Search

Your search keyword '"Claudio Barbosa"' showing total 38 results
Start Over Author "Claudio Barbosa"
38 results on '"Claudio Barbosa"'

1. Proposal for a remote sensing trophic state index based upon Thematic Mapper/Landsat images

Author

Evlyn Márcia Leão de Moraes Novo, Luciana de Resende Londe, Claudio Barbosa, Carlos A. S. de Araujo, and Camilo Daleles Rennó

Subjects
water quality, phytoplankton, monitoring, Environmental sciences, GE1-350
Abstract

This work proposes a trophic state index based on the remote sensing retrieval of chlorophyll-α concentration. For that, in situ Bidirectional Reflectance Factor (BRF) data acquired in the Ibitinga reservoir were resampled to match Landsat/TM spectral simulated bands (TM_sim bands) and used to run linear correlation with concurrent measurements of chlorophyll-α concentration. Monte Carlo simulation was then applied to select the most suitable model relating chlorophyll-α concentration and simulated TM/Landsat reflectance. TM4_sim/TM3_sim ratio provided the best model with a R2 value of 0.78. The model was then inverted to create a look-up-table (LUT) relating TM4_sim/TM3_sim ratio intervals to chlorophyll-α concentration trophic state classes covering the entire range measured in the reservoir. Atmospheric corrected Landsat TM images converted to surface reflectance were then used to generate a TM4/TM3 ratio image. The ratio image frequency distribution encompassed the range of TM4_sim/TM3_sim ratio indicating agreement between in situ and satellite data and supporting the use of satellite data to map chlorophyll- concentration trophic state distribution in the reservoir. Based on that, the LUT was applied to a Landsat/TM ratio image to map the spatial distribution of chlorophyll- trophic state classes in Ibitinga reservoir. Despite the stochastic selection of TM4_sim/TM3_sim ratio as the best input variable for modeling the chlorophyll-α concentration, it has a physical basis: high concentration of phytoplankton increases the reflectance in the near-infrared (TM4) and decreases the reflectance in the red (TM3). The band ratio, therefore, enhances the relationship between chlorophyll- concentration and remotely sensed reflectance.

Published
2013
Full Text
View/download PDF

2. João Cândido e a revolta da chibata: disputas e memórias

Author

Claudio Barbosa de Sousa

Subjects
Arts in general, NX1-820, History (General), D1-2009
Abstract

A Revolta da Chibata eclodiu no Rio de Janeiro, em 1910, nas fileiras da Marinha brasileira. Entre seus alvos figuravam o fim dos castigos corporais infligidos aos marujos e a obtenção de melhores soldos. Esse episódio marcante da Primeira República se converteu, sob vários aspectos, num palco de disputas de memórias diversas, quando não inteiramente conflitantes. Neste artigo se procura lançar uma ponte entre ela e seus ecos na área cultural. Dentre outras opções possíveis, privilegiam-se, aqui, num primeiro momento, os sons da revolta na música popular. Na sequência, o tema é recolocado ao se enveredar pela relação estabelecida entre o líder dos marinheiros, João Cândido e a estatuária. Por último, a questão é repensada nas tramas da recriação de um romance. Palavras-chave: Revolta da Chibata; João Cândido; disputas de memórias.

Published
2016

3. Hidrófitas fanerogâmicas de ecossistemas aquáticos temporários da planície costeira do Estado do Rio de Janeiro, Brasil Phanerogamic hydrophytes from the temporary swampy environments of coastal plains of northern Rio de Janeiro State, Brazil

Author

Claudia Petean Bove, André dos Santos Bragança Gil, Claudio Barbosa Moreira, and Renata Fabiana Barros dos Anjos

Subjects
hidrófitas, florística, brejo temporário, Rio de Janeiro, planície costeira, hydrophytes, floristics, temporary swamp, coastal plains, Botany, QK1-989
Abstract

Foi realizado o levantamento florístico das hidrófitas fanerogâmicas de ambientes aquáticos temporários da planície costeira do norte fluminense. O material botânico foi coletado em 27 expedições entre setembro/1998 a julho/2001, herborizado e identificado segundo a metodologia tradicional. As exsicatas foram depositadas no Herbário da Universidade do Rio de Janeiro (HUNI). Foram encontrados 113 táxons, distribuídos em 40 famílias. Os ambientes estudados podem ser caracterizados floristicamente pela família Cyperaceae, representada por 23 táxons (cerca de 20%); seguida pelas famílias Fabaceae e Onagraceae (sete táxons), Poaceae (seis táxons), Asteraceae e Scrophulariaceae (cinco táxons) e Apiaceae, Lentibulariaceae e Polygonaceae (quatro táxons). Estes ambientes sofrem alterações fitofisionômicas marcantes relacionadas com a hidrogeologia. Algumas espécies são anuais, desaparecendo completamente na estiagem; outras suportam a seca, mas têm a população profundamente reduzida, alterando substancialmente a paisagem. Algumas espécies consideradas exclusivamente aquáticas foram encontradas em solo úmido, inclusive em floração. Isto demonstra a necessidade da inclusão de espécies anfíbias nos estudos da flora aquática pois, algumas vezes, a delimitação dos tipos biológicos não é muito definida, além de caracterizar de forma mais adequada estes ambientes.A floristic inventory of phanerogamic hydrophytes from the temporary swampy environments of coastal plains of northern of Rio de Janeiro State was made. The botanical vouchers were collected in 27 expeditions between September/1998 and July/2001. They were herborized and identified by the traditional methodology. The exsicatae were deposited in the UNIRIO herbarium (HUNI). One hundred and thirteen taxa, distributed among 40 families were found. The environment analyzed could be floristically characterized by the Cyperaceae, represented by 23 taxa (ca. 20%), followed by Fabaceae and Onagraceae (seven taxa), Poaceae (six taxa), Asteraceae and Scrophulariaceae (five taxa) and Apiaceae, Lentibulariaceae and Polygonaceae (four taxa). These environments have great phytophysionomic changes according to hydrogeology. Some species are annual, disappearing completely in the dry season; another species tolerates the dryness but the population reduce drastically, changing substantially the landscape. Some species regarded as strictly aquatic were found in humid soil, producing flowers. This shows the necessity to include amphibious species on the aquatic flora studies because sometimes the boundaries between the biological types were not well defined.

Published
2003
Full Text
View/download PDF

4. Produção in vitro de Baccharis myriocephala DC: Efeitos de auxinas e citocininas.

Author

Alice Sato, Simone da Silva, Claudio Barbosa Moreira, Sharon Santos de Lima, and Maria Apparecida Esquibel

Subjects
Baccharis myriocephala, Asteraceae, carqueja, cultivo in vitro, reguladores de crescimento., Plant culture, SB1-1110
Abstract

