68 resultados para Didactic investigation

em Brock University, Canada


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In 2002, The Ontario Federation of School Athletic Associations (OFSAA) identified that in providing extracurricular sport programs schools are faced with the 'new realities' of the education system. Although research has been conducted exploring the pressures impacting the provision of extracurricular school sport (Donnelly, Mcloy, Petherick, & Safai, 2000), few studies within the field have focused on understanding extracurricular school sport from an organizational level. The focus of this study was to examine the organizational design (structure, systems, and values) of the extracurricular sport department within three Ontario high schools, as well as to understand the context within which the departments exist. A qualitative multiple case study design was adopted and three public high schools were selected from one district school board in Ontario to represent the cases under investigation. Interviews, observations and documents were used to analyze the extracurricular sport department design of each case and to better understand the context within which the departments exist. As the result of the analysis of the structure, systems and values of each case, two designs emerged- Design KT1 and Design KT2. Differences in the characteristics of design archetype KT1 and KT2 centered on the design dimension of values, and therefore this study identified that contrasting organizational values reflect differences in design types. The characteristics of the Kitchen Table archetype were found to be transferable to the sub-sector of extracurricular school sport, and therefore this research provides a springboard for further research in organizational design within the education sector of extracurricular high school sport. Interconnections were found between the data associated with the external and internal contexts within which the extracurricular sport departments exist. The analysis of the internal context indicated the important role played by organizational members in shaping the context within which the departments exist. The analysis of the external context highlighted the institutional pressures that were present within the education environment. Both political and cultural expectations related to the role of extracurricular sport within schools were visible and were subsequently used by the high schools to create legitimacy and prestige, and to access resources.

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The purpose ofthis study was to investigate the emotion assumptions underlying just-world theory. This theory proposes that people have a need to believe in a just world - a world where people get what they deserve. The first emotion assumption is that people, therefore, find injustices (Le., undeserved outcomes) threatening and thus emotionally arousing. Second, it is this arousal that is assumed to drive subsequent strategies for maintaining the belief in a just world. One strategy an individual may use to maintain this belief is derogating victims of injustice, or seeing their character in a more negative light. To test these two assumptions, 102 participants viewed a video depicting either a victim who presumably presented a high threat to people's belief in ajust world (she was innocent and, therefore, undeserving of her fate) or low threat (she was not innocent and, therefore, more deserving of her fate) while their heart rate and EDA was measured. Half of the participants were then given the opportunity to help the victim whereas the other half were not given this opportunity. The manipulations were followed by both explicit and indirect measures of evaluations ofthe victim as well as self-report measures of affect experienced while watching the victim video, and an individual difference scale assessing the strength of participants' just-world beliefs (as well as other measures that were part ofa larger study). Results indicated that participants did report feeling more threatened by the innocent victim. Although there was some evidence of victim derogation on the implicit measure of victim evaluation, there was no evidence that emotional arousal drove the negative evaluations of the victim who could not be helped. Some interaction effects with individual differences in just-world beliefs did occur, but these were not entirely consistent with the rationale behind the individual difference scales. These results provide only weak support for the first emotion assumption ofjust-world theory. Implications of these findings as well as limitations of the study and future directions concerning just-world theory are discussed.

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The present study explored the connections among adolescents' sense of self, sexuality, and perceptions of risk. Such an exploration may help educators to further understand why adolescents engage in risk-taking behaviours such as unprotected sex. The study involved secondary analysis on the data collected from the Youth Lifestyle Choices - Community University Research Alliance 2000 (YLC - CURA) Youth Resilience Questionnaire (YRQ). Participants were 300 male and female students in Grades 9, 1 1 and OAC. Data analyses involved both descriptive and inferential statistics (correlational and multivariate analysis). Chi-square analyses were performed on the open-ended self-description question. Separate analyses were conducted on gender and age (grade levels). Correlational analyses revealed that adolescents with a more positive sense of self were more likely to perceive sexual involvement as a relatively high-risk behaviour. Specifically, results found that male adolescents were less likely than females to perceive sex to be risky. Results are discussed in relation to previous research in the area of selfcognitions and risk-taking sexual behaviour. Results are also discussed in terms of educational implications in that the current results may provide the beginnings of a framework for more holistic sexual education programs.

