Showing papers by "Pierre-and-Marie-Curie University published in 1987"
TL;DR: In this paper, concentrations of polynuclear aromatic hydrocarbons (PAHs) were reported in relation to particle size for aerosols of remote marine areas, and the HC concentrations were found to be dependent on the origin of the air masses.
620 citations
TL;DR: In this article, a two-mode optical parametric oscillator operating above threshold was used to generate high-intensity twin beams which exhibit quantum correlations, and the noise power measured on the intensity difference between two such beams was reduced by 30% below the shot-noise limit.
Abstract: We have used a two-mode optical parametric oscillator operating above threshold to generate high-intensity twin beams which exhibit quantum correlations. The noise power measured on the intensity difference between two such beams is reduced by 30% below the shot-noise limit. Noise reduction is observed over a broad range of frequencies.
521 citations
TL;DR: In this paper, the mean free path of a Xenon adsorbed on various zeolites was determined by computing the dependence of the chemical shift σ on the free path.
247 citations
TL;DR: In this article, the authors show that the associated minimization problem provides a mathematical model for matter to come into frictionless contact with itself but not interpenetrate, and they also extend J. Ball's theorems on existence to this case by establishing the existence of a minimizer of the energy in the space W1,p(Ω;ℝ3), p > 3, that is injective almost everywhere.
Abstract: Let Ω be a bounded open connected subset of ℝ3 with a sufficiently smooth boundary. The additional condition ∫ det ▽ψ dx ≦ vol ψ(Ω) is imposed on the admissible deformations ψ: ¯Ω → ℝ of a hyperelastic body whose reference configuration is ¯Ω. We show that the associated minimization problem provides a mathematical model for matter to come into frictionless contact with itself but not interpenetrate. We also extend J. Ball's theorems on existence to this case by establishing the existence of a minimizer of the energy in the space W1,p(Ω;ℝ3), p > 3, that is injective almost everywhere.
214 citations
TL;DR: Partial deletion of the exon 5' to S. cerevisiae intron a5, a self-splicing mitochondrial class II intron, reveals the existence of several sites of intron-exon interaction and the possible role of one of the intronic sites in aligning exons for the ligation step is discussed.
199 citations
175 citations
TL;DR: In this paper, a new method for the analysis of multicomponent exponential functions (either real and/or complex) is presented based upon the combined use of the Laplace transform and of Pade approximants.
Abstract: The analysis of a curve as a sum of exponentials is one of the most common problems encountered in experimental 'curve-fitting' in such diverse areas as electrophysiology, chemical kinetics, electrical engineering and nuclear science. In this paper, a new method for the analysis of multicomponent exponential functions (either real and/or complex) is presented. This method is based upon the combined use of the Laplace transform and of Pade approximants. As compared with approximation procedures, it does not require an a priori hypothesis as to the number n of components, which is an output of the analysis1. It thus becomes possible, under realistic numerical conditions, to address the problem of unambiguous detection of the exponential components. Performance comparisons show that several practical limitations reported in previous works are overcome. Detailed derivations relevant to the fundamental basis of the method described here are presented in ref. 2 and further developments pertaining to numerical analysis aspects may be found in ref. 13.
168 citations
TL;DR: In this paper, a theory about suites de polynomes orthogonaux is presented, i.e., suites of polynome orthogons whose derivees are quasi-orthogonale.
Abstract: On etablit une theorie generale des suites de polynomes orthogonaux dont la suite des derivees est une suite quasi-orthogonale.
143 citations
TL;DR: In this paper, a two-mode, above-threshold, optical parametric oscillator can generate nonclassical states of light with a large average number of photons: the fluctuation spectrum of the various fields is calculated, and several quantities have squeezed fluctuations.
Abstract: We describe how a two-mode, above-threshold, optical parametric oscillator can generate nonclassical states of light with a large average number of photons: the fluctuation spectrum of the various fields is calculated, and several quantities are shown to have squeezed fluctuations. In particular, a perfect quantum noise suppression is predicted on the difference between the intensities of the two generated beams. We describe an experiment designed to demonstrate such an effect and show how it can be used to generate high-intensity amplitude-squeezed states.
143 citations
TL;DR: In this paper, a theoretical model for the kinetics of a glassy carbon electrode with a [Ru(bpy)2 poly(4′-vinylpyridine)Cl]Cl film was proposed.
