Showing papers by "Université du Québec à Montréal published in 1992"

The Academic Motivation Scale: A Measure of Intrinsic, Extrinsic, and Amotivation in Education

Abstract: A new measure of motivation toward education has been developed in French, namely the Echelle de Motivation en Education (EME). The EME is based on the tenets of self-determination theory and is composed of 28 items subdivided into seven sub-scales assessing three types of intrinsic motivation (intrinsic motivation to know, to accomplish things, and to experience stimulation), three types of extrinsic motivation (external, introjected, and identified regulation), and a motivation. The purpose of this investigation was to cross-culturally validate in English the EME. The EME was translated in English through appropriate methodological procedures and completed by university students. Results revealed that the English version of the scale renamed the Academic Motivation Scale (AMS), has satisfactory levels of internal consistency (mean alpha value = .81) and temporal stability over a one-month period (mean test-retest correlation = .79). In addition, results of a confirmatory factor analysis (LISREL) confirm...

Intrinsic, extrinsic, and amotivational styles as predictors of behavior: A prospective study.

Abstract: This research ascertained the role of intrinsic, extrinsic, and amotivational styles as predictors of behavioral persistence in a real-life setting. At the beginning of the academic year, 1,042 first-term junior-college students enrolled in a compulsory college course completed a scale assessing intrinsic motivation, four styles of extrinsic motivation (namely, external regulation, introjection, identification, and integration), and amotivation toward academic activities. At the end of the semester, individuals who had dropped out of the course and those who had persisted were identified. Results showed that individuals who persisted in the course had reported at the beginning of the semester being more intrinsically motivated, more identified and integrated, and less amotivated toward academic activities than students who dropped out of the course. Gender differences also emerged. These revealed that females

The Euler Equations of Motion with Hydrostatic Pressure as an Independent Variable

Abstract: A novel form of the Euler equations is developed through the use of a different vertical coordinate system. It is shown that the use of hydrostatic pressure as an independent variable has the advantage that the Euler equations then take a form that parallels very closely the form of the hydrostatic equations cast in isobaric coordinates. This similarity holds even when topography is incorporated through a further transformation into terrain-following coordinates. This leads us to suggest that hydrostatic-pressure coordinates could be used advantageously in nonhydrostatic atmospheric models based on the fully compressible equations.

Impaired cortisol stress response in fish from environments polluted by PAHs, PCBs, and mercury.

Abstract: The cortisol stress response to capture was investigated in two species of fish (Perca flavescens and Esox lucius) from sites polluted by high levels of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and mercury, and from reference sites in the St. Lawrence river system. Fish from the reference sites exhibited the normal elevation of serum cortisol in response to the acute stress of capture and had large pituitary corticotropes. In contrast, fish from the most polluted sites were unable to increase their serum cortisol in response to the acute stress of capture and their pituitary corticotropes were atrophied. These results suggest that a life-long exposure to chemical pollutants may lead to an exhaustion of the cortisol-producing endocrine system, possibly as a result of prolonged hyperactivity of the system.

Varieties of Increasing Trees

Abstract: An increasing tree is a labelled rooted tree in which labels along any branch from the root go in increasing order. Under various guises, such trees have surfaced as tree representations of permutations, as data structures in computer science, and as probabilistic models in diverse applications.

Cloning, Characterization, and Expression of a cDNA Encoding a 50-Kilodalton Protein Specifically Induced by Cold Acclimation in Wheat

Abstract: We have isolated, sequenced, and expressed a cold-specific cDNA clone, Wcs120, that specifically hybridizes to a major mRNA species of approximately 1650 nucleotides from cold-acclimated wheat (Triticum aestivum L.). The accumulation of this mRNA was induced in less than 24 hours of cold treatment, and remained at a high steady-state level during the entire period of cold acclimation in the two freezing-tolerant genotypes of wheat tested. The expression of Wcs120 was transient in a less-tolerant genotype even though the genomic organization of the Wcs120 and the relative copy number were the same in the three genotypes. The mRNA level decreased rapidly during deacclimation and was not induced by heat shock, drought, or abscisic acid. The Wcs120 cDNA contains a long open reading frame encoding a protein of 390 amino acids. The encoded protein is boiling stable, highly hydrophilic, and has a compositional bias for glycine (26.7%), threonine (16.7%), and histidine (10.8%), although cysteine, phenylalanine, and tryptophan were absent. The WCS120 protein contains two repeated domains. Domain A has the consensus amino acid sequence GEKKGVMENIKEKLPGGHGDHQQ, which is repeated 6 times, whereas domain B has the sequence TGGTYGQQGHTGTT, which is repeated 11 times. The two domains were also found in barley dehydrins and rice abscisic acid-induced protein families. The expression of this cDNA in Escherichia coli, using the T7 RNA polymerase promoter, produced a protein of 50 kilodaltons with an isoelectric point of 7.3, and this product comigrated with a major protein synthesized in vivo and in vitro during cold acclimation.

