Percorrer por autor "Ferreira, Fernando"
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- Desenvolvimento de ferramenta computacional para ajuste automático de controladores em veículos aéreos não-tripuladosPublication . Ferreira, FernandoEste trabalho está enquadrado na missão do Centro de Investigação da Academia da Força Aérea (CIAFA) e tem como objectivo desenvolver uma ferramenta computacional, para o ajuste dos ganhos do piloto automático Piccolo. Em particular, esta ferramenta visa contribuir para a sistematiza ção dos processos associados ao ajuste dos ganhos dos controladores do Piccolo, com vista ao aperfeiçoamento do desempenho dos Unmanned Aerial Vehicle (UAV) do CIAFA, no seguimento de comandos de referência. Inicialmente, são analisadas as leis de controlo do Piccolo, no que respeita ao controlo do movimento lateral das aeronaves, identificando-se ainda quais os ganhos e parâmetros que permitem modificar o comportamento das mesmas. De seguida, e desenvolvido um modelo computacional da dinâmica lateral do UAV ANTEX-X02 Alfa 07, procedendo-se posteriormente a implementação do método de ajuste dos ganhos. O método implementado e o Root Locus, fazendo uso do Simulink e da toolbox Control System Designer do MATLAB®, que irá estimar o conjunto dos valores dos ganhos, para obter uma resposta criticamente amortecida. Finalmente, demonstra-se formalmente a coerência entre a resposta estimada pelo modelo computacional e a resposta da aeronave, apresentando-se resultados obtidos em ensaios em voo, realizados no Centro de Forma ção Militar e Técnica da Força Aérea (CFMTFA), para diferentes condições de voo.
- fHER2, PR, ER, Ki-67 and cytokeratin 5/6 expression in benign feline mammary lesionsPublication . Soares, Maria; Correia, Assunção N.; Batista, Mariana R.; Correia, Jorge; Ferreira, FernandoBiomarkers are essential in the characterization of neoplastic lesions and aid not only in the classification of the nature of the lesions, but also in the understanding of their ontogeny, development and prognosis. In cats, while mammary carcinomas are increasingly being characterized, information on their benign lesions is still scarce. Indeed, a better characterization of benign lesions could have an important role in unravelling mammary oncogenesis, similar to that in human breast cancer. Thus, in this study, the expression of five markers was analyzed in 47 benign mammary lesions (hyperplasia, dysplasia and benign tumors) collected from 27 queens. Dysplastic and hyperplastic lesions were the most common (41/47, 81.7%). Most of the lesions were classified as ER positive (43/47, 91.5%), PR negative (30/47, 63.8%), fHER2 negative (29/47, 64.4%), CK 5/6 negative (36/47, 76.6%) and with a low Ki-67 index (37/47, 78.7%). Statistical analysis revealed a correlation between younger ages and ER positivity (p = 0.013) and between larger lesions and negative PR status (p = 0.038). These results reinforce the importance of evaluating the expression of the ER status, prevalent in benign lesions, as a putative precursor in cancer progression.
- A lógica matemática como empreendimento fundamentadorPublication . Ferreira, Fernando
- Perfil Terapêutico da Hipertensão na rede Médicos Sentinela : 12 Anos DepoisPublication . Souto, Diana; Simões, José Augusto; Torre, Carla; Mendes, Zilda; Falcão, Isabel Marinho; Ferreira, Fernando; Miranda, Ana da Costa; Dias, Carlos MatiasObjectives: To determine the treatment profile of hypertension in theQPortuguese sentinel practice network and compare the results 12 years after an initial study. Study design: Cross-sectional study Setting: Portuguese sentinel practice network Participants: Hypertensive patients over 18 years of age on the lists of general practitioners in the sentinel practice network who attended a consultation with their physician between June 7, 2010 and December 31, 2010. Results: In 2010, 616 hypertensive patients were included in the study. Between the two periods (1998 and 2010) there was a slight increase in the average age of the participants (62.0 years in 1998 and 64.3 years in 2010), with a higher proportion of female patients in both periods. The meanQaverage duration of hypertension since the time of diagnosis increased significantly (<0.0001). Approximately half of the hypertensive patients presented target organ damage, in both periods with heart disease as the most common lesion. Dyslipidemia, hyperuricemia and diabetes were the most common co-morbid conditions. From 1998 to 2010, the proportion of patients on monotherapy decreased from 47.6% to 30.3%. Angiotensin-converting enzyme inhibitors were the most frequently prescribed drugs for monotherapy in both periods. In 1998, the antihypertensive treatment most frequently prescribed was angiotensin-converting enzyme inhibitors as monotherapy (24.3%). In 2010 the combination of angiotensin receptor blockers with thiazide diuretics was the most common treatment (15.4%). Conclusions: Drugs acting on the renin-angiotensin system were the antihypertensive drugs most frequently prescribed in both periods as monotherapy and in combination with other drugs. The number of antihypertensive drugs prescribed differed between the two periods in relation to the existence and type of co-morbidities.
- Predicting the chances of live birth for couples undergoing IVF-ICSI: a novel instrument to advise patients and physicians before treatmentPublication . Veiga, Bruna Estácio da; Guimarães, Beatriz Brás de; Tavares, Duarte Pedro; Metello, José Luis; Ferreira, Fernando; Ferreira, Pedro; Fonseca, José ManuelBackground: The prevalence of infertility ranges from 3.5% to 16.7% in more developed countries. For this reason, the number of In Vitro Fertilization(IVF) technique and Intracytoplasmic Sperm Injection (ICSI) treatments has been significantly increasing. Several factors affect the success rate of in vitro treatments, which can be used to calculate the probability of success for each couple. As these treatments are complicated, expensive and with a variable probability of success, the most common question asked by IVF patients is “What are my chances of conceiving before starting an IVF/ICSI treatment?”. The main aim of this study is to develop a validated model that estimates the chance of a live birth before the start of an IVF/ICSI non-donor cycle. Methods: A logistic regression model was developed based on the retrospective study of 737 IVF/ICSI cycles. Overall 14 pre-treatment variables were evaluated (woman’s and man’s age, duration of infertility, cause of infertility, woman’s and man’s Body Mass Index (BMI), Anti-Müllerian Hormone (AMH), Antral Follicle Count (AFC), woman’s and man’s ethnicity, woman’s and man’s smoking status and woman’s and man’s previous live children) and the outcome of the treatment was discriminated as "live birth" or "no live birth". Results: From the 14 variables acquired before starting the IVF/ICSI procedures, only male factor, man’s BMI, man's mixed ethnicity and level of AMH were statistically significant. The interactions between infertility duration and woman’s age, infertility duration and man’s BMI, AFC and AMH, AFC and woman’s age, AFC and woman’s BMI, and AFC and disovulation were also statistically significant. The Area Under the Receiver Operating Characteristic (AUROC) curve test for the discriminatory ability of the final prediction model was 0.700 (95% Confidence Interval (CI) 0.660–0.741). Conclusions: This model might result in a new validated decision support system to help physicians to manage couples’ pre-treatment expectations.
- The Finitistic Consistency of Heck’s Predicative Fregean SystemPublication . Cruz-Filipe, L.; Ferreira, FernandoFrege’s theory is inconsistent (Russell’s paradox). However, the predicative version of Frege’s system is consistent. This was proved by Richard Heck in 1996 using a model-theoretic argument. In this paper, we give a finitistic proof of this consistency result. As a consequence, Heck’s predicative theory is rather weak (as was suspected).