125 resultados para AK43-4877
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Incluye Bibliografía
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We evaluated associations between the concentrations of heat shock proteins (hsp60 and hsp70) and their respective antibodies, alterations in maternal reproductive performance, and fetal malformations in pregnant rats with hyperglycemia. Mild diabetes (MD) or severe diabetes (SD) was induced in Sprague-Dawley rats prior to mating; non-treated non-diabetic rats (ND) served as controls. On day 21 of pregnancy, maternal blood was analyzed for hsp60 and hsp70 and their antibodies; and fetuses were weighed and analyzed for congenital malformations. Hsp and anti-hsp levels were correlated with blood glucose levels during gestation. There was a positive correlation between hsp60 and hsp70 levels and the total number of malformations (R∈=∈0.5908, P∈=∈0.0024; R∈=∈0.4877, P∈=∈0.0134, respectively) and the number of malformations per fetus (R∈=∈0.6103, P∈=∈0.0015; R∈=∈0.4875, P∈=∈0.0134, respectively). The anti-hsp60 IgG concentration was correlated with the number of malformations per fetus (R∈=∈0.3887, P∈=∈0.0451) and the anti-hsp70 IgG level correlated with the total number of malformations (R∈=∈0.3999, P∈=∈0.0387). Moreover, both hsp and anti-hsp antibodies showed negative correlations with fetal weight. The results suggest that there is a relationship between hsp60 and hsp70 levels and their respective antibodies and alterations in maternal reproductive performance and impaired fetal development and growth in pregnancies associated with diabetes. © 2012 Cell Stress Society International.
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Lead-free solid solutions (1-x)Bi0.5Na0.5TiO 3 (BNT)-xBaZr0.25Ti0.75O3 (BZT) (x=0, 0.01, 0.03, 0.05, and 0.07) were prepared by the solid state reaction method. X-ray diffraction (XRD) and Rietveld refinement analyses of 1-x(BNT)-x(BZT) solid solution ceramic were employed to study the structure of these systems. A morphotropic phase boundary (MPB) between rhombohedral and cubic structures occured at the composition x=0.05. Raman spectroscopy exhibited a splitting of the (TO3) mode at x=0.05 and confirmed the presence of MPB region. Scanning electron microcopy (SEM) images showed a change in the grain shape with the increase of BZT into the BNT matrix lattice. The temperature dependent dielectric study showed a gradual increase in dielectric constant up to x=0.05 and then decrease with further increase in BZT content. Maximum coercive field, remanent polarization and high piezoelectric constant were observed at x=0.05. Both the structural and electrical properties show that the solid solution has an MPB around x=0.05. © 2012 Elsevier Ltd and Techna Group S.r.l.
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O ensaio imunoenzimático para identificação de repastos sangüíneos apresenta especificidade até nível de gênero, sensibilidade para identificação de repastos sangüíneos parciais e detecção de repastos múltiplos. Foram identificadas as fontes alimentares de 82% dos anofelinos coletados em campo. Foram testados seis anticorpos monoclonais (humano, suíno, cão, bovino, rato e galinha) e destes, apenas o anti- IgG bovino apresentou instabilidade. Obteve-se 55,7% (519/932) dos repastos positivos para sangue humano, o que demonstra, a preferência alimentar destes anofelinos por humanos. Dos 206 mosquitos que apresentaram repasto único, 27,6% foi em humanos. O Anopheles darlingi apresentou 41% dos repastos em humanos e o Índice de Sangue Humano (HBI) no intradomicílio foi de 0,71. An. marajoara apresentou 51,3% dos repastos em humanos, embora tenha sido encontrada em grande quantidade no ambiente extradomiciliar e apresentando HBI no intradomicílio de 0,76. O An. nuneztovari foi a espécie mais abundante, apresentando comportamento exofílico e antropofílico, com 53,8% de repastos em humano e HBI no intradomicílio de 0,65. O método ELISA Sanduíche está implantado, identificando a fonte alimentar das espécies de anofelinos coletadas em campo, exceto para bovino. É a primeira vez que esta técnica é utilizada para determinação de repastos sanguíneos em anofelinos na região Amazônica brasileira. É importante a determinação da fonte alimentar das espécies de anofelinos no sentido de caracterizar o comportamento antropofílico e assim associá-las ou não à transmissão de malária.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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This research presents a study on mathematics teacher education, examining the bibliographic production in 15 years of the journal Zetetiké (1993-2007), totalizing 140 papers. From these, 49 were classified as ‘teacher formation’, thus constituting the corpus of the investigation. The research focused on three units of recording and analysis: (i) problems of research; (ii) the meanings of ‘being a teacher’ and their ‘duties’; and (iii) the meanings of ‘teacher’s education’. For the processes of categorization we use Textual Analysis, which allowed us to observe some trends. Regarding the problems of research we found that the research actions involve a range from: to report, disclose, describe, identify up to study, discuss, understand, evaluate. With reference to ‘being teacher’ and its ‘duties’ in the whole period of this study it were pointed problems related to the mathematical content and to the pedagogical project of the school unit, with 30 papers giving prescriptions for the teachers actions in its educational context. With regard to the meanings on teacher education, the most frequent references concern: the functions of teacher formation; what is expected of the teacher during and after the education processes; and the emphasis on the importance of initial formation for mathematics teacher’s education.
