Optimization of breast tomosynthesis image reconstruction using parallel computing

Breast cancer is the most common cancer among women, being a major public health problem. Worldwide, X-ray mammography is the current gold-standard for medical imaging of breast cancer. However, it has associated some well-known limitations. The false-negative rates, up to 66% in symptomatic women, and the false-positive rates, up to 60%, are a continued source of concern and debate. These drawbacks prompt the development of other imaging techniques for breast cancer detection, in which Digital Breast Tomosynthesis (DBT) is included. DBT is a 3D radiographic technique that reduces the obscuring effect of tissue overlap and appears to address both issues of false-negative and false-positive rates. The 3D images in DBT are only achieved through image reconstruction methods. These methods play an important role in a clinical setting since there is a need to implement a reconstruction process that is both accurate and fast. This dissertation deals with the optimization of iterative algorithms, with parallel computing through an implementation on Graphics Processing Units (GPUs) to make the 3D reconstruction faster using Compute Unified Device Architecture (CUDA). Iterative algorithms have shown to produce the highest quality DBT images, but since they are computationally intensive, their clinical use is currently rejected. These algorithms have the potential to reduce patient dose in DBT scans. A method of integrating CUDA in Interactive Data Language (IDL) is proposed in order to accelerate the DBT image reconstructions. This method has never been attempted before for DBT. In this work the system matrix calculation, the most computationally expensive part of iterative algorithms, is accelerated. A speedup of 1.6 is achieved proving the fact that GPUs can accelerate the IDL implementation.

Hydrogen permeation in parabolic trough receivers

The continued economic and population development puts additional pressure on the already scarce energetic sources. Thus there is a growing urge to adopt a sustainable plan able to meet the present and future energetic demands. Since the last two decades, solar trough technology has been demonstrating to be a reliable alternative to fossil fuels. Currently, the trough industry seeks, by optimizing energy conversion, to drive the cost of electricity down and therefore to place itself as main player in the next energetic age. One of the issues that lately have gained considerable relevance came from the observation of significant heat losses in a large number of receiver modules. These heat losses were attributed to slow permeation of traces of hydrogen gas through the steel tube wall into the vacuum annulus. The presence of hydrogen gas in the absorber tube results from the decomposition of heat transfer fluid due to the long-term exposure to 400°C. The permeated hydrogen acts as heat conduction mean leading to a decrease in the receivers performance and thus its lifetime. In order to prevent hydrogen accumulation, it has been common practice to incorporate hydrogen getters in the vacuum annulus of the receivers. Nevertheless these materials are not only expensive but their gas absorbing capacity can be insufficient to assure the required level of vacuum for the receivers to function. In this work the building of a permeation measurement device, vulnerabilities detected in the construction process and its overcome are described. Furthermore an experimental procedure was optimized and the obtained permeability results, of different samples were evaluated. The data was compared to measurements performed by an external entity. The reliability of the comparative data was also addressed. In the end conclusions on the permeability results for the different samples characteristics, feasibility of the measurement device are drawn and recommendations on future line of work were made.

O impacto da Rede Nacional de Cuidados Continuados Integrados (RNCCI) na demora média hospitalar

