Análise de Redes Metabólicas foi aplicada à cepa de Saccharomyces cerevisiae CEN.PK113-7D, e a alguns mutantes interrompidos em genes que codificam para proteínas regulatórias envolvidas no fenômeno de repressão por glicose. Todas as cepas foram cultivadas em aerobiose, em meio mínimo contendo [1-13C]glicose como substrato limitante. As células eram recolhidas em situação de crescimento balanceado e submetidas à hidrólise, seguida de derivação e posterior injeção da amostra resultante num cromatógrafo gasoso acoplado a um espectrômetro de massa, para análise da marcação em alguns fragmentos de metabólitos intracelulares. Estes dados serviram como base para a identificação da atividade de algumas vias metabólicas no metabolismo central de S. cerevisiae. Além disto, utilizando-os juntamente com um modelo estequiométrico, foi possível obter uma estimativa para os fluxos no metabolismo central na cepa referência e nos mutantes estudados. Num primeiro momento, a metodologia foi validada para cultivos contínuos e descontínuos. Calculou-se um desvio padrão para a medida da marcação em cada fragmento de metabólito detectado pela metodologia empregada. Na cepa referência, observou-se que o ciclo de Krebs opera de forma cíclica em células que respiram e de forma não cíclica em células que apresentam metabolismo respiratório-fermentativo. Verificou-se que uma maior parte da glicose consumida é desviada para a via das pentoses fosfato no primeiro caso, em relação ao segundo. Foram encontradas evidências para a biossíntese de glicina através da enzima treonina aldolase e para a atividade da enzima málica. A ausência das proteínas Mig1 e Mig2 não altera os padrões de crescimento, produção de etanol e de marcação em metabólitos intracelulares de S. cerevisiae. Já a ausência de Hxk2, Reg1 ou Grr1 provoca alívio na repressão por glicose, observado pelo aumento das atividades respiratórias. / Metabolic Network Analysis was applied to the reference strain CEN.PK113-7D of Saccharomyces cerevisiae, as well as to some mutants disrupted in genes which code for regulatory proteins involved in the glucose repression cascade. All strains were cultivated under aerobic conditions, using minimal medium with [1-13C]glucose as the limiting substrate. Cells were harvested under balanced growth conditions and submitted to hydrolysis, derivatization and injection of the sample into a gas chromatograph coupled to a mass spectrometer for analysis of the labeling pattern in some fragments of intracellular metabolites. These data were used for identifying the activity of some pathways in the central metabolism of S. cerevisiae. Furthermore, using the data together with a stoichiometric model, it was possible to estimate the fluxes in the central metabolism of the reference strain and in the mutant strains. First, the methodology was validated for batch and continuous cultivations. Standard deviations were calculated for the measurement of the fractional labeling in each of the detected fragments. In the reference strain, it was observed that the Krebs cycle operates in a cyclic manner in respiratory cells, whereas it operates in a non cyclic manner under respiro-fermentative metabolism. It was also seen that a greater part of the glucose consumed by the cells enters the pentose phosphate pathway in the former than in the later case. Evidence for the activity of the threonine aldolase and the malic enzyme catalyzed reactions was also found. The absence of the Mig1 and Mig2 proteins does not alter the growth, ethanol formation and labeling pattern of intracellular metabolites in S. cerevisiae. In contrast, the absence of Hxk2, Reg1, or Grr1 provoques a relief in glucose repression, which was observed by an increased respiratory activity.

