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Showing papers by "University of Valencia published in 1987"


Journal ArticleDOI
TL;DR: In this article, an algorithm for a finer description of cavities in continuous media and for a more efficient selection of sampling points on the cavity surface is described, with applications to the evaluation of solute surface and volume and to the calculation of the solute-solvent electrostatic interaction energy, as well as of the cavitation energy.
Abstract: Algorithms for a finer description of cavities in continuous media and for a more efficient selection of sampling points on the cavity surface are described. Applications to the evaluation of solute surface and volume and to the calculation of the solute-solvent electrostatic interaction energy, as well as of the cavitation energy are shown as examples.

442 citations


Journal ArticleDOI
TL;DR: A branch and bound algorithm for project scheduling with resource constraints based on the idea of using disjunctive arcs for resolving conflicts that are created whenever sets of activities have to be scheduled whose total resource requirements exceed the resource availabilities in some periods is described.

387 citations


Journal ArticleDOI
TL;DR: In this paper, a class of models which extend the standard model by adding new neutral fermions is analyzed. But the authors do not consider the effect of neutrinos on the superstring.

319 citations


Journal ArticleDOI
TL;DR: In this article, the experimental constraints and theoretical plausibility of neutrino and antineutrino scattering in a supernova supernova explosion were discussed. But neutrinos are massless as a consequence of an exact symmetry -such as total lepton number -they can oscillate into one another if the weak interaction has a small nonuniversal component, whose existence would signal physics beyond the standard model.

215 citations


Journal ArticleDOI
TL;DR: In this paper, a many-body expansion in terms of ph and Δh excitations and the spin-isospin induced interaction is used to evaluate the Δ self-energy in a nuclear medium.

179 citations


Journal ArticleDOI
TL;DR: Bioautography showed that the antimicrobial activity of chloroform and methanol extracts of the plants employed as antimicrobial agents in folk medicine are probably due to flavonoids, terpenoids and phenolic acids.

125 citations


Journal ArticleDOI
TL;DR: Preliminary results suggest that previous personal experience of success can infuse the pattern of the psychoend(KTine re-sponse to a contest situation) of hormonal responses to winning and losing.
Abstract: Departamento de Psicologia Fisiologica (A.S., V.S., F.S.) and Laboratorio de MedicinaNuclear e Isotopos (L.L.), Hospital Clinico Universitario, Universitat de Valencia, Valencia,SpainSerum testosterone and cortisol levels were measured by radioimmunoassay in 14young male judo competitors, in samples taken 10 minutes before and 45 minutes aftertwo different pr(Redures. The first involved physical exercise and the second competi-tive fighting. Both procedures were of 5 minutes duration and sessions took plate atthe same time (between 10:00 \.M. and 12:00 P.M. liR-al lime) but on different days.Comparing the two situations over all subjects revealed that testosterone increasedafter exercise and decreased slightly after competition. Between subject comparisonssuggested that contrary to previous claims, winning or losing did not significantlychange the testosterone and cortisol levels. Comparisons of subjects who were membersof the Regional Team with individuals who were not part of thai gronp confirmed thatmemhers increased their testosterone levels after competition, whereas the nonniem-bers showed a significant decrease. Moreover, success of the individuals, in theirsporting record, correlated positively and significantly with the changes of testosteroneohserved during the competition. These preliminary results suggest that previouspersonal experience of success can infiuence the pattern of the psychoend(KTine re-sponse to a contest situation.Key words: physical exercise, judo competition, victory, defeatINTRODUCTIONPhysiological responses to the experiences oi victory and defeat include the modi-fication of circulating levels of some hormones. Clinically, sporting competitions havebeen seen as suitable situations to study hormonal responses to winning and losing.Mazur and Lamb 11980] found that the pattern in changes of testosterone was differentin winners and losers of a tennis match. Winners generally showed increases andlosers decreases in titers of this steroid and significant differences were evident I to2 hours after the match. Hlias [1981] found that subjects winning a wrestling matchshowed significantly greater increases than losers when he compared percentagechanges between testosterone levels seen 10 minutes before and 10 minutes after thematch. Winners also showed significantly greater increases in cortisol than losers.

105 citations


Journal ArticleDOI
TL;DR: In this article, it was suggested that the neutrino resonant amplification in the sun is caused by the spontaneous breaking of R parity in the standard supergravity model which implies the existence of a majoron which is strongly constrained by astrophysics.

104 citations


Journal ArticleDOI
TL;DR: In this article, the aerial parts of Artemisia assoana have been isolated from root extracts of the same plant 1H and 13C NMR spectra of some of these compounds are given and taxonomic aspects are discussed.

