980 resultados para 240401 Optics and Opto-electronic Physics


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Rapid and large accumulation of GABA (y-aminobutyric acid) in response to a number of plant stresses has been well documented. But the role(s) of GABA in plants is not well defined. In recent years, the possibility of GABA involvement in regulating plant growth and development has been raised. In the present study, this possibility was examined. First, to rapidly and accurately determine GABA levels in plant tissues, a spectrometric method for GABA determination was developed based on a commercially available enzyme Gabase. Seventy mM LaCb almost completely removed water-soluble pigments from plant tissues which greatly interfere with the absorbance reading at 340nm. Inactivation of GAD (glutamate decarboxylase) by immediately adding methanol to a frozen plant tissue powder was suggested to prevent GABA production during extraction. The recovery of GABA with this method was approximately 100%. Second, the relationship between GABA levels and hypocotyl elongation in soybean seedlings was analyzed using different approaches to regulate in vivo GABA levels and the elongation of hypocotyls. The following major observations were made. (1) Mechanical stimulation by stroking elevated GABA levels and concurrently induced a rapid and significant reduction in hypocotyl elongation. (2) External GABA was demonstrated to penetrate into the hypocotyls using '*C-GABA. Application of external GABA elevated in vivo GABA levels, but failed to inhibit hypocotyl elongation. (3) LaCla and blue light irradiation caused an inhibition in the elongation of dark-grown hypocotyls, whereas GABA levels were not significantly affected. (4) Ca^was suggested to be involved in the signal transduction pathway leading from mechanical stimulation to GABA production, as indicated by the ability of La'* to inhibit GABA production in stimulated hypocotyls. (5) Bicuculline, saclofen and baclofen (agonists and antagonists of GABA receptors in animals) had no effect on hypocotyl elongation. It might indicate that GABA-binding components which are structurally similar to animal GABA receptors and functionally capable of regulating plant growth may not exist in plants. Therefore, the conclusion was drawn that GABA alone is not sufficient to inhibit hypocotyl elongation. Third, chloride influx in isolated Asparagus cells was enhanced by lOmM GABA during a 3 hour incubation, but the effect was not specific for GABA. Chloride efflux was not influenced by GABA. Both influx and efflux of chloride were significantly inhibited by NPPB, a chloride channel blocker. These results suggest that GABA does not influence the activity of plant chloride channels.

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This thesis tested a path model of the relationships of reasons for drinking and reasons for limiting drinking with consumption of alcohol and drinking problems. It was hypothesized that reasons for drinking would be composed of positively and negatively reinforcing reasons, and that reasons for limiting drinking would be composed of personal and social reasons. Problem drinking was operationalized as consisting of two factors, consumption and drinking problems, with a positive relationship between the two. It was predicted that positively and negatively reinforcing reasons for drinking would be associated with heavier consumption and, in turn, more drinking problems, through level of consumption. Negatively reinforcing reasons were also predicted to be associated with drinking problems directly, independent of level of consumption. It was hypothesized that reasons for limiting drinking would be associated with lower levels of consumption and would be related to fewer drinking problems, through level of consumption. Finally, among women, reasons for limiting drinking were expected to be associated with drinking problems directly, independent of level of consumption. The sample, was taken from the second phase of the Niagara Young Aduh Health Study, a community sample of young adult men and women. Measurement models of reasons for drinking, reasons for limiting drinking, and problem drinking were tested using Confirmatory Factor Analysis. After adequate fit of each measurement model was obtained, the complete structural model, with all hypothesized paths, was tested for goodness of fit. Cross-group equality constraints were imposed on all models to test for gender differences. The results provided evidence supporting the hypothesized structure of reasons for drinking and problem drinking. A single factor model of reasons for limiting drinking was used in the analyses because a two-factor model was inadequate. Support was obtained for the structural model. For example, the resuhs revealed independent influences of Positively Reinforcing Reasons for Drinking, Negatively Reinforcing Reasons for Drinking, and Reasons for Limiting Drinking on consumption. In addition. Negatively Reinforcing Reasons helped to account for Drinking Problems independent of the amount of alcohol consumed. Although an additional path from Reasons for Limiting Drinking to Drinking Problems was hypothesized for women, it was of marginal significance and did not improve the model's fit. As a result, no sex differences in the model were found. This may be a result of the convergence of drinking patterns for men and women. Furthermore, it is suggested that gender differences may only be found in clinical samples of problem drinkers, where the relative level of consumption for women and men is similar.

