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Search Results: 1 - 10 of 334398 matches for " Fábio R;Kropf "
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Forest spatial heterogeneity and palm richness, abundance and community composition in Terra Firme forest, Central Amazon
Cintra, Renato;Ximenes, Arimatéa de Carvalho;Gondim, Fábio R;Kropf, Marcela S;
Brazilian Journal of Botany , 2005, DOI: 10.1590/S0100-84042005000100007
Abstract: the mechanisms that maintain tree diversity in tropical rain forests are still in debate. variations in forest structural components produce forest microenvironmental heterogeneity, which in turn may affect plant performance and have been scarcely analyzed in the amazon. palms are widespread in the neotropical rainforests and have relatively well known taxonomy, apart from being ecologically and economically important. the understanding of how palms respond to variation in the forest structural components may help to explain their abundance and richness in a given area. in this study, we describe a palm community and analyze how it is affected by forest microenvironmental heterogeneity. in a pristine "terra firme" forest at reserva ducke, manaus, we recorded all adult palm trees in twenty 100 × 10 m plots. in the same plots we recorded the variation in canopy openness, the leaflitter thickness and counted all non-palm forest trees. a total of 713 individuals in 29 palm species were found. the three most abundant species were astrocaryum sciophilum (miq.) pulle, a. gynacanthum mart. and attalea attaleoides (barb. rodr.) wess. boer. the most locally abundant species were also very frequent or occurred in a larger number of plots. there were no significant effects of litter depth, forest canopy openness and forest tree abundance on palm richness. however, in areas where leaf litter was thicker a significant lower number of palm trees occurred. in microsites where proportionally more incident light was reaching the forest understory, due to higher canopy opening, significantly more palm trees were present.
Reconhecimento de variedades de soja por meio do processamento de imagens digitais usando redes neurais artificiais
Khatchatourian, Oleg;Padilha, Fábio R. R.;
Engenharia Agrícola , 2008, DOI: 10.1590/S0100-69162008000400016
Abstract: digital image processing with artificial neural network (ann) was used to identify some soybean varieties through the form and size of the seeds. the following varieties were analyzed: embrapa 133, embrapa 184, coodetec 205, coodetec 206, embrapa 48, syngenta 8350, fepagro 10 and monsoy 8000 rr, 2005/2006 harvest. the image processing was constituted by the following stages: 1) image acquisition: the samples of each variety were photographed by photographic camera coolpix995, nikon, with resolution of 3.34 megapixels; 2) pre-processing: an anti-aliasing filter was applied to convert the true-color image to the grayscale intensity image; 3) segmentation: it was made the seeds edges detection (method of prewitt), edge dilation and removal of needless segments; 4) representation: each seed was represented in the form of a binary matrix 130x130, and 5) recognition and interpretation: feedforward multiple-layer network was used with three hidden layers. the training of the network was accomplished by backpropagation. the validation of the trained ann showed that applied processing can be used for identification of the considered soybean varieties.
Analysis of the initial stages of electrocrystallization of Fe, Co and Fe-Co alloys in chloride solutions
Bento, Fábio R.;Mascaro, Lucia H.;
Journal of the Brazilian Chemical Society , 2002, DOI: 10.1590/S0103-50532002000400015
Abstract: the electrodeposition of fe, co and fe-co alloys onto pt has been investigated from chloride solutions at ph 2.0. the fe-co alloys were deposited from solutions with molar ratio of 1:10, 1:1 and 10:1. electrocrystallization of metals was studied by potentiostatic steps. the scharifker and hills model was used to analyze current transients. a progressive nucleation mechanism was found to fit the experimental results for both co and fe-co alloys deposited from 1:10 solution. in the case of pure fe and fe-co alloy, deposited from 1:1 and 10:1 solutions, the nucleation process occurred by the instantaneous mechanism. the nuclei number densities and rate of nucleation were calculated and their values were 2.6 to 19.1 x 103 cm-2 for fe and 0.10 to 15.8 x 106 cm-2 s-1 for co deposition.
