Showing papers by "University of Córdoba (Spain) published in 1987"
TL;DR: The objective of this research is to reveal the level of lead and cadmium pollution in fresh vegetable samples from the Cordovan fertile lowland region of the Guadalquivir River and to establish a base level of contamination to serve as a reference point in further studies.
Abstract: The objective of this research is to reveal the level of lead and cadmium pollution in fresh vegetable samples from the Cordovan fertile lowland region of the Guadalquivir River and to establish a base level of contamination to serve as a reference point in further studies. At the same time, the possible health risks for the consumer are discussed.
77 citations
TL;DR: In this paper, an automatic stopped-flow system featuring a mixing module and real-time data collection and treatment is presented, which is compatible with a number of spectrophotometers and spectrofluorimeters.
73 citations
TL;DR: This paper represents a departure from the traditional LP approach by formulating the diet formulation problem as a GP model incorporating penalty functions that make the specification of minimum levels of nutrients more flexible and realistic.
70 citations
TL;DR: In this article, a real case involving the establishment of workers' cooperatives within an agrarian reform program in Andalusia (Spain) is studied, where the underlying problem is to find a compromise between the following objectives: employment, seasonal labor, and business profitability.
Abstract: This article shows how multiobjective programming, compromise programming, and filtering techniques can be used to tackle some problems found in agricultural planning. A real case involving the establishment of workers' cooperatives within an agrarian reform program in Andalusia (Spain) is studied. The underlying problem is to find a compromise between the following objectives: employment, seasonal labor, and business profitability. The multiobjective programming approach is used to find the efficient set among these objectives, and after a filtering procedure, a compromise between the objectives is established based on the compromise programming approach.
70 citations
TL;DR: From 1970 to 1985, 973 outbreaks of abortion in sheep and goats from southern Spain were studied and the mean rates of attach (X + SD) of abortions by leptospirosis have been estimated as 16.9 + 6.5% in ovine outbreaks and 20.7 + 8.3% among goats.
Abstract: From 1970 to 1985, 973 outbreaks of abortion in sheep and 262 outbreaks of abortion in goats from southern Spain were studied. Of these, 1.7 and 2.6% respectively were caused by leptospiras, chiefly by the serovar pomona (11 flocks of sheep, 64.7%, and six herds of goats, 75.0%) and in a lower proportion the serovars sejroe (three flocks of sheep 17.6%, and one herd of goats, 12.5%), icterohaemorrhagiae (two and one outbreaks respectively) and grippotyphosa in one ovine flock (5.8%). The mean rates of attach (X + SD) of abortions by leptospirosis have been estimated as 16.9 + 6.5% in ovine outbreaks and 20.7 + 8.3% among goats.
68 citations
TL;DR: In this paper, the sonochemical synthesis of chalcones, catalyzed by an activated barium hydroxide catalyst under interfacial solid-liquid conditions, is carried out with very good yields.
65 citations
TL;DR: In this paper, the similarities and differences between flow injection analysis (FIA) and high-performance liquid chromatography (HPLC) are discussed, and the objectives pursued with the formation of different types of interfaces in FIA are discussed: preconcentration, sample clean-up, etc.
53 citations
TL;DR: Girdling was found usefully to increase fruit size and advance maturity in six early-season peach and nectarine cultivars, but injuries were caused in some trees because of poor healing.
Abstract: SummaryGirdling was found usefully to increase fruit size and advance maturity in six early-season peach and nectarine cultivars, but injuries were caused in some trees because of poor healing. The degree of callusing was found to depend on the cultivar and the width of the girdle. Cv Springtime was the most tolerant cultivar to girdling and a girdle width between 5 and 10 mm gave the best results. A girdle width greater than 5 mm decreased callus formation on the other cultivars, and even caused the death of some trees of cv Armking, the most sensitive cultivar.
44 citations
TL;DR: The results fail to show a consistent correlation between ethanol tolerance and ADH activity in the adults of LR lines, but indicate that adaptation of D. melanogaster to ethanol-containing food could be accomplished without significant changes on the ADHactivity in the adult flies.
