Showing papers by "University of Oviedo published in 1986"
TL;DR: The present state of knowledge of the mechanisms of dye-surfactant interactions for "normal" aqueous micelles is surveyed and some discussion along these lines on related systems (reverse micells, vesicles, polyelectrolytes) is included.
235 citations
TL;DR: It is shown that Sugeno's fuzzy integral is a particular case of them and they are studied to study their principal properties.
160 citations
TL;DR: For establishing optimality criteria of testing, the definition of probability of a fuzzy event is used in order to extend both Neyman-Pearson and Bayes theories, to the fuzzy framework, and the goodness of optimal procedures in both the fuzzy and the nonfuzzy situation is compared for each criterion.
80 citations
TL;DR: The problem of testing statistical hypotheses about an experiment when the available sample information is vague, is approached as a particular fuzzy decision problem (as defined by Tanaka, Okuda and Asai).
79 citations
TL;DR: The Mondonedo nappe as discussed by the authors is one of the main units in the internal zone of the Hercynian belt in the Iberian Peninsula, and it consists of low to medium grade metasediments, late Precambrian and Palaeozoic in age, folded by large D 1 E-verging recumbent structures, and thrusted several tens of km towards the east during a D 2 deformation episode.
71 citations
TL;DR: The morphology and functional activity of isolated membranes of S. antibioticus can be retained when dehydrated in the presence of trehalose, and it is suggested that this substance may serve to protect cellular components during dehydration by acting as a substitute for water.
Abstract: Dormant spores of Streptomyces antibioticus contain large amounts of trehalose (11–12% of dry weight) and can be subjected to a dehydration treatment without a significant loss of viability. Loss of dehydration resistance coincided with a decrease in the trehalose level of the spores, under different conditions of incubation. The viability of dehydration-sensitive cells was enhanced by the presence of exogenous trehalose during dehydration. The morphology and functional activity of isolated membranes of S. antibioticus can be retained when dehydrated in the presence of trehalose. It is suggested that, in dormant spores of S. antibioticus, trehalose may serve to protect cellular components during dehydration by acting as a substitute for water.
52 citations
TL;DR: It is concluded that trehalase activation is mediated by an intracellular acidification and is independent of the membrane potential.
Abstract: It has been reported that the addition of glucose, uncouplers and nystatin to yeast cells grown in a sugarfree medium causes trehalase activation; it has been postulated that this activation might be mediated by the depolarization of the plasma membrane. In this article the values of membrane potential and pH gradient across the plasma membrane of Saccharomyces cerevisiae have been determined under the same conditions as those in which trehalase is activated. Membrane potential was evaluated from the distribution of triphenyl-methylphosphonium, the pH gradient from the distribution of benzoic acid across the plasma membrane. When the effect of several agents on the two components of the electrochemical proton gradient across the plasma membrane of ethanol-grown yeast cells were studied, under trehalase activation conditions, the following observations were made. (a) The addition of glucose activated trehalase and caused internal acidification of the cells, but had practically no effect on the membrane potential. (b) The addition of 200 mM KCl depolarized the cell membrane but did not affect the internal pH, nor trehalase activity. (c) Although carbonyl cyanide m-chlorophenylhydrazone depolarized the cells at external pH 6.0 and 7.0, it only activated trehalase at an external pH 6.0, leading to the acidification of the internal medium at this pH. (d) Nystatin caused an increase in the triphenylmethylphosphonium accumulation at external pH 6.0 and 7.0, but only activated trehalase at external pH 6.0, causing acidification of the cell interior at this pH. (e) Activation of trehalase was also observed when the internal acidification was caused by addition of a weak acid such as acetate. It is concluded that trehalase activation is mediated by an intracellular acidification and is independent of the membrane potential.
42 citations
TL;DR: In this paper, the structure of fac -[SCNMn(CO) 3 (dppm)] has been determined by X-ray diffraction and the crystals are monoclinic, space group P 2 1 / n, and the structure has been refined to R = 0.058 for 4123 reflexions measured in the range 2⩽ θ ⩽ 30 at room temperature.
35 citations
TL;DR: Fluorescence quenching of the pH gradient sensitive dye acridine orange and that of the membrane potential sensitive dye Di-S-C3(5) have been studied in purified basolateral membrane vesicles obtained from rabbit small intestine and it can be estimated that at least half of the observed proton fluxes are due to the activity of the exchanger.
32 citations
TL;DR: In both species variability in gonad stages for a given month reduces as size increases, indicating a certain synchrony.
Abstract: Populations of Monodonta lineata and Gibbula umbilicalis were studied at Aramar beach (Luanco, Asturias) from October 1982 to November 1983. Both species show a sexual ratio of 1:1 but differ in their gonadal cycle patterns. M. lineata gonadal development stages are found from November to May–June in a significant part of the population. Breeding stages occur from June–July to September, and in some individuals to November, with complete discharge of all spawn at the end of the reproductive season. Some degree of inter-annual variation is detected. Spawning stages of mature G. umbilicalis are found through the year but the higher frequencies occur in summer and autumn samples, with development phases predominating in January to May. Animals over 10 mm in shell diameter maintain their gonads close to spawning stages, completely spawned individuals being less than 10 percent. In both species variability in gonad stages for a given month reduces as size increases, indicating a certain synchrony.
