Comportement des bacheliers : modèle de choix de disciplines

1979

The paper tries to take into account the choices taken by the high school graduates at the time of their immatriculation in higher education. The purpose is not a statistical description, but an attempt to test theoretical hypothesis of the individual behaviour. The analytical framework is based on the trade-off carried out by every student between the economical attractiveness of the different fields of education and professional careers which are linked on one hand, and the personal probability of success in every field on the other hand. In a first section, success models are estimated in various disciplines to get estimations of the objective chances of success for every student in ever…

The mechanism of epithelial shedding after ischemic damage to the small intestinal mucosa

1979

The intestinal mucosa of the rat was examined by light and electron microscopy 15, 30, 60 and 120 min after complete ligation of the vessel arcades of the proximal jejunum. The characteristic sign of ischemic damage to the small intestinal mucosa and the reason for epithelial shedding is the appearance of membrane enclosed cytoplasmic blebs which arise at the cell base of the enterocytes and detach the epithelium from the basement membrane. This process begins at the tip of the villi before the enterocytes display signs of irreversible damage and progress to the base of the villi with continuation of the ischemia.

Studies on the mechanism of mineralocorticoid-induced blood pressure increase in man.

1979

1. To gain insight into the mechanism of mineralocorticoid-induced blood pressure rise in man we performed haemodynamic studies in six normotensive volunteer subjects before and during administration of the synthetic steroid 9α-fluorocortisol (0·8 mg daily) for a period of 6 weeks. In a further study, performed in seven subjects, plasma noradrenaline concentration and reactivity to exogenous noradrenaline were determined before and during administration of the mineralocorticoid. 2. Within the first week of steroid administration an increase in mean arterial blood pressure could be demonstrated, which was due to an increase in cardiac output. After the sixth week the elevated blood pressure …

The Influence of Sex, of Castration in New-Born Males and of Androgen Treatment in New-Born Females on the Mouse-Killing Behaviour of the Rat

1979

AbstractThe results we have got on the mouse-killing behaviour of the rat point out the remarkable percentage difference between control males and control females, between integral males and males castrated at birth, and between normal females and females under the effects of androgens.Such results make us believe that the appearance of the killer behaviour is affected by the presence of testosterone in the first days of life of the rat.

�ber Kreisebenen mit Potenzlinie

1979

Interaction of phenylbutazone with racemic phenprocoumon and its enantiomers in rats.

1979

The interaction of phenylbutazone with the enantiomers and racemic [ 3 H]phenprocoumon was studied in male inbred Wistar-Lewis rats following a single i.v. dose of the three forms of phenprocoumon and chronic oral treatment with phenylbutazone (average plasma concentration of about 60 Μg/ml). Phenylbutazone augmented the anticoagulant effect of R(+), S(−), and R, S (±) phenprocoumon to a similar extent. The free fraction of drug in the plasma of the enantiomers and racemic phenprocoumon increased in the presence of phenylbutazone. However, the rate of elimination of total drug from plasma and liver and the distribution between liver and plasma of all three forms of phenprocoumon remained ne…

Le ralentissement de la croissance des dépenses publiques d'éducation dans le monde

1979

Téléchargeable sur le site du CREDOC : https://www.credoc.fr/publications/revue-consommation-le-ralentissement-de-la-croissance-des-depenses-publiques-deducation-dans-le-monde; International audience; Le but de cette brève note est de retracer l’évolution des dépenses publiques d’éducation dans le monde, de montrer que l’euphorie des années 60, durant lesquelles l’éducation bénéficiait d’une priorité incontestée, ne trouve plus sa traduction dans un accroissement des budgets, mais que l’on assiste au contraire à un sensible ralentissement. D’où la question : à la théorie des années 60 établissant un lien positif, étroit et consistant entre les dépenses d éducation et la croissance économiqu…

31. Lokalisationsdiagnostik beim Hyperparathyreoidismus

1979

Im Hinblick auf die hohe chirurgische Erfolgsrate beim Auffinden pathologischer Epithelkorperchen ist eine invasive Lokalisationsdiagnostik mit Angiographie und selektiver Blutentnahme zur PTH-Bestimmung vor Erstoperationen nicht indiziert. Nichtinvasive Masnahmen wie Sonographie und Computertomographie lassen sich auch vor Erstoperationen einsetzen. Dabei eignet sich die Sonographie nur fur den Cervicalbereich, die Computertomographie im wesentlichen fur den vorderen Mediastinalbereich.

