Showing papers by "Carleton University published in 1977"

Auditory sensitivity of the albino rat.

Abstract: The auditory sensitivity of the (Sprague-Dawley strain) albino rat was determined by the conditioned suppression technique. The three animals tested were found to have a range of hearing from 250 Hz to 80 kHz at 70 dB (SPL). They were most sensitive to tones of 8 kHz but were almost as sensitive at 38 kHz. In contrast to previously published data, there was no evidence for a highly specialized tuning of the audiogram to tones in the 30-40 kHz region. In general, the audiogram of this strain of albino rat is quite typical of mammals of the same size and, furthermore, closely approximates the mammalian mean in most essential features.

Sampled analog filtering using switched capacitors as resistor equivalents

Abstract: The equivalence between resistor-capacitor (RC) filtering circuits and circuits containing switches and ratioed capacitors is examined. The authors have demonstrated the advantages of ratioed capacitors for integrated active filters experimentally, using a specially designed integrated MOS test chip. Polysilicon gate technology was used to fabricate the chip, with the capacitors being formed by two levels of polysilicon. For the theoretical description, and as a design aid, attention is drawn to the general equivalence between a resistor and a circuit element consisting of a capacitor and two switches. Nonideal effects, which set limits to the generality, are also discussed.

A simple two-dimensional model for IGFET operation in the saturation region

Abstract: A model is developed for an IGFET operating in saturation and accounting for the two-dimensional potential distribution in the section of the surface space-charge region adjacent to the drain. This section is treated as a volume obeying Gauss's law, thereby enabling the charge contained in it to be related to the integral of the electric displacement density normal to its surface without the need to consider the detailed distribution of charge inside. The resulting model shows, explicitly, the dependence of device output characteristics on applied potentials, geometric and processing parameters. It is also shown that by making adequate approximations, simple yet accurate forms of the model are obtained. The accuracy of the model is demonstrated by comparisons between calculated and measured device output characteristics.

The critical measure diffusion process

Abstract: A multiplicative stochastic measure diffusion process is the continuous analogue of an infinite particle branching diffusion process. In this paper the limiting behavior of the critical measure diffusion process is investigated. Conditions are found under which a non-trivial steady state random measure exists and in this case a spatial central limit theorem is established.

Culture of Spontaneously Contracting Myocardial Cells from Adult Rats

Abstract: A method is described for isolating single myocardial cells from adult rats and for establishing them in culture. Isolation is achieved by simul-taneous enzymatic and mechanical treatment of excised cardiac tissue. Exposure to the enzymes, a mixture of trypsin and collagenase, is carried out in a specially designed apparatus in which enzyme-loosened cells are liberated from the tissue. Cells are spontaneously contractile upon isolation, establish in culture, and continue to contract for up to 60 days. Features of the isolation procedure are discussed and are compared with those of conventional procedures. Preliminary results are reported showing that isolated cells are sensitive to electric stimulation and to application of L-epinephrine.

Territoriality and the evolution of brain asymmetry.

Abstract: When I was first invited t o contribute t o this conference, its very title seemed t o imply an opportunity t o engage in some theorizing and speculation. Accordingly, 1 decided from the outset t o go onto the proverbial limb and t o share some thoughts about the evolutionary origins of brain lateralization. This sort of exercise can on occasion be useful in generating and making explicit conceptual frameworks within which one can consider brain asymmetry in animals and man. One can approach the problem of brain asymmetry in animals from at least two different perspectives. First, one can regard it from a human perspective and ask what sorts of parallels or precursors might one expect to find in animals, given what we suspect about the nature of complementary hemispheric specialization in man. Despite a long history assuming that brain lateralization and language are somehow closely linked together, it is now clear that there are processes or functions other than speech and language that are lateralized in the human brain, and that animals might share with man some of these dimensions. As well, an argument might be made for the position that what is lateralized in the case of the apparently uniquely human behavior of language are underlying mechanisms or modes of information processing, rather than the behaviors them; again, these underlying mechanisms or processes could be lateralized in nonhumans, although manifest in behaviors other than language4 A second approach is t o look at the phenomenon of brain lateralization from a somewhat wider perspective-the biological-and to ask just what biological significance brain lateralization might have, and what sorts of selective pressures might have favored its evolution. It is this latter approach I would like t o adopt in this paper. For purposes of stimulating discussion, I would like t o argue that the biological significance of brain lateralization may be found in problems related t o the analysis and memory of spatial position, and perhaps t o territoriality. I would like to suggest (or really t o reiterate a suggestion made by others5) that brain asymmetry represents a mechanism that facilitates spatial orientation and the memory of spatial position. Furthermore, I would like t o suggest that brain asymmetry evolved because this facilitation in the analysis and memory of spatial location can facilitate reproduction either directly, in the sense of helping t o find a mate, or indirectly, through its association with the definition and defense of territory, upon which successful mating is predicated in so many species.

