Showing papers by "Pierre-and-Marie-Curie University published in 1978"
TL;DR: In Ketamine-anaesthetized rats the nigral efferents to the ipsilateral striatum, to both VL/VM thalamic nuclei and to both superior colliculi were studied and some of these neurons were found to have branching axons projecting at least to two of the different target nuclei studied.
Abstract: In Ketamine-anaesthetized rats the nigral efferents to the ipsilateral striatum, to both VL/VM thalamic nuclei and to both superior colliculi were studied. Nigral output neurons were antidromically activated from these target nuclei and characterized by their spontaneous activity and cellular localization within the substantia nigra. Neurons in the pars compacta, which give rise to the dopaminergic nigro-striatal pathway, exhibited a low spontaneous discharge rate (3 to 6/sec) and their axon had a slow conduction velocity (0.33 to 1 m/sec). They were antidromically activated from the striatum only. Neurons in the pars reticulata were characterized by a higher spontaneous activity (20 to 40/sec) and a faster conduction velocity (1.9 m/sec to 10 m/sec). They were antidromically activated from the thalamus, superior colliculus and striatum. Furthermore, some of these neurons were found to have branching axons projecting at least to two of the different target nuclei studied.
287 citations
TL;DR: It was shown that infants will suck more for their mother's voices under the intonated condition only, and it was concluded that a young infant prefers its own mother's voice provided the mother speaks normally.
Abstract: Each of a group of one-month-old infants was reinforced, contingent upon nonnutritive sucking, with its mother's voice and the voice of a stranger. In this experiment, two conditions were applied. Under the first, the mother's speech was aimed at communicating with the infant, while, under the second, the mother's speech lacked prosodic and intonational aspects of normal speech. It was shown that infants will suck more for their mother's voices under the intonated condition only. It was concluded that a young infant prefers its own mother's voice provided the mother speaks normally.
263 citations
TL;DR: In this paper, the fundamental absorption edge of InSe under high-resolution conditions was investigated and an effective Rydberg energy of 14.5 meV was obtained from a three-dimensional model and a simple analytical expression was obtained which accounts for the temperature dependence of the band gap.
Abstract: We report an investigation of the fundamental absorption edge of InSe under high-resolution conditions. We resolve three components of the direct exciton series and obtain an effective Rydberg energy of 14.5 meV. From this value an effective mass ($m=0.10 {m}_{0}$) of electrons in the $\ensuremath{\Gamma}$ minimum of the conduction band is obtained. We analyze the absorption coefficient with a three-dimensional model and find a remarkable agreement. We deduce an interband matrix element in polarization $\stackrel{\ensuremath{\rightarrow}}{\mathrm{E}}\ensuremath{\perp}\stackrel{\ensuremath{\rightarrow}}{\mathrm{C}}:{P}_{\ensuremath{\perp}}^{2}=0.6$ eV. Next we investigate the temperature dependence of the fundamental absorption edge. We find a strong interaction with a 14-meV phonon which accounts for (i) the shift of the band-gap energy in the full temperature range between liquid-helium temperature and 300\ifmmode^\circ\else\textdegree\fi{}K and (ii) the temperature dependence of the broadening parameter (exciton lifetime). A simple analytical expression is obtained which accounts for the temperature dependence of the band gap and the $n=1$ exciton structure. Last, we deduce the electron-phonon coupling constant.
206 citations
TL;DR: In this paper, the possibility of CP or T violation in neutrino oscillation was discussed and it was shown that if more than two neutrinos exist, the oscillation probability can be violated even drastically.
203 citations
TL;DR: In this paper, the mixed finite element approximation of variational inequalities is studied, taking as model problems the so-called "obstacle problem" and "unilateral problem".
Abstract: We study the mixed finite element approximation of variational inequalities, taking as model problems the so called "obstacle problem" and "unilateral problem" Optimal error bounds are obtained in both cases
196 citations
TL;DR: The subthalamonigral projection was studied with extracellular techniques in the rat and it was shown that the subthalamofugal fibers are excitatory to cells located in the pars compacta as well as in the Pars reticulata of the substantia nigra.
188 citations
TL;DR: The organization of subthalamic projections to the substantia nigra, entopeduncular nucleus and globus pallidus were studied in the rat to suggest that STN output neurons might be of only one type and influence SN, EN and GP synchronously.
