Presence du Messinien dans la vallee du Rhone

According to the paleontological (molluscs and ostracods) and stratigraphical data, the Congeria rhodanicacclays are of Upper Messinian age. This oligohaline facies points out the local transgression of mediterranean origin in the Rhone basin, following a Lower Messinian erosive episode with coarse subaerial partial valley infill.     

Influence du traitement sylvicole sur la flore forestiere: Cas de la futaie et du taillis-sous-futaie

Summary In a previous study, 772 floristics relevés, made in a large forest on calcareous soils (north-east France), had been treated by factorial analysis of correspondences in order to establish a site typology. The third axis separated chiefly Fagus and Quercus, which are very common in the forest, and various other ligneous or herbaceous species (see fig. 1). Two groups of relevés, homogeneous as for edaphic conditions, were choosen, having a significant position on this axis (with either positive or negative values). From this, floristic tables have been elaborated; they show clearly the influence of silvi culture (here high forest or coppice-with-standards) on part of both ligneous and herbaceous flora. Considering plant sociology, it appears that treating a stand as a coppice-with-standards can convert a Melico-Fagetum typicum (Eu-Fagion) into a Querceto Carpinetum typicum (Fraxino-Carpinion), and a Carici-Fagetum (Cephalanthero-Fagion) into a Querceto-Carpinetum primuletosum (Fraxino-Carpinion). Fortunately a large number of species are not influenced by the silviculture; this allows the identification of isopotential sites. Possible ecological causes are briefly discussed.

Nomenclature suivant: P. Fournier, 1961. Les quatre flores de France. Edition P. Le Chevalier, Paris. 1154 p.     

Etude cytologique de la prehypophyse du pigeon pendant la couvaison et la lactation

Résumé Les hypophyses de 22 Pigeons des deux sexes sacrifiés soit pendant la couvaison, soit pendant la période de soins aux jeunes, ou lactation, ont été comparées à celles de 43 Pigeons des deux sexes, adultes non lactants ou prépubères, normaux ou soumis à divers traitements (lumière permanente, métopirone, thyroxine). Elles ont toutes été examinées en microscopie optique et 13 d'entre elles ont été en outre étudiées au microscope électronique.Sur la base de leurs affinités tinctoriales et de leurs caractères histochimiques, 6 types cellulaires ont pu être identifiés (Tableau 2). Seuls trois d'entre eux, tous localisés dans le lobe céphalique de l'adénohypophyse, sont intensément modifiés pendant la couvaison et la lactation. D'une part, la cellule eta, érythrosinophile, et la cellule kappa, cyanophile mais PAS négative, sont fortement stimulées. D'autre part, la cellule delta, cyanophile et PAS positive, est déprimée.Les caractères ultrastructuraux de ces six types cellulaires sont décrits et plus particulièrement ceux des cellules sollicitées pendant la couvaison et la lactation.La confrontation de l'évolution respective de ces trois types cellulaires avec celle de la paroi du jabot montre que la cellule eta érythrosinophile élabore la prolactine. La signification fonctionnelle de la cellule kappa demeure hypothétique: elle élaborerait l'hormone mélanophorotrope, MSH. La valeur thyréotrope des cellules delta est démontrée par les modifications déclenchées à leur niveau par des injections de thyroxine; ces modifications sont identiques à celles observées pendant la lactation.

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Summary The pituitaries of 22 pigeons of both sexes fixed either during incubation or lactation (care for the young) were compared with those of 43 adult pigeons that were either adult but non-lactating, or prepuberal; these were either normal or variously treated (permanent illumination, administration of metopirone or thyroxin). All were studied with the light microscope and 13 among them were also examined with the electron microscope. On the basis of their staining properties and histochemical characteristics, six cellular types were identified. Only three among these, all located in the cephalic lobe of the adenohypophysis are intensively modified during incubation and lactation On the one hand, the eosinophilic eta cell and the cyanophilic but PAS-negative kappa cell are strongly stimulated. On the other hand, the cyanophilic and PAS-positive delta cell is depressed. The ultrastructural characteristics of these six cell types are described, in particular of those involved in incubation and lactation. Comparison of the development of these three cell types and of the crop shows that the eta cell furnishes prolactine. The functional significance of the kappa cell remains hypothetical; it may produce the melanophorotropic hormone (MSH). The thyrotropic nature of the delta cell is demonstrated by its modification in response to thyroxin administration; these changes are identical with those observed during lactation.