RESUMO - Enquadramento: O envelhecimento dos indivíduos nos países mais desenvolvidos e o aumento da incidência de doenças crónicas associadas a estados de dependência e incapacidade têm contribuído para o desenho e implementação de novas políticas de saúde e sociais. Assiste-se, por isso, atualmente, a uma mudança no paradigma da procura de cuidados de saúde, sendo crescente a procura de cuidados de longa duração ou cuidados continuados. O desenvolvimento e implementação de novos modelos de prestação de cuidados de saúde pretendem dar resposta à crescente procura de cuidados continuados, bem como promover a eficiência dos serviços e a disponibilização de camas nos hospitais, retirando dos serviços de agudos as pessoas que não necessitam de cuidados hospitalares, mas sim de cuidados continuados. Neste contexto foi criada em Portugal a Rede Nacional de Cuidados Continuados Integrados (RNCCI), como resposta ao aumento do número de pessoas em situação de dependência, e que necessitam tanto de cuidados de saúde como sociais, e à necessidade de reorganizar e promover a eficiência dos serviços de internamento hospitalar. Objetivo: Determinar o impacto da RNCCI na demora média hospitalar, no período de tempo compreendido entre 1 de Janeiro de 2009 e 31 de Junho de 2011. Métodos: O estudo realizado, com base na revisão da literatura, descreve os principais aspectos referentes ao envelhecimento dos indivíduos e aos cuidados continuados. Foram descritos diferentes modelos e programas organizacionais de prestação de cuidados continuados e o seu impacto na demora média hospitalar. Foi determinada a população em estudo no período de tempo compreendido entre 1 de Janeiro de 2009 e 31 de Junho de 2011. A população foi caraterizada de acordo com o ano e distribuída por dez trimestres para melhor tratamento estatístico e leitura dos dados. Foi considerado o sexo e a faixa etária dos indivíduos sinalizados, de acordo com o GDH de internamento hospitalar e respetiva sub-região de saúde. Foi comparada por trimestre a demora média dos internamentos hospitalares e a demora média hospitalar dos episódios referenciados a nível nacional e ao nível das sub-regiões de saúde. Foram caraterizados os GDH que representam 50% das sinalizações. Foram analisados, por semestre, os três GDH com maior número de referenciações para a RNCCI de acordo com as diferentes regiões de saúde, comparando as respetivas demoras médias nacionais e regionais. Resultados: No periodo de tempo em análise foi verificado que a população com maior utilização dos serviços da RNCCI encontra-se na faixa etária entre 65 ou mais anos, com 79,4% do total de sinalizações efetuadas. Tendo 50% das sinalizações sido referentes aos GDH 14, GDH 211, GDH 533, GDH 818, GDH 810 e GDH 209. Foi apurada uma demora média nacional compreendida entre os 7,3 dias e os 7,7 dias, comparativamente a uma demora média dos episódios referenciados para a RNCCI compreendida entre os 21,9 dias e os 33 dias, para o mesmo período de tempo. Em termos regionais a região de LVT apresenta os valores de demora média mais elevados, com um intervalo entre os 28,8 dias e os 50,3 dias de demora média. Para o GDH 14 foi observada uma demora média dos episódios referenciados compreendida entre os 14,4 dias e os 26,7 dias. No mesmo período de tempo o a demora média nacional para o mesmo GDH situava-se entre os 9,8 dias e os 10,2 dias. Para o GDH 211 foi observada uma demora média dos episódios referenciados compreendida entre os 17,2 dias e os 28,9 dias. Comparativamente a demora média nacional para o mesmo GDH situava-se entre os 12,5 dias e os 13,5 dias. Para o GDH 533 foi observada uma demora média dos episódios referenciados compreendida entre os 23,3 dias e os 52,7 dias. Comparativamente, no mesmo período de tempo, a demora média nacional para o mesmo GDH situava-se entre os 18,7 dias e os 19,7 dias. Conclusões: Foi possível concluir, quanto ao impacto da RNCCI na demora média hospitalar, que a demora média dos episódios referenciados para a Rede é superior à demora média nacional em todo o período de tempo em análise. Relativamente à demora média dos GDH com maior número de referenciações, os GDH 14, 211 e 533, verifica-se que todos eles apresentam uma demora média de referenciação superior à demora média nacional, e demora média regional para o mesmo GDH, em todo o período de tempo do estudo. Ou seja, foi possível verificar que a demora média para indivíduos com o mesmo GDH é superior nos que são referenciados para a RNCCI.

Multi-Enzymatic Systems for Cleaning-up Synthetic Dyes from the Environment

Environmental pollution is one of the major and most important problems of the modern world. In order to fulfill the needs and demands of the overgrowing human population, developments in agriculture, medicine, energy sources, and all chemical industries are necessary (Ali 2010). Over the last century, the increased industrialization and continued population growth led to an augmented production of environmental pollutants that are released into air, water, and soil, with significant impact in the degradation of various ecosystems (Ali 2010, Khan et al. 2013).(...)

Zara: Marketing in Fast Fashion: A case-study

Zara was founded in 1975 by Amancio Ortega Gaona, soon becoming the largest and most successful chain of the Galician group Inditex (Industria de Diseño Textil) and a pioneer of the rising fashion category of Fast Fashion. Its innovative vertically-integrated strategies, combined with its emphasis on quality and demand-based offer have shaped the world of fashion and brought forth many questions on its future sustainability and growth. Zara has always relied on its store network for advertising its product offer; allowing its garments to “speak for themselves”. With the continued pressure felt in the industry, management has pressed some concerns about future company growth and creative, innovating solutions must be implemented to guarantee Zara’s future growth. The case-study narrative focuses on these issues and leaves readers with an open question regarding what decision to implement.

