Showing papers by "University of Western Ontario published in 1989"
TL;DR: The outcome of multiple sclerosis, assessed according to the Kurtzke Disability Status Scale, was reviewed in 1,099 consecutive patients followed in London, Canada, between 1972 and 1984 and the rate at which disability develops after the onset of a progressive phase of MS is presented.
Abstract: The outcome of multiple sclerosis (MS), assessed according to the Kurtzke Disability Status Scale (DSS), was reviewed in 1,099 consecutive patients followed in London, Canada, between 1972 and 1984. A geographically based subgroup of 196 patients representing 90% of Middlesex County MS patients as well as a group of 197 patients seen from onset of disease were separately analysed. The clinical course was progressive from onset in 33% of the total population and in 28% of the Middlesex County subgroup. Of those with duration of 6-10 yrs, 30-40% with initially remitting disease developed progressive MS. The cross-sectional distribution of disability was bimodal with peaks at DSS 1 (no disability) and DSS 6 (assistance required for walking). Actuarial analysis showed that the median time to reach DSS 6 from onset of MS was 14.97 +/- 0.31 yrs in the total population and 9.42 +/- 0.44 yrs in the "seen from onset' subgroup. Survival was minimally altered; 87% of patients followed up to 40 yrs were still alive, although ascertainment of cases with this duration of MS was incomplete. Data describing the rate at which disability develops after the onset of a progressive phase of MS are also presented. The implications of these data in planning and interpretation of clinical therapeutic trials are discussed.
1,506 citations
1,285 citations
TL;DR: In this article, the authors present a new conceptualization of IJV control, as well as a conceptual frame work for studying control of IJVs, and synthesize prior studies addressing the conceptualization and operationalization of control within IJV.
Abstract: Control is a critical concept for successful management and performance of international joint ventures (IJVs). This paper reviews and synthesizes prior studies addressing the conceptualization and operationalization of control within IJVs, as well as the IJV control-performance relationship. The paper also presents a new conceptualization of IJV control, as well as a conceptual frame work for studying control of IJVs.
957 citations
TL;DR: In this article, Adams and Yellen show that bundling can serve as a useful price discrimination device, even when all consumers' willingnesses to pay for each of the goods individually are unaffected by whether they are also consuming the other product.
Abstract: Through what selling strategy can a multiproduct monopolist maximize his profits when his knowledge about individual consumers' preferences is limited? One possibility, extensively studied in the context of a single-good monopoly, is to use quantity-dependent pricing as a means of discriminating among customers with differing tastes (see, for example, Oi [1971] and Maskin and Riley [1984]). An alternative technique for price discrimination, first suggested by Stigler [1968] and analyzed further by Adams and Yellen [1976], is for the monopolist to package two or more products in bundles rather than selling them separately.' Through a series of examples Adams and Yellen illustrate that bundling can serve as a useful price discrimination device, even when all consumers' willingnesses to pay for each of the goods individually are unaffected by whether they are also consuming the other product. A typical example is illustrated in Figure I (adapted from Figure IV in Adams and Yellen), where there are two goods, three consumers (AB,C) who consume at most one unit of each good (with reservation values for each good that are independent of whether the other good is consumed), and zero costs of production. There, a bundle offered at a price of 100 fully extracts all potential surplus, which would be impossible pricing the goods independently. Unfortunately, though, these authors do not provide any general characterization of the circumstances in which bundling is actually a multiproduct monopolist's optimal strategy. Their examples, however (such as Figure I), create the impression that the profitable use of bundling
866 citations
TL;DR: Diversification strategy was significantly related to MNE performance, extending Rumelt's seminal research to international business and degree of internationalization was also significantlyrelated to M NE performance.
Abstract: This study examines potential explanations for performance differenlces among mnultinational enterprises (MNEs). The research variables, diversification strategy and degree of internationalization, involve basic elements of firms' strategy: range and relatedness of products, and relative emphasis on foreign versus domestic operations. The samnple included the 100 largest MNEs from the U.S. and Europe. Diversification strategy was significantly related to MNE performance, extending Rumelt's seminal research to international business. Degree of internationalization was also significantly related to MNE performance. An important phenomenon within international business is the increased role of multinational enterprises (MNEs), particularly large multinationals. In 1981 the sales of the largest 500 MNEs were equal to over 20 per cent of the world's gross domestic product, over 50 per cent of the world's traded output, and over 80 per cent of the foreign direct investment (Rugman, 1987; Stopford and Dunning, 1983). Management of these enterprises and their immense resources is a more complex and challenging task than for firms whose activities are largely confined to a single nation. Because of their important role in the world economy, much attention has been lavished upon MNEs, including examination of the rationale for their existence; their influence upon politics, culture, and industries; and their structure, strategies and management. One observation reported by several researchers involves
853 citations
TL;DR: The authors found that only Communicative anxiety is a factor in both the acquisition and production of French vocabulary, while test anxiety, audience sensitivity, trait anxiety, and other types of anxiety did not correlate with any of the production measures.