Experienced involuntariness and response to hypnotic suggestions

Abstract: Since the last century, it has been commonly observed that good hypnotic subjects typically report that their overt response to motoric suggestions are experienced as involuntary occurrences.’. ? These responses feel as if they “happened to” the subject, rather than feeling like self-initiated, self-guided acts. Our paper addresses itself to this phenomenon. The first part reviews theoretical approaches and empirical findings associated with the problem of experienced involuntariness. The second presents an experiment aimed at clarifying some of the methodological issues raised by previous research.

Amino Acid Metabolism of Pea Leaves: Diurnal Changes and Amino Acid Synthesis from 15N-Nitrate 1

Abstract: In the young leaves of pea (Pisum sativum L.) plants, there was a diurnal variation in the levels of amino acids. In the light, total amino nitrogen increased for the first few hours, then stabilized; in the dark, there was a transient decrease followed by a gradual recovery. Asparagine, homoserine, alanine, and glutamine accounted for much of these changes. The incorporation of 15N into various components of the young leaves was followed after supply of 15N-nitrate. 15N appeared most rapidly in ammonia, due to reduction in the leaf, and this process took place predominantly in the light. A large proportion of the primary assimilation took place through the amide group of glutamine, which became labeled and turned over rapidly; labeling of glutamic acid and alanine was also rapid. Asparagine (amide group) soon became labeled and showed considerable turnover. Slower incorporation and turnover were found for aspartic acid, γ-aminobutyric acid, and homoserine. Synthesis and turnover of all of the amino acids continued at a low rate in the dark. γ-Aminobutyric acid was the only compound found to label more rapidly in the dark than in the light.

Silicon solar cells using natural inversion layers found in thermally-oxidized p-silicon

Abstract: Inversion layer silicon solar cells are described which employ the natural inversion layer occurring at the surface of thermally-oxidized p-type silicon as one side of an induced n-p junction. Very shallow junctions are predicted theoretically with high electric fields in a direction to aid the collection of carriers generated by light of ultra-violet wavelengths. Collection efficiency calculations show the inversion layer cell to be less sensitive to lifetime and surface recombination velocity variations than diffused junction cells. Experimental 2 cm × 2 cm cells have been fabricated with the inversion layer contacted via a fine diffused n+ grid overlaid with a Ni-Cu-Au contact. The contact grid, specially designed to minimize the effect of the high inversion layer sheet resistance, produced a total shading of 16%. Illuminated I-V measurements confirm the induced junction to be near ideal, with an ideality factor A ⋍ 1.05 and a reverse saturation current approaching that predicted theoretically. Conversion efficiencies of ⋍ 8% have been obtained, with no special precautions being taken to reduce the series resistance of the back contact, or reflections at the front surface.

The Reliability of Difference Scores When Errors Are Correlated

Abstract: The usual formulas for the reliability of differences between two test scores X and Y are based on the assumption that the error scores EX and EY are uncorrelated. In modern developments of test score theory, such as that of Lord and Novick, a true score is defined as the expected value of an individual's observed score. This definition implies that true scores on any test are uncorrelated with error scores on any test, but it does not imply that error scores on distinct tests X and Y are uncorrelated. A zero correlation between the errors can be obtained only by introducing an additional assumption of "experimental independence" that does not follow from the other axioms in the model. This assumption restricts severely the class of random variables to which the usual formulas for reliability of differences will apply. The present paper investigated the reliability of difference scores in more general cases where it is not assumed that error scores on distinct tests are uncorrelated. The formulas derived ...