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The main goal of this work is to build a sketch on how language is used in mathematics classrooms. We specifically try to understand how teachers use language in order to share meanings with their students. We initially present our main intentions, summarizing some studies that are close to our purposes. The two theoretical frameworks which support our study – the Model of Semantic Fields and the Wittgensteinian “games of language” – are then presented and discussed about their similarities and distinctions. Our empirical data are some classroom activities recorded and turned into “clips”. Such clips were transcribed and our analysis was based on these transcriptions. Data analysis – developed according to our theoretical framework – allowed us to build the so-called “events” and, then, comment on some understandings on how language can be used in mathematics classrooms.
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The starting point of this paper are some avaliable analyses and characterizations about the academic production in History of Mathematics Education in Brazil. A specific reading of such readings – an hermeneutical approach of those avaliable reviews – allows us to put the focus on some features of Oral History thought as a qualitative methodological approach to researches in Mathematics Education.
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The teaching of acoustics has been characterized by a banking model that little contributes to the ideal training of citizens capable of understanding and acting to improve their environment soundscapes. Equally distant from the world of sound and musical culture, audio technology and acoustic environment, it is disconnected from the ever-increasing effort to raise awareness on hearing and sound education, as defended by the Canadian educator Prof. Raymond Murray Schafer. In order to provide elements for reflection on how Mathematics can be itself a language to compete in a sound education, we developed, in a dialogical and problematizing method applied to the technological and cultural world, one further research and teaching with Math students of UNEMAT in Barra do Bugres. This study pointed to the feasibility of educating consciences capable of of improving their acoustic environment, modifying the landscapes where we live, under our responsibility.
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We studied the influence of surveyed area size on density estimates by means of camera-trapping in a low-density felid population (1-2 individuals/100 km(2) ). We applied non-spatial capture-recapture (CR) and spatial CR (SCR) models for Eurasian lynx during winter 2005/2006 in the northwestern Swiss Alps by sampling an area divided into 5 nested plots ranging from 65 to 760 km(2) . CR model density estimates (95% CI) for models M0 and Mh decreased from 2.61 (1.55-3.68) and 3.6 (1.62-5.57) independent lynx/100 km(2) , respectively, in the smallest to 1.20 (1.04-1.35) and 1.26 (0.89-1.63) independent lynx/100 km(2) , respectively, in the largest area surveyed. SCR model density estimates also decreased with increasing sampling area but not significantly. High individual range overlaps in relatively small areas (the edge effect) is the most plausible reason for this positive bias in the CR models. Our results confirm that SCR models are much more robust to changes in trap array size than CR models, thus avoiding overestimation of density in smaller areas. However, when a study is concerned with monitoring population changes, large spatial efforts (area surveyed ≥760 km(2) ) are required to obtain reliable and precise density estimates with these population densities and recapture rates.
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We present a barium (Ba) isotope fractionation study of marine biogenic carbonates (aragonitic corals). The major aim is to provide first constraints on the Ba isotope fractionation between modern surface sea water and coral skele- ton. Mediterranean surface sea water was found to be enriched in the heavy Ba isotopes compared to previously reported values for marine open ocean authi- genic and terrestrial minerals. In aquarium experiments with a continuous sup- ply of Mediterranean surface water, the Ba isotopic composition of the bulk sample originating from cultured, aragonitic scleractinian corals (d137/134Ba between +0.16 +/- 0.12permil and +0.41 +/-0.12permil) were isotopically identical or lighter than that of the ambient Mediterranean surface sea water (d137/134Ba = +0.42 +/- 0.07permil, 2SD), which corresponds to an empirical maximum value of Ba isotope fractionation of D137/134Bacoral-seawater = -0.26 +/- 0.14permil at 25°C. This maximum Ba isotope fractionation is close and identical in direction to previous results from inorganic precipitation experiments with aragonite- structured pure BaCO3 (witherite). The variability in measured Ba concentrations of the cultured corals is at odds with a uniform distribution coefficient, DBa/Ca, thus indicating stronger vital effects on isotope than element discrimination. This observation supports the hypothesis that the Ba isotopic compositions of these corals do not result from simple equilibrium between the skeleton and the bulk sea water. Complementary coral samples from natural settings (tropical shallow-water corals from the Bahamas and Florida and cold- water corals from the Norwegian continental shelf) show an even wider range in d137/134Ba values (+0.14 +/- 0.08permil and +0.77 +/- 0.11permil), most probably due to additional spatial and/or temporal sea water heterogeneity, as indicated by recent publications.
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La presente investigación se propone analizar la aparición de la recarga virtual, detallando sus ventajas y desventajas, frente a la tarjeta de recarga física, la cual a futuro reemplazará. Se realizará un análisis de cómo es la distribución de la recarga virtual en Mendoza, de donde surge, cuales son las empresas que la proveen y cómo. Para esto, en primer lugar se hará una reseña de la teoría de lo que significa la "Logística de un producto o servicio", luego se analizará cómo surge la recarga virtual en nuestro país y principalmente en nuestra provincia. Como es un proceso de recarga, quien lo realiza y cuáles son los requisitos. Se realizará un Análisis FODA del negocio, es decir que se detallarán las fortalezas y debilidades del negocio, junto a las amenazas y oportunidades que ofrece el mercado, donde actúa dicho negocio. Para esto, previamente se analizará cómo está compuesto el micro y macro entorno de la recarga virtual. Y por último se utilizará la Matriz BCG (Boston Consulting Group), para determinar qué tipo de negocio es la recarga virtual, en función de su posición en el mercado y el crecimiento del mismo. Por último, se establecerá cuáles son las próximas tendencias de la recarga virtual, es decir hacia dónde va este negocio, y cual es realmente el objetivo que desea alcanzar, para ofrecerle mayores beneficios a sus clientes, que son los usuarios de la telefonía celular.