112 citations
TL;DR: In this article, the chemical state and environment of palladium supported on silica, titania, and alumina have been studied by uv-visible and X-ray photoelectron spectroscopy.
105 citations
TL;DR: Results show that nigrothalamic neurons exert an inhibitory effect on VL cells and can modulate the information running along the cerebellothalamocortical pathway, suggesting that the SN controls the activity of the thalamic neurons which interfere with axial and proximal musculature.
96 citations
TL;DR: Particulate matter was collected from the surface water of the southwest Indian Ocean and the Antarctic Ocean in the area of Kerguelen, Heard, and Crozet islands.
84 citations
TL;DR: Petrological and mineralogical data on amphibolitized gabbros from an Alpine ophiolite massif (Chenaillet Massif, France) are presented in this article.
TL;DR: The purpose of the experiments described in this report was to determine whether it would be possible to observe this phenomenon of tolerance development in the cat by prolonged stimulation of raphe nuclei and whether the eventual decrease of analgesia following the application of long periods of central stimulation was affected by the administration of a serotonin precursor.
TL;DR: In this paper, the thermal conductivity and two viscosities of the classical one-component plasma in a rigid, uniform background were derived for the Coulomb case, and it was shown that some care has to be taken in defining the Kubo currents in order to avoid divergences arising from the long range of Coulomb interactions.
Abstract: We present molecular-dynamics computations of the thermal conductivity, and two viscosities of the classical one-component plasma in a rigid, uniform background. The Kubo formulas are proved for the Coulomb case, and it is shown that some care has to be taken in defining the Kubo currents in order to avoid divergences arising from the long range of the Coulomb interactions.
TL;DR: The labelling observed in the cochlear nucleus and the inferior colliculus was in agreement with previous studies of both the physiology and anatomy of these regions and provides an anatomical demonstration of the organization of frequency selectivity under conditions of functional activity.
TL;DR: The following theorem is proved that G is a graph with vertex-set V and ƒ, g contains a factor F such that g(x) ⩽d F (x)⩽ƒ( x) for all x ∈ V if and only if for every subset X of V, Ɠ is at least equal to the number of connected components C of G.
TL;DR: From a mathematical standpoint, numerical methods can be divided in two classes: direct methods, which give an exact result after some finite number of computations, and approximate methods,Which only give an approximate result after any finite numberof computations.
01 Aug 1978
TL;DR: In this paper, optical absorption and electron paramagnetic resonance (EPR) were used to study natural colored fluorites by means of optical absorption, and the results showed that strong irradiation of the crystals with ionizing radiation leads to coagulation of color centers, and precipitation of metallic calcium colloids.
Abstract: Natural colored fluorites were studied by means of optical absorption and electron paramagnetic resonance (EPR). Complex centers involving rare-earth ions and/or oxygen give rise to the various colors observed. These include yttrium-associated F centers (blue), coexisting yttrium and cerium-associated F centers (yellowish-green), the (YO2) center (rose) and the O
3
−
molecule ion (yellow). Divalent rare-earth ions also contribute to the colorations, as for instance Sm3+ (green fluorites), or they are at the origin of strong fluorescence observed (Eu2+). Strong irradiation of the crystals with ionizing radiation leads to coagulation of color centers, and to precipitation of metallic calcium colloids. There is probably no simple relation connecting the coloration and the growth process of the crystal. Thermal stability studies, however, have allowed to partially classify the colors as being of primary or secondary origin.
01 Jan 1978
TL;DR: The Ionian Sea forms the westernmost part of the eastern Mediterranean basin and is linked to the Adriatic by the relatively narrow and shallow (65 km wide, less than 100 m deep) straits of Otranto as mentioned in this paper.
