Showing papers by "University of Bordeaux published in 1982"
TL;DR: In this article, structural and textural characterization of the phases involved in nickel hydroxide electrodes is discussed with the object of throwing some light on traditionally unexplored features of such electrodes.
806 citations
TL;DR: In this article, the first-order Raman scattering intensity in terms of the vibrational density of states of a single graphite layer weighted by the electron-phonon couping of the modes to the electromagnetic radiation is derived.
512 citations
TL;DR: The results show that electric footshocks and environmental stimuli associated to previous shocks both activate central dopaminergic systems, although the patterns of activation are different.
421 citations
386 citations
TL;DR: In this article, the existence of states made of four heavy quarks in the context of potential models already used in the study of heavy mesons and baryons was discussed, where the quarks have the same mass and interact through a two-body potential due to color-octet exchange.
Abstract: We discuss the existence of states made of four heavy quarks in the context of potential models already used in the study of heavy mesons and baryons. We first consider the situation where the quarks have the same mass and interact through a two-body potential due to color-octet exchange. In this case, we show that for any reasonable confining potential there is no state below the threshold corresponding to the spontaneous dissociation into two mesons. We investigate in detail different possibilities of modifying this negative result. This concerns the effect of hyperfine corrections, the case of orbitally excited states, the case of unequal quark masses, and the use of the static potential derived from the bag model treated in the adiabatic approximation.
271 citations
TL;DR: In this paper, NaxCrO2 and NaxNiO2 were obtained for the first time by electrochemical desintercalation from NaCrO 2 and NaNiO 2.
191 citations
TL;DR: It is shown that an attribute system can be translated (in a certain way) into a recursive program scheme if and only if it is strongly noncircular, which is decidable in polynomial time.
156 citations
TL;DR: By exchange reaction from the sodium bronze Na 0, 70 CoO 2 (P2), a new layer variety of LiCoO 2(O2) has been obtained by sheet glidings as mentioned in this paper.
147 citations
TL;DR: It is demonstrated that Ro 15-1788 is not a pure benzodiazepine antagonist, but has partial agonist properties and blocked the anti-conflict effect of clorazepate.
122 citations
TL;DR: The coelomic fluid and the cocoon albumen of the earthworm Eisenia fetida andrei are demonstrated to possess an antibacterial activity as discussed by the authors, which is only directed against the highly pathogenic soil bacteria, only these pathogenic bacteria strains possess at least one common antigen with the sheep red blood cells.
115 citations
TL;DR: An enzymatic complex able to transform l-malate to l-lactate was obtained from a Leuconostoc mesenteroides strain isolated from grapes and at pH values substantially different from the optimum, a positive cooperativity between malate molecules was observed.
Abstract: An enzymatic complex able to transform l-malate to l-lactate was obtained from a Leuconostoc mesenteroides strain isolated from grapes. The molecular weight was about 235,000, the isoelectric point was at pH 4.35, and the optimal pH for activity was 5.75. The malolactic activity followed a sequential pattern concerning the involved substrates. At pH values substantially different from the optimum, a positive cooperativity between malate molecules was observed. Oxamate, fructose-1, 6-diphosphate, and l-lactate acted as noncompetitive inhibitors, whereas succinate, citrate, and tartrate isomers produced a competitive inhibition.
TL;DR: The cochleo- and vestibulotoxicities of a new aminoglyco-sidic antibiotic, dibekacin, have been compared, in the guinea pig, with those of gentamicin and tobramycin.
Abstract: The cochleo- and vestibulotoxicities of a new aminoglyco-sidic antibiotic, dibekacin, have been compared, in the guinea pig, with those of gentamicin and tobramycin Besides an untreated control group, three groups of pigmented guinea pigs have been treated with 20 consecutive daily subcutaneous injections of one of these antibiotics respectively, with a dosage of 90 mg/kg/day (30 times the recommended human therapeutic dose which is the same for the three aminosides studied: 3 mg/kg/day) The auditory and vestibular functions in the awake animal were studied respectively by the measurement of thresholds of click-evoked responses at the auditory cortex and by the recording of eye movements (electronystagmography) during damped sinusoidal rotatory stimulation These functions were monitored before, during and after the treatments in a few guinea pigs in each group, chronically implanted with auditory cortex and periocular electrodes These functions were assessed only at the end of the experiments in the o
TL;DR: In this article, Raman spectroscopy in VV and VH polarisations of fluorophosphate glasses obtained by fluorination of NaPO3, xNaPO3−yAlF3 or tNaPO 3−wAlF 3−vCaF2 have been studied.
Abstract: Some fluorophosphate glasses obtained by fluorination of NaPO3, xNaPO3−yAlF3 or tNaPO3−wAlF3−vCaF2 have been studied by Raman spectroscopy in VV and VH polarisations. The observed bands have been assigned by comparison with those vitreous NaPO3 and Na4P2O7, as well as crystallised K2PO3F and KPO2F2, and molten cryolite. Structural models are proposed for the various compositions. They are built up with arrangements of following species: (PO3)2n−n chains; (P2O7)4− dimers, (AlF6)3− octahedra, P(O, F)4, (AlF4)− and (AlOF3)2− tetrahedral groups. For glasses rich in phosphate −OPO2F− and −OPOF2 terminal groups are displayed; the latter being favoured for a higher fluorine concentration.
