20 research outputs found
Fator de Reflectância Bidirecional de imagens adquiridas por câmara digital para calibração radiométrica de sensores
Para que haja uma única transformação entre os números digitais registrados por uma câmara digital e a radiância dos alvos imageados, é necessário que o sensor da câmara tenha sido submetido à uma calibração radiométrica relativa. Logo, é necessário conhecer qual a área deste sensor que possui resposta uniforme à radiação incidente. Este trabalho tem como objetivo a verificação da homogeneidade entre quatro áreas amostrais, de 100 pixels cada, da câmara Sony DSC-R1. Foram adquiridas imagens de uma placa Spectralon em quatro geometrias distintas em condições de radiação eletromagnética difusa, em campo com céu encoberto por nuvens e sem incidência direta de radiação solar. A geometria de aquisição que apresentou resultados mais promissores foi aquela na qual o sensor está inclinado 45o no plano vertical posicionado à nordeste da placa Spectralon. A área homogênea foi validada por meio de uma nova aquisição de imagens, utilizando esta melhor geometria de visada, de alvos coloridos, onde o desvio padrão dos valores de ND registrados representou 0,39% do total de 256 níveis digitais possíveis de serem registrados pela câmara.
Structure and tree diversity of an inland Atlantic Forest–A case study of Ponte Branca Forest Remnant, Brazil
The Atlantic Forest is the most fragmented and threatened domain in Brazil. The main remnants are in the coastal regions. This paper describes a study performed at a protected federal reserve in Brazil located in western of São Paulo state, which is a transition with the Savannah. A forestry survey was made for understanding the forest structure, diversity, and floristic composition of an inland Atlantic Forest area. A total of 3,181 individuals with a Diameter at Breast Height over 3.5 cm were sampled. The data sample was composed of 29 families and 64 species from 15 plots. Forty-seven percent of the species were classified as a pioneer, 42% as secondary, and 11% as climax. The species Eugenia uniflora presented the highest importance value index. The values of Shannon-Weaver diversity and Pielou equitability index indicate the area has less diversity than others in the same phytophysiognomy and was dominated by a few species with many individuals. Several anthropogenic disturbances altered the forest cover of the Ponte Branca Forest remnant, which is in the process of secondary succession
Benchmarking Anchor-Based and Anchor-Free State-of-the-Art Deep Learning Methods for Individual Tree Detection in RGB High-Resolution Images
rban forests contribute to maintaining livability and increase the resilience of cities in the face of population growth and climate change. Information about the geographical distribution of individual trees is essential for the proper management of these systems. RGB high-resolution aerial images have emerged as a cheap and efficient source of data, although detecting and mapping single trees in an urban environment is a challenging task. Thus, we propose the evaluation of novel methods for single tree crown detection, as most of these methods have not been investigated in remote sensing applications. A total of 21 methods were investigated, including anchor-based (one and two-stage) and anchor-free state-of-the-art deep-learning methods. We used two orthoimages divided into 220 non-overlapping patches of 512 × 512 pixels with a ground sample distance (GSD) of 10 cm. The orthoimages were manually annotated, and 3382 single tree crowns were identified as the ground-truth. Our findings show that the anchor-free detectors achieved the best average performance with an AP50 of 0.686. We observed that the two-stage anchor-based and anchor-free methods showed better performance for this task, emphasizing the FSAF, Double Heads, CARAFE, ATSS, and FoveaBox models. RetinaNet, which is currently commonly applied in remote sensing, did not show satisfactory performance, and Faster R-CNN had lower results than the best methods but with no statistically significant difference. Our findings contribute to a better understanding of the performance of novel deep-learning methods in remote sensing applications and could be used as an indicator of the most suitable methods in such applications
Caracterização espectral de espécies de Mata Atlântica de Interior em nível foliar e de copa
