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Showing papers by "University of Córdoba (Spain) published in 1980"


Journal ArticleDOI
TL;DR: Gibberellic acid increased the content of reducing sugars, especially in K-deficient plants, and osmotic potential differences within the elongating first internode were increased by GA3 treatment.
Abstract: The effects of gibberellic acid (GA3) on whole sunflower (Helianthus annuus L.) plants grown at three potassium (K) levels (0.0, 0.5 and 5.0 mM) were studied. A tenfold increase in the length of the first internode was observed when plants grown without K were treated with GA3. The uneven K distribution along the plant (higher K content in the higher internodes) was enhanced by GA3 treatment. Gibberellic acid increased the content of reducing sugars, especially in K-deficient plants. An increase in the K level in the nutrient solution resulted in a decrease of the osmotic potential of stem segments. Osmotic potential differences within the elongating first internode were increased by GA3 treatment.

95 citations


Journal ArticleDOI
TL;DR: Although catalytic methods continue their dominance in the number of methods published, a noticeable decrease in the use of inhibition and activation of catalytic systems has been observed in the past 2 years.
Abstract: The organizational structure of previous reviews has been, basically, retained in the preparation of this report. The papers reviewed have been selected from those that appeared since November 1983 and were received for the authors' consideration through approximately November 15, 1985. Although catalytic methods continue their dominance in the number of methods published, a noticeable decrease in the use of inhibition and activation of catalytic systems has been observed in the past 2 years. Worth noting also is the increased use of electrochemical techniques in general and in flow systems in particular. Differential procedures have shown an increase in the number of papers dedicated to them in the past 2 years. 323 references, 2 tables.

57 citations


Journal ArticleDOI
TL;DR: Fluorimetric methods for the determination of mercury(II) (80-320 ppb) and copper(II)-II (0.4-1 ppb), which catalyse the autoxidation of 2,2'-dipyridylketone hydrazone, were described in this paper.

31 citations


Journal ArticleDOI
TL;DR: In this article, the liquid phase reduction of different substituted nitrobenzene derivatives with the formic acid-triethylamine system has been carried out by the use of a supported palladium (0,6%) on AlPO4/SIO2 (20:80 weigth) catalyst.
Abstract: The liquid phase reduction of different substituted nitrobenzene derivatives with the formic acid-triethylamine system has been carried out by the use of a supported palladium (0,6%) on AlPO4/SIO2 (20:80 weigth) catalyst. The reduction rate of nitrocompounds containing electron-acceptor substituents is much higher than that of electron donor-containing substrates.

16 citations


Journal ArticleDOI
TL;DR: Diphenylglyoxal bis(2-hydroxybenzoylhydrazone) forms an orange-yellow complex with titanium(IV) in weakly acid solution as discussed by the authors.

