O efeito da reprovação na motivação dos alunos

O mundo mudou muito e o modelo escolar existente, que vem desde o século XVIII, manifesta dificuldades de adaptação ao novo mundo. As dificuldades de ensino e aprendizagem também são muito mais vastas do que as do passado, num ensino obrigatório e massificado, e a capacidade de captação da atenção que a escola antes produzia, é hoje mais difícil de obter. A motivação, sem a qual não há aprendizagem, revela a dificuldade da educação escolar em lidar com a realidade atual. Dentro de um referencial teórico sustentado, importa analisar e interpretar o modo como decorre a aprendizagem e o modelo de avaliação do terceiro ciclo do ensino básico, bem como investigar os fatores que influenciam a motivação dos alunos. Para atingir os objetivos do estudo optou-se por uma abordagem metodológica qualitativa, recorrendo à realização de entrevistas semiestruturadas aos vários intervenientes educativos e à análise de documentos, numa escola selecionada para o efeito. Constatou-se, através dos dados obtidos, que a reprovação tem um impacto extremamente significativo no desempenho escolar dos alunos, e que se umas vezes provoca um efeito pedagógico, noutras tem o efeito exatamente inverso. Este trabalho consiste num estudo de caso sobre o efeito que a reprovação provoca na motivação dos alunos que ficam retidos e tem como intuito encontrar estratégias para aumentar a motivação desses mesmos alunos.

O papel modulatório do ferro sobre a resposta imune na Leishmaniose Visceral

Iron is an essential element for many cellular functions, including the immune response against intracellular pathogens. In this study, we aimed evaluate the effect of iron on IRP2, IFN-γ, TNF-α, IL-6, IL-10, MIG and IP10 expression in PBMC and assess the effect of the spleen parasite load on the expression of these genes in the spleen of L. infantum naturally infected dogs. Blood sample from 7 DTH+ donor was collected and PBMC was obtained. The cells were cultivated in absence (iron chelator desferroximane, DFO 10 μM supplemented media) or in presence of iron (hemin 6 mM) for 1 h, followed by stimulation with Leishmania infatum antigen for 4 h. 44 dog spleen samples were obtained and parasite load in this organ was determinate by qPCR. Gene expression was analyzed by qPCR and cytokine production quantified by flow cytometry. In antigen stimulated cells, genes involved in immune response are significantly more expressed in presence of iron. T CD4+ and TCD8+ lymphocytes produces IFN-γ, TNF-α and IL-10 possibly in iron dependent pathway. Monocytes antigen stimulated reduced TNF-α, IL-6 and IL-10 production in presence of iron. We found spleen of infected dogs IRP2 expression increases according to parasite load in that organ, while an inverse profile was found for IFN-γ, TNF-α e IL-10 expression. These results suggest that T lymphocytes depends on iron to produce IFN-γ, TNF-α and IL-10, while iron seems to inhibit cytokine production in monocytes. So, we propose an immunoregulatory mechanism carried out by iron during L. infantum infection in humans and dogs

Perdas fermentativas e composição bromatológica da entrecasca de palmito pupunha ensilada com aditivos químicos

Objetivou-se avaliar o efeito da inclusão de aditivos químicos na ensilagem de resíduos (entrecasca) da produção de palmito pupunha (Bactris gasipaes, Kunth). Utilizaram-se silos experimentais (baldes de 20 litros) providos de aparatos para determinação gravimétrica de perdas por gases e efluentes. Os tratamentos aplicados foram: controle (sem aditivos); ureia (1% da MV) e cal virgem (1% da MV). Decorridos 70 dias de armazenagem, os silos foram pesados, abertos e amostrados. As perdas por efluentes e gases aumentaram com a aplicação de cal virgem na ensilagem. As perdas totais de MS foram de 15,1; 14,4 e 26,6% nas silagens controle, ureia e cal, respectivamente. em todas as silagens, houve redução no teor de FDN e elevação da fração FDA, o que indica desaparecimento da fração hemicelulose. A relação cálcio:fósforo aumentou substancialmente com a adição de cal virgem, de 4,1:1 na silagem controle para 15,6:1 na silagem com cal. O resíduo da extração do palmito pupunha pode ser classificado como alimento de média qualidade e alto teor de umidade. Os aditivos aplicados na ensilagem não são efetivos em reduzir as perdas fermentativas no processo de conservação.

