Responses of vegetative gametophytes of Undaria pinnatifida to high irradiance in the process of gametogenesis

The population of Undaria pinnatifida in its ecologic niche sustains itself in high temperature summer in the form of vegetative gametophytes, the haploid stage in its heteromorphic life cycle. Gametogenesis initiates when seawater temperature drops below the threshold levels in autumn in the northern hemisphere. Given that the temperature may fall into the appropriate range for gametogenesis, the level of irradiance determines the final destiny of a gametophytic cell, either undergoing vegetative cell division or initiating gametogenesis. In elucidating how vegetatively propagated gametophytes cope with changes of irradiance in gametogenesis, we carried out a series of culture experiments and found that a direct exposure to irradiance as high as 270 mu mol photons m(-2) s(-1) was lethal to dim-light (7-10 mu mol photons m(-2) s(-1)) adapted male and female gametophytes. This lethal effect was linearly corelated with the exposure time. However, dim-light adapted vegetative gametophytes were shown to be able tolerate as high as 420 mu mol photons m(-2) s(-1) if the irradiance was steadily increased from dim light levels (7-10 mu mol photons m(-2) s(-1)) to 90, 180 and finally 420 mu mol photons m(-2) s(-1), respectively, at a minimum of 1-3 h intervals. Percentage of female gametophytic cells that turned into oogonia and were eventually fertilized was significantly higher if cultured at higher but not lethal irradiances. Findings of this investigation help to understand the dynamic changes of population size of sporophytic plants under different light climates at different site-specific ecologic niches. It may help to establish specific technical details of manipulation of light during mass production of seedlings by use of vegetatively propagated gametophytes.

Aglacins I-K, three highly methoxylated lignans from Aglaia cordata

Further chemical investigation of the stem bark of Aglaia cordata has led to the isolation and identification of three new lignans, namely, aglacins I-K (1-3), all of which contain two contiguous trimethoxylated phenyl systems. Among them, aglacins I and J (1 and 2) are new members of the aryltetralin cyclic lactol class, while aglacin K (3) is a new example of tetralrydrofuran lignan. The structures of these compounds were established on the basis of spectroscopic data interpretation.

牙鲆Paralichthys olivaceus（♀）×夏鲆Paralichthys dentaus（♂）分子遗传学及数量遗传学研究

本论文采用扩增片段长度多态性（AFLP）技术对牙鲆Paralichthys olivaceus群体和夏鲆Paralichthys dentaus 群体进行了种群鉴定和遗传结构分析。共用8 对引物对两个群体（每个群体30 个个体）进行了分析。总共产生了379 个条带，条带大小在60－1000bp。牙鲆与夏鲆的遗传多态性分别为53.83%和22.22%。牙鲆群体的多态位点数显著低于夏鲆群体。牙鲆群体和夏鲆群体种的特异条带分别为27.3% 和 29.61%。两群体平均杂和度分别为0.0701 和 0.1556，香农氏多态指数分别为0.1044 和0.2387。群体内平均遗传距离分别为0.0705 （0.0214 到0.1377）和0.1656 （0.0629 到 0.2338），两群体间的平均遗传距离为0.6328。 AFLP 技术是进行种间群体结构分析的一个很好的分子标记方法，对牙鲆和夏鲆亲本群体进行遗传背景析为今后的杂交育种阐明种间杂交的遗传机理奠定基础。 在本论文中我们采用5×8 因子交配设计建立了牙鲆P. olivaceus（♀）× 夏鲆P. dentaus（♂）杂交家系，对生长相关性状的遗传力进行分析。所有家系都混合养殖在同一养殖池中，40 日龄，在养殖池中随机采集600 个个体，测量体长，体宽，体重等数量性状；然后提取杂交子代DNA 进行家系的鉴定。首先从牙鲆的微卫星中筛选了在牙鲆、夏鲆以及杂交子代扩增多态性较好的10 对微卫星引物（Po1, Po13, Po20, Po35, Po42, Po48, Po56, Po58, Po91, Poli 23TUF）。我们采用了三对引物对600 个个体进行了家系鉴定，共有400 多个体鉴定出自己的亲本，成功率达到80％以上。基于以上结果我们认为微卫星标记可以做为一个有效的标记来代替现实的物理标记，并且可以在子代的早期进行亲本的鉴定。 在养殖过程中，我们对自交和杂交家系生长状况进行了跟踪分析，在181刘清华 牙鲆（♀）×夏鲆（♂）分子遗传学及数量遗传学研究 博士学位论文II日龄之前杂交鲆体长和体重均为未表现出杂种优势，杂种优势率值始终为负值，但是绝对值在逐渐减小。从196 日龄之后杂交鲆杂种优势开始表现出来，并且在196 日龄之后杂种优势率显著的增加。256 日龄体长杂种优势率为14.29%，体重杂种优势率为59.78%, 271 日龄体长杂种优势率达到27.36%，体重杂种优势率为 102.32%。 本研究对杂交鲆在40 日龄的体长，体高、尾柄长、尾柄高，以及全长和体重的遗传力进行了估计，5 个性状的体长半同胞遗传力h2 S 为0.00146－0.719，5个性状的全同胞遗传力h2D 为0.00121－0.632，5 个性状的半同胞和全同胞的平均遗传力h2SD 为0.001335－0.6755。其中全长的遗传力最大。实验结果说明对早期幼鱼进行体长、体重等性状实施选育策略可能会显著影响后期杂交鲆的生长。