86 citations


Journal ArticleDOI
TL;DR: In this paper, the catalytic activity, selectivity, catalyst decay, thermal and hydrothermal stability, and acidity of H-Beta and HY zeolites with Si Al ratios of 7.5 and 10, respectively, have been studied during cracking of n-heptane at 450 °C and atmospheric pressure.

76 citations


Journal ArticleDOI
01 Oct 1987-Cancer
TL;DR: Five atypical Ewing's sarcoma of bone tumors are isolated, which resemble closely immature neuroepithelioma of soft tissue but are superimposable on those described as “neuroectodermal tumors of bone.”
Abstract: Ewing's sarcoma (ES) of bone may occasionally display rosette-like textures mimicking Homer-Wright ones, as seen in neuroectodermic neoplasms (neuroblastoma, peripheral neuroepithelioma). Of a group of 39 cases of ES, reviewed with electron microscopic study, the authors have isolated five atypical ES, which histologically also possessed neuroectodermic traces. These tumors were composed of small round blue cells with rosette-like figures and cytoplasmic glycogen. The immunohistochemical analysis showed positivity for neuron-specific enolase (NSE) as well as for HNK-1 (leu-7) monoclonal antibody. Electron microscopic examination confirmed the tumor cell as being of small round type, with a dense chromatine pattern and the presence of isolated dendritic processes, as well as synaptic-like buttons; intermediate filaments, neurotubuli, and dense-core neurosecretory granules also were seen. Moreover, in two cases basement-like condensations surrounded some cells. Scanning electron microscopic study in one case confirmed the presence of rosette-like figures and cell elongations with short dendritic projections of the cytoplasm. Clinically and radiologically these cases showed features similar to ES of bone; one case, located in the chest wall, had a local relapse after treatment, with the histologic features of a pleomorphic neuroblastoma. The authors conclude that these tumors resemble closely immature neuroepithelioma of soft tissue but, being primary to bone, are superimposable on those described as "neuroectodermal tumors of bone."

Journal ArticleDOI
TL;DR: The results support the idea that regeneration of walls by protoplasts occurs in two steps: firstly, a chitin microfibrillar skeleton is formed, and in a later step glucan-mannoprotein complexes are added to the growing structure.
Abstract: SUMMARY: Incorporation of polysaccharides into the walls of regenerating protoplasts of Candida albicans was followed in the presence of papulacandin B, tunicamycin and nikkomycin. With the first drug, chitin was incorporated normally whereas incorporation of glucans and mannoproteins was significantly decreased. Tunicamycin decreased incorporation of all wall polymers when added at the beginning of the regeneration process but blocked only mannan and alkali-insoluble glucan incorporation when added after 5 h. Nikkomycin inhibited chitin synthesis, and the walls formed by the protoplasts were enriched in alkali-soluble glucan. Pulse-chase experiments suggested that a precursor-product relationship between the alkali-soluble and alkali-insoluble glucans existed in the wall. The results obtained with the antibiotics were confirmed and extended by cytological studies using wheat-germ agglutinin labelled with colloidal gold and concanavalin A-ferritin as specific markers of chitin and mannoproteins respectively. The results support the idea that regeneration of walls by protoplasts occurs in two steps: firstly, a chitin microfibrillar skeleton is formed, and in a later step glucan-mannoprotein complexes are added to the growing structure. The chitin skeleton probably allows the orderly spatial arrangement of the other polymers giving rise to the regenerated cell wall.

Journal ArticleDOI
01 Dec 1987-Polymer
TL;DR: In this paper, the ageing behaviour of polyvinyl chloride was examined using enthalpy relaxation measurements and it was observed that the presence of plasticizer accelerates the ageing process, probably due to the greater mobility of the chains in the plasticized samples.

Journal ArticleDOI
TL;DR: In this paper, different aspects of the etho-ecology of the stray dog population in Valencia (Spain) were investigated and it was suggested that stray dogs possess remarkable behavioral plasticity allowing them to adjust their social system to prevailing ecological constraints.

