Showing papers by "University of British Columbia published in 1986"
TL;DR: Freeze-fracture electron microscopy revealed that vesicles produced at very high lipid concentrations exhibit size distributions and extent of multilamellar character comparable to systems produced at lower lipid levels.
1,689 citations
TL;DR: In hypoxia-tolerant animals, metabolic arrest and stabilized membrane functions are the most effective strategies for extending tolerance to Hypoxia through a number of biochemical and physiological mechanisms.
Abstract: Because aerobic metabolic rates decrease in hypoxia-sensitive cells under oxygen-limiting conditions, the demand for glucose or glycogen for anaerobic glycolysis may rise drastically as a means of making up for the energetic shortfall. However, ion and electrical potentials typically cannot be sustained because of energy insufficiency and high membrane permeabilities; therefore metabolic and membrane functions in effect become decoupled. In hypoxia-tolerant animals, these problems are resolved through a number of biochemical and physiological mechanisms; of these metabolic arrest and stabilized membrane functions are the most effective strategies for extending tolerance to hypoxia. Metabolic arrest is achieved by means of a reversed or negative Pasteur effect (reduced or unchanging glycolytic flux at reduced O2 availability); and coupling of metabolic and membrane function is achievable, in spite of the lower energy turnover rates, by maintaining membranes of low permeability (probably via reduced densities of ion-specific channels). The possibility of combining metabolic arrest with channel arrest has been recognized as an intervention strategy. To date, the success of this strategy has been minimal, mainly because depression of metabolism through cold is the usual arrest mechanism used, and hypothermia in itself perturbs controlled cell function in most endotherms.
1,094 citations
TL;DR: The problem of finding a description, at varying levels of detail, for planar curves and matching two such descriptions is posed and solved and the result is the ``generalized scale space'' image of a planar curve which is invariant under rotation, uniform scaling and translation of the curve.
Abstract: The problem of finding a description, at varying levels of detail, for planar curves and matching two such descriptions is posed and solved in this paper. A number of necessary criteria are imposed on any candidate solution method. Path-based Gaussian smoothing techniques are applied to the curve to find zeros of curvature at varying levels of detail. The result is the ``generalized scale space'' image of a planar curve which is invariant under rotation, uniform scaling and translation of the curve. These properties make the scale space image suitable for matching. The matching algorithm is a modification of the uniform cost algorithm and finds the lowest cost match of contours in the scale space images. It is argued that this is preferable to matching in a so-called stable scale of the curve because no such scale may exist for a given curve. This technique is applied to register a Landsat satellite image of the Strait of Georgia, B.C. (manually corrected for skew) to a map containing the shorelines of an overlapping area.
894 citations
TL;DR: The authors reviewed the work of significant humanities and social science scholars for their thoughts and theories about advertising's social and cultural consequences, in brief, they view adverti cation as a form of marketing.
Abstract: This article reviews the work of significant humanities and social science scholars for their thoughts and theories about advertising's social and cultural consequences. In brief, they view adverti...
656 citations
TL;DR: In a double-blind trial in 21 patients with spasmodic torticollis botulinum-A toxin, both subjective and objective improvement were recorded, including significant pain relief in 14 of the 16 patients presenting with pain.
641 citations
TL;DR: The relationship between the evolutionary fitness of individual foragers and the size of foraging groups is investigated by means of a series of simple mathematical models, leading to the concept of Behaviorally Robust Strategies.
622 citations
TL;DR: A biochemical model that explains bio-P removal mechanisms occurring under anaerobic, aerobic and anoxic conditions of the process is presented and polyphosphate is suggested to be as a source of energy both for the reestablishment of the proton motive force and for substrate storage.
511 citations
Book•
01 Jan 1986TL;DR: The main thesis is that focus has a uniform grammatical identification only as a syntactic element with – in English at least – a certain systematic phonological interpretation and – presumably universally – a range of semantic interpretations.
Abstract: The topic of this book is the notion of ‘focus’ and its linguistic characterization. The main thesis is that focus has a uniform grammatical identification only as a syntactic element with – in English at least – a certain systematic phonological interpretation and – presumably universally – a range of semantic interpretations. In broad respects, the framework within this investigation is conducted is that of Chomsky & Lasnik (1977) and the subsequent Government and Binding framework. After considering defining the location of prominence in a focused phrase in terms of constituent structure, the author argues that an argument structure approach to the focus phrase/prominence relation is more promising. This is then exemplified in analyses of cleft focus and constructional focus.