A new approach to the theory and modeling of insulated-gate field-effect transistors

Abstract: Consideration of basic charge relationships in the IGFET has led to a new formulation of the theory of the device which allows model characterization in a more general manner, and with greater accuracy, than previously achieved. The contribution of the mobile channel charge to the silicon surface potential, which is believed to have a significant influence on the device characteristics, is taken into account in this approach. Accurate device modeling is achieved over a very wide range of operation, extending from weak channel (subthreshold) to high level channel conditions. An important feature of the model is that it is expressed in terms of a constant effective channel mobility. Further, the current and charge relationships involved take the form of a single set of analytic closed-form expressions in terms of the terminal voltages for all conditions of device operation, and are thus appropriate for CAD implementation. The scope and accuracy of this approach to IGFET modeling are demonstrated by comparisons between measured and theoretical dc and small-signal characteristics for sample metal and silicon gate devices.

Earthquake response of steel‐framed multistorey buildings with set‐backs

Abstract: A study is made of the dynamic behaviour of multistorey steel rigid-frame buildings with set-back towers. The effects of set-backs upon the building frequencies and mode shapes are examined. Then the effects of set-backs on seismic response are investigated by analysing the response of a series of set-back building frame models to the El Centro ground motion. Finally, the computed responses to the El Centro earthquake are compared with some code provisions dealing with the seismic design of set-back buildings. The conclusions derived from the study include the following: 1.The higher modes of vibration of a set-back building can make a very substantial contribution to its total seismic response; this contribution increases with the slenderness of the tower. 2.Some of the important response parameters for the tower portion of a set-back building are substantially larger than for a related uniform building. 3.For very slender towers, the transition region between the tower and the base may be subjected to very large storey shears.

Amino Acid Metabolism of Pea Leaves Labeling Studies on Utilization of Amides

Abstract: Short term (2-hour) incorporation of nitrogen from nitrate, glutamine, or asparagine was studied by supplying them as unlabeled (14N) tracers to growing pea (Pisum sativum L.) leaves, which were previously labeled with 15N, and then following the elimination of 15N from various amino components of the tissue. Most components had active and inactive pools. Ammonia produced from nitrate was assimilated through the amide group of glutamine. When glutamine was supplied, its nitrogen was rapidly transferred to glutamic acid, asparagine, and other products, and there was some transfer to ammonia. Nitrogen from asparagine was widely distributed into ammonia and amino compounds. There was a rapid direct transfer to glutamine, which did not appear to involve free ammonia. Alanine nitrogen could be derived directly from asparagine, probably by transamination. Homoserine was synthesized in substantial amounts from all three nitrogen sources. Homoserine appears to derive nitrogen more readily from asparagine than from free aspartic acid. A large proportion of the pool of γ-aminobutyric acid turned over, and was replenished with nitrogen from all three supplied sources.

Aging and Decision Criteria for the Detection of Tones in Noise

Abstract: The performance of young (18--22 years) and old adults (55--64 years) on an auditory task was compared using signal detection procedures Subjects used a confidence rating scale to report the presence or absence of a 6000 Hz pure tone embedded in Gaussian noise The tone was set at eigher 35, 50, or 65 dB SPL Younger subjects showed perfect sensitivity at all dB levels, and the sensitivity of older subjects increased as a function of the dB level Discrimination was then tested at 20 and 30 dB in another sample of younger subjects We found that this group tended to respond much less conservatively than the older group, even though the task was of comparable difficulty

Prenatal morphine administration alters behavioral development in the rat

Abstract: Female rats were administered increasing doses of morphine sulfate 5 days prior to mating and during gestation until 4-6 days before the birth of their litters. Prenatal morphine exposure altered the normal during the 3rd and 4th postnatal weeks. This disruption in behavioral ontogeny did not coincide with changes in physical parameters. Decreased body weight ant postnatal week. The appearance of behavioral disturbances in the absence of physical abnormalities stresses the need for follow-up studies of infants born to narcotic-dependent mothers after signs of physical withdrawal or retarded growth have disappeared.

Regular right part grammars and their parsers

Abstract: This paper introduces an alternative to context-free grammars called regular right part (RRP) grammars, which resemble PASCAL syntax diagrams. Formally, RRP grammars have production right parts, which are nondeterministic finite state machines (FSMs), and, as a special case, regular expression, since these can be converted to FSMs. RRP grammars describe the syntax of programming languages more concisely and more understandably than is possible with CF grammars. Also introduced is a class of parsers, RRP LR(m, k) parsers, which includes the CF LR(k) parsers and provides the same advantages. Informally, an RRP LR(m, k) parser can determine the right end of each handle by considering at most k symbols to the right of the handle and the left end, after the right end has been found, by considering at most m symbols to the left of the handle. A mechanism for determining the left end is required because there is no bound on the length of the handle.

