The development of the negative ion source constitutes a crucial step in the construction of the neutral beam injector of ITER. To fulfil the ITER requirements in terms of heating and current drive, the negative ion source should deliver 40 A of D-. The achievement of such a source is challenging from technical and scientific points, and it requires a deeper understanding of the underlying physics. The present knowledge of the ion extraction mechanism from the negative ion source is limited due to the complexity of the problem that involves the comprehension of the behaviour of magnetized plasma sheaths when negative ions and electrons are pulled out from the plasma. Moreover, due to the asymmetry induced by the crossed magnetic configuration used to filter the electrons, any realistic study of this problem must consider the three spatial dimensions. To address this problem in a realistic way, a 3D Particles-in-Cell electrostatic code specifically designed for this system was developed. The code uses Cartesian coordinate system and it can deal with complex boundary geometry as it is the case of the extraction apertures. The complex magnetic field that is applied to deflect electrons is also taken into account. This code, called ONIX, was used to investigate the plasma properties and the transport of negative ions and electrons close to a source extraction aperture. Results on the formation of the plasma meniscus and the screening of the extraction field by the plasma are presented here, as well as negative ions trajectories. Negative ion extraction efficiency from volume and surfaces was investigated showing the capital importance of the surface negative ion production.

The self-regulation of exercise for the purposes of disease prevention and rehabilitation is a complex process that includes temporary lapses from exercise adherence. Research is lacking in the understanding of the cognitive experiences associated with lapsing and the impact of possible negative thoughts, emotions, and self-evaluations on future exercise self-regulation. Using a Social Cognitive Theory (SCT) framework, the primary purpose of the present experimental study was to examine the impact of potential negative reactions to exercise lapse experiences on exercise self-regulatory cognitions (i.e., decisional struggle, exercise self-regulatory efficacy, action planning, and willingness to self-regulate) using an experimental message designed to induce negative thoughts and affect about exercise lapsing. A secondary purpose of the study was to examine the potential moderating influences of the relatively unexplored construct of emotional self-efficacy on possible negative reactions. Forty-four adult participants were recruited from two exercise therapy programs run by the local health region to participate in this study. Participants filled out baseline measures of demographics, exercise self-regulatory efficacy (exercise SRE), and emotional self-efficacy at the first meeting. At the second meeting, participants were randomly assigned to read either an information control message or a negative lapse message. After reading the message, participants responded to affect measures and recorded their acute exercise thoughts. Next, self-regulatory cognitions were measured including decisional struggle, exercise SRE, action planning, and willingness to self-regulate. There were no significant differences between experimental groups on any of the measures, F(9, 34) = .80, Wilks ë = .825, p = .619. Possible explanations for these nonsignificant results are discussed. Given the opportunity to compare the present results to past research on acute positive and negative exercise thoughts by Gyurcsik and colleagues, and to potentially extend these findings to a population of exercise therapy maintainers, post hoc analysis of related research questions was carried out. Groups of positive and negative thinkers were formed based on the measure of acute thoughts. The omnibus MANOVA comparing positive and negative thinkers on social-cognitive measures was significant, F(8, 31) = 2.72, Wilks ë = .588, p = .021. As hypothesized, positive thinkers were found to have higher positive affect (p = .03), lower decisional struggle (p = .006), higher exercise SRE (p = .013), and higher willingness to self-regulate (p = .003). Positive thinkers also exercised more frequently than negative thinkers both at the program, F(1, 36) = 9.5, p = .004, and independently, F(1, 36) = 5.4, p = .026. Results are discussed in relation to SCT and past research on acute exercise thoughts. Limitations of the original experiment are discussed in terms of the negative lapse message. Future research is discussed both for the study of negative reactions to lapsing and for positive and negative thinking related to exercise.

