oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2020 ( 9 )

2019 ( 342 )

2018 ( 511 )

2017 ( 554 )

Custom range...

Search Results: 1 - 10 of 332544 matches for " Haroldo F. de;Silva Neto "
All listed articles are free for downloading (OA Articles)
Page 1 /332544
Display every page Item
Evaluation of radiances generated by solving the radiative-transfer equation with different approaches
Chalhoub, Ezzat Selim;Campos Velho, Haroldo F. de;Silva Neto, Ant?nio José da;
Journal of the Brazilian Society of Mechanical Sciences and Engineering , 2012, DOI: 10.1590/S1678-58782012000200010
Abstract: radiative transfer is the main phenomenon in the basis of several relevant problems of scientific and technological interest. examples of application of the mathematical and computational modeling of such phenomenon can be found in astronomy, environmental sciences, engineering and medicine among many different areas. the integro-differential equation known as boltzmann equation describes mathematically the interaction of the radiation with the participating medium, i.e. a medium which may absorb, scatter and emit radiation. several methods have been developed for the solution of the bolztmann equation. in the present work we present a comparison of the solutions obtained for the one-dimensional problem with four different methods: (i) monte carlo (mc) method; (ii) discrete ordinates method (sn) combined with a finite difference approximation; (iii) analytical discrete ordinates method (asn); and (iv) laplace transform discrete ordinates method (ltsn). our final objective is to solve the inverse radiative transfer problem and for that purpose, we want to investigate methods that may provide accurate and fast solutions for the direct problem.
Novel insights into the genomic basis of citrus canker based on the genome sequences of two strains of Xanthomonas fuscans subsp. aurantifolii
Leandro M Moreira, Nalvo F Almeida, Neha Potnis, Luciano A Digiampietri, Said S Adi, Julio C Bortolossi, Ana C da Silva, Aline M da Silva, Fabrício E de Moraes, Julio C de Oliveira, Robson F de Souza, Agda P Facincani, André L Ferraz, Maria I Ferro, Luiz R Furlan, Daniele F Gimenez, Jeffrey B Jones, Elliot W Kitajima, Marcelo L Laia, Rui P Leite, Milton Y Nishiyama, Julio Rodrigues Neto, Letícia A Nociti, David J Norman, Eric H Ostroski, Haroldo A Pereira, Brian J Staskawicz, Renata I Tezza, Jesus A Ferro, Boris A Vinatzer, Jo?o C Setubal
BMC Genomics , 2010, DOI: 10.1186/1471-2164-11-238
Abstract: We have sequenced the genomes of strains B and C to draft status. We have compared their genomic content to X. citri subsp. citri and to other Xanthomonas genomes, with special emphasis on type III secreted effector repertoires. In addition to pthA, already known to be present in all three citrus canker strains, two additional effector genes, xopE3 and xopAI, are also present in all three strains and are both located on the same putative genomic island. These two effector genes, along with one other effector-like gene in the same region, are thus good candidates for being pathogenicity factors on citrus. Numerous gene content differences also exist between the three cankers strains, which can be correlated with their different virulence and host range. Particular attention was placed on the analysis of genes involved in biofilm formation and quorum sensing, type IV secretion, flagellum synthesis and motility, lipopolysacharide synthesis, and on the gene xacPNP, which codes for a natriuretic protein.We have uncovered numerous commonalities and differences in gene content between the genomes of the pathogenic agents causing citrus canker A, B, and C and other Xanthomonas genomes. Molecular genetics can now be employed to determine the role of these genes in plant-microbe interactions. The gained knowledge will be instrumental for improving citrus canker control.Citrus canker is a disease with worldwide distribution that has severe economic impact on the citrus industry [1,2]. Disease symptoms consist of water soaked lesions that develop into blisters, then pustules, and, finally, cankers. In severe cases, citrus canker can lead to defoliation and premature fruit drop [3]. Eradication of infected plants is the method of choice to control the disease where it is not yet endemic. When the disease is endemic, control is attempted by planting disease-free trees, limiting the spread between orchards, and using preventive copper sprays [4-6]. However, none of these measures
Estado nutricional de crian as menores de dez anos residentes em invas o do "Movimento dos Sem-Terra", Porto Calvo, Alagoas
