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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
351

Vad krävs för att beräkna när automatiserade användargränssnitt (GUI) tester lönar sig? : Vilka styrkor och svagheter finns med automatiserade GUI-test? / What is required in order to calculate when the automated user interface (GUI) testing is worthwhile?

Vikström, Todd, Kaiser Löv, Sara January 2019 (has links)
ROI och break-even finns för att beräkna vinster i verksamheter men det är svårt att veta hur dessa metoder kan appliceras på automatiserade GUI-test. Genom en utförd fallstudie där litteraturstudier, dokumentstudier, enkäter och intervjuer använts har det visat sig att dessa metoder kan anpassas för att beräkna vinster med automatiserade GUI-tester. Nackdelarna med dessa metoder är att de är svåra att använda om inte automatiseringen är gjord. Det behövs konkreta uppgifter över till exempel tidsåtgång för körning av både manuella och automatiserade testfall. Även om metoderna kan visa att det finns ekonomiska vinster med automatiserade GUI-tester så kan det vara många andra vinster som inte kan identifieras genom att metoderna appliceras. Dessa immateriella vinster och förluster har i arbetat identifierats genom intervjuer och enkäter och resultatet presenteras med en SWOT-analys. Flera viktiga immateriella vinster som till exempel ökad kvalitet och tidsvinst har framkommit. Även några materiella förluster har framkommit som att det kan vara kostsamt att införa automatiserade GUI-tester. Även immateriella förluster har identifierats, en av dessa är att det krävs särskild kompetens för att konstruera och köra de automatiserade testerna. / ROI and break-even are available for calculating profits in operations, but it is difficult to know how these methods can be applied to automated GUI tests. By a conducted case study in which literature review, document studies, questionnaires and interviews have been used, it has been shown that these methods can be adapted to calculate the profits with automated GUI-tests. The disadvantages with these methods are that they are difficult to use unless the automation is made. There is a need for concrete data on, for example, the time taken for the execution of both manual and automated test cases. Although the methods can show that there are financial gains with automated GUI tests, there may be many other gains that cannot be identified by applying the methods. These intangible profits and losses have been identified in the work through interviews and surveys and the results are presented with a SWOT analysis. Several important intangible benefits such as increased quality and time savings have emerged. Some material losses have also come to light as it can be costly to introduce automated GUI tests. Even intangible losses have been identified, one of these is that it requires special skills to design and run the automated tests.
352

Quebra molecular em ambiente de baixa pressão: caracterização de um stripper gasoso para a implementação de um sistema AMS de baixas energias / Molecular break up process under low pressure conditions: characterization of a gaseous stripper for the implementation of a low energy AMS

