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Showing papers by "University of Córdoba (Spain) published in 1986"


Journal ArticleDOI
01 Aug 1986-Talanta
TL;DR: A review is presented of the fundamental principles and analytical applications of synchronous excitation fluorescence spectroscopy, constant-energy synchronous fluorescence Spectroscopy and variable-separation synchronous Excitation FluorescenceSpectroscopy.

125 citations


Journal ArticleDOI
TL;DR: A survey of the literature on Goal Programming from 1970 through 1982 is provided, categorized according to 18 areas of application and according to 12 different variants of GP.

109 citations


Journal ArticleDOI
TL;DR: In this paper, the chemical composition, texture, and surface reactivity of three samples of aluminum phosphate prepared by aging of aluminum chloride and orthophosphoric acid in different media (aqueous ammonia, ethylene, and propylene oxide) have been studied.

76 citations


Book ChapterDOI
TL;DR: The role of legumes in protein production is discussed, which plays a role in the fight against erosion in soil establishment and afforestation in numerous areas of the world.
Abstract: Publisher Summary This chapter analyzes the lupin crop as an alternative source of protein. Lupin is considered one of the legumes with the greatest future potential because of its high protein content, even in a wild state, and because of its adaptation to poor soils and dry climates. The wild species of Lupinus are distributed in two large areas: The Mediterranean and the Western Hemisphere. The Mediterranean zone ranges from southern Europe to the highlands in northern and eastern Africa. The range in the Americas includes the western part of North and South America, and excludes the tropical lowlands and the Amazonian basin. Cultivated lupins appear in agricultural production in diverse forms and for very different purposes: Grain production and forage in crop rotation, green manure, soil conservation, agroforestry, and also as a permanent pasture for livestock. Lupins not cultivated for grain are usually ploughed in as green manure, or used alone or mixed with cereals or grasses as fodder. Lupin also plays a role in the fight against erosion in soil establishment and afforestation in numerous areas of the world. This chapter discusses the role of legumes in protein production. Botany and ecology of lupin is also described.

76 citations


Journal ArticleDOI
TL;DR: In vitro complementation tests with mutant nit-1 of C. reinhardtii indicate that this mutant has defective NR-diaphorase subunits but intact terminal subunits, suggesting that subunits are exchangeable to form hybrid enzymes.
Abstract: In vivo complementation between different wild and mutant strains defective for nitrate assimilation has been performed by isolating diploid strains from the appropriate crosses. Twenty-two diploids homozygous or heterozygous with respect to nitrate reduction and able to grow on nitrate medium were obtained and their diploid character demonstrated from analyses of mating type, cell volume, nuclear size and progeny of crosses with haploid wild-type. All diploids were assayed for overall- and terminal-nitrate reductase (NR) activity and for the occurrence of the NR-diaphorase subunit. Data on NR activities in heterozygotes carrying mutation(s) in structural gene(s) (nit-1 or nit-1a, nit-1b) agree with the heteromultimeric nature of the enzyme complex previously described (Franco et al. (1984) EMBO J 3: 1403–1407), and indicate that subunits are exchangeable to form hybrid enzymes. In addition, in vitro complementation tests with mutant nit-1 of C. reinhardtii indicate that this mutant has defective NR-diaphorase subunits but intact terminal subunits. Super-repression caused by the mutant allele nit-2 is suppressed by the wild allele in heterozygotes, which suggests a positive control by the nit-2 product on structural gene(s) transcription. Mutant alleles of genes for the biosynthesis of molybdenum-containing cofactor, either nit-4 or nit-5 and nit-6, were recessive in diploids carrying them. The mutant allele of nit-3, from strain 307, was codominant in all heterozygotes suggesting that nit-3 codes for a protein whose activity is limiting for the molybdenum-cofactor biosynthetic pathway.

