834 resultados para Age factors in disease.
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Teachers at local elementary and secondary schools were invited to participate in a survey research study by completing a questionnaire containing 26 statements regarding educational issues (e.g., "I am satisfied with the quality of my interactions with students."). Teachers were asked to indicate whether they agreed, were neutral, or disagreed with each statement; and further, to make a suggestions for appropriate change; to indicate a level at which the change could be implemented (classroom, school, board, ministry, society); and to indicate to what extent they perceive they have influence on change in the area represented in the statement. The responses of 50 elementary and 50 secondary teachers were randomly chosen from among the completed questionnaires and the information was recorded for analysis. Results of frequency counts of responses showed teachers were generally satisfied with their experiences of the areas referred to in the statements. Seventy-two percent of the responses agreed with the statements; 15% of the responses indicated disagreement, and 13% of the responses were neutral. Cross-tabulations of the survey data with demographic information showed differences among the responses of female and male teachers; elementary and secondary teachers; and teachers grouped according to their total years of teaching experience.
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The present research study examined the relationships in a work motivation context among perceived importance and achievement of work values, locus of control and internal work motivation. The congruence of a work value was considered to be the discrepancy between the importance of a work value and the perceived achievement of that value. The theoretical framework utilized was based on a self-perpetuating cycle of motivation which included the perceived importance and achievement of work values and internal work motivation as separate and distinct, yet interrelated factors. It was hypothesized that individuals who experienced high congruence of work values would experience higher levels of internal work motivation than individuals who had low congruence of work values. It was also hypothesized that individuals who had an internal locus of control would experience more internal work motivation individuals well, the and have higher congruence of work values than who had an external locus of control. As possibility of locus of control as a moderator between importance of work values and internal work motivation was explored. Survey data were collected from 184 managerial level employees of the XYZ company during an ongoing training session. The following instruments were employed to measure the variables: Elizur's (1984) Importance of Work Values, Hunt and Saul's (1985) Achievement of Work Values, Hatfield, Robinson and Huseman's (1975) Job Perception Scale, a modified version of Rotter's (1966) I-E Locus of Control Scale and the Internal Work Motivation Scale (Hackman & Oldham, 1980) which is a part of the Job Diagnostic Survey. The findings indicated that locus of control was not a significant factor in determining congruence between work values or internal work motivation for this sample. Furthermore, locus of control was also found not to be a moderator between the importance of work values and internal work motivation. All individuals in this study had relatively high levels of internal work motivation. However, individuals who had higher congruence of work values did have significantly higher internal work motivation than those who had low congruence of work values for a majority of the 21 values. This was particularly true for the intrinsic values which included responsibility, meaningfulness and use of abilities. In addition, the data were analysed into a hierarchy of needs to indicate possible organizational development or human resource development needs for the XYZ corporation.
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Student enrolment rates in optional health and physical education (HPE) classes have been steadily declining, to the point where most Ontario students stop taking HPE after completion of their one required credit, typically taken in grade nine. This study looked at factors that could contribute to HPE enrolment, sampling 227 grade ten students from five schools. These factors included selfefficacy (SE), perceived autonomy support (PAS), task value (TV), motivational regulation (autonomous, AR; controlled, CR), HPE grade average and body size discrepancy (BSD). Qualitative information was also gathered from students regarding likes and dislikes ofHPE, as well as reasons for their HPE enrolment choice. Cronbach Alpha values of each scale fell within acceptable values. ANOVA analysis revealed differences between enrolment groups in SE, TV, AR, HPE grade average, and BSD (p < .05). Reasons students reported for not taking HPE included a dislike of health classes, scheduling challenges, not needing HPE for future endeavors, concerns about social self-presentation, and a dislike of sports and/or competition. This research shows important differences between students and their HPE class choices and calls for a re-evaluation of how HPE classes are structured, advertised and scheduled by high school practitioners. Future works should look toward what other factors could be at play in students' decisions for or against optional HPE and how those factors interact with the constructs that were found to be of significance in this study. Keywords: Health and physical education, high school students, participation.
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Abstract The Relative Age Effect (RAE), defined as a skewed birth date distribution, has been identified as a known phenomenon in minor ice hockey. The purpose of this study was to investigate the relationship between the RAE, physical measurements, and skating ability/in-game performance in forty-four youth male ice hockey players competing in the same age cohort. Physical anthropometrics, grip strength, in-game performance and skating abilities were measured. An RAE was found in the sample (χ2(3, N = 44) = 12.18, p = 0.007). Players born in the first half of the age cohort had longer leg length (F(1,42) =4.49 , p = 0.04), larger body mass (F(1,42) = 3.90, p = 0.05), and stronger grip strength (F(1,42) = 7.58, p = 0.009). Performance scores were negatively associated with grip strength (r = -.443, p = 0.003). Findings suggest that adequate skill development can help relatively younger players overcome physical maturity disadvantages.
