McGill University Thèses et mémoires publiés en 1987

The problem of domestic solid wastes buried in landfill sites is viewed from the aspect of leachate contamination and migration in the substrate. Generally, this occurs through the penetration of the contaminant into the liner material. This study assesses the efficiency of natural clay barriers as an expedient economic lining material. Various chemical constituents of the landfill leachate of an actual waste containment site at Lachenaie (35 km east of Montreal) were determined from samples collected from specially designed basins. In companion laboratory tests, these leachate samples were permeated through laboratory columns that contained the natural clay compacted at the …  Lire la suite

The major aim of this thesis has been to contribute to the understanding of the CH$ sb2$/OH/NH$ sb2$ group interactions by means of studies of alcohol-amine mixtures in the gas and liquid phases. To study these interactions in the gas phase a Burnett type equipment was designed, built and operated at low pressure, obtaining experimental pressure-temperature (P-T) data for various systems including alcohol-amylamine mixtures. The P-T data were reduced by a method developed in this work to give values of second virial coefficients. Measurements on known systems were in excellent agreement with values reported in the literature. A group contribution …  Lire la suite

Stearn, Colin W. (Supervisor)  Lire la suite

This work describes the characterization of the CAN1 gene, thought to encode the arginine permease of yeast. I have identified the RNA transcript of this gene and obtained the DNA sequence, which specifies a highly hydrophobic protein with multiple potential membrane-spanning domains. I use a gene fusion approach to identify sequences within the CAN1 protein that can translocate adjacent sequences across the E.R. membrane in vitro and extend these observations by finding that the topology of E.R. insertion is conserved up to the plasma membrane in vivo. Using a series of CAN1 gene fusions to the secreted yeast killer toxin, …  Lire la suite

Planar optical waveguides fabricated by K$ sp+$-Na$ sp+$ ion-exchange in soda-lime glass substrates are investigated. Experimental characterizations of planar waveguide with respect to a wide range of fabrication conditions have been carried out, including detailed measurements of the refractive index anisotropy resulting from the large induced surface stresses. Parallel to this, the non-linear diffusion process of ion-exchange was simulated numerically to provide, along with the results of the characterizations, a complete description of the refractive index profile from any set of fabrication conditions. The magnitude of the maximum surface index change observed was shown theoretically to be almost entirely due …  Lire la suite

Integral (holistic) and separable (analytic) processing were studied in ADD-H and normal children using restricted classification tasks composed of separable dimensions and triad/tetrad combinations. In Studies One and Three classifications of ADD-H children and controls were compared on size/brightness and length/density combinations. In Study Two classifications of four age groups of normal subjects (mean ages 5-3, 7-9, 11-1 years and adults) were compared on size-brightness combinations. ADD-H children demonstrated significantly fewer separable responses than normal controls only on the tetrads. Normal subjects showed a developmental trend towards differential separable responding to size as compared to brightness. ADD-H children appear to …  Lire la suite

What constitutes an adequate solution to a mathematical problem? When is an adequate solution a 'good' solution? In this thesis I consider these questions in relation to two Diophantine equations, namely, x$ sp2$ + k = y$ sp3$ and 6y$ sp2$ = x(x + 1)(2x + 1). The first dates back to Diophantus himself (c. 250 AD) while the second can be traced to a puzzle proposed by Edouard Lucas in 1875. Each of these equations has attracted a number of solutions and each solution reveals something about its era. An examination and comparison of these solutions will give us …  Lire la suite

A murine model of host resistance to infection with Francisella tularensis, live vaccine strain, has been established. This facultative intracellular bacterium causes in mice an acute infection which lasts for approximately 12 days. Resistance to infection is associated with the appearance in the spleens of cells with the ability to transfer anti-tularemic resistance to naive mice, a response which is maximal 7 days following infection. Depletion of B cells does not compromise the ability of immune cells to transfer resistance. Treatment of mice with immune serum prior to infection leads to an increased hepatic and decreased splenic growth of Francisella. …  Lire la suite

