Showing papers by "University of Paris published in 1988"
TL;DR: A new memory test in rats, based on the differential exploration of familiar and new objects, which is comparable to memory tests currently used in man and allows interspecies comparisons.
2,970 citations
TL;DR: The glycopeptide antibiotic agents vancomycin and teicoplanin are useful in the treatment of severe infections due to gram-positive bacteria.
Abstract: THE glycopeptide antibiotic agents vancomycin and teicoplanin are useful in the treatment of severe infections due to gram-positive bacteria.1 2 3 Staphylococci, streptococci, and enterococci are a...
1,379 citations
TL;DR: Soit Ω un ensemble ouvert borne regulier et connexe de R N, N≥3. On considere u:Ω→R telle que −Δu=u (N+2)/(N−2) dans Ω, u>0 dans ǫ, u=0 sur ∂Ω as discussed by the authors.
Abstract: Soit Ω un ensemble ouvert borne regulier et connexe de R N , N≥3. On considere u:Ω→R telle que −Δu=u (N+2)/(N−2) dans Ω, u>0 dans Ω, u=0 sur ∂Ω. On note par Hd(Ω; Z 2 ) l'homologie de diemnsion d de Ω a coefficients Z 2 . S'il existe un entier positif d tel que Hd(Ω, Z 2 )¬=0, alors l'equation a une solution
756 citations
TL;DR: In this paper, the authors study the regularity of the moment √ u(x, v) dμ(v) in terms of fractional Sobolev spaces.
495 citations
TL;DR: In this article, the authors describe a general local smoothing effect for dispersive equations and systems, including the K-dV, Benjamin-Ono, intermediate long wave, various Boussinesq, and Schrodinger equations.
Abstract: Is it possible for time evolution partial differential equations which are reversible and conservative to smooth locally the initial data? For the linear wave equation, for instance, the answer is no. However, in [10] T. Kato found a local smoothing property of the Korteweg-de Vries equation: the solution of the initial value problem is, locally, one derivative smoother than the initial datum. Kato's proof uses, in a curcial way, the algebraic properties of the symbol for the Korteweg-de Vries equation and the fact that the underlying spatial dimension is one. Actually, judging from the way several integrations by parts and cancellations conspire to reveal a smoothing effect, one would be inclined to believe this was a special property of the K-dV equation. This is not, however, the case. In this paper, we attempt to describe a general local smoothing effect for dispersive equations and systems. The smoothing effect is due to the dispersive nature of the linear part of the equation. All the physically significant dispersive equations and systems known to us have linear parts displaying this local smoothing property. To mention only a few, the K-dV, Benjamin-Ono, intermediate long wave, various Boussinesq, and Schrodinger equations are included. We study, thus, equations and systems of the form
444 citations
367 citations
TL;DR: In a series of 14 patients operated on between January 1980 and December 1986 in this institution, only one patient with an associated atrioventricular septal defect required a tricuspid valve replacement and all of the other patients were able to benefit from this conservative technique.
335 citations
TL;DR: The combination of nerve and muscle sampling increases the chance of visualizing characteristic arterial lesions in vasculitic neuropathy.
Abstract: We have reviewed the clinical and morphological data from 100 patients with necrotizing arteritis in muscle and/or in nerve samples taken by biopsy. The neuropathy occurred in the context of a multisystem disorder (Group 1) or in apparent isolation (Group 2). The average age of patients was 59 in Group 1 and 61 in Group 2. Females were more commonly affected than males, especially in the first group. Necrotizing arteritis complicated the course of rheumatoid arthritis in 25 patients. In 3 patients necrotizing arteritis was associated with infection with the human immunodeficiency virus, the agent of AIDS. Tests for hepatitis B surface antigen were positive in 19 patients. Mononeuritis was present in 13, mononeuritis multiplex in 62, and distal symmetrical sensory or sensorimotor neuropathy in 19 patients. In both groups of patients, the muscle biopsy was more frequently diagnostic for arteritis than was the nerve biopsy (80% versus 55%). The average incidence of isolated fibers undergoing axonal degeneration was 64.8%; that of demyelinated/remyelinated fibers was 1.9%. We conclude that the combination of nerve and muscle sampling increases the chance of visualizing characteristic arterial lesions in vasculitic neuropathy.
