Showing papers by "University of Valencia published in 1990"
TL;DR: It was observed that the structural features for active polyhydroxylated compounds were different from those of polymethoxylated flavones, antiperoxidative flavonoids possessing a high lipophilicity.
328 citations
TL;DR: The GEPOL algorithm as mentioned in this paper computes the MS by first searching the spaces inaccessible to the solvent and consequently filling them with a new set of spheres with van der Waals radii.
Abstract: The algorithm used by the program GEPOL to compute the Molecular Surface (MS), as defined by Richards, is presented in detail. GEPOL starts like other algorithms from a set of spheres with van der Waals radii, centered on the atoms or group of atoms of the molecule. GEPOL computes the MS by first searching the spaces inaccessible to the solvent and consequently filling them with a new set of spheres. Here we study the behavior of the method with its parameters, presenting several examples of application.
251 citations
TL;DR: The heterogeneity of the rat liver mitochondrial population, from a structural, metabolic and functional and functional (active and non-active mitochondrial population dispersion) point of view could thus be demonstrated by flow-cytometry analysis.
Abstract: Washed and purified rat- or mouse-liver mitochondria exhibiting high membrane integrity and metabolic activity were studied by flow cytometry. The electrophoretic accumulation/redistribution of cationic lipophilic probes, rhodamine 123, safranine O and a cyanine derivative, 3,3'-dihexyloxadicarbocyanine iodide, during the energization process was studied and was consistent with the generation of a negative internal membrane potential. An exception to this was nonylacridine orange which spontaneously bound to the mitochondrial membrane by hydrophobic interactions via its hydrocarbon chain. Energized purified mitochondria stained with potentiometric dyes exhibited both higher fluorescence and population homogeneity than the non-energized or deenergized (nigericin plus valinomycin) mitochondria. By contrast, under non-energized or deenergized conditions, the mitochondrial population exhibited fluorescence intensity heterogeneity related to the residual membrane potential; two subpopulations were evident, one of low fluorescence which may be related to the autofluorescence of the mitochondria (plus non-specific dye binding) and a second population which exhibited high fluorescence. Flow cytometry of the unpurified, simply washed, rat-liver mitochondria stained with rhodamine 123, a classically used dye, provided evidence of their heterogeneity in terms of light-scattering properties and membrane-potential-related fluorescence. One third of the washed mitochondria were found to be non-functional by such assays. The fluorescence of purified rat-liver mitochondria due to the membrane potential built up by endogenous substrates indicates heterogeneity of the mitochondrial population with respect to levels of endogenous substrates. The low-angle light scattering increases upon energization and provides some original information about the shape and modification of the inner mitochondrial conformation accompanying the energization. The heterogeneity of the rat liver mitochondrial population, from a structural, metabolic (existence of endogenous substrates) and functional (active and non-active mitochondrial population dispersion) point of view could thus be demonstrated by flow-cytometry analysis. Two animal models were examined with regard to the alteration of the mitochondrial membrane potential under the effects of drugs (rat-liver mitochondria), and the effects of ammonium toxicity (mouse-liver mitochondria). These results are promising and open new perspectives in the study of mitochondriopathies.
238 citations
TL;DR: The theorem supplies sufficient conditions on the initial point to ensure the convergence of Halley iterates, by means of a system of “recurrence relations” analogous to those given for the Newton method by Kantorovich, improving previous results by Döring.
Abstract: In this paper we present a system of a priori error bounds for the Halley method in Banach spaces. Our theorem supplies sufficient conditions on the initial point to ensure the convergence of Halley iterates, by means of a system of “recurrence relations”, analogous to those given for the Newton method by Kantorovich, improving previous results by Doring [4]. The error bounds presented are optimal for second degree polynomials. Other rational cubic methods, as the Chebyshev method, will be treated in a subsequent paper.
