Showing papers by "University of British Columbia published in 1982"
3,443 citations
TL;DR: A key development in the economic theory of index numbers has been the demonstration that many index number formulas can be explicitly derived from particular aggregator functions as mentioned in this paper, which provides a powerful new basis for selecting an index number procedure.
Abstract: Early in this century economists began to give serious attention to making comparisons using index number techniques. There was extensive debate as to which index number formulas were the most appropriate for carrying out comparisons.1 The debate was extensive in no small part due to the lack of agreement as to criteria for preferring one formula over another. In recent decades there has been a resurgence of interest in index numbers, resulting from discoveries that the properties of index numbers can be directly related to the properties of the underlying aggregator functions that they represent. The underlying functions - production functions, utility functions, etc. - are the building blocks of economic theory, and the study of relationships between these functions and index number formulas has been referred to by Samuelson and Swamy (I974) as the economic theory of index numbers.2 A key development in the economic theory of index numbers has been the demonstration that numerous index number formulas can be explicitly derived from particular aggregator functions. This development provides a powerful new basis for selecting an index number procedure. Rather than starting the selection process with a number of plausible index number formulas, one can specify an aggregator function with desirable properties and derive the corresponding index number procedure. The resulting index is termed exact for that particular aggregator function. Diewert (I976) makes a strong case for limiting the consideration of aggregator functions to those which are flexible, i.e. those which can provide a second order approximation to an arbitrary aggregator function. He has termed index numbers that are exact for flexible aggregator functions 'superlative '. There are two superlative index numbers that are of particular interest - the Fisher Ideal index and the Tornqvist-Theil-translog index. Fisher (I 922) dubbed the following index Ideal since it best satisfied his several criteria for choosing among index numbers:
1,660 citations
TL;DR: For example, the authors presents examples in which a decision, preference, or emotional reaction is controlled by factors that may appear irrelevant to the choice made, such as decision weights, reference points, framing, and regret.
Abstract: Presents examples in which a decision, preference, or emotional reaction is controlled by factors that may appear irrelevant to the choice made. The difficulty people have in maintaining a comprehensive view of consequences and their susceptibility to the vagaries of framing illustrate impediments to rational decision making. However, experimental surveys indicate that such departures from objectivity tend to follow regular patterns that can be described mathematically. The descriptive study of preferences also challenges the theory of rational choice, as it is often unclear whether the effects of decision weights, reference points, framing, and regret should be considered as errors or biases or whether they should be accepted as valid elements of human experience. (PsycINFO Database Record (c) 2012 APA, all rights reserved) Language: en
1,470 citations
TL;DR: It is confirmed that illusory conjunctions are frequently experienced among unattended stimuli varying in color and shape, and that they occur also with size and solidity (outlined versus filled-in shapes).
1,262 citations
TL;DR: This paper presents a versatile and efficient procedure for the construction of oligodeoxyribonucleotide directed site-specific mutations in DNA fragments cloned into M13 derived vectors, and production of a transition mutation in a clone of the yeast MATa1 gene is described.
Abstract: This paper presents a versatile and efficient procedure for the construction of oligodeoxyribonucleotide directed site-specific mutations in DNA fragments cloned into M13 derived vectors. As an example, production of a transition mutation in a clone of the yeast MATa1 gene is described. The oligonucleotide is hybridized to the template DNA and covalently closed closed double stranded molecules are generated by extension of the oligonucleotide primer with E. coli DNA polymerase (large fragment) and ligation with T4 DNA ligase. The resulting double stranded closed circular DNA (CC-DNA) is separated from unligated and incompletely extended molecules by alkaline sucrose gradient centrifugation. This purification is essential for production of mutants at high efficiency. Competent E. coli JM101 cells are transformed with the CC-DNA fraction and single stranded DNA is isolated from individual plaques. The recombinants are screened for mutant molecules by 1) restriction endonuclease screening for the loss of the Hinf I site in the target region, and 2) by dot blot hybridization using the mutagenic oligonucleotide as probe. Double stranded DNA is isolated from the sequencing. Efficiency of mutant production is in the range of 10-45% and no precautions to prevent mismatch repair are required.
1,011 citations
TL;DR: The effects of perceptual grouping on search for targets defined by separate features or by conjunction of features is explored, suggesting that preattentive grouping creates separate feature maps within each separable dimension rather than one global configuration.
