日本凋毛藻碳酸酐酶基因及其编码的蛋白特征

碳酸酐酶CA(EC 4.2.1.1)是含锌原子的金属蛋白酶,该酶的基本功能是催化CO₂与HCO₃-间的相互转换[1].该反应在许多生物过程中都发挥着重要的作用,例如离子交换、呼吸作用、pH稳定性、捕获CO₂和光合作用等[2~5].CA广泛分布于各种生物中,已知的CA酶根据氨基酸序列被分为-αCA,-βCA和γ-CA三种类型[5~7].这3种类型的CA酶序列间的相似性很低,被认为是由不同的途径进化而来的[7].α-型的CA酶在动物、植物、绿藻、细菌和蓝细菌中都有发现[7],在藻类中报道的α-型CA还很少.迄今为止只在衣藻中发现2种异构体,在盐藻中发现3种[8,9],在红藻中还未见报道.     

北部湾海蛇血清对红血球溶血及抗蛇毒溶血作用的初步研究

海蛇剧毒,这是沿海渔民都知道的.海蛇毒的活性作用主要由四种组分起主导作用,其中之一就是毒液中的卵磷酯酶,可造成红血球破损而导致溶血.有关很多种蛇对本身毒液及其他蛇毒的毒伤有阻抵作用的研究已有报道(Strazght and Glenn,1976)[1].此外,Nahas等人[2]也曾对某些蛇的血浆对蛇毒的凝血活性进行过研究,发现蛇血浆对蛇毒的凝血作用有显著的抑制.     

活性中心突变型胃蛋白酶原的酵母表达及高效激活研究

针对活性中心突变型胃蛋白酶原难以被激活且稳定性差的问题,本文研究了活性中心突变对胃蛋白酶原激活及其稳定性的影响。根据猪胃蛋白酶原A的基因序列设计引物,通过RT-PCR和重叠延伸PCR法分别获得野生型(rPG)和突变型(D32A和D215A)胃蛋白酶原基因片段,其中突变型胃蛋白酶原分别为活性中心关键氨基酸天冬氨酸(D)突变为丙氨酸(A)。将野生型和突变型胃蛋白酶原分别在酵母中成功表达,研究其激活、激活后的稳定性和活性情况。研究表明,可以成功地在酵母中表达并纯化野生型和突变型重组猪胃蛋白酶原rPG、D32A和D215A。在pH=2.0条件下,rPG在5min内即可全部激活,且在37℃具有良好的稳定性,而D32A和D215A需24h以上才可激活。通过在激活反应中加入野生型胃蛋白酶,D32A和D215A的激活时间可缩短至1h,虽然激活过程有部分酶原发生降解,但激活后获得的突变型胃蛋白酶可稳定3d,激活后的突变型胃蛋白酶无蛋白水解活性。研究结果表明,活性中心关键氨基酸突变后的胃蛋白酶原仍可激活,虽然在激活过程中胃蛋白酶原的稳定性差,但激活后产生的胃蛋白酶稳定性良好,这为进一步研究突变型胃蛋白酶提供了可能和保证。     

夏、冬两季黑鲷消化酶活力的比较及反应温度和pH对酶活力的影响

消化酶活力是反映鱼类消化生理机能的一项重要指标,鱼类消化酶活力的高低决定鱼类对营养物质消化吸收的能力,从而决定鱼类生长发育的速度,因此近年来对鱼类消化酶活力的研究也越来越受到重视.但有关鱼类消化酶的研究在淡水鱼中报道较多,海水鱼的报道较少[1~9].黑鲷Sparus macrocephalus,隶属于鲈形目Perciformes、鲷科Spari-dae、鲷属Sparus,其肉嫩味美,营养丰富,市场需求大,是我国近海重要的海产经济鱼类,近年来养殖规模不断扩大.在人工饲养过程中,由于季节、水温和pH不同,黑鲷的生长、发育、成活率都有差异[10].     

海南海莲红树林土壤CH4的产生及其某些影响因素

全球CH₄预算的估算表明,湿地是大气CH₄最大的生物排放源[1].旨在估算全球大气CH₄湿地源强的工作大多集中在内陆淡水环境,因为在此环境的CH₄通量较大[2].国外对海岸盐沼的CH₄排放也有一些报道,发现其通量变化范围较大,并进而研究了温度、土壤湿度、盐度以及土壤有机碳含量等因素对CH₄排放的影响[3].     

