Unidirectionality
Mostrando 1-6 de 6 artigos, teses e dissertações.
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1. A gramaticalização do item "fora" no Português do Brasil: a unidirecionalidade do processo / Grammaticalization of lexical item "fora" in portuguese of Brazil: the unidirectionality of process
In a theoretical functionalist framework, which prioritizes the study of the language in constant change from its use (HALLIDAY, 1978), it is analyzed the grammatical and semantic alterations on a lexical item that suffers grammaticalization in the Portuguese from Brazil. The most general objective is to evaluate the existing difference among the models of a
Publicado em: 2008
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2. Prefixes derived from prepositions in texts of the portuguese of the 17th and 18th centuries. / Prefixos derivados de preposições em textos de língua portuguesa dos séculos XVII e XVIII.
This research, of the functionalist type, named Prefixes derived from prepositions in texts of the Portuguese of the 17th and 18th centuries, is intended to identify the processes and principles of grammaticalization applicable to the change preposition >prefix, as well as to analyze the semantic aspects of such a change, based on the theories of localism an
Publicado em: 2006
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3. Direction of deoxyribonucleic acid transfer and replication in a derivative of plasmid R100-1.
The site of integration and the molecular orientation of a prophage Mu integrated within the resistance transfer factor component of plasmid R100-1 have been determined on the physical map of the plasmid. This allowed us (i) to determine the direction of deoxyribonucleic acid transfer from oriT during conjugation and (ii) to demonstrate the unidirectionality
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4. Tandem insertion sequence-like elements define the expression site for variable antigen genes of Borrelia hermsii.
The spirochete Borrelia hermsii avoids the immune response of its mammalian host through multiphasic antigenic variation. Serotype specificity is determined by variable antigens, Vmp proteins, in the outer membrane. Through nonreciprocal recombination between linear plasmids, a formerly silent vmp gene replaces another vmp gene downstream from a common expre
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5. Apparently unidirectional polyamine transport by proton motive force in polyamine-deficient Escherichia coli.
A transport system for polyamines was studied with both intact cells and membrane vesicles of an Escherichia coli polyamine-deficient mutant. Polyamine uptake by intact cells and membrane vesicles was inhibited by various protonophores, and polyamines accumulated in membrane vesicles when D-lactate was added as an energy source or when a membrane potential w
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6. Evidence for two active branches for electron transfer in photosystem I
All photosynthetic reaction centers share a common structural theme. Two related, integral membrane polypeptides sequester electron transfer cofactors into two quasi-symmetrical branches, each of which incorporates a quinone. In type II reaction centers [photosystem (PS) II and proteobacterial reaction centers], electron transfer proceeds down only one
The National Academy of Sciences.