Showing papers by "Université libre de Bruxelles published in 1976"
TL;DR: In this article, it was shown that trace anomalies in a conformal invariant theory do not arise when its invariance in four dimensions is extended to an arbitrary number n of space-time dimensions.
226 citations
TL;DR: The early components of the somatosensory evoked potential (SEP) were analysed in normal newborns in REM sleep, normal awake children between 1 month and 9 years and 16 normal awake adults to serve as a useful reference for subsequent studies on developmental changes of the brain and for clinical applications to diseased children.
159 citations
TL;DR: Molecular hybridizations between BLV/[3H]cDNA and several viral RNAs show that BLV is not related to Mason-Pfizer monkey virus, simian sarcoma associated virus, feline leukemia virus, or avian myeloblastosis virus.
Abstract: Short-term cultures of bovine leukemic lymphocytes release virus particles with biochemical properties of RNA oncogenic viruses. These particles, tentatively called bovine leukemia virus (BLV), have a high molecular weight RNA-reverse transcriptase complex and a density of 1.155 g/ml in sucrose solutions. Molecular hybridizations between BLV/[3H]cDNA and several viral RNAs show that BLV is not related to Mason-Pfizer monkey virus, simian sarcoma associated virus, feline leukemia virus, or avian myeloblastosis virus. These results were confirmed by hybridization between BLV 70S RNA and [3H]cDNA synthesized in the various viruses tested. The high preference of BLV reverse transciptase for Mg++ as the divalent cation suggests that BLV might be an atypical mammalian leukemogenic "type C" virus. DNA-DNA hybridization studies using BLV [3H]cDNA as a probe strongly suggest that the DNA of bovine leukemic cells contains viral sequences that cannot be detected in normal bovine DNA.
150 citations
TL;DR: First application of this method on marine sediments gives results in good agreement with information provided by other methods, and can be quantitatively related to the rate of nitrogen oxidation by autotrophic nitrifiers.
126 citations
109 citations
TL;DR: Induction kinetics and the half life of the inducible mutagenic DNA repair (SOS-repair) in E. coli have been determined using phage λ assays using ultraviolet induction patterns that very much resembles that of λ prophage in lysogenic induction.
Abstract: Ultraviolet mutagenesis of phage λ is produced by host functions which are inducible by ultraviolet irradiation of the host cell Induction kinetics and the half life of the inducible mutagenic DNA repair (SOS-repair) in E coli have been determined using phage λ assays At 37°C, both mutagenic and repair activities are maximal approximately 30 min following irradiation and decay with a half life of approximately 30 min The presence of 100 μg/ml chloramphenicol during the first 40 min after irradiation completely abolishes induction of repair and mutagenesis The ultraviolet induction pattern of SOS repair very much resembles that of λ prophage in lysogenic induction (Monk and Kinross, 1975)
108 citations
TL;DR: In this paper, the scattering of 1 keV Ar atoms in thin amorphous and monocrystalline Cu targets has been studied, using the computer simulation program MARLOWE.
98 citations
TL;DR: Habituation kinetics were found to vary considerably in different polysynaptic pathways of the brain stem in man, including the exteroceptive reflex of the digastric muscle and that of the masseter muscle.
91 citations
01 Jan 1976
86 citations
TL;DR: In vivo, phage Mu-1 is only slightly sensitive to several restriction enzymes, and the Mu modification function seems to be expressed at a higher level after induction of a Mu prophage than after lytic infection with Mu.
86 citations
TL;DR: The fluorescence spectra, quantum yields and lifetimes of [10, [11]-, [12], [13], [14]-helicene and 3,15-ethanoheptahelicenes have been observed in 1,4-dioxan solution at room temperature as mentioned in this paper.
TL;DR: By treating mutant populations as fluctuations relating to the structural stability of the equations of population dynamics, a criterion is developed permitting the prediction of long-term population trends in an evolving eco-system.
Abstract: By treating mutant populations as fluctuations relating to the structural stability of the equations of population dynamics, a criterion is developed permitting the prediction of long-term population trends in an evolving eco-system. As an illustration it is shown that the ratio of predator to prey biomass increases under the effects of their combined evolution.
TL;DR: Mu-mediated transposition offers a new way to isolate F′ episomes and to localize and order bacterial genes as far apart as three minutes.
TL;DR: In the starfish (Asterias rubens) coelomocytes are produced in the coelomic epithelium, and the theory that they imply self-replication of free cells is confirmed.
