Optical and mechanical characterization of thin membranes for X-ray lithography

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1994.Includes bibliographical references (leaves 60-61).by Gabrielle M. Owen.M.Eng

Points de vue d’enseignants de sciences au premier cycle du secondaire sur les manuels scolaires dans le contexte de l’implantation des nouveaux programmes au Québec

Cet article présente les résultats d’une enquête réalisée auprès d’enseignants de sciences et technologies au secondaire, pour connaître leurs points de vue sur les manuels scolaires produits dans le contexte de la récente réforme éducative au Québec. Les données recueillies montrent que les enseignants préfèrent des manuels qui leur présentent de manière opérationnelle les savoirs disciplinaires et s’attendent à ce que ces manuels les soutiennent dans la préparation et dans la mise en oeuvre de leur enseignement. Ils se montrent par ailleurs très critiques au regard des manuels qui leur présentent des démarches d’enseignement-apprentissage dans lesquelles le cheminement est préétabli et fermé.This article presents the results of a survey conducted with secondary science and technology teachers to obtain their points of view on textbooks developed in the context of the recent education reform in Quebec. The data collected show that the teachers prefer to have textbooks that present an operational approach to the disciplines. The teachers also expect the textbooks to provide a support for the preparation and the implementation of their teaching. The teachers are very critical of textbooks that present teaching-learning approaches with pre-established and closed progressions.El artículo presenta los resultados de una encuesta que se llevó a cabo con docentes de ciencias y tecnologías en la secundaria para conocer sus puntos de vistas sobre los libros de texto producidos en el contexto de la reciente reforma educativa en Quebec. Los datos recolectados muestran que los docentes prefieren libros de texto que presentan los saberes disciplinarios de manera operacional y cuentan con que estos manuales les apoyan en la preparación y la elaboración de su enseñanza. Por otro lado, se muestran muy críticos con los libros de texto que presentan los pasos a seguir en el procesos de enseñanza-aprendizaje y en los cuales el camino está preestablecido y cerrado

Characterization of transgene expression in adenoviral vector-based HIV-1 vaccine candidates

Recombinant adenovirus vectors have been extensively used in gene therapy clinical studies. More recently, the capability of inducing potent cell-mediated and humoral immunity has made these vectors equally attractive candidates for prophylactic or therapeutic vaccine applications. Merck and Co., Inc., developed HIV-1 vaccine candidates based on adenovirus serotype 5 (Ad5) vectors in which the E1 gene, a critical component for adenovirus replication, was replaced by the cytomegalovirus immediate/early promoter, followed by mutated versions of the HIV-1 gag, pol or nef genes (constructs referred to as MRKAd5gag, MRKAd5pol and MRKAd5nef, respectively). Vaccine performance was evaluated in vitro in a novel assay that measures the level of transgene expression in non-permissive A549 cells. Various combinations of vectors were studied. The results indicate that the vaccine induces a dose-dependent expression of the HIV-1 transgenes in vitro. Furthermore, the gag, pol, and nef transgenes are expressed differentially in A549 cells in an MOI-dependent and formulation-dependent manner, yielding an unexpected enhancement of protein expression in trivalent vs. monovalent formulations. Our data suggest that the presence of additional virus in multivalent formulations increases individual transgene expression in A549 cells, even when the amount of DNA encoding the gene of interest remains constant. This enhancement appears to be controlled at the transcriptional level and related to both the total amount of virus and the combination of transgenes present in the formulation

D-Tree substitution grammars

There is considerable interest among computational linguists in lexicalized grammatical frame-works; lexicalized tree adjoining grammar (LTAG) is one widely studied example. In this paper, we investigate how derivations in LTAG can be viewed not as manipulations of trees but as manipulations of tree descriptions. Changing the way the lexicalized formalism is viewed raises questions as to the desirability of certain aspects of the formalism. We present a new formalism, d-tree substitution grammar (DSG). Derivations in DSG involve the composition of d-trees, special kinds of tree descriptions. Trees are read off from derived d-trees. We show how the DSG formalism, which is designed to inherit many of the characterestics of LTAG, can be used to express a variety of linguistic analyses not available in LTAG