1,132 research outputs found

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

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    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

    A GEOBIA approach for multitemporal land-cover and land-use change analysis in a Tropical Watershed in the southeastern Amazon

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    The southeastern Amazon region has been intensively occupied by human settlements over the past three decades. To evaluate the effects of human settlements on land-cover and land-use (LCLU) changes over time in the study site, we evaluated multitemporal Landsat images from the years 1984, 1994, 2004, 2013 and Sentinel to the year 2017. Then, we defined the LCLU classes, and a detailed “from-to” change detection approach based on a geographic object-based image analysis (GEOBIA) was employed to determine the trajectories of the LCLU changes. Three land-cover (forest, montane savanna and water bodies) and three land-use types (pasturelands, mining and urban areas) were mapped. The overall accuracies and kappa values of the classification were higher than 0.91 for each of the classified images. Throughout the change detection period, ~47% (19,320 km2) of the forest was preserved mainly within protected areas, while almost 42% (17,398 km2) of the area was converted from forests to pasturelands. An intrinsic connection between the increase in mining activity and the expansion of urban areas also exists. The direct impacts of mining activities were more significant throughout the montane savanna areas. We concluded that the GEOBIA approach adopted in this study combines the advantages of quality human interpretation and the capacities of quantitative computing

    The efficacy of topical antibiotics in reducing conjunctival microbiota of healthy patients with senile cataract

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    PURPOSE: To evaluate the conjunctival bacterial flora of healthy patients and its antibiotic resistance pattern and determine the effective of a regime of topical antibiotics on reduction of endogenous microbiota. METHODS: Its a prospective non randomized study. Fourty eyes of 40 patients, divided in 4 groups of 10 eyes each, used four differents topical antibiotics (ciprofloxacin, tobramycin and gatifloxacin). One group served as a control group. Were performed conjunctival cultures before instillation of the antibiotics drops and after 15, 30 and 60 minutes. Were performed susceptibility tests of the specimes isolated to these antibiotics. We compared the reduction of bacterium growth by assessing the number of UFC (colonies forming units) before and after the instillation of antibiotics drops. RESULTS: Of the 40 eyes, 92,5% had positive cultures. The coagulase-negative Staphylococcus (CNS) was the most frequent organism isolated (50%), followed by Staphylococcus Aureus (23%) and gram-negative bacteria (26%). More than 81% of the isolates of this bacterium were susceptible to all antibiotics tested. Five bacterium isolates were resistant to ciprofloxacin and tobramycin and two to gatifloxacin. All groups had diminished the number of patients with positive culture specimes from the conjuntiva compared to moment zero and to placebo. CONCLUSION: The gram positive bacterium, specially the coagulase-negative Staphylococcus, were the most frequent microorganism found on conjunctiva of healthy patients. The most of the bacterium isolated were sensitivity to the antibiotics tested. The proposed regime of use of these antibiotics reduced the number of UFC (colonies forming units) compared to placebo although without statics relevance in most of cases.OBJETIVOS: Identificar as bactérias que compõem a microbiota conjuntival de pacientes sadios com catarata senil, a susceptibilidade delas aos antibióticos testados e a eficácia de um regime de administração de antibióticos tópicos na redução dessa microbiota. MÉTODOS: Coorte prospectiva, não-randomizada, de 40 olhos de 40 pacientes divididos em 4 grupos de 10 pacientes cada, que utilizaram diferentes antibióticos tópicos (tobramicina, ciprofloxacino e gatifloxacino). Foram realizadas culturas de material conjuntival antes do uso dos medicamentos e 15, 30 e 60 minutos após o uso dos mesmos. Foram realizados testes de resistência bacteriana das bactérias isoladas e comparação da redução do crescimento bacteriano pela análise do número de unidade formadoras de colônias (UFC). RESULTADOS: Houve crescimento bacteriano em 92,5% dos pacientes. O estafilococo coagulase negativo foi a bactéria mais comumente encontrada (50% dos casos), seguido pelo Staphylococcus Aureus (23%) e pelas bactérias gram negativas (26%). Das bactérias isoladas, 81,8% foram sensíveis a todos os antibióticos utilizados no estudo. Houve cinco casos de resistência ao ciprofloxacino e à tobramicina e dois de resistência ao gatifloxacino. Em todos os grupos houve diminuição do número de pacientes com cultura positiva em relação ao momento zero e em relação ao placebo. CONCLUSÃO: As bactérias gram-positivas, especialmente o estafilococo coagulase negativo, foram os microrganismos mais encontrados na conjuntiva normal dos pacientes estudados. As bactérias isoladas mostraram alta taxa de susceptibilidade aos antibióticos testados. O regime de uso desses antibióticos diminuiu o número de unidades formadoras de colônias em relação ao grupo controle, embora sem significância estatística na maioria dos casos.Universidade Federal de São Paulo (UNIFESP) Setor de Córnea e Doenças ExternasInstituto Brasileiro de Oftalmologia Médico do Setor de Retina e VítreoUniversidade Federal de São Paulo (UNIFESP)Universidade Federal do Rio de JaneiroUniversidade Federal do Rio de Janeiro Hospital Universitário Clementino Fraga Filho Laboratório de Bacteriologia ClínicaUNIFESP, Setor de Córnea e Doenças ExternasUNIFESPSciEL

