Statistical Modeling of Monthly Anomalies of Atmospheric Precipitations for the Region of the Ukraine and Black Sea     

Efimov  V. V.  Shokurov  M. V.  Barabanov  V. S. 《Physical Oceanography》2002,12(1):10-23

The data array accumulated for the period 1946–1995 is used to select the most significant predictor of monthly anomalies of precipitation in the region of the Ukraine and Black Sea, namely, a large-scale circulation in a sector covering the North Atlantic and Europe. Three large-scale predictors (geopotential at a level of 500GPa, sea-level pressure, and the difference between the geopotentials at levels of 500 and 1000GPa) give almost identical results: their correlation with anomalies of precipitation is equal to 0.7–0.8 in winter and 0.4–0.5 in summer. The predominant mechanism of the influence of circulation on precipitations at low frequencies is the response of the trajectories of European cyclones to changes in the upper-tropospheric jet currents in the Atlantic-European sector described as the superposition of the North-Atlantic oscillation and the Eurasian mode. The decomposition of the fields of precipitations and circulation in the eigenmodes of the canonical correlation analysis opens a possibility of direct computation of the monthly average fields of precipitations for the entire territory of the Ukraine and Black Sea region according to the large-scale geopotential fields.  相似文献   

Evaluation of acetylcholinesterase activity in several zooplanktonic crustaceans     

Minutoli R  Fossi MC  Guglielmo L 《Marine environmental research》2002,54(3-5):799-804

Zooplankton are an essential component of the marine and estuarine food chains. The ecotoxicological risk to zooplanktonic communities, estimated through the use of the biomarkers, can be used as an early warning signal of a potential alteration of the ecosystem health. The aim of this project was to evaluate the potential use of several biomarkers (esterases, mixed function oxidases, porphyrins) in zooplanktonic organisms. The acetylcholinesterase activity (AChE) was determined in homogenates of whole organisms of 10 different zooplanktonic crustaceans. Mean activity of AChE was 10.05 micromol/min/g for Acartia margalefi; 3.30 for Acartia latisetosa; 79.70 for Siriella clausi; 49.97 for Diamysis bahirensis; 7.48 for Siriella armata; 14.20 for Mysidopsis gibbosa; 4.49 for Euphausia crystallorophias; 1.66 for Euphausia superba; 2.74 for Streetsia challengeri; 13.26 for Meganycthiphanes norvegica. The species moreover showed a linear increase in enzyme activity in relation to the increase in sample concentration. The key result of this study concerns the different AChE activity basal values of the crustaceans' different species.  相似文献   

In situ determination on food consumption and ecological conversion efficiency of a marine fish species, Hyporhamphus sajori     

Sun Yao  Yu Miao  Zhang Bo  Tang Qisheng 《海洋学报(英文版)》2002,21(3):407-414

The food consumption and ecological conversion efficiency of a species marine pelagic andsmall size fish, Hyporhamphus sajori, were determined by using in situ stomach content method presented by Eggers. The results showed that: (1) the fish was taken in food all day, so empty-stomach rate was very low, taking up about 4.5% of the total determined fish number. However, the fish still has significant daily feeding rhythm. A feeding peak was found 0:00 o'clock at night, but feeding level was always high in the daytime; (2) relationship between instantaneous food content in stomach and corresponding time could be described as S_t = a ·e ~(-b ·t). There was not significant difference of instantaneous gastric evacuation rate between two determinations, with average value being 0.13 × 10~(-2)g/ (g·d) (wet weight); (3) the daily food consumption tended to change in irregular waving form, with average value being (10.16×l0~(-2)±1.19×l0~(-2) g/ (g·d) (wet weight) or (55.56 × 10~(-2) ±6.51 × 10~(-2) kJ/  相似文献   

Control over natural resources in ecological economical systems     

I. E. Timchenko  E. M. Igumnova 《Physical Oceanography》2001,11(6):525-541

We consider the problem of stable development of natural economical complexes from the viewpoint of basic balances in an ecological economical system. We construct a basic dynamical model of the complex capable of predicting various scenarios of the industrial development, consumption of natural resources, and pollution of the environment and propose a mechanism of control over the process of development by introducing rent payments for the use of natural resources and ecological fines for the pollution of the environment. The efficiency of the applied model is demonstrated by analysing the process of control over the concentration of biological resources in marine media as an example. We describe the results of numerical experiments performed to show the possibility of creation of the information technology of control over marine bioresources. Translated by Peter V. Malyshev and Dmitry V. Malyshev  相似文献   

Evaluation of toxicity in tributaries of the Mersey estuary using the isopod Asellus aquaticus (L.)     