Abstract: THE various theories proposed to explain the origin of echinoderm coelomocytes can be classified into two groups, depending on whether they refer to a cytopoietic organ or tissue (Tiedemann bodies1–3, Polian vesicles1, axial organ1,4, connective tissue5,6 and coelomic epithelium7–9) or whether they imply self-replication of free cells9–11. So far no theory has been confirmed. We now report that in the starfish (Asterias rubens) coelomocytes are produced in the coelomic epithelium.
TL;DR: It is suggested that, in the process of glucose-induced insulin release, glycolysis may regulate physiological processes possibly located in the micro-environment of the cell boundary.
Abstract: When isolated islets of Langerhans are suddenly exposed to glucose, the entry of the hexose into islet cells first occurs at a high rate resulting in rapid equilibration of free glucose across the cell membrane; thereafter, the rate of net glucose uptake depends on its metabolism. More than 95% of the glucose taken up by the islets is converted to triosephosphate. The fractional contribution of the sorbitol and pentose-phosphate pathways to such a process does not exceed 10%. The output of lactate from the islets accounts for approximately half of the glycolytic flux. At increasing glucose concentrations up to 4.3 mM, the rate of glycolysis increases towards a first asymptotic value; at higher glucose levels (up to 27.8 mM), a sigmoidal pattern is seen tending towards a second saturation value. The total ATP content of the islets does not correlate with their insulin-secretory activity. It is suggested that, in the process of glucose-induced insulin release, glycolysis may regulate physiological processes possibly located in the micro-environment of the cell boundary.
TL;DR: Systematic observations were carried out on the longitudinal changes in hand preference in a normal baby chimpanzee from the third day after birth until the age of 27 months, consistent in showing laterality for several voluntary movements.
TL;DR: In this article, the isolation and complete structure determination of four marine sesquiterpenoids: Δ9(12)-capnellene-8β,10α-diol (1), Δ9 (12)-CAPNE-3β, 8β, 10α-triol (3), Δ 9(12-CAPNE)-5α, 8 β, 10 α-trioline (5), and Δ 9 (12) CAPNE-2ξ,8β and 10α trioline (7) from the soft coral Capnella imbric
TL;DR: In this article, the goodness of the symplectic symmetry is discussed by investigating the distributions with fixed seniority in every orbit, and the results compared with those of the shell model.
Abstract: 2014 Configuration-seniority spectral distributions are used to analyse some properties of Ni62, and the results compared with those of shell model. The goodness of the symplectic symmetry is discussed by investigating the distributions with fixed seniority in every orbit. LE JOURNAL DE PHYSIQUE LETTRES Classification Physics Abstracts 4.161 TOME 37, JANVIER 1976, During the last few years significant progress has been made in the study of the spectra of complex nuclei involving a large number of configurations, by the introduction of the spectral distribution method [1-3]. Applications of this method to the calculation of low excitation spectra and level densities and to the study of symmetries have been carried out in some cases. In a series of papers we intend to study the symplectic symmetry, connected with the seniority quantum number, for systems of n identical nucleons distributed in a finite set of levels with total degeneracy 2 ~2. In a former work [4] we studied fixed generalized seniority distributions, associated with the chain of groups V(2 0) ::) Sp (2 ~2). In this paper we give preliminary results for configuration-seniority distributions, connected with the chain of groups wherein the averages are taken over subspaces characterized by
TL;DR: A significant correlation was found between the blood and urine mercury levels and the total amount of cells with chromosomal aberrations and frequencies of Cells with other than chromatid type aberration on the other.
TL;DR: Observations are consistent with previous conclusions drawn from light microscopic studies that the clearing up of CF debris in the molecular layer is completed within the short time of three days, and that the inferior olive seems to be the only source of CFs.
Abstract: The cerebellar molecular layer in adult rats has been studied with the electron microscope at several early and consecutive survival times following 3-acetylpyridine intoxication. Climbing fiber (CF) terminals underwent a fast process of electron-dense degeneration which became apparent from 16 hours onwards. A small proportion of degenerating terminals were depleted of vesicles and filled with a dark flocculent and granular homogeneous matrix. Microtubular changes in degenerating CF tendrils were observed. CF terminals were found in relation with every Purkinje cell in normal animals and completely disappeared within 72 hours after the treatment. CF synapses were found on Purkinje dendritic and somatic thorns, sometimes also on the dendritic shafts or even on the Purkinje soma. Convincing evidence of synaptic contacts of CF varicosities on either basket or stellate cells could not be obtained. CF synapses with Golgi II cell dendrites in the molecular layer were described. Decrease in the number of post-synaptic dendritic thorns normally assigned fo CF synapses was observed consequential to CF anterograde degeneration. The observations are consistent with previous conclusions drawn from light microscopic studies that the clearing up of CF debris in the molecular layer is completed within the short time of three days, and that the inferior olive seems to be the only source of CFs.
