956 resultados para Systematic investigations
Resumo:
Background: Genetic and epigenetic factors interacting with the environment over time are the main causes of complex diseases such as autoimmune diseases (ADs). Among the environmental factors are organic solvents (OSs), which are chemical compounds used routinely in commercial industries. Since controversy exists over whether ADs are caused by OSs, a systematic review and meta-analysis were performed to assess the association between OSs and ADs. Methods and Findings: The systematic search was done in the PubMed, SCOPUS, SciELO and LILACS databases up to February 2012. Any type of study that used accepted classification criteria for ADs and had information about exposure to OSs was selected. Out of a total of 103 articles retrieved, 33 were finally included in the meta-analysis. The final odds ratios (ORs) and 95% confidence intervals (CIs) were obtained by the random effect model. A sensitivity analysis confirmed results were not sensitive to restrictions on the data included. Publication bias was trivial. Exposure to OSs was associated to systemic sclerosis, primary systemic vasculitis and multiple sclerosis individually and also to all the ADs evaluated and taken together as a single trait (OR: 1.54; 95% CI: 1.25-1.92; p-value, 0.001). Conclusion: Exposure to OSs is a risk factor for developing ADs. As a corollary, individuals with non-modifiable risk factors (i.e., familial autoimmunity or carrying genetic factors) should avoid any exposure to OSs in order to avoid increasing their risk of ADs.
Resumo:
Background: A primary characteristic of complex genetic diseases is that affected individuals tend to cluster in families (that is, familial aggregation). Aggregation of the same autoimmune condition, also referred to as familial autoimmune disease, has been extensively evaluated. However, aggregation of diverse autoimmune diseases, also known as familial autoimmunity, has been overlooked. Therefore, a systematic review and meta-analysis were performed aimed at gathering evidence about this topic. Methods: Familial autoimmunity was investigated in five major autoimmune diseases, namely, rheumatoid arthritis, systemic lupus erythematosus, autoimmune thyroid disease, multiple sclerosis and type 1 diabetes mellitus. Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines were followed. Articles were searched in Pubmed and Embase databases. Results: Out of a total of 61 articles, 44 were selected for final analysis. Familial autoimmunity was found in all the autoimmune diseases investigated. Aggregation of autoimmune thyroid disease, followed by systemic lupus erythematosus and rheumatoid arthritis, was the most encountered. Conclusions: Familial autoimmunity is a frequently seen condition. Further study of familial autoimmunity will help to decipher the common mechanisms of autoimmunity.
Resumo:
Stressors and traumatic events may contribute to the development of many psychopathologies, PTSD among them. People with this disorder can present significant cognitive impairments and losses in memory, particularly autobiographical memory (AM).This paper aims to present a systematic review of literature considering changes on autobiographical memory in people exposed to potentially traumatic stressors. Therefore, we performed a computerized search in databases PsycINFO, PubMed, Web of Science and Pilots in March 2012.A total of 29 articles were selected and grouped into three categories: studies comparing Trauma X PTSD, studies comparing PTSD X Trauma X Control and comparison studies according to post-traumatic symptoms. Results demonstrate that people with PTSD presents alterations in a larger number of AM components compared to the cases in which PTSD did not developed. In the same way, subjects never exposed to trauma did not demonstrate significant alterations on AM when compared to the other groups. The results of this study allowed concluding that changes of some components of the AM are primarily associated with PTSD, but it was not possible to clarify whether such changes are related to the timely development of the disorder, or if they are also observed in traumatic memories even in the absence of disorder.