Carmignotto, Marco Antonio Pannunzio 07 April 2010 (has links)
O objetivo desse trabalho foi estudar a viabilidade de adaptação do Implantador Iônico da Universidade de São Paulo para a técnica de Accelerator Mass Spectrometry (AMS), tendo em vista as baixas energias utilizadas por este acelerador de partículas. A técnica de AMS, amplamente utilizada para a análise de Carbono-14 no estudo de datação de fósseis, requer que algum componente do acelerador garanta a quebra de moléculas de massa 14, contaminantes no processo de medição dos átomos de carbono com massa 14. Com a utilização de energias da ordem de dezenas de keV no acelerador, o estudo do processo de quebra de moléculas para estas energias foi realizado através do projeto, construção e caracterização de um stripper gasoso. Para caracterizar o stripper implementado foram realizadas medidas de seção de choque para troca de carga do feixe e quebra molecular em função da pressão de gás injetado no stripper. Também investigou-se a influência do átomo utilizado como gás, através de três diferentes gases injetados no stripper: Hélio, Argônio e Xenônio. Alguns feixes posivos foram produzidos no Implantador para o estudo destas seções de choques: Ar+, Ar(2+), CO+, CO2(+) e O2(+). O projeto do stripper foi idealizado para minimizar a variação de pressão no interior do implantador, visando preservar as condições da fonte de íons. Curvas de perfil de pressão de gás dentro do tubo do stripper foram calculadas segundo as teorias da Tecnologia do Vácuo que permitiram tanto a estimativa desta variação quanto a quantidade de gás no interior do stripper. Também foram realizados estudos do perfil de pressão em stripper com outras geometrias (cônicas abertas e fechadas), buscando estimar a otimização da espessura do stripper em função da injeção de gás em sua base. Baseando-se nos resultados, foram apontadas mudanças necessárias no atual estágio de adaptação desse acelerador de partículas para que se torne possível a concepção de um sistema AMS em sua linha de pesquisa. / The present work aimed on studying the feasibility of adapting the Ion Implanter of University of Sao Paulo to the Accelerator Mass Spectrometry technique, taking into account the low energies employed by this type of particle accelerator. The AMS technique, largely applied to the Carbon-14 analysis for fossil dating, requires the breaking of molecules with mass 14 by some component in the accelerator, since these lead to interference on the Carbon-14 counting process. By employing energies on the level of keV in the accelerator, the study of the breaking process of the molecules for this energy was accomplished by means desiring, building and characterization of a gaseous stripper. In order to characterize the installed stripper, measurements were taken of the charge state exchange and molecular break up process as a function of the pressure of the gas injection into the stripper. The influence of the atom employed as gas was also investigated. The experiments were realized with the following different gases: Helium, Argon and Xenon. Some positive beams were produced on the implanter: Ar+, \\Ar(2+), CO+, CO2(+) and O2(+). The designed stripper was idealized to minimize the pressure variation on the inside of the implanter in order to preserve the conditions of the ion source. Pressure profiles of the gas inside the stripper were calculated according to the Vacuum Technology theory, which allowed estimating the quantity of gas inside the stripper. Studies on the pressure profile for different stripper geometries (open and closed conic forms) were also carried out to estimate the optimization of the stripper thickness as a function of the gas injection on its base. Based on the results, specifications for further work and changes on the current system were listed to make it possible to implement the AMS system.
353

Estudo da função de correlação do modelo de Potts na rede de Bethe. / Study of pair correlation function of the Potts model in the Bethe lattice.