Ocean urea fertilization for carbon credits poses high ecological risks

The proposed plan for enrichment of the Sulu Sea, Philippines, a region of rich marine biodiversity, with thousands of tonnes of urea in order to stimulate algal blooms and sequester carbon is flawed for multiple reasons. Urea is preferentially used as a nitrogen source by some cyanobacteria and dinoflagellates, many of which are neutrally or positively buoyant. Biological pumps to the deep sea are classically leaky, and the inefficient burial of new biomass makes the estimation of a net loss of carbon from the atmosphere questionable at best. The potential for growth of toxic dinoflagellates is also high, as many grow well on urea and some even increase their toxicity when grown on urea. Many toxic dinoflagellates form cysts which can settle to the sediment and germinate in subsequent years, forming new blooms even without further fertilization. If large-scale blooms do occur, it is likely that they will contribute to hypoxia in the bottom waters upon decomposition. Lastly, urea production requires fossil fuel usage, further limiting the potential for net carbon sequestration. The environmental and economic impacts are potentially great and need to be rigorously assessed. (C) 2008 Elsevier Ltd. All rights reserved.

东营凹陷幔源流体对原油生物标志化合物的影响研究

A large number of mantle-derived fluid activities occurred in the Dongying Sag. On the basis of the studies on the geochemical characteristics of these fluids in this sag, the spatial distribution of biomarkers in petroleum and their relationships with the parameters of mantle-derived fluids were studied, to reveal the influence of mantle-derived fluids on the biomarkers and to evaluate the reliability of these biomarkers when applied to oil-source correlation and maturity analysis. Most biomarkers used in oil correlation kept the characteristics of their sources during burial thermal evolution. Even some of them were not influenced by mantle derived fluids, such as the relative content of C27-C29 steroid（ααα20R）and C21/C23 tricyclic terpane. However, Pr/Ph and C35/C34 hopanes were sensitive to both heat energy and materiel input by the mantle-derived fluids. γ-waxnae/C30hopanes and C24 tetracyclic terpanes /C26 tricyclic terpanes responded only to thermal influence by mantle-derived fluids. They did not chemically reacted with the mantle-derived fluids. Fluorene series compounds reacted with hydrogen and / or carbon dioxide from the mantle. Mantle-derived fluids affected most maturity index. The huge thermal energy with mantle-devied fluids weakened the relationship between the maturity parameters and depth. Among them, pregnane/C27-29 steroid and Ts/(Ts+Tm) were more sensitive to the heat of the fluids. ααα20S/(20S+20R) took the second place. αββ/(ααα+αββ) and 22S/(22S+22R) were not thermally influenced by the mantle-derived fluid. Besides, the substance of mantle-derived fluids reacted with fragrants, hopanes or moretanoids and thus altered the values of MPI1, MPI2, MPR, C30 hopanes/(C30 hopanes + moretanoids) and alkyl-diben zothiophene/diben zothiophene. The thermal alernation of phenanthrene series and their spatial distribution show that the heat energy carried by mantle-derived fluids was not fierce but spread widely in Dongying Sag, which is favorable to hydrocarbon generation with little destroy. In sum, mantle-derived fluids affected biomarkers through thermal energy and chemical reactions and changed the values of oil-source correlation and maturity parameters in the deep-seated fault belts. Therefore, in the deep-seated fault belts, oil-source correlation should be restudied and the new parameters need to be explored.