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The main objective of the present investigation was to continue the research initiated by Hay and colleagues (2004) in examining the efficacy of the Children's Self-Perceptions of Adequacy in and Predilection for Physical Activity (CSAPPA) scale as a proxy for the short form of the Bruininks-Oseretsky Test of Motor Proficiency (BOTMP-SF) in screening for Developmental Coordination Disorder (DCD) in children. To better appreciate DCD knowledge outside Canada, the measurements of this investigation were expanded in Greece. A translated Greek CSAPP A scale and the BOTMP-SF were administered for the first time in Greek children. A second objective was to investigate the relationship between DCD and various risk factors of coronary artery disease (CAD) in Canadian and Greek children. A sample of 591 (Ms=322; Fs=269) Canadian and 392 (Ms=211; Fs=181) Greek children, aged 9 to 13 years, consented to the BOTMP-SF, CSAPP A Scale, participation in physical activity questionnaire, Leger 20-meter Multistage Shuttle Run test, and body fat using bioelectric impedance. Prevalence of DCD in Canada and Greece was 8% and 19%, respectively. Significant agreement (p

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The cyanobacterium Synechococcus sp. PCC 7942 (Anacystis nidulans R2) adjusts its photosynthetic function by changing one of the polypeptides of photosystem II. This polypeptide, called Dl, is found in two forms in Synechococcus sp. PCC 7942. Changing the growth light conditions by increasing the light intensity to higher levels results in replacement of the original form of D 1 polypeptide, D 1: 1, with another form, D 1 :2. We investigated the role of these two polypeptides in two mutant strains, R2S2C3 (only Dl:l present) and R2Kl (only Dl:2 present) In cells with either high or low PSI/PSII. R2S2C3 cells had a lower amplitude for 77 K fluorescence emission at 695 nm than R2Kl cells. Picosecond fluorescence decay kinetics showed that R2S2C3 cells had shorter lifetimes than R2Kl cells. The lower yields and shorter lifetimes observed in the D 1 and Dl:2 containing cells. containing cells suggest that the presence of D 1: 1 results in more photochemical or non-photochemical quenching of excitation energy In PSII. One of the most likely mechanisms for the increased quenching in R2S2C3 cells could be an increased efficiency in the transfer of excitation energy from PSII to PSI. However, photophysical studies including 77 K fluorescence measurements and picosecond time resolved decay kinetics comparing low and high PSI/PSII cells did not support the hypothesis that D 1: 1 facilitates the dissipation of excess energy by energy transfer from PSII to PSI. In addition physiological studies of oxygen evolution measurements after photoinhibition treatments showed that the two mutant cells had no difference in their susceptibility to photoinhibition with either high PSI/PSII ratio or low PSI/PSII ratio. Again suggesting that, the energy transfer efficiency from PSII to PSI is likely not a factor in the differences between Dl:l and Dl:2 containing cells.

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The prlmaiy objective of this study was to Identify and describe the physical and psychological stress factors that elementary school teachers experience and how teachers cope with stress. A secondary objective was to offer boards and teachers potential coping strategies counteracting stress and the effects of stress. The sample consisted of 120 elementaiy teachers from southern Ontario. Ten elementaiy schools were randomly chosen. The Teacher Stress Inventory questionnaire (Flmian, 1989) was used. Data were analyzed using a variety of statistics. Test norms and interpretations were performed based on standard results obtained from the author of the questionnaire (Flmian, 1988). Overall, the results indicated that work-related stressors were the main factor for teacher stress. This Included such factors as caseload/class is too big, too much administrative paperwork, and having little time to prepare lessons. Implications for further research and practical suggestions for further reseairch are discussed. Also a variety of recommendations to boards and for individual use are discussed. Some recommendations are having counselling available for teachers, workshops on how to handle stress, and learning how to breathe and using calm visualization.

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The present study was a phenomenological investigation of adolescent constructs of stress and academic achievement. The study utilised a modified version of George Kelly's Repertory Grid Technique to provide direct insight into adolescent stress and academic achievement. The premise of the study was that only students who exhibited extreme cases of stress and academic achievement levels would be examined. The investigation identified and examined the adolescents who exhibited these extremes and explored the underlying constructs that defined these differences. It was expected that if adolescents were able to identify the stressors in their lives, how these stressors affect their lives, and how these stressors affect their academic performance, then suggestions could be made to help students to better cope with stress and to improve their academic achievement level. Further, based on the results of the study, the pedagogical implications for classroom research are provided. Phenomenological inquiries, using modified, and less complex versions of the repertory grid, can be conducted pre-, mid-, and postacademic terms, to determine and to monitor the stressors and the academic performance of the students in a classroom. Specific assessments for individual students will help teachers to better exercise their knowledge and understanding of the realm of teaching and learning strategies (e.g., Gardiner's Multiple Intelligences) that exist.

