Du probleme de l'origine des Dinosauriens d'apres les donneesde l'ichnologie du Trias

With the data of the osteological paleontology and these of the ichnology, the authors attempt to restore the biotopes where lived the trackmakers, biotopes which have favoured in the Triassic the evolution and the expansion of the Archosaurs, the specialized Reptiles in the easy and rapid locomotion. They pointed out that the chirotheroid footprints cannot be attributed at all events to the Pseudosuchians and they come to the conclusion that Dinosaurs and Pseudosuchians, as separated groups, are appeared as early as the lower Triassic.     

Reflexions sur la systematique et l'evolution des metazoaires

Coming again to the implications, on the Metazoan systematics, of their first appearance modalities, the authors show the need of a truly phylogenetic classification; cladistic classifications are somewhat engaging and might be applicated tentatively to primitive Metazoan. Parallel to animal Protista, three independant series (sub-kingdoms) evolved: Spongiaria (+ Archaeata), non-surpassing morula-blastula larval stages, evolved the slowest (lower cambrian first-appearance); Cnidaria, at the gastrula-stage, emerged during Ediacarian and progressed little after Cambrian; Coelomata, because achieving the highest embryologic level, underwent the fastest evolution, nearly all their phyla being roughed out since the Ediacarian.     

Variations circadiennes des acides aminés libres de l'hemolymphe de Penaeus japonicus

The non-essential free amino acids of Peneaus japonicus hemolymph (asp, ser, glu, pro, gly, tyr, arg, ala, cys, tau) are more common than the essential ones: 750 pmol μl^?1 of hemolymph vs 330 pmol. Under a light-dark (L-D); 12-12 photoperiod, tricircadian variations of males or tetracircadian variations of females are more pronounced for non-essential amino acids then for essential ones. In the first case, free amino acid concentrations of hemolymph can be multiplied by a factor of three, and in the second case by a factor of six; but circadian variations of females are greater than those of males. Differences between the maximum and minimum of essential free amino acid concentrations of male and female hemolymph are more frequent than for non-essential amino acids. A differences of 2 h between the minimum of essential and non-essential amino acid concentrations in males only appeared during the afternoon. The more concentrated free amino acids in P. japnicus hemolymph are glycine, proline, histidine, and alanine; the less concentrated are lysine, cysteine and glutamic acid while others, like leucine, isoleucine, phenylalanine and tyrosine can only be estimated at 10.00 and 24.00 h.     

Remarques sur la stratigraphie des terrains tertiaires des bassins de Narbonne-Sigean et de Leucate (aude) a l'aide des micromammiferes

The discovery of rodents in the lacustrine and brackish deposits of the Narbonne-Leucate area classicaly dated as Oligocene, indicate that they are Oligocene and lower Miocene (Aquitanian) in the Narbonne-Sigean basin, and that the marls and limestones of the Leucate plateau and cliff are Pliocene.     

L'etude des tests d'Ostracodes au microscope electroniquea balayage: Remarques et mise au point d'une technique de preparation

Examination under the scanning electron microscope of paleozoic ostracode tests is limited by the conservationof the shells. When the fossilized specimens are stuck on the top of a delicate wire with a varnish, they are observable from various sides without changing the preparation.     

Isoenzymes de l'anhydrase carbonique d'un poisson euryhalin: Variations en relation avec l'osmoregulation

A chemical study of carbonic anhydrase (EC 4.2.1.1) from the red blood cells and the gills of an euryhaline fish (Anguilla anguilla) is presented. Animals adapted to fresh water were compared to those adapted to sea water.The physicochemical constants of the various molecular forms isolated by chromatograhy and isoelectric focusing were determined; isoeleletric pH, molecular weight, and the K_m and V/E of the enzyme dehydration activity were compared.In both red cells and gills of fish adapted in either media various forms were isolated, characterized by different enzymatic kinetics (high- and low-activity forms) but having the same molecular weight (27 250). Some isoenzymes isolated from the gills differed significantly from those isolated from the red cells.Adaptation to fresh water or sea water is accompanied by modifications in the distribution of yhe isoenzymes in both red cells and gills: adaptation to sea water is characterized by a shift of the molecular forms towards an isoelectric pH higher than pH = 6.The role of these enzymes is discussed under both a physiological and biochemical point of view in relation to the electrolyte exchange across fish gill. The origin of the different molecular forms of the carbonic anhydrase is discussed in relation to the prevailing theories on this subject.     

