Showing papers by "Paul Sabatier University published in 1981"
TL;DR: The problem of deriving the uncertainty, on a sum of variables whose values lie within fuzzy intervals, is addressed, and the problem of computing mathematical expectations with fuzzy probabilities is solved.
Abstract: This paper provides an account of an approach to modeling unknown data by means of fuzzy-set theory, and addresses the problem of deriving the uncertainty, on a sum of variables whose values lie within fuzzy intervals. The first part is an extensive presentation of the theoretical background of the approach: the extension principle is stated in terms of possibility of an event; the concept of variable interaction is investigated at length. Section II gives new results regarding the effective practical computation of additions of fuzzy numbers. Its originality lies in the introduction of interaction which enables to control the growth of uncertainty, in calculations. Moreover, the problem of computing mathematical expectations with fuzzy probabilities is solved. The results derived in this paper can easily be used in decision problems where values of parameters or decision variables are not yet precisely fixed or assessed. Typical applications could be multicriteria optimization and decision making under uncertainty where fuzzy expected utilities can be obtained out of uncompletely assessed probabilities. More generally, fuzzy arithmetic can be an important tool for sophisticated, computationally tractable sensitivity analysis in systems modeling, computer-aided design and operations research.
266 citations
TL;DR: In this paper, the problem of interference between regional and local strain fields, the latter corresponding to a pluton ballooning, is investigated and two distinct patterns have been recognized, according to whether transcurrent motions or thrusting motions predominate in the regional deformation.
202 citations
TL;DR: In this article, pseudopotential SCF calculations were performed on tetrahedral X4 molecules using double-zeta basis sets with and without d functions, and the inclusion of d orbitals shortens the bond lengths, stabilizes the X4 structures and intensifies the electron density inside the tetrahedron.
90 citations
TL;DR: The contamination of vacuole preparations was found to be low, as judged by enzymic markers and microscopic inspection, and several hydrolases were found in vacuoles from sweet clover, which were also examined for their amino acid content.
Abstract: Methods for the preparation of protoplasts and vacuoles from mesophyll tissues of sweet clover (Melilotus alba Desr.) are described. Vacuoles are obtained using a new procedure which involves lysis of the plasmalemma during a brief centrifugation of protoplasts through a diethylaminoethyl dextran layer. This method combines the release of vacuoles and their purification in one step. The contamination of vacuole preparations was found to be low, as judged by enzymic markers and microscopic inspection. The method described is rapid and gives a good yield of vacuoles without causing changes in osmotic pressure. Several hydrolases were found to be located in vacuoles from sweet clover, which were also examined for their amino acid content.
88 citations
TL;DR: The relationship between nutritional patterns and physiological levels of endogenous hormones, in some species of cytosomes and fish, is studied and insulin seems to play a major role in regulating the nutritional metabolism, which is largely dependent on gluconeogenesis and on amino acids supply.
68 citations
TL;DR: In this paper, ground-state calculations for alkali dimers were performed using a pseudopotential method derived from atomic ab initio Hartree-Fock calculations, and the influence of basis set size upon the results was underlined.
52 citations
TL;DR: Behavioural experiments showed that the insect orientates with differing precision depending on the distances to targets of constant angular size, and the possible role of other mechanisms is discussed, particularly that involving movement parallax using both eyes.
Abstract: . In post-embryonic development, the visual system of the cricket Nemobius sylvestris (Bosc) shows a regular increase in the length and number of the ommatidia and a decrease of inter-ommatidial angle so that the adult's is a third of the value in the first larval instar. Further, a 20° widening of the binocular visual field, in the horizontal plane at least, and a three-fold increase of the inter-ocular distance improve the potential for binocular vision. Behavioural experiments showed that the insect orientates with differing precision depending on the distances to targets of constant angular size. Further, in a choice situation between two such vertical targets, the cricket orientates most strongly towards the closer of the two, even at target distances of 52 and 130 cm from its point of decision. In fixed tethered animals, discrimination between a close and a distant target is still possible, but disappears when the head is waxed to the thorax, so that any relative movement between the animal and the object is prevented. As these capabilities exceed the possibilities of binocular triangulation, the possible role of other mechanisms is discussed, particularly that involving movement parallax using both eyes.