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The 5a-reductase of Penicillium decumbens ATCC 10436 was used as a model for the mammalian enzyme to investigate the mechanism of reduction of testosterone to 5adihydrotestosterone . The purpose of this study was to search for specific 5a-reductase inhibitors which antagonize prostate cancer . In a whole-cell biotransformation mode, this organism reduced testosterone (1) to 5a-dihydrosteroids (8) and 5aandrostane- 3, 17-dione (9) in yields of 28% and 37% respectively. Control experiments have shown that 5aandrostane- 3, 17-dione (9) can be produced from the corresponding alcohol (8) in a subsequent reaction separate from that catalysed by the 5a-reductase enzyme . Androst-4- ene-3, 17-dione (2) is reduced to give only (9) with a recovery of 80% The stereochemistry of the reduction was determined by 500 MHz ^H NMR analysis of the products resulting from the deuterium labelled substrates. The results were obtained by an analysis of the NOE difference spectra, double-quantum filtered phase sensitive COSY 2-D spectra, and ^^c-Ir 2-D shift correlation spectra of deuterium labelled products. According to the unambiguous assignment of the signals due to H-4a and H-4Ii in 5a-dihydro steroids, the NMR data show clearly that addition of hydrogen to the 4{5)K bond has occurred in a trans manner at positions 413 and 5a. To Study the reduction mechanism of this enzyme, several substrates were prepared as following; 3-methyleneandrost-4-en- 17fi-ol(3), androst-4-en-17i5-ol(5) , androst-4-en-3ii, 17fi-diol (6) and 4, 5ii-epoxyandrostane-3, 17-dione (7) . Results suggest that this enzyme system requires an oxygen atom at the 3-position of the steroid in order to bind the substrate. Furthermore, the mechanism of this 5a-reductase may proceed via direct addition of hydrogen at the 4,5 position without involvement of a carbonyl group as an intermediate.

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Epoxides can be hydrolyzed by fungi to produce chiral diols. The first part of this thesis presents an investigation of the microbial hydrolysis of aziridines comparable in structure to epoxide biotransformation substrates. Biotransformation of the aziridines 1 -methyl-2-phenyl aziridine, 2- phenylaziridine and N-methyl-7-aza bicyclo[4.1.0] heptane was studied using Beauveria sulfurescens, Aspergillus niger and Diplodia gossypina but no evidence for enzymic hydrolysis was obtained. The hydroxylation reaction performed by the fungus Beauveria sulfurescens ATCC 7159 has been studied for many years and several models describing the hydroxylating pattern exhibited by this fungus have been proposed. The second part of this thesis presents a test of the proposed models. The ability of Beauveria sulfurescens to hydroxylate thirty potential substrates was examined, and the data suggest that none of the earlier proposed models accounts for all of the bioconversion results. A possible explanation is proposed, suggesting that there is more than one enzyme responsible for the hydroxylation reactions performed by Beauveria sulfurescens.