Efeitos da temperatura sobre a atividade de fungos no controle biológico de Meloidogyne javanica E M. incognita ra?a 3
Alves, Fábio R.;Campos, Vicente Paulo;
Ciência e Agrotecnologia , 2003, DOI: 10.1590/S1413-70542003000100011
Abstract: the effects of arthrobotrys conoides, duddingtonia flagrans, paecilomyces lilacinus, paecilomyces variotii, monacrosporium doedycoides and an isolate of rhizobacterium on reproductivity of meloidogyne javanica and m. incognita race 3 on santa clara tomato plants, susceptible to meloidogyne spp., were studied in three different environments: 1) greenhouse without temperature control; 2) room with air temperature controlled at 24oc; 3) watherbath with soil temperature controlled at 29-30oc, placed in the room with the temperature controlled at 24oc. greatest m. javanica and m. incognita race 3 reproductivity occurred in waterbath warmed soil than in greenhouse and temperature controlled room. galls number caused by m. javanica and m. incognita race 3 was greater in waterbath warmed soil and temperature controlled room than in greenhouse. in waterbath warmed soil and in temperature controlled room, a. conoides and rhizobacterium reduced (p< 0,05) the galls number of m. incognita race 3 compared to control. a. conoides also reduced the eggs number of m. incognita race 3 compared to control in waterbath warmed soil. in greenhouse, all antagonistics used reduced the eggs number compared to control.
Historiografia Brasileira e a No o de Poder Disciplinar
Fábio Gutemberg R. B. de Sousa
S?culum : Revista de História , 1998,
Abstract: Partindo da apresenta o dos pressupostos teórico-metodológicos que fundam as no es de poder e de cidade disciplinar busca-se analisar, a partir das obras de Margareth Rago (Do Cabaré ao Lar) e de Marisa Carpintéro (A Constru o de um Sonho), como a historiografia brasileira as incorporou, e em especial, à no o foucaltiana de "poder disciplinar",transformando-o em modelo. O artigo apresenta, ainda, algumas das críticas de Marshall Berman e de Michel de Certeau à essa no o.
Analysis of the initial stages of electrocrystallization of Fe, Co and Fe-Co alloys in chloride solutions
Bento Fábio R.,Mascaro Lucia H.
Journal of the Brazilian Chemical Society , 2002,
Abstract: The electrodeposition of Fe, Co and Fe-Co alloys onto Pt has been investigated from chloride solutions at pH 2.0. The Fe-Co alloys were deposited from solutions with molar ratio of 1:10, 1:1 and 10:1. Electrocrystallization of metals was studied by potentiostatic steps. The Scharifker and Hills model was used to analyze current transients. A progressive nucleation mechanism was found to fit the experimental results for both Co and Fe-Co alloys deposited from 1:10 solution. In the case of pure Fe and Fe-Co alloy, deposited from 1:1 and 10:1 solutions, the nucleation process occurred by the instantaneous mechanism. The nuclei number densities and rate of nucleation were calculated and their values were 2.6 to 19.1 x 103 cm-2 for Fe and 0.10 to 15.8 x 10(6) cm-2 s-1 for Co deposition.
Avalia??o da acurácia no direcionamento com piloto automático e contraste da capacidade de campo operacional no plantio mecanizado da cana-de-a?úcar
Baio, Fábio H. R.;Moratelli, Rodrigo F.;
Engenharia Agrícola , 2011, DOI: 10.1590/S0100-69162011000200017
Abstract: with the growth of mechanization on the sugar cane plantation, the processes need to be speeded up, such as with the use of precision farming techniques to decrease the production cost. the purpose of this study was to compare the accuracy achieved by an auto guidance system driving the passes of a sugar cane planter machine over the field versus the manual system, compare the operational field capacity and compare the operational efficiency. two treatments were analyzed: auto guidance by rtk gps and manual guidance on the sugar cane planting operation. the evaluations were conducted under field conditions at iaco agrícola s/a mill, in chapad?o do sul-ms. according to the results, it was stated that the use of auto guidance system on sugar cane planting operation gathered an accuracy of 0.033 m pass to pass. this accuracy is five times greater than the obtained by the manual steering system. the use of an auto guidance steering did not increase the operational efficiency of the mechanized system, which is limited by the harvesting and transporting system of the sugar cane seeding to the planter.
