Showing papers by "University of Western Ontario published in 1976"

The observation and analysis of stellar photospheres

Abstract: 1. Background 2. Fourier transforms 3. Spectroscopic tools 4. Light detectors 5. Radiation terms and definitions 6. The black body and its radiation 7. Radiative and convective energy transport 8. The continuous absorption coefficient 9. The model photosphere 10. The measurement of stellar continua 11. The line absorption coefficient 12. The measurement of spectral lines 13. The behavior of spectral lines 14. The measurement of stellar radii and temperatures 15. The measurement of photospheric pressure 16. Chemical analysis 17. Velocity fields in stellar photospheres 18. Stellar rotation.

Optimized effective atomic central potential

Abstract: A self-consistent set of equations is derived for an atomic central potential such that the energy given by the orbitals for the potential is minimized. It is shown that this effective potential behaves like $\frac{\ensuremath{-}{e}^{2}}{r}$ for large $r$ values. The equations have been solved for carbon, neon, and aluminum, and the resulting total energies exceed the Hartree-Fock total energies by less than 0.005%. The theory leads to an effective, local, central exchange potential analogous to the $X\ensuremath{\alpha}$ potential.

"Braille" reading by a blind volunteer by visual cortex stimulation.

Abstract: THE possibility of developing functional visual prostheses was supported by the pioneering case of Brindley and Lewin1,2 and confirmed by our subsequent report on two other blind patients3.

Soil‐pile interaction in vertical vibration

Abstract: The interaction between a soil layer and an end bearing pile is theoretically investigated. The pile is assumed to be vertical and elastic, the soil is considered as a linear visco-elastic layer with hysteretic type damping. The layer alone is solved first and the wave modes of the layer are used in the analysis of the pile response. The pile response to a harmonic load is obtained in a closed form and used to define stiffness and damping at the level of the pile head. The dimensionless parameters of the problem are identified. A parametric study is conducted to determine the main features of the response and of the equivalent stiffness and damping. The validity of equivalent viscous damping is examined. A comparison is made with the simpler plane strain theory used previously and its accuracy is assessed.

The Neural Basis of Language Qua Gesture

Abstract: Publisher Summary This chapter discusses the neural basis of language qua gesture. Evidence from normal and neurological studies has been reviewed to show that speaking and some manual activities are associated. The chapter discusses the facts such as: (1) the association between hand preference and speech lateralization in the brain; (2) the frequent occurrence of certain hand movements during speaking; (3) the relation of limb apraxia with aphasia, in left-hemisphere lesions; and (4) the association of manual communication disorders in the deaf, with left-hemisphere damage. It has been proposed that the left parietal region is an important part of a system controlling certain motor sequences, vocal and manual. Such left-hemisphere specialization for manual skills—and possibly manual communication—appears to have evolved as early as for speech. The symbolic-language functions of the left hemisphere are assumed to be a secondary consequence of specialization for motor function.

Steroidogenesis in rat leydig cells: changes in activity of 5-ane and 5-ene 3beta-hydroxysteroid dehydrogenases during sexual maturation.

Abstract: The activities of hydroxysteroid dehydrogenases of 5-ane and 5-ene steroids were examined in interstitial tissue from testes of rats at different ages. The enzyme reactions were localized in the Leydig cell cytoplasm of isolated cells and in frozen tissue slices. Relative reaction velocities of the NADlinked hydroxysteroid dehydrogenases were obtained spectrophotometrically with 17 steroid substrates using the 12,000 i g supernatant of isolated interstitial cells from 28–29 clay old rats; the rate of 3(α,β) dehydrogenation of 5-ane-3β steroids was markedly (10 to 20i) higher than that of 5-ene-3β steroids and 5-ane-3α steroids. The hydroxysteroid dehydrogenase activities of testes from 124 rats between the ages of 15 and 138 days were determined using as substrates, 3β-hydroxy- 5β-androstan-17-one, 3β-hydroxy-5a-androstan- 17-one, 3β,17β-dihydroxy-5α-androstane, dehydroepiandrosterone and pregnenolone. Between the ages of 15 and 32 or 34 days the gonads grow in size more rapidly than the body and the 5-an...

