Showing papers by "University of Oviedo published in 1985"
117 citations
TL;DR: The Malpica-Tuy (MT) unit is a narrow band of basement in Galicia (northwest Spain) composed of mica schists, paragneisses and calc-alkaline to peralkaline orthogneisses with minor amounts of metamorphosed basic rocks as discussed by the authors.
76 citations
TL;DR: This paper is devoted to the extension of the Bayesian method for the point estimation, when the available information is ‘vague’, by looking at the parametric estimation in the fuzzy case as a special situation inThe fuzzy decision problem.
45 citations
TL;DR: The results show that galactose was less effective as a repressor than glucose, and fructose 1,6-bisphosphatase and isocitrate lyase were completely inactivated by both sugars but at different rate.
Abstract: The synthesis of isocitrate lyase was induced by the presence of ethanol in the chemostat reaching a specific activity of 200 mU·mg-1 at this induced state. In glucoselimited, derepressed cells, 20 mU·mg-1 were detected and under repressed conditions isocitrate lyase activity was not detected.
41 citations
TL;DR: A treatment that increased the sexual capacity in males had no detectable effects on the reproductive behavior of females and a positive role of this phenomenon in nature is suggested, as the offspring of stressed mothers would be more capable of facing difficult and selective environments.
36 citations
TL;DR: In this paper, the preparation of γ-titanium phosphate from mixtures of β and γ phases by treatment with NaCl and subsequent reverse reaction with HCl is described.
32 citations
TL;DR: In this article, the lattice parameter (a0), cation distribution, and oxygen parameter (u) for each spinel are determined by X-ray diffraction. But the results are interpreted in terms of the interplay of the different factors which determine the crystal chemistry of metal oxides.
Abstract: Spinels MgxNi1–xGa2O4 (x = 0, 0.2, 0.4, 0.6, 0.8, 1) are synthesized, in polyerystalline form, by solid-state reaction at 1273 K of the individual metal oxides. X-ray diffraction is used to determine the lattice parameter (a0), cation distribution, and oxygen parameter (u) for each spinel. Complete solid solution formation between MgGa2O4 and NiGa2O4 is found, and a0 increases linearly with the composition parameter, x; the oxygen parameter, however, remains approximately constant at u = 0.382 (±1). The cation distribution is found to be dependent upon chemical composition, the proportion of octahedral Ni2+ increasing as the amount of Mg2+ is raised. These results are interpreted in terms of the interplay of the different factors which determine the crystal chemistry of metal oxides.
Au moyen d'une reaction a l'etat solide (1273 K) dans les oxydes metalliques individuels, on a synthetise la serie de spinelles MgxNi1–xGa2O4 (x = 0; 0,2; 0,4; 0,6; 0,8; 1) et l'on a determine, moyennant diffraction de rayons X, le parametre de maille (a0), la distribution de cations et le parametre de l'anion (u) correspondant a chaque spinelle. On a trouve que les composes MgGa2O4 et NiGa2O4 forment une serie de solutions solides ou a0 augmente de facon lineaire a mesure que le parametre de composition, x, augmente. Le parametre de l'anion, par le contraire, garde la valeur pratiquement constante u = 0,382 (±1). Il se trouve que la distribution des cations est dependante de la composition chimique, car la proportion de Ni2+ hexacoordonne augmente a mesure que l'on augmente le contenu de Mg2+ des spinelles. Ces resultats sont interpretes en termes de l'interrelation qui existe parmi les differents facteurs qui determinent la structure cristalline des oxydes metalliques.
31 citations
TL;DR: The use of formol-thionin under controlled conditions of concentration and pH provides a highly reliable method for the staining of nerve cells in blue and fiber tracts in red, making any posterior differentiation redundant.
30 citations
29 citations
TL;DR: In this paper, 2-Aza-1,3-butadiene derivatives were synthesized by dimerization of imines 1 by means of a cycloaddition reaction with aldehydes.
Abstract: 2-Aza-1,3-butadiene derivatives 2 are synthesized by dimerization of imines 1. These azadienes are precursors of 5,6-dihydro-2H-1,3-oxazine derivatives 4 and 5 by means of a [4 + 2]cycloaddition reaction with aldehydes.
