Showing papers by "University of Alicante published in 1985"
TL;DR: The increase in salt concentration was correlated with increase in diurnal temperature and biomass present and with decrease in oxygen concentrations, and all organisms found at the lower salt concentrations disappeared, and instead large populations of halobacteria developed.
Abstract: A multi-pond saltern that creates a gradient of salt concentrations has been studied with respect to some characteristics of the resulting environments and their microbial populations. The increase in salt concentration was correlated with increase in diurnal temperature and biomass present and with decrease in oxygen concentrations. Many types of organisms below 15% (w/v) total salts, were found, many of them normal inhabitants of seawater and even freshwater. Most organisms over 15% salts were halophilic. The salt concentrations comprised two ranges, each characterized by different microbial populations. First, between 15 and 30% salts, the populations ofDunaliella increased, reaching large numbers; moderately halophilic eubacteria and some fast-growing halobacteria predominated as heterotrophic microorganisms and, among the first, thePseudomonas-Alteromonas-Alcaligenes group andVibrio were the more abundant taxonomic groups; and gram-positive cocci appeared mainly over 25% salts. Phototrophic bacteria, both oxygenic and anoxygenic, were also found in this range, and among the anoxygenic type,Chromatium species andRodospirillum salexigens were probably predominant. Second, over 30% salts the diversity decreased greatly, all organisms found at the lower salt concentrations disappeared, and instead large populations of halobacteria developed. Over 50% salts, only three species of halobacteria were found.
196 citations
TL;DR: Phytochemical study of the aerial parts of INULA VISCOSA resulted in the isolation of sixteen flavonoids, one of them, 3- O-acetylpadmatin, which was isolated for the first time as a natural compound.
Abstract: Phytochemical study of the aerial parts of INULA VISCOSA resulted in the isolation of sixteen flavonoids. One of them, 3- O-acetylpadmatin [(2 R,3 R)-3-acetoxy-5,3',4'-trihydroxy-7-methoxyflavanone], was isolated for the first time as a natural compound. Ferulic aldehyde, 2-methylphloroacetophenone, inuviscolide and 2-deacetoxyxanthinin were also isolated.
87 citations
TL;DR: In this article, the microporosity of activated carbons was investigated using two botanically similar agricultural by-products, plum and peach stones, as precursors for the preparation of activated carbonons.
69 citations
TL;DR: A bacteriocin produced by Halobacterium mediterranei ATCC33500 active against many other halobacteria has been studied and was little affected by the salt concentration or the complexity of the medium, and was not induced by UV treatment.
Abstract: A bacteriocin produced by Halobacterium mediterranei ATCC33500 active against many other halobacteria has been studied. Bacteriocin production is very common in eubacteria, but not in halobacteria which are representatives of a different primary kingdom: the archaebacteria. Halocin H4 production was little affected by the salt concentration or the complexity of the medium, and was not induced by UV treatment. It is a 28-kDa protein consisting of a single polypeptide chain. It is adsorbed by the target cell in which it induces lysis. The presence of bacteriocins in members of the archaebacteria is another point of similarity with eubacteria.
66 citations
01 Aug 1985
TL;DR: In this paper, the n-nonane preadsorption technique has been applied to two series of activated carbons with a wide range of microporosity, and the results have been compared with the direct adsorption of N2 (77°K) and CO2 (273°K).
Abstract: The n-nonane preadsorption technique has been applied to two series of activated carbons with a wide range of microporosity. Both series have been prepared from two different agricultural by-products by carbonization in N2 and activation in a CO2 flow and they cover a 8–82% burn-off range. The results have been compared with the direct adsorption of N2 (77°K) and CO2 (273°K). The preadsorption technique provides very good results and similar to those obtained from the Dubinin-Radushkevich equation only when the microporosity is narrow (when more than 85% of the pore volume is filled with N2 at P/P0 = 0.1); for wider microporosity (samples with a burn-off larger than 60%) the technique fails because the n-nonane is removed from the wider micropores when outgassing at room temperature.
54 citations
TL;DR: The technique of real-time holographic interferometry is used to study free diffusion in a liquid mixture at 25°C and a new mathematical method is derived for determining diffusion coefficients.
Abstract: The technique of real-time holographic interferometry is used to study free diffusion in a liquid mixture at 25°C. A new mathematical method is derived for determining diffusion coefficients. The results obtained for the KCl-water system from the mathematical method are compared with the results obtained using the mathematical treatment developed by Gabelmann-Gray and Fenichel.
43 citations
TL;DR: The use of classic interferometry to study liquid diffusion has been well known since the 1940's and much more recently holographic interfereometry was introduced in this field of study as discussed by the authors.
Abstract: The use of classic interferometry to study liquid diffusion has been well known since the 1940's. Much more recently holographic interfereometry was introduced in this field of study. In this paper a description of the general characteristics of holographic interferometry is presented. The evolution as well as the improvements of the technique are describged.