Abstract: Reviews of the literature on foreign-language anxiety show a considerable amount of ambiguity arising from the conflicting results of past studies. This study attempts to show that these difficulties can be resolved given an awareness of the theoretical perspective from which this research has developed. Specifically, it was predicted that anxiety based in the language environment would be associated with language learning whereas other types of anxiety would not show consistent relationships to performance. Eleven anxiety scales were factor analyzed yielding two orthogonal dimensions of anxiety which were labelled General Anxiety and Communicative Anxiety. It was found that only Communicative Anxiety is a factor in both the acquisition and production of French vocabulary. Analyses of the correlations between the anxiety scales and the measures of achievement show that scales of foreign-language anxiety and state anxiety are associated with performance. Scales of test anxiety, audience sensitivity, trait anxiety, and other types of anxiety did not correlate with any of the production measures. Finally, a model is proposed which describes the development of foreign-language anxiety.
839 citations
TL;DR: The Canadian American Ticlopidine Study (CATS) as discussed by the authors is a randomized, double-blind, placebo-controlled trial to assess the effect of ticloopidine (250 mg twice daily) in reducing the rate of subsequent occurrence of stroke, myocardial infarction, or vascular death in patients who have had a recent thromboembolic stroke.
824 citations
TL;DR: The time to reach successive levels of disability defined by the Kurtzke Disability Status Scale in 1,099 MS patients followed at University Hospital, London, Canada between 1972 and 1984 is recorded.
Abstract: Controversy exists regarding the predictive value of the early clinical course of multiple sclerosis (MS). Three parameters often considered are the attack rate, the first interattack interval and the rate at which disability develops in the early years of the disease. We have recorded the time to reach successive levels of disability defined by the Kurtzke Disability Status Scale (DSS) in 1,099 MS patients followed at University Hospital, London, Canada between 1972 and 1984. Our population is particularly suitable because of its size, the high degree of ascertainment of cases in the community, and the regular follow-up provided. Life table analysis was used to compare survival in patients stratified according to the above three parameters using DSS 6 as end point. Significant differences were evident in the survival distributions. Despite the extensive interindividual variation in the rate at which disability developed, the early course of MS may be useful in determining the relative risk of rapid progression.
605 citations
TL;DR: This article examined the interactive influence of three different leadership styles and two levels of group productivity norms on individuals' adjustment and performance on a decision-making task and found that participants working under the charismatic leader had high task performance, task adjustment, and adjustment to the leader and to the group.
563 citations
TL;DR: Depression during pregnancy was related to different sociodemographic variables than was postpartum depression, suggesting that depression at these two times may be associated with different psychological or etiological factors.
Abstract: Examined the prevalence of depression in a heterogeneous sample of 360 pregnant women. Subjects were assessed with respect to both depressive symptomatology and diagnostic status during pregnancy and after delivery. At both assessments, approximately 25% of the sample reported elevated levels of depressive symptomatology. In contrast, 10% of the women met diagnostic criteria for depression during pregnancy, and 6.8% were depressed postpartum. However, only half of the cases of postpartum depression were new onset (3.4%); the remaining women receiving a diagnosis in the postpartum had also been depressed during pregnancy. Finally, depression during pregnancy was related to different sociodemographic variables than was postpartum depression, suggesting that depression at these two times may be associated with different psychological or etiological factors.
562 citations
TL;DR: Mouse 3T3 cell lines capable of constitutively synthesizing an RNA complementary to the messenger RNA encoding TIMP, tissue inhibitor of metalloproteinases, were constructed by transfection with appropriate plasmid constructs and indicate that TIMP suppresses oncogenicity, at least in immortal murine 3T 3 cells.
Abstract: Mouse 3T3 cell lines capable of constitutively synthesizing an RNA complementary to the messenger RNA encoding TIMP, tissue inhibitor of metalloproteinases, were constructed by transfection with appropriate plasmid constructs. Many of the lines were down-modulated for TIMP messenger RNA levels and secreted less TIMP into the culture medium. In comparison to noninvasive, nontumorigenic controls, these cells not only were invasive in a human amnion invasion assay, but also were tumorigenic and metastatic in athymic mice. These results indicate that TIMP suppresses oncogenicity, at least in immortal murine 3T3 cells.
