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Showing papers by "University of Western Ontario published in 1990"


Journal ArticleDOI
TL;DR: A new method for automatic indexing and retrieval to take advantage of implicit higher-order structure in the association of terms with documents (“semantic structure”) in order to improve the detection of relevant documents on the basis of terms found in queries.
Abstract: A new method for automatic indexing and retrieval is described. The approach is to take advantage of implicit higher-order structure in the association of terms with documents (“semantic structure”) in order to improve the detection of relevant documents on the basis of terms found in queries. The particular technique used is singular-value decomposition, in which a large term by document matrix is decomposed into a set of ca. 100 orthogonal factors from which the original matrix can be approximated by linear combination. Documents are represented by ca. 100 item vectors of factor weights. Queries are represented as pseudo-document vectors formed from weighted combinations of terms, and documents with supra-threshold cosine values are returned. initial tests find this completely automatic method for retrieval to be promising.

12,443 citations


Journal ArticleDOI
TL;DR: In this article, the authors proposed a three-component model of organizational commitment, which integrates emotional attachment, identification with, and involvement in the organization, and the normative component refers to employees' feelings of obligation to remain with the organization.
Abstract: Organizational commitment has been conceptualized and measured in various ways. The two studies reported here were conducted to test aspects of a three-component model of commitment which integrates these various conceptualizations. The affective component of organizational commitment, proposed by the model, refers to employees' emotional attachment to, identification with, and involvement in, the organization. The continuance component refers to commitment based on the costs that employees associate with leaving the organization. Finally, the normative component refers to employees' feelings of obligation to remain with the organization. In Study 1, scales were developed to measure these components. Relationships among the components of commitment and with variables considered their antecedents were examined in Study 2. Results of a canonical correlation analysis suggested that, as predicted by the model, the affective and continuance components of organizational commitment are empirically distinguishable constructs with different correlates. The affective and normative components, although distinguishable, appear to be somewhat related. The importance of differentiating the components of commitment, both in research and practice, is discussed.

10,654 citations


Journal ArticleDOI
TL;DR: This work suggests "new" response criteria for phase II studies of supratentorial malignant glioma and favor rigorous criteria similar to those in medical oncology, with important modifications, to minimize misinterpretations of response.
Abstract: We suggest "new" response criteria for phase II studies of supratentorial malignant glioma and favor rigorous criteria similar to those in medical oncology, with important modifications. Four response categories are proposed: complete response (CR), partial response (PR), stable disease (SD), and progressive disease (PD). Response in this scheme is based on major changes in tumor size on the enhanced computed tomographic (CT) or magnetic resonance imaging (MRI) scan. Scan changes are interpreted in light of steroid use and neurologic findings. We advocate careful patient selection, emphasize pitfalls in the assessment of response, and suggest guidelines to minimize misinterpretations of response.

2,307 citations



Journal ArticleDOI
TL;DR: The rationale and development of the COPM, an outcome measure designed for use by occupational therapists to assess client outcomes in the areas of self-care, productivity and leisure, are described.
Abstract: The Canadian Association of Occupational Therapists, in collaboration with Health and Welfare Canada have developed and published a conceptual model for occupational therapy, the Occupational Performance model. This paper describes the development of an outcome measure, The Canadian Occupational Performance Measure (COPM), which is designed to be used with these guidelines for client-centred clinical practice. The COPM is an outcome measure designed for use by occupational therapists to assess client outcomes in the areas of self-care, productivity and leisure. Using a semi-structured interview, the COPM is a five step process which measures individual, client-identified problem areas in daily function. Two scores, for performance and satisfaction with performance are obtained. This paper describes the rationale and development of the COPM as wellas information about its use for therapists.

