Amostragem compressiva em análise de Clifford

Doutoramento em Matemática e Aplicações (PDMA)Compressed sensing is a new paradigm in signal processing which states that for certain matrices sparse representations can be obtained by a simple l1-minimization. In this thesis we explore this paradigm for higher-dimensional signal. In particular three cases are being studied: signals taking values in a bicomplex algebra, quaternionic signals, and complex signals which are representable by a nonlinear Fourier basis, a so-called Takenaka-Malmquist system.Amostragem Compressiva é um novo paradigma em processamento de sinal, no qual se assegura, para determinadas matrizes, que as representações esparsas de sinais podem ser obtidas por intermédio de um simples procedimento de l1-minimização. Nesta tese, exploramos este paradigma para sinais em dimensões superiores. Estudaremos três casos particulares: sinais com valores na álgebra bi-complexa, sinais quaterniónicos e, finalmente, sinais complexos representáveis por uma base de Fourier não-linear, dito sistema de Takenaka-Malmquist

Amostragem uniforme e não-uniforme

Mestrado em Psicologia ForenseNeste trabalho vamos apresentar alguns conceitos básicos da teoria da amostragem uniforme e da não-uniforme, e sua ligação à teoria de interpolação. Numa primeira parte focaremos essencialmente os conceitos de amostragem clássica de Nyquist e de Bessel, bem como a respectiva ligação à interpolação de Lagrange e de Bessel. Na segunda parte, estudaremos a implementação numérica do método de amostragem por intermédio de funções q-Bessel (introduzido por D. Abreu [2]). O ramo da análise que estuda este tipo de funções é conhecido como q-cálculo. Foram implementadas as termos básicos, como sejam, o q-factorial (equivalente ao factorial clássico), o cálculo das funções q-Bessel, suas derivadas e respectivo método de amostragem. No final deste trabalho será dedicado a exemplos numéricos deste método.In this thesis we present Basic concepts of uniform and non-uniform sampling theory and their connection with interpolation theory. In the first part we will study the connection between the classic Nyquistsampling and Bessel-sampling and Lagrange- and Besselinterpolation. In the second part we study the numerical implementation of the sampling method using q-Bessel function introduced by D. Abreu [2]. To this end we implement basic terms of the q-Calculus, such as the q-factorial (equivalent to the classic factorial), the computation of q-Bessel functions and their derivatives, as well as the sampling method itself. In the end we present numerical examples for this method

Artérias da bolsa cloacal de galinhas (Gallus gallus) da linhagem Hybro PG

http://dx.doi.org/10.5007/2175-7925.2009v22n4p153 A pesquisa baseou-se no estudo da origem, número e ordenação dos vasos arteriais e seus ramos os quais irrigam a bolsa cloacal de 30 galinhas (Gallus gallus) da linhagem Hybro PG. Inicialmente, foi injetada, na artéria isquiática dos exemplares, uma solução aquosa a 50% de Neoprene Látex 450 e, posteriormente, realizada a dissecação. Os resultados evidenciaram a participação das artérias pudendas interna esquerda e direita e bursocloacal, em todos os animais estudados, variando apenas o número e a ordenação de seus ramos. Houve também vasos oriundos das artérias caudal mediana (23%) e pudenda externa esquerda (3,33%). O número total de ramos variou de um a quatro e sua distribuição seguiu de forma singular para cada exemplar

Arterial supply to the cloacal bursa of Hybro PG lineage hens (Gallus gallus)

A study was carried out on the origin, number and disposition of the arterial vessels and their branches which irrigated the cloacal bursas of 30 hens (Gallus gallus) of the Hybro PG lineage. First of all, the left isquiadic artery from the samples was cannulated and injected with a 50% colored solution of Neoprene latex “450”; then, we continued the experiment with dissection whose results confi rmed that the cloacal bursa was supplied by direct branches from the left and right internal pudendal arteries and bursocloacal arteries in 100% of the cases, varying only in terms of the numbers and disposition of their branches. There were also some branches from the median caudal artery (23%) and left external pudendal (3.33%). The total number of branches varied from 1 to 4 and their distribution was unique in each sample

