Explantationsin vitro de blastodermes de Poissons(Salmo,Esox)

Summary Blastula of trout (Salmo irideus) and pike (Esox lucius), deprived of their yolk, are cultivated in the Holtfreter solution. The differenciation of the germ of the trout stops; that of the pike germ is carried on almost normally. That difference might be due to the influence of nucleic acids contained in it.     

Etude comparative sur l'action de différents liquides (eau distillée,solution physiologique de chlorure de sodium,liquide de Tyrode) sur le développement de l'embryon de poulet

Summary The injection of small doses of distilled water, physiological solution of natrium chloride and liquid of Tyrode, is well tolerated by the embryos; large doses have a stronger lethal action. The three liquids have no specific teratogenic action. The injection of 1/10 cm³ of Tyrode at the 24th h of incubation seems to be the quantity of solvent and the period for the injection which are ideal for testing the effects of an hydrosoluble substance in the chick embryo.

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Ces recherches ont été faites grâce à un subside du Fonds national suisse de la recherche scientifique et de la Fondation E. Barell.     

Form and functions of the regular surface array (S-layer) of Aeromonas salmonicida

The principal virulence factor of Aeromonas salmonicida is its S-layer (A-layer) which is comprised of tetragonally arrayed approximately 50,000 Mr protein subunits tethered to the cell surface via LPS. The detailed composition of its LPS is known, as is the primary sequence, and three-dimensional disposition of the A protein subunits. The A-layer physically protects the cell against bacteriophage, proteases, as well as immune and non-immune complement. The A-layer appears to be uniquely adapted towards binding biologically important molecules such as heme, and to various basement membrane proteins. In addition, the A-layer is required for macrophage infiltration and resistance. Specific mutants containing a disorganized A-layer are avirulent and provide significant protection to salmonids when applied by immersion.     

On the brain of the Amazon dolphinInia geoffrensis de Blainville 1817 (Cetacea,Susuidae)

Zusammenfassung Bei einem durchschnittlichen Körpergewicht von 44,7 kg beträgt das mittlere Frischhirngewicht vonInia geoffrensis 550 g. Das Kleinhirngewicht macht 12,4% des Totalhirngewichtes aus. Das optische System vonInia ist sehr reduziert, das akustische System dagegen stark entwickelt.I. geoffrensis ist weniger zephalisiert alsDelphinus delphis.

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Carried out with the support of the Swiss National Fund (Grant No. 4606). Contributions to the morphology of Cetacea: XXXV.     

Mise en évidence de l'excrétion urinaire d'antigènes de la membrane basale glomerulaire (MBG) dans l'urine de 3 rongeurs (rat,souris et cobaye)

Summary Immunodiffusion technique, with rabbits antibodies against rat glomerular basement membrane (GBM), permits to evidence the presence of GBM antigens into normal urines of 3 rodents (rat, mouse and guinea-pig). These results confirm the earlier works in human and rabbit urines and show the antigenic communauty existing between the 3 rodents GBM, since we can evidence antigens of 3 different mammals with the same antibody. The origin and the nature of this patterns and the signification of this presence into mammalian urines are discussed.

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Nous remercions sincèrement le Docteur Mahieu (Laboratoire de Clinique et Séméiologie Médicales, Institut de Médecine de l'Hôpital Universitaire de Bavière à Liège, Belgique) de l'aide précieuse qu'il a bien voulu nous accorder.     

Caryotypes de quelques hybrides interspécifiques dePitymys (Mammalia,Rodentia)

Summary The Robertsonian polymorphism ofPitymys subterraneus involves only 1 pair of metacentric autosomes. The crosses of forms with 52, 53 and 54 chromosomes do not show any differences in their reproductive rate. So a single autosome trivalent does not affect the fecondity. Many hybrids have been obtained betweenP. subterraneus (2N=52 or 54) andP. multiplex (2N=48) with 50 or 51 chromosomes, respectively. Even with a heterogenous karyotype they are not entirely sterile. 2 progeny were produced from back-crosses. The 2 parental species seem to result from recent speciation. Only fecondation or embryogenesis occurs in crossingP. duodecimcostatus withP. subterraneus orP. multiplex. The chromosome complement of 1 hybrid embryo ofP. duodecimcostatus (2N=62)×P. multiplex (2N=48) has been studied showing 55 chromosomes.P. duodecimcostatus appears to belong to a more distant evolutionary group.     

Action d'un inhibiteur de la carboanhydrase (Diamox) sur le pH de l'humeur aqueuse

Summary In 26 rabbits, the normal pH of the aqueous humor, measured with a glass electrode, was found to be 7.59±0.102. With an improved technique, the corresponding measures on ten other rabbits gave an average value of 7.57±0.043.Three hours after the injection of Diamox, a carbonic anhydrase inhibitor, a significant drop of 0.13 pH units was observed.These effects seem to be dependent on the inhibition of the ciliary body carbonic anhydrase; however there may be some participation of the metabolic acidosis of renal origin. The fall of pH in aqueous humor produced by Diamox is to be correlated with the decrease of potassium concentration previously reported; these facts suggest the hypothesis of a competition between potassium and hydrogen ions in the secretion of aqueous humor.     