L'emploie de l'interferometrie classique pour etudier la diffusion dans les liquides est bien connu depuis les annees 1940; ce n'est que plus recemment que l'interferometrie holographique a ete introduite dans ce domaine. On presente une description des caractaristiques generales de l'interferometrie holographique. On discute l'evolution etles ameliorations de cette technique.
30 citations
TL;DR: In this article, the authors compared a simple method proposed by Puri (retention of ethylene glycol and n-nonane) and a new test proposed by this article.
23 citations
TL;DR: A new classification of non‐nevoid pigmented benign, premalignant and malignant melanocytic lesions of the conjunctiva is proposed and the question of prognostic features in conjunctival melanoma is briefly discussed.
22 citations
TL;DR: In this article, two commercial activated carbons and corresponding demineralized samples have been used as catalyst supports for platinum, in order to learn about the role played by the inorganic constituents of the carbons on the catalyst characteristics.
22 citations
TL;DR: In this article, a sensitivity analysis is made for solutions to linear equation systems involving M-matrices, and a theorem which tells about relative changes of elements of the solution vector when the coefficients of a given M -matrix shift is presented.
TL;DR: In this article, five phenylpropanoids related to hemanticine have been obtained from Thapsia villosa roots, and the trivial names are isohelmanticine, neohelmantine, isoneohelmantines, epoxyhelmanticines and epoxyhemanticine angelate; these substances are based on (1S,2R)1-(3-methoxy-4,5-methylenedioxyphenyl)-1,2-propanediol, which is esterified variously by acetic, angelic, ep
TL;DR: In this article, the mesoxalate anion oxidizes on a polycrystalline gold electrode through a two-electron process giving carbonate and oxalate ion as final products.
TL;DR: The cathodic reduction in an aprotic medium of α-bromopropiophenone produces 1,4-diphenyl-2,3,dimethyl-1,4 butanedione as discussed by the authors.
01 Jan 1985
TL;DR: In this article, a refinement of an important result of the semi-infinite Motzkin alternative theorem, characterizing those sets which generate a closed convex cone, is obtained.
Abstract: In the first part of this paper, some consequences of the semi-infinite Motzkin alternative theorem are given. In particular, a refinement of an important result of Duffin, Jeroslow and Karlovitz, characterizing those sets which generate a closed convex cone, is obtained. In the second part, we apply these results to supply different sufficient conditions for the Farkas-Minkowski property of a semi-infinite linear system. Finally, by means of the methodology introduced in the paper, an application to the regularization of the linear semi-infinite programming problem is given.
TL;DR: In this paper, the results obtained when studying the purification of wet process phosphoric acid wdith dibutyl ether are reported, and the results have been compared with those corresponding to other solvents previously studied.
Abstract: The results obtained when studying the purification of wet process phosphoric acid wdith dibutyl ether are reported. Percent PA, and impurities: Fe, Al, Mg SO4 − and F− extracted into the organic phase are shown. The variation of the percent extracted in to the organic phase for the different components has been studied as a function of the PA wt% in the organic phase. Results have been compared with those corresponding to other solvents previously studied. Dibutyl ether shows good purification behaviour for metallic impurities and SO4 −, but seems to be not very suitable for F− purification due to its high F− extraction capacity.
TL;DR: The possibility of using the method of sections in the determination of quaternary liquid-liquid equilibrium data using only the analysis of one of the components is shown in the first part of this work as mentioned in this paper.
TL;DR: In this article, further results are presented for alloys of the Al-Cu, Al-Mg-Si and Al-Zn-mg series, showing that the previous conclusions strongly depend on the particular alloy.
TL;DR: The residue of a commercial hexane has been fractionated by preparative chromatography and triphenylphosphate and other not definitely identified OP compounds were detected by gas chromatography/mass spectrometry, together with several adipates and phthalates, including di-n-butylphthalate.
Abstract: Cholinesterase (ChE) inhibitors have been described in the distillation residue of hexane and other industrial solvents. The residue of a commercial hexane has been fractionated by preparative chromatography. The anticholinesterase (antiChE) activity was isolated in two fractions (F-5, F-7) which contained only 0.61 and 0.16% respectively of the original dry weight hexane residue. In the former fraction, reversible and irreversible progressive inhibition was observed, and organophosphorus compounds (OPs) were detected colorimetrically and by gas chromatography. This fraction was subfractionated in a second chromatographic step. One subfraction containing the highest antiChE activity and 88% phosphorus of F-5 was isolated. In this subfraction triphenylphosphate and other not definitely identified OP compounds were detected by gas chromatography/mass spectrometry, together with several adipates and phthalates, including di-n-butylphthalate. This phthalate could explain the reversible inhibition of ChE by the hexane residue, and triphenylphosphate and the unidentified OP the irreversible inhibition. A possible toxicological role of these impurities is discussed in relation to occupational neuropathies by exposure to solvents.