TL;DR: A new theory of attraction and liking based on kin selection suggests that people detect genetic similarity in others in order to give preferential treatment to those who are most similar to themselves as mentioned in this paper.
Abstract: A new theory of attraction and liking based on kin selection suggests that people detect genetic similarity in others in order to give preferential treatment to those who are most similar to themselves. There are many sources of empirical and theoretical support for this view, including (1) the inclusive fitness theory of altruism, (2) kin recognition studies of animals raised apart, (3) assortative mating studies, (4) favoritism in families, (5) selective similarity among friends, and (6) ethnocentrism. Specific tests of the theory show that (1) sexually interacting couples who produce a child are genetically more similar to each other in blood antigens than they are either to sexually interacting couples who fail to produce a child or to randomly paired couples from the same sample; (2) similarity between marriage partners is most marked in the more genetically influenced of sets of anthropometric, cognitive, and personality characteristics; (3) after the death of a child, parental grief intensity is correlated with the child's similarity to the parent; (4) long-term male friendship pairs are more similar to each other in blood antigens than they are to random dyads from the same sample; and (5) similarity among best friends is most marked in the more genetically influenced of sets of attitudinal, personality, and anthropometric characteristics. The mechanisms underlying these findings may constitute a biological substrate of ethnocentrism, enabling group selection to occur.
TL;DR: In this paper, the impact of childhood sexual abuse is conceptualized as a post-traumatic stress disorder, and a study supporting this formulation is presented, which includes 71 sexually abused children and their mothers and involved measures of abuse severity, children's attributional style and child adjustment.
TL;DR: WOMAC is a purposebuilt multidimensional instrument capable of measuring clinically important, patient-relevant symptoms in OA of the hip and/or knee, and Doyle et al’ have modified the Ritchie Index to develop a joint count applicable to OA subjects.
TL;DR: In this article, the influence of the immediate social environment on the child's ability to cope during painful medical procedures was examined using the Child- Adult Medical Procedure Interaction Scale (CAMPIS).
TL;DR: It is found that 1- to 2-mm residual necks seen in postoperative angiography have been thought to pose little risk, but a surprising number of cases have been presented in which this seemingly unimportant remnant of the neck dilated over a long period to become a dangerous aneurysm.
Abstract: It is recognized that incomplete treatment of an aneurysm may result in recurrent hemorrhage with serious or fatal consequences. For this reason, patients treated at the authors' institution in whom a large portion of the aneurysm neck or sac remained after application of a clip or ligature have been subjected to reoperation. However, 1- to 2-mm residual necks seen in postoperative angiography have been thought to pose little risk. Some cases of aneurysms recurring from a narrow residual neck after clipping have been reported, and a few instances of recurrent aneurysm have been described after apparently complete occlusion of the neck (as observed angiographically or in the surgeon's judgment). In recent years, a surprising number of cases have been presented in which this seemingly unimportant remnant of the neck dilated over a long period to become a dangerous aneurysm. This finding stresses the importance of complete aneurysm occlusion and of postoperative angiography for the recognition of a residual aneurysm neck. This should be important not only in aneurysm clipping but also in the endovascular treatment of intracranial aneurysms with detachable balloons.
TL;DR: In this article, the authors model the bidding for a government contract in which there is imperfect competition and each bidder is better informed about his own costs than either his rival bidders or the government.
TL;DR: A retrospective analysis of factors affecting the length of survival of 285 consecutive adults with newly diagnosed biopsy-proven supratentorial anaplastic glioma found that age, duration of symptoms, preirradiation performance status, tumor histology, accessibility to resection, extent of resection and radiotherapy, and prior low-gradeglioma were significant independent variables influencing survival.
