Os solos brasileiros apresentam baixa disponibilidade de fósforo (P). Devido à natureza mineralógica desses solos, a adubação é uma tarefa difícil, em função dos processos de adsorção específica e precipitação, que causam baixa recuperação do P aplicado. Os fertilizantes totalmente acidulados (FTA), com praticamente todo P solúvel em água, são as fontes mais utilizadas no Brasil. Porém, a utilização dessas fontes, pode não ser o mais indicado para esses solos. Teoricamente, o fertilizante fosfatado ideal possibilitaria suprir a demanda inicial da planta, apresentando ainda liberação lenta durante o ciclo da cultura, resultando em cinética de liberação do P mais ajustada a demanda das culturas. Com base nessa premissa, objetivou-se com esse trabalho avaliar a eficiência de fertilizantes fosfatados produzidos por meio da mistura no mesmo grânulo de FTA, fosfato natural reativo de Bayóvar (FN) e enxofre elementar (S0). Os fertilizantes foram avaliados em experimentos de incubação, casa de vegetação e campo. O estudo de incubação foi conduzido com objetivo de avaliar a difusão, disponibilidade e produtos de reação do P e S dos fertilizantes: fosfato monoamônico (MAP), superfosfato triplo (SFT) e MES (MicroEssentials®); e os fertilizantes produzidos: MAP+FN, MAP+FN+S0[2:1], MAP+FN+S0[1:1], SFT+FN e SFT+FN+S0[2:1], obtidos por meio da granulação dos FTA com o FN, na relação 1:1, com base no P total das fontes, com ou sem adição de S0 na composição. Os fertilizantes produzidos com MAP proporcionaram maiores difusões e disponibilidade do P, do que os fertilizantes com SFT. O S0 melhorou a difusão e disponibilidade do P dos fertilizantes produzidos, principalmente nos fertilizantes contendo MAP. Dois experimentos foram conduzidos em casa de vegetação, destacando-se como objetivos principais: estudar a proporção entre os FTA o FN e a presença do S0 na mistura; quantificar o efeito do S0 no aumento da absorção de P do FN, utilizando o 32P e avaliar os fertilizantes com S0 na composição em fornecer S para a cultura do milho, comparando-os com fertilizantes comerciais. Nos fertilizantes com 50% de MAP ou SFT, o aumento na absorção de P dos fertilizantes em função da adição do S0 foi de 26 e 18%, respectivamente. Os fertilizantes com S0 na composição foram menos eficientes no fornecimento de S para o milho do que o S0 aplicado em pó, mas, foram mais eficientes do que o fertilizante contendo S0 pastilhado com bentonita. O estudo de campo foi conduzido com a cultura da soja em um Latossolo Vermelho na região do Cerrado, município de Itiquira-MT. Os fertilizantes avaliados foram: MAP, FN, MAP+FN, MAP+FN+S0[2:1] e MAP+FN+S0[1:1], aplicados a lanço e localizado. Os fertilizantes MAP+FN[2:1] e MAP+FN[1:1] obtiveram eficiência agronômica superior à do MAP+FN e semelhantes à do MAP. Os fertilizantes produzidos com S0 na composição apresentam potencial para serem utilizados na agricultura, podendo ser fontes alternativas aos FTA, ainda com fornecimento de S. Este foi provavelmente o primeiro estudo de campo utilizando essa associação. Outros estudos, em outras condições de solo e clima, devem ser realizados para confirmar a viabilidade do uso dessas fontes. / Brazilian soils has low phosphorus (P) availability. Due to the mineralogical composition of these soils, fertilization is a challenge, because of the specific adsorption and precipitation processes, causing low P recovery from fertilizers. Fully acidulated P fertilizers (FAP), practically with all P soluble in water, are the most used sources in Brazil. However, they may not be the most appropriate sources for these soils. Theoretically, the ideal phosphate fertilizer would be the one which supplies the initial plant demand as well as releases slowly P during the crop cycle, allowing better synchronization between the plant demand and dissolution of P source. Based on this premise, the aim of this study was to evaluate the efficiency of phosphate fertilizers produced by mixture of