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Showing papers by "University of Alberta published in 1979"


Journal ArticleDOI
TL;DR: In this paper, the root mean square and the mean square of the first derivative of a surface profile were used to measure the joint roughness coefficient of the surface profiles presented by Barton and Choubey.

710 citations


Journal ArticleDOI
TL;DR: In this paper, an experiment is presented which tests whether this approach yields viable predictions about the manner in which people comprehend and remember pictures of real-world scenes, and the results show that subjects generally notice only the changes that had been made to the unexpected objects, despite the fact that the proportions of correct rejections were made conditional on whether the target objects had been fixated.
Abstract: In general, frame theories are theories about the representation and use of knowledge for pattern recognition. In the present article, the general properties of frame theories are discussed with regard to their implications for psychological processes, and an experiment is presented which tests whether this approach yields viable predictions about the manner in which people comprehend and remember pictures of real-world scenes. Normative ratings were used to construct six target pictures, each of which contained both expected and unexpected objects. Eye movements were then recorded as subjects who anticipated a difficult recognition test viewed the targets for 30 sec each. Then, the subjects were asked to discriminate the target pictures from distractors in which either expected or unexpected objects had been changed. One consequence of the embeddedness of frame systems is that global frames may function as "semantic pattern detectors," so that the perceptual knowledge in them could be used for relatively automatic pattern recognition and comprehension. Thus, subjects might be able to identify expected objects by using automatized encoding procedures that operate on global physical features. In contrast, identification of unexpected objects (i.e., objects not represented in the currently active frame) should generally require more analysis of local visual details. These hypotheses were confirmed with the fixation duration data: First fixations to the unexpected objects were approximately twice as long as first fixations to the expected objects. On the recognition test, subjects generally noticed only the changes that had been made to the unexpected objects, despite the fact that the proportions of correct rejections were made conditional on whether the target objects had been fixated. These data are again consistent with the idea that local visual details of objects represented in the frame are not neccesary for identification and are thus not generally encoded. Further, since subjects usually did not notice when expected objects were deleted or replaced with different expected objects, it was concluded that if two events instantiate the same frame, they may often be indistinguishable, as long as any differences between them are represented as arguments in the frame. Thus, for the most part, the only information about an event that is episodically "tagged" is information which distinguishes that particular event from others of the same general class. The data reinforce the utility of a frame theory approach to perception and memory.

609 citations


Journal ArticleDOI
TL;DR: In this article, Babcock et al. showed that hole elongation occurs in siltstones, sandstones, limestones, dolomites and one shale formation, and through the stratigraphic column from Devonian to Cretaceous.

496 citations


Journal ArticleDOI
TL;DR: In this article, the authors considered the hydraulic geometry of straight reaches of wide, active rivers with beds and banks composed of loose gravel and derived dimensionless relations for hydraulic geometry, which provided channel properties as functions of bed pavement size and two specified variables.
Abstract: The hydraulic geometry of straight reaches of wide, active rivers with beds and banks composed of loose gravel is considered. Naive mechanistic formulations lead to the stable channel paradox; stable width is incompatible with an active bed. A resolution of the paradox based on bed stress redistribution due to turbulent lateral transfer of downstream momentum is outlined and is used to obtain three rationally derived regime relations.These dimensionless relations provide channel properties as functions of bed pavement size and two specified variables, e.g., water and sediment discharge, or water discharge and width. Reduction to relations for hydraulic geometry is shown to require information concerning watershed mechanics that is external to the river, and thus fluvially indeterminate. An empirical relation is determined for this purpose, allowing for derivation of dimensionless relations for hydraulic geometry.

