A Experiência da Construção do Sujeito Ético-político nos Espaços do Fórum Bem Maior

RESUMO Esta dissertação discute a construção do sujeito ético-político nos espaços de um fórum de desenvolvimento comunitário, chamado Bem Maior, localizado na cidade de Vitória - ES. A partir da narrativa de algumas experiências vivenciadas junto ao Fórum Bem Maior e com base nas entrevistas que realizamos com 16 lideranças atuantes nesse espaço, buscamos acompanhar o processo de constituição ético-política da subjetividade engendrada quando do encontro com a alteridade. Recorremos, principalmente, ao pensamento de Michel Foucault, utilizando alguns de seus principais conceitos como ferramentas teóricas de modo a problematizar a relação entre política e ética. Isso possibilitou-nos pensar a experiência política situada exatamente na trama articulada entre o poder e a resistência, tomada nos termos éticos do cuidado de si. Esse estudo pretendeu ressaltar o componente ético de constituição da subjetividade como indispensável para a construção do sujeito político como cidadão e a possibilidade de limitação de relações de dominação e sujeição por meio de um exercício ético do cuidado e cultivo da liberdade. Palavras-chave: Cidadania; Ética; Política

Rab7A Is Required for Efficient Production of Infectious HIV-1

Retroviruses take advantage of cellular trafficking machineries to assemble and release new infectious particles. Rab proteins regulate specific steps in intracellular membrane trafficking by recruiting tethering, docking and fusion factors, as well as the actin- and microtubule-based motor proteins that facilitate vesicle traffic. Using virological tests and RNA interference targeting Rab proteins, we demonstrate that the late endosome-associated Rab7A is required for HIV-1 propagation. Analysis of the late steps of the HIV infection cycle shows that Rab7A regulates Env processing, the incorporation of mature Env glycoproteins into viral particles and HIV-1 infectivity. We also show that siRNA-mediated Rab7A depletion induces a BST2/Tetherin phenotype on HIV-1 release. BST2/Tetherin is a restriction factor that impedes HIV-1 release by tethering mature virus particles to the plasma membrane. Our results suggest that Rab7A contributes to the mechanism by which Vpu counteracts the restriction factor BST2/Tetherin and rescues HIV-1 release. Altogether, our results highlight new roles for a major regulator of the late endocytic pathway, Rab7A, in the late stages of the HIV-1 replication cycle

Effects of surfactant and urea on dynamics and viscoelastic properties of hydrophobically assembled supramolecular hydrogel

\u3cp\u3ePhysically associated hydrogels based on strong hydrophobic interactions often have attractive mechanical properties that combine processability with elasticity. However, there is a need to study such interactions and understand their relation to the macroscopic hydrogel properties. Therefore, we use the surfactant sodium dodecyl sulfate (SDS) and urea as reagents that disrupt hydrophobic interactions. The model hydrogel is based on a segmented copolymer between poly(ethylene glycol) (PEG) and hydrophobic dimer fatty acid (DFA). We show that both agents influence viscoelastic properties, dynamics, and relaxation processes of the model hydrogel. In particular, the relaxation time is significantly reduced by urea, as compared to SDS, whereas the surfactant causes a decrease of the modulus of the hydrogel more efficiently. The reversibility of the effects of SDS and urea can be exploited, for instance, by using an injectable sol that solidifies when the SDS or urea diffuses out of the sample. Surfactant-induced processability may be advantageous in future applications of hydrophobically assembled physical hydrogels.\u3c/p\u3

Nonlinear Viscoelasticity of Colloidal Supercooled Liquids

Many metastable complex fluids such as colloidal glasses and gels show distinct nonlinear viscoelasticity with increasing oscillatory-strain amplitude; the storage modulus decreases monotonically as the strain amplitude increases whereas the loss modulus has a distinct peak before it decreases at larger strains. We present a qualitative argument to explain this ubiquitous behavior and use mode-coupling theory (MCT) to confirm it. We compare theoretical predictions to the measured nonlinear viscoelasticity in a dense hard-sphere colloidal suspension; reasonable agreement is obtained. The argument given here can be used to obtain new information about linear viscoelasticity of metastable complex fluids from nonlinear strain measurements

Diffusing-wave spectroscopy of concentrated alumina suspensions during gelation

Using diffusing-wave spectroscopy, we followed the aggregation and gelation of concentrated (30 vol%) alumina suspensions. The suspensions were destabilized by either shifting the pH to the isoelectric point or by increasing the ionic strength. Both effects can be achieved continuously and homogeneously by using an enzyme-catalyzed internal chemical reaction. Based on the light-scattering data, we could derive quantitative information about the sol–gel transition and the viscoelastic properties of the gels, as well as a characterization of changes in the microstructure. The elastic moduli determined from light scattering are found to be in good agreement with rheological measurements