Florestas têm importante papel na manutenção da biodiversidade, retenção de carbono e regulação do regime hidrológico, além de garantir proteção ao solo e às fontes d’água. Podem ser classificadas em diferentes estádios de desenvolvimento, caracterizados pela presença de espécies secundárias e clímax. Atualmente, no Brasil, as florestas estão reduzidas em fragmentos espalhados em diversas regiões do país sendo seu monitoramento necessário para realização de planos de manejo. Uma das formas de realizar o monitoramento florestal é utilizando o Sensoriamento Remoto hiperespectral, que fornece informação espectral detalhada dos alvos as quais são úteis para a discriminação das espécies de vegetação que compõem o remanescente florestal. Sensores hiperespectrais acoplados a VANTs (Veículos Aéreos Não Tripulados) possibilitam a aquisição de dados para posterior delimitação das copas das espécies de vegetação. A Mata Atlântica, bioma rico em biodiversidade, está distribuída de norte a sul do Brasil, sendo classificada conforme a localização e características de cada formação florestal, dentre elas a Mata Atlântica de Interior. O objetivo desse trabalho é a caracterização espectral de espécies de vegetação em nível foliar e de copa para contribuir com informações que possam ser utilizadas para o monitoramento florestal. Foram adquiridas imagens hiperespectrais com câmara baseada no Interferômetro de Fabry-Perot acoplada em VANT. As imagens foram adquiridas na gleba Ponte Branca, pertencente à Estação Ecológica Mico-Leão-Preto. O processamento das imagens considerou 5 diferentes correções que permitiram mostrar a importância da geometria de aquisição das imagens e do ajustamento radiométrico em bloco. Copas de 12 espécies de vegetação foram delimitadas manualmente no mosaico de imagens gerado e nelas foram medidos valores de Fator de Reflectância Hemisférico Cônico. A caracterização espectral em nível foliar de 16 espécies de vegetação foi realizada em laboratório utilizando espectrorradiômetro. Por meio da análise de agrupamento, verificou-se a similaridade entre as respostas espectrais de tais espécies, tanto em nível de copa como foliar. Para minimizar a similaridade entre tais respostas, foram aplicados e normalizados 7 índices de vegetação. Por fim, utilizando os índices que apresentaram menor correlação entre si, uma nova análise de agrupamento foi realizada onde se verificou que a similaridade entre as espécies foi atenuada.Forests have an important role to support biodiversity, carbon stocks and water regime. In addition, provide fundamental protection to soil and water resources. Pioneers and climax species characterize successional stages of forest. In Brazil, forests are reduced to fragments spread out over the country, being their monitoring necessary to perform management plans. Hyperspectral Remote Sensing provides detailed spectral information about targets and is feasible to discriminate trees species. Hyperspectral sensor attached to UAVs (Unmanned Aerial Vehicles) makes possible the delineation of trees canopies. The Atlantic Forest, biome rich in biodiversity, is distributed from north to south in Brazil, being classified according to the different locations and characteristics, such as the Interior Atlantic Forest. The main objective of this project is spectral characterization of tree species in leaf and canopy level to contribute with forest monitoring. Hyperspectral images acquired with camera based on Fabry-Perot Interferometer coupled to an UAV were acquired. The interest area, Ponte Branca, belongs to the ecological station called Estação Ecológica Mico-Leão-Preto in the western region of São Paulo State. Imaging process where realized with 5 different corrections showing the importance of geometry during image acquisition and radiometric block adjustment. Trees canopies from 12 species were manually delimited in the images mosaic and Hemispherical Conical Reflectance Factor were obtained. Leaf spectral characterization was realized in laboratory using spectrorradiometer. Clustering analyses were applied to verify similarity between spectral responses of species, in canopy and leaf level. 7 vegetation indexes were applied and normalized in order to reduce the similarity between the spectral responses. Lastly, a new clustering analyses was realized using the less correlated normalized indexes, concluding that the similarity between species was reduced.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq
Estimativa de radiância baseada em imagens de câmeras digitais convencionais