412 citations


Journal ArticleDOI
TL;DR: Jurors were unable to distinguish accurate from inaccurate witnesses across the 42 cross-examina tion sessions, and jurors in the leading-questions conditions were significantly more likely to believe accurate than inaccurate witnesses, whereas the reverse effect held for nonleading questions.
Abstract: Subjects of both sexes individually witnessed the staged theft of a calculator. The 127 witnesses were then given the opportunity to identify the thief from a six-person picture array; from this sample, 24 accurate-iden tification witnesses and 18 inaccurate-id entification witnesses were cross-examined with either leading or nonleading questions. Jurors were unable to distinguish accurate from inaccurate witnesses across the 42 cross-examina tion sessions (d' = .02). However, jurors in the leading-questions conditions were significantly more likely to believe accurate than inaccurate witnesses (

383 citations


Journal ArticleDOI
TL;DR: In this article, the variations in the compressive strength, splitting and flexural-tension strengths, and the modulus of elasticity of concrete are reviewed, and representative probability distributions are suggested.
Abstract: The variations in the compressive strength, splitting, and flexural-tension strengths, and the modulus of elasticity of concrete are reviewed, and representative probability distributions are suggested The effects of volume, rate of loading, and in-situ casting of concrete are included

280 citations




Journal ArticleDOI
TL;DR: In this paper, the results of approximately 4000 published and unpublished tensile tests on deformed reinforcing bars are studied to obtain statistical relationships for various mechanical properties, including the mean and coefficients of variation of the mill test yield strength.
Abstract: The results of approximately 4000 published and unpublished tensile tests on deformed reinforcing bars are studied to obtain statistical relationships for various mechanical properties. The sample included No. 3 through No. 18, Grades 40 and 60, bars. The means and coefficients of variation of the mill test yield strengths were found to be 48.8 ksi (337 MN/sq m) and 10.7% for Grade 40 and 71 ksi (MN/sq m) and 9.3% for Grade 60 bars. Beta distributions were used to represent both of these sets of data. The static yield strength was found to be 3.5 ksi (24 MN/sq m) lower on the average than the mill test yield strength in both cases, with a coefficient of variation of 13.4%. The trend to lower yield strengths with increased bar sizes observed early in the 1970's was not present in more resent test data, apparently due to more stringent production control in recent years. /Authors/

219 citations



Journal ArticleDOI
TL;DR: In this paper, a hydrogenic model with Zener screening constant is used to calculate generalized oscillator strengths of K-shell ionization, the optical values showing good agreement with X-ray absorption data.


Journal ArticleDOI
TL;DR: In this article, the relation between transient relativistic thermodynamics and kinetic theory in the formulation of Israel was discussed, and identical results for the characteristic velocities of thermal transients were obtained.
Abstract: This paper, the sequel to Stewart (1977), discusses the relation between transient relativistic thermodynamics and kinetic theory in the formulation of Israel (1972, 1976) which differs (mathematically) from that of the previous paper. The difference is that the moment expansions are truncated in different ways. However, identical results for the characteristic velocities of thermal transients are obtained, and this lends credence to both approaches. In this approximation at least, the Grad method of moments is insensitive to the truncation procedure.

Journal ArticleDOI
TL;DR: It is suggested that N2 is the best, single measure of diversity, and that the only other index worth considering is N1.

Journal ArticleDOI
TL;DR: In this paper, a three-dimensional constitutive relationship for concrete is developed and results are compared to experimental data available in the literature, using the concept of equivalent uniaxial strain, the nonlinear stress-strain equation of Saenz, and the Argyris failure surface for concrete strength.
Abstract: A three-dimensional constitutive relationship for concrete is developed and results are compared to experimental data available in the literature. The model uses the concept of equivalent uniaxial strain, the nonlinear stress-strain equation of Saenz, and the Argyris failure surface for concrete strength. The technique of evaluating the parameters to adjust the constitutive relationship for various concretes is examined. Comparison is made with the biaxial experimental data of Kupfer, Hilsdorf, and Rusch, and with the three-dimensional experimental data of Schickert and Winkler. The model appears capable of simulating the stress-strain response of concrete under a large range of conditions and is easily incorporated into finite element programs. Flow charts for implementation of the constitutive relationship are presented.

