<p>Renal cell carcinoma (RCC) is the most frequently lethal of urological cancers. It arises in the lining of the proximal convoluted tubule of the kidney and is most common in men ages 50–70. Often, partial or radical nephrectomy is needed to effectively treat the disease, leaving patients with reduced kidney function. RCC frequently displays significant radiation resistance, limiting the usefulness of traditional radiation therapy which might spare patients’ normal tissue. The enzyme carbonic anhydrase 9 (CA9), a product of the hypoxia pathway, is found upregulated in the majority of RCC, particularly the clear cell type. It catalyses the dissolution of carbon dioxide into water as bicarbonate and has been linked to increased invasion and migration in RCC tumour cells. The radiation resistance of two RCC cell lines 786-O (human CCRCC) and RAG (murine renal adenocarcinoma) was investigated by the clonogenic assay in the presence of a CA9 inhibitor or silencing RNA. The interference with CA9 by either of these methods significantly sensitizes 786-O cells to the effects of ionizing radiation <em>in vitro</em>. Moreover, fractionation of the dose delivered can increase this sensitization effect. It is hoped that current targeting of CA9 can make radiation therapy a more feasible option in the treatment of RCC.</p> / Master of Science (MSc)

Neste trabalho estudamos o efeito da exposição de células humanas à radiação ionizante e em associação a campos elétricos exógenos estáticos. A linhagem T47D de células de carcinoma ductal mamário foi irradiada com gamas no intervalo 0 8 Gy. A viabilidade celular da linhagem T47D exposta à radiação gama e campo elétrico estático (CEE) de 1.250 V/cm foi cerca de 12% inferior à viabilidade observada apenas com irradiação. Quando aplicado isoladamente por 24 e 72 horas o CEE não induziu toxicidade. A imunofluorescência realizada na linhagem normal MRC5 (fibroblasto de pulmão humano normal) quantificou a expressão da histona -H2AX. A quantidade de histonas fosforiladas foi cerca de 40% maior após irradiação com 2 Gy mais CEE aplicado por 1h, indicando que o campo elétrico interferiu negativamente no processo de reparo das quebras duplas de DNA. A análise de citometria de fluxo (FACS) mostrou que em células T47D tratadas com 1 e 2 Gy por 24 horas o CEE também interferiu negativamente no processo de reparo do DNA, notadamente pelo maior acúmulo de células na fase S. / Our goal is the study in human cells of the effect resulting from the association of irradiation with exposure to exogenous static electric fields. The T47D cell line of breast cancer cells was irradiated with gammas in the 0 8 Gy doses range. The viability of this T47D cells exposed to both gamma radiation and 1.250 V/cm static electric field (SEF) was about 12% lower than when only irradiated. The sole exposure of the cells to SEF by 24 and 72 hours didnt induce toxicity. Immunofluorescence runs carried out in irradiated normal MRC5 cell line of human lung fibroblast have quantified the expression of the g-H2AX histone. The amount of phosphorylated histones was approximately 40% higher after irradiation with 2 Gy plus exposure to a SEF by 1 hour, showing that the electric field negatively interfered in the repairing process of the DNA double strand breaks. The flow cytometry analysis with FACS showed that in T47D cells treated with 1 and 2 Gy by 24 hours the SEF also negatively interfered in the DNA repairing process, as evidenced by the higher accumulation of cells in the S phase.

