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Showing papers by "University of Montpellier published in 1980"


Journal ArticleDOI
TL;DR: The neurosecretory systems producing mesotoc in and vasotocin (MT andVT) (the avian homologues of oxytocin and vasopressin, respectively) were characterized in the brains of the domestic mallard and Japanese quail by means of indirect immunofluorescence techniques using specific antisera.
Abstract: The neurosecretory systems producing mesotocin (MT) and vasotocin (VT) (the avian homologues of oxytocin and vasopressin, respectively) were characterized in the brains of the domestic mallard and Japanese quail by means of indirect immunofluorescence techniques using specific antisera. In the anterior preoptic region, including the organum vasculosum of the lamina terminalis, and at different levels of the supraoptic and paraventricular nuclei, separate mesotocin- and vasotocin-producing neurons were identified. Mesotocinergic and vasotocinergic neurons were also located in the tuberomammillary area, among the ectomammillary tract fibers. The supraoptico-neurohypophysial tract, formed by vasotocin- and mesotocin-containing axons, enters the internal zone of the median eminence and ends in the posterior lobe of the pituitary. The external zone of the rostral median eminence appears to contain vasotocin and mesotocin fibers, which terminate in close contact with the capillaries of the hypophysial portal system.

81 citations


Journal ArticleDOI
TL;DR: Mossbauer, ESR and magnetization measurements have been carried out on a basalt glass heat-treated at different temperatures (600, 650, 700, 800 and 900°C for 8 h).
Abstract: Mossbauer, ESR and magnetization measurements have been carried out on a basalt glass heat-treated at different temperatures (600, 650, 700, 800 and 900°C for 8 h). The as-annealed glass and the above five samples showed two-doublet Mossbauer spectra, while the last two samples also showed a six line magnetic hyperfine pattern at 300 K. At 4 K, the last four samples showed magnetic hyperfine patterns, while the as-annealed glass showed that there was already short range magnetic ordering present. High field Mossbauer data at 4 K showed that the surface spins are canted. The minimum quadrupole splitting and the maximum isomer shift around 700°C are related to the improved symmetry of the magnetite lattice. ESR spectra showed paramagnetic resonances at g = 4.3 and g = 2.0 for the first two samples, while the last four samples showed superparamagnetic resonance centred around g = 2.0 at 300 K. At lower temperatures, the 650 and 700°C samples showed ferrimagnetic resonance. Magnetization curves against H/T superpose well both at 300 and 77 K, showing the typical superparamagnetic behaviour of the small magnetite particles. The saturation magnetization (at 270 K) showed a sharp change around 700°C, showing the formation of magnetite. The magnetic structure of the small magnetite particles are discussed in terms of the above results.

62 citations


Journal ArticleDOI
TL;DR: In this paper, the viscosity-temperature relationship in the pressing temperature interval was determined for mixed gels of SiO 2 TiO 2, SiO O 2, P 2 O 5 and B 2 O 3 systems, which were prepared by sol-gel and/or hydrolysis and polycondensation of organometallic compounds.
Abstract: Mixed gels of SiO 2 TiO 2 , SiO 2 P 2 O 5 and SiO 2 B 2 O 3 systems were prepared by sol-gel and/or hydrolysis and polycondensation of organometallic compounds. The conversion of gel into glass was achieved by hot-pressing of the previously dehydrated gel. The kinetics of densification obey the WILLIAMS, ROGERS and MURPHY model; from this the viscosity-temperature relationship in the pressing-temperature interval was determined. The comparison of physical constants of glasses obtained from gels with those of glasses obtained by the OVPO method shows slight differences in some cases which may be ascribed to impurities or to the different thermal histories of the samples.

51 citations


Journal ArticleDOI
TL;DR: The effect of vestibular efferent system stimulation on thevestibular action potential (VAP) recorded after brief mechanical ampullopetal stimulation of the lateral canal crista was studied in the cat and the hypothesis of a double Efferent system is discussed.
Abstract: The effect of vestibular efferent system stimulation on the vestibular action potential (VAP) recorded after brief mechanical ampullopetal stimulation of the lateral canal crista was studied in the cat. When an inhibitory action was recorded it had an effect on the VAP component N2 potential and was also characterized by a positive post potential. When stimulation seemed to have no effect, computer averaging showed a weak facilitating action affecting the N1 potential. The hypothesis of a double efferent system is discussed.

35 citations


Journal ArticleDOI
TL;DR: Myelinated cell bodies of spiral ganglion in kittens during development can first be distinguished by light microscopic observation at the end of the first postnatal week and by mean of electron microscopic observation around the time of birth.
Abstract: Myelinated cell bodies of spiral ganglion in kittens during development can first be distinguished by light microscopic observation at the end of the first postnatal week. By mean of electron microscopic observation, the first signs of myelinated perikarya can be observed around the time of birth. Myelination is preceded by the ensheathment of the ganglion cell body by two or three layers of Schwann cell cytoplasmic processes. At birth, the first sign of myelination is visible at the basal part of the cochlea with thin thickenings which contain two or three major dense lines. At this stage, these thickenings cover only a small perikaryal area. Later on, the thickness and the number of thickenings increase and cover the major part of the cell body. The onset of myelination of the processes seems to precede the perikaryal myelination.