1,025 citations


Journal ArticleDOI
TL;DR: In this article, Meyer et al. present an analysis factorielles confirmatoires, tests de modeles causaux non recursifs, based on the concept of implicit affective and continuéimplication.
Abstract: Examen des liens causaux reliant l'implication affective et la continuation de l'implication dans une organisation. Etude de la structure factorielle des echelles d'evaluation de ces 2 concepts (ACS et CCS, Meyer et Allen, 1984). 3 echantillons d'employes nouvellement embauches dont 1 repondant a 3 occasions durant la premiere annee d'exercice (etude longitudinale). Analyses factorielles confirmatoires, tests de modeles causaux non recursifs

815 citations


Journal ArticleDOI
TL;DR: This article found that newcomers' organizational socialization experiences were negatively related to role innovation after they had been on their jobs, while role innovation was positively related to newcomers' socialization experience.
Abstract: In this replication and extension of an earlier study, we found that newcomers' organizational socialization experiences were negatively related to role innovation after they had been on their jobs...

726 citations


Journal ArticleDOI
TL;DR: The results provide qualified support for the hypothesis that the high levels of gonadal steroids present at the luteal phase of the cycle may facilitate skills favoring females, but be detrimental to skills favoring males.

567 citations


Journal ArticleDOI
TL;DR: Enhanced performance on tests of articulatory and fine motor skills was observed during the late follicular phase of the menstrual cycle, while performance on Tests of spatial ability was poorer at that time, compared with performance during menses.

522 citations


Journal ArticleDOI
TL;DR: The present study contrasted the widely cited "buffer" model of social support with an alternative mediator model, and found that chronic parenting stress was associated with lowered perceptions of emotional support, and greater symptoms of depression and anxiety.
Abstract: The present study contrasted the widely cited "buffer" model of social support with an alternative mediator model. Distinctions were drawn between the functions of social support under chronic vs. acute stress conditions, and between situation-specific stressors and major life events. Ongoing parenting stress was assessed in 96 mothers of deaf children and 118 matched controls. Tests of the competing models showed no moderating effects for social support. However, path analyses suggested that social support mediated the relationship between stressors and outcomes. Chronic parenting stress was associated with lowered perceptions of emotional support, and greater symptoms of depression and anxiety. Furthermore, parenting stress accounted for a substantial proportion of the variance in psychological distress scores in contrast to life event stress, which was only weakly related to psychological outcomes. The implications of mediational models for understanding adaptation to chronic stress are discussed.

454 citations


Journal ArticleDOI
01 Oct 1990-Geology
TL;DR: The role of Synechococcus in biomineralization of gypsum and calcite in aquatic environments has been investigated in this paper, showing that it is responsible for a major proportion of the marl sediment and carbonate bioherms in Green Lake.
Abstract: Results from transmission electron microscopy provide direct evidence for cyanobacterial biomineralization of gypsum and calcite in aquatic environments. Laboratory simulations using filter-sterilized natural lake water inoculated with Synechococcus sp., isolated from Fayette ville Green Lake, New York, revealed epicellular biomineralization of gypsum, calcite, and magnesite. Experimental, electron microscopical, and sedimentological evidence indicates that Synechococcus is responsible for a major proportion of the marl sediment and carbonate bioherms in Green Lake. The elucidated role of Synechococcus in biomineralization and its ubiquitous distribution in nature have widespread implications for cyanobacterial mineralization in marine and freshwater environments since late Archean time.

Journal ArticleDOI
TL;DR: Small-bowel/liver grafting is feasible for patients with the short-gut syndrome and associated liver disorders and further experience is needed to determine the specific risks, benefits, and general applicability of this procedure.


Journal ArticleDOI
TL;DR: In this paper, the authors use basic tools of economic theory to construct a simple model of the behavior of dictatorships and show that a decline in economic performance will lead a tin-pot regime to increase its repression of the population, whereas it will lead to a totalitarian government to reduce repression.
Abstract: I use basic tools of economic theory to construct a simple model of the behavior of dictatorships. Two extreme cases are considered: a “tin-pot” dictatorship, in which the dictator wishes only to minimize the costs of remaining in power in order to collect the fruits of office (palaces, Mercedes-Benzes, Swiss bank accounts), and a “totalitarian” dictatorship, whose leader maximizes power over the population. I show that the two differ in their responses to economic change. For example, a decline in economic performance will lead a tin-pot regime to increase its repression of the population, whereas it will lead a totalitarian government to reduce repression. The model also shows why military dictatorships (a subspecies of tin-pots) tend to be short-lived and often voluntarily hand power over to a civilian regime; explains numerous features of totalitarian regimes; and suggests what policies will enable democratic regimes to deal with dictatorships effectively.