海蜇中常量和微量元素的同时测定

海蜇(Rhopilema esculentum Kishinouye),钵水母纲,根口水母,广泛分布于我国的沿海近岸,是我国传统渔业生产的主要大型经济水母[1].海蜇的营养十分丰富,除含有蛋白质、脂肪酸和维生素外,还含有大量的矿物质[2].海蜇的药用价值在我国早有记录[3],在韩国海蜇被作为减肥和美容的食品,而澳大利亚的土族人则用干海蜇粉治疗烫伤[4].近代研究表明海蜇有治疗高血压、慢性气管炎、哮喘、胃溃疡和单纯性甲状腺肿大的作用[5].美国Auburn大学的研究小组报道:Stomolophus meleagris水母的胶原质对实验鼠抗原引起的关节炎有一定的抑制作用[6].     

输入海洋的沿岸区地下水研究进展

海底地下水排泄(Submarine Groundwater Dis-charge,简称SGD)最早以泉的形式被人们发现,从发现海底地下水排泄现象至今,已有近20个世纪,古罗马地理学家Strabo(63B.C.～21A.D.)最早记载了这一现象.他在著作中提到:"在地中海距离叙利亚西北部一海港Latakia 2.5 miles的地方有处海底泉水,人们将泉水用铅漏斗和皮革管收集到小船上,然后运到Latakia城作为生活用水"[1].     

有效群体大小对海湾扇贝F_1生长和存活的影响

1　引言有效群体大小(Ne)为群体内所具有的相当于理想群体繁殖个体的数目[1~3],在群体遗传学中占有十分重要的地位,这方面的研究在国外已有很多报道[4~6].当 Ne 较小时,由于瓶颈效应,野生或养殖群体倾向于近交水平的增加[7].早期研究表明,为了避免近交衰退,确保群体短期内的生存能力,最小的Ne值应为 50; 如果要维持适当的遗传变异,进而确保长期的生存能力,Ne 数量不应小于500[8,9].在贝类养殖方面也有一些研究[10,11],如Hedge cock等[10](1992)估计了牡蛎(Crassostrea gigas 及C. virginica)和硬壳蛤(Mercenaria mercenaria)等16个人工…     

恒河猴实验性前庭型减压病及时加压治疗的效果观察

减压病的处理原则是及早进行正确的加压治疗,疗效在很大程度上取决于早期采取这样的措施.Flliott(1974年)报道;发病后30分钟以内进行治疗者,治愈率可达80%,留有后遗症的可能性仅1%[1].Farmer(1976、1981年)提出迅速加压治疗与症状解除、不留后遗症之间存在着明显的相关,主张发病后立即加压治疗[2,3].     

石鲽卵巢雌二醇及其受体和睾酮受体免疫组织化学研究

细胞核的雌激素受体(ER)是参与调节脊椎动物发育和繁殖的转录因子,哺乳动物具有两种类型的ER(ER-α和ER-β),它们一旦与配体结合就能够形成二聚体,和其他转录激活因子相互作用,参与靶基因调节[1].目前,在鱼类中发现3种ER类型,即ER-α,ER-β和ER-γ[2~4],这说明鱼类ER生理功能比高等动物复杂,但对每种ER的功能研究较少.雄激素在脊椎动物(包括鱼类)的性别分化和性腺发育过程中起着十分重要的作用,一般认为这种作用是通过雄激素受体(AR)介导的[5].AR属于配体活性转录因子,是核受体家族的一员[6].     

The effect of the horizontal structure for symmetric tropical cyclones on their movement

In this paper, using Holland's method, the effect of the horizontal structure of tropical cyclones on their motion is investigated. The "characteristic radius", r0 characterized as the horizontal structure of a tropical cyclone,in which m and p are the parameters of the vortex, has been found by the author. And then it has been shown that there is but one "characteristic radius" for each cyclone with horizontal structure. Two direct analytic solutions for the uniform and non-uniform basic flows in steady situations are presented with rc Results show that the change in the horizontal structure of the tropical cyclone itself will have obvious effect on the cyclone motion, on both its direction and speed. Therefore it must be considered in the research on the tropical cyclone motion.     