TL;DR: In this paper, unit recordings were performed in the postcentral cortex and focused on area 5 of awake monkeys during the execution of a learned movement of the contralateral forearm so that the time relationship between the motor act and any modification of neuronal activity could be precisely correlated.
TL;DR: Gross changes in the habenula perforata and in the spiral ganglion are described, together with ultrastructural alterations of organelles important for the cell metabolism and axonal transport, which suggest a direct influence of toxic substances on theganglion cells.
Abstract: Morphological changes of the eighth nerve were observed in the guinea pig between 1 month and 1 year after treatment with large doses of the antibiotic amikacin which resulted in complete cochlear hair cell destruction. The neural retrograde degeneration was found to be relatively fast, with a considerable loss (30 to 55%) of ganglion cells one month after treatment, continuously increasing (up to 85%) after one year. Gross changes in the habenula perforata and in the spiral ganglion are described, together with ultrastructural alterations of organelles important for the cell metabolism and axonal transport. The rapid degeneration and the morphological findings suggest a direct influence of toxic substances on the ganglion cells.
TL;DR: The results suggest that regulation of D-1 receptors is not solely dependent on the presynaptic DA innervation and that other non-DA fibres may contribute to it.
Abstract: The dopaminergic (DA) innervation of the prefrontal cortex in rat originates from neurones distributed in the anterior medial part of the ventral tegmental area (VTA)1. Biochemical2,3 and electrophysiological4 studies have demonstrated that these mesocortico-prefrontal neurones are distinct from others located in the VTA which project to subcortical structures such as the nucleus accumbens. DA receptors coupled to an adenylate cyclase (D-1 receptors) are present in the prefrontal cortex and their topographical distribution closely resembles that of DA nerve terminals5–7. We have now further analysed the properties of the cortical D-1 receptors and compared them with those of a subcortical limbic structure examining, in the rat, the effects on DA-sensitive adenylate cyclase activity in the prefrontal cortex and the nucleus accumbens of (1) bilateral 6-hydroxydopamine (6-OHDA) microinjections in the VTA and (2) bilateral electrolytic lesions of the VTA. The results suggest that regulation of D-1 receptors is not solely dependent on the presynaptic DA innervation and that other non-DA fibres may contribute to it.
TL;DR: The transformation from BTiO 2 to anatase either above 550°C under normal pressure or at room temperature under 60 kb is explained by a process of crystallographic shear with elimination of an equal number of anionic and cationic vacancies as discussed by the authors.
TL;DR: In this paper, a mesomorphic sequence of 4-nonyloxyphenyl 4-nitrobenzoyloxybenzoate was obtained from microscopic observations and X-ray experiments.
Abstract: 2014 We report a remarkable new mesomorphic sequence in a pure polar substance « 4-nonyloxyphenyl 4-nitrobenzoyloxybenzoate », at atmospheric pressure : K(SC2)S?SA1NreSAd reNreSAdNI. In this sequence obtained from microscopic observations and X-ray experiments we observe the first example of two reentrant nematic phases. At low temperature a novel bidimensional fluid smectic phase (S?) occurs, then a metastable bilayer smectic C phase labelled SC2 is identified before crystallization. From the study of several binary mixtures we confirm the existence of a SAd-SA1 transition which for the first time is evidenced by direct microscopic observation. Finally, in a (x, T) binary diagram, we discuss the different thermodynamic behaviour of the two reentrant nematic phases. J. Physique 43 (1982) 1127-1131 1 JUILLET 1982, Classification Physics Abstracts 61. 30E 64. 70E
TL;DR: In this paper, a microscopic calculation of nuclear state densities was performed starting from realistic single-particle levels, and a correspondence between microscopic ground state energy corrections and microscopic effects on state density was deduced.
Abstract: A microscopic calculation of nuclear state densities was performed starting from realistic single-particle levels. Within this concept, a correspondence between microscopic ground state energy corrections and microscopic effects on state densities was deduced. It is shown that the approximations introduced by a simple analytical expression for the nuclear state density are comparable to the uncertainties of microscopically calculated state densities for nuclei in their ground state configuration. Guidelines for the determination of the parameters of this analytical expression were deduced from the microscopic computations.
TL;DR: In Crustacea, recordings from isolated stomatogastric nervous system (Fig. 1) indicate that the pyloric output can be generated only when the STG is afferented (i.e., connected to the more rostral oesophageal and commissural ganglia).
Abstract: In Crustacea the central pattern generator for the pyloric motor rhythm (filtration to the midgut) is known to be located within the stomatogastric ganglion (STG); its cycling activity is known to be organized by three endogenous burster neurons acting as pacemakers and driving 11 follower neurons. In Homarus, recordings from the isolated stomatogastric nervous system (Fig. 1) indicate that (1) the pyloric output can be generated only when the STG is afferented (i.e., connected to the more rostral oesophageal and commissural ganglia) (Fig. 2) and (2) the deafferentation of the STG results in a complete loss of the bursting properties of the pacemaker neurons (Fig. 4). Manipulation of the STG inputs responsible for unmasking the properties of the pacemakers strongly suggests that (1) they are not phasic inputs (Fig. 5) and (2) they are long-term acting inputs (Fig. 6). These results provide evidence for a neural all-or-none control of the bursting properties of the pacemaker neurons of a motor pattern generator.