Abstract: This article explores the effects of perceptual grouping on search for targets defined by separate features or by conjunction of features. Treisman and Gelade proposed a feature-integration theory of attention, which claims that in the absence of prior knowledge, the separable features of objects are correctly combined only when focused attention is directed to each item in turn. If items are preattentively grouped, however, attention may be directed to groups rather than to single items whenever no recombination of features within a group could generate an illusory target. This prediction is confirmed: In search for conjunctions, subjects appear to scan serially between groups rather than items. The scanning rate shows little effect of the spatial density of distractors, suggesting that it reflects serial fixations of attention rather than eye movements. Search for features, on the other hand, appears to independent of perceptual grouping, suggesting that features are detected preattentively. A conjunction target can be camouflaged at the preattentive level by placing it at the boundary between two adjacent groups, each of which shares one of its features. This suggests that preattentive grouping creates separate feature maps within each separable dimension rather than one global configuration. Language: en
883 citations
TL;DR: In this article, the authors argue that state jurisdictions in Black Africa have been maintained primarily by the international society of states, and that these serious empirical weaknesses have not led to enforced jurisdictional change.
Abstract: State institutions and organizations in Black Africa are less developed than almost anywhere else, and political instability has been prevalent. Yet, these serious empirical weaknesses have not led to enforced jurisdictional change. In order to explain the persistence of some of the weakest states in the world, the authors argue that state jurisdictions in Black Africa have been maintained primarily by the international society of states. Unlike the states that formed in Europe at an earlier period, many Black African states evolved—and survived—in the absence of effective national governments. Whereas state jurisdictions and international society once were consequences of the success and survival of states, today in Black Africa—and perhaps elsewhere, especially in the Third World—they are more likely to be conditions.
883 citations
TL;DR: The methods presented in this paper are aimed to overcome numerical difficulties of closed mathematical solutions of the frequency-dependent line equations in the time domain.
Abstract: The parameters of transmission lines with ground return are highly dependent on the frequency. Accurate modelling of this frequency dependence over the entire frequency range of the signals is of essential importance for the correct simulation of electromagnetic transient conditions. Closed mathematical solutions of the frequency-dependent line equations in the time domain are very difficult. Numerical approximation techniques are thus required for practical solutions. The oscillatory nature of the problem, however, makes ordinary numerical techniques very susceptible to instability and to accuracy errors. The, methods presented in this paper are aimed to overcome these numerical difficulties.
876 citations
834 citations
TL;DR: In this paper, an extensive act of sensible heat (Reynolds flux and dissipation methods) and latent heat (dissipation method) flux measurements from a stable deep water tower and from ships on the deep sea is presented.
Abstract: This papar presents an extensive act of sensible heat (Reynolds flux and dissipation methods) and latent heat (dissipation method) flux measurements from a stable deep water tower and from ships on the deep sea. Operational difficulties associated with ship spray and flow distortion and with sensor calibration, response and contamination are discussed. The influence of atmospheric stability on the dissipation measurements and the bulk transfer coefficients is considered and a parameterization of Z/ L in terms of wind speed and the sea-air potential temperature difference is found to be adequate. Temperature variances, Stanton numbers and w–t cospectra from the Roynolds flux measurements are compared to previous results. The dissipation method is shown to be a viable means of measuring the heal fluxes over the deep sea by comparison with simultaneous Reynolds flux measurements, using our data for the sensible heat and the data of others for the latent heat. The neutral drag coefficient at 10 m hei...
783 citations
TL;DR: The hypothesis that loss of nigrostriatal dopaminergic neurons results from a regional GSH deficiency could have important therapeutic implications for the management and prevention of Parkinson's disease.
TL;DR: A negative analysis of non-regressive prediction is outlined and a positive analysis of judgmental error in terms of heuristics may be supplemented by a negative analysis, which seeks to explain why the correct rule is not intuitively compelling.
TL;DR: These novel reagents were used to indirectly label antigen sites on human red blood cells and thymocytes for visualization by scanning and transmission electron microscopy and could be separated from unlabeled cells.
TL;DR: This comprehensive literature review of the phosphorus nutrition and metabolism of eukaryotic microalgae deals sequentially with extracellular P-compounds available for algal utilization and growth and includes specific macroalgae in considering certain subtopics where such algae were better investigated and provided a good basis for comparison.