Abstract: A retrospective analysis is presented of factors affecting the length of survival of 285 consecutive adults with newly diagnosed biopsy-proven supratentorial anaplastic glioma (188 cases of glioblastoma multiforme, 76 of anaplastic astrocytoma, 11 of anaplastic mixed glioma, and 10 of anaplastic oligodendroglioma) treated at a regional cancer center from July, 1982, through December, 1987. The approach to initial therapy included maximum feasible resection and radiotherapy. The median survival time for all patients was 35 weeks. Multivariate analysis demonstrated that age, duration of symptoms, preirradiation performance status, tumor histology, accessibility to resection, extent of resection, radiotherapy, and prior low-grade glioma were significant independent variables influencing survival. The prognostic importance of age, duration of symptoms, performance status, and tumor histology are already recognized, but three "new" findings are reported. First, patients with anaplastic oligodendroglioma had the longest median survival time (278 weeks). Second, corrected for accessibility and all other variables, patients with gross total resection lived longer than those with partial resection, and patients with any degree of resection lived longer than those who underwent only a biopsy procedure. Third, patients with anaplastic glioma in whom there was a prior history of low-grade glioma lived significantly longer after the diagnosis of anaplastic glioma than did patients in whom the anaplastic glioma apparently arose de novo.
TL;DR: A review of numerical algorithms for the analysis of viscous flows with moving interfaces is presented, finding that the existing methods are effective in dealing with small to medium interface deformations.
Abstract: A review of numerical algorithms for the analysis of viscous flows with moving interfaces is presented. The review is supplemented with a discussion of methods that have been introduced in the context of other classes of free boundary problems, but which can be generalized to viscous flows with moving interfaces. The available algorithms can be classified as Eulerian, Langrangian, and mixed, ie, Eulerian-Lagrangian. Eulerian algorithms consist of fixed grid methods, adaptive grid methods, mapping methods, and special methods. Langrangian algorithms consist of strictly Langrangian methods, Langrangian methods with rezoning, free Lagrangian methods and particle methods. Mixed methods rely on both Lagrangian and Eulerian concepts. The review consists of a description of the present state-of-the-art of each group of algorithms and their applications to a variety of problems. The existing methods are effective in dealing with small to medium interface deformations. For problems with medium to large deformations the methods produce results that are reasonable from a physical viewpoint; however, their accuracy is difficult to ascertain.
TL;DR: Conditional adsorption capacity constants, obtained graphically from the data, showed that biofilm metal uptake at a neutral pH level was enhanced by up to 12 orders of magnitude over acidic conditions.
Abstract: Microbial biofilms were grown on strips of epoxy-impregnated filter paper submerged at four sites in water contaminated with metals from mine wastes. At two sample stations, the water was acidic (pH 3.1); the other sites were in a lake restored to a near neutral pH level by application of a crushed limestone slurry. During a 17-week study period, planktonic bacterial counts increased from 10 to 10 CFU/ml at all sites. Biofilm counts increased rapidly over the first 5 weeks and then leveled to 10 CFU/cm in the neutral pH system and 10 CFU/cm at the acidic sites. In each case, the biofilms bound Mn, Fe, Ni, and Cu in excess of the amounts adsorbed by control strips covered with nylon filters (pore size, 0.22 mum) to exclude microbial growth; Co bound under neutral conditions but not under acidic conditions. Conditional adsorption capacity constants, obtained graphically from the data, showed that biofilm metal uptake at a neutral pH level was enhanced by up to 12 orders of magnitude over acidic conditions. Similarly, adsorption strength values were usually higher at elevated pH levels. In thin sections of the biofilms, encapsulated bacterial cells were commonly found enmeshed together in microcolonies. The extracellular polymers often contained iron oxide precipitates which generated weak electron diffraction patterns with characteristic reflections for ferrihydrite (Fe(2)O(3) . H(2)O) at d equaling 0.15 and 0.25 nm. At neutral pH levels, these deposits incorporated trace amounts of Si and exhibited a granular morphology, whereas acicular crystalloids containing S developed under acidic conditions.
TL;DR: The data presented suggest that the conclusions of the National Cooperative Dialysis Study may be reinterpreted by assigning a major role to the nutritional status of patients in morbidity, with satisfactory nutritional status attained only in patients receiving adequate dialysis which, in turn, ensures control of plasma urea levels.
TL;DR: It is concluded that immuno- and biologically active CRH is produced not only in the human placenta, but also in the fetal membranes, raising the possibility of a regulatory system similar to that of the hypothalamic pituitary axis, but residing within the placentA and fetal membranes.
Abstract: The levels of immunoreactive CRH are elevated in both maternal and fetal plasma in late gestation and labor, but fall precipitously after parturition. The major source of this peptide is thought to be the placenta. We determined if the placenta and also the amnion, chorion, and decidua produce CRH, whether this material has biological activity, and whether CRH output is modulated by glucocorticoids and progesterone. In an in vitro monolayer culture system CRH was produced by the fetal membranes and decidua. Media immunoreactive CRH concentrations averaged 625 ± 45 (se) pg/105 cells in amnion, 701 ± 56 pg/106 cells in chorion, and 580 ± 60 pg/105 cells in decidual tissue obtained at cesarean section. This output was similar to that by the placenta (906 ± 121 pg/105 cells). These values increased in tissue obtained after spontaneous labor. A single peak of CRH immunoreactivity eluting at the same position as synthetic human CRH, and possessing biological activity, was found in all tissues. There was a dose-...
