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Search Results: 1 - 10 of 204615 matches for " Raquel N Afonso-Lehmann "
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Microscopy and molecular biology for the diagnosis and evaluation of malaria in a hospital in a rural area of Ethiopia
Maria A Santana-Morales, Raquel N Afonso-Lehmann, Maria A Quispe, Francisco Reyes, Pedro Berzosa, Agustin Benito, Basilio Valladares, Enrique Martinez-Carretero
Malaria Journal , 2012, DOI: 10.1186/1475-2875-11-199
Abstract: A cross-sectional survey of 471 individuals was carried out in a hospital in the rural area of Gambo (Ethiopia). Blood samples were prepared for microscopic observation and collected in filter paper for Seminested-Multiplex PCR (SnM-PCR) and real time PCR (qPCR) testing. The SnM-PCR was considered as the gold standard technique and compared with the rest. Thus, agreement between SnM-PCR and LM was determined by calculating Kappa Statistics and correlation between LM and qPCR quantification was calculated by pair-wise correlation co-efficient.Samples analysed by LM and SnM-PCR were positive for Plasmodium sp. 5.5% and 10.5%, respectively. Sensitivity was 52.2% by LM and 70% by qPCR. Correlation co-efficient between microscopy counts and qPCR densities for Plasmodium vivax was R2?=?0.586. Prevalence was estimated at 7% (95% CI: 4.7–9.3). Plasmodium vivax was the dominant species detected and the difference was statistically significant (χ2?=?5.121 p?<?0.05). The highest prevalence of the parasite (10.9%) was observed in age groups under 15?years old.Accurate malaria diagnostic methods have a great effect in the reduction of the number of malaria-infected individuals. SnM-PCR detection of malaria parasites may be a very useful complement to microscopic examination in order to obtain the real prevalence of each Plasmodium species. Although SnM-PCR shows that it is a good tool for the determination of Plasmodium species, today light microscopy remains the only viabletool for malaria diagnosis in developing countries. Therefore, re-inforcement in the training of microscopists is essential for making the correct diagnosis of malaria. Plasmodium vivax was the predominant species in Gambo, a meso-endemic area for this species.
Producción de materiales en lámina delgada mediante técnicas láser
Afonso, C. N.
Revista de Metalurgia , 1998,
Abstract: Pulsed laser deposition is a recently developed technique with a large potential in producing materials of technological interest that are not easily produced by more conventional techniques, such as complex oxides or hard ceramics. We will first review the special features of this technique to then show current results of our own research in producing optically doped waveguides either with rare-earth ions or metal nanoparticles. Mediante la moderna técnica de depósito por láser pulsado (PLD) se pueden obtener materiales de alto interés tecnológico, como son óxidos complejos o cerámicas duras que no son fáciles de obtener por otras técnicas más convencionales. En el presente trabajo, se revisan, en primer lugar, las características especiales de esta técnica. A continuación, se presentan los resultados obtenidos en las investigaciones actualmente en marcha en nuestro laboratorio sobre dopado óptico de materiales mediante especies activas, como los iones de tierras raras o partículas nanocristalinas en matrices aislantes.
A evolu??o da balan?a analítica
Afonso, Júlio Carlos;Silva, Raquel Medeiros da;
Química Nova , 2004, DOI: 10.1590/S0100-40422004000600030
Abstract: this work intends to describe the historical evolution of the balance based on its technical improvement. this instrument has always been used for commercial and industrial purposes, but its value in research and chemistry was only recognized much later. the classical balance was the two-pan model for about 40 centuries, but when its importance in chemistry was established, particularly beginning at the end of the xviiith century, many improvements were made in order to increase sensitivity and shorten the weighing procedure. the balance design greatly changed along the xxth century: the classical two-pan models were replaced by one-pan balances that were replaced by electronic instruments.
A evolu o da balan a analítica
Afonso Júlio Carlos,Silva Raquel Medeiros da
Química Nova , 2004,
Abstract: This work intends to describe the historical evolution of the balance based on its technical improvement. This instrument has always been used for commercial and industrial purposes, but its value in research and chemistry was only recognized much later. The classical balance was the two-pan model for about 40 centuries, but when its importance in chemistry was established, particularly beginning at the end of the XVIIIth century, many improvements were made in order to increase sensitivity and shorten the weighing procedure. The balance design greatly changed along the XXth century: the classical two-pan models were replaced by one-pan balances that were replaced by electronic instruments.