Abstract: The suggestion of Oakeshott et al. (1984) that selection at the Adh locus, as a response to ethanol, is restricted to D. melanogaster laboratory-adapted populations, is tested in this paper with the "Lagar de los Reyes" (LR) lines. For this purpose, homozygous lines for the AdhF and the AdhS alleles were maintained on food supplemented with ethanol. After the selection, the ethanol tolerance and the ADH activity of the selected flies (LRSeF and LRSeS) were determined and compared with those of the control flies (LRCF and LRCS), maintained on standard medium. Then, the effects of the selection, genotype and sex, and the relation between ethanol tolerance and ADH activity were analysed. Our results fail to show a consistent correlation between ethanol tolerance and ADH activity in the adults of LR lines. Our findings also indicate that adaptation of D. melanogaster to ethanol-containing food could be accomplished without significant changes on the ADH activity in the adults. The possibility that the adaptation of D. melanogaster to environmental ethanol could be independent of the Adh locus is discussed.
41 citations
TL;DR: In this article, radio telemetry was used to study the movements of European eels,Anguilla anguilla, in a small (12 ha) lake in southwestern Spain in March and April, 1985 Observations were taken on the locations of 7 eels at least once each 2 h for a combined total of 1713 h.
Abstract: Radio telemetry was used to study the movements of European eels,Anguilla anguilla, in a small (12 ha) lake in southwestern Spain in March and April, 1985 Observations were taken on the locations of 7 eels at least once each 2 h for a combined total of 1713 h The size of individual activity regions varied from 2700 to 1300 m2 Eels covered a larger area at night than during the day, with an average of 23% and 42% of the activity region used during the day and night respectively Average distance moved between observations was significantly greater at night than in the day Eels tracked during rainy and cloudy weather were more active during the day and used a larger total area than did those tracked during drier, more stable weather The standing crop of eels was estimated to be about 77 kg ha−1
38 citations
TL;DR: In this article, chloride and iodide are injected into a carrier silver nitrate and the precipitates formed are retained on a stainless-steel filter, so that total chloride and Iodide can be determined by the decrease in the atomic absorption signal for silver.
TL;DR: The results indicate that reversibly inactivated nitrate reductase from C. reinhardtii is the main target for a degradation system, and that nitrate reducectase related diaphorase must be integrated in a reversibly inactive nitrate reduction complex to undergo degradation.
Abstract: All nitrate reductase-related activities of Chlamydomonas reinhardtii wild-type and mutant 305 cells were degraded in vivo under conditions in which the reversible inactivation could take place. When the enzyme was in the inactive form, half-lives of all nitrate reductase-related activities in wild and mutant 305 strains decreased significantly. The only nitrate reductase-related activity present in mutant 104, nitrate reductase-diaphorase, was incapable of undergoing reversible inactivation and was not degraded under any of the conditions tested. Addition of nitrate to inactive nitrate reductase of mutant 305 caused the in vivo reactivation of the enzyme and halted its degradation. Our results indicate that reversibly inactivated nitrate reductase from C. reinhardtii is the main target for a degradation system, and that nitrate reductase related diaphorase must be integrated in a reversibly inactive nitrate reductase complex to undergo degradation. A physiological role for the interconversion process of nitrate reductase can be understood on the basis of these facts.
TL;DR: It is concluded that mutants 2170 from Chlamydomonas reinhardtii carries a single mendelian mutation which results in a decreased rate of uptake of both ammonium and methamphetamine without being affected either in uptake of nitrate or nitrite or any of the tested enzyme activities related to ammonium assimilation.
Abstract: A methylammonium-resistant mutant, named hereafter strain 2170 (ma-1), was isolated for the first time from a eukaryotic phototrophic organism. Mutant 2170 from Chlamydomonas reinhardtii carries a single mendelian mutation which results in a decreased rate of uptake of both ammonium and methylammonium without being affected either in uptake of nitrate or nitrite or any of the tested enzyme activities related to ammonium assimilation. Mutant cells could not use methylammonium as nitrogen source nor excrete ammonium into the medium but they had derepressed nitrate and nitrite reductases when growing in the presence of ammonium. Mutant 2170 also exhibited a diminished methylammonium transport rate in comparison with the wild-type cells. We conclude that mutant 2170 is affected in a transport system responsible for the entrance of both ammonium and methylammonium into the cells.
TL;DR: The present study shows that the L-arabinose resistance test with Salmonella typhimurium detects that freshly infused tea is highly mutagenic in the absence of mammalian microsomal activation.