TL;DR: In this paper, single crystal structure studies at room temperature have been made for the first stage Mn Cl 2 intercalated graphite and the nominal composition was C 5·6 MnCl 2·4, as deduced from chemical analyses and X-ray diffraction intensities.
TL;DR: In this paper, the existence of a fluid mesophase built with ribbons forming a two-dimensional oblique lattice was shown based on structure factor calculations and a crude model based upon structure factor calculation was proposed.
Abstract: 2014 From microscopical observations and structural studies on the mesophases of a new thermotropic polar compound 2014 the nitrobenzoyloxybenzoate of octylphenyl 2014 we have shown the existence of a novel fluid mesophase built with ribbons forming a two-dimensional oblique lattice. We propose a crude model based upon structure factor calculations. J. Physique LETTRES 43 (1982) L-327 L-331 ler MAI 1982, Classification Physics Abstracts 61. 30E 64. 70E
TL;DR: Haemolymph volume of 20-day-old adult locusts was measured in vivo using a dye dilution method and shows that a corpora cardiaca material permits the release of the suboesophageal ganglion vasopressin-like factor which increases directly the Malpighian tubules diuresis.
TL;DR: In this paper, the low-temperature phase transitions of tetramethyltetrathiafulvalene thiocyanate are described through magnetic and structural studies, and it is shown that a first transition occurs at 160 K, which drives the electron gas into a localized state and is associated with a superstructure formation.
Abstract: The low-temperature phase transitions of tetramethyltetrathiafulvalene thiocyanate are described through magnetic and structural studies. A first transition, which occurs at 160 K, drives the electron gas into a localized state and is shown to be associated with a superstructure formation. Then, the condensation of an unexpected antiferromagnetic ground state is observed around 7 K. We suggest that this striking behavior is related to the peculiar wave vector (${a}^{*}, \frac{1}{2}{b}^{*}, \frac{1}{2}{c}^{*}$) of the 160-K superstructure.
TL;DR: In those proteins for which two domains of different type can be defined the accuracy of the prediction appears better for the carboxyl terminal part than for the amino one, and the prediction level is clearly better for proteins with a single type of secondary structure.
TL;DR: Honeybees affected by a disorder resembling the classical “May disease” in southwestern France contained numerous helical, motile organisms in their digestive tracts and hemolymph that multiplication and the induced lethal effect of the agent could be prevented by tetracycline but not penicillin.
Abstract: Honeybees affected by a disorder resembling the classical "May disease" in southwestern France contained numerous helical, motile organisms in their digestive tracts and hemolymph. Two strains of the organism (B31 and B39) were cultured and triply cloned in the BSR spiroplasma medium. The electrophoretic patterns of spiroplasmal proteins in 1 - and 2-dimensional polyacrylamide gels were similar to those of group IV spiroplasmas F1 and F2, cultured previously from flower surfaces in France. The organism could be introduced into adult bees by injection or food ingestion at various stages after emergence. Agent administered by either route multiplied to high titers in the hemolymph and killed the bees. Both multiplication and the induced lethal effect of the agent could be prevented by tetracycline but not penicillin. Spiroplasmas that were nearly identical to the B31 and B39 strains were also recovered from the surface of flowers collected within the area visited by the bees from the diseased hives.
TL;DR: In this paper, a simple model for age dependent population diffusion when the dynamics is submitted to external constraints is presented, and the existence, uniqueness and dependence on the parameters of the solution are discussed.
Abstract: We present a simple model for age dependent population diffusion when the dynamics is submitted to external constraints. Existence, uniqueness and dependence on the parameters of the solution are discussed.
TL;DR: In this article, a quantum theory of the gas-phase infrared and Raman spectra of toluene C6D5 CHD2 and nitromethane NO2CHD2 was put forward, assuming an anharmonic coupling of the νCH mode with the internal rotation of the CH D2 group in the adiabatic approximation.
TL;DR: Five new spiroplasma strains were analyzed in reciprocal growth inhibition, metabolism inhibition (MI), and deformation (DF) serological tests andSerological distinctiveness of a sixth group (VI) fromIxodes ticks was confirmed.
Abstract: Five new spiroplasma strains were analyzed in reciprocal growth inhibition, metabolism inhibition (MI), and deformation (DF) serological tests. New provisional groups from the waspMonobia quadridens (VII) and the syrphid flyEristalis arbustorum (VIII) were added to the existing classification. Three serovars—represented by the LB-12 green leaf bug spiroplassignificantly with subgroup I-4 and with each other. These new groups and serovars bring the number of recognized spiroplasma serovars to 16. Serological distinctiveness of a sixth group (VI) fromIxodes ticks was confirmed. Simple DF and/or MI procedures are described for typing new isolates.