FAP, Bayóvar phosphate rock (PR) and elemental sulfur (S0) in the same granule. The fertilizers were evaluated in incubation, greenhouse and field trials. The incubation study was carried out to evaluate the diffusion, availability and reaction products of P and S from the fertilizers: monoammonium phosphate (MAP), triple superphosphate (TSP) and MES (MicroEssentials®); and the produced fertilizers: MAP+PR, MAP+PR+S0[2:1], MAP+PR+S0[1:1], TSP+PR and TSP+PR+S0[2:1], obtained by granulation of FAP with PR in the ratio 1:1, based on total P content, with or without S0 in the composition. Fertilizers with MAP in the composition resulted in better P diffusion and availability than the fertilizers with TSP. The S0 improved the P diffusion and availability mainly from fertilizers produced with MAP. Two experiments were carried out in greenhouse, with the objectives to: study the FAP and PR ratio and S0 presence in the mixture; quantify the S0 effect for increasing the P uptake from PR, using 32P; and evaluate the fertilizers with S0 in the composition to provide sulfur (S) for maize, comparing them with commercial sources. The S0 presence in the granule improved the P uptake on 26 and 18% from the fertilizers produced with 50 % from MAP or TSP, respectively. The fertilizers with S0 in the composition were less efficient than powdered S0 providing S to maize, but they were better than commercial fertilizer with bentonite+S0. The field trial was carried out with soybean in an Oxisol in Cerrado region, Itiquira-MT. The fertilizers evaluated were: MAP, PR, MAP+PR, MAP+PR+S0[2:1] and MAP+PR+S0[1:1] applied in band or broadcast. The fertilizers MAP+PR+S0[2:1] and MAP+PR+S0[1:1] were better than MAP+PR and similar to MAP on soybean yield and agronomic efficiency. Fertilizers produced by MAP+PR and S0 in the same granule can be potential sources to be used in agriculture, could be alternative sources for FAP, moreover can supply S to crops. Probably this was the first study using the abovementioned association. Other studies in others soils and weather conditions should be carried out to confirm the potential use of these sources.

A crescente introdução de variados poluentes em matrizes ambientais de áreas urbanas causa prejuízos ao ecossistema e dificulta as medidas de controle ambiental. Essas substâncias, após liberadas, se distribuem e interagem de acordo com suas características e as do meio receptor. Indicadores precoces de contaminação permitem a adoção de medidas preventivas aos danos causados pela poluição ambiental. O presente estudo teve por objetivo investigar a ação de substâncias genotóxicas em diferentes frações de material particulado atmosférico e solos, analisando a presença de contaminantes orgânicos e inorgânicos. Para este fim, foi empregado o ensaio Salmonella/microssoma em amostras de áreas urbanas caracterizadas como urbano-residencial e urbano-industrial, na cidade de Rio Grande, RS. Amostras de material particulado atmosférico (PTS e PM2,5) e de solo superficial (composição granulométrica total e fração <0,5mm) foram preparadas por diferentes métodos de extração. Este estudo apresenta uma primeira caracterização de PM2,5, através do ensaio Salmonella/microssoma, no Brasil. O estudo de extratos orgânicos e aquosos de PTS e PM2,5 evidenciou a presença de compostos metálicos na fração aquosa, potencialmente biodisponíveis, bem como maior risco de exposição associado à fração de compostos orgânicos das partículas finas. A mutagênese foi detectada, mesmo em amostras de particulados que se encontravam em conformidade com os parâmetros de qualidade recomendados. A análise das extrações ácidas dos solos mostrou que as chuvas da região podem atuar como rota de contaminação ambiental, com risco adicional na disponibilização de substâncias tóxicas nos eventos de precipitação ácida. O estudo mostrou que o emprego do solo com mínima alteração é mais apropriado para os ensaios de mutagênese. A utilização conjunta de