Showing papers by "University of Córdoba (Spain) published in 1989"
TL;DR: In this article, six essential elements, cadmium and lead, were determined in some horticultural species cultivated in greenhouse borders by atomic absorption spectrophotometry to evaluate the contribution of these vegetables to the daily intake of the heavy metals in Spain.
Abstract: Six essential elements, cadmium and lead were determined in some horticultural species cultivated in greenhouse borders by atomic absorption spectrophotometry to evaluate the contribution of these vegetables to the daily intake of cadmium and lead in Spain. The existence of significant differences (P 0.05) between the concentration of the soil and that of corresponding vegetable species was found. The heavy metal uptake from soil to plants is a function of the physical and chemical nature of the soil and is altered by innumerable environmental and human factors. If the mean levels of cadmium and lead (0.029 mg kg−1 and 0.221 mg kg−1 respectively) are taken into account, the daily intake contribution of these metals will be 1.4 μg day−1 for cadmium and 11 μg day−1 for lead.
120 citations
TL;DR: It is concluded that vector control using insecticides against this species would be most effective at the onset of winter, when recovery of any surviving populations would be inhibited by low temperatures.
Abstract: Using experimental chicken houses at a site in central Argentina where the bug Triatoma infestans (Klug) is endemic, nine populations of this vector of Chagas disease were monitored during a 34-month period Bug populations with four chickens as hosts were consistently larger than those with two chickens as hosts Age structure of the bug population followed a similar pattern irrespective of the initial age structure Egg to adult mortality was consistently around 985% and there was no consistent evidence for density-dependent mortality There was some evidence for density dependence in fecundity and recruitment rates, but these were heavily constrained by low temperatures during the winter months Nymphal development rates correlated most strongly with mean minimum temperatures rather than with mean maximum temperatures We conclude that vector control using insecticides against this species would be most effective at the onset of winter, when recovery of any surviving populations would be inhibited by low temperatures
87 citations
TL;DR: A quantitative analysis of the aorta at different levels revealed no significant changes proximal and distal to the coarctation segment; however, at the level of coarCTation, a significant and homogeneous increment was observed after dilation that was unchanged at follow-up.
85 citations
01 Jan 1989
TL;DR: About 60,000 ha are sown annually to chickpea in Andalucia, southern Spain, approximately 66% of the total national acreage of the crop, and resistance to race 1 is conferred by recessive alleles from at least two independent loci.
Abstract: About 60,000 ha are sown annually to chickpea (Cicer arietinum L.) in Andalucia, southern Spain, approximately 66% of the total national acreage of the crop. Wilt induced by Fusarium oxysporum Schlecht. emend. Snyd. & Hans. f. sp. ciceri (Padwick) Snyd. & Hans. (Foc) severely affects chickpeas in that region causing an average 10% yield loss (Trapero-Casas and Jimenez-Diaz 1985). Control of the disease is mainly by the use of resistant cultivars (Haware and Nene 1980a; Nene and Haware 1980; Nene and Reddy 1987), the efficacy of which is curtailed by the occurrence of pathogen races. Haware and Nene (1982) were the first to show the existence of races of Foc, namely races 1,2,3 and 4, based on the differential interaction among 10 chickpea cultivars and isolates of the pathogen from India. Recent work indicates that resistance to race 1 is conferred by recessive alleles from at least two independent loci (Upadhyaya et al 1983a, 1983b; Singh et al 1987). Cultivars WR 315, CPS 1, BG 212 and JG 74, carrying recessive alleles at both loci, are completely resistant, while cultivars C 104 and K 805, which are homozygous recessive at one of the loci, show a delayed wilt (late-wilting, Haware and Nene 1980b). Cultivar JG 62, which is susceptible to all four races of Foc in India, carries neither of the recessive alleles and shows wilt symptoms within 20 days after sowing (early-wilting).
79 citations
TL;DR: An overview of the most representative problems solved by flow injection analysis (FIA) in drug analysis is presented and special emphasis is placed on the possibilities of FIA in dissolution test control.
68 citations
TL;DR: In this paper, a method for simultaneous determiantion of carbon dioxide and sulphur dioxide in complex matrices is proposed, which involves pre-separation of the analysis with a flow-through gas-diffusion unit.