Análise da estabilidade genética de células-tronco mesenquimais humanas

Human multipotent mesenchymal stromal cells (MSCs), also known as mesenchymal stem cells, have become an important and attractive therapeutic tool since they are easily isolated and cultured, have in vitro expansion potential, substantial plasticity and secrete bioactive molecules that exert trophic effects. The human umbilical cord as a cell source for cell therapy will help to avoid several ethical, political, religious and technical issues. One of the main issues with SC lines from different sources, mainly those of embryonic origin, is the possibility of chromosomal alterations and genomic instability during in vitro expansion. Cells isolated from one umbilical cord exhibited a rare balanced paracentric inversion, likely a cytogenetic constitutional alteration, karyotype: 46,XY,inv(3)(p13p25~26). Important genes related to cancer predisposition and others involved in DNA repair are located in 3p25~26. Titanium is an excellent biomaterial for bone-implant integration; however, the use can result in the generation of particulate debris that can accumulate in the tissues adjacent to the prosthesis, in the local bone marrow, in the lymph nodes, liver and spleen. Subsequently may elicit important biological responses that aren´t well studied. In this work, we have studied the genetic stability of MSC isolated from the umbilical cord vein during in vitro expansion, after the cryopreservation, and under different concentrations and time of exposition to titanium microparticles. Cells were isolated, in vitro expanded, demonstrated capacity for osteogenic, adipogenic and chondrogenic differentiation and were evaluated using flow cytometry, so they met the minimum requirements for characterization as MSCs. The cells were expanded under different concentrations and time of exposition to titanium microparticles. The genetic stability of MSCs was assessed by cytogenetic analysis, fluorescence in situ hybridization (FISH) and analysis of micronucleus and other nuclear alterations (CBMN). The cells were able to internalize the titanium microparticles, but MSCs preserve their morphology, differentiation capacity and surface marker expression profiles. Furthermore, there was an increase in the genomic instability after long time of in vitro expansion, and this instability was greater when cells were exposed to high doses of titanium microparticles that induced oxidative stress. It is necessary always assess the risks/ benefits of using titanium in tissue therapy involving MSCs, considering the biosafety of the use of bone regeneration using titanium and MSCs. Even without using titanium, it is important that the therapeutic use of such cells is based on analyzes that ensure quality, security and cellular stability, with the standardization of quality control programs appropriate. In conclusion, it is suggested that cytogenetic analysis, FISH analysis and the micronucleus and other nuclear alterations are carried out in CTMH before implanting in a patient

Dimensão ética da conduta das empresas e dos trabalhadores: Factos empíricos de um estudo exploratório realizado em Portugal

O artigo apresenta uma selecção dos resultados de um estudo empírico realizado em Portugal em 2004, numa amostra por conveniência, sobre diversos aspectos da conduta ética das empresas e seus trabalhadores. A dimensão ética da conduta das empresas e dos trabalhadores foi assumida como conceito composto pelos seguintes aspectos: reflexão ética, legalidade da conduta, relações entre a ética e a eficiência, responsabilidade das empresas, percepção da conduta não ética e denúncia da sua ocorrência, institucionalização e formalização da ética nas empresas. Dos resultados destacam-se: o impacto positivo ao nível cognitivo da implementação dos elementos de ética formal na empresa, o qual pode, contudo, conduzir à supressão da responsabilidade e à desculpabilização pelos actos potencialmente imorais; o crescimento da imagem positiva do tecido empresarial com a ascendência na posição hierárquica e o inverso com o decréscimo do poder organizacional; o decréscimo de confiança nas empresas nacionais à medida que o sentimento de segurança de/no emprego se reduz e a sua transferência para as empresas estrangeiras; o crescimento de confiança depositada pelos inquiridos nas empresas com o aumento da dimensão destas últimas; a predominância de documentos escritos de ética nas empresas de origem estrangeira e a sua escassez nas empresas nacionais.