A model study of Hartree-Fock and Linear Response in coordinate space

1979

A fast procedure for spherical Hartree-Fock is obtained by coordinate space representation and a modification of gradient iteration. Along similar lines, the corresponding Linear Response equations are derived and solved, in order to achieve a fully consistent treatment. The Linear Response equations are applied to a change in particle numbers, i.e. to the description of isotopic differences. In a model study we look for their physical and numerical properties, i.e. linearity of the response, numerical stability and consistency requirements for the Hartree-Fock basis.

Spread of hepatitis B virus infection among family contacts of asymptomatic HBsAg carriers

1979

Family members of 34 asymptomatic HBsAg carriers were tested for different hepatitis B virus (HBV) markers. Among 67 family members tested 24 (36%) presented signs of a past or ongoing HBV-infection. Spread of HBV-infection was particularly high in those families in which the HBsAg carrier was positive for HBeAg and Dane particle-associated DNA polymerase activity. Non-parenteral “horizontal” transmission of HBV among spouses and brothers and sisters and probably parenteral vertical transmission of HBV from carrier mothers to their infants occurred in approximately the same frequency. Fathers transmitted HBV unfrequently to their offsprings. The results show that the risk to acquire a HBV-i…

Early auditory evoked potentials (EAEP) in vertebral basilar insufficiency

1979

Stimulation with a short tone pip elicits an acoustic nerve compound action potential (I) and different waves (II--VII) in the inital 10 ms. Seven waves have been studied in 40 control subjects and five waves in 12 patients with vertebral-basilar insufficiency. Abnormalities of the different waves were observed at levels such as cochlea and/or acoustic nerve, medulla, caudal pons, rostral pons, and midbrain. The recording of early auditory evoked potentials (EAEP) is a noninvasive method of confirming impairment of the auditory pathway caused by a reduced vascular supply of vertebral and basilar arteries.

THYROID ADMINISTRATION LOWERS MORTALITY IN PREMATURE INFANTS

1979

Ricerca Clinica Comparativa Fra Cotrimoxazolo Ed Una Nuova Associazione Sulfamidico Trimethoprim Nelle Infezioni Dell'Apparato Urinario: Nota Prelimi…

1979

Die Kooperativität bei der CO2-Hb-Bindung: Messungen mit Hilfe der 13C-NMR-Spektrometrie / The Cooperativity of the CO2 Hb Binding: Measurement by 13…

1979

The detailed structure of the CO2 Hb binding curve is of considerable physiological interest, because the carbamino derivates, which are formed by the reaction of CO2 with Hb, are respon­sible for the well known Haldane effect. Under physiological conditions CO2 binds to the four terminal NH2-groups of the protein chains of Hb and it is generally assumed, that there exists no cooperativity between these groups. To examine whether this assumption is correct or not, we have measured the CO2Hb binding curve over a wide PCO2-range (from 0 kPa to about 70 kPa) by using 13C-NMR spectrometry. Morrow and coworkers (1976) have shown that carbamino-Hb causes a specific NMR signal. The quantitative an…

Boundary regularity and the uniform convergence of quasiconformal mappings

1979

Die Reaktion von 2-Halogenethoxycarbonyl-Verbindungen mit tertiären Phosphanen

1979

(2-Bromethoxycarbonyl)aminosauren 1, einschlieslich der Sarkosin-Derivate 13 und 15, reagieren mit Methyldiphenylphosphan zu den 2-Phosphonioethoxycarbonyl-Verbindungen, welche unter milden basischen Bedingungen zu den freien Aminoverbindungen gespalten werden. Die gleiche Schutzgruppenumwandlung gelingt an 2-Bromethoxycarbonyl-geschutzten Alkoholen 3. Phenolen 4 und den sekundaren Aminen 11 und 12 sowie an Aminosaure- und Peptid-(2-bromethylestern) nicht. In diesen Fallen bildet sich das Ethylen-1,2-bisphosphoniumsalz 6. Reaction of 2-Haloethoxycarbonyl Compounds with Tertiary Phosphanes (2-Bromoethoxycarbonyl)amino acids 1 including the sarcosine derivatives 13 and 15 react with methyldip…

Mobilization of proline in the starchy endosperm of germinating barley grain.

