15,409 research outputs found
Intrinsic disorder in cell signaling and gene transcription
No full textStructural disorder, which enables unique modes of action often associated with molecular recognition and folding induced by a partner, is widespread in eukaryotic proteomes. Due to the ensuing advantages, such as specificity without strong binding, adaptability to multiple partners and subtle regulation by post-translational modification, structural disorder is prevalent in proteins of signaling and regulatory functions, such as membrane receptors, scaffold proteins, cytoskeletal proteins, transcription factors and nuclear hormone receptors. In this review we survey the most important aspects of structural disorder, with major focus on features and advantages pertinent to signal transduction. Our major goal is to elucidate how the functional requirements of these protein classes concur with specific functional modes disorder enables.open
Sobre la evolución de los tantos de interes
No full textRESUMENEl propósito de este trabajo es desarrollar una metodología general de la variación delos tantos de interés que juegan un importante papel en la valoraci´on de la funciones actuariales.Se extiende la teoría tradicional irrealista de los tantos de interés deterministas ygeneralmente constantes, a la teoría que considera distintos modelos de variabilidad de lostantos de interés: modelos de