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Search Results: 1 - 10 of 174500 matches for " Octavio E. Sousa "
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Trypanosoma rangeli sialidase: lack of activity in stocks from Panama and other regions
Sousa, Octavio E;Lombardo, Maritza;Salda?a, Azael;
Memórias do Instituto Oswaldo Cruz , 2005, DOI: 10.1590/S0074-02762005000300004
Abstract: a total of 33 crude and cloned trypanosoma rangeli stocks found as natural infections in human from panama and other endemic areas of central and south america were evaluated as producers of sialidase (sa) activity through the mu-nana fluorescence test. negative results were observed in 6 of the isolates: panama (4), honduras (1), and brazil (1). in addition, an immunoblotting analysis confirm the presence of the sa antigen in these stocks without enzymatic activity. these findings must be considered in the interpretation of the biological significance of t. rangeli sa and in the proper characterization and identification of this parasite.
Molecular characterization of human Trypanosoma cruzi isolates from endemic areas in Panama
Sousa, Octavio E;Samudio, Franklyn;Juncá, Corina de;Calzada, José E;
Memórias do Instituto Oswaldo Cruz , 2006, DOI: 10.1590/S0074-02762006000400018
Abstract: the present work provides information on trypanosoma cruzi genotype circulating in endemic areas of chagas disease in panama. a total of 26 crude stocks of t. cruzi, isolated from the blood of persons with different clinical profiles of chagas disease were collected and crio-conserved until used. most of the stocks had been characterized by means of isoenzyme electrophoresis on cellulose acetate membranes. the clinical profiles of infected persons included 9 (34.6%) asymptomatic and 17 acute (65.4%) including 5 (19.2%) fatal cases, 2 under 5 years old and 3 adults. a multiplex-pcr assay based on the amplification of the non-transcribed spacer of the mini-exon gene was performed. all stocks of t. cruzi included in the study were found to correspond to tc i group. this result supports the predominance of t. cruzi-i in the transmission cycles affecting the human population in the republic of panama.
AFLP Polymorphisms Allow High Resolution Genetic Analysis of American Tegumentary Leishmaniasis Agents Circulating in Panama and Other Members of the Leishmania Genus
Carlos M. Restrepo, Carolina De La Guardia, Octavio E. Sousa, José E. Calzada, Patricia L. Fernández, Ricardo Lleonart
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0073177
Abstract: American Tegumentary Leishmaniasis is caused by parasites of the genus Leishmania, and causes significant health problems throughout the Americas. In Panama, Leishmania parasites are endemic, causing thousands of new cases every year, mostly of the cutaneous form. In the last years, the burden of the disease has increased, coincident with increasing disturbances in its natural sylvatic environments. The study of genetic variation in parasites is important for a better understanding of the biology, population genetics, and ultimately the evolution and epidemiology of these organisms. Very few attempts have been made to characterize genetic polymorphisms of parasites isolated from Panamanian patients of cutaneous leishmaniasis. Here we present data on the genetic variability of local isolates of Leishmania, as well as specimens from several other species, by means of Amplified Fragment Length Polymorphisms (AFLP), a technique seldom used to study genetic makeup of parasites. We demonstrate that this technique allows detection of very high levels of genetic variability in local isolates of Leishmania panamensis in a highly reproducible manner. The analysis of AFLP fingerprints generated by unique selective primer combinations in L. panamensis suggests a predominant clonal mode of reproduction. Using fluorescently labeled primers, many taxon-specific fragments were identified which may show potential as species diagnostic fragments. The AFLP permitted a high resolution genetic analysis of the Leishmania genus, clearly separating certain groups among L. panamensis specimens and highly related species such as L. panamensis and L. guyanensis. The phylogenetic networks reconstructed from our AFLP data are congruent with established taxonomy for the genus Leishmania, even when using single selective primer combinations. Results of this study demonstrate that AFLP polymorphisms can be informative for genetic characterization in Leishmania parasites, at both intra and inter-specific levels.
Asymptotic Behavior of a Bi-Dimensional Hybrid System  [PDF]
Pedro Gamboa, Jaime E. Mu?oz, Octavio Vera, Margareth Alves
Applied Mathematics (AM) , 2015, DOI: 10.4236/am.2015.68115
Abstract: We study the asymptotic behavior of the solutions of a Hybrid System wrapping an elliptic operator.