Laurus nobilis L.: assessment of the cytotoxic and genotoxic potential of aqueous extracts by micronucleus and Allium cepa assays

Laurus nobilis L. is a large shrub belonging to the Lauracea family. Its leaves are widely used for food seasoning as well as in folk medicine. Various studies have demonstrated the antiproliferative, antifungal and antibacterial effects of Laurus nobilis, but no studies have investigated the genotoxic effect of the aqueous extract of the plant. The objective of this study was to analyze the genotoxic potential of an aqueous extract of leaves, using the Allium cepa assay and mouse peripheral blood cell micronucleus test. The results showed that the extract did not have any genotoxic activity, but cytotoxic activity was observed in the two experimental models used. The extract had an antiproliferative effect, detected through the reduction of the mitotic index and the polychromatic/normochromatic erythrocyte (PCE/NCE) ratio. The tests also demonstrated a large number of cells undergoing apoptosis and with nuclear abnormalities related to cell death processes. These results can be explained by the presence of phenolic compounds, saponins, flavonoids and alkaloids, detected in the phytochemical analysis of the extract. Therefore, the extract from L. nobilis in the form generally used by the population does not pose risks related to its genotoxic potential, and also contains components with apoptotic and antigenotoxic potential

Effect of lung recruitment and titrated Positive End-Expiratory Pressure (PEEP) vs low PEEP on mortality in patients with acute respiratory distress syndrome - A randomized clinical trial

IMPORTANCE: The effects of recruitment maneuvers and positive end-expiratory pressure (PEEP) titration on clinical outcomes in patients with acute respiratory distress syndrome (ARDS) remain uncertain. OBJECTIVE: To determine if lung recruitment associated with PEEP titration according to the best respiratory-system compliance decreases 28-day mortality of patients with moderate to severe ARDS compared with a conventional low-PEEP strategy. DESIGN, SETTING, AND PARTICIPANTS: Multicenter, randomized trial conducted at 120 intensive care units (ICUs) from 9 countries from November 17, 2011, through April 25, 2017, enrolling adults with moderate to severe ARDS. INTERVENTIONS: An experimental strategy with a lung recruitment maneuver and PEEP titration according to the best respiratory-system compliance (n = 501; experimental group) or a control strategy of low PEEP (n = 509). All patients received volume-assist control mode until weaning. MAIN OUTCOMES AND MEASURES: The primary outcome was all-cause mortality until 28 days. Secondary outcomes were length of ICU and hospital stay; ventilator-free days through day 28; pneumothorax requiring drainage within 7 days; barotrauma within 7 days; and ICU, in-hospital, and 6-month mortality. RESULTS: A total of 1010 patients (37.5% female; mean [SD] age, 50.9 [17.4] years) were enrolled and followed up. At 28 days, 277 of 501 patients (55.3%) in the experimental group and 251 of 509 patients (49.3%) in the control group had died (hazard ratio [HR], 1.20; 95% CI, 1.01 to 1.42; P = .041). Compared with the control group, the experimental group strategy increased 6-month mortality (65.3% vs 59.9%; HR, 1.18; 95% CI, 1.01 to 1.38; P = .04), decreased the number of mean ventilator-free days (5.3 vs 6.4; difference, −1.1; 95% CI, −2.1 to −0.1; P = .03), increased the risk of pneumothorax requiring drainage (3.2% vs 1.2%; difference, 2.0%; 95% CI, 0.0% to 4.0%; P = .03), and the risk of barotrauma (5.6% vs 1.6%; difference, 4.0%; 95% CI, 1.5% to 6.5%; P = .001). There were no significant differences in the length of ICU stay, length of hospital stay, ICU mortality, and in-hospital mortality. CONCLUSIONS AND RELEVANCE: In patients with moderate to severe ARDS, a strategy with lung recruitment and titrated PEEP compared with low PEEP increased 28-day all-cause mortality. These findings do not support the routine use of lung recruitment maneuver and PEEP titration in these patients. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01374022