Baccharis myriocephala DC., pertencente a seção Caulopterae (Asteraceae, Astereae) é um subarbusto ramificado com caule trialado (Nurnberg, 1997). Esta característica é comum entre as outras espécies desta seção e por serem morfológica e anatomicamente semelhantes, são todas conhecidas popularmente como carqueja (Gianello et al., 2000). As carquejas apresentam como característica marcante a presença de cladódios que fazem o papel de folha, uma vez que estas estão totalmente ausentes ou mostram-se reduzidas, com função fisiológica restrita para a planta (Budel et al., 2005). No Brasil, as carquejas estão entre as dez plantas mais comercializadas (Budel et al., 2004), sendo amplamente utilizadas na medicina popular no combate a problemas de estômago, diabetes, reumatismo e feridas de pele (Simões-Pires et al., 2005) Uma das técnicas mais utilizadas na cultura de tecidos vegetais é a propagação in vitro ou micropropagação. Tratase de um método rápido e eficiente para a produção em massa de plantas livres de patógenos, geneticamente uniformes e com independência da sazonalidade. A micropropagação viabiliza a produção vegetal quando há dificuldades nos mecanismos naturais de reprodução, bem como a preservação de espécies ameaçadas de extinção e a manutenção de coleções ativas ou de base de germoplasma vegetal, sendo o único recurso da cultura de tecidos vegetais que tem documentado de forma efetiva a possibilidade de se produzir espécies de interesse em larga escala [George, 1996; Honda et al., 2001; Giri et al., 2004). Além de melhoramento de linhagem, métodos de seleção de linhagens de alta produção e otimização do meio podem levar a um incremento na produção de princípios ativos (Dornenburg & Knorr, 1995; Silva et al., 2005). Assim sendo, o desenvolvimento de um cultivo sistemático de plantas medicinais através da cultura de tecidos vegetais é fundamental tanto para promover o uso da própria planta como medicamento, como para permitir a conservação da biodiversidade química e a obtenção controlada de material para estudos biológicos e fitoquímicos, assegurando a sobrevivência e a disponibilidade do material genético para pesquisas científicas. Devido à importância desta planta para múltiplos propósitos, justifica-se a aplicação de metodologia que forneça grande número de plantas de B. myriocephala clonadas, visando selecionar linhagens de alta qualidade para plantio extensivo e extração de fitofármacos.

Published
2007
Full Text
View/download PDF

5. Simultaneous Retrieval of Selected Optical Water Quality Indicators From Landsat-8, Sentinel-2, and Sentinel-3

Author

Nima Pahlevan, Brandon Smith, Krista Alikas, Janet Anstee, Claudio Barbosa, Caren Binding, Mariano Bresciani, Bruno Cremella, Claudia Giardino, Daniela Gurlin, Virginia Fernandez, Cédric Jamet, Kersti Kangro, Moritz K. Lehmann, Hubert Loisel, Bunkei Matsushita, Nguyên Hà, Leif Olmanson, Geneviève Potvin, Stefan G.H. Simis, Andrea VanderWoude, Vincent Vantrepotte, and Antonio Ruiz-Verdù

Subjects
Earth Resources and Remote Sensing
Abstract

Constructing multi-source satellite-derived water quality (WQ) products in inland and nearshore coastal waters from the past, present, and future missions is a long-standing challenge. Despite inherent differences in sensors’ spectral capability, spatial sampling, and radiometric performance, research efforts focused on formulating, implementing, and validating universal WQ algorithms continue to evolve. This research extends a recently developed machine-learning (ML) model, i.e., Mixture Density Networks (MDNs) (Pahlevan et al., 2020; Smith et al., 2021), to the inverse problem of simultaneously retrieving WQ indicators, including chlorophyll-a (Chla), Total Suspended Solids (TSS), and the absorption by Colored Dissolved Organic Matter at 440 nm (acdom(440)), across a wide array of aquatic ecosystems. We use a database of in situ measurements to train and optimize MDN models developed for the relevant spectral measurements (400–800 nm) of the Operational Land Imager (OLI), MultiSpectral Instrument (MSI), and Ocean and Land Color Instrument (OLCI) aboard the Landsat-8, Sentinel-2, and Sentinel-3 missions, respectively. Our two performance assessment approaches, namely hold-out and leave-one-out, suggest significant, albeit varying degrees of improvements with respect to second-best algorithms, depending on the sensor and WQ indicator (e.g., 68%, 75%, 117% improvements based on the hold-out method for Chla, TSS, and acdom(440), respectively from MSI-like spectra). Using these two assessment methods, we provide theoretical upper and lower bounds on model performance when evaluating similar and/or out-of-sample datasets. To evaluate multi-mission product consistency across broad spatial scales, map products are demonstrated for three near-concurrent OLI, MSI, and OLCI acquisitions. Overall, estimated TSS and acdom(440) from these three missions are consistent within the uncertainty of the model, but Chla maps from MSI and OLCI achieve greater accuracy than those from OLI. By applying two different atmospheric correction processors to OLI and MSI images, we also conduct matchup analyses to quantify the sensitivity of the MDN model and best-practice algorithms to uncertainties in reflectance products. Our model is less or equally sensitive to these uncertainties compared to other algorithms. Recognizing their uncertainties, MDN models can be applied as a global algorithm to enable harmonized retrievals of Chla, TSS, and acdom(440) in various aquatic ecosystems from multi-source satellite imagery. Local and/or regional ML models tuned with an apt data distribution (e.g., a subset of our dataset) should nevertheless be expected to outperform our global model.

Published
2022
Full Text
View/download PDF

6. ACIX-Aqua: A Global Assessment of Atmospheric Correction Methods for Landsat-8 and Sentinel-2 Over Lakes, Rivers, and Coastal Waters

Author

Nima Pahlevan, Antoine Mangin, Sundarabalan V. Balasubramanian, Brandon Smith, Krista Alikas, Kohei Arai, Claudio Barbosa, Simon Bélanger, Caren Binding, Mariano Bresciani, Claudia Giardino, Daniela Gurlin, Yongzhen Fan, Tristan Harmel, Peter Hunter, Joji Ishikaza, Susanne Kratzer, Moritz K. Lehmann, Martin Ligi, Ronghua Ma, François-Régis Martin-Lauzer, Leif Olmanson, Natascha Oppelt, Yanqun Pan, Steef Peters, Nathalie Reynaud, Lino A. Sander de Carvalho, Stefan Simis, Evangelos Spyrakos, François Steinmetz, Kerstin Stelzera, Sindy Sterckx, Thierry Tormos, Andrew Tyler, Quinten Vanhellemont, and Mark Warren

Subjects
Earth Resources And Remote Sensing
Abstract

Atmospheric correction over inland and coastal waters is one of the major remaining challenges in aquatic remote sensing, often hindering the quantitative retrieval of biogeochemical variables and analysis of their spatial and temporal variability within aquatic environments. The Atmospheric Correction Intercomparison Exercise (ACIX-Aqua), a joint NASA – ESA activity, was initiated to enable a thorough evaluation of eight state-of-the-art atmospheric correction (AC) processors available for Landsat-8 and Sentinel-2 data processing. Over 1000 radiometric matchups from both freshwaters (rivers, lakes, reservoirs) and coastal waters were utilized to examine the quality of derived aquatic reflectances (ρ̂w). This dataset originated from two sources: Data gathered from the international scientific community (henceforth called Community Validation Database, CVD), which captured predominantly inland water observations, and the Ocean Color component of AERONET measurements (AERONET-OC), representing primarily coastal ocean environments. This volume of data permitted the evaluation of the AC processors individually (using all the matchups) and comparatively (across seven different Optical Water Types, OWTs) using common matchups. We found that the performance of the AC processors differed for CVD and AERONET-OC matchups, likely reflecting inherent variability in aquatic and atmospheric properties between the two datasets. For the former, the median errors in ρ̂w560 and ρ̂w664 were found to range from 20 to 30% for best-performing processors. Using the AERONET-OC matchups, our performance assessments showed that median errors within the 15–30% range in these spectral bands may be achieved. The largest uncertainties were associated with the blue bands (25 to 60%) for best-performing processors considering both CVD and AERONET-OC assessments. We further assessed uncertainty propagation to the downstream products such as near-surface concentration of chlorophyll-a (Chla) and Total Suspended Solids (TSS). Using satellite matchups from the CVD along with in situ Chla and TSS, we found that 20–30% uncertainties in ρ̂w490≤λ≤743nm yielded 25–70% uncertainties in derived Chla and TSS products for top-performing AC processors. We summarize our results using performance matrices guiding the satellite user community through the OWT-specific relative performance of AC processors. Our analysis stresses the need for better representation of aerosols, particularly absorbing ones, and improvements in corrections for sky- (or sun-) glint and adjacency effects, in order to achieve higher quality downstream products in freshwater and coastal ecosystems.

