Showing papers by "University of Ottawa published in 1971"

Evolution of sedimentary rocks

Abstract: For almost a century, it has been recognized that the present-day thickness and areal extent of Phanerozoic sedimentary strata increase progressively with decreasing geologic age. This pattern has been interpreted either as reflecting an increase in the rate of sedimentation toward the present or as resulting from better preservation of the younger part of the geologic record. The study of the rocks themselves led to similarly opposing conclusions. The observed secular (= age) variations in relative proportions of lithologic types and in chemistry of sedimentary rocks were mostly given an evolutionary interpretation. An opposing, uniformitarian approach was proposed by Garrels and Mackenzie. For most isotopes, the consensus favors deviations from the present-day steady state as the likely cause of secular trends. This chapter attempts to show that recycling and evolution are not opposing but complementary concepts. It will concentrate on the lithologic and chemical attributes of sediments but will not deal with the evolution of sedimentary mineral deposits and of life, both well amenable to the outlined conceptual treatment.

Fine structure of the ura 2 locus in Saccharomyces cervisiae. I. In vivo complementation studies.

Abstract: Studies of complementation patterns of ura2 mutants of the pyrimidine pathway in Saccharomyces cerevisiae suggest the existence of at least two different structural genes in the ura2 locus: one coding for carbamyl phosphate synthetase, ura2C and the other coding for aspartic transcarbamylase, ura2A. An interallelic type of complementation takes place among some ura2A mutants, but was not noted among the ura2C class (Fig. 2). Preliminary results of the mapping of suppressible mutants indicate that the complex is transcribed into a single messenger RNA, with the direction of transcription proceeding from the CPSase region to the ATCase region.

Distribution of acetylcholinesterase and monoamine oxidase in the amygdala of the guinea pig.

Abstract: A study of the amygdala of the guinea pig was carried out on material stained by the Nissl, acetylcholinesterase (AChE) and monoamine oxidase (MAO) methods. The material stained for Nissl substance was used primarily as a reference in determining the distribution of the two enzymes. Regional differences in cell size and/or distribution were noted within the lateral, basal, medial and cortical nuclei. In the AChE preparations, it was observed that the large-celled part of the basal nucleus stained very intensely, the small-celled part of the basal nucleus and ventromedial part of the lateral nucleus more moderately, and the dorsolateral part of the lateral nucleus and cortical nucleus lightly. The central and medial nuclei showed almost no reaction. With the MAO method, the greatest staining reaction was seen in the medial nucleus, the medial part of the cortical nucleus, the anterior amygdaloid area and the ventromedial wedge of the putamen adjacent to the central nucleus. In addition, fibres of the stria terminalis stained very darkly.

Fourier Analysis of Evoked Potentials and Human Intelligence

Abstract: PARAMETERS of the Fourier transform of averaged evoked potentials (AEP) have recently been related to psychometric intelligence1,2 and I have attempted a similar analysis of a larger sample of subjects of high and low intelligence. This was carried out several months before the publication of the previous reports. Because the original objective was not replication, there are inevitably some major differences of technique. In general, this is a field in which meaningful replication is difficult3, but there are grounds for believing that the differences between this and the previous techniques and recording locations probably do not explain the different results.

The presence of delayed hypersensitivity reactions in patients toward cellular extracts of their malignant tumors. 3. The frequency, duration, and cross reactivity of this phenomenon in patients with breast cancer, and its correlation with survival.

Abstract: The presence of delayed hypersensitivity reactions (DHRs) in patients toward extracts of cells of their breast cancer was studied over a period of 5 years. The skin of 10 of the 56 patients tested with the extract of their breast cancer had a positive result showing induration and erythema of more than 10 mm in 2 diameters between 24 and 48 hours. 1 patient had a positive result of 5 mm induration and erythema at 24 hours and another had a negative initial testing but was positive when tested 27 months later. Antigen stored at -20 degrees C caused a positive DHR after 5 years in some patients and cross-reactivity occurred in about 1/2 of the cases. 77.5% of the patients who had a negative DHR were still alive at least 2 1/2 years later whereas only 41.5% of those who had a positive DHR were still alive. If the presence of DHR to the tumor reflects a cellular defense mechanism by the host it failed in 70% of the patients with anaplastic tumors. 3 patients with an intense round cell infiltrate and a DHR to the tumor survived 5-5 1/2 years.

