Showing papers by "University of Córdoba (Spain) published in 1982"

Regulation of the nitrate-reducing system enzymes in wild-type and mutant strains of Chlamydomonas reinhardii

Abstract: Six mutant strains (301, 102, 203, 104, 305, and 307) affected in their nitrate assimilation capability and their corresponding parental wild-type strains (6145c and 21gr) from Chlamydomonas reinhardii have been studied on different nitrogen sources with respect to NAD(P)H-nitrate reductase and its associated activities (NAD(P)H-cytochrome c reductase and reduced benzyl viologen-nitrate reductase) and to nitrite reductase activity. The mutant strains lack NAD(P)H-nitrate reductase activity in all the nitrogen sources. Mutants 301, 102, 104, and 307 have only NAD(P)H-cytochrome c reductase activity whereas mutant 305 solely has reduced benzyl viologen-nitrate reductase activity. Both activities are repressible by ammonia but, in contrast to the nitrate reductase complex of wild-type strains, require neither nitrate nor nitrite for their induction. Moreover, the enzyme from mutant 305 is always obtained in active form whereas nitrate reductase from wild-types needs to be reactivated previously with ferricyanide to be fully detected. Wild-type strains and mutants 301, 102, 104, and 307, when properly induced, exhibit an NAD(P)H-cytochrome c reductase distinguishable electrophoretically from contitutive diaphorases as a rapidly migrating band. Nitrite reductase from wild-type and mutant strains is also repressible by ammonia and does not require nitrate or nitrite for its synthesis. These facts are explained in terms of a regulation of nitrate reductase synthesis by the enzyme itself.

Physicochemical Changes Occurring During Storage of Precured Beef Blends at Different Temperatures and Two Levels of Salt

Abstract: Preblends of lean beef (20% water, 75 ppm nitrite, 3 or 6% salt) were stored at -10, 0 and 15°C and samples were analyzed at 0, 1, 2 and 3 days of storage. Emulsifying capacity (per 100 mg of total protein) was not significantly different between the 3 and 6% salt levels; and, was not significantly affected by storage temperature but decreased with storage time. The viscosities of the extracts were not significantly affected by the amount of added salt or the temperature of storage; however, they increased significantly during storage. Water-holding capacity increased significantly with the quantity of salt and length of storage time. Correlation analysis resulted in a negative correlation between pH and viscosity and a positive correlation between pH and salt soluble proteins. Surprising was the significant negative correlation between emulsifying capacity and water-holding capacity.

Les peuplements de fourmis dans la Sierra Morena centrale (Espagne) rapports avec l'exposition et la vegetation

Abstract: Le but de ce travail est d'etudier l'influence d'un facteur biotique (la vegetation) et d'un facteur abiotique (l'exposition) sur la distribution des especes de fourmis dans une zone de la Sierra Morena Centrale (Sud de l'Espagne). Pour cela, on a realise des echantillonnages stratifies dans chaque unite de vegetation, en soulane et en ombree.

Immunohistochemical detection of adenohypophyseal cells containing hormones in Rana ridibunda

Abstract: The pars distalis of the pituitary of Rana ridibunda captured throughout the spring and summer was examined with immunofluorescence techniques using antisera to mammalian pituitary hormones. On the basis of their immunoreactivity, four different cell types of recognized: 1) cells immunoreactive to anti-bovine LTH, 2) cells immunoreactive to anti-bovine STH, 3) cells immunoreactive to anti-ovine LH, and 4) cells immunoreactive to anti-synthetic ACTH beta (1-24). Their distribution and morphology as well as their staining characteristics (classical histological techniques) are reported in this study.

Kinetic Fluorimetric Determination of Microamounts of Copper by its Catalytic Effect On The Hydrolysis of 2-Hydroxybenzaldehyde Azine

Abstract: A kinetic fluorimetric method is developed for the determination of microamounts of copper(II) on the basis of its catalytic activity on the hydrolysis of 2-hydroxybenzaldehyde azine. To monitor the reaction, the appearance rate of fluorescence in the hydrolysis reaction product, the 2-hydroxy benzaldehyde hydrazone (λexe = 355 nm., λem = 465 nm.), is measured. The determination of copper at the 100–500 ng/ml level suffers very few interferences. The mechanism of this catalyzed reaction is proposed.

Reduction by hydrogen transfer processes, II. Reduction of substituted derivatives of benzaldehyde

Abstract: In the present paper, date are reported on transfer hydrogenation of aromatic aldehydes with commercial and synthetic Pd catalysts, based on SiO2−AlPO4 (20∶80 mass). Cyclohexenes and α,β-unsaturated alcohols have been tested as hydrogen donors. The reaction products obtained upon reduction of benzaldehyde were benzyl alcohol and toluene (hydrogenation) and benzene and formaldehyde (hydrogenolysis), while methyl, ethoxycarbonyl and hydroxyl groups also present are not affected by the reaction. The selectivity towards each product depends on both the hydrogen donor and the catalyst used. When electron-donor substituents exist on the substrate, a decrease of the reaction rate towards the hydrogenolysis products is observed.