Published
2021
Full Text
View/download PDF

7. A Chlorophyll-a Algorithm for Landsat-8 Based on Mixture Density Networks

Author

Brandon Smith, Nima Pahlevan, John Schalles, Steve Ruberg, Reagan Errera, Ronghua Ma, Claudia Giardino, Mariano Bresciani, Claudio Barbosa, Tim Moore, Virginia Fernandez, Krista Alikas, and Kersti Kangro

Subjects
Earth Resources And Remote Sensing
Abstract

Retrieval of aquatic biogeochemical variables, such as the near-surface concentration of chlorophyll-a (Chla) in inland and coastal waters via remote observations, has long been regarded as a challenging task. This manuscript applies Mixture Density Networks (MDN) that use the visible spectral bands available by the Operational Land Imager (OLI) aboard Landsat-8 to estimate Chla. We utilize a database of co-located in situ radiometric and Chla measurements (N = 4,354), referred to as Type A data, to train and test an MDN model (MDN(A)). This algorithm’s performance, having been proven for other satellite missions, is further evaluated against other widely used machine learning models (e.g., support vector machines), as well as other domain-specific solutions (OC3), and shown to offer significant advancements in the field. Our performance assessment using a held-out test data set suggests that a 49% (median) accuracy with near-zero bias can be achieved via the MDN(A) model, offering improvements of 20 to 100% in retrievals with respect to other models. The sensitivity of the MDN(A) model and benchmarking methods to uncertainties from atmospheric correction (AC) methods, is further quantified through a semi-global matchup dataset (N = 3,337), referred to as Type B data. To tackle the increased uncertainties, alternative MDN models (MDN(B)) are developed through various features of the Type B data (e.g., Rayleigh-corrected reflectance spectra ρ(s)). Using held-out data, along with spatial and temporal analyses, we demonstrate that these alternative models show promise in enhancing the retrieval accuracy adversely influenced by the AC process. Results lend support for the adoption of MDN(B) models for regional and potentially global processing of OLI imagery, until a more robust AC method is developed. Index Terms—Chlorophyll-a, coastal water, inland water, Landsat-8, machine learning, ocean color, aquatic remote sensing.

Published
2021
Full Text
View/download PDF

8. Direitos humanos e o controle de convencionalidade na violência de gênero

Author

Flávia Claudio Barbosa, Isabella Carvalho de Sousa, and Josemar Figueiredo Araújo

Subjects
Marketing, Pharmacology, Organizational Behavior and Human Resource Management, Strategy and Management, Drug Discovery, Pharmaceutical Science
Abstract

O presente estudo aborda violência contra a mulher como afronta aos Direitos Humanos, com base no controle de convencionalidade. Assim, este estudo utiliza-se do método qualitativo, tendo em vista que o foco não é auferir resultados estatísticos, sim analisar o discurso, empregando como principal método o estudo de caso através de entrevistas. Como primeiro objetivo, buscamos compreender os impactos da violência de gênero na vida das mulheres. A segunda questão consiste em refletir sobre o efetivo papel das normas jurídicas de repressão à violência de gênero. Além de analisar os aspectos culturais e históricos, demos especial atenção aos Tratados internacionais próprios, dos quais a República Federativa do Brasil é signatária, sem descurar da legislação interna.

Published
2022
Full Text
View/download PDF

13. ACIX-Aqua: A global assessment of atmospheric correction methods for Landsat-8 and Sentinel-2 over lakes, rivers, and coastal waters

Author

Nima Pahlevan 1, 2, Antoine Mangin 3, Sundarabalan V. Balasubramanian 4, Brandon Smith 1, Krista Alikas 5, Kohei Arai 6, Claudio Barbosa 7, Simon Bélanger 8, Caren Binding 9, Mariano Bresciani 10, Claudia Giardino 10, Daniela Gurlin 11, Yongzhen Fan 12, Tristan Harmel 13, Peter Hunter 14, Joji Ishikaza 15, Susanne Kratzer 16, Moritz K. Lehmann 17, Martin Ligi 5, Ronghua Ma 18, Leif Olmanson 19, Natascha Oppelt 20, Yanqun Pan 8, Steef Peters 22, Nathalie Reynaud 23, Lino A. Sander de Carvalho 24, Evangelos Spyrakos 14, François Steinmetz 25, Kerstin Stelzer 26, Sindy Sterckx 27, Thierry Tormos 28, Andrew Tyler 14, Quinten Vanhellemont 29, and Mark Warren 30

Subjects
landsat, lakes, atmospheric correction, sentinel
Abstract

Atmospheric correction over inland and coastal waters is one of the major remaining challenges in aquatic remote sensing, often hindering the quantitative retrieval of biogeochemical variables and analysis of their spatial and temporal variability within aquatic environments. The Atmospheric Correction Intercomparison Exercise (ACIX-Aqua), a joint NASA - ESA activity, was initiated to enable a thorough evaluation of eight state-of-the-art atmospheric correction (AC) processors available for Landsat-8 and Sentinel-2 data processing. Over 1000 radiometric matchups from both freshwaters (rivers, lakes, reservoirs) and coastal waters were utilized to examine the quality of derived aquatic reflectances (??w). This dataset originated from two sources: Data gathered from the international scientific community (henceforth called Community Validation Database, CVD), which captured predominantly inland water observations, and the Ocean Color component of AERONET measurements (AERONET-OC), representing primarily coastal ocean environments. The volume of our data permitted the evaluation of the AC processors individually (using all the matchups) and comparatively (across seven different Optical Water Types, OWTs) using common matchups. We found that the performance of the AC processors differed for CVD and AERONET-OC matchups, likely reflecting inherent variability in aquatic and atmospheric properties between the two datasets. For the former, the median errorsin ??w(560) and ??w(664) were found to range from 20 to 30% for best-performing processors. Using the AERONET-OC matchups, our performance assessments showed that median errors within the 15- 30% range in these spectral bands may be achieved. The largest uncertainties were associated with the blue bands (25 to 60%) for best-performing processors considering both CVD and AERONET-OC assessments. We further assessed uncertainty propagation to the downstream products such as near-surface concertation of chlorophyll-a (Chla) and Total Suspended Solids (TSS). Using satellite matchups from the CVD along with in situ Chla and TSS, we found that 20- 30% uncertainties in ??w(490

Published
2021

14. Effect of auxin and cytokinin on phenolic content of Baccharis myriocephala DC. (Asteraceae) produced in vitro

Author

Claudio Barbosa Moreira, Alice Sato, Sharon Santos de Lima, Simone da Silva, and Celso Luiz Salgueiro Lage

Subjects
0106 biological sciences, Pharmaceutical Science, Plant Science, 01 natural sciences, chemistry.chemical_compound, Dry weight, Auxin, Drug Discovery, Botany, Pharmacology, chemistry.chemical_classification, biology, 010405 organic chemistry, Baccharis, food and beverages, biology.organism_classification, 0104 chemical sciences, Horticulture, Complementary and alternative medicine, chemistry, Micropropagation, Germination, Polyphenol, Cytokinin, Kinetin, 010606 plant biology & botany
Abstract

A protocol for large-scale in vitro production of Baccharis myriocephala was developed. Total phenolic content was analyzed in plants cultured on MS + 1.0 mg.L-1 of indoleacetic acid (IAA), benzyladenine (BA) or kinetin (KIN). Nodal segments obtained from seeds germinated in vitro on Murashige and Skoog basal medium (MS) were subcultured on MS basal medium, hormone-free or with different growth regulators added: IAA, BA or KIN. The total phenolic content was determined using the Folin-Denis spectrophotometric method, and the content of phenolics of extracts was expressed in terms of gallic acid-equivalent (µg GA/mg dry weight). The best growth and development of the plants was induced by MS + 1.0 mg.L-1 IAA, which stimulated the production of 23 new nodal segments from a single phytomer after 60 days of in vitro culture. However, MS + 1.0 mg.L-1 IAA accumulated the lowest phenolic content, and only 18.46 µg/mg dry weight. A significant negative correlation was noted, since the phenolic content increased when the dry weight decreased. This culture system is capable of supplying good-quality raw material in adequate quantity to meet the growing demand for medicinal plants. However, the accumulation of polyphenols is lower in cultures with higher dry weight. Key words: Carqueja, micropropagation, growth regulators, phenolics accumulation.