The self-regulation of exercise for the purposes of disease prevention and rehabilitation is a complex process that includes temporary lapses from exercise adherence. Research is lacking in the understanding of the cognitive experiences associated with lapsing and the impact of possible negative thoughts, emotions, and self-evaluations on future exercise self-regulation. Using a Social Cognitive Theory (SCT) framework, the primary purpose of the present experimental study was to examine the impact of potential negative reactions to exercise lapse experiences on exercise self-regulatory cognitions (i.e., decisional struggle, exercise self-regulatory efficacy, action planning, and willingness to self-regulate) using an experimental message designed to induce negative thoughts and affect about exercise lapsing. A secondary purpose of the study was to examine the potential moderating influences of the relatively unexplored construct of emotional self-efficacy on possible negative reactions. Forty-four adult participants were recruited from two exercise therapy programs run by the local health region to participate in this study. Participants filled out baseline measures of demographics, exercise self-regulatory efficacy (exercise SRE), and emotional self-efficacy at the first meeting. At the second meeting, participants were randomly assigned to read either an information control message or a negative lapse message. After reading the message, participants responded to affect measures and recorded their acute exercise thoughts. Next, self-regulatory cognitions were measured including decisional struggle, exercise SRE, action planning, and willingness to self-regulate. There were no significant differences between experimental groups on any of the measures, F(9, 34) = .80, Wilks ë = .825, p = .619. Possible explanations for these nonsignificant results are discussed. Given the opportunity to compare the present results to past research on acute positive and negative exercise thoughts by Gyurcsik and colleagues, and to potentially extend these findings to a population of exercise therapy maintainers, post hoc analysis of related research questions was carried out. Groups of positive and negative thinkers were formed based on the measure of acute thoughts. The omnibus MANOVA comparing positive and negative thinkers on social-cognitive measures was significant, F(8, 31) = 2.72, Wilks ë = .588, p = .021. As hypothesized, positive thinkers were found to have higher positive affect (p = .03), lower decisional struggle (p = .006), higher exercise SRE (p = .013), and higher willingness to self-regulate (p = .003). Positive thinkers also exercised more frequently than negative thinkers both at the program, F(1, 36) = 9.5, p = .004, and independently, F(1, 36) = 5.4, p = .026. Results are discussed in relation to SCT and past research on acute exercise thoughts. Limitations of the original experiment are discussed in terms of the negative lapse message. Future research is discussed both for the study of negative reactions to lapsing and for positive and negative thinking related to exercise.

This thesis analyzes some aspects of electromagnetic wave propagation in double negative materials. Double negative materials have negative refractive indices. They are backward-wave materials. Plane waves undergo negative refraction at interfaces between double positive and double negative media. Causality principle implies these properties. High frequency plane wave scattering from a double negative infinitely long cylinder has been analyzed by using modified Watson transform, geometrical optics and Mie series. Mie series results and the modified Watson transform results have been found to be in good agreement. Hence, the physical mechanism of the scattering has been revealed.

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Universiẗat, Diss.--Dortmund, 2006.

Depression is one of the most common psychological disorders and may be considered as one of the most prevalent forms of emotional/psychological illness among children. The prevalence of depressive disorders tends to rise dramatically during adolescence. Cognitive diathesis-stress models maintain that depression is produced through an interaction between cognitive vulnerability and negative life events. According to Beck, core beliefs are at the core of cognitive vulnerability. After the occurrence of a negative life event, the core belief is activated and influences how the individual interprets the negative life event. Beck maintains that three core beliefs are central to the development and maintenance of depressive disorders: the belief that one is helpless, unlovable, and/or worthless. The purpose of this study was to investigate whether a coding system for a storytelling task could reliably assess Beck’s core beliefs. In doing so, this study sought to build upon previous research on the relations between negative life events, core beliefs, and depressive symptomatology among pre- and early adolescent females. Participants were 130 girls ranging in age from 9 to 14. All girls completed a self-report measure of life events and a projective story-telling measure that was used to assess their core beliefs. Participants also completed a semi-structured diagnostic interview, which served as the primary measure of depressive symptom severity. In support of previous research, both negative life events and negative core beliefs uniquely predicted the severity of depressive symptoms. Consistent with Beck’s cognitive model, the helpless and unlovable core beliefs uniquely predicted severity of depressive symptoms, although the worthless core belief did not. Further examination indicated that the helpless core belief was a more powerful influence on depressive symptoms than were the unlovable and worthless core beliefs. Contrary to Beck’s diathesis-stress model, however, negative core beliefs did not moderate the effects of negative life events on depressive symptomatology. For girls aged 9-11, however, a helpless core belief moderated the effects of negative life events on depressive symptom severity. Implications of these results, limitations, and future directions for research are discussed. / text

