Investigations on the phosphoenolpyruvate carboxylase activity of spruce needles relative to the occurrence of novel forest decline

1991

Summary Investigations were carried out on phosphoenolpyruvate carboxylase (PEPC) activity in needles of Norway spruce trees [ Picea abies (L.) Karst.] at two natural sites during the course of three vegetation periods. PEPC activity found in needles of damaged trees was considerably higher than in needles of undamaged trees. Annual average figures varied up to 100%. The positive correlation between PEPC activity and the extent of damage of the investigated needles indicates a significant relationship between both parameters: the PEPC activity in spruce needles seems to be not only a qualitative, but also a quantitative indicator of the extent of damage. Higher PEPC activity in needles of d…

Elementary theory and brief history

1991

In the history of the theory of deuteron photodisintegration one may distinguish roughly three periods: (i) the primitive period of the elementary theory using very simple wave functions and forces and considering lowest multipoles (E1, M1) only, (ii) the classical period still in the framework f conventional nuclear physics, but using realstic forces with correspondingly elaborate wave functions and considering also higher multipole transitions, (ii) the post-classic period with explicit treatment of subnuclear degrees of freedom like meson and isobar degrees of freedom and very recently quark-gluon degrees of freedom.

Intracellular glutathione in human hepatocytes incubated with S-adenosyl-L-methionine and GSH-depleting drugs

1991

Abstract The present study was undertaken to investigate (a) whether S- adenosyl- L -methionine (SAMe) added to culture medium can increase intracellular glutathione (GSH) levels in human hepatocytes and (b) whether SAMe can prevent the GSH depletion found in human hepatocytes incubated with GSH-depleting drugs (paracetamol, opiates, ethanol). Incubation of hepatocytes with increasing concentrations of SAMe resulted in a dose-dependent elevation of intracellular GSH content, which reached its maximum (35% increase) at 30 μM after 20 h. SAMe, as the only sulfur source in the medium, was efficient in repleting GSH-depleted hepatocytes following treatment with diethyl maleate. Incubation of hu…

"Les Heures Bourguignonnes" : une relecture communiste de l'histoire locale (1937-1939)

1991

International audience; De janvier 1937 à août 1939, le Travailleur, hebdomadaire régional du Parti communiste, consacre chaque semaine une notice à l'histoire bourguignonne. Cette relecture communiste de l'histoire locale s'inscrit dans un contexte général de réappropriation par les communistes de l'histoire nationale. L'étude de ce contexte politico-culturel permet de mieux comprendre les finalités et modalités d'application de l'initiative du journal communiste.

La acumulación del capital comercial a través de la documentación notarial (algunas reflexiones acerca de la obra de Jaqueline Guiral)

1991

Las servidumbres de una epistemología utópica: la sociedad valenciana en "Valencia, puerto mediterráneo en el siglo XV"

1991

Laminar Micrite Crusts and Associated Foreslope Processes, Red Sea

1991

ABSTRACT Forereef slopes in the Red Sea of Sudan exhibit a uniform biozonation that is independent from the topography of the slopes. Below - 120 m, ledges protrude horizontally from sleep cliffs of barrier reefs and atolls as well as from patches of in situ lithified slope sediment on inclined fringing reef slopes. Free surfaces and cavities within these ledges are partly covered by laminar micrite crusts of 7-20 mm thickness. The ledges are formed by an organic framework of living azooxanthellate corals, bryozoans, serpulids and fossil red algae. They are affected by repeated episodes of boring, infilling, and cementation which obliterate much of the original fabric. Concomitant cementati…

Ergebnisse der Endosonographie bei der präoperativen Stadienbeurteilung von Ösophagus- und Magenkarzinomen

1991

Durch die Entwicklung flexibler Fiberendoskope, in deren Spitze eine Schallsonde integriert ist, hat die Diagnostik gastrointestinaler Tumoren eine wesentliche Erweiterung erfahren. Die Endosonographie erlaubt eine systematische Untersuchung der einzelnen Darmwandschichten sowie angrenzender Lymphknoten und Nachbarorgane. Im folgenden mochten wir unsere Erfahrungen mit der Endosonographie bei der praoperativen Stadienbeurteilung von Osophagus- und Magenkarzinomen vorstellen.