Journal ArticleDOI
TL;DR: In this article, businesses competing in global industries were categorized into three groups according to the integration-responsiveness framework for conceptualizing industry pressures confronting business competing internationally, and contextual conditions associated with each group were examined.
Abstract: In this study, businesses competing in global industries were categorized into three groups according to the integration-responsiveness framework for conceptualizing industry pressures confronting business competing internationally. Using this framework, contextual conditions associated with each group were examined. Competitive attributes distinguishing each group were then identified to clarify alternate business-level strategies for competing within a global industry context. Beyond providing additional insight into the nature of competition in global industries, several broad extensions to the integration-responsiveness framework are suggested.

Journal ArticleDOI
01 Dec 1990-Pain
TL;DR: The findings are based upon the recollection of individuals with respect to the period of 12 months prior to interview and upon the occurrence of depression in the previous week as indicated by the answers to the Depression Scale of the Centre for Epidemiologic Studies (CES‐D).
Abstract: Chronic pain and depression frequently occur together. A selection bias afflicts all hospital clinic and family practice populations in which this relationship has been examined. We report here some of the results from civilian populations outside institutions, examined in the United States in national surveys. The findings are based upon the recollection of individuals with respect to the period of 12 months prior to interview and upon the occurrence of depression in the previous week as indicated by the answers to the Depression Scale of the Centre for Epidemiologic Studies (CES-D). They indicate that 14.4% of the United States population between the ages of 25–74 suffer from definite chronic pain related to the joints and musculoskeletal system. Another 7.4% have some pain of uncertain duration. Eighty-three percent of the definite pain group received treatment. Chronic pain subjects scored significantly higher than normals on the CES-D (10.68 ± S.E.M. 0.76 vs. 8.05 ± 0.23, P < 0.01) with subjects with pain of uncertain duration scoring similar to the definite chronic pain population (11.13 ± 0.76). Using a high cut-off score for depression, 18% of the population with chronic pain were found to have depression. This is in contrast to 8% of the population who did not have chronic pain.

Journal ArticleDOI
TL;DR: Saccadic control signals accurately reflect the properties of three-dimensional rotations, as predicted by a new quaternion model of the saccadic system; models that approximate rotational kinematics using vectorial addition and integration do not predict these findings.

Journal ArticleDOI
TL;DR: Using the Q-sort procedure, mothers of more secure infants were more frequently characterized as noticing their babies' signals and using these signals to guide their behavior; they were more knowledgeable about their infant and appeared to enjoy them more than mothers of less secure infants.
Abstract: 40 mothers and their 12-month-old infants were observed twice at home by 2 observers for 2 hours. After the second visit, the observers described the infant using the Waters Attachment Behavior Q-sort and the mother's interactive behavior with the Maternal Behavior Q-sort developed by the present authors and Ainsworth's rating scales. Maternal sensitivity was unrelated to maternal age, income, or SES, but correlated positively with maternal education. Mothers of more difficult children were less sensitive. A strong relation was found between infant attachment and maternal sensitivity as measured by the Maternal Behavior Q-sort and by the Ainsworth scales. Using the Q-sort procedure, mothers of more secure infants were more frequently characterized as noticing their babies' signals and using these signals to guide their behavior; they also were more knowledgeable about their infant and appeared to enjoy them more than mothers of less secure infants.

