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S. Kojima S. Ohta T. Yamamoto T. Miura Y. Fujiwara K. Fujikura J. Hashimoto 《Marine Biology》2002,141(1):57-64
The nucleotide sequence of part (624 bp) of a mitochondrial gene for cytochrome oxidase I was determined for 46 escarpiid vestimentiferans collected from seven sites in the western Pacific and 49 individual specimens of Arcovestia ivanovi from two sites in the Manus Basin. Phylogenetic analysis, based on the newly obtained and previously reported sequences, indicated that escarpiids in the western Pacific can be divided into two tentative species, as we proposed in a previous report. While members of the first tentative species have been collected exclusively from a seep area at a depth of 300 m off the coast of central Japan, the members of the second species inhabit some sites at depths greater than 1,100 m, namely, seep areas in Japanese and Papua-New Guinean waters as well as hydrothermal vent fields in the Okinawa Trough and the Manus Basin. We detected no genetic structure among populations of the second tentative species. The first tentative species was more closely related to a species in the eastern Pacific, Escarpia spicata, and to a species in the Gulf of Mexico, Escarpia laminata, than to the second tentative species in the western Pacific. Sequences obtained from all arcovestiids were identical with the exception of those from three individuals, each of which included a single synonymous nucleotide substitution relative to the dominant haplotype, and no genetic differences were detected between specimens from the two sites in the Manus Basin. 相似文献
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E.W. Lees 《Natural resources forum》1993,17(4):288-293
Energy efficiency is often stated to be the most cost-effective measure for satisfying our energy demand with minimal environmental damage. However, the potential energy savings attainable in 'the real world' are frequently overestimated, as is shown in an industrial case study of the glass industry. Nevertheless, there are significant energy savings to be realized, and the role of new technologies in this is important. However, the key to the effective use of new technology for improved energy efficiency is good management and. for best effect, it must be integrated into the normal resource management activities of a company. 相似文献
26.
K. Pilegaard 《Environmental monitoring and assessment》1993,27(3):221-232
The purpose of this investigation was to monitor airborne dipersion of particulates in connection with exploration activities at a niobium-mineralization in the Sarfartoq area, SW Greenland, during the summer of 1989, and to provide a basis for monitoring strategies in later phases of the development of the mining site. During three periods moss bags were exposed at 9 stations close to the outcrop and at 3 background stations, and indigenous lichens and mosses were sampled before and after the exploration work.Analyses of element concentrations showed that the natural enrichment of elements in the indigenous vegetation is restricted to areas immediately at or on the outcrop. The elements found in elevated concentrations were Nb, La, Ce, Th and U.The moss bags and the indigenous monitor organisms showed rises in concentrations of the elements Nb, Ce, Cd, Pb and Zn after the exploration activities during the summer. This shows that some dispersion of dust has occurred in the area. 相似文献
27.
P Joseph S Viswanatha M K Krishnakumari 《Journal of environmental science and health. Part. B》1992,27(3):269-280
The haematotoxicity of technical hexachlorocyclohexane (HCH) (1000 ppm) was investigated in male albino rats fed with diet free of vitamin A or containing vitamin A at 2000 or 10(5) I.U./kg. Assessment of HCH-induced haematotoxicity at the end of the 7 weeks feeding period was done on the basis of haemoglobin content, total count of red blood cells and white blood cells and the differential counts of the white blood cells as well as by parameters such as packed cell volume, mean corpuscular volume, mean corpuscular haemoglobin, mean corpuscular haemoglobin content, prothrombin time and clotting time. In the rats fed with vitamin A-free diet containing HCH, significant reductions were noticed in the total white blood cells count, clotting time and prothrombin time indicating severe haematotoxicity. Differential count of the white blood cells of these rats revealed a non-significant reduction in the lymphocyte count. The only indication of haematotoxicity caused by hexachlorocyclohexane in the vitamin A supplemented rats was a slight but statistically significant reduction of the total count of white blood cells. These results demonstrate that the haematotoxicity of hexachlorocyclohexane in the rats is enhanced by vitamin A-deficiency and its supplementation particularly in excess but not at hypervitaminotic level is protective against the toxicity. 相似文献
28.
As part of a programme to characterize floating anthropogenic debris in the aquatic environment, the US Environmental Protection Agency (EPA) conducted 18 field surveys in the harbours of major metropolitan cities of the east, west, and Gulf coasts of the United States and the Mid-Atlantic Bight. the surveys were designed to provide information on the types, relative amounts, and distributions of aquatic debris in different geographic regions of the United States. Neuston nets (0.33 mm mesh) were used to collect surface debris during outgoing tides on two or three consecutive days in selected areas of each city. After each net tow, the debris, which ranged in size from small resin pellets to large plastic sheeting pieces, was identified, categorized, and counted. the data are being used to qualitatively characterize aquatic debris in coastal metropolitan areas, to examine potential regional variations, and to tentatively identify potential sources. 相似文献
29.
An experimental investigation of explanations for inconsistencies in responses to second offers in double referenda 总被引:1,自引:0,他引:1
Anthony C. Burton Katherine S. Carson Susan M. Chilton W. George Hutchinson 《Journal of Environmental Economics and Management》2003,46(3):472
This paper demonstrates the potential for induced preference experiments to test previously unverified explanations of observed behavior in contingent valuation surveys. The NOAA Panel on Contingent Valuation called for experimental evidence on potential biases in the double referendum format. We test Carson, Groves, and Machina's (Incentives and informational properties of preference questions, Plenary address to the European Association of Resource and Environmental Economists, Oslo, Norway, June 1999) simple cost uncertainty and weighted averaging explanations of inconsistent responses to follow-up offers in such double referenda against a baseline of certainty and truthful preference revelation. The results find evidence to support the Weighted Average hypothesis. Results regarding the cost uncertainty hypothesis are more ambiguous and merit further investigation. 相似文献
30.
W. F. Wood 《Marine Biology》1987,96(1):143-150
During spring and summer, 1982–1986, experiments were carried out near Marmion Reef, Western Australia. In summer, nearly 30% of the surface solar ultraviolet radiation (280 to 400 nm) penetrates offshore waters to 5 m depth. Experimental removal of the mature Ecklonia radiata kelp canopy in summer results in tissue damage, photopigment destruction, reduced growth, and low survivorship of subcanopy kelp sporophytes. These effects do not occur with canopy removal in winter. Laboratory experiments revealed that the UV component of radiation, rather than intense photosynthetically active radiation, was responsible for the inhibition of growth and photodamage. UV radiation probably affects survival of the settlement stages of E. radiata sporophytes, thus excluding them from otherwise suitable substrata in shallow waters. UV radiation is implicated in the reduction of canopy productivity in summer. 相似文献