diferentes métodos de extração de compostos orgânicos e inorgânicos permite uma avaliação integradora da qualidade de matrizes ambientais complexas, favorecendo a adoção de medidas preventivas para a proteção do ecossistema. / The increasing introduction of different pollutants into the environmental matrices of urban areas damages the ecosystem and makes it difficult to perform environmental control. After these substances are released, they are distributed and interact according to their own characteristics and those of the receiving environment. Early indicators of contamination allow measures to be adopted to prevent damage caused by environmental pollution. The purpose of this study was to investigate the action of genotoxic substances in different fractions of atmospheric particulate matter and soils, analyzing the presence of organic and inorganic contaminants. For this, the Salmonella/microsome assay was used on samples of urban areas characterized as urban-residential and urban-industrial, in the city of Rio Grande, RS. Samples of atmospheric particulate matter (TSP and PM2.5) and of surface soil (total grain size composition and fraction <0.5mm) were prepared using different extraction methods. This study presents a first characterization of PM2.5 in Brazil, through the Salmonella/microsome assay. The study of organic and aqueous extracts of TSP and PM2.5 showed the presence of potentially bioavailable metallic compounds in the aqueous fraction, as well as a greater risk of exposure associated with the fraction of organic compounds of the fine particles. Mutagenesis was detected even in samples of particulates that were in accordance the recommended quality parameters. Analysis of acid extractions from the soils showed that rainfall in the region may act as an environmental contamination route, with an additional risk of making toxic substances available in acid precipitation events. The study showed that the use of minimally altered soil is more appropriate for mutagenesis assays. The joint use of different methods for organic and inorganic compound extractions allows an integrated evaluation of the quality of complex environmental matrices, favoring the adoption of preventive measures to protect the ecosystem.

Breast cancer is the most common malignancy among women and represents a serious health problem around the world. Despite of the progression in cancer research, there is a few biomarker validated to be used in clinical routine. Thus, this work aimed to investigate the levels of four serum proteins related with the mostly earlier events of breast cancer. For this purpose, serum levels of EGFR1, HER-2, TSP-1 and RANKL were investigated in twenty-eight patients with breast cancer in the early and advanced stage by ELISA method. Nineteen volunteers with no breast cancer were included in this study as controls. The results showed that serum EGFR1 (sEGFR1) levels decrease with disease progression. The mean sEGFR1 concentration in control group was 61.7 ng/mL, 38.0 ng/mL in initial breast cancer and 34.2 ng/mL in metastatic breast cancer. The best cutoff value was 46.85 ng/mL, it was able to distinguish volunteers and breast cancer patients with 75% sensitivity, and 94.7% specificity. Regarding sHER-2, its levels were found to increase with disease progression. Serum HER-2 (sHER-2) median in control group was 5.13 ng/mL, and in initial breast, and metastatic breast cancer women the mean was 5.99 ng/mL and 6.18 ng/mL, respectively. A cutoff value of 5.38 ng/mL of HER-2 was able to distinguish healthy and breast cancer individuals with 81.5% of sensitivity and 78.9% of specificity. Regarding TSP-1, women with metastatic breast cancer had significantly lower levels than control group and initial breast cancer. Besides although initial patients tend to have a higher concentration than control group, no statistical difference was observed. Concerning serum RANKL no differences was observed between the groups. In