186 citations
TL;DR: Results show a relationship between iron deficiency of the mother at delivery and the development of iron deficiency in the infants, which could be important in theDevelopment of new prevention programmes applied to pregnant women.
Abstract: A prospective cohort study with a 1-year follow-up of 156 neonates was carried out specifically designed to test the hypothesis that there is a positive relationship between iron deficiency during pregnancy and the development of the same disease in newborn infants. Exposure was defined as being born of a mother with ferropenic anaemia at delivery, and cases as the infants who developed iron deficiency during their first year of life. A statistically significant positive association was detected with an odds ratio of 6.57 (95% confidence limits 1.81-25.97). A stratified analysis was also performed to control the effect of potential confounders such as socio-economic variables, feeding practices and other factors linked with the iron status of infants. This second analytical procedure showed no alteration in the association detected in the simple analysis but that there was a statistically significant strong interaction between the quantity of cow's milk intake and the ferropenic status of the mother. These results show a relationship between iron deficiency of the mother at delivery and the development of iron deficiency in the infants. These new findings could be important in the development of new prevention programmes applied to pregnant women.
169 citations
TL;DR: In this paper, a theoretical model that helps the interpretation of the remotely sensed thermal infrared measurements carried out over citrus orchards was developed. But the model was validated under vertical observation in a citrus orchard during seven nights.
Abstract: In this work we have developed a theoretical model that helps the interpretation of the remotely sensed thermal infrared measurements carried out over citrus orchards. A detailed analysis of the different factors which take part in the definition of the effective emissivity and temperature (observation height, viewing angle, type of soil, dimensions and separation between orange trees) is made. The model was validated under vertical observation in a citrus orchard during seven nights. In this situation we have determined that the model performs to an accuracy of about 1%.
161 citations
01 Jan 1990
TL;DR: This chapter proposes a model of evolution of FMDV and discusses its implications for vaccine design and disease control, reflected in several serotypes and subtypes of the virus.
Abstract: Foot-and-mouth disease (FMD) is an acute systemic disease of cloven-hooved animals, including cattle, swine, sheep, and goats. Despite mortality rates being generally below 5%, FMD severely decreases livestock productivity and trade. It is considered the economically most important disease of farm animals. Near two thousand million doses of vaccine are used annually to try to control FMD, which, nevertheless, is enzootic in most South American and African countries, parts of Asia, the Middle East, and the south of Europe. The causative agent, foot-and-mouth disease virus (FMDV), is an aphthovirus of the family Picornaviridae, a historically important virus as it was the first recognized viral agent (Loeffler and Frosch, 1898). In this chapter we review briefly the structure of FMDV and the organization and expression of its genome (Section II) and, in more detail, recent results on genetic variability (Section III) and antigenic diversity (Section V), reflected in several serotypes and subtypes of the virus. Such a diversity has implications for vaccine design and disease control, as discussed in Section V. Finally, we propose a model of evolution of FMDV and discuss its implications (Sections VI and VII).
157 citations
TL;DR: In this paper, the authors investigated isosinglet neutrino production and decays within different models and concluded that these may discover the existence of singlets neutrinos and substantially improve and extend present limits on their mass and coupling strength.
116 citations
TL;DR: In this article, the crystal structure of Li2CuO2 has been investigated and its magnetic structure solved by neutron powder diffraction, and the magnetic moment of copper atoms at 1.5 K is 0.96(4)microB, which is very close to the saturation moment of spin only Cu+2 (d9).
108 citations
TL;DR: A triangular tesselation approach to build up surfaces has been adapted to the study of biomolecules by using a data-coded generic pentakisdodecahedron each atom is assigned a particular sphere whose radii are chosen according to any suitable property.
106 citations
TL;DR: In this article, the role of nuclear polarization, due to the spin-isospin ΣN → ΛN interaction, in the reduction of the Σ widths is discussed.
TL;DR: In this paper, the role of vector meson resonances in radiative K decay is analyzed within the context of chiral perturbation theory, and a weak deformation model inspired by the geometry of the coset space is introduced to estimate the direct weak contributions.