1979

In germinating grains of barley, Hordeum vulgare L. cv. Himalaya, free proline accumulated in the starchy endosperm during the period of rapid mobilization of reserve proteins. When starchy endosperms were separated from germinating grains and homogenized in a dilute buffer of pH 5 (the pH of the starchy endosperm), the liberation of proline continued in these suspensions. The process was completely inhibited by diisopropylfluorophosphate, indicating that it was totally dependent on serine carboxy-peptidases. The carboxypeptidases present in the starchy endosperms of germinating grains were fractionated by chromatography on DEAE-cellulose. Four peaks were obtained, all with different activi…

Konstruktion eines vollautomatischen präzisionschromatographen auf der basis der phasendistributionschromatographie (PDC)

1979

The design of a fully automatized chromatograph based on Phase Distribution Chromatography (PDC) is presented and some of the most important results of the measurements shown. PDC represents a dynamical phase separation as column method: the separation of the polymer components in a PDC-column is based on thermodynamic-kinetical interactions of the mobile phase (the polymer to be analyzed) below the theta temperature of the system by a gel of the same high polymer situated on the surface of small glass beads. The sigmoidal shape of the measured PDC calibration curves can be explained by introducing a dynamical flow-equilibrium in the system sol/gel which highly differs from the thermodynami…

Gelchromatographische refraktionierung, molekulargewichtsabhängigkeit der axialen dispersionsfunktion

1979

The knowledge of axial dispersion is necessary for the determination of molecular weight distributions from gel permeation chromatograms. This work deals with the determination of the axial dispersion function and its dependence on the molecular weight using refractionation method. The results of a number of fractionated and unfractionated samples of polystyrene reveal that peak dispersion in GPC arises mainly from diffusion in the stationary phase on the basis of the theoretical expression proposed by Kubin.

Einfluß einer orientierung der moleküle auf die kinetik der kristallisation von polyethylenterephthalat

1979

Röntgenkleinwinkel-untersuchungen zur struktur der crazes (fließzonen) in polycarbonat und polymethylmethacrylat

1979

Es wurden Rontgenkleinwinkel-Untersuchungen an Polycarbonat- und Polymethylmethacrylat-Proben mit Crazes durchgefuhrt. Die Streuung in Richtung senkrecht zur Verstreckrichtung zeigt ein scharf ausgepragtes Maximum, das durch interpartikulare Interferenz zwischen den Polymerfibrillen in den Crazes verursacht wird. Der mittlere Fibrillendurchmesser ā kann aus der Lage des Beugungsmaximums und aus dem asymptotischen Verhalten der Streukurve bestimmt werden.

false

1979

The kinetics of the anionic polymerization of styrene were investigated under pressure (1≤p/bar < 1800) with Na+ as counter ion in tetrahydropyran (THP) as solvent and with Cs+ as counter ion in 1,2-dimethoxyethane (DME) as solvent. The results yielded the activation volume of the contact ion pair ΔV and the sum (ΔV + ΔVcs) of the activation volume of the solvent separated ion pair ΔV and the volume change upon formation of solvent separated ion pairs from contact ion pairs ΔVcs. The numerical values are negative. The activation volume of the solvent separated ion pairs could be estimated.