国立情報学研究所で電子化したコンテンツを使用している。

INTRODUÇÃO: o câncer de mama é uma doença heterogênea. Há necessidade de critérios diagnósticos e prognósticos mais refinados. O emprego da imunohistoquímica, através do painel prognóstico, fez despontar a figura do carcinoma triplonegativo e, da mesma forma, a histogenética trouxe à evidência o carcinoma basal. Paralelamente, o conhecimento sobre a origem biológica das neoplasias e da sua heterogeneidade vem sendo acentuadamente debatido através do tema das células-tronco tumorais. OBJETIVOS: investigar a prevalência de carcinomas basais e pentanegativos, numa amostra de carcinomas triplonegativos, e estabelecer associações com a expressão de células-tronco tumorais nestes tumores. Verificar diferenças entre estes subtipos com as variáveis clinicopatológicas. MÉTODOS: 94 carcinomas mamários triplonegativos foram testados para CK5/6, HER1, CD44 e CD24. As expressões desses marcadores por imuno-histoquímica automatizada foram avaliadas através de escore simples de positividade (porcentagem de células) e correlacionadas com os dados clínico-patológicos e análise de sobrevivência. RESULTADOS: carcinomas basais apresentam maior grau tumoral que carcinomas pentanegativos (p=0,004). A negatividade para CD44 (p=0,007) e o perfil CD44- CD24+ (p=0,013) foram associados com maior invasão vascular entre carcinomas triplonegativos. A expressão de CD44 foi associada aos carcinomas basais (p=0,007). O perfil CD44-CD24-/low foi associado aos carcinomas pentanegativos (p=0,04). Nenhuma das variáveis em estudo foi associada com os desfechos clínicos. CONCLUSÃO: Carcinomas mamários basais e pentanegativos são subtipos tumorais bastante próximos. Nosso estudo é o primeiro desenhado especificamente para avaliar a presença células tronco-tumorais mamárias entre carcinomas basais e pentanegativos, onde o perfil CD44-CD24-/low foi associado ao subtipo pentanegativo, e o perfil CD44-CD24+ à invasão vascular, resultados que merecem confirmação por histogenética em estudos de maior porte. / INTRODUCTION: Breast cancer is a heterogeneous disease, and there is a need for more refined diagnostic and prognostic criteria. Immunohistochemistry, as a breast prognostic panel, has given rise to triple-negative carcinoma, as well as histogenetics highlighted basal carcinoma. Concomitantly, the understanding of the biological origins of neoplasia and its heterogeneity has been strongly debated through the theme of cancer stem cells. OBJECTIVES: To investigate the prevalence of basal and penta-negative carcinomas in a sample of triple-negative carcinomas and to establish associations with cancer stem cells (CD44/CD24 expression profiles) and the clinicopathological variables within these tumors. METHODS: Ninety-four triplenegative breast carcinomas were tested for CK5/6, HER1, CD44 and CD24. The expression of these markers was evaluated by automated immunohistochemistry using a simple positivity score (percentage of cells) and was correlated with the clinicopathological and survival analysis data. RESULTS: Basal carcinomas had higher tumor grades than penta-negative carcinomas (p=0.004). CD44 negativity (p=0.007) and the CD44-CD24+ phenotype (p=0.013) were associated with increased vascular invasion amongst the triple-negative carcinomas. CD44 expression was associated with basal carcinomas (p=0.007). The CD44-CD24-/low phenotype was associated with penta-negative carcinomas. None of the variables in the study were associated with clinical outcome. CONCLUSION: Basal and penta-negative breast carcinomas are closely related tumor subtypes. Our study is the first to be specifically designed to assess the presence of breast cancer stem cells in basal and pentanegative carcinomas. The CD44-CD24-/low phenotype was associated with the pentanegative subtype, and the CD44-CD24+ phenotype was associated with vascular invasion. These results require histogenetic confirmation in larger studies.