The radiometric calibration of digital cameras are becoming even more important because its enhance your use in applications such as monitoring crops or geological mapping. The radiometric calibration consists in quantify data gained through cameras, and it is represented through of radiance, which is physical measure of Remote Sensing. This paper presents an evaluation of a methodology used in the radiometric calibration of digital camera Sony R1. For this calibration, were acquired 160 images on the radiometer lab based in Finland. The images are from a Spectralon reference target, in the same conditions of illumination, environment, Fstop, and time of exposition, where was verified its stability and then was verified the spectral sensibility of the camera based on images from the target illuminated by a monochromator which produces energy at specific wavelengths. In the field, there were taken data of spectral radiance and pictures of colored targets and then it was calculated and analyzed the transformation function of digital level values for the radiance. The results achievedwere satisfactory and they demonstrate the data collected and calculated were adequate for the calculation of the transformation function. However, it could be necessary to be adjusted if the images come from aerial platforms, because it can occur an alteration of the parameters of transformation on the values of digital level to the radiance.Pages: 9159-916
Fator de Reflectância Bidirecional de imagens adquiridas por câmara digital para calibração radiométrica de sensores
Para que haja uma única transformação entre os números digitais registrados por uma câmara digital e a radiância dos alvos imageados, é necessário que o sensor da câmara tenha sido submetido à uma calibração radiométrica relativa. Logo, é necessário conhecer qual a área deste sensor que possui resposta uniforme à radiação incidente. Este trabalho tem como objetivo a verificação da homogeneidade entre quatro áreas amostrais, de 100 pixels cada, da câmara Sony DSC-R1. Foram adquiridas imagens de uma placa Spectralon em quatro geometrias distintas em condições de radiação eletromagnética difusa, em campo com céu encoberto por nuvens e sem incidência direta de radiação solar. A geometria de aquisição que apresentou resultados mais promissores foi aquela na qual o sensor está inclinado 45o no plano vertical posicionado à nordeste da placa Spectralon. A área homogênea foi validada por meio de uma nova aquisição de imagens, utilizando esta melhor geometria de visada, de alvos coloridos, onde o desvio padrão dos valores de ND registrados representou 0,39% do total de 256 níveis digitais possíveis de serem registrados pela câmara.
Oral administration of a catalase-producing Lactococcus lactis can prevent a chemically induced colon cancer in mice
Reactive oxygen species, such as hydrogen peroxide (H2O 2), are involved in various aspects of tumour development. Decreasing their levels can therefore be a promising approach for colon cancer prevention. The objective of this study was to evaluate the effect of catalase-producing Lactococcus lactis on the prevention of an experimental murine 1,2-dimethylhydrazine (DMH)-induced colon cancer. DMH-treated BALB/c mice received either a catalase-producing L. lactis strain or the isogenic non-catalase-producing strain as a control, whereas other untreated mice did not receive bacterial supplementation. Catalase activity and H2O 2 levels in intestinal fluids and blood samples were measured, and changes in the histology of the large intestines during tumour progression were evaluated. The catalase-producing L. lactis strain used in this study was able to slightly increase catalase activities in DMH-treated mice (1.19 ± 0.08 U ml-1) and reduce H2O2 levels (3.4 ± 1.1 μM) compared to (i) animals that received the non-catalase-producing strain (1.00 ± 0.09 U ml-1, 9.0 ± 0.8 μM), and (ii) those that did not receive bacterial supplementation (1.06 ± 0.07 U ml-1, 10.0 ± 1.1 μM). Using the histopathological grading scale of chemically induced colorectal cancer, animals that received the catalase-producing L. lactis had a significantly lesser extent of colonic damage and inflammation (2.0 ± 0.4) compared to animals that received the non-catalase-producing L. lactis (4.0 ± 0.3) or those that did not receive bacterial supplementation (4.7 ± 0.5). The catalase-producing L. lactis strain used in this study was able to prevent tumour appearance in an experimental DMH-induced colon cancer model.Fil: de Moreno, Maria Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Leblanc, Jean Guy Joseph. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Perdigon, Gabriela del Valle. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia; ArgentinaFil: Miyoshi, Anderson. Universidade Federal de Minas Gerais; BrasilFil: Langella, Philippe. Institut National de la Recherche Agronomique; FranciaFil: Azevedo, Vaso. Universidade Federal de Minas Gerais; BrasilFil: Sesma, Fernando Juan Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; Argentin
