Showing papers by "University of Valencia published in 1994"
TL;DR: The conceptual model underlying the empirical tests is based on economic and political incentives for providing greater detail in corporate annual reports and accounts as discussed by the authors, which provides evidence that the amount of detail in Spanish corporate annual report and accounts is increasing in firm size and stock exchange listing, and decreasing in liquidity.
Abstract: Not much information exists in the international accounting literature on Spanish accounting. Spain is selected as a subject of study because it is different from those countries that are subjects of the research concerned with investigating the multivariate impact of firm characteristics on disclosure in annual reports and accounts. The conceptual model underlying our empirical tests is based on economic and political incentives for providing greater detail in corporate annual reports and accounts. The paper provides evidence that the amount of detail in Spanish corporate annual reports and accounts is increasing in firm size and stock exchange listing, and decreasing in liquidity.
877 citations
TL;DR: The new algorithm for computing the Solvent‐Excluding Surface included in the GEPOL93 program is described and is controlled by three parameters: the number of triangles per sphere, controlled by NDIV; the maximum overlap among the new spheres (OFAC); and the size of the smallest sphere that can be created (RMIN).
Abstract: To understand and calculate the interactions of a solute with a solvent, a good method of computing the molecular surface is needed. Three kinds of surfaces may be used: the van der Waals Surface, the Accessible Surface, and the Molecular Surface. The latter is redefined in this article as the Solvent-Excluding Surface. The new algorithm for computing the Solvent-Excluding Surface included in the GEPOL93 program is described. GEPOL93 follows the same concept as former versions of GEPOL but with a full new algorithm. Thus, it computes the Solvent-Excluding Surface by filling the spaces not accessible to the solvent with a set of new spheres. The computation is controlled by three parameters: the number of triangles per sphere, controlled by NDIV; the maximum overlap among the new spheres (OFAC); and the size of the smallest sphere that can be created (RMIN). The changes introduced for the computation of the ESURF make GEPOL93 not just a new version but a new program. An estimation is made of the error in the area and volume obtained in the function of the parameters. © 1994 by John Wiley & Sons, Inc.
753 citations
Purdue University1, University of Granada2, Simón Bolívar University3, University of Valencia4, University of Murcia5, Autonomous University of Madrid6, Technical University of Madrid7, University of Nottingham8, University of Basel9, University of Rouen10, University College London11, Sapienza University of Rome12, University of Cincinnati13
TL;DR: An overview of the subject of robust Bayesian analysis is provided, one that is accessible to statisticians outside the field, and recent developments in the area are reviewed.
Abstract: Robust Bayesian analysis is the study of the sensitivity of Bayesian answers to uncertain inputs. This paper seeks to provide an overview of the subject, one that is accessible to statisticians outside the field. Recent developments in the area are also reviewed, though with very uneven emphasis.
587 citations
TL;DR: In this paper, the authors compared the performance of the (l, r) search algorithm with the genetic approach to feature subset search in high-dimensional spaces and found that the properties inferred for these techniques from medium scale experiments involving up to a few tens of dimensions extend to dimensionalities of one order of magnitude higher.
Abstract: The combinatorial search problem arising in feature selection in high dimensional spaces is considered. Recently developed techniques based on the classical sequential methods and the (l, r) search called Floating search algorithms are compared against the Genetic approach to feature subset search. Both approaches have been designed with the view to give a good compromise between efficiency and effectiveness for large problems. The purpose of this paper is to investigate the applicability of these techniques to high dimensional problems of feature selection. The aim is to establish whether the properties inferred for these techniques from medium scale experiments involving up to a few tens of dimensions extend to dimensionalities of one order of magnitude higher. Further, relative merits of these techniques vis-a-vis such high dimensional problems are explored and the possibility of exploiting the best aspects of these methods to create a composite feature selection procedure with superior properties is considered.
252 citations
TL;DR: Rolliniastatin-2 shows unique properties as its interaction, although mutually exclusive to that of piericidin, appears to be mutually non-exclusive toThat of rotenone, the first time that a potent inhibitor of Complex I is found not to overlap the active site of rotonone.
Abstract: Natural products from the plants of the family Annonaceae, collectively called Annonaceous acetogenins, are very potent inhibitors of the NADH-ubiquinone reductase (Complex I) activity of mammalian mitochondria. The properties of five of such acetogenins are compared with those of rotenone and piericidin, classical potent inhibitors of Complex I. Rolliniastatin-1 and rolliniastatin-2 are more powerful than piericidin in terms of both their inhibitory constant and the protein-dependence of their titre in bovine submitochondrial particles. These acetogenins could be considered therefore the most potent inhibitors of mammalian Complex I. Squamocin and otivarin also have an inhibitory constant lower than that of piericidin, but display a larger protein-dependence of the titre. Squamocin and otivarin, contrary to the other acetogenins, behave qualitatively like rotenone. Rolliniastatin-2 shows unique properties as its interaction, although mutually exclusive to that of piericidin, appears to be mutually non-exclusive to that of rotenone. It is the first time that a potent inhibitor of Complex I is found not to overlap the active site of rotenone.
