Submitted by Rosivalda Pereira (mrs.pereira@ufma.br) on 2017-09-15T17:59:28Z No. of bitstreams: 1 AugustoSilva.pdf: 4699819 bytes, checksum: cf18a43cf817a3264880d015853561f6 (MD5) / Made available in DSpace on 2017-09-15T17:59:29Z (GMT). No. of bitstreams: 1 AugustoSilva.pdf: 4699819 bytes, checksum: cf18a43cf817a3264880d015853561f6 (MD5) Previous issue date: 2017-08-16 / In this work the theoretical study of the bimetallic clusters of Au-Ag and Au-Cu was carried out, in which such clusters were determined by the addition of Ag and Cu atoms in pure structures of Au clusters, through the GA-DFT joint methodology. The AuCu and Au-Ag structures were described in a classical way using the Gupta potential via the genetic algorithm. The lower energy structures were optimized via DFT using the PBE functional through the SIESTA 3.2 program package. The most stable clusters were those with 13 atoms for Au-Ag bimetallic clusters, Au-Cu bimetallic clusters stabilized with 13, 15 and 20 atoms. Both clusters have a degree of aromaticity, more pronounced in the AuAg atoms, than in the Au-Cu atoms. The Au-Ag clusters adsorb the oxygen more favorably in end-on or bridge, whereas the bimetallic clusters of Au-Cu adsorb the molecular oxygen generally according to the bridge or double bridge model. The adsorption of oxygen in bimetallic clusters is intrinsically related to the ability of oxygen to perform π backdonation for the metallic atoms in the cluster. / Neste trabalho fora realizado o estudo teórico dos clusters bimetálicos de Au-Ag e Au-Cu, em que tais clusters foram determinados através da adição de átomos de Ag e Cu em estruturas puras de clusters de Au, através da metodologia conjunta GA-DFT. As estruturas de Au-Cu e Au-Ag, foram descritas de forma clássica usando o potencial Gupta via algoritmo genético. As estruturas de mais baixa energia foram otimizadas via DFT usando o funcional PBE através do pacote de programas SIESTA 3.2. Os clusters de maior estabilidade foram os com 13 átomos para clusters bimetálicos de Au-Ag, os clusters bimetálicos de Au-Cu estabilizaram com 13, 15 e 20 átomos. Ambos os clusters possuem um certo grau de aromaticidade, mais pronunciada nos átomos de Au-Ag, que nos átomos de Au-Cu. Os clusters de Au-Ag adsorvem o oxigênio de forma mais favorável em end-on ou ponte, enquanto que os clusters bimetálicos de Au-Cu adsorvem o oxigênio molecular em geral segundo o modelo ponte ou dupla ponte. A adsorção do oxigênio nos clusters bimetálicos está intrinsecamente relacionada à habilidade do oxigênio em realizar retrodoação π para os átomos metálicos.