The Development of Spatial Location in Finnish

1991

Abstract The purpose of this research was to study the shift from mono- to bi-referential spatial location in the language of Finnish children. Monoreferential location is based on the intrinsic properties of a referent object and the proximity relationship, and bireferential location requires coordinated spatial relationships involving referent objects and a projective relationship. Locative expressions which are monoreferential include: in/on/under and intrinsic front/back, and those which are bireferential include deictic front/back and between. A pictorial representation of locative relationships with a sentence-picture matching task was used to present the mono- vs bi-referential contr…

Pathophysiological approaches to identifying tumor hypoxia in patients

1991

The present report summarizes observations of the authors on tumor oxygenation and on techniques for characterizing tumor hypoxia in patients. Cryospectrophotometric measurements of HbO2 saturations in tumor microvessels allow for estimates of the proportion of well oxygenated tissue regions. Labeling of tissue areas at oxygen (O2) tensions (pO2) less than 10 mm Hg with misonidazole may be used for a general characterization of the oxygenation status in patient tumors rather than for the determination of the radiobiologically hypoxic cell fraction. Quantitative bioluminescence and single photon imaging make it possible to determine ATP concentrations in absolute terms with a spatial resolut…

REY GONZÁLEZ, Antonio. Estudios médico-sociales sobre marginados en la España del siglo XIX [Reseña]

1991

Estudios médico-sociales sobre marginados en la España del siglo XIX [Reseña]

Genetic control of pheromones in Drosophila simulans. I. Ngbo, a locus on the second chromosome

1991

0016-6731 (Print) Journal Article; 7-Tricosene and 7-pentacosene are predominant hydrocarbons on the cuticle of both sexes in Drosophila simulans. The pheromonal role of 7-tricosene has been clearly established for conspecific males, while a synergistic effect for 7-pentacosene has been postulated. Interstrain variation for the production of both compounds is very marked, but similar for both sexes. The genetic basis of this polymorphism was investigated. A major role was found for the second chromosome, which controls the 7-tricosene:7-pentacosene ratio. The main locus involved in controlling this variation, Ngbo, was mapped to position 65.3 on the second chromosome. The production of 7-pe…

The Construction of Subjectivity

1991

The doctrinal antagonisms that have appeared in the history of philosophy have often been an expression of tensions existing in those very problems that have generated philosophical thinking. I think that the fundamental task of phenomenology must consist in the clarification of those problems, insofar as they are constituted by strictly phenomenal situations that have provided both the riddles provoking philosophical theories as well as the basic materials for their theoretical construction.

Explanation of Notation

1991

For the presentation of all 288 polarization observables in the next section we have adopted the following scheme. Each observable is a function of the angle and the photon energy. With respect to the latter we have chosen five energies, namely 4.5 MeV, the maximum of the total cross section, 20 MeV, 60 MeV, 100 MeV, and 140 MeV. For each observable and for each of these energies we have studied the following topics: (i) The influence of meson exchange currents (MEC), isobar configurations (IC) and relativistic corrections (RC). Since the various potential models give qualitatively very similar results, we use in this case the r-space version of the Bonn model (OBEPR). (ii) The contribution…

Variational Cluster Methods in Coordinate Space for Small Systems: Center of Mass Corrections Made Easy

1991

A reexamination of the center of mass problem for light systems in the context of coupled cluster theory has produced a new variational version of the method which is developed entirely in coordinate space. It involves independent cluster functions which depend only on the relative coordinates of the subclusters of the system. In applications to the 4He nucleus described via a number of phenomenological and quasirealistic microscopic Wigner potentials, the method is shown to be quantitatively rather accurate, producing in all cases almost exact results for the ground-state energies at the SUB(3) level of approximation.

