24 research outputs found

    Classificação da cobertura da terra na planície de inundação do Lago Grande de Curuai (Amazônia, Brasil) utilizando dados multisensor e fusão de imagens

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    Given the limitations of different types of remote sensing images, automated land-cover classifications of the Amazon várzea may yield poor accuracy indexes. One way to improve accuracy is through the combination of images from different sensors, by either image fusion or multi-sensor classifications. Therefore, the objective of this study was to determine which classification method is more efficient in improving land cover classification accuracies for the Amazon várzea and similar wetland environments - (a) synthetically fused optical and SAR images or (b) multi-sensor classification of paired SAR and optical images. Land cover classifications based on images from a single sensor (Landsat TM or Radarsat-2) are compared with multi-sensor and image fusion classifications. Object-based image analyses (OBIA) and the J.48 data-mining algorithm were used for automated classification, and classification accuracies were assessed using the kappa index of agreement and the recently proposed allocation and quantity disagreement measures. Overall, optical-based classifications had better accuracy than SAR-based classifications. Once both datasets were combined using the multi-sensor approach, there was a 2% decrease in allocation disagreement, as the method was able to overcome part of the limitations present in both images. Accuracy decreased when image fusion methods were used, however. We therefore concluded that the multi-sensor classification method is more appropriate for classifying land cover in the Amazon várzea

    Precocious and late pregnancy in adolescents: is there a difference comparing the obstetric risks?

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    PURPOSE: to describe the obstetric outcomes in pregnant adolescents at a tertiary hospital and to compare the maternal and labor outcomes between precocious and late adolescents. METHODS: in a transversal analytical study, 2058 cases were evaluated, considering 322 (15.65%) from the precocious group and 1736 (84.35%) from the late group that delivered at the Maternidade Escola Assis Chateaubriand/UFC from January 1, 2000 to December 31, 2000. The clinical complications in the prenatal period, kind of delivery, indications for cesarean section, birth gestational age at birth, birth weight, comparison of birth weight and gestational age, Apgar score at the first and fifth minute, presence of malformations, and neonatal death were analyzed. The exact Fisher and the chi2 tests were used to compare both groups. The prevalence ratio was calculated. RESULTS: from of total of deliveries, 25.95% belonged to adolescents. The average age was 17.19 years. Prenatal visits were made by 88% of the patients, but 60% had an insufficient number of visits. The most frequent clinical situations were preeclampsia (14.72%), anemia (12.97%) and urinary tract infections (6.37%), with no statistical difference between the groups. Thirty-one and three percent of the births were by cesarean section, preeclampsia being the main indication in the two age groups (25 and 23%, respectively). The frequency of an Apgar score less than 7 at the first minute was 19,9% in the precocious adolescent group and 14,2% in the late adolescent group (x²=6,96, p=0.008). There was no statistical difference regarding prematurity rate (20.2 vs 16.1%), low-birth weight infants (12.4 vs 10.4%), low Apgar score at the fifth minute (5.3 vs 3.3%), congenital malformations (3.1 vs 2.7%), and neonatal death (5.3 vs 3.3%). CONCLUSIONS: the precocious and late pregnant adolescents presented similar pregnancy evolution and obstetric outcomes, except for the differences of the first minute Apgar scores.OBJETIVOS: descrever aspectos da assistência e resultados obstétricos da gravidez em adolescentes atendidas em um centro de atendimento terciário do Ceará e comparar os resultados maternos e perinatais entre adolescentes precoces e tardias. MÉTODOS: em estudo transversal, analítico, avaliaram-se 2.058 casos, sendo 322 (15,6%) de adolescentes precoces e 1.736 (84,4%) tardias, atendidas no ano de 2000. Foram analisados as intercorrências clínicas no pré-natal, tipo de parto, indicações de cesárea, idade gestacional no parto, peso do recém-nascido ao nascimento, adequação do peso à idade gestacional, índices de Apgar no primeiro e quinto minuto de vida, presença de malformações e óbito neonatal. Utilizaram-se o teste exato de Fisher e o chi2 na comparação entre os dois grupos. Calculou-se também a razão de prevalência. RESULTADOS: do total de partos ocorridos no período, 25,9% eram de adolescentes e a média de idade destas foi de 17,2 anos. Constatou-se que 88% freqüentaram o pré-natal, sendo 60% com número insuficiente de consultas. As intercorrências clínicas mais freqüentes foram a pré-eclâmpsia (14,7%), a anemia (12,9%) e a infecção do trato urinário (6,4%), sem diferença de freqüência entre os grupos. Ocorreram 31,3% de nascimentos por cesárea, sendo a pré-eclâmpsia a principal indicação nas duas faixas etárias (25 e 23%, respectivamente). A freqüência de Apgar menor que 7 no primeiro minuto foi de 19,9% no grupo das adolescentes precoces e 14,2% entre as tardias (x²=6,96, p=0,008). Não houve diferença quanto à freqüência de prematuridade (20,2 vs 16,1%), recém-nascido pequeno para idade gestacional (12,4 vs 10,4%), baixos escores de Apgar de quinto minuto (5,3 vs 3,3%), malformações congênitas (3,1 vs 2,7%) e morte neonatal (1,6 vs 3,1%). CONCLUSÕES: as gestantes adolescentes precoces e tardias apresentaram evolução da gestação e desempenho obstétrico semelhantes, exceto pela diferença nos escores de Apgar no primeiro minuto.Universidade Federal do Ceará Maternidade-Escola Assis ChateaubriandUniversidade Federal do CearáUniversidade Federal do Ceará Departamento de Matemática e EstatísticaUniversidade Federal do Ceará Departamento de Saúde Materno-InfantilUniversidade Federal de São Paulo (UNIFESP), Escola Paulista de Medicina (EPM) Departamento de ObstetríciaUNIFESP, EPM, Depto. de ObstetríciaSciEL

