McGill University Thèses et mémoires publiés en 1983

Since cortisol (F) can influence fetal lung maturation in late gestation, interconversion between cortisol and its inactive analogue cortisone (E), catalyzed by 11(beta)-hydroxysteroid dehydrogenase (11-HSD) (E.C.1.1.1.146), may be an important mechanism for controlling the level of F in the fetal lung parenchyma. The objects of this study were to: (1) resolve conflicting data; and (2) to study possible regulating factors of the 11-HSD. Human fetal lungs (HFL) of gestational ages 9-20 weeks were grown as monolayer cultures or as explants with ('3)H-F and ('3)H-E or ('14)C-E (0.01-17 ng/ml), for 6-16 days. Extracts of tissue culture medium were chromatographed to separate …  Lire la suite

This study analyzes ownership and directorship links among larger Canadian-owned corporations. These links have received insufficient attention from Canadian economists. It shows that these corporations did not undergo the radical changes predicted for their counterparts in other countries: proprietor ownership remains high, and the board of directors persists as the centre of power. Ownership links form the basis for the development and empirical investigation of the "Shadow Group" concept. The taxonomical classification of shadow groups reveals complex structures accompanying diversification strategies. Interlocking directorships exist among "core" corporations inside the groups and are frequent between the shadow groups and the rest …  Lire la suite

Une partie de la region de Paspebiac a ete recouverte par deux glaces contemporaines, lors du dernier stade glaciaire du Wisconsinien. Une premiere s'est ecoulee du nord-nord-ouest, a recouvert la partie ouest de la region a l'etude et a erige une grande moraine laterale nord-sud a sa marge orientale; il n'a pu etre determine si cette glace etait l'inlandsis laurentidien ou une calotte gaspesienne. Une seconde glace progressant vers le nord-ouest a englace le sud-est du territoire et a construit une moraine terminale ouest-est, perpendiculaire et jointive a la premiere moraine. Un lac proglaciaire s'est forme a l'encoignure des deux …  Lire la suite

The production of charmed particles and a limit to tau lepton production have been measured using a hybrid emulsion spectrometer in the Fermilab wide-band neutrino beam. The relative cross section for charged current charmed particle production is (DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE DAI) and the energy dependence of the cross section and the kinematic distributions of the charm events are given. One event with charm pair production was observed. A limit of (sigma)((nu)(--->)(mu)cc)/(sigma)((nu)(--->)(mu)c) < 0.06 (90%C.L.) is set to the ratio of charged current pair and single charm production. The relative rates of D(DEGREES), D('+), F('+), and (LAMDA)(,c)('+) production …  Lire la suite

Bradley, Martin A. (Supervisor)  Lire la suite

The development of precise data for the effect of chemistry and processing variables on the fracture toughness of low to medium carbon cast steels, is paramount to an increased understanding of the fracture behaviour of these important engineering materials. This knowledge would, in itself, lead to improvements in alloy development/selection rationale and increased cast steel usage, particularly in critical areas. Toward this end, an investigation into the influence of Cr, Mn and Ni additions on the room temperature fracture toughness and flow properties of 0.30, 0.40 and 0.55 wt% C cast alloys was conducted. In order to avoid the chemical …  Lire la suite

Efficient allocation of scarce resources to health programs involves measuring the economic benefits of life saving and/or improvement in health status. While several attempts have been made to quantify individual preferences for life, only a few, if any, have attempted to measure individual preferences for quality of life. In this thesis, we develop a methodology based on the estimation of individual preference functions to arrive at monetary measures of the value of marginal improvements in health status. The first chapter reviews conventional methodologies for estimating the value of human life, and points out many theoretical and empirical propositions related to …  Lire la suite

This study explored the ability of public students labelled emotionally disturbed toI school think divergently. The specific purpose was to discover whether these students would have greater difficulty than normal students on divergent thinking tasks. A second purpose was to evaluate the effects of an intervention course in creative problem-solving that was taught to a sample of students labelled emotionally disturbed. Subjects consisted of forty-five students from one of three public high schools under the Protestant School Board of Greater Montreal. Twenty-two of these subjects were labelled emotionally disturbed and the remaining twenty-three were classified as normal. […]  Lire la suite

The lipopolysaccharide (LPS) translocation process was studied by a pulse-chase experimental procedure designed to follow the fate of newly synthesized LPS through the cell wall fractions of the marine bacterium Alteromonas haloplanktis, strain 214, variant 3 (ATCC 19855). It was determined that newly synthesized LPS I (the prominent LPS species under the conditions employed) initially enters an LPS fraction which can be released from the cell wall along with periplasmic material. This is followed by rapid entry of the newly synthesized LPS into a loosely bound LPS fraction (released from the cell wall by washing with NaCl) before final insertion …  Lire la suite

Although computed tomography has received wide acceptance and rapid diffusion, its clinical efficacy relative to that of competing technologies has not been clearly demonstrated in non-neurological applications. Two-hundred and thirty-one consecutive in-patients investigated for suspected hepatic masses or pancreatic disorders at Royal Victoria Hospital were randomly assigned to computed tomography, nuclear medicine or ultrasonography. Each of the three technologies was assessed on various measures of diagnostic and management efficacy. […]  Lire la suite

A general method for the formation of acetals using chlorotrimethylsilane has been developed. Dioxolanes are formed from most carbonyl groups whereas methyl acetals are only formed from electron-poor carbonyl groups. The intermediacy of a silicon-bound carbonyl species is discussed. The method has been extended to the formation of esters. In a solution of the alcohol to be esterified, methyl, ethyl, benzyl and 2-trimethylsilylethyl esters are readily formed in the presence of chlorotrimethylsilane. Using ('29)Si-N.M.R., a trimethylsilyl ester has been shown to be an intermediate in the reaction. The Lewis acid catalyzed condensation of 1,3-bis-trimethylsiloxy-1-methoxy-1,3-butadiene with a variety of dielectrophiles, in …  Lire la suite