Description versus Interpretation: Competing Alternative Strategies for Qualitative Research

Abstract: In the contemporary scene, psychological researchers seeking alternative (qualitative) research strategies are turning increasingly toward interpretation theory. However, other strategies are also available, and one of these is descriptive science. Descriptive practices as the basis for the clarification of meanings have received less emphasis because of several epistemological assumptions about meaning that have appeared in the literature of interpretive science. Based upon the work of contemporary transcendental philosophers, especially J. N. Mohanty, this article argues that a descriptive scientific perspective can respond to some of the hermeneutic arguments about meaning and that solid findings can be established descriptively. It is argued that both description and interpretation are legitimate but that they are tied to different conditions and interests.

Early effects of normal aging on perseverative and non‐perseverative prefrontal measures

Abstract: Current neuropsychological research supports a model postulating that prefrontal functions are among the first to decline in normal aging, but this model has rarely been empirically tested with subjects of 65 years or less. This study tests the following hypotheses: (a) A significant decline occurs prior to age 65 in a wide ranging set of prefrontal performance measures and (b) a significant increase occurs on measures of perseveration based on the same prefrontal tasks. A group of young adults (n = 70) aged 20 to 35 and a group of elderly adults (n = 58) aged 45 to 65, group‐matched for education and sex, were evaluated by means of six neuropsychological prefrontal tasks: the Self‐Ordered Pointing Task, the Wisconsin Card Sorting Test, the Porteus Mazes, a Verbal Fluency Task, a Design Fluency Task, and the Stroop Test. Four of the six prefrontal scores and four of six measures of perseveration manifested significant declines in the elderly group, suggesting that normal aging prior to age 65 may exhibit ...

Mapping of an idiosyncratic schema

Abstract: Among researchers interested in organizations and management, some of those who use cognitive mapping share a common objective: to improve organizational action. Some intervene directly at the level of the organization while others prefer to achieve this indirectly, by working at the individual level. Nevertheless those who work at the individual level rely on the ‘emancipatory’properties of a cognitive map, which facilitates reflectiveness. After calling upon the notions of natural logic, schematization, contextuality, representation, knowledge and schema to characterize the cognitive map and its construction, we present a case, that of the idiosyncratic map of the owner-manager of a small business. We describe the mode of construction of the map and its content. A critical discussion follows underlining the traps to avoid, the elements to be improved and those that should be kept for construction of future idiosyncratic maps.

Integrating the daughter into family business management

Abstract: This paper presents guidelines for integrating daughters into family business management. Based upon the results of an empirical study of daughters working with their founder/fathers in 18 family-o...

Evidence for recent warming from perturbed geothermal gradients : examples from eastern Canada

Abstract: Recent variations of the surface temperature of the Earth can be inferred from borehole temperature measurements. Generalized inversion is used to extract the information from the data; the potential of the method is evaluated. Tests were performed with synthetic data to demonstrate the effectiveness of the inversion to recover the gross features of the surface temperature history even when the data are affected by noise and errors. The tests show that it is possible to reconstruct the long term changes in ground temperature during the past 300 years; the resolution decreases with time, in particular if noise and errors must be filtered. Temperature logs, obtained in eastern Canada, and not suspected of being affected by non-climatic factors, have been inverted. The analysis confirms that eastern Canada has experienced warming by 1 to 2°C over the past 100–200 years. The relationship between air and ground temperatures has been examined. In eastern Canada ground temperature follows air temperature closely in summer but stays well above air temperature in winter. The number of days with snow on the ground correlates with the difference between annual mean ground and air temperature.