Sexo do julgador, educa??o formal em Direito, e decis?o penal: O caso do processo-crime de viola??o frustrada envolvendo assimetria de estatuto
Análise Psicológica , 1997,
Abstract: this paper deals with knowledge, university law training and gender. it inspects legal and extra-legal variables in the case of a female rape-crime case involving assymetric social membership of both the victim and the offender. after reviewing recent literature on psychology, we hypothezised divergent perspectives as a function of gender, and of the configuration of membership of social groups of both the intervenients, as well as similar perspectives as a function of formal education (1st and 5th year of the university) in terms of representational complexity, inference and decision, be it legal components of the case, law-relevant and irrelevant inference itens or penal decisions in terms of both verdict and penalty. the results of multivariate analyses of variance revealed the importance of both the legal and the ex-tra-legal variables on the legal framing of the crime-case and inference. law training, which did neither have a significant effect on penalty nor on representational complexity, presented a significant effect on the legal components of the case, and produced less extreme irrelevant knowledge. also, judge's gender affected the legal components of the case, namely the perceived contribution of the victim, and penalty. females were slightly harsher. finally, the configuration of assymetric social membership of both the victim and the offender affected the legal framing of the case. results are discussed in terms of psychology, social justice and law considerations on rape.
Phase Diagram of the Two-Dimensional Ising Model with Random Competing Interactions
Octavio R. Salmon,J. Ricardo de Sousa,Fernando D. Nobre
Physics , 2009, DOI: 10.1016/j.physleta.2009.05.035
Abstract: An Ising model with ferromagnetic nearest-neighbor interactions $J_{1}$ ($J_{1}>0$) and random next-nearest-neighbor interactions [$+J_{2}$ with probability $p$ and $-J_{2}$ with probability $(1-p)$; $J_{2}>0$] is studied within the framework of an effective-field theory based on the differential-operator technique. The order parameters are calculated, considering finite clusters with $n=1,2, {\rm and} 4$ spins, using the standard approximation of neglecting correlations. A phase diagram is obtained in the plane temperature versus $p$, for the particular case $J_{1}=J_{2}$, showing both superantiferromagnetic (low $p$) and ferromagnetic (higher values of $p$) orderings at low temperatures.
The quantum J_{1}-J_{1'}-J_{2} spin-1/2 Heisenberg antiferromagnet: A variational method study
Orlando D. Mabelini,Octavio Salmon,J. Ricardo de Sousa
Physics , 2012, DOI: 10.1016/j.ssc.2013.03.019
Abstract: The phase transition of the quantum spin-1/2 frustrated Heisenberg antiferroferromagnet on an anisotropic square lattice is studied by using a variational treatment. The model is described by the Heisenberg Hamiltonian with two antiferromagnetic interactions: nearest-neighbor (NN) with different coupling strengths J_{1} and J_{1'} along x and y directions competing with a next-nearest-neighbor coupling J_{2} (NNN). The ground state phase diagram in the ({\lambda},{\alpha}) space, where {\lambda}=J_{1'}/J_{1} and {\alpha}=J_{2}/J_{1}, is obtained. Depending on the values of {\lambda} and {\alpha}, we obtain three different states: antiferromagnetic (AF), collinear antiferromagnetic (CAF) and quantum paramagnetic (QP). For an intermediate region {\lambda}_{1}<{\lambda}<1 we observe a QP state between the ordered AF and CAF phases, which disappears for {\lambda} above some critical value {\lambda}_{1}. The boundaries between these ordered phases merge at the quantum critical endpoint (QCE). Below this QCE there is again a direct first-order transition between the AF and CAF phases, with a behavior approximately described by the classical line {\alpha}_{c}{\simeq}{\lambda}/2.
