Showing papers by "Université catholique de Louvain published in 1979"
TL;DR: In this paper, the authors considered a non-cooperative market where consumers are assumed to make indivisible and mutually exclusive purchases and the dependence of the latter on income distribution and quality parameters is analyzed.
1,116 citations
TL;DR: In this article, the problem of correct revelation in a collective decision model is presented as a game with incomplete information, and two approaches to incomplete information are used, a first where the individual beliefs are not introduced and a second where they are.
788 citations
TL;DR: In this paper, stable algorithms for the computation of the Kronecker structure of an arbitrary pencil were developed, which can be viewed as a generalization of the wellknown eigenvalue problem of pencils of the type LambdaI-A.
555 citations
TL;DR: The surface spline interpolation problem is closely connected with the classical problem of minimizing a Sobolev seminorm under interpolatory constraints; the intrinsic structure of surface splines is accordingly that of a multivariate extension of natural splines as discussed by the authors.
Abstract: The concrete method of ‘surface spline interpolation’ is closely connected with the classical problem of minimizing a Sobolev seminorm under interpolatory constraints; the intrinsic structure of surface splines is accordingly that of a multivariate extension of natural splines. The proper abstract setting is a Hilbert function space whose reproducing kernel involves no functions more complicated than logarithms and is easily coded. Convenient representation formulas are given, as also a practical multivariate extension of the Peano kernel theorem. Owing to the numerical stability of Cholesky factorization of positive definite symmetric matrices, the whole construction process of a surface spline can be described as a recursive algorithm, the data relative to the various interpolation points being exploited in sequence.
437 citations
324 citations
TL;DR: Conditions are described for attaching anticancer drugs to polyalkylcyanoacrylate nanoparticles, a new drug delivery system for cells that exhibit endocytic uptake, which are ultrafine, metabolizable, and able to associate with various drugs in a nonspecific manner.
182 citations
TL;DR: In this article, the 100-year-alten Wursterschen Salze sind seit langem als Verbindungen with Radikalkationen erkannt worden.
Abstract: Die 100 Jahre alten Wursterschen Salze sind seit langem als Verbindungen mit Radikalkationen erkannt worden. Ihre ungewohnliche Stabilitat beruht teilweise auf capto-dativer (cd) Substitution. Dieses Prinzip wird nun als Faktor der Radikalstabilisierung diskutiert und auf Methinderivate angewendet. cd-Substitution ist fur Synthesezwecke nutzlich: cd-Substituenten am gleichen Kohlenstoffatom ermoglichen selektive Dehydrodimerisierung; Olefine mit geminalen und daher kreuzkonjugierten cd-Substituenten sind „radikophil” und konnen zwei Kohlenstoffradikale addieren; cd-substituierte Olefine sind wirksame Antioxidantien, Polymerisationsinhibitoren und vielversprechende Agentien fur die Kontrolle biologischer Radikalreaktionen. Ganz allgemein konnten viele Reaktionen cd-substituierter Molekule uber Radikale verlaufen.
150 citations
TL;DR: In this article, a set of simple trigonometrical formulae allowing the computation of long-term variations of the Earth's orbital elements, mid month daily insolations have been computed for each 10-deg latitude and, by steps of 1000 y, for one million years before present (YBP) and one hundred thousand years after present.
Abstract: From a set of simple trigonometrical formulae allowing the computation of long-term variations of the Earth's orbital elements, mid month daily insolations have been computed for each 10-deg latitude and, by steps of 1000 y, for one million years before present (YBP) and one hundred thousand years after present. The deviations from present values and especially from mean values computed over the past 10/sup 6/ y are graphically reproduced for 60 degrees N latitude which is thought to be one of the most sensitive latitudes as far as glacial-intergalactic sequences of the Quaternary period are concerned. From these data, some specific features, called insolation signatures, of the insolation pattern are found to be significantly related to well-established climatic changes, like the 125000 YBP interglacial, the 70000 YBP persistent-cooling tend and the 20000 YBP glacial maximum. Mathematical techniques of data analysis, like harmonic analysis and principal-component analysis, have been used to statistically improve the validity of the relationship that has been found between glaciation extent, mainly their triggering, and April to October insolations.
142 citations
TL;DR: The model described correctly the drain current and the small signal parameters in all regions of operation, including the subthreshold regime and the saturation regime, in this article, where mobility variations along the channel, resulting from the normal and lateral electric fields, can be taken into account.