Neste trabalho estudamos o efeito da exposição de células humanas à radiação ionizante e em associação a campos elétricos exógenos estáticos. A linhagem T47D de células de carcinoma ductal mamário foi irradiada com gamas no intervalo 0 8 Gy. A viabilidade celular da linhagem T47D exposta à radiação gama e campo elétrico estático (CEE) de 1.250 V/cm foi cerca de 12% inferior à viabilidade observada apenas com irradiação. Quando aplicado isoladamente por 24 e 72 horas o CEE não induziu toxicidade. A imunofluorescência realizada na linhagem normal MRC5 (fibroblasto de pulmão humano normal) quantificou a expressão da histona -H2AX. A quantidade de histonas fosforiladas foi cerca de 40% maior após irradiação com 2 Gy mais CEE aplicado por 1h, indicando que o campo elétrico interferiu negativamente no processo de reparo das quebras duplas de DNA. A análise de citometria de fluxo (FACS) mostrou que em células T47D tratadas com 1 e 2 Gy por 24 horas o CEE também interferiu negativamente no processo de reparo do DNA, notadamente pelo maior acúmulo de células na fase S. / Our goal is the study in human cells of the effect resulting from the association of irradiation with exposure to exogenous static electric fields. The T47D cell line of breast cancer cells was irradiated with gammas in the 0 8 Gy doses range. The viability of this T47D cells exposed to both gamma radiation and 1.250 V/cm static electric field (SEF) was about 12% lower than when only irradiated. The sole exposure of the cells to SEF by 24 and 72 hours didnt induce toxicity. Immunofluorescence runs carried out in irradiated normal MRC5 cell line of human lung fibroblast have quantified the expression of the g-H2AX histone. The amount of phosphorylated histones was approximately 40% higher after irradiation with 2 Gy plus exposure to a SEF by 1 hour, showing that the electric field negatively interfered in the repairing process of the DNA double strand breaks. The flow cytometry analysis with FACS showed that in T47D cells treated with 1 and 2 Gy by 24 hours the SEF also negatively interfered in the DNA repairing process, as evidenced by the higher accumulation of cells in the S phase.

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Orientador: Maria Márcia Pereira Sartori / Resumo: O estudo da longevidade é uma ferramenta importante na análise da qualidade fisiológica em sementes. A modelagem da curva de sobrevivência em sementes permite a predição do seu período de vida, que baliza os mais variados estudos em conservação e tecnologia de sementes. O modelo de Probit foi inicialmente proposto como o modelo ideal para predição da longevidade das sementes, contudo, estudos têm reportado certa dificuldade de predição do modelo em diferentes condições de estresse e armazenagem a que as sementes são submetidas. A equação da viabilidade em sementes a partir do modelo de Probit permite calcular o valor do P50, que é o período em que um lote de sementes leva para perder 50% da sua viabilidade. O modelo de Logit é similar ao de Probit, com a vantagem de ser mais simples, e de se adequar melhor ao comportamento dos dados com caudas pesadas. Assim, o objetivo deste estudo foi avaliar os modelos de Probit e Logit quanto a sua robustez na predição da longevidade das sementes. Para tanto, sementes de soja foram selecionadas quanto ao seu vigor, em delineamento inteiramente casualizado, e armazenadas à 35°C e 75% de umidade relativa, até que fosse constatada sua morte, por meio de testes de germinação realizados periodicamente. A construção das curvas de sobrevivência, após o experimento encerrado, permitiu a análise dos modelos de Probit e Logit, por meio dos parâmetros R2, Rajustado, e do coeficiente de correlação de Pearson. O estudo da normalidade dos resíduos tamb... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The study of longevity is an important tool in the analysis of physiological quality in seeds. The modeling of the survival curve in seeds allows the prediction of their half time life, which could be used to reference for the most varied studies on conservation and seed technology. The Probit model was initially proposed as the ideal model for seed longevity prediction, however, studies have reported about some errors found after applying the model under different stress and storage conditions in which seeds are submitted. The seed viability equation from the Probit model allows to calculate the value of P50, which is the period in which a seed lot loss 50% of its viability. The Logit model is similar to the Probit model, with the advantage of being simpler and better suited to heavy tails data, as occurs in seed longevity data. The aim of this study was to evaluate the Probit and Logit models for their robustness in predicting seed longevity. For this purpose, soybean seeds were selected according to their vigor, in a completely randomized design, and stored in 35 °C and 75% relative humidity until their death was verified by periodic germination tests. The construction of survival curves, after the experiment ended, allowed the analysis of Probit and Logit models, through the parameters R2 , Radjusted, and the Pearson correlation coefficient. The study of the normality of the residues was also performed to evaluate the models. The results showed the superiority of the Logi... (Complete abstract click electronic access below) / Doutor

