Análise Espaço-Temporal de Áreas de Queimadas no Estado do Maranhão a partir de Imagens MODIS e Classificação Random Forest

O mapeamento de áreas queimadas através de imagens de sensoriamento remoto apresenta uma série de questões importantes no gerenciamento espacial de estudos de detecção de focos de calor, análise de risco de incêndio, avaliação de danos e gerenciamento de processos de regeneração florestal. Neste estudo foi apresentada uma abordagem metodológica para mapeamento de áreas de queimadas no estado do Maranhão de 2001 a 2019 a partir de dados do satélite Terra/MODIS e do Algoritmo de Classificação Binária Random Forest. A avaliação da qualidade dos mapas gerados foi realizada a partir do produto padrão NASA MCD64A1 de áreas queimadas do sensor MODIS, que resultou num Coeficiente de Determinação geral (R²) de 0,55 e Correlação de Spearman de 0,78. O modelo Random Forest com 400 árvores permitiu avaliar a banda espectral de maior contribuição na classificação, bem como os erros relacionados ao número de árvores empregado. Algumas feições de áreas queimadas foram superestimadas, apresentando elevados erros de comissão. Os resultados mostraram que esta abordagem é útil para determinar áreas queimadas derivadas de dados de satélite de órbita polar. O modelo Random Forest mostrou-se aplicável em áreas de transição entre biomas. Constatou-se uma relação não linear entre a variabilidade espaço-temporal de incêndio e o clima em ecossistemas temperados. A Metodologia estabelecida e validada neste estudo poderá ser aplicada em outras regiões de clima temperado

Avaliação de incêndio em ambiente de Caatinga a partir de imagens Landsat-8, índice de vegetação realçado e análise por componentes principais

Fires generate negative environmental and socioeconomic impacts that directly and indirectly influence the Earth's regional and global climate changes. Forest fires and fires play a relevant ecological role as they affect the local biodiversity, soil properties and water supply. The Caatinga biome has a high level of degradation of human and natural activities, being extremely affected by fires that burn predominantly due to human activities. Remote orbital sensing, as it presents specific spatial, spectral and temporal characteristics, is an essential technological alternative in monitoring areas affected by fire on the Earth's surface. This work aimed to analyze, in a spatial, spectral and temporal scope, the behavior of a fire in a Caatinga environment from the multivariate statistical analysis of Landsat-8 Images data, Enhanced Vegetation Index and Analysis by theMajor Components. The quantification of characteristics of vegetation derived from the spectral index provides a better assessment of the physical condition of the earth's surface under the effects of fire. Remote sensing techniques and multivariate statistics were used to assess the spectral behavior of wildfires in the Caatinga biome. The results of the Kolmogorov-Smirnov Normality Test showed a significance level of 5%. The integration of the statistical methods of Simple Linear Regression and Analysis by the Principal Components enabled important diagnoses in the estimates and/or relationships between the random variables. The multivariate technique allowed 94% of the data variation to be assessed. The maps resulting from the tested methodology represent an important improvement in mapping the distribution of vegetation. This study generates indications for future scientific research related to the management of space concerning to vulnerability and recovery of vegetation landscapes from the semi-arid climate under fire situations generated by burnings.O fogo é um fator importante na perturbação e perda de florestas secas tropicais globais. Os incêndios florestais exercem um papel ecológico relevante, pois afetam a biodiversidade local, as propriedades do solo e o suprimento de água. O bioma Caatinga apresenta um alto nível de degradação de atividades antrópicas e naturais, sendo extremamente afetado por incêndios originados predominantemente por atividades humanas. O sensoriamento remoto orbital, por apresentar características espaciais, espectrais e temporais específicas, é uma alternativa tecnológica imprescindível no monitoramento de áreas afetadas pelo fogo na superfície terrestre. Este trabalho teve como objetivo analisar, no âmbito espacial, espectral e temporal, o comportamento de um incêndio em ambiente de Caatinga a partir de Imagens Landsat-8, Índice de Vegetação Realçado e Análise por Componentes Principais. A quantificação de características da vegetação derivada do índice espectral fornece uma melhor avaliação da condição física da superfície terrestre sob efeitos do fogo. Técnicas de sensoriamento remoto e estatística multivariada foram utilizadas para avaliar comportamento espectral da vegetação nativa exposta a eventos de incêndio do bioma Caatinga. Os resultados do Teste de Normalidade Kolmogorov-Smirnov apresentaram um nível de significância de 5 %. A integração dos métodos estatísticos de Regressão Linear Simples e Análise por Componentes Principais possibilitaram diagnósticos importantes nas estimativas e/ou relacionamentos entre as variáveis aleatórias. A técnica multivariada permitiu avaliar 94% da variação de dados. Os mapas resultantes da metodologia testada representam um aprimoramento importante no mapeamento da distribuição da vegetação. Este estudo gera indicativos para futuras pesquisas científicas vinculadas ao gerenciamento do espaço relacionado à vulnerabilidade e recuperação de paisagens de vegetação do clima semiárido sob situações de fogo geradas por incêndios