On the spatial–temporal variations in the chlorophyll-<Emphasis Type="Italic">a</Emphasis> concentration on the Peter the Great Bay shelf during the winter–spring phytoplankton bloom according to satellite and subsatellite data

Chlorophyll-a concentration (C _chl) variations in the cross section within and outside the Peter the Great Bay shelf during different stages of the winter–spring phytoplankton bloom in 2003–2005 has been considered based on a ship (obtained during the R/V Akademik M.A. Lavrent’ev voyage of February 26 to March 9, 2003) and MODIS-Aqua spectroradiometer and the SeaWiFS color-scanner satellite data. A comparison of the C _chl variability obtained from the ship and satellite data indicates that these data are inconsistent. According to satellite data obtained at the MUMM atmospheric correction, the C _chl variability is distorted less than the NIR-correction data. Studying the variations in the coefficients of light absorption by the detritus and yellow substance (a _dg) and light backscattering by suspended particles (b _bp), C _chl, chlorophyll-a fluorescence (F _chl) according to the satellite data allow us to state that the variations in the discrepancy between the satellite and ship C _chl values are mainly caused by the variations in the content of the detritus and yellow substance in water. Based on the satellite data, it has been revealed that the a _dg values increase with increasing wind mixing after the phytoplankton bloom (about 2–5 km areas where the a _dg, C _chl, F _chl, and bbp values abruptly increased in 2005, apparently due to eddy formation). It has been indicated that the F _chl characteristic, which is close to C _chl, increases when the favorable conditions for the phytoplankton bloom deteriorate. Therefore, this characteristic cannot be used to identify C _chl under the indicated conditions.     

The biogeochemistry of major elements of the suspended particulate matter of the Cretan Sea

The biogeochemistry of the following elements Al, Fe, Si_bio, POC, PN_tot, Ca_bio, S_org, P and Mn has been studied within waters of the Cretan Sea in March and September 1994, as part of the PELAGOS project. Particulate aluminosilicate concentrations, exemplified by Al, are very low (<1 μgl⁻¹) especially in the upper waters. Higher concentrations occur below 200 m, especially at depths of 200 m and 500–700 m in the central and eastern areas, and are thought to result from sediment injections from the shelf edge and slope. The results for Si_bio, Ca_bio, P and S_org show much higher concentrations within the photic waters. Temporal and spatial high concentrations in these waters closely relate to the existence of cyclonic eddies on the east and west sides of the sea, while low concentrations are associated with an intervening anticyclonic eddy. However in September, discharge of Black Sea Water in the west sufficiently suppresses the thermocline to prevent upwelled water from reaching the surface and hence these substances are prevented from forming.Particulate Fe (expressed as Fe_excess) concentrations show much higher concentrations relative to Al in September, and are thought to result from additional atmospheric inputs. The low particulate Mn concentrations in the upper water compared with deeper waters are considered to be a product of photoinhibition of MnO_x precipitation from Mn(II).An attempt has been made to assess input/output budgets of Al, Ca, Fe and Mn through the Antikithira and Kassos Straits. Much of the outflows leave through the Kassos Strait and, except for Ca, net outflows through the Antikithira Straits are negligible.     

Geophysical and geochemical observations on actively seeping hydrocarbon gases on the south-eastern Yellow Sea continental shelf

In the southeastern Yellow Sea, active seepage of hydrocarbon gases has been observed by high-resolution (3.5 kHz) seismic profiling both in 1987 and 2001, occurring through a large number of plumes from the topmost pre-Holocene sedimentary layer. It is strong enough to compensate for current speed, extending vertically up to the sea surface. The gas seepage often appears to be explosive to form craters and diapirs, although pockmarks are rare due to the redistribution of mobile palimpsest sands. In core-top seawater and sediments, the gases are characterized by high amounts of C₂, homogenous ¹³C₁ values and a large difference (19.7 on average) between ¹³C₁ (–55.2 to –53.6 PDB) and ¹³C₂ (–36.8 to –32.5 PDB) values. The gases are considered to be generated with a smaller amount of C₁ at the early thermal cracking stage of labile source materials, after which the C₂ gas is enriched in ¹³C by diffusion or biological alternation at the generation or accumulation site. The homogenous ¹³C₁ values may be one of the geochemical characteristics of gases acquired at depth which are less altered in the case of rapid diffusive gas migration to the seafloor.     

