Absolute absorption coefficient of C6H2 in the mid-UV range at low temperature; implications for the interpretation of Titan atmospheric spectra

The interpretation of mid-UV albedo spectra of planetary atmospheres, especially that of Titan, is the main goal of the SIPAT (Spectroscopie uv d'Interet Prebiologique dans l'Atmosphere de Titan) research program. This laboratory experiment has been developed in order to systematically determine the absorption coefficients of molecular compounds which are potential absorbers of scattered sunlight in planetary atmospheres, with high spectral resolution, and at various temperatures below room temperature. From photochemical modelling and experimental simulations, we may expect triacetylene (C6H2) to be present in the atmosphere of Titan, even though it has not yet been detected. We present here the first determination of the absolute absorption coefficient of that compound in the 200-300 nm range and at two temperatures (296 K and 233 K). The temperature dependence of the C6H2 absorption coefficient in that wavelength range is compared to that previously observed in the case of cyanoacetylene (HC3N). We then discuss the implications of the present results for the interpretation of Titan UV spectra, where it appears that large uncertainities can be introduced either by the presence of trace impurities in laboratory samples or by the variations of absorption coefficients with temperature.     

Cloning and sequence analysis of the self-fertilizing fish Rivulus marmoratus immediate early gene c-fos

We have cloned the proto-oncogene c-fos from a self-fertilizing fish Rivulus marmoratus (Cyprinodontiformes, Rivulidae) after screening of R. marmoratus lambdaGEM-11 genomic DNA library, and sequenced over 12 kb including all exons, introns and the promoter region. The R. marmoratus c-fos gene consisted of one noncoding exon and four exons with high similarity to those of fugu and mammals. We sequenced approximately 7 kb of the R. marmoratus c-fos gene promoter region to gain a better understanding of the molecular anatomy of the immediate response of this gene upon cellular damage. In the promoter region, R. marmoratus c-fos gene has seven xenobiotic response elements (XREs) and eight metal response elements (MREs) as well as two estradiol (E2), 4 NFkappaB, 2 CarG, 2 prolactin (PRL) motifs and one pit1 site, while the 3'-UTR of this gene contains the estrogen response element (ERE). The seven XRE and eight MRE motifs raise the possibility of its regulation by exposure to environmental pollutants. In this paper, we discuss the gene structure of R. marmoratus c-fos gene and compare its promoter region with those of other organisms' c-fos genes. We propose its potential use in ecotoxicology.     

真鲷(Pagrus major)脂蛋白脂肪酶基因表达与内脏脂肪蓄积营养调控定量研究

采用竞争性PCR方法 ,进行 4种营养状况对真鲷脂蛋白脂肪酶 (LPL)基因mRNA表达水平与内脏脂肪蓄积影响的定量研究。结果表明 ,真鲷LPL基因在肝脏存在营养诱导性表达 ,饥饿、高脂食物均是其表达诱导因子 ;在腹腔肠系膜脂肪组织存在组成性表达 ,其表达水平受摄食状态的影响 ,但饲料脂肪水平却不起作用。当真鲷喂食高脂食物时 ,诱导产生的大量肝脏LPL将为肝脏提供更多的来源于食物的游离脂肪酸 ,使肝脏有可能出现营养诱导性脂肪蓄积 ,但真鲷腹腔肠系膜脂肪组织LPL基因表达水平未出现适应性变化 ,其腹腔肠系膜脂肪组织将不可能作为营养诱导性蓄脂器官。由于上述营养状况对真鲷体重、腹脂指数、肝指数均没有产生显著性影响 ,说明真鲷具有在不同营养状况下与哺乳类相似的维持其内脏脂肪蓄积稳定的代谢机制 ,推测真鲷应存在某种在功能上与哺乳类相似的肥胖基因。     

On sedimentation of phosphorus in specified area outside of the Changjiang Estuary

ＩＮＴＲＯＤＵＣＴＩＯＮＥｎｖｉｒｏｎｍｅｎｔａｌｐｏｌｌｕｔｉｏｎｈａｓｂｅｃｏｍｅａｖｅｒｙｓｅｒｉｏｕｓｐｒｏｂｌｅｍｗｉｔｈｔｈｅｒａｐｉｄｉｎｄｕｓｔｒｉａｌｉｚａ ｔｉｏｎ .Ｔｈｅｐｏｌｌｕｔｉｏｎｃａｕｓｅｄｂｙｐｏｌｌｕｔａｎｔｓｓｕｃｈａｓｎｕｔｒｉｅｎｔｓ ,ｈｅａｖｙｍｅｔａｌｓａｎｄｏｒｇａｎｉｃｃｏｍｐｏｕｎｄｓ(ｉｎｃｌｕｄｉｎｇｐｅｓｔｉｃｉｄｅｓ)ｅｔｃ .ｃｏｕｌｄｄａｍａｇｅｔｈｅｗｅｌｌ ｂａｌａｎｃｅｄｃｉｒｃｕｌａｔｉｏｎｏｆｎａｔｕｒａｌｅｃｏｓｙｓｔｅｍａｎ…     

A survey for paralytic shellfish poisoning (PSP) in Vancouver Harbour

Shellfish samples were collected from seven inter-tidal and two sub-tidal sites between 23 May and 8 June 1999 in Vancouver Harbour and were analysed for paralytic shellfish poisoning (PSP) using a mouse bioassay. PSP was detected in mussels collected at four sampling sites in English Bay and Burrard Inlet, at a concentration below 20 microg saxitoxin equivalents (STXeq)/100 g wet weight.     

法国气象局的业务半球模式

一、引言 自1985年初以来,一个新的半球谱模式已在法国气象局的CRAY—Ⅰ计算机上业务化运行了。这个模式的目标是提供直到4天的准确的预报产品。尽管这个模式已经完成了它的任务,但还有几个问题必须逐步解决;热带附近的预报场和分析场之间的误差,由于变量从分析高度到模式高度来回插值引起的初始震荡以及在物理过程参数化中出现的缺陷,有关修改已在模式中采用并证明是有效的。这项工作很容易用纬向平均诊断的方法来做。这种诊断对于指出模式的缺陷和检验它们的订正是有用的工具。     

A DECADE OF MARINE PHYTOPLANKTON RESEARCH IN CHINA

A brief account is given of the progress of marine phyto-plankton research in the People's Republic of China for the last ten years. Most of these studies have been carried out, particularly before 1957, in close connection with investigations on fishing grounds and sea-farming inshore waters. During the last two years the progress of marine phyto-plankton research has been especially rapid and the area investigated has been greatly enlarged in pace with the comprehensive oceanographic investigation of the four seas, Peihai, Yellow Sea, East China Sea and South China Sea.