Selective effects of some anesthetics and detergents on lipid peroxidation of mouse heart homogenates.

1991

Abstract 1. 1. The effects of some anesthetics and detergents on the Fe2+/ascorbate-stimulated non-enzymatic lipid peroxidation potential and on the NADPH-dependent enzymatic lipid peroxidation capacity were characterized in mouse heart homogenates. 2. 2. Chlorpromazine turned out to be the most efficient inhibitor, causing a 50% inhibition at a concentration of 0.03 mM in the non-enzymatic assay, and at a concentration of 0.02 mM in the enzymatic assay. 3. 3. Tetracaine was about a 10-times weaker inhibitor with IC50-values of 0.25 mM. High concentration of dibucaine (1 mM) exerted a 60% inhibition in the non-enzymatic assay, but lidocaine and procaine had no prominent effect with the conc…

Quelques réflexions sur le coût et le financement de l'éducation

1991

International audience; Les activités de formation mobilisent des ressources rares : main d'oeuvre qualifiée, bâtiments, équipements, etc ... Ce coût doit être évalué si on veut faire les choix optimaux et si on souhaite comparer différentes filières et différents systèmes. Mais la mesure du coût de l'éducation pose beaucoup plus de problèmes que celle du coût d'un bien marchand ordinaire. Les données disponibles doivent être interprétées avec précautions, même si elles donnent des ordres de grandeurs intéressants. Les prévisions concernant les besoins de financements créés par les objectifs très volontaristes retenus par les pouvoirs publics français, font appara\ⁱtre un déséquilibre impor…

Un criminaliste bourguignon : François Serpillon (1695-1772)

1991

International audience

Numerical approximation of mixed models for digital integrated circuits

1991

To analyse an electrical network many CAD (Computer Aided Design) circuit simulators are available today. The most well-known is probably SPICE -Nagel [1975]. Although this type of simulator is able to precisely compute the transient performances (as delay time), the usage of complete models of devices implies an extremely high time consumption. So, the circuit simulators are unappropriate for the initial stage of VLSI design where a high speed timing analyser (“timing simulator”) is required. To this goal, alternative approaches using either simpler device models or simpler numerical algorithms or easily computable formulae for delay time approximation, have been developed in the past deca…

Actual physical and chemical problems of ferroelectrics

1991

UTILIZZO DI UNA POMPA DI CALORE ELIOASSISTITA IN UNA CANTINA DELLA SICILIA OCCIDENTALE

1991

Special Calixarenes, Synthesis and Properties

1991

In the previous chapter the standard one step procedures for the synthesis of calixarenes from p-tert-butyl phenol and several p-alkyl phenols have been described. However, these procedures necessarily lead to calixarenes consisting of one single type of phenolic unit. This remains true even for those compounds in which all the terf-butyl groups are removed and replaced by other functional groups. The construction of more sophisticated, special calixarenes which could serve for instance as enzyme models, requires new synthetic approaches capable of producing molecules with selected functionalization.

Nonrelativistic limit of superfield theories

1991

Condensation nuclei measurements at theGeorg von Neumayer-Station (F.R.G.), Coastal Antarctica

1991

The analysis of nearly continuous records of surface-based atmospheric condensation nucleiconcentration (CNC) since 1984 up to the present at the Georg von Neumayer-Station (GvN) shows clearly: u - an annual cycle of CNC with low values in winter time; - a significantly increasing frequency of CNC of more than 1000 particles per cm3 over the years.