TL;DR: In this article, the tetraalkylammonium groups are present in the extracellular region of the erythrocyte membrane, which could explain why erythcytes are lysed by SiO 2, but not by TiO 2.
TL;DR: In this paper, an example describing the use of the interactive computer program CONGEN in the identification of the tricyclic sesquiterpene alcohol, [+]-palustrol, in extracts of a marine Xeniid (Cespitularia sp., aff subviridis ) is provided.
TL;DR: Sesquiterpenes, diterphenes and sterols found in Alcyonaceans are briefly reviewed in this paper, where their biogenetical origin, their distribution and their biological significance are discussed.
Abstract: Sesquiterpenes, diterpenes and sterols found in Alcyonaceans are briefly reviewed. Their biogenetical origin, their distribution and their biological significance are discussed.
TL;DR: In this paper, the shape of DTA endothermic peak associated with the dehydration of goethite FeOOH into hematite depends strongly on the size of the particles.
Abstract: The shape of DTA endothermic peak, associated with the dehydration of goethite FeOOH into hematite, depends strongly on the size of the goethite particles. With samples of low specific surface, two distinct peaks were observed. The dehydration process of a low-specific surface goethite was followed by X-ray diffraction and lowtemperature nitrogen adsorption. The results are in good agreement with the hypothesis of the formation of an impermeable hematite layer on each grain which temporarily stops the dehydration process of the internal part of the grain.
TL;DR: In this article, a visual input reduced to a single luminous point in complete darkness, but not with a textured background, was used to measure immediate reaction to conflict and aftereffects.
Abstract: Despite the often encountered affirmation that vision completely dominates other modalities in intersensory conflict, there are cases where discordant auditorv information affects the localization of a visual signal. Experiment I shows that “auditory capture” occurs with a visual input reduced to a single luminous point in complete darkness, but not with a textured background. The task was to point at a flashing luminous point alternately in the presence of a synchronous sound coming from a source situated 15° to one side (“conflict trials,” designed to measure immediate reaction to conflict) and in its absence (“test trials,” to measure aftereffects). Adaptive immediate reactions and aftereffects were observed in the dark, but not with a textured background. In Experiment II, on the other hand, “visual capture” of auditory localization was observed at the levels of both measures in the dark and with the textured background. That visual texture affects the degree of auditory capture of vision, but not the degree of visual capture of audition was confirmed at the level of aftereffects in Experiment III, where bisensory monitoring was substituted for pointing during exposure to conflict. The empirical finding eliminates apparent contradictions in the literature on ventriloquism, but cannot itself be explained in terms either of relative accuracy of visual and auditory localization or attentional adjustments.
TL;DR: In this paper, the authors studied the growth kinetics of polycarbonate over a wide range of stress and temperature and found that the delay time for appearance of crazing varies with stress and temperatures following a rate process equation, and that activation energy and activation volume are smaller for crazing than for shear-resolvable yielding.
Abstract: Craze growth kinetics in polycarbonate are studied over a wide range of stress and temperature. The delay time for appearance of crazing is found to vary with stress and temperature following a rate process equation. Activation energy and activation volume are smaller for crazing than for shear-resolvable yielding.
TL;DR: In this paper, an extension of the Skyrme-Hartree-Fock formalism is proposed for calculating binding energies in hypernuclei throughout the periodic table, including the self-consistent nuclear polarization by the hyperon.
TL;DR: In this paper, a method for the analysis of dilution heats of micellar systems is proposed for the simultaneous determination of critical mousellar concentration and micellization enthalpy from measurements performed at a single temperature.
Abstract: A method is proposed for the analysis of dilution heats of micellar systems. Simultaneous determination of critical micellar concentration and of micellization enthalpy can be derived from measurements performed at a single temperature.
TL;DR: In this paper, the authors analyzed the coherence length beyond which fluctuations can amplify and induce instabilities at a macroscopic scale and established the existence of diverging form factors and long range correlations.
Abstract: Recent analyses of fluctuations in non-equilibrium systems by Prigogine, Malek-Mansour and Nicolis have indicated the existence of a minimal coherence length beyond which fluctuations can amplify and induce instabilities at a macroscopic scale. Conversely, this observation suggests the emergence of long range spatial correlations in systems undergoing non-equilibrium unstable transitions. In the present paper, this problem is analyzed for reaction-diffusion systems and illustrated on a specific model. The existence of diverging form factors and of long range correlations is established. The connection between the multi-variate master equation and the local equation developed recently by Prigogine, Malek-Mansour and Nicolis is discussed.