15 citations


Journal ArticleDOI
TL;DR: In this article, the authors present a number of critical reflections on some ideological distortions which have adversely biased research on the peasantry as a class, as a cultural universe and as a political force.
Abstract: SUMMARY This paper presents a number of critical reflections on some ideological distortions which have adversely biased research on the peasantry as a class, as a cultural universe and as a political force. The authors look at the two main traditions in the theory of modernization - the “liberal” and the “marxist” - to prove that both assume the disappearance of the peasantry as a necessary event and that therefore the peasantry as such has inevitably become scientifically uninteresting for their representatives. They explore each tradition in some detail and establish the existence of a certain amount of open hostility towards the peasantry among certain sociologists, economists, planners, and policy makers. Significant countertrends in current rural sociology are, however, detected and a conclusion calls for greater attention to the values and possibilities of peasant culture and life, without falling into a romanticised vision of the peasantry, is reached in the end. Resume Cet article propose un ensemble de reflexions critiques a propos des deformations ideologiques qui ont influencee negativement la recherche sur la paysannerie que ce soit comme classe, comme univers culturel ou comme force politique. Les auteurs interrogent les deux principaux courants de la theorie de la modernisation - le courant “marxiste” et le courant “liberal”. lis montrent que chacun d'eux postule la disparition de la paysannerie comme un fait necessaire, que, des lors, celle-ci est devenue un objet de peu d'interet scientifique pour les representants de ces courants. lis analysent ces traditions theoriques en detail, et mettent a jour un certain degre d'hostilitye ouverte a L'egard de la paysannerie de la part de certains sociologues, economistes, planificateurs ou decideurs. Toutefois des tendances inverses dans la sociologie rurale contempo-raine sont signalees; et, sans tomber dans une vision romantique de la paysannerie, la conclusion appelle a une plus grande attention aux vaieurs at aux possibilites de la vie et de la culture paysannes. Zusammenfassung Dieser Artikcl stellt eine Reihe kritischcr Gedanken zu einigen ideologischen Verzerrungen vor, die die Forschung uber die Bauern als eine Klasse, eine kulturelle Einheit und als eine politische Kraft nachteilig beeinflust haben. Die Autoren betrachten die beiden traditionellen Hauptrichtungen der Modernisierungstheorie - die “liberale” und die “marxistische” - und stellen fest, das beide das Verschwinden der bauerlichen Landwirtschaft als eine norwendige Entwicklung ansehen und deshalb die Bauern als solche unvermeidlich wissenschaftlich uninteressant geworden sind fur ihre Reprasentanten. Sie untersuchen jede dieser Forschungstraditionen genauer und weisen eine gewisse Zunahme offener Feindschaft gegenuber den Bauern bei einzelnen Soziologen, Okonomen, Planern und Politkern nach. In der gegenwartigen Landlichen Soziologie werden jedoch auch bedeutsame Gegenstromungen entdeckt und am Ende wird die Schlusfolgerung gezogen, das grosere Aufmerksamkeit den Wertvorstellungen und Entwicklungsmoglichkeiten der bauerlichen Kultur und des bauerlichen Lebens geschenkt werden sollte, ohne in eine romantische Verklarung des Bauertums zu verfallen.

10 citations


Journal ArticleDOI
TL;DR: Diphenylglyoxal bis(2-hydroxybenzoylhydrazone) has been used as a sensitive reagent for the spectrophotometric determination of tin this article.

10 citations


Journal ArticleDOI
01 Aug 1980-Talanta
TL;DR: Monitoring the fluorescence provides one non-kinetic and three kinetic methods for determination of Ti(IV) at the 60-400 ng/ml level and the variables affecting these methods have been optimized and the tolerance levels for foreign ions determined.

9 citations


Journal ArticleDOI
TL;DR: In this article, a kinetic method is described for the determination of trace amounts of magnesium in the presence of calcium, based on the inhibition of the manganese(II) catalyzed aerial oxidation of 1,4-dihydroxyphthalimide dithiosemicarbazone reaction by 2.

9 citations


Journal ArticleDOI
TL;DR: In this paper, the determination procedures are based exclusively on the different pH values of the formation complexes, hence the extraction step is not necessary, and have been applied to the analysis of these metal ions in binary, ternary, and quaternary mixtures.

8 citations


Journal ArticleDOI
01 Jul 1980-Talanta
TL;DR: The synthesis, characteristics and analytical properties of diphenylglyoxal and dipyridyl Glyoxal bis(benzoylhydrazone)s are described and reactions with common cations are reported.

Journal ArticleDOI
TL;DR: In this paper, a potentiometric method for the determination of thiosemicarbazones involving the formation of a complex with Ag(I) was described, and the stability constants of the complexes were determined by Ringbom and Harju's method.

Journal ArticleDOI
TL;DR: Cell activation, because of either the normal active period in the frog cycle or the experimental treatments, seems to be correlated with the occurrence annulate lamellae.

Journal ArticleDOI
TL;DR: The high zinc content found in pancreatic islet cells and in the hippocampus suggests a functional relationship with the endocrine pancreas and the ammon's horn, and two cross‐over experiments using rats conducted in which alternating lesions were created.
Abstract: The high zinc content found in pancreatic islet cells and in the hippocampus suggestsa functional relationship. Two cross-over experiments using rats were conducted in whichalternating lesions on the endocrine pancreas and in the ammon's horn were created.