458 citations
TL;DR: This article conducted a correlation and regression analysis of inner-city gentrification in the Canadian urban system between 1971 and 1981 and found that economic and urban amenity factors perform most strongly in the analysis, but demographic and housing factors have less effect.
Abstract: Within the rapidly expanding literature on inner-city revitalization (or gentrification), there has been no attempt to assess in a comparative and systematic manner a range of explanations that have emerged from studies of single cities or even single neighborhoods. Four major explanations of gentrification are reviewed here and then made operational in a correlation and regression analysis of inner-city gentrification in the Canadian urban system between 1971 and 1981. Several of the posited explanations are not supported. Economic and urban amenity factors perform most strongly in the analysis, but demographic and housing factors have less effect. I develop an integrated model and discuss its theoretical implications, including its consistency with staple theory and the interrelatedness demonstrated between housing and labor markets.
452 citations
TL;DR: The ascending projections of cholinergic neurons in the laterodorsal tegmental nucleus (TLD) were investigated in the rat by using Phaseolus vulgaris leucoagglutinin (PHA-L) and wheat germ agglutin-conjugated horseradish peroxidase (WGA-HRP) anterograde tracing techniques as discussed by the authors.
Abstract: The ascending projections of cholinergic neurons in the laterodorsal tegmental nucleus (TLD) were investigated in the rat by using Phaseolus vulgaris leucoagglutinin (PHA-L) and wheat germ agglutinin-conjugated horseradish peroxidase (WGA-HRP) anterograde tracing techniques. Two ascending pathways were identified after iontophoretic injections of PHA-L into the TLD. A long projection system courses through the dorsomedial tegmentum, caudal diencephalon, medial forebrain bundle, and diagonal band. Different branches of this system innervate the midbrain (superior colliculus, interstitial magnocellular nucleus of the posterior commissure, and anterior pretectal nucleus), the diencephalon (lateral habenular nucleus, parafascicular, anteroventral, anterodorsal, mediodorsal, and intralaminar thalamic nuclei), and the telencephalon (lateral septum and medial prefrontal cortex). The second system is shorter and more diffuse and innervates the median raphe, interpeduncular, and lateral mammillary nuclei. Retrograde tracing with WGA-HRP, combined with choline acetyltransferase immunohistochemistry, revealed that most of the TLD projections to the tectum, pretectum, thalamus, lateral septum, and medial prefrontal cortex are cholinergic. Afferents to the TLD were studied by anterograde and retrograde tracing techniques. Injection of tracers into the TLD retrogradely labelled neurons bilaterally in the midbrain reticular formation, the periaqueductal gray, the medial preoptic nucleus, the anterior hypothalamic nucleus, and the perifornical and lateral hypothalamic areas. Retrogradely labelled cells were also located bilaterally in the premammillary nucleus, paraventricular hypothalamic nucleus, zona incerta, and lateral habenular nucleus. In the telencephalon, the nucleus of the diagonal band and the medial prefrontal cortex contained retrogradely labelled neurons ipsilateral to the TLD injection site. The projections of the medial prefrontal cortex, the bed nucleus of the stria terminalis, and the lateral habenular nucleus to the TLD were confirmed in anterograde tracing studies. These findings indicate that the TLD gives rise to several ascending cholinergic projections that innervate diverse regions of the forebrain. Afferents to the TLD arise in hypothalamic and limbic forebrain regions, some of which appear to have reciprocal connections with the TLD. The latter include the lateral habenular nucleus and medial prefrontal cortex.
433 citations
TL;DR: The straight-forward hydration of lipid to produce multilamellar vesicles (MLVs) results in systems which exhibit low trapped volumes and where solutes contained in the aqueous buffer are partially excluded from the MLV interior.
TL;DR: In this article, the effect of corporate debt offerings on stock prices was analyzed, and the authors found no relation between offer-induced price effects and offering size, rating, post-offer changes in abnormal earnings or debt-related tax shields.
TL;DR: In this paper, the authors model the constraints imposed on entrepreneurs' activities by these two problems and endogenously determine the various organisational forms of production, as well as the allocation of resources that will obtain.