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I will argue that the doctrine of eternal recurrence of the same no better interprets cosmology than pink elephants interpret zoology. I will also argue that the eternal-reiurn-of-the-same doctrine as what Magnus calls "existential imperative" is without possibility of application and thus futile. To facilitate those arguments, the validity of the doctrine of the eternal recurrence of the same will be tested under distinct rubrics. Although each rubric will stand alone, one per chapter, as an evaluation of some specific aspect of eternal recurrence, the rubric sequence has been selected to accommodate the identification of what I shall be calling logic abridgments. The conclusions to be extracted from each rubric are grouped under the heading CONCLUSION and appear immediately following rubric ten. Then, or if, at the end of a rubric a reader is inclined to wonder which rubric or topic is next, and why, the answer can be found at the top of the following page. The question is usually answered in the very first sentence, but always answered in the first paragraph. The first rubric has been placed in order by chronological entitlement in that it deals with the evolution of the idea of eternal recurrence from the time of the ancient Greeks to Nietzsche's August, 1881 inspiration. This much-recommended technique is also known as starting at the beginning. Rubric 1 also deals with 20th. Century philosophers' assessments of the relationship between Nietzsche and ancient Greek thought. The only experience of E-R, Zarathustra's mountain vision, is second only because it sets the scene alluded to in following rubrics. The third rubric explores .ii?.ih T jc,i -I'w Nietzsche's evaluation of rationality so that his thought processes will be understood appropriately. The actual mechanism of E-R is tested in rubric four...The scientific proof Nietzsche assembled in support of E-R is assessed by contemporary philosophers in rubric five. E-R's function as an ethical imperative is debated in rubrics six and seven.. .The extent to which E-R fulfills its purpose in overcoming nihilism is measured against the comfort assured by major world religions in rubric eight. Whether E-R also serves as a redemption for revenge is questioned in rubric nine. Rubric ten assures that E-R refers to return of the identically same and not merely the similar. In addition to assemblage and evaluation of all ten rubrics, at the end of each rubric a brief recapitulation of its principal points concludes the chapter. In this essay I will assess the theoretical conditions under which the doctrine cannot be applicable and will show what contradictions and inconsistencies follow if the doctrine is taken to be operable. Harold Alderman in his book Nietzsche's Gift wrote, the "doctrine of eternal recurrence gives us a problem not in Platonic cosmology, but in Socratic selfreflection." ^ I will illustrate that the recurrence doctrine's cosmogony is unworkable and that if it were workable, it would negate self-reflection on the grounds that selfreflection cannot find its cause in eternal recurrence of the same. Thus, when the cosmology is shown to be impossible, any expected ensuing results or benefits will be rendered also impossible. The so-called "heaviest burden" will be exposed as complex, engrossing "what if speculations deserving no linkings to reality. To identify ^Alderman p. 84 abridgments of logic, contradictions and inconsistencies in Nietzsche's doctrine of eternal recurrence of the same, I. will examine the subject under the following schedule. In Chapter 1 the ancient origins of recurrence theories will be introduced. ..This chapter is intended to establish the boundaries within which the subsequent chapters, except Chapter 10, will be confined. Chapter 2, Zarathustra's vision of E-R, assesses the sections of Thus Spoke Zarathustra in which the phenomenon of recurrence of the same is reported. ..Nihilism as a psychological difficulty is introduced in this rubric, but that subject will be studied in detail in Chapter 8. In Chapter 2 the symbols of eternal recurrence of the same will be considered. Whether the recurrence image should be of a closed ring or as a coil will be of significance in many sections of my essay. I will argue that neither symbolic configuration can accommodate Nietzsche's supposed intention. Chapter 3 defends the description of E-R given by Zarathustra. Chapter 4, the cosmological mechanics of E-R, speculates on the seriousness with which Nietzsche might have intended the doctrine of eternal recurrence to be taken. My essay reports, and then assesses, the argument of those who suppose the doctrine to have been merely exploratory musings by Nietzsche on cosmological hypotheses...The cosmogony of E-R is examined. In Chapter 5, cosmological proofs tested, the proofs for Nietzsche's doctrine of return of the same are evaluated. This chapter features the position taken by Martin ' Heidegger. My essay suggests that while Heidegger's argument that recurrence of the same is a genuine cosmic agenda is admirable, it is not at all persuasive. Chapter 6, E-R is an ethical imperative, is in essence the reporting of a debate between two scholars regarding the possibility of an imperative in the doctrine of recurrence. Their debate polarizes the arguments I intend to develop. Chapter 7, does E-R of the same preclude alteration of attitudes, is a continuation of the debate presented in Chapter 6 with the focus shifted to the psychological from the cosmological aspects of eternal recurrence of the same. Chapter 8, Can E-R Overcome Nihilism?, is divided into two parts. In the first, nihilism as it applies to Nietzsche's theory is discussed. ..In part 2, the broader consequences, sources and definitions of nihilism are outlined. My essay argues that Nietzsche's doctrine is more nihilistic than are the world's major religions. Chapter 9, Is E-R a redemption for revenge?, examines the suggestion extracted from Thus Spoke Zarathustra that the doctrine of eternal recurrence is intended, among other purposes, as a redemption for mankind from the destructiveness of revenge. Chapter 10, E-R of the similar refuted, analyses a position that an element of chance can influence the doctrine of recurrence. This view appears to allow, not for recurrence of the same, but recurrence of the similar. A summary will recount briefly the various significant logic abridgments, contradictions, and inconsistencies associated with Nietzsche's doctrine of eternal recurrence of the same. In the 'conclusion' section of my essay my own opinions and observations will be assembled from the body of the essay.