在醫療科技與衛生技術飛快地進步下，死亡率不斷改善所帶來不確定產生的長壽風險，已經成為世界各國重視的議題之一，為了因應長壽風險所帶來的衝擊，壽險公司與退休基金發展出多種避險策略，商品內自然避險為其中一種。 本文以淨值免疫和現金流免疫的方法來探討商品內自然避險的效果，發現因為長壽風險造成錯誤定價的緣故，在被保人邁向高年齡時，壽險商品因死亡率改善的效果與一般預期有明顯出入，造成商品保單期間末期自然避險效果消失，本文定義此現象為“壽險反轉效果”，本文並進一步探討其生成原因與解決方法，發現其與亡率改善以及生存曲線矩形化的現象有關，本文接著探討台灣的生存曲線矩形化現象，以釐清“壽險反轉效果”的發生原因。 / Thanks to the improvement of technology and medicine, mortality rate has been improved but also triggered the uncertainty of longevity risk, making longevity risk an important issue around the world. In order to decrease longevity risk, the insurers and pension funds has developed several hedging strategies. Natural internally hedging is one of the common hedging strategies. Some of the insurance products share the concept of Natural internally hedging, such as endowment. The advantage of Natural internally hedging is that it helps the insurer to avoid basis risks and lower the management costs and expenses. However, it fails to be adjustable by varies of the unexpected mortality rate. This thesis will discuss and analyze the trend of cash flow of life insurance and annuity, aiming at establishing principles for insurance product design, which are designated to hedge longevity risk by the offset of the value of life insurance and annuity. During the research, this thesis found that the longevity risk can’t be hedged because the impact of “The reversion of Life product”. The following parts of this thesis discussed the reason why “The reversion of Life product” happened and how to solve it.

<p>Modeling microbial inactivation has a great influence on the optimization, control and design of food processes. In the area of food safety, modeling is a valuable tool for characterizing survival curves and for supporting food safety decisions. The modeling of microbial behavior is based on the premise that the response of the microbial population to the environment factors is reproducible. And that from the past, it is possible to predict how these microorganisms would respond in other similar environments. Thus, the use of mathematical models has become an attractive and relevant tool in the food industry.</p> <p>This research provides tools to relate the inactivation of microorganisms of public health importance with processing conditions used in nonisothermal and non-thermal food processing technologies. Current models employ simple approaches that do not capture the realistic behavior of microbial inactivation. This oversight brings a number of fundamental and practical issues, such as excessive or insufficient processing, which can result in quality problems (when foods are over-processed) or safety problems (when foods are under-processed). Given these issues, there is an urgent need to develop reliable models that accurately describe the inactivation of dangerous microbial cells under more realistic processing conditions and that take into account the variability on microbial population, for instance their resistance to lethal agents. To address this urgency, this dissertation focused on mathematical models, combined mathematical tools with microbiological science to develop models that, by resembling realistic and practical processing conditions, can provide a better estimation of the efficacy of food processes. The objective of the approach is to relate the processing conditions to microbial inactivation. The development of the modeling approach went through all the phases of a modeling cycle from planning, data collection, formulation of the model approach according to the data analysis, and validation of the model under different conditions than those that the approach was developed.