Sustainable development (SD) is a pressing global issue that is becoming increasingly prominent on clients and governing bodies agendas. In order to survive, organisations are seeking ways to negate their detrimental environmental impacts. This is no easy feat: SD is both complex and dynamic. To be successful, organisations need to leverage and expand their most valuable asset – knowledge. Civil engineering plays a significant role in SD – it shapes our environment and governs our interaction with it. However, extant research asserts that civil engineering related disciplines have been slow to adopt SD oriented practices; a possible result of their complex and fragmented organisational environments. The literature suggests that effective knowledge sharing (KS) can overcome these barriers, thus driving enhanced SD performance. Consequently, this research aims to investigate how the civil engineering sector can improve its intra-organisational sharing of SD knowledge, using an international civil engineering consultancy as an exemplar. Whilst there has been much research surrounding KS and SD there has been limited research that has investigated KS for SD, thus this thesis contributes to this limited body of knowledge. Mixed-method research was used to address the abovementioned aim. An increasingly popular approach, it is widely believed to generate greater value through complementary integration of quantitative and qualitative research paradigms. This approach lends itself also to the ethnographic inclinations of the reported research: the author was embedded within the case organisation, and sought a rich and reliable understanding of the study phenomena. An initial set of semi-structured interviews suggested that the case organisation’s members exhibit positive attitudes towards KS and SD, yet are often constrained by a number of common KS barriers, namely: a lack of organisation slack (i.e. time); a silo mentality; and poor SD ICT systems. These socio-cultural and technical barriers were subsequently investigated and contested using social network analysis techniques and an intranet acceptance model. A number of observations are made on the relationships between the findings from the research activities. It is believed the organisation often exhibits a reactive approach to KS for SD, which is deemed undesirable. This signals the need for greater senior management support to cultivate a culture where KS for SD is the norm and is integrated with work practices. A series of recommendations are provided to help the case organisation understand how such change could be cultivated. Several implications follow from this work. The mixed-method approach revealed a number of contradictions between the findings of each research activity. It is therefore postulated that mixed-method designs can provide a richer understanding, thus reducing misconceptions of KS phenomena. Following from this, the research contends that it may be too easy for researchers to identify with ubiquitous KS barriers as the reported research suggests that these may be perceived rather than actual. The research also reinforces the need for senior management support. These individuals govern the systems in which organisational members operate and thus have the ability to enhance KS for SD. Finally, the research demonstrates that SD ICT systems have little impact unless they are embedded in receptive contexts. Thus, an action research approach to KS system development is advocated to ensure systems are shaped to meet user expectations and drive desired KS behaviours. This research is presented in five peer-reviewed articles.

Information System (IS) implementations are a risky business with studies showing only a 16%-29% success rate. This research explores the use of social capital to support technology implementations. This research brings together two distinct bodies of knowledge: social network analysis (SNA) and technology acceptance models, in order to better understand the relationship between social capital and technology acceptance. The first aspect of the research looks at social network centrality and influence measures as an alternative means to measure social influence in the Unified Theory of Acceptance and Use of Technology (UTAUT) model. The social influence construct has proven to be inconsistent in past research. An individual‟s decision to adopt a new technology is influenced by their social context or the informal social network within which they work. The social capital of others influences their attitudes and decision to adopt a new technology. Social Capital, as measured through social network analysis, could be substituted for the social influence construct of the UTAUT model. Two revised UTAUT models are developed and tested. The second aspect of this research uses social capital to inform membership of a Community of Practice (CoP) to support a Finance Management System implementation in a higher education organization. SNA can be used to gain an understanding of the social network and identify individuals with high social capital. There is growing evidence that CoP support successful organizational change initiatives but it is less clear how CoP membership might be determined. SNA provides an evidence-based approach to CoP formation. The IS implementation cases described in the paper demonstrate an innovative approach to IS implementation grounded in social capital and technology acceptance research that add to the body of knowledge in both theory and practice.

From the individual to species level, it is common for animals to have connections with one another. These connections can exist in a variety of forms; from the social relationships within an animal society, to hybridisation between species. The structure of these connections in animal systems can be depicted using networks, often revealing non-trivial structure which can be biologically informative. Understanding the factors which drive the structure of animal networks can help us understand the costs and benefits of forming and maintaining relationships. Multivariate modelling provides a means to evaluate the relative contributions of a set of explanatory factors to a response variable. However, conventional modelling approaches use statistical tests which are unsuitable for the dependencies inherent in network and relational data. A solution to this problem is to use specialised models developed in the social sciences, which have a long history in modelling human social networks. Taking predictive multivariate models from the social sciences and applying them to animal networks is attractive given that current analytical approaches are predominantly descriptive. However, these models were developed for human social networks, where participants can self-identify relationships. In contrast, relationships between animals have to be inferred through observations of associations or interactions, which can introduce sampling bias and uncertainty to the data. Without appropriate care, these issues could lead us to make incorrect or overconfident conclusions about our data. In this thesis, we use an established network model, the multiple regression quadratic assignment procedure (MRQAP), and propose approaches to facilitate the application of this model in animal network studies. Through demonstrating these approaches on three animal systems, we make new biological findings and highlight the importance of considering data-sampling issues when analysing networks. Additionally, our approaches have wider applications to animal network studies where relationships are inferred through observing dyadic interactions.

