444 research outputs found
Produtos infinitos
TCC (graduação) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas, Curso de Matemática.Este trabalho foi feito para dar aos alunos da graduação uma oportunidade de conhecer um pouco sobre Produtos Infinitos, já que este assunto não é estudado nas disciplinas de cálculo. Ao fazer uma pesquisa sobre P.I., vimos que existe uma grande dificuldade de encontrar livros de cálculo que tratam deste assunto. Alguns deles citam poucos exemplos, mas não trazem nenhuma explicação a mais. Um levantamento histórico também foi feito no inicio deste trabalho, mas nada foi achado. Alem do livro citado na bibliografia, do qual foi tirada toda a parte teórica, alguns artigos tirados da Internet ajudaram a complementar este trabalho. Enfim, diante da dificuldade de achar material para este trabalho, tudo o queconseguimos é de grande importância
Role of c-Jun NH-terminal Kinase in Bcr/Abl Induced Cell Transformation: a dissertation
The c-Jun NH2-terminal kinase (JNK) group of kinases include ten members that are created by alternative splicing of transcripts derived from Jnk1, Jnk2 and Jnk3 genes. The JNK1 and JNK2 protein kinases are ubiquitously expressed while JNK3 is expressed in a limited number of tissues. The JNK signaling pathway is implicated in multiple physiological processes including cell transformation. There is growing evidence that JNK signaling is involved in oncogenesis. Nevertheless, the role that JNK plays in malignant transformation is still unclear. The aim of this thesis is to examine the role of JNK in malignant transformation. For this purpose, I used the Bcr/Abl oncogene as a transforming agent. Bcr/Abl is a leukemogenic oncogene that is created by reciprocal translocation between chromosome 9 and 22. The translocation breakpoint is variable and several different Bcr/Abl isoforms have been identified such as Bcr/AblP185 and Bcr/AblP210, whose expression is associated with different types of leukemia. Bcr/Abl activates the JNK signaling pathway in hematopoietic cells and increases AP-1 transcription activity. Furthermore, dominant negative approaches demonstrate that inhibition of c-Jun or JNK prevents Bcr/ Abl-induced cell transformation in vitro. These data implicate the JNK signaling pathway in Bcr/Abl transformation although the role that JNK might have in this process is unclear. Thus, I examined the importance of JNK signaling in Bcr/Abl-induced lymphoid or myeloid transformation. For this purpose I compared Bcr/AblP185- and Bcr/AblP210- induced transformation of wild-type and JNK1-deficient cells using three approaches: in vitro, in vivo and ex vivo. The results obtained with the in vitro approach suggest that both Bcr/AblP185 and Bcr/AblP210 require JNK activity to induce lymphoid transformation. While JNK1-deficiency inhibits Bcr/AblP210 oncogenic potential in lymphoid cells both in vitro and in vivo, pharmacological inhibition of JNK activity (JNK1 and/or JNK2) blocked Bcr/AblP185 induced malignant proliferation in vitro. The differential requirement for JNK observed in the two Bcr/Abl isoforms can be ascribed to the presence in Bcr/AblP210 of the Dbl domain which can activate the JNK pathway in vitro. In the case of Bcr/AblP210, JNK1 is critical for the survival of the ex vivo derived transformed lymphoblasts upon growth factor removal. This result correlates with the fact that mice reconstituted with Bcr/AblP210 transformed Jnk1-l- bone marrow showed normal malignant lymphoid expansion in the bone marrow yet they had reduced numbers of lymphoblast in the bloodstream and lacked peripheral organ infiltration. Thus JNK1 is essential for the survival of the transformed lymphoblast outside the bone marrow microenvironment in Bcr/AblP210induced lymphoid leukemia. Interestingly, while JNK1 is essential for lymphoid transformation, it is dispensable for the proliferation of transformed myeloblasts.