    ATLANTIC EPIPHYTES: a data set of vascular and non-vascular epiphyte plants and lichens from the Atlantic Forest

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    Epiphytes are hyper-diverse and one of the frequently undervalued life forms in plant surveys and biodiversity inventories. Epiphytes of the Atlantic Forest, one of the most endangered ecosystems in the world, have high endemism and radiated recently in the Pliocene. We aimed to (1) compile an extensive Atlantic Forest data set on vascular, non-vascular plants (including hemiepiphytes), and lichen epiphyte species occurrence and abundance; (2) describe the epiphyte distribution in the Atlantic Forest, in order to indicate future sampling efforts. Our work presents the first epiphyte data set with information on abundance and occurrence of epiphyte phorophyte species. All data compiled here come from three main sources provided by the authors: published sources (comprising peer-reviewed articles, books, and theses), unpublished data, and herbarium data. We compiled a data set composed of 2,095 species, from 89,270 holo/hemiepiphyte records, in the Atlantic Forest of Brazil, Argentina, Paraguay, and Uruguay, recorded from 1824 to early 2018. Most of the records were from qualitative data (occurrence only, 88%), well distributed throughout the Atlantic Forest. For quantitative records, the most common sampling method was individual trees (71%), followed by plot sampling (19%), and transect sampling (10%). Angiosperms (81%) were the most frequently registered group, and Bromeliaceae and Orchidaceae were the families with the greatest number of records (27,272 and 21,945, respectively). Ferns and Lycophytes presented fewer records than Angiosperms, and Polypodiaceae were the most recorded family, and more concentrated in the Southern and Southeastern regions. Data on non-vascular plants and lichens were scarce, with a few disjunct records concentrated in the Northeastern region of the Atlantic Forest. For all non-vascular plant records, Lejeuneaceae, a family of liverworts, was the most recorded family. We hope that our effort to organize scattered epiphyte data help advance the knowledge of epiphyte ecology, as well as our understanding of macroecological and biogeographical patterns in the Atlantic Forest. No copyright restrictions are associated with the data set. Please cite this Ecology Data Paper if the data are used in publication and teaching events. © 2019 The Authors. Ecology © 2019 The Ecological Society of Americ

    Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

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    Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

    Dual-season and full-polarimetric C band SAR assessment for vegetation mapping in the Amazon várzea wetlands

