60 research outputs found
CHANGE DETECTION IN FORESTS AND SAVANNAS USING STATISTICAL ANALYSIS BASED ON GEOGRAPHICAL OBJECTS
The aim of this work was to assess techniques of land cover change detection in areas of Brazilian Forest and Savanna, using Landsat 5/TM images, and two iterative statistical methodologies based on geographical objects. The sensitivity of the methodologies was assessed in relation to the heterogeneity of the input data, the use of reflectance data and vegetation indices, and the use of different levels of confidence. The periods analyzed were from 2000 to 2006, and from 2006 to 2010. After the segmentation of images, the descriptive statistics average and standard deviation of each object were extracted. The determination of change objects was realized in an iterative way based on the Mahalanobis Distance and the chi-square distribution. The results were validated with an early visual detection and analyzed according to Receiver Operating Characteristic (ROC) Curve. Significant gains were obtained by using vegetation masks and bands 3 and 4 for both areas tested with 94,67% and 95,02% of the objects correctly detected as changes, respectively for the areas of Forest and Savanna. The use of the NDVI and different images were not satisfactory in this study
Extended Method for Several Dichotomous Covariates to Estimate the Instantaneous Risk Function of the Aalen Additive Model
The instantaneous risk function of Aalen’s model is estimated considering dichotomous covariates, using parametric accumulated risk functions to smooth cumulative risk of Aalen by grouping the individuals into sets named parcels. This methodology can be used for data with dichotomous covariates
Intensive Computational Method Applied for Assessing Specialty Coffees by Trained and Untrained Consumers
The sensory analysis of coffees assumes that a sensory panel is formed by tasters trained according to the recommendations of the American Specialty Coffee Association. However, the choice that routinely determines the preference of a coffee is made through experimentation with consumers, in which, for the most part, they have no specific ability in relation to sensory characteristics. Considering that untrained consumers or those with basic knowledge regarding the quality of specialty coffees have little ability to discriminate between different sensory attributes, it is reasonable to admit the highest score given by a taster. Given this fact, probabilistic studies considering appropriate probability distributions are necessary. To access the uncertainty inherent in the notes given by the tasters, resampling methods such as Monte Carlo’s can be considered and when there is no knowledge about the distribution of a given statistic, p-Bootstrap confidence intervals become a viable alternative. This text will bring considerations about the use of the non-parametric resampling method by Bootstrap with application in sensory analysis, using probability distributions related to the maximum scores of tasters and accessing the most frequent region (mode) through computational resampling methods
New orders of 2k factorial designs generated by simulated annealing adapted to optimality criteria
Excessive changes in factor levels can lead to a high cost in practice and hinder the conduction of experiments, in addition to adding a higher computational cost and loss of the orthogonality property, resulting in numerical problems in estimating the parameters of a model. The sequential specification of experimental points, seen as treatments in a 2k factorial design, results in a high-order bias in some factors, which is caused by the accumulation of −1 or +1 signals. This study aimed to propose new designs generated by the simulated annealing technique, respecting the main A-optimal and D-optimal optimality criteria as random execution orders that minimize the order bias. This approach allowed the generation of 24 and 25 factorials, which were compared to the designs in standard order. The simulated annealing technique is a viable method to generate optimal designs with the same efficiency as the usual designs to obtain A-optimal and D-optimal designs with new execution orders, which minimize the effect of order bias relative to standard order designs. Regarding efficiency, the generated designs were precise in the variance of model parameter estimates, similar to the original designs
Pharmacological therapies for patients with human coronavirus infections : a rapid systematic review