01 Mar 1985
TL;DR: In this paper, it was shown that in a nonlinear Leontief model, if some elements of the final demand vector are increased, then each activity level (i.e., gross output) goes up or remains unchanged and the maximum rate of increase in activity levels must be realized among those sectors for which the final demands are raised.
Abstract: We have shown that in a nonlinear Leontief model where non-decreasing returns are allowed for, if some elements of the final demand vector are increased, then each activity level (i. e., gross output) goes up or remain unchanged and the maximum rate of increase in activity levels must be realized among those sectors for which the final demand is raised. It is also shown that this maximum rate of increase in activity levels is not greater than the maximum rate of increase in the final demands.
TL;DR: The secretory response to TEA or 4‐AP was little affected by changes in external Ca2+, Mg2+, Na+, Cl−, H2PO4− or by tetrodotoxin, and the HCO3− requirements for thesecretory response are probably related to the ability of CO2/H CO3− solutions to mobilize and release Ca2+ from intracellular organelles.
Abstract: Cat splenic slices prelabelled with [3H]-noradrenaline were incubated in oxygenated Krebs-bicarbonate solution at 37 degrees C, and the spontaneous total 3H release into different incubation media monitored. In normal Krebs bicarbonate solution, the spontaneous tritium fractional release amounted to 3.7% of the tissue radioactivity content per 5 min collection period. Tetraethylammonium (TEA) increased spontaneous transmitter release in a concentration-dependent manner; the release was maximal at 30 mM and was 3.5 times the basal release. 4-Aminopyridine (4-AP) also enhanced the spontaneous release of tritium. The response increased linearly with 4-AP concentration (1-10 mM). With 10 mM 4-AP, the release was as much as 6 times the basal transmitter release. Guanidine was much less potent than either TEA or 4-AP. The secretory response to TEA or 4-AP was little affected by changes in external Ca2+, Mg2+, Na+, Cl-, H2PO4- or by tetrodotoxin. However, transmitter release evoked by TEA or 4-AP strongly depended upon the concentration of HCO3- of the incubation solution; in fact, the secretory response varied almost linearly between 1 and 25 mM HCO3-. The mechanisms underlying these effects are probably related to the well-known ability of TEA and 4-AP to block K+ conductance that would cause depolarization of the splenic sympathetic nerve terminals. The HCO3- requirements for the secretory response are probably related to the ability of CO2/HCO3- solutions to mobilize and release Ca2+ from intracellular organelles.
15 Oct 1985
TL;DR: The present articulo responde, en lineas generales, a Comunicacion that, con identico titulo, fue presentada en el VII Congreso Nacional de Historia de la Medicina, celebrado en Alicante del 6 al 9 de abril del ano 1983.
Abstract: El presente articulo responde, en lineas generales, a la Comunicacion que, con identico titulo, fue presentada en el VII Congreso Nacional de Historia de la Medicina, celebrado en Alicante del 6 al 9 de abril del ano 1983.
TL;DR: In this article, it was shown that the only way to fulfil the transferability principle is to use the same rate equation for iso and anisothermal kinetics, and this conclusion was further illustrated on two largely different reactions, namely, recrystallization in a commercial aluminium alloy and curing of an epoxy resin.
Journal Article•
TL;DR: The lexicografia espanola cuenta en su haber con una impotante nomina de autores y de obras que reclaman la atencion del especialista as mentioned in this paper.
Abstract: De entre las distintas parcelas que conforman el panorama de la historia de la filologia hispanica, el desarrollo de la actividad lexicografica reviste una especial importancia y brillantez. Desde la aparicion en 1492 del Vocabulario Latino-Espanol de Nebrija hasta el Diccionario de Autoridades de la Real Academia Espanola, la lexicografia espanola cuenta en su haber con una impotante nomina de autores y de obras que, desde hace tiempo, reclaman la atencion del especialista.
TL;DR: In this article, it was shown that in economies with just two consumers, it is impossible to implement the Lindahl performance correspondence at Nash equilibrium points, and that the Walrasian performance cannot be computed at any Nash equilibrium point.
TL;DR: In this article, the adsorption of D-araboascorbic acid (DAA) on mercury in aqueous solutions of 10−2 M HClO4 has been determined from electrocapillary and capacity measurements.
TL;DR: In this article, electron correlation and electron-phononon effects are discussed in connection with the electronic properties of the dangling bond surface states of Si(111) faces, and both effects are shown to be important and crucial for the understanding of those surfaces.
15 Oct 1985
TL;DR: Este trabajo se inscribe dentro de la problematica tratada en la tesis doctoral que vengo realizando sobre El Bajo Segura en el siglo XVII as mentioned in this paper.
Abstract: Este trabajo se inscribe dentro de la problematica tratada en la tesis doctoral que vengo realizando sobre El Bajo Segura en el siglo XVII.