258 citations
TL;DR: In this article, the existence of a solution of the following variational inequality was proved: the obstacle ψ is a measurable function with values in the range ψ −∞, recovering the case where (*) is an equation.
Abstract: This paper proves the existence of (at least) one solution of the following variational inequality:
(*)
$$\left\{ {\begin{array}{*{20}c} {u \in W_0^{1,v} (\Omega ) \cap L^\infty (\Omega ), u \geqslant \psi a.e. in \Omega ,} \\ {\langle A(u),\upsilon - u\rangle + \int\limits_\Omega {{\rm H}(x,u,Du)(\upsilon - u) \geqslant 0,} } \\ {\forall \upsilon \in W_0^{1,v} (\Omega ) \cap L^\infty (\Omega ), u \geqslant \psi a.e. in \Omega .} \\ \end{array} } \right.$$
Here A is an operator of Leray-Lions type acting from W
0
1,p
(Ω) into W−1,p′(Ω) and H grows like ¦Du¦p. The obstacle ψ is a measurable function with values in
$$\bar R$$
, the only hypothesis being
$$\{ \upsilon \in W_0^{1,v} (\Omega ) \cap L^\infty (\Omega ):\upsilon \geqslant \psi a.e in \Omega \}
e 0/$$
. This allows ψ to be −∞, recovering the case where (*) is an equation. Finally there is no smoothness assumptions on the data: Ω is a bounded open set inR
N
, A and H are defined from Caratheodory functions.
256 citations
TL;DR: Preliminary data suggest that combining early mechanical ventilation with the administration of diazepam and epinephrine may be effective in the treatment of severe chloroquine poisoning.
Abstract: No therapy has been proved to be effective for patients with severe chloroquine poisoning, which is usually fatal. In a retrospective study of 51 cases, we found that ingestion of more than 5 g of chloroquine was an accurate predictor of a fatal outcome, and therefore chose this dose as the criterion for severe chloroquine poisoning. We selected as a control group 11 consecutive patients who had ingested more than 5 g of chloroquine between July 1983 and December 1985. We then undertook a prospective study to determine whether a better outcome could be obtained with immediate mechanical ventilation and the administration of diazepam and epinephrine. Eleven consecutive patients who ingested more than 5 g of chloroquine in 1986 received this combination therapy. Ten of these patients survived, whereas only one control had survived (P = 0.0003). There was no significant difference between the combination-therapy and control groups in age (29 +/- 3 vs. 27 +/- 2 years), amount of chloroquine ingested (7.5 +/- 0.5 vs. 8.5 +/- 0.8 g), systolic arterial pressure (74 +/- 2 vs. 74 +/- 3 mm Hg), or QRS duration (0.14 +/- 0.01 vs. 0.14 +/- 0.01 second). In our combination-therapy group, blood chloroquine levels ranged from 40 to 80 mumol per liter, whereas a literature search showed that no patient in whom blood levels were more than 25 mumol per liter had survived. These preliminary data suggest that combining early mechanical ventilation with the administration of diazepam and epinephrine may be effective in the treatment of severe chloroquine poisoning.
247 citations
TL;DR: The Gulf of Suez is a Neogene rift which has evolved as one arm of the Sinai triple junction together with the Gulf of Aqaba and the Red Sea.
TL;DR: It is suggested that pyrimethamine/sulfadiazine is highly efficacious in neurotoxoplasmosis and that life-long therapy is needed to prevent relapses in patients with AIDS.
TL;DR: The available evidence is consistent with the hypothesis of a worldwide P-element invasion of D. melanogaster during the past 30 years and suggests that the putative invasion of the Americas possibly preceded by approximately a decade that in Europe, Africa, and the rest of the world.