Abstract: The present study shows that the l -arabinose resistance test with Salmonella typhimurium detects that freshly infused tea is highly mutagenic in the absence of mammalian microsomal activation. Both the mutagenesis protocol (preincubation test) and the additional genetic characteristics of the bacterial tester strain (excision repair deficiency, normal lipopolysaccharide barrier and the presence of plasmid pKM101) were critical factors in the optimal induction by tea of forward mutations to l -arabinose resistance. The TA104 strain — a histidine auxotroph specific to oxidative mutagens — was the most sensitive tester strain of the Ames test to the direct-acting mutagenicity of tea. In comparison with strain TA104, the sensitivity of the Ara forward mutation test was 18 times higher, one cup of tea (200 ml) inducing 3 × 10 6 Ara R mutants. More than 90% of the mutagenicity of 150μl of a fresh tea infusion, or that of the equivalent amount (1.32 mg) of the corresponding lyophilized residue, was suppressed by 10 units of catalase. In contrast to catalase, superoxide dismutase was rather ineffective. These results indicate that hydrogen peroxide is produced in tea solutions, playing an essential role in its mutagenicity. In comparison, the role of superoxide anion seems negligible. Like catalase, the chelating agent DETAPAC showed a protective effect with respect to the mutagenicity of tea, suggesting the additional implication of hydroxyl radicals.
TL;DR: In this article, different multidetection flow-injection techniques are considered for the manipulation of analytical sensitivity and for broadening the determination range of an analyte with maximum accuracy.
TL;DR: Analysis of isolates and several clones from Trypanosoma cruzi confirmed the heterogeneity of T. cruzi subspecies in nature and the usefulness of DNA probes to group them.
TL;DR: In this paper, the effects of ultrasonic irradiation on transport and reactions in several flow-injection manifolds are described and the influences of ultrasound on the physical dispersion of the injected plug are considered.
TL;DR: Increased sensitivities towards compounds known to interact with cellular GSH were observed in glutathione reductase deficient strains, although these effects were enhanced in strains additionally deficient in GSH biosynthesis.
Abstract: The intracellular concentrations of total glutathione, GSSG and protein · S-SG, the total excreted glutathione concentration, and the susceptibility towards GSH-reacting compounds were assayed in strains of Escherichia coli deficient in biosynthesis and/or reduction of glutathione. A deficiency in glutathione reductase displaced the glutathione status towards the oxidized forms. This displacement was more clearly appreciated in strains additionally deficient in glutathione biosynthesis. A deficiency in catalase activity also produced an increase in the oxidation of glutathione. The most severe changes were observed in the concentrations of protein-glutathione mixed disulfides and in the amount of glutathione excreted to the medium. Increased sensitivities towards compounds known to interact with cellular GSH were observed in glutathione reductase deficient strains, although these effects were enhanced in strains additionally deficient in GSH biosynthesis
TL;DR: The species composition of 20,697 mosquitoes collected in chicken-baited traps and 2,752 collected in a horsebaited trap is discussed, along with data on engorgement rates following entry of mosquitoes into the bait traps.
Abstract: Blood meals from 277 engorged mosquitoes collected in CDC light traps during December 1982 in Santa Fe Province, Argentina, during a western equine encephalitis (WEE) epizootic were identified by precipitin test. Blood meals from 348 engorged mosquitoes collected in the same general area during February 1984 were also identified, along with blood meals from 18 engorged mosquitoes from Rio Negro Province and 58 from Chubut Province. The total of 701 mosquitoes was composed of 297 Aedes albifasciatus , 16 Ae. scapularis , 1 Anopheles albitarsis , 4 Culex (Melanoconion) delpontei , 102 Culex (Culex) spp., 99 Mansonia titillans , 15 Mansonia spp., 3 Psorophora albigenu , 6 Ps. ciliata , 4 Ps. confinnis , 50 Ps. cyanescens , 1 Ps. dimidiata , 3 Ps. discrucians , 16 Ps. pallescens , and 84 Ps. varinervis . Most of the mosquitoes (679 specimens) had fed on mammals, especially cattle; a few (19) had fed on birds. One Cx. (Mel.) delpontei had fed on an amphibian, and 2 mosquitoes contained a mixture of avian and mammalian bloods. In addition, the species composition of 20,697 mosquitoes collected in chicken-baited traps and 2,752 collected in a horsebaited trap is discussed, along with data on engorgement rates following entry of mosquitoes into the bait traps. A few mosquitoes also were collected in Nutriabaited traps (6 specimens) and in traps baited with domestic rabbits (143 specimens).
TL;DR: The dehydration process of lepidocrocite, γ-FeOOH, induced by wet grinding procedures has been studied in this article, where the authors attributed the higher crystallinity of ground microcrystals as revealed by the values of crystallite size and microstrains.
TL;DR: The genetics of resistance of common vetch (Vicia sativa L.) to broomrape (Orobanche crenata Forsk) was studied for two years by using the P1, P2, F1, BC 1, BC 2, F2 F3, and F4 generations obtained from crosses between resistant and susceptible lines as discussed by the authors.