Charge-induced conformational changes of dendrimers
Ronald Blaak,Swen Lehmann,Christos N. Likos
Physics , 2008, DOI: 10.1021/ma800283z
Abstract: We study the effect of chargeable monomers on the conformation of dendrimers of low generation by computer simulations, employing bare Coulomb interactions. The presence of the latter leads to an increase in size of the dendrimer due to a combined effect of electrostatic repulsion and the presence of counterions within the dendrimer, and also enhances a shell-like structure for the monomers of different generations. In the resulting structures the bond-length between monomers, especially near the center, will increase to facilitate a more effective usage of space in the outer-regions of the dendrimer.
La Medición de la Eficiencia Universitaria: Una Aplicación del Análisis Envolvente de Datos
Martín,Raquel;
Formación universitaria , 2008, DOI: 10.4067/S0718-50062008000200004
Abstract: the degree of technical efficiency with which university departments develop their activities is analyzed. as study case the analysis is done using data for one academic year in the university of la laguna in spain. the methodology used is the data envolvent analysis, method that allows knowing better the functioning of the university departments. in addition, the methodology gives information to improve efficiency and to facilitate the university management. the most important conclusion of the study is that the resources assigned to higher education can be improved in aspects related to the efficiency in the use of them.
La ciudad, la poesía, Juan Gelman
Guzmán, Raquel;
Tópicos del seminario , 2010,
Abstract: the poem, due to its particular discursive configuration, permits the construction of spaces that design themselves in a fragmentary plot of contractions and expansions that is not foreign to the discursive voyage itself. in this article we analyze, valer la pena (2001), a collection of poems by the argentine writer juan gelman in order to follow the semiosis that makes possible the constitution of the city as a cenestesic space in which the shame of the lyric self shapes places and sites. it concerns a kaleidoscopic work where each edge allows us to follow an autonomous course (that which we follow is just one) in order to try to comprehend a wide poetic world.
CONTRA LA OBJETIVIDAD EL MITO DE LA NEUTRALIDAD PERIODíSTICA Y LAS ALTERNATIVAS PARA REPENSARLO
Raquel San Martín
Revista Perspectivas de la Comunicación , 2008,
Abstract: La objetividad es uno de los valores fundantes del periodismo como profesión. Como desiderátum ético y práctica concreta, la neutralidad y la distancia del periodista frente a los hechos que narra se siguen sosteniendo en las representaciones que muchos periodistas construyen sobre sí mismos. Sin embargo, la propia organización y funcionamiento del campo mediático y la creciente complejidad de los fenómenos de los que debe dar cuenta el periodismo desmienten hoy la posibilidad de la objetividad. A la vez, la neutralidad y la distancia han sido cuestionadas por imposibles pero también por perjudiciales frente al público. Esgrimir la objetividad se ha convertido en un ritual de defensa que esconde la necesaria construcción de realidad que implica el periodismo y la postura institucional, social y profesional de los periodistas frente a los hechos. El artículo recorre estos cuestionamientos y describe las alternativas que se han ido proponiendo para reemplazar a la objetividad como valor y como práctica concreta, con la idea de que transparentar la inevitable presencia del periodista en el acontecimiento que relata mejora la calidad de su trabajo y a la vez lo obliga a cuestionamientos más profundos y comprometidos.
Estudo sobre os Ceratopogonídeos de Minas Gerais: I - Descri??o dos machos de Heteromyia chaquensis Duret & Lane, 1955 e Dasyhelea paulistana Forattini & Rabello, 1957 (Diptera, Ceratopogonidae)
Espínola, Hélio N.;Pelli, Afonso;
Memórias do Instituto Oswaldo Cruz , 1989, DOI: 10.1590/S0074-02761989000800034
Abstract: this paper describes some results of a systematic survey of the ceratopogonidae midges of the state of minas gerais, brazil. three species, stilobezzia punctulata lane, 1947, heteromyia chaquensis duret & lane, 1955 and dasyhelea paulistana forattini & rabello, 1957 were identified from a small lake, "lagoinha" or "olhos d'água", near to the main lake of lagoa santa. the first descriptions of the males of heteromyia chaquensis and dasyhelea paulistana are presented.
Un acercamiento a las palabras de acentuación indistinta en el Espa ol An approach to Spanish indistinctaccented words
Ramón Diego Afonso Fernández
Humanidades M??dicas , 2005,
Abstract:
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