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In the work reported here, optically clear, ultrathin TEOS derived sol-gel slides which were suitable for studies of tryptophan (Trp) fluorescence from entrapped proteins were prepared by the sol-gel technique and characterized. The monitoring of intrinsic protein fluorescence provided information about the structure and environment of the entrapped protein, and about the kinetics of the interaction between the entrapped protein and extemal reagents. Initial studies concentrated on the single Trp protein monellin which was entrapped into the sol-gel matrices. Two types of sol-gel slides, termed "wet aged", in which the gels were aged in buffer and "dry-aged", in which the gels were aged in air , were studied in order to compare the effect of the sol-gel matrix on the structure of the protein at different aging stages. Fluorescence results suggested that the mobility of solvent inside the slides was substantially reduced. The interaction of the entrapped protein with both neutral and charged species was examined and indicated response times on the order of minutes. In the case of the neutral species the kinetics were diffusion limited in solution, but were best described by a sum of first order rate constants when the reactions occurred in the glass matrix. For charged species, interactions between the analytes and the negatively charged glass matrix caused the reaction kinetics to become complex, with the overall reaction rate depending on both the type of aging and the charge on the analyte. The stability and conformational flexibility of the entrapped monellin were also studied. These studies indicated that the encapsulation of monellin into dry-aged monoliths caused the thermal unfolding transition to broaden and shift upward by 14°C, and causedthe long-term stability to improve by 12-fold (compared to solution). Chemical stability studies also showed a broader transition for the unfolding of the protein in dry-aged monoliths, and suggested that the protein was present in a distribution of environments. Results indicated that the entrapped proteins had a smaller range of conformational motions compared to proteins in solution, and that entrapped proteins were not able to unfold completely. The restriction of conformational motion, along with the increased structural order of the internal environment of the gels, likely resulted in the improvements in themial and long-term stability that were observed. A second protein which was also studied in this work is the metal binding protein rat oncomodulin. Initially, the unfolding behavior of this protein in aqueous solution was examined. Several single tryptophan mutants of the metal-binding protein rat oncomodulin (OM) were examined; F102W, Y57W, Y65W and the engineered protein CDOM33 which had all 12 residues of the CD loop replaced with a higher affinity binding loop. Both the thermal and the chemical stability were improved upon binding of metal ions with the order apo < Ca^^ < Tb^"^. During thermal denaturation, the transition midpoints (Tun) of Y65W appeared to be the lowest, followed by Y57W and F102W. The placement of the Trp residue in the F-helix in F102W apparently made the protein slightly more thermostable, although the fluorescence response was readily affected by chemical denaturants, which probably acted through the disruption of hydrogen bonds at the Cterminal end of the F-helix. Under both thermal and chemical denaturation, the engineered protein showed the highest stability. This indicated that increasing the number of metal ligating oxygens in the binding site, either by using a metal ion with a higher coordinatenumber (i.e. Tb^*) which binds more carboxylate ligands, or by providing more ligating groups, as in the CDOM33 replacement, produces notable improvements in protein stability. Y57W and CE)OM33 OM were chosen for further studies when encapsulated into sol-gel derived matrices. The kinetics of interaction of terbium with the entrapped proteins, the ability of the entrapped protein to binding terbium, as well as thermal stability of these two entrapped protein were compared with different levels of Ca^"*^ present in the matrix and in solution. Results suggested that for both of the proteins, the response time and the ability to bind terbium could be adjusted by adding excess calcium to the matrix before gelation. However, the less stable protein Y57W only retained at most 45% of its binding ability in solution while the more stable protein CDOM33 was able to retain 100% binding ability. Themially induced denaturation also suggested that CDOM33 showed similar stability to the protein in solution while Y57W was destabilized. All these results suggested that "hard" proteins (i.e. very stable) can easily survive the sol-gel encapsulation process, but "soft" proteins with lower thermodynamic stability may not be able to withstand the sol-gel process. However, it is possible to control many parameters in order to successfully entrap biological molecules into the sol-gel matrices with maxunum retention of activity.

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Recent dose-response sleep restriction studies, in which nightly sleep is curtailed to varying degrees (e.g., 3-, 5-, 7-hours), have found cumulative, dose-dependent changes in sleepiness, mood, and reaction time. However, brain activity has typically not been measured, and attentionbased tests employed tend to be simple (e.g., reaction time). One task addressing the behavioural and electrophysiological aspects of a specific attention mechanism is the Attentional Blink (AB), which shows that the report accuracy of a second target (T2) is impaired when it is presented soon after a first target (Tl). The aim of the present study was to examine behavioural and electrophysioiogical responses to the AB task to elucidate how sleep restriction impacts attentional capacity. Thirty-six young-adults spent four consecutive days and nights in a sleep laboratory where sleep, food, and activity were controlled. Nightly sleep began with a baseline sleep (8 hours), followed by two nights of sleep restriction (3,5 or 8 hours of sleep), and a recovery sleep (8 hours). An AB task was administered each day at 11 am. Results from a basic battery oftests (e.g., sleepiness, mood, reaction time) confirmed the effectiveness of the sleep restriction manipulation. In terms of the AB, baseline performance was typical (Le., T2 accuracy impaired when presented soon after Tl); however, no changes in any AB behavioural measures were observed following sleep restriction for the 3- or 5-hour groups. The only statistically significant electrophysiological result was a decrease in P300 amplitude (for Tl) from baseline to the second sleep restriction night for the 3-hour group. Therefore, following a brief, two night sleep restriction paradigm, brain functioning was impaired for the TI of the AB in the absence of behavioural deficit. Study limitations and future directions are discussed.

