共查询到20条相似文献,搜索用时 0 毫秒
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《Cryptogamie Bryologie ☆》1999,20(4):267-270
The occurrence of Orthotrichum philibertii Vent. in the Iberian Peninsula, Balearic islands and northern Morocco is reported, extending its area to the westernmost Mediterranean basin. The new populations supply some new elements that enlarge the variability range of this species. 相似文献
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Jean J. Burton 《Primates; journal of primatology》1977,18(2):359-366
A short observation of a free ranging Japanese macaque troop at her feeding place provides some evidence about the absence of spontaneous instrumental cooperative behavior in a food getting situation. The experimental situation was designed to test the posibility inMacaca fuscata of collaborative action (removing of heavy baited stones) and sharing of reward. Out of approximately 100 situations only 26 were of social interest. Sixteen in a tolerant fashion and 10 in aggressive one. Of special interest is that the tolerant cases are almost all the fact of individuals from same affiliative groups and/or from same age’s class (juveniles). Conversely the aggressive cases occur between individuals from different affiliative groups. This is to be related with the social organisation ofMacaca fuscata troop. If the environmental pressure was powerful enough to associate some individuals on the same job this was likely to happen between already acquainted (through grooming for example) individuals. 相似文献
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Claude Monniot 《Systematic parasitology》1986,8(2):151-162
Resumé Deux formes femelles différentes de Pachypygus macer sont décrites des ascidies Styela partita et Microcosmus exasperatus, récoltées dans un port de Guadeloupe. L'auteur suggère que ces deux formes sont des phénotypes dérivés de parents communs qui auraient été introduits en Guadeloupe par un navire entre 1974 et 1980. Styela partita semble avoir une influence régressive sur le copépode. Ce phénomène est discuté en relation avec l'existence de deux phénotypes mâles chez l'espèce européenne Pachypygus gibber.
Summary Two distinctive female forms of Pachypygus macer are described from the ascidians Styela partita and Microcosmus exasperatus, collected from a harbour in Guadeloupe. The author suggests that these two forms are phenotypes derived from common parents that could have been introduced into Guadeloupe by a ship between 1974 and 1980. S. partita appears to have a regressive influence upon the copepod. This phenomenon is discussed in relation to the existence of two male phenotypes in a European species, Pachypygus gibber. ac]19850412相似文献
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Marc Verlaque 《Plant biosystems》2013,147(1-2):29-39
Abstract Studies on the genus Peyssonnelia (Rhodophyceae). X. Presence of Peyssonnelia codana (Rosenvinge) Denizot in the Mediterranean.—Peyssonnelia codana (Rosenvinge) Denizot, previously known only from Denmark, is recorded from the vicinity of a thermal power plant outlet (Martigues-Ponteau, Gulf of Fos, France). Mediterranean specimens are described and new details about the morphology of sporangial and sexual nemathecia are given. 相似文献
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Comparison of pollen from the Paleogene in south England, the Paris Basin and Alès Basin (Gard) with the present-day Araliaceae pollen allow us to establish the presence of the following genera: Acanthopanax, Aralia, Brassaiopsis, Scheffleropsis and Panax. Five new species which show a close affinity with present-day Asiatic species are described. 相似文献
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《Biochimica et biophysica acta》1953,10(1-2):405-411
Spectrographic and manometric study, at 37°C, of the oxidation reaction of adrenalin by oxygen (Cu++ acting as catalyst), in the presence of potassium maleate buffer solution (pH 6.5), shows that, under these conditions, adrenalin is transformed into adrenochrome. However, adrenochrome thus formed undergoes very slowly oxidative transformation and the large consumption of oxygen measured depends on the oxidation of the maleate by adrenochrome. The control tests show that neither copper nor adrenalin catalyses the oxidation of maleate in an oxygen atmosphere; in a nitrogen atmosphere the adrenalin-copper system is equally without effect.During the oxidation of adrenalin in phosphate buffer solution, the maleate (or fumarate) added is susceptible to oxidation because of the intervention of adrenochrome, formed intermediately. However, under these conditions, adrenochrome undergoes a subsequent oxidative transformation nearly as rapid as if the reaction had taken place in pure phosphate buffer solution. 相似文献
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A. Mirimanoff 《Protoplasma》1953,42(2):250-260