Abstract: Approximately 100 strains derived from natural populations of Drosophila melanogaster were tested for the presence or absence of P-element sequences by using two molecular probes derived from internal regions of a full-sized P element. Strains that had been collected from several continents at varying times during the past 60 years were examined. The oldest available strains, representing most major geographical regions of the world, exhibited no detectable hybridization to the P-element probes. In contrast, all recently collected natural populations that were tested carried P-element sequences. The earliest appearance of P elements occurred in collections made during the 1950s and early 1960s in the Americas and during the late 1960s on other continents. The youngest strains that were completely devoid of P elements originated in populations sampled during the mid-1960s in America, but as late as 1974 in populations from the USSR. There are differences in the patterns of hybridization to the two P-element probes between populations from different geographical regions. These differences are consistent with the varying P-M phenotypic properties of these populations. Taken together with the results of phenotypic tests reported in earlier studies, the available evidence is consistent with the hypothesis of a worldwide P-element invasion of D. melanogaster during the past 30 years and suggests that the putative invasion of the Americas possibly preceded by approximately a decade that in Europe, Africa, and the rest of the world.
TL;DR: This work reports that functional changes in single neurons of area 17, analogous to those known to take place during epigenesis of visual cortex5,6, can be induced experimentally during the time of record?
Abstract: Neuronal activity plays an important role in the development of the visual pathway. The modulation of synaptic transmission by temporal correlation between pre- and postsynaptic activity is one mechanism which could underly visual cortical plasticity1–4. We report here that functional changes in single neurons of area 17, analogous to those known to take place during epigenesis of visual cortex5,6, can be induced experimentally during the time of record? ing. This was done by a differential pairing procedure, during which iontophoresis was used to artificially increase the visual response for a given stimulus, and to decrease (or block) the response for a second stimulus which differed in ocularity or orientation. Long-term modifications in ocular dominance and orientation selectivity were produced in 33% and 43% of recorded cells respectively. Neuronal selectivity was nearly always displaced towards the stimulus paired with the reinforced visual response. The largest changes were obtained at the peak of the critical period in normally reared and visually deprived kittens, but changes were also observed in adults. Our findings support the role of temporal correlation between pre- and postsynaptic activity in the induction of long-lasting modifications of synaptic transmission during development, and in associative learning.
TL;DR: In this paper, limits on leptonic mixing matrix elements are inferred from the results of a dedicated neutrino-decay search; an improvement of more than two orders of magnitude is achieved over previous results for a wide range of the Neutrino mass.
TL;DR: In this paper, the density or non-density of smooth functions between two compact manifolds M n and N k in Sobolev spaces W 1, p (M n, N k ).
TL;DR: In this paper, it was shown that direct CP violation may also occur in the decay of K2 into two pions with a relative amplitude?′, which is non-zero in the case of a phase difference between the amplitudes A0 and A2 for the decay into isospin O and 2 states of two charged pions.
TL;DR: In this article, a new approach to crew-pairing problems arising in the context of airline companies is proposed, in which the column generation subproblem is shown to be equivalent to a shortest path problem in an associated graph.
TL;DR: The data do not provide evidence yet for the existence of NK2 binding sites in the rat brain, but the structure is particularly rich in SP and NKA and contains functional tachykinin receptors of the NK1 and NK2 types as suggested by physiological studies.
TL;DR: Theory locale. Diffusion de la chaleur sur des groupes de Lie connexes. Les conditions de Sobolev modifiees as discussed by the authors, i.e.
TL;DR: In this paper, the stability of a solitary wave solution of the Korteweg-de Vries equation was investigated when a fifth order spatial derivative term is added, and it was shown that the solution ceases to be strictly localized but develops an infinite oscillating tail.
TL;DR: A combination of three complementary secondary structure prediction methods is presented and a hydropathy scale was developed for this purpose, which shows that beta-sheet runs are much better located by the Combine method in comparison to the other methods.
