oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 164 )

2018 ( 288 )

2017 ( 309 )

2016 ( 467 )

Custom range...

Search Results: 1 - 10 of 230204 matches for " Valter R;Melo "
All listed articles are free for downloading (OA Articles)
Page 1 /230204
Display every page Item
Extension of the geographical distribution of some brachyuran and porcellanid decapods (Crustacea) to the coast of the State of S?o Paulo, Brazil
Alves, Douglas F. R.;Cobo, Valter J.;Melo, Gustavo A. S. de;
Revista Brasileira de Zoologia , 2006, DOI: 10.1590/S0101-81752006000400045
Abstract: investigations of the distribution of marine organisms provide a better understanding of the patterns of distribution and dispersal of these animals. extensions of the distributional limits of decapod crustaceans in brazilian waters have been recorded steadily and gradually, but these limits still remain poorly understood. the present study provides information extending the known range of eight species of brachyuran crabs and one species of porcellanid crab. the animals were obtained by scuba diving during a sampling program carried out near vitória island, ilhabela, on the northeastern coast of the state of s?o paulo (23o44'04"s-45o01'35"w) between february, 2004 and january, 2005. these new records extend the geographical distributions of the porcellanid petrolisthes amoenus (guérin menéville, 1855), the majoids mithrax caribbaeus rathbun, 1920, mithrax verrucosus h. milne edwards, 1832, nemausa acuticornis (stimpson, 1871) and teleophrys ornatus rathbun, 1901, and the xanthoids domecia acanthophora acanthophora (desbonne & schramm, 1867), garthiope spinipes (a. milne edwards, 1880), xanthodius denticulatus (white, 1847) and xanthodius parvulus (fabricius, 1793) to the s?o paulo coast. these new records may be related to different mechanisms of larval dispersal, larval transport by ballast water, or may simply be exceptional records.
Desidrata??o de etanol sobre material nanoestruturado do tipo LaSBA-15
Luz Jr, Geraldo E.;Melo, Ana C. R.;Lima, Stevie H.;Araujo, Ant?nio S.;Fernandes Jr., Valter J.;
Química Nova , 2010, DOI: 10.1590/S0100-40422010000800005
Abstract: la-incorporated sba-15 mesopourous molecular sieves (lasba-15) were directly synthesized with aim to convert ethanol to ethylene. the samples were characterized by xrd, xrf, nitrogen sorption and acidity, by thermodesorption of n-buthylamine. the results have indicated that all the samples have showed high ordered mesostructure with a large average pore size, and that the lanthanum incorporation has caused an increase in the acidity of the sba-15. the lasba-15 samples have improved, with low deactivation rate, the conversion of the ethanol to water, ether, acetaldehyde and ethylene. in addition, they have increased the ethylene selectivity.
Desafios e oportunidades para o agronegócio da cebola no Brasil
Vilela, Nirlene J.;Makishima, Nozomu;Oliveira, Valter R.;Costa, Nivaldo D.;Madail, Jo?o Carlos M.;Camargo Filho, Waldemar P.;Boeing, Guido;Melo, Paulo César T. de;
Horticultura Brasileira , 2005, DOI: 10.1590/S0102-05362005000400034
Abstract: the main objective of this work was to describe some socieconomic aspects of the onion production in brazil and to detect the principal challenges and opportunities for the onion agribusiness. the onion cultivation in brazil is a family activity (88%), generating about 250 thousand jobs directly involved in the production. the onion consumption in brazil is nearly 85 thousand t per month. with the consolidation of the mercosul, the onion import from argentina and the national production has caused excess of supply in some months, generating losses and consequent damages for the producers. the brazilian productive sector needs to improve the technological level of the onion production to reach greater technical and economic efficiency. however, it is necessary that brazilian and argentinian producers look for a better production forecast to avoid excess of supply during some periods of the year.