Taken together these results indicate that the JNK signaling pathway plays an essential role in the survival of Bcr/AblP210 lymphoblasts and that JNK-deficiency decreases the leukomogenic potential of Bcr/AblP210 in vivo. Thus, cell survival mediated by JNK may contribute to the pathogenesis of proliferative diseases
Perceived and actual level of knowledge of diabetes among medical-surgical nurses
The purpose of this study was three fold: To survey the level of perceived and actual knowledge of diabetes mellitus among medical-surgical nurses, to investigate the relationship of perceived to actual knowledge of diabetes, and to identify factors that affect nurses\u27 level of perceived and actual knowledge of diabetes mellitus. Tools used to gather data were the Demographic Data Sheet (DDS), Diabetes Self-Report Tool (DSRT), and Diabetes Basic Knowledge Test (DBKT). The DSRT measured the perceived knowledge of medical surgical nurses. The DSRT revealed a mean score of 67.5 points indicating that the subjects had a moderately high level of perception regarding their knowledge of diabetes. The actual knowledge level of diabetes was measured by the DBKT. A mean score of 66% demonstrated that nurses had less than an adequate level of knowledge of diabetes. A Pearson\u27s Correlation indicated that there was a positive relationship between the subjects\u27 perceived and actual level of knowledge. Multiple Regression statistics on variables obtained from the DDS indicated that reading literature affected the subjects perception while no significant factors were found to affect their actual level of knowledge. (Abstract shortened by UMI.)
Collaboration within a curriculum of support in the classroom: occupational therapists' and educators' perceptions and experiences
Introduction: According to South Africa's key education policies, all children can learn and need support, necessitating collaboration between occupational therapists and educators. Collaboration between occupational therapists and educators within the classroom is however a relatively new practice in South Africa and there is a dearth of literature that report on studies in this regard. The aim of this study was thus to explore occupational therapists' and educators' experiences in adopting a classroom approach in three primary mainstream schools in the Metro North education district in the Western Cape. Methodology: A qualitative research approach andexploratory descriptive design was utilised. Data collection included semi-structured interviews and focus groups with educators and occupational therapists who participated in the curriculum of support in the classroom programme. Thematic data analysis was conducted. Findings: Three themes highlighting the meaning and value the participants assigned to classroom collaboration, andfactors that facilitate or limit the implementation of the curriculum of support emerged from the analysis. Conclusion: The study is useful in expanding the understanding of the changing role of occupational therapists within the context of inclusive education and contributes to the development of educator support strategies utilising the whole classroom approach. This approach entails the educator and occupational therapist working together in implementing activities in the classroom to all learners. These learning activities are based on curriculum themes and occupational therapy principles and components. IMPLICATIONS FOR PRACTICE Occupational therapists' roles in the education practice context are expanding from traditionally working in special school settings to providing support to educators within public mainstream schools. The role of the occupational therapist within public mainstream schools is evolving from a consultative role and providing input into the individual support of learners to providing hands-on support to educators and collaborating with them within the classroom
Crossing Boundaries: Organization Design Parameters Surrounding CDOs and Their Digital Transformation Activities
More and more companies are installing Chief Digital Officer (CDO) positions in order to support the progress of their digital transformation. Since the employment of CDOs may influence companies’ organizing logics, we conducted a multiple case study analysis to investigate the organization design parameters surrounding CDOs and their digital transformation activities. By examining the governance architectures in which the companies embed their CDOs (vertical dimension) and the horizontal coordination mechanisms utilized by CDOs (horizontal dimension), we shed light on two dimensions of companies’ organizing logics. Our results indicate that CDOs need sufficient influence in the organization to pursue transformation activities and that the vertical and horizontal dimensions of companies\u27 organizing logics are not independent of each other
Reserve Textbooks: To Buy, or Not to Buy?