232 citations
TL;DR: In this paper, a split-window equation for land surface temperature is derived, yielding T = T4 + A(T4 − T5) + B(e), where T is the true surface temperature, T4 and T5 are the brightness temperatures measured in AVHRR channels 4 and 5.
Abstract: A split-window equation is derived for land surface temperature, yielding T = T4 + A(T4 − T5) + B(e), where T is the true surface temperature, T4 and T5 are the brightness temperatures measured in AVHRR channels 4 and 5, A is a coefficient related to the atmospheric transmittances in AVHRR channels 4 and 5, being dependent on the atmosphere type and independent on surface emissivity, and B(e) takes into account the emissivity effect, which depends on both the channel surface emissivities (e4 and e5) and the atmosphere type. The atmospheric dependence of split-window coefficients, A and B(e), is discussed by means of satellite measurements simulations and in situ data. It is shown that linear, global-scale algorithms can produce inaccurate estimates of surface temperature when they are applied to areas of reduced atmospheric variability. A simple, non-linear split-window algorithm has been proposed, in which A = a0+ a1(T4− T5). The constants a0and a1 have been calculated from a set of in situ and ...
214 citations
TL;DR: The non-linear dynamics of cosmological perturbations of an irro- tational collisionless fluid is analyzed within General Relativity and the dynamical role of the magnetic part of the Weyl tensor is elucidated.
Abstract: The nonlinear dynamics of cosmological perturbations of an irrotational collisionless fluid is analyzed within general relativity. Relativistic and Newtonian solutions are compared, stressing the different role of boundary conditions in the two theories. Cosmological implications of relativistic effects, already present at second order in perturbation theory, are studied and the dynamical role of the magnetic part of the Weyl tensor is elucidated.
183 citations
TL;DR: The results allowed us to establish the relationship between the structure and anti-inflammatory activity on the basis of the different patterns of substitution, particularly hydroxylation, unsaturation, and acylation.
Abstract: Twelve iridoid glycosides have been evaluated for their anti-inflammatory activity on two models: the carrageenan-induced mouse paw edema and the TPA-induced mouse ear edema. Loganic acid was the most active (44.4% edema inhibition) on the former test, whereas the catalpol derivative mixture isolated from Scrophularia, aucubin, verbenalin, and loganin, showed the highest activity (from 72.0 to 80.0% edema inhibition) on the latter. The results allowed us to establish the relationship between the structure and anti-inflammatory activity on the basis of the different patterns of substitution, particularly hydroxylation, unsaturation, and acylation.
177 citations
TL;DR: In this paper, the effects of heavy metal treatment on rice plants were investigated and it was shown that heavy metal treatments not only interfered with nutrient uptake but also with nutrient distribution into the different plant parts.
Abstract: Rice plants accumulate high quantities of Cd and Ni when grown for 10 days in a medium containing these heavy metals. Accompanying Cd and Ni uptake, a decrease in shoot and root length was observed, though dry matter accumulation was not affected accordingly. Metal treatments also induced a decrease in K, Ca and Mg contents in the plants, particularly in the shoots, indicating that Cd and Ni interfered not only with nutrient uptake but also with nutrient distribution into the different plant parts. Addition of abscisic acid (ABA) or gibberellic acid (GA3) to the external solution could not overcome the depressing effects of the metals on nutrient acquisition, and even induced a further decrease of Ca content in Ni-treated plants. Both hormones also reduced, significantly, heavy metal incorporation into the plants. Additionally, hormonal applications affected the transport of Cd and Ni to the shoots, resulting in a higher percentage of the metals taken up remaining in the roots.
164 citations
TL;DR: RTMS may be useful as a non-invasive tool for the study of verbal memory processes and was consistently significantly diminished only after left mid-temporal and bilateral dorsofrontal rTMS at both 0 and 250 ms latencies.
Abstract: WE used rapid-rate, repetitive transcranial magnetic stimulation (rTMS) for the noninvasive study of verbal recall. Five right-handed normal subjects were studied. Recall followed immediately after presentation of a 12-word list. Focal rTMS was applied with a figure eight coil in trains of 500 ms duration to F7, F8, T5, T6, P3, P4, or 01, 02 at latencies of 0, 250, 500, or 1000 ms during word list presentation. Recall was consistently significantly diminished only after left mid-temporal and bilateral dorsofrontal rTMS at both 0 and 250 ms latencies. We conclude that rTMS may be useful as a non-invasive tool for the study of verbal memory processes.
