Conduits souterrains en relation avec les terrasses fluviatiles

in Annales de la Société Géologique de Belgique (1961), LXXXIV

Complexe acide téichoique-mucopeptide des parois cellulaires de Bacillus megaterium KM

in Biochimica et Biophysica Acta (1961), 50(3), 413-429

Walls of a batch of Bacillus megalerium KM contain a polyol phosphate compound which, in contrast with BADDILEY'S teichoic acids, is not extracted by cold tri-chloroacetic acid. It has been isolated by ... [more ▼]

Walls of a batch of Bacillus megalerium KM contain a polyol phosphate compound which, in contrast with BADDILEY'S teichoic acids, is not extracted by cold tri-chloroacetic acid. It has been isolated by paper electrorheophoresis from the non-dialysable fraction obtained after incubation of the walls by lysozyme. Owing to the chemical analysis, it is associated with mucopeptide residues and the whole complex represents 40%, dry weight, of the walls. The degradation of this complex by two Streptomyces enzymes enables the identi-fication of three fragments: a teichoic fragment of polyol phosphate, glucose and N-acetylglucosamine; a mucopeptide fragment of amino acids and N-acetylmuramic acid; a disaccharide fragment 6-O-fl-N-acetylglucosaminyl-N-acetyl-muramic acid. It is believed that the latter represents an unit of a poly-N-acetylhexosamine back-bone of the basal mucopeptide of the wall. The teichoic fragment is liberated from the whole colnplex under the action of both Streptomyces enzymic preparations FI or F2B. It can also be obtained by in-cubating directly the walls with each of those preparations. The disaccharide fragment is liberated under the action of the F2B amidase. Approx. 6 %, dry weight, of the walls consist of glucose (probably a polyglucose) non associated with the teichoic acid-mucopeptide complex. N-acetylmuramic acid and various oligosaccharides consisting of N-acetyl- glucosamine alone or of both N-acetylglucosamine and N-acetylmuramic acid, give, on paper, a pink coloration with the diphenylamine-trichloroacetic reagent which allows them to be distinguished from N-acetylglucosamine. [less ▲]

A.H. Niemeyer, pédagogue du Goethezeit

in Revue des Langues Vivantes = Tijdschrift voor Levende Talen (1961), 2

On the Classification of Leptons

in Physica (1961), 27

The formulae giving the electric charge and the neutrinonic charge in terms of T3 and S are generalized in order to apply them to leptons. There remains an unknown parameter. For a particular value of ... [more ▼]

The formulae giving the electric charge and the neutrinonic charge in terms of T3 and S are generalized in order to apply them to leptons. There remains an unknown parameter. For a particular value of this parameter these formulae assume the particularly symmetric forms (15) and (16). Values for S, T and T3 are assigned to the different leptons. At the time this investigation was carried out the following difficulty arose: in addition to the known leptons (neutrino, electron and muon) there remained a vacancy for an undisovered lepton, which, with regard to the charges, is similar to the neutrino. Yet this has no longer to be considered as a difficulty but well as a prediction of the theory since one was recently led to admit the existence of two neutral leptons instead of one, namely the neutrino. [less ▲]

Déterminants culturels de la pédagogie de Niemeyer

in Paedagogica Historica (1961), (1-2), 187-212

Précisions sur la structure des complexes disaccharide-peptide libérés des parois de Micrococcus lysodeikticus sous l'action des [beta] (I --> 4) N-acetylhexosaminidases

in Biochimica et Biophysica Acta (1961), 47(3), 561-568

Two types of disaccaride-peptide complexes have been studied. In a first type of complex, the fragment 6-O-[beta]-N-acetylglucosaminyl-N-acetyl-muraminyl is joined to a peptide moiety consisting of 2 ... [more ▼]

Two types of disaccaride-peptide complexes have been studied. In a first type of complex, the fragment 6-O-[beta]-N-acetylglucosaminyl-N-acetyl-muraminyl is joined to a peptide moiety consisting of 2 alanines, 1 glycine, 1 glutamic acid and 1 lysine, by an amide bond between the COOH of N-acetylmuramic acid and the NH2 of one of the alanine residues of the peptide. The reaction with 1-fluoro-2,4 dinitrobenzene shows that the [epsilon]-NH2 group of lysine is free. The electroheophoretic properties suggest that the [gamma]-COOH group of glutamic acid and an unspecified [alpha]-COOH group are free too. The second type of complex is a dimer of the former, joined by a peptide linkage between an [epsilon]-NH2 group of lysine and, very probably, an [alpha]-COOH group. THe F2B amidase splits the amidic acetylmuraminyl-alanine linkage. Consequently, the disaccharide is liberated and a new free [alpha]-NH2 group of alanine appears in the peptide moiety. [less ▲]

Action différentielle d'un excitant nerveux central mis en évidence par une technique de conditionnement operant chez le chat

in Archives Internationales de Physiologie et de Biochimie (1961), 69