    PERFIL DOS PECUARISTAS DE TOCANTINS E CRIAÇÃO DE GADO VERDE

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    The purpose of this article is to study and evaluate the profile of ranchers of beef cattle located in the State of Tocantins. Applied in a first moment a closed questionnaire focused on charting the social profile of the ranchers. Then we applied a questionnaire with open questions in which the ranchers issued their opinion on economic activity, logistics, environmental indicators, animal, pasture and technology. It was adopted the method of saturation to analyze qualitative data, discursive. The study was divided into two steps: data collection, with semistructured interviews with ranchers in the three regions of the State (North, central and South). In another step they have tabbed the data obtained in the collection and analyzed the profiles of ranchers highlighting its specificities. For the analysis, the ranchers were separated into 3 groups: small, medium and large ranchers. All ranchers analyzed are cattle breeders, who sell directly or indirectly to refrigerators. This article identifies the cattleman profile state of Tocantins and the Green supply chain management system and its competitive edge in the creation of cattle.O objetivo deste artigo é estudar e avaliar o perfil dos pecuaristas de corte localizados no estado do Tocantins. Aplicou-se em um primeiro momento um questionário fechado focalizado em traçar o perfil social dos pecuaristas. Em seguida, aplicou-se um questionário com questões abertas em que os pecuaristas emitiram sua opinião sobre atividade econômica, logística, indicadores ambientais, sanidade animal, pastagem e tecnologia. Foi adotado o método de saturação para analise dos dados qualitativo, discursivo. O estudo foi dividido em duas etapas: Coleta de dados, com entrevistas semi estruturadas com pecuaristas das três regiões do estado (norte, central e sul). Na outra etapa tabularam-se os dados obtidos na coleta e analisaram-se os perfis dos pecuaristas destacando as suas especificidades. Para a análise, os pecuaristas foram separados em 3 grupos: pequenos, médios e grandes pecuaristas. Todos os pecuaristas analisados são criadores de gado de corte, que vendem direta ou indiretamente para frigoríficos. Este artigo identifica o perfil do pecuarista do estado do Tocantins e o sistema de gestão verde da cadeia e seus diferenciais competitivos na criação de gado de corte

    Aedes fluviatilis cell lines as new tools to study metabolic and immune interactions in mosquito‑Wolbachia symbiosis

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    In the present work, we established two novel embryonic cell lines from the mosquito Aedes fluviatilis containing or not the naturally occurring symbiont bacteria Wolbachia, which were called wAflu1 and Aflu2, respectively. We also obtained wAflu1 without Wolbachia after tetracycline treatment, named wAflu1.tet. Morphofunctional characterization was performed to help elucidate the symbiont-host interaction in the context of energy metabolism regulation and molecular mechanisms of the immune responses involved. The presence of Wolbachia pipientis improves energy performance in A. fluviatilis cells; it affects the regulation of key energy sources such as lipids, proteins, and carbohydrates, making the distribution of actin more peripheral and with extensions that come into contact with neighboring cells. Additionally, innate immunity mechanisms were activated, showing that the wAflu1 and wAflu1.tet cells are responsive after the stimulus using Gram negative bacteria. Therefore, this work confirms the natural, mutually co-regulating symbiotic relationship between W. pipientis and A. fluviatilis, modulating the host metabolism and immune pathway activation. The results presented here add important resources to the current knowledge of Wolbachia-arthropod interactions

    Recombinant Plasmodium vivax circumsporozoite surface protein allelic variants: antibody recognition by individuals from three communities in the Brazilian Amazon

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    Circumsporozoite protein (CSP) variants of P. vivax, besides having variations in the protein repetitive portion, can differ from each other in aspects such as geographical distribution, intensity of transmission, vectorial competence and immune response. Such aspects must be considered to P. vivax vaccine development. Therefore, we evaluated the immunogenicity of novel recombinant proteins corresponding to each of the three P. vivax allelic variants (VK210, VK247 and P. vivax-like) and of the C-terminal region (shared by all PvCSP variants) in naturally malaria-exposed populations of Brazilian Amazon. Our results demonstrated that PvCSP-VK210 was the major target of humoral immune response in studied population, presenting higher frequency and magnitude of IgG response. The IgG subclass profile showed a prevalence of cytophilic antibodies (IgG1 and IgG3), that seem to have an essential role in protective immune response. Differently of PvCSP allelic variants, antibodies elicited against C-terminal region of protein did not correlate with epidemiological parameters, bringing additional evidence that humoral response against this protein region is not essential to protective immunity. Taken together, these findings increase the knowledge on serological response to distinct PvCSP allelic variants and may contribute to the development of a global and effective P. vivax vaccine

    Process control in the geneses and evolution of a lagoon-barrier system inside of the patos lagoon, south of Brazil

