RESUMEN El objetivo del estudio fue comparar el significado otorgado de buen profesor por profesores y estudiantes universitarios pertenecientes a sistemas presenciales y a distancia. Se utilizó una muestra no probabilística y la técnica de redes semánticas como instrumento de recolección de datos. Para analizar la información, se emplearon métodos lineales y no lineales, basados en el análisis de grafos. Se elaboraron tres categorías genéricas de análisis, para ambos sistemas. Se encontró que los estudiantes y profesores de ambos sistemas difieren en cuanto a la jerarquía de las categorías y su contenido. Los estudiantes valoran los atributos personales sobre cualquier otra categoría, independientemente del sistema; mientras que los profesores sí hubo diferencias en el significado del constructo en función del sistema. Se señala la necesidad de diseñar estrategias de enseñanza de acuerdo con el sistema formativo.

RESUMO O objectivo deste documento era comparar o significado dado ao bom professor por professores universitários e estudantes pertencentes a sistemas de ensino presencial e à distância. Uma amostra não probabilística e a técnica da rede semântica foram utilizadas como instrumento de recolha de dados. Foram utilizados métodos lineares e não lineares baseados na análise gráfica para analisar a informação. Foram desenvolvidas três categorias genéricas de análise para ambos os sistemas. Verificou-se que estudantes e professores em ambos os sistemas diferiam em termos da hierarquia das categorias e do seu conteúdo. Os estudantes valorizam os atributos pessoais acima de qualquer outra categoria, independentemente do sistema; enquanto os professores diferiram no significado da construção de acordo com o sistema. A necessidade de conceber estratégias de ensino de acordo com o sistema formativo é apontada.

ABSTRACT The aim of this study was to compare the meaning given to good teacher by university professors and students belonging to on-site and distance learning systems. A non-probabilistic sample and the semantic network technique were used as data collection instruments. Linear and nonlinear methods based on graph analysis were used to analyze the information. Three generic categories of analysis were elaborated for both systems. It was found that students and teachers of both systems differed in terms of the hierarchy of the categories and their content. Students value personal attributes above any other category, regardless of the system; while teachers did differ in the meaning of the construct as a function of the system. The need to design teaching strategies according to the formative system is pointed out.

Neste trabalho, realizou-se um estudo por ressonância magnética nuclear de ¹H, 13C e 15N de derivados de 1,4-dihidropiridinas que contêm, nos grupos ésteres das posições C-3 e C-5, longas cadeias alquílicas ou funcionalizadas. Atribuíram-se inequivocamente os sinais dos espectros utilizando experimentos 1D e 2D (DEPT, nOe, HMQC, HMBC, COSY).

The ¹H , 13C and 15N NMR spectroscopic data for 1,4-dihydropyridine endowed with long alkyl and functionalized chain on C-3 and C-5, have been fully assigned by combination of one- and two dimensional experiments (DEPT, HMBC, HMQC, COSY, nOe).

This study examined the effects of domain of task and the intrasession verbal descriptions, as promoters of the formulation of a rule. An Experimental design with coupled group was used. The experimental group was exposed to different types of incomplete texts in three training conditions, to pass from one condition to another, the participants should show domain of task. The participants of coupled group for pass from one condition to another depended of the performance of the paired experimental participant. At the end of the training conditions, all participants were subjected to three transfer tests. Both groups of participants reported the rule at the end of each session. Results showed differences between groups in extrasituational test. A qualitative change was observed along of the conditions in both groups with regard to the rules reported. The results are discussed emphasizing the role played by the descriptions and the domain of the task and their relation with formulating general rules of performance.

El presente estudio evaluó los efectos del dominio de la tarea y las descripciones verbales intrasesión, como promotores de la formulación de una regla. Se utilizó un grupo experimental y otro acoplado. Los participantes del grupo experimental completaron diferentes tipos de textos incompletos a lo largo de tres condiciones de entrenamiento. Para pasar de una condición de entrenamiento a otra, los participantes debían mostrar el dominio de la tarea. Los participantes del grupo acoplado pasaron de una condición a otra según la ejecución del participante experimental apareado. Al término de las condiciones de entrenamiento todos los participantes solucionaron tres pruebas de transferencia. Ambos grupos de participantes reportaron la regla general de ejecución al término de cada sesión. Los resultados mostraron diferencias entre los grupos en la prueba extrasituacional. Se observó un cambio cualitativo a lo largo de las condiciones en ambos grupos con relación a las reglas reportadas. Los resultados se discuten enfatizando el papel jugado por las descripciones y el dominio de la tarea sobre la formulación de reglas generales de ejecución.

Se evaluó el efecto de las descripciones verbales y diferentes densidades de consecuencias en la adquisición y transferencia de una respuesta de igualación de primer orden, así como en la formulación de reglas. Participaron veinte estudiantes asignados a cuatro grupos que se diferenciaron por la presentación de textos incompletos al final de cada sesión y las densidades de las consecuencias. Las reglas solicitadas al final de cada sesión se analizaron elaborando categorías a partir de estudios previos. Se observaron efectos en la adquisición de la respuesta en entrenamiento y transferencia. Se discute que la ejecución efectiva no siempre conlleva la emergencia de reglas precisas, por otro lado se reveló efecto instruccional de los textos sobre la formulación de reglas precisas, así como la densidad de las consecuencias.

The effect of verbal descriptions and different amounts of consequences on the acquisition and transfer of a first order matching-to-sample response, as well as rule-formulation, was assessed. Twenty undergraduate students were assigned to four groups, which differentiated regarding the inclusion of incomplete texts and feedback at the end of each session. The rules, wrote down at the end of each session, were analyzed using categories derived from previous studies. The effects were observed at the response acquisition during the trainings and tests. It is discussed that an effective performance does not always lead to precise verbal descriptions and the instructional effect of the incomplete texts upon the formulation of effective rules.

Cytotoxicity assays of 24 new 3,5-disubstituted-tetrahydro-2H-1,3,5-thiadiazin-2-thione derivatives were performed. The 17 compounds with higher anti-epimastigote activity and lower cytotoxicity were, thereafter, screened against amastigote of Trypanosoma cruzi. Out of these 17 derivatives S-2d was selected to be assayed in vivo, because of its remarkable trypanocidal properties. To determine toxicity against J774 macrophages, a method based on quantification of cell damage, after 24 h, was used. Cell respiration, an indicator of cell viability, was assessed by the reduction of MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] to formazan. Anti-amastigote activity was estimated after 48 h by microscopic counts of May Grünwald-Giemsa-stained monolayers. Nifurtimox and benznidazole were used as reference drugs. For the in vivo experiences, mice were infected with 10(4) blood trypomastigotes and then treated during 15 days with S-2d or nifurtimox by oral route. All of the compounds were highly toxic at 100 µg/ml for macrophages and a few of them maintained this cytotoxicity even at 10 µg/ml. Of the derivatives assayed against amastigotes 3k and S-2d showed an interesting activity, that was held even at 1µg/ml. It is demonstrated that the high anti-epimastigote activity previously reported is mainly due to the non-specific toxicity of these compounds. In vivo assays assessed a reduction of parasitemia after administration of S-2d to infected mice.