Published
2017
Full Text
View/download PDF

16. Effects Of Chemotherapy On Muscle Performance In Women With Breast Cancer

Author

Paulo Gentil, Vitor Alves Marques, Thaynã Coelho Guimarães, Rafael Ribeiro Alves, João Batista Ferreira Júnior, Claudio Barbosa de Lira, Carlos A. Vieira, Mário Hebling Campos, and Weder Alves da Silva

Subjects
Oncology, medicine.medical_specialty, Chemotherapy, Breast cancer, business.industry, Internal medicine, medicine.medical_treatment, medicine, Physical Therapy, Sports Therapy and Rehabilitation, Orthopedics and Sports Medicine, business, medicine.disease
Published
2019
Full Text
View/download PDF

17. Uranium removal by chitosan impregnated with magnetite nanoparticles: adsorption and desorption

Author

Stopa, Luiz Claudio Barbosa and Yamaura, Mitiko

Subjects
Uranium -- Chemical properties, Wastewater -- Chemical properties, Radioactive wastes -- Control, Petroleum, energy and mining industries
Abstract

Byline: Luiz Claudio Barbosa Stopa, Mitiko Yamaura A magnetic biosorbent composed of nanoparticles of magnetite covered with chitosan, denominated magnetic chitosan, was prepared. The magnetic chitosan showed a magnetic response of intense attraction in the presence of a magnetic field without becoming magnet, a typical behaviour of superparamagnetic material. Its adsorption performance was evaluated by the adsorption isotherm models of Langmuir and Freundlich for uranium ions, and the desorption behaviour using carbonate and oxalate ions was investigated. The adsorption equilibrium data fitted well to the Langmuir model, being the maximum adsorption capacity equal 42 mg g.SUP.−1. In the desorption studies, 94% of recovered UO.SUB.2.SUP.+2 with carbonate ion was verified under the conditions studied. The chitosan, available as a byproduct of marine food processing, is environmentally safe and can be a low cost adsorbent for U removal from wastewater. The magnetic chitosan as adsorbent of U to treat radioactive wastewater is a sustainable technology.

Published
2010

18. João Cândido e a revolta da chibata: disputas e memórias

Author

de Sousa, Claudio Barbosa

Abstract

The Revolt of the Lash broke out in Rio de Janeiro in 1910 in the ranks of the Brazilian navy. Its goals included the end of corporal punishment inflicted on sailors and better pay. This remarkable episode of the First Republic became, in many ways, a stage where several memories are in dispute, if not entirely conflicting. This article seeks to build a bridge between the Revolt of the Lash and its echoes through the cultural area. Choosing among different possible options, we first approach its sounds in popular music. Then we reframe this topic from the angle of the relationship between the leader of the sailors, João Cândido, and statuary. Finally, the issue is reconsidered in the framework of plots for recreating a novel. Keywords: Revolt of the Lash; João Cândido; memory disputes. A Revolta da Chibata eclodiu no Rio de Janeiro, em 1910, nas fileiras da Marinha brasileira. Entre seus alvos figuravam o fim dos castigos corporais infligidos aos marujos e a obtenção de melhores soldos. Esse episódio marcante da Primeira República se converteu, sob vários aspectos, num palco de disputas de memórias diversas, quando não inteiramente conflitantes. Neste artigo se procura lançar uma ponte entre ela e seus ecos na área cultural. Dentre outras opções possíveis, privilegiam-se, aqui, num primeiro momento, os sons da revolta na música popular. Na sequência, o tema é recolocado ao se enveredar pela relação estabelecida entre o líder dos marinheiros, João Cândido e a estatuária. Por último, a questão é repensada nas tramas da recriação de um romance. Palavras-chave: Revolta da Chibata; João Cândido; disputas de memórias.

Published
2016

19. Solasodine accumulation in regenerated plants of Solanum torvum Sw

Author

Claudio Barbosa Moreira, Maria Apparecida Esquibel, Sharon Santos de Lima, and Alice Sato

Subjects
Pharmacology, Horticulture, chemistry.chemical_compound, Complementary and alternative medicine, biology, chemistry, Botany, Steroidal alkaloid, Solanum torvum, biology.organism_classification, Solasodine
Abstract

RESUMO: Acumulo de solasodina em plantas micropropagadas de Solanum torvum Sw. A regeneracao de Solanum torvum e a avaliacao do conteudo de solasodina foram os objetivos de cultura de segmentos nodais. A influencia de auxinas (acido 3-indolacetico, acido naftalenoacetico) e de 6-benzilaminopurina no crescimento de S. torvum na micropropagacao foi investigado. Cultura de segmentos nodais foi iniciada por sementes germinadas em meio basico MS acrescido de GA 3 e cultivadas em diferentes concentracoes de AIA, AIA + BAP e ANA + BAP. Plantas da cultura in vitro com 60 dias foram coletadas, congeladas e liofilizadas e o metodo de alaranjado de metila foi utilizado para quantificacao de solasodina para o ensaio espectrofotometrico. Os melhores resultados para regeneracao vegetal e acumulo de solasodina foram alcancados no meio MS sem adicao de reguladores de crescimento havendo, porem grande producao de calos de base friaveis. Esses resultados mostram que a partir desses calos, cultura de celulas pode ser iniciada com aplicacao de outras auxinas e citocininas para o aumento da producao de solasodina alem de diferentes eliciadores, intensidades luminosas e concentracoes de sacarose. Palavras-chave: Solanaceae, jurubeba, auxina, citocinina, alcaloide esteroidal