Transcriptoma diferencial entre células-tronco mesenquimais humanas jovens e senescentes

Human mesenchymal stem cells (MSC) are powerful sources for cell therapy in regenerative medicine. The long time cultivation can result in replicative senescence or can be related to the emergence of chromosomal alterations responsible for the acquisition of tumorigenesis features in vitro. In this study, for the first time, the expression profile of MSC with a paracentric chromosomal inversion (MSC/inv) was compared to normal karyotype (MSC/n) in early and late passages. Furthermore, we compared the transcriptome of each MSC in early passages with late passages. MSC used in this study were obtained from the umbilical vein of three donors, two MSC/n and one MSC/inv. After their cryopreservation, they have been expanded in vitro until reached senescence. Total RNA was extracted using the RNeasy mini kit (Qiagen) and marked with the GeneChip ® 3 IVT Express Kit (Affymetrix Inc.). Subsequently, the fragmented aRNA was hybridized on the microarranjo Affymetrix Human Genome U133 Plus 2.0 arrays (Affymetrix Inc.). The statistical analysis of differential gene expression was performed between groups MSC by the Partek Genomic Suite software, version 6.4 (Partek Inc.). Was considered statistically significant differences in expression to p-value Bonferroni correction ˂.01. Only signals with fold change ˃ 3.0 were included in the list of differentially expressed. Differences in gene expression data obtained from microarrays were confirmed by Real Time RT-PCR. For the interpretation of biological expression data were used: IPA (Ingenuity Systems) for analysis enrichment functions, the STRING 9.0 for construction of network interactions; Cytoscape 2.8 to the network visualization and analysis bottlenecks with the aid of the GraphPad Prism 5.0 software. BiNGO Cytoscape pluggin was used to access overrepresentation of Gene Ontology categories in Biological Networks. The comparison between senescent and young at each group of MSC has shown that there is a difference in the expression parttern, being higher in the senescent MSC/inv group. The results also showed difference in expression profiles between the MSC/inv versus MSC/n, being greater when they are senescent. New networks were identified for genes related to the response of two of MSC over cultivation time. Were also identified genes that can coordinate functional categories over represented at networks, such as CXCL12, SFRP1, xvi EGF, SPP1, MMP1 e THBS1. The biological interpretation of these data suggests that the population of MSC/inv has different constitutional characteristics, related to their potential for differentiation, proliferation and response to stimuli, responsible for a distinct process of replicative senescence in MSC/inv compared to MSC/n. The genes identified in this study are candidates for biomarkers of cellular senescence in MSC, but their functional relevance in this process should be evaluated in additional in vitro and/or in vivo assays

Desigualdades en mortalidad prematura según indicadores de bienestar material en Navarra: estudio poblacional de seguimiento 2001-2008

Fundamento. Mostrar las desigualdades en mortalidad prematura según indicadores de bienestar material en Navarra. Método. Todos los ciudadanos menores de 75 años residentes en Navarra en 2001 fueron seguidos durante 7 años para conocer su estado vital. El indicador de posición socioeconómica usado ha sido la superficie de la casa y el número de vehículos del hogar. Se han estimado las tasas de mortalidad general y por causa de muerte ajustadas por edad según estos indicadores. Resultados. La razón de tasas por todas las causas de muerte en las categorías inferiores es según la superficie de la vivienda de 1,14 (IC 95%: 1,05-1,24) y 1,25 (IC 95%: 1,18-1,32) en mujeres y hombres respectivamente y de 1,46 (IC 95%: 1,36-1,57) y 1,97 (IC 95%: 1,89-2,05) según el número de vehículos. El sida es la causa de muerte que presenta una mayor diferencia en las tasas de mortalidad entre las personas con menor y mayor bienestar material. Otras causas de muerte con elevada diferencia en las tasas de mortalidad son las enfermedades digestivas y la diabetes mellitus en mujeres y las enfermedades del aparato digestivo y respiratorio en hombres. Conclusiones. La tasa de mortalidad en la población navarra muestra un gradiente inverso con el bienestar material, a excepción de algunas localizaciones de cáncer. Este gradiente es mayor entre los hombres que entre las mujeres.