Journal ArticleDOI
TL;DR: This review will concentrate on the molecular properties of two other biologically important classes of extracellular steroid binding proteins: corticosteroid binding globulin (CBG) and the sex-steroid binding proteins; sex hormone binding Globulin (SHBG) and androgen binding protein...
Abstract: I Introduction AVARIETY of extracellular binding proteins enhance the solubility of steroid hormones in biological fluids and facilitate their transport from steroidogenic tissues to target cells (1) In mammals, albumin is quantitatively the most important of these proteins and provides a large reservoir of loosely bound hormone that may be released within some target tissues (2) Two albumin-related proteins, vitamin D binding protein and α-fetoprotein, also appear to have arisen by duplication of a common ancestral gene (3) and are characterized by higher affinities and specificities for steroid ligands The molecular composition and structure of the vitamin D binding protein have already been described in detail (4), and this review will concentrate on the molecular properties of two other biologically important classes of extracellular steroid binding proteins: corticosteroid binding globulin (CBG) and the sex-steroid binding proteins; sex hormone binding globulin (SHBG) and androgen binding protein

Journal ArticleDOI
TL;DR: It is recommended that at least a 2-step change is needed to be confident of an important change in the degree of disability or response to treatment in this disease and differences of a single step on these scales may not reflect an important functional change.
Abstract: We describe the interrater variability in the Expanded Disability Status Scale (EDSS) and Functional Systems (FS) in a multiple sclerosis clinical trial. Two physicians blinded to their previous assessments and to each other's scores consecutively examined 168 patients (545 paired examinations). Perfect agreement on the assignment of the disability scores ranged from 48% (cerebellar functional group) to 69% (EDSS and pyramidal functional group). Only 31% to 62% of this agreement occurred independently of that expected by chance (kappa). With the exception of the cerebellar and sensory functional groups, agreement within 1 step occurred in at least 92% of cases. These findings suggest that differences of a single step on these scales may not reflect an important functional change. We recommend that at least a 2-step change (1.0 point on the EDSS and 2 points on the FS) is needed to be confident of an important change in the degree of disability or response to treatment in this disease.

Journal ArticleDOI
TL;DR: The present argument seems to render the "evolution of co-operation" ultimately inevitable in the case of the repeated prisoner's dilemma, as any evolutionary game possessing several evolutionarily stable strategies, or ESSs, with differing payoffs.

Journal ArticleDOI
TL;DR: Experimental studies suggest that immature endothelial cells forming the capillaries of the developing brain are less resistant to the effects of lead, permitting fluid and cations including lead to reach newly formed components of the brain, particularly astrocytes and neurons.
Abstract: Neurotoxicity is the major health effect from exposure to lead for infants and young children, and there is current concern regarding possible toxic effects of lead on the child while in utero. There is no placental-fetal barrier to lead transport. Maternal and fetal blood lead levels are nearly identical, so lead passes through the placenta unencumbered. Lead has been measured in the fetal brain as early as the end of the first trimester (13 weeks). There is a similar rate of increase in brain size and lead content throughout pregnancy in the fetus of mothers in the general population, so concentration of lead probably does not differ greatly during gestation unless exposure of the mother changes. Cell-specific sensitivity to the toxic effects of lead, however, may be greater the younger the fetus. Lead toxicity to the nervous system is characterized by edema or swelling of the brain due to altered permeability of capillary endothelial cells. Experimental studies suggest that immature endothelial cells forming the capillaries of the developing brain are less resistant to the effects of lead, permitting fluid and cations including lead to reach newly formed components of the brain, particularly astrocytes and neurons. Also, the ability of astrocytes and neurons to sequester lead in the form of lead protein complexes occurs only in the later stages of fetal development, permitting lead in maturing brain cells to interact with vital subcellular organelles, particularly mitochondria, which are the major cellular energy source. Intracellular lead also affects binding sites for calcium which, in turn, may affect numerous cell functions including neurotransmitter release.


Journal ArticleDOI
TL;DR: This paper presents algorithms for computing eye position quaternions and eye angular velocity from two search coils, and shows how differentiation of eye position signals yields poor estimates of all three components of eye velocity.