Downes, J. A. (Supervisor)  Lire la suite

A novel technique was developed to immobilize plant cells. The cells are deposited on a surface of man-made fibrous material which provides for strong binding of the plant tissue biomass growing in the submerged culture. It was shown that the plant cells need to be fully viable for the attachment process to occur. The scale-up of this technique to laboratory size specifically designed bioreactors was performed successfully. The cell immobilizing matrix was formed into a vertical spirally wound configuration to provide for a high immobilizing area-to-volume ratio (0.8-1.2 cm$ sp{-1}$). A modified airlift (riser-to-downcomer area ratio of 0.03 and vessel …  Lire la suite

The responses and morphology of nine sound-sensitive interneurons are described in the cricket Teleogryllus oceanicus. Each of the neurons receives direction-specific input in the prothoracic ganglion, and each projects at least one interganglionic axon. Five of the neurons respond best to high frequencies ($>$10 kHz); four are most sensitive to low frequencies (3-10 kHz). Responsiveness to model calling songs was examined in addition to testing sensitivity to wind and light. Anatomical observations reveal that seven of the neurons receive auditory input via polysynaptic pathways, and that at least five of the neurons have morphology consistent with them providing input to …  Lire la suite

At present, the only effective treatment for atherosclerotic arterial obstruction is surgical revascularization. Unfortunately, in some patients, this is unsuccessful due to the extent of the disease; most of these patients require amputation of the limb because of severe pain or gangrene. By expanding on the experimental work of others, we were able to successfully save the limbs of experimental animals (canine) with obstructed arteries by restoring circulation via the use of the venous system (which is not affected by atherosclerosis). Subsequently, we have also been able to save the limbs of a small group of patients using a similar …  Lire la suite

Factors influencing testicular gonadotropin receptors and testis responsiveness to luteinizing hormone (LH) stimulation were studied during the seasonal sexual cycle of the adult ram. The normal variation in testis content of gonadotropin receptors was mapped out in relation to changes in (1) testis size, (2) testis responsiveness to LH stimulation and (3) mean serum concentration of LH, follicle stimulating hormone (FSH), testosterone and prolactin (PRL). The increase in gonadotropin receptor numbers during testicular redevelopment was preceded by elevated serum concentrations of PRL and associated with increases in both the frequency of endogenous pulses of LH and the responsiveness of the …  Lire la suite

Zsombor-Murray, Paul J. (Supervisor)  Lire la suite

Lock, Margaret (Supervisor)  Lire la suite

This thesis deals with the behaviour and design of triangular trusses fabricated from Hollow Structural Sections (HSS), with two Warren-type web planes and a single tension chord. Experimental programs are described in which triangular truss segments and simplified joints were tested in order to investigate the behaviour of compression web members and tension-chord welded joints. The mechanics of joint deformations are analysed in relation to the yield line theory, and simple models are shown to give a good prediction of the joint stiffnesses and strengths. Complex yield line models are investigated, but are slightly or not superior to the simple …  Lire la suite

This thesis deals with the curricular development of modern languages in the schools of England between 1864 and 1918. At the beginning of the period, modern languages were fringe curricular subjects; by the end of the period, they had achieved full curricular status in the secondary schools. The vehicles for investigating the curricular development of modern languages are the reports of the Royal Commissions and Board of Education. This thesis shows that modern languages became an integral part of the liberal curriculum and hence were taught chiefly in the secondary schools as instruments of cultural and mental formation for the …  Lire la suite

Given a finite set X of states, a finite set of transformations of X (generators), and another transformation f of X, we analyze the complexity of the membership problem, which consists in deciding whether f can be obtained by composition of the generators. This problem is studied for various classes (pseudovarieties) of monoids. It is shown that the complexity is NP-hard for monoids of threshold 2 or more, and NP-complete in commutative, J- and R-trivial monoids. For idempotent monoids (aperiodic of threshold one), the problem is NP-complete in the general case; subcases are analyzed, and a largest class of aperiodic …  Lire la suite

Provan, Professor  Lire la suite

This study of migration of workers from Quebec to Northeastern Ontario, based on a survey of 362 migrants in the Hearst area, analyzes how the autonomy of the social actor is intertwined with the constraints of structural factors. To accomplish this, two methods of analysis have been linked: the model of microeconomic equilibrium with the historical-structural perspective. A perceived opportunity for economic improvement can be identified as the primary cause provoked by development differentials on a regional scale. Quebec's economic history--distinguished by the dual development of industry and agriculture, as well as relative overpopulation, sustained by a religious ideology pertaining …  Lire la suite