Resumo:
O interesse em estudar o papel de variáveis sócio-demográficas no funcionamento cognitivo vem ganhando destaque nos últimos anos. Alguns estudos em neuropsicologia têm mostrado que os fatores sócio-culturais podem ser variáveis importantes na execução de tarefas neuropsicológicas. No entanto, pesquisas com populações saudáveis ainda são recentes na área. O presente artigo teve por objetivo realizar uma revisão sistemática da literatura sobre o papel das variáveis sócio-demográficas escolaridade, idade e gênero no processamento da tomada de decisão avaliado pelo Iowa Gambling Task (IGT). Foram consultadas as bases de dados Medline, Pubmed, Psycinfo e Web of Science, no período de 2000 até 2010, com as seguintes palavras-chaves na sintaxe “education OR schooling AND Iowa Gambling Task” OR “somatic marker” para a variável escolaridade; “age” OR “aging” AND “Iowa Gambling Task” OR “somatic marker” para a variável idade e; “sex” OR “gender” AND “Iowa Gambling Task” OR “somatic marker” para a variável sexo/gênero. Dos abstracts que preenchiam os critérios de inclusão, foram examinados 9 artigos completos para a variável idade, 3 artigos para a variável escolaridade e 6 artigos para a variável gênero. Foram encontrados poucos estudos sobre os fatores idade, escolaridade e gênero e seu impacto no desempenho do IGT. A variável mais estudada foi a idade. A maioria dos estudos mostrou que os adultos jovens tiveram uma melhor aprendizagem ao longo da tarefa do que os adultos idosos, mas não tiveram diferenças quanto ao desempenho total no instrumento. Já quanto ao fator escolaridade poucos estudos foram encontrados e quanto à variável gênero os resultados são contraditórios. Assim, evidencia-se a necessidade de um maior número de investigações com populações saudáveis que esclareçam o papel das variáveis idade, escolaridade e gênero na tomada de decisão mensurada pelo IGT.
Resumo:
El diagnóstico de cáncer ha sido asociado con un alto riesgo de presentar ideación suicida en comparación con la población no oncológica, sin embargo se ha considerado al apoyo social como un factor protector para la ocurrencia de esta conducta. La presente investigación tuvo como objetivo identificar la relación entre el apoyo social percibido y la ideación suicida en 90 pacientes oncológicos adultos en Bogotá, bajo la hipótesis de que a mayor apoyo social percibido, menor presencia de ideación suicida. Se midió la variable de apoyo social a través del cuestionario Duke UNC y la ideación suicida a través de cuatro instrumentos: Escala de Ideación Suicida (SSI), Escala de Desesperanza de Beck (BHS), el ítem 9 del Inventario de Depresión de Beck (BDI-IA) y una entrevista semiestructurada. Los resultados mostraron que no existe relación entre el apoyo social percibido y la ideación suicida. Por otro lado se identificó una prevalencia de suicidio entre 5,6% y 22,77%, confirmando que el paciente con cáncer considera el suicidio y es fundamental evaluar esta variable en esta población. Se considera importante continuar con la realización de investigaciones que permitan generalizar los resultados a la población oncológica colombiana.
Resumo:
Esta investigación pretende alcanzar dos objetivos. Cubrir el vacío existente en los estudios de las funciones comunicativas del habla de profesores, en este caso de inglés como Lengua Extranjera (ILE) destinado a nivel preescolar, y configurar una interfaz discurso-gramática de las funciones reguladoras del lenguaje.. En primer lugar, para lograr un análisis discursivo-semántico, en este trabajo se diseña la Red Sistémica de Funciones Reguladoras, RSFR, una herramienta que resume las diferentes opciones discursivo-semánticas de los contextos de las funciones reguladoras. A continuación, se analizan los datos en el estrato léxico-gramatical para facilitar conclusiones sobre la relación función-realización formal. Por último se exponen las similitudes y diferencias en la producción lingüística de las funciones reguladoras entre profesores nativos y no nativos.. Las aportaciones más destacadas de esta investigación son cuatro: hacer posible un estudio sistemático del significado mediante el diseño de una herramienta; la propuesta de una taxonomía de funciones reguladoras; el análisis de la dependencia entre las funciones reguladoras, y sus realizaciones lingüísticas; y las diferencias encontradas en la comparación del discurso del profesor nativo y no-nativo..
Resumo:
EL mensaje de que la ciencia no es sólo un conjunto de conocimientos, sino también una forma de trabajar parece que ha llegado a los profesores, pero todavía no ha calado en los niños. A pesar de los esfuerzos por acercar la Ciencia a los alumnos de primaria, éstos no comprenden del todo bien el proceso o los efectos de la investigación científica. Por este motivo, el objetivo de este texto es ayudar a los docentes a saber transmitir este mensaje a sus alumnos, y lo que es más importante, que éstos sientan muy de cerca la Ciencia.