Ferreira Haroldo da Silva,Albuquerque Maria de Fátima M. de,Ataide Terezinha da Rocha,Morais Maria das Gra?as Cavalcante
Cadernos de Saúde Pública , 1997,
Abstract: Descreve-se o perfil nutricional de 357 crian as (1 a 10 anos) residentes na Fazenda Concei o, área invadida pelo "Movimento dos Sem-Terra" e recentemente desapropriada pelo INCRA para fins de reforma agrária. As prevalências de déficits nutricionais (Z <=-2 desvios-padr o da mediana do padr o antropométrico, (NCHS) relativas aos índices massa corporal para idade, estatura para idade e massa corporal para estatura foram, respectivamente, 19,6%, 39,8% e 2%, superando os valores divulgados recentemente para a zona rural do estado de Alagoas (8,4%, 22,7% e 1,3%). Estes achados sugerem que estas crian as encontram-se fortemente afetadas pelo nanismo. Apesar de esta condi o ser amplamente reconhecida como uma das mais visíveis manifesta es da desnutri o nos países em desenvolvimento, é importante destacar que o caráter concentracionista da propriedade da terra, parte integrante do modelo de desenvolvimento concentrador de renda adotado no Brasil, é também um importante fator na determina o desse perfil de saúde. Existe, portanto, uma necessidade urgente de que os setores responsáveis pela elabora o das políticas públicas realoquem recursos para a interven o imediata nestas comunidades agrárias, a fim de se reduzirem as graves conseqüências advindas de um quadro dessa magnitude.
Enriquecimento do sistema solo-serapilheira com espécies arbóreas aptas para recupera??o de áreas degradadas
Braga, Antonio Jorge Tourinho;Griffith, James Jackson;Paiva, Haroldo Nogueira de;Silva, Fabiana Cabral da;Corte, Viviana Borges;Meira Neto, Jo?o Augusto Alves;
Revista árvore , 2007, DOI: 10.1590/S0100-67622007000600019
Abstract: this study evaluated the behavior of an organic soil-litter system seeded with native species with implications for revegetation of disturbed lands. the experiment was carried out in a greenhouse and on benches exposed to open sunlight at the research nursery of the department of forestry of the universidade federal de vicosa (ufv). the inventory identified 508 individuals, out of which 38 species were identified, belonging to 34 genera and distributed among 22 families. evaluation of both introduced seeds and seed bank did not show any differences in germination for the environmental regimes tested. seedling growth for species originating from litter and topsoil propagules and for species inserted for enrichment was greater under shade. unfertilized soils had a higher percentage of germinated seeds than fertilized soils. fertilization was shown to be fundamental for seedling growth. hence, results demonstrate improved efficiency by enriching a seed bank and confirm the potential of this technique for revegetation of disturbed lands.
Influência da satura??o por bases e do fósforo no crescimento de mudas de angico-branco
Gomes, Keli Cristina de Oliveira;Paiva, Haroldo Nogueira de;Neves, Júlio César Lima;Barros, Nairam Félix de;Silva, Sérgio Ricardo;
Revista árvore , 2004, DOI: 10.1590/S0100-67622004000600003
Abstract: this study aimed at evaluating the seedling performance of angico-branco (anadenanthera colubrina (vell.) brenan), under different conditions of phosphorus availability and variable levels of base saturation. the treatments were represented by a 6 (p doses: 0, 100, 200, 300, 400 and 500 mg/dm3) by 5 (percentage of basis saturation: original, 40, 50, 60 and 70%) factorial arrangement, distributed in randomized blocks with five replications. 170 days after sowing, stalk height and diameter of all "angico-branco" plants were measured, finishing the experiment. the addition of corrective mixed to substrate did not show significant response on the species studied. this absence of response can be related to the fact that the levels of ca (0,9 cmolc/dm3) and mg (0,4 cmolc/dm3) in the soil used, might be efficient to supply the needs of the plants in that phase. however, it was observed that "angico-branco" responded positively to p fertilization. p doses that leaded to 90% of the maximum dry matter production were 127 mg/dm3 on 40% base saturation and 126 mg/dm3 on 60% base saturation.according to the adjusted model for recorred p, relative to addedp; the dose that lead to available p at todays were 976,2 mg/dm3 ,with v=40% and 1277,3 mg/dm3 ,with v=60%. the critical p level at v=40% and v=60% were 13,88 and 12,87 mg/dm3 in the soil and 0,14 and 0,12 dag/kg on the shoot, respectively.
