Substitution Operators
Mostrando 1-12 de 13 artigos, teses e dissertações.
-
1. Fluxo de carga trifasico com modelagem de incertezas via função de pertinencia sinusoidal / Three-phase power flow with modelling of sinusoidal membership function
A fuzzy direct approach for unbalanced three-phase distribution load flow solutions was developed in this work. The special topological characteristics of distribution networks have been fully utilized to make the direct solution possible. Due to the distinctive solution techniques of the proposed method, the time-consuming LU decomposition and forward/backw
Publicado em: 2010
-
2. Substitution operators
NÃs estudamos um novo tipo de processo estocÃstico a tempo discreto, que nÃs chamamos de processos de substituiÃÃo. Como o tempo à discreto, nÃs podemos denir este processo atravÃs de um operador que transforma uma medida de probabilidade (em um certo espaÃo) em outra. Vale a pena notar que a maioria dos estudos de processos de partÃculas interagen
Publicado em: 2009
-
3. Multidimensional robust control, uncertainty and finance / Multidimensional robust control, uncertainty and finance
Optimal control theory has being a source of useful tools (including Euler equations, ztransforms, lag operators, Bellman equations, Kalman filtering) to study dynamic economics problems. A more recent field of optimal control, namely robust control, has recently been adopted by some leading economists (Thomas Sargent, Lars Hansen and coauthors) to study imp
Publicado em: 2006
-
4. MOORING PATTERN OPTIMIZATION USING GENETIC ALGORITHMS / OTIMIZAÇÃO DA DISPOSIÇÃO DE LINHAS DE ANCORAGEM UTILIZANDO ALGORITMOS GENÉTICOS
With the increasing demand for oil, oil companies have been forced to exploit new fields in deep waters. Due to the high cost of oil exploitation operations, the development of technologies capable of increasing efficiency and reducing costs is crucial. In this context, the use of floating units in deep waters has become more frequent. The positioning of the
Publicado em: 2005
-
5. Computação evolutiva empregada na reconstrução de arvores filogeneticas
This dissertation presents a study about one of the bioinformatic problems: the phylogenetic tree reconstruction. The solution space for this problem is calculated using a factorial formula. This is a combinatorial optimization problem. Evolutionary Computation, one of the component paradigms of computational intelligence, was proved to be a good tool to tac
Publicado em: 2001
-
6. Characterization of the interaction of the glp repressor of Escherichia coli K-12 with single and tandem glp operator variants.
The glp operons of Escherichia coli are negatively controlled by the glp repressor. Comparison of the repressor-binding affinities for consensus and altered consensus operators in vivo showed that all base substitutions at positions 3, 4, 5, and 8 from the center of the palindromic operator caused a striking decrease in repressor binding. Substitutions at ot
-
7. Analysis of the sequence-specific interactions between Cro repressor and operator DNA by systematic base substitution experiments.
We measured quantitatively the binding affinities of purified Cro repressor to the chemically synthesized wild-type and mutant OR1 operators, consisting of all three possible base-pair substitutions and of thymine to uracil substitutions at each base-pair position of the 17-base-pair operator sequence. The sequence-specific interactions between Cro repressor
-
8. Repression of bacteriophage promoters by DNA and RNA oligonucleotides.
We are interested in creating artificial gene repressors based on duplex DNA recognition by nucleic acids rather than polypeptides. An in vitro model system involving repression of bacteriophage T7 RNA polymerase initiation has been employed to demonstrate that certain DNA oligonucleotides can repress transcription by site-specific triple-helix formation at
-
9. Operator-bound GalR dimers close DNA loops by direct interaction: tetramerization and inducer binding
The assembly of the Gal repressosome, a higher order nucleoprotein complex that represses transcription of the gal operon in Escherichia coli, involves the formation of a DNA loop encompassing the promoter segment. GalR dimers bound to two spatially separated operators, OE and OI, specifically interact with the histone-like protein HU and close the loop in s
Oxford University Press.
-
10. Modified nucleotides reveal the indirect role of the central base pairs in stabilizing the lac repressor-operator complex.
Guanine residues in the lac operator were replaced by 2-aminopurine or purine analogues, pairing the modified nucleotides with C. The observed equilibrium dissociation constants for lac repressor binding to substituted operators were measured in 10 mM Tris, 150 mM KCl, 0.1 mM EDTA, 0.1 mM DTE, pH 7.6 at 25 degrees C. These measurements revealed five position
-
11. Studies on gene control regions XII. The functional significance of a lac operator constitutive mutation.
The functional significance of a lac operator constitutive mutation has been determined. The transition adenine-thymine to guanine-cytosine was shown to be a constitutive mutation simply because thymine contains the functionally important 5-methyl group whereas cytosine does not. The remainder of the base pair is of no consequence. The experimental approach
-
12. Two-hybrid system as a model to study the interaction of beta-amyloid peptide monomers.
The kinetics of amyloid fibril formation by beta-amyloid peptide (Abeta) are typical of a nucleation-dependent polymerization mechanism. This type of mechanism suggests that the study of the interaction of Abeta with itself can provide some valuable insights into Alzheimer disease amyloidosis. Interaction of Abeta with itself was explored with the yeast two-