There is convincing evidence that academic libraries are used less frequently for research than in the past, due to the advent of the Internet. This begs the question: what role does the current library have for students? It can be argued that we simply need to convince students and faculty of library viability, or, another route would be to give students what they are asking for. And textbooks, via course reserves, are what they request most at Grossmont College. Collection development policies typically contain some verbiage that equates to “the library does not collect textbooks, unless they are donated by faculty.” Grossmont College Library, however, recently reexamined its philosophical approach to reserves and refined its collection development policy and reserves policies and procedures as a result. The end product was a much more user-friendly, viable, and timely reserves collection that included onthe- spot service. Getting to that result was not without its challenges, however. Many policies and procedures had to be rethought and revised in tandem with these changes
The Influence of Local Food Environments on Adolescents\u27 Food Purchasing Behaviors
This study examined the relationship between the neighborhood food environment and the food purchasing behaviors among adolescents. Grade 7 and 8 students (n = 810) at 21 elementary schools in London, Ontario, Canada completed a questionnaire assessing their food purchasing behaviors. Parents of participants also completed a brief questionnaire providing residential address and demographic information. A Geographic Information System (GIS) was used to assess students\u27 home and school neighborhood food environment and land use characteristics. Logistic regression analysis was conducted to assess the influence of the home neighborhood food environment on students\u27 food purchasing behaviors, while two-level Hierarchical Non-Linear Regression Models were used to examine the effects of school neighborhood food environment factors on students\u27 food purchasing behaviors. The study showed that approximately 65% of participants reported self-purchasing foods from fast-food outlets or convenience stores. Close proximity (i.e., less than 1 km) to the nearest fast-food outlet or convenience store in the home neighborhood increased the likelihood of food purchasing from these food establishments at least once per week by adolescents (p \u3c 0.05). High fast-food outlet density in both home and school neighborhoods was associated with increased fast-food purchasing by adolescents (i.e., at least once per week; p \u3c 0.05). In conclusion, macro-level regulations and policies are required to amend the health-detracting neighborhood food environment surrounding children and youth\u27s home and school
Obesogenic Neighborhoods: The Impact of Neighborhood Restaurants and Convenience Stores on Adolescents\u27 Food Consumption Behaviors
To examine the relationship between the neighbourhood food environment and dietary intake among adolescents. Cross-sectional design using: (i) a geographic information system to assess characteristics of the neighbourhood food environment and neighbourhood socio-economic status; (ii) the modified Healthy Eating Index (HEI) to assess participants\u27 overall diet quality; and (iii) generalized linear models to examine associations between HEI and home and school food environmental correlates. Mid-sized Canadian city in Ontario, Canada. Participants Grade 7 and 8 students (n 810) at twenty-one elementary schools. Students living in neighbourhoods with a lower diversity of land-use types, compared with their higher diversity counterparts, had higher HEI scores (P \u3c 0.05). Students with more than 1 km between their home and the nearest convenience store had higher HEI scores than those living within 1 km (P \u3c 0.01). Students attending schools with a distance further than 1 km from the nearest convenience store (P \u3c 0.01) and fast-food outlet (P \u3c 0.05) had higher HEI scores than those within 1 km. Those attending schools with three or more fast-food outlets within 1 km had lower HEI scores than those attending schools with no fast-food outlet in the school surroundings (P \u3c 0.05). Close proximity to convenience stores in adolescents\u27 home environments is associated with low HEI scores. Within adolescents\u27 school environments, close proximity to convenience and fast-food outlets and a high density of fast-food outlets are associated with low HEI scores
The Influence of Local Food Environments on Adolescents’ Food Purchasing Behaviors
This study examined the relationship between the neighborhood food environment and the food purchasing behaviors among adolescents. Grade 7 and 8 students (n = 810) at 21 elementary schools in London, Ontario, Canada completed a questionnaire assessing their food purchasing behaviors. Parents of participants also completed a brief questionnaire providing residential address and demographic information. A Geographic Information System (GIS) was used to assess students’ home and school neighborhood food environment and land use characteristics. Logistic regression analysis was conducted to assess the influence of the home neighborhood food environment on students’ food purchasing behaviors, while two-level Hierarchical Non-Linear Regression Models were used to examine the effects of school neighborhood food environment factors on students’ food purchasing behaviors. The study showed that approximately 65% of participants reported self-purchasing foods from fast-food outlets or convenience stores. Close proximity (i.e., less than 1 km) to the nearest fast-food outlet or convenience store in the home neighborhood increased the likelihood of food purchasing from these food establishments at least once per week by adolescents (p < 0.05). High fast-food outlet density in both home and school neighborhoods was associated with increased fast-food purchasing by adolescents (i.e., at least once per week; p < 0.05). In conclusion, macro-level regulations and policies are required to amend the health-detracting neighborhood food environment surrounding children and youth’s home and school
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