Darstellung und Reaktivitat von 2-Aza-1,3-butadienen: Ein Diels-Alder-Weg zu 5,6-Dihydro-2H-1,3-oxazin-Derivaten
Die 2-Aza-1,3-butadien-Derivate 2 wurden durch Dimerisierung von Iminen 1 synthetisiert. Durch Reaktion von 2 mit Aldehyden entstehen durch [4 + 2]-Cycloaddition die 5,6-Dihydro-2H-1,3-oxazin-Derivate 4 und 5.
27 citations
TL;DR: In this paper, a number of σ-alkynyl carbonyl complexes of manganese (I), [Mn(CO) n (L) 5− n Br] by treatment with silver(I) or copper (I) actylides, have been obtained from bromocarbonyl compounds.
TL;DR: This work wishes to state and to study a criterion in order to compare fuzzy information systems by the ‘quantity of information of a fuzzy information system’ (defined by Tanaka et al.)
TL;DR: Substrate specificity studies indicate that the purified enzyme specifically hydrolyzes peptide bonds involving the carboxyl group of prolyl residues penultimate to unprotected termini unless arginine is the N-terminal amino acid, however, X-Ala-arylamide structures are not attacked.
TL;DR: A new speetrofluorimetric method based on solvent extraction into chloroform of the ion-pair formed between the positively-charged cryptate of lead with cryptand 2.2.2 and the eosinate anion for determination of ultratraces of lead is based on fundamental extraction studies.
TL;DR: Plantlets were successfully regenerated from shoot and cotyledonary node segments excised from 20 day old filbert seedlings and the histological origin of neoformed organs was studied.
Abstract: Plantlets were successfully regenerated from shoot and cotyledonary node segments excised from 20 day old filbert seedlings. In both cases the optimum initiation and elongation of shoot buds was obtained after 15 days culture in 1/2K(h) medium plus BAP (25 μM) followed by 20 days culture in the same medium in presence of a reduced BAP concentration (0.5 or 2.5 μM).Maximum of functional roots were readily formed after 5 days of submersion of the basal end of shoots in 1/2K(h) liquid medium plus IBA (50 μM), then transferred to a fresh 1/2K(h) solid medium for a further 15 days. Following these two consecutive steps, root initiation and development was achieved in 80% of the explants.The histological origin of neoformed organs was studied.
TL;DR: The results suggest that the activation by cholera toxin of adenylate cyclase located at the basal lateral membrane requires ADPribosylation of proteins in the brush border membrane.
Abstract: ADP-ribosylation of membrane proteins from rabbit small intestinal epithelium was investigated following incubation of membranes with [32P]NAD and cholera toxin. Cholera toxin catalyzes incorporation of 32P into three proteins of 40 kDA, 45 kDA and 47 kDA located in the brush-border membrane. In contrast, basal lateral membrane do not contain any protein which becomes labeled in a toxin-dependent manner when incubated with cholera toxin and [32P]NAD. The modification of membrane proteins from brush border occurred in spite of the virtual absence in these membranes of adenylate cyclase activatable either by cholera toxin, vasoactive intestinal peptide (VIP) or fluoride. The three agents activated adenylate cyclase when crude plasma membrane were used. Cholera toxin activated fivefold at 10 μg/ml. Vasoactive intestinal peptide activated at concentrations from 10–300 nM, the maximal stimulation being sixfold. Fluoride activated 10-fold at 10 mM. When basal lateral membranes were assayed for adenylate cyclase it was found that, with respect to the crude membranes, the specific activity of fluoride-activated enzyme was 3.3-fold higher, VIP stimulated enzyme was maintained while choleratoxin-stimulated enzyme showed half specific activity. Moreover, while fluoride stimulated ninefold and_VIP stimulated fivefold, cholera toxin only stimulated twofold at the highest concentration. The results suggest that the activation by cholera toxin of adenylate cyclase located at the basal lateral membrane requires ADPribosylation of proteins in the brush border membrane.
TL;DR: Intrapopulational variation on interspecific crossing ability between D. melanogaster andD.