Martinez, Alexandre Souto 21 November 1988 (has links)
Neste trabalho consideramos o modelo de Potts na árvore de Cayley submetida a um campo magnético. Esse campo pode ser representado pela interação dos spins da árvore com um spin adicional, denominado spin fantasma. Essa nova rede passa a ser chamada de árvore de Cayley fechada e assimétrica. Sendo uma rede hierárquica, ela representa soluções exatas que são obtidas quando as técnicas do grupo de renormalização no espaço real são aplicadas. Subtraindo os efeitos de superfície e considerando somente o interior da árvore (rede de Bethe), esses resultados reproduzem os resultados da aproximação de campo médio de Bethe-Peierls. Com a finalidade de estudar a função de correlação do modelo de Potts na rede de Bethe, consideramos primeiramente uma cadeia de Potts interagindo com um spin fantasma. Através das regras de composição em série e paralelo e do método da quebra e colapso para as trasmissividades térmicas (função de correlação) obtemos uma fórmula de recorrência para a função de correlação entre quaisquer dois spins na cadeia. Mostramos então que pela invariança translacional da rede de Bethe qualquer par de spins pode ser mapeado no sistema anterior. A seguir consideramos o modelo de Potts de um estado na árvore de Cayley fechada e assimétrica. Decimando os spins interiores da unidade geradora da rede, obtemos um mapa polinomial quadrático para a transformação do grupo de renormalização (mapa de Bethe-Peierls). O diagrama de fase desse sistema é então obtido do conjunto de Mandelbrot através de uma transformação de Mobius. O mapa de Bethe-Peierls apresenta dois pontos fixos, que são relacionados com as fases ferro e paramagnética e o regime caótico é identificado com a fase vidro de spin. Esse sistema revela ser o exemplo mais simples de vidro de spin de McKay-Berker-Kirkpatrick. Na rede de Bethe e a campo nulo esse sistema apresenta transições de fase de segunda ordem. Analisando o comportamento crítico da função de correlação e de suas derivadas, vemos que se identificarmos a função de correlação entre o spin fantasma e qualquer spin da rede com a magnetização (por spin) e a função de correlação entre dois spins primeiros vizinhos com a energia interna do sistema, cinco expoentes críticos ((&#948, &#946, &#947 &#8217, &#945, &#945 &#8217) são calculados e satisfazem as relações de escala. Para ilustrar o procedimento recursivo apresentado para calcular a função de correlação entre dois spins separados por ligações m na rede de Bethe, consideramos os spins de Potts de um estado. Obtemos então de forma explícita as correlações para m=1, 2 e 3.0 / In this work we consider the Potts model on the Cayley tree subjected to a magnetic Field. This field can be represented by the interaction of the tree spins with an additional one, denominated ghost spin. This new lattice is then called closed-asymmetric Cayley tree. Being a hierarchical lattice it comes to have exact solutions which are obtained when the real-space renormalization group techniques are applied. Subtracting the surface effects and considering only the tree interior (Bethe lattice), these results reproduce the results of Bethe-Peierls mean-field approximation. With the objective of studying the pair-correlation function of the Potts model on the Bethe lattice, we at first consider a Potts chain interacting with a ghost spin. Throughout the series-parallel composition rules and the break-collapse method for the thermal transmissivities (pair-correlation function) we obtain a recursive relation for the correlation function between any two spins on the chain. We then show, due to the translational invariance of the Bethe lattice, that any pair of spins can be mapped into the latter system. Next we consider the one-state Potts model on the closed asymmetric tree. Decimating the inner spins of the generating unit for the lattice, we obtain a quadratic polynomial map for the renormalization group transformation (Bethe-Peierls map). The phase diagram of this system is obtained from the Mandelbrot set throughout a Mobius transformation. The Bethe-Peierls map has two stable fixed points which are related to the ferro and paramagnetic phases and the chaotic regime is identified with the spin-glass phase. This system turns out to be the simplest example of a McKay-Berker-Kirkpatrick spin glass. On the Bethe lattice with vanishing field this system presents second-order phase transitions. Analyzing the critical behavior of the pair-correlation function and of this derivatives, we see that if we identify the correlation function between the ghost spin and any spin on the lattice with the magnetization (per spin), and the correlation function between two nearest-neighbor spins with the internal energy of the system, five critical exponents (&#948, &#946, &#947 &#8217, &#945, &#945 &#8217) are calculated and they satisfy the scaling relations. In order to illustrate the recursive procedure presented to calculate the pair-correlation function between spins m bonds apart on the Bethe lattice, we consider the one-state Potts spins. We obtain explicitly the correlation for m=1, 2 and 3.
354

Deslocamentos de populações ribeirinhas e passivos sociais e econômicos decorrentes de projeto de aproveitamento hidrelétrico: A UHE Tijuco Alto/SP - PR / Riverside population displacements and passive social and passive economic resulting of projects of hydroelectric utilizations: to UHE of Tijuco High/SP-PR