Abstract: This comprehensive literature review of the phosphorus nutrition and metabolism of eukaryotic microalgae deals sequentially with (1) extracellular P-compounds available for algal utilization and growth; (2) orthophosphate uptake mechanisms, kinetics, and influence from environmental variables; (3) phosphatase-mediated utilization of organic phosphates involving multiple enzymes, induction and cellular location of repressible and irrepressible phosphatases, and their role in growth physiological processes; (4) intracellular phosphate metabolism covering diversity of phosphometabolites. ATP-linked energy regulation, polyphosphate pools and storage roles, phospholipids and phospholipases; (5) steady-state and transient-state models relating phosphate utilization to growth; (6) ecological aspects covering manifestations of phosphorus limitation, interspecific competition for phosphonutrients among microorganisms, and current views on phosphorus cycling and turnover in aquatic ecosystems. Although concentrating on the microalgae, the review often points out sounder conclusions drawn from bacteria and fungi, and includes specific macroalgae in considering certain subtopics where such algae were better investigated and provided a good basis for comparison with the microalgae.
TL;DR: In this paper, the authors used field data to study the size distribution of bedload in paved gravel-bed streams and found that all grain size ranges are of approximately equal transportability when the critical condition for breaking the pavement is exceeded.
Abstract: Field data are used to study the size distribution of bedload in paved gravel-bed streams Similarity analysis yields the results that all grain size ranges are of approximately equal transportability when the critical condition for breaking the pavement is exceeded This result is only approximately correct due to deviations from similarity However, it is adequate to justify development of a method for calculating total bedload, which requires only the subpavement median grain size rather than the size distribution A method for calculating bedload size distribution that accounts for deviation from similarity is also developed
TL;DR: The immunohistochemical localization of calcium-binding protein (CaBP) in the cerebellum, hippocampal formation and olfactory bulb of the rat was examined using rabbit anti-human or sheep anti-chick antisera purified by affinity chromatography to observe CaBP-like immunoreactivity.
TL;DR: The existence of crossed multisynaptic pathways that allow for the interdependent control of activity in one substantia nigra and its contralateral counterpart has been inferred from a number of recent biochemical and neurophysiological investigations and prompted a reexamination of the connections of the substantia Nigra with an emphasis on crossed inputs to and crossed projections from that nucleus.
Abstract: The existence of crossed multisynaptic pathways that allow for the interdependent control of activity in one substantia nigra and its contralateral counterpart has been inferred from a number of recent biochemical and neurophysiological investigations. This prompted a reexamination of the connections of the substantia nigra with an emphasis on crossed inputs to and crossed projections from that nucleus. Male albino rats received 20-50-nl pressure injections of a 1% wheat germ agglutinin-conjugated horse-radish peroxidase (WGA-HRP) solution into the substantia nigra or into surrounding areas as controls. Following a 24-hour survival period the animals were processed according to the tetramethylbenzidine protocol for the visualization of HRP. The pattern of anterograde transport of WGA-HRP after substantia nigra injections, confirming for the most part previous reports, demonstrated ipsilateral nigral efferent projections to the striatum; globus pallidus; subthalamic nucleus; the lateral dorsal, paralamellar mediodorsal, ventromedial, and parafascicular thalamic nuclei; central gray, midbrain reticular formation; superior colliculus; and peribrachial area, including the pedunculopontine nucleus. Additionally, the nigral projections to the paralamellar mediodorsal and ventromedial thalamic nuclei and to the superior colliculus were demonstrated to be bilateral. Most of these connections were confirmed by the complementary retrograde experiment. In accordance with previous reports, intranigral WGA-HRP injections retrogradely labeled neurons located in the ipsilateral prefontal cortex, motor cortex, striatum, globus pallidus, central nucleus of the amygdala, anterior hypothalamic area, subthalamic nucleus, and dorsal raphe. Additionally, labeled perikarya were observed in the ipsilateral parafascicular thalamic nucleus, in the contralateral posterior lateral hypothalamic area, and in the ipsilateral and contralateral peribrachial-pedunculopontine area. These latter nigral afferents were confirmed with complementary WGA-HRP injections into each of the regions of origin. While bilateral peribrachial-pedunculopontine innervation of the substantia nigra has been reported in the cat there has been no previous demonstration of a crossed nigral afferent system from the contralateral posterior lateral hypothalamic area. The results are discussed with reference to the pathways that may mediate the interdependent control of the activity of neurons in the left and right substantia nigra. Additionally, the association of the substantia nigra with a variety of neuronal circuits, including the cerebellofugal, tectothalamic, thalamocortical, thalamostriatal, and basal ganglia pathways, are discussed.