Abstract: Intrapopulational variation on interspecific crossing ability betweenD. melanogaster andD. simulans has been measured. When themelanogaster females andsimulans males were crossed, hybridization ranged from 3 to 34%, the female component of variation being more important than the male component. This point is discussed in relation with the role played by each sex in sexual isolation.
TL;DR: In this paper, a local realistic model is proposed that agrees approximately with quantum mechanics in the predictions about experiments testing Bell's inequalities by measuring polarization correlations of photon pairs emitted in atomic cascades.
TL;DR: A quality test for the SCF wave function based on separate examination of the one and two-electron contributions to the total energy is proposed in this article, which allows for a reduction in the cancellation of errors detected in some applications of the standard SCF procedure.
Abstract: A quality test for the SCF wave function based on separate examination of the one- and two-electron contributions to the total energy is proposed. The test is applied to 12 different STO basis sets for the ground state of the Ni atom and its predictions compared with those deduced for the minimization of the total energy. The new test allows for a reduction in the cancellation of errors detected in some applications of the standard SCF procedure. Some relations between the quality of the basis set and its size and structure are discussed.
TL;DR: It can be concluded that malnutrition in utero and while suckling affects fundamental parameters of both development and reproductive function in the male offspring 4 mo after feeding ad libitum is begun at weaning.
Abstract: The effects of undernourishment during gestation and suckling on rats subsequently fed ad libitum for 4 mo after weaning are explored. We measured the following: weight at birth and over a 5-mo period; sexual behavior of adult males; curiosity; basal physical activity; morphometric measures; organ weights (absolute and relative) including brain, testicles and seminal vesicles in males 5 mo of age; and the O2 uptake of some brain and glandular structures in males at 5 mo of age. Body weight of the malnourished animals was consistently lower than that of the controls. Compared to controls sexual behavior in undernourished males was significantly reduced, while curiosity test and basal physical activity were increased. The absolute weights of all organs (except the pituitary gland) were significantly lower in malnourished males at 5 mo than in controls. Compared to controls, relative weight of brain was greater and that of seminal vesicles was less in the male rats. Oxygen uptake was significantly lower in the pituitary gland and testicles of malnourished males than of controls. In view of these results, it can be concluded that malnutrition in utero and while suckling affects fundamental parameters of both development and reproductive function in the male offspring 4 mo after feeding ad libitum is begun at weaning.
TL;DR: The results indicate a highly significant decrease in body and organ weights in experimental dams, which may be an important determinant of growth retardation in pups whose body andorgan weights were significantly smaller than the controls.
TL;DR: In this article, a set of Hartree-Fock-Roothaan (HFR) wave functions for the nickel atom (3d84s2:3F) was constructed by simply adding one STO (Slater Type Orbital) to the 2-ζ Clementi-Roetti basis set.
Abstract: A set of Hartree-Fock-Roothaan (HFR) wave functions {αi}i=1-−6 for the nickel atom (3d84s2:3F) has been constructed by simply adding one STO (Slater Type Orbital) to the 2-ζ Clementi-Roetti basis set. The application of several quality tests and the calculation of some atomic properties show that some of the wave functions obtained, {αi}i=2,4,5,6, are comparable with the high-quality multi-term HFR basis sets. The intermediate size of the {αi}i=2,4,5,6 wave functions makes them specially appropriate for molecular calculations.
01 Jan 1985
TL;DR: Results showing that H + conductors and polyene antibiotics affect H + and K + fluxes in different ways are presented, suggesting the existence of independent carriers which appear to be coupled.
Abstract: Publisher Summary This chapter reviews the coupling of proton and potassium fluxes in Saccharomyces crevisiae. It presents results showing that H + conductors and polyene antibiotics affect H + and K + fluxes in different ways, suggesting the existence of independent carriers which appear to be coupled. The chapter highlights the concept of a thermodynamic coupling between H + and K + fluxes. The delayed effect of H + conductors on K + influx when compared with H + efflux and the delayed effect of polyene antibiotics on H + fluxes when compared with K + movement suggest that even though H + and K + gradients are thermodynamically coupled, their exchange should not necessarily occur through the same carrier.
