Wind impact on pollutant transport in a shallow estuary

A three-dimensional numerical model, EFDC （ environmental fluid dynamics code） is applied to the Pamlico River Estuary （PRE） in eastern North Carolina of the United States to examine the wind impact on pollutant age distributions and residence time. A series of model experiments representing base case, remote-wind-induced water level set-up and local winds cases are conducted. Model results indicate that the pollutant mean age and the system residence time are functions of gravitational circulation in the PRE. The system responses to remote-wind-induced water level set-up are different in different portions of the PRE. Under such condition, dissolved substances in the upstream portion of the PRE have a younger age and shorter residence time （compared with the base case） , by contrast, they have a older age and longer residence time in the downstream portion of the PRE. Upriver and downriver local winds appear to have opposite impacts on pollutant age distributions. The substances are retained much longer within the PRE under upriver wind than those under downriver wind. The model results also suggest that across - river winds may lead to longer residence time through enhanced turbulence mixing, which slows down the gravitational circulation in the PRE.     

4种微生态制剂对对虾育苗水体主要水质指标的影响

研究了由球形红假单胞菌(Rhodopseudomlonas sphaeroides)、噬菌蛭弧菌(Bdellovibrio bacteriovorus)及黏红酵母(Rhodotorula glutinis)制成的4种微生态制剂对中国对虾(Fenneropenaeus chinensis)育苗水质的影响.结果表明,试验组与对照组相比都能明显净化水质,试验组中以添加噬菌蛭弧菌和黏红酵母组的效果最差,添加球形红假单胞茵和噬茵蛭弧茵组的效果最好,此组水质的pH值稳定,NH4+-N明显下降,而亚硝酸盐、化学需氧量及硫化物等指标也优于其他试验组.统计分析显示,试验组与对照组相比,细菌数降低了3个数量级,添加嗜菌蛭弧菌试验组在减少异养茵(包含有害细菌)方面效果较好.同时用鳗弧菌攻毒,在5 d内,对照组的死亡率显著高于试验组(P<0.05),试验组免疫保护率为29.4%～58.5%,以添加嗜菌蛭弧菌和球形红假单胞菌组最高.建议联合使用噬菌蛭孤菌和球形红假单胞菌,混合密度初步定为2×105个/mL.     

贻贝抗菌肽的研究进展

抗菌肽是一类广泛存在于整个生物界中的双亲性小分子碱性多肽,是生物体固有免疫的关键因子之一.自Steiner等在天蚕(Hyaophora cecropia)中发现世界上第一个抗菌肽-天蚕素(Cecropin)后,到目前为止,在各种生物中总共发现了1 200多种抗菌肽.     

����ARģ�͵��Ϻ������������Ԥ�����

????AR?????????????????????????????????????AIC?????AR????????????????????,AR??4?????????????????????AR(4)???????????δ??10???????????????????     

Cloning and sequence analysis of a full-length cDNA of <Emphasis Type="Italic">SmPP1cb</Emphasis> encoding turbot protein phosphatase 1 beta catalytic subunit

Reversible protein phosphorylation, catalyzed by protein kinases and phosphatases, is an important and versatile mechanism by which eukaryotic cells regulate almost all the signaling processes. Protein phosphatase 1 （PP1） is the first and well-characterized member of the protein serine/threonine phosphatase family. In the present study, a full-length cDNA encoding the beta isoform of the catalytic subunit of protein phosphatase l（PPlcb）, was for the first time isolated and sequenced from the skin tissue of flatfish turbot Scophthalmus maximus, designated SmPPlcb, by the rapid amplification of cDNA ends （RACE） technique. The cDNA sequence of SmPPlcb we obtained contains a 984 bp open reading frame （ORF）, flanked by a complete 39 bp 5＇ untranslated region and 462 bp 3＇ untranslated region. The ORF encodes a putative 327 amino acid protein, and the N-terminal section of this protein is highly acidic, Met-Ala-Glu-Gly-Glu-Leu-Asp-Val-Asp, a common feature for PP1 catalytic subunit but absent in protein phosphatase 2B （PP2B）. And its calculated molecular mass is 37 193 Da and pI 5.8. Sequence analysis indicated that, SmPPlcb is extremely conserved in both amino acid and nucleotide acid levels compared with the PPlcb of other vertebrates and invertebrates, and its Kozak motif contained in the 5＇UTR around ATG start codon is GXXAXXGXXATGG, which is different from mammalian in two positions A6 and G3, indicating the possibility of different initiation of translation in turbot, and also the 3＇UTR of SmPPlcb is highly diverse in the sequence similarity and length compared with other animals, especially zebraf＇lsh. The cloning and sequencing of SmPPlcb gene lays a good foundation for the future work on the biological functions of PP1 in the flatfish turbot.     