Com o objetivo de determinar a influência dos sistemas de produção e de alimentação sobre as características do leite, dados coletados de produtores de leite do sul do Brasil e de experimentos sobre níveis de restrição alimentar e de atendimento das exigências energéticas de vacas em lactação foram submetidos à análise de fatores principais, de correlação e médias canônicas, agrupamento e comparação de médias dos grupos. Os atributos estudados comuns em todos os sistemas foram produção leiteira diária, componentes lácteos, estabilidade do leite, peso corporal e escore de condição corporal. Na análise dos sistemas de produção, três grupos de produtores foram formados pela análise de agrupamento, com características de sistemas especializados, semi-especializados e não especializados em ambas as regiões avaliadas. Grupos de produtores especializados produziam leite em conformidade com as especificações da Instrução Normativa Nº 62. Enquanto que para os produtores da região sul do Rio Grande do Sul, as estratégias de alimentação foram determinantes para distinção entre os grupos de produtores, no extremo oeste de Santa Catarina a estrutura das propriedades foi mais determinante. Níveis de restrição severos (40 e 50%) alteraram significativamente a produção leiteira diária, os teores de proteína e lactose e a estabilidade do leite. O atendimento das exigências energéticas para vacas em lactação possui uma relação direta com a produção diária de leite, com o teor da lactose e com a estabilidade do leite. A produção leiteira, os componentes lácteos e a estabilidade do leite diferenciam-se entre os sistemas de produção e alimentação. / Aiming to determine the influence of production and feeding systems on milk characteristics, data collected from dairy producers in southern Brazil and experiments on levels of feed restriction and attendance of the energy requirements of lactating cows were subjected to principal factor, correlation and means canonical, cluster analysis and comparison of means between groups. The variables common to all systems were daily milk production, milk components contents, ethanol stability, body weight and body condition score. In the analysis of production systems, three producers groups were formed by cluster analysis, with characteristics of specialized, semi-specialized and unspecialized systems in both regions evaluated. Groups of specialized dairy farmers produced milk in accordance with Normative Instruction Nº 62. While for the producers in southern Rio Grande do Sul, the feeding strategies were crucial to distinguish groups, at the far west of Santa Catarina structure of the properties was more important. Severe feed restriction levels (40 and 50%) altered significantly the daily milk yield, protein and lactose contents and ethanol stability. Attendance of the energy requirements for lactating cows showed a direct relationship with the daily milk production, content of lactose and milk stability. Milk production, milk components and milk stability are different between production and feeding systems.

Genomic integrity in mouse embryonic and induced pluripotent stem cells can be compromised by factors such as extended time in culture and cellular reprogramming. Surprising, only a few studies have thus far examined the accumulation of chromosomal imbalances in mouse pluripotent populations upon prolonged propagation in vitro. It is presumed that specific recurring genetic changes can confer selective growth advantage and resistance to apoptosis and/or differentiation to the affected cells, although the genes that drive these processes remain elusive. The presence of these changes in published studies can confound the analysis of the data and hinder the reproducibility of the results. At the transcriptional level, aneuploidy manifests as large chromosomal regions of aberrant gene expression. This thesis presents a method to identify these regions in large-scale datasets and interrogate for recurrent patterns. The present analysis shows that over half of the 315 mouse pluripotent samples examined carry whole or partial-chromosome spanning clusters of aberrant transcription. Furthermore, there are common gene expression changes across samples with any type of predicted aneuploidy and samples with chromosome-specific aberrations. These transcriptional signatures have been used to train classification models which can predict aneuploid samples with over 90% accuracy. This is an important step towards the development of a low-cost and reliable transcriptional validation assay for the presence of aneuploidy.

Este trabalho tem como objetivo principal desenvolver um sistema de avaliação de desempenho de clusters, capaz de analisar as vantagens potenciais que um cluster pode oferecer e concluir a respeito do aproveitamento dessas vantagens e dos aspectos que podem ser aprimorados. Para isso, o trabalho se propõe a: (i) identificar os constructos e variáveis que devem ser utilizados para representar as vantagens potenciais que um cluster industrial pode oferecer; (ii) desenvolver um sistema de avaliação do aproveitamento das vantagens potenciais de um cluster, baseado nos constructos e variáveis identificados; (iii) testar o sistema, avaliando o nível de desenvolvimento, no que tange ao aproveitamento de vantagens potenciais em que se encontra o cluster moveleiro do Oeste de Santa Catarina; e (iv) estabelecer um plano para aprimoramento das operações e consolidação do referido cluster. Esta tese está baseada numa abordagem quantitativa e qualitativa, utilizando questionário aplicado em 112 empresas, grupo focado e entrevistas. Uma das principais contribuições desta tese é a proposição de um modelo capaz de avaliar o aproveitamento das vantagens potenciais de um cluster, auxiliando na tomada de decisão dos envolvidos (poder público, instituições de classe, empresas) e melhoria da competitividade das empresas do cluster em relação às empresas externas. Outra contribuição deste trabalho é a proposição de ações que possam aumentar o aproveitamento das vantagens oferecidas às empresas pertencentes ao cluster moveleiro do oeste de Santa Catarina e à sua competitividade. / The main objective of this work is to develop a performance evaluation system of clusters, able of analyzing the potential advantages that a cluster can offer to its member companies and conclude about the use of these advantages and about the aspects which could be improved. Considering this general objective, this work intends: (i) identify the constructs and variables that should be utilized for represent the potential advantages that an industrial cluster can offer; (ii) develop an evaluation system for access the use of the potential advantages of a cluster, based on the constructs and identified variables; (iii) test the system, evaluating the development level of the west of Santa Catarina furniture cluster, regarding the use of the potential advantages, (iv) establish a plan for the improvement of operations and consolidation of the mentioned cluster. This dissertation is based on a qualitative and quantitative approach, comprising a survey involving 112 companies, focus group and interviews. One of the main contributions of this dissertation is the proposal of a model capable of evaluate the use of the potential advantages of a cluster, assisting on the decision making of the stakeholders (government, class association and companies) and competitiveness improvement of the cluster member companies compared to outside companies. Other contribution of this work is the proposal of a plan of actions that could increase the use of the advantages offered to the member companies of the west of Santa Catarina furniture cluster and their respective competitiveness.