TL;DR: A spectrophotometric method for the détermination of trace amounts of Nb(V) based on the formation of a ternary complex with Bromopyrogallol Red (L) and cetylpyridinium bromide (CPB) in 1M hydrochloric acid/15% dimethylformamide medium has been developed.
24 Jun 1985
TL;DR: In this article, a new type of two-output dc-to-dc converter is proposed, which is based on the discontinuous-conduction mode operation of one output and the continuousconduction operation of the other output.
Abstract: A new type of two-output dc-to-dc converter is proposed. With this “double converter”, two completely regulated outputs can be obtained using only one switching element and very often without a transformer. The operating principle is based on the discontinuous-conduction mode operation of one output and the continuous-conduction mode operation of the other output. Both outputs are sensed and the duty-cycle of the switching element and the frequency are controlled. A prototype has been built and the results obtained are discussed.
TL;DR: In this article, the thermodynamics of H + Li + ion exchange on α-Ti(HPO4)2·H2O have been studied, and titration curves and exchange isotherms have been obtained at 298.15, 313.15 and 328.15(± 0.1) K. The molar enthalpies of the exchange reaction have been measured calorimetrically.
TL;DR: The method involves extraction with methanol, isolation of the acid fraction, diazomethane methylation, separation of the hormones through reverse-phase preparative high-performance liquid chromatography, and quantification of both compounds by gas-liquid chromatography.
TL;DR: In this article, the monocarbonyls of manganese with two chelating diphosphinestrans were prepared fromtrans-[Mn(CO)(diphos)2Br].
Abstract: Monocarbonyls of manganese(I) with two chelating diphosphinestrans-[Mn(CO)(diphos)2(L)]A, [diphos = 1,2-bis(diphenylphosphino)ethane, dppe, or bis(diphenylphosphino)methane, dppm; L=nitriles, NCR (NCMe, NCEt, NCPh, or NCCH2Ph), dinitriles, NCGCN (NCCH2CN, NCCH2CH2CN, oro-(NC)2C6H4), isonitriles, CNR, (CNPh, or CNBut); A = C1O 4 − or PF 6 − ],trans-[(Mn(CO)(dppm)2)2(μ-NCCH2CH2CN)](ClO4)2 and the monocarbonyl with one diphosphine,mer-[Mn(CO)(dppe)(CNBut)3]ClO4, have been prepared fromtrans-[Mn(CO)(diphos)2Br].
TL;DR: In this paper, pine-bark sawdust was oxidized with nitric acid (5-20% by weight) and further ammoniated with NH3 or NH4OH.
Abstract: Pine-bark sawdust was oxidized with nitric acid (5-20% by weight) and further ammoniated with NH3 or NH4OH. Ammoniation with NH3 was carried out in a fluidized bed reactor at 100 and 250°C and a NH, flow of 126 L/h (0°C; 101.3 kPa). Ammoniation with NH4OH was carried out in a batch reactor by reacting the oxidized sample with NH4OH (2 kmol/m3) at total reflux. Data on total nitrogen, ammonia nitrogen and KMnO4 soluble nitrogen content are reported for the resulting product.
On a oxyde de la sciure d'ecore de pin avec de l'acide nitrique (5 a 20% en poids), puis on l'a ammoniaquee avec NH3 ou NH4OH. On a fait le traitement avec NH3 dans un reacteur a lit fluidise a 100 et 250°C et un debit de NH3 de 126 L/h (O°C, 101.3 kPa). On a fait l'ammoniation avec NH4OH dans un reacteur discontinu, en faisant reagir l'echantillon oxyde avec NH4OH (2 kmol/m3) a reflux total. On rapporte, pour le produit resultant, les donnees obtenues pour l'azote total, l'azote ammoniacal et la teneur en azote soluble dans KMnO4.
TL;DR: In this paper, Zirconium dioxide, prepared by dehydration of a zirconia gel, was calcined in a vacuum at temperatures ranging from 573 to 1173K, in order to investigate the evolution of specific surface area and porosity as a function of the calcination temperature.