Quadriceps femoris muscle activity in patellofemoral pain syndrome

Abstract: To elucidate and attempt to dissociate the two mechanisms, neuromuscular and mechanical, underlying patellofemoral pain syndrome, 18 subjects, divided into two groups based on a diagnosis of patellofemoral pain syndrome and the knee Q angle, were studied. The control group was asymptomatic and exhibited a normal Q angle (mean, 8.25 degrees), whereas the other group, diagnosed as patellofemoral pain syndrome patients, reported knee pain and had an above-normal Q angle (mean, 21.05 degrees). All subjects were tested for isometric maximum knee extension at 90 degrees, 30 degrees, and 15 degrees of knee flexion while they were seated in a special restraining chair. During testing, surface electromyography at the oblique and long fibers of the vastus medialis, and at the vastus lateralis were recorded along with the knee moment of force. The integrated electromyographic signals associated with the peak torque for all of the vastus muscles, along with the vastus medialis obliquus:vastus lateralis and vastus medialis longus:vastus lateralis activity ratios showed no significant differences between groups nor between the three angles, suggesting that all vasti measured were consistently active throughout the studied range of motion. This suggests that the neural drive was not affected in the patellofemoral pain syndrome patients. However, when the five patients showing the largest Q angles were isolated, they revealed a significantly smaller vastus medialis obliquus:vastus lateralis ratio when compared to the other group. The same ratio was also significantly smaller at 15 degrees compared to 90 degrees.(ABSTRACT TRUNCATED AT 250 WORDS)

Neurobehavioral manifestations in obstructive sleep apnea syndrome before and after treatment with continuous positive airway pressure.

Abstract: Obstructive sleep apnea syndrome (OSAS) is characterized by recurrent apneas during sleep, resulting in repetitive hypoxemic episodes and a constant interruption of the normal sleep pattern. Vigilance impairment and neuropsychological deficits are among the main symptoms seen in this condition. One of the major questions in this field concerns the reciprocal interactions between nocturnal hypoxemia, sleep disruption, excessive daytime sleepiness and cognitive deficits. Results of this study suggest that vigilance impairment is attributable mostly to nocturnal hypoxemia. However, in cognitive deficits, hypoxemia seems to play a major role in executive and psychomotor tasks, whereas attention and memory functions appear to be related to vigilance impairment. After treatment, hypoxemia-related deficits and some degree of sleepiness persist. These results raise the possibility of an irreversible anoxic central nervous system (CNS) damage in severe OSAS.

On the universality of crossing probabilities in two-dimensional percolation

Abstract: Six percolation models in two dimensions are studied: percolation by sites and by bonds on square, hexagonal, and triangular lattices. Rectangles of widtha and heightb are superimposed on the lattices and four functions, representing the probabilities of certain crossings from one interval to another on the sides, are measured numerically as functions of the ratioa/b. In the limits set by the sample size and by the conventions and on the range of the ratioa/b measured, the four functions coincide for the six models. We conclude that the values of the four functions can be used as coordinates of the renormalization-group fixed point.

Study of spatial components of forest cover using partial Mantel tests and path analysis

Abstract: . Plant species distributions are generally thought to be chiefly under environmental control, although they may be affected by disturbance events or dispersion properties of the species. The relative importance of these different factors is not easy to evaluate because they often share common spatial patterns, such that an inextricable network of relationships occurs between plant distributions, environmental conditions, disturbance events and endogenous factors such as propagule dispersion. In this paper we propose a method for untangling the common spatial component from the relationship between environmental conditions and the distribution of tree species. Using partial Mantel tests and path analysis, we test models of relationships between these data sets. Results show that in our study area, spatial patterns of species associated with hydric conditions remain largely correlated with environmental conditions. However, mesic sites show more complex forest covers, in which a significant spatial component persists when environmental variation is statistically controlled for. This remaining spatial variability suggests that other factors possessing spatial structure partly explain species distributions.

A molecular marker to select for freezing tolerance in Gramineae

Abstract: We isolated, and expressed in Escherichia coli, a gene (Wcs120) that is strongly induced during cold acclimation of wheat. The gene product was purified and used to produce antibodies. Immunoblotting experiments with the anti-WCS120 antibody identified several cold-induced proteins named FTMs for Freezing Tolerance Markers since they are associated with the development of freezing tolerance. This protein family was found to be coordinately regulated specifically by low temperature, highly hydrophilic, stable to boiling, and to have a pI above 6.5. The accumulation kinetics during the acclimation period indicated a positive correlation with the capacity of each genotype to develop freezing tolerance. Accumulation of the proteins was higher in the freezing-tolerant genotype than in the less tolerant one. In addition, their accumulation was more pronounced in the crown and leaf tissues compared with roots, confirming a relationship to the capacity of the different tissues to develop freezing tolerance. Analysis of different species (eight monocots and four dicots) indicated that this protein family is specific for freezing-tolerant cereals. The antibody did not cross-react with any of the non-cereal species examined. The anti-FTMs antibody represents a potential tool for breeders to select for freezing tolerance traits in the Gramineae.

Will greenhouse warming lead to Northern Hemisphere ice-sheet growth?