133 citations
12 Jan 1994
TL;DR: In this article, an analysis of recent science teacher education research is offered, which answers the major question: What does research tell us about the recent trends in teacher preparation? We are beginning to understand that in the in-service or pre-service training is very important to know the effects of limited content knowledge, the "commonsense" beliefs, behaviors and attitudes about different aspects of science teaching; the need of integration knowledge practice in programs of teacher education and that; the obstacles to didactic knowledge acquisition alone will be overcome when the teachers are placed in a situation wt
Abstract: In the last few years, there has been a significant growth of interest in science teacher education. An analysis of recent science teacher education research is offered in this paper. This study answers the major question: What does research tell us about the recent trends in teacher preparation? We are beginning to understand that in the in-service or pre-service training is it very important to know the effects of: a) a limited content knowledge, b) the «commonsense» conceptions, behaviors and attitudes about different aspects of science teaching; c) the need of integration «knowledge -practice» in programs of teacher education and that; d) theses obstacles to didactic knowledge adquisition alone will be overcome when the teachers are placed in a situation wt ich explicitly demands a collective reflection through the research.
TL;DR: In this article, the effects induced by new neutral fetmions below their mass threshold, due to their possible mixing with the standard neutrinos, were studied. But the experimental constraints on lepton universality and the measurement of the,X decay rate were not considered.
TL;DR: Charcoal analysis reveals various palaeo-ecological phases from the Neolithic to the Bronze Age as discussed by the authors, showing that pine wood or scrub reached its maximum during the Bell Beaker phase and Bronze Age in the Cova de les Cendres.
Abstract: Charcoal analysis reveals various palaeo-ecological phases from the Neolithic to the Bronze Age. Agriculture starts about 7000 B.P. in favourable ecological conditions. Most of the charcoal spectra from sites on the coast represent thermomediterranean holm-oak forest; those from the inland mountains represent mesome-diterranean holm-oak forest. The Neolithic I Impressed Ware people were the first to clear the forest to plant their crops. This clearance of primary woodland resulted in the development of secondary vegetation of pine woods or scrub. The scrub reached its maximum during the Bell Beaker phase and Bronze Age in the Cova de les Cendres. In the Neolithic II open air sites, the percentages of Quercus ilex/coccifera remain high. This may be the result of a different exploitation of the land, or suitable conditions for the growth and survival of the vegetation.
TL;DR: Using mitochondrial DNA restriction endonuclease analysis, the dynamics of the natural Saccharomyces cerevisiae strains present in spontaneous wine fermentations have been studied and a sequential substitution of Sacch.
TL;DR: ABPM is feasible in children, the values obtained are useful as a departure point in establishing reference values, and a significant positive correlation was observed between casual blood pressure and 24-h ambulatory blood pressure.
Abstract: OBJECTIVE To assess reference values of ambulatory blood pressure in normotensive children. SUBJECTS AND DESIGN Twenty-four-hour non-invasive ambulatory blood pressure monitoring (ABPM) was carried out in 241 healthy normotensive children aged from 6 to 16 years (126 boys, mean +/- SD age 11.2 +/- 2.7 years; 115 girls, mean +/- SD age 10.9 +/- 2.9 years). The subjects were subdivided into three age-sex groups: 6-9, 10-12 and 13-16 years. SETTING Primary care. MAIN OUTCOME MEASURES ABPM was performed using an oscillometric device (SpaceLabs model 90207) and appropriate cuff size during a regular school day. Blood pressure was measured every 20 min from 0600 to 2400 h, and thereafter every 30 min. At each monitoring session the following parameters were calculated for both systolic (SBP) and diastolic blood pressure (DBP): means and centiles for 24-h, daytime (0800-2200 h) and night-time (2400-0600 h); circadian variability, estimated as the blood pressure fall between the day and the night periods and the day: night ratio; and load, as the percentage of measurements above the age- and sex-specific 95th centile (P95). RESULTS The upper limits of 'normality' for the mean of 24-h SBP and DBP estimated as the P95 in each age subgroup were 121/71 and 119/71 mmHg, 123/78 and 120/74 mmHg, and 124/78 and 125/75 mmHg, for boys and girls, respectively. A progressive increase in SBP with age was observed in both sexes, in contrast, DBP was similar throughout the age range. A nocturnal blood pressure fall of approximately 11 mmHg was observed for both SBP and DBP in all subgroups. The day:night ratio was 1.12 and 1.22 for SBP and DBP, respectively. The upper limit of blood pressure load, estimated as the P95 in all children, was 39% for SBP and 26% for DBP. A significant positive correlation was observed between casual blood pressure and 24-h ambulatory blood pressure (SBP: r = 0.61, P < 0.0001; DBP: r = 0.31, P < 0.0001). In general, mean ambulatory blood pressure, during the 24-h or the daytime period, was higher than casual blood pressure for both SBP and DBP. CONCLUSION ABPM is feasible in children, and the values obtained are useful as a departure point in establishing reference values.