Abstract: The model describes correctly the drain current and the small signal parameters in all regions of operation, including the subthreshold regime and the saturation regime. The model contains as an approximation the charge-sheet model proposed b Brews (see ibid., vol.21, p.345, 1978). Mobility variations along the channel, resulting from the normal and lateral electric fields, can be taken into account.
102 citations
TL;DR: In this article, necessary and sufficient conditions for central simple algebras to have involutions of the first kind and to be tensor products of quaternion subalgeses were developed.
Abstract: We develop necessary and sufficient conditions for central simple algebras to have involutions of the first kind, and to be tensor products of quaternion subalgebras. The theory is then applied to give an example of a division algebra of degree 8 with involution (of the first kind), without quaternion subalgebras, answering an old question of Albert; another example is a division algebra of degree 4 with involution (*) has no (*)-invariant quaternion subalgebras.
102 citations
TL;DR: In this paper, the effect of impregnation by NH4F or HF solutions, followed by calcination at 600°C, provoke the same modifications of the alumina surface.
TL;DR: Children who become hypothyroid between 1 and 12 months of age are usually not mentally retarded and show minor neuropsychological disorders and only some signs of “minimal brain dysfunction” which compensate with advancing age and normal IQ are found in these children if therapy is started before one month of age.
Abstract: . Wolter, R., Noel, P., De Cock, P., Craen, M., Ernould, Ch., Malvaux, P., Verstraeten, F., Simons, J., Mertens, S., Van Broeck, N. and Vanderschueren-Lodeweyckx, M. (Departments of Paediatrics, Universities of Brussels, Leuven, Ghent, Liege and Louvain, Belgium). Neuropsychological study in treated thyroid dysgenesis. Acta Paediatr Scand, Suppl. 277: 41, 1979.—Neuropsychological assessment was carried out in 57 patients aged 3.0 to 17.5 years (mean 8.5) with thyroid dysgenesis under adequate long-term therapy. Starting age of hypothyroidism as estimated by bone age at diagnosis was prenatal in 32 cases, close to birth in 13 cases and postnatal of 1–12 months in 12 cases. Hypothyroidism of prenatal onset results in severe neuropsychological disorders and mental retardation if not treated early. Only some signs of “minimal brain dysfunction” which compensate with advancing age and normal IQ are found in these children if therapy is started before one month of age. Hypothyroidism starting at birth does not result in mental retardation but neuropsychological disorders are found. They are more frequent if treatment is started after 6 months of age. Children who become hypothyroid between 1 and 12 months of age are usually not mentally retarded and show minor neuropsychological disorders.
TL;DR: In this article, the Eemian (s.s.) (oxygen isotope substage 5e) temperate forest was replaced by a pine-spruce-birch taiga within ~150+/-75 yr.
Abstract: Close study of past interglacials might indicate how and when the present interglacial will end and whether the limit is heading towards a warming or a cooling. No certain prediction has been possible because of man's interference with the environment. But it is reported that when exploring the records of past temperate intervals frequent signs of abrupt changes of local environment were observed. In particular, abrupt shifts in forest composition end each Pleistocene interglacial whose record was studied in detail. In Grand Pile (north-east France), the Eemian (s.s.) (oxygen isotope substage 5e) temperate forest was replaced by a pine-spruce-birch taiga within ~150+/-75 yr. These results are based on rich pollen content of continuously deposited laminated gyttja and on the assumption of a constant sedimentation rate during the last 11000-yr long interglacial.
TL;DR: It is suggested that the primary defect in reeler mice may be in the plasma membrane of cortical plate cells, resulting in a loss of their capacity for mutual recognition and binding, which could account for the cytoarchitectonic disorganization in this mutant.
Abstract: Brains of reeler and normal mouse embryos have been studied on semi-thin sections and with Golgi impregnations. No change can be seen in the neuroepithelium or in the primary cortical organization. The first evidence of a morphological abnormality appears at E 14, in the cortical plate. Instead of being closely packed and radially oriented, nerve cells are loosely arranged and show quite variable orientations of their long axis and apical dendrite. The axons run obliquely through the cortical plate and do not display the characteristic angular course seen in the normal animal. It is suggested that the primary defect in reeler mice may be in the plasma membrane of cortical plate cells, resulting in a loss of their capacity for mutual recognition and binding. This could account for the cytoarchitectonic disorganization in this mutant, especially the absence of a molecular layer and the inversion of the histogenetic gradient in the developing cerebral cortex.
