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Search Results: 1 - 10 of 18959 matches for " Manoel Victor Franco;Romano "
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Identifica??o de genes cry de Bacillus thuringiensis no controle de Sphenophorus levis, o bicudo da cana-de-a?úcar
Cícero, Elaine Aparecida Silva;Ferraudo, Antonio Sergio;Lemos, Manoel Victor Franco;
Bragantia , 2009, DOI: 10.1590/S0006-87052009000400001
Abstract: bacillus thuringiensis is well known for its ability to produce toxic proteins to different insect orders which are encoded by the cry genes. this work was carried out aiming to select among different b. thuringiensis isolates, by morphological and molecular characterization, identifying different classes of cry3 and cry35 genes, and to determine the level of pathogenicity against sphenophorus levis larvae, which is one of the most important sugar-cane pests in brazil. a total of 1163 bacterial isolates were used in this survey in which phase microscopy and molecular markers were used for evaluation that resulted in 30 isolates positive for cry3 and cry35 genes potentially active against coleopterans. these bacterial isolates together with type strains such as b. thuringiensis var. tenebrionis, b.t. var. morrissone e b.t. var. tolworthi were used in bioassays using sphenophorus levis larvae. using discriminating analysis four groups of isolates were produced when b. thuringiensis toxicity was taken into account. these groups involved one set of two isolates with up to 10% mortality; another set caused mortality of up to 39% and was made up of ten isolates and three type strains; another set caused mortality of up to 52% containing thirteen isolates and a last set of isolated whose mortality index was 70% containing only five isolates which were considered promising bacterial strains for biological control of s. levis.
Requirement for cobalamin by Salmonella enterica serovars Typhimurium, Pullorum, Gallinarum and Enteritidis during infection in chickens
Paiva, Jacqueline Boldrin de;Penha Filho, Rafael Antonio Casarin;Berchieri Junior, Angelo;Lemos, Manoel Victor Franco;
Brazilian Journal of Microbiology , 2011, DOI: 10.1590/S1517-83822011000400024
Abstract: salmonella enterica serovar typhimurium synthesizes cobalamin (vitamin b12) only during anaerobiosis. two percent of the s. typhimurium genome is devoted to the synthesis and uptake of vitamin b12 and to b12-dependent reactions. to understand the requirement for cobalamin synthesis better, we constructed mutants of salmonella serovars enteritidis and pullorum that are double-defective in cobalamin biosynthesis (δcobsδcbia). we compared the virulence of these mutants to that of their respective wild type strains and found no impairment in their ability to cause disease in chickens. we then assessed b12 production in these mutants and their respective wild type strains, as well as in s. typhimurium δcobsδcbia, salmonella gallinarum δcobsδcbia, and their respective wild type strains. none of the mutants was able to produce detectable b12. b12 was detectable in s. enteritidis, s. pullorum and s. typhimurium wild type strains but not in s. gallinarum. in conclusion, the production of vitamin b12 in vitro differed across the tested salmonella serotypes and the deletion of the cbia and cobs genes resulted in different levels of alteration in the host parasite interaction according to salmonella serotype tested.
Expression of the sigma35 and cry2AB genes involved in Bacillus thuringiensis virulence
Guidelli-Thuler, Ana Maria;Abreu, Irlan Leite de;Lemos, Manoel Victor Franco;
Scientia Agricola , 2009, DOI: 10.1590/S0103-90162009000300016
Abstract: there are several genes involved in bacillus thuringiensis sporulation. the regulation and expression of these genes results in an upregulation in cry protein production, and this is responsible for the death of insect larvae infected by bacillus thuringiensis. gene expression was monitored in bacillus thuringiensis during three developmental phases. dna macroarrays were constructed for selected genes whose sequences are available in the genbank database. these genes were hybridized to cdna sequences from b. thuringiensis var. kurstaki hd-1. cdna probes were synthesized by reverse transcription from b. thuringiensis rna templates extracted during the exponential (log) growth, stationary and sporulation phases, and labeled with 33padctp. two genes were differentially expressed levels during the different developmental phases. one of these genes is related to sigma factor (sigma35), and the other is a cry gene (cry2ab). there were differences between the differential levels of expression of various genes and among the expression detected for different combinations of the sigma factor and cry2ab genes. the maximum difference in expression was observed for the gene encoding sigma35 factor in the log phase, which was also expressed at a high level during the sporulation phase. the cry2ab gene was only expressed at a high level in the log phase, but at very low levels in the other phases when compared to the sigma35.