TL;DR: A strong association was found between mental adjustment to cancer and reported vague physical symptomatology at the first assessment and ‘Helpless/hopeless’, ‘Anxious preoccupation’ and ’Fatalism’ responses were negatively correlated with well‐being.
Abstract: This study explores the relationship between adjustment to cancer and quality of life in a sample of 68 newly diagnosed non-metastatic breast cancer patients. Responses were assessed on three occasions following communication of the diagnosis and included the Mental Adjustment to Cancer (MAC) scale, a measure of denial and a Spanish quality of life questionnaire for breast cancer patients. Appropriate medical variables were considered and included in the analysis. MAC subscales showed adequate internal consistency; nevertheless, there was overlap between subscales and a second order factorial analysis suggested that two dimensions (‘perceived threat’ and ‘perceived control’) suffice to describe mental adjustment to cancer. A strong association was found between mental adjustment to cancer and reported vague physical symptomatology at the first assessment. Older patients showed higher ‘Denial’ scores and lower scores for ‘Anxious preoccupation’. ‘Fighting spirit’ and ‘Denial’ were associated with better present and future quality of life; ‘Helpless/hopeless’, ‘Anxious preoccupation’ and ‘Fatalism’ responses were negatively correlated with well-being. These results are discussed from a theoretical point of view.
TL;DR: In this article, the distribution of stock returns is examined in six stock markets and the empirical distributions present common features and are best represented by Student's t-distribution, while several alternative distributions are rejected.
Abstract: Although financial theory rests heavily on the normality assumption, daily stock returns display significant departures from normality. Different researchers have proposed alternative distributions. In this paper, the distribution of stock returns is examined in six stock markets. The empirical distributions present common features and are best represented by Student's t-distribution, while several alternative distributions are rejected.
TL;DR: The facial structure of this unbounded full-dimensional polyhedron is tried to characterize and sets of valid inequalities inducing facets have been studied as well as their use in a cutting-plane algorithm.
TL;DR: Several strains of the four sibling species of the genus Saccharomyces were characterized by using a rapid and simple method of restriction analysis of mitochondrial DNA to assign these strains to a known taxon by means of electrophoretic karyotyping.
Abstract: Several strains of the four sibling species of the genus Saccharomyces (S. bayanus, S. cerevisiae, S. paradoxus, and S. pastorianus) were characterized by using a rapid and simple method of restriction analysis of mitochondrial DNA. Patterns obtained with four-cutter endonucleases (such as AluI, DdeI, HinfI, and RsaI) made it possible to differentiate each species. S. cerevisiae and S. paradoxus presented a greater number of large fragments than S. pastorianus and S. bayanus with all the assay enzymes. With AluI and DdeI, species-specific bands clearly permitted differentiation between S. pastorianus and S. bayanus. To test the resolution of this method, wild Saccharomyces strains were analyzed. The correct assignment of these strains to a known taxon by this rapid method was confirmed by means of electrophoretic karyotyping.
TL;DR: In this article, six flavonoid derivatives were tested for their influence on Naja naja and human recombinant synovial phospholipase A2, and they showed a selectivity for the last enzyme with IC50 = 14.3, 17.6, 12.2 and 28.2 microM.
01 Feb 1994
TL;DR: In this article, a multiconfigurational second-order perturbation theory (CASPT2) was applied to the singlet and triplet excited states of naphthalene.
Abstract: Ab initio calculations have been carried out for the singlet and triplet excited states of naphthalene. Excitation energies have been calculated using multiconfigurational second order perturbation theory (CASPT2). The study comprises a total of 32 states, ten singlet and ten triplet excited states, in addition to the 1au→3s, 3p, dipole-allowed 3d, and 2b1u→3s, 3p Rydberg states. Computed excitation energies and oscillator strengths make possible confident assignments of the main features reported in the singlet-singlet and triplet-triplet experimental spectra.
TL;DR: The psychological functioning of child victims is studied, particularly in their emotional and cognitive adjustment, in terms of the learned helplessness' model proposed and developed by Seligman, Kaslow, Alloy, Peterson, Tanenbaum, and Abramson (1984).