TL;DR: Little is known of the control of breathing during exercise, the switch from rhythmic to ram ventilation at high water velocities may be initiated by mechanoreceptors on the gill surface.
Abstract: Gas exchange across fish gills is reviewed and the respiratory and cardio-vascular changes associated with exercise and hypoxia described. Heart rate is controlled by inhibitory vagal cholinergic activity which increases during hypoxia and decreases during exercise. Stimulation of receptors on the first gill arch during hypoxia initiates bradycardia. The increase in stroke volume during hypoxia in dogfish appears to be related to cardiac slowing rather than β-adrenergic stimulation of the heart. Stimulation of cardiac β-adrenergic receptors causes positive inotropic and chronotopic responses in many fish, whether these are operative during exercise and hypoxia is not clear. Gill water flow is inversely related to arterial oxygen content in resting fish and there is probably an arterial oxygen content receptor coupled to gill ventilation. Little is known of the control of breathing during exercise, the switch from rhythmic to ram ventilation at high water velocities may be initiated by mechanoreceptors on the gill surface. Note: This article was written while the author was a Killam Fellow at the Flinders Medical Centre South Australia.
TL;DR: Findings support the view that the reinforcing effects of D-amphetamine are mediated by central dopamine-containing neurons, and in particular those of the mesolimbic system.
TL;DR: In this paper, a theoretical model for relative price movements is derived for the case of exogenous technical change and endogenous change in the grade of ores mined, which suggests a U-shaped time path for relative prices.
TL;DR: Microdissection of the hippocampus revealed that, within a particular region, CaBP can have a marked differential distribution, suggesting that it is found in specific cell types.
TL;DR: A general method for systematically replacing amino acids in an enzyme is described, which allows analysis of their molecular roles in substrate binding or catalysis and could eventually lead to the engineering of new enzymatic activities.
Abstract: We describe here a general method for systematically replacing amino acids in an enzyme. This allows analysis of their molecular roles in substrate binding or catalysis and could eventually lead to the engineering of new enzymatic activities. The gene encoding the enzyme is first cloned into a vector from which the enzyme is expressed and is then mutated in vitro to change a particular nucleotide and hence the amino acid sequence of the enzyme. We have cloned the gene for the tyrosyl tRNA synthetase of Bacillus stearothermophilus into a vector derived from the single-stranded bacteriophage M13 to facilitate mutagenesis with mismatched synthetic oligodeoxynucleotide primers. From the recombinant M13 clone we have obtained high levels of the enzyme (∼50% of soluble protein) expressed in the Escherichia coli host and have converted cysteine (Cys35) at the enzyme's active site to serine. This leads to a reduction in enzymatic activity that is largely attributable to a lower Km for ATP.
TL;DR: The chapter discusses a variety of other duality theorems—that is, other methods for equivalently describing tastes or technology, either locally or globally, in the one-output, N-inputs context.
Abstract: Publisher Summary This chapter develops the duality between cost and production functions. The chapter derives the regularity conditions that a cost function C must have and shows how a production function is constructed from a given cost function. The chapter considers the duality between a (direct) production function F and the corresponding indirect production function G. Under certain regularity conditions, G can also completely describe the technology, and thus there is a duality between direct and indirect production functions. The duality theorems have two interpretations: one in the producer context and the other in the consumer context. The chapter discusses a variety of other duality theorems—that is, other methods for equivalently describing tastes or technology, either locally or globally, in the one-output, N-inputs context. The mathematical theorems presented in the chapter appear to be only theoretical results devoid of practical applications. However, this is not the case. The chapter also surveys some of the applications of the duality theorems developed earlier. These applications fall in two main categories: (1) the measurement of technology or preferences and (2) the derivation of comparative statics results.
TL;DR: In this paper, it was shown that the Bekenstein limit for the entropy-to-energy ratio of matter confined by a box of size R is not needed for the validity of the generalized second law of thermodynamics.