conclusion, our results bring evidence that sEGFR1 and sHER-2 should be investigated in a large clinical trial in an attempt to validate these proteins as potentials biomarkers for earlier detection of breast cancer. / O câncer de mama é a neoplasia maligna mais comum entre as mulheres e representa um sério problema de saúde pública em todo o mundo. Apesar dos avanços em pesquisas na área de cancerologia, há poucos biomarcadores validados para uso na rotina clínica. Assim, este trabalho teve como objetivo investigar os níveis de quatro proteínas do soro relacionadas com os eventos em sua maioria anteriores do câncer de mama. Para este efeito, os níveis séricos de EGFR1, HER-2, TSP-1 e RANKL foram investigados em vinte e oito pacientes com câncer de mama em estádio inicial e avançado, pelo método de ELISA. Dezenove voluntárias sem câncer de mama foram incluídas neste estudo como grupo controle. Os resultados mostraram que os níveis séricos de EGFR1 (sEGFR1) diminui com a progressão da doença. A concentração média de sEGFR1 no grupo controle foi de 61,7 ng/mL, 38,0 ng/mL no câncer de mama inicial e 34,2 ng/mL no câncer de mama metastático. O melhor valor de cutoff foi 46,85 ng/mL, com sensibilidade de 75% e 94,7% de especificidade para distinguir entre pacientes com câncer de mama e grupo controle. Com relação ao sHER-2, as concentrações foram encontradas para aumentar com a progressão da doença. A concentração mediana de sHER-2 no grupo de controle foi de 5,13 ng/mL, e em pacientes com a neoplasia em sua fase inicial e com câncer de mama metastático a mediana foi de 5,99 ng/mL e 6,18 ng/mL, respectivamente. Um valor de cutoff de 5,38 ng/mL de HER-2 foi capaz de distinguir indivíduos saudáveis e de câncer de mama, com 81,5% de sensibilidade e 78,9% de especificidade. Quanto à sTSP-1, mulheres com câncer de mama metastático têm níveis mais baixos do que o grupo controle e pacientes com câncer inicial. Além disso, embora as pacientes iniciais tendessem a ter uma concentração mais elevada do que o grupo controle, não houve diferença estatística. Quanto ao sRANKL nenhuma diferença foi observada entre os grupos. Por último, os nossos resultados trazem evidências de que os níveis de sEGFR1 e sHER-2 devem ser investigados em ensaios clínicos com tamanho amostral significativo na tentativa de se validar estas proteínas como potenciais biomarcadores para a detecção precoce do câncer de mama. / Mestre em Imunologia e Parasitologia Aplicadas

A crescente introdução de variados poluentes em matrizes ambientais de áreas urbanas causa prejuízos ao ecossistema e dificulta as medidas de controle ambiental. Essas substâncias, após liberadas, se distribuem e interagem de acordo com suas características e as do meio receptor. Indicadores precoces de contaminação permitem a adoção de medidas preventivas aos danos causados pela poluição ambiental. O presente estudo teve por objetivo investigar a ação de substâncias genotóxicas em diferentes frações de material particulado atmosférico e solos, analisando a presença de contaminantes orgânicos e inorgânicos. Para este fim, foi empregado o ensaio Salmonella/microssoma em amostras de áreas urbanas caracterizadas como urbano-residencial e urbano-industrial, na cidade de Rio Grande, RS. Amostras de material particulado atmosférico (PTS e PM2,5) e de solo superficial (composição granulométrica total e fração <0,5mm) foram preparadas por diferentes métodos de extração. Este estudo apresenta uma primeira caracterização de PM2,5, através do ensaio Salmonella/microssoma, no Brasil. O estudo de extratos orgânicos e aquosos de PTS e PM2,5 evidenciou a presença de compostos metálicos na fração aquosa, potencialmente biodisponíveis, bem como maior risco de exposição associado à fração de compostos orgânicos das partículas finas. A mutagênese foi detectada, mesmo em amostras de particulados que se encontravam em conformidade com os parâmetros de qualidade recomendados. A análise das extrações ácidas dos