Abstract: ALTHOUGH model simulations predict a higher mean global temperature by the middle of the next century in response to increased atmospheric concentrations of greenhouse gases1, the response of the cryosphere to specific changes in latitudinal and seasonal temperature distribution is poorly constrained by modelling2,3 or through instrumental measurements of recent variations in snow cover4and ice thickness5,6. Here we examine the recent geological record (130 kyr to present) to obtain an independent assessment of ice-sheet response to climate change. The age and distribution of glacial sediments, coupled with marine and terrestrial proxy records of climate, support arguments that initial ice-sheet growth at the beginning of the last glacial cycle occurred at high northern latitudes (65–80° N) under climate conditions rather similar to present. In particular, the conditions most favourable for glacier inception are warm high-latitude oceans, low terrestrial summer temperature and elevated winter temperature. We find that the geological data support the idea that greenhouse warming, which is expected to be most pronounced in the Arctic and in the winter months, coupled with decreasing summer insolation7 may lead to more snow deposition than melting at high northern latitudes8 and thus to ice-sheet growth.

Quantitative assessment of carbonate dissolution in marine sediments from foraminifer linings vs. shell ratios: Davis Strait, northwest North Atlantic

Abstract: A new method to evaluate quantitatively the degree of calcium carbonate preservation and dissolution in high-latitude marine sediments is proposed on the basis of relative abundance of CaCO 3 shells and organic linings of benthic foraminifers. This method was applied to a late Quaternary sequence from Davis Strait in the northwest North Atlantic and shows that CaCO 3 dissolution in sediments has increased since the last glacial maximum (ca. 18,000 B.P.) and peaked when subpolar interglacial conditions were established in surface waters. The dissolution in Davis Strait sediments appears to be closely related to organic biogenic production in surface waters, with a regional pattern of bottom-water formation and circulation.

Evaluation of nafion as media for glucose oxidase immobilization for the development of an amperometric glucose biosensor

Abstract: A novel glucose biosensor has been prepared by deposition of a mixture containing glucose oxidase dissolved in water and Nafion dissolved in methanol at the surface of a platinum disk electrode. Glucose concentration is evaiuated by measuring the amperometric current corresponding to hydrogen peroxide electrooxidation at 0.7 V vs. SCE. The addition of glucose oxidase to Nafion resulted in a Nafion-glucose oxidase film that was more permeable to anionic species than Nafion alone. The calibration curve for glucose is linear from 5 μM up to about 10 mM. In oxygen-saturated solution, the linear range extended to 15 mM. The optimum pH for the assay was found to be 5.5. The enzyme is not stabilized against temperature deactivation when it is immobilized in Nafion. The Pt/Nafion-glucose oxidase electrodes showed good stability when stored dry at room temperature with 80% of the initial response retained after 250 days.

A Decomposition of the Descent Algebra of a Finite Coxeter Group

Abstract: The purpose of this paper is twofold. First we aim to unify previous work by the first two authors, A. Garsia, and C. Reutenauer (see l2r, l3r, l4r, l5r and l10r) on the structure of the descent algebras of the Coxeter groups of type An and Bn. But we shall also extend these results to the descent algebra of an arbitrary finite Coxeter group W. The descent algebra, introduced by Solomon in l14r, is a subalgebra of the group algebra of W. It is closely related to the subring of the Burnside ring B(W) spanned by the permutation representations W/WJ, where the WJ are the parabolic subgroups of W. Specifically, our purpose is to lift a basis of primitive idempotents of the parabolic Burnside algebra to a basis of idempotents of the descent algebra.

Effects of Eubothrium salvelini (Cestoda) on the behaviour of Cyclops vernalis (Copepoda) and its susceptibility to fish predators

Abstract: To facilitate the completion of their life-cycle, many helminth parasites have evolved the ability to manipulate the behaviour of their intermediate host in order to make it more likely to be eaten by the parasite's definitive host. Here, we determined whether the cestode Eubothrium salvelini modifies the behaviour of its intermediate host, the copepod Cyclops vernalis, and makes it more susceptible to predation by brook trout, Salvelinus fontinalis, the parasite's final host. Following the experimental infection of copepods, the spontaneous activity of infected and control subjects was quantified weekly. In addition, we regularly quantified predation by individual brook trout fry on known numbers of infected and control copepods. At approximately the time when the cestode larvae became infective to fish (2–3 weeks following infection), the infected copepods started to swim more actively than uninfected controls. Also at that time, infected individuals became more likely to be captured by fish than uninfected ones. Copepod size and intensity of infection had no significant effect on their behaviour or their risk of being eaten by fish. Thus cestode- induced changes in copepod swimming activity can lead to infected copepods becoming highly vulnerable to fish predators, and may have resulted from selection on the parasite to increase its transmission success