TL;DR: Electron microscopic examination of intestinal contents by negative staining has shown the presence of many viral particles which have a diameter of 24 nm and whose profile is consistent with an icosahedral shape.
Abstract: At necropsy, several dogs which died showing symptoms of hemorrhagic diarrhea, had significant lesions of the mucosa that were found especially in the duodenum and upper part of the small bowel.
TL;DR: Involvement of IgE antibody in macrophage cytotoxicity against Schistosoma mansoni schistosomula suggests a cytophilic interaction of this class of antibody with the membrane of macrophages.
TL;DR: Results suggest that cinnarizine and papaverine antagonize vascular contraction by different mechanisms, and cinnARizine seems to act by reducing membrane permeability to extracellular calcium.
01 Jan 1979
TL;DR: In this article, the reproducing kernel of the surface spline interpolation method is shown to be in a Hilbert function space, with no functions more complicated than logarithms.
Abstract: The mathematical theory underlying the practical method of “surface spline interpolation” provides approximation theory with an intrinsic concept of multivariate spline ready for use. A proper abstract setting is shown to be some Hilbert function space, the reproducing kernel of which involves no functions more complicated than logarithms. The crux of the matter is that convenient representation forpiulas can be obtained by resorting to convolutions or to Fourier transforms of distributions.
TL;DR: It is shown that the definition without limiting procedure by a formal series expansion has the same ambiguities as the definition through discretization, these last ones being related to ordering problems.
Abstract: We study functional integrals in phase space and show that the definition without limiting procedure by a formal series expansion has the same ambiguities as the definition through discretization, these last ones being related to ordering problems. We exhibit the way to obtain the prescription that makes the series expansion unambiguous and study the mechanism that makes the expansion independent of the chosen discretization.
TL;DR: The results confirm the existence of two specific binding sites for ouabain in guinea‐pig heart and suggest that the inhibition of the Na pump is not the only mechanism responsible for the positive inotropic effect of cardiac glycosides.
Abstract: 1 The actions of ouabain, ouabagenin and dihydroouabain on the contractility and on the ionic content have been investigated in left guinea-pig atria stimulated at 3.3 Hz. The specific binding of ouabain and its displacement by the other cardenolides have been determined. 2 The action of either ouabain or ouabagenin on Na and K content was qualitatively different according to the concentration employed. Low doses evoked a reduction of Nai whereas high doses produced an increase. Dihydroouabain evoked only a Nai gain. 3 The increase of KCl concentration from 2.7 to 12 mM decreased Nai in untreated atria and displaced ouabain dose-effect curves to the right. 4 ED50 values for the positive inotropic effect were lower than ED50 values for the inhibition of the pump and were not similarly affected by an increase in KCl concentration. 5 The specific binding of ouabain occurred at high and low affinity sites, related to Na pump stimulation and inhibition respectively. 6 The increase in KCl reduced the affinity of the two groups of sites for ouabain and increased the capacity of the high-affinity sites whereas the capacity of the other sites remained unchanged. 7 The results confirm the existence of two specific binding sites for ouabain in guinea-pig heart and suggest that the inhibition of the Na pump is not the only mechanism responsible for the positive inotropic effect of cardiac glycosides.
TL;DR: These studies indicated that rat macrophages can bind rat IgE through a specific receptor, with no interference of the classical Fc (γ) receptor, and are triggered to release lysosomal enzymes upon conformational changes of the IgE molecule by anti-IgE antibody.
TL;DR: It is proposed that the transferrin molecule, after binding and internalisation in endocytic vacuoles, gains access to lysosomes where its iron is released, and the transferin molecule is released.
TL;DR: In this article, a mixed finite element method for solving plane and axisymmetric flow of a viscoelastic fluid is applied to several examples, in particular, the hole pressure error and the die entry flow in a 2:1 contraction.
Abstract: A mixed finite element method for solving plane and axisymmetric flow of a viscoelastic fluid is applied to several examples. In particular, the authors consider the hole pressure error and the die entry flow in a 2:1 contraction.
TL;DR: In this article, X-Ray photoelectron spectroscopic (XPS) measurements have been made on unsupported, fully sulfided, cobalt-molybdenum catalysts which had previously operated catalytically until attainment of steady activity.
TL;DR: The resistance of the respiratory-chain observed in vitro in the drug-resistant mutants and the allelism relationships between respiratory-competent, drug- resistant loci and coQH2-cyt c reductase deficient, BOX, loci strongly suggest that each of the three drug- resisting loci codes for a structural gene-product which is essential for the normal coQh2- Cytochrome c reduCTase activity.
