Showing papers by "University of Almería published in 2004"
TL;DR: In this article, the synthesis and structural properties of PTA and derivatives, their transition metal complexes, catalytic, medicinal and photoluminescence uses are reviewed and compared.
370 citations
TL;DR: The population dynamics of the yeasts during spontaneous fermentation of six varieties of grape must from the “Valle del Andarax” area (Spain) are analyzed and Saccharomyces cerevisiae and Candida stellata were able to consume virtually all the initial glucose, producing ethanol contents typical of table wines.
243 citations
TL;DR: The authors compared specific acceptance-based strategies and cognitive-controlbased strategies for coping with experimentally induced pain and found that ACT participants showed significantly higher tolerance to pain and lower believability of experienced pain compared to the CONT condition.
233 citations
TL;DR: In this paper, the authors defined the environmental strategies of 268 Spanish hotels, based on their environmental protection activities and the use of these as an argument for competition, and observed the difference between each of these environmental strategies as regards certain contextual variables and performance.
Abstract: This article is a study of the environmental strategies adopted in the service industry and their impact on a firm's performance. More specifically, we define the environmental strategies of 268 Spanish hotels, based on their environmental protection activities and the use of these as an argument for competition. They have been categorised into four groups. We observed the difference between each of these environmental strategies as regards certain contextual variables and performance. Our findings suggest that firms in the groups with more developed environmental strategies are associated with a higher level of environmental performance but not necessarily with economic performance.
224 citations
TL;DR: C. ligniaria C8 (NRRL 30616) was effective at eliminating furfural and 5-HMF from CSH, and may be useful in developing a bioprocess for inhibitor abatement in the conversion of lignocellulosic biomass to fuels and chemicals.
Abstract: Acid pretreatment of lignocellulosic biomass releases furan and phenolic compounds, which are toxic to microorganisms used for subsequent fermentation. In this study, we isolated new microorganisms for depletion of inhibitors in lignocellulosic acid hydrolysates. A sequential enrichment strategy was used to isolate microorganisms from soil. Selection was carried out in a defined mineral medium containing a mixture of ferulic acid (5 mM), 5-hydroxymethylfurfural (5-HMF, 15 mM), and furfural (20 mM) as the carbon and energy sources, followed by an additional transfer into a corn stover hydrolysate (CSH) prepared using dilute acid. Subsequently, based on stable growth on these substrates, six isolates--including five bacteria related to Methylobacterium extorquens, Pseudomonas sp, Flavobacterium indologenes, Acinetobacter sp., Arthrobacter aurescens, and one fungus, Coniochaeta ligniaria--were chosen. All six isolates depleted toxic compounds from defined medium, but only C. ligniaria C8 (NRRL 30616) was effective at eliminating furfural and 5-HMF from CSH. C. ligniaria NRRL 30616 may be useful in developing a bioprocess for inhibitor abatement in the conversion of lignocellulosic biomass to fuels and chemicals.
220 citations
TL;DR: An attempt to identify the hydrogeochemical processes that accompany current or past intrusion of seawater in the Castell de Ferro coastal aquifer (SE Spain) was made using ionic deltas, ionic ratios and saturation indices as mentioned in this paper.
216 citations
TL;DR: The role of lichen crusts in soil water conservation has been demonstrated even when the properties of the soil beneath do not favor water storage as mentioned in this paper, and the influence of rainfall partitioning on soil moisture patterns has been found below intershrub (open) areas and below shrubs.
213 citations
TL;DR: A photodegradation study of triclosan, a commonly used antimicrobial agent, was carried out in order to investigate the formation of dibenzodichlorodioxin as a byproduct of photodegrad in various environmental matrices and under different conditions.
205 citations
Journal Article•
TL;DR: In this article, the authors discuss the stress derived from the context of caregiving and stress related to life and death situations, and how to cope with this stress in their work.
184 citations
TL;DR: A wide class of bivariate copulas depending on two univariate functions which generalizes many known families of copulas is studied, which exhibit several properties concerning symmetry, dependence concepts, and concordance ordering.