solos mostrou que as chuvas da região podem atuar como rota de contaminação ambiental, com risco adicional na disponibilização de substâncias tóxicas nos eventos de precipitação ácida. O estudo mostrou que o emprego do solo com mínima alteração é mais apropriado para os ensaios de mutagênese. A utilização conjunta de diferentes métodos de extração de compostos orgânicos e inorgânicos permite uma avaliação integradora da qualidade de matrizes ambientais complexas, favorecendo a adoção de medidas preventivas para a proteção do ecossistema. / The increasing introduction of different pollutants into the environmental matrices of urban areas damages the ecosystem and makes it difficult to perform environmental control. After these substances are released, they are distributed and interact according to their own characteristics and those of the receiving environment. Early indicators of contamination allow measures to be adopted to prevent damage caused by environmental pollution. The purpose of this study was to investigate the action of genotoxic substances in different fractions of atmospheric particulate matter and soils, analyzing the presence of organic and inorganic contaminants. For this, the Salmonella/microsome assay was used on samples of urban areas characterized as urban-residential and urban-industrial, in the city of Rio Grande, RS. Samples of atmospheric particulate matter (TSP and PM2.5) and of surface soil (total grain size composition and fraction <0.5mm) were prepared using different extraction methods. This study presents a first characterization of PM2.5 in Brazil, through the Salmonella/microsome assay. The study of organic and aqueous extracts of TSP and PM2.5 showed the presence of potentially bioavailable metallic compounds in the aqueous fraction, as well as a greater risk of exposure associated with the fraction of organic compounds of the fine particles. Mutagenesis was detected even in samples of particulates that were in accordance the recommended quality parameters. Analysis of acid extractions from the soils showed that rainfall in the region may act as an environmental contamination route, with an additional risk of making toxic substances available in acid precipitation events. The study showed that the use of minimally altered soil is more appropriate for mutagenesis assays. The joint use of different methods for organic and inorganic compound extractions allows an integrated evaluation of the quality of complex environmental matrices, favoring the adoption of preventive measures to protect the ecosystem.

Submitted by Carla Santos (biblioteca.cp2.carla@bahiana.edu.br) on 2018-11-12T17:15:36Z No. of bitstreams: 1 Adenilda Lopes Martins.pdf: 4438150 bytes, checksum: 19b5db198be60cf56e04df208034b075 (MD5) / Approved for entry into archive by JOELMA MAIA (ebmsp-bibliotecacp2@bahiana.edu.br) on 2018-11-12T19:42:18Z (GMT) No. of bitstreams: 1 Adenilda Lopes Martins.pdf: 4438150 bytes, checksum: 19b5db198be60cf56e04df208034b075 (MD5) / Made available in DSpace on 2018-11-12T19:42:18Z (GMT). No. of bitstreams: 1 Adenilda Lopes Martins.pdf: 4438150 bytes, checksum: 19b5db198be60cf56e04df208034b075 (MD5) Previous issue date: 2018-04-23 / O V??rus Linfotr??pico Humano de C??lulas T do tipo 1 (HTLV-1) infecta cerca de cinco a dez milh??es de pessoas em todo o mundo e em Salvador afeta cerca de 9% das mulheres acima de 50 anos. Existem relatos de uma associa????o entre S??ndrome de Sj??gren, ceratoconjuntivite seca e xerose com a infec????o pelo HTLV-1. Al??m disso, maior preval??ncia de Disfun????o Er??til (DE) est?? relatada em homens com HTLV-1. Contudo, em mulheres infectadas pelo HTLV-1, n??o existem estudos sobre disfun????o sexual (DS), ou a preval??ncia de vagina seca. Objetivo: Investigar se existe associa????o entre a infec????o pelo HTLV-1 em mulheres e a presen??a de disfun????o sexual (DS), bem como avaliar a presen??a de vagina seca nestas mulheres. M??todos: Corte transversal em que