Abstract: The study of the kinetics of an electrode coated with a redox polymer film has been carried out using an impedance technique. A theoretical model is proposed which takes into account the diffusion of the active centres. Experimental results are presented for a glassy carbon electrode coated with a [Ru(bpy)2 poly(4′-vinylpyridine)Cl]Cl film. There is good agreement between these results and the model.
139 citations
TL;DR: 5-HT, as well as opiates, might generate analgesia by acting--at least partly--on primary afferent nociceptive fibres at the spinal level through receptor binding sites within the superficial layers of the dorsal horn.
TL;DR: In this article, a cross-linked network was proposed to explain the thermally induced swelling and desolvatation of pluronic micelles in aqueous solutions.
01 Oct 1987
TL;DR: In this article, the authors examined the adaption and flocculation properties of Na-morillonite copolymers of acrylamide with a cationic monomer.
Abstract: Adsorption and flocculation properties were examined for the system Na-morillonite copolymers of acrylamide with a cationic monomer. Adsorption isotherms underlined the high affinity of the highly charged polymers for the clay surface and showed the crucial role of the interfacial conformation of the polyelectrolyte according to its cationicity. Performances of these copolymers when used as flocculants were followed as a function of their ionicity and molecular weight. The results are consistent with a balance between two flocculation mechanisms: charge neutralization which prevails for highly charged polymers and interparticular bridging which occurs at low cationicity when the optimal flocculation concentration (ofc) is strongly molecular weight dependent.
TL;DR: A procedure based on affinity chromatography was used for the purification to homogeneity of isopentenyl pyrophosphate isomerase and geranylgeranyl pyroph phosphate synthase from Capsicum chromoplasts.
TL;DR: In this paper, the Miocene basin evolution of southeastern Spain and eastern Morocco is linked to a "shear zone" elongated from SW across the Alboran Sea, from Miocene to present time.
Abstract: The Miocene basin evolution of southeastern Spain and eastern Morocco is linked to a "shear zone" elongated from SW across the Alboran Sea. In Spain the magmatism is mostly calc-alkaline (or K-rich calc-alkaline). Most of the products are locatred on strike-slip faults (Almeria-Cabo de Gata). Lavas of dacitic compositions are interpreted as products of crustal anatexis. During Messinian time, lamproites are erupted over an extended area. Later (Plio-Quaternary), alkali basalts are located near Cartagena. In Morocco, calc-alkaline magmatism is not as developed as in Spain; late Tortonian-Messinian volcanoes (Gourougou, Guilliz) have erupted of shoshonitic lavas. Alkali basalts are abundant and appear from the end of Messinian to Quaternary all over northwestern Africa. In the studied area, there are no chronological nor geochemical polarity of the magmatism according to the existence of a Miocene subduction. The association of the magmatism with tectonics and basin evolution shows that it is linked with their aperture. The structure of the lithosphere, as it appears from the geophysical data, shows the existence of two different crusts, separated by the western part of the "shear zone". Trans-Alboran calc-alkaline magmatism is clearly correlated with the activity of this "shear zone", from Miocene to present time.
TL;DR: One of the anti- Rh(D)-producing EBV-transformed clones was used to produce an anti-Rh(D) typing reagent which has proved satisfactory for 2 years in routine blood typing in several laboratories.
TL;DR: In this paper, the Fourier transform spectra of samples of ozone were analyzed to obtain accurate line positions and an extended set of upper state rotational levels (J up to 69, K a up to 20).
TL;DR: The subsurface thermal structure in the tropical Atlantic Ocean (30°N-20°S, East of 80°W) is studied on the basis of an extensive data bank of subsursurface soundings as discussed by the authors.
Abstract: The subsurface thermal structure in the tropical Atlantic Ocean (30°N–20°S, East of 80°W) is studied on the basis of an extensive data bank of subsurface soundings. Calendar monthly maps are presented showing mixed layer depth, base of thermocline, thermocline thickness, and vertical temperature gradient across the thermocline. These maps are complemented by vertical cross sections depicting mixed layer depth, base of thermocline, and selected isotherms: a zonal profile along the equator (50°W–10°E), a meridional transect across the Eastern Atlantic (4°N–18°S), and a meridional section across the Central Atlantic (30°N–18°S). The basinwide subsurface thermal structure is dominated by the annual cycle of the surface wind field with extrema around April and August. The mixed layer is relatively shallow between 20°N and 10°S, with overall grater depth in the western as compared to the eastern portion of the basin. Two systems of annual cycle variation of mixed layer depth stand out. (i) Along the eq...