O objetivo deste trabalho foi avaliar efeitos de tratamentos medicamentosos para infecções por coronavírus. Revisão sistemática rápida com buscas nas bases MEDLINE, EMBASE, Cochrane, BVS, Global Index Medicus, Medrix, bioRxiv, Clinicaltrials.gov e International Clinical Trials Registry Platform. Foram incluídos 36 estudos avaliando alternativas medicamentosas contra SARS, SARS-CoV-2 e MERS. A maioria dos estudos incluídos foi conduzida na China com delineamento observacional para tratamento da COVID-19. Os tratamentos mais estudados foram antimaláricos e antivirais. Nos antimaláricos, a metanálise de dois estudos com 180 participantes não identificou benefício da hidroxicloroquina em relação à negativação da carga viral via reação em cadeia de polimerase em tempo real e o uso de antivirais comparado ao cuidado padrão foi similar em relação aos desfechos. As evidências científicas disponíveis são preliminares e de baixa qualidade metodológica, o que sugere cautela na interpretação dos dados. Pesquisas que avaliem a eficácia comparativa em ensaios clínicos randomizados, controlados, com tempo de acompanhamento adequado e com os métodos devidamente divulgados e sujeitos à revisão científica por pares são necessárias. Recomenda-se atualização periódica da presente revisão.This work aimed to evaluate the effects of drug therapies for coronavirus infections. Rapid systematic review with search in the MEDLINE, EMBASE, Cochrane, BVS, Global Index Medicus, Medrix, bioRxiv, Clinicaltrials.gov and International Clinical Trials Registry Platform databases. Thirty-six studies evaluating alternative drugs against SARS, SARS-CoV-2 and MERS were included. Most of the included studies were conducted in China with an observational design for the treatment of COVID-19. The most studied treatments were with antimalarials and antivirals. In antimalarial, the meta-analysis of two studies with 180 participants did not identify the benefit of hydroxychloroquine concerning the negative viral load via real-time polymerase chain reaction, and the use of antivirals compared to standard care was similar regarding outcomes. The available scientific evidence is preliminary and of low methodological quality, which suggests caution when interpreting its results. Research that evaluates comparative efficacy in randomized, controlled clinical trials, with adequate follow-up time and with the methods properly disclosed and subject to scientific peer review is required. A periodic update of this review is recommended
As mestiçagens da arte e os cruzamentos experienciais das linguagens artísticas das atividades cotidianas na escola / Art mixtures and experiential crossings of artistic languages of daily activities in school
Este artigo é uma reflexão sobre as atividades experienciais do cotidiano da escola e da sala de aula. Utilizou-se como tema discutir a interdisciplinaridade da música com as outras linguagens artísticas e com outras áreas de conhecimento que permeiam o currículo escolar, objetivando introduzir o cotidiano da escola como conteúdo a ser explorado e estudado cientificamente como apontam (NÓVOA, 1995; COUTINHO, 2012; FAZENDA, 2012), retirando destas vivências no espaço escolar, a característica de trivialidade do fazer. O fazer na sala de aula é sistematizado, baseado em um currículo geralmente fechado, rígido, no entanto, esse fazer na escola é carente da visão e representação científica. Utilizou-se duas imagens para representar o fazer da educação, uma representando a culminância das atividades relacionadas aos festejos juninos na escola e outra imagem (a fotografia de uma pintura/tela/quadro) realizada num espaço informal (Ong) de ensino de arte. A abordagem é a da mestiçagem da/na arte, a interdisciplinaridade (FAZENDA, 1993; 2012), que por vezes está ligada às atividades realizadas na sala de aula. A Arte na escola (Artes Visuais, Teatro, Música, Dança) está definida enquanto componente curricular, mas no seu fazer, as linguagens desse componente se entrelaçam, se utilizam umas das outras – é a interdisciplinaridade. Do resultado desse entrelaçamento, surgem a mestiçagem e o hibridismo na arte. Como manter a identidade na/da arte diante disso? Objetiva-se problematizar o cotidiano escolar e tecer algumas considerações acerca de conceitos relacionados à prática artística como a mestiçagem, a interdisciplinaridade e o hibridismo na/da arte e a polivalência.
Preliminary observation of the use of sodium bicarbonate solution as an adjunct in the treatment of coronavirus 2019 disease (COVID-19): prognosis improvement in patients requiring intensive care / Observação preliminar do uso de solução de bicarbonato de sódio como coadjuvante no tratamento da doença coronavírus 2019 (COVID-19): melhora do prognóstico na necessidade de terapia intensiva
Introduction: This study aimed to evaluate the use of sodium bicarbonate solution as an adjunct in the treatment of critically ill patients in an intensive care unit (ICU). Methods: A group of 76 patients were followed up, of which 44 received treatment with a sodium bicarbonate (NaHCO3) solution along with the conventional treatment, and 32 patients used only the conventional treatment. Results: In patients treated, there was an improvement in radiological findings, a decrease in opacity and bilateral consolidations, as well as reduced length of stay in the ICU, and mortality. Conclusion: The use of NaHCO3 solution as an adjunct in the treatment of COVID-19 improved prognosis compared to conventional treatment.