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The strength of adolescents' moral identity was examined in relation to their sense of social responsibility, frequency of community engagement, and interactions with parents and friends. Participants were 191 applicants to national youth conferences, ranging in age from 14-19, who completed a 40-minute survey. 76% of the participants were female. Social responsibility, community engagement, and discussion with parents and friends were measured using self-report questionnaires. Participants also reported on the importance of various values to themselves, their parents, and their friends, which were used to create an index of the degree of disagreement between the youth and their parents and friends. In addition, participants provided self-descriptions, which were used to measure moral identity with both a coding scheme and a ratings measure. Moral identity as measured by coding was not related to social responsibility, community engagement, or any other study variables, and thus did not appear to be a valid measure of moral identity. However, moral identity as measured by ratings was related to both social responsibility and community engagement, and thus appeared to be a valid measure. Neither disagreement nor discussion with friends was related to moral identity. However, disagreement with parents was positively related to moral identity ratings, and for girls only was negatively related to social responsibility. Furthermore, discussion with parents was positively related to moral identity for boys only. The hypothesis predicting a mediational model was not supported. Results were discussed in terms of theoretical positions on the role of parents and friends in children's moral development and suggestions for ftiture research were made.

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Beliefs about the rightness or wrongness of engaging in various antisocial acts, referred to here as nonnative beliefs legitimizing antisocial behaviour (nblab), have been shown to playa role in the emergence oflater antisocial behaviour. The current study represented an attempt to understand whether parental monitoring and parent-child attachment have differential relationships with these antisocial nonnative beliefs in adolescents of different temperaments. The participants, 7135 adolescents in 25 high schools (ages 10- 18 years, M = 15.7) completed a wide-ranging questionnaire as part of the broad Youth Lifestyle Choices - Community University Research Alliance project, whose goal is to identify and describe the major developmental pathways of risk behaviours and resilience in youth. Two aspects of monitoring (monitoring knowledge and surveillance/tracking), attachment security, and two measures of temperament (activity level and approach) were examined for main effects and in interactions as predictors of adolescent nonnative beliefs. All of these measures were based on adolescent self-ratings on either 3- or 4-point Likert-type scales. Several important results emerged from the study. Males were higher than females in nblab; parental monitoring knowledge and adolescent attachment security were negatively related to nblab; and temperamental activity level was positively related. Monitoring knowledge, the strongest of the predictors, was much more strongly related to nonnative beliefs than was parental surveillance/tracking, supporting the contention that it is how much parents actually know, and not their surveillance efforts, that predict adolescent nonnative beliefs. A surprising finding that is of the utmost importance was that, although several of the interactions tested were significant, none were considered to be of a meaningful magnitude (defined as sr^ > .01). The current study supported the suggestion that normative beliefs legitimizing antisocial behaviour are multiply determined, and the results were discussed with respect to the observed differential relations of parental monitoring, parent-child attachment, temperament, age, and gender to antisocial normative beliefs in adolescents. Also discussed were the need to test other parenting, temperament, and other variables that may be involved in the development of nblab; the need to directly test possible mechanisms explaining the links among the variables; and the usefulness of longitudinal research in determining possible directions of causality and developmental changes in the relationships.

