Thesis (M.A.)--Boston University / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / Recently, many studies have used T1 and T2 quantitative MRI in examining the brain and other body structures, to evaluate and follow up diseases, or simply for better understanding of the human body. Quality control on MRI scanners has been performed since the early eighties and nowadays the ACR MRI phantom is being used for the accreditation of the scanners, and quality control of their qualitative performance. In this study the same phantom is being used to obtain quantitative values of three regions in the phantom that might be used as reference for quantitative quality control. The results of the scans provided quantitative values that can be used as reference for the quality control of qMRI, and there was no difference after scanning the same regions twice. Further study is recommended to provide quantitative values for different MRI scanners strength to assure the use of ACR phantom as a tool for quality control of qMRI scanners. / 2031-01-02

Made available in DSpace on 2015-04-22T22:08:49Z (GMT). No. of bitstreams: 1 Dissertacao Alberto Fabio.pdf: 1667176 bytes, checksum: 403f0e8f6a8e2e64c6ad93d68efc80d1 (MD5) Previous issue date: 2010-02-05 / Fundação de Amparo à Pesquisa do Estado do Amazonas / The Amazon region has a large territory, where there are few economic centers with great distance from those of most developed country. Moreover, due to its geological formation, the main cities of the region not have material available that can be economically employed in construction. Moreover, the main capitals have displayed a high level of economic growth with an accelerated pace of new works with the consequent generation of waste construction. Thus, the technical solution for pavements with the use of construction and demolition waste is presented as an alternative technology of great economic and environmental interest. With the objective of obtaining parameters that allow an assessment of technical and economic feasibility of concrete made with the inclusion of construction and demolition wastes (CDW), specifically the RCA (recycled concrete aggregate), to the production interlocking pavers for pavement, in this work is presented a study of determination of its main mechanical properties, considering the partial replacement of the aggregate by the construction and demolition waste. In the development this work, we carried out tests of chareterizatian of the mechanical and physics properties concrete made with RCA, according to the Brazilian standards. / A região Amazônica possui uma grande extensão territorial, onde se concentram poucos núcleos econômicos, distantes daqueles mais desenvolvidos do país. Além disso, devido à sua formação geológica, as principais cidades da região não possuem disponível material pétreo que economicamente possa ser empregado na construção civil. Por outro lado, as principais capitais têm apresentado um nível de crescimento econômico elevado, traduzindo-se em um ritmo acelerado de novas obras com conseqüente geração de resíduos de construção. Desta forma, a solução técnica com a utilização de resíduos de construção e demolição em pavimentos apresenta-se como uma alternativa tecnológica e econômica de grande interesse ambiental. Com a finalidade de se obter parâmetros que possibilitem uma avaliação de viabilidade técnica de argamassas e concretos fabricados com a inclusão de resíduos de construção e demolição (RCD), especificamente o ACR (agregado de concreto reciclado), na produção de corpos-de prova e Peças de Concreto Prémoldadas para pavimentação intertravada, neste trabalho é apresentado um estudo de determinação de suas principais propriedades mecânicas, considerando a substituição parcial do agregado miúdo por agregado reciclado de concreto. Para tanto, foram realizados no desenvolvimento desta pesquisa ensaios de caracterização das principais propriedades mecânicas e físicas da argamassa e do concreto produzido com o ACR, conforme normas da ABNT e ASTM.

Este trabalho tem por objetivo avaliar o desempenho dos equipamentos de radilogia digital, especificamente, mamógrafo de campo total e mamógrafos convencionais no que se refere à detecção de sinais e em termos da geometria da exposição. O trabalho se desenvolve a partir da formação de um conjunto de imagens mamográficas do simulador ACR modelo 156; este conjunto é composto por imagens mamográficas de equipamentos convencionais e digitais de campo total e imagens obtidas por um simulador radiográfico incorporado a um pacote computacional que fornece informações características de equipamentos radiológicos quanto ao desempenho do sistema em termos da geometria de exposição como ponto focal, limites de resolução e ruído aleatório produzido. A partir dos resultados das interpretações das imagens do simulador ACR pelos observadores, determina-se o índice de acertos; paralelamente analisam-se os dados relativos à geometria da exposição. / This work is aimed at evaluating the performance of digital radiology especially full digital mammograph and conventional mammograph in order to detect signals send in terms of geometry of the exposition. The work is developed from the formation of a pool of mammographic images of the ACR Phantom 156; this bank is formed by mammograph images of both conventional and full field digital equipments and images got by a radiographic test gadget linked to a software package that provides typical information of radiologic equipments concerning the system\'s performance regarding geometric of exposition like focal spot, margins of resolution and aleatory noise. From the results of the interpretation of the ACR simulator\'s images by the observers, then, we are able to determine what is right, at the same time to analyze the data related to the geometry of exposition.

