国际构造图:四十年的道路

本文回顾了国际构造图的创意及编制历史,揭示了该项工作对地质科学发展的重要性。它既反映了关于地球演化观念之变化,也反映了固定论地槽—造山带—地台说为活动论板块构造理论所取代的过程。 早在18世纪就有了编制地质图的最初尝试,但基本上是没有时代概念的岩性图。19世纪初,随着真正地质图的出现,地质学才真正成为科学。然而,普通地质图不能充分反映地壳构造     

美国地貌学情况综述

我们根据地貌工作者和第四纪地质学工作的人数、专业团体会员人数及其有关出版物等情况对美国地貌学家的活动状况做一个综述。美国的地貌学出现于19世纪末期。当时的地质学和地理学还紧密联系在一起的。当地理学成为一个独立学科时,其成员主要是自然地理学家和学过地质学的地貌学工作者。在本世纪30年代期间,地理学家们反对环境决定论的模式,地貌学的重要性有所下降。     

Types of rural out-migration in Turkey

An analysis of changes in migration patterns since World War II between inner Anatolia and eastern Anatolia in Turkey is presented. Four periods are distinguished, the exploratory period until 1950, seasonal migration until 1960, mass migration up to the present, and marriage migration from 1975 to the present. The linkages between previous and potential migrants are noted. (SUMMARY IN ENG)     

影响西太平洋台风形成的大尺度环流条件

根据全球热带气旋频率的统计[1],这些频率有明显的年际变化。在过去二十年中全球热带气旋数年变化的百分率为其平均数的-13%-+23%,最多和最少年热带气旋数差达28个,相当于全球年平均热带气旋数(79)的35%。目前认为有三个原因可能影响热带气旋频率:大尺度环流,海面温度和地球以外的因子。     

Evidence from heterologous expression of glutathione S-transferases A and A1 of the plaice (Pleuronectes platessa) that their endogenous role is in detoxification of lipid peroxidation products

cDNA clones for glutathione S-transferases A (GST-A) and A1 (GST-A1) from plaice (Pleuronectes platessa) were expressed as N-terminally 6XHis tagged proteins in Escherichia coli and purified to homogeneity from Ni-NTA silica. GST-A was an efficient catalyst for conjugation of unsaturated alkenals derived from peroxidation of polyunsaturated fatty acids with the highest activity observed with trans-non-2-enal (8 micromol min(-1) mg(-1)). GST-A1 was a very efficient Se-independent glutathione peroxidase with an activity towards cumene hydroperoxide of 25 micromol min(-1) mg(-1). Although the enzymes exhibited moderately high activities towards the model substrate 1-chloro-2,4-dinitrobenzene (CDNB) they exhibited little or no activity towards other common prototypical xenobiotic substrates. Together with data for ontogeny, tissue distribution and inducibility of these enzymes, we contend that a primary function of these enzymes is protection from the harmful effects of lipid peroxidation products generated naturally or exacerbated by xenobiotic exposure.     

Effects of prolonged exposure to 4-tert-octylphenol on toxicity and indices of oestrogenic exposure in the sand goby (Pomatoschistus minutus, Pallas)

Alkylphenolic compounds are present in estuarine and marine environments. They are moderately bioaccumulative, and oestrogenic to fish following three week, in vivo, exposures. The effects of prolonged exposure are, as yet, unclear. Sand goby (Pomatoschistus minutus) were exposed to measured concentrations of 4-tert-octylphenol (OP) in a 28-day, dose-ranging study, and a six month temporal response study. Following 28-days exposure to measured 31+/-6 or 101+/-47 microg l(-1) OP (mean+/-SD), immature male sand goby showed elevated vitellogenin (VTG) mRNA expression. Plasma alkali-labile phosphate concentrations were elevated in both sexes and were higher in females than males. Although measured OP concentrations were variable, they were significantly different for each treatment and a range of concentration-dependent effects were observed. The LC(50) for chronic OP exposure (8 weeks) was 29+/-6 microg l(-1), and both sexes demonstrated concentration and duration dependent increases in VTG mRNA expression. Exposure to 28+/-20 microg l(-1) OP (median+/-95% CI) for 6 months inhibited development of male nuptial colouration and sperm duct glands. These findings are discussed in relation to environmental concentrations of alkylphenols and ecological concerns.     

Variations of antioxidant efficiency and presence of endosymbiotic diatoms in the Antarctic porifera Haliclona dancoi

The role of endosymbiotic diatoms as pro-oxidant stressors in porifera has been investigated in the Antarctic sponge Haliclona dancoi in which the presence of diatoms is influenced by marked seasonal variations during the austral summer. Both chlorophaeopigments and frustules were absent in sponge tissues sampled in early November at the beginning of the summer and increased from the mid of December with slightly shifted temporal trends. The efficiency of antioxidant defenses in the sponge showed a marked response to symbionts with clearly enhanced values corresponding to the peak of diatoms.     

海洋微生物学的主要任务

海——微生物栖息的特殊环境。特殊的盐类成分,低温,高压,低浓度的有机物质,植物及动物区系的稀少等组成了微生物生命活动的广阔海洋区域一些主要生态特征。 海洋中最初的微生物学研究,早在上一世纪就已进行了,但足它们局限于较狭小的任务——