Análise experimental do efeito da diversificação em carteiras de ações: a relação entre risco e quantidade de ativos sob a ótica da estratégia ingênua

The objective is to analyze the relationship between risk and number of stocks of a portfolio for an individual investor when stocks are chosen by "naive strategy". For this, we carried out an experiment in which individuals select actions to reproduce this relationship. 126 participants were informed that the risk of first choice would be an asset average of all standard deviations of the portfolios consist of a single asset, and the same procedure should be used for portfolios composed of two, three and so on, up to 30 actions . They selected the assets they want in their portfolios without the support of a financial analysis. For comparison we also tested a hypothetical simulation of 126 investors who selected shares the same universe, through a random number generator. Thus, each real participant is compensated for random hypothetical investor facing the same opportunity. Patterns were observed in the portfolios of individual participants, characterizing the curves for the components of the samples. Because these groupings are somewhat arbitrary, it was used a more objective measure of behavior: a simple linear regression for each participant, in order to predict the variance of the portfolio depending on the number of assets. In addition, we conducted a pooled regression on all observations by analyzing cross-section. The result of pattern occurs on average but not for most individuals, many of which effectively "de-diversify" when adding seemingly random bonds. Furthermore, the results are slightly worse using a random number generator. This finding challenges the belief that only a small number of titles is necessary for diversification and shows that there is only applicable to a large sample. The implications are important since many individual investors holding few stocks in their portfolios

O argumento de inclusão enquanto política de acesso à universidade pública

There are a great number of evidences showing that education is extremely important in many economic and social dimensions. In Brazil, education is a right guaranteed by the Federal Constitution; however, in the Brazilian legislation the right to the three stages of basic education: Kindergarten, Elementary and High School is better promoted and supported than the right to education at College level. According to educational census data (INEP, 2009), 78% of all enrolments in College education are in private schools, while the reverse is found in High School: 84% of all matriculations are in public schools, which shows a contradiction in the admission into the universities. The Brazilian scenario presents that public universities receive mostly students who performed better and were prepared in elementary and high school education in private schools, while private universities attend students who received their basic education in public schools, which are characterized as low quality. These facts have led researchers to raise the possible determinants of student performance on standardized tests, such as the Brazilian Vestibular exam, to guide the development of policies aimed at equal access to College education. Seeking inspiration in North American models of affirmative action policies, some Brazilian public universities have suggested rate policies to enable and facilitate the entry of "minorities" (blacks, pardos1, natives, people of low income and public school students) to free College education. At the Federal University of the state Rio Grande do Norte (UFRN), the first incentives for candidates from public schools emerged in 2006, being improved and widespread during the last 7 years. This study aimed to analyse and discuss the Argument of Inclution (AI) - the affirmative action policy that provides additional scoring for students from public schools. From an extensive database, the Ordinary Least Squares (OLS) technique was used as well as a Quantile Regression considering as control the variables of personal, socioeconomic and educational characteristics of the candidates from the Brazilian Vestibular exam 2010 of the Federal University of the state Rio Grande do Norte (UFRN). The results demonstrate the importance of this incentive system, besides the magnitude of other variables

La puesta en escena de la serie de comedias de magia "Cuando hay falta de hechiceros lo quieren ser los gallegos" y "Asombro de Salamanca" (1741-1775), de Nicolás González Martínez

Esta tesis comienza en el punto donde concluía el trabajo pionero sobre comedia de magia del XVIII emprendido por Joaquín Álvarez Barrientos. Planteaba él entonces la necesidad de saber más sobre los hombres y mujeres de la época para comprender mejor la comedia de magia como género escénico, con el objetivo de responder la pregunta que tantos dieciochistas nos hemos hecho: ¿por qué la comedia de magia tuvo tanto éxito? Mi investigación partió también de sus respuestas: se debió, sobre todo, a motivos ideológicos y espectaculares. Comprender la comedia de magia como género escénico quiere decir comprender todos los mecanismos de la materialidad de su puesta en escena y de la relación establecida entre espectáculo y espectadores. Implica comprender la teatralidad a un nivel que no es solo textual, sino físico y relacional. Las relaciones y reacciones que desataba la comedia de magia eran tremendamente pasionales y opuestas, como demuestran los datos de que disponemos: las espectaculares recaudaciones, de un lado, y las múltiples diatribas y prohibiciones, de otro. Así que, la siguiente pregunta que era necesario plantear era: ¿por qué molestaban tanto las comedias de magia? En el siglo XVIII ocurrió un acontecimiento especialmente traumático, el denominado «Motín contra Esquilache», que tuvo numerosas consecuencias para la sociedad en general pero, sobre todo, para el teatro. De hecho, una de las primeras medidas que el gobierno del conde de Aranda emprende nada más acabar con las revueltas es la Reforma del teatro. Haciendo un razonamiento inverso, surgía la hipótesis de que el teatro, en un sentido amplio, y en concreto la comedia de magia, hubiera tenido más intervención en el motín de lo que se piensa, tanto por sus temáticas, como por las posibilidades de encuentro y organización social que la asistencia al teatro propiciaba. Surgía pues, la necesidad de profundizar en la reconstrucción de una teoría estética de la comedia de magia, así como de estudiar el hecho teatral durante los años centrales del siglo, en concreto, desde la construcción de los nuevos coliseos, pues parecía probable que el cambio de espacio hubiera propiciado algún cambio de mentalidad…

