1000 resultados para 1908-1963


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ENGLISH: The Inter-American Tropical Tuna Commission was created by a Convention between the Republic of Costa Rica and the United States of America. The Convention came into force in 1950. One of the provisions of the Convention was that other governments whose nationals participate in the fisheries covered by the Convention could adhere if they so desired and if the existing members agreed. Under this arrangement, the Republic of Panama adhered to the COl1vention in 1953. The Republic of Ecuador adhered in 1961. The Senate of the Republic of Mexico approved adherence in 1963; and the Republic of Colombia has indicated her desire to adhere. Full members during 1963 were Costa Rica, Ecuador, Panama, and the United States. SPANISH: La Comisión Interamericana del Atún Tropical fue creada en virtud de una Convención entre la República de Costa Rica y los Estados Unidos de América. La Convención entró en vigencia en 1950. Una de las estipulaciones de la Convención, permite a los gobiernos de otros países cuyos habitantes participen en las pesquerías a que dicha Convención se refiere, adherirse a ella si así lo desean y si los Gobiernos Miembros están de acuerdo. Acogiéndose a esa estipulación, la República de Panamá se adhirió a la Convención en 1953. La República del Ecuador se adhirió en 1961. El Senado de la República de México aprobó la adhesión en 1963; y la República de Colombia ha manifestado su deseo de adherirse. Durante el año de 1963 han sido miembros Costa Rica, Ecuador, Panamá y los Estados Unidos. (PDF contains 89 pages.)

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This brief chapter describes the occurrence Macrocyclops distinctus in the littoral zone of the Rybinsk Reservoir. Sampling was undertaken in summer and autumn 1961. In order to facilitate distinction of M. distinctus and Macrocyclops fuscus the author presents drawings of the whole species and certain characteristic parts of the body, and also gives a description of M. distinctus, comparing it with M. fuscus.

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Planktobenthos was sampled in 1957-58 in the river Amur. A determination of the kind of organisms drifting in the mass of water of the Amur was carried out. Of special interest for the authors was the activity of drifting of benthic larvae.

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The passive spread of a high percentage of freshwater organisms is one of the most important requirements in short-lived and insular communities for species to attai n and survive - and consequently to balance the lack of a topographical continuity of most inland waters. Unfortunately hardly anything is known about the amounts of seed material typical for any lake into which it is carried. The causes of passive dissemination - wind, water and animals as well as man - are confirmed by many examples. It has been assumed now for at least a hundered years that , among animals, birds play a prominent role, although also disappointingly few facts are at hand. The passage and spread through birds' intestines has up to now been supported only by some limited data. This paper reports on experimental research where the eggs of Daphnia magna, Triops cancriformis, Artemia salina, Diaptomus spinosus and Cypris pubera were introduced by means of gelatine capsules into the oesophagus of a drake. The bird's excrements were inspected under a microscope for eggs and resting stages, and these were transferred into corresponding cultures.

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Representatives from the family of Lemnaceae (duckweed) make ideal experimental material for research into a succession of phytophysiological processes with regard to growth rate and vegetative reproduction. They are also easy to maintain in sterile cultures. Lemnaceae belong to the higher flowering plants (flowers are rarely produced), however they are distinguished by a much simplified morphological and anatomical structure. As water plants they possess the advantage, that they can be cultivated in synthetic media under laboratory conditions controlled by the application of both a known light intensity and temperature. This paper describes experimental research of growth of Lemnaceae in different conditions. Some of the variables were mineral media, illumination and aeration.

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The dynamics of the fecundity of roach, with emphasis on Rutilus rutilus (L.), were studied in waters in the European parts of the USSR. This translation provides conclusions, and figures and table captions only.

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Taxonomic observations are given on Dangeardia sporapiculata n. sp. Furthermore the term 'apiculus' and the species limitation of some chytrids are being discussed. It is concluded that the newly described species Dangeardia sporapiculata does not fit satisfactorily into the present system of phlyctidiacee, because their characteristics do not agree exactly with any genus.

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During hydrographic and plankton studies carried out since 1960 in the coastal zone between the Ebro and Castellon (western Mediterranean), data has been collected which confirms the importance of ciliates in the composition and activity of the plankton. The ciliates in 413 samples of 100 ml of water were counted, having been examined with the Utermohl microscope after sedimentation. The samples studied were distributed according to the density of their population. subject for study. The author concludes that recognition of the role of ciliates as an important link in the food chain of the sea would simplify the interpretation of certain problems posed by the nutrition of certain groups of planktonic animals.

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11 cartas (mecanografiadas y manuscritas); entre 170x215mm y 215x315mm

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[es]organización del trabajo en la industria del automovil en el s. XX.

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From several sources of data, the authors study seasonal variations of larval abundance for five species of tuna in Eastern Tropical Atlantic and its relation to the hydrological conditions. Distributional maps and TS graphs are given.

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1 carta (manuscrita) ; 225x165 mm