Rockfalls and rockfall inventory data: Some observations from surprise valley, Jasper National Park, Canada

Abstract: The major controls of rockfall activity are divided into two interacting groups. (a)Climatic factors which, through their control of temperatures and the availability and state of water, are primary controls of rockfall trigger mechanisms. (b) Geologic factors which, via cliff form (plan, profile, dissection etc.) and the character and availability of materials, influence the type, spatial distribution and intensity of rockfall activity. Detailed examination of these controls suggest that both seasonal and daily patterns of rockfall activity can vary markedly over a very small area. The implications of this variability for the design and interpretation of rockfall inventories are discussed using sample data from Surprise Valley, Jasper National Park, for the period from May-October 1969. On a seasonal basis rockfall activity showed a major spring peak with secondary maxima in the fall and associated with major summer storms. Two sites of differing aspect and morphology were studied in more detail revealing marked differences in the mean hourly frequency (0·94:0·20), mean hourly probability (0·40:0·16, hours with rockfall/hours observed) and daily pattern of rockfall activity. The west facing site showed equal hourly probability of rockfalls from 1000 to 2000 hr whereas the east facing slope had a greater hourly probability when it was in the sun (1100 1400hr) than in the shade (1400-1900hr). The differences in rockfall frequency and probabilities reflect the physical characteristics of the individual sites whereas the daily pattern of rockfalls is related to microclimate. These results suggest that if future inventory studies are to make a significant contribution, they must be carefully designed field experiments in which. (i) Data are restricted to the study or comparison of single continuously observed sites. (ii) Study sites and/or data periods are carefully selected to isolate and investigate specific controls e.g. the influence of cliff form, aspect, periods of rainfall etc. on rockfall patterns. (iii) Good on-site microclimate data are available. Also comparison of frequency measures based on the arithmetic mean should be avoided since the distribution of rockfalls per hour closely follows a Poisson distribution with occasional high values which unduly influence the value of the arithmetic mean. It is suggested that rockfall probabilities, based on the binary decision of whether or not a rockfall occurs in a given period, are a more useful measure for daily patterns of rockfall activity.

Some effects of tectonic recrystallisation on fluid inclusions in vein quartz

Abstract: Filling temperature data obtained from tectonic vein quartz varies according to the state of intracrystalline deformation. Strain free domains within grains exhibit abundant primary fluid inclusions, from which internally consistent temperatures are recorded. The onset of optical features associated with intracrystalline deformation by dislocation creep is accompanied by a decrease in the number of fluid inclusions and an increase of filling temperatures. At higher states of strain tectonic recrystallisation, evidenced by the formation of new subgrains, leads to the complete destruction of inclusion arrays. Empty cavities are swept out of the new grains during recrystallisation, into subgrain walls. Heterogeneous deformation of vein quartz at the intracrystalline level may be due in part to selective hydrolytic weakening in areas where fluid inclusions have leaked and thereby increased the structural water content.

Health Patterns Associated with Type a Behavior: A Managerial Population

Abstract: Type A Behavior is a behavioral syndrome found to be related to coronary heart disease and characterized by excessive drive, ambition, and competitiveness. Managers from 12 different companies were examined for this syndrome and for a number of the known risk factors in coronary heart disease (blood pressure. cholesterol, triglycerides, uric acid, smoking. and fitness). Those individuals exhibiting extreme Type A Behavior (Type A1) showed significantly higher blood pressure (systolic and diastolic) and higher cholesterol and triglyceride levels. A greater percentage of these individuals were cigarette smokers. On serum uric acid there were no differences. In each age group. Type A's were less interested in exercise, although differences in cardio-respiratory fitness were found only in the oldest age group. Type A Behavior also was related to age, education, company growth rates, and stress symptoms. Overall, the Type A1's were found to be higher on a number of risk factors known to be associated ...

Neurofibrillary tangles and the pathogenesis of dementia: a quantitative study

Abstract: A morphometric technique employing Congo red staining and scanning light microscopy with appropriate filters provided a sensitive sampling method for counting hippocampal neurons bearing neurofibrillary tangles in serially sectioned temporal lobes from mentally normal subjects of different ages as well as from demented patients. The number of tangled neurons per mm3 of cortex was compared with patients' ages. Tangle formation in controls increased only slightly with age; whereas the ‘Tangle Index’ of cases with the organic dementia of Alzheimer's disease exceeded by many times that of age-matched controls. The posterior portion of the hippocampus was found to be more susceptible to this augmented neurofibrillary degeneration than the anterior part of the hippocampus of demented subjects.

