9 resultados para Bérgson, Henri, 1859-1941.
em Aquatic Commons
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(Document contains 79 pages.)
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Industrial effluents in the lower Patapsco area, which constitutes the navigable portion of the river and includes Baltimore Harbor, are many and include waste acid, distillery waters, tannery wastes and copper as (ferrous sulphate) from pigment and steel industries. (PDF contains 22 pages (2 on 1)
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Cases of red colouration in small lake basins, due to the abundant appearance of microorganisms have long been known. Usually it is caused by a fast, sudden, intensive propagation (so called ”bloom”) of Cyanophycae and bacteria. (e.g. Oscillatoracae, thiobacteria etc.). An exception to this is the red colouration of Tovel-See, an alpine lake basin in the Dolomites of the Brenta group (Trentino), lying at a height of 1178 m and hidden in the woodland of a valley. Here the red bloom has a double rhythm: a daily and a yearly rhythm. The colouration of one part of the lake takes place in the warmest months of the year (i.e. July, August, September) and in the middle hours of the day. The immediate origin of the bloom has been known for a long time: it is caused by the Peridinacae Glenodinium sanguineum. This paper describes the phenomenon of red colouration of the lake and discusses its conditions.
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During recent years in connection with the industrialisation of the Kola Peninsula, the study of this district in the botanical respect, in particular the study of the microflora of various bodies of water, began to advance markedly. This article describes the algal flora of the Kola Peninsula. Morphological descriptions are given for three Tetraspora: Tetraspora simplex, Tetraspora tenera, Tetraspora imperfecta. Chlorophysema aduata is also described, and short descriptions of further algae found in the Kola Peninsula are given.
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Three diets were formulated using locally available feed ingredients in Malawi to test the effect of replacing animal protein (fish meal, meat and bone meal) with soybean meal (10:0, 5:5, 0:10% of diet) as the protein source on growth and feed conversion of Oreochromis karongae. There were no significant differences in growth rate (GR), specific growth rate (SGR) and feed conversion ratios (FCR) among the three diets. It can be concluded that more expensive and limited animal protein sources can totally be replaced by cheaper soybean in order to get similar growth rates in O. karongae.
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Charles Henry Gilbert (1859-1928) was a pioneering ichthyologist who made major contributions to the study of fishes of the American West. As chairman of the Department ofZoology at Leland Stanford Junior University in Palo Alto, Calif., during 1891-1925, Gilbert was extremely devoted to his work and showed little patience with those ofa different mindset. While serving as Naturalist-in-Charge of the U.S. Fish Commission Steamer Albatross during her exploratory expedition to the Hawaiian Islands in 1902, Gilbert engaged in an acrimonious feud with the ship's captain, Chauncey Thomas, Jr. (1850-1919), U.S.N., over what Gilbert perceived to be an inadequate effort by the captain. This essay focuses on the conflict between two strong figures, each operatingf rom different world views, and each vying for authority. Despite the difficulties these two men faced, the voyage of the Albatross in 1902 must be considered a success, as reflected by the extensive biological samples collected, the many new species of animals discovered, and the resulting publication of important scientific papers.
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Fishery science pioneers often faced challenges in their field work that are mostly unknown to modern biologists. Some of the travails faced by ichthyologist and, later, fishery biologist Charles Henry Gilbert (1859-1928) during his service as Naturalist-in-Charge of the North Pacific cruise ofthe U.S. Bureau of Fisheries Steamer Albatross in 1906, are described here, as are accomplishments of the cruise. The vessel left San Francisco, Calif., on 3 May 1906, just after the great San Francisco earthquake, for scientific exploration of waters of the Aleutian islands, Bering Sea, Kamchatka, Sakhalin, and Japan, returning to San Francisco in December. Because the expedition occurred just after the war between Japan and Russia of 1904-05 floating derelict mines in Japanese waters were often a menace. Major storms caused havoc in the region, and the captain of the Albatross, Lieutenant Commander LeRoy Mason Garrett (1857-1906), U.S.N., was lost at sea, apparently thrown from the vessel during a sudden storm on the return leg of the cruise. Despite such obstacles, Gilbert and the Albatross successfully completed their assigned chores. They occupied 339 dredging and 48 hydrographic stations, and discovered over 180 new species of fishes and many new species of invertebrates. The expedition's extensive biological collections spawned over 30 descriptive publications, some of which remain today as standards of knowledge.
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Genetic variation of Contracaecum ogmorhini (sensu lato) populations from different otariid seals of the northern and southern hemisphere was studied on the basis of 18 enzyme loci as well as preliminary sequence analysis of the mitochondrial cyt b gene (260 bp). Samples were collected from Zalophus californianus in the boreal region and from Arctocephalus pusillus pusillus, A. pusillus doriferus and A. australis from the austral region. Marked genetic heterogeneity was found between C. ogmorhini (sensu lato) samples from the boreal and austral region, respectively. Two loci (Mdh-2 and NADHdh) showed fixed differences and a further three loci (Iddh, Mdh-1 and 6Pgdh) were highly differentiated between boreal and austral samples. Their average genetic distance was DNei = 0.36 at isozyme level. At mitochondrial DNA level, an average proportion of nucleotide substitution of 3.7% was observed. These findings support the existence of two distinct sibling species, for which the names C. ogmorhini (sensu stricto) and C. margolisi n. sp., respectively, for the austral and boreal taxon, are proposed. A description for C. margolisi n. sp. is provided. No diagnostic morphological characters have so far been detected; on the other hand, two enzyme loci, Mdh-2 and NADHdh, fully diagnostic between the two species, can be used for the routine identification of males, females and larval stages. Mirounga leonina was found to host C. ogmorhini (s.s.) inmixed infections with C. osculatum (s.l.) (of which C. ogmorhini (s.l.) was in the past considered to be a synonym) and C. miroungae; no hybrid genotypes were found,confirming the reproductive isolation of these three anisakid species. The hosts and geographical range so far recorded for C. margolisi n. sp. and C. ogmorhini (s.s.) are given.
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Like pages of a "natural coastal diary", successive layers of anoxic varved sediment in the central Santa Barbara Basin have been used by paleoceanographers to reconstruct aspects of past coastal climate. This report focuses on the end of the "Little Ice Age" (15th to 19th century) and on the beginning of this century, a period known to encompass extreme climate excursions and weather events in the Santa Barbara Basin and other parts of Southern California. El Niño events are known to disrupt Southern California's coastal ecosystems and to cause anomalous weather conditions, but El Niño events in Southern California before 1990 have been largely undocumented.