Centrality measures in network analysis have become a popular measurement tool for identifying coherent nodes within a network. In the context of stock markets, the centrality measure helps to identify key performing ele- ments and strengths for specific stocks and determine their impact on disrupting market value and performance. Multiple studies presented practical implementations of centrality measures for determining trends and perform- ance of a particular market. However, fewer studies applied centrality measures to predict trends in the stock market.

Orientador: Arthur Magon Whitacker / Banca: Doralice Sátyro Maia / Banca: Everaldo Santos Melazzo / Resumo: Discutir a dinâmica da centralidade urbana em São Luís de ontem e de hoje foi a questão norteadora da dissertação. De ontem, a partir da espacialização das atividades de comércio e serviços em dois marcos histórico-geográficos, buscando a formação, sustentação ou fragmentação da centralidade urbana no centro da cidade. E de hoje, com a tentativa de identificação de determinantes históricas e econômicas que comparecem no recorte analítico do núcleo da área central ou o core, definida por sua diferenciação no conjunto da cidade pela concentração do capital produtivo e que torna visível a predominância dos equipamentos urbanos públicos e privados de gestão ou controle, a forte especialização do uso do solo para as atividades de comércio e serviços, a convergência da fluidez de produtos, informações e dos transportes. Desse modo, o objetivo desta dissertação é contribuir para análise da produção do espaço urbano de São Luís, articulando a formação histórica da centralidade urbana aos processos espaciais determinantes, a partir da distribuição das atividades de comércio e serviços, identificando no uso do solo urbano suas tendências, tendo como foco o núcleo da área central. Trabalhamos com bancos de dados da Delegacia da Receita Previdenciária em São Luís, da Associação Comercial do Maranhão e do Cadastro Empresarial do SEBRAE, em São Luís - MA... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The main question of this dissertation was to discuss the dynamics of urban centrality in São Luis yesterday and today. From yesterday, starting from the spatial distribution of trade activities and services in two historical and geographical landmarks, formation, support, fragmentation or even degradation of urban centrality in the city center was searched. And today, in an attempt to identify historical and economic factors that show up in the analytical approach of the core area which is defined by its differentiation throughout the city by the concentration of productive capital that makes the predominance of public and private urban equipments of either management or control, the strong specialization of land use for trade activities and services, the convergence of products and information flow and transport visible. This way, the objective of this study is to contribute to the analysis of the spatial configuration of São Luis, by articulating the historical formation of the urban centrality to the spatial processes determinants, from the distribution of trade activities and services, identifying the urban land use trends, focusing on the core area. We have worked with the database of the Social Welfare Department in São Luis, the Commercial Association of Maranhão... (Complete abstract click electronic access below) / Mestre

Made available in DSpace on 2014-06-11T19:28:25Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-11-27Bitstream added on 2014-06-13T19:57:47Z : No. of bitstreams: 1 garcez_kmg_me_prud.pdf: 8405180 bytes, checksum: b43309b40aa432c21d2d8b45c32e0298 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Discutir a dinâmica da centralidade urbana em São Luís de ontem e de hoje foi a questão norteadora da dissertação. De ontem, a partir da espacialização das atividades de comércio e serviços em dois marcos histórico-geográficos, buscando a formação, sustentação ou fragmentação da centralidade urbana no centro da cidade. E de hoje, com a tentativa de identificação de determinantes históricas e econômicas que comparecem no recorte analítico do núcleo da área central ou o core, definida por sua diferenciação no conjunto da cidade pela concentração do capital produtivo e que torna visível a predominância dos equipamentos urbanos públicos e privados de gestão ou controle, a forte especialização do uso do solo para as atividades de comércio e serviços, a convergência da fluidez de produtos, informações e dos transportes. Desse modo, o objetivo desta dissertação é contribuir para análise da produção do espaço urbano de São Luís, articulando a formação histórica da centralidade urbana aos processos espaciais determinantes, a partir da distribuição das atividades de comércio e serviços, identificando no uso do solo urbano suas tendências, tendo como foco o núcleo da área central. Trabalhamos com bancos de dados da Delegacia da Receita Previdenciária em São Luís, da Associação Comercial do Maranhão e do Cadastro Empresarial do SEBRAE, em São Luís – MA... / The main question of this dissertation was to discuss the dynamics of urban centrality in São Luis yesterday and today. From yesterday, starting from the spatial distribution of trade activities and services in two historical and geographical landmarks, formation, support, fragmentation or even degradation of urban centrality in the city center was searched. And today, in an attempt to identify historical and economic factors that show up in the analytical approach of the core area which is defined by its differentiation throughout the city by the concentration of productive capital that makes the predominance of public and private urban equipments of either management or control, the strong specialization of land use for trade activities and services, the convergence of products and information flow and transport visible. This way, the objective of this study is to contribute to the analysis of the spatial configuration of São Luis, by articulating the historical formation of the urban centrality to the spatial processes determinants, from the distribution of trade activities and services, identifying the urban land use trends, focusing on the core area. We have worked with the database of the Social Welfare Department in São Luis, the Commercial Association of Maranhão... (Complete abstract click electronic access below)