59 citations
TL;DR: It is suggested that AFR may be involved in some plasma membrane events related to the initiation of plant cell elongation in merislems of Allium cepa roots by promoting a high vacuolization.
Abstract: . Ascorbate free radical (AFR) induced cell elongation in merislems of Allium cepa roots by promoting a high vacuolization as shown by the increased vacuole volume, vacuole volume density, tonoplast surface and tonoplast surface density. Accordingly, both plasma membrane- and tonoplast-associated ATPases and vacuole soluble acid phosphatase of meristematic cells were also increased. Neither the other subcellular organelles nor cell proliferation appeared to be significantly affected. It is suggested that AFR may be involved in some plasma membrane events related to the initiation of plant cell elongation.
57 citations
TL;DR: In this paper, an integrated retention/spectrophotometric method is proposed for the determination of iron based on the Fe (III)-thiocyanate complex, which has good selectivity, with a determination limit of 10 ng ml−1 and a linear range of 10−400 n−1.
55 citations
TL;DR: The differences found in growth and reproduction between the two age groups suggest that life-history tactics may vary not only between different stocks but also within the same stock among its different components.
Abstract: SUMMARY. 1. The age, growth and reproduction of the small, introduced fish Gambusia affinis (Baird & Girard, 1853) were studied in the estuary of the Guadalquivir river.
2. The life-span was very short, the stock contained only two age groups: with annulus (1+ group; 10–12 months old) and without annulus (0+ group).
3. In both sexes growth restarted in April when the annulus appeared, but whilst 1+ males stopped growth, 1+ females grew steadily to June. Growth of 0+ spawners was only evident in September, the last month of the reproductive period. A differential growth rate between sexes was also evident.
4. 1+ specimens reproduced during May and June and their offspring from July to September. In both age groups somatic condition progressively declined during the spawning period.
5. The loss of condition and the disappearance of 1 + and the larger 04-specimens after reproduction may indicate the cost of a prolonged high level of reproductive effort.
6. The total fecundity (taken as the number of embryos) of 1 + females was represented by the formula: Fec=5.08 T.L. (mm) -170.07 and that of 0+ specimens by: Fec=2.23 T.L. (mm) -42.92. The maximum average monthly fecundity was reached in June when the length of the mother was at its greatest.
7. Length at first maturity was smaller in 0+ group than in the 1 + group; the difference between the two groups was greater in males (≅5 mm, T.L.) than in females (≅3 mm, T.L.). Also the average total length of 14-spawners was greater than 0+ spawners. There were significant differences in the overall sex ratio of 956 males to 2057 females.
8. The differences found in growth and reproduction between the two age groups suggest that life-history tactics may vary not only between different stocks but also within the same stock among its different components.
54 citations
TL;DR: The results indicate that the increase in mast cell numbers was estrogen-dependent, specifically related to the testis and did not seem to be a consequence of the increased in the connective interstitial tissue.
Abstract: Mast cells in the testis of control adult rats were found almost exclusively around subcapsular blood vessels. Discrete mast cells were distributed throughout the stroma of the epididymis and sex accessory glands. In neonatally estrogen-treated rats, a greater number of mast cells was present in the testicular interstitium, whereas no significant increase in the number of mast cells per square millimeter of stroma was found for the epididymis and sex accessory glands, despite stromal proliferation. On the other hand, androgen-treated rats did not have increased mast cell numbers in any organ. These results indicate that the increase in mast cell numbers was estrogen-dependent, specifically related to the testis and did not seem to be a consequence of the increase in the connective interstitial tissue.
52 citations
Journal Article•
TL;DR: It was found that most patients with pollinotic patients sensitive to pollen grains from Chenopodium continued to show them until September each year, and on evaluation of the time evolution of the symptoms, most patients continued to shows them untilSeptember each year.
Abstract: We have studied the annual and daily variation of pollen grains from Amaranthaceae and Chenopodiaceae for 3 consecutive years. Samples of pollen grains from both families, which make a stenopalynologic group, were collected by the volumetric method with the aid of a Burkard spore-trap. These pollen grains were found to occur in the atmosphere of the city of Cordoba virtually throughout the year, although their presence was continual only between April and October with maximum concentrations detected in the summer months. We have also studied the daily variation of pollen concentration, which peaked between 10 AM and 3 PM. In order to determine the incidence of pollinotic patients sensitive to pollen grains from Chenopodium, we reviewed 1000 clinical records available in the Allergy Unit and found 8.42% to be allergic. On evaluation of the time evolution of the symptoms we found that most patients continued to show them until September each year.