foram estudadas 72 mulheres infectadas pelo HTLV-1 (15 com e 57 sem Mielopatia Associada ao HTLV-1/Paraparesia Esp??stica Tropical - HAM/TSP), atendidas no Centro de Neuroci??ncias do Ambulat??rio Docente Assistencial da Escola Bahiana de Medicina e Sa??de P??blica (EBMSP) selecionadas sequencialmente no momento da consulta. Foram crit??rios de inclus??o: diagn??stico de infec????o pelo HTLV-1 (ELISA e Western blot positivos), idade entre 20 e 50 anos, vida sexual ativa nas ??ltimas quatro semanas. O grupo n??o infectado pelo HTLV-1 (n=49), foi selecionado entre familiares, relacionados ou acompanhantes dos pacientes atendidos no mesmo servi??o e obedecendo os mesmos crit??rios, diferindo apenas em que o ELISA e Western blot tinham resultado negativo. Ap??s assinatura do termo de consentimento livre e esclarecido (TCLE), as mulheres responderam um question??rio com dados s??cio-demogr??ficos e o Female Sexual Function Index (FSFI), para avaliar a DS. A seguir, foram submetidas a exame ginecol??gico para coleta de secre????o c??rvico-vaginal objetivando realiza????o do Papanicolaou, ??ndice de Matura????o Vaginal (MV) e medida da lubrifica????o vaginal com uso da fita de Schirmmer. FSFI < 26,5 foi considerado como presen??a de DS. Raz??es de Preval??ncia brutas (RP) e ajustadas (RPaj) foram obtidas com a regress??o de Poisson com erro robusto. Resultados: A preval??ncia geral de DS foi de 53,70% (65/121), significativamente maior entre as mulheres com HAM/TSP (80,00%; RP: 1,78; IC 95%: 1,19-2,66) quando comparadas as n??o infectadas (44,90%). N??o foi observada maior frequ??ncia de DS entre as mulheres HTLV-1 assintom??ticas em rela????o ??s n??o-infectadas (54,40%; RP: 1,21; IC 95%: 0,82-1,79). Ap??s ajuste para idade, n??mero de filhos e renda o diagn??stico de HAM/TSP se manteve como um fator independente associado ?? presen??a de DS (RPaj:1,89; IC 95%:1,23- 2,90). A mediana (p25-p75), no dom??nio de lubrifica????o do FSFI foi semelhante nas mulheres assintom??ticas [4,8 (3,6-5,4)] e no grupo n??o infectado [4,8 (4,2-5,7)], mas reduzido nas mulheres com HAM/TSP [(4.2 (2.7-5.1); p = 0.032]. O teste de umidade vaginal mostrou uma m??dia (DP), de 13.21(4.71); 13.16(5.04) e 9.53(4.87) mm no filtro de papel, respectivamente (p = 0,027) para HTLV-1 assintom??ticos, n??o infectados e HAM/TSP mulheres. Nessa mesma ordem, as medianas (p25-p75) da MV foram de 70,00 (63,00-85,00) %; 78,00 (69,00-84,00) % e 62,50 (51,00-75,00) %, respectivamente (p=0,039). Conclus??es: Foi encontrada associa????o entre DS e a presen??a de HAM/TSP em mulheres infectadas pelo HTLV-1, bem como indicadores de maior secura vaginal nestas mulheres.

Adaptation of host receptor system to optimal detection of infection-related structures is one of the key evolutionary challenges of immunity in host-pathogen interactions. Toll-like receptors (TLRs) are genetically variable molecules of vertebrate innate immunity that recognise danger signals, e.g. pathogenic molecules. Examination of genetic variation in TLRs may reveal mechanisms of host immunity adaptation to pathogenic pressure at molecular level. Trans-species polymorphism (TSP) is a phenomenon which assumes that several identical alleles or allelic lineages are inherited from ascendant to descendant species and these may be subsequently maintained over a long period of time in a polymorphic state. Whereas in adaptive immune genes the concept of TSP is well understood, little is presently known about TSP in innate immune genes such as TLRs. In this thesis I describe genetic polymorphism in functionally-relevant regions of TLR4 and TLR5 in 192 individuals representing 20 species Paridae family (tits, chickadees and titmice). These two receptors bind mainly bacterial ligands (TLR4 detects lipopolysaccharide and TLR5 detects flagellin), being among the first ones to trigger immune response to bacterial pathogens. To differentiate presumed TSP from gene flow among species, intron sequences of six...

