Showing papers by "University of Western Ontario published in 1970"
TL;DR: The concept of bending energy adequately explains the shape of the erythrocyte and predicted a swelling sequence for a single cell which was similar to the observed series of Rand (1967) .
1,450 citations
TL;DR: In this article, a finite-difference solution of the equations of motion for steady incompressible flow around a circular cylinder has been obtained for a range of Reynolds numbers from R = 5 to R = 100, where the wake length increases linearly with R over the whole range from the value, just below R = 7, at which it first appears.
Abstract: Finite-difference solutions of the equations of motion for steady incompressible flow around a circular cylinder have been obtained for a range of Reynolds numbers from R = 5 to R = 100. The object is to extend the Reynolds number range for reliable data on the steady flow, particularly with regard to the growth of the wake. The wake length is found to increase approximately linearly with R over the whole range from the value, just below R = 7, at which it first appears. Calculated values of the drag coefficient, the angle of separation, and the pressure and vorticity distributions over the cylinder surface are presented. The development of these properties with Reynolds number is consistent, but it does not seem possible to predict with any certainty their tendency as R → ∞. The first attempt to obtain the present results was made by integrating the time-dependent equations, but the approach to steady flow was so slow at higher Reynolds numbers that the method was abandoned.
816 citations
01 Jan 1970
496 citations
TL;DR: Both in vitro and in cells about 7% of the methylation of DNA by MNNG occurs at the 6-oxygen atom of guanine, but dimethyl sulphate does not yield O(6)-methylguanine.
Abstract: 1. In neutral aqueous solution N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) yields salts of nitrocyanamide as u.v.-absorbing products. With cysteine, as found independently by Schulz & McCalla (1969), the principal product is 2-nitraminothiazoline-4-carboxylic acid. Both these reactions liberate the methylating species; thiols enhance the rate markedly at neutral pH values. An alternative reaction with thiols gives cystine, presumably via the unstable S-nitrosocysteine. 2. Thiols (glutathione or N-acetylcysteine) in vitro at about the concentration found in mammalian cells enhance the rate of methylation of DNA markedly over that in neutral solution. 3. Treatment of cultured mammalian cells with MNNG results in rapid methylation of nucleic acids, the extent being greater the higher the thiol content of the cells. Rodent embryo cells are more extensively methylated than mouse L-cells of the same thiol content. Cellular thiol concentrations are decreased by MNNG. Proteins are less methylated by MNNG than are nucleic acids. 4. Methylation of cells by dimethyl sulphate does not depend on cellular thiol content and protein is not less methylated than nucleic acids. Methylation by MNNG may therefore be thiol-stimulated in cells. 5. Both in vitro and in cells about 7% of the methylation of DNA by MNNG occurs at the 6-oxygen atom of guanine. The major products 7-methylguanine and 3-methyladenine are given by both MNNG and dimethyl sulphate, but dimethyl sulphate does not yield O(6)-methylguanine. Possible reaction mechanisms to account for this difference between these methylating agents and its possible significance as a determinant of their biological effects are discussed.
474 citations
TL;DR: The greater left-ear scores for nonverbal stimuli suggests that cerebral lateralization for such auditory functions may be present by age five, and male superiority on a nonverbal task was also found with nondichotic presentation of Animal Sounds.
272 citations
186 citations
TL;DR: In this paper, a multi-component radiation survival curve using an in-vivo Tumour Model is presented, and the model is used to predict the survival rate of cancer patients.
Abstract: (1970). A Multi-component Radiation Survival Curve Using an in Vitro Tumour Model. International Journal of Radiation Biology and Related Studies in Physics, Chemistry and Medicine: Vol. 18, No. 5, pp. 491-495.
177 citations
TL;DR: In this paper, subjects were required to generate mediators for 30 concrete or 30 abstract noun pairs, in each case half the pairs being linked by nonverbal images and half by verbal mediators.
132 citations
131 citations
TL;DR: From the clinical and pathological evidence presented, neologistic jargon appears to follow disturbance affecting both the auditory association area (Wernicke's Aphasia) and the arcuate fasciculus (Conduction AphasIA).
119 citations
TL;DR: The Early Proterozoic Gowganda Formation of Ontario has long been considered to be a glacial. as discussed by the authors showed that the chemical composition of tillite matrix materials and laminated argillites from most of these areas shows a remarkable homogeneity which may reflect the homogeneous nature of a large part of the Superior craton.