TL;DR: By increasing biomass, as well as biomass production per unit water used, winter planting offers a promising avenue towards increasing sunflower yields in rainfed cropping systems of mediterranean climates.
TL;DR: These data show that ketoconazole induce marked changes on corticotrope morphology and ACTH secretion in pituitary cells obtained from patients with Nelson's syndrome.
Abstract: The direct effects of ketoconazole on the secretion of ACTH by human pituitary adenoma cells from 2 patient with Nelson's syndrome were studied in vitro. Stereologically quantified, intracellular changes affect the surface density of the endoplasmic reticulum (it decreased by 73%), the volume density of the secretion granules (it decreased by 49%), and the volume density of lysosomes (it decreased by 67%). The hormone released in the culture medium decreased depending on the doses of ketoconazole used; 10 mumol/l decreased ACTH levels by 31%. These data show that ketoconazole induce marked changes on corticotrope morphology and ACTH secretion in pituitary cells obtained from patients with Nelson's syndrome.
TL;DR: A classification analysis, based on 17 different European eel populations revealed that populations in brackish waters grew faster than those in fresh waters, but latitude also had an influence.
Abstract: A total of 1068 eels were examined from a population located in the Guadalquivir river estuary (37°N, 6°25′W). Maximum ages recorded were 4 + (males) and 7+ (females), and maximum lengths were 39-1 cm (males) and 54.1 cm (females). No growth was recorded between November and April, most occurring in May and, to a lesser extent, in June-October. Females grew to be larger than males. A classification analysis, based on 17 different European eel populations revealed that populations in brackish waters grew faster than those in fresh waters, but latitude also had an influence. Length-weight relationships obtained for three eel categories (males, females and undifferentiated) were used to estimate relative condition: condition cycles were similar between sexes, with increases in autumn and decreases in winter. There were monthly fluctuations in the sex ratio, and females dominated significantly in the combined catch (234 males/276 females).
TL;DR: The role of micellar media in analytical reaction-rate methods is discussed in this article, where the authors show that micelles in terms of sensitivity and enhanced selectivity are also discussed.
TL;DR: In this article, the use of ultrasonic treatment to accomplish partial solubilization of the sample components is applied to the determination of total boron in soils, eliminating time-consuming prior dissolution steps.
TL;DR: Allelic frequencies in Mediterranean countries are thus quite unstable and it is proposed that this phenomenon be called a “Mediterranean instability”.
Abstract: The relationship between allelic frequencies at the Adh locus and latitude of origin was studied using selected published data from various parts of the world and original observations. An overall increase of Adh-F with increasing latitude was observed but the relationship is not linear. Tropical populations are generally similar, having a low frequency of the F allele (average 15 per cent) and a smooth increase with latitude (one per cent for one degree). Between 30 and 42° latitude, populations living in a Mediterranean climate in various parts of the world (Mediterranean countries, Australia's east coast and North America's west coast) are also similar, with a much higher average frequency of F (70 per cent), a steeper slope (two per cent) and a broader range of variability for a given latitude. In a restricted area (near Cordoba in southern Spain) numerous wild collected samples also showed a large variability, sometimes over a very short distance. Allelic frequencies in Mediterranean countries are thus quite unstable and it is proposed that this phenomenon be called a “Mediterranean instability”. Further north, numerous samples from France were characterized by an even higher frequency of F (95 per cent) and a greater homogeneity over a broad geographic area. These observations are discussed and the need for more field studies is emphasized.
TL;DR: The study emphasizes and appraises the analytical features of the methods so far proposed and considers the determination of low molecular-weight substances, such as therapeutic agents, drugs of abuse and hormones.
TL;DR: In this article, the effects of surface dehydration on crystal unity, textural properties (surface area and pore volume) and surface acid-base properties of differently prepared AlPO 4 -Al 2 O 3 (75:25 wt%) systems have been studied.
TL;DR: Absorption spectra are resolved on the basis of lognormal distribution and a procedure is described for resolving absorption spectra in terms of skewed bands.