Molecular differentiation between Salmonella enterica subsp enterica serovar Pullorum and Salmonella enterica subsp enterica serovar Gallinarum
Ribeiro, Simone Alves Mendes;Paiva, Jaqueline Boldrin de;Zotesso, Fábio;Lemos, Manoel Victor Franco;Berchieri Júnior, ?ngelo;
Brazilian Journal of Microbiology , 2009, DOI: 10.1590/S1517-83822009000100032
Abstract: s. pullorum (sp) and s. gallinarum (sg) are very similar. they are the agents of pullorum disease and fowl typhoid, respectively, and the two diseases are responsible for economic losses in poultry production. although sp and sg are difficult to be differentiated in routine laboratory procedures, the ability to metabolize ornithine is a biochemical test that may be used to achieve this aim. while sp is able to decarboxylate this amino acid, sg is not. however, the isolation of strains showing atypical biochemical behavior has made this differentiation difficult. one of the genes associated with the metabolization of the amino acid ornithine is called spec, and is found in both serovars. the analysis of 21 sp and 15 sg strains by means of pcr did not enable the differentiation of the two serovars, because fragments produced were identical. however, after enzymatic treatment with restriction enzyme eco ri, the band pattern of each serovar showed to be different, even in samples of atypical biochemical behavior. this fact enabled the standardization of the technique for a quick and safe differentiation of serovars pullorum and gallinarum.
Diversidade filogenética de archaea metanogênica em dietas com diferentes propor??es de feno
Neves,Marta de Campos; Kishi,Luciano Takeshi; Alves,Eliane Cristina da Cunha; Ezequiel,Jane Maria Bertocco; Lemos,Manoel Victor Franco;
Revista de Ciências Agrárias , 2010,
Abstract: the objective of this research was to detect the presence of archaea in the bovine rumen using genetic sequences from the conserved region of the 16s rdna. samples were collected from bovines that were fed two different experimental dietetic ratios of roughage to concentrate. the 16s rdna region was amplified using pcr and analyzed using the phred/phrap/consed programs. for the treatment with 70% hay diet 96 sequences related to the methanobacteriaceae family, 47 sequences from non-cultured archaea, and 60 sequences from unknown archaea were identified by the blast analysis. for the treatment with 30% hay diet the blast analysis identified 125 sequences belonging to the methanobacteriaceae fa-mily 42 sequences from non-cultured archaea, and 32 sequences from unknown archaea. the analysis of the 16s rdna sequences of archaea collected from the bovine rumen, allows more sequences matching the unknown archaea were identified in the treatment with 70% hay.
Molecular characterization of accessions of crabgrass (Digitaria nuda) and response to ametryn = Caracteriza o molecular de acessos de capim-colch o (Digitaria nuda) e resposta à ametrina
Viviane Cristina Vieira,Pedro Luís da Costa Aguiar Alves,Simone Cristina Picchi,Manoel Victor Franco Lemos
Acta Scientiarum : Agronomy , 2010,
Abstract: Digitaria species are sugar cane crop weeds in Brazil and are being controlled with herbicides, although there are some reports of control failure, notably to the triazine group. Molecular techniques are recommended to analyze the genetic variability in weeds. RAPD (Random Amplified Polymorphic DNA), PCR-RFLP (Polymerase Chain Reaction – Restriction Fragment Length Polymorphism) and, in combination with sequencing, allow the localization of resistance genes, as well as possible mutations related to the onset of resistant individuals in some species. Thus, the objective of this work was to characterize ten accessions of Digitaria spp. by RAPD and PCR-RFLP markers, to sequence a conserved region of the psbA gene and evaluate the accessions response to ametryn. As showed by molecular analysis there was high genetic similarity among the accessions, all of them presented similar genetics profiles and were susceptible to ametryn. As espécies de Digitaria s o plantas daninhas nas lavouras de cana-dea úcar no Brasil e est o sendo controladas com herbicidas, porém há alguns relatos de falha no controle, notavelmente ao grupo das triazinas. Técnicas moleculares s o recomendadas para análise da variabilidade genética em plantas daninhas, como o RAPD (DNA Polimórfico Amplificado ao Acaso) e PCR-RFLP (Rea o da Polimerase em Cadeia – Polimorfismo no Comprimento de Fragmentos de Restri o) e, aliadas ao sequenciamento, permitem a localiza o de genes de resistência, bem como possíveis muta es relacionadas ao surgimento de indivíduos resistentes em algumas espécies. Com isso, o objetivo deste trabalho foi caracterizar dez acessos de Digitaria spp. por meio de marcadores RAPD e PCR-RFLP, sequenciar uma regi o conservada do gene psbA e analisar a resposta destes à ametrina. Pela análise molecular houve elevada similaridade genética entre os acessos, pois todos apresentaram perfis genéticos semelhantes e foram suscetíveis à ametrina.