Resumo:
Este documento es un intento de dar orientación y apoyo a los profesores en la organización de la enseñanza de las ciencias de investigación, en el nivel primario. Se presentan distintas actividades, flexibles para los docentes, a fin de que los niños participen en las distintas etapas del proceso de investigación: planificación, obtención y visualización de resultados y, conclusión y evaluación. Así, desarrolla unos conceptos que permitan la progresión en los conocimientos y en las pruebas prácticas de los alumnos, a nivel individual y, para los diferentes niveles educativos. Se incluyen hojas en blanco para ser rellenadas por los alumnos con sus conclusiones de cada uno de los procesos investigados.
Resumo:
Para animar a los niños a practicar y consolidar la utilización y aplicación de las matemáticas. Las investigaciones desarrollan la capacidad para resolver problemas, otras habilidades y conceptos para que los niños puedan aplicar sus conocimientos matemáticos a otras áreas del currículo. Contiene aproximadamente sesenta investigaciones, cada una corresponde a un objetivo del currículo renovado que pueden ser integradas en la lección diaria de matemáticas. Ofrece orientación sobre la forma de evaluar el progreso del alumno. Viene con un CD-ROM de modo que el profesor pueda adaptar la investigaciones a las necesidades de su clase.
Resumo:
Para animar a los niños a practicar y consolidar la utilización y aplicación de las matemáticas. Las investigaciones desarrollan la capacidad para resolver problemas, otras habilidades y conceptos para que los niños puedan aplicar sus conocimientos matemáticos a otras áreas del currículo. Contiene aproximadamente sesenta investigaciones, cada una corresponde a un objetivo del currículo renovado que pueden ser integradas en la lección diaria de matemáticas. Ofrece orientación sobre la forma de evaluar el progreso del alumno. Viene con un CD-ROM de modo que el profesor pueda adaptar la investigaciones a las necesidades de su clase.
Resumo:
Monográfico con el título: 'Aprendizaje basado en problemas'.Resumen basado en el de la publicación
Resumo:
Resumen tomado de la publicación
Resumo:
Resumen basado en la publicaci??n
Resumo:
An analytic method to evaluate nuclear contributions to electrical properties of polyatomic molecules is presented. Such contributions control changes induced by an electric field on equilibrium geometry (nuclear relaxation contribution) and vibrational motion (vibrational contribution) of a molecular system. Expressions to compute the nuclear contributions have been derived from a power series expansion of the potential energy. These contributions to the electrical properties are given in terms of energy derivatives with respect to normal coordinates, electric field intensity or both. Only one calculation of such derivatives at the field-free equilibrium geometry is required. To show the useful efficiency of the analytical evaluation of electrical properties (the so-called AEEP method), results for calculations on water and pyridine at the SCF/TZ2P and the MP2/TZ2P levels of theory are reported. The results obtained are compared with previous theoretical calculations and with experimental values
Resumo:
The influence of the basis set size and the correlation energy in the static electrical properties of the CO molecule is assessed. In particular, we have studied both the nuclear relaxation and the vibrational contributions to the static molecular electrical properties, the vibrational Stark effect (VSE) and the vibrational intensity effect (VIE). From a mathematical point of view, when a static and uniform electric field is applied to a molecule, the energy of this system can be expressed in terms of a double power series with respect to the bond length and to the field strength. From the power series expansion of the potential energy, field-dependent expressions for the equilibrium geometry, for the potential energy and for the force constant are obtained. The nuclear relaxation and vibrational contributions to the molecular electrical properties are analyzed in terms of the derivatives of the electronic molecular properties. In general, the results presented show that accurate inclusion of the correlation energy and large basis sets are needed to calculate the molecular electrical properties and their derivatives with respect to either nuclear displacements or/and field strength. With respect to experimental data, the calculated power series coefficients are overestimated by the SCF, CISD, and QCISD methods. On the contrary, perturbation methods (MP2 and MP4) tend to underestimate them. In average and using the 6-311 + G(3df) basis set and for the CO molecule, the nuclear relaxation and the vibrational contributions to the molecular electrical properties amount to 11.7%, 3.3%, and 69.7% of the purely electronic μ, α, and β values, respectively