关中盆地东部浅层地下水水化学与CFC年龄研究

Hydrochemistry, isotope and CFCs were used to determine groundwater transport in the eastern part of the Guanzhong Basin. In this paper, we systematically collected water samples and measured major ions, 2H-18O and CFCs in surface water and shallow groundwater. Groundwater in this region can be divided into three categories based on total dissolved solids (TDS): fresh water with TDS < 1g/L, brackish water with TDS between 1～3g/L, and saline water with TDS > 3g/L. Saline water is mainly located in the north of the Wei River, and saline groundwater is not in the south. Tributaries in the south of the Wei River and underlain groundwater had similar 2H-18O values, indicating a close hydraulic connection between them. Tributaries in the north of the Wei River characterized certain extent of evaporation, and 2H-18O values deviated to a differing extent between surface water and groundwater, indicating that surface water in the north bank of the Wei River has little hydraulic connection with underlain groundwater. The CFCs age of groundwater from the piedmont recharge area was young, and became older toward the Wei River valley. Vertically, the CFCs age of groundwater increased with well depth. The shallow groundwater is mainly composed of young water with ages < 60 years and old water with ages > 60 years. Young water is in a larger proportion. The NO3-N concentration positively correlates with the CFC-12 concentration in the groundwater, which indicates that young water is subjected to be contaminated. Keyword: Guanzhong Basin , shallow groundwater, isotope, CFC

Characteristic infrared spectroscopic patterns in the protein bands of human breast cancer tissue

Infrared (IR) spectra of normal, hyperplasia, fibroadenoma and carcinoma tissues of human breast obtained from 96 patients have been determined and analyzed statistically. Several spectral differences were detected in the frequency regions of N-H stretching, amide I, II and III bands: (1) the bands in the region 3000-3600cm-1 shifted to lower frequencies for the carcinomatous tissue; (2) the A(3300)/A(3075) absorbance ratio was significantly higher for the fibroadenoma than for the other types of tissues; (3) the frequency of the a-helix amide I band decreased for the malignant tissue, while the corresponding beta -sheet amide I band frequency increased; (4) the A(1657)/A(1635) and A(1553)/A(1540) absorbance ratios were the highest for fibroadenoma and carcinoma tissues; (5) the A(1680)/A(1657) absorbance ratio decreased significantly in the order of normal > hyperplasia > fibroadenoma > carcinoma; (6) the A(1651)/A(1545) absorbance ratio increased slightly for the fibroadenoma and the carcinoma tissues; (7) the bands at 1204 and 1278 cm(-1), assigned to the vibrational modes of the collagen, did not appear in the original spectra as resolved peaks and were distinctly stronger in the deconvoluted spectra of the carcinoma tissue and (8) the A(1657)/A(1204) and A(1657)/A(1278) absorbance ratios, both yielding information on the relative content of collagen, increased in the order of normal < hyperplasia < carcinoma < fibroadenoma. The said differences imply that the information is useful for the diagnosis of breast cancer and malignant breast abnormalities, and may serve as a basis for further studies on conformational changes in tissue proteins during carcinogenesis. (C) 2001 Elsevier Science B.V. All rights reserved.