TL;DR: In this article, the discovery potential of isosinglet neutrino isoscelet NHLs within various models taking also into account cosmological limits on relic neutrinos abundances.
TL;DR: In this article, it was shown that CP conservation may be violated in the leptonic decays of the Z0 to a level that may be probed at LEP, where one of the charged leptons is a τ and the other is an e or μ.
TL;DR: In this article, a two-dimensional radiance model was proposed for interpreting the directional remotely-sensed thermal infrared data obtained over a vegetative surface when the effects of the shadows are minimal.
TL;DR: A simple theory for multi-ionic transport, nonequilibrium water dissociation, and space-charge effects in bipolar membranes is developed on the basis of some of the concepts used in the solid-state n-p junction.
Abstract: A simple theory for multi-ionic transport, nonequilibrium water dissociation, and space-charge effects in bipolar membranes is developed on the basis of some of the concepts used in the solid-state n-p junction. Ion transport is described in terms of the Nernst-Planck flux equation and nonequilibrium water dissociation is accounted for by the Onsager theory of the second Wien effect. The model is expected to be of interest for biological and synthetic membranes, and can explain a number of observed effects.
TL;DR: The experimental results show that the mtDNA polymorphisms observed in natural populations are affected by interactions among nuclear polymorphisms, random genetic drift, and direct selection on the mt DNA haplotypes.
Abstract: When two mitochondrial DNA (mtDNA) haplotypes of Drosophila subobscura compete in experimental populations with discrete generations, one or the other approaches fixation, depending on the nuclear background with which they are associated. The approach to fixation, however, is strongly dependent on the effective number of females in the population, Nf. Whether or not the ultimate fate of a given mtDNA haplotype is determined by random genetic drift depends on Nf as well as on the relative fitnesses. Our experimental results show that the mtDNA polymorphisms observed in natural populations are affected by interactions among nuclear polymorphisms, random genetic drift, and direct selection on the mtDNA haplotypes.
TL;DR: The results of both analyses strongly support two different events of horizontal transfer of the IPNS gene from bacteria to filamentous fungi, the first example of such a type of transfer from prokaryotes to eukaryotes.
Abstract: Evolutionary distances between bacterial and fungal isopenicillin N synthetase (IPNS) genes have been compared to distances between the corresponding 5S rRNA genes. The presence of sequences homologous to the IPNS gene has been examined in DNAs from representative prokaryotic organisms and Ascomycotina. The results of both analyses strongly support two different events of horizontal transfer of the IPNS gene from bacteria to filamentous fungi. This is the first example of such a type of transfer from prokaryotes to eukaryotes.
TL;DR: In this article, must and wine from grapes harvested in two vintages (1986 and 1987) were anlyzed during vinification for physicochemical and microbiological characteristics.
Abstract: Must and wine from grapes harvested in two vintages (1986 and 1987) were anlyzed during vinification for physicochemical and microbiological characteristics. The 1986 vintage would be considered abnormal or poor vintage because of higher rainfall at harvest, and the 1987 one a normal vintage. Low reducing sugars and high volatile acidity at the beginning of the poor fermentation was observed as compared to normal vinification. The yeast population showed atypical evolution through the process since oxidative yeasts were isolated in the first stages of the poor vinification.
TL;DR: The aerial parts of Hypericum reflexum contain six xanthones, two pyranoxanthones and two xanthonolignoids as mentioned in this paper, and a biphenyl.
TL;DR: In this paper, the DELPHI detector at the e+e− storage ring LEP at the center of mass energies around 91.5 GeV was used to measure the production rates for 2-, 3-, 4, and 5-jet hadronic final states.
TL;DR: The method described here consists of rapid and simple-to-perform steps, and does not require neither phenol treatment nor the use of carcinogenic dyes (ethidium bromide and bis-benzimide).