Este trabalho tem por objetivo avaliar o desempenho dos equipamentos de radilogia digital, especificamente, mamógrafo de campo total e mamógrafos convencionais no que se refere à detecção de sinais e em termos da geometria da exposição. O trabalho se desenvolve a partir da formação de um conjunto de imagens mamográficas do simulador ACR modelo 156; este conjunto é composto por imagens mamográficas de equipamentos convencionais e digitais de campo total e imagens obtidas por um simulador radiográfico incorporado a um pacote computacional que fornece informações características de equipamentos radiológicos quanto ao desempenho do sistema em termos da geometria de exposição como ponto focal, limites de resolução e ruído aleatório produzido. A partir dos resultados das interpretações das imagens do simulador ACR pelos observadores, determina-se o índice de acertos; paralelamente analisam-se os dados relativos à geometria da exposição. / This work is aimed at evaluating the performance of digital radiology especially full digital mammograph and conventional mammograph in order to detect signals send in terms of geometry of the exposition. The work is developed from the formation of a pool of mammographic images of the ACR Phantom 156; this bank is formed by mammograph images of both conventional and full field digital equipments and images got by a radiographic test gadget linked to a software package that provides typical information of radiologic equipments concerning the system\'s performance regarding geometric of exposition like focal spot, margins of resolution and aleatory noise. From the results of the interpretation of the ACR simulator\'s images by the observers, then, we are able to determine what is right, at the same time to analyze the data related to the geometry of exposition.

A produção de energia elétrica em usinas de açúcar e álcool em sistema de co-geração tendo como combustível o bagaço da cana-de-açúcar é uma prática tradicional. No Brasil, desde os anos 1980, as usinas evoluíram para uma posição de quase auto-suficiência na produção de eletricidade, indicando um forte potencial de produção de eletricidade excedente que pode ser incorporado à matriz energética nacional como complemento. O interesse pela geração de energia por fontes renováveis ganhou destaque devido ao risco de desabastecimento e à necessidade de adequações tecnológicas por parte das usinas. Entretanto, embora o potencial exista, há fatores que influenciam e colocam em risco a decisão de uma usina investir na geração de excedentes que devem ser analisados, dentre eles a volatilidade dos preços da energia. O objetivo deste trabalho é analisar o processo de formação de preço da energia elétrica gerada a partir de biomassa negociada no Ambiente de Contratação Livre (ACL). Neste ambiente, a energia gerada por biomassa pode ser negociada bilateralmente por agentes privados (geradores e consumidores livres). Mais precisamente, pretende-se mostrar como o risco hidrológico incorporado no processo de formação de preço e no despacho físico da geração do sistema hidrotérmico brasileiro afeta o preço da energia elétrica gerada a partir de biomassa negociada no ACL, dadas suas atuais características institucionais. Para isso, desenvolve-se um mercado artificial de energia elétrica gerada por biomassa que busca captar as principais características institucionais do ACL. Várias simulações são geradas pelo modelo computacional, as quais mostram o impacto negativo da volatilidade do preço de curto prazo sobre os preços da energia elétrica gerada por biomassa negociada no ACL. / Electricity generation in ethanol and sugar mills using bagasse as a fuel in cogeneration process is a traditional practice. In Brazil, since the 1980s mills have evolved to a position of almost self-sufficiency in electricity production, which indicates a strong potential of electricity surplus that can be used as a complement in the electricity national matrix. Such interest for electricity generation from renewable sources got outstanding due to the lack of supply risk and also the mills necessity of technological adaptations. However, even though the potential exists, there are some factors that influence and put in risk a mills decision to invest in electricity surplus generation which must be evaluated, such as energy prices volatility. The objective of this work is to analyze the electricity price setting process generated by sugarcane biomass and negotiated in the Free Agreement Environment (ACL). In this environment, biomass generated electricity can be negotiated among private agents (free consumers and generators). More precisely, the aim is to show how the hydrological risk that is part of the price setting process and of the system physical dispatch affects the price of the biomass electricity in the ACL, given its actual institutional features. To enable that, an electricity biomass artificial market is developed with the aim to capture the main institutional features of ACL. Several simulations are generated by this computational model, which show the negative impact of spot price volatility over the biomass electricity prices in ACL.