Journal ArticleDOI
TL;DR: In this paper, the Debye scalar superpotentials were extended to curved spaces to yield a constructive procedure for neutrino, electromagnetic, and gravitational perturbations of algebraically special spacetimes.
Abstract: The method of Debye scalar superpotentials has previously been extended by the authors to curved spaces to yield a constructive procedure for neutrino, electromagnetic, and gravitational perturbations of algebraically special spacetimes. The solution of a decoupled scalar wave equation is differentiated to give the solution of the corresponding spinor or tensor perturbation field equations. In this paper covariant formulations and proofs are given. The results are derived in a general spinor formalism framework which extends earlier exterior differential form and tensor treatments of the electromagnetic case.

Journal ArticleDOI
TL;DR: The authors examined the relationship between the perception and fear of crime on the one hand and neighborhood cohesion, social activity and affect for the community on the other, using survey data collected from interviews with a sample of residents of a western Canadian city.
Abstract: This research examines the relationship between the perception and fear of crime on the one hand and neighborhood cohesion, social activity and affect for the community on the other, using survey data collected from interviews with a sample of residents of a western Canadian city. The hypotheses that the perception of increased crime and the fear of crime would be inversely related to neighborhood cohesion and social activity were not supported. But as hypothesized, the fear of crime was negatively related to affect for the community. And the prediction that the experience of actual victimization would not affect these hypothesized relationships was supported. When various social and residential variables were included with fear of crime in a multiple regression to predict community affect, low fear and older age were found to result in greater affect both for the neighborhood and the city. In addition, females and the less well-educated had more affect for the city. An exploration of possible interaction effects between fear of crime and the social and residential variables did not yield any significant results.

Journal ArticleDOI
TL;DR: In this article, asphaltenes and their pyrolysis products from biodegraded and non-biodegraded oils were studied and it was concluded that the overall composition of the oil produced from them was similar to, yet significantly different from, that of the parent oil.

Journal ArticleDOI
TL;DR: In this paper, the effect of discrete bar sizes on the ratio of the furnished area to calculated area of reinforcement is also considered and modified log-normal distribution is proposed for these quantities.
Abstract: Variations in cross-sectional dimensions and in the location of reinforcing bars in slabs, beams, and columns are reviewed Normal distributions are proposed for these quantities The effect of discrete bar sizes on the ratio of the furnished area to calculated area of reinforcement is also considered and modified log-normal distribution is proposed

Journal ArticleDOI
TL;DR: The results demonstrate that anaerobic bacteria unable to carry out oxygen- or nitrate-dependent electron transport are resistant to streptomycin and gentamicin because of failure to transport aminoglycosides.
Abstract: Cell-free amino acid incorporation using ribosomes from strains of either Clostridium perfringens or Bacteroides fragilis was shown to be susceptible to inhibition by streptomycin and gentamicin. Ribosomes bound dihydrostreptomycin as effectively as ribosomes from Escherichia coli. No inactivation of streptomycin or gentamicin was detected by cell extracts of either anaerobic bacterial species. B. fragilis, grown without added hemin, menadione, and fumarate, and C. perfringens did not show any time-dependent accumulation of dihydrostreptomycin or gentamicin at concentrations tested. Decreased resistance to aminoglycosides and time-dependent uptake of dihydrostreptomycin at 500 mug/ml was observed with B. fragilis grown with hemin, menadione, and fumarate. With the last additions, cytochrome b was detected by cytochrome spectra of B. fragilis. These results demonstrate that anaerobic bacteria unable to carry out oxygen- or nitrate-dependent electron transport are resistant to streptomycin and gentamicin because of failure to transport aminoglycosides. The induction of fumarate-dependent electron transport in B. fragilis is associated with some aminoglycoside transport that is of poor efficiency relative to bacteria with electron transport to oxygen or nitrate.