Résumé Le présent travail expose quelles sont les réactions de la cellule végétale lorsque cette dernière est soumise à l'association d'un toxique et d'un « mouillant » (Netzmittel).Les variables sont: la nature de la cellule végétale, celle du toxique et celle du mouillant.Alors que les mouillants cationiques, eux-mêmes toxiques, exercent une simple action additive, les mouillants anioniques révèlent dans de nombreux cas une synergie de toxicité. Celle-ci se manifeste surtout avec les champignons et les bactéries Gram+, les végétaux supérieurs se montrant indifférents. Cette synergie varie également avec la structure moléculaire du mouillant.Les mouillants non ioniques peuvent au contraire exercer une action antagoniste, c'est-à-dire diminuer la toxicité.Ce dernier phénomène se produit dans certains cas à la suite d'une réaction chimique entre le mouillant et le toxique; la nature de la cellule est alors indifférente. Dans d'autres cas, il y a absence de réaction chimique et le phénomène ne se produit qu'avec certains types de cellules (champignons surtout).La nature chimique du toxique joue, dans la synergie, un rôle moins important que dans l'antagonisme.Des hypothèses sont formulées pour tenter d'élucider le mécanisme des cas de synergie et d'antagonisme. 相似文献
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Résumé H. chlorinus Tul., Ascomycète parasite des carpophores deBoletus sp. est déficient partiel en biotine.Les caractéristiques ultrastructurales des hyphes obtenues en présence de biotine sont données. Différentes techniques de fixation et de coloration (Thiery, Rambourg) ont été utilisées pour définir la localisation des polysaccharides et l'origine des vésicules apicales. La présence d'un appareil de Golgi chez cet Ascomycète est discutée.La carence en vitamine entraÎne,in vitro, des variations ultrastructurales telle que: l'hypertrophie de certaines cellules; l'épaississement des parois fongiques qui ont un aspect stratifié et qui présentent des irrégularités dans leur épaisseur leur donnant un aspect irrégulier; la mise en évidence moins nette du plasmalemme; la fréquence moins importante des systèmes endomembranaires; la présence d'inclusions lipidiques et de glycogène.Ces observations sont mises en relation avec les résultats de recherches biochimiques que nous effectuons parallèlement. La carence en biotine entraÎne une déviation du métabolisme cellulaire qui s'oriente vers la constitution de réserves cytoplasmiques plutÔt que vers la synthèse de nouvelles structures, ce qui aboutit à un développement réduit du mycélium.
Summary H. chlorinus Tul., Ascomycete, parasite on carpophores ofBoletus sp., require biotin for optimal growth.The ultrastructural features of hyphae grown on biotin optimal medium are described. Several methods of fixation and coloration (Thiery, Rambourg) are applied for localization of polysaccharides and research of apical vesicles origin. Occurrence of Golgi apparatus in this Ascomycete is discussed.Morphological and ultrastructural changes induced by biotin deficiency consist of: hypertrophy of many cells; thickening of cell walls which appear stratified with variations in their thickness; decreased distinctness of plasmalemma; decreased number of organelles (mitochondria, endoplasmic reticulum); occurrence of numerous lipidic and glycogenic storage granules.These observations on changes in fine structure are related to changes in chemical composition of cells, specially cell walls and to part played by the different organelles in cellular metabolism. This, is oriented to formation of cytoplasmic storage rather than synthesis of new structures leading to a very poor mycelial development.相似文献
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M.-D. Desruet C. Bolot F. Bourrel A. Francois-Joubert I. Couret M. Pelegrin E. Ouhayon M.-L. Biechlin-Chassel S. Lao R. Sauvan 《Médecine Nucléaire》2010,34(11):620-624
Use of radiopharmaceuticals in French nuclear medicine departments depends on marketing authorization and their development may be compromised by a limited return on investment. As an alternative, radiopharmaceuticals may also be prepared in the form of a magistral preparation, like in some European countries. In this case, these preparations are subjected to restrictions and requirements for radiopharmacies relating to quality assurance, facilities and equipment, quality of starting materials and final radiopharmaceutical products defined in French good preparation practice. Labelled tracers used as magistral preparations have to be prepared under the full responsibility of a radiopharmacist and used under the responsibility of the prescribing physician. Conditions of sufficient guarantees for the safety of the patient and adherence to pharmaceutical rules must be evaluated individually. However, this form of preparation intends to supply specific medical needs for an individual patient and is not an answer in the framework of development of radiopharmaceuticals. 相似文献
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Présence d'invaginations nucléaires dans les cellules de quelques nectaires floraux et hydathodes 总被引:1,自引:0,他引:1
Summary Although nectaries and hydathodes differ in many anatomical and physiological aspects, they have some identical features. The purpose of this paper is to expose such features in the nuclear morphology. Special attention is devoted to invaginations containing cytoplasm. Many organelles are found in the cytoplasmic pockets; among them, mitochondria and plasts appear frequently deeply enclosed by the nuclear membrane.It is postulated that the form of these nuclei is related to the process of secretion and guttation. 相似文献