65 citations


Journal ArticleDOI
TL;DR: Seven patients, mean age 8 +/- 3.6 years, with clinical and hemodynamic diagnoses of discrete subaortic stenosis were treated by percutaneous transluminal balloon dilatation (PTBD) of the membrane during cardiac catheterization with results consistent with hemodynamic findings.
Abstract: Seven patients, mean age 8 +/- 3.6 years, with clinical and hemodynamic diagnoses of discrete subaortic stenosis were treated by percutaneous transluminal balloon dilatation (PTBD) of the membrane during cardiac catheterization. One patient had an associated aortic coarctation that was first dilated. After PTBD left ventricular (LV) systolic pressure decreased significantly, from 181 +/- 25 to 139 +/- 11 mm Hg (p less than 0.005); peak gradient diminished from 65 +/- 18 to 12 +/- 9 mm Hg (p less than 0.001). Mild aortic regurgitation was present in 6 patients during basal conditions. After PTBD, the same degree of regurgitation was observed in all but 1 patient, in whom it disappeared. There were no major complications. Clinical observations after PTBD were consistent with hemodynamic findings. Precordial thrill always disappeared and the peak murmur became earlier in systole. In 2 patients the discrete subaortic stenosis was clearly visualized at 2-dimensional echocardiography as a fixed subvalvular structure throughout the cardiac cycle. After dilatation this was only identifiable at its implantation base; during contraction there was no fixed structure at the LV outflow tract. Four patients were hemodynamically reevaluated 6.7 +/- 1.7 months later and were found to have LV pressure relief and a degree of aortic regurgitation similar to those observed immediately after PTBD.

56 citations


Journal ArticleDOI
TL;DR: In this paper, the potential of the use of the diode-array detector in conjunction with flow injection analysis is outlined, and methods for multicomponent resolution can be based on the formation of complexes absorbing at different wavelengths.

46 citations


Journal ArticleDOI
01 Nov 1986-Talanta
TL;DR: A flow-injection analysis method for simultaneous determination of silicate and phosphate, based on the different rates of formation of their molybdate heteropoly acids is suggested, which permits the determination of these anions in the range 30-600 ng ml in ratios from 1:10 to 10:1.

38 citations


Journal ArticleDOI
TL;DR: The individual and simultaneous enzymatic determination of ethanol and acetaldehyde in wine by flow injection analysis is described, based on the use of alcohol dehydrogenase and aldehyde dehydrogenases.

35 citations


Journal ArticleDOI
TL;DR: The results demonstrate that C. reinhardtii cells take up nitrite via a highly specific carrier, probably energy-dependent, kinetically responsive to environmental changes, distinguishable from the enzymic nitrite reduction and endowed with an active site for nitrite not usable for nitrate transport.
Abstract: Kinetics of nitrite uptake and reduction by Chlamydomonas reinhardtii cells growing phototrophically has been studied by means of progress curves and the Michaelis-Menten integrated equation. Both uptake and reduction processes exhibited hyperbolic saturation kinetics, the nitrite uptake system lacking a diffusion component. Nitrite uptake and reduction showed significant differences in Ks for nitrite at pH 7.5 (1.6 versus 20 micromolar, respectively), optimal pH, activation energy values, and sensitivity toward reagents of sulfhydryl groups. Ks values for nitrite uptake were halved in cells subjected to darkness or to nitrogen-starvation. Nitrate inhibited nitrite uptake by a partially competitive mechanism. The same inhibition pattern was found for nitrite uptake by C. reinhardtii mutant 305 cells incapable of nitrate assimilation. The results demonstrate that C. reinhardtii cells take up nitrite via a highly specific carrier, probably energy-dependent, kinetically responsive to environmental changes, distinguishable from the enzymic nitrite reduction and endowed with an active site for nitrite not usable for nitrate transport.

35 citations


Journal ArticleDOI
TL;DR: In this article, an approximate method applicable to electrochemical processes either coupled or not to first-order chemical reactions in differential pulse polarography is proposed, which has been tested with the aid of well-known oxidation and reduction processes.

Journal ArticleDOI
TL;DR: In this article, the atomic absorption signal of copper in the organic phase was measured to determine mixtures of these anions at μg ml −1 levels for nitrate/nitrite ratios from 10:1 to 1:10, with a sampling frequency of ca. 20 h −1.

Journal Article
TL;DR: A morphometric study of rat testis development and ageing (from 5 to 360 days of age) has been carried out, finding that from this age onwards the tubular growth was similar in both length and diameter.
Abstract: A morphometric study of rat testis development and ageing (from 5 to 360 days of age) has been carried out. The testicular volume increases from 10.28 +/- 0.35 mm3 (5 days of age) to 1819.43 +/- 52.67 mm3 (360 days of age), showing the most rapid increase between 20 and 70 days of age (22.6 times). The mean tubular diameter increases from 62.25 +/- 1.50 micron (5 days of age) to 280.81 +/- 9.77 microns (360 days of age) and the tubular length from 2.74 +/- 0.18 m (5 days of age) to 25.45 +/- 1.76 m (360 days of age). Up to 15 days of age, the increase in testicular volume was mainly due to the increase in tubular length, whereas from this age onwards the tubular growth was similar in both length and diameter. Tubular development had nearly finished at 70 days of age.