Fluorescent amplified fragment length polymorphism (fAFLP) analyses and genetic diversity in Litopenaeus vannamei (Penaeidae)
Gon?alves, Michelle Mantovani;Lemos, Manoel Victor Franco;Galetti Junior, Pedro Manoel;Freitas, Patrícia Domingues de;Furtado Neto, Manuel Antonio Andrade;
Genetics and Molecular Biology , 2005, DOI: 10.1590/S1415-47572005000200016
Abstract: the pacific white shrimp, litopenaeus vannamei (penaeidae), represents about 95% of all brazilian shrimp production. the brazilian l. vannamei foundation broodstock was made up of specimens collected from different american pacific sites, but little information was collected on the genetic structure of the broodstock. we used the fluorescence amplified fragment length polymorphism (faflp) method to study the genetic diversity of l. vannamei broodstock lines 03cmf1 and 03cbf1 originally produced by breeder-shrimps imported mainly from panama and ecuador, although wild individuals from other localities may also have been used in producing these two lines. our results showed a total of 93 polymorphic bands ranging from 50 to 500 bp, the mean nei's genetic diversity calculated for the total sample was 13.4% and identity and genetic distance analyses indicated high genetic homogeneity within and between both the broodstock lineages studied which suggests that they had similar genetic structure. these results may represent an important tool for the appropriate management of l. vannamei broodstocks.
Brazilian coffee genome project: an EST-based genomic resource
Vieira, Luiz Gonzaga Esteves;Andrade, Alan Carvalho;Colombo, Carlos Augusto;Moraes, Ana Heloneida de Araújo;Metha, ?ngela;Oliveira, Angélica Carvalho de;Labate, Carlos Alberto;Marino, Celso Luis;Monteiro-Vitorello, Claúdia de Barros;Monte, Damares de Castro;Giglioti, éder;Kimura, Edna Teruko;Romano, Eduardo;Kuramae, Eiko Eurya;Lemos, Eliana Gertrudes Macedo;Almeida, Elionor Rita Pereira de;Jorge, érika C.;Albuquerque, érika V. S.;Silva, Felipe Rodrigues da;Vinecky, Felipe;Sawazaki, Haiko Enok;Dorry, Hamza Fahmi A.;Carrer, Helaine;Abreu, Ilka Nacif;Batista, Jo?o A. N.;Teixeira, Jo?o Batista;Kitajima, Jo?o Paulo;Xavier, Karem Guimar?es;Lima, Liziane Maria de;Camargo, Luis Eduardo Aranha de;Pereira, Luiz Filipe Protasio;Coutinho, Luiz Lehmann;Lemos, Manoel Victor Franco;Romano, Marcelo Ribeiro;Machado, Marcos Antonio;Costa, Marcos Mota do Carmo;Sá, Maria Fátima Grossi de;Goldman, Maria Helena S.;Ferro, Maria Inês T.;Tinoco, Maria Laine Penha;Oliveira, Mariana C.;Van Sluys, Marie-Anne;Shimizu, Milton Massao;Maluf, Mirian Perez;Eira, Mirian Therezinha Souza da;Guerreiro Filho, Oliveiro;Arruda, Paulo;Mazzafera, Paulo;Mariani, Pilar Drummond Sampaio Correa;Oliveira, Regina L.B.C. de;Harakava, Ricardo;Balbao, Silvia Filippi;Tsai, Siu Mui;Mauro, Sonia Marli Zingaretti di;Santos, Suzana Neiva;Siqueira, Walter José;Costa, Gustavo Gilson Lacerda;Formighieri, Eduardo Fernandes;Carazzolle, Marcelo Falsarella;Pereira, Gon?alo Amarante Guimar?es;
Brazilian Journal of Plant Physiology , 2006, DOI: 10.1590/S1677-04202006000100008
