Oxidative stress in ecotoxicology: from the analysis of individual antioxidants to a more integrated approach     

Regoli F  Gorbi S  Frenzilli G  Nigro M  Corsi I  Focardi S  Winston GW 《Marine environmental research》2002,54(3-5):419-423

An integrate approach will be discussed for investigations on oxidative stress in xenobiotic toxicity. While the analysis of individual antioxidants is useful for their sensitivity and to understand the mode of action of a stressor, the integration with the analysis of the total antioxidant capacity provides a more holistic assessment of the overall biological significance of such variations. TOSC has a greater predictive value on the health condition of the organisms and allows to discriminate the different role of specific ROS in oxidative stress syndrome.  相似文献   

High-resolution acoustic mapping of shallow gas in unconsolidated sediments beneath the strait of Georgia,British Columbia     

B. S. Hart  T. S. Hamilton 《Geo-Marine Letters》1993,13(1):49-55

Gassy sediments are detectable acoustically in subbottom profiles of Canada's Fraser Delta slope and prodelta areas. Interstitial gas is typically represented by zones of acoustic turbidity on high-resolution seismic profiles and by gas brightening on air-gun profiles. The top of the acoustically turbid zone is generally highest within the sediment column closest to the river mouths and lies within 10 ms (two-way travel time) of the sea floor in a nearly continuous area that covers over 530 km². Most of the gas is believed to be biogenic in origin, although thermogenic gas derived from underlying Tertiary sedimentary rocks may be present in places.  相似文献   

Magnetic studies over the northern extension of the Prathap Ridge complex,eastern Arabian Sea     

K. S. Krishna  G. Prabhakar S Murty  K. Srinivas  D. Gopala Rao 《Geo-Marine Letters》1992,12(1):7-13

The northern parts of the Prathap and Laccadive Ridge system, eastern Arabian Sea, consist of three parallel basement ridge peaks at varied depths. The topographic highs are associated with either well-developed or subdued magnetic signatures. Model studies, constrained by seismic results, determine the varied nature and depth to the top of the causative basement bodies. Similarities of the geophysical signatures of the ridges and their structural resemblance perhaps point to their common origin. Hence we propose that the Prathap Ridge complex may be a part of the Chagos-Laccadive Ridge system and formed because of the Reunion hotspot activity.  相似文献   

A simple and precise analytical method for the determination of caesium-137 in sea water     

Roger  S.; Wilson  T. 《ICES Journal of Marine Science》1974,36(1):87-89

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Egg Weight in Atlantic Herring (Clupea harengus L.)     

Hempel  G.; Blaxter  J. H. S. 《ICES Journal of Marine Science》1967,31(2):170-195

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The effect of boundary conditions and turbulent exchange intensity on the adaptation calculations of the tropical Atlantic hydrothermodynamic fields     

E. N. Mikhailova  N. B. Shapiro 《Physical Oceanography》1993,4(6):443-452

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Ecotone or Ecocline: Ecological Boundaries in Estuaries   总被引：1，自引：0，他引：1  

M. J. Attrill  S. D. Rundle 《Estuarine, Coastal and Shelf Science》2002,55(6):929

Two main ecological boundaries, ecotone and ecocline, have been defined in landscape ecology. At this scale, the estuary represents a boundary between rivers and the sea, but there has been no attempt to fit empirical data for estuaries to these boundary models. An extensive data set from the Thames estuary was analysed using multivariate techniques and species-range analysis, in order to investigate whether the ecocline or the ecotone model was most relevant to this estuary. Data for periods of high and low freshwater flow allowed the impact of large-scale fluctuations implicit in both models to be determined.A continuum of assemblages existed along the salinity gradient from freshwater river to the North Sea, with shifts in the ranges of organisms apparent in response to changes in freshwater flow. This pattern closely fits an ecocline model. However, the estuary differs from previously defined ecoclines in having two overlapping gradients in the major stressor: from river to mid-estuary for freshwater species and from sea to mid-estuary for marine species. We propose, therefore, that the estuary represents a two-ecocline model, with fauna inhabiting the mid-estuary being either freshwater or marine species at the edge of their range, rather than ‘ true estuarine organisms ’. This allows a redefinition of the Remane diagram, with estuarine species removed, and supports previous arguments that brackish-water species do not exist. Such two-ecocline models may also exist in other marine systems, such as rocky shores.  相似文献   

The composition and distribution of saturated and aromatic hydrocarbons in nearshore sediments, river sediments, and coastal peat of the Alaskan Beaufort Sea: Implications for detecting anthropogenic hydrocarbon inputs     

Margarete S. Steinhauer  Paul D. Boehm   《Marine environmental research》1992,33(4)

A 3-year program, to determine spatial and temporal trends in sediment concentrations of hydrocarbons and metals from oil and gas exploration and development activities, was conducted in the US Beaufort Sea. Concentrations of saturated and aromatic hydrocarbons in sediments from the Beaufort Sea were elevated in comparison to non-polluted shelf-sediments from other regions of the US coast. Potential natural sources for hydrocarbons that were examined included riverine sediments and coastal peat. Significant quantities of fossil hydrocarbons characterize the surface sediments from the entire region. Sediment inputs from river discharges appear to account for this observation. The use of source-diagnostic ratios has allowed the differentiation of various sources in an area with high naturally-occurring hydrocarbon concentrations where effects due to oil and gas exploration and development activities may be obscured.  相似文献   

Statistical analysis of a global photochemical model of the atmosphere     

V. A. Frol’kis  I. L. Karol’  A. A. Kiselev  Yu. E. Ozolin  V. A. Zubov 《Izvestiya Atmospheric and Oceanic Physics》2007,43(4):413-422

This is a study of the sensitivity of model results (atmospheric content of main gas constituents and radiative characteristics of the atmosphere) to errors in emissions of a number of atmospheric gaseous pollutants. Groups of the model variables most dependent on these errors are selected. Two variants of emissions are considered: one without their evolution and the other with their variation according to the IPCC scenario. The estimates are made on the basis of standard statistical methods for the results obtained with the detailed onedimensional radiative—photochemical model of the Main Geophysical Observatory (MGO). Some approaches to such estimations with models of higher complexity and to the solution of the inverse problem (i.e., the estimation of the necessary accuracy of external model parameters for obtaining the given accuracy of model results) are outlined.  相似文献   

Mud and fluid migration in active mud volcanoes in Azerbaijan   总被引：7，自引：2，他引：7  

S. Planke  H. Svensen  M. Hovland  D. A. Banks  B. Jamtveit 《Geo-Marine Letters》2003,23(3-4):258-268

Mud volcanic eruptions in Azerbaijan normally last for less than a few hours, and are characterized by vigorous extrusion of mud breccias, hydrocarbon gases, and waters. Recent fieldwork and mapping on four active mud volcanoes show that dormant period activity ranges from quiet to vigorous flow of mud and fluids. Geochemical analyses of expelled waters show a wide range in solute concentrations, suggesting the existence of a complex plumbing system. The mud and fluids have a deep origin, but are sometimes stored in intermediate-depth mud chambers. A mixing model between deep-seated saline waters and shallow meteoric water is proposed.  相似文献