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The primary purpose of this study was to develop a questionnaire that assesses both forgiveness-seeking motives and behaviours. This questionnaire was based on the premise that, following the commitment of an offense in the context of a relationship, a perpetrator will be motivated to reduce the damage that has taken place. The . ' questionnaire examined several motives that a perpetrator might have for seeking forgiveness. These motives were divided into five proposed domains of posttransgression concerns: God, Self, Victim, Others/Society, and Relationship. Within these domains, the following more specific types of concern were explored: Avoidance of punishment, concern about public image, emotional well-being, self-image, sense of fairness/justice, loss of relationship, loss or gain of power, and loss of ability to trust. The questionnaire also assessed which behaviours (approach and avoidance) a perpetrator might use in order to address these concerns. In addition, this study explored whether or not the severity of the situation and the personality of the perpetrator influenced post transgression motives and behaviours. Participants were 221 individuals from the community and Brock University. They filled out a questionnaire package that assessed personality traits, social desirability, and forgiveness-seeking motives and behaviours. In order to answer items assessing motives and behaviours, participants were asked to imagine themselves as perpetrators in three hypothetical transgression scenarios. These scenarios ranged in severity fi^om low to high. Participants were asked to rate their motives and behaviours both in an immediate time frame (immediately following the transgression) and in the long-term (in order to move on from the situation). Results indicated that the motivation items could be classified into the following subscales:Concern about God, Damaged Self-worth Concerns, Justice Concerns, Impression Management Concerns, Victim and Others Concerns, and Relationship Concerns. The behaviour items formed the following subscales: Approach, Avoidance, Denial and Hiding, and Groveling. Results also indicated differences in motivations and behaviours based on the severity of the situation as well as the personality (assessed using the HEXACO inventory) of the perpetrator.

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This thesis explores the debate and issues regarding the status of visual ;,iferellces in the optical writings of Rene Descartes, George Berkeley and James 1. Gibson. It gathers arguments from across their works and synthesizes an account of visual depthperception that accurately reflects the larger, metaphysical implications of their philosophical theories. Chapters 1 and 2 address the Cartesian and Berkelean theories of depth-perception, respectively. For Descartes and Berkeley the debate can be put in the following way: How is it possible that we experience objects as appearing outside of us, at various distances, if objects appear inside of us, in the representations of the individual's mind? Thus, the Descartes-Berkeley component of the debate takes place exclusively within a representationalist setting. Representational theories of depthperception are rooted in the scientific discovery that objects project a merely twodimensional patchwork of forms on the retina. I call this the "flat image" problem. This poses the problem of depth in terms of a difference between two- and three-dimensional orders (i.e., a gap to be bridged by one inferential procedure or another). Chapter 3 addresses Gibson's ecological response to the debate. Gibson argues that the perceiver cannot be flattened out into a passive, two-dimensional sensory surface. Perception is possible precisely because the body and the environment already have depth. Accordingly, the problem cannot be reduced to a gap between two- and threedimensional givens, a gap crossed with a projective geometry. The crucial difference is not one of a dimensional degree. Chapter 3 explores this theme and attempts to excavate the empirical and philosophical suppositions that lead Descartes and Berkeley to their respective theories of indirect perception. Gibson argues that the notion of visual inference, which is necessary to substantiate representational theories of indirect perception, is highly problematic. To elucidate this point, the thesis steps into the representationalist tradition, in order to show that problems that arise within it demand a tum toward Gibson's information-based doctrine of ecological specificity (which is to say, the theory of direct perception). Chapter 3 concludes with a careful examination of Gibsonian affordallces as the sole objects of direct perceptual experience. The final section provides an account of affordances that locates the moving, perceiving body at the heart of the experience of depth; an experience which emerges in the dynamical structures that cross the body and the world.

