975 resultados para class size


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An improved class of nonlinear bidirectional Boussinesq equations of sixth order using a wave surface elevation formulation is derived. Exact travelling wave solutions for the proposed class of nonlinear evolution equations are deduced. A new exact travelling wave solution is found which is the uniform limit of a geometric series. The ratio of this series is proportional to a classical soliton-type solution of the form of the square of a hyperbolic secant function. This happens for some values of the wave propagation velocity. However, there are other values of this velocity which display this new type of soliton, but the classical soliton structure vanishes in some regions of the domain. Exact solutions of the form of the square of the classical soliton are also deduced. In some cases, we find that the ratio between the amplitude of this wave and the amplitude of the classical soliton is equal to 35/36. It is shown that different families of travelling wave solutions are associated with different values of the parameters introduced in the improved equations.

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In machine learning and pattern recognition tasks, the use of feature discretization techniques may have several advantages. The discretized features may hold enough information for the learning task at hand, while ignoring minor fluctuations that are irrelevant or harmful for that task. The discretized features have more compact representations that may yield both better accuracy and lower training time, as compared to the use of the original features. However, in many cases, mainly with medium and high-dimensional data, the large number of features usually implies that there is some redundancy among them. Thus, we may further apply feature selection (FS) techniques on the discrete data, keeping the most relevant features, while discarding the irrelevant and redundant ones. In this paper, we propose relevance and redundancy criteria for supervised feature selection techniques on discrete data. These criteria are applied to the bin-class histograms of the discrete features. The experimental results, on public benchmark data, show that the proposed criteria can achieve better accuracy than widely used relevance and redundancy criteria, such as mutual information and the Fisher ratio.

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β-d-glucans from basidiomycete strains are powerful immunomodulatory agents in several clinical conditions. Therefore, their assay, purification and characterization are of great interest to understand their structure-function relationship. Hybridoma cell fusion was used to raise monoclonal antibodies (Mabs) against extracellular β-d-glucans (EBGs) from Pleurotus ostreatus. Two of the hybridoma clones (1E6-1E8-B5 and 3E8-3B4) secreting Mabs against EBGs were selected. This hybridoma cell line secreted Mabs of the IgG class which were then purified by hydroxyapatite chromatography to apparent homogeneity on native and SDS-PAGE. Mabs secreted by 1E6-1E8-B5 clone were found to recognize a common epitope on several β-d-glucans from different basidiomycete strains. This Mab exhibited high affinity constant (KA) for β-d-glucans from several mushroom strains in the range of 3.20 × 109 ± 3.32 × 103-1.51 × 1013 ± 3.58 × 107 L/mol. Moreover, they reacted to some heat-treated β-d-glucans in a different mode when compared with the native forms; these data suggest that this Mab binds to a conformational epitope on the β-d-glucan molecule. The epitope-binding studies of Mabs obtained from 1E6-1E8-B5 and 3E8-3B4 revealed that the Mabs bind to the same epitope on some β-d-glucans and to different epitopes in other antigen molecules. Therefore, these Mabs can be used to assay for β-d-glucan from basidiomycete mushrooms. © 2015 Elsevier Ltd. All rights reserved.

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Trabalho de Projeto apresentado ao Instituto de Contabilidade e Administração do Porto para a obtenção do grau de Mestre em Tradução e Interpretação Especializadas, sob orientação da Doutora Clara Sarmento

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Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em Biotecnologia

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in RoboCup 2007: Robot Soccer World Cup XI

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Proceedings of the 10th Mediterranean Conference on Control and Automation - MED2002 Lisbon, Portugal, July 9-12, 2002

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BACKGROUND: Valve surgery in children is aimed at restoring correct hemodynamics with few reoperations and limited resort to prostheses, which would imply early deterioration or definitive hypocoagulation. OBJECTIVES: Report a series of paediatric pts with acquired mitral valve disease, mostly due to rheumatic disease, in whom it was possible, for the great majority, to repair the damaged valve. DEMOGRAPHICS: Fifty children with predominant mitral valve disease, 47 rheumatic (94%) and 3 after endocarditis were consequently operated by the same surgical team over the last five years. Ages were 12.5+/-3.1 yrs and weights 33.2+/-8.4 Kg, 30 pts presented with predominant mitral regurgitation and 20 pts had significant stenosis. In 8 pts there also moderate to severe aortic regurgitation and in 2 pts severe tricuspid regurgitation was present. Patients were not operated during the acute phase of the disease. Five pts were reoperations and from those, all but one received mechanical prosthesis. RESULTS: In all operations the intention was to repair the mitral valve. In 46 pts complex mitral valvuloplasties were performed extended comissurotomies, shortening of chordae, chordal replacement with PTFE, and reconstruction of valve leaflefts by direct patching or pericardial extension of the retracted posterior leaflet (78.2% cases), plus reshaping of the annulus by using a fixed prosthetic CE ring (sizes 26 to 32) in every case. Ring sizes correlated poorly with body weights, but correlation was close and positive for the use of pericardial advancement of the posterior leaflet (p<0.01). There was no operative mortality, but one pt died early from sepsis and there was no late mortality. Maximum follow up extends now to 50 months (median 28 months) and functional evaluation, at latest follow up, as assessed by Doppler Echocardiography, showed residual mitral regurgitation, mild-moderate in 4 pts and LA-LV gradients mild in 5 and moderate in 2 pts. NYHA functional class, at present follow-up is class I for 43 pts (88%) and class II in the remaining 6 pts. Along the follow-up period 2 pts had to be reoperated for early repair failures and other three for late failures, presently freedom for reoperation is 91.8% at 5 years. CONCLUSIONS: Mitral valve repair in children with rheumatic lesions can be achieved for the great majority of cases by using different techniques. Pericardial extension of the retracted posterior leaflet allowed the use of a bigger size prosthetic ring. Intermediate functional results are good with fair functional classes and few reoperations but follow-up is short and does not allow us to draw conclusions about the long-term results of the repair in these rheumatic patients.