Cholinergic–Adrenergic Presynaptic Interactions in the Heart and Characterization of the Receptors Involved

1991

ABSTRACT The rabbit perfused atria preparation with the extrinsic sympathetic and vagus innervation intact has been used to study the mutual interactions between the two branches of the autonomic nervous system by measuring the respective transmitter overflow rates upon electrical stimulation. Using this method the stimuli exciting vagus and sympathetic nerves can be applied at selected time intervals which provides an advantage over the common method of field stimulation where all kinds of neurons are stimulated simultaneously. In the absence of drugs, presynaptic interactions resulting in a decreased noradrenaline overflow occurred when the vagal stimuli preceded the sympathetic ones by 3…

Digestion and absorption of polyunsaturated fatty acids

1991

Polyunsaturated fatty acids play an important part in the structure and function of cellular membranes and are precursors of lipid mediators which play a key role in cardiovascular and inflammatory diseases. Dietary sources of essential fatty acids are vegetable oils for either linoleic or alpha-linolenic acids, and sea fish oils for eicosapentaenoic and docosahexaenoic acids. Because of the specificity of the pancreatic lipid hydrolases, triglyceride fatty acid distribution is an essential parameter in the digestibility of fats. The efficiency of the intestinal uptake depends on the hydrolysis and especially on their micellarization. n-3 polyunsaturated fatty acid ethyl ester digestion is …

Katalizator tytanowo-magnezowy polimeryzacji etylenu na podstawie MgCl2 kompleksowanego octanem etylu

1991

The activity of titanium-magnesium catalysts in the low-pressure polymerization of ethylene was investigated. MgCl2 modified with ethyl acetate was used as catalyst carrier. The effect of main parameters of catalyst synthesis and of polymerization conditions (e.g. of Mg; Ti- molar ratios and of titanium concentration) and the effect of ethyl acetate (as an internal or as an external base) on the catalytic system activity was determined. The kinetics of ethylene polymerization in the case of catalysts containing ethyl acetate bound originally either with MgCl2 or TiCl4 was compared.

Lateralidad motora y esquizofrenia

1991

Preliminary-Analysis of the Pentad of 13CH4 from Raman and Infrared-Spectra

1991

0022-2852

El Triásico de Alicante: un efecto Lázaro en los estudios paleontológicos.

1991

The Triassic Bivalves study from Alicante (Spain) was a very important subject for paleonto logists at the begin­ ning of this century. A lot of new Spanish Triassic species were described in this Prebetic zone. The revision of the Triassic fossil collections of the 'Museu Historie Municipa l' of Novelda (Alicante) has allowed us now to point out the interest in the study of this Muschelkalk record. The revised associations are very closed to those in the Subbetic zone and Iberic Range in the Ladinian. El estudio de los Bivalvos del Triásico de Alicante, llamó poderosamente la atención a paleontólogos de princi­ pios de siglo. Muchas de las especies nuevas del Triásico español fueron creada…

Modèles morphométriquesen paléontologie évolutive

1991

Resume La mise en evidence des changements evolutifs est longtemps restee fondee sur des appreciations qualitatives des differences morphologiques. Puis la formulation du concept d'espece biologique a suscite des approches populationnelles et quantitatives. Cependant les demarches classiques font appel a des mesures lineaires qui ne donnent qu'une image approchee de la forme et de ses changements. Pour repondre aux besoins de quantification et de modelisation de la forme des organismes, deux autres types de modeles sont presentes: 1) des modeles analogiques qui s'appuient sur des parametres mathematiques generant des representations geometriques analogues aux formes des organismes; 2) des m…

Les mécanismes de défense des plantes

1991

National audience

Development of New Antiasthmatic Drugs from Traditional Medicine?

1991

Several plants are used in traditional medicine in the treatment of bronchial asthma. We are trying to identify the active compound(s) and their mode of action.

Linear and ellipsoidal restrictions in linear regression

1991

The problem of combining linear and ellipsoidal restrictions in linear regression is investigated. Necessary and sufficient conditions for compactness of the restriction set are proved assuring the existence of a minimax estimator. When the restriction set is not compact a minimax estimator may still exist for special loss functions arid regression designs

Las medidas cautelares indeterminadas (Art. 1428 Lec.)

1991

On maximal subgroups of finite groups

1991

(1991). On maximal subgroups of finite groups. Communications in Algebra: Vol. 19, No. 8, pp. 2373-2394.