Disseny i ajust d'una nova xarxa geodèsica a l'Hospitalet de Llobregat

A través del present projecte, col·laborant amb l’Institut Cartogràfic de Catalunya i els responsables de l’Ajuntament de l’Hospitalet de Llobregat, s’ha mesurat una nova xarxa utilitària mitjançant tècniques GPS a l’Hospitalet de Llobregat. Per aconseguir el màxim rendiment del sistema GPS, optimitzant el millor possible el temps invertit a camp i assegurant un bon control de qualitat de la xarxa, s’han escollit els criteris de disseny i observació apropiats. Donant preferència a l’accessibilitat dels vèrtexs, estudiant rigorosament, la seva ubicació. L’ús de quatre receptors GPS per realitzar les mesures ha estat essencial per aportar redundància a la xarxa i aconseguir fiabilitat dels resultats. Per referenciar la xarxa al sistema WGS84, s’ha utilitzat l’estació de referència de l’EPSEB i el vèrtex de la plaça d’Espanya de Barcelona, pertanyent a la xarxa utilitària de Catalunya. Utilitzant el programa Ski-pro, de Leica Geosystem, s’ha calculat l’ajust de la xarxa a través del mètode per mínims quadrats. Podent, d’aquesta manera, analitzar els resultats obtinguts mitjançant l’estudi de les el·lipses d’error de cada vèrtex i la qualitat dels test estadístics. S’han realitzat dos ajustos addicionals utilitzant estacions de referència diferents. D’aquesta manera, aplicant diferents alternatives per referenciar la xarxa al sistema WGS84, es podran analitzar i comparar la solució de cada un dels ajustos. Finalment, s’han transformat les coordenades definitives al mateix sistema de referència que es troba la cartografia

Linear and Non-linear time series analysis: forecasting financial markets

JEL Classification: C32, C45, C53Time series analyses in financial area have been attract some special attention in the recent years. The stock markets are examples of systems with a complex behaviour and, sometimes, forecasting a financial time series can be a hard task. In this thesis we compare linear against non-linear models, ARIMA and Artificial Neural Networks. Using the log returns of nine countries we tried to demonstrate that neural networks can be used to uncover the non-linearity that exists in the financial field. First we followed a traditional approach by analysing the characteristics of the nine stock series and some typical features. We also produce a BDS test to investigate the nonlinearity, the results were as expected, and none of the markets exhibit a linear dependence. In consequence, traditional linear models may not produce reliable forecasts. However, this didn’t mean that neural networks can. We trained four types of neural networks for the nine stock markets and the results between them were quite similar varying most in their structure and suggesting that more studies about the hidden units between the input and output layer need to be done. This study stresses the importance of taking into account nonlinear effects that are quite evident in the stock market MODELS.A analise de séries temporais na area financeira tem atraido especial atenção nos últimos anos. Os mercados financeiros são exemplos de sistemas com um comportamento complexo e, por vezes, a previsão de séries temporais nesta àrea pode se tornar numa tarefa árdua. Nesta tese, iremos comparar os retornos logarítmicos proveninetes de nove mercados e monstrar que as redes neuronais podem ser utilizadas para detectar a não-linearidade existente nestes modelos. Primeiro, seguimos uma abordagem tradicional onde foram analisadas as características inerentes a cada um dos mercados. Executamos ainda o teste BDS para investigar a não-linearidade nas séries e, tal como esperado, os resultados confirmaram que nenhum dos mercados se apresenta como tendo um padrão linear. Dado este facto, os modelos lineares tradicionais poderão não produzir previsões fiáveis. Contudo, tal não quer dizer que as redes neuronais o façam. Foram treinadas quatro tipologias de redes para cada um dos nove mercados, sendo que, os resultados entre as mesmas foram bastante similares(variando em grande parte na estrutura que cada um das redes exibia) e, sugerindo que mais estudos devem ser feitos de modo a analisar o peso que as camadas ocultas possuem entre os neurónios de entrada e os de saída. Este estudo, enfatisa a importancia de se ter em conta que os efeitos não lineares devem ser estudados com certa significância nos mercados financeiros

The valuation game : an empirical study of Portuguese startups’ success factors

Valuing startups is a complex task, as these companies often have limited financial history and uncertain future cash flows. In addition, startups are typically high­risk ventures, requiring valuation techniques that consider this higher level of risk. In this study, I examine the impact of some factors in the valuation of Portuguese startups. To do this, I developed a multiple linear regression model and created nine hypotheses on the effects of each variable on valuations. The study is based on a Portuguese startup sample and uses multiple regression analysis to test the hypotheses. The study results provide insights into the factors most important in the valuation of Portuguese startups and can inform the development of more effective valuation techniques for these companies. The factors that were found to increase valuations included having a B2B focus, having a headquarters outside of Portugal, having a SaaS business model, having registered patents, and being a Fintech company. It was also found that having a female founder or attending a top university was associated with higher valuations. However, having prior startup experience or investing in R&D did not positively impact valuations.A valorização de startups é uma tarefa complexa, uma vez que estas empresas têm frequentemente uma história financeira limitada e fluxos de caixa futuros incertos. Além disso, as startups são tipicamente empreendimentos de alto risco, exigindo técnicas de avaliação que consideram este nível de risco mais elevado. Neste estudo, examino o impacto de alguns fatores na avaliação de startups portuguesas. Para tal, desenvolvi um modelo de regressão linear múltipla e criei nove hipóteses sobre os efeitos de cada variável nas avaliações. O estudo baseia se numa amostra inicial portuguesa e utiliza a análise de regressão múltipla para testar as hipóteses. Os resultados do estudo fornecem informações sobre os fatores mais importantes na avaliação das empresas portuguesas em fase de arranque e podem ajudar no desenvolvimento de técnicas de avaliação mais eficazes para estas empresas. Os fatores que se verificou aumentarem as avaliações incluíram ter um foco B2B, ter uma sede fora de Portugal, ter um modelo de negócio SaaS, ter patentes registadas, e ser uma empresa Fintech. Verificou­se também que ter uma fundadora (sexo feminino) ou frequentar uma universidade de topo estava associado a avaliações mais elevadas. Contudo, ter experiência prévia de criação de startup ou investir em I&D não teve um impato positivo nas avaliações