Diversidade genética em germoplasma tropical de cebola estimada via marcadores RAPD
Santos, Maria do Desterro M dos;Ragassi, Carlos Francisco;Fonseca, Maria Esther de N;Buzar, Anne Gizelle R;Oliveira, Valter R;Melo, Paulo César T de;Boiteux, Leonardo S;
Horticultura Brasileira , 2012, DOI: 10.1590/S0102-05362012000100019
Abstract: onion is a crop of significant socioeconomic importance to brazil. onion germplasm with adaptation to tropical and sub-tropical conditions has played an important role in the development of this crop in the country. in this context, we studied the genetic diversity in a germplasm collection potentially useful for the development of cultivars for tropical and subtropical regions. the genetic variability of 21 accessions/cultivars that have been used as germplasm and/or were developed by onion breeding programs in brazil was evaluated via rapd markers. the following accessions were included in the study :'red creole', 'roxa ipa-3', 'valenciana 14', 'beta cristal', 'diamante', 'composto ipa-6', 'aurora', 'bojuda rio grande', 'alfa tropical', 'pêra ipa-4', 'primavera', 'belém ipa-9', 'crioula alto vale', 'conquista', 'pira-ouro', 'vale-ouro ipa-11', 'franciscana ipa-10', 'serrana', 'cnph 6400', 'petroline', and 'baia periforme'. from the 520 primers used in the initial screening only 38 displayed stable polymorphisms. they produced 624 amplicons, of which 522 (83.7%) were monomorphic and 102 (16.3%) were polymorphic. an average similarity coefficient of 0.72 was calculated among accessions based upon this subgroup of polymorphic amplicons. this allowed the discrimination of this germplasm collection into six groups with only one of them comprising more than one accession. the main group was formed by 16 accessions ('diamante', 'composto ipa-6', 'aurora', 'bojuda rio grande', 'conquista', 'pira-ouro', 'serrana', 'vale-ouro ipa-11', 'baia periforme', 'primavera', 'franciscana ipa-10', 'belém ipa-9', 'crioula alto vale', 'petroline', 'pêra ipa-4' and 'alfa tropical'), for which the genetic origin (with few exceptions) can be traced back to the variety 'baia periforme'. the populations 'red creole', 'roxa ipa-3', 'beta cristal', 'cnph 6400', and 'valenciana 14' comprised a set of five isolated groups, showing genetic divergence among them and in relation to main 'baia perif
In vitro inhibition of Plasmodium falciparum by substances isolated from Amazonian antimalarial plants
Andrade-Neto, Valter F de;Pohlit, Adrian M;Pinto, Ana Cristina S;Silva, Ellen Cristina C;Nogueira, Karla L;Melo, Márcia RS;Henrique, Marycleuma C;Amorim, Rodrigo CN;Silva, Luis Francisco R;Costa, M?nica RF;Nunomura, Rita CS;Nunomura, Sergio M;Alecrim, Wilson D;Alecrim, M das Gra?as C;Chaves, F Célio M;Vieira, Pedro Paulo R;
Memórias do Instituto Oswaldo Cruz , 2007, DOI: 10.1590/S0074-02762007000300016
Abstract: in the present study, a quassinoid, neosergeolide, isolated from the roots and stems of picrolemma sprucei (simaroubaceae), the indole alkaloids ellipticine and aspidocarpine, isolated from the bark of aspidosperma vargasii and a. desmanthum (apocynaceae), respectively, and 4-nerolidylcatechol, isolated from the roots of pothomorphe peltata (piperaceae), all presented significant in vitro inhibition (more active than quinine and chloroquine) of the multi-drug resistant k1 strain of plasmodium falciparum. neosergeolide presented activity in the nanomolar range. this is the first report on the antimalarial activity of these known, natural compounds. this is also the first report on the isolation of aspidocarpine from a. desmanthum. these compounds are good candidates for pre-clinical tests as novel lead structures with the aim of finding new antimalarial prototypes and lend support to the traditional use of the plants from which these compounds are derived.
