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Registros recuperados: 1.958 | |
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Desbruyeres, Daniel; Laubier, Lucien. |
Several unknown animal forms have recently been collected in the immediate vicinity of hot hydrothermal vents in the Eastern Pacific Ocean, forming a flourishing community of organisms. A tubicolous polychaete builds parchment like tubes around some of the hydrothermal vents. The tubes are covered with particles of metallic sulfur. This annelid is a new species, and is called Alvinella pompejana, new genus and species. The new sub-family Alvinellinae, erected to contain this new species, can be included in the family Ampharetidae (order Terebellida), in spite of several aberrant features. In addition to its morphological and taxonomic peculiarities. Alvinella pompejana also exhibits some remarkable biological features, in particular the existence of two... |
Tipo: Text |
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Ano: 1980 |
URL: http://archimer.ifremer.fr/doc/1980/publication-5411.pdf |
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Stoffers, A.L.. |
Herbs, rarely shrubs, vines or trees. Leaves alternate or opposite, sessile or petiolate, simple, mostly entire. Stipules wanting. Inflorescence consisting of various clusters, terminal spikes or axillary heads. Flowers hermaphrodite or unisexual, actinomorphic, bracteate and bibracteolate. Tepals 5(—1), free or partly united, equal or the inner ones smaller, scarious, persistent. Stamens as many as the tepals and epitepalous; filaments free or united into a lobed tube; anthers 2- or 4-celled, with longitudinal dehiscence; staminodes present or wanting. Ovary superior, free or adnate to the base of the perianth, uni-locular, ovoid, ellipsoid or globose; styles 1—2 or wanting; stigma capitate, penicillate or the stigmatic branches 2—3, short or elongate.... |
Tipo: Article / Letter to the editor |
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Ano: 1980 |
URL: http://www.repository.naturalis.nl/record/503222 |
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CNEXO; Ministère de l’Environnement et du Cadre de Vie. |
Il nous a paru indispensable, après la catastrophe de l'Amoco Cadiz, de suivre les publications parues sur le sujet: articles ou communications scientifiques sur l'impact écologique, rapports sur la lutte contre la pollution, textes et mises au point juridiques ou encore bilans économiques ... Le colloque qui se déroule au Centre Océanologique de Bretagne, du 19 au 22 novembre, est une occasion de publier la dernière mise à jour du dossier, au moment où cette réunion viendra en grossir tout d'un coup le volume. |
Tipo: Text |
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Ano: 1980 |
URL: http://archimer.ifremer.fr/doc/00306/41736/40947.pdf |
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Zuiderwijk, Annie. |
Mechanisms controlling the distribution of amphibians in western Europe have been studied in France where related species, isolated from each other at least during the last glacial period, are now sympatric. Occurrences and biotope preferences of the various species were investigated in several regions, with attention to the position of each region within the ranges of the species: central or peripheral. For some species the previously known distribution boundary is partially precised. The population densities of related species in their zones of overlap are discussed. Three pairs of species are considered in particular. Triturus helveticus and T. vulgaris have a large sympatric area in which they appear to be gradually replacing one another. Competition... |
Tipo: Article / Letter to the editor |
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Ano: 1980 |
URL: http://www.repository.naturalis.nl/record/504319 |
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Stock, J.H.. |
In 1980 members of the Institute of Taxonomic Zoology (Zoölogisch Museum) of the University of Amsterdam, have sampled the stygofauna fauna of a number of West Indian islands. The present report records the stations in which stygobionts (= groundwater organisms) were collected. The main purpose of the program was to test the value of various biogeographic models for explaining the insular fauna. |
Tipo: Article / Letter to the editor |
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Ano: 1980 |
URL: http://www.repository.naturalis.nl/record/506335 |
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Stock, Jan H.. |
A new species of Amphipoda, Psammogammarus caesicolus, is described from interstitial, anchihaline waters in Blauwbaai cave, Curaçao, Netherlands Antilles. By the morphology of the third uropod, the new species links the somewhat aberrant Ps. longiramus from the Red Sea with the type-species of the genus, Ps. coecus, from the Mediterranean. The classification of the Eriopisa complex, to which Psammogammarus belongs, is reviewed, resulting in a stricter delimitation of, presumably monophyletic, genera, and the creation of three new genera: Madapisella (type-species Eriopisa madagascarensis Ledoyer, 1968), Nippopisella (type-species Eriopisella nagatai Gurjanova, 1965), and Tunisopisa (type-species Eriopisa seurati Gauthier, 1936). The distribution of the... |
Tipo: Article / Letter to the editor |
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Ano: 1980 |
URL: http://www.repository.naturalis.nl/record/503871 |