TL;DR: This work uses martingale inequalities in the probabilistic analysis of stochastic models of NP-complete problems to obtain sharp bounds on Pr(|Un − EUn| > t), where Un is the objective function value of the problem with n random data.
Abstract: We use martingale inequalities in the probabilistic analysis of stochastic models of NP-complete problems. We give examples of applications to the Bin Packing and Traveling-Salesman Problems. In both cases, we obtain sharp bounds on Pr(|Un − EUn| > t), where Un is the objective function value of the problem with n random data.
TL;DR: The growth rate of a diatom was followed during transfers from moderate to higher or lower irradianccs (PAR) with differing spectral compositions, providing that the photosynthetically usable radiation (PUR) is made equal.
Abstract: The growth rate of a diatom (Chaetoceros protubcram) was followed during transfers from moderate to higher or lower irradianccs (PAR) with differing spectral compositions (“white,” “blue,” and “green” light). Chlorophyll-specific and carbon-specific absorption coefficients of the algae were monitored, allowing changes in the quantum yield for growth (@),) to be assessed. All the parameters appear to be practically unaffected by chromatic conditions, provided that the photosynthetically usable radiation (PUR) is made equal. Diatoms respond to the energy level whatever the color. Nevertheless, due to opposite influences of the modifications in the “package” eflt thereafter it remains low and steady. Conversely the enhanced value observed just after transfer to low irradiance is not maintained beyond 2 or 3 d; after that, a’, is restored practically to its initial value.
TL;DR: A vitellogenesis-inhibiting factor has been characterized from extracts of lobster sinus glands (SG) using an in vivo bioassay developed in the shrimp, Palaemonetes varians, and the presence of only one band corresponding to a 7—8 kD peptide is revealed.
Abstract: A vitellogenesis-inhibiting (VI) factor has been characterized from extracts of lobster sinus glands (SG) using an in vivo bioassay developed in the shrimp, Palaemonetes varians. After a two-step purification by reversedphase high-performance liquid chromatography (RP-HPLC), the bioactivity is recovered in one symmetrical peak. Sodium dodecyl sulfate-urea-polyacryl-amide gel electrophoresis (SDS-urea-PAGE) of the bioactive fractions reveals, after silver staining, the presence of only one band corresponding to a 7—8 kD peptide.
TL;DR: A large composite calc-alkaline batholith, in the Iforas region, Mali, occurs close to the Pan-African suture between the 2000 Ma old West African craton and the Trans-Saharan mobile belt as mentioned in this paper.
Abstract: A large composite calc-alkaline batholith, in the Iforas region, Mali, occurs close to the Pan-African suture between the 2000 Ma old West African craton and the Trans-Saharan mobile belt. Its location in an embayment of the West African craton is probably responsible for the important production of magma. The Iforas batholith intrudes the western border of an old continental segment affected by early nappe tectonics (D1 event) and is flanked to the west by the Tilemsi palaeo–island arc. The batholith comprises several successive stages. The cordillera (>620 Ma), probably post-dating the D1 event, is essentially composed of volcanosedimentary sequences. The collision (620–580 Ma) is marked by the production of abundant granitoids mostly emplaced by the end of the D2 EW compressional event. The post-collision tectonic stages (D3 and D4; 580–540 Ma) are characterized by strike-slip movements, reversals in the stress field, and a rapid switch from calc-alkaline to alkaline magmatism. Magmas corresponding to each step show distinctive geochemical trends but all share low 87Sr/86Sr initial ratios (0·7035–0·7061). The possible successive sources have been evaluated from different entities in the Inforas region: Eburnean granulites for lower crust, Tilemsi palaeo–island arc for depleted subduction source and the Tadhak undersaturated province for asthenospheric more primitive mantle. A geodynamic model is proposed where all the calc-alkaline groups originated from a classical subduction source (depleted upper mantle modified by hydrous fluids from the subducted oceanic plate) which, some fifty million years after the beginning of the collision, was taken over by an asthenospheric source producing the alkaline province.