Journal ArticleDOI
01 Jan 1986-Talanta
TL;DR: A survey of the use of flow-injection analysis for speciation studies is presented in this article, where comments are made about the future potential of the technique, and suggestions are made for further research.

Journal ArticleDOI
TL;DR: The results support the view that, in green tissues, the reducing equivalents photogenerated in the chloroplasts are more directly used for NO - 2 reduction than for NO- 2 reduction.

Journal ArticleDOI
TL;DR: In this article, the texture of AlPO/sub 4/ treated at different temperatures (770-1270 K) and impregnated with fluoride ions (1-3 wt%) as well as their catalytic activities for the cyclohexene skeletal isomerization were investigated.

Journal ArticleDOI
TL;DR: The yeast species most frequently occurring in industrial fermentations, in a fermentation process carried out in a laboratory under extreme conditions of reducing sugars, SO 2 and acidity, and in the flor veil have been isolated and shown to differ.

Journal ArticleDOI
TL;DR: In this paper, the simultaneous or sequential determination of chromium(VI) and total chromium in water by flow injection analysis, using different configurations with a double- or single-beam spectrophotometer as detector, is investigated.

Journal ArticleDOI
TL;DR: A flow-injection configuration based on a closed flow system which includes a single spectrophotometric detector and allows iterative detection by passage of the reacting plug n times through the same detector is described in this article.

Journal ArticleDOI
TL;DR: In this article, a linear free-energy relationship (LFER) was shown to be associated with the existence of a linear relationship between the differential adsorption heat, Δω, and differential entropy factors.

Journal ArticleDOI
TL;DR: In this paper, a flow injection system coupled on-line with a continuous liquid-liquid extractor is used for the indirect determination of nitrate and nitrite with an atomic-absorption detection system.
Abstract: A flow injection system coupled on-line with a continuous liquid-liquid extractor is used for the indirect determination of nitrate and nitrite with an atomic-absorption detection system. These anions form ion-pairs with the copper(I)-neocuproine chelate which are extracted into methyl-isobutyl-ketone, the atomic-absorption signal of copper from the organic phase being proportional to the nitrate or nitrite concentration. The methods proposed herein are suitable for determining nitrate or nitrite at the βg ml−1 level with a sampling frequency of 35 ± 5 h−1. The methods compare favourably with their batch counterparts with regard to sensitivity, selectivity, sample volume and sampling frequency.

Journal ArticleDOI
TL;DR: Multidetection (on obtient 2 signaux ou plus plus pour 1 seul echantillon) sequentielle et simultanee as mentioned in this paper ) is a type of multi-signal detection.
Abstract: Multidetection (on obtient 2 signaux ou plus pour 1 seul echantillon) sequentielle et simultanee

Journal ArticleDOI
TL;DR: The liquid test proved the most sensitive mutagenesis protocol and was proposed to select the L-arabinose-resistant mutants in plates supplemented with 0.5 mg of D-glucose, and to express the mutagenic response as the absolute number of induced mutants.
Abstract: Different conditions of mutagenesis have been compared in order to optimize the use of the L-arabinose resistance test with Salmonella typhimurium. The mutagenesis protocols compared were the plate-incorporation, the pre-incubation and the liquid tests. Fourteen chemicals were used in the comparison: six direct-acting mutagens and eight pre-mutagens. Five concentrations of S9 (3, 7.5, 10, 15 and 33% v/v) were compared in the liquid test with pre-mutagens, and three densities of bacteria (ranging from 10(8) to 10(6) cells) were used in the comparison between the plate-incorporation and the pre-incubation mutagenesis test. In general, the liquid test proved the most sensitive mutagenesis protocol. When carrying out this test in a mass screening of mutagens, we propose to select the L-arabinose-resistant mutants in plates supplemented with 0.5 mg of D-glucose, and to express the mutagenic response as the absolute number of induced mutants. The plate-incorporation and the pre-incubation mutagenesis protocols could be considered as alternative procedures in the case of previous negative results with the liquid test. Two recommendations can be finally made in order to avoid false negative results: (a) a large population of bacteria (ranging from 10(8) to 10(7) cells) must be exposed to the mutagens in both the plate-incorporation and the pre-incubation mutagenesis tests, and (b) ideally, several S9 concentrations (ranging from 3 to 30% v/v) would be employed for testing in liquid samples of unknown mutagenicity.