30 citations
TL;DR: In this paper, a wide variety of nucleophiles (F, Cl, Br, I, SCN, pyridine, OAc, anisole, H) react with bis(pyridine)iodo(I) tetrafluoroborate to give 1,2-iodofunctionalized olefins.
TL;DR: In this paper, the neutral complexes cis-trans-[MnX(CO)2(bipy)- (P(OPh)3)] (X=I, CN or SCN) have been prepared by nucleophilic substitution of P(Oph)3 by X− in the cationic complex cistrans]-Mn(CO)-trans-(MnI(CO),(Bipy) P( OPh)2]+, or, in the case of X=CN, by reacting the iodo-dicarb
TL;DR: Observation of the carbon catabolite repression of selected enzymes showed that invertase and maltase synthesis were not repressed when hexokinase PII was phosphorylated, which indicated that the mechanism was dependent on the presence of MgATP and was irreversible.
Abstract: Summary: The mechanism of inactivation of hexokinase PII of Saccharomyces cerevisiae by D-xylose was characterized. Inactivation was dependent on the presence of MgATP and was irreversible. Inactivation involved phosphorylation of the protein. Observation of the carbon catabolite repression of selected enzymes showed that invertase and maltase synthesis were not repressed when hexokinase PII was phosphorylated.
TL;DR: A large set of hourly Rn atmospheric concentration data collected during 1976, 1978, 1979 and 1980 has been obtained and the Fourier analysis of the mean daily course of Rn by month shows that to accurately represent such a wave two terms are sufficient.
Abstract: A large set of hourly Rn atmospheric concentration data collected during 1976, 1978, 1979 and 1980 has been obtained. These data follow a log-normal distribution law. The Fourier analysis of the mean daily course of Rn by month (Rn wave) shows that to accurately represent such a wave two terms are sufficient. Assuming that with a great deal of data the influence of the meteorological variables is very low, the two terms have been interpreted taking into account only the atmospheric stability, which depends on the solar flux. By applying the same treatment to Rn concentration data from other sites it was found that: (a) the phase of the first harmonic is a constant, independent of the site; (b) the phase of the second harmonic is a linear function of the hourly difference between sunrise and sunset; (c) the amplitude of the first harmonic is a linear function of the solar flux; and (d) no reliable correlation was found for the amplitude of the second harmonic, for which reason a mean value was taken. The error obtained in the prediction of the Rn wave was tolerable.
TL;DR: In this article, a local hidden variable model predicting exact agreement with quantum mechanics in all experiments with correlated photon pairs is proposed, and it proves that LHV theories cannot be refuted by atomic cascade experiments.
TL;DR: The authors showed that a broad family of measures of inequality can be accurately estimated when the tax data are known in groups (more precisely, when we know the number of returns in each of several class intervals and their corresponding average income).
Abstract: In a previous paper Gastwirth shows that a broad family of measures of inequality can be accurately estimated when the tax data are known in groups (more precisely, when we know the number of returns in each of several class intervals and their corresponding average income). In the present paper we show that some measures of the preceding family can be unbiasedly estimated when the tax data are individually known for a sample from the population. Specifically, we construct unbiased estimators of a particular measure of inequality in the samplings with and without replacement, and in the stratified samplings with and without replacement.
TL;DR: The reaction of 2-Propin-1-ols with 2-amino alcohols 7 and mercury(II) chloride start with an oxidative aminomercuration step followed by a series of highly stereoselective processes leading to cis-[1,4]oxazino[3,2-b]-1-4-oxazine derivatives as discussed by the authors.
Abstract: The reactions of 2-Propin-1-ols 1 with 2-amino alcohols 7 and mercury(II) chloride start with an oxidative aminomercuration step followed by a series of highly stereoselective processes leading to cis-[1,4]oxazino[3,2-b]-1,4-oxazine derivatives 10. X-Ray analyses of 10c,f,g show that these compounds have the same geometrical arrangement around their central fusion bond in such a way that anomeric stabilisation reaches a maximum.
Oxidative Aminomercurierung von 2-Propin-1-olen. Stereoselektive Synthese und Struktur von cis-[1,4]Oxazino[3,2-b]-1,4-oxazin-Derivaten
Die Reaktion von 2-Propin-1-olen 1 mit 2-Aminoalkoholen 7 in Gegenwart von Quecksilber(II)-chlorid beginnt mit einer oxidativen Aminomercurierung, gefolgt von hoch stereo-selektiven Reaktionsschritten, die zu cis-[1,4]Oxazino[3,2-b]-1,4-oxazin-Derivaten 10 fuhren. Nach den Rontgenstrukturanalysen von 10c,f,g zeigen diese Verbindungen die gleiche Anordnung um die zentrale Bindung, und zwar so, das die anomere Stabilisierung ein Maximum erreicht.