How to increase and attract more tourists into Kenya throught experiental marketing

This marketing plan project is a culmination of extensive strategies with the use of experiential marketing to address issues confronting the Kenyan tourism industry in order to have a sustainable tourism sector. Following the terrorist attack carried out by Islamist militants’ belonging to al-Shabaab terrorist organization on Nairobi’s Westgate shopping mall in September 2013, tourist forecast has gone down sharply with an average of 20% fall in tourists’ arrivals which is likely to have an impact on the tourism sector in Kenya. Even before the deadly attack on Westgate, the most lethal attack by Islamist terrorists in 15 years in Kenya, the government through the Kenya tourist board had announced that in 2013 tourist arrivals were down by 12%, at 495,978, according to an October 2013 report by Bloomberg. Tourism revenues were also down by 7.4%, over FY12/13 (July-June) to reach KES96.24bn, according to a September 2013 report on the local Capital FM website. Beyond 2013, much will depend on how quickly the Kenya tourist board can regain control of the situation. The Kenyan government believes that the Westgate mall attack was a 'one-off' incident, with a low probability of a similar event happening again over the short term period. Germany, United States, United Kingdom, Australia, Italy, France and Canada continue to be the key source market however; the Kenya tourist board can make continued growth stronger from new emerging markets in order to increase new arrivals into the country. The marketing plan outlines the objectives to be implemented and provides the implementation strategy, activity plans, monitoring and evaluation plans, financial requirements projections and proposes a new structure of experiential marketing. A number of regional forces are identified that will impact tourism into the country including global, social and economic forces, emerging trends in visitor motivations and behavior, emerging forces in experiential marketing. A major component of the strategy identifies target markets for Kenya to commensurate with the level of resources that will be available for marketing and promotion, in keeping with the forces and trends identified and the nature of the Kenya tourism environment. The agreed upon target market segments are: generic/mass travel, experiential travel, creative travel, adventure seeking travel, senior/extended/long stay travel, and business related travel. The strategy phases the development of the target markets over the years of the marketing strategies in order to yield the best opportunity for results. A core activity in developing a marketing strategy is determining the nature of experiences Kenya offers in tourism. The strategy’s experience development process will continue to develop within the context of the products identified which will be promoted regionally: culture/heritage, nature, community-based. Each county in the country has a significant number of attractions and experiences and the challenge of the country is to bring these together in a creative and innovative way in order to encourage tourists to visit more than one county in Kenya.

The Environmental History of Cetaceans in Portugal: Ten Centuries of Whale and Dolphin Records

The history between cetaceans and humans is documented throughout time not only in reports, descriptions, and tales but also in legal documents, laws and regulations, and tithes. This wealth of information comes from the easy spotting and identification of individuals due to their large size, surface breathing, and conspicuous above water behaviour. This work is based on historical sources and accounts accounting for cetacean presence for the period between the 12th and 17th centuries, as well as scientific articles, newspapers, illustrations, maps, non-published scientific reports, and other grey literature from the 18th century onwards. Information on whale use in Portugal's mainland has been found since as early as the 12th century and has continued to be created throughout time. No certainty can be given for medieval and earlier events, but both scavenging of stranded whales or use of captured ones may have happened. There is an increasing number of accounts of sighted, stranded, used, or captured cetaceans throughout centuries which is clearly associated with a growing effort towards the study of these animals. Scientific Latin species denominations only started to be registered from the 18th century onwards, as a consequence of the evolution of natural sciences in Portugal and increasing interest from zoologists. After the 19th century, a larger number of observations were recorded, and from the 20th century to the present day, regular scientific records have been collected. Research on the environmental history of cetaceans in Portugal shows a several-centuries-old exploitation of whales and dolphins, as resources mainly for human consumption, followed in later centuries by descriptions of natural history documenting strandings and at sea encounters. Most cetaceans species currently thought to be present in Portuguese mainland waters were at some point historically recorded.

Evaluation of long term persistence of Diabetes Mellitus Type II treatment newly diagnosed patients in Lisbon and Tagus health administration region : a three year follow up study