Journal ArticleDOI
TL;DR: In this article, a good relationship is found between crystallite size and specific surface area, and an explanation of the differences in textural properties found among the samples studied is given on the basis of data obtained by X-ray powder diffraction, infrared spectroscopy, scanning electron microscopy and nitrogen adsorption techniques.

Journal ArticleDOI
TL;DR: In this article, a flow injection configuration is suggested for the simultaneous determination of ammonia and hydrazine at the μg ml−1 level by formation of zones of different pH values, where analytes react with o-phthalaldehyde and mercaptoethanol to form fluorescent derivatives.

Journal ArticleDOI
TL;DR: The difference in proportion of the fibromuscular stroma between the two glands is evidence that the size of the whole seminal vesicles has increased whereas the sizeof the ventral prostate has decreased, which suggests that the growth is dependent on testicular factors.
Abstract: In a morphometric study on the ventral prostate and seminal vesicles in the rat, we investigated the changes in fibromuscular stroma, glandular epithelium, and glandular lumen. Animals were studied at 15, 30 and 45 days of age. The rapid prepubertal growth started earlier in the ventral prostate than in seminal vesicles. In addition, the effects of neonatal administration of estrogens on the different tissue compartments were studied, comparing rats that had been castrated and/or treated with estrogen at birth to intact animals at 15 days of age. Estrogens caused a decrease in the volume of the glandular epithelium and increased the volume of the fibromuscular stroma in both ventral prostate and seminal vesicles. Castration partially abolished the estrogen-induced growth of the stroma, which suggests that the growth is dependent on testicular factors. The difference in proportion of the fibromuscular stroma between the two glands is evidence that the size of the whole seminal vesicles has increased whereas the size of the ventral prostate has decreased.

Journal ArticleDOI
TL;DR: The object of the present paper is to provide data on the levels of mercury contents in mushroom species collected in the Cordoba area (Spain) and to suggest members of the genus Agaricus could be used as indicator organisms in the study of mercury pollution.
Abstract: Numerous investigations have established that fish is the food which shows the highest levels of mercury, thus being the most hazardous for humans. Recently much research has been carried out in several places of Europe on the high capacity of mushrooms to accumulate heavy metals. It has been noticed that the various species differ in their tendency to accumulate heavy metals. Two genera in which mercury accumulation was very marked are Agaricus and Lycoperdon. It is suggested that members of the genus Agaricus could be used as indicator organisms in the study of mercury pollution. The object of the present paper is to provide data on the levels of mercury contents in mushroom species collected in the Cordoba area (Spain).

Journal ArticleDOI
TL;DR: An experimental animal model of surgical wound infection applicable to antibiotic prophylaxis and comparison between metronidazole used alone or in combination with either ampiciUin or doxycycline is presented.
Abstract: elective colorectal surgery. Journal of Hospital Infection 1983, 4: 65-69. 6. Roland, M., Bergan, K., Andenaes, T., Bjerkestet, T., Brabrand, G. et al.: Prophylactic regimes in colorectal surgery. Comparison between metronidazole used alone or in combination with either ampiciUin or doxycycline. Scandinavian Journal of Surgery 1984, 19, Supplement 19: 37-52. 7. Moesgaard, F., Lykkegaa~d Nielsen, M. C., Justesen, T.: Experimental animal model of surgical wound infection applicable to antibiotic prophylaxis. European Journal of Clinical Microbiology 1983, 2: 459-462.

Journal ArticleDOI
01 Mar 1986-Talanta
TL;DR: The analytical potential of a closed flow-injection system with multidetection by a single detector is extended to simultaneous determinations for chromium speciation, with injection of the reagent(s) into the sample solution (which acts as the carrier).

Journal ArticleDOI
TL;DR: Nitrate completely suppressed nitrite uptake, whereas ammonia or l -methionine- dl -sulfoximine, which immediately stopped nitrate entrance, only inhibited partially nitrite consumption and it is concluded that in Rps.