Features of the atmospheric boundary layer block for three versions of the WAM wind wave model

The estimated characteristics of the atmospheric boundary layer, obtained by the simulation of wind wave fields using three versions of the WAM numerical model are compared with the well-known empirical dependences of drag coefficient C _d on wind speed U ₁₀ and wave age A, as well as with the dependence of dimensionless roughness height z _n on inverse wave age u*/с р. Calculations carried out for several years in the areas of the Pacific and Indian oceans, based on the ERA-interim and CFSR wind reanalyses have shown good agreement between the model and empirical dependences C _d (U ₁₀) and C _d (A). The range of estimated variability for z _n (u*/с _р ) has been found to be significantly less than empirical. It has been also found that estimated values of wind speed U _10W (t) are overestimated from 5 to 10% in all versions of WAM models compared with the input wind reanalysis U _10R (t) at the moments of appearance maximum values of wind U _10R (t). The reasons for the established features of the WAM model and their dependence on the model version are discussed.     

Using the acoustic-pulse conservation law in estimating the energy of surface acoustic sources by remote sounding

The atmospheric effect on the characteristics of infrasonic signals from explosions has been studied. New methods have been proposed to remotely estimate the energy of explosions using the data of infrasonic wave registration. One method is based on the law of conservation of acoustic pulse I, which is equal to the product of the wave profile area S/2 of the studied infrasonic signal and the distance to the source E_I [kt] = 1.38 × 10^–10 (I [kg/s])^1.482. The second method is based on the relationship between the explosion energy and the dominant period T of the recorded signal, EТ [kt] =1.02 × (Т [s]²/σ)^3/2, where σ is a dimensionless distance used for determining the degree of manifestation of nonlinear effects in the propagation of sound along ray trajectories. When compared to the conventional E_W (Whitaker’s) relation, the advantage of the EI relation is that it can be used for pulsed sources located at an arbitrary height over the land surface and having an arbitrary form of the initial-pulse profile and for any type of infrasonic arrivals. A distinctive feature of the expression for E_Т is that the atmospheric effect on the characteristics of recorded infrasonic signals is explicitly taken into account. These methods have been tested using infrasonic data recorded at a distance of 322 km from the sources (30 explosions caused by a fire that occurred at the Pugachevo armory in Udmurtia on June 2, 2011). For the same explosion, empirical relations have been found between energy values obtained by different methods: E_I = 1.107 × E _W , E _Т = 2.201 × E _I .     

Evaluation of anthropogenic carbon in the Nordic Seas using observed relationships of N, P and C versus CFCs

Several methods to compute the anthropogenic component of total dissolved inorganic carbon () in the ocean have been reported, all in some way deducing (a) the effect by the natural processes, and (b) the background concentration in the pre-industrial scenario. In this work we present a method of calculating using nutrient and CFC data, which takes advantage of the linear relationships found between nitrate (N), phosphate (P) and CFC-11 in the Nordic Seas sub-surface waters. The basis of the method is that older water has lower CFC-11 concentration and also has been exposed to more sinking organic matter that has decayed, resulting in the slopes of P versus CFC-11 and N versus CFC-11 being close to the classic Redfield ratio of 1:16. Combining this with the slope in total alkalinity (A_T) versus CFC-11 to correct for the dissolution of metal carbonates gives us the possibility to deduce the concentration of anthropogenic C_T in the Nordic Seas. This further allowed us to compute the inventory of anthropogenic C_T below 250 m in the Nordic Seas in spring 2002, to ∼1.2 Gt C.     

Impacts of fossil anisotropy on the electric and permeability anisotropy of highly fossiliferous limestone: a case study

