Modifications faunistiques engendrées par une faible variation de débit dans une grande rivière

Artificial substrates suspended in the water column and benthic dredging were employed to study the drift of macrofauna and the macrobenthic populations respectively, in a cross section of the Rhône River upstream of Lyon, France. The samples were collected in autumn 1979: first in September under a low flow egime around 400 m³·s^–1, then in October during a discharge increase up to 630 m³·s^–1.The first factor of correspondence analysis showed a clear cleavage between the two periods, especially for drift communities. The differences are most important in the centre of the stream channel. In October, the water column was invaded by unusual and abundant fauna. This dynamics is due to the increase in number of Crustacea (Gammarus fossarum, Asellus aquaticus), the decrease of some insect larvae (Leuctra fusca, Simuliidae, Baetis fuscatus, stages 1 and 2 of Hydropsyche) and the appearance of typical wetland taxa (some limnophilous Coleoptera and Trichoptera). For some other dominant invertebrates, a modification may occur only in their distribution (stages 3 to 5 of Hydropsyche, Heptagenia sulphurea) while the distribution of Psychomyia pusilla remains the same.These results are discussed with respect to the effects of species biology and the unusual consequences caused by a minor increase in discharge.

Structure et fonctionnement des écosystèmes du Haut Rhône français n° 46.     

Rapport entre l'évolution ultrustructurale des plastes de feuilles de plantules étiolées de maïs soumises à l'action de la lumière et la synthèse de nouvelles molécules de phosphatidylgycérol

Relations between light-induced modifications of plastid ultrastructure and phosphatidylglycerol synthesis in the leaves of etiolated maize seedlingsChanges in the ultrastructure and lipid composition of plastids isolated intact from leaves of maize seedlings (Zea mays L.) have been followed during the transformation of etioplasts into chloroplasts. The contents of polar lipids and fatty acids per plastid showed a 3-fold increase during greening of leaves. There was a clear relation between the synthesis of phopphatidyglycerol (PG) with a trans-Δ³-hexadecenoic acid residue in position 2 and the development of granar stacks.     

Synthèse in vitro de la β-galactosidase et de la phosphatase alcaline par les fractions subcellalaires particulées isolées à partir d'escherichia coli

Treatment of the protoplasts of Escherichia coli by digitonin enables to separate particulate fractions. These fractions are shown to be able to perform the synthesis in vitro of specific proteins, such as β-galactosidase and alcaline phosphatase. The purification and the isolation of the enzymes synthesized from radioactive amino acids leads to the conclusion that synthesis has been accomplished in vitro. DNA plays a specific role. A stimulation is obtained by the enzymes synthesising RNA. The nature of synthesis in vitro is discussed.     

Hypothèse de parcours diagnostique du déficit érectile à la lumière de connaissances récentes sur l’anatomo-physiologie de l’érection et sur la thérapie des troubles érectiles

Nowadays the diagnosis of erectile disfunction is based on a wide range of clinical and instrumental investigations in order to obtain specific and detailed information on the pathogenesis of this syndrome, but at same time these investigations are useless to know much about the aetiology. Therefore the erectile failure must be related to organic and psychological causes always detected in each patient. Sixty-six men complaining of erectile failure were evaluated with nocturnal penile activity registration (NPT), echo-color-doppler (ECD) and dynamic infusion cavernosometry (FCM) and the reports were, even empirically, compared. This study pointed-out that the nocturnal rigidity is not reliable either to differentiate between erection trouble having a psychogenic or organic origin, or in anticipating the therapeutic response. Furthermore, the records of instrumental investigations (NPT, ECD, FMC) failed to point-out the aetiology of erectile failure. Therefore, in our opinion, the main goal of the andrologist should be the prompt control of the symptom and we propose an early assessment of the patient by means of medical history, physical examination, hormonal assays, intracavernous injection of vasoactive drug, and nocturnal activity monitoring. Further investigations, including ECD and FCM, should be performed in non respondent patients or when surgical therapy is indicated.     

Diminution de la capacité de surfusion au cours de l'embryogenèse et du développement larvaire chez un coléoptère

Potential cold resistance of non-diapause eggs and first instar larvae of Osmoderma eremita (Coleoptera, Cetoniidae, Trichiinae) during embryogenesis and post-embryonic growth was assessed by measuring individual supercooling points (SCP): sterile eggs had a mean SCP of −24.3 ± 2.0 °C; fertilized newly laid eggs a mean SCP of −23.4 ± 3.2 °C and eggs about to hatch a mean SCP of −9.2 ± 2.9 °C. Water absorption by fertilized eggs is a necessary requirement for the development of the embryo and results in an increase in weight and water content: fertilized newly laid eggs had a mean fresh weight of 10.687 ± 1.072 mg and a mean water content (expressed as a percentage of the dry weight) of 79.5 ± 10.83%; eggs about to hatch had a mean fresh weight of 19.127 ± 3.183 mg and a mean water content of 250.10 ± 74.15%. The ex-ovo larvae, hatched 30 days after oviposition, had a mean SCP of −10.1 ± 3.6 °C (no significant difference with eggs about to hatch) and had gained in weight (24.845 ± 3.911 mg) and in water content (499.72 ± 55.49%). Feeding 1st instar larvae had a decreased supercooling ability (mean SCP = −5.7 ± 0.4 °C) whereas their mean fresh weight (99.858 ± 53.091 mg) and mean water content (665.83 ± 82.74%) increased. The eggs and larvae of O. eremita are freezing intolerant. Before overwintering, all larvae switch to being freezing tolerant and can survive ice formation in their tissues and body fluids, whereas their mean SCP stays at around −5 °C. However, recent experiments in the winter of 1996 have shown that frozen larva mortality does occur at temperatures lower than about −12 °C.     