INTRODUÇÃO: o câncer de mama é uma doença heterogênea. Há necessidade de critérios diagnósticos e prognósticos mais refinados. O emprego da imunohistoquímica, através do painel prognóstico, fez despontar a figura do carcinoma triplonegativo e, da mesma forma, a histogenética trouxe à evidência o carcinoma basal. Paralelamente, o conhecimento sobre a origem biológica das neoplasias e da sua heterogeneidade vem sendo acentuadamente debatido através do tema das células-tronco tumorais. OBJETIVOS: investigar a prevalência de carcinomas basais e pentanegativos, numa amostra de carcinomas triplonegativos, e estabelecer associações com a expressão de células-tronco tumorais nestes tumores. Verificar diferenças entre estes subtipos com as variáveis clinicopatológicas. MÉTODOS: 94 carcinomas mamários triplonegativos foram testados para CK5/6, HER1, CD44 e CD24. As expressões desses marcadores por imuno-histoquímica automatizada foram avaliadas através de escore simples de positividade (porcentagem de células) e correlacionadas com os dados clínico-patológicos e análise de sobrevivência. RESULTADOS: carcinomas basais apresentam maior grau tumoral que carcinomas pentanegativos (p=0,004). A negatividade para CD44 (p=0,007) e o perfil CD44- CD24+ (p=0,013) foram associados com maior invasão vascular entre carcinomas triplonegativos. A expressão de CD44 foi associada aos carcinomas basais (p=0,007). O perfil CD44-CD24-/low foi associado aos carcinomas pentanegativos (p=0,04). Nenhuma das variáveis em estudo foi associada com os desfechos clínicos. CONCLUSÃO: Carcinomas mamários basais e pentanegativos são subtipos tumorais bastante próximos. Nosso estudo é o primeiro desenhado especificamente para avaliar a presença células tronco-tumorais mamárias entre carcinomas basais e pentanegativos, onde o perfil CD44-CD24-/low foi associado ao subtipo pentanegativo, e o perfil CD44-CD24+ à invasão vascular, resultados que merecem confirmação por histogenética em estudos de maior porte. / INTRODUCTION: Breast cancer is a heterogeneous disease, and there is a need for more refined diagnostic and prognostic criteria. Immunohistochemistry, as a breast prognostic panel, has given rise to triple-negative carcinoma, as well as histogenetics highlighted basal carcinoma. Concomitantly, the understanding of the biological origins of neoplasia and its heterogeneity has been strongly debated through the theme of cancer stem cells. OBJECTIVES: To investigate the prevalence of basal and penta-negative carcinomas in a sample of triple-negative carcinomas and to establish associations with cancer stem cells (CD44/CD24 expression profiles) and the clinicopathological variables within these tumors. METHODS: Ninety-four triplenegative breast carcinomas were tested for CK5/6, HER1, CD44 and CD24. The expression of these markers was evaluated by automated immunohistochemistry using a simple positivity score (percentage of cells) and was correlated with the clinicopathological and survival analysis data. RESULTS: Basal carcinomas had higher tumor grades than penta-negative carcinomas (p=0.004). CD44 negativity (p=0.007) and the CD44-CD24+ phenotype (p=0.013) were associated with increased vascular invasion amongst the triple-negative carcinomas. CD44 expression was associated with basal carcinomas (p=0.007). The CD44-CD24-/low phenotype was associated with penta-negative carcinomas. None of the variables in the study were associated with clinical outcome. CONCLUSION: Basal and penta-negative breast carcinomas are closely related tumor subtypes. Our study is the first to be specifically designed to assess the presence of breast cancer stem cells in basal and pentanegative carcinomas. The CD44-CD24-/low phenotype was associated with the pentanegative subtype, and the CD44-CD24+ phenotype was associated with vascular invasion. These results require histogenetic confirmation in larger studies.