A produção de energia elétrica em usinas de açúcar e álcool em sistema de co-geração tendo como combustível o bagaço da cana-de-açúcar é uma prática tradicional. No Brasil, desde os anos 1980, as usinas evoluíram para uma posição de quase auto-suficiência na produção de eletricidade, indicando um forte potencial de produção de eletricidade excedente que pode ser incorporado à matriz energética nacional como complemento. O interesse pela geração de energia por fontes renováveis ganhou destaque devido ao risco de desabastecimento e à necessidade de adequações tecnológicas por parte das usinas. Entretanto, embora o potencial exista, há fatores que influenciam e colocam em risco a decisão de uma usina investir na geração de excedentes que devem ser analisados, dentre eles a volatilidade dos preços da energia. O objetivo deste trabalho é analisar o processo de formação de preço da energia elétrica gerada a partir de biomassa negociada no Ambiente de Contratação Livre (ACL). Neste ambiente, a energia gerada por biomassa pode ser negociada bilateralmente por agentes privados (geradores e consumidores livres). Mais precisamente, pretende-se mostrar como o risco hidrológico incorporado no processo de formação de preço e no despacho físico da geração do sistema hidrotérmico brasileiro afeta o preço da energia elétrica gerada a partir de biomassa negociada no ACL, dadas suas atuais características institucionais. Para isso, desenvolve-se um mercado artificial de energia elétrica gerada por biomassa que busca captar as principais características institucionais do ACL. Várias simulações são geradas pelo modelo computacional, as quais mostram o impacto negativo da volatilidade do preço de curto prazo sobre os preços da energia elétrica gerada por biomassa negociada no ACL. / Electricity generation in ethanol and sugar mills using bagasse as a fuel in cogeneration process is a traditional practice. In Brazil, since the 1980s mills have evolved to a position of almost self-sufficiency in electricity production, which indicates a strong potential of electricity surplus that can be used as a complement in the electricity national matrix. Such interest for electricity generation from renewable sources got outstanding due to the lack of supply risk and also the mills necessity of technological adaptations. However, even though the potential exists, there are some factors that influence and put in risk a mills decision to invest in electricity surplus generation which must be evaluated, such as energy prices volatility. The objective of this work is to analyze the electricity price setting process generated by sugarcane biomass and negotiated in the Free Agreement Environment (ACL). In this environment, biomass generated electricity can be negotiated among private agents (free consumers and generators). More precisely, the aim is to show how the hydrological risk that is part of the price setting process and of the system physical dispatch affects the price of the biomass electricity in the ACL, given its actual institutional features. To enable that, an electricity biomass artificial market is developed with the aim to capture the main institutional features of ACL. Several simulations are generated by this computational model, which show the negative impact of spot price volatility over the biomass electricity prices in ACL.