TL;DR: In this article, the deformation kinetics of zirconium and Zircaloy-2 strips, resulting from oxidation at 500°C in dry oxygen, were measured as a function of time.
Abstract: The deformation kinetics of zirconium and Zircaloy-2 strips, resulting from oxidation at 500°C in dry oxygen, were measured as a function of time. The stress distribution in the oxidized specimens was analyzed using a stress model based on the theory of elasticity and was correlated with the oxidation kinetics. The magnitude of the stress generated during oxidation differed significantly between zirconium and Zircaloy-2; while a simple linear relationship appeared to exist between the stress and the oxide thickness on zirconium, the stresses in oxides on Zircaloy-2 increased very rapidly and discontinuously to a maximum at a film thickness near the transition in the kinetic curve. In order to characterize the stress distribution in the oxide film, vacuum annealing experiments were performed on preoxidized specimens. These indicated that the stress relaxation which occurs during vacuum annealing resulted from dissolution in the metal of the highly stressed inner layers of the oxide film. Although these measurements have provided valuable information on the stresses generated during the oxidation of zirconium and Zircaloy-2, they do not require a causal relationship between the stresses and any oxidation process (e.g., transition).
TL;DR: In this paper, the free lipids of Nocardia asteroides contain a series of corynomycolic acids ranging from C28H54O3 to C36H68O3.
TL;DR: Results were consistent with the theory that RSA accompanies voluntary behavior, but do not support the notion that RSA is indicative of a state of arousal.
TL;DR: In this paper, X-ray diffraction studies by both reflection and transmission techniques were made on oxide films formed on crystal-bar zirconium and Zircaloy-2 in oxygen at 500 °C.
TL;DR: In the Danakil Alps of coastal Eritrea as mentioned in this paper, an asymmetrically subsided block of old sialic crust has been uplifted along the Ethiopian rift and is covered by an evaporite-basalt veneer.
Abstract: Mesozoic and Precambrian rocks are exposed in the Danakil Alps of coastal Eritrea, but the Danakil Depression between the Alps and the Ethiopian plateau is covered by Tertiary-Quaternary rocks. The physiography, structural geology, regional stratigraphy and evaporite lithof acies distribution of this area all suggest that it is underlain by an asymmetrically subsided block of old sialic crust. The western edge of this block has subsided deeply along the Ethiopian rift and is covered, in the Danakil Depression, by an evaporite-basalt veneer, but its eastern edge has been uplifted as the Danakil Alps. These are bounded on the east by a rift escarpment facing the Red Sea. Although geologic data here is sparse compared to the Danakil region, certain features suggest that a similar asymmetrically subsided block of older sialic rocks, with an evaporite-basalt veneer, may also lie beneath much of the Red Sea. This tectonic evolution apparently commenced in Miocene time with rifting near the centre of an earlier Mesozoic-Paleogene sedimentary basin. Uplift along this central rift caused tensional failure along a secondarily induced rift to the west, and east-side-down subsidence along this structure formed the asymmetrically subsided block. There were apparently two successive cycles of this tectonic activity. The earlier, of Miocene age, formed the easterly (Red Sea) block with a thicker veneer of older evaporitebasalt, and the later, of Plio-Pleistocene age formed the westerly (Danakil) block with a thinner veneer of younger evaporite-basalt. The separation of Arabia from Ethiopia across the southern Red Sea would thus be relatively minor, presumably represented by the width of the Red Sea’s axial trough plus a few kilometres across each of the Danakil Alp and Ethiopian rifts. Similar tectonic developments may accompany initial rifting and separation in the development of ocean basins by seafloor spreading, and might explain why oceans like the Atlantic, that have apparently developed in this manner, are fringed by shallow continental shelves with thick evaporite sequences and steep walled submarine canyons.
TL;DR: The development of the retinal pigment epithelium, choriocapillaris and Bruch's membrane in the albino rat was studied by electron microscopy during the last fetal week and the first 2 weeks of neonatal life.
TL;DR: In this paper, the use of seed-dressings containing mercury was found to increase the levels of mercury in pheasants and partridges collected in Southern Alberta, where the seeddressings are extensively used.