Despite strong evidence supporting the existence of posttraumatic growth (PTG), some investigators question whether the construct measured by the Posttraumatic Growth Inventory (PTGI) is that of perceived growth or “actual” growth. In a replication of a recent investigation, the present study sought to refine the methodology used by employing the construct of event centrality. Due to its limited sample size, the results of this analysis did not provide strong evidence in support of the hypothesis that limiting analyses to individuals rating their trauma as high in event centrality improves the ability of the PTGI to reflect “actual” growth. However, results did support the idea that investigations of PTG conducted immediately following a trauma may be more reflective of a coping process, rather than growth. Further research is warranted to investigate the role of event centrality in posttraumatic growth, and the effect of time on the progression of growth following trauma.

The thesis focuses on the social web and on the analysis of social networks with particular emphasis on their temporal aspects. Social networks are represented here by Time Varying Graphs (TVG), a general model for dynamic graphs borrowed from distributed computing. In the first part of the thesis we focus on the temporal aspects of social networks. We develop various temporal centrality measures for TVGs including betweenness, closeness, and eigenvector centralities, which are well known in the context of static graphs. Unfortunately the computational complexities of these temporal centrality metrics are not comparable with their static counterparts. For example, the computation of betweenness becomes intractable in the dynamic setting. For this reason, approximation techniques will also be considered. We apply these temporal measures to two very different datasets, one in the context of knowledge mobilization in a small community of university researchers, the other in the context of Facebook commenting activities among a large number of web users. In both settings, we perform a temporal analysis so to understand the importance of the temporal factors in the dynamics of those networks and to detect nodes that act as “accelerators”. In the second part of the thesis, we focus on a more standard static graph representation. We conduct a propagation study on YouTube datasets to understand and compare the propagation dynamics of two different types of users: subscribers and friends. Finally, we conclude the thesis with the proposal of a general framework to present, in a comprehensive model, the influence of the social web on e-commerce decision making.

Computational modeling is of fundamental significance in mapping possible disease spread, and designing strategies for its mitigation. Conventional contact networks implement the simulation of interactions as random occurrences, presenting public health bodies with a difficult trade off between a realistic model granularity and robust design of intervention strategies. Recently, researchers have been investigating the use of agent-based models (ABMs) to embrace the complexity of real world interactions. At the same time, theoretical approaches provide epidemiologists with general optimization models in which demographics are intrinsically simplified. The emerging study of affiliation networks and co-affiliation networks provide an alternative to such trade off. Co-affiliation networks maintain the realism innate to ABMs while reducing the complexity of contact networks into distinctively smaller k-partite graphs, were each partition represent a dimension of the social model. This dissertation studies the optimization of intervention strategies for infectious diseases, mainly distributed in school systems. First, concepts of synthetic populations and affiliation networks are extended to propose a modified algorithm for the synthetic reconstruction of populations. Second, the definition of multi-coaffiliation networks is presented as the main social model in which risk is quantified and evaluated, thereby obtaining vulnerability indications for each school in the system. Finally, maximization of the mitigation coverage and minimization of the overall cost of intervention strategies are proposed and compared, based on centrality measures.

The contemporary era is witnessing a systemic transition in the Canadian science and research paradigm. The research world is shrinking rapidly in response to modern technological developments, commercial and regulatory integration, faster communications and transportation and proactive science, technology and innovation policy. It is increasingly challenging to make competitive progress in world-class innovation or to gain global leadership in science. Big-science is now proposed as one of the means to realize national innovation goals and international competitiveness. As a result, government support for large-scale innovation projects has increased multifold. This dissertation examines a range of hypotheses large-scale research projects enhance investigator exchanges and generate social capital that has significant downstream benefits, which would provide a reason to support big science beyond the instrumental goals of the projects themselves. Taking Genome Canada as an example, this dissertation examines the production and role of social capital generated through large-scale research projects to assess the evidence base for funding big science research. A group of 139 investigators who raised capital in the Genome Canada Applied Bioproducts and Crops (ABC) Competition in 2009 are examined in the context of their engagements and networks in 2000-2009 in four relational arenas, namely their area of expertise, institutional connections, research grants, and co-publications. The investigation reveals three main findings. First, large-scale innovation projects as delivered through Genome Canada, comply with the fundamentals of contemporary innovation network theory. Second, the ties amongst investigators generate social capital, which offers positional advantage and differential superior access to networked resources. Third, the social capital generated in actor relations has pronounced long term impacts on downstream research success. Inter-disciplinary and cross-institutional large-scale research projects that have strong elements of knowledge production and financial exchange are found to assist the federal government in advancing research and innovation objectives. The results of the current investigation provide a strong rationale for the integration of people, disciplines, and institutions under the umbrella of large-scale genomics and proteomics research, and possible lessons for other research fields.