While journalists were once viewed as gatekeepers, dispensing news and information via one-way communication channels, their role as information provider has evolved. Nowhere is this more apparent than on the social networking site Twitter, where information seekers have unprecedented access to information providers. The two-way communication that these information seekers have come to expect can be challenging for organizations such as ESPN who have multiple Twitter accounts and millions of followers. By designating one team of people as responsible for the organization's largest Twitter account, SportsCenter, ESPN has sought to establish manageable methods of interacting with this account's followers, while furthering the goals of the organization and providing sports news around the clock. This study provides a better understanding of the group responsible for ESPN's SportsCenter Twitter account: the motivation and strategies behind the group's Twitter use as well as the dynamics of this network, such as information flow and collaboration. Relying on the Information Seeking and Communication Model, this study also provides a better understanding of information exchanges with those outside the network, specifically a selection of the account's Twitter followers. Additionally, the role of journalist as information provider and certain themes that emerged from the content of the tweets are discussed. The research employed social network analysis and exploratory, descriptive case study methods. The results of this study contribute to social network and information theory as well as to journalistic and information science practice.

Made available in DSpace on 2015-03-05T18:40:07Z (GMT). No. of bitstreams: 0 Previous issue date: 27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Esta dissertação procura analisar aglomerações geográficas de empresas a partir de uma abordagem relacional, partindo da hipótese de que as relações sociais, tanto internas, quanto externas a rede, impactam no desempenho individual das organizações em tais ambientes. A base destas relações é a confiança, que é ao mesmo tempo elemento formador e estruturador do conjunto de relações e que é analisada a partir de seus componentes baseados em características, processos e instituições. Foram estudados os 53 curtumes e indústrias químicas para curtumes de Estância velha, sendo citadas ao todo 250 empresas, em um estudo quantitativo em que utilizou-se como metodologia a análise de redes sociais por esta permitir a mensuração destas relações e criação de um índice relacional. Os principais resultados obtidos permitem afirmar que as relações baseadas em processo e em instituições têm impacto significativo sobre o índice relacional, que as relações extra-rede têm grande importância para estas empresas, sendo que em al / This dissertation seeks analyze geographic agglomerations of companies starting a relational approach, based on the hypothesis that social relations, both internal as external to the network, impacting on the performance of individual organizations in such environments. The basis of these relations is trust, which is both building and structuring element of the set of relationships and is considered as of its components based on characteristics, processes and institutions. We studied all 53 leather and chemical industries of Estancia Velha, and in all 250 companies are listed in a quantitative study in which it was used as methodology of social networks analysis that enable the measurement of these relationships and create a relational index. The main results show that the relations based on process and institutions have significant impact on the relational index, that relations extra-network have great importance for these companies, while some cases end up occupying the central position in the network, in p