Improved parametric characterization of flow geometries

Abstract: An improved parametric method is presented for characterization of the flow geometry in the rectilinear flow of non-Newtonian fluids in open and closed conduits of arbitrary crosssection and in purely viscous, inelastic flow of non-Newtonian fluids through packed beds and porous media. In the new formulation, an infinite number of geometric parameters characterize the flow geometry. The actual number required in a particular application is shown to be determined by the fluid model equation representing the rheological behavior of the fluid. For Ostwald-de-Waele and Ellis fluids with flow behavior indices s = 1/n and α integers, the number of geometric parameters required to represent the relationship between flow rate and pressure drop is given by s + 1 and α + 1, respectively. The efficacy of the present method is demonstrated by comparisons with available results for various fluid models and flow geometries.

Hospital Sanitation: the Massive Bacterial Contamination of the Wet Mop

Abstract: Following the demonstration of massive spread of bacterial contamination throughout the hospital by the wet-mopping techniques in use, quantitative studies were undertaken to determine the source of contamination and to institute measures of control. It was found that mops, stored wet, supported bacterial growth to very high levels and could not be adequately decontaminated by chemical disinfection. Laundering and adequate drying provided effective decontamination, but build-up of bacterial counts occurred if mops were not changed daily or if disinfectant was omitted from the wash-water. Recommendations were based upon the experimental findings.

Lattice Dynamics and Thermodynamic Properties of β-ZnS, GaP and β-SiC

Abstract: The lattice dynamics of β-ZnS, GaP and β-SiC has been investigated on the basis of a rigid ion model with seven parameters. Results are obtained for the dispersion curves and effective calorimetric and X-ray Debye temperatures and are shown to compare favourably with the available experimental data. Calculated values of equivalent Debye frequencies are also reported.

Metabolic control mechanisms in mammalian systems. Involvement of adenosine 3′:5′-cyclic monophosphate in androgen action

Abstract: 1. The ability of exogenously administered cyclic AMP (adenosine 3':5'-monophosphate) to exert andromimetic action on certain carbohydrate-metabolizing enzymes was investigated in the rat prostate gland and seminal vesicles. 2. Cyclic AMP, when injected concurrently with theophylline, produced marked increases in hexokinase, phosphofructokinase, glyceraldehyde phosphate dehydrogenase, pyruvate kinase, and two hexose monophosphate-shunt enzymes, as well as alpha-glycerophosphate dehydrogenase activity in accessory sexual tissues of castrated rats. The 6-N,2'-O-dibutyryl analogue of cyclic AMP caused increases of enzyme activity that were greater than those induced by the parent compound. 3. Time-course studies demonstrated that, whereas significant increases in the activities of most enzymes occurred within 4h after the injection of cyclic AMP, maximal increases were attained at 16-24h. 4. Increase in the activity of the various prostatic and vesicular enzymes was dependent on the dose of cyclic AMP; in most instances, 2.5mg of the cyclic nucleotide/rat was sufficient to elicit a statistically significant response. 5. Administration of cyclic AMP and theophylline also produced stimulation of enzyme activities in secondary sexual tissues of immature rats. 6. Cyclic AMP and theophylline did not affect significantly any of the enzymes studied in hepatic tissue. 7. Stimulation of various carbohydrate-metabolizing enzymes in the prostate gland and seminal vesicles by cyclic AMP was independent of adrenal function. 8. Concurrent treatment with actinomycin or cycloheximide prevented the cyclic AMP- and theophylline-induced increases in enzyme activities in both castrated and adrenalectomized-castrated animals. 9. Administration of a single dose of testosterone propionate (5.0mg/100g) to castrated rats caused a significant increase in cyclic AMP concentration in both accessory sexual tissues. 10. In addition, treatment with theophylline potentiated the effects of a submaximal dose of testosterone (1.0mg/100g) on all those prostatic and seminal-vesicular enzymes that are increased by exogenous cyclic AMP. 11. The evidence indicates that cyclic AMP may be involved in triggering the known metabolic actions of androgens on secondary sexual tissues of the rat.

The enigmatic behavior of breast cancer.