48 citations
TL;DR: Gastrin, pancreatic polypeptide and somatostatin immunoreactive cells in the gut of two fish with stomachs (perch and catfish) and a stomachless fish (carp) were studied by immunocytochemistry.
Abstract: Gastrin, pancreatic polypeptide and somatostatin immunoreactive cells in the gut of two fish with stomachs (perch and catfish) and a stomachless fish (carp) were studied by immunocytochemistry. In the gastric mucosa of perch and catfish, cells showing gastrin and somatostatin-like immunoreactivity are found, scattered among the surface mucous cells and mucous neck cells. No pancreatic polypeptide (P.P.) immunoreactive cells are detected in the gastric mucosa. Cells showing gastrin and P.P.-like immunoreactivity are observed in the intestinal mucosa of perch, catfish and carp. In this location no somatostatin immunoreactive cells are found.
48 citations
TL;DR: Enhanced survival during starvation in 1/3 sea water was observed to be associated with maintenance of plasma protein and elevation of hepatic glucose-6-phosphate dehydrogenase activity, and it is suggested that sea breams be transferred to an iso-osmotic medium whenever the threat of starvation prevails.
Abstract: Red sea breams were kept at 20°C without food at 3 salinities (full sea water, 950 mOsm kg-1; 2/3 sea water, 640 mOsm kg-1; 1/3 sea water, 330 mOsm kg-1). In fish adapted to all 3 salinities, starvation resulted in marked decline of plasma FFA and β-hydroxybutyrate and liver glycogen levels but plasma glucose and lactate concentrations were maintained. These findings suggest that with the onset of starvation, enhanced hepatic glycogenolysis and decreased fat utilization occurred. Fish, adapted to full and 2/3 sea water, could not survive for more than 19 d without food. However, fish adapted to 1/3 sea water could tolerate 27 d of starvation. Enhanced survival during starvation in 1/3 sea water was observed to be associated with maintenance of plasma protein and elevation of hepatic glucose-6-phosphate dehydrogenase activity. It is suggested that sea breams be transferred to an iso-osmotic medium whenever the threat of starvation prevails, but this suggestion has yet to be evaluated in economic terms.
46 citations
TL;DR: In this article, the authors performed Raman scattering experiments in mixed crystals Ga1−xAlxAs in the spectral range 20 − 400 cm−1 and found a new band at lower energy, which they interpreted as due to disorder activated transverse acoustical phonons.
42 citations
TL;DR: From Mycobacterium fortuitum, a new kind of mycolic acid, containing an epoxy group, has been isolated, for which a structure is proposed, based on chemical degradations and mass spectrometry as discussed by the authors.
TL;DR: In this paper, the authors used pseudopotentials and including electron correlation to perform quantum calculations on double ζ (+ d orbitals) basis sets of H 2 GeO (1) and H 2 GEO (2) with double σ and π Ge O bond polarities, which suggest that the bonding is intermediate between σ (H 2 GeO) and semipolar (h 2 Ge:→ ) bonding.
TL;DR: Large variations were found in the plasma levels of testosterone and dihydrotestosterone during the annual reproduction cycle of the toad, with highest levels during clasping in both males and females.
01 Jan 1981
TL;DR: In this article, the authors describe Gelfand pairs to statisticians and probabilists and deal with six typical examples: euclidean space, sphere and cube; Poincare half-plane, homogeneous tree and commutative group.
Abstract: This paper describes Gelfand pairs to statisticians and probabilists and deals with six typical examples : euclidean space, sphere and cube; Poincare half-plane, homogeneous tree and commutative group. It explains the role of spherical functions, specially the positive definite ones. In a second part, classical problems in probability are raised in that context : random walks, factorisations of probability distributions, stationary processes, and problems of Schoenberg type.
TL;DR: In this article, the substitution of O2− for 2(OH− was verified to be completely reversible on specimen exposure to H2O vapor at 1000°C, taking place with the carbon atom on or near the hexad axis, and so changes the space group fromP6676 3m to one without a screw axis.