Published
2010
Full Text
View/download PDF

21. Quitosana magnética para remoção de urânio (VI)

Author

Luiz Claudio Barbosa Stopa, Mitiko Yamaura, Alcídio Abrão, and Dione Mari Morita

Abstract

A quitosana, um poliaminossacarídeo formado por unidades repetidas de D-glucosamina, é derivada da quitina pela retirada do grupo acetila. Apresenta propriedades iônicas favoráveis agindo como quelante, sendo considerado um removedor de contaminantes de águas residuárias. Possui ampla bioatividade, ou seja, é biocompatível, biodegradável, bioadesivo e biossorvente. A quitosana interage por ligações intramoleculares por meio de seus grupos ativos com outras substâncias, pode revestir materiais magnéticos como as nanopartículas superparamagnéticas de magnetita, produzindo um conjugado polímero-magnetita. Materiais superparamagnéticos são susceptíveis ao campo magnético, assim estas partículas podem ser atraídas e agrupadas por aplicação de um campo magnético e como não retêm a magnetização, podem ser desagrupadas e reutilizadas em processos para remoção de contaminantes de rejeitos aquosos. No presente trabalho, preparam-se as partículas magnéticas de magnetita revestidas e funcionalizadas com quitosana (PMQ). O pó de PMQ exibiu uma resposta magnética de atração intensa na presença de um campo magnético sem, contudo tornar-se magnético, um comportamento típico de material superparamagnético. Foi caracterizado por espectrometria de infravermelho por transformada de Fourier e medidas de magnetização. Avaliou-se o seu desempenho de adsorção de urânio (VI), na forma de íon uranilo UO2 2+, com relação às influências da dose, velocidade de agitação, do pH, do tempo de equilíbrio e estudaram-se as isotermas de adsorção bem como o comportamento de dessorção com os íons de carbonato e oxalato. Constatou-se que a melhor remoção ocorreu em pH 5 e que o aumento da dose aumenta a remoção, tornando-se constante acima de 20 g.L-1. Na cinética de adsorção, o tempo para atingir o equilíbrio foi de 20 minutos. O modelo de isoterma que melhor se aplicou aos dados experimentais de adsorção de UO2 2+ foi de Langmuir, sendo a capacidade máxima de adsorção encontrada igual a 41,7 mg.g-1. Do estudo de dessorção com os íons carbonato verificou-se uma recuperação de 94% de UO2 2+ do PMQ contra 49,9% com ío The chitosan, an aminopolysaccharide formed for repeated units of Dglucosamine, is a deacetylation product of chitin. It presents favorable ionic properties acting as chelant, being considered a removing ionic of contaminants from water effluents. It has ample bioactivity, that is, is biocompatible, biodegradable, bioadesive and biosorbent. The chitosan interacts for crosslinked by means of its active groups with other substances, can still coat superparamagnetic materials as magnetite nanoparticles producing one conjugated polymer-magnetite. Superparamagnetic materials are susceptible for the magnetic field, thus these particles can be attracted and grouped by a magnetic field and as they do not hold back the magnetization, they can be disagrouped and reused in processes for removal of contaminants from industrial effluents and waste water. The present work consisted of preparing coated magnetic magnetite particles with chitosan (PMQ). The PMQ powder has showed a magnetic response of intense attraction in the presence of a magnetic field without however becoming magnetic, a typical behavior of superparamagnetic material. It was characterized by Fourier transform infrared spectrometry and measurements of magnetization. Its performance of Uranium (VI) adsorption as uranyl species, UO2 2+, was evaluated with regard to the influence of adsorbent dose, speed of agitation, pH, the contact time and had studied the isotherms of adsorption as well as the behavior of desorption using ions of carbonate and oxalate. The optimal pH to the best removal occurred in pH 5 and that the increase of the dose increases the removal, becoming constant above of 20 g.L-1. In the kinetic study the equilibrium was achieved after 20 minutes. The results of equilibrium isotherm agreed well with the Langmuir model, being the maximum adsorption capacity equal 41.7 mg.g-1. In the desorption studies were verified 94% of UO2 2+ recovered with carbonate ion and 49.9% with oxalate ion.

Published
2015
Full Text
View/download PDF

22. Hidrófitas fanerogâmicas de ecossistemas aquáticos temporários da planície costeira do Estado do Rio de Janeiro, Brasil

Author

Renata Fabiana Barros dos Anjos, Claudio Barbosa Moreira, André dos Santos Bragança Gil, and Claudia Petean Bove

Subjects
geography, temporary swamp, geography.geographical_feature_category, Coastal plain, Ecology, Lentibulariaceae, brejo temporário, Forestry, Plant Science, Biology, biology.organism_classification, Floristics, Herbarium, Taxon, hydrophytes, florística, Rio de Janeiro, planície costeira, Cyperaceae, coastal plains, floristics, hidrófitas
Abstract

Foi realizado o levantamento florístico das hidrófitas fanerogâmicas de ambientes aquáticos temporários da planície costeira do norte fluminense. O material botânico foi coletado em 27 expedições entre setembro/1998 a julho/2001, herborizado e identificado segundo a metodologia tradicional. As exsicatas foram depositadas no Herbário da Universidade do Rio de Janeiro (HUNI). Foram encontrados 113 táxons, distribuídos em 40 famílias. Os ambientes estudados podem ser caracterizados floristicamente pela família Cyperaceae, representada por 23 táxons (cerca de 20%); seguida pelas famílias Fabaceae e Onagraceae (sete táxons), Poaceae (seis táxons), Asteraceae e Scrophulariaceae (cinco táxons) e Apiaceae, Lentibulariaceae e Polygonaceae (quatro táxons). Estes ambientes sofrem alterações fitofisionômicas marcantes relacionadas com a hidrogeologia. Algumas espécies são anuais, desaparecendo completamente na estiagem; outras suportam a seca, mas têm a população profundamente reduzida, alterando substancialmente a paisagem. Algumas espécies consideradas exclusivamente aquáticas foram encontradas em solo úmido, inclusive em floração. Isto demonstra a necessidade da inclusão de espécies anfíbias nos estudos da flora aquática pois, algumas vezes, a delimitação dos tipos biológicos não é muito definida, além de caracterizar de forma mais adequada estes ambientes. A floristic inventory of phanerogamic hydrophytes from the temporary swampy environments of coastal plains of northern of Rio de Janeiro State was made. The botanical vouchers were collected in 27 expeditions between September/1998 and July/2001. They were herborized and identified by the traditional methodology. The exsicatae were deposited in the UNIRIO herbarium (HUNI). One hundred and thirteen taxa, distributed among 40 families were found. The environment analyzed could be floristically characterized by the Cyperaceae, represented by 23 taxa (ca. 20%), followed by Fabaceae and Onagraceae (seven taxa), Poaceae (six taxa), Asteraceae and Scrophulariaceae (five taxa) and Apiaceae, Lentibulariaceae and Polygonaceae (four taxa). These environments have great phytophysionomic changes according to hydrogeology. Some species are annual, disappearing completely in the dry season; another species tolerates the dryness but the population reduce drastically, changing substantially the landscape. Some species regarded as strictly aquatic were found in humid soil, producing flowers. This shows the necessity to include amphibious species on the aquatic flora studies because sometimes the boundaries between the biological types were not well defined.

Published
2003
Full Text
View/download PDF

24. Data Protection and Digital Services – European Union Perspectives // Protecţia datelor cu caracter personal şi serviciile digitale – perspective ale Uniunii Europene

Author

Andreea Șerban and Cláudio Barbosa Teixeira

Subjects
data protection, digital services, digital markets, online platforms, content moderation, gdpr, dsa, dma, Law in general. Comparative and uniform law. Jurisprudence, K1-7720
Abstract

The EU is taking further steps towards the regulation of the digital space. Following on the adoption of the General Data Protection Regulation (GDPR), the European Commission now proposes two new regulation proposals aimed at regulating online markets and create a safer online environment, where the fundamental rights of users are protected: the Digital Services Act and the Digital Markets Act. However, it is still up for discussion how these proposals will articulate with GDPR provisions. In this study, we shall discuss the potential impact on data protection rules of the latest EU legislative push and how it intends to balance the new horizontal regulation for digital markets with already existing legislation, in particular on data protection.