Abstract: There are two problems, both universal, that entrepreneurs in any economy must contend with. Firstly, an agent generally has access only to a limited amount of working capital. Secondly, workers hired by an agent are subject to moral hazard, and this necessitates their supervision. This paper models, for an agrarian economy, the constraints imposed on entrepreneurs' activities by these two problems and endogenously determines the various organisational forms of production, as well as the allocation of resources that will obtain. With a simple model we endeavour to explain a diverse set of empirical observations pertaining to the less developed countries in terms of the general processes that determine the distribution of income among the various agents and the hierarchical relationships that develop among them. Agricultural production typically involves a period of several months between the time the inputs are purchased and the time the output is marketed. Access to working capital and hence to the credit market thus plays an important role in a farmer's production decisions; the distribution of access to credit, in turn, tends to be an important determinant of income distribution. In poor agrarian economies, credit is invariably rationed according to the ability to offer collateral.' The amount of working capital a farmer can mobilise, therefore, depends on the amount of land he owns, which is often a good proxy for his overall wealth and, thus, his ability to offer collateral. Further, since hired hands have a propensity to shirk, they need to be supervised, and, therefore, the
TL;DR: Treize des temoins ont accepte de se preter a des entretiens cinq mois apres l'evenement; qualite du rappel des elements visuels apres ce delai.
Abstract: Vingt et un temoins ont observe un echange de coups de feu au cours duquel une personne a ete tuee et une seconde gravement blessee. L'incident s'est produit a un grand carrefour en plein midi. Treize des temoins ont accepte de se preter a des entretiens cinq mois apres l'evenement; qualite du rappel des elements visuels apres ce delai
TL;DR: Since total GSH is consumed only by conjugation in detoxification processes, nigral GSH deficiency in PD patients implies continued local presence of a possible causative neurotoxin up to the time of death.
TL;DR: It is demonstrated here that adriamycin can be rapidly and efficiently accumulated into egg phosphatidylcholine and egg PC-cholesterol LUVs in response to a transmembrane pH gradient (interior acidic) in the absence of ionophores.
TL;DR: On donne des estimations qui minimisent la somme des sommes residuelles des carres et une penalite de difficulte as discussed by the authors, i.e.
Abstract: On donne des estimations qui minimisent la somme des sommes residuelles des carres et une penalite de difficulte
TL;DR: Evidence is reviewed supporting the proposal that factors related to the polymorphic capabilities of lipids provide a rationale for lipid diversity, which is related to a generalized shape property.
TL;DR: In this article, a battery of process instruments are used to measure process patterns in context and to relate these to outcome, and a context-sensitive process research needs to be developed.
Abstract: Research on change processes is needed to help explain how psychotherapy produces change. To explain processes of change it will be important to measure three types of outcomes—immediate, intermediate, and final—and three levels of process—speech act, episode, and relationship. Emphasis will need to be placed on specifying different types of in-session change episodes and the intermediate outcomes they produce. The assumption that all processes have the same meaning (regardless of context) needs to be dropped, and a context-sensitive process research needs to be developed. Speech acts need to be viewed in the context of the types of episodes in which they occur, and episodes need to be viewed in the context of the type of relationship in which they occur. This approach would result in the use of a battery of process instruments to measure process patterns in context and to relate these to outcome.
TL;DR: In this article, it is shown that properties of the theory at nonzero fermion density can be deduced from its behavior at finite imaginary chemical potential, and Monte Carlo simulations are proposed which would check these ideas.
TL;DR: The regime diagram approach of Reh (1971) is modified and extended to cover the operating regions of common reactors and contactors where a gas flows upwards through a bed of solids including fixed and moving packed beds, conventional fluidized beds, circulating beds, spouted beds, and pneumatically conveyed suspensions.
Abstract: An attempt is made to extend schemes for classifying the behaviour of gas—solid contacting modes and other two-phase systems. The regime diagram approach of Reh (1971) is modified and extended to cover the operating regions of common reactors and contactors where a gas flows upwards through a bed of solids including fixed and moving packed beds, conventional fluidized beds, circulating beds, spouted beds, and pneumatically conveyed suspensions. New boundaries are proposed between groups A and B and between groups B and D of the Geldart (1972, 1973) powder classification scheme. These boundaries reflect more recent data and allow the classification scheme to be used for gases other than air and for temperatures and pressures other than atmospheric.