Biological activity of neosergeolide and isobrucein B (and two semi-synthetic derivatives) isolated from the Amazonian medicinal plant Picrolemma sprucei (Simaroubaceae)
Silva, Ellen CC;Cavalcanti, Bruno C;Amorim, Rodrigo CN;Lucena, Jorcilene F;Quadros, Dulcimar S;Tadei, Wanderli P;Montenegro, Raquel C;Costa-Lotufo, Letícia V;Pessoa, Cláudia;Moraes, Manoel O;Nunomura, Rita CS;Nunomura, Sergio M;Melo, Marcia RS;Andrade-Neto, Valter F de;Silva, Luiz Francisco R;Vieira, Pedro Paulo R;Pohlit, Adrian M;
Memórias do Instituto Oswaldo Cruz , 2009, DOI: 10.1590/S0074-02762009000100008
Abstract: in the present study, in vitro techniques were used to investigate a range of biological activities of known natural quassinoids isobrucein b (1) and neosergeolide (2), known semi-synthetic derivative 1,12-diacetylisobrucein b (3), and a new semi-synthetic derivative, 12-acetylneosergeolide (4). these compounds were evaluated for general toxicity toward the brine shrimp species artemia franciscana, cytotoxicity toward human tumour cells, larvicidal activity toward the dengue fever mosquito vector aedes aegypti, haemolytic activity in mouse erythrocytes and antimalarial activity against the human malaria parasite plasmodium falciparum. compounds 1 and 2 exhibited the greatest cytotoxicity against all the tumor cells tested (ic50 = 5-27 μg/l) and against multidrug-resistant p. falciparum k1 strain (ic50 = 1.0-4.0 g/l) and 3 was only cytotoxic toward the leukaemia hl-60 strain (ic50 = 11.8 μg/l). quassinoids 1 and 2 (lc50 = 3.2-4.4 mg/l) displayed greater lethality than derivative 4 (lc50 = 75.0 mg/l) toward a. aegypti larvae, while derivative 3 was inactive. these results suggest a novel application for these natural quassinoids as larvicides. the toxicity toward a. franciscana could be correlated with the activity in several biological models, a finding that is in agreement with the literature. importantly, none of the studied compounds exhibited in vitro haemolytic activity, suggesting specificity of the observed cytotoxic effects. this study reveals the biological potential of quassinoids 1 and 2 and to a lesser extent their semi-synthetic derivatives for their in vitro antimalarial and cytotoxic activities.
Lobectomia temporal no infarto cerebral com efeito de massa
Martins, Luis Fernando;Costa, Valter da;Costa, Joaquim da;Melo-Souza, Sebasti?o Eurico de;
Arquivos de Neuro-Psiquiatria , 1993, DOI: 10.1590/S0004-282X1993000100019
Abstract: cerebral edema secondary to ischemia can threaten life, mainly due to frequent failure of medical management. imminent herniation of the temporal lobe can be timely detected by clinical signs and ct-scan. eight patients (4m, 4f; 48-74 years, mean 62) with ischemic stroke and imminent herniation, were surgically decompressed by a standard temporal lobectomy as described by olivier for temporal lobe epilepsy. six patients survived, two died and were considered failure of the procedure, probably due to late surgical indication. in conclusion, temporal lobectomy is life-saving for patients with large ischemic cerebral infarction with mass effect land deteriorating signs of brain stem compression.
Desigualdades associadas à n o realiza o de mamografia na zona urbana de Teresina-Piauí-Brasil, 2010-2011 Inequalities associated with lack of mammography in Teresina-Piauí-Brazil, 2010-2011
Rafael Bandeira Lages,Giuliano da Paz Oliveira,Valter Morais Sime?o Filho,Felipe Melo Nogueira
Revista Brasileira de Epidemiologia , 2012,
Abstract: FUNDAMENTOS: Estudos demonstram que a realiza o da mamografia em programas de rastreamento diminui a mortalidade do cancer de mama. Entretanto, há indícios de grande desigualdade no acesso à realiza o deste exame no Brasil. OBJETIVOS: Analisar o percentual de mulheres que n o realizaram mamografia segundo variáveis socioecon micas e demográficas em mulheres de 40 a 69 anos de Teresina-PI. MéTODOS: Estudo transversal realizado em 2010/2011, com amostragem multifásica em cinco etapas, realizando-se entrevista face a face com cada mulher sorteada. Processou-se os dados com programa SPSS 19.0, realizando-se análise uni e multivariada. RESULTADOS: Dentre as 433 mulheres que responderam o questionário, a taxa de realiza o de mamografia foi de 75,3%,sendo que, destas, 17,2% a haviam realizado há mais de dois anos. A n o realiza o de mamografia esteve relacionada com ra a parda/negra (p = 0,030), ausência de companheiro (p = 0,041), menor grau de instru o (p = 0,010), menor renda (p < 0,001), tabagismo (p = 0,006), n o possuir plano ou seguro de saúde (p < 0,001). O Sistema único de Saúde (SUS) foi responsável por realizar 56,3% das mamografias. CONCLUS O: 24,7% das mulheres teresinenses nunca haviam realizado mamografia e 37,9% n o a haviam realizado nos últimos dois anos. A n o realiza o deste exame foi associada à existência de desigualdades racial e socioecon mica. INTRODUCTION: Randomized studies have shown that screening for breast cancer with mammography reduces the breast cancer mortality. However there are signs of a great inequality in access to mammography in Brazil. OBJECTIVES: To analyze the percentage of women who did not undergo mammography according to socioeconomic and demographic variables in women aged from 40 to 69 years in Teresina, Piauí State, Brazil. METHODS: This was a cross-sectional population-based study in women aged 40-69 years in Teresina-Piauí in 2010/2011. The sampling was randomly conducted in five stages. The data were processed by SPSS 19.0 and it was performed univariate and multivariate analysis. RESULTS: Among 433 women who answered the questionnaire, 75,3% had a mammography and 17,2% of these women had not a mammography over the last two years. The lack of breast cancer screening was associated with non-white skin color (p = 0,030), never being married (p = 0,041), low levels of education (p = 0,010), low family income (p < 0,001), smoking (p = 0,006), having no private health insurance (p < 0,001). The Unified National Health System (SUS) performed 56,3% of reported mammograms. CONCLUSION: About 24.7% of women in t
Estimativa da diversidade genética de germoplasma de cebola via descritores morfológicos, agron?micos e bioquímicos
Buzar, Anne Giselle R;Oliveira, Valter R;Boiteux, Leonardo S;
Horticultura Brasileira , 2007, DOI: 10.1590/S0102-05362007000400007
Abstract: the genetic diversity of 64 tropical and subtropical onion accessions (allium cepa l.) belonging to the embrapa hortali?as collection was estimated using 23 morphological, agronomic, and biochemical descriptors. methods of multivariate statistical analysis (mahalanobis' d2 distances, tocher's cluster analysis and nearest-neighbor method) were employed in order to obtain the average genetic distances among accessions and to perform the clustering. the onion germplasm displayed a relatively large genetic base. cultivars ex 3000 and régia were the two most similar accessions. the highest mean genetic distance was observed between cultivars val 14 and beta cristal. the tocher's optimization method revealed the formation of 13 groups, whereas the nearest-neighbor method revealed the formation of 12 groups (cutting point of 43% of dissimilarity. the majority of the accessions belonging to grano and granex cultivars (agronomically classified as short-day and early-maturing types) clustered together in the same group. the white bulb accessions for processing (beta cristal; dehydrator # 8; dehydrator # 6; primero and white creole), with the exception of tampico white, displayed a small genetic divergence. the accessions tx 24, baia periforme super precoce, ex 3001, excel, red creole, h 688, franciscana ipa 10 and roxa ipa 3 displayed a large genetic divergence. the descriptors total sugar content, bulb length, number of days from planting to harvesting (i.e. plant cycle), percentage of bulbs with transversal diameter between 70 and 90 mm, and average bulb weight were responsible for 58% of the genetic variability present among accessions. studies of divergence among accessions are important to choose divergent parentals but complementary genetic materials would allow the development of useful segregating populations with wide genetic basis for tropical onion breeding programs.
Crítica e contradi??o: qual heran?a marxista?
Melo, Rúrion;
Novos Estudos - CEBRAP , 2011, DOI: 10.1590/S0101-33002011000200003
Abstract: in his book trabalho e reflex?o [labor and reflexivity], josé arthur giannotti's considerations about late capitalist rationality forces him to develop some of marx's original concepts. this article offers a critical reading of the consequences of a renewd understanding of the dialectics of capitalist sociability elaborated by giannotti for the survival of a marxist critical legacy that aims at refreshing marx's immanent critique of capitalism.
Page 1 /230204
Display every page Item


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