Abstract: The genetics of resistance of common vetch (Vicia sativa L.) to broomrape (Orobanche crenata Forsk.) was studied for two years by using the P1, P2, F1, BC1, BC2, F2 F3, and F4 generations obtained from crosses between resistant and susceptible lines. Resistant lines were selected by screening a world collection m a naturally infested plot. Resistance was tested both under field and greenhouse conditions. The best index to measure resistance was the number of emerged broomrapes per host plant. The results fit the additive-dominance model. The main component of the variation was additivity; dominance and interaction effects seemed to depend on the environment. When dominance is expressed, a low number is dominant over a high number of broomrapes per host plant.
TL;DR: Several photometric and fluorimetric methods are proposed for the determination of cholesterol by use of enzymes immobilized on controlled-pore glass and the normal and stopped-flow injection modes, achieving linear ranges of the calibration curves between 26-776 mumol/l and 5-265 mumol /l with excellent regression coefficients and good coefficients of variation.
TL;DR: In this article, a sequential method for determination of glucose and fructose involving the use of enzymes (hexokinase and glucose-6-phosphate dehydrogenase) immobilized on controlled-pore glass is proposed.
TL;DR: The present study shows that the L-arabinose resistance test in Salmonella typhimurium detects coffee as a strong mutagen in the absence of mammalian microsomal activation.
Abstract: The present study shows that the L-arabinose resistance test in Salmonella typhimurium detects coffee as a strong mutagen in the absence of mammalian microsomal activation. The response of the Ara forward mutation assay was 8.5 times higher than that of TA104, which is the most sensitive to coffee of the tester strains of the Ames test. Both the mutagenesis protocol (preincubation test) and the additional genetic characteristics of the bacterial tester strain (excision repair deficiency, normal lipopolysaccharide barrier, and the presence of plasmid pKM101) were critical factors in the optimal induction by coffee of forward mutations to L-arabinose resistance. All ten samples of roasted coffee analyzed with the Ara assay were highly mutagenic: one cup of coffee (150 ml) was calculated to induce 3-4 X 10(6) AraR mutants. In contrast, coffee prepared from unroasted beans (green coffee) had no mutagenic activity. Regular- and sugar-roasted coffees showed similar mutagenicities, but the specific mutagenic activity of instant coffees (1559 AraR mutants/mg) was almost 2 times that of noninstant ones (834 AraR mutants/mg). The Ara assay allowed the direct testing of coffee, although it was demonstrated that lyophilization has no effect on the mutagenicity of this beverage. Like roasted coffee, roasted barley induced a large number of AraR mutants per mg (227), though its specific mutagenic activity was approximately 4 and 7 times lower than that of noninstant and instant coffees, respectively.
TL;DR: Results for 24-h urine specimens correlated well with those obtained by an extraction-ion-exchange chromatography combined method, and the proposed method is inexpensive and requires no sophisticated detection equipment.
Abstract: The second-derivative synchronous fluorescence spectroscopic technique is applied to the simultaneous and direct assay of coproporphyrins and uroporphyrins in human urine. This technique resolves the overlapping conventional spectra, obviating the need for pre-analysis sample separation techniques, and measurements can be made in a single scan. The amplitudes of the derivative peaks are linearly related to uroporphyrin (0.4 to 300 micrograms/L) and coproporphyrin (0.4 to 250 micrograms/L) concentrations. The detection limit for both porphyrins is 0.1 microgram/L. Analytical recoveries range between 98 and 101%. Within- and between-assay CVs are reported. Results for 24-h urine specimens correlated well with those obtained by an extraction-ion-exchange chromatography combined method. The proposed method is inexpensive and requires no sophisticated detection equipment.
TL;DR: In this article, the injection of a large sample volume (ca. 1 ml) into a single-channel flow-injection system was studied with a dye and with chemical systems having easily-controlled reaction rates.
TL;DR: Results show that UEA I, GS I, and SBA are good markers to distinguish different cell types and the degree of keratinocytes differentiation.
TL;DR: In this paper, cyclic voltammetry at a carbon paste electrode has been used to study the electrochemical behavior of the tris(1,10-phenanthroline)iron(II), ferroin, and tris (1, 10-phenanoline)iron (III), ferriin, complexes in aqueous solutions of pH 0 to 5.
TL;DR: In this paper, a phase structurally related to LiCoO2 was obtained by comminution of stoichiometric mixtures of LiOH·H2O and Co(OH)2 for 10 h.