Mon travail de thèse porte sur l’analyse cosmologique de surveys d’amas de galaxies en rayons X. Les amas sont détectés par le satellite XMM grâce à leur émission X produite par effet Bremsstrahlung du gaz intra-amas. L’étude de la distribution des amas en fonction de leur masse et de leur distance permet de mesurer m, _8 et de contraindre l’équation d’état de l’énergie noire. Une nouvelle approche cosmologique, développée par Clerc et al (2012), se base uniquement sur la distribution de quantités observables en rayons X (flux et couleur). Mon travail a consisté à étendre cette approche en y adjoignant la mesure de la taille apparente de l’émission X des amas. C’est un paramètre qui dépend de la masse de l’amas et de sa distance et qui intervient directement dans la fonction de sélection du survey. J’ai tout d’abord évalué les performances de cette méthode avec une analyse de Fisher. J’ai également étudié l’effet de la dispersion de la relation masse-rayon sur le taux de détection des amas et donc sur les contraintes cosmologiques. Pour valider ces calculs j’ai, dans une seconde partie, utilisé des surveys d’amas X simulés : 100-10000 deg2 à partir d’un modèle purement analytique et 1000 deg2 avec un modèle semi-analytique sur des simulations numériques de matière noire (Aardvark). J’ai déterminé les erreurs sur les paramètres cosmologiques à partir des diagrammes de diagnostic X simuls en utilisant des logiciels de minimisation (MCMC, Amoeba). Ces calculs ont confirmé les prédictions de l’analyse de Fisher. En conclusion, les diagrammes X sont au moins aussi performants que la m´méthode traditionnelle basée sur N(M,z) et d’utilisation beaucoup plus rapide et simple. Je propose quelques applications pour le survey XXL. / Cosmology is one of the fundamental pillars of astrophysics, as such it contains many unsolvedpuzzles. To investigate some of those puzzles, we analyze X-ray surveys of galaxy clusters. These surveys are possible thanks to the bremsstrahlung emission of the intra-cluster medium. The simultaneous fit of cluster counts as a function of mass and distance provides an independent measure of cosmological parameters such as m, _8, and the dark energy equation of state w0. A novel approach to cosmological analysis using galaxy cluster data, called top-down, was developed in N. Clerc et al. (2012). This top-down approach is based purely on instrumental observables that are considered in a two-dimensional X-ray color-magnitude diagram. The method self-consistently includes selection effects and scaling relationships. It also provides a means of bypassing the computation of individual cluster masses. My work presents an extension of the top-down method by introducing the apparent size of the cluster, creating a three-dimensional X-ray cluster diagram. The size of a cluster is sensitive to both the cluster mass and its angular diameter, so it must also be included in the assessment of selection effects. The performance of this new method is investigated using a Fisher analysis. In parallel, I have studied the effects of the intrinsic scatter in the cluster size scaling relation on the sample selection as well as on the obtained cosmological parameters. To validate the method, I estimate uncertainties of cosmological parameters with MCMC method Amoeba minimization routine and using two simulated XMM surveys that have an increasing level of complexity. The first simulated survey is a set of toy catalogues of 100 and 10000 deg2, whereas the second is a 1000 deg2 catalogue that was generated using an Aardvark semi-analytical N-body simulation. This comparison corroborates the conclusions of the Fisher analysis. In conclusion, I find that a cluster diagram that accounts for the fluxes, colors, sizes, and redshifts of the clusters performs well. Additionally, I find that it is at least as efficient as the traditional M,z method for the same cluster samples. I also discuss a proposition to apply this method to the XXL survey data