Jeronymo, Alexandre Cosme José 27 April 2007 (has links)
Tratamos nesta pesquisa dos reflexos socioeconômicos gerados pela apropriação de espaço para instalação da Usina Hidrelétrica de Tijuco Alto, cujo agente investidor é a Companhia Brasileira de Alumínio (CBA). As apropriações iniciaram ao final dos anos 1980 e foram prolongadas ao longo da década de 1990. Neste processo houve pressão do agente investidor para os proprietários dos imóveis negociarem as suas propriedades. Alguns dos reflexos das apropriações de imóveis são os passivos sociais (deslocamento populacional, rupturas na sociabilidade) e os passivos econômicos (rupturas nas dinâmicas econômicas comunitárias agrícola e comercial). Finalizamos fornecendo ênfase a desorganização produzida pela Companhia Brasileira de Alumínio no espaço comunitário designado como Área de Influência Direta após o início do processo de apropriação de propriedades rurais e urbanas e os passivos socioeconômicos decorrentes. / The aim of this work is to broach the assumption correlated to the reflected socioeconomics generated by the appropriation of the space for installation of the hydroeletric plant of High Tijuco, whose investing is the agent Brazilian Company of Aliminium (CBA). The appropriations had initiated to the end of years 1980 and had been drawn out throughout the decade of 1990. In this process it had pressure of the interested party for the appropriations being directed for the proprietors of property to negotiate its properties. Some of results of the appropriations of property are the social passive (population displacement, ruptures in the sociability) and economic passive (rupture in the economic dynamics communitarian agriculturist and commercial). We finalize supplying emphasis to disorganize produced by the Brazilian Company of Aluminum in the communal space assigned like Area of Straight Influence after the beginning of the urban and rural estates appropriation trial and the passive socioeconomics resulting.
355

Efeitos do Phyllanthus niruri em parâmetros metabólicos de portadores de litíase urinária / Effect of Phyllanthus niruri on metabolic parameters of patients with kidney stone disease