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A 75-year old female patient, with previous inferior acute myocardial infarction (AMI) in December 2000, was admitted in April 2001 with angina and heart failure. Transthoracic echocardiography (TTE) was suggestive of a postero-inferior pseudoaneurysm (PA) of the left ventricle (LV), with 61x49 mm. of size and mitral regurgitation. Cardiac catheterization was suspected of a PA of the LV and revealed a three vessels coronary artery disease. On 20th April she was submitted to cardiac surgery with resection of a large LV aneurysm (AN) and triple coronary artery bypass surgery. Afterwards, she was on NYHA class III and subsequent TTE and transesophagic echocardiography (TEE) were suggestive of a 90x60 mm LV posterior PA (confirmed by nuclear magnetic resonance) and severe mitral regurgitation, with good LV systolic function. She underwent a new cardiac surgery on 31st May 2002, with resuturing of the LV postero-inferior wall patch and removal of the PA. The patient is in good condition and on NYHA functional class I-II.

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This research focuses on the influence of company sector and size on the level of utilization of Basic and Advanced Quality Tools. The paper starts with a literature review and then presents the methodology used for the survey. Based on the responses from 202 managers of Portuguese ISO 9001:2008 Quality Management System certified organizations, statistical tests were performed. Results show, with 95% confidence level, that industry and services have a similar proportion of use of Basic and Advanced Quality Tools. Concerning size, bigger companies show a higher trend to use Advanced Quality Tools than smaller ones. For Basic Quality Tools, there was no statistical significant difference at a 95% confidence level for different company sizes. The three basic Quality tools with higher utilization were Check sheets, Flow charts and Histograms (for Services) or Control Charts/ (for Industry), however 22% of the surveyed organizations reported not using Basic Quality Tools, which highlights a major improvement opportunity for these companies. Additional studies addressing motivations, benefits and barriers for Quality Tools application should be undertaken for further validation and understanding of these results.

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Recent advances in psychosocial treatments for schizophrenia have targeted social cognitive deficits. A critical literature review and effect-size (ES) analysis was conducted to investigate the efficacy of comprehensive programs of social cognitive training in schizophrenia. Results revealed 16 controlled studies consisting of seven models of comprehensive treatment with only three of these treatment models investigated in more than one study. The effects of social cognitive training were reported in 11/15 studies that included facial affect recognition skills (ES=.84) and 10/13 studies that included theory-of-mind (ES=.70) as outcomes. Less than half (4/9) of studies that measured attributional style as an outcome reported effects of treatment, but effect sizes across studies were significant (ESs=.30-.52). The effect sizes for symptoms were modest, but, with the exception of positive symptoms, significant (ESs=.32-.40). The majority of trials were randomized (13/16), selected active control conditions (11/16) and included at least 30 participants (12/16). Concerns for this area of research include the absence of blinded outcome raters in more than 50% of trials and low rates of utilization of procedures for maintaining treatment fidelity. These findings provide preliminary support for the broader use of comprehensive social cognitive training procedures as a psychosocial intervention for schizophrenia.

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We present a new deterministic dynamical model on the market size of Cournot competitions, based on Nash equilibria of R&D investment strategies to increase the size of the market of the firms at every period of the game. We compute the unique Nash equilibrium for the second subgame and the profit functions for both firms. Adding uncertainty to the R&D investment strategies, we get a new stochastic dynamical model and we analyse the importance of the uncertainty to reverse the initial advantage of one firm with respect to the other.

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Toxoplasmosis is an usually asymptomatic worldwide disseminated infection. In its congenital presentation it may lead to abortion or fetal malformations. Antenatal evaluation is considered of paramount importance to identify seronegative women and allow for prophylaxis. Recent improvements in sensitivity of IgM tests has made IgM detection an extremely protracted acute phase marker, and IgG avidity evaluation test became necessary. Observation has shown that a correlation can be established between IgM levels and avidity percentages, suggesting that frequently the avidity test may not be necessary. In this study we analyzed Toxoplasma gondii IgM levels of 202 samples and their IgG avidity percentages, in order to define specific levels whose IgM quantification could by itself define serodiagnosis and therefore make the avidity evaluation unnecessary. We showed that for IgM levels bellow 2.0 and above 6.0 serodiagnosis of toxoplasmosis could be established without need of IgG avidity test. IgM levels between these two parameters are associated with varying avidity indexes highlighting the importance of its evaluation as a means to confirm toxoplasmosis. Following this demonstration it was possible to avoid the avidity test for 75% of the cases, to reduce the turnaround time and to reduce costs.

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The pathogenic potential of Blastocystis sp. in experimental models requires further investigation. In this work, the pathogenicity of this parasite in the gastrointestinal tract of male Swiss mice was evaluated according to the inoculum size and period of infection. Animals were infected intragastrically, with 100, 500, 1,000, 5,000 and 10,000 Blastocystis sp. vacuolar forms obtained from a mixture of eight human isolates cultured axenically in Jones' medium. After seven, 14, 21, 28 and 60 days of infection, the animals were sacrificed and fragments of the small intestine (duodenum), large intestine, and cecum were subjected to histopathological analysis. Blastocystis sp. triggered an inflammatory response in the different tissues analyzed, with a predominance of mononuclear cells. The parasite was found in the muscular layer of the cecum, showing its invasive character. Larger inocula triggered inflammatory processes earlier (seven days) than smaller ones (from 21 days). We conclude that, in the proposed model, the pathogenicity of Blastocystis sp. isolates that were studied is related to inoculum size and period of infection.