Les amas de galaxies sont des outils cosmologiques et astrophysiques essentiels, car ce sont les objets les plus grands et les plus massifs gravitationnellement liées dans l'Univers. L'étude de leur fonction de masse, de leur fonction de corrélation et des relations d'échelle entre leur masse et différentes observables nous permettent de tester les prévisions des modèles cosmologique et les scenarii de formation des structures. Ils sont aussi d'intéressants laboratoires pour l'étude de la formation et de l'évolution des galaxies, et de leur interactions avec le milieu qui les entourent, dans d’environnements denses. Pour y parvenir, estimer précisément leur masse revêt une importance fondamentale. J’ai étudié la précision de la richesse optique calculée par l’algorithme de détection d’amas RedGOLD (Licitra et al. 2016) en tant que mass proxy, en utilisant des mesures de lentilles gravitationnelles (weak lensing) et des observations en rayon X. J’ai mesuré les masses cumulées d’un échantillon de 1323 amas de galaxies dans le CFHTLS et NGVS à 0.2<z<0.5, dans l’intervalle de richesse 10-70. J'ai testé différents modèles prenant en compte les erreurs sur la position du centre de l'amas, les effets de lentille non faible (non-weak shear), le "two-halo term", la contribution de la galaxie centrale brillante et la dispersion intrinsèque de la relation masse-richesse. J'ai montré que la correction de la position du centre est nécessaire pour éviter un biais dans la mesure de la masse, alors que l'ajout de la galaxie centrale n'affecte pas les résultats. J'ai calculer les coefficients de la relation masse-richesse et ceux de la relation d'échelle entre masses issues du weak lensing et celle estimées à partir d'observations dans les rayons X. Mes résultats sont en accord avec les simulations et les précédents travaux publiés. / Galaxy clusters are essential cosmological and astrophysical tools, since they represent the largest and most massive gravitationally bound structures in the Universe. Through the study of their mass function, of their correlation function, and of the scaling relations between their mass and different observables, we can probe the predictions of cosmological models and structure formation scenarios. They are also interesting laboratories that allow us to study galaxy formation and evolution, and their interactions with the intra-cluster medium, in dense environments. For all of these goals, an accurate estimate of cluster masses is of fundamental importance. I studied the accuracy of the optical richness obtained by the RedGOLD cluster detection algorithm (Licitra et al. 2016) as a mass proxy, using weak lensing and X-ray mass measurements. I measured stacked weak lensing cluster masses for a sample of 1323 galaxy clusters in the CFHTLS W1 and in the NGVS at 0.2<z<0.5, in the optical richness range 10-70. I tested different weak lensing mass models that account for miscentering, non-weak shear, the two-halo term, the contribution of the Brightest Cluster Galaxy, and the intrinsic scatter in the mass-richness relation. I found that the miscentering correction is necessary to avoid a bias in the measured halo masses, while the inclusion of the BCG mass does not affect the results. I calculated the coefficients of the mass-richness relation, and of the scaling relations between the lensing mass and X-ray mass proxies. My results are consistent with simulations and previous works in the literature.