Evidence syntheses to support decision-making related to the Covid-19 pandemic
A pandemia de covid-19 gerou um numeroso volume de produções científicas com diferentes níveis de qualidade. A velocidade com que o conhecimento era produzido e compartilhado a nível mundial impôs à gestão em saúde o desafio de buscar meios de identificar as melhores evidências disponíveis para subsidiar suas decisões. Em resposta a este desafio, o Departamento de Ciência e Tecnologia do Ministério da Saúde do Brasil estabeleceu um serviço para elaborar e disponibilizar conhecimento científico abordando questões prioritárias de saúde pública no cenário da pandemia. Entre os temas abordados estão tratamentos medicamentosos, medidas não farmacológicas, testagem, reinfecção e resposta imunológica, imunização, fisiopatologia, síndrome pós-covid e eventos adversos. Neste artigo, discute-se os pontos fortes e lições aprendidas, bem como os desafios e perspectivas que fornecem um exemplo real sobre como disponibilizar as melhores evidências científicas, em tempo hábil e de forma oportuna, para auxiliar o processo decisório durante uma emergência em saúde pública.The COVID-19 pandemic generated a large volume of scientific productions with different quality levels. The speed with which knowledge was produced and shared worldwide imposed on health management the challenge of seeking ways to identify the best availableevidence to support its decisions. In response to this challenge, the Department of Science and Technology of the Brazilian Ministry of Health started offering a service to produce and provide scientific knowledge addressing priority public health issues in the pandemic scenario.Drug treatments, non-pharmacological measures, testing, reinfection and immunological response, immunization, pathophysiology, post-COVID syndrome and adverse events are among the topics covered. In this article, we discuss the strengths and lessons learned, as well as the challenges and perspectives that present a real example of how to offer the best scientific evidence in a timely manner in order to assist the decision-making process during a public health emergency
Why Are Outcomes Different for Registry Patients Enrolled Prospectively and Retrospectively? Insights from the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF).
Background: Retrospective and prospective observational studies are designed to reflect real-world evidence on clinical practice, but can yield conflicting results. The GARFIELD-AF Registry includes both methods of enrolment and allows analysis of differences in patient characteristics and outcomes that may result. Methods and Results: Patients with atrial fibrillation (AF) and ≥1 risk factor for stroke at diagnosis of AF were recruited either retrospectively (n = 5069) or prospectively (n = 5501) from 19 countries and then followed prospectively. The retrospectively enrolled cohort comprised patients with established AF (for a least 6, and up to 24 months before enrolment), who were identified retrospectively (and baseline and partial follow-up data were collected from the emedical records) and then followed prospectively between 0-18 months (such that the total time of follow-up was 24 months; data collection Dec-2009 and Oct-2010). In the prospectively enrolled cohort, patients with newly diagnosed AF (≤6 weeks after diagnosis) were recruited between Mar-2010 and Oct-2011 and were followed for 24 months after enrolment. Differences between the cohorts were observed in clinical characteristics, including type of AF, stroke prevention strategies, and event rates. More patients in the retrospectively identified cohort received vitamin K antagonists (62.1% vs. 53.2%) and fewer received non-vitamin K oral anticoagulants (1.8% vs . 4.2%). All-cause mortality rates per 100 person-years during the prospective follow-up (starting the first study visit up to 1 year) were significantly lower in the retrospective than prospectively identified cohort (3.04 [95% CI 2.51 to 3.67] vs . 4.05 [95% CI 3.53 to 4.63]; p = 0.016). Conclusions: Interpretations of data from registries that aim to evaluate the characteristics and outcomes of patients with AF must take account of differences in registry design and the impact of recall bias and survivorship bias that is incurred with retrospective enrolment. Clinical Trial Registration: - URL: http://www.clinicaltrials.gov . Unique identifier for GARFIELD-AF (NCT01090362)
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