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Ce travail est dédié à M. le Prof. Bargmann à l'occasion de son 60^e anniversaire et en témoignage de notre respectueuse admiration.

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Avec la collaboration technique de Mmes Denise Lescanne, et Renée Picart et de M. Claude Pennarun pour les photos.     

Influence de la cure chirurgicale de la varicocele sur la qualite du sperme

The aim of this study was to assess the efficacy of surgical varicocèle repair in terms of sperm quality. We have performed a retrospective study including 62 patients. All of them underwent clinical evaluation. A sperm analysis has been done before and after surgical repair. Before sugery, the spermogram was normal in only 11.3%. Oligospermia was found in 62.1 % of cases while 6.5% of patients had azoospermia. Abnormalities like microcephalia were encountered in 36.8% of cases. All patients underwent surgical varicocele repair. They were followed up every three months up to 18 months. A significant improvement of sperm count was found in 18 cases, with a pregnancy rate of 6.45%. Alterations of sperm quality was most severe in older patients. We think that as far as natural history of varicocele is not well established, the duration of its evolution is well correlated with the severity of sperm alterations. So, need for precocious diagnosis in order to lessen the risk of infertility.     

Le metabolisme du soufre dans la rhumerie

Résumé Le rhum, comparativement aux autres eaux-de-vie, se singularise par la variété et les teneurs relativement élevées de composés organo-soufrés qu'il contient. La composition de la canne à sucre ainsi que les apports de sulfate et d'acide sulfurique tout au long de la filière industrielle font que les milieux de fermentations sont riches en dérivés soufrés. En aval de la distillerie, la méthanisation des effluents pose le problème d'un équilibre précaire entre les flores méthanigène et sulfato-réductrice. La fraction organo-soufrée mérite une étude approfondie et systématique, car elle présente un intérêt analytique et organoleptique pour la caractérisation des rhums.

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The metabolism of sulphur during the manufacture of rum

Summary Rum distinguishes itself from other brandies by the variety and the relatively high content of organic sulphur compounds. Composition of sugar-cane as well as additions of sulphate and sulphuric acid along the industrial process gives fermentation media that are rich in sulphur-compounds. Downstream from the distillery, biomethanation of effluents is difficult because of a precarious equilibrium between the methanogenic and the sulphate-reducing bacterial floras. The organic sulphur-fraction requires a systematic study because the latter are involved in the organoleptic properties of rums.

     

Etude de L'influence de la Concentration Saline et du Rapport Sodium/Calcium du Milieu Nutritif sur la Sensibilite de la Tomate a la Fusariose Vasculaire

Resume Les auteurs étudient chez la tomate l'influence de la concentration saline et du rapport Na/Ca du milieu nutritif sur le développement de la fusariose vasculaire. A concentration saline élevée (50,4 meq/l), les plantes fanent tardivement mais brusquement et sans jaunissement préalable. La colonisation des tiges parF. oxysporum f. sp.lycopersici est tardive et faible; cependant à rapport Na/Ca élevé, elle augmente rapidement. Il n'y a pas d'acides aminés détectables dans la sève des plantes de 14 jours mais la teneur en N inorganique est toujours supérieure à 2.8 μg/ml. A concentration saline faible (2.5 meq/l), les feuilles jaunissent progressivement et précocement. La colonisation du xylème est précoce et dense; l'influence du rapport Na/Ca est faible. Les acides aminés sont présents dans la sève en quantités relativement importantes et d'autant plus que le Na/Ca cro?t. Ces résultats de l'évolution de la maladie sont discutés en relation avec la composition chimique des tissus et de la sève et la localisation histochimique du Na et du Ca.

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Summary The influence of the salt concentration and of the Na/Ca ratio of the nutrient solution on the development of the fusarial wilt of the tomato has been studied. At high salt concentration (50.4 meq/l), plants wilt lately but suddenly without yellowing. The stem colonization byF. oxysporum f. sp.lycopersici is poor and late; however at higher Na/Ca it increases rapidly. There are no amino acids detectable in xylem sap of 14 days old plants but the content of inorganic N is always higher than 2.8μg/ml. At low salt concentration (2.5 meq/l), the yellowing of the leaves begins early and progressively. The xylem colonization by the parasite is dense and precocious; the influence of the Na/Ca is weak. The amino-acids are relatively abundant in xylem sap and their content increases with the increase of the Na/Ca ratio. These results of the development of the disease are discussed in relation to the chemical composition of the tissues and the xylem sap and the histochemical localization of Na and Ca.