Pucci, Nidia Denise 04 July 2017 (has links)
Introdução: O Phyllanthus niruri (P. niruri) ou quebra pedra é uma planta com ação antilitogênica. No entanto, estudos clínicos nesta área ainda são escassos na literatura. O objetivo principal deste estudo foi avaliar prospectivamente os efeitos do P. niruri nos parâmetros metabólicos de pacientes com litíase urinária e, secundariamente, avaliar o impacto da ingestão do chá da planta na eliminação de cálculos urinários. Material e Métodos: Foram estudados 56 pacientes portadores de cálculos renais <10 mm. Avaliação clínica, metabólica e ultrassonográfica do trato urinário foram realizadas antes do uso do P. niruri (infusão de 500 ml/dia com 9 g do extrato seco da planta), após a administração deste por 15 semanas e, finalmente após 12 semanas sem o uso (período de \"Wash out\"). Utilizamos o teste ANOVA e o teste de Tukey para comparação entre os períodos do estudo. O nível de significância considerado foi de 5%. Resultados: Trinta e seis pacientes (64%) eram mulheres. A média de idade dos 56 pacientes foi 44,1±9,16 anos. O IMC médio foi 27,2±4,4 Kg/m2. Não se observou alteração nos parâmetros antropométricos, séricos, no volume urinário ou efeitos adversos significativos durante todo o período de estudo. Houve redução da pressão arterial diastólica de 76±10,5 para 72,5±10,5 mmHg (p=0,02), quando comparado o período de uso do chá e o período de \"Wash out\". Aumento significativo dos valores do potássio urinário de 50,5±20,4 para 56,2±21,8 mEq/vol.24h (p=0,017); da relação magnésio/creatinina de 58±22,5 para 69,1±28,6 mEq/gCr.24h (p=0,013) e da relação potássio/creatinina, de 39,3±15,1 para 51,3±34,7 mEq/gCr.24h (p=0,008) foi observado ao final do período de uso do chá quando comparado com a avaliação inicial. O número de cálculos renais por paciente reduziu de 3,21±2,02 para 2,02±2,07 cálculos (p < 0,001) após o consumo do P. niruri quando comparado com o momento inicial. Na avaliação inicial, 24 pacientes apresentaram hipercalciúria e hipocitratúria (42,8%), seis apresentaram hiperuricosúria (10,7%) e cinco hiperoxalúria (8,9%). Após o uso do P. niruri, nos pacientes portadores de hiperuricosúria houve redução de 0,77±0,22 para 0,54±0,07 mg/vol.24h (p=0,0057) no valor do ácido úrico urinário. Nos portadores de hipocitratúria, o citrato urinário aumentou de 211,8±123,7 para 322,3±145,8 mg/vol.24h (p=0,0282) e nos pacientes com hiperoxalúria houve a redução no oxalato urinário de 59,0±11,7 para 28,8±16,0 mg/vol.24h (p=0,0002). Conclusão: O consumo do P. niruri se mostrou seguro e não provocou efeitos adversos ou alterações séricas relevantes e elevou a excreção urinária de magnésio e potássio. Algumas alterações metabólicas urinárias predisponentes a formação de cálculos normalizaram em subgrupos de pacientes estudados. O consumo do P. niruri contribuiu na eliminação de cálculos urinários / Introduction: Phyllanthus niruri (P. niruri) or breake-stone is a plant commonly used to reduce stone risk, however, clinical studies on this issue are lacking. The aim of this study was to prospectively evaluate the effects of P. niruri in metabolic parameters of patients with kidney stones and secondarily to evaluate the impact of the plant intake in the elimination of urinary calculi. Material and Methods: We studied 56 patients with kidney stones < 10 mm. Clinical, metabolic, and imaging studies were performed prior to P. niruri (tea infusion of 500 ml/day with 9 g of the dried plant extract), after 15 weeks of tea administration and finally after 12 weeks without the intake plant (wash out). ANOVA test for repeated measures and Tukey test and McNemars test for categorial variables. The significance level was set at 5%. Results: Thirty-six patients (64%) were female and mean age was 44.1±9.16 years-old. The mean BMI was 27.2±4.4 Kg/m2. There was no change in anthropometric and serum parameters or urinary volume throughout the study period. There was a reduction in diastolic blood pressure from 76±10.5 during the tea use to 72.5±10.5 mmHg after the wash out (p=0.02). When the tea use period was compared to the baseline assessment, there was a significant increase in urinary potassium from 50.5±20.4 to 56.2±21.8 mg/24-hour (p=0.017), magnesium/creatinine ratio from 58±22.5 to 69.1±28.6 mg/gCr24-hour (p=0.013) and potassium/creatinine ratio from 39.3±15.1 to 51.3±34.7 mg/gCr24-hour (p=0.008). The number of kidney stones per patient decreased from 3.21±2.02 to 2.02±2.07 calculi (p < 0.001) after consumption of tea compared with the initial stage. Initial evaluation showed hypercalciuria and hypocitraturia in 24 patients (42.8%), hyperuricosuria in six (10.7%) and hyperoxaluria in five cases (8.9%). In patients with hyperuricosuria there was a decrease in the amount of urinary uric acid from 0.77±0.22 to 0.54±0.07 mg/24-hour (p=0.0057). After the use of P. niruri, in patients with hypocitraturia, urinary citrate increased from 211.8±123.7 to 322.3±145.8 mg/24-hour (p=0.0282). In patients with hyperoxaluria there was a reduction in urinary oxalate from 59.0±11.7 to 28.8±16.0 mg/24-hour (p=0.0002). Conclusion: P. niruri intake is safe and does not cause significant adverse effects or significative serum metabolic changes. The use of the tea plant increases urinary excretion of magnesium and potassium. Some urinary metabolic changes predisposing to the formation of calculi normalized in subgroups of patients studied. The consumption of P. niruri contributed to the elimination of urinary calculi
356

A economia solidária e a qualificação social dos trabalhadores empobrecidos

Silva, Alex Pizzio da 07 March 2007 (has links)
Made available in DSpace on 2015-03-04T22:00:55Z (GMT). No. of bitstreams: 0 Previous issue date: 7 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Neste trabalho apresento um estudo comparativo entre dois empreendimentos econômicos solidários na área da reciclagem e de um grupo de catadores que não optaram pela forma coletiva de trabalho. Busco avaliar as possibilidades da economia solidária a partir da adesão a suas práticas e valores propiciarem um processo de qualificação social capaz de superar processos de desqualificação social, conforme os descrevem Serge Paugam. Para dar conta deste objetivo, inicialmente reviso o contexto histórico dos trabalhadores empobrecidos. Posteriormente, revisarei os estudos acerca da marginalidade e da exclusão no Brasil, a fim de melhor fundamentar o que vem a ser um processo de qualificação social. Finalmente, busco demonstrar como os trabalhadores da reciclagem, a partir do desenvolvimento de uma identidade de resistência superam os estigmas e os rótulos resultantes do exercício da atividade de catação, os quais se configuram em verdadeiros obstáculos para uma inserção como cidadãos de direitos / In this work show a comparative study between two economics solidaries enterprises in the area of recycling, and a group of collectors who did not choose by collective work way. I try evaluating the possibilities of solidary economy since your adhesion its practices and values to make possible a process of social qualification able to get over the process of lost of social qualification, according Serge Paugam. For this purpose, firstly I will review the context of the poor workers. After, I will review the studies about poorness and exclusion in Brazil, due to get a better base in relation what is a process of social qualification. Finally, I try to explain how the workers from recycling, since the development of an identity of resistance win the stigmas and the labels that came from their activity of collectors, what are truths obstacles to insertion how citizens with rights
357