Abstract: A combination of three complementary secondary structure prediction methods is presented. The methods used are the GOR III method, the Homologue method and a new method, the bit pattern method, which is based on hydrophilic/hydrophobic residue patterns. For this purpose a hydropathy scale was developed and is presented here. The combination algorithm (Combine method) was designed to take the best results of each method and use their differences in order to improve the prediction. The combination yields 65.5% correctly predicted residues in three states: alpha-helix (H), beta-strand (E) and aperiodic structure (C) which is an improvement ranging from 2.5 to 6.5% compared with the individual methods when tested with a 67-polypeptide chain database. Seventy-five per cent of the regular secondary structure (H and E) runs are correctly located and beta-sheet runs are much better located by the Combine method in comparison to the other methods.
TL;DR: There is a loss of information when moving from a geometrical object to its drawing, but pupils often have the illusion that they can, thanks to a drawing sufficiently sophisticated and close to the object, make a representation of it in which there is no ambiguity at all.
Abstract: There is necessarily a loss of information when moving from a geometrical object to its drawing, but pupils (even sixth graders) frequently have the illusion that they can, thanks to a drawing sufficiently sophisticated and close to the object, make a representation of it in which there is no ambiguity at all.
TL;DR: In this article, it was shown that stationary vector ARMA processes are geometrically completely regular and hence geometrical strong mixing, provided the innovations have a continuous distribution with respect to Lebesgue measure.
TL;DR: In this paper, a Yaglom type theorem was proved for the conditional distribution of the spatial tree in the limit as t → + ∞, where T is the position of the rightmost particle at time t in a one dimensional branching brownian motion.
Abstract: If R
t
is the position of the rightmost particle at time t in a one dimensional branching brownian motion, u(t, x)=P(R
t
>x) is a solution of KPP equation:
$$\frac{{\partial u}}{{\partial t}} = \frac{1}{2}\frac{{\partial ^2 u}}{{\partial x^2 }} + f(u)$$
where f(u)=α(1-u-g(1-u))
g is the generating function of the reproduction law and α the inverse of the mean lifetime; if m=g′(1)>1 and g(0)=0, it is known that:
$$\frac{{R_t }}{t}\xrightarrow{P}c_0 = \sqrt {2a(m - 1)} ,{\text{ when }}t \to + \infty .$$
For the general KPP equation, we show limit theorems for u(t, ct+ζ), c>c
0
, ξ ∈ ℝ, t → +∞. Large deviations for R
t
and probabilities of presence of particles for the branching process are deduced: (where Z
t
denotes the random point measure of particles living at time t) and a Yaglom type theorem is proved. The conditional distribution of the spatial tree, given {Z
t
(]ct, +∞[)>0}, is studied in the limit as t → +∞.
TL;DR: In this article, the authors define a "topologie" naturelle based on "l'ensemble" of a set of spaces metriques of a group of arbres reels.
Abstract: Les objets que nous etudions sont les espaces metriques munis d'une action par isometrie d'un groupe fixe Γ. Nous definissons une «topologie» naturelle sur «l'ensemble» de ces espaces. Nous montrons un critere de compacite sequentielle par des methodes inspirees des travaux de M. Gromov. Nous utilisons ce critere pour donner une preuve plus courte et plus geometrique de deux theoremes: celui de M. Culler et J. Morgan sur la compacite de l'espace des arbres reels a petits stabilisateurs d'aretes; et celui de J. Morgan sur la compactification de l'espace des structures hyperboliques sur une variete par des arbres reels a petits stabilisateurs d'aretes.
TL;DR: In this paper, the authors study different solutions to a simple one-dimensional linear quadratic game with a large number of private agents and a government and show how control theory should be applied to calculate the equilibrium and how to relate these equilibria to the differential game literature.
Abstract: We study different solutions to a simple one-dimensional linear quadratic game with a large number of private agents and a government. A "time-consistent" solution is defined as a solution to the Hamilton-Jacobi-Bellman equation, i.e. as a policy for which the government has noprecommitment capability. This solution is compared to a policy where the government has an "instantaneous" pre-commitment, i.e. an equilibrium in which the government has a period by period leadership. In both cases, we show how control theory should be applied to calculate the equilibrium and how to relate these equilibria to the differential game literature.
TL;DR: In this article, it was shown that a weak dissipation (of order zero) is sufficient to impose a finite dimensional behavior for Korteweg-de Vries equations with periodic boundary conditions.