Kettenlängenabhängiger polymerabbruch im system methylmethacrylat/2,2′-azoisobutyronitril

1979

false

1979

The demixing behavior of 20 representatives of the system oligo(dimethylsiloxane)/oligo(propylene glycol) (ODMS/OPG)1 is investigated at pressures up to 1 500 bar. The degrees of oligomerization range from 2 to 5 for the first and from 1 to 57, 6 for the second component. The experimental results are compared with those for the previously studied system oligoisobutene/oligo(propylene glycol) (OIB/OPG). In both cases the observed upper critical temperatures Tc increase with the number of monomeric units of the less polar component, whereas they run through a minimum when the number of monomeric units of the glycol is raised. For the present system the Tc values are found to be considerably h…

Nuclear Spins of the IsomersHg191m−185mDetermined by On-Line Quantum-Beat Spectroscopy

1979

The nuclear spins of the very neutron-deficient $^{191m\ensuremath{-}185m}\mathrm{Hg}$ isomers were measured on line at the mass separator ISO LIDE at CERN using pulsed-laser excitation and observation of the time-resolved quantum beats from selected hyperfine-structure states. The spins of these isomers are with $I=\frac{13}{2}$ equal to those of the long-lived isomers $^{199m\ensuremath{-}193m}\mathrm{Hg}$ already known. The persistence of this spin value for eight isomers is explained by the model of rotation-aligned coupling.

H�modynamische Untersuchungen zur blutdrucksteigernden Wirkung von Mineralocorticoiden

1979

Bei 6 gesunden freiwilligen Probanden wurde der Einflus einer langerfristigen hochdosierten Mineralocorticoid-Applikation auf die Hamodynamik untersucht. Die Versuchspersonen erhielten das synthetische Mineralocorticoid 9α-Fluorhydrocortison in einer Dosierung von 0,8 mg p.o. taglich. Vor der Gabe des Steroids sowie nach 1- und 6wochiger Steroidbehandlung wurden der zentrale Venendruck und der arterielle Blutdruck direkt gemessen, das Herzzeitvolumen wurde mittels Farbstoffverdunnungsmethode bestimmt.

Histamin in der Interstitialfl�ssigkeit der befallenen und klinisch nicht befallenen Haut bei chronisch rezidivierender Urticaria

1979

Bei 8 Patienten mit idiopathischer chronisch rezidivierender Urticaria wurden in der Periumbilicalregion Saugblasen gleichzeitig auf frischen urticariellen Herden und der unveranderten Haut daneben produziert und Histamin in der Blasenflussigkeit bestimmt. Hierzu wurde die von Siraganian entwickelte Methode der Autoanalyzer-Technik in modifizierter Form verwendet. Die Histaminspiegel lagen bei diesen Patienten in unveranderter Haut in derselben Grosenordnung wie bei 10 Normalpersonen, wahrend alle 8 Urticaria-Patienten hohere Histamin-Werte in den Urticae verglichen mit der nicht befallenen Haut aufwiesen; bei 4 der Patienten waren diese Unterschiede jedoch nur gering ausgepragt.

Specificity of H-2-linked Ir gene control in mice: recognition of the core structure A--L in defined sequence analogues of (T,G,)-A--L.

1979

For further characterization of the processes involved in Ir gene control, the specificity of antibodies and the cross-reaction on the level of helper T cells was studied for a series of polypeptide antigens related to poly-L(Tyr,Glu)-poly-DL-Ala–poly-LLys[(T,G)-A–L] but carrying more defined side chains. Helper cell specificity was assayed in an in vitro secondary anti-dinitrophenyl (DNP) response by cross-stimulation of primed T cells with the various polypeptide carriers. It was established that these polypeptides, although showing the same response pattern, were recognized as distinct entities in the immune response by B and T cells. If this common pattern is due to the effect of the sa…

Demixing of unsheared and sheared solutions of polystyrene in tert-butylacetate and the pressure influence on their flow behaviour

1979

For the system tert-butyl acetate/polystyrene (M= 670000) the phase separation behaviour (upper critical solution temperatures, upper critical solution pressures) is investigated by means of visual and turbidimetric cloud-point measurements and by viscometry. For near-critical concentrations the visually determined cloud-points are found at higher, for low concentrations at lower temperatures as compared with the turbidimetrically determined binodal temperature,Tbin Plots of the invers of the turbidity measured atTbin as a function of the polymer concentration,w2, yield a minimum from which the critical composition can be determined. The viscometrically obtained demixing points (break-down …