TL;DR: Compliance to distinct combinations of hormone replacement therapy was assessed in 331 postmenopausal women treated for 1 to 5 years in the Menopause Unit of a third level referral Academic Hospital.
TL;DR: Daphnia magna was exposed to sublethal levels (1/4, 1/2, and 2/3 LC50 and LC50) of endosulfan and diazinon to determine the effect of these pesticides on filtration and ingestion rates.
12 Aug 1994
TL;DR: In this paper, the main features of the electronic spectrum of free base porphin are determined by means of multiconfigurational second-order perturbation (CASPT2) theory.
Abstract: The main features of the electronic spectrum of free base porphin are determined by means of multiconfigurational second-order perturbation (CASPT2) theory. The calculations comprise the optically allowed singlet states associated to the Q and B bands and the corresponding triplet states. The computed excitation energies deviate from the available experimental data by less than 0.3 eV in all the cases where a comparison is possible. It is found that both σ- and π-electron correlation contributions have to be taken into account in order to give a balanced description of the excited states. A limited theoretical treatment, based on only β-electron correlation or only partially including the correlation of the σ electrons, is not sufficient.
TL;DR: The virulence mechanisms of Vibrio vulnificus biotype 2 have been studied and compared with those of biotype 1 in mice as the experimental animals and the implication of biotypes 2 strains in human infections is discussed.
Abstract: The virulence mechanisms of Vibrio vulnificus biotype 2 have been studied and compared with those of biotype 1 in mice as the experimental animals. Biotype 2 isolates from European eels were as virulent for mice as biotype 1 strains (50% lethal dose, about 10(5) CFU per mouse); a septicemic infection developed in less than 24 h. These strains had several properties in common with biotype 1 organisms including capsule expression, uptake of various iron sources, and production of exoproteins, whose role in mouse virulence has been demonstrated. We also discuss the implication of biotype 2 strains in human infections.
TL;DR: Amentoflavone, quercetagetin- 7-O -glucoside, apigenin, fisetin, kaem pferol, luteolin and Quercetin were the most potent inhibitors of β-glucuronidase and lysozyme release and a correlation between degranulation and arachidonic acid release was found for this series of compounds.
Abstract: We assessed the effects of 24 flavonoid derivatives, reported as anti-inflammatory, on lysosomal enzyme secretion and arachidonic acid release in rat neutrophils Amentoflavone, quercetagetin-7-O-glucoside, apigenin, fisetin, kaempferol, luteolin and quercetin were the most potent inhibitors of beta-glucuronidase and lysozyme release The first compound was also able to inhibit basal release These flavonoids besides chrysin and to a reduced extent, naringenin, significantly inhibited arachidonic acid release from membranes A correlation between degranulation and arachidonic acid release was found for this series of compounds Structure-activity relationships and implications for the anti-inflammatory effects of these flavonoids were discussed
TL;DR: A rapid kinetic assay of MMP in isolated rat hepatocytes is described, based upon the quantitation of the initial rate of Rh123 uptake by living cells, selected by their scattering properties, which indicates that at an appropriate dye-to-cell ratio, the initial rates are a highly reproducible and sensitive parameter for estimation of M MP.
Abstract: Rhodamine 123 (Rh123) is widely used as a flow cytometric probe for mitochondrial membrane potential (MMP) in metabolic, pharmacologic, and toxicological studies. However, the use of relatively high concentrations of Rh123 (up to 10 micrograms/ml) and prolonged incubation times (up to 1 h), including washing steps, may be inconvenient for certain applications in which labile cells are used or which demand rapid or repeated analysis. In this paper we describe a rapid kinetic assay of MMP in isolated rat hepatocytes, based upon the quantitation of the initial rate of Rh123 uptake by living cells, selected by their scattering properties. The results indicate that at an appropriate dye-to-cell ratio (in our experiments, 50 ng Rh123/ml for 250,000-300,000 cells/ml), the initial rate of Rh123 uptake is a highly reproducible and sensitive parameter for estimation of MMP, as demonstrated by the effects of substrates and inhibitors of the glycolytic pathway and mitochondrial respiration. Because of its simplicity, rapidity (about 5 min) and metabolic implications, this assay would be also suitable for the routine evaluation of metabolic state of cell suspensions, as a complementary test to the standard dual-staining tests of viability. Other possible applications in screening pharmacologic and toxicological analysis are discussed.
TL;DR: A dysfunction in mitochondrial oxidative phosphorylation in brain aging is suggested by a significant decrease in complexes IV and V in old as compared with adult mice.