TL;DR: In this paper, three relatively homogeneous group risk compositions consisting of high, medium, and low risk takers, respectively, were compared with mixed groups composed of two High, one Medium, and two Low risk members, and the results were predicted by Brown's value hypothesis but were either not predicted by, or contradictory to, the Leadership, Diffusion of Responsibility, and Familiarization hypotheses.
TL;DR: In this paper, a universal representation of galloping response of square and rectangular cantilevered prisms is derived directly from wind tunnel experiments, which can be used to predict the aeroelastic instability of buildings of square cross section in either open country or urban areas.
Abstract: Lateral oscillations of square and rectangular prisms resulting from its aerodynamic instability (often called galloping oscillations) are analyzed theoretically and studied experimentally in turbulent flow with a vertical profile of mean wind velocity. It appears that these vibrations exist even in a highly turbulent flow, but are somewhat less intense and more random in character than in a smooth flow. The possibility of a universal representation of galloping oscillations for bodies having different mass and damping has been shown earlier in smooth flow. The experiments described extend this concept to include turbulent flow. Such a universal representation of the galloping response of square and rectangular cantilevered prisms is derived directly from wind tunnel experiments. The results for example can be used to predict the aeroelastic instability of buildings of square cross section in either open country or urban areas. The effect of aeroelastic instability on excited oscillations in the region of stability is also investigated.
TL;DR: V virtually total solubilization is possible with no apparent loss of acetylcholine esterase activity and only partial loss of sodium-potassium sensitive adenosine triphosphatase activity.
TL;DR: The study of facial similarities between parents and their adult was undertaken with the hope that prediction of future completed size of the face would be sufficiently accurate to be useful in the estimation of remaining facial growth potential at or before puberty.
TL;DR: In this paper, a number of properties of harmonic oscillator wave functions in three dimensions are derived using a generating function technique, such as the matrix element between two-particle central potentials.
TL;DR: In this article, the conditions under which crack propagation is initiated in an isotropic, brittle solid of the Griffith type when the solid is subjected to a homogeneous, uniform but otherwise arbitrary triaxial system of stresses at infinity.
Abstract: Summary
A calculation has been carried out of the conditions under which crack propagation is initiated in an isotropic, brittle solid of the Griffith type when the solid is subjected to a homogeneous, uniform but otherwise arbitrary triaxial system of stresses at infinity. The cracks have been taken to be flattened ellipsoidal cavities. The results are in broad agreement with results obtained in the two-dimensional treatment of the problem, and with experimental observations. Tensile and shear fracture is possible and the Mohr envelope is of parabolic form. Fracture initiation is shown to be independent of the intermediate principal stress.
TL;DR: Frequency spectra of wall vibration downstream from experimental arterial stenoses are examined and it is concluded that fluid flow through isolated arteries with an experimental stenosis excites the artery wall to vibrate over a wide range of frequencies within which are discrete frequencies that coincide with the resonant frequencies of the artery walls.
Abstract: It has been suggested that poststenotic weakening of arterial walls is caused by arterial wall vibration and structural fatigue initiated by pressure disturbances in turbulent blood flow. We examined the frequency spectra of wall vibration downstream from experimental arterial stenoses and compared them with the natural resonant vibration characteristics of the artery walls. Spectra of arterial wall displacement of isolated perfused dog and human arteries were measured with a noncontacting capacitance transducer during conditions of fluid flow through the artery; resonant vibration characteristics were determined during pure sine and random sound stimulation of the artery walls in the absence of flow. It is concluded that fluid flow through isolated arteries with an experimental stenosis excites the artery wall to vibrate over a wide range of frequencies within which are discrete frequencies that coincide with the resonant frequencies of the artery wall.
TL;DR: In this paper, the authors considered the He-He, He-H(1s), H-H (1s) and H-1s)-H(2s interactions as model systems for studying how charge overlap effects in second-order dispersion energies vary as a function of the nature of the interacting species.
Abstract: The He-He, He-H(1s), H(1s)-H(1s) and H(1s)-H(2s) interactions are considered as model systems for studying how charge overlap effects in second-order dispersion energies vary as a function of the nature of the interacting species. The non-expanded second-order energy and the corresponding multipole R -1 expansions, through all powers of R -1, are obtained for each interaction using Unsold's average energy approximation. The results are used to discuss the limitations of the usefulness of the R -1 expansions.