Published
2021
Full Text
View/download PDF

25. THE RESTART PROFESSION: WHAT MOVES AN EMPLOYEE TO GET IDENTIFIED WITH A STRUCTURE CHANGING GOVERNMENT COMPANY

Author

CLAUDIO BARBOSA DA ROCHA, JOSE ROBERTO GOMES DA SILVA, MARIA DO CARMO LEITE DE OLIVEIRA, and URSULA WETZEL

Abstract

PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO Este trabalho tem por objetivo principal o estudo de como os fatores de formação da identificação do indivíduo com a organização onde trabalha são afetados pelas mudanças de rumo e estrutura que acontecem na Empresa Pública, levando em conta os vários contextos de transição nos quais está inserida e passando pela identificação dos diversos atores sociais que compõem este cenário, visando à sugestão de programas capazes de resgatar a identificação dos empregados com a organização para a consecução de sua missão. A busca às respostas para a questão central da pesquisa é feita à luz da Teoria da Identidade Social e de outras a respeito da construção da identidade, da identificação, imagem e cultura organizacionais e do contrato psicológico entre o funcionário e a empresa, neste caso a Financiadora de Estudos e Projetos - FINEP. Esta dissertação é caracterizada como um estudo de caso, de natureza descritiva, fazendo uso precípuo de entrevistas dos funcionários da empresa, que são interpretadas através do emprego da análise de conteúdo dos depoimentos colhidos em campo. Os resultados revelam que os processos de identificação e frustração dos indivíduos com a empresa pública caminham em paralelo e são determinados pelos valores fundamentais da missão da empresa, pelo idealismo, pelo companheirismo e pela busca de auto-realização, em meio a um quadro de desorganização, desorientação e desmotivação decorrente das freqüentes mudanças de estrutura organizacional. This research has as its main objective the study of how the formation factors for the individual s identification with the organization he works are affected by the course and structure changes that take place in Government Companies, taking into account several transition contexts they are immersed in and by revealing the social actors that compose this scenery, aiming to suggest programs that are able to recover the employees identification with the organization for the attainment of its mission. The search to the answers for the research`s central question is made under the scope of the Social Identity Theory and other theories regarding identity construction and organizational identification, image and culture, besides the psychological contract between the employee and the company, in this case Financiadora de Estudos e Projetos - FINEP. This dissertation is characterized as a case study, with a descriptive nature and makes use of a set of employees interviews, that are interpreted by means of content analysis techniques applied to the organizational members` statements collected through field research. The results reveal that the individual`s identification and frustration processes with the government company are developed in parallel and given by core values of the company`s mission, its members` idealism, fellowship and self-accomplishment needs, in spite of a mess, disorientation and discouraging environment due to the routine organizational structure changes.

Published
2004

26. Uma proposta de modelo para avaliação de websites de comércio eletrônico: aplicação ao varejo de CD'S

Author

Oliveira, Luiz Claudio Barbosa de, Escolas::EBAPE, Botelho, Delane, Leite, Valdeci Faria, and Joia, Luiz Antonio

Subjects
Design de website, Internet, Administração de empresas, Website design, SEM, Comportamento do consumidor, Comércio eletrônico, Varejo de CD, E-commerce, Sites da Web - Desenho, CD retail market, Consumer behavior
Abstract

The aim of this dissertation is to investigate the relationship between the design of website for CD e-commerce and the virtual consumer behavior based on its purchase's attitude and intention. The main goal is to measure the virtual store design effect working as sales agent on Internet. The analysis of the virtual CD retailer was chosen, since the CD is one of the most popular products sold on this channel. This study is based on theoretical framework which describe the following main characteristics: i) Internet play the role as sales channel, ii) the CD retail market and iii) the consumer behavior and its decision processo Further on theoretical reference framework, it is showed the existing different models for website assessment: mo deI based on marketing, theory of two factors, quality assessment, web assessment mo deI (W AM) and the technology acceptance model (T AM). The analysis of its power and weakness will be base to development of the model proposed by this research. The concepts and the methods described were employed to ensure the consistency of its model. The final issue is the research design itself, applying a survey via web. The data collection was used for statistical validation of the relationship on proposed model. The structural equation model (SEM) was the statistical tool for quantitative analysis and to investigate all hypotheses generated on proposed model, supported by the theoretical reference framework. A dissertação tem como objeto a investigação das relações entre a o design de um website de comércio eletrônico de CDs e o comportamento do consumidor virtual, com ênfase a sua atitude e intenção de compra. O objetivo principal é mensurar o efeito do design da loja virtual (website) em seu papel de agente de vendas na Internet. A análise do comércio varejista de CDs foi escolhida, pois este produto é um dos principais artigos de venda neste canal. O estudo é apoiado em um referencial teórico, no qual são analisadas as características dos seguintes pontos: i) a Internet atuando como canal de vendas; ii) o comércio varejista de CD no Brasil e iii) o comportamento do consumidor e o seu processo decisório. Ainda no referencial teórico são apresentados os diversos modelos de avaliação de website existentes: baseado em Marketing, Teoria dos Dois Fatores, avaliação da qualidade, avaliação da web (W AM) e aceitação da Tecnologia na Web (T AM). A análise e comparação destes modelos serviu como base para o desenvolvimento da proposta do modelo de avaliação website. O estudo é complementado pelo desenvolvimento de uma pesquisa, com aplicação de questionário via web (websurvey). A coleta dos dados é utilizada como forma de validação estatística das relações existentes no modelo desenvolvido. Isto é feito por meio do uso da ferramenta de análise de Equações Estruturadas (SEM), suportada pelos conceitos e métodos de abordagem descritos no referencial teórico. A ferramenta permite tanto avaliar um modelo de mensuração e um modelo estrutural simultaneamente.

Published
2003

28. Uranium removal by chitosan impregnated with magnetite nanoparticles: adsorption and desorption

Author

Mitiko Yamaura and Luiz Claudio Barbosa Stopa

Subjects
Langmuir, Materials science, Langmuir adsorption model, Chitosan, symbols.namesake, chemistry.chemical_compound, Adsorption, Nuclear Energy and Engineering, chemistry, Desorption, symbols, Freundlich equation, Nuclear chemistry, Magnetite, Superparamagnetism
Abstract

A magnetic biosorbent composed of nanoparticles of magnetite covered with chitosan, denominated magnetic chitosan, was prepared. The magnetic chitosan showed a magnetic response of intense attraction in the presence of a magnetic field without becoming magnet, a typical behaviour of superparamagnetic material. Its adsorption performance was evaluated by the adsorption isotherm models of Langmuir and Freundlich for uranium ions, and the desorption behaviour using carbonate and oxalate ions was investigated. The adsorption equilibrium data fitted well to the Langmuir model, being the maximum adsorption capacity equal 42 mg g -1 . In the desorption studies, 94% of recovered UO2 2+ with carbonate ion was verified under the conditions studied. The chitosan, available as a byproduct of marine food processing, is environmentally safe and can be a low cost adsorbent for U removal from wastewater. The magnetic chitosan as adsorbent of U to treat radioactive wastewater is a sustainable technology.

Published
2010
Full Text
View/download PDF

30. João Cândido e a revolta da chibata: disputas e memórias.

Author

de Sousa, Claudio Barbosa

Abstract

The Revolt of the Lash broke out in Rio de Janeiro in 1910 in the ranks of the Brazilian navy. Its goals included the end of corporal punishment inflicted on sailors and better pay. This remarkable episode of the First Republic became, in many ways, a stage where several memories are in dispute, if not entirely conflicting. This article seeks to build a bridge between the Revolt of the Lash and its echoes through the cultural area. Choosing among different possible options, we first approach its sounds in popular music. Then we reframe this topic from the angle of the relationship between the leader of the sailors, João Cândido, and statuary. Finally, the issue is reconsidered in the framework of plots for recreating a novel. [ABSTRACT FROM AUTHOR]

Published
2014

31. CRIAÇÃO E TESTE DE UM MODELO PARA AVALIAÇÃO DE WEBSITES DE COMÉRCIO ELETRÔNICO.

Author

Joia, Luiz Antonio and de Oliveira, Luiz Claudio Barbosa

Subjects
*ELECTRONIC commerce, *WEB development, *BUSINESS to consumer transactions, *CONSUMER behavior, *CONSUMER attitudes, *TECHNOLOGY Acceptance Model, *STRUCTURAL equation modeling, *INTERNET sales
Abstract

The scope of this research is to develop and test a model for evaluating B2C e-commerce websites quantitatively. Consequently, this study seeks to investigate the relationship between the website interface of B2C e-commerce and virtual customer behavior, emphasizing the purchasing attitude and intention. The objective of this paper is, therefore, to research which features of a virtual store effectively influence the user purchasing process via the Internet. In order to achieve this aim, the Technology Acceptance Model (TAM) was adapted for pertinent theoretical references about consumer behavior on the web. The model developed was then tested and validated through a Structural Equation Modeling (SEM) approach. An empirical analysis of the CD e-retailing industry in Brazil was then conducted, as this is one of the most important areas of the B2C e-commerce realm. The study concludes that, for the electronic commerce of CDs, ease of use, trust, pleasure and attractiveness as perceived by visitors to CD e-retailing websites are key issues for understanding customer attitude and purchasing intention. Lastly, recommendations associated with the conclusions of this research are made, and further research options are proposed [ABSTRACT FROM AUTHOR]

