(II) (0.5 mM) produced a mutation rate 2.8 fold above that corresponding to the sum of the individual rates of the separate agents. 3. The enhancing effect of nickel chloride on the mutagenicity of UV or Cr(VI) is interpreted by an interference of Ni(II) with the repair of DNA lesions. 相似文献
94.
95.
G. Bronzetti A. Galli P. Boccardo R. Vellosi R. Del Carratore E. Sabbioni 《毒物与环境化学》2013,95(1-2):103-111
The genotoxicity of chromium chloride was investigated in cells of D7 strain of Saccharomyces cerevisiae harvested either from logarithmic or stationary growth phase. A weak induction of mifotic gene conversion and point reverse mutation was obtained when the incubations were performed using phosphate buffer. No genetic effect was observed when the incubations were performed using Tris‐HCl buffer. The experiments with 51Cr radiotracer demonstrated that Cr3+ ion enters the yeast cells and binds to DNA even if the incubation mixture was performed with Tris HCl buffer. This behaviour could be due to the highest concentration of CrCl3 that cause some damages to cytoplasmatic membrane. 相似文献
96.
R.R. Dalvi T.J. Robbins M.K. Williams D.P. Deoras F. Donastorg C. Banks 《Journal of environmental science and health. Part. B》2013,48(8-9):703-712
Abstract A single i.p. dose (120 mg/kg) of thiram given to male Sprague‐Dawley rats caused a significant increase in the activity of SGOT and SGPT 24 hr post‐treatment indicating liver damage. A considerable diminution in the serum cholinesterase activity was also noted in the treated rats as against the control animals. Additional evidence for thiram‐induced liver toxicity is provided by the observation that there was approximately 50% inhibition of the activity of hepatic microsomal benzphetamine N‐demethylase with a concomitant decrease in the concentration of cytochrome P‐450, an important component of the mixed‐function oxidase system. Although not significant, hepatic glutathione levels were also depleted by thiram, probably making the liver susceptible to toxic injury. 相似文献
97.
洪水灾害损失信息系统—FLOODIS系统设计 总被引:3,自引:0,他引:3
本文借助遥感技术,设计出一个专题地理信息系统一洪灾损失信息系统FLOODIS,为损失评估模型提供评估区域洪水灾害损失的各种自然地理和社会经济信息以及经系统内专家模块处理后的专题信息,同时对其计算结果进行多种方式输出。 相似文献
98.
震害预测的软件程序一般都是基于结构分析的原理,大都采用FORTRAN语言来编写,而震害预测工作中又大量用到分组和排序,这又是数据库语言的特长。本文介绍了在震害预测工作中应用数据库语言的一些体会,主要讨论了两种语言的接口问题。 相似文献
99.
This paper presents an integrated system for the assessmentof technical and non-technical measures that are putforward in order to reduce air pollution levels in urbanareas. In contrast to the majority of the currentlyemployed assessment tools, this system allows for theevaluation of any proposed air pollution control measure interms of its combined impact on air quality and socialwelfare, by correlating the environmental and economicaspects of alternative air pollution abatement solutions.Based on the multi-pollutant, multi-effect concept, thesystem presented aims in providing policy-makers with areliable tool for the objective assessment of the mostcost-effective packages of measures, the latter beingallocated according to the particular features and needs ofthe areas examined. 相似文献
100.
邓民宪 《防灾减灾工程学报》1999,(2)
根据震害调查分析和试验研究结果,建立了由环境因素和管道结构参数组成的,对架空管道震害预测进行二级多因素模糊综合评判的方法。文中给出了计算、评价构成二级评判因素地震烈度、场地类型、工作状态和结构种类各档次正态模糊数范数ak的参数和对实际情况如何确定的方法。本文为面广量大的已建架空管道的震害预测工作提供了一套科学性强,方便实用的计算方法。 相似文献