</p> <p>A non-linear ordinary differential equation was used to describe the inactivation curves with the hypothesis that the momentary inactivation rate is not constant and depends on the instantaneous processing conditions. The inactivation rate was related to key process parameters to describe the inactivation kinetics under more realistic processing conditions. From the solution of the non-linear ordinary differential equation and the optimization algorithm, safety inferences in the microbial response can be retrieved, such as the critical lethal variable that increases microbial inactivation. For example, for nonisothermal processes such as microwave heating, time-temperature profiles were modeled and incorporated into the inactivation rate equation. The critical temperature required to increase the microbial inactivation was obtained from the optimization analysis. For non-thermal processes, such as cold plasma, the time-varying concentration of reactive gas species was incorporated into the inactivation rate equation. The approach allowed the estimation of the critical gas concentration above which microbial inactivation becomes effective. For Pulsed Electric Fields (PEF), the energy density is the integral parameter that groups the wide range of parameters of the PEF process, such as the electric field strength, the treatment time and the electrical conductivity of the sample. The literature has shown that all of these parameters impact microbial inactivation. It has been hyphothesized that the inactivation rate is a function of the energy density and that above a threshold value significant microbial inactivation begins. </p> <p>The differential equation was solved numerically using the Runge-Kutta method (<i>ode45</i> in MATLAB ®). The<i> lsqcurvefit</i> function in MATLAB ® estimated the kinetic parameters. The approach to model microbial inactivation, whether when samples were subjected to nonisothermal or to non-thermal food processes, was validated using data published in the literature and/or in other samples and treatment conditions. The modeling approaches developed by this dissertation are expected to assist the food industry in the development and validation process to achieve the level of microbial reduction required by regulatory agencies. In addition, it is expected to assist the food industry in managing food safety systems through support food safety decision-making, such as the designation of the minimal critical parameter that may increase microbial inactivation. Finally, this dissertation will contribute in depth to the field of food safety and engineering, with the ultimate outcome of having a broad and highly positive impact on human health by ensuring the consumption of safe food products.</p>

醫療技術的進步以及生活品質的提升，預計人類平均壽命將持續延長，以臺灣為例，男、女性平均壽命將從2011年的75.98歲、82.65歲，增加到2060年的82.0歲、88.0歲（資料來源：行政院經濟建設委員會2012年推估）。壽命延長意謂更長的退休生活，世界各國在21世紀均面對需求日殷的老年生活照顧，包括退休金制度以及老人醫療等，這些社會福利及保險勢必增加國家財務負擔，因此壽命是否繼續延長或存有極限成為大家關心的議題。近年來，不少研究透過死亡壓縮(Mortality Compression)連結壽命議題，亦即探討死亡年齡是否將集中至更窄的範圍，但因為資料及研究方法的限制，死亡壓縮是否成立仍無定論。 本研究以統計方法、分配假設、資料品質，三個面向來探討死亡壓縮與延壽之間的關係。本研究提出三種數值優化方法：加權最小平方法(Weighted Least Squares；WLS)、非線性極值法(Nonlinear-Maximization；NM)及最大概似估計法(Maximal Likelihood Estimation；MLE)，透過電腦模擬衡量方法優劣，與過去常見的方法比較（Kannisto的SD(M+)），探討何者具有較小的均方誤差(Mean Squared Error；MSE)。其次若死亡年齡之真實死亡分配為t分配時，探討以常態假設代入計算所產生的偏誤；最後則是套入各國實際死亡資料，使用上述較佳的估計方法，檢視死亡壓縮是否存在。 研究結果顯示，NM具有不偏性質且具有較小的均方誤差，過去研究常用的SD(M+)反而有明顯偏誤，且隨著觀察值越多變異數反而增加。而若真實死亡分配若為t分配時，以原先利用常態假設所計算的年金險保費皆有低估的情形，分配的重要性可見一斑，進而探討在實務上常態分配之假設，發現與仍與實際情形有明顯之差異，不論是NM及SD(M+)在死亡壓縮的探討下，皆受到資料的限制而有待商榷。 / Due to the advance in medical technology and the change of life style, the human life expectancy has been increasing since the end of the Second World War II and it is expected to continue the pace of increment. Longer life expectancy also means a longer life after retirement. People living in the 21st century are faced with growing demand for the retirement life, such as the pension funds and medical needs to the individuals, as well as the social welfare and insurance for the elderly to the government. Thus, the issue whether the lifespan has a limit receives a lot of attention. In particular, many studies focus on the topic of mortality compression, which means that the expectancy of lifespan has a limit and variance of lifespan converge. However, due to the availability of elderly data, there is still no consensus if the mortality compression is true. In this study, we propose estimation methods to estimate modal age and variance of the age-at-death. Three types of methods are involved: weighted least squares (WLS) method, nonlinear maximization (NM) method, and maximum likelihood estimation (MLE) method, and they are compared to the method proposed by Kannisto, namely SD(M+), in 2000. We found that the NM method has a smaller MSE, and we cannot decide the mortality compression is true based on the data from Human Mortality Database. We also applied the normality and t distribution assumption to the age-at-death and compute the pure premiums for annuity products. We found that normality distribution would produce larger premiums than using the empirical mortality rates. Similarity, the bankruptcy probability would be higher if the t distribution is used.