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    This study answered the following questions: 1) Is polarimetric C-band SAR (PolSAR) more efficient than dual-polarization (dual-pol) C-band SAR for mapping várzea floodplain vegetation types, when using images of a single hydrological period? 2) Are single-season C-band PolSAR images more accurate for mapping várzea vegetation types than dual-season dual-pol C-band SAR images? 3) What are the most efficient polarimetric descriptors for mapping várzea vegetation types? We applied the Random Forests algorithm to classify dual-pol SAR images and polarimetric descriptors derived from two full-polarimetric Radarsat-2 C-band images acquired during the low and high water seasons of Lago Grande de Curuai floodplain, lower Amazon, Brazil. We used the Kappa index of agreement (κ), Allocation Disagreement (AD) and Quantity Disagreement (QD), and Producer's and User's accuracy measurements to assess the classification results. Our results showed that single-season full-polarimetric C-band data can yield more accurate classifications than single-season dual-pol C-band SAR imagery and similar accuracies to dual-season dual-pol C-band SAR classifications. Still, dual-season PolSAR achieved the highest accuracies, showing that seasonality is paramount for obtaining high accuracies in wetland land cover classification, regardless of SAR image type. On average, single-season classifications of low-water periods were less accurate than high-water classifications, likely due to plant phenology and flooding conditions. Classifications using model-based polarimetric decompositions (such as Freeman-Durden, Yamaguchi and van Zyl) produced the highest accuracies (κ greater than 0.8; AD ranging from 7.5% to 2.5%; QD ranging from 15% to 12%), while eigenvector-based decompositions such as Touzi and Cloude-Pottier had the worst accuracies (κ ranging from 0.5 to 0.7; AD greater than 10%; QD smaller than 10%). Vegetation types with dense canopies (Shrubs, Floodable Forests and Emergent Macrophytes), whose classification is challenging using C-band, were accurately classified using dual-season full-polarimetric SAR data, with Producer's and User's accuracies between 80% and 90%. We conclude that full polarimetric C-band imagery can yield very accurate classifications of várzea vegetation (κ ~0.8, AD ~3% and QD ~10%) and can be used as an operational tool for forested wetland mapping

    Emprego de imagens TM/Landsat-5 para estudo da expansão urbana em sistemas de dunas na região costeira de Torres - RS e Passo de Torres - SC

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    The coastal zone comprises a dynamic environment between the continent and ocean, with high energy exchange and sediment transport. These sites usually show increasingly urban occupation and activities of summer tourism, which leads to changes in land cover and use. Coastal dunes represent one of the most impacted components by urban development. In this context an analysis of temporal changes of land cover in the coastal dunes was performed in Torres - RS and Passo de Torres SC, using two images of the TM / Landsat-5 for a period of 19 years (1991-2010). Digital image processing was performed using ENVI 4.7. Subsequently, an object based image analysis was made with Definiens 7.0, followed by editing in ArcGIS 10.0. From the final map it was calculated the areas which coastal dunes have changed into other classes. The main change in land cover was from dune type to urban areas, which total changed area was estimated in 1.42 km². The classification maps achieved a kappa indexes of 0.79 (1991) and 0.81 (2010). As product of this analysis, a thematic map with spatial distribution of land cover change detected was made. These results are important since the coastal dunes play an important role in the sediment budget of the beach environment, besides representing the habitat of several species of animals and plants highly adapted to that niche.Pages: 5361-536

    CHANGE VECTOR ANALYSIS TO DETECT DEFORESTATION AND LAND USE/LAND COVER CHANGE IN BRAZILIAN AMAZON

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    O presente trabalho tem como objetivo utilizar a Análise por Vetor de Mudança para detectar desmatamentos e outras mudanças no uso e cobertura da terra entre os anos de 1989 e 2010 no município de Tapurah/MT a partir de dados TM/LANDSAT-5. Como resultado, obteve-se um mapa de mudanças no uso e cobertura da terra no período mencionado, que permitiu a identificação satisfatória das áreas de desmatamento em Tapurah, apresentando índice Kappa de 0,6464 e 33,9% de área desmatada

    Backscattering response of different land cover types in the Lago Grande de Curuai floodplain (Amazon, Brazil) determined from Radarsat-2 and TerraSAR-X data

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    We analyzed the radiometric responses of main vegetation groups and other classes of interest at the Lago Grande de Curuai floodplain, in the Brazilian Amazon, to determine the influence of several radar imaging parameters (incidence angle, wavelength, spatial resolution and polarization) on the backscattering. Overall, images from the Radarsat-2 sensor, from the S1 imaging mode were the most effective to differentiate the analyzed cover types, mainly due to its greater target penetration capability in relation to TerraSAR-X images. Images with higher spatial resolution showed good potential to characterize local variations in target structure, while HH, VV and HV polarizations had smaller differences in their response variability, with HH polarization showing the largest responses magnitudes. Changes in incidence angle did not significantly affect target differentiation, except in the case of open water surfaces. We also noticed larger variation in target responses related to the time of imaging along the flooding season, evidencing the importance of multitemporal imagery for proper target identification. Overall, Radarsat-2 S1 and TerraSAR-X Stripmap or Spotlight modes offer the most promising capabilities for target discrimination and structure detection in the Amazon floodplain.Pages: 8475-848
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