     

Regulation de la secretion androgenique du testitule

Although LH undoubtedly remains the major factor controlling testicular androgen production, there is increasing evidence for the existence of a complex network of paracrine and autocrine intratesticular factors capable of modulating the development, differenciation and activity of the Leydig cells. This review summarizes the present understanding of intratesticular factors affecting Leydig cell function. Attention has been focussed upon the identification of tubular agonist which might mediate the effects of FSH on the production of androgens by Leydig cells. The findings discussed illustrate that even for such a welldefined function there are many candidates, and that the major agonists remain to be characterized. Moreover, all our present knowledge is based on invitro data, and the in-vivo role of all these agonists remains to be evaluated.     

Importance de la qualité du sperme

The semen quality and sperm chromatin alteration have added a new dimension to the evaluation of male factors in repeated spontaneous abortion (RSA). The aim of the study was to evaluate the importance of the sperm quality in RSA conjugal partners. In RSA group, when husbands sperm having more 50% of normal forms and more 50% of native DNA, the paternal lymphocytes injection may lead to a positive immunization. However, no benefit of immunotherapy between conjugal partners if the conventional semen parameters and chromatin quality were altered. Our data indicates that among the vast array of male factors, sperm morphology and chromatin quality seems to be an important criterion to conceive or maintain pregnancy of women with a RSA.     

Recherches sur la nature chimique du chondriome

Sans résuméCes recherches nous ont donc permis de prouver microchimiquement dans le chondriosome la présence de protides et leur complexité. Elles nous amènent à concevoir que, en partie du moins, les groupements à fonction sulfhydrile qui s'y rencontrent sont plus ou moins intimement liées à ces substances.     

Radio-anatomie de la prostate et du pelvis

Development and use of new tracers in tumoral prostatic exploration by nuclear medicine require specifying the pelvic anatomical knowledge. This article offers a reminder of the prostate–pelvic anatomy by studying CT-scanner and MRI to know the essential structures for the writing of the medical report.     

Effets des fluctuations rapides de la lumiere sur la photosynthese du phytoplancton

[¹⁴C]-assimilation rates were measured on cultures of two unicellulargreen algae (Chlamydomonas sp. and Oocystis sp.) as a functionof light intensities (saturation curves), under steady lightand also under rapidly alternating high and low light intensities.Assimilation rates vary according to the frequency of the intermittentlight regime and it falls under two categories: (1) at 0.1 and0.2 Hz, the assimilation rate is equal to the average of therates observed at high and low light intensities under steadylight, and (2) under 1.0, 1.6 and 10 Hz the assimilation rateis equal to the rate observed under a mean steady irradiance.Moreover, the range of assimilation rates at a given frequencydepends on the difference between the high and the low intensities.Batch cultures of Oocystis sp. have been grown under intermittentlight of 0.1, 1.0 and 10.0 Hz (same mean intensity). Growthrate under intermittent light of 0.1 Hz is –40% lowerthan the control under steady light. Photosynthetic potential(P^B_max)and efficiency () change with the growth stages of thecultures. At the end of the logarithmic growth phase, both photosyntheticparameters are maximum at 1.0 Hz and minimum at 0.1 Hz. Averagecell concentrations of chlorophyll a increase as the frequencyof the light regime decreases. During the log phase, concentrationof carotenoids relative to chlorophyll a increases at 1.0 Hz,decreases at 0.1 Hz, and remains constant at 10.0 Hz. Underclear sky conditions, wave-induced light fluctuations in thephotic layer may therefore enhance primary production, especially(1) in the lower part of the photic layer, where low frequencylight changes might cause cell chlorophyll a to increase, and(2) at a depth of 1–4 m, where the main frequencies (ofthe order of 1.0 Hz), might cause a significant increase ofboth the photosynthetic potential (P^B_max)and efficiency (). ¹Contribution au programme du GIROQ (Groupe interuniversitairede recherches océanographiques du Québec) ²Adresse actuelle: Centre de recherches en nutrition, UniversitéLaval, Québec, Qué. G1K 7P4, Canada