Genetic diversity and population structure of Prochilodus costatus and Prochilodus argenteus preceding dam construction in the Paraopeba River, São Francisco River Basin, Minas Gerais, Brazil  [PDF]
Tatiana M. Barroca, Fábio P. Arantes, Bárbara F. Magalh?es, Flávia F. Siqueira, Carolina C. R. Horta, Isabella F. Pena, Jorge A. Dergam, Evanguedes Kalapothakis
Open Journal of Genetics (OJGen) , 2012, DOI: 10.4236/ojgen.2012.22017
Abstract: Curimat?-pioa (Prochilodus costatus) and curimat?-pacu (Prochilodus argenteus) are migratory fish species endemic to the S?o Francisco River Basin in Brazil. Both species play important roles in local fisheries and ecology in the Paraopeba River. A dam was recently constructed on this river and to help in the development and conservation programs, we characterized the genetic variation of both species before dam construction. Complex hypervariable repeats micro-satellite was used to asses genetic variation for both species within and between the five collection sites in order to detect population substructuring. Nucleotide substitutions and insertion/deletion polymorphisms (indels) resulted in 35 P. costatus haplotypes (sample size = 89) and 22 P. argenteus haplotypes (sample size = 32). Significant genetic diversity and population differentiation was detected between five sampling sites for both species. Therefore, each of the five sites should be regarded as a group comprising significant genetic differences in species conservation and maintenance plans. Comparing these results to genetic diversity measures after dam construction will be critical for future management in this region.
Avalia??o da acurácia de uma barra de luz utilizada na agricultura de precis?o, em rela??o ao marcador de espuma
Baio, Fábio H. R.;Balastreire, Luiz A.;Torres, Fábio;Ribeiro Filho, Affonso C.;
Revista Brasileira de Engenharia Agrícola e Ambiental , 2001, DOI: 10.1590/S1415-43662001000200031
Abstract: some equipments are used in precision farming to improve operational conditions. a light bar is an equipment used to guide a vehicle in adjacent bands, reducing the overlap of the parallel swathing and optimizing the efficiency of the agricultural application. the objective of this work was to determine the accuracy of a light bar compared to a foam marker, and to verify the adaptation of the operators to this new technology. experiments were conducted at two different places with several operators. the overlap errors and missed applications in the parallel swathing system were compared for both systems. there was a high adaptability of the operators to the light bar since this system was easier to operate than the foam marker. it was concluded that the light bar for the application of agricultural chemicals could replace the foam marker.
Carcinoma mucoepidermóide de cabe?a e pesco?o: estudo clínico-patológico de 173 casos
Pires, Fábio R.;Alves, Fábio de A.;Almeida, Oslei P. de;Kowalski, Luiz P.;
Revista Brasileira de Otorrinolaringologia , 2002, DOI: 10.1590/S0034-72992002000500013
Abstract: introduction: mucoepidermoid carcinoma (mec) is the most common malignant salivary gland tumor, however few studies have been reported in brazilian populations. objective: to report clinical and pathologic data from 173 head and neck mec treated in the centro de tratamento e pesquisa hospital do cancer a. c. camargo in s?o paulo. study design: clinical randomized. material and method: from 1953 to 1997, 173 cases of mec were found in the files of the centro de tratamento e pesquisa hospital do cancer a. c. camargo. data were obtained from the patients' records and histological review of all cases. results: the mean age of the patients was 44 years and 93 (53,8%) were men; parotid glands were affected in 61 cases (35,2%) and intra-oral minor salivary glands in 75 (43,4%). tnm revealed 50,3% of the cases in stages i and ii, and histological grading revealed 45,2%, 18,5% and 36,3% low-grade, intermediate-grade and high-grade tumors, respectively. surgical treatment was employed in 80,3% of the cases, with neck dissection in 52 cases (30,1%), and radiotherapy in 73 (42,2%). local recurrence, regional and distant metastasis were found in 12,7%, 9,8% and 9,2% of the patients, respectively; 5-year and 10-year overall survival rates were 70% and 60%, respectively. conclusions: mec affected mainly the parotid gland and the palate of adults, without gender predilection. half of the cases were diagnosed in initial clinical stages and 64% of the tumors were low or intermediate-grade lesions. surgery was the treatment of choice and prognosis was good.
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