Made available in DSpace on 2016-08-29T15:33:16Z (GMT). No. of bitstreams: 1 tese_4602_.pdf: 978024 bytes, checksum: 68d510098defbd15aab47bc0b03dd189 (MD5) Previous issue date: 2004-09-27 / Organizar a produção de materiais de diferentes tipos para garantir o suprimento deles no momento necessário e na quantidade desejada é uma tarefa complicada. Para empresas do ramo de celulose, o fornecimento de madeiras para a produção na fábrica é um bom exemplo. Nesse contexto, saber onde estão localizados os diferentes tipos de madeira e quando as árvores podem ser cortadas é muito importante. Com essa informação, um analista de planejamento deve ser capaz de organizar as áreas plantadas em grupos para indicar quando e quais áreas serão cortadas no decorrer de um período. Com o objetivo de auxiliar essa análise, buscou-se uma solução para o problema de agrupamento de áreas florestais baseado na existência de grupos homogêneos na área total analisada. Dentro das abordagens em Análise de Cluster, desenvolveu-se uma ferramenta que implementa o algoritmo HCS (Highly Connected Subgraphs) e comparou-se o resultado com uma simulação do processamento realizado por um analista humano. O algoritmo conseguiu soluções mais detalhadas e homogêneas do que a simulação e, com algumas adaptações ou apoio de outras ferramentas, pode gerar resultados de forma mais rápida para fornecer soluções para grandes volumes de dados em tempo hábil.

Made available in DSpace on 2016-08-29T15:33:18Z (GMT). No. of bitstreams: 1 tese_5950_.pdf: 1565644 bytes, checksum: 43f4342be309a5412d660526cd99eb64 (MD5) Previous issue date: 2012-08-24 / Este trabalho propõe um algoritmo para a detecção de anomalias em séries temporais, baseado em técnicas de agrupamento, utilizando a função de distância de Mahalanobis. Após uma revisão das principais e mais recentes contribuições feitas neste campo de pesquisa, uma descrição formal e detalhada do algoritmo é apresentada, seguida por uma discussão sobre como configurar seus parâmetros. A fim de avaliar sua efetividade, ele foi aplicado a casos reais, e seus resultados foram comparados com outra técnica aplicável ao mesmo problema. Os resultados obtidos sugerem que esta proposta pode ser aplicada com sucesso na detecção de anomalias em séries temporais.

O objetivo deste estudo foi registrar e analisar narrativas autobiográficas sobre o processo de saída da situação de rua de adultos com esta vivência e que alcançaram uma condição habitacional estável. O instrumento utilizado foi a Entrevista Narrativa Autobiográfica, que consiste em um convite amplo e não-diretivo para que cada participante conte a sua história de vida de forma livre. As narrativas foram transcritas integralmente e codificadas de acordo com três matrizes interpretativas: estruturas autobiográficas; temas de agência/comunhão; e temas de origem êmica. Participaram deste estudo dois adultos, com trajetórias e perfis heterogêneos, que foram contatados em serviços da rede de assistência social. As narrativas analisadas demonstraram a recusa a internalizar estigmas atribuídos à situação de rua, e foram marcadas por temas de controle de si, empoderamento, e cuidado com os outros, retratando transformações pessoais associadas à saída da situação de rua. / The aim of this study was to record and analyze autobiographical narratives about the process exiting homeless of ex-homeless adults who have achieved stable housing. The instrument used was the Autobiographical Narrative Interview, consisting of a broad and non-directive invitation to each participant tell freely his/her life history. The narratives were transcribed and coded according to three interpretive matrices: autobiographical structures; themes of agency / communion; and emic themes. The study included two adults, with heterogeneous paths and profiles, which were contacted among the social care network. The narratives analyzed demonstrated a refusal to internalize stigma attributed to homeless people, and were marked by themes of self-control, empowerment, and care for others, portraying personal transformations associated with the process of exiting homelessness.