Published
2008
Full Text
View/download PDF

32. ANÁLISE DA APLICABILIDADE DOS ELEMENTOS DE QUALIDADE DE DADOS APLICADOS AO SENSORIAMENTO REMOTO DA ÁGUA: ESTUDO DE CASO NO RESERVATÓRIO DE NOVA AVANHANDAVA, SÃO PAULO, BRASIL

Author

Thanan Rodrigues, Ivana Ivánová, Enner Alcântara, Milton Shimabukuro, Fernanda Watanabe, Luiz Rotta, Nilton Imai, and Cláudio Barbosa

Subjects
qualidade de dados espaciais, sensoriamento remoto da água, dados hiperespectrais, Geography. Anthropology. Recreation, Cartography, GA101-1776
Abstract

Informações sobre as propriedades espectrais de alvos naturais ou artifi ciais da superfície terrestre são relevantes para o desenvolvimento de modelos bio-ópticos, que posteriormente devem ser aplicados em imagens de satélite visando a estimativa de parâmetros de qualidade da água. Por esta razão, o conjunto de dados radiométricos adquiridos em campo devem atender requisitos de qualidade que garantam a acurácia das informações sobre os alvos. Dessa forma, o objetivo deste trabalho foi analisar os elementos de qualidade de dados espaciais que possam ser aplicados aos dados radiométricos, propondo ainda, um fl uxograma que visa fornecer os protocolos relacionados as etapas de planejamento de campo, aquisição, análise e requisitos para um metadado aplicado às medidas radiométricas de alvos aquáticos. Para isso, um estudo de caso no reservatório de Nova Avanhandava, Estado de São Paulo, foi utilizado para demonstrar as etapas mencionadas, enfatizando como produto fi nal, a construção de curvas espectrais de reflectância de sensoriamento remoto coletadas em campo por meio do espectroradiômetro TriOS. Como resultado, foi possível observar que para amostrar dados confiáveis é recomendado seguir os protocolos disponíveis para aquisição e análise de dados radiométricos, assim como, garantir que as principais informações relevantes à campanha de campo, do alvo e do ambiente sejam armazenadas.

Published
2019

33. AJUSTAMENTO DE MODELOS BIO-ÓPTICOS PARA ESTIMAR A CONCENTRAÇÃO DE SÓLIDOS SUSPENSOS TOTAIS NO RESERVATÓRIO DE BARRA BONITA

Author

Nariane Bernardo, Enner Alcântara, Fernanda Watanabe, Nilton Imai, Marcelo Curtarelli, Cláudio Barbosa, and Thanan Rodrigues

Subjects
monitoramento aquático, propriedades óticas inerentes, algoritmos empíricos, Geography. Anthropology. Recreation, Cartography, GA101-1776
Abstract

O objetivo deste trabalho foi avaliar o potencial de aplicação de dados hiperespectrais em estimar a concentração de sólidos suspensos totais no reservatório de Barra Bonita, em São Paulo. O uso de dados de sensoriamento remoto é uma poderosa ferramenta de monitoramento da qualidade da água, devido a sua capacidade de produzir dados temporais e espaciais. Técnicas de monitoramento tradicionais não produzem informação espacial e temporal periódica adequada e os dados de sensoriamento remoto podem auxiliar na superação dessa lacuna. Com o objetivo de estimar parâmetros da qualidade da água, de modo quantitativo, podem ser utilizados modelos bio-ópticos que relacionem a concentração de componentes aquáticos e suas propriedades espectrais registradas por sensores remotos. Dados hiperespectrais medidos in situ foram utilizados para calibrar e validar modelos bio-ópticos previamente divulgados na literatura, e gerar um novo modelo empírico, baseado na correlação entre a concentração de sólidos suspensos totais e a refl ectância de sensoriamento remoto. Os resultados obtidos foram avaliados por meio de análise de erros (Raiz Quadrada do Erro Médio Quadrático Percentual – RMSE, Erro Médio Absoluto em Porcentagem - MAPE, coefi ciente de determinação - R²). O melhor modelo para estimar as concentrações de sólidos em suspensão utilizou a região espectral do infravermelho próximo, apresentando menor erro de estimativas de sólidos suspensos totais.

Published
2019

34. Retrieving Total and Inorganic Suspended Sediments in Amazon Floodplain Lakes: A Multisensor Approach

Author

Daniel Maciel, Evlyn Novo, Lino Sander de Carvalho, Cláudio Barbosa, Rogério Flores Júnior, and Felipe de Lucia Lobo

Subjects
suspended sediments, Amazon Floodplains, Optically Complex Waters, Monte Carlo Simulation, inorganic sediments, Science
Abstract

Remote sensing imagery are fundamental to increasing the knowledge about sediment dynamics in the middle-lower Amazon floodplains. Moreover, they can help to understand both how climate change and how land use and land cover changes impact the sediment exchange between the Amazon River and floodplain lakes in this important and complex ecosystem. This study investigates the suitability of Landsat-8 and Sentinel-2 spectral characteristics in retrieving total (TSS) and inorganic (TSI) suspended sediments on a set of Amazon floodplain lakes in the middle-lower Amazon basin using in situ Remote Sensing Reflectance (Rrs) measurements to simulate Landsat 8/OLI (Operational Land Imager) and Sentinel 2/MSI (Multispectral Instrument) bands and to calibrate/validate several TSS and TSI empirical algorithms. The calibration was based on the Monte Carlo Simulation carried out for the following datasets: (1) All-Dataset, consisting of all the data acquired during four field campaigns at five lakes spread over the lower Amazon floodplain (n = 94); (2) Campaign-Dataset including samples acquired in a specific hydrograph phase (season) in all lakes. As sample size varied from one season to the other, n varied from 18 to 31; (3) Lake-Dataset including samples acquired in all seasons at a given lake with n also varying from 17 to 67 for each lake. The calibrated models were, then, applied to OLI and MSI scenes acquired in August 2017. The performance of three atmospheric correction algorithms was also assessed for both OLI (6S, ACOLITE, and L8SR) and MSI (6S, ACOLITE, and Sen2Cor) images. The impact of glint correction on atmosphere-corrected image performance was assessed against in situ glint-corrected Rrs measurements. After glint correction, the L8SR and 6S atmospheric correction performed better with the OLI and MSI sensors, respectively (Mean Absolute Percentage Error (MAPE) = 16.68% and 14.38%) considering the entire set of bands. However, for a given single band, different methods have different performances. The validated TSI and TSS satellite estimates showed that both in situ TSI and TSS algorithms provided reliable estimates, having the best results for the green OLI band (561 nm) and MSI red-edge band (705 nm) (MAPE < 21%). Moreover, the findings indicate that the OLI and MSI models provided similar errors, which support the use of both sensors as a virtual constellation for the TSS and TSI estimate over an Amazon floodplain. These results demonstrate the applicability of the calibration/validation techniques developed for the empirical modeling of suspended sediments in lower Amazon floodplain lakes using medium-resolution sensors.