TL;DR: In this paper, el concepto de esquizofrenia en base a sintesis of la literatura reciente sobre la evolucion a largo plazo de la enfermedad.
Abstract: ResumenSe revisa el concepto de Esquizofrenia en base a una sintesis de la literatura reciente sobre la evolucion a largo plazo de la enfermedad. De acuerdo con el modelo de enfermedad de diatesis-stress, se analizan los indicadores de la vulnerabilidad, la influencia de los acontecimientos vitales, de los stressores psicosociales cronicos, especialmente de la Expresion Emocional familiar, y del mantenimiento con medicacion antipsicotica, en el curso de la Esquizofrenia. Se sugiere la existencia de una relacion entre la llamada «Esquizofrenia Cronica» y las influencias yatrogenicas.
TL;DR: In this article, a series of seven-coordinate molybdenum(II) complexes containing carbonyl, triphenylphosphine, bromide and/or O-donor and S-donator anionic bidentate ligands have been prepared in high yield.
TL;DR: In this article, active alumina prepared by thermolysis of ammonium alum has been characterized by X-ray diffraction and nitrogen adsorption at 77 K. The material was found to have a defective spinel-type structure in which 2 2 3 octahedral cation sites per unit cell are vacant.
TL;DR: Filbert cotyledonary nodes were used as explants in order to study the effect of auxins, cytokinins and culture period on embryoid induction and development, and Benzylaminopurine acts as the main agent in restoring polarized development.
TL;DR: In this article, the reactions of conjugated dienes with I(py) 2 BF 4 were reported, which allowed the regiospecific 1,2-addition of iodine and a nucleophile to terminal diene and the 1,4-additions to internal dienen.
TL;DR: In this paper, a simple physical model based on the occurrence of rod and plate-like shape anisotropies is proposed to explain the behavior of magnetic anisotropy in oblique-deposited thin films.
TL;DR: Hexokinase PII is not inhibited by high Mg-ATP concentrations if the Mg2+-free ATP is kept at low levels (0.01 mM) in the assay mixture and hexokinase PI activities appear not to be regulated by substrate inhibition as proposed previously.
Abstract: Hexokinase PII is not inhibited by high Mg-ATP concentrations if the Mg2+-free ATP is kept at low levels (0.01 mM) in the assay mixture. Hexokinase PI activity is not affected either by Mg2+-free ATP nor by free Mg2+ in the assay mixture. Thus, hexokinase PI and PII activities appear not to be regulated by substrate inhibition as proposed previously [Kopetzki, E. & Entian, K. D. (1985) Eur. J. Biochem. 146, 657-662]. However, the level of Mg2+-free ATP in the hexokinase PII assay mixture strongly affects the enzyme activity by decreasing the Vmax and increasing the Km value for Mg-ATP from 0.15 mM to 5.0 mM. The physiological role of this inhibition, which has not been described previously, was investigated by determining the cytosolic ATP and Mg2+ concentrations in yeast cells grown under derepressing and repressing conditions. Derepression is accompanied by an important loss of Mg2+ from the cells, maintaining the ATP concentration constant. This produces an increase of Mg2+-free ATP in the cytosol from 0.01 mM to 0.1 mM. This free ATP concentration would lead to a maximal inhibition of hexokinase PII.
TL;DR: In this article, the maximum overlap method of weighted least squares with orthogonality restrictions is applied to the problem of basis set reduction, and an analytical solution for the linear parameters of the reduced set is given.
TL;DR: The presence of PKC in small intestine epithelial cells might have important implications in the Ca2+ mediated control of ionic transport in this tissue.
TL;DR: In this paper, LiPPh 2 and NH 4 Br were used to synthesize the "piano-stool" complexes [WCl(PPh2 CH 2 R)(CO) 2 (η-C 5 H 5 )][BF 4 ], and [W(NCMe) and [NCMe] respectively.
TL;DR: In this paper, Richardson et al. showed that the dependence of the predicted geometry on the type of core-valence partition adopted in the unprojected description is due to insufficient corevalence orthogonality.
TL;DR: An increase in the number of the synaptic ribbons after stimulation of the SCG supports the hypothesis that the numerical reduction of dense cores of nerve vesicles in the cat pineal gland influences the level of synaptic ribbon formation.
Abstract: The nerve vesicles and synaptic ribbons were quantified in the cat pineal gland after electrical stimulation of the pineal sympathetic nerve fibers. It has been shown that the bilateral electrical stimulation of the preganglionic fibers innervating the superior cervical ganglia (SCG) markedly reduces the number of dense cores of small dark vesicles (SDV) and, on the other hand, modifies the number and shape of the large dark vesicles (LDV). An increase in the number of the synaptic ribbons after stimulation of the SCG supports the hypothesis that the numerical reduction of dense cores of nerve vesicles in the cat pineal gland influences the level of synaptic ribbon formation.