Journal ArticleDOI
TL;DR: Results of an analysis of five markers of primary liver carcinoma confirmed that in the geographical area from which these tumors proceed, PLC is closely correlated with HBsAg positivity and with cirrhosis.
Abstract: Primary liver carcinoma (PLC) may express a certain number of markers. Here we communicate results of an analysis of five such markers (alpha-1-antitrypsin--AAT--, carcino-embryonic antigen --CEA--, alpha-fetoprotein --AFP--, and superficial --HBsAg-- and core --HBcAg-- antigens of hepatitis B virus) by means of PAP techniques in 130 cases of PLC, comparing the neoplastic tissue and the non-tumorous liver. Three variants of PLC are distinguished: hepatocarcinoma (HC) (108 cases); cholangiocarcinoma (CC) (19 cases); and three cases of hepatocholangiocarcinoma (HCC). AAT was positive in 29 HC, 2 HCC, and negative in all 19 CC. CEA appeared positive in 16 HC, 16 CC and only one HCC. AFP was positive in two HC, and negative in all CC and HCC. HBsAg displayed positivity in 15 HC and one HCC, being negative in all 19 CC. HBcAg was positive in 4 HC, and negative in all CC and HCC. HBsAg was also positive in two neoplastic emboli associated with HC. On the non-tumorous liver tissue the immunohistochemical results showed positivity for AAT and CEA, but not for AFP. Therefore the present results confirm that in the geographical area from which these tumors proceed, PLC is closely correlated with HBsAg positivity and with cirrhosis.

Journal ArticleDOI
TL;DR: Using linear-regression analysis, the area density of Timm-positive bouton profiles as well as the numerical and volume density of stained vesicles were found to be closely correlated with the light-microscopic densitometric values obtained for each Timm -positive cortical zone.
Abstract: In cortical areas of the lizard, Podarcis hispanica, Timm staining reveals a distinct pattern of lamination At the electron-microscope level, virtually all of the reaction product is located in the synaptic vesicles of Timm-positive boutons Using linear-regression analysis, the area density of Timm-positive bouton profiles as well as the numerical and volume density of stained vesicles were found to be closely correlated with the light-microscopic densitometric values obtained for each Timm-positive cortical zone We discuss the possibility of estimating stereological electron-microscopic data parameters from densitometric measurements at the light-microscope level

Journal ArticleDOI
TL;DR: Micrococcal nuclease digestion has been used to investigate some fine details of the chromatin structure of the yeast SUC2 gene for invertase, and a dramatic change occurs in the 3' flank, whose involvement in the structural transitions of chromatin upon gene activation is postulated.
Abstract: Micrococcal nuclease digestion has been used to investigate some fine details of the chromatin structure of the yeast SUC2 gene for invertase. Precisely positioned nucleosomes have been found on a 2 kb sequence from the 3' non-coding region, and four nucleosomes also seem to occupy fixed positions on the 5' flank. Eleven nucleosomes lie on the coding region, although their positioning is not as precise as in the flanks. When the gene is derepressed, these latter nucleosomes adopt a more open conformation and so do two of the nucleosomes positioned on the 5' flank. A dramatic change occurs in the 3' flank, whose involvement in the structural transitions of chromatin upon gene activation is postulated. All the observed features are conserved when the gene is inserted in either a single copy centromeric plasmid or in a multicopy, 2 micron circle-based plasmid.

Journal ArticleDOI
TL;DR: Mannoproteins from cell walls of Saccharomyces cerevisiae synthesized at successive stages of the population growth cycle have been solubilized with Zymolyase and subsequently analyzed and demonstrate the presence of mannoprotein in close contact with the structural glucan molecules throughout the wall.
Abstract: Mannoproteins from cell walls of Saccharomyces cerevisiae synthesized at successive stages of the population growth cycle have been solubilized with Zymolyase and subsequently analyzed. The major change along the population cycle concerned a large size mannoprotein material; the size of the newly-synthesized molecules varied from 120,000–500,000 (mean of about 200,000) at early exponential phase to 250,000–350,000 (mean of about 300,000) at late exponential phase. These differences are due to modifications in the amount of N-glycosidically linked mannose residues, since the size of the peptide moiety was 90,000–100,000 at all growth stages and the level of O-glycosylation changed only slightly. After, incubation of the purified walls with concanavalin A-ferritin and subsequent analysis by electron microscopy, labelling was localized at the external and internal faces of the walls. The middle space of these was labelled after digestion of the glucan network with Zymolyase, which demonstrate the presence of mannoproteins in close contact with the structural glucan molecules throughout the wall.

Journal ArticleDOI
TL;DR: Evaluating the degree of toxicity of various heavy metals (chromium, cadmium and mercury) to freshwater crayfish Procambarus clarkii at various temperatures finds chromium, an essential trace element for humans and animals, is involved in normal carbohydrate metabolism.
Abstract: Chromium, an essential trace element for humans and animals is involved in normal carbohydrate metabolism; however, it is toxic at high concentrations. There is no evidence that cadmium and mercury are biologically essential but their toxicity for organisms is well known. Both cause toxic effects at low concentrations to most organisms, especially in combination with other environmental variables such as temperature. Lake Albufera and the surrounding rice field waters are subjected to very heavy loads of sewage and toxic industrial residues (including heavy metals) from the many urban and waste waters in this area. In 1978, the American red crayfish Procambarus clarkii appeared in lake Albufera and in the surrounding rice fields. Without adequate sanitary control, the crayfish is presently being fished commercially for human consumption. The purpose of the present study is to evaluate the degree of toxicity of various heavy metals (chromium, cadmium and mercury) to freshwater crayfish Procambarus clarkii at various temperatures.