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Career identity exploration is a central component of the lives of undergraduate university students. Although students are encouraged to explore, it is unclear whether different methods of exploration are better suited for certain individuals. In the present study, quantitative data were collected to examine the relationship between shyness and various methods of exploration. Two hundred fifty-seven university undergraduate students (29 male), ranging in age from 17-25 years completed a 60-minute self-report questionnaire. Shyness, identity, identity distress, subjective dimensions of exploration (satisfaction with exploration, reasons for not exploring, helpfulness of exploration methods), foci of exploration (non-social, social, self, and environmental), approaches to exploration (breadth, depth), and moderating variables (social support, sociability) were measured. Shyness was positively correlated with moratorium (high exploration, low commitment) and uncorrelated with the other identity statuses. Shyness was also positively correlated with identity distress, and a predicted interaction between shyness and identity diffusion predicting career identity distress was supported. Shyness was negatively correlated with satisfaction with amount of exploration engaged in to-date. In addition, shyness was correlated with the likelihood of selecting too stressful and too anxiety provoking as reasons for engaging in less exploration than one would like. Expected relationships between shyness and beliefs about, and engagement in, various methods of exploration were largely non-significant. Exceptions to this were the negative correlations between shyness and engagement in social exploration, and beliefs about the helpfulness of social self-exploration, both of which were significant at a trend level. A predicted interaction between shyness and social support predicting total social exploration was supported, showing that high social support buffers the negative relationship between shyness and exploration; such a moderating relationship did not exist, however, between sociability, shyness and social exploration. Results suggest that although shy university students are engaged in career exploration, they are experiencing feelings of distress and dissatisfaction with their career identity exploration and development. Thus, to help shy students become successfiil in their exploration, it is important for counsellors, family members, and peers to be aware of the feelings the individuals are experiencing and help them reduce the anxiety and stress associated with the exploration process. One promising method, supported by the results in this study, is by encouraging shy individuals to explore with social support.

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Kierkegaardian Intersubjectivity and the Question of Ethics and Responsibility By Kevin Krumrei. Kierkegaard's contributions to philosophy are generally admitted and recognized as valuable in the history of Western philosophy, both as one of the great anti-Hegelians, as the founder (arguably) of existentialism, and as a religious thinker. However valid this may be, there is similarly a generally admitted critique of Kierkegaard in the Western tradition, that Kierkegaard's philosophy of the development of the self leads the individual into an isolated encounter with God, to the abandonment of the social context. In other words, a Kierkegaardian theory of intersubjectivity is a contradiction in terms. This is voiced eloquently by Emmanuel Levinas, among others. However, Levinas' own intersubjective ethics bears a striking resemblance to Kierkegaard's, with respect to the description and formulation of the basic problem for ethics: the problem of aesthetic egoism. Further, both Kierkegaard and Levinas follow similar paths in responding to the problem, from Kierkegaard's reduplication in Works of Love, to Levinas' notion of substitution in Otherwise than Being. In this comparison, it becomes evident that Levinas' reading of Kierkegaard is mistaken, for Kierkegaard's intersubjective ethics postulates, in fact, the inseparability and necessity of the self s responsible relation to others in the self s relation to God, found in the command, "you shall love your neighbour as yourself."

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This study's objective was to examine how thirteen year-old females perceive and describe their lived experiences of being physically active in school PE (physical education) and organized youth sport settings through a self-determination theory (Deci & Ryan, 1985) lens. Motivational factors and links between both settings were discussed with five participants using in-depth interviews. Participants discussed factors that facilitated and disrupted their motivation to be active in PE and sport settings. The selfdetermination theory was used as a framework in this qualitative study and results are based on participants' own words and perspectives. Results indicate that participants' positive experiences in school PE and organized sport have the potential to meet their needs of autonomy, competence and relatedness. The autonomy supportive behaviours of social agents, feeling challenged and successful at activities and the strong relationships formed in both settings are all things that motivated young people in this study to continue being physically active throughout high-school and into adulthood.