The Middle Eocene Lutetian Samalut formation is among the best examples of anisotropic fossiliferous rocks in Egypt, where the effect of the anisotropic Nummulite Gizehensis fossils on the petrophysical behavior can be traced. The Samalut formation has been sampled and studied at Wadi Feiran in SW Sinai. Petrographically, it is composed of two microfacies; Nummulitic packstone and Fusulinid mudstone. Tight cementation by micro to pseudosparite, aggrading neomorphism and compaction with increasing load pressure are the most important porosity-reducing factors. The anisotropy of the fossil content (λ_F), due to shape and orientation, and its effect on the petrophysical properties were assigned by measuring the lengths of the longest and shortest axes. Petrophysically, both microfacies are characterized by low porosity values (1.47 ≤ \({\emptyset _{{\text{He}}}}\) ≤ 5.29%). The formation resistivity factor (F) and permeability (k) were measured in the horizontal and vertical directions (parallel and perpendicular to the bedding plane, respectively). The studied samples are characterized by high to very high formation resistivity factor (190?≤?F?≤?8938) and relatively very low permeability (0.012?≤?k?≤?0.110 md). The studied samples are characterized by fair to medium electric anisotropy ‘λ_E’, which is attributed to a relatively medium to fair degree of electric foliation. It has been shown that, the fossil shape anisotropy and orientation ‘λ_F’ (1.5?≤?λ_F?≤?3.5) is the main contributor for the electric and permeability anisotropy that corrected for the same porosity value (1.61?≤?λ_EC?≤?2.25 and 1.03?≤?λ_kC?≤?2.04; respectively). Foliation of the studied microfacies has been contributed to the orientation of the fossil remains parallel to the bedding plane. The anisotropy degree is relatively greater for the Nummulitic packstone microfacies than that of the Fusulinid mudstone. The present study refers to the possible anisotropic effect of fossil content (due to shape and orientation) on the petrophysical properties of the studied rocks which may be extended to the anisotropy of reservoir rocks on the bedding scale.     

Effects of ligand speciation on determinations of the complexing abilities of strong ligands in natural waters

The presence of organic ligands (L) whose conditional stability constants (K_ML) are strong enough to allow them to form complexes with copper has been reported in oceanic waters. However, there is no general agreement on the distributional characteristics of such strong ligands in the water column. We present that these inconsistencies are derived from not only different analytical methods employed for their detection but also different oceanographic conditions. In particular, the nature and quantities of detectable natural ligands are affected by what kind of form the ligands are presentin situ in different marine environments, that is, chemical speciation of natural ligands (ligand speciation), which depends strongly on the variations in concentrations of coexisting trace metals. Using published data from observations in the laboratory and the field, we provide limits to the ranges of conditional stability constants of organic ligands for copper, zinc and cadmium that are detectable by the extensively used direct metal-titration method. For example, our model indicates that organic ligands for copper with log K_CuL(Cu)>12.4 in surface water and with log K_CuL(Cu)>9.9 in deep water might not have been detected because stronger ligands had formed complexes with ambient metalsin situ at a station in the North Pacific. The estimation suggests that there is a basinscale difference in speciation of natural organic ligands and, moreover, that this difference influences metal speciation. It is postulated that comparisons of the occurrence and levels of organic ligands might not be possible among spatially and temporally different observations without reconciliation of the effects of speciation of the ligands, even if an identical method is used in every case.     

A real-time observation network of ocean-bottom-seismometers deployed at the Sagami trough subduction zone,central Japan

We installed a real-time operating regional observation network of Ocean-Bottom-Seismometers, connected to an electro-optical fiber communication cable, at the Sagami trough subduction zone, just south of the Tokyo metropolitan area, central Japan. The network, called ETMC, has six seismic observation sites at approximately 20 km spacing. In addition, there are three tsunami observation sites along the ETMC network to monitor the propagation process of tsunamis around the Sagami trough region.The on-line data from the ETMC has been improving the detection capability of smaller-magnitude earthquakes even at areas close to the margin of the trough. The ETMC data analyzing system, which has a function of real-time digital filtering for each seismic channel, can read the arrival times of P- and S-waves precisely, constraining well the automatic on-line hypocenter locations. The network has been providing useful information regarding the bending and downgoing process of the Philippine sea plate at the Sagami trough subduction zone.The pressure sensors of the installed network have a detection capability of tsunami wave trains with an amplitude of less than 1 cm. For example, the sensors recorded the full time history of tsunami wave trains, with mm order resolution, originating from a tsunami earthquake with 5.7 M_W and the tsunami magnitude of 7.5 occurred near Tori Shima (Tori Is.) of the Izu-Bonin Is. arc on September 4, 1996. The maximum amplitude of the tsunami signals on the trough-floor was approximately 1 cm (P-P), in contrast with approximately 20 cm (0-P) at a coastal site on Izu-Oshima, near the trough. Also, the pressure sensors observed tsunamis due to a large tsunami earthquake (7.1 M_W) at the northern New Guinea, on July 17, 1998.