Abstract: A series of 502 patients with metastatic and/or recurrent breast cancer has been reviewed to study some of the time characteristics of the reactivated disease Metastases become clinically apparent over an unexplainably wide range of time, but the median time of appearance becomes shorter with the more advanced presenting clinical stages Survival after metastases also varies over an unexplainably wide range of time, but the median survival time after the appearance of the metastases becomes shorter with the more advanced presenting clinical stage, suggesting that clinical stage indicates tumor-host potential more than the chronological age of the tumor Metastases at specific sites occur at no constant relative time in the treatment-to-death interval, suggesting varying growth rates throughout the course of the disease Metastases occurring within the first 18 months of treatment or in patients presenting with advanced clinical stages are more evenly distributed throughout the treatment-to-death interval than those occurring more than 36 months after initial treatment or with small primary lesions This suggests that the ease of establishment of a metastasis is probably independent from its subsequent behavior

A STRUCTURAL APPROACH vs. A SITUATIONAL APPROACH TO FOREIGN-LANGUAGE TEACHING†

Abstract: Two approaches to foreign-language instruction were compared in an experiment in which American children learned Japanese. In the “structural approach,” materials were sequenced in order of increased difficulty of grammatical and lexical forms. In the “situational approach,” the same materials were presented in the form of meaningful dialogues; sequencing did not depend upon the relative difficulty of grammatical and lexical items. The principal findings of the experiment were: (1) that the situational approach produced results equal to or better than those of the structural approach, (2) that the situational approach produced significantly better results among students of high language aptitude and intelligence; and (3) that there was no significant difference between approaches among students of lower aptitude and intelligence. A major implication of this study for foreign language teaching is that in elementary courses for children, it is unnecessary to sequence content materials according to the linguistic difficulty of grammatical and lexical forms. In classes which are heterogeneous or of generally high intelligence and language aptitude, sequencing by situations is more beneficial than sequencing according to relative linguistic difficulty.

Neurology and sleep research.

Abstract: This brief review documents some of the important contributions of recent sleep research to the understanding of a number of neurological conditions. Narcoleptic attacks have been shown to be either episodes of NREM or REM sleep; and cataplexy, sleep paralysis and vivid hypnagogic hallucinations consist of dissociated or inappropriate REM sleep. Important relationships of the hypersomnias and various comas to sleep mechanisms are being increasingly elucidated. Various types of epileptic seizures have been found to be affected differentially by the two types of sleep and by arousal from them; and sleep deprivation may activate or perpetuate epilepsy. Finally, some miscellaneous conditions, such as dyskinesias, cerebrovascular accidents, migraine, and memory and repair functions have been considered. As well as being of pathophysiological interest, much of this new knowledge has a direct diagnostic and therapeutic relevance.

Mechanism of potentiation of contractor responses to catecholamines by methylxanthines in aortic strips

Abstract: 1. Caffeine and theophylline increased the amplitude of contractor esponses of untreated and reserpine pretreated rabbit aortic strips to catecholamines (adrenaline, α-methylnoradrenaline, noradrenaline). Responses to amines without both the 3- and 4-OH groups in the benzene ring (methoxamine, phenylephrine, Synephrine) were not increased by theophylline and only those to Synephrine were slightly enhanced by caffeine. 2. Compounds which inhibit catechol-O-methyltransferase (pyrogallol, tropolone, U-0521) potentiated responses to catecholamines and abolished the enhancing effect of theophylline and caffeine. Also, the potentiation produced by inhibitors of O-methylation was significantly reduced in the presence of the methylxanthines. 3. Experiments done with the aid of the technique of oil immersion, to eliminate the diffusion of drug from the tissue into the bathing medium, showed that theophylline and caffeine decreased the rate of inactivation of adrenaline by O-methylation. 4. These findings indicate that methylxanthines potentiate the contractor responses to catecholamines in aortic strips by inhibiting their extraneuronal inactivation.

The ultimobranchial gland of birds and the effects of nutritional variations.

Abstract: Histological studies have revealed that the ultimobranchial gland of birds consists of duct-like follicles which are of pharyngeal origin and parenchymal cords apparently derived from the neural crest. Aberrant parathyroid tissue, lymphoid cells and pseudo-eosinophils are frequently found. The arterial supply of the ultimobranchial body is regulated by the presence of a sprial type of spincter. The parenchymal cells respond by hypertrophy and hyperplasia to hypercalcemia and by a decrease in secretory activity during prolonged hypocalcemia. At the electron microscopic level, these cells resemble the C cells of the mammalian thyroid. In the chick, they are presumed to be the only source of calcitonin. In other birds, such as the pigeon and the turtle-dove, the ultimobranchial gland shares this function with the thyroid. The calcium-lowering factor, calcitonin, acts on bone at least partly by inhibiting the bone resorptive activity of the osteocytes (osteocytic osteolysis) which is governed by the parathyroid hormone.