Published
2019
Full Text
View/download PDF

35. Impact of the 2009 extreme water level variation on phytoplankton community structure in Lower Amazon floodplain lakes Impacto da variação extrema do nível da água em 2009 sobre a estrutura da comunidade fitoplanctônica de lagos da planície do Baixo Amazonas

Author

Simone Casali, Maria do Carmo Calijuri, Bernard Barbarisi, Vivian Fróes Renó, Adriana Gomes Affonso, Cláudio Barbosa, Thiago Sanna Freire Silva, and Evlyn Márcia Leão de Moraes Novo

Subjects
fitoplâncton, planície de inundação Amazônica, eventos hidrológicos extremos, phytoplankton, Amazon floodplain, extreme hydrological events, Ecology, QH540-549.5
Abstract

AIM: This paper examines the effect of the extreme water level change in 2009 on the structure and diversity of the phytoplankton communities in lakes of the Lower Amazon Floodplain, and compares it to phytoplankton community structure data reported in the literature for 2002 and 2003 high water periods, closer to the normal hydrological conditions. METHODS: Sub-surface integrated water samples for phytoplankton and chlorophyll-a analyses were collected during high and low water phases in 2009. Water temperature (°C), pH, turbidity (NTU) and electrical conductivity (µS.m-1) were measured, and the Shannon diversity index was calculated. RESULTS: The results showed striking differences in taxonomic composition between phases (high and low) and also between normal (2002 and 2003) and extreme (2009) hydrological conditions, all related to the flood pulse intensity. CONCLUSIONS: Extreme water level fluctuations can result in shifts in phytoplankton community structure and diversity. This work represents a valuable contribution to phytoplankton research since presents the community structure under extreme hydrological events in the Amazon floodplain.OBJETIVO: Esse trabalho investiga o efeito da extrema variação da mudança do nível da água em 2009 na estrutura e diversidade das comunidades de fitoplâncton nos lagos da planície de inundação do Baixo Amazonas,e compara estes resultados à estrutura da comunidade de fitoplâncton reportada na literatura para os períodos de água alta em 2002 e 2003, próximos a condições hidrológicas normais. MÉTODOS: Amostras de água da sub-superfície foram coletadas para a análise de fitoplâncton e clorofila-a nos períodos de água alta e baixa em 2009. Temperatura da água (°C), pH, turbidez (NTU) e condutividade elétrica (µS.m-1) foram medidas, e o índice de diversidade de Shannon calculado. RESULTADOS: Os resultados revelaram diferenças marcantes na composição taxonômica entre fases da inundação (alta e baixa) e também entre eventos hidrológicos normais (2002 e 3003) e extremos (2009), todos relacionados com a intensidade do pulso de inundação. CONCLUSÕES: Flutuações extremas do nível da água podem resultar em alterações na estrutura da comunidade e na diversidade. Esse trabalho é uma contribuição valiosa a pesquisa em fitoplâncton, pois apresenta a estrutura da comunidade sob condições hidrológicas extremas na planície de inundação Amazônica.

Published
2011

36. Identificação de funcionários com empresa pública no contexto de mudanças: o caso Finep Employees' identification with a state-owned company in a changing context: the case of Finep

Author

Cláudio Barbosa da Rocha and José Roberto Gomes da Silva

Subjects
identidade organizacional, identificação, empresa pública, mudança organizacional, organizational identity, identification, public organization, organizational change, Political institutions and public administration (General), JF20-2112
Abstract

O quadro atual de mudanças nas empresas públicas tende a influenciar o processo de identificação de seus empregados com elas. Nesse cenário, incluem-se algumas instituições do segmento de ciência e tecnologia. Este artigo verifica os aspectos que influenciam o processo de identificação dos indivíduos com uma organização pública desse segmento em face das freqüentes mudanças de rumo e estrutura nela ocorridas. O objeto de análise é a Financiadora de Estudos e Projetos (Finep), empresa que atua no fomento de estudos, pesquisas, programas e projetos econômicos, sociais, científicos e tecnológicos no país. Usando pesquisa documental e entrevistas com 24 funcionários, o artigo permitiu a composição de dois quadros conceituais sobre os aspectos que contribuem positiva (mapa da identificação) ou negativamente (mapa da frustração) para a relação dos indivíduos com a organização.The recent changing scenario in public organizations tends to influence their employees' identification process. This is also the case of some science and technology institutions. This article identifies which aspects influence the identification of individuals with an S&T public organization, considering its frequent changes of direction and structure. The object of analysis is the case of Finep, a public agency which finances economic, social, scientific, and technological studies, researches, projects, and programs in Brazil. Based on documental data collection and interviews with 24 employees, the study has permitted the composition of two conceptual frameworks corresponding, respectively, to the aspects contributing positively (identification map) as well as negatively (frustration map) to the relation between individuals and the organization.

Published
2007
Full Text
View/download PDF

37. Técnicas avançadas de sensoriamento remoto aplicadas ao estudo de mudanças climáticas e ao funcionamento dos ecossistemas amazônicos Advanced remote sensing techniques for global changes and Amazon ecosystem functioning studies

Author

Evlyn Márcia Leão de Moraes Novo, Laerte Guimaraes Ferreira, Cláudio Barbosa, Claudio Carvalho, Edson E. Sano, Yosio Shimabukuro, Alfreado Huete, Christopher Potter, Dar.A. Roberts, Laura L. Hess, John J. Melack, Hiroki Yoshioka, Steven Klooster, Vipin Kumar, Ranga Myneni, Piyachat Ratana, Kamel Didan, and Tomoaki Miura

Subjects
Sensoriamento remoto, padrões, processos, Remote sensing, pattern, processes, Science (General), Q1-390
Abstract

Este artigo se propõe a apresentar exemplos de questões científicas que puderam ser respondidas no contexto do Projeto LBA (Large Sale Biosphere-Atmosphere Experiment in Amazonia) graças à contribuição de informações derivadas de sensoriamento remoto. Os métodos de sensoriamento remoto permitem integrar informações sobre os vários processos físicos e biológicos em diferentes escalas de tempo e espaço. Nesse artigo, são enfatizados aqueles avanços de conhecimento que jamais seriam alcançados sem a concorrência da informação derivada de sensoriamento.This paper aims to assess the contribution of remote sensing technology in addressing key questions raised by the Large Scale Biosphere-Atmosphere Experiment in Amazonia (LBA). The answers to these questions foster the knowledge on the climatic, biogechemical and hydrologic functioning of the Amazon, as well as on the impact of human activities at regional and global scales. Remote sensing methods allow integrating information on several processes at different temporal and spatial scales. By doing so, it is possible to perceive hidden relations among processes and structures, enhancing their teleconnections. Key advances in the remote sensing science are summarized in this article, which is particularly focused on information that would not be possible to be retrieved without the concurrence of this technology.

Published
2005
Full Text
View/download PDF

38. ESTADO E NOVOS AGENTES SOCIAIS NA RECONSTRUÇÃO DO ESPAÇO

Author

Cláudio Barbosa da Costa

Subjects
Human ecology. Anthropogeography, GF1-900, Geography (General), G1-922
Abstract

Este estudo tem como objetivo principal sistematizar novas questões referentes à complexidade das ações dos agentes sociais na construção do espaço contemporâneo, e que vem interferindo, de maneira significativa, na forma como o Estado vem realizando o processo de intervenção no território. Os eixos analíticos do estudo serão constituídos pelo novo patamar de acumulação que constitui a globalização, os grandes agentes econômicos internacionais e as novas referências da chamada lógica civilizatória, na qual emergem sujeitos sociais que ao buscarem romper com idéia dominante de desenvolvimento e de crescimento, vêm construindo novas formas de lidar com a natureza, com o território e com o trabalho, estabelecendo a alteridade, a partir da luta pela sua legitimidade. A compreensão teórica dos novos movimentos sociais possibilitou um melhor entendimento do papel histórico destes agentes na construção contemporânea do espaço e das suas relações com o vetor ecológico e o desenvolvimento sustentável. Para finalizar, realizamos uma análise histórica das intervenções do Estado brasileiro na construção do território nacional, buscando identificar a complexidade dos agentes da sociedade civil, e as possibilidades e os limites da constituição de um projeto geopolítico através de um novo pacto social, que resguardando as diferenças, consideram-se as territorialidades dos setores sociais historicamente excluídos do processo de

Published
2010
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results