Abstract: Parallel experiments on human tooth enamel with sp.g. >2.95 and synthetic hydroxyapatite have been carried out to study the substitution of CO
3
2−
for OH−, produced at 1000°C in dry CO2, with the complementary use of neutron diffraction, x-ray diffraction, infrared spectroscopy and thermochemical techniques. It was verified that the substitution (i) is CO
3
2−
↔ 2(OH− and is completely reversible on specimen exposure to H2O vapor at 1000°C, (ii) takes place with the carbon atom on or near the hexad axis, (ii) places one CO
3
2−
group per unit cell in an ordered fashion and so changes the space group fromP6
3/m to one without a screw axis, (iii) was consistent, by its incompleteness, with the occurrence of substitution of O2− for 2(OH−) in 25 to 40% of the unit cells, (iv) produced similar marked changes in the neutron powder diffraction patterns of both tooth enamel and hydroxyapatite, and (v) took place at a site where only a minor portion of the CO
3
2−
in normal untreated human tooth enamel occurs. From comparative Rietveld analysis results from x-ray and neutron powder diffraction patterns it is suggested that the carbon atom of this A-site CO
3
2−
is near 0,0,0.12 and the CO
3
2−
plane makes an angle of ≈18° with thec direction. On being heated at 400°C in H2O vapor, tooth enamel retained much of its CO
3
2−
but its a lattice parameter changed from 9.445(3) A to 9.420(1) A, essentially that of hydroxyapatite. After once being heated at high temperatures, “tooth enamel” and hydroxyaptite showed similar responses to various treatments, including carbonation. After heating, more β-Ca3(PO4)2 was found in the tooth enamel specimen. Comparative weight change, IR, and other data for tooth enamel and hydroxyapatite heated in He, then in CO2, and then in H2O vapor showed a 20% or more deficiency of structural OH− in the untreated tooth enamel.
TL;DR: Carp amyloglucosidase and carp and catfish leucine-aminopeptidase activities were found to be widespread among enterocytes from all parts of the gut, and γ-glutamyl-transferase activity was rather found in the distal part of the intestine.
TL;DR: In this paper, the electrical conductivity of finely-divided spinels of composition (ZnFeFe)O is studied in vacuum as a function of temperature, and it is concluded that fast electron exchange takes place between Fe3+ and Fe2+ ions situated on B-sites in the spinel lattice.
Abstract: The electrical conductivity of finely-divided spinels of composition (ZnFeFe)O is studied in vacuum as a function of temperature. From this study it is concluded that fast electron exchange takes place amongst Fe3+ and Fe2+ ions situated on B-sites in the spinel lattice. For some compositions a break of the conductivity-temperature curves is found near the Curie point. The profile of the δ = f(t) curves during oxidation of those n-type spinels in defect phases γ-x(ZnFe2O4), (3/2)(1–x)Fe2O3 in the temperature range 190 to 300°C is related to the presence of vacancies on B-sites which upset the electron exchange Fe3+Fe2+. When the temperature is raised (t > 400°C) the log δ = f(1/T) curves show discontinuities attributed to the precipitation of hematite.
La conductivite electrique des spinelles finement divises (ZnFeFe)O est etudiee sous vide en fonction de la temperature. A partir de cette etude il est conclu que le rapide echange d'electrons se fait entre lesions Fe3+ et les ions Fe2+ sur les sites B du reseau spinelle. Pour plusieurs compositions une cassure dans les courbes conductivite-temperature a ete trouvee dans le domaine du point de Curie. L'evolution des courbes δ = f(t) lors de l'oxydation de ces spinelles de type n en phase lacunaire γ-x(ZnFe204), (3/2)(1–x)Fe2O3 dans le domaine de temperature 190 a 300 °C est reliee a l'introduction de lacunes dans les sites B qui perturbent l'echange electronique Fe2+-Fe3+. Lors d'une elevation de temperature (t > 400 °C) les courbes log δ = f(t) presentent une dis-continuite attribuee a la precipitation d'hematite.
TL;DR: 3 aziridino (ethylene-imino) derivatives of the thiatriazadiphosphorine ring system with formula (NPAz2)2NSOX (X = F, Az, Ph) were found to exhibit significant antitumor activity.