Histoire et Singularités de la Solution de Schwarzschild (1915–1923)

Sans résumé Mémoire présenté par J. D. North     

Végétalisation de l'œuf de l'oursinParacentrotus lividus par l'hydrazide de l'acide isonicotinique (isoniazide)

Summary Isonicotinic acid hydrazide (isoniazid) causes vegetalization of whole larvae of the sea urchinParacentrotus lividus. The effects of isoniazid are compared with those of chloramphenicol and lithium ions. The protein synthesis during the phase of reversible determination, i.e. to the late blastula stage, appears to be of paramount importance in the differentiation of larvae. It is suggested that the protein synthesis connected with the determination of ectodermal structures is more sensitive to the action of vegetalizing agents than the protein synthesis connected with the determination of entomesodermal structures.     

Der Mathematiker Abraham de Moivre (1667–1754)

Summary Before examining de Moivre's contributions to the science of mathematics, this article reviews the source materials, consisting of the printed works and the correspondence of de Moivre, and constructs his biography from them.The analytical part examines de Moivre's contributions and achievements in the study of equations, series, and the calculus of probability. De Moivre contributed to the continuing development from Viète to Abel and Galois of the theory of solving equations by means of constructing particular equations, the roots of which can be written in the form . He also discovered the reciprocal equations. In the course of this work de Moivre discovered an expression equivalent to (cos +i sin ) ⁿ =cos n +i sin n and, following Cotes, he succeeded in expressing the nth roots of unity in trigonometric form.In the theory of series, de Moivre developed a polynomial theorem encom-passing Newton's binomial theorem and, in particular, a theorem of recurrent series useful in the calculus of probability.The demands of the calculus of probability led de Moivre to an approximation for the binomial coefficients for large values of n. The interaction between de Moivre and James Stirling, particularly in regard to the asymptotic series for log (n!), is treated at length. This work supplied the foundation for de Moivre's limit theorem for the binomial distribution.The calculus of probability, which occupied him from 1708 onward, became in time ever more the center of de Moivre's inquiries. Proceeding from contemporary collections of gambling exercises, de Moivre, by introducing an explicit measure of probability for the so-called Laplace experiments, found the beginnings of a theory of probability. De Moivre expanded the classic application of probability calculus to games of chance by addressing himself to the problem of annuities and by adopting Halley's work with its conception of Probability of life. De Moivre was the first to publish a mathematically formulated law for the decrements of life derived from mortality tables.

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Abkürzungen a.a.O. am angegebenen Ort = Verweis auf das nach Verfassern alphabetisch geordnete Literaturverzeichnis. Eine vor a.a.O. in runden Klammern angegebene Zahl kennzeichnet die entsprechende Nummer der im Literaturverzeichnis aufgeführten Arbeiten eines Autors. - AC Ars conjectandi = Jakob Bernoulli (4) a.a.O. - AE Acta Eruditorum - a.S. alter Stil⁴⁷ - BM Bibliotheca Mathematica - DMV Deutsche Mathematiker-Vereinigung - JL Journal Literaire - MA Miscellanea Analytica, London 1730 - n.S. neuer Stil⁴⁷ - PT Philosophical Transactions of the Royal Society of London - r.F. rekurrente Folge - r.R. rekurrente Reihe - SMA Miscellaneis Analyticis Supplementum, London 1730 - v. veröffentlicht (nur im Briefverzeichnis verwendet) Prof. Dr. Kurt Vogel zum 80. Geburtstag Vorgelegt von J. E. Hofmann     

Etude de l'influence d'une microsporidiose sur les électrophorégrammes (protéinogramme et zymogramme) des protéines de l'hémolymphe deCarcinus mediterraneus (Crustacé, Brachyoure)

Summary The use of the method of concentration gradient of polyacrylamide gel, electrophoresis has permitted to reveal a difference in zymograms when studying the hemolymph of healthy crabs and that of crabs parasitized by the muscular microsporidaThelohania, maenadis., The zymograms of the parasitized crabs present an increase in chymotrypsin activity and variations in the zones of esterase activity.

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Contribution n^o 1 du Centre de Parasitologie et de Pathologie comparées de l'Université des Sciences et Techniques du Languedoc, F-34060 Montpellier Cédex.     

Effet de l'oxygène et deO-(β-hydroxyaethyl)-rutosidea sur (HR)1 l'artère mésentérique de l'embryon de poulet expantée in vitro

Summary The effect of oxygen and of the semisynthetic flavonoidO-(-hydroxyaethyl)-rutosidea (HR) on the mesenteric artery of chicken embryo explanted in vitro has been studied. The protective effect of HR on the explants appears in anoxic (N₂) and hypoxic (2% O₂) atmosphere, but only during the first 24h of culture. In hyperoxic atmosphere (97% O₂) only after 3 days of culture HR has a protective action on the explants against the toxic effects of oxygen.

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Zyma S.A., Nyon.

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Ces recherches ont été faites grâce à un subside du Fonds National suisse de la Recherche scientifique et de la Fondation E. Barell.