TL;DR: Low self-esteem and depressed subjects overestimated consensus on opinions and underestimated consensus on abilities less than high self- esteem and nondepressed subjects and there was a reliable FCE for both attributes.
Abstract: On the basis of a self-validation perspective, it was predicted that distortions in consensus estimates would vary as a function of attribute type (opinions versus abilities), relevance of the attribute, and individual differences in self-esteem and depression. Students rated themselves on seven opinion and ability dimensions using 5-point Likert scales. Then they estimated the percentage of the other students who held each opinion/ability position, and rank ordered the opinions/abilities for personal relevance. Absolute and directional accuracy scores were computed (comparing estimated percentages with actual percentages in the sample), as well as false consensus (FCE) scores (comparing estimates of subjects holding and not holding a particular position). Subjects overestimated consensus for their opinions and low abilities, but underestimated consensus for their high abilities. Although subjects exhibited a larger FCE on opinions than abilities, there was a reliable FCE for both attributes. Relevance affected the magnitude of these biases. Higher opinion relevance was associated with increased accuracy, lower FCE scores, and smaller overestimates. Higher ability relevance was associated with decreased accuracy, greater overestimation on low abilities, and greater underestimation on high abilities. Finally, low self-esteem and depressed subjects overestimated consensus on opinions and underestimated consensus on abilities less than high self-esteem and nondepressed subjects.
Journal Article•
TL;DR: The Critical Incident Technique (CIT) as mentioned in this paper is an exploratory qualitative method of research that has been shown both reliable and valid in generating a comprehensive and detailed description of a content domain.
Abstract: The critical incident technique is an exploratory qualitative method of research that has been shown both reliable and valid in generating a comprehensive and detailed description of a content domain. After being used widely in industrial psychology during the 1950's, the technique fell into diverse and is only now enjoying a renaissance. The critical incident technique basically consists of asking eyewitness observers for factual accounts of behaviours (their own or others') which significantly contribute to a specified outcome. The emphasis is on incidents (things which actually happened and were directly observed) which are critical (things which significantly affected the outcome). This paper tells how to do a critical incident study, using illustrations from the author's and others' research. The many and varied applications of the technique are indicated. These uses range from criterion development and test construction to foundational work and theory development. It is concluded that the critical incident technique should contribute significantly to the development of a unique methodology for the discipline of counselling.
TL;DR: Subjects with sleep apnea demonstrated several alterations in craniofacial form that may reduce the upper airway dimensions and subsequently impairupper airway stability.
TL;DR: In this article, various techniques for computing the fractional fermion number of topological solitons are reviewed, and the connections between the FPN calculation and the general properties of the spectrum, in particular spectral asymmetry of the pertinent Dirac operator are exposed.
TL;DR: It is suggested that both the mechanical properties of the cytoskeleton as well as the durability of the cellular attachment to groove edges may play a role in the contact guidance effected by grooved surfaces produced by micromachining.
TL;DR: In this article, an informational asymmetry exists between investors and the issuer of an initial public offering about the value of the security, and a solution is proposed in which the issuer makes a disclosure about firm value that is verified by an investment banker.
TL;DR: The combined report, which integrated the advantages associated with both tabular and graphical presentation, was the superior report format in terms of performance ad was rated very highly by decision makers.
Abstract: A laboratory experiment was conducted to assess the influence of color and information presentation differences on user perceptions and decision making under varying time constraints. Three different information presentations were evaluated: tabular, graphical, and combined tabular-graphical. Tabular reports led to better decision making and graphical reports led to faster decision making when time constraints were low. The combined report, which integrated the advantages associated with both tabular and graphical presentation, was the superior report format in terms of performance ad was rated very highly by decision makers. Color led to improvements in decision making; this was especially pronounced when high time constraints were present.
TL;DR: The hypothesis is that Alzheimer's disease, Parkinson's disease (PD), and motoneurone disease are due to environmental damage to specific regions of the central nervous system and that the damage remains subclinical for several decades but makes those affected especially prone to the consequences of age-related neuronal attrition.
TL;DR: In this paper, the authors investigate the implication of clientele theories that changes in dividend policy should result in a marked increase in trading volume as shareholder clienteles change and find that volume increases primarily in response to the signal about future earnings contained in the dividend.