Autonomous underwater vehicles have become a popular countermeasure to naval mines. Saab’s AUV62-MR detects, locates and identifies mine-like objects through three phases. By extracting functionality from the AUV62-MR and placing it on a second vehicle, it is suggested that the second and third phases can be performed in parallel. This thesis investigates how to design the second vehicle so that the runtime of the mine reconnaissance process is minimized. A simulation framework is implemented to simulate the second and third phases of the mine reconnaissance process in order to test various design choices. The vehicle design choices in focus are the size and the route planning of the second vehicle. The route-planning algorithms investigated in this thesis are a nearest neighbour algorithm, a simulated annealing algorithm, an alternating algorithm, a genetic algorithm and a proposed Dubins simulated annealing algorithm. The algorithms are evaluated both in a static environment and in the simulation framework. Two different vehicle sizes are investigated, a small and a large, by evaluating their performances in the simulation framework. This thesis takes into account the limited travelling distance of the vehicle and implements a k-means clustering algorithm to help the route planner determine which mine-like objects can be scanned without exceeding the distance limit. The simulation framework is also used to evaluate whether parallel execution of the second and third phases outperforms the current sequential execution. The performance evaluation shows that a major reduction in runtime can be gained by performing the two phases in parallel. The Dubins simulated annealing algorithm on average produces the shortest paths and is considered the preferred route-planning algorithm according to the performance evaluation. It also indicates that a small vehicle size results in a reduced runtime compared to a larger vehicle.

A sensitivity analysis was performed on the transit signal priority (TSP) requesting threshold to evaluate its impact on bus performance and general traffic. Two distinct bus routes were evaluated to determine the optimal requesting threshold that would balance the positive impacts on bus performance with the negative impacts on general traffic. Route 217, a conventional bus route, and the Utah Valley Express (UVX), a bus rapid transit line, utilize a dedicated short-range communication (DSRC)-based TSP system as part of their normal, day-to-day operations. Using field-generated data exclusively, bus performance and general traffic were evaluated over a 7-month period from February through August 2019. Bus performance was evaluated through on-time performance (OTP), schedule deviation, travel time, and dwell time, while the traffic analysis was performed by evaluating split failure, change in green time, and the frequency at which TSP was served. The requesting thresholds evaluated for Route 217 were 5-, 3-, 2-, and 0-minutes, which stipulate how far behind schedule the bus must be in order to request TSP. For UVX, 5-minutes and 2-minutes, as well as ON and OFF scenarios were evaluated; ON meant the buses were always requesting regardless of how late they were, while OFF meant that no requests were made and operations would be as if there were no TSP at all. A combination of observational and statistical analyses concluded with convincing evidence that OTP, schedule deviation, and travel time improve as the requesting threshold approaches zero with negligible impacts to general traffic. For Route 217, as the requesting threshold changed from 3, to 2, to 0 minutes, OTP increased 2.0 and 2.5 percent, respectively, mean schedule deviation improved 15.9 and 20.9 seconds, respectively, and travel time decreased at 72 percent of timepoints. Meanwhile, negative impacts to traffic occurred if an increase in split failure was measured after TSP was served, a phenomenon observed a maximum of once every 43 minutes. For UVX, as the requesting threshold changed from 5, to 2 minutes, to ON, OTP increased 7.6 and 4.7 percent, respectively, mean schedule deviation improved 24.3 and 15.0 seconds, respectively, and travel time decreased between 72 percent of timepoints. Thus, it is concluded that under the TSP system as implemented, bus performance improves as the requesting threshold approaches zero with inconsequential impacts to general traffic.

No description available.