An investigation of computer vision syndrome with smart devices

Abdul Rahim, Muhammad Afzam Shah Bin January 2018 (has links)
The overarching theme of the thesis was to investigate the association between smart device use and computer vision syndrome. The initial study designed and developed the Open Field Tear film Analyser (OFTA) enabling a continuous, real-time assessment of the tear film and blink characteristics during smart device use. The monocular OFTA prototype was validated and showed good intra- and inter-observer repeatability relative to the Oculus Keratograph 5M and Bausch and Lomb one position keratometer. Subsequently, tear osmolarity following engagement with reading and gaming tasks on smart device and paper platforms was investigated. Discrete measures of osmolarity pre- and post-engagement with the tasks were obtained with the TearLab osmometer; osmolarity values differed between platforms when participants were engaged in a gaming task but no such difference was observed with the reading task. In addition, the influence of repeated measurements on tear osmolarity was also explored. To simulate the habitual binocular viewing conditions normally associated with smart device use, the binocular OFTA was developed. The device was used to assess the tear film and blink characteristics whilst engaging with reading and gaming tasks on smart device and paper platforms. The results revealed differences in blink characteristics and non-invasive tear break up time between the different platforms and tasks assessed. In addition, the thesis also reports on an investigation examining the real-time accommodative response to various targets displayed on smart devices using an open-field autorefractor with a Badal lens system adaptation. The results showed that accommodative latency, accommodative lag, mean velocity of accommodation, speed of disaccommodation and mean velocity of disaccommodation varied across the different platforms. Through the use of validated subjective questionnaires and smartphone apps, the relationship between duration of smartphone use and symptoms of dry eye were examined. The findings of this study demonstrated that longer duration of smartphone and personal computer use were associated with higher risk of dry eyes as indicated by subjective questionnaire outcomes.
358

Deslocamentos de populações ribeirinhas e passivos sociais e econômicos decorrentes de projeto de aproveitamento hidrelétrico: A UHE Tijuco Alto/SP - PR / Riverside population displacements and passive social and passive economic resulting of projects of hydroelectric utilizations: to UHE of Tijuco High/SP-PR

Alexandre Cosme José Jeronymo 27 April 2007 (has links)
Tratamos nesta pesquisa dos reflexos socioeconômicos gerados pela apropriação de espaço para instalação da Usina Hidrelétrica de Tijuco Alto, cujo agente investidor é a Companhia Brasileira de Alumínio (CBA). As apropriações iniciaram ao final dos anos 1980 e foram prolongadas ao longo da década de 1990. Neste processo houve pressão do agente investidor para os proprietários dos imóveis negociarem as suas propriedades. Alguns dos reflexos das apropriações de imóveis são os passivos sociais (deslocamento populacional, rupturas na sociabilidade) e os passivos econômicos (rupturas nas dinâmicas econômicas comunitárias agrícola e comercial). Finalizamos fornecendo ênfase a desorganização produzida pela Companhia Brasileira de Alumínio no espaço comunitário designado como Área de Influência Direta após o início do processo de apropriação de propriedades rurais e urbanas e os passivos socioeconômicos decorrentes. / The aim of this work is to broach the assumption correlated to the reflected socioeconomics generated by the appropriation of the space for installation of the hydroeletric plant of High Tijuco, whose investing is the agent Brazilian Company of Aliminium (CBA). The appropriations had initiated to the end of years 1980 and had been drawn out throughout the decade of 1990. In this process it had pressure of the interested party for the appropriations being directed for the proprietors of property to negotiate its properties. Some of results of the appropriations of property are the social passive (population displacement, ruptures in the sociability) and economic passive (rupture in the economic dynamics communitarian agriculturist and commercial). We finalize supplying emphasis to disorganize produced by the Brazilian Company of Aluminum in the communal space assigned like Area of Straight Influence after the beginning of the urban and rural estates appropriation trial and the passive socioeconomics resulting.
359