32 citations


Journal ArticleDOI
TL;DR: Modifications of cortical geometry were discussed with reference to measurements of cortical thickness and ultrastructural observations on postnatal days 2, 5 and 15, suggesting that both supranormal involution and growth processes might result from the neurotoxin treatment.
Abstract: Newborn rats received an intracisternal injection of 6-hydroxydopamine (100 μg) within 16 h after birth. Treatment effects upon noradrenaline uptake (with or without desmethylimipramine pre-incubation), endogenous noradrenaline, dopamine, and serotonin were biochemically assayed. Noradrenaline uptake and endogenous noradrenaline content were permanently reduced to less than 5% of control values. Reduction of endogenous dopamine content was less marked: at day 60, values were about 40% of controls. Serotonin content remained unaffected.

31 citations


Journal ArticleDOI
TL;DR: In this article, the critical stress intensity factor (K Ic) was measured for glasses in the Na 2 OSiO 2, PbO ǫ o 2, ZnOB 2 O 3, B 2 Oǫ b 2 o 3, Na 2 oǫ g o n, Na O Ǫ g o 2 n, Na G o n, Pb o à o n à n, B 2 à 0.
Abstract: Measurements of the critical stress intensity factor K Ic are reported for glasses in the Na 2 OSiO 2 , PbOSiO 2 , ZnOB 2 O 3 , PbOB 2 O 3 , Na 2 OGeO 2 and 20Na 2 O−(80 − x ) B 2 O 3 − x SiO 2 systems. The variations of K Ic with composition are not directly related to the simultaneous variations of Young's modulus. A tentative interpretation is given.

29 citations


Journal ArticleDOI
TL;DR: Comparison of allelic frequencies at the polymorphic loci between fish populations of infected and healthy lagoons yielded no significant differences.
Abstract: Biochemical genetics of a Atherinid species, Atherina boyeri were undertaken to determine variability. Among the 17 loci studied, 7 were polymorphic, of which three were retained for a more detailed comparison of populations inhabiting the French Mediterranean coastal lagoons. A microsporidiosis is present in these fishes and is limited to certain lagoons. Comparison of allelic frequencies at the polymorphic loci between fish populations of infected and healthy lagoons yielded no significant differences. Several hypotheses are discussed and attempt to agree parasite distribution with genetical results.

22 citations


Journal ArticleDOI
TL;DR: In this paper, simultaneous data from a movie camera, a coaxial shunt amperometer, a network of electric field mills, and a weather radar, were collected during the initial phase of a particular triggered event.
Abstract: During the 1978 campaign of the triggered lightning program at Saint-Privat d•'Allier (France), simultaneous data from a movie camera, a coaxial shunt amperometer, a network of electric field mills, and a weather radar, were collected during the initial phase of a particular triggered event. These data are shown to exhibit a high degree of consistency, leading to the conclusion that charges totaling several coulombs were present in cloudfree air in the vicinity of a stormy area.

22 citations


Journal ArticleDOI
TL;DR: The concentration of available cytoplasmic estradiol receptor was quantified in the postnatal hypothalamus and pituitary of male and female rats, aged from 4 to 28 days to avoid non-specific contamination of cytosol from very young animals by plasma proteins, especially alpha-feto-protein (AFP).

19 citations


Journal ArticleDOI
TL;DR: The pattern of circulating hormones in the teal was less clear cut, although the highest concentrations of GH were found in August, and significant correlations between GH and T 4 were observed in both teal and ducks.

Journal ArticleDOI
TL;DR: The second peak of internal friction in oxide glasses is explained by means of a model in which non bridging oxygens establish hydrogen bonds with OH − groups present in the structure as mentioned in this paper.
Abstract: The second (H.T.) peak of the internal friction in oxide glasses is explained by means of a model in which non bridging oxygens establish hydrogen bonds with OH − groups present in the structure. Some glasses containing transition metal ions show, however, relaxation effects which cannot be explained by usual models and are possibly due to electron-hopping phenomena.


Journal ArticleDOI
TL;DR: In this paper, a construction explicite et elementaire du groupe des extensions cycliques de degre premier d'un anneau et le calcule dans certains cases particuliers is presented.

Journal ArticleDOI
TL;DR: In this article, the internal friction behavior of Na2O-3SiO2 glasses having different redox ratios has been studied and the importance of this structural change on the electronic conductivity behaviour of these types of glasses is mentioned.
Abstract: The Mossbauer and ESR spectra and internal friction behaviour of Na2O-3SiO2 glasses having different redox ratios have been studied. As the redox ratio changes over a considerable range, there is a significant structural change associated with both the Fe3+ and Fe2+ ions, as evidenced from the analysis of the molar volume and Mossbauer data. The ESR data qualitatively supports the Mossbauer data on the Fe3+ ions. The change of internal friction behaviour of these glasses around 50% Fe3+ is described in terms of the structural changes associated with the Fe ions, which is thought to influence the oxygen structure of these glasses. The importance of this structural change on the electronic conductivity behaviour of these types of glasses is mentioned.