RESUMO: Raional: A persistência à terapêutica é o tempo em qualquer antidiabético oral, desde o seu início até à descontinuação de todas as medicações ou até ao fim do período do estudo. Os objetivos deste estudo foi a análise da persistência à terapêutica no segundo e terceiro anos após início do tratamento em doentes adultos diagnosticados na região de Lisboa e Vale do Tejo e determinar o efeito de determinadas variáveis na persistência a longo prazo. Métodos: Um estudo retrospetivo não interventivo foi desenhado com base nos dados a obter do SIARS (prescrições e aquisições na farmácia) e Pordata. A persistência foi quantificada como a percentagem de doentes que continuam a adquirir pelo menos um antidiabético oral ao segundo e terceiro anos após a compra da primeira receita. A associação entre a persistência e o segundo e terceiro anos com cada uma das co-variáveis foi aferido pelo teste qui-quadrado e os odd ratios foram calculados com recurso a um modelo de regressão logística. Resultados: A persistência à terapêutica obtida foi de 80% e 62% para o segundo e terceiro anos após início da terapêutica. Odd ratios para primeiro e segundo ano: número de grupos farmacoterapêuticos diferentes (OR = 2.167, 1.807 – 2.598, p = 0.000 / OR = 1.863, 1.621 – 2.142, p = 0.000); idade (OR = 0.914, 0.772 – 1.081, p = 0.294 / OR = 0.875, 0.764 – 1.002, p = 0.054); sexo (OR = 1.163, 0.983 – 1.377, p = 0.079); número de diferentes prescritores (OR = 3.594, 3.030 – 4.262, p = 0.000 / OR = 2.167, 1.886 – 2.491, p = 0.000); instituição de prescrição (OR = 0.725, 0.698 – 0.753, p = 0.000 / OR = 0.683, 0.650 – 0.717, p = 0.000); grupo farmacoterapêutico (OR = 1.056, 1.043 – 1.069, p = 0.000 / OR = 1.077, 1.060 – 1.095, p = 0.000); relação com o médico (OR = 0.834, 0.816 – 0.852, p = 0.000 / OR = 0.799, 0.777 – 0.821, p = 0.000) e custo médio mensal por grupo farmacoterapêutico (OR = 0.954, 0.942 – 0.968, p = 0.000 / OR = 0.930, 0.914 – 0.947, p = 0.000). Conclusões: O valor da persistência à terapêutica no segundo ano é ligeiramente acima do que é mencionado na literatura e não existem dados para comparar os resultados do terceiro ano. Relativamente ao efeito das co-variáveis no segundo e terceiro anos após o início do tratamento, os resultados são sobreponíveis, sendo que o sexo não está associado à persistência ao terceiro ano.----------------------------------ABSTRACT: Background: Therapy persistence is the time on any antidiabetic medication, from initiation of therapy to discontinuation of all medications or the end of the study period. The aim of the study was to analyse the therapy persistence in the second and third years after treatment initiation in newly diagnosed adult patients in the Lisbon and Tagus Valley region and to determine the effect of several co-variables in the long term persistence. Methods: A retrospective non-interventional study based on SIARS data (drug prescriptions and acquisitions) and Pordata was designed. Persistence was quantified as the percentage of patients that continued to purchase at least one type of antidiabetic at year 2 and 3 after the date of first prescription acquisition. Association between persistence at second and third years with each of the other co-variables were verified by using the Chi-Square test and odds ratio were calculated using a regression logistic model. Results: Therapy persistence obtained was 80% and 62% for the second and third years after treatment initiation. Odd ratios for second and third years: number of different pharmacotherapeutic groups (OR = 2.167, 1.807 – 2.598, p = 0.000 / OR = 1.863, 1.621 – 2.142, p = 0.000); age (OR = 0.914, 0.772 – 1.081, p = 0.294 / OR = 0.875, 0.764 – 1.002, p = 0.054); gender (OR = 1.163, 0.983 – 1.377, p = 0.079); number of different prescribers (OR = 3.594, 3.030 – 4.262, p = 0.000 / OR = 2.167, 1.886 – 2.491, p = 0.000); institution of prescription (OR = 0.725, 0.698 – 0.753, p = 0.000 / OR = 0.683, 0.650 – 0.717, p = 0.000); pharmacotherapeutic group (OR = 1.056, 1.043 – 1.069, p = 0.000 / OR = 1.077, 1.060 – 1.095, p = 0.000); relationship with the physician (OR = 0.834, 0.816 – 0.852, p = 0.000 / OR = 0.799, 0.777 – 0.821, p = 0.000) and average cost per month and per pharmacotherapeutic group (OR = 0.954, 0.942 – 0.968, p = 0.000 / OR = 0.930, 0.914 – 0.947, p = 0.000). Conclusions: Second year therapy persistence value is slightly above of what is referenced in literature and no data was found to compare the third year value. Regarding the effect of the co-variables analysed at second and third years after treatment initiation, the results were overlapping with gender being not associated with persistence at the third year.

