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421.
In this study male largemouth bass (LMB) were exposed to the naturally occurring androgens, dihydrotestosterone (DHT) or 11-ketotestosterone (11-KT) in order to identify genes that are differentially regulated by these steroid hormones. Using subtractive hybridization on livers of fish treated with DHT against vehicle control, many novel LMB genes were cloned. These genes were added to our gene library and arrayed. Six genes were up-regulated and five were down-regulated by both androgens. But, each androgen also regulated specific genes. One gene that was identified as a potential androgen marker was spermidine-spermine-N(1)-acetyltransferase that was up-regulated by both androgens. Determining which genes are responsive to natural androgens will help to identify biochemical pathways that are impacted.  相似文献   
422.
423.
DNA single-strand breaks were measured by the comet assay in both gill and hemolymph cells of mussels collected in 3 sampling areas of the French coast (Pointe du Castelli, Pen Bron and Saint-Nazaire Harbour). Whole mussel tissue samples were also collected for the chemical determination of PAH, PCB and heavy metal concentrations. In mussel, a higher level of DNA strand breaks was measured in gill than in hemolymph cells (p < 0.01). Despite a factor of contamination from 2 to 3 between sites, no difference in the extent of mussel DNA strand breaks was shown between sampling locations (p > 0.05), questioning the sensitivity of the assays used in biomonitoring studies.  相似文献   
424.
The results of a comprehensive field trial of nearly all commercially available directional wave measurement systems at the Edda field in the North Sea during winter 1985-86 are presented. The results summarize the accuracy of the principal engineering wave parameters from each system and the dependence on sea state. Limiting factors on system performance and operational problems are also included in the assessment. Overall experience has been good with systems utilizing widely different measurement principles returning consistent results.  相似文献   
425.
426.
Within the framework of the linear theory taking into account the action of the Coriolis force, we study waves induced in a continuously stratified fluid with one thermocline by periodic variations of pressure on the free surface. The fluid fills a bounded basin of constant depth. We establish the dependences of the wave amplitudes and wave velocities on the period of disturbing pressure. The sequence of transformations of generated waves from the barotropic character of motion to baroclinic depending on changes in the period of disturbing pressure is studied in detail.  相似文献   
427.
cDNA's coding for cytochrome P4501A1 (CYP1A1), phenol UDP-glucuronosyltransferase (UDPGT) and glutathione S-transferase (GST-A) were cloned and sequenced from an expression library prepared from the liver of a 3-methylcholanthrene (3-MC) induced plaice. Plaice CYP1A1 and Phenol UDPGT display a high degree of structural conservation with homologous mammalian isoforms and their mRNAs were shown to be highly induced in liver after 3-MC treatment of fish. Expression of plaice GST-A, which displays closer homology to GSTs from plants and invertebrates than those of mammals, is repressed after 3-MC treatment.  相似文献   
428.
Internal waves occurring near an oceanic ridge as a result of impingement of a barotropic tide are scrutinized in terms of the long theory for long waves. The ocean is assumed to be double-layered, the relief continuously changing, and the tidal wave on-running at an arbitrary angle. The dependences of the wave amplitudes and horizontal velocities on the ridge's latitude, the angle of tide running, and the depth of the density jump layer are obtained. Similar investigations for the model bottom relief have been conducted in refs 1 and 3.Translated by Vladimir A. Puchkin.  相似文献   
429.
The currents and surface level oscillations in the Sea of Azov ensuing from contraction of the mouth of Taganrog Bay are computed using the grid technique on the basis of a numerical solution to the system of quasi-linear, degenerate, parabolic, partial derivative equations (shallow-water equations). It is demonstrated what changes are to be expected in the dynamics of the Sea of Azov should this project be realized. The computations were carried out for typical wind directions.Translated by Vladimir A. Puchkin.  相似文献   
430.
Marine tourism has surfaced as a pressing topic in the field of ocean and coastal management. Neither necessarily good, nor bad, this tourism is inherently controversial. Today, demand for travel exhibits greater variation and magnitude than ever in history. In response, the tourism industry has become the largest business on earth. This, coupled with the respect people profess for marine environments and local peoples, creates feelings of ambivalence for the tourist. Sociologically, the activity of tourism may be studied as a symbolic interaction fostering social solidarity. Ecotourism, a recent phenomenon attuned to the ideal of sustainable development, is suggested to emerge through the social construction processes of restoration and enhancement. The papers in this theme volume add fuel to the proposition that the resolution of tourism problems in the coastal zone will require the scientific study of environmental and social conditions, policy analyses, planning, and public education.  相似文献   
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