Journal ArticleDOI
13 Sep 1979-Nature
TL;DR: Structural evidence is presented that the enzyme forms from liver, kidney and serum from a patient with Paget's disease of bone are products of the same structural gene and can be easily distinguished from either the intestinal or placental isoenzymes.
Abstract: The number of structural gene loci that code for the different molecular forms of human alkaline phosphatase is unknown. Physical properties of the enzymes, immunological data, chemical inhibition and genetic studies suggest that at least three structural genes1 are involved: one coding for alkaline phosphatase from placenta, another for the enzyme from intestine, and one or more for the enzymes from liver, kidney and bone. Badger and Sussman2 have shown that alkaline phosphatases from human liver and placenta are products of different structural genes, and Greene and Sussman3 have shown that alkaline phosphatase from a metastasised bronchogenic carcinoma was nearly identical to the enzyme from placenta. However, other tumour-associated alkaline phosphatases and the enzymes from normal tissues other than placenta and liver have not been identified by conclusive structural criteria4, and thus it is not known whether these onco-alkaline phosphatases represent ectopic production or unusual post-translational modification of the enzymes found in normal tissues. We present here, using a sensitive peptide-mapping technique5, structural evidence that the enzyme forms from liver, kidney and serum from a patient with Paget's disease of bone (osteitis def ormans) are products of the same structural gene and can be easily distinguished from either the intestinal or placental isoenzymes. The technique seems to be useful for the classification of tumour-associated alkaline phosphatases on a structural basis.

Journal ArticleDOI
TL;DR: In this paper, the effect of P on acid phosphatase activity and production in some Alberta soils may be related to soil properties and past fertilizer history, soils of varying organic matter content, extractable P and P fertilization history were assayed for acid-phosphatase using p -nitrophenyl phosphate as substrate.
Abstract: To find out how acid phosphatase activity and production in some Alberta soils may be related to soil properties and past fertilizer history, soils of varying organic matter content, extractable P and P fertilization history were assayed for acid phosphatase using p -nitrophenyl phosphate as substrate. The effect of solution P concentration during the phosphatase assay was examined. The effect of P on the production of new phosphatase was examined in soils incubated with an added energy supply or orthophosphate. Phosphatase activity was influenced by P fertilization practices during the 5 yr before sampling. In a Black Chernozemic soil (Malmo SiCL) with a high organic matter content and high initial phosphatase activity, P fertilization at 27 or 54 kg P ha −1 y −1 for 5 yr reduced phosphatase activity by about 20%. However, in a Grey Luvisolic soil (Cooking Lake L) with low organic matter and initial phosphatase, P fertilization at 54 kg P ha −1 y −1 for 5 yr tended to increase activity, probably by increasing plant root growth and organic matter additions. Assay solutions containing orthophosphate at 0.55 mM reduced activity by 25% and 47% in a Malmo SiCL and Maleb L (Orthic Brown Chernozem) soil respectively. Further increases of phosphate concentration to 5.5 mM reduced phosphatase activity by 50% and 76% in the Malmo and Maleb L soils respectively. Phosphatase activity was increased up to 6-fold by incubation of soil with glucose and NH 4 NO 3 . Addition of P to produce an added C: added P ratio of 20:1 completely prevented synthesis of phosphatase by proliferating organisms and had a slight inhibitory effect on phosphatase already present. Similarly, addition of P without C in a 6-week incubation had only a small effect on phosphatase activity and maintained P concentrations in the assay solutions slightly below 0.55 mM. It was concluded that the effect of phosphate on soil phosphatase operates more through its effect on phosphatase synthesis than on activity of existing phosphatase.

Journal ArticleDOI
R.R Gilpin1
TL;DR: In this paper, a mathematical model of the liquid-like layer that exists between ice and a substrate is developed and used to show the relationship between two problems in which a foreign object moves through ice.