Acupuncture in Chronic Pain

Abstract: A course of 10 daily acupuncture treatments was given to 200 patients who suffered from chronic pain syndromes of at least one year duration and the result assessed at the end of the course of treatment and after an interval of at least 2 months. Treatments were individualized using needling of body loci distally and near the site of pain, and ear acupuncture. In 38 patients suffering from chronic headaches, including 13 cases of migraine-type headache, 81% reported an improvement in their condition, but only one patient was pain free for the 2-month observation period. In 162 patients with other chronic pain problems, 99 or 61% were improved or pain free at the end of treatment; in 69 of these a worthwhile degree of improvement persisted over the observation period of 2 months. Thirteen percent of all patients did not respond to acupuncture and in 26% the response was considered as transient only. Daily treatments are not more effective than weekly or biweekly treatments. Pain in the neck and shoulder region, in the knee and low back pain responded to acupuncture with prolonged improvement in over 50% of the patients treated. Facial pain syndromes and pain in the region of the trunk were least responsive and only 3 of 11 patients with post-herpetic neuralgia reported still having less pain after 2 months. Needling of effective loci and particularly ear needling often causes an instantaneous reduction or disappearance of pain; the speed of this response can only be explained by a mechanism within the nervous system. Based on our experience acupuncture represents a useful therapeutic modality in the management of pain.

Oscillation, Nutation and Wobble of an Elliptical Rotating Earth with Liquid Outer Core

Abstract: We have constructed a general first-order theory describing those small oscillations of a rotating elliptical earth that are affected by the presence of a liquid outer core The theory is applicable to free core oscillations and earth tides Care has been taken to include the effects of the wobble or nutation due to the rotation of the outer core relative to the solid earth On the basis of the theory the free spheroidal modes of degree 2 and order 1 have been investigated We have searched for and listed undertones with periods less than 28 hr No upper limit to the eigenperiods has been detected It is shown that stable, unstable and neutral polytropic cores are capable of free oscillation At a period close to the sidereal day the spheroidal mode is accompanied by rigid rotation of the liquid outer core with respect to the solid earth This is the well-known diurnal wobble of the Earth It appears probable that the diurnal wobble is one of a class of similar wobbles that involve large toroidal motions in the outer core Finally, the amplitudes of the 18·6-yr principal nutations has been computed Excellent agreement is found with observed values

Hormonal Control of Metabolism in Insects

Abstract: Publisher Summary The postembryonic development of insects is characterized by a series of synchronized events, controlled by the moulting and juvenile hormones. In the adult insect, tissue maintenance, homeostasis, and reproduction are also under hormonal control. The needs of these processes are met by anabolic or catabolic metabolism. As the requirement for amino acids, carbohydrate, and lipid used in the synthesis of structural elements and the energy required for endothermic reactions varies during different stages of development, and under different environmental conditions, a mechanism of metabolic control seems imperative. There is no evidence to support the notion that any of the known hormones occurring in insects functions as a “metabolic” hormone. The idea that such a hormone exists, and may be one of those already described, has been extant since the metabolic effects of hormones were first described and originated in the observation that allatectomy decreased the oxygen consumption of whole insects. Insects provide excellent model systems for the study of a number of metabolic problems, the importance of which extends far beyond the insects. More specifically, it seems certain that, because synthetic JH is now available, much attention will be directed toward the metabolic aspects of its action, particularly because of its potential use as an insecticide. The interaction of JH with female fat body to initiate the synthesis of vitellogenin in relatively large quantities may well prove a powerful instrument in elucidating the complex mechanisms by which hormones control the synthesis of proteins. The most pressing need in the immediate future is to isolate the various hormones and factors, which have been shown to be biologically active.

Subjective Perception of Deterrence (Continued)

Abstract: High school students were questioned about their perceptions of the certainty and severity of punishment for marijuana use and shoplifting. It was found that those respondents who perceived a higher certainty of punishment engage in less marijuana use and shoplifting. Those respondents who perceive a higher severity of punishment do not engage in less marijuana use and shoplifting. Those respondents who perceive marijuana use or shoplifting to be offenses mala in se engage in fewer offenses, but also, in the case of shoplifting, are less deterred by threat of punishment than are respondents who define that shoplifting as mala prohibita. This difference is not true for marijuana use.