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L'assemblage des nucléosomes est étroitement couplée à la synthèse des histones ainsi qu’à la réplication et la réparation de l’ADN durant la phase S. Ce processus implique un mécanisme de contrôle qui contribue soigneusement et de manière régulée à l’assemblage de l’ADN en chromatine. L'assemblage des nucléosomes durant la synthèse de l’ADN est crucial et contribue ainsi au maintien de la stabilité génomique. Cette thèse décrit la caractérisation par spectrométrie de masse(SM) des protéines jouant un rôle critique dans l’assemblage et le maintien de la structure chromatinienne. Plus précisément, la phosphorylation de deux facteurs d’assemblage des nucléosome, le facteur CAF-1, une chaperone d’histone qui participe à l'assemblage de la chromatine spécifiquement couplée à la réplication de l'ADN, ainsi que le complexe protéique Hir, jouant de plus un rôle important dans la régulation transcriptionelle des gènes d’histones lors de la progression normale du cycle cellulaire et en réponse aux dommages de l'ADN, a été examiné. La caractérisation des sites de phosphorylation par SM nécéssite la séparation des protéines par éléctrophorèse suivi d’une coloration a l’argent. Dans le chapitre 2, nous demontrons que la coloration à l’argent induit un artéfact de sulfatation. Plus précisément, cet artéfact est causé par un réactif spécifiquement utilisé lors de la coloration. La sulfatation présente de fortes similitudes avec la phosphorylation. Ainsi, l’incrément de masse observé sur les peptides sulfatés et phosphorylés (+80 Da) nécéssite des instruments offrant une haute résolution et haute précision de masse pour différencier ces deux modifications. Dans les chapitres 3 et 4, nous avons d’abord démontré par SM que Cac1, la plus grande sous-unité du facteur CAF-1, est cible de plusieurs sites de phosphorylation. Fait intéréssant, certains de ces sites contiennent des séquences consensus pour les kinases Cdc7-Dbf4 et CDKs. Ainsi, ces résultats fournissent les premières évidences que CAF-1 est potentiellement régulé par ces deux kinases in vivo. La fonction de tous les sites de phosphorylation identifiés a ensuite été évaluée. Nous avons démontré que la phosphorylation de la Ser-503, un site consensus de la DDK, est essentielle à la répréssion transcriptionelle des gènes au niveau des télomères. Cependant, cette phosphorylation ne semble pas être nécéssaire pour d’autres fonctions connues de CAF-1, indiquant que le blocage de la phsophorylation de Cac1 Ser-503 affecte spécifiquement la fonction de CAF-1 aux structures hétérochromatiques des télomères. Ensuite, nous avons identifiés une intéraction physique entre CAF-1 et Cdc7-Dbf4. Des études in vitro ont également demontré que cette kinase phosphoryle spécifiquement Cac1 Ser-503, suggérant un rôle potential pour la kinase Cdc7-Dbf4 dans l’assemblage et la stabilité de la structure hétérochromatique aux télomères. Finalement, les analyses par SM nous ont également permi de montrer que la sous-unité Hpc2 du complexe Hir est phosphorylée sur plusieurs sites consensus des CDKs et de Cdc7-Dbf4. De plus, la quantification par SM d’un site spécifique de phosphorylation de Hpc2, la Ser-330, s’est révélée être fortement induite suite à l’activation du point de contrôle de réplication (le “checkpoint”) suite au dommage a l’ADN. Nous montrons que la Ser-330 de Hpc2 est phopshorylée par les kinases de point de contrôle de manière Mec1/Tel1- et Rad53-dépendante. Nos données préliminaires suggèrent ainsi que la capacité du complex Hir de réguler la répréssion transcriptionelle des gènes d'histones lors de la progression du cycle cellulaire normal et en réponse au dommage de l'ADN est médiée par la phosphorylation de Hpc2 par ces deux kinases. Enfin, ces deux études mettent en évidence l'importance de la spectrométrie de masse dans la caractérisation des sites de phosphorylation des protéines, nous permettant ainsi de comprendre plus précisement les mécanismes de régulation de l'assemblage de la chromatine et de la synthèse des histones.
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The influence of salinity on phytoplankton varies widely, because different species have different salinity preferences. Like marine and aquatic species, many phytoplankton species exhibit tolerance to certain salinity, beyond which, it can inhibit their growth. Light is the most important factor that influences phytoplankton growth. In aquatic environments (lakes, sea or estuary) the light incident on the surface is rapidly reduced exponentially with depth (Krik, 1994). In estuaries, the major factor influencing the light availability is the suspended particulate matter, which attenuates and scatters the light. The light changes with time of the day and the season, affecting the amount of light penetrating the water column. Similarly, biological factor like copepod grazing is a major factor influencing the standing crop of phytoplankton. The copepod can actively graze up to 75% of the phytoplankton biomass in a tropical estuary (Tan et. al., 2004). It is in the context that the present study investigates the salinity, light (physical factors) and copepod grazing (biological factor) phytoplankton as the factors controlling phytoplankton growth and distribution
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This paper discusses an ongoing project that aims at improving the potential for resilience of a system responsible for the planning of rail engineering work delivery. It focuses on the use of a human factors based approach as a way to achieve this end. In particular, the paper discusses the initial data collected by means of interviews and how this process gave way to a two fold goal: Understanding how the planning process works in reality and identifying any critical aspects of the system from a Resilience Engineering perspective. Given the nature of the process under study, information flows and communication issues have been given particular attention throughout the data collection and analysis stages. Initial data confirms that the planning process is greatly reliant on the capability of people using their knowledge and skills to communicate in a dynamic informational environment. Finally, the added value of the interviews is discussed from a human factors perspective and as a mean towards the aim of better understanding resilience in rail engineering planning.
Development, maturation, and necessity of transcription factors in the mouse suprachiasmatic nucleus