Journal ArticleDOI
TL;DR: In this paper, the fairness of lineups used for criminal identification is discussed in the context of a distinction between nominal size and functional size, and empirical estimates of functional size can be obtained through pictures of the corporal lineup from which mock witnesses make guesses of whom they believe the police suspect.
Abstract: Issues regarding the fairness of lineups used for criminal identification are discussed in the context of a distinction between nominal size and functional size. Nominal size (the number of persons in the lineup) is less important for determining the fairness of a lineup than is functional size (the number of lineup members resembling the criminal). Functional size decreases to the extent that the nonsuspect members of the lineup are easily ruled out as not being suspected by the police. The extent to which the identification of the suspect can be considered an independently derived piece of incriminating evidence is positively related to functional size. Empirical estimates of functional size can be obtained through pictures of the corporal lineup from which mock witnesses make guesses of whom they believe the police suspect. A distinction is made between a functional size approach and hypothesis testing approaches. Uses of functional size notions in the court, by police, and in research are discussed.


Journal ArticleDOI
01 Jan 1979-Toxicon
TL;DR: Responses to ANTX-A on the isolated frog-rectus abdominus muscle were qualitatively similar to those obtained with acetylcholine, carbachol and decamethonium, with AN TX-A being the most potent.

Journal ArticleDOI
TL;DR: Evidence of a somatostatin (SRIF)-like antigen has been found in the brain and digestive tract of rainbow trout and in the gut, where material immunoreactive for luteinizing hormone-releasing hormone has the same distribution in the pituitary as SRIF.

Journal ArticleDOI
TL;DR: The periovulatory pattern of circulating gonadotropin is described for the first time in a poikilothermic vertebrate and indicates that the goldfish provides a valuable model for the study of ovulation in teleosts.

Journal ArticleDOI
TL;DR: In this article, the authors describe variability in the synaptic connections of an identified interneuron in two species of locust (Locusta migratoria and Schistocerca gregaria) and show that this variability is associated with a large variation in the structure of the Interneuron.
Abstract: Numerous reports have described variability in the morphology of identified neurons; none, however, has previously reported variability in the pattern of synaptic connection. In this report we describe variability in the synaptic connections of an identified interneuron in two species of locust (Locusta migratoria and Schistocerca gregaria) and show that this variability is associated with a large variation in the structure of the interneuron. The morphology of the descending contralateral movement detector (DCMD) interneuron was determined in the thoracic ganglia by intracellularly staining with cobalt sulphide followed by Timm's silver-intensification of whole-mount preparations. The striking characteristic of the structure of this interneuron was the variability from animal to animal. This was so large we were unable to describe a “normal” structure. However, five distinct branches of the interneuron were identified in the metathoracic ganglion. In each animal the structure of DCMD could be described by specifying which of these branches were present. One or more of these branches were usually absent, and there were differences in the probability of any particular branch being absent. Corresponding to the variation in the structure of DCMD there was a large variation in the synaptic connections made by this interneuron. DCMD can make monosynaptic connections to the fast extensor tibiae (FETi) motoneuron, fast and intermediate flexor tibiae motoneurons, and depressor and elevator flight motoneurons. These functional connections were not found in all animals. The absence of an EPSP from DCMD in FETi was associated with either the complete absence of a ventral branch or with the absence of an identifiable process of a ventral branch, and the absence of an EPSP from DCMD in flight motoneurons was associated with the absence of the dorsal branch. The connection of each of these specific branches of DCMD to FETi and flight motoneurons respectively was confirmed by double staining the motoneurons and DCMD in cases which had the functional connection. The implication of our findings is that the connections of interneurons in invertebrates may, in some cases, be far more variable than is generally believed at the present time.

Journal ArticleDOI
TL;DR: A system for imaging occult bronchogenic carcinoma by the fluorescence of previously-injected, tumor-specific compound hematoporphyrin-derivative has been assembled and successfully used to locate a tumor 1 mm thick.
Abstract: A system for imaging occult bronchogenic carcinoma by the fluorescence of previously-injected, tumor-specific compound hematoporphyrin-derivative has been assembled and successfully used to locate a tumor 1 mm thick. The violet excitation source is a krypton ion laser coupled to fused quartz fiber light conductor. An electrostatic image intensifier attached to a standard flexible fiberoptic bronchoscope provides a bright image even at relatively low irradiance. A red secondary filter rejects most reflected background and autofluorescence. Sensitivity and contrast capability of the system should permit detection of a tumor less than 0.1 mm thick.