A. J. O'Neill  T. S. Galloway  M. A. Browne  A. Dissanayake  M. H. Depledge 《Marine environmental research》2004,58(2-5):327

Increasing numbers of industrial, agricultural and natural chemicals are present in sewage effluent and are known to elicit toxic effects in laboratory exposures, but little is known of their combined sub-lethal effect in the field. In this study, a combination of esterase activity and ventilation rate assays was performed to determine the neurological and physiological function of the freshwater crustacean Asellus aquaticus (L.) at sites above and below a sewage treatment works (STW). Cholinesterase and carboxylesterase activities were significantly inhibited (n=8, P<0.05) and ventilation rates increased (n=8, P=0.0001) in A. aquaticus at STW sites compared to those from reference sites, indicating a decrease in neurological and physiological function. The ecological relevance of these findings for the population dynamics of the organisms in the field is discussed.  相似文献   

珠江口东南近海海区污损生物研究   总被引：4，自引：2，他引：4  

严涛  严文侠  董钰  梁冠和  严岩  王华接 《海洋学报》2003,25(6):117-125

为研究珠江口东南近海海区污损生物状况,于1986年5月至1987年6月,在香港东南约114和160km,水深为95和113m处布设了两个生物浮标站,并对距香港约172km,水深为115m处的Marex水文气象浮标上的污损生物群落进行调查.此次调查共采集和鉴定出污损生物78种,其中在浸海只有3个月的试板上,主要有柄蔓足类、水螅和藻类,优势种是细板条茗荷、茗荷和直杯螅.至于浸海时间达6～12个月的浮标(包括沉标)及锚链系统,其上还有相当数量的多种双壳类软体动物、无柄蔓足类和苔藓动物等硬性污损生物附着.在种类垂直分布方面,污损生物群落组成随深度发生明显变化.  相似文献   

地球信息科学的研究与发展     

于冬梅 《海岸工程》2002,21(2):59-65

信息时代的召唤,地球信息科学应运而生.经过10a左右的发展,地理信息科学已见雏形.总结了10a来地球信息科学的研究结果,并介绍了地球信息科学的研究内容和发展前景.  相似文献   

Esterases as biomarkers in Nereis (Hediste) diversicolor exposed to temephos and Bacillus thuringiensis var. israelensis used for mosquito control in coastal wetlands of Morbihan (Brittany,France)     

Fourcy D  Jumel A  Heydorff M  Lagadic L 《Marine environmental research》2002,54(3-5):755-759

Since 1998, a biomonitoring programme has been implemented to assess the potential impact of chemical mosquito control on macroinvertebrates of the coastal wetlands of Morbihan (Brittany, France). Acetylcholinesterase and carboxylesterases were used as biomarkers to assess the effects of Abate 500e (a.i. temephos) and Vectobac 12 AS (a.i. endotoxins of Bacillus thuringiensis var. israelensis, Bti) in Nereis (Hediste) diversicolor. Esterase inhibition revealed a marked impact of temephos, suggesting preferential contamination of the worms through the food. In Bti-exposed N. diversicolor, random variations of esterase activities were observed, that could not be attributed to the larvicide. However, esterases only reflected indirect physiological effects of Bti, and further investigations are needed to identify biomarkers more specific of Bti endotoxins.  相似文献   

The CANALES experiment (1996-1998). Interannual, seasonal, and mesoscale variability of the circulation in the Balearic Channels     

J. -M. Pinot  J. L. Lpez-Jurado  M. Riera 《Progress in Oceanography》2002,55(3-4)

Repeated hydrographic casts, mooring time series and satellite sea surface temperature collected during the CANALES experiment (1996–98) are used to describe the thermohaline circulation in the Balearic Channels (western Mediterranean) and to analyze its variability. Mass transports are estimated by inverse calculations. The role played by each channel in the meridional water exchange is clarified: the Ibiza Channel funnels southward cool, saline, northern waters whereas the Mallorca Channel appears as the preferred route for the northward progression of warm, fresh, southern waters. A neat interannual trend is revealed by the continuous decrease of the amount of Western Mediterranean Intermediate Waters (WIW) brought by the Northern Current, reflecting the increase in temperature of the winter mixed layer in the northern Mediterranean that occurred each year between 1996 and 1998. A clear seasonal signal was also seen in the transport of the Northern Current which decreased from 1 to 1.4 Sv in winter to < 0.5 Sv in summer. The current intensified again in fall. A number of mesoscale eddies, from 20 to 70 km in size, most of them anticyclonic vortex eddies were brought by the unstable Northern Current, these eddies strongly perturbed the water exchange in the Ibiza Channel forcing retroflections of northern waters back to the north-east into the Balearic Current. These eddies either stayed stalled for several months in the Gulf of Valencia to the north of the channel, or were slowly funnelled southward through the channel narrows. A decreasing trend was observed in the mesoscale activity of the Northern Current between 1996 and 1998. Conversely, large, anticyclonic eddies, 150-km diameter, progressively invaded the Algerian Basin to the south of the channels in 1997–98 and forcing northward inflows (up to 0.75 Sv) of fresh and warm waters of Atlantic origin (AW) into the Mallorca Channel. The marked interannual differences observed in both northern and southern eddy activity may be linked to the interannual variability of the large scale thermohaline circulation.  相似文献   

黄鳍鲷LDH同工酶的组织特异性研究   总被引：10，自引：0，他引：10  

朱友芳  许玉德  林加涵 《台湾海峡》2001,20(3):386-389

以黄鳍鲷为材料进行两方面研究:（1）用聚丙烯酰胺凝胶电泳方法，对其肌肉，心脏，肝脏，血清，玻璃体，晶状体，脑等组织器官进行LDH同工酶分析比较，结果表明，不同组织中LDH的同工酶谱带不相同，存在着组织特异性：（2）用聚丙烯酰胺等电聚焦电泳法对其肌肉，血清的LDH同工酶进行分离 ，结果得到12－15条电泳区带，等电点范围在pH为3．65－9．58之间。  相似文献