Narrative frameworks provide a unique method for understanding how important events and relationships become central to individual identity. Informed by these frameworks, the Centrality of Event Scale (CES; Berntsen & Rubin, 2006) serves as a means to quantify the extent to which a specific event has become central to personal identity. Utilizing the CES, Berntsen and Rubin and colleagues demonstrate the strong link between central traumatic events and psychopathology. Despite this work, however, far less literature explicates the factors that lead to growth and adaptive functioning. In order to address this limitation across the literature, a modified version of Berntsen and Rubin's CES was created in order to assess the importance of close positive social relationships to identity. Data were collected from 255 individuals from undergraduate psychology courses at Southern Illinois University Carbondale. Specifically, it was hypothesized that the component structure of the Centrality of Event Scale modified for social relationships (CESpr) would be commensurate with Berntsen and Rubin's original scale, and it would predict several measures of adaptive functioning. Furthermore, it was hypothesized that positive relational centrality would predict these measures of adaptive functioning, even after controlling for positive event centrality and social support. Congruent with Berntsen and Rubin's original CES, the CESpr yielded a one-component solution, and correlated with several measures of adaptive functioning. Furthermore, after controlling for positive event centrality and social support, positive relational centrality significantly predicted positive affect, resilience, gratitude, and post-traumatic growth. Results of the current study suggest increased personal meaning and relevance attributed to close positive social relationships is indicative of increased adaptive functioning. These findings are consistent with narrative conceptualizations of the self, which suggest that central events and relationships affect the functioning of the individual. Implications and future directions are discussed.

Made available in DSpace on 2014-06-11T19:28:26Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-06-15Bitstream added on 2014-06-13T19:47:58Z : No. of bitstreams: 1 ajonas_acs_me_prud.pdf: 6412772 bytes, checksum: 52e4b20b57c669edee7acf10db0b6c8c (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Secretaria de Estado da Educação / Essa pesquisa teve como objetivo realizar uma análise do processo de reestruturação urbana, enfatizando as mudaças geradas na centralidade urbana. Para isso, tomamos como recorte territorial o município de Itu – SP. Desse modo, buscamos compreender as transformações que se processam na área central do município de Itu e que podem ser observadas na relação entre as formas herdadas e as novas dinâmicas que lhe são impostas pelo desenvolvimento econômico, pela expansão de seu tecido urbano e pelo crescimento populacional. Essas novas dinâmicas modificam o centro, atribuindo-lhe novos conteúdos, identificáveis, entre outros, pela intensificação de seus fluxos, implicando em novas centralidades. Com isso, gera-se o descompasso entre formas e funções no centro histórico. Procuramos apreender essas transformações indentificando suas conseqüências no plano da morfologia urbana, por meio da criação de novas centralidades. Para o desenvolvimento dessa pesquisa, priorizamos o enfoque econômico, por meio de análise das empresas existentes em nossa área de estudo. Os dados evidenciaram aspectos do centro que permitiram um maior entendimento de sua dinâmica e estrutura, bem como o conteúdo informacional existente nas novas centralidades que se configuram. / This research had the objective to achieve an analyze of the restructuring urban process, emphasizing the changes generated in the centrality urban. For this, we assumed as territories bound the Itu municipality – SP. This way, we tried to understand the changes that occurs in the central area of the Itu municipality and it can be observed in the relation between the inherited forms and the new dynamics which are attributed for the economic development, for the urban tissue’s expansion and for the population increase. These new dynamics change the center, attributing to it new contents, identified, among others, for the intensification of its flows, resulting in news centralities. So, generate itself the incompatibility between forms and functions in the historical center. We tried to apprehend these changes identifying its consequences in the urban morphology’s plane, through the creation of news centralities. For this research’s development, we priorited the economic point, through the analyze of the companies existent in our study area. The datuns evidenced centre’s aspects that allowed a greater understanding of its dynamic and structure, as well as the informational content existent in the new centralities that configures itself.

Alzheimer’s disease (AD) patients could benefit from a more effective treatment than the current FDA-approved options. Because amyloid-beta (Aβ) is thought to play a central role in AD pathogenesis, many experimental drugs attempt to reduce Aβ-induced pathology. Preventing amyloid accumulation may be a more effective strategy than clearing Aβ plaques after they form. If preventing Aβ accumulation can treat or prevent AD, then understanding Aβ primary nucleation may aid rational drug design. This study examines Aβ residue interaction networks and reports network and structural observations that may provide insight into primary nucleation. While many studies identify structural features of Aβ that promote aggregation, this study reports features that may resist primary nucleation by examining Aβ42 studies in more and less polar solvents. In Aβ42 in a less polar solvent (PDB ID: 1IYT), Val24 and Ile31 have higher betweenness and residue centrality values. This may be due to a predicted interaction between Val24 and Ile31. Residues in the central hydrophobic cluster (CHC) of Aβ40 and Aβ42 had significantly higher betweenness values compared to the average betweenness of the structures, highlighting the CHC’s reported role in oligomerization. The predicted interaction between Val24 and Ile31 may reduce the likelihood of primary nucleation of Aβ.