In this dissertation, we develop novel approaches to independently address two issues that are commonly encountered in machine scheduling problems: uncertainty of problem parameters (in particular, due to job processing times), and batching of jobs for processing on capacitated machines. Our approach to address the uncertainty issue regards the indeterminate parameters as random variables, and explicitly considers the resulting variability of a performance measure. To incorporate variability into the schedule selection process, we develop a method to evaluate both the expectation and variance of various performance measures for a given schedule. Our method is based on the use of mixture models to approximate a variety of distribution types. The Expectation-Maximization algorithm of Dempster et al. (1977) is applied to derive mixture models of processing time distributions. Our method, then, utilizes these mixture models to calculate the distributions of other random variables in order to derive the expectation and variance of various scheduling performance measures, assuming that the job sequencing decisions are known a priori. To make our method more computationally efficient, we adapt a mixture reduction method to control the number of mixture components used in the intermediate steps. We apply our method to two different scheduling problems: the job shop makespan scheduling problem and the single machine total weighted tardiness scheduling problem, and compare its performance with that of Monte-Carlo method. The results show the efficacy of our mixture approximation method. It generates fairly accurate results while requiring significantly less CPU times. The proposed method offers a good compromise between the Monte Carlo method, which requires extensive effort, and use of simple normal approximation, which produces lower-quality results. Next, we introduce and demonstrate for the first time in the literature the use of conditional-value-at-risk (CVaR) as a criterion for stochastic scheduling problems in order to obtain risk-averse solutions. This criterion has the tendency of minimizing both the expectation and variance of a performance measure simultaneously, which is an attractive feature in the scheduling area as most of the literature in this area considers the expectation and variance of a performance measure separately. Also, the CVaR has an added advantage of maintaining a linear objective function. We develop a scenario-based mixed integer programming formulation to minimize CVaR for the general scheduling problem involving various performance measures, and employ a decomposition-based approach for its solution. Furthermore, a set of valid inequalities are incorporated to strengthen the relaxed master problem of this decomposition scheme. The proposed approach is demonstrated on the single machine total weighted tardiness scheduling problem. Our computational investigation reveals the efficacy of the proposed decomposition approach and the effectiveness of using the CVaR as an optimization criterion for scheduling problems. Besides providing an exact approach to solve our stochastic scheduling problem, we also develop an efficient heuristic method to enable the use of CVaR for large-sized problems. To that end, we modify the Dynasearch method of Grosso et al. (2004) to minimize CVaR for a stochastic scheduling problem. Furthermore, we extend the application of CVaR to a parallel-machine total weighted tardiness problem. The use of CVaR appears to be quite promising for simultaneously controlling both the expected value and variability of a performance measure in a stochastic scheduling environment. Scenario-based formulations have frequently been used for stochastic scheduling problems. However, the determination of a lower bound can be a time-consuming task for this approach. Next, we develop a new method for scenario generation that is computationally competitive and that assures attainment of an exact lower bound. Our approach is based on discretization of random parameter distributions of job processing times. We use the idea of Recursive Stratified Sampling to partition the probability space, so that the conditional expectations in each region yield scenario-wise parameter values. These scenarios are, then, used to formulate a two-stage stochastic program, which yields a lower bound for the original stochastic problem. We provide theoretical basis of our bounding approach for both the expectation and CVaR objectives. Our discrete bounding method generates exact lower bounds, as against the probabilistic bounds generated by Sample Average Approximation. We also present results of our numerical experimentation to compare the performances of these two approaches in terms of the bound value obtained and the CPU time required. The problem pertaining to integrated batching and scheduling of jobs on capacitated parallel machines that we consider arises in the primary manufacturing sector of a pharmaceutical supply chain. We, first, develop a comprehensive mathematical programming model that can accommodate various realistic features of this problem. These features include batch production, sequence-dependent setup time/cost, and inter-period carryover of setup status. We further derive several valid inequalities that are based on the embedded subproblem structure. We also consider an alternative formulation (termed the Plant Location model) based on the lot-sizing perspective of the problem. Noting the resemblance of the campaign sequencing subproblem to the high multiplicity asymmetric traveling salesman problem (HMATSP), we adapt various ideas from the HMATSP to enforce the connectivity of the sequencing graph. Due to the complexity of this problem, we also explore the possibility of applying column generation technique for its solution. Various schemes of problem decomposition are considered, along with the use of dual stabilization technique to improve the convergence of the column generation procedure. We also develop heuristic methods to generate initial feasible solutions that further enhance the performance of the column generation method. A computational experimentation has been conducted on a data set that mimics real-life problem instances. It illustrates the effectiveness of using the proposed column generation method. / Ph. D.