Biologic therapies have revolutionized the treatment of rheumatoid arthritis, a common chronic inflammatory disease, mainly characterized by the chronic inflammation of the joints. The activity and progression of the disease are highly variable, both between subjects and between the successive assessments for the same subject. Standardized assessments of clinical variables have been developed to reflect the disease activity and evaluate new therapies. Pharmacokinetics-pharmacodynamic (PKPD) models and methods for analyzing the generated time-course data are needed to improve the interpretation of the clinical trials’ outcomes, and to describe the variability between subjects, including patients characteristics, disease factors and the use of concomitant treatments that may affect the response to treatment. In addition, good simulation properties are also desirable for predicting clinical responses for various populations or for different dosing schedules. The aim of this thesis was to develop methods and models for analyzing pharmacokinetic and pharmacokinetic-pharmacodynamic (PKPD) data from rheumatoid arthritis patients, illustrated by treatment with a new anti-TNFα biologic drug under clinical development, certolizumab pegol. Two models were developed that characterized the relationship between the exposure to the drug and the efficacy ACR variables that represent improvement of the disease; a logistic-type Markov model for 20% improvement (ACR20) and a continuous-type Markov model for simultaneous analysis of 20% (ACR20), 50% (ACR50) and 70% (ACR70) improvement. Both models accounted for the within-subjects correlation in the successive clinical assessments and were able to capture the observed ACR responses over time. Simulations from these models of the ACR20 response rate supported dosing regimens of 400 mg at weeks 0, 2 and 4 to achieve a rapid onset of response to the treatment, followed by 200 mg every 2 weeks, or alternative maintenance regimen of 400 mg every 4 weeks. The immunogenicity induced by the biologic drug was characterized by a time to event model describing the time to appearance of antibodies directed against the drug. The immunogenicity was predicted to appear mainly during the first 3 months following the start of the treatment and to be reduced at higher trough concentrations of CZP, as well as with concomitant administration of MTX. The full time-course of sequential events, such as dose-exposure-efficacy relations, is most accurately described by a simultaneous analysis of all data. However, due to the complexity and runtime limitations of such an analysis, alternatives are often used. In this thesis, a method, IPPSE, was developed and compared to the reference simultaneous method and to existing alternative methods. The IPPSE method was shown to provide accuracy and precision of estimates similar to the simultaneous method, but with easier implementation and shorter run times. In conclusion, two PKPD models and one immunogenicity model were developed for evaluation of the response of a biologic drug against rheumatoid arthritis that allowed accurate analysis and simulation of clinical trial data, as well as serving as examples for how a model-informed basis for decisions about biological drugs can be created.

No description available.

Reumatoid artrit (RA) är den vanligaste autoimmuna sjukdomen och prevalensen är 0.5-1.0% av populationen i industriella länder. Diagnos av RA sker bland annat genom analys av markörerna reumatoid faktor (RF) samt antikroppar mot cykliskt citrullinerad peptid (anti-CCP). Nefelometrisk metod samt CMIA har båda varit huvudmetoder för markörerna RF och anti-CCP respektive vid utredning av RA på Laboratoriemedicin på Länssjukhuset Ryhov i Jönköping. Införskaffning av instrumentet Phadia 250 har gjort det möjligt att sammanställa analyserna för markörerna på samma enhet. Syftet med studien var att verifiera EliA-metoden för anti-CCP samt RF på instrumentet Phadia 250 för att kunna ersätta nuvarande analysmetoder för de båda RA-markörerna. Bestämning av cut-off, mellanliggande precision, inomserieprecision samt överensstämmelse med tidigare metod utfördes. Totalt 115 prover (70 blodgivare, 30 patientprover och 15 konsekutiva prover) användes. En korrelation utfördes för CMIA respektive nefelometriska metoden med EliA-metoden samt en kategoriöverensstämmelse för nefelometrisk metod, CMIA och EliA-metoden. God korrelation erhölls för anti-CCP mellan CMIA och EliA-metoden (r=0.953, p=0.001) samt för RF mellan nefelometriska metoden och EliA-metoden (r=0.835, p=0.048). Analys av samtliga markörer bör inkluderas som screening för RA för att upptäcka sjukdomen. Metoden EliA tillät analys av båda markörer och verifieringen möjliggjorde övergången till EliA-metoden för Laboratoriemedicin i Jönköping. / Rheumatoid arthritis (RA) is the most common autoimmune disease and the prevalence is 0.5-1.0% among the population in industrial countries. Diagnosis of RA is based partially on detection of the autoantibodies rheumatoid factor (RF) and anti-cyclic citrullinated peptide antibodies (anti-CCP). Nephelometry and CMIA have been the main methods for detection of the antibodies at Laboratoriemedicin at the County Hospital Ryhov in Jönköping. The purpose of this study was to verify the EliA-method for anti-CCP and RF on Phadia 250 in order to replace the current methods with the EliA-method. Determination of cut-off, intermediate precision, within-run precision and consistency with the previous method was performed on a total of 115 samples (70 blood-donors, 30 patient samples and 15 consecutive samples). A correlation between CMIA and the nephelometric method with EliA-method was performed and a cathegorical correspondance was done to assess the accordance between the previous methods with the EliA-method. A good correlation was obtained for anti-CCP between CMIA and the EliA-method (r=0.953, p=0.001) and RF obtained good correlation between the nephelometric method and the EliA-method (r=0.835, p=0.048). Analysis of both markers simultaneously has been recommended and the verification enabled the transition to the EliA-method on Phadia 250 for Laboratoriemedicin in Jönköping.

No description available.