Assessment of k-Nearest Neighbor and Random Forest classifiers for mapping forest fire areas in central Portugal using Landsat-8, Sentinel-2, and Terra Imagery

Forest fires threaten the population’s health, biomass, and biodiversity, intensifying the desertification processes and causing temporary damage to conservation areas. Remote sensing has been used to detect, map, and monitor areas that are affected by forest fires due to the fact that the different areas burned by a fire have similar spectral characteristics. This study analyzes the performance of the k-Nearest Neighbor (kNN) and Random Forest (RF) classifiers for the classification of an area that is affected by fires in central Portugal. For that, image data from Landsat-8, Sentinel-2, and Terra satellites and the peculiarities of each of these platforms with the support of Jeffries–Matusita (JM) separability statistics were analyzed. The event under study was a 93.40 km2 fire that occurred on 20 July 2019 and was located in the districts of Santarém and Castelo Branco. The results showed that the problems of spectral mixing, registration date, and those associated with the spatial resolution of the sensors were the main factors that led to commission errors with variation between 1% and 15.7% and omission errors between 8.8% and 20%. The classifiers, which performed well, were assessed using the receiver operating characteristic (ROC) curve method, generating maps that were compared based on the areas under the curves (AUC). All of the AUC were greater than 0.88 and the Overall Accuracy (OA) ranged from 89 to 93%. The classification methods that were based on the kNN and RF algorithms showed satisfactory results.Research was supported by PAIUJA-2019/2020 and CEACTEMA from University of Jaen (Spain), and RNM-282 research group from the Junta de Andalucia (Spain). Special thanks to the four anonymous reviewers for their insightful comments

Analysis of spectral separability for detecting burned areas using Landsat-8 OLI/TIRS images under different biomes in Brazil and Portugal