Abstract: Diuron-resistance, DIU (Colson et al., 1977), antimycin-resistance, ANA (Michaelis, 1976; Burger et al., 1976), funiculosin-resistance, FUN (Pratje and Michaelis, 1977; Burger et al., 1977) and mucidin-resistance, MUC (Subik et al., 1977) are each coded by a pair of genetic loci on the mit DNA of S. cerevisiae. In the present paper, these respiratory-competent, drug-resistant loci are localized relative to respiratory-deficient BOX mutants deficient in coenzyme QH2-cytochrome c reductase (Kotylak and Slonimski, 1976, 1977) using deletion and recombination mapping. Three drug-resistant loci possessing distinct mutated allelic forms are distinguished. DIU1 is allelic or closely linked to ANA2, FUN1 and BOX1; DIU2 is allelic or closely linked to ANA1, MUC1 and BOX4/5; MUC2 is allelic to BOX6. The high recombinant frequencies observed between the three loci (13% on the average for 33 various combinations analyzed) suggest the existence of either three genes coding for three distinct polypeptides or of a single gene coding for a single polypeptide but subdivided into three easily separable segments. The resistance of the respiratory-chain observed in vitro in the drug-resistant mutants and the allelism relationships between respiratory-competent, drug-resistant loci and coQH2-cyt c reductase deficient, BOX, loci strongly suggest that each of the three drug-resistant loci codes for a structural gene-product which is essential for the normal coQH2-cyt c reductase activity and is obviously a good candidate for a gene product of the drug-resistant loci mapped in this paper. Polypeptide length modifications of cytochrome b were observed in mutants deficient in the coQH2-cyt c red and localized at the BOX1, BOX4 and BOX6 genetic loci (Claisse et al., 1977, 1978) which are precisely the loci allelic to drug resistant mutants as shown in the present work. Taken together these two sets of data provide a strong evidence in favor of the idea that there exist three non contiguous segments of the mitochondrial DNA sequence which code for a single polypeptide sequence of cytochrome b. In each segment mutations which modify the polypeptide sequence can occur leading to the loss (BOX mutants) or to a modification (drug resistant mutants) of the enzyme activity.
TL;DR: Using this method, doxorubicin and its metabolites in plasma and urine are determined after an intravenous injection into DBA 2 and NMRI mice.
TL;DR: X-ray powder microanalyses of ZIO precipitates formed both in the presence or absence of tissues are identical with those of CuOsO4 and CuRuO4, and based on indexation methods, Zn OsO4 was found to be the formula of the ZIO mixture reduction; this zinc osmate has an orthorhombic crystalline lattice.
Abstract: A mechanism of osmium reduction during zinc iodide-osmium tetroxide (ZIO) fixation is proposed. X-ray powder microanalyses of ZIO precipitates formed both in the presence or absence of tissues are identical with those of CuOsO4 and CuRuO4. Therefore, and based on indexation methods, ZnOsO4 was found to be the formula of the ZIO mixture reduction; this zinc osmate has an orthorhombic crystalline lattice. In smooth muscle preparations, ZIO electron dense deposits are localized in both cisternae of the sarcoplasmic reticulum and in mitochondria after a short fixation time. According to the microanalysis results, the zinc osmate has been associated to Ca2+ high affinity sites since Zn2+ is either replacing Ca2+ and/or displacing it by having a higher affinity for Ca2+ binding sites. Consequently, the ZIO mixture might be useful in revealing some Ca2+ storage sites in cells. This hypothesis was tested in ABRM preparations by selectively depleting sites which are known to bind Ca2+. In this case, the sarcoplasmic reticulum only retains the staining deposits after a short ZIO fixation. It is likely that OsO4 alone, used as fixative in cytology might be due to the formation of metallic osmates (e.g., divalent osmates like CaOsO4). In addition, of course, reduction of osmium during tissue fixation is accompanied by oxidation of double bonds of lipoproteic complexes or unsaturated lipids, and oxidation of sulfhydryl groups and amino groups.
TL;DR: In this article, the authors show that labor-managed firms seem to respond to price incentives with an incomplete specification of the objective function of these firms, and that this perversity is only due to the incomplete specification.
TL;DR: In this paper, the binding energy and intensities of two catalysts, namely Mo/SiO2 and CoMoO2 in the oxidic form, are reported, and the results confirm the existence of a relatively strong interaction between molybdenum and SiO2.