Abstract: A rapid method for the extraction of yeast mitochondrial DNA (mtDNA) is described. The method is based on: preparation of spheroplastis, lysis of the cellular membrane, isopicnic purification of mitochondria, lysis of the mitochondrial membranes, and mtDNA isolation without using CsCl gradient centrifugation. In comparison with previous methods (1, 2), the method described here consists of rapid and simple-to-perform steps, and does not require neither phenol treatment nor the use of carcinogenic dyes (ethidium bromide and bis-benzimide). The resulting mtDNA is sufficiently pure for RFLP analyses, and the yield is high even from wild strains.
TL;DR: Treatment of the inactive enzyme with dithiothreitol results in partial recovery of both carboxylase activity and resistance to proteolysis, which may explain the specific degradation of ribulose-1,5-bisphosphate carboxyase/oxygenase that occurs in vivo during leaf senescence.
TL;DR: In this paper, a manifold has been developed for on-line microwave oven digestion and flame atomic absorption spectrometric (FAAS) determination of metallic elements in solid samples, using a closed flow system with a limit of detection of 0.2 μg Pb g−1.
TL;DR: Fab fragments prepared from the immunoglobulin G monoclonal antibody (MAb) 4C 12, which reacts with a determinant expressed on the hyphal extension of germ tubes of Candida albicans, inhibited germ tube formation, but intact MAb 4C12 did not.
Abstract: Fab fragments prepared from the immunoglobulin G monoclonal antibody (MAb) 4C12, which reacts with a determinant expressed on the hyphal extension of germ tubes of Candida albicans, inhibited germ tube formation, but intact MAb 4C12 did not. Indirect immunofluorescence showed a punctate binding pattern on cells incubated with Fab fragments but a confluent binding on cells incubated with intact MAb 4C12.
TL;DR: In this paper, a methode basee sur l'arbre maximal is presented for determiner the dimension of Hausdorff d'une distribution of points in the universe.
Abstract: L'etude du survey des redshifts CfA montre que la distribution des galaxies dans l'Univers obeit a une loi d'echelle sur des echelles de longueur inferieures a environ 5 h −1 Mpc. Cependant, l'Univers n'est pas bien represente par une fractale homogene sur ces echelles. La dependance de la longueur de correlation avec la profondeur des echantillons et la luminosite est etudiee. Une methode basee sur l'arbre maximal est presentee pour determiner la dimension de Hausdorff d'une distribution de points. Cette technique est ensuite appliquee au catalogue CfA
TL;DR: It may be postulated that StEs displays neuroectodermal features somewhat similar to those seen in peripheral neuroepithelioma as well as in atypical Ewing's sarcoma of bone.
Abstract: This study characterizes the histogenesis of soft tissue Ewing’s sarcoma (StEs) based upon an analysis of three tumors. Long-term cultured cell lines and nude mice xenografts were established from original neoplasms or from their metastases. Histologically they revealed a small round cell pattern without signs of differentiation. Several ultrastructural features of neural type were found; the same were also seen on culture cell lines. Moreover, immunohistochemical study for neural markers revealed the presence of HNK-1, NSE, LIRC-LON 36, S-100 protein, glial fibrillary acidic protein, neurofilaments (70 kilodaltons), and chromogranin; some of these markers were present only in the transplants. Cytokeratin was also seen. The translocation t(11;22)(q24;q12) was found in all three neoplasms together with other chromosomal abnormalities. N-myc RNA gave negative results whereas c-myc RNA was expressed. Therefore it may be postulated that StEs displays neuroectodermal features somewhat similar to those seen in peripheral neuroepithelioma as well as in atypical Ewing’s sarcoma of bone. Cancer 66:2589-2601,1990.
TL;DR: The aerial parts of Artemisia herba-alba subsp. valentine yielded a new germacranolide, six new eudesmanolides and ilicic acid methyl ester as discussed by the authors.