Abstract: It is shown that the Bekenstein limit, S/E< or =2..pi..R, for the entropy-to-energy ratio of matter confined by a box of size R is not needed for the validity of the generalized second law of thermodynamics. If one attempts to slowly lower a box containing rest energy E and entropy S into a black hole there will be an effective buoyancy force on the box caused by the acceleration radiation felt by the box when it is suspended near the black hole. As a result there is a finite lower bound on the energy delivered to the black hole in this process and thus a minimal area increase which turns out to be just sufficient to ensure that the generalized second law of thermodynamics is satisfied. By reversing this process, we can ''mine'' energy from a black hole. The nature of these processes is also analyzed from an inertial point of view and the mechanism by which energy is transported into and out of the black hole is explained. Analogous effects for accelerating boxes in flat spacetime are also analyzed.
TL;DR: The authors investigated the hypothesis that insufficient metacomprehension is one possible cause underlying learning disabled adolescents' comprehension problems, and that training them to monitor their understanding of important textual elements fosters metaconception and, consequently, improves their comprehension performance.
Abstract: This study investigated the hypothesis that insufficient metacomprehension is one possible cause underlying learning disabled adolescents' comprehension problems, and that training them to monitor their understanding of important textual elements fosters metacomprehension and, consequently, improves their comprehension performance. A total of 120 learning disabled eighth and ninth graders and normally achieving sixth graders participated in the study. Half the subjects were randomly assigned to receive a 5-step self-questioning training in which they learned to monitor their understanding of important textual units. The results clearly showed that training substantially increased learning disabled adolescents' awareness of important textual units, as well as their ability to formulate good questions involving those units. Moreover, training facilitated their comprehension performance. However, training did not substantially increase normally achieving sixth graders' metacomprehension or comprehension perf...
TL;DR: It is concluded that cocaine can produce place preference conditioning through a mechanism that is independent of its effects on catecholamine-containing neurons and that may be related to its local anaesthetic properties.
TL;DR: In this article, three widely used decision rules (the Kaiser-Guttman, scree, and likelihood ratio tests) are isolated for empirical study, and three widely-used decision rules are applied to the population data in Part I and all three rules were applied to sample data sets in Part II.
Abstract: issues related to the decision of the number of factors to retain in factor analysis are identified, and three widely-used decision rules -- the Kaiser-Guttman, scree, and likelihood ratio tests -- are isolated for empirical study. Using two differing structural models and incorporating a number of relevant independent variables (such as number of variables, ratio of number of factors to number of variables, variable communality levels, and factorial complexity), the authors simulated 144 population data sets and, then, from these, 288 sample data sets, each with a precisely known (or incorporated) number of factors. The Kaiser-Guttman and scree rules were applied to the population data in Part I of the study, and all three rules were applied to the sample data sets in Part II. Overall trends and interactive results, in terms of the independent variables examined, are discussed in detail, and methods are presented for assessing the quality of the number-of-factors indicated by a particular rule.
TL;DR: A model of two-state attention switching similar to that of Sperling and Melchnor (1978) is proposed to explain these data, and the final experiment confirmed the somewhat unusual prediction that sometimes processing under focusing-attention conditions can be slower than that under divided-att attention conditions.
Abstract: This article deals with the problem of how attention is distributed to different levels of detail (global, local) in visual scenes. Six experiments explore the effect of a previous level of processing on current processing. The contention that processing at a given level of detail biases the distribution of attention so that more is allocated to that level for future processing is supported by the presence in the data of a robust level-readiness effect, whereby processing is faster at a given level if previous processing has been at that level. The level-readiness effect occurs regardless of the conspicuity of features at the various levels. Conflict between levels seems to depend on the imbalance of conspicuity and attention allocation between levels, with the more conspicuous or attended-to-level interfering more. A model of two-state attention switching similar to that of Sperling and Melchnor (1978) is proposed to explain these data. the final experiment confirmed the somewhat unusual prediction of this model that sometimes processing under focusing-attention conditions can be slower than that under divided-attention conditions. Language: en
TL;DR: In this article, a method for decomposing the deviations from a full frontier cost function into Farrell (1957) measures of technical and allocative efficiency is presented, which is applicable to a broad class of cost functions, including flexible functions such as the translog.
TL;DR: In this article, the authors investigated the relationship between manganous carbonate precipitation in sediment horizons of coarser mean grain size and a mixed carbonate phase of composition (Mn48 Ca47 Mg5)CO3 was recovered from an ash band.