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Personality traits and personal values are two important domains of individual differences. Traits are enduring and distinguishable patterns of behaviour whereas values are societally taught, stable, individual preferences that guide behaviour in order to reach a specific end state. The purpose of the present study was to investigate the relations between self and peer report within the domains of personality traits and values, to examine the correlations between values and traits, and to explore the amount of incremental validity of traits and values in predicting behaviour. Two hundred and fiftytwo men and women from a university setting completed self and peer reports on three questionnaires. In order to assess personality traits, the HEXACO-PI (Lee & Ashton, 2004) was used to identify levels of 6 major dimensions of personality in participants. To assess values, the Schwartz Value Survey (Schwartz, 1992) was used to identify the importance each participant placed on each of Schwartz's 10 value types. To measure behaviour, a Behavior Scale, created by Bardi and Schwartz (2003), consisting of items designed to measure the frequency of value-expressive behaviour was used. As expected, correlations between self and peer reports for the personality scales were high indicating that personality traits are easily observable to other people. Correlations between self and peer reports for the values and behaviour scales were only moderate, suggesting that some goals, and behaviours expressive of those goals, may not always be observable to others. Consistent with previous research, there were many strong correlations between traits and values. In addition to the similarities with past research, the present study found that the personality factor Honesty-Humility was correlated strongly with values scales (with five correlations exceeding .25). In the prediction of behaviour, it was found that both personahty and values were able to account for significant and similar amounts of variance. Personality outpredicted values for some behaviours, but the opposite was true of other behaviours. Each domain provided incremental validity beyond the other domain. The impUcations for these findings, along with limitations, and possibilities for future research are also discussed.

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The human a-tocopherol transfer protein (h-a-TTP) is understood to be the entity responsible for the specific retention of a-tocopherol (a-toc) in human tissues over all other forms of vitamin E obtained from the diet. a-Tocopherol is the most biologically active form of vitamin E, and to date has been studied extensively with regard to its antioxidant properties and its role of terminating membrane lipid peroxidation chain reactions. However, information surrounding the distribution of a-tocopherol, specifically its delivery to intracellular membranes by a-TTP, is still unclear and the molecular factors influencing transfer remain elusive. To investigate the mechanism of ligand transfer by the h-a-TTP, a fluorescent analogue of a-toc has been used in the development of a fluorescence resonance energy transfer (FRET) assay. (/?)-2,5,7,8-tetramethyl-2-[9-(7-nitro-benzo[l,2,5]oxdiazol-4-ylamino)-nonyl]- chroman-6-ol (NBD-toc) has allowed for the development of the FRET-based ligand transfer assay. This ligand has been utilized in a series of experiments where changes were made to acceptor lipid membrane concentration and composition, as well as to the ionic strength and viscosity of the buffer medium. Such changes have yielded evidence supporting a collisional mechanism of ligand transfer by a-TTP, and have brought to light a new line of inquiry pertaining to the nature of the forces governing the collisional transfer interaction. Through elucidation of the transfer mechanism type, a deeper understanding of the transfer event and the in vivo fate of a-tocopherol have been obtained. Furthermore, the results presented here allow for a deeper investigation of the forces controlling the collisional protein-membrane interaction and their effect on the transfer of a-toc to membranes. Future investigation in this direction will raise the possibility of a complete understanding of the molecular events surrounding the distribution of a-toc within the cell and to the body's tissues.

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Growth rates of etiolated Avena sativa coleoptiles in pH 7.0 buffered medium are stimulated in a synergistic manner by IAA and 320 ~l/l carbon dioxide. The suggestion that carbon dioxide stimulated growth involves dark fixation is supported by the ability of 1 mM malate to replace carbon dioxide, with neither factor able to stimulate growth in the presence of the other (Bown, Dymock and Aung, 1974). The regulation of Avena coleoptile growth by ethylene has been investigated in the light of this data and the well documented antagonism between carbon dioxide and ethylene in the regulation of developmental processes. The influence of various permutations of ethylene, IAA, carbon dioxide and malate on the rates of growth, l4c-bicarbonate incorporation, l4C-bicarbonate fixation, and malate decarboxylation have been investigated. In the presence of 320 ~l/l carbon dioxide, 10.8 ~l/l ethylene inhibited growth both in the absence and presence of 20 ~M IAA with inhibition times, of 8-10 and 12-13 minutes respectively. In contrast ethylene inhibition of growth was not significant in the absence of growth stimulation by CO2 or 1 mM malate, and the normal growth increases in response to CO2 and malate were blocked by the simultaneous application of ethylene. The rates of incorporation and dark fixation of l4C-bicerbonate were not measurably. influenced by ethylene, IAA or malate, either prior to or during the changes in growth ,ates induced by these agents. The data does not support the hypothesis that ethylene inhibition of growth results from an inhibition of dark fixation, but suggests that ethylene may inhibit a process which is subsequent to fixation.