死亡壓縮(Mortality Compression)意指死亡年齡更集中，是最近廣受注意的研究議題，和生存曲線矩形化（Rectangularization）關係密切，以統計分佈的角度描述，則是死亡年齡會逐漸退化到某個特定年齡。換言之，如果死亡壓縮和壽命有上限兩者都成立，以統計術語而言，代表壽命的期望值有上限、變異數會收斂，可藉由死亡年齡分配探討壽命變化。 本文希望以統計方法與資料品質等兩個面向探討死亡壓縮與延壽之間的關係。除了過去使用的無母數方法，如檢視各年度生命表上死亡分佈的最短區間（25%、50%及75%）與死亡人數最多的年齡（Modal Age）的變化，探討死亡壓縮與壽命是否有延長；另一方面，也將對死亡曲線作參數設定，觀察死亡年齡分佈的標準差變化。由於過往的研究多使用的生命表資料，本研究將比較使用生命表資料（死亡資料經過修勻）或原始死亡人數資料對結果的影響。 本研究藉由電腦模擬比較各種估計標準差方法的差異，包括Kannisto (2000) 提出的SD(M+)法與本文考量的非線性極值法(Nonlinear-Maximization)，衡量何者具有較小的均方誤差，並探討錯誤設定分配偵誤的敏感度；另外，本文可討論使用經過修勻的死亡率及原始死亡率對於估計結果的影響。除了電腦模擬，本研究也套入實際死亡資料（如臺灣、美國、…等國資料，資料來源：Human Mortality Database），檢視死亡壓縮是否存在。 / Mortality compression is one of the popular research issues in longevity risk. It means that the age-at-death would concentrate on a narrower range, and it is also related to the concept of rectangularization of survival curve. In terms of statistical distribution, mortality compression indicates that the age-at-death degenerates to a certain age, and it can be used to study changes of lifespan. If the lifespan has a limit, or mortality compression does exist, this suggests that the life expectancy has a limit and the variance of age-at-death would converge. In the study, we evaluate the mortality compression using the statistical methods and considering the issue of data quality. In addition to the nonparametric methods used in the previous studies, such as shortest confidence interval on the distribution of age-at-death and the modal age, we consider optimization methods for estimating the standard deviation of age-at-death distribution. In specific, we compare the SD(M+) proposed by Kannisto (2000) and the method of Nonlinear-Maximization, and check which method has a smaller MSE (Mean Squared Error). For the issue of data quality, we compare the estimation results of using mortality rates from life table data with those using the raw data. In addition to computer simulation, we consider the sensitivity analysis of age-at-death distribution, to evaluate the estimation method. Furthermore, based on the data from Human Mortality Database, we apply the method of Nonlinear-Maximization to life table data (i.e., graduated mortality rates) and raw data, and check if there are significant differences. The estimation results of empirical study are also used to evaluate if there is mortality compression and if there is a longevity limit.