Crescimento de mudas de garapa em resposta à calagem e ao fósforo
Gomes, Keli Cristina de Oliveira;Paiva, Haroldo Nogueira de;Neves, Júlio César Lima;Barros, Nairam Félix de;Silva, Sérgio Ricardo;
Revista árvore , 2008, DOI: 10.1590/S0100-67622008000300001
Abstract: this study aimed to evaluate the initial performance of apuleia leiocarpa (vogel) macbride, in variable conditions of phosphorus (p) availability and base saturation (v) in the soil. the treatments were arranged in a factorial design of 6 p levels (0; 100; 200; 300; 400 and 500 mg dm-3) and 5 base saturation levels (original = 24; 40; 50; 60 and 70%), in complete randomized blocks with five replicates. within one hundred twenty days after seed sowing, plant heights and basal stalk diameters were measured; plants were harvested, separated into roots and shoots, and dried to constant mass. the results showed that the maximum recommended lime rate for a. leiocarpa is 60% of base saturation. under these conditions the recommended p dose is 54 mg dm-3. the p critical level in the soil was influenced by the base saturation, ranging from 6 (v = 60 %) to 33 mg dm-3 (v = 40 %). the p critical level in the shoot dry matter was also influenced by base saturation, varying from 0.11 (v = 60 %) to 0.18 dag kg-1 (v = 50 %).
Desenvolvimento de cafeeiros enxertados 'Apoat? IAC 2258' cultivados em recipiente de 250 litros
Dias, Fábio Pereira;Mendes, Ant?nio Nazareno Guimar?es;Vallone, Haroldo Silva;Carvalho, Alex Mendon?a de;Carvalho, Samuel Pereira de;
Ciência e Agrotecnologia , 2008, DOI: 10.1590/S1413-70542008000200006
Abstract: this study was carried out during the period from january 2004 until may 2005, aimed to obtain information on the development of coffee trees grafted in 'apoat? iac 2258' and ungrafted coffee trees. the experimental design used was a randomized block with a (2 x 3) + 2 factorial split-plot arrangement and four replications, as follows: two c. arabica l. cultivars, three types of seedling (grafted, self-grafted and ungrafted), two apoat? rootstock control, ungrafted and self-grafted evaluated in four period of time. the experiments were evaluated for plant height, aerial parts dry matter, root system dry matter, plagiotropic shoots number and plagiotropic shoots nodes number. the results obtained let verify that grafted seedling was not superior to the ungrafted one for all the evaluated characteristics, regardless of the cultivar. no stress effect caused by grafting was observed, but apoat? rootstock effect was observed for all features. apoat? plants have more root system dry matter than c. arabica l. plants. the use of grafted seedling is not recommended for nematoid-free areas.
Estudo anat?mico de cafeeiros enxertados
Dias, Fábio Pereira;Castro, Daniel Melo de;Mendes, Ant?nio Nazareno Guimar?es;Vallone, Haroldo Silva;Carvalho, Alex Mendon?a de;Carvalho, Gladyston Rodrigues;
Ciência e Agrotecnologia , 2009, DOI: 10.1590/S1413-70542009000300011
Abstract: this work aimed at evaluating the anatomic features of grafted, self-grafted and ungrafted coffee tree stems. the longitudinal and transversal sections were performed at 30, 60, and 90 days after grafting in catucaí amarelo 2 sl and topázio mg 1190 (coffea arabica l.) cultivars, as well as in the apoat? rootstock. the results did not show evident signs of incompatibility of tissue reconstruction and formation between the cultivars studied.