Arctic Coccolithophorids: Wigwamma arctica gen. et sp.nov. from Greenland and Arctic Canada, W. annulifera sp.nov. from South Africa and S. Alaska and Calciarcus alaskensis gen. et sp.nov. from S. Alaska

Abstract: Two new genera of coccolithophorids, one with two species, have been described and illustrated by means of electron microscopy of wild material from various sources in the northern or southern hemisphere. The main diagnostic features of the new genus Wigwamma (type species W. arctica sp.nov.) include 'ring-shaped' coccoliths, attached to the edges of unmineralized plates with characteristic surface patterning, and with some or all carrying superstructures composed of four (or sometimes two) rod-shaped crystallites, converging to a point distally and attached proximally to the subtending calcified scale-rim in a characteristic manner. After comparisons with the unmineralized scales of Chrysochromulina, these coccoliths are interpreted as equivalent to the bases, including the support struts, of certain spined scales comparable in a general way with those of C. pringsheimii but with the spine itself undeveloped or vestigial. Analogous changes, carried out independently and with many differences of detail implying a different prototype source, are inferred to explain the coccolith morphology of another new genus, Calciarcus, at present only known in a preliminary way in the north Pacific (near Homer, S. Alaska). The coccoliths of this organism have been investigated chemically by means of the electron probe CORA. Further comparisons between Wigwamma, more especially W. annulifera sp.nov., and other coccolithophorids, notably Ceratolithus, Pappomonas and Papposphaera have emphasized the value of crystallographic details as taxonomic and phyletic markers, in situations where coccolith morphology as a whole is equivocal as a result of convergence. The available distributional data for all known arctic coccolithophorids are then summarized and the conclusion is drawn that collectively they may represent a highly selected community adjusted to arctic conditions and perhaps able to perennate locally but ultimately derived by immigration from the north Pacific. Other conclusions to which the arctic coccolithophorids collectively have led are summarized in a final paragraph.

Flow Survey of the Vortex Wake behind Wings

Abstract: Flowfield surveys of the wake behind three different wings have been carried out in a low-speed wind tunnel. The mean flow properties have been measured using a small non-nulling five-hole probe. The results include the three mean velocity components, complete definition of the viscous wake, and detailed loading on one of the wings. The three components of vorticity were calculated and the vortical wake completely defined. It was found that the vortical wake always is contained within the viscous wake (region of total pressure loss). The vortex system is never fully rolled up, in the traditional sense, within the reasonably large downstream distance tested of 13 wing spans. The overall lift coefficient calculated from the distribution of streamwise component of vorticity is found to be smaller (87-100%) than that measured directly on the wing. The total circulation accounted for, at any streamwise station, decreases slightly with downstream distance. Comparison was made between the measured tangential velocity profiles and circulation distribution and those calculated using Betz theory, based on measured spanwise loading. Agreement is reasonable over a radius more or less equal to that of the vortex viscous core (<0.25 6/2). Outside of this region, the Betz model assumes that roll-up is complete when, in fact, it is not. Agreement is also poor very near the vortex center because of the strong viscous effects there.

Cognitive strategies, reported goal-directed fantasy, and response to suggestion in hypnotic subjects.

Abstract: Suggestions instructing subjects to carry out a goal-directed fantasy (GDF suggestions) were no more effective than non-GDF suggestions in augmenting either reported goal-directed fantasy (GDFr) or response to suggestion in hypnotic subjects. However, GDFr was associated both with overt suggestibility and subjects' experience of their response as an involuntary occurrence. The magnitude of GDFr was in part a function of the type of questions used to elicit subjects' testimony.

On Estimating the Variance in Sampling with Probability Proportional to Aggregate Size

Abstract: The problem of estimating the variance of the ratio estimator in sampling with probability proportional to aggregate size is investigated. The form of nonnegative unbiased variance estimators is found. For sample size n = 2, it is shown that there is at most one nonnegative unbiased variance estimator, whereas for n > 2, two different, possibly nonnegative, unbiased variance estimators are proposed. The performance of the proposed unbiased variance estimators, as regards their stabilities and probabilities of getting a negative value, is empirically investigated employing a variety of real populations.