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    The origin and geological evolution of a complex of a beach ridgeplain in the Feitoria lagoon-barrier, located on the western margin of the southern cell Patos lagoon, Brazil was influenced by the interactions between the alocyclic (climate change and relative sea level) and autocyclic (sediment supply, waves, longshore drift and storm surges) forcing. The study of this regressive beach ridgeplain included the analysis of orthophotos; topographic detail (PRO-XRS Trimble®-post-processed); and shallow geophysical data with Ground Penetrating Radar (GPR), 150, 200 and 400 MHz antennae, combined with facies analysis and radiocarbon dating (AMS) and Optically Stimulated Luminescence (OSL) from shallow borehole samples. The analysis of orthophotos allowed for the definition of at least nine morphologically distinct series of progradation, marked by truncations of progressive orientation changes. The integration of topographically corrected GPR data, sedimentary records, and geochronological data determined the beginning of the progradation occurred at 7.2 kaBP. At the beginning of progradation, the low tide terrace was at the height of 1.9m (EGM96) Above the Sea Current Level (ASCL). The swash zone was in the 2.5m, and the crest reached 4.3m ASCL. Currently, the low tide terrace quota is -0.4m, the swash zone to 0.3m and the crest reaches 2.1m ASCL. Among other factors, the fall of the lagoon base levels was associated with sea level fall during the Holocene regression. However, crest construction control is dependent on the lagoon base level oscillation, which in turn is controlled by the precipitation regime and storms surges. Moreover, these results suggest that the orientation of the ridges was controlled by changes in the internal lagoon hydrodynamics, due to the progressive narrowing of the lagoon connection with the open ocean

    Bovine Mastitis Caused by Multidrug-Resistant Nocardia farcinica

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    Background: Mastitis caused by Nocardia is characterized by pyogranulomatous inflammation related to inadequate hygiene conditions and is difficult to treat. Prompted by the absence of documentation of Nocardia farcinica associated to bovine mastitis in the Northeast region of Brazil, this is the first report to describe bovine mastitis caused by multidrug-resistant N. farcinica. Case: Four milk samples (one from each teat) obtained from a 3-year-old Jersey cow raised on a property located in the metropolitan region of Recife, Pernambuco state, Brazil, were submitted to the Laboratory of Infectious-Contagious Diseases of the Veterinary Hospital at Universidade Federal Rural de Pernambuco. At the laboratory, samples were cultured in base agar enriched with 7% sheep blood (blood agar) in a microbiological incubator at 37°C under aerobic conditions for 72 h. After only 48 h, however, pure bacterial colony growth was observed in all samples. Macroscopic analysis revealed small colonies, with an irregular shape, dry aspect, and greyish in color. Gram-positive rods forming filaments and/or ramifications were observed using a Gram staining method. Nocardia spp. were identified according to morphotinctorial characteristics. Susceptibility testing using the disc-diffusion method in agar (antibiogram) was performed using the following antibiotics: penicillin (10 IU), tetracycline (30 µg), amoxicillin (10 µg), gentamicin (10 µg), cephalexin (30 µg), erythromycin (15 µg), cephalothin (30 µg) and ampicillin (30 µg). However, the organism exhibited resistance to all drugs; as such, a new milk sample was obtained at the same location the initial samples were collected. Samples (approximately 5 mL) were collected aseptically and separately from all four teats in sterile bottles, during which the presence of granular material was noted. Bacterial culture was performed as previously described and, after 48 h, colony growth with the same characteristics as the first isolation were observed, and with same morphotinctorial characteristics in the Gram stain. A resistance profile was observed for 14 of the antimicrobial drugs tested; sensitivity was verified only for ciprofloxacin and amoxicillin with clavulanic acid. One bacterial colony was selected and sent to the Center of Strategic Technology of Northeast (CETENE-PE) for species identification using a matrix-associated laser desorption ionization-time of flight (MALDI-TOF/MS) technique, which confirmed the species to be N. farcinica. Molecular characterization of 16s ribosomal DNA was performed using polymerase chain reaction with universal prokaryotic primers 516F-13R. Subsequently, the amplified product was subjected to sequencing, and the result was analyzed for quality using Phred base calling software; bases with a Phred value > 20 were kept. The sequence was evaluated using GenBank, in which the isolate exhibited 99% similarity to N. farcinica. Discussion: Clinical findings and animal history associated with microbiological culture and bacterial identification using the MALDI-TOF technique, as well as DNA sequencing, confirmed the case of clinical mastitis to be caused by N. farcinica. These bacteria are considered saprophytes, and their occurrence is associated with deficiencies in hygienic-sanitary management, such as not using pre- and post-dipping, which may favor mammary gland infection. Treatment of N. farcinica mastitis is effective only when properly performed, with agent identification and antibiotic sensitivity tests in vitro associated with the adoption of hygienic-sanitary measures. This is the first description of bovine mastitis caused by N. farcinica in the northeast of Brazil. Multidrug resistance should raise awareness of producers searching for laboratory aids in agent identification as well as antibiotic sensitivity tests, and to develop a proper therapeutic protocol based on results obtained in laboratory examinations
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