Journal ArticleDOI
TL;DR: In this article, a RMN 1 H (250MHz and effet LIS) analysis of acides phenyl-3 and cyclohexyl -3 cyclobutanecarboxyliques en solution montre que ces composes presentent des geometries voisines de celles observees a l'etat solide.

Proceedings ArticleDOI
23 Jun 1980
TL;DR: Methods for generalized deductive fault simulation of digital networks are described by introducing the notion of unknown fault list, and the propagation algorithm through gates modelized with rise and fall times are simplified with the same accuracy.
Abstract: In this paper, the authors describe methods for generalized deductive fault simulation of digital networks. By introducing the notion of unknown fault list, the propagation algorithm through gates modelized with rise and fall times are simplified with the same accuracy.

Journal ArticleDOI
TL;DR: Quarter-micron serial sectioning is a technique useful for 3-D analyses in which light microscopical resolution is not sufficient and the maximal resolution of the electron microscope is not necessary and less sections are needed to reconstruct tissue elements contained in a bloc of a given size.

Journal ArticleDOI
01 Nov 1980
TL;DR: In this article, the second maximum of the internal friction spectra is due to the simultaneous presence of the alkali ions (Li+, Na+, K+) and the hydrogen bonding established between the water and the non-bridging oxygens present in these glasses.
Abstract: 2014 The internal friction spectra of alkali-borate glasses have been studied as a function of temperature. These spectra, contrary to those of the alkali silicates and phosphates, do not show the second maximum (high temperature peak). The same feature was noted for some alkali-borosilicates as well. The investigation of the structure of these glasses, in particular the type of hydroxyl groupings which can exist, made us think that the second maximum of the internal friction spectra is due to the simultaneous presence of the alkali ions (Li+, Na+, K+) and the hydrogen bonding established between the water and the non-bridging oxygens present in these glasses. Revue Phys. Appl. 15 (1980) 1579-1584 NOVEMBRE 1980, 1

DOI
01 Aug 1980
TL;DR: Using a method previously applied to the treatment of the Mathieu differential equation, this paper solved the Hill's differential equation of lunar theory through the way of operational calculus, which avoids the cumbersome infinite determinants of the classical procedure The one-sided Laplace transformation changes it into a difference equation with an infinite number of terms and variable coefficients.
Abstract: Using a method previously applied to the treatment of the Mathieu differential equation, we solve the Hill's differential equation of lunar theory through the way of operational calculus, which avoids the cumbersome infinite determinants of the classical procedure The one-sided Laplace transformation changes it into a difference equation with an infinite number of terms and variable coefficients When its first member is divided by a suitable factor, this difference equation is the image of an integral equation of the Volterra type which is equivalent to the initial Hill's differential equation Solution of this Volterra integral equation is unique and it is the general solution of the Hill's differential equation This solution is a series in the powers of a small dimensionless parameter∈2 which appears as a factor in the second member of the Hill's differential equation We reduce it to the sum of its terms of degree ≤12 with respect to ɛ which is the precision usually required in a lunar theory and we write down effectively the coefficients of the terms in∈2, (∈2)2 and the coefficient of the term in (∈2)3 which depends upon the initial valuey(0) of the Hill's differential equation

Journal ArticleDOI
TL;DR: A petrological study of the basic rocks of magmatic activity in the Pokhara and Beri Khola regions of Central and Western Nepal suggests that the volcanic activities were not related to collision or continental subduction as mentioned in this paper.


Book ChapterDOI
01 Jan 1980
TL;DR: In this paper, the authors describe a method based on the study of the intensity and the spectrum of light scattered by hypersonic waves in a solid, where one end of the sample was exposed in a Ka-band waveguide to an rf field of frequency ω/2π≃35 GHz generating phonons at the surface via piezoelectric excitation.
Abstract: The method we describe here is based on the study of the intensity and the spectrum of light scattered by hypersonic waves in a solid. One end of the sample was exposed in a Ka-band waveguide to an rf field of frequency ω/2π≃35 GHz generating phonons at the surface via piezoelectric excitation. By adjusting the direction of the incident laser light (wavevector \({\overrightarrow k _o}\)) and the direction of the scattering (wavevector \({\overrightarrow k _s}\)), the phonon beam gives rise to an anti-Stokes Brillouin line provided that the conservation of energy and momentum relations are fulfilled. The Stokes Brillouin line arises from the beam reflected at the opposite end of the crystal.

Journal ArticleDOI
TL;DR: In this article, the authors describe original laboratory experimental work on artificial discontinuities, carried out by measuring heating of the joint during triaxial tests on pre-cut artificial joints.