A combination magnetic plus Si(Li)-Si(Li) sum-coincidence technique for in-beam studies of internal pair transitions

1979

Abstract An intermediate-image magnetic plus Si(Li) combination pair spectrometer featuring an excellent energy resolution and a pair-line efficiency of 10 −3 , recently presented and demonstrated, has been made more universally applicable by reducing the background underlying the pair lines. The best background reduction is achieved by using two standard Si(Li) detectors and a sum-coincidence method. An experimental coincidence pair-line efficiency of 2.1 × 10 −4 for the 1911 keV E0 pair line in 64 Zn is achieved. In this typical case, the high-energy background (mainly caused by β + activity) is reduced by a factor of about 200 as compared with the direct spectrum of a single detector.

Increase by ?-adrenolytic drugs of acetylcholine release evoked by field stimulation of the guinea-pig ileum

1979

The release of acetylcholine evoked by field stimulation of the guinea-pig ileum (3 Hz) is increased by yohimbine and tolazoline but not affected by phentolamine. It is proposed that yohimbine and tolazoline by blocking alpha-adrenoceptors of the cholinergic nerves abolish the inhibition caused by endogenous noradrenaline, and thus facilitate the output of acetylcholine.

Inhibitory Effects of the Insecticides Allethrin, Lindane, and Jacutin-Fogetten Sublimate on Photosynthetic Electron Transport

1979

Abstract The inhibitory effects of the insecticides Allethrin, Lindane, and Jacutin-Fogetten sublimate on photosynthetic electron transport of broken chloroplasts were tested. 50 μmol l-1 Allethrin caused an inhibition of 80% of the benzoquinone and ferricyanide Hill-reactions. 39 μmol l-1 Lindane inhibited the basal, coupled and uncoupled electron transport to ferricyanide up to 35%. The precipitate formed by the sublimation of Jauctin-Fogetten containing Lindane depressed electron transport much more than pure Lindane. 50 μg ml-1 of the sublimate led to an 80% inhibition of ferricyanide Hill-reaction.

Muscle strength and body composition as determinants of blood pressure in young men

1979

The correlations of blood pressure to various indices of muscularity and fatness were studied in 183 young healthy men (mean age 19.7, SD 2.1 years). Systolic pressure showed significant positive correlations with body fat percentage, isometric strength of trunk extensors, body mass index, lean body mass, strength of leg extensors, heart rate, and the sum of four skinfolds. Diastolic pressure had significant positive correlations with body mass index, lean body mass, body fat percentage, sum of skinfolds, strength of leg extensors, strength of trunk extensors, and age. A stepwise selective multiple regression analysis for systolic pressure resulted in four significantly correlating variable…

Viscosity studies of solutions of water inn-aliphatic alcohols at various temperatures

1979

Viscosity measurements have been made at 25°C on solutions of water inn-propanol, and at 15, 25, 35, and 45°C on solutions of water inn-butanol,n-pentanol, andn-hexanol over the respective solubility ranges. For most of the systems, water decreases the viscosity of the dry alcohols, while for the lower members of the series literature data report an increase in viscosity on addition of water. These results are rationalized in terms of two kinds of interaction between water molecules and alcohols: participation of water molecules in chain formation for the lower alcohols and formation of water-centered complexes for butanol and higher alcohols.

false

1979

Electromechanical delay in human skeletal muscle under concentric and eccentric contractions.

1979

In contraction of skeletal muscle a delay exists between the onset of electrical activity and measurable tension. This delay in electromechanical coupling has been stated to be between 30 and 100 ms. Thus, in rapid movements it may be possible for electromyographic (EMG) activity to have terminated before force can be detected. This study was designed to determine the dependence of the EMG-tension delay upon selected initial conditions at the time of muscle activation. The right forearms of 14 subjects were passively oscillated by a motor-driven dynamometer through flexion-extension cycles of 135 deg at an angular velocity of approximately equal to 0.5 rad/s. Upon presentation of a visual s…