Terapia de resincronización cardíaca para sujetos con insuficiencia cardíaca asintomáticos o levemente sintomáticos: Un cambio de paradigma: del rescate a la prevención

Hacia fines de la década de 1990 comenzó a utilizarse con éxito la estimulación cardíaca en ambas cámaras ventriculares (resincronización venticular) como terapia en insuficiencia cardíaca refractaria al tratamiento farmacológico convencional en pacientes con complejo QRS ensanchado. Fue hasta el 2005 que el estudio CARE-HF demostró que la resincronización reducía la mortalidad en forma significativa, incluso sin necesidad de acompañarla de un cardiodesfibrilador implantable (DAI o desfibrilador automático implantable). En forma más reciente, a través de los estudios REVERSE, MADIT-CRT y RAFT, se ha comprobado la utilidad de la terapia de resincronización incluso en individuos con insuficiencia cardíaca poco sintomática, es decir en clase funcional I o II, lo cual constituye un cambio cualitativo y cuantitativo en este tratamiento eléctrico para la insuficiencia cardíaca. Al mismo tiempo se han hecho significativos avances en la selección del paciente considerando la enfermedad de base, el patrón de bloqueo en el electrocardiograma, la duración del complejo QRS, y la presencia o no de fibrilación auricular. Como resultado de esto, la terapia de resincronización ha producido mejoría en la calidad de vida, ha demostrado que favorece el fenómeno de remodelado inverso y que también disminuye la mortalidad en individuos en clase funcional I o II.

Obtenção de polímeros de LCC para aplicação como antioxidante de biodiesel de soja

Biodiesel is a fuel obtained from vegetable oils, such as soy, castorbean, among others. The monoester of fatty acid of these oils have chains with mono, di and tri double connections. The presence of these insaturations are susceptible to oxidization. Antioxidants are substances able to prevent oxidization from oils, fats, fat foods, as well as esters of Alquila( biodiesel). The objective of this work is to summarize a new antioxidant from the Cashew Nut Shell Liquid (CNSL) using the electrolysis technique. A current of 2 amperes was used in a single cell of only one group and two eletrodos of stainless steel 304 in a solution of methanol, together with the eletrolits: acetic acid, sodium chloride and sodium hydroxide, for two hours of agitation. The electrolysis products are characterized by the techniques of cromatography in a thin layer, spectroscopy of infrared and gravimetric analysis. The material was submitted to tests of oxidative stability made by the techniques of spectropy of impendancy and Rancimat (EN 14112). The analyses of characterization suggest that the polimerization of the electrolytic material ocurred. The application results of these materials as antioxidants of soy biodiesel showed that the order of the oxidative stability was obtained by both techniques used

Suupa uchinaanchu : a construção da rede transnacional okinawana

Tese (doutorado)—Universidade de Brasília, Instituto de Ciências Sociais, Departamento de Antropologia, Programa de Pós-graduação em Antropologia Social, 2016.

Indícios no insólito : Avalovara através do espelho

Tese (doutorado)—Universidade de Brasília, Instituto de Letras, Departamento de Teoria Literária e Literatura, Programa de Pós-Graduação em Literatura, 2015.

Transição de fase topológica e transporte eletrônica em grafenos e nanofitas zigzag grafeno tensionados

Tese (doutorado)—Universidade de Brasília, Instituto de Física, 2015.