Accelerated adaptation through stimulated copy number variation in Saccharomyces cerevisiae

Hull, Ryan January 2018 (has links)
Accelerated Adaptation through Stimulated Copy Number Variation in Saccharomyces cerevisiae Ryan Matthew Hull Repetitive regions of the genome, such as the centromeres, telomeres and ribosomal DNA account for a large proportion of the genetic variation between individuals. Differences in the number of repeat sequences between individuals is termed copy number variation (CNV) and is rife across eukaryotic genomes. CNV is of clinical importance as it has been implicated in many human disorders, in particularly cancers where is has been associated with tumour growth and drug resistance. The copper-resistance gene CUP1 in Saccharomyces cerevisiae is one such CNV gene. CUP1 is transcribed from a copper inducible promoter and encodes a protein involved in copper detoxification. In this work I show that yeast can regulate their repeat levels of the CUP1 gene through a transcriptionally stimulated CNV mechanism, as a direct adaptation response to a hostile environment. I characterise the requirement of the epigenetic mark Histone H3 Lysine 56 acetylation (H3K56ac) for stimulated CNV and its limitation of only working at actively transcribed genes. Based upon my findings, I propose a model for how stimulated CNV is regulated in yeast and show how we can pharmacologically manipulate this mechanism using drugs, like nicotinamide and rapamycin, to stimulate and repress a cell's ability to adapt to its environment. I further show that the model is not limited to high-copy CUP1 repeat arrays, but is also applicable to low-copy systems. Finally, I show that the model extends to other genetic loci in response to different challenging environments, such as formaldehyde stimulation of the formaldehyde-resistance gene SFA1. To the best of our knowledge, this is the first example of any eukaryotic cell undergoing genome optimisation as a novel means to accelerate its adaptation in direct response to its environment. If conserved in higher eukaryotes, such a mechanism could have major implications in how we consider and treat disorders associated with changes in CNV.
360

Time Series Analysis of Going Private Transactions: Before and after the Sarbanes-Oxley Act

Kim, Jaehoon 08 1900 (has links)
Using 1,473 going private transactions completed between 1985 and 2007, I assess whether the increase in going private transactions that occurred after the passage of the Sarbanes-Oxley Act of 2002 (SOX) was driven by SOX, or whether this phenomenon continues an ongoing historical trend. To examine this issue, I initially used structural break tests and intervention analysis. From the initial techniques, I find support that the passage of SOX increased going private transactions for these categories. Secondarily, I use Granger causality tests and impulse response functions to examine the link between going private transactions and the public stock market. When I categorize going private transactions according to the type of acquirer, transaction size, and target industry, I find bi-directional Granger causality relationships between smaller-sized going private transactions and the S&P 500 Index (or Tobin's Q). I also find several unidirectional Granger causality relationships for some categories of going private transactions, based on the type of acquirer or the target industry, to the S&P 500 Index (or to Tobin's Q). The impulse response of going private transactions (or the public stock market) to a shock in the public stock market (or going private transactions) is not immediate, but is delayed two to three quarters. The link between going private transactions and the public stock market is an ongoing phenomenon, continuing a historical trend for going private transactions. For going private transactions with structural breaks, SOX affects the linkage but not for going private transactions with no structural break.

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