Facteurs prédictifs de la toxicité hépatique de la radio-embolisation par microsphères marquées à l’Yttrium-90 dans les hépatocarcinomes

IntroductionThe toxicity associated with hepatic radioembolization (RE) by microspheres labeled with Yttrium 90 (⁹⁰Y) has a very variable incidence between studies and depends on a multitude of parameters. The objective of this study is to assess the various predictive factors of this toxicity, inherent of the patient or the type of procedure.Patients and methodsSingle-center retrospective study including 85 patients with hepatocarcinoma treated by hepatic RE. The medico-technical and clinical-biological parameters were studied over a defined time interval and the toxicity of the latter graded according to the Common Terminology Criteria for Adverse Events. Dosimetry was carried out on the basis of the ⁹⁰Y PET/CT using the “Simplicit90Y” software and the statistical analysis using the “SAS” software.ResultsPost-RE hepatotoxicity observed in 77.7% of our population with maximum grade 3 toxicity in 10.6% of cases. The presence post-RE of hyperbilirubinemia and ascites were detected in 32.1% (only grade 1-2) and 27.1% (4.7% grade 3) of patients, respectively. The pre-therapeutic presence of cirrhosis and/or hyperbilirubin are predictive of post-RE toxicity. Other biological elements studied are less relevant in practice. Radioembolization-induced liver disease (REILD) was observed in 15.3% of cases, mainly of moderate form (13.0%). No impact of the dosimetric approach was observed.ConclusionA personalized dosimetric approach does not generate additional side effects, while maximizing the tumor dose and therefore the therapeutic effect. The presence of cirrhosis and hyperbilirubinemia pre-RE seem to be the two predominant in the appearance of REILD.     

Action de la quinoline sur les mitoses de segmentation des eufs d'urodèles: le blocage de la centrosphère

Quinoline in saturated solution (0,46 M) progressively destroys spindle and astral fibers, beginning in the juxtacentromeric region; it blocks the centrosphere material around the centriole. Chromosomes are immobilized in equatorial position far off the blocked centrospheres and may undergo telophasic transformation into karyomeres. Diastema may be inactivated before mitosis. Centrospheres are first deprived of some fibers, then granular and more or less dissociated, last completely smooth and segregated into cortex and medulla. Breaks and recombinations of chromosomes may appear after a long while, when a brief action is interrupted. With less concentrated solutions monopolar mitoses and monopolar telophases (rosettes) are observed (1/8 saturated solution), then shortened bipolar mitoses (1/16 saturated). Qualitative differences between quinoline and colchicine actions are evident.     

Stimulation de l'ovogenèse par la copulation chez les femelles de Drosophila melanogaster privées de leur complexe endocrine rétrocérébral

The extirpation of the corpus allatum-corpus cardiacum complex in Drosophila melanogaster females strongly reduced egg production but did not completely stop it. When the females were inseminated after the operation the increase of fertility which was observed is proportionally as important as in control females. It was concluded that the stimuli occurring from insemination were mainly acting on the neurosecretory cells of the brain. In the control of oögenesis, it is probable that the brain hormones are more important than the corpus allatum hormone.     

La systématique infraspécifiquede l'Anthyllis vulneraria (Leguminosae) vue à la lumière de la biochimie flavonique

Twenty-six experimental populations of A. vulneraria were surveyed for leaf flavonoids. The distribution of 34 flavonol glycosides showed, after factor analysis, the existence of for distinct chemical taxa, each exhibiting characteristic glycosides of 7-methylkaempferol. These results, and others obtained from further factor analysis, are discussed in relation to Couderc's taxonomic studies, and allow a better definition of infraspecific units of A. vulneraria. Flavonoid and morphological data are generally correlated.     

Quelques apports à la théorie de l’Évolution,de la « Synthèse orthodoxe » à la « Super synthèse évo-dévo » 1970–2009 : un point de vue

Some contributions to evolutionary theory, from the “orthodox” Synthesis to the “Evo-devo Super synthesis” 1970–2009: A point of view. The “Modern Synthesis” of evolutionary biology coalesced and revitalized evolutionary theory beginning in the 1930s. It stressed the explanatory power of natural selection and gradual change to account for the processes that govern natural populations today, as well as patterns in the history of life. In the past 40 years, the synthesis has been challenged on various fronts ranging from paleontology to developmental biology, systematics, biogeography, and molecular and developmental biology. Several of its central propositions have been modified and expanded as a result. How well the synthesis continues to be effective will depend on its continued ability to test its central propositions and the efficacy of its central mechanisms, particularly on the basis of new evidence from emerging fields of study.