Journal ArticleDOI
TL;DR: Although a monolayer of dipalmitoylphosphatidylcholine, the major component of pulmonary surfactant, is thought to be responsible for the reduction of the surface tension at the air-liquid interface of the alveolus, the participation of unsaturated and anionic phospholipids and the three surfactants-associated proteins is suggested in the generation and maintenance of this surface-active monolayers.
Abstract: Although a monolayer of dipalmitoylphosphatidylcholine, the major component of pulmonary surfactant, is thought to be responsible for the reduction of the surface tension at the air-liquid interface of the alveolus, the participation of unsaturated and anionic phospholipids and the three surfactant-associated proteins is suggested in the generation and maintenance of this surface-active monolayer. We have examined the effects of surfactant-associated protein A (SP-A) purified from bovine lavage material on the surface activity of lipid extract surfactant (LES), an organic extract of pulmonary surfactant containing all of the phospholipids and SP-B and SP-C, but lacking SP-A. Measurements of the surface tension during dynamic compression were made on a pulsating bubble surfactometer. Addition of SP-A to LES reduces the number of pulsations required to attain surface tensions near zero at minimum bubble radius. This increase in surface activity is dependent upon the presence of Ca2+ in the assay mixture. Maximal enhancement is observed at or below 1% of the lipid concentration (w/w). The addition of two blood proteins, fibrinogen and albumin, at physiological concentrations to LES causes severe inhibition of surface activity. Addition of SP-A in the presence of Ca2+ completely counteracts the inhibition by fibrinogen. The amount of SP-A required for full reversal of this inhibition was less than 0.5% of the lipid concentration. Complete reversal of inhibition by albumin was also observed, even though there was a approximately 5000-fold molar excess of inhibitor. Addition of lysophosphatidylcholine also inhibits LES; however, SP-A has no effect on this inhibition.

Journal ArticleDOI
TL;DR: The notion of subject specificity has been widely discussed in the literature on critical thinking as discussed by the authors, and it has been a hot topic in the last 30 years or so, especially since Ennis' recent Educational Researcher article.
Abstract: Robert Ennis' recentEducational Researcher article (1989) helps to clarify the troublesome notion of subject specificity in the growing literature on critical thinking. It brings a welcome breath of fresh air to a set of questions that has vexed research efforts and educational programs that attempt to promote critical thinking. In calling for clarification on this matter, Ennis has also raised the level of discussion about the meaning of the terms subjects, domains, and even psychological transfer. No longer can we simply gloss over questions about the precise scope and limits of the putative skills that various critical thinking programs are alleged to promote. The recent paper in this journal by Perkins and Salomon (1989) also provides a useful historical overview of just how vexing this problem has been over the past 30 years. This article both replies to Ennis and continues the discussion.

Journal ArticleDOI
TL;DR: This is the first report of the demonstration of a cortical region wherein stimulation affects heart rate and no other parameter, and it is unclear whether the cardiac effects are primary or secondary to these.


Journal ArticleDOI
TL;DR: Etude du stockage de l'amidon, du point de vue concentration and localisation dans les differents tissus, afin d'etablir une correlation avec le mecanisme d'adaptation de chaque espece.

Journal ArticleDOI
TL;DR: A physiological role for CBG in the delivery of cortisol to sites of inflammation is suggested and three small molecular size fragments are detected after elastase cleavage, and carbohydrate analysis of these fragments suggests that they represent the same polypeptide fragment which has been differentially glycosylated.
Abstract: In human blood, cortisol is transported by a plasma protein known as corticosteroid-binding globulin (CBG). As anticipated from primary structure comparisons of CBG and alpha 1-proteinase inhibitor (A1-PI), CBG acts as a substrate for neutrophil elastase. However, unlike A1-PI, CBG does not alter the activity of this enzyme, but is cleaved by it at a single location close to its carboxy-terminus, and this reduces its molecular size by 5 kDa with the concomitant release of more than 80% of CBG-bound cortisol. Three small molecular size fragments are detected after elastase cleavage, and carbohydrate analysis of these fragments suggests that they represent the same polypeptide fragment which has been differentially glycosylated. To assess the biological significance of these observations, CBG was incubated with either mononuclear cells or granulocytes obtained from patients with acute inflammation (sepsis) and from a normal volunteer. Only granulocytes from septic patients reduced the mol wt of CBG by about 5 kDa and destroyed its steroid-binding activity. Preincubation with A1-PI prevented this, which demonstrates that neutrophil elastase plays a key role in this event. These results suggest a physiological role for CBG in the delivery of cortisol to sites of inflammation.