Formation of saddle dolomites in Upper Cambrian carbonates, western Tarim Basin (northwest China): Implications for fault-related fluid flow

The saddle dolomites occur more intensely in cores closely to fault than that in cores far away from the fault in Upper Cambrian carbonate of western Tarim basin, suggesting that formation of the saddle dolomites is likely related to fault-controlled fluid flow. They partially fill in fractures and vugs of replacement dolomite. The saddle dolomites exhibit complex internal textures, commonly consisting of core and cortex. In comparison with the matrix dolomites, the saddle dolomites show lower Sr-content and ⁸⁷Sr/⁸⁶Sr ratios, higher Fe- and Mn-content, and more negative δ¹⁸O values. Combined with high Th (100–130 °C) of primary fluid inclusions, it is suggested that the saddle dolomites precipitated from hydrothermal fluid derived from the deep evaporite-bearing Middle Cambrian strata, and the magnesium source may be due to dissolution of host dolomite during hydrothermal fluid migration. Fault activity resulted in petrographic and geochemical difference of the core and cortex of the saddle dolomites. The cores precipitated from the formation water mixed by deep brines at the early stage of fault activity, and the cortexes precipitated from the deep fluid with higher temperatures through the Middle Cambrian later. In summary, the formation of the saddle dolomites implies a hydrothermal fluid event related to fault activity, which also resulted in high porosity in Upper Cambrian carbonate in western Tarim Basin.     

海道测量水位改正通用软件研制

综合近几年海道测量水位改正的最新理论研究成果,以"海洋测量信息处理工程"软件系统为基础平台,根据直观性、通用性、可靠性等基本原则,开发了适用于单波束、多波束多种测深数据接口的海道测量水位改正通用软件,并从内、外符合精度方面对软件的水位改正效果进行了检验评估。     

茂名地区海雾的微物理结构特征

2007年3月16日至4月29日期间,在广东茂名海洋气象科学实验基地对海雾进行了连续观测,共取得51个雾滴谱样本,在此基础上分析了茂名地区海雾的微物理结构特征。观测分析表明:茂名地区海雾的雾滴谱分布符合Junge分布,平均数密度为57.1个/cm3,平均含水量为0.018 3 g/m3,算术平均直径为4.7μm,算术峰值直径为2.9μm。文中还比较了雾和轻雾情况下雾滴谱分布的不同特征,分析了能见度与含水量之间的关系。     

喀斯特山区石漠化成因的差异性定量研究——以贵州省盘县典型石漠化地区为例

珠东区的轻中度石漠化主要由人为因素引起,强度以上石漠化则由人为因素和恶劣的自然条件共同造成;保基区的轻中度石漠化主要是人为因素引起,强度以上石漠化则由自然因素造成;红果区的自然条件好于其它两个研究区,石漠化尤其是强度石漠化主要是土地利用强度大造成的,坡耕地发生中度甚至极强度石漠化。喀斯特石漠化土地的成因类型与恢复治理模式密切相关,在确定石漠化土地的治理恢复模式和治理重点时,有必要考虑石漠化土地的土地利用成因和成因的地域差异性。