BIOSYNTHESIS OF INDUSTRIAL ENZYMES BY FREE AND IMMOBILIZED Alicyclobacillus spp IN DIFFERENT MATRICES AND THE USE OF ULTRAFILTRATION IN THE ENZYMES CONCENTRATION
The biosynthesis of amylase and collagenase, produced by A. acidocaldarius and A. sendaiensis respectively, were studied, and different matrices evaluated for the microorganisms immobilization and enzymes production optimization, such as loofa sponge, alginate-sponge and alginate, followed by concentration through ultrafiltration. Using a wheat bran substrate, the amylase enzyme displayed enzymatic activity of 0.45 U mL-1 and optimum temperature and pH conditions of 75 °C and pH 3.0, respectively. Thermal stability was in the range of 55 to 60 °C. The apparent Km and Vmax were 3.2 mg mL-1 and 0.5 U mL-1, respectively. The production of collagenase by A. sendaiensis was carried out with potato dextrose broth substrate and the activity obtained was 7.2 U mL-1. For amylase, the best results were obtained from immobilization in loofa sponge and the use of ultrafiltration (0.67 U mL-1) and for the collagenase extract, from the free biomass and ultrafiltration (13.6 U mL-1). The use of an ultrafiltration system enabled an average increase of 54% in the activity of both enzymes. Therefore, Alicyclobacillus are capable of producing enzymes of industrial interest, with the possibility of economically viable application of the substrate, and the use of immobilization and ultrafiltration produced positive results
Anti-inflammatory properties of lactic acid bacteria: Current knowledge, applications and prospects
Lactic acid bacteria (LAB) represent a heterogeneous group of microorganisms that are naturally present in many foods. Some selected strains are frequently added as probiotics in order to confer specific benefits to consumers. Many studies have shown that LAB possess therapeutic properties since they are able to prevent the development of some diseases, as shown mostly on animal models for cancer, infections and gastrointestinal disorders such as intestinal inflammation. They have been shown to regulate mucosal immune responses by modulating the production and liberation of regulatory agents such as cytokines by the host. Some of these cytokines, such as the anti-inflammatory interleukin-10 (IL-10), modulate the inflammatory immune response, thus immunomodulation is a mechanism by which LAB can prevent certain inflammatory bowel diseases (IBD). Since oxidative stress participates to the inflammatory processes and to the appearance of damages in pathologies of the gastrointestinal tract of humans such as IBD, LAB could also prevent inflammation by eliminating reactive oxygen species (ROS) through the activity of antioxidant enzymes. Engineering LAB to produce either antioxidant enzymes (such as catalases and superoxide dismutases) or anti-inflammatory cytokines (such as IL-10) is a strategy currently exploited by several groups. These novel strains have successfully been used to prevent inflammatory bowel diseases in animal models and could be evaluated in human clinical trials. Here, we present an overview of the current knowledge of the mechanisms by which LAB can be used to prevent undesired intestinal inflammatory responses.Fil: Leblanc, Jean Guy Joseph. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: de Moreno, Maria Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Perdigon, Gabriela del Valle. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia; ArgentinaFil: Miyoshi, Anderson. Universidade Federal de Minas Gerais; BrasilFil: Rochat, Tatiana. Institut National de la Recherche Agronomique; FranciaFil: Bermudez Humaran, Luis. Institut National de la Recherche Agronomique; FranciaFil: Langella, Philippe. Institut National de la Recherche Agronomique; FranciaFil: Sesma, Fernando Juan Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Azevedo, Vasco. Universidade Federal de Minas Gerais; Brasi