Accès à des sulfures d'alkyle et de furannyle à partir de dithio-acétals de pentoses

Sodium iodide—zinc in N,N-dimethylformamide at 150° converted 2,5-anhydro-3,4-di-O-p-tolylsulfonyl-D-xylose diisobutyl dithioacetal into a mixture of three substituted furans, namely 2-[(isobutylthio)methyl]furan (2), and its 3-isobutylthio- (3), and 4-isobutylthio- (5) derivatives. The relative proportions of 2, 3, and 5, determined by g.l.c.—mass spectrometry, varied according to the relative proportions of reactants employed. A similar type of transposition—elimination is also encountered in the absence of sodium iodide. Compound 3 is also produced from D-xylose disobutyl dithioacetal by extended treatment with 2-methylpropanethiol—hydrochloric acid. The furan derivatives 3 and 5 were characterized mainly by n.m.r.—spectral studies on their Diels—Alder adducts with maleic anhydride, and the mechanism of their formation is discussed. 2,5-Anhydro-3,4-di-O-p-tolylsulfonyl-D-xylose ethylene dithioacetal (13), its ribo epimer (15), and its L-arabino diisobutyl dithioacetal analog (20) all reacted with sodium iodide—zinc in N,N-dimethylformamide exclusively by an E2 type of elimination with formation of the anticipated 3-alkenes, namely 2,5-anhydro-3,4-dideoxy-D-glycero-pent-3-enose ethylene dithioacetal (14) and its diisobutyl dithioacetal analog.     

Regulation d'activité de l'α-Amylase à différentes températures d'adaptation et en fonction de l'ablation des pédoncules oculaires et du stade de mue chez Palaemon serratus

The influence of thermal acclimatisation of the shrimp Palaemon serratus on the specific activity of α-amylase and the soluble proteins of the hepato pancreas show the presence of a metabolic compensation kinetic within this organ. The kinetic properties of partially purified α-amylase show that 2 sites are able to fix starch in the absence of NaCl but only 1 site when NaCl is present. The importance of conformational changes of the enzyme is shown by examining its regulatory properties according to the different temperatures of adaptation, and to the removal of eyestalks and the molt cycle. During these changes there are no qualitative variations in α-amylase isoenzymes.     

Synthèse de l'apiose et de composés voisins par des réactions de wittig

Treatment of 1,2-O-isopropylidene-α-D-glycero-tetros-3-ulofuranose (7) with cyanomethylenetriphenylphosphorane gave in excellent yield a mixture of the geometrical isomers of the corresponding cyanomethylenic derivative. After treatment with potassium permanganate, and then with sodium borohydride, this unsaturated, branched-chain sugar derivative was stereospecifically converted into 3-C-hydroxymethy]-1,2-O-isopropylidene-β-L-threofuranose. Similarly, treatment of the L-enantiomer of 7 with methylthiomethylenetriphenylphosphorane gave the expected methylthiomethylenic analogs, from which 3-deoxy-3-C-methyl and 3-deoxy-3-C-dimethoxymethyl derivatives were prepared. Wittig reactions thus allow the synthesis of branched-chain sugars bearing the side-chain on the more hindered side of the ring, compounds which are difficult to obtain by other methods.     

Influence des effets orbitalaires sur l'équilibre conformationnel des sucres à insaturation terminale de configuration E

The glycenoses and alkenes bearing an alkoxy group on the allylic carbon atom and having the general formula RCH(OR)′CHCHX (E configuration) preferentially adopt, in solution, a conformation in which the alkoxylgroup eclipses the double bond. This conformation is particularly favored when X is an electron-withdrawing group by resonance; it becomes less favored or totally unfavored when X is electron-donating by resonance. This phenomenon, which cannot be attributed to steric hindrance, is explained by inter-orbital interactions.     

L'age des “Calcaires a petites huitres” de l'Ile Cremieu (Jura meridional tabulaire); Correlation des formations du Bajocien superieur de la region lyonnaise

Parkinsonids (Ammonitina) of the Subfurcatum Zone (Upper Bajocian) were found in the “Calcaires à petites huitres” formation from the northern part of Ile Crémieu. Correlations are established between different Upper Bajocian lithostratigraphic units of Mont d'Or lyonnais, Ile Crémieu and folded Jura.     

Etude au microscope électronique à balayage de la morphologie des mandibules chez les Cladocères marins

The mandibles of the parthenogenetic females of the marine calyptomeran and gymnomeran Cladocera have been examined by means of the scanning electron microscope. These investigations reveal great differences beween Calyptomera and Gymnomera with respectively pulverizing and cutting mechanisms. The appendages of the Gymnomera are morphologically very similar and these species seem able to deal with a wide variety of food.

     

Sur l'origine du suboculaire des Actinopterygiens fossiles

The embryological study of ArapaimaMüller 1843, the only modern teleost still possessing a subocular, shows that that bone has an opercular and not ocular origin as generally thought.     

Les crustaces decapodes du Cenomanien de Navarra (Espagne):Premiers resultats de l'etude des Galatheidae

Preceded by a short report on the fauna associated with Decapods in the Cenomanian from Orobe and by historical references, this note is an account on the results obtained after elaborate study of 187 specimens of Anomura belonging to Galatheidae family. Those results allow the systematic delimitation of two genera: ParagalatheaPATRULIUS, 1960 and Eomunidopsis n. gen., which produce the revision of 5 species belonging to those two genera. A provisional determination of the rest of the material (14 Brachyurans), still under consideration, is proposed.