Journal ArticleDOI
TL;DR: A method for identifying carbohydrates (mono-, di- and trisaccharides) in honey is presented, based on the separate preparation of both trimethylsilyl ethers and oxime trimethylfiltration of the sugars followed by their gas chromatographic separation on a fused-silica capillary column coated with OV-101.

Journal ArticleDOI
TL;DR: In this article, a simple and accurate analysis of a single-mode optical fiber interferometric displacement detection technique is presented, and it is shown that angular alignment between the fiber and the sensor is the most critical parameter.
Abstract: A simple and accurate analysis of a single-mode optical fibre interferometric displacement detection technique is resented. This analysis is in good agreement with experimental measurements, and shows that angular alignment between the fibre and the sensor is the most critical parameter.

Journal ArticleDOI
TL;DR: Factors such as concentration of cytokinin (6-benzyladenine) and time and method of exposure (liquid or solid induction medium) strongly influenced bud formation and development and the high content in nitrogen of Murashige & Skoog formulation seems to be deleterious for this in vitro system.
Abstract: Embryos of slash pine (Pinus elliottii Engelm.) were induced to form adventitious buds when placed in culture on nutrient media supplemented with cytokinin. Buds were induced on media containing Risser & White major salts. The high content in nitrogen of Murashige & Skoog formulation seems to be deleterious for this in vitro system, since morphogenic responses were only promoted when nitrogen concentration was drastically reduced in the macronutrient formulation. Factors such as concentration of cytokinin (6-benzyladenine) and time and method of exposure (liquid or solid induction medium) strongly influenced bud formation and development. The greatest number of buds and shoots were obtained from 22.0 μM cytokinin, but these shoots showed less and slower development than those induced with low dosages of cytokinin. The presence of naphthaleneacetic acid in combination with cytokinin in the induction medium decreased the frequency of bud formation.

Journal ArticleDOI
01 Jan 1987
TL;DR: It was shown that lyophilized aqueous extract caused a dose-dependent decreased of the systemic arterial blood pressure and the presence of steroids-triterpenes, catechin tannins, flavonoids, sugars, resins and saponins was found.
Abstract: The present studies were undertaken to confirm the hypotensive effect of Pistacia lentiscus L. in normotensive urethane anaesthetized Wistar rats. It was shown that lyophilized aqueous extract caused a dose-dependent decreased of the systemic arterial blood pressure. Acute toxicity was also determined. Phytochemical analysis revealed the presence of steroids-triterpenes, catechin tannins, flavonoids, sugars, resins and saponins.

Journal ArticleDOI
TL;DR: In this article, the neutrino's smallness of its mass is attributed to the spontaneous breaking of R parity in superstring models with an additional gauge boson coupled to the right-handed neutrinos.

Journal ArticleDOI
TL;DR: The occurrence of retinal pigment epithelium hypertrophy may be considered a genetic ocular marker that provides evidence of patients at risk years before the occurrence of the polyposis of the intestinal tract.


Journal ArticleDOI
TL;DR: The verification of the Triangle Inequality by the DTW-based Dissimilarity Measure utilized seems to be an important prerequisite for these methods to be properly applicable.
Abstract: Recently, some new and promising methods have been proposed to reduce the number of Dynamic Time Warping (DTW) computations in Isolated Word Recognition. For these methods to be properly applicable, the verification of the Triangle Inequality (TI) by the DTW-based Dissimilarity Measure utilized seems to be an important prerequisite.

Journal ArticleDOI
TL;DR: In this article, the effects of surfactant polysorbate 80 in colonic absorption of 4-alkylanilines are extended to the absorption of the same compounds in the rat small intestine, where compound behavior seems to be complicated by the existence of a pore diffusion pathway simultaneous with membrane absorption.

Journal ArticleDOI
TL;DR: In this paper, a method for obtaining Formal Group Laws from the structure constants of Affine Kac-Moody groups and then applying a group manifold quantization procedure which permits construction of physical representations by using only canonical structures on the group.
Abstract: We describe a method for obtaining Formal Group Laws from the structure constants of Affine Kac-Moody groups and then apply a group manifold quantization procedure which permits construction of physical representations by using only canonical structures on the group. As an intermediate step we get an explicit expression for two-cocycles on Loop Groups. The programme is applied to the AffineSU(2) group.