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Abstract: Nietzsche's Will-to-Power Ontology: An Interpretation of Beyond Good and Evil § 36 By: Mark Minuk Will-to-power is the central component of Nietzsche's philosophy, and passage 36 of Beyond Good and Evil is essential to coming to an understanding of it. 1 argue for and defend the thesis that will-to-power constitutes Nietzsche's ontology, and offer a new understanding of what that means. Nietzsche's ontology can be talked about as though it were a traditional substance ontology (i.e., a world made up of forces; a duality of conflicting forces described as 'towards which' and 'away from which'). However, 1 argue that what defines this ontology is an understanding of valuation as ontologically fundamental—^the basis of interpretation, and from which a substance ontology emerges. In the second chapter, I explain Nietzsche's ontology, as reflected in this passage, through a discussion of Heidegger's two ontological categories in Being and Time (readiness-to-hand, and present-at-hand). In a nutshell, it means that the world of our desires and passions (the most basic of which is for power) is ontologically more fundamental than the material world, or any other interpretation, which is to say, the material world emerges out of a world of our desires and passions. In the first chapter, I address the problematic form of the passage reflected in the first sentence. The passage is in a hypothetical style makes no claim to positive knowledge or truth, and, superficially, looks like Schopenhaurian position for the metaphysics of the will, which Nietzsche rejects. 1 argue that the hypothetical form of the passage is a matter of style, namely, the style of a free-spirit for whom the question of truth is reframed as a question of values. In the third and final chapter, 1 address the charge that Nietzsche's interpretation is a conscious anthropomorphic projection. 1 suggest that the charge rests on a distinction (between nature and man) that Nietzsche rejects. I also address the problem of the causality of the will for Nietzsche, by suggesting that an alternative, perspectival form of causality is possible.

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Based on a critical analysis of recent Canadian and British media, academic, and political representations of rave, in conjunction with the author's and ten female interviewees' past experiences as active rave participants, the purpose of this thesis is to show the ways that rave can be understood as political. Drawing on a post-structural understanding of politics, which understands macro social issues and micro personal experiences as intimately linked and inseparable, this thesis fills a gap in the existing rave literature by explicitly drawing out (a) the ways that active rave participation is entangled in dominant understandings of age and gender-appropriate activities, and (b) the implications that these entanglements have on the ways that some women experience and construct their past active rave participation. Specifically, the author examines the ways that age and gender intersect and inform the discourses on which research participants drew to describe and rationalize their experiences of becoming, being, and ceasing to be active rave participants in Toronto, Ontario, Canada. At the same time that the majority of research participants' introductions to rave followed heterosexualized and heternormative patterns, they also constructed active rave participation as a way to challenge popular representations of rave as an inappropriate activity, especially for young women. When rationalizing the cessation of their active rave participation, however, these women reproduced depictions of rave participation as a transitory and juvenile phase where older women are particularly misplaced. The various ways that these women simultaneously challenged, experienced, and facilitated dominant ageist and patriarchal discourses about who does and does belong in rave are interpreted as evidence that micro rave experiences cannot be divorced from macro discriminatory discourses, and that "the personal is political."

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The purpose of this study was to identify factors related to successful university course completion for students with disAbilities including the knowledge that faculty members and students with disAbilities have about accommodation issues; the accommodations that students with disAbilities and faculty use and find effective in the university setting; faculty members' perceptions of and attitudes toward students with disAbilities; and the attitudes that students with disAbilities have toward faculty. Fiftyseven participants were involved in the research, eight students with disabilities and forty-nine faculty members. The main objective of the research was to describe how the skills, knowledge, and attitudes of students and faculty members, and organizational supports interact to support students' academic success. The utilization and effectiveness of accommodations to overcome barriers associated with disAbility in a post-secondary setting are described in relation to students' and faculty members' perceptions of academic success.