Abstract: coffee is one of the most valuable agricultural commodities and ranks second on international trade exchanges. the genus coffea belongs to the rubiaceae family which includes other important plants. the genus contains about 100 species but commercial production is based only on two species, coffea arabica and coffea canephora that represent about 70 % and 30 % of the total coffee market, respectively. the brazilian coffee genome project was designed with the objective of making modern genomics resources available to the coffee scientific community, working on different aspects of the coffee production chain. we have single-pass sequenced a total of 214,964 randomly picked clones from 37 cdna libraries of c. arabica, c. canephora and c. racemosa, representing specific stages of cells and plant development that after trimming resulted in 130,792, 12,381 and 10,566 sequences for each species, respectively. the ests clustered into 17,982 clusters and 32,155 singletons. blast analysis of these sequences revealed that 22 % had no significant matches to sequences in the national center for biotechnology information database (of known or unknown function). the generated coffee est database resulted in the identification of close to 33,000 different unigenes. annotated sequencing results have been stored in an online database at http://www.lge.ibi.unicamp.br/cafe. resources developed in this project provide genetic and genomic tools that may hold the key to the sustainability, competitiveness and future viability of the coffee industry in local and international markets.
Characterization and selection of Bacillus thuringiensis isolates effective against Sitophilus oryzae
Silva, Najara da;Thuler, Ana Maria Guidelli;Abreu, Irlan Leite de;Davolos, Camila Chiaradia;Polanczyk, Ricardo Antonio;Lemos, Manoel Victor Franco;
Scientia Agricola , 2010, DOI: 10.1590/S0103-90162010000400015
Abstract: the entomopathogenic bacterium bacillus thuringiensis is a control agent with toxic and environmental characteristics that allows the control of pest insects according to the integrate pest management (ipm) precepts. in order to find new strains, potentially toxic to sitophilus oryzae l. 1763 (coleoptera: curculinidae), 1.073 strains of b. thuringiensis from parts of brazil were used. genetic material was extracted with instagene matrix kit, used for the amplification of sequences in polymerase chain reaction (pcr), and viewed in 1.5% agarose gel. the gene cry35ba class was represented by 60 b. thuringiensis isolates (5.6%), which were then subjected to bioassays with s. oryzae larvae. among the isolates studied, four caused more than 50% mortality in pathogenicity tests, and the isolates 544 and 622 were the most virulent, as determined by cl50 estimates. the four toxic isolates had spherical, bi-pyramidal and cuboid crystals, and a 44-kda protein was found in sodium dodecyl sulphate - polyacrylamide gel electrophoresis (sds-page), which coded for the product of cry35ba genes. these data demonstrate the potential of b. thuringiensis for the management of s. oryzae larvae.
Electron-hydrogen excitation to the n=3 and n=4 levels in the Glauber approximation
Victor Franco
Physics , 2005,
Abstract: We have calculated the differential and integrated cross sections for excitation of atomic hydrogen to its n=3 and n=4 levels by electron impact using the Glauber approximation. Results are compared with measurements at 20, 30, 40, and 60 eV and also shown for 120 and 480 eV. At momentum transfers not too large at all energies considered, the calculated n=3 differential cross sections are qualitatively similar to but a factor of somewhat less than 3 larger than the calculated n=4 cross sections. The calculated integrated cross sections attain broad maxima near 41 eV.
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