Submitted by Vanessa Nunes (vnunes@unisinos.br) on 2015-03-23T19:03:21Z No. of bitstreams: 1 MarciaCezar.pdf: 4782700 bytes, checksum: 2a4c5c536b06af7bb72c21aca8d4f147 (MD5) / Made available in DSpace on 2015-03-23T19:03:21Z (GMT). No. of bitstreams: 1 MarciaCezar.pdf: 4782700 bytes, checksum: 2a4c5c536b06af7bb72c21aca8d4f147 (MD5) Previous issue date: 2010 / FAPEMAT - Fundação de Amparo à Pesquisa do Estado de Mato Grosso / Os modelos de estrutura organizacional usualmente demonstrados desenvolvem aspectos extremamente técnicos, que deixam esquecidas as relações pessoais como variáveis imprescindíveis na própria organização. Considerando esse aspecto primordial, este estudo se demonstra relevante principalmente por analisar essa variável para identificar a influência das relações pessoais na estrutura multicampi da Universidade do Estado de Mato Grosso, justificando-se a escolha do objeto pelo fato de a UNEMAT possuir campus em 11 cidades do Estado de Mato grosso, com uma distância média de 500 km entre cada campus. Além dos empecilhos que essa geografia determina, foram identificados na instituição escolhida problemas na estrutura de comunicação, falta de sistemas interligados e outros entraves que fragilizam a sua estrutura. Nota-se, ainda, que a atual formação organizacional e administrativa da UNEMAT pode ser relacionada dentro de uma operacionalidade convencional, em que a organização individual segue o princípio da hierarquia funcional na qual os responsáveis por cada unidade recebem autoridade para efetuar a coordenação regional, demonstrando que esta, por sua vez, ocorre com a definição das tarefas e a supervisão das atividades feitas de cima para baixo. A metodologia utilizada foi a análise de redes sociais, permitindo, através de uma pesquisa quantitativa, chegar a um resultado de influência das relações pessoais, tendo embasamento em estudos de teóricos concernentes à ARS – Análise de Redes Sociais, análise de redes, dentre outros. / Models of organizational structure usually demonstrated shows highly technical aspects that leave personal relationships forgotten as essential variables in the organization. Considering this main aspect, this study is mainly relevant for analyzing this variable to identify the influence of personal relationships in the multicampi structure of University of Mato Grosso State, justifying the object choiced because the fact of UNEMAT has campi in 11 cities around Mato Grosso State, with an average distance of 500 km from each campus. Besides the obstacles determined because of this geographical situation, also were identified in the institution problems about communication infrastructure, lack of interconnected systems and other obstacles that weaken the structure of the institution. Moreover, the actual organizational and administrative formation of UNEMAT can be related within a conventional operation, where the individual organization follows the principle of the functional hierarchy, which those people responsible for each unit receives the authority to regional coordination, which occurs since the definition of tasks and supervision of activities carried out from top to bottom. The methodology used was the analysis of social networks, by allowing a quantitative analysis serching for a result of the influence of personal relationships, and grounding in theoretical studies concerning theSNA - Social Network Analysis, network analysis, among others.

Present day email is provided by centralized services running in the cloud. The services transparently connect users behind middleboxes and provide backup, redundancy, and high availability at the expense of user privacy. In present day mobile environments, users can access and modify email from multiple devices with updates reconciled on the central server. Prioritizing updates is difficult and may be undesirable. Moreover, legacy email protocols do not provide optimal email synchronization and access. Recent phenomena of the Internet of Things (IoT) will see the number of interconnected devices grow to 27 billion by 2021. In the first part of my dissertation I am proposing a decentralized email architecture which takes advantage of user's a IoT devices to maintain a complete email history. This addresses the email reconciliation issue and places data under user control. I replace legacy email protocols with a synchronization protocol to achieve eventual consistency of email and optimize bandwidth and energy usage. The architecture is evaluated on a Raspberry Pi computer. There is an extensive body of research on Social Network Analysis (SNA) based on email archives. Typically, the analyzed network reflects either communication between users or a relationship between the email and the information found in the email's header and the body. This approach discards either all or some email attachments that cannot be converted to text; for instance, images. Yet attachments may use up to 90% of an email archive size. In the second part of my dissertation I suggest extracting the network from email attachments shared between users. I hypothesize that the network extracted from shared email attachments might provide more insight into the social structure of the email archive. I evaluate communication and shared email attachments networks by analyzing common centrality measures and classication and clustering algorithms. I further demonstrate how the analysis of the shared attachments network can be used to optimize the proposed decentralized email architecture.

Author Cocitation Analysis (ACA), multidimensional scaling (MDS) and Social Network Analysis (SNA), has been used to analyze and visualize the invisible college of the journal European Union Politics. The concept invisible college was first introduced in the fifteenth century, through the creation of the “the Royal Society of London”, and it was reintroduced in the 1960:ies and the 1970:ies by scholars such as Price and Crane. It is said to have been interpreted in as many ways as there are authors who have used it. Here it has been used synonymously with the term citation network. To show changes over time in the invisible college and in its research themes and trends, citation data from two separate periods of time have been compared; 2003-2004 and 2007-2008. The analysis shows a shift in the invisible college on the actor level –such as changes in density, actors’ positions in the network - and changes in the research agenda towards public opinion research and integration research. Connected to these trends is the theme of “Eurosceptism” – which had a breakthrough after the first period of analysis. This seems to follow the development of the researched object itself (the European Union). The invisible college of European Union Politics has been understood to be relatively young, as is the journal and the field of European Union Politics.

Thesis. 1975. Ph.D.--Massachusetts Institute of Technology. Dept. of Civil Engineering. / Bibliography: leaves 221-224. / Ph.D.