Made available in DSpace on 2014-06-12T23:15:53Z (GMT). No. of bitstreams: 2 arquivo9310_1.pdf: 749987 bytes, checksum: d03a71267ab8f8c1cf0ea307fd5e5d79 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2002 / Nosso estudo sobre o Movimento dos Trabalhadores Sem-Teto procura conectar as célebres questões como e por que os sujeitos se mobilizam, para empreender tal ação coletiva; num diálogo estabelecido com o modelo analítico proposto por Melucci. O objetivo geral é perceber o processo de formação de sua identidade coletiva, considerando tal mobilização como um indicador das contradições do sistema capitalista, em termos de reprodução da força de trabalho e acumulação de capital, a partir da renda fundiária, mediada pela ação do Estado. Analisando, inclusive, as especificidades dessas contradições na urbanização brasileira e de Recife, em particular. A emergência do movimento é condicionada por estas questões estruturais e por uma conjuntura política favorável. Isto significa, do ponto de vista interno, as questões relativas ao processo de formação da identidade coletiva. O mesmo envolve as concepções em torno do projeto político, dos processos organizativos e da motivação dos indivíduos para a participação. O discurso construído pelas lideranças em torno da ocupação de terrenos vazios e da resistência como única forma de obter uma casa, estrutura as motivações, concepções e rumos do movimento. Destaca-se a estreita relação com o Movimento dos Trabalhadores Sem-Terra e o Partido dos Trabalhadores, referências para o projeto político e articulação estratégica

Cerium oxide nanoparticles have been utilized widely nowadays in cancer research. It has been suggested by many studies that these nanoparticles are capable of having dual antioxidant behavior in healthy and cancer microenvironment; where in physiological condition, they act as antioxidant and do not affect the healthy cells, while in tumor-like condition; they act as an oxidase, and result in a selective killing for the cancer cells. In this experiment, the interaction of nanoceria with glioblastoma and healthy astrocyte cells was examined, and further correlated with the in vitro cytotoxic effects of various nanoceria concentrations (100 and 300 µg/ml) and exposure times (12, 24, and 48 hours). Electron microscopes were used to investigate the cellular-NPs interactions, and to examine the related cytotoxic effects in combination with trypan blue and propidium iodide viability assays. Our data suggest the following results. First, the two cell lines demonstrated capability of taken up the ceria through endocytosis pathway, where the NPs were recognized engulfed by double membrane vesicles at various regions over the cellular cytoplasm. Secondly, cerium oxide nanoparticles were found to affect the glioblastoma cells, but not so severely the corresponding healthy astrocytes at the various concentrations and incubation times, as revealed by the viability assays and the electron microscopy analysis. Thirdly, the viability of the glioblastoma cells after the treatment displayed a declined trend when increasing the ceria concentrations, but did not show such dependency with regard to the different time points. In all cases, the healthy astrocyte cells showed slight alterations in mitochondrial shape which did not influence their viability. Among the various nanoceria concentrations and exposure times, the most efficient dose of treatment was found to be with a concentration of 300 µg/ml at a time point of 24-hour, where higher reduction on the viability of glioblastoma cells was achieved, with minimal toxicity to the healthy astrocyte cells.

Cerium oxide nanoparticles have been proposed as an anticancer agent, thanks to their ability of tuning the redox activity in accordance to different conditions, which lead to selective roles on healthy and cancer cells. Recent evidence suggested the ability of these nanoparticles to be toxic against cancer cells, while confer protection from oxidative stress, toward healthy cells. The main focus of this study was to determine the ultrastructural effects of cerium oxide nanoparticles over multiple incubation time of 1, 3, and 7 days on breast healthy and cancer cells. Cellular characterizations were carried out using electron microscopes, both transmission and scanning electron microscopes, while the viability assessments were performed by propidium iodide and trypan blue viability assays. The obtained results of the viability assays and electron microscopy suggested higher toxic effects on the cancer cell line viability by using a nanoceria dose of 300 μg/mL after 1 day of treatment. Such effects were shown to be preserved at 3 days, and in a longer time point of 7 days. On the contrary, the healthy cells underwent less effects on their viability at time point of 1 and 7 days. The 3 days treatment demonstrated a reduction on the number of cells that did not correlate with an increase of the dead cells, which suggested a possible initial decrease of the cell growth rate, which could be due to the high intracellular loading of nanoparticles. To conclude, the overall result of this experiment suggested that 300 μg/mL of CeO2 nanoparticles is the most suitable dose, within the range and the time point tested, which induces long-lasting cytotoxic effects in breast cancer cells, without harming the normal cells, as highlighted by the viability assays and ultrastructural characterization of electron microscopy analysis.