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Hartmann-Schröder, Gesa. |
Nineteen species were collected, twelve of which were already known to science, three were not or not exactly determinable and three others as well as a subspecies were new to science and described: Microphthalmia stocki n. sp., Typosyllis bifurcata n. sp., Brania glandulosa n. sp., Sphaerosyllis hystrix anoculata n. subsp. Four of the known species are widely distributed, three are circumtropical-subtropical, two have an Indo-West-Pacific distribution, one species has an amphi-Central-American distribution, and two species are endemics. |
Tipo: Article / Letter to the editor |
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Ano: 1980 |
URL: http://www.repository.naturalis.nl/record/504338 |
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Godden, David P.; Helyar, K.R.. |
A model of fertilizer response is outlined which makes a distinction between conventional fertilizer response curves, and the relationship between product yield and maintenance application of fertilizer. The derivation of optimal fertilizer rates for two enterprises on three soil types is used to illustrate the model. A simple rule-of-thumb, which can be used to avoid some computations, is also discussed. In the Australian context, the model has implications for the derivation of optimal super-phosphate rates, and also has important implications for the type of applied super-phosphate research which should be conducted in the future. |
Tipo: Journal Article |
Palavras-chave: Demand and Price Analysis. |
Ano: 1980 |
URL: http://purl.umn.edu/9343 |
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Laker-Ojok, Rita. |
This paper evaluates two recently implemented strategies to control land use conflict and overgrazing in Kajiado district of southern Kenya, stressing the importance of analyzing attempts to alter traditional pastoralist production systems in terms of the "complex ethno-ecological mosaic in which political power allocates access to strategic resources". A situation, structure, performance paradigm is applied to the problem. Factors central to the situation which underlie the issue of overgrazing are grounded in the ecological and historical context. Highly unpredictable rainfall, repeated drought, and an increasingly constricted resource base form the primary constraints of the Masai production system. In response, complex cultural adaptations and herd... |
Tipo: Thesis or Dissertation |
Palavras-chave: Land Economics/Use. |
Ano: 1980 |
URL: http://purl.umn.edu/11021 |
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Phoofolo, Marabe. |
Lesotho is largely agrarian. More than 90 percent of the Basotho population lives in rural areas. Agriculture provides an important source of income for over 50 percent of the rural population and is the largest contributor to GDP. Apart from migrant labour in the Republic of South Africa (RSA) and limited work in administration and commerce in the few urban centers, there are few employment opportunities other then agriculture. Under production of maize coupled with a growing population has lead to great shortages of maize in Lesotho. The hunger and nutritional problems associated with the maize shortage problem prompted the Government of Lesotho to set out self-sufficiency goals, which if met would help solve the maize shortage problem. In view of... |
Tipo: Thesis or Dissertation |
Palavras-chave: Crop Production/Industries. |
Ano: 1980 |
URL: http://purl.umn.edu/11239 |
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Tweeten, Luther G.. |
The purpose of this study is to estimate the impact of general inflation on prices paid and received by farmers. Specific objectives are: (1) to test the hypothesis that the farm commodity domestic demand function at the farm level is homogeneous of degree zero in price and income; and (2), conditional on not rejecting the hypothesis in (1), to test the hypothesis that general inflation changes the ratio of prices received to prices paid by farmers because of impacts unevenly on prices and income in the demand function versus the supply function for farm output. Empirical results provided no basis to reject the hypothesis that economic functions determining demand for output at the farm level are homogenous of degree zero in income and prices. A truly... |
Tipo: Journal Article |
Palavras-chave: Agricultural Finance. |
Ano: 1980 |
URL: http://purl.umn.edu/32398 |
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Danielopol, Dan L.. |
The freshwater ostracods living exclusively in interstitial and/or interstitial and cavernous habitats belong to the Candoninae, Pseudolimnocytherinae, Timiriaseviinae, Kliellinae and Darwinulidae. An assessment of the antiquity of several interstitial ostracod groups has been attempted using direct evidence from the phylogenetical affinities between living hypogean and fossil ostracod species, and indirect evidence from the morphological characters of the subterranean ostracods and from the bio- and paleobiogeographical distribution of the different ostracod groups. |
Tipo: Article / Letter to the editor |
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Ano: 1980 |
URL: http://www.repository.naturalis.nl/record/504463 |
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Registros recuperados: 1.958 | |
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