TL;DR: In this paper, the effect of substitution extent on formation of superstructure-ordered vacancies in zinc-substituted lacunar spinels of type ( Zn 2+ x Fe 3+ 1−x ) A ( Fe 3 + (5+x) 3 □ (1−x) 4 ) B O 2− 4 was investigated using ir spectrometry.
TL;DR: La part prise par les aliments vegetaux decroit dans la serie Arcynopteryx -Isoperla - Periodes - Perla et Dinocras dans le même cas de cette evolution morphologiques sont plus nettes pour les Baetis que pour les Chironomides.
Abstract: La part prise par les aliments vegetaux decroit dans la serie Arcynopteryx -Isoperla - Periodes - Perla et Dinocras Des differences morphologiques sont liees a cette evolution Les regimes alimentaires des Isoperla, Perla et Dinocras varient au cours de la vie larvaire Les relations entre la taille du predateur et celle des proies sont plus nettes pour les Baetis que pour les Chironomides Pour les Chironomides, elles sont de plus en plus marquees dans la serie Arcynopteryx - Isoperla - Perlidae
TL;DR: In this article, the reaction of organohydrogermanes Ph n GeH 4−n or digermanes Ph 2 n Ge 2 H 4− n (n = 1, 2) with dialkylmercury R 2 Hg.
TL;DR: In this paper, a new family of mixed valence complexes of platinum involving S-donor ligands was investigated, where L = thiourea, thiocaprolactam, tetrahydro-2 pyrimidine-2 thione, 2-imidazolidinethione, and 2-ethylenethiouera.
TL;DR: The technique described here is a combination of the sandwich-method and cell culture that allows a daily observation of the morphological events and study at the cellular and/or molecular level.
TL;DR: The first synthesis of a monomeric C-unsubstituted silole was described in this article, where photo-oxygenation of 1,1-dimethyl-1-silacyclopent-3-ene leads to an allylic hydroperoxide with a shifted carobon-carbon double bond (ene reaction).
TL;DR: The electron-withdrawing ligand effect of halogen is a long-range effect which uses the collective properties of the metal surface as mentioned in this paper, due to a lowering of the electron back donation from the metal to the 2π ∗ antibonding orbitals of the chemisorbed CO molecules.
TL;DR: In this paper, Gagneur et al. describe recoltes d'exuvies nymphales de Chironomides obtenues par derive dans 14 stations reparties sur les 178 km amont d'une riviere de basse montagne du Massif Central francais ont permis de recenser 109 especes.
Abstract: Des recoltes d'exuvies nymphales de Chironomides obtenues par derive dans 14 stations reparties sur les 178 km amont d'une riviere de basse montagne du Massif Central francais ont permis de recenser 109 especes. En ajoutant les 17 especes recoltees en vol par Gagneur (1976), 126 especes ont ete identifiees ce qui represente 31 % du total des especes d'invertebres du benthos. Avec 72 especes, la sous-famille des Orthocladiinae est particulierement bien representee notamment par les 3 genres les plus frequents et les plus diversifies : Eukiefferiella (14 especes), Cricotopus (16 especes) et Orthocladius (9 especes). La sous-famille des Buchonomyiinae et l'espece Buchonomyia thienemanni Fitt. sont citees pour la premiere fois en France. L'ecologie de plusieurs especes est precisee. La succession des especes apparait comme un phenomene continu ; on peut cependant reconnaitre 4 groupements avec leur biocenoses respectives, compatibles avec le systeme de zonation de Illies et Botosaneanu (1963).
TL;DR: In this paper, the NMR spectra of a large number of aryl and benzyl-mercuric compounds (ArHgX and ArCH 2 HgX) have been obtained, in order to throw more light on the relationship between the coordination state of the mercury atom and its NMR parameters.
TL;DR: In this article, the boric acid-catechol system in aqueous solutions has been studied by means of 11B, 1H and 13C NMR over wide ranges of concentration and pH.
Abstract: The boric acid–catechol system in aqueous solutions has been studied by means of 11B, 1H and 13C NMR over wide ranges of concentration and pH. 11B spectra show a striking difference between the complexation possibilities of dilute and more concentrated solutions of boric acid. Both the 1:1 and 1:2 complexes can be simultaneously observed by 13C NMR.