Phylogeography and Genetic Variation of Triatoma dimidiata, the Main Chagas Disease Vector in Central America, and Its Position within the Genus Triatoma
María Dolores Bargues ,Debora R. Klisiowicz,Fernando Gonzalez-Candelas,Janine M. Ramsey,Carlota Monroy,Carlos Ponce,Paz María Salazar-Schettino,Francisco Panzera,Fernando Abad-Franch,Octavio E. Sousa,Christopher J. Schofield,Jean Pierre Dujardin,Felipe Guhl,Santiago Mas-Coma
PLOS Neglected Tropical Diseases , 2008, DOI: 10.1371/journal.pntd.0000233
Abstract: Background Among Chagas disease triatomine vectors, the largest genus, Triatoma, includes species of high public health interest. Triatoma dimidiata, the main vector throughout Central America and up to Ecuador, presents extensive phenotypic, genotypic, and behavioral diversity in sylvatic, peridomestic and domestic habitats, and non-domiciliated populations acting as reinfestation sources. DNA sequence analyses, phylogenetic reconstruction methods, and genetic variation approaches are combined to investigate the haplotype profiling, genetic polymorphism, phylogeography, and evolutionary trends of T. dimidiata and its closest relatives within Triatoma. This is the largest interpopulational analysis performed on a triatomine species so far. Methodology and Findings Triatomines from Mexico, Guatemala, Honduras, Nicaragua, Panama, Cuba, Colombia, Ecuador, and Brazil were used. Triatoma dimidiata populations follow different evolutionary divergences in which geographical isolation appears to have had an important influence. A southern Mexican–northern Guatemalan ancestral form gave rise to two main clades. One clade remained confined to the Yucatan peninsula and northern parts of Chiapas State, Guatemala, and Honduras, with extant descendants deserving specific status. Within the second clade, extant subspecies diversity was shaped by adaptive radiation derived from Guatemalan ancestral populations. Central American populations correspond to subspecies T. d. dimidiata. A southern spread into Panama and Colombia gave the T. d. capitata forms, and a northwestern spread rising from Guatemala into Mexico gave the T. d. maculipennis forms. Triatoma hegneri appears as a subspecific insular form. Conclusions The comparison with very numerous Triatoma species allows us to reach highly supported conclusions not only about T. dimidiata, but also on different, important Triatoma species groupings and their evolution. The very large intraspecific genetic variability found in T. dimidiata sensu lato has never been detected in a triatomine species before. The distinction between the five different taxa furnishes a new frame for future analyses of the different vector transmission capacities and epidemiological characteristics of Chagas disease. Results indicate that T. dimidiata will offer problems for control, although dwelling insecticide spraying might be successful against introduced populations in Ecuador.
Luciano Melo e Sousa
Olhar de Professor , 2012, DOI: 10.5212/olharprofr.v.15i1.0005
Abstract: This article reports the elaboration and implementation of three scientific initiation projects (PIBIC-Jr) carried out by high school students of a school for farmer families (EFA in the Portuguese acronym) in the municipality of Pedro II (PI), in partnership with the State University of Piauí. Citizenship development, knowledge building and the systematization of learning were some of the experiences lived by the students during the research initiative. For the university, theses experiences meant the opportunity to integrate research and outreach projects and a demonstration of its role in the democratization of our society. For the school, the experiences represented the opportunity to work in partnership and reading about its role in education. During one year, nineteen students and a professor, with the support of the school, developed three researches that reflected on the everyday dimensions of life in rural areas and the challenges for their development. Resumo: O presente artigo relata o processo de constru o e realiza o de três projetos de inicia o científica (PIBIC-Jr) protagonizados por alunos de ensino médio de uma EFA, no município de Pedro II (PI), em parceria com a Universidade Estadual do Piauí. Forma o cidad , constru o de saberes e sistematiza o de aprendizados foram experiências vividas pelos estudantes, provocadas pela iniciativa das pesquisas. Para a universidade, essas experiências representaram uma oportunidade de integra o entre pesquisa e extens o e demonstra o de seu papel na democratiza o de nossa sociedade. Para a escola, um exercício de parceria e leitura de sua fun o de educar. Durante um ano, dezenove estudantes e um professor universitário, com o apoio da escola, desenvolveram três pesquisas que refletiram sobre dimens es do cotidiano do campo e os desafios para seu desenvolvimento.
Colección grasa yuxtacava: variante anatómica que simula un tumor graso. Diagnóstico con TAC
Triana,Carlos E; Segura,Octavio; Suárez,Antonio;
Revista Colombiana de Gastroenterologia , 2003,
Abstract: a great benefit of ct is the possibility to measure body cissues density, specially to detect fact coefficients, given values between - 30 to 150 hounsfields units. other ct property is the optimal anatomic detail in transaxial slices, including vascular structures,which leads to diagnose non invasive pathology of inferior vena cava.
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