TL;DR: Some tripeptides obtained by enzymic digestion of caseins possess immunomodulating properties and X‐ray analysis has been applied to two of them Leu‐Leu‐Tyr and Gly‐Leo‐Phe in order to correlate activity and structure.
TL;DR: In this paper, the Bloch transformation is used to decompose the time-dependent Schrodinger equation and to construct an effective evolution with the BLoch effective hamiltonian, which is calculated in a tight-binding approximation as a function of the number of ligand active units.
TL;DR: In this article, the exact eigenvectors and eigenvalues of O(2 N ) symmetric two-dimensional theories (vertex models and quantum field theories) were constructed by means of a generalization of the nested Bethe ansatz method.
TL;DR: The results indicated that, with or without triggering agent, the amount of O2 metabolites release was a linear function pattern with time and could be a useful parameter in the assessment of the activity of ILD.
Abstract: The ability of alveolar macrophages (AM) to release O2 metabolites was studied in 8 children with interstitial lung disease (ILD), and in 11 children without lung parenchyma disorder. AM were collected by bronchoalveolar lavage. The experiments were performed on unstimulated AM and on AM stimulated by phorbol myristate acetate (PMA) or zymosan. Our results indicated that, with or without triggering agent, the amount of O2 metabolites release was a linear function pattern with time. The accumulation of superoxide anion (O2-) and hydrogen peroxide (H2O2) into the extracellular medium differed depending on the triggering agent used: with PMA, the amount of O2- released was threefold the amount of H2O2 detected in the medium, whereas with zymosan the O2- accumulation was tenfold higher than the amount of H2O2 measured. In patients with ILD, a significant increase in the amount of H2O2 release was observed for both unstimulated and stimulated AM (p less than 0.001). In this group, the measurement was repeated after a 2-month steroid treatment: prednisone had markedly improved the clinical, radiologic, and functional status of the patients, and this improvement was in good correlation with the decrease of O2 metabolite production. The amount of H2O2 release in each case was within the range of control values. Evaluation of O2 metabolite release by AM could be a useful parameter in the assessment of the activity of ILD.
TL;DR: The hypothesis of selection of diploid cells for transformation or root initiation is discussed as well as the observed auxin-like symptoms.
TL;DR: To learn whether early interactions between fibers of each eye play a role in generating a mixed ipsi + contralateral projection pattern, mice developed after one eye was destroyed at very early embryonic ages were studied.
Abstract: In mammals binocular vision is made possible by the existence in the temporal retina of ipsilaterally projecting ganglion cells (IGCs) (with axons that do not cross the brain midline and join optic fibers from the opposite eye). To learn whether early interactions between fibers of each eye play a role in generating a mixed ipsi + contralateral projection pattern, we studied with horseradish peroxidase the origin of uncrossed retinal projections in mice that developed after one eye was destroyed at very early embryonic ages. One eye was removed on embryonic day 16 (E16; when optic fibers have grown past the chiasm bilaterally, but very few have grown into the visual centers) or on E13 or E12 (when few or no optic fibers have passed the presumptive chiasm region).
Normal adult mice have a mean of 946 IGCs (range: 784–1,073) within the temporal sector of the retina, and less than 25 in the rest of the retina. In adult mice enucleated at E16, an average of 1,354 (1,215–1,484) IGCs are present within a clearly demarcated temporal sector of the remaining retina and 265 (152–312) are present throughout the rest of the retina. In both the temporal and nasal retina the excess IGCs in these mice have, generally, very small somas. In some of these mice the most peripheral part of the temporal sector contains fewer IGCs. In E12 or E13 enucleates, IGCs are also generally located in a narrow (often narrower than normal) region along the temporo-inferior retinal border, but their number is less than in normal or E16-enucleated mice: E13 enucleates have a mean of 639 cells (range: 361–875) in the temporal sector and 109 (8–275) in the rest of the retina. Following enucleation of one mouse at E12, the respective values are 349 and 31 cells. The reduction in numbers of IGCs in these mice is especially pronounced for ganglion cells with small cell bodies.
These findings suggest that the development of uncrossed projections in mice depends on selective guidance mechanisms of axons from temporal retina through the chiasm. These may consist of interactions of optic axons with guidance cues distributed in the presumptive chiasm (possibly at early stages) and also of fiber-fiber guidance mechanisms, in particular between fibers from each eye.