Data supporting the findings of this study are available in the public domain. Landsat-8 data (https://earthexplorer.usgs.gov/, accessed on 20 April 2020). BDQueimadas vector data (https://queimadas.dgi.inpe.br/queimadas/aq30m/, accessed on 20 April 2020). ICNF burned areas vector data (https://www.icnf.pt/florestas/gfr/gfrgestaoinformacao/dfciinformacaocartgrafica, accessed on 20 April 2020).Fire is one of the natural agents with the greatest impact on the terrestrial ecosystem and plays an important ecological role in a large part of the terrestrial surface. Remote sensing is an important technique applied in mapping and monitoring changes in forest landscapes affected by fires. This study presents a spectral separability analysis for the detection of burned areas using Landsat-8 OLI/TIRS images in the context of fires that occurred in different biomes of Brazil (dry ecosystem) and Portugal (temperate forest). The research is based on a fusion of spectral indices and automatic classification algorithms scientifically proven to be effective with as little human interaction as possible. The separability index (M) and the Reed–Xiaoli automatic anomaly detection classifier (RXD) allowed the evaluation of the spectral separability and the thematic accuracy of the burned areas for the different spectral indices tested (Burn Area Index (BAI), Normalized Burn Ratio (NBR), Mid-Infrared Burn Index (MIRBI), Normalized Burn Ratio 2 (NBR2), Normalized Burned Index (NBI), and Normalized Burn Ratio Thermal (NBRT)). The analysis parameters were based on spatial dispersion with validation data, commission error (CE), omission error (OE), and the Sørensen–Dice coefficient (DC). The results indicated that the indices based exclusively on the SWIR1 and SWIR2 bands showed a high degree of separability and were more suitable for detecting burned areas, although it was observed that the characteristics of the soil affected the performance of the indices. The classification method based on bitemporal anomalous changes using the RXD anomaly proved to be effective in increasing the burned area in terms of temporal alteration and performing unsupervised detection without relying on the ground truth. On the other hand, the main limitations of RXD were observed in non-abrupt changes, which is very common in fires with low spectral signal, especially in the context of using Landsat-8 images with a 16-day revisit period. The results obtained in this work were able to provide critical information for fire mapping algorithms and for an accurate post-fire spatial estimation in dry ecosystems and temperate forests. The study presents a new comparative approach to classify burned areas in dry ecosystems and temperate forests with the least possible human interference, thus helping investigations when there is little available data on fires in addition to favoring a reduction in fieldwork and gross errors in the classification of burned areas.The article processing charge (APC) was funded by the University of Jaén through the Center for Advanced Studies on Earth Sciences, Energy and Environment CEACTEMA and the University of Minho.Research was supported by the project “Applied Remote Sensing in the Study of Hot Spots in Forests in Brazil and the Iberian Peninsula” from the Department of Cartographic Engineering and Surveying (DECart) of the Federal University of Pernambuco (UFPE/Brazil), by POIUJA-2023/2024 and CEACTEMA from University of Jaén (Spain), and RNM-282 research group from the Junta de Andalucía (Spain). This work was also supported by national funding awarded by FCT—Foundation for Science and Technology, I.P., projects UIDB/04683/2020 and UIDP/04683/2020

Em busca da identidade dos instrumentos musicais no Brasil: um estudo exploratório da literatura de cordel

Based on a collection of 2340 poems, the present article aims to explore the identity of musical instruments considered most popular by the printed Literatura de Cordel (Cordel Literature) in the countryside of Northeastern and Northern regions of Brazil, from the end of the 19th Century to present days. The Cordel Literature is known for representing the views of the social group from which it is originated rather than the creative work of its poets/writers. In search of musical instruments mentioned in the text, some of them were selected due to frequency and relevance of the context found: e.g. the Brazilian viola (a five course guitar), the violão (the six string guitar), the violin, the mandolin, the rabeca (Brazilian fiddle), the electric guitar and the piano. The violão and the Brazilian viola, which are similar in shape, are seen by that population in quite different ways. The fiddle is a popular instrument, but had only a few mentions. Other instruments like the violin, the mandolin, the piano and the electric guitar are described as urban instruments, thus less known in that context.O presente trabalho procura, em consulta a uma coleção de 2340 obras da Literatura de Cordel, explorar identidades culturais presentes nos instrumentos musicais aparentemente mais populares junto à população cultora de tal forma literária - sertão nordestino e parte da Região Norte do Brasil - desde o final do século XIX até o presente. Há no trabalho o pressuposto de que a Literatura de Cordel representa, muito mais que o trabalho criativo dos seus autores, as práticas vigentes no grupo social que a origina. Assim, à procura de menções a instrumentos musicais, este estudo detém-se em alguns deles, pela frequência e relevância da sua caracterização: viola caipira, violão, violino, bandolim, rabeca, guitarra elétrica e piano. Instrumentos aparentemente próximos como a viola e o violão são vistos de formas muito distintas pela população considerada. A rabeca, instrumento popular, poucas vezes é citada. Outros instrumentos, como violino, bandolim, piano e guitarra elétrica, são retratados como instrumentos urbanos e menos conhecidos