Physicochemical and Electrochemical Properties of CuCo2 O 4 Electrodes Prepared by Thermal Decomposition for Oxygen Evolution

Abstract: Copper cobalt oxide with the spinel structure was investigated as an anode material for alkaline water electrolysis. This catalyst was prepared by thermal decomposition of nitrate precursors on titanium and nickel supports. Scanning electron microscopy analysis and electrochemical surface area measurements indicate that the electrodes are highly porous. Such preparation variables as the concentration of the mixed nitrates in isopropanol, the temperature of nitrate decomposition, the time of annealing, the catalyst loading, the nature of the substrate, the air flow during the thermal decomposition, and the cooling rate of the electrode have been investigated in detail to determine their influence on the morphology, the composition, the mechanical stability, and the electrocatalytic activity for oxygen evolution of the oxide films. It is shown that the performances can be ascribed to the variation in the roughness factor of the oxide layers. At 400°C, a resistive phase, presumably , is formed and dispersed on the surface of . This has a deleterious effect on the electrocatalytic activity. Copper cobalt oxide is oxidized and reduced prior to the oxygen evolution through a reaction which can involve the formation of the CoIV/CoIII redox couple on the surface of cobaltite. The material prepared on nickel at 275°C for 1 h at a catalyst loading of 3.3 mg cm−2 shows fairly low overvoltages for oxygen evolution.

A Diagnosis of the Explosive Development of Two Extratropical Cyclones

Abstract: This paper examines the 24-h explosive development periods of two extratropical cyclones, the first occurring over the Gulf Stream off the coast of New England from 18 to 19 January 1979 and the second occurring over the southeastern United States from 20 to 21 January 1979 The data used in this study are the First GARP (Global Atmospheric Research Program) Global Experiment (FGGE) level IIIb (SOP I) global analyses on a 4 deg latitude x 5 deg longitude grid The parameter used to diagnose development is the geostrophic relative vorticity tendency calculated using an extended form of the Zwack-Okossi development equation This development equation is similar to the Petterssen-Sutcliffe development equation, but is shown to be more complete by explicitly coupling surface development with forcing at all levels above the surface Cyclonic-vorticity advection, warm-air advection, and latent heat release act to develop the two cyclones, while adiabatic cooling in the ascending air opposes development Further, vertical profiles of the development quantities for these two cases reveal that vorticity and temperature advection maximize in the 200-300-mb layer, while the latent heat release maximum is typically below 500 mb

Ground temperature histories for central and eastern Canada from geothermal measurements: Little Ice Age signature

Abstract: Deep borehole temperature profiles have been analyzed to determine ground temperature histories in central and eastern Canada. Clear signs of a cold period between 1500 and 1800 A.D., corresponding to the little ice age, have been found. A warming trend after 1800 A.D. was detected throughout eastern and central Canada. Temperature profiles from western Ontario are consistent and were inverted simultaneously to yield a regional ground temperature history. The recent warming appears to be correlated with the increase of atmospheric CO2 reported for a Greenland ice core.

Estimation of interhemispheric dynamics from simple unimanual reaction time to extrafoveal stimuli.

Abstract: This essay reviews research on interhemispheric transfer time derived from simple unimanual reaction time to hemitachistoscopically presented visual stimuli. Part 1 reviews major theoretical themes including (a) the significance of the eccentricity effect on interhemispheric transfer time in the context of proposed underlying neurohistological constraints; (b) the significance of gender differences in interhemispheric transfer time and findings in dyslexics and left-handers in the context of a fetal brain testosterone model; and (c) the significance of complexity effects on interhemispheric transfer time in a context of "dynamic" vs. "hard-wired" concepts of the underlying interhemispheric communication systems. Part 2 consists of a meta-analysis of 49 published behavioral experiments, in view of drawing a portrait of the best set of experimental conditions apt to produce salient, reliable, and statistically significant measures of interhemispheric transfer time, namely (a) index rather than thumb response, (b) low rather than high target luminance, (c) short rather than prolonged target display, and (d) very eccentric rather than near-foveal stimulus location. Part 3 proposes a theoretical model of interhemispheric transfer time, postulating the measurable existence of fast and slow interhemispheric channels. The proposed mechanism's evolutionary adaptive value, the neurophysiological evidence in its support, and favorable functional evidence from studies of callosotomized patients are then presented followed by proposals for critical experimental tests of the model.