ABO, Lewis, secretor and non-secretor phenotypes in patients infected or uninfected by the Helicobacter pylori bacillus
Mattos, Luiz Carlos de;Cintra, Juliana Rodrigues;Sanches, Fábio Eduardo;Silva, Rita de Cássia Martins Alves da;Ruiz, Milton Artur;Moreira, Haroldo Wilson;
Sao Paulo Medical Journal , 2002, DOI: 10.1590/S1516-31802002000200006
Abstract: context: epidemiological studies have demonstrated higher frequencies of the o blood group and the non-secretor phenotype of abh antigens among patients suffering from peptic ulcers. since helicobacter pylori has been established as the main etiological factor in this disease, controversies about the associations of the abo and lewis blood group phenotypes and secretor and non-secretor phenotypes in relation to susceptibility towards infection by this bacillus have been presented. objective: to verify the frequencies of abo, lewis blood group phenotypes, secretor and non-secretor phenotypes in patients infected or uninfected by h. pylori. design: cross-sectional study. setting: outpatient clinic. participants: one hundred and twenty patients with dyspeptic symptoms who underwent endoscopy.main measurements: abo and lewis blood group phenotypes were determined by a standard hemagglutination test and the secretor and non-secretor phenotypes were evaluated by saliva samples using the inhibitor hemagglutination test. results: the diagnosis of infection, made via breath and urea tests and confirmed using polymerase chain reaction (pcr) in gastric biopsy fragments, showed the presence of h. pylori in 61.7% of the patients and absence in 38.3%. the differences between the frequencies of the abo blood group phenotypes among infected (a 27.0%; b 12.2%; ab 4.0% and o 56.8%) and uninfected patients (a 58.7%; b 13.0%; ab 4.3% and o 24.0%) were significant. the lewis blood type, secretor and non-secretor phenotypes showed homogeneous distribution between the groups of patients analyzed. conclusions: our results suggest that the infection of h. pylori can be related to abo blood groups but not to the lewis blood group nor to secretor and non-secretor phenotypes.
The Effect of Different Irrigation Levels in Cowpea Production in the Mid-Northern Region of Tocantins—Brazil  [PDF]
Francisco Maurício Alves Francelino, Fábio Cunha Coelho, Carmen Maria Coimbra Manh?es, Danilo Gomes de Oliveira, Levi Rodrigues Neto, Mírian Peixoto Soares da Silva
American Journal of Climate Change (AJCC) , 2018, DOI: 10.4236/ajcc.2018.74033
Abstract: The objective of this study was to evaluate the effects of the application of irrigation levels in the productivity and water use efficiency, in the soil and climatic conditions of the municipality of Colinas do Tocantins, located in the Mid-Northern region of the State of Tocantins. The cowpea cultivation system was submitted to the application of five irrigation blades, based on ET0—Reference Evapotranspiration: Blade 0% of ET0, Blade 50% of ET0, Blade 75% of ET0, Blade 100% of ET0 and Blade 125% of ET0 (B0, B50, B75, B100 and B125% of ET0). The descriptive statistics were used to analyze the data, applying the 95% confidence interval to discriminate the differences between the treatments, since the replicates were constituted of 100 plants harvested at random within the plot for each treatment and no design method was performed. A significant effect of the different levels was found on all evaluated components, with the exception of the length of the pod, which did not differ in the irrigation levels. The increase in irrigation contributed to the increase of the results of the components that compete directly for higher productivity, such as number of pods per plant, weight of pods and number of seeds per pod. In these results, it was found that higher irrigation levels confer higher yields. Water-use efficiency—WUE behaved as per productivity trend, that is, it decreased with the reduction of irrigation levels.
Page 1 /332544
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.