Journal Article•
TL;DR: A study on the annual and diurnal variation of pollen from the Gramineae family in the atmosphere of Córdoba (Southern Spain) during three consecutive years found this family is responsible for most of the pollenoses diagnosed in the city.
Abstract: We have carried out a study on the annual and diurnal variation of pollen from the Gramineae family in the atmosphere of Cordoba (Southern Spain) during three consecutive years. This family, according to its high sensitizing capacity and to data from allergologists, is responsible for most of the pollenoses diagnosed in the city. Pollen grains from Gramineae were found to occur in the atmosphere virtually throughout the year, starting in February. Yet, they reach their highest levels in spring, particularly in May and the first fortnight of June. Such levels decrease gradually during the summer and become virtually imperceptible from October. The concentration of pollen grains from Gramineae were found to be positively correlated with the average temperature, and negatively correlated with the average humidity. The diurnal variation pattern of the concentration of pollen grains from this family was rather homogeneous throughout the three years studied, with a marked increase early in the morning, a moderate decrease in the afternoon and stable values throughout the night.
TL;DR: In this paper, the extent and level of proteolysis were evaluated in Cabrales and five other European blue vein cheese varieties, Bleu de Bresse, Danablu, Edelpilzkase, Gorgonzola and Roquefort, by analysing their different N-containing constituents and determining the degree of casein hydrolysis.
Abstract: The extent and level of proteolysis were evaluated in Cabrales and five other European blue vein cheese varieties, Bleu de Bresse, Danablu, Edelpilzkase, Gorgonzola and Roquefort, by analysing their different N-containing constituents and determining the degree of casein hydrolysis. The electrophoretic patterns of the caseins in the cheeses confirmed their strong proteolysis, components featuring the lowest electrophoretic mobility offering the greatest resistance to subsequent hydrolysis. Component αs1 — I was detected in all varieties studied with the exception of Roquefort cheese.
TL;DR: In the phototrophic nonsulfur bacterium Rhodobacter capsulatus E1F1, L-Alanine dehydrogenase aminating activity functions as an alternative route for ammonia assimilation when glutamine synthetase is inactivated and deaminating activity participates in the supply of organic carbon to cells growing on L-alanine as the sole carbon source.
Abstract: In the phototrophic nonsulfur bacterium Rhodobacter capsulatus E1F1, L-alanine dehydrogenase aminating activity functions as an alternative route for ammonia assimilation when glutamine synthetase is inactivated. L-Alanine dehydrogenase deaminating activity participates in the supply of organic carbon to cells growing on L-alanine as the sole carbon source. L-Alanine dehydrogenase is induced in cells growing on pyruvate plus nitrate, pyruvate plus ammonia, or L-alanine under both light-anaerobic and dark-heterotrophic conditions. The enzyme has been purified to electrophoretic and immunological homogeneity by using affinity chromatography with Red-120 agarose. The native enzyme was an oligomeric protein of 246 kilodaltons (kDa) which consisted of six identical subunits of 42 kDa each, had a Stokes' radius of 5.8 nm, an s20.w of 10.1 S, a D20,w of 4.25 x 10(-11) m2 s-1, and a frictional quotient of 1.35. The aminating activity was absolutely specific for NADPH, whereas deaminating activity was strictly NAD dependent, with apparent Kms of 0.25 (NADPH), 0.15 (NAD+), 1.25 (L-alanine), 0.13 (pyruvate), and 16 (ammonium) mM. The enzyme was inhibited in vitro by pyruvate or L-alanine and had two sulfhydryl groups per subunit which were essential for both aminating and deaminating activities.
TL;DR: In this paper, the X-ray diffractograms and electron microscopy data reveal the occurrence of vacancy ordering in a tetragonal superstructure, which is similar to γ-Fe 2 O 3 in cubic phases and implies a ′ = a and c � = 3 c for tetragonally distorted spinels.
TL;DR: In this article, a method for determining the formation and decay rate constants of the chemiluminescence process based on a fitting program is presented. But the method is not suitable for the measurement of peak height or peak area.
TL;DR: In this paper, the principles and use of precipitate formation and dissolution in continuous flow systems are presented and discussed using automatic analytical methodologies such as indirect determinations of both organic and inorganic anions and preconcentration-determination of metal traces using an atomic absorption spectrophotometer.