TL;DR: Investigation of microcomputer usage among professionals and managers indicates that a strong, significant, and positive relationship exists between participation in computer training programs and MIS success, as measured by micro computer usage.
TL;DR: In this paper, a fine film of graphite is observed on the grain boundaries in three rocks from the Laramie Anorthosite Complex, showing that graphite was stable during igneous crystallization but in the other it was not.
Abstract: THE origin of zones of high electrical conductivity in the lower continental crust is a long-standing mystery; possible explanations include the presence of brines1,2, partial melt3, serpentine4 and graphite5. When discussing the occurrence of graphite in the crust many petrologists have considered phase relations as they would have existed at the peak of metamorphism or during igneous emplacement6-10. Here we show that a fine film of graphite is present on the grain boundaries in three rocks from the Laramie Anorthosite Complex. In two of these rocks graphite was stable during igneous crystallization but in the other it was not. We maintain that in all of the rocks the grain-boundary graphite precipitated from a CO2-rich fluid during cooling. The chemical processes that produced the grain-boundary graphite in these rocks are likely to operate in many lower-crustal rocks. We therefore contend that, because the films we observe are capable of producing the high conductivity that is seen in the lower crust, grain-boundary graphite should be considered as a possible cause for some conductivity anomalies.
TL;DR: It is demonstrated that osteopontin is identical to a transformation-associated phosphoprotein whose level of expression by cultured cells and abundance in human sera has been correlated with tumorigenicity.
Journal Article•
TL;DR: It is concluded that n-butyl 2-cyanoacrylate (NBCA), a tissue adhesive approved for surgical use in some countries, has clinical and biologic behaviors similar to IBCA, and therefore should be an acceptable alternative to I BCA for intravascular use.
Abstract: Despite the development of new alternative embolic agents, the endovascular treatment of brain arteriovenous malformations continues to frequently require the use of cyanoacrylic glue, especially in situations where particulate or sclerosing agents are ineffective, such as when flow is very rapid or fistulous. Because isobutyl 2-cyanoacrylate (IBCA), the most commonly used embolic glue, is no longer available or manufactured, a real need exists for an alternative fast polymerizing agent. In vivo and in vitro studies were performed to compare IBCA with n-butyl 2-cyanoacrylate (NBCA, supplied as Histoacryl Blue), a tissue adhesive approved for surgical use in some countries. Polymerization times in static plasma were compared, and the effect of the addition of iophendylate oil or glacial acetic acid on polymerization was assessed. Polymerization times in vivo were compared after intraarterial injection into the internal carotid artery in pigs using a standardized technique. The histopathologic reactions to each glue in the embolized pig rete were assessed and compared over a period of 0-60 days after embolization. Our results show that while NBCA polymerization is demonstrably faster than IBCA in vitro, intraarterial injections of each glue show no significant difference in polymerization times. Like IBCA, NBCA polymerization can be predictably prolonged by the addition of oil or glacial acetic acid, though the effect is less for NBCA. Histopathologic reactions were similar, with acute vasculitis observed, becoming chronic and granulomatous after about 1 month. Both glues showed frequent foci of extravascular extrusion through the embolized rete and recanalization of previously occluded embolized vessels. We conclude that NBCA has clinical and biologic behaviors similar to IBCA, and therefore should be an acceptable alternative to IBCA for intravascular use.
TL;DR: A creative management model is explained, which goes beyond conventional strategic management, and the behaviors of top managers needed for the ongoing renewal of their business are identified.
Abstract: Increasingly the makeup of the top management group is believed to affect the development, identification and exploitation of strategic opportunities. This paper explains a creative management model, which goes beyond conventional strategic management, and identifies the behaviors of top managers needed for the ongoing renewal of their business. It is proposed these behaviors cluster and can be aligned with different and distinct cognitive styles or types. The implication is that top management groups should be composed of a mix of types. This paper posits a mix of Jungian types, Intuitives, Feelers, Thinkers and Sensors. This diversity can yield great strength if the differences can be focused and unified. Propositions and suggestions for further empirical research are developed.