Papel da localização da carga em determinação dos parâmetros do canal iônico

To aureus α-HL channel, we used the cysteine-scanning mutagenesis technique. Twenty-four mutants were produced from the substitution of a single aminoacid of the primary structure of the α-HL pro this yzed after the incorporation of a mutant channel in planar lipid bilayer membranes. The modified proteins were studied in the absence and presence of watersoluble specific sulphydryl-specific reagents, in order to introduce a strong positive or negative harge at positions of substitution. The introduction of a negative charge in the stem region onverted the selectivity of the channel from weak anionic to more cationic. However, the troduction of a positive charge increased its selectivity to the anion. The degree of these alterations was inversely dependent on the channel radius at the position of the introduced harge (selectivity). As to the asymmetry of the conductance-voltage, the influence of the harge was more complex. The introduction of the negative charge in the stem region (the trans art of the pore) provoked a decrease. The intensity of these alterations depended on the radius, and on the type of free charge at the pore entrance. These results suggest that the free charge at surrounds the pore wall is responsible for the cation-anion selectivity of the channel. The istribution of the charges between the entrances is crucial for determining the asymmetry of e conductance-voltage curves. We hope that these results serve as a model for studies with other nanometric channels, in biological or planar lipid bilayer membranes or in iotechnological applications

Acionamento de frames e esquemas no processo de construção de sentidos no padrão discursivo charge por alunos do ensino médio

Our research has as goal to describe and analyze the main processes related to the activation of conceptual domains underlying the comprehension in the discourse pattern cartoons by the students of third grades of high school, at Professor Antonio Basílio Filho School. Theoretically, we are grounded on assumptions of Conceptual Linguistics, whose interest analyzes our cognitive apparatus in correlation with our socio-cultural and bodies experiences. We intend to check how is the process of meaning construction and integration of various cognitive domains that are activated during the reading activity. That s why, we take the concept of cognitive domains as equivalent to the structures that are stored in our memory from our sociocultural and corporeal experiences and they are stabilized, respectively, through the frames and schemas. The activation of these conceptual domains, as evidenced by our data, supports the assumption that previous knowledge from our inclusion in specific sociocultural contexts, concurrently with the functioning of our sensory-motor system are essential during the construction activity direction. With this research, we still intend to present a proposal confront the expectations of responses produced by students from the activation of frames and schemas with our predictions

Uma visão axiológica do riso na charge

O objetivo deste trabalho é investigar a construção axiológica do riso na charge. Nesse gênero discursivo abordaremos a construção do riso, partindo da hipótese de que o riso constitutivo das relações dialógicas na charge é construído axiologicamente, ou seja, é um riso que presentifica enunciativamente e é por meio dele que chegamos ao axiológico, aos posicionamentos, ao ideológico. Para tanto, nos deteremos na investigação dos elementos verbo-visuais presentes na forma composicional como também do projeto de dizer constituidor/constituinte da forma arquitetônica. Tomamos como fundamento teórico-metodológico as formulações sobre linguagem advindas do Círculo de Bakhtin (2010, 2011, 1998) e outros tais como Faraco (2009), Brait (2009, 2006), Ponzio (2009) que comungam dessa concepção de linguagem. Especificamente sobre o gênero discursivo charge, nos reportamos a Ramos (2009, 2010, 2011) e Vergueiro (2009, 2010). Quanto ao riso, apoiamo-nos em autores como Possenti (2010), Minois (2003), Propp (1992), Bergson (2001), Skinner (2002), no entanto, tendo por principal referência a obra de Bakhtin sobre cosmovisão carnavalesca e riso (1997, 2010). Este trabalho se insere na área da Linguística Aplicada de perspectiva sócio-histórica e tem como tema linguagem, axiologia e riso