The Jurassic (Oxfordian) Smackover Formation in Little Cedar Creek Field, Alabama is composed of microbial thrombolitic buildups. Core description, petrography, SEM, and isotopic analysis were used to identify the succession of organisms, microbial carbonate deposition, and diagenesis that contributed to formation of these thrombolitic buildups. The microbial thrombolite reef facies in this study accounts for 38.5% of the total Smackover Formation. This facies was deposited 0.5 to 6.75 miles from the paleo-coastline. Today it is located 10,225 to 11,750 feet in the subsurface and contains buildups 26 to 50 feet thick. Four microfacies were defined: A- Black Renalcis-like layers, B- Digitate, C- Chaotic and D- Brown laminated centimeter-scale cycles. In most of the buildup, distinct layers of microbially precipitated micrite forms in succession. Microfacies A (Black Renalcis-like Layer) is the relatively least porous and permeable, acting as a potential barrier to flow in contrast to the other more porous microfacies.

Thesis advisor: Hao Wu / Thesis advisor: Ehri Ryu / In SEM, fit indexes provide useful information about how well a hypothesized model fits the population. Bootstrap has been applied to construct confidence internals for fit indexes. We proposed the most recent method for constructing confidence intervals (CIs) of fit indexes (Cheng & Wu, 2017): the bootstrap-test-based method. This dissertation includes the most popular bootstrap CI methods and the bootstrap-test-based method. In addition to the percentile bootstrap CI method used in Zhang and Savalei (2016), we also included other popular bootstrap CI methods. For all bootstrap CI methods, we explored their performances with and without the transformation proposed by Yuan, Hayashi, and Yanagihara (2007). In this process, we also solved computation difficulty for Studentized CI. The bootstrap-test-based method is improved by using alternative search statistics. As the previous approaches were not extended to nonnormal conditions, the CI estimation for fit indexes with nonnormal data are investigated for both bootstrap CI and bootstrap-test-based methods, using adjusted definitions of fit indexes for nonnormal data. Different nonnormal data generation techniques are applied. This dissertation presents a comprehensive comparison of bootstrap CI methods and the bootstrap-test-based method under various conditions. From the simulation results, the CIs for fit indexes under the bootstrap-test-based method are more accurate than most bootstrap CI methods. The results also show that the bootstrap-test-based method can be generalized well to non-normal data. The confidence bounds coverage by bootstrap-test-based method are closer to their nominal levels. / Thesis (PhD) — Boston College, 2021. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Psychology.

This study uses scanning electron microscopy (SEM) to examine the occurrence of bacteria and their exopolysaccharide slime layer in microbial enhanced oil recovery experiments. A test of SEM preservation techniques showed that air drying and 10% glutaraldehyde fixation preserved the slime layer but distorted and flattened bacteria. Techniques with ethanol dehydration preserved the bacterial textures but fragmented the slime layer. In sandstones that had been plugged during microbial enhanced oil recovery experiments, bacteria are sparsely distributed. An irregular, confluent slime sheet covers grains and coats pore spaces and is responsible for permeability modification in microbial enhanced oil recovery. The development of the slime layer over time involves several steps: growth of ultramicrobacteria into full-sized bacteria; creation of a slime capsule; growth of globular masses, ropy masses, webs, thin sheets; and growth of a thicker, poreilling mass of slime associated with large balls of slime.

Little information regarding the flagellar sensilla of the Vespidae, particularly Polistes, exists in the literature. A variety of social behaviors in vespids, such as alarm pheromones and pheromone response, involve intraspecific communication. Therefore, an understanding of sensory receptors in social wasps would benefit further behavioral and neurological studies of wasps. The flagellar sensilla of female paper wasps Polistes dorsalis, Polistes metricus, and the solitary wasp Monobia quadridens were examined by scanning and transmission electron microscopy. A number of olfactory receptors, contact chemoreceptors, and mechanoreceptors were named and described. Possible functions of these receptors were proposed based on morphological and ultrastructural data for each type of sensillum. Counts of several sensilla were made over the whole of five flagellae of each species and results were compared among species, flagellomeres, medial and lateral surfaces.