Canagliflozin and renal outcomes in type 2 diabetes and nephropathy

BACKGROUND Type 2 diabetes mellitus is the leading cause of kidney failure worldwide, but few effective long-term treatments are available. In cardiovascular trials of inhibitors of sodium–glucose cotransporter 2 (SGLT2), exploratory results have suggested that such drugs may improve renal outcomes in patients with type 2 diabetes. METHODS In this double-blind, randomized trial, we assigned patients with type 2 diabetes and albuminuric chronic kidney disease to receive canagliflozin, an oral SGLT2 inhibitor, at a dose of 100 mg daily or placebo. All the patients had an estimated glomerular filtration rate (GFR) of 30 to <90 ml per minute per 1.73 m2 of body-surface area and albuminuria (ratio of albumin [mg] to creatinine [g], >300 to 5000) and were treated with renin–angiotensin system blockade. The primary outcome was a composite of end-stage kidney disease (dialysis, transplantation, or a sustained estimated GFR of <15 ml per minute per 1.73 m2), a doubling of the serum creatinine level, or death from renal or cardiovascular causes. Prespecified secondary outcomes were tested hierarchically. RESULTS The trial was stopped early after a planned interim analysis on the recommendation of the data and safety monitoring committee. At that time, 4401 patients had undergone randomization, with a median follow-up of 2.62 years. The relative risk of the primary outcome was 30% lower in the canagliflozin group than in the placebo group, with event rates of 43.2 and 61.2 per 1000 patient-years, respectively (hazard ratio, 0.70; 95% confidence interval [CI], 0.59 to 0.82; P=0.00001). The relative risk of the renal-specific composite of end-stage kidney disease, a doubling of the creatinine level, or death from renal causes was lower by 34% (hazard ratio, 0.66; 95% CI, 0.53 to 0.81; P<0.001), and the relative risk of end-stage kidney disease was lower by 32% (hazard ratio, 0.68; 95% CI, 0.54 to 0.86; P=0.002). The canagliflozin group also had a lower risk of cardiovascular death, myocardial infarction, or stroke (hazard ratio, 0.80; 95% CI, 0.67 to 0.95; P=0.01) and hospitalization for heart failure (hazard ratio, 0.61; 95% CI, 0.47 to 0.80; P<0.001). There were no significant differences in rates of amputation or fracture. CONCLUSIONS In patients with type 2 diabetes and kidney disease, the risk of kidney failure and cardiovascular events was lower in the canagliflozin group than in the placebo group at a median follow-up of 2.62 years

Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

Evaluation of the Ability of SLSTR (Sentinel-3B) and MODIS (Terra) Images to Detect Burned Areas Using Spatial-Temporal Attributes and SVM Classification

Forest fires are considered one of the major dangers and environmental issues across the world. In the Cerrado biome (Brazilian savannas), forest fires have several consequences, including increased temperature, decreased rainfall, genetic depletion of natural species, and increased risk of respiratory diseases. This study presents a methodology that uses data from the Sea and Land Surface Temperature Radiometer (SLSTR) sensor of the Sentinel-3B satellite and the Moderate Resolution Imaging Spectroradiometer (MODIS) of the Terra satellite to analyze the thematic accuracy of burned area maps and their sensitivity under different spectral resolutions in a large area of 32,000 km2 in the Cerrado biome from 2019 to 2021. The methodology used training and the Support Vector Machine (SVM) classifier. To analyze the spectral peculiarities of each orbital platform, the Transformed Divergence (TD) index separability statistic was used. The results showed that for both sensors, the near-infrared (NIR) band has an essential role in the detection of the burned areas, presenting high separability. Overall, it was possible to observe that the spectral mixing problems, registration date, and the spatial resolution of 500 m were the main factors that led to commission errors ranging between 15% and 72% and omission errors between 51% and 86% for both sensors. This study showed the importance of multispectral sensors for monitoring forest fires. It was found, however, that the spectral resolution and burning date may gradually interfere with the detection process