Staphylococcus aureus promotes autophagy by decreasing intracellular cAMP levels

Staphylococcus aureus is an intracellular bacterium responsible for serious infectious processes. This pathogen escapes from the phagolysosomal pathway into the cytoplasm, a strategy that allows intracellular bacterial replication and survival with the consequent killing of the eukaryotic host cell and spreading of the infection. S. aureus is able to secrete several virulence factors such as enzymes and toxins. Our recent findings indicate that the main virulence factor of S. aureus, the pore-forming toxin α-hemolysin (Hla), is the secreted factor responsible for the activation of an alternative autophagic pathway. We have demonstrated that this noncanonical autophagic response is inhibited by artificially elevating the intracellular levels of cAMP. This effect is mediated by RAPGEF3/EPAC (Rap guanine nucleotide exchange factor (GEF)3/exchange protein activated by cAMP), a cAMP downstream effector that functions as a GEF for the small GTPase Rap. We have presented evidence that RAPGEF3 and RAP2B, through calpain activation, are the proteins involved in the regulation of Hla and S. aureus-induced autophagy. In addition, we have found that both, RAPGEF3 and RAP2B, are recruited to the S. aureus-containing phagosome. Of note, adding purified α-toxin or infecting the cells with S. aureus leads to a decrease in intracellular cAMP levels, which promotes autophagy induction, a response that favors pathogen intracellular survival, as previously demonstrated. We have identified some key signaling molecules involved in the autophagic response upon infection with a bacterial pathogen, which have important implications in understanding innate immune defense mechanisms.Fil: Mestre Gimenez, Maria Belen. Universidad Católica de Cuyo - Sede San Juan. Facultad de Ciencias Médicas. Departamento de Neurociencia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Colombo, Maria Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; Argentin

Mycobacterium tuberculosis

Tese de mestrado em Biologia Molecular e Genética apresentada à Universidade de Lisboa através da Faculdade de Ciências, 2007The Beijing/W family of Mycobacterium tuberculosis represents a global threat in tuberculosis control. It has been frequently associated with drug resistance and its wide distribution suggests that these strains may have selective advantages over others. On the present study a collection of Beijing/W strains isolated in different countries was analyzed under the genetic markers: Large Sequence Polymorphisms (LSPs) and Single Nucleotide Polymorphisms (SNPs). Through a Multiplex-PCR isolates were tested for the presence or absence of the LSPs, described by a previous study for the Beijing/W family (RD105, RD181, RD150, RD142). The analysis of these regions proved to be very useful for defining and broadly subdivide the Beijing/W family in four groups. Furthermore, it provided a support for selection of representative isolates for the further study of other markers like SNPs in recently identified polymorphic DNA repair, recombination and replication (3R) genes. Selected 3R genes were sequenced for representative Beijing/W isolates to search for variations and comparative analysis with M.tuberculosis H37Rv identified SNPs for all genes. Almost half corresponded to not previously described SNPs and a large proportion seemed specific to Beijing/W strains. SNPs were much more informative than LSPs distinguishing twenty-four groups for which a hypothetic phylogenetic network was constructed. Phylogenetic relations originated by SNPs were found to be congruent with the ones originated by LSPs and also with previous studies on mutT2, muT4 and ogt putative DNA repair genes. Analysis according to geographic origin of isolates suggested that the collection used might be representative of the Beijing/W family. Certain genes were found to be more polymorphic than others with the accumulation of several non-synonymous SNPs (nsSNPs) that may potentially affect the function of the protein. Altered function in proteins involved in such important mechanisms in genome dynamics and stability might be associated with mutator phenotypes strains having high mutation rates in Beijing/W strains, as previously suggested. This might explain their higher adaptability and frequent association with resistance to antibiotics. Overall, this study provided useful information that, although may need to be validated using a larger set of isolates, it could be the start point for several future studies. It may contribute to clarify the role of the Beijing/W family in the tuberculosis pandemic.Resumo alargado disponível em portuguê

Com la carn de xinxa

Abstract not availabl

Development of a methodology to analyze leaves from Prunus dulcis varieties using near infrared spectroscopy

Peer ReviewedPostprint (published version

Multivariate classification of prunus dulcis varieties using leaves of nursery plants and near infrared spectroscopy

The emergence of new almond tree (Prunus dulcis) varieties with agricultural interest is forcing the nursery plant industry to establish quality systems to keep varietal purity in the production stage. The aim of this study is to assess the capability of near-infrared spectroscopy (NIRS) to classify different Prunus dulcis varieties as an alternative to more expensive methods. Fresh and dried-powdered leaves of six different varieties of almond trees of commercial interest (Avijor, Guara, Isabelona, Marta, Pentacebas and Soleta) were used.Peer ReviewedPostprint (published version