Abstract: The principles and use of precipitate formation and dissolution in continuous flow systems are presented and discussed. Automatic analytical methodologies such as indirect determinations of both organic and inorganic anions and preconcentration-determination of metal traces using an atomic absorption spectrophotometer are compared with their batch (manual) counterparts.
01 Jan 1989
TL;DR: Three races of Fusarium oxysporum Schlecht, namely races 0, 5 and 6, infect chickpeas (Cicer arietinum L.) in Andalucia, southern Spain (Jimenez-Diaz et al unpublished).
Abstract: Three races of Fusarium oxysporum Schlecht. emend. Snyd. & Hans. f. sp. ciceri (Padwick) Snyd. & Hans (Foc), namely races 0, 5 and 6, infect chickpeas (Cicer arietinum L.) in Andalucia, southern Spain (Jimenez-Diaz et al unpublished). These races are different from races 1, 2, 3 and 4 described in India (Haware and Nene 1982). Race 0 induces a progressive foliar yellowing with vascular discolouration and late death of the plant (yellowing syndrome) mainly in local ‘kabuli’ cultivars, and it is not pathogenic to cultivar JG 62 which is the universal suscept to all other Foc races (Cabrera de la Colina et al 1985; Haware and Nene 1982; Trapero Casas and Jimenez-Diaz 1985). In contrast, races 5 and 6 induce a severe chlorosis and flaccidity, with vascular discolouration and early plant death (wilt syndrome), and they are highly virulent to most ‘kabuli’ and ‘desi’ cultivars (Cabrera de la Colina et al 1985; Jimenez-Diaz et al unpublished).
TL;DR: Analysis of internal fluctuations of ammonium, 2-oxoglutarate, and the amino acid pool as well as the variations of certain enzymes involved in carbon metabolism indicate that glutamate dehydrogenase animating activity is adaptative, being involved in the maintenance of intracellular levels of L-glutamate when they cannot be maintained by the GS-GOGAT cycle.
Abstract: . Under stress conditions (darkness, nitrogen starvation, high ammonium concentrations, glutamine synthetase and glutamate synthase inhibition) glutamate dehydrogenase animating activity levels of Chlamydomonas cells varied inversely to those of glutamine synthetase. Nitrogen and carbon sources also influenced glutamate dehydrogenase levels in Chlamydomonas, the highest values being found in cells cultured mixotrophically with ammonium, under which conditions glutamate dehydrogenase and glutamine synthetase levels were likewise inversely related. These facts, together with the analysis of internal fluctuations of ammonium, 2-oxoglutarate, and the amino acid pool as well as the variations of certain enzymes involved in carbon metabolism indicate that glutamate dehydrogenase animating activity is adaptative, being involved in the maintenance of intracellular levels of L-glutamate when they cannot be maintained by the GS-GOGAT cycle, and probably more connected with carbon than nitrogen metabolism.
TL;DR: A modular stopped-flow system and a new continuous-addition approach to fast reactions are presented and discussed and the implementation of these simple automated approaches is of great value in solving real problems.
Abstract: Kinetic-based determinations have been given a new impetus in the last few years by the automation of the instrumentation used in this field. In this article a modular stopped-flow system and a new continuous-addition approach to fast reactions are presented and discussed. The implementation of these simple automated approaches is of great value in solving real problems.
TL;DR: In this article, the convergence/stability results of two numerical methods for solving the nonstationary Navier-Stokes equations have been investigated, which are of a particular kind in what regards time discretization (more precisely, of the Peaceman-Rachford and the Strang type resp).
Abstract: This paper deals with some convergence/stability results concerning two numerical methods for solving the incompressible nonstationary Navier-Stokes equations The algorithms are of a particular kind in what regards time discretization (more precisely, of the Peaceman-Rachford and the Strang type resp), and have been obtained by modifying slightly the numerical treatment of the nonlinear terms in other schemes due to Glowinski et al (1980) We first describe the full discretization of the homogeneous Dirichlet problem using a (general) external approximation of the spatial functional spaces involved (a particular and simple choice of such an approximation is the standardP 2-Lagrange finite element for the velocity field when the fluid is bidimensional) Then we establish and prove convergence and stability and make some comments on the numerical treatment of other (generally nonhomogeneous) boundary conditions The theoretical results show that the schemes are (at least) conditionally stable and convergent, which justifies the success of Glowinski's methods