Staying under the radar - the multifunctional LANA Protein

Many viruses have developed numerous strategies to recruit and take advantage of cellular protein degradation pathways to evade the cellular viral immune system. One such virus is the Kaposi´s Sarcoma associated herpesvirus (KSHV), first discovered in Kaposi´s Sarcoma lesions found in AIDS patients. Latency-Associated Nuclear Antigen (LANA) is a KSHV multifunctional protein responsible for tethering viral DNA to the chromosome ensuring maintenance and segregation of the viral genome during cell division. Besides its main role of viral maintenance, LANA also physically interacts with several host proteins to modulate cell functions. One such function is to recruit the EC5S ubiquitin-ligase complex by interacting with Elongin BC complex and Cullin 5 protein, which in turn ubiquitinate substrates such as NF-κB and p53 to allow persistent viral infection. Like any other post-translation modifications, ubiquitination is reversible through deubiquitination enzymes (DUBs). LANA also interacts with ubiquitin specific protease 7 (USP7), a deubiquitination enzyme involved in regulation of several proteins including p53. Interaction with USP7 is made through a conserved peptide motif, which is also present in LANA. This work addresses the role of LANA in the recruitment and modulation of the ubiquitination and deubiquitination pathways. Despite the continued efforts in uncovering new LANA interacting partners to form a functional EC5S ubiquitin-ligase complex, only MHV-68 LANA interacted directly with Elongin BC, other interactions were not direct and may require a linker protein. On the other hand, LANA interaction with USP7 was able to be analysed by X-ray structure determination. In addition to a conserved P/AxxS motif, a novel Glutamine (Gln) residue from KSHV LANA was shown to make a specific interaction with USP7. This Gln residue is also present in other herpesvirus protein and hence it might be a conserved motif within herpesviruses.

A arte ao serviço do império e das colónias: o contributo de alguns programas expositivos e museológicos para o discurso de legitimação territorial

Artigo escrito no âmbito da realização de tese de doutoramento em História da Arte financiado por bolsa FCT (SFRH/BD/63763/2009)

A negociação no mercado a prazo do MIBEL

This master thesis has been developed during the internship in the Supervision Department of Supervision of the Intermediation and Market Structures of CMVM. My collaboration in such department was mainly focused on the derivatives market of the Iberian Electricity Market (MIBEL). MIBEL embodies two organized markets – the derivatives market in Portugal and the spot market in Spain The trading activity in the derivatives market of MIBEL is processed through the trading platform of the regulated market managed by OMIP, however, much of the negotiation is over-the-counter. The aim of this work is to describe the market from a legal and economic perspective and to analyse the evolution of the negotiation, namely the impact of OTC in the regulated market trading. To achieve this, I propose to analyse also MiFID and EMIR rules over derivative contracts and the role of central counterparties, as they both are important to the discussion. In parallel, we found that OTC transactions are considerably higher than those traded in the regulated market managed by OMIP, those findings can be justified by the contractual relationships based on trust already established between the partiesarties. Nevertheless, since 2011 this trend changed by an increase of the registered OTC. Thereafter, although the parties continued to trade bilaterally, these transactions were registered in a central counterparty in order to eliminate the inherent risks related to the OTC derivatives transactions. This change in the negotiation pattern may also be influenced by the mandatory reporting of transactions imposed by EMIR, that requires for some classes of derivatives the centralized clearing and for all other requires the implementation of risk mitigation techniques.

Impactos territoriais de processos de cooperação transfronteiriça : caso de estudo : Elvas e Badajoz

A cooperação transfronteiriça é vista na União Europeia como um modelo de integração territorial e como uma alternativa para o desenvolvimento das regiões de fronteira, devido ao seu afastamento em relação aos grandes centros urbanos. No início da década de 90 foi lançado o programa do INTERREG tendo em vista a maior permeabilidade da fronteira e o desenvolvimento destes territórios, entre os quais o das regiões do Alto Alentejo e da Extremadura. A grande proximidade territorial entre Elvas e Badajoz permitiu desde sempre relações de cooperação mais ou menos intensas e consentidas, mesmo antes da abertura da fronteira, motivadas sobretudo pela diferença de valor entre as duas moedas. Contudo, com a entrada conjunta dos países ibéricos na CEE (1986), essas relações intensificaram-se ao nível do comércio, do emprego, do turismo, do lazer e da procura de serviços. Impactos territoriais como a procura e utilização conjunta de infraestruturas e de espaços públicos pelas populações das duas cidades, a promoção e realização de espetáculos culturais, a prática de cross-border shopping, a procura de uma segunda residência, em ambos os lados da fronteira, e a tendência para uma urbanização contínua no futuro, justificaram a criação da Eurocidade Elvas-Badajoz (2013). Esta iniciativa tem como principais objetivos promover a conceção, gestão e prestação conjunta de serviços, desenvolver projetos de cooperação em áreas de interesse comum, estimular a cooperação entre empresas e atrair investimentos geradores de novos postos de trabalho. No entanto os desafios para ambas as cidades prendem-se com a existência de um quadro jurídico e legal distinto que tem condicionado algumas das ações ou iniciativas e o desenvolvimento territorial conjunto ainda carece de uma proposta estratégica.