Pyridoxal Nicotinylhydrazone as Fluorimetric Reagent for the Determination of Zinc by Ternary Complex FORMATION

Abstract: A new spectrofluorimetric method for the determination of zinc using pyridoxal nicotinylhydrazone as the reagent has been developed. This system forms a ternary complex with ammonia, ethylenediamine or pyridine with a stoichiometry ratio of 1:1:1. The interferences of foreign ions have been determined.

Topografía craneoencefálica del caballo (Raza española) basada en métodos radiológicos

Abstract: A study of cranial topographic anatomy was carried out in adult horses, with attention to the topography of parts of the brain. These studies included radiographic studies of the skull, with and without radiographic contrast media injected into the cerebral ventricles. Radiographic studies were correlated with cross sectional anatomic drawings made in saggital and transverse coordinates upon clear plastic which were overlaid onto radiographs for localization of anatomic structures. The methodology and results are outlined in detail. The significance of cranio-encephalic topographic anatomy is discussed. Resumen Se realize un estudio topografico del craneoencefalo del caballo mediante tecnicas radiologicas, en base a radiografi laterales (Paralelas al plano mediano) y ventrodorsales (paralelas al plano basicraneal) obtenidas nates y despues de someter los especimenes, bajo control radioscopico, a inyeccion topografica y topometrica de las fimagenes radiograficas se base en la utilizatio de caudriculas ortometricas disenadas en acetatos a laminas transparentes superponibles a dichas imagenes y sobre las que se trasan sistemas cartesianos XY y XZ, proporcionales a las cabezas de superficie y su correlacion topografica con estructuras encefalicas, precisar la trayectoria de los ejes y planos basicraneales y basiencefalicas, precisar la trayectoria de los ejes y planos basicranelaes y basiencefalicas, precisar la trayectoria de los ejes y planos basicraneales y basiencefalicos, valorar los ejes y angulo craneofaciales y establecer ejes complementrrios de seccion. Todos estos datos, son objeto de una ulterior comprobacion mediante el analisis de cortes anatomocos fde los craneoencefalos funtilizados en los niveles que se preconizan, asi como a partir de las imagenes homalograficas corresfpondientes. Zysannebfassybg Rontgenologische Untersuchungen zur krabuiebzeogakeb Tioigraogue des Oferdes (soabuscge Rasse) Eine topographische Untersuchung des Hirnschadels des Pferdes wird mit Hilfe der Rontgentechnik durchgefuhrt. Jeweils vor und nach der Injektion kontrolle werden Rontgenaufnahmen im laterolateralen und ventrodorsalen Strahelengang hergestellt. Die topographische und topometrische Auswertung der Aufnahmen erfolgte unter Verwendfung orthometrischer Zeichennetze auf durchsichtigen Plastikfolien und mittels des Systems Cartessischer Koordinaten. Auf diese Weise werden Strukturen des Gehirns und des Schadels aufgezeichnet und entsprechende Ebenen, Achsen und Winkel festgelegt. Die Uberprufung der erhobenen Daten erfolgte am anatomischen schnittpraparat. Summary The craniocephalic topography in the Horse (Spanish breeds) based on radiologic methodologies A topographic examination of cranium was conducted in the horse, with the aid of radiography. Intraventricular injection of radiographic contrast cranial structures. Topographic and topometric examination of radiographs were made with the aid of plastic overlays and a system of Cartesian coordinates were plotted for structure localization. Resume Topographie crânio-encephalique du Cheval (Race espagnole) basee sur les methodes radiologiques On a realise une etude topographique crânio-encephalique du Cheval par des techniques radiologiques, a l'aide de prises de vue laterales (paralleles au plan median) et ventro-dorsales (paralleles au plan basicrânien)effectuees avant et apres injection ventriculaire directe par trepanation, sous controle radioscopique, de liquide de contraste. L'explotation topographique et topometrique des images radiologiques repose sur I'utilisation de quadrillages orthometriques sur feuilles plastiques transparentes, superposables aux cliches et pourvues d'un systeme de coordonnees cartesinnes XY et XZ, tracees en rapport avec la taille des tetesf utilisees. De cette maniere il a ete possible de determiner les points de reperes de surface et leur correlation topographique avec les structures encephaliques, de preciser la trajectoire des axes et des plans basi-crâniens et basi-encephaliques, d'estimer les axes et angles crâniofaciaux et d'etablir des axes eomplementaires de sectionl. Ces domuments ainsi realises out ete ulterieurement compares aux coupes anatomiques des pieces utilisees, en section et lieu %eAquivalents, ainsi qu'aux images homalographiques correspondantes.