Since the 9/11 attacks by Al Qaeda members against the United States, counterterrorism has become a top priority for policymakers and academic researchers. A critical aspect of this mandate is the prevention and intervention of future terrorist attacks by U.S.-based jihadist and Salafist extremists. This study aims to generate a typology of homegrown terrorists who have been prosecuted by the United States federal government for terrorism offenses within the United States since the 9/11 attacks. The current study uses a sample of 115 cases, involving 194 offenders. Three clusters of offenders who share a set of demographic, social, and behavioral characteristics were identified through a two-step cluster analysis. These clusters include: Cyber Attackers, Convert Affiliates, and Trained Allies. Clusters also exhibited variation in the nature of terrorist activity and degree of operational success. The unique characteristics of each cluster suggest possible policy implications for international travel, cyber regulation, and community outreach programs to address the unique threats posed by subgroups of offenders. Efforts to prevent future terrorist plots and attacks may be more effective if the type of offender is considered.

In many spatial epidemiologic studies, investigators use residential location at diagnosis as a surrogate for unknown environmental exposures or as a geographic basis for assigning measured exposures. Inherently, they make assumptions about the timing and location of pertinent exposures which may prove problematic when studying long latency diseases such as cancer. In this work we explored how the association between environmental exposures and disease risk for long-latency health outcomes like cancer is affected by residential mobility. We used simulation studies conditioned on real data to evaluate the extent to which the commonly held assumption of no residential mobility 1) affected the ability of generalized additive models to detect areas of significantly elevated historic environmental exposure and 2) increased bias in the estimates of the relationship between environmental exposures and disease in a case-control study. While the literature suggests that some researchers have begun to develop methods to incorporate historic locations in studies of health outcomes, a number of questions remain. One reason for the knowledge gap is that residential histories have not been collected in most U.S. epidemiologic studies. In our work we evaluated the impact of using public-record database generated histories to estimate the effects of exposure in lieu of using subject-reported addresses collected during a study. Finally, we evaluated the effect of environmental exposure on cancer risk in a case-control study using an approach that combined a multiple membership conditional autoregressive (CAR) model with an environmental exposure index for temporally correlated time-varying exposure assigned based on residential histories. We used this model in a data application to explain bladder cancer risk in the New England Bladder Cancer Study. We included a temporal arsenic exposure index in the model to assess a large number of correlated arsenic exposures.

The work presented in this dissertation has been focused on structure, stability, electronic properties, and chemical bonding of atomic clusters and solid-state compounds. The common thread was development of chemically intuitive models and theoretical methods capable of describing and interpreting bonding and hence, structures of these compounds. Understanding how interactions between atoms in sub-nano clusters and solid-state compounds of certain compositions determine their structures, physical properties, and reactivities is essential for rational design of new materials, catalysts, and molecular devices. A significant part of this work presents joint experimental and theoretical studies of doped boron clusters. Several projects on carbon- and aluminum-substituted boron clusters were aimed at establishing their structures, energetic and electronic properties, and understanding bonding interactions. The dissertation introduces a series of peculiar clusters containing transition metal atoms inside perfectly symmetrical boron rings. These clusters, featuring planar octa-, nona-, and decacoordinated transition metal atoms, were designed based on a simple chemical bonding model governing stabilities of such species. One of the most important parts of this dissertation deals with chemical bonding in the solid state. The Adaptive Natural Density Partitioning method previously developed by the Boldyrev group at Utah State University has proven very efficient for understanding chemical bonding in clusters and complex molecules. In this work, a periodic implementation of this method has been developed, yielding a new theoretical tool capable of interpretation of bonding in solid state in chemically intuitive terms of localized and multi-center bonds.

"July 2003." / Bibliography: p. 203-211. / xxii, 211 p. : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Investigates properties of magnetic fields in galaxy clusters via both statistical Faraday rotation measures and diffuse source polarimetry, and investigates the nature and generation mechanisms for diffuse radio emission in the ACO cluster A3667. / Thesis (Ph.D.)--University of Adelaide, Dept. of Physics and Mathematical Physics, 2003