Abstract: The Ionian Sea forms the westernmost part of the eastern Mediterranean basin. The eastern limit of the sea lies along the western margin of the East Mediterranean Ridge, which ends at about the longitude of Syrte. To the northeast it washes the shores of Greece, but geologically the Hellenic Trough (or Matapan Trench) forms part of the Hellenic Arc, and thus does not belong to the Ionian Sea. To the north the Ionian Sea is linked to the Adriatic by the relatively narrow and shallow (65 km wide, less than 100 m deep) straits of Otranto. The narrow Messina Straits (3.5 km) provide a link with the Tyrrhenian Sea and form the northwestern shore of the Ionian Sea. The Ionian Sea is in open communication to west with a region sometimes regarded as its extension and sometimes distinguished as the Pelagian Basin. The latter connects with the western Mediterranean through the Silican Channel, which, though 140 km wide, seldom attains a depth in excess of 300m. To the south the Ionian Sea against the Libyan shore.
TL;DR: A haploid cell line established from a mutant of Drosophila melanogaster, with a simple karyotype, will provide valuable experimental material for somatic cell geneticists.
Abstract: EFFORTS to establish haploid animal cell lines have produced encouraging results only for the frog1,2 and cockroach3, the genetics of which are poorly understood. Attempts to use mouse teratocarcinoma, which would be more suitable in this respect, have failed4, perhaps because of the presence of recessive lethal genes4,5. I describe here a haploid cell line established from a mutant of Drosophila melanogaster. Because of its simple karyotype (n = 4), this line will provide valuable experimental material for somatic cell geneticists.
TL;DR: The anorogenic complex of Evisa (Corsica) is made up of riebeckite hypersolvus granite and of albite-riebeckite-aegirine granite.
Abstract: The anorogenic complex of Evisa (Corsica) is made up of riebeckite hypersolvus granite and of albite-riebeckite-aegirine granite. Ten samples from the southern part of the complex provided Rb-Sr whole-rock isochrons for each facies. The ages of the two granites are indistinguishable at 246±7m.yr. corresponding to the Upper Permian. 87Sr/86Sr initial ratio (0.7034±0.0011) is in the mantle range of values and precludes any important crustal contamination. Li and Rb contents are controlled by the peralkaline fluid phase, reflected by deuteric changes. These alterations are weak in the hypersolvus facies but are obvious in the albite facies: replacement of preexisting perthite by albite, late precipitations of aegirine and fluorite, associated weak mineralization. The low value of 87Sr/86Sr initial ratio and the similarity of this ratio for both facies indicate that the fluid phase interacted with the crystallized rocks soon after the emplacement of the complex and provoked autometamorphic reactions without important external supplies.
TL;DR: Findings agree with the hypothesis that somatostatin infusion leads to both a decrease of acetylcholine release at nerve endings and to a direct inhibition at the level of pancreatic effector cells.
TL;DR: There is a possible inhibitory function of the nigro vectal pathway in the rat, and the problem of coactivation of pedunculus cerebri and tractus opticus (To) fibers is discussed.
TL;DR: In this article, a typical example of low misfit quaternary heterojunction Ga 0.7 Al 0.3 As 1- y P y /GaAs has been characterized by several X-ray techniques.
01 Jan 1978
TL;DR: In this paper, it was shown that peloidal oolitic sand-size grains composed basically of Fe oxides are transformed into the Fe(III)-smectite nontronite in sediments of Lake Chad.
TL;DR: In this paper, a model of the epitaxy with a layer-by-layer growth mechanism is proposed, which involves a transition alloy wich forms at the interface Au/AuPb2.
TL;DR: In this article, reversible hydration of amorphous V 2 O 5 has been performed in order to study the effect of water upon the properties of the oxide, which turns from anisotropic to isotropic upon hydration.
TL;DR: In this article, the authors used the piezothermal method to determine the thermal expansivity of benzene up to 4 kbar along 9 isothermal paths, in the range 250-350 K.
TL;DR: In this paper, the effects of very thin Ag surface layers on the propagation of surface plasma waves (S.P.W.) excited by ATR at an Al surface are investigated in the vicinity of the Ag plasma frequency and the S.PW dispersion relations, are obtained.
Abstract: 2014 The effects of very thin Ag surface layers on the propagation of surface plasma waves (S.P.W.) excited by ATR at an Al surface are investigated in the vicinity of the Ag plasma frequency and the S.P.W. dispersion relations, are obtained. A splitting of the dispersion curves is found for Ag layers 26, 39 and 58 Å thick, but does not appear for thinner layers. Experimental and computed dispersion curves are compared. LE JOURNAL DE PHYSIQUE TOME 39, JUIN 1978,