165 citations
TL;DR: The object of this study was to assess the change towards a biopsychosocial health concept among medical researchers in the last two decades, after the explicit criticism of the biomedical model in the late 1970s because of its somatic reductionism.
TL;DR: Combined effect in wastewater showed synergistic toxic effects at low concentration level (2 microg/l) and individual and combined effects on Daphnia magna were evaluated for both therapeutic groups.
TL;DR: The results showed that P. cruentum and Ph. tricornutum biomass had comparable functional properties to those of soybean flour, due to the high percentage of exopolysaccharides that the microalgal biomass shows.
TL;DR: The Bayesian framework for ANN, named as automatic relevance determination method (ARD), was employed to obtain the relative relevance of a large set of atmospheric and radiometric variables used for estimating hourly direct solar irradiance, proving the reliability of the ARD method.
TL;DR: Two GC-MS methods, based on the application of N,O-bis(trimethylsilyl)trifluoroacetamide-derivatization-GC-MS (selected-ion monitoring) and GC- MS-MS without derivatization, respectively, were optimised and applied to the determination of a group of five selected endocrine disrupting compounds (EDCs) in wastewaters.
TL;DR: In this article, the authors used cluster and principal component analysis to divide Spain in a limited number of climatically homogeneous zones, based on seasonal rainfall for 32 Spanish localities for the period 1912-2000.
Abstract: . In this work, cluster and principal component analysis are used to divide Spain in a limited number of climatically homogeneous zones, based on seasonal rainfall for 32 Spanish localities for the period 1912–2000. Using the hierarchical technique of clustering Ward's method, three clusters have been obtained in winter and spring, and four clusters have been obtained in summer and autumn. Results are similar to those obtained by applying principal component analysis. Centroid series of each cluster and principal component series of each EOF have been compared to analyze the temporal patterns. The comparison of both methods indicates that cluster analysis is suitable to establish spatio-temporal patterns of seasonal rainfall distribution in Spain. Key words. Meteorology and atmospheric dynamics (climatology; precipitation; general or miscellaneous)
TL;DR: In this article, the relationship between the spatial distribution of ground cover and terrain attributes was examined in the Tabernas badlands (SE Spain) in order to understand the terrain-dependent driving forces of the spatially heterogeneous ground cover.
Abstract: The relationships between the spatial distribution of ground-cover and terrain attributes were examined in the Tabernas badlands (SE Spain) in order to understand the terrain-dependent driving forces of the spatially heterogeneous ground cover. Ground cover was mapped in the field and terrain attributes were derived from a 1-m resolution Digital Elevation Model (DEM). The association of spatial distribution of the landforms resulting from a regionalisation (using a nonhierarchical classification of the topographic overlays) and the ground-cover pattern was proved. From the analysis of relationships between terrain attributes and proportional abundance of ground-cover types, it was found that ground cover is arranged along topographic gradients: plant-covered surfaces are more abundant on low slope angles, concave slopes, relatively large contributing areas and with low length slope factor values. Unvegetated surfaces show contrary trends and lichens are associated with intermediate conditions. Relationships with local terrain attributes, such as slope angle or elevation, are more pronounced than those with terrain attributes related to sediment and water transfer, such as contributing area, wetness index or length slope factor which could be explained by the heterogeneity of runoff that is usually shorter than the hillslope length. The relationships established between the spatial distribution of ground-cover types and terrain attributes provide the basis for future development of a tool for mapping spatial distribution of ground cover in similar areas from only topographic information.
TL;DR: A simplified and automatic heliostat positioning offset correction control system using artificial vision techniques and common CCD devices and basic threshold-based image processing techniques are used for automatic correction.
TL;DR: The results show that the soil concentration of these heavy metals is lower than mentioned in the European and Spanish normative, but they are higher than those reported by other authors working on agricultural soils.
TL;DR: Analysis of dynamic heterogeneities in a colloidal fluid close to gelation shows that the environment of the fast particles relaxes much faster than that of the slow ones, but at short times the bonds between fast particles are longer lived due to the flexibility of their structure.
Abstract: Dynamical heterogeneities in a colloidal fluid close to gelation are studied by means of computer simulations. A clear distinction between some fast particles and the rest, slow ones, is observed yielding a picture of the gel composed of two populations with different mobilities. Analyzing the statics and dynamics of both sets of particles, it is shown that the slow particles form a network of stuck particles, whereas the fast ones are able to move over long distances. Correlation functions show that the environment of the fast particles relaxes much faster than that of the slow ones, but at short times the bonds between fast particles are longer lived due to the flexibility of their structure. No stringlike motion is observed for the fast particles, but they occupy preferential sites in the surface of the structure formed by the slow ones.
TL;DR: In this paper, the effect of wind speed on the natural ventilation of an Almeria-type greenhouse is analyzed by means of computational fluid dynamics (CFD), using the commercial program ANSYS/FLOTRAN v6.1 based on the finite elements method.
TL;DR: In this paper, the mixing behavior of three geometrically equivalent 0.06 m3 bubble column and air-lift photobioreactors was compared for use in microalgal culture.
Abstract: Mixing behavior of three geometrically equivalent 0.06 m3 bubble column and airlift photobioreactors was compared for use in microalgal culture. Mixing was characterized in terms of the axial dispersion coefficient, mixing time, circulation time and Bodenstein number. Measurements were reported in tap water and sea water, as used in growing microalgal biomass. Compared with the two airlift reactors (a split-cylinder and a draft-tube sparged device, both of aspect ratio 9.1), the bubble column (aspect ratio = 9.1) had a shorter mixing time at any aeration rate (superficial aeration velocity of up to 0.05 m s−1 in all reactors). Values of the various mixing parameters in the two fluids were quite comparable at identical aeration rates in any specific geometry of the reactors. Existing correlations of mixing times satisfactorily correlated the data in the bubble column, but not in the airlift reactors. The following correlations were established for the airlift devices: B o LG = β ( F r 1 / 3 ) λ B o = k t m t c where Bo is the liquid-phase Bodenstein number, Fr is the Froude number, BoLG is the Bodenstein number based on the superficial velocity of the gas, tm is the mixing time, tc is the circulation time, and k, β and γ are constants that depend on the geometry of the reactor and the fluid used.
TL;DR: It is proposed that the main advantage provided by production of staminate flowers in olive is to enhance male fitness by increasing pollen output at the whole plant level, although a relict function of attracting pollinators cannot be completely discarded.
TL;DR: In this article, a branch-and-bound on-off model-based predictive control (MPC) strategy is proposed to control pH and minimise CO2 losses in a microalgal tubular photobioreactor.
TL;DR: The phenotype of the sft fa double mutants indicates that SFT and FA participate in two parallel pathways that regulate the switch from vegetative to reproductive phase in tomato, and that both genes are indispensable for flowering.
Abstract: The characterisation of the single flower truss (sft) mutant phenotype of tomato (Lycopersicon esculentum Mill.), as well as its genetic interactions with other mutations affecting FALSIFLORA (FA) and SELF PRUNING (SP) genes, has revealed that SFT is a key gene in the control of floral transition and floral meristem identity. The single sft mutation produces a late-flowering phenotype in both long-day and short-day conditions. In combination with fa, a mutation affecting the tomato gene orthologous to LFY, sft completely blocks the transition to flowering in this species. Thus, the phenotype of the sft fa double mutants indicates that SFT and FA participate in two parallel pathways that regulate the switch from vegetative to reproductive phase in tomato, and that both genes are indispensable for flowering. On the other hand, the replacement of flowers by vegetative shoots observed in the sft inflorescence suggests that SFT regulates flower meristem identity during inflorescence development of tomato. In addition to these two main functions, SFT is involved in the development of both flowers and sympodial shoots of tomato. First, the mutation produces a partial conversion of sepals into leaves in the first floral whorl, and a reduction in the number of floral organs, particularly carpels. Secondly, the sympodial development in the mutant plants is altered, which can be related to the interaction between SFT and SP, a gene controlling the number of nodes in sympodial shoots. In fact, we have found that the sft phenotype is epistatic to that of sp, and that the level of SP mRNA in the apical buds of sft around flowering is reduced. SFT can therefore co-ordinate the regulation of two simultaneous developmental processes in the tomato apical shoot, the promotion of flowering in one sympodial segment and the vegetative development of the next segment.
TL;DR: The predictions of the mode-coupling theory of the glass transition (MCT) for the tagged-particle density-correlation functions and the mean-squared displacement curves are compared quantitatively and in detail to results from Newtonian- and Brownian-dynamics simulations of a polydisperse quasi-hard-sphere system close to the glass Transition.
Abstract: The predictions of the mode-coupling theory of the glass transition (MCT) for the tagged-particle density-correlation functions and the mean-squared displacement curves are compared quantitatively and in detail to results from Newtonian- and Brownian-dynamics simulations of a polydisperse quasi-hard-sphere system close to the glass transition. After correcting for a 17% error in the dynamical length scale and for a smaller error in the transition density, good agreement is found over a wide range of wave numbers and up to five orders of magnitude in time. Deviations are found at the highest densities studied, and for small wave vectors and the mean-squared displacement. Possible error sources not related to MCT are discussed in detail, thereby identifying more clearly the issues arising from the MCT approximation itself. The range of applicability of MCT for the different types of short-time dynamics is established through asymptotic analyses of the relaxation curves, examining the wave-number and density-dependent characteristic parameters. Approximations made in the description of the equilibrium static structure are shown to have a remarkable effect on the predicted numerical value for the glass-transition density. Effects of small polydispersity are also investigated, and shown to be negligible.
TL;DR: The authors proposed the Shannon residual entropy as a dynamic measure of uncertainty and used it to define a stochastic order and two classes of distributions, DURL and IURL, and obtained new results on this function and corrected some mistakes in preceding literature.
Abstract: Ebrahimi and Pellerey (1995) and Ebrahimi (1996) proposed the Shannon residual entropy function as a useful dynamic measure of uncertainty. They studied the characterization problem from the residual entropy. They also used this function to define a stochastic order and two classes of distributions, DURL and IURL. In this paper, we obtain some new results on this function and we correct some mistakes in the preceding literature.
TL;DR: Copulas and quasi-copulas are employed to find similar best-possible bounds on arbitrary sets of bivariate distribution functions with given margins when the values of H are known at quartiles of X and Y.
TL;DR: A new analytical method was developed using liquid chromatography with tandem mass spectrometry for the routine analysis of 31 multi-class pesticide residues and applied to approximately 50 fresh fruit and vegetable samples.
01 Apr 2004
TL;DR: A pruning heuristic and two updating strategies for minimizing the pruning distance are proposed and used in the design of three non-incremental branch-and-bound algorithms for K-CPQ between spatial objects stored in two R-trees.
Abstract: This paper addresses the problem of finding the K closest pairs between two spatial datasets (the so-called, K closest pairs query, K-CPQ), where each dataset is stored in an R-tree. There are two different techniques for solving this kind of distance-based query. The first technique is the incremental approach, which returns the output elements one-by-one in ascending order of distance. The second one is the nonincremental alternative, which returns the K elements of the result all together at the end of the algorithm. In this paper, based on distance functions between two MBRs in the multidimensional Euclidean space, we propose a pruning heuristic and two updating strategies for minimizing the pruning distance, and use them in the design of three non-incremental branch-and-bound algorithms for K-CPQ between spatial objects stored in two R-trees. Two of those approaches are recursive following a Depth-First searching strategy and one is iterative obeying a Best-First traversal policy. The plane-sweep method and the search ordering are used as optimization techniques for improving the naive approaches. Besides, a number of interesting extensions of the K-CPQ (K-Self-CPQ, Semi-CPQ, K-FPQ (the K-farthest pairs query), etc.) are discussed. An extensive performance study is also presented. This study is based on experiments performed with real datasets. A wide range of values for the basic parameters affecting the performance of the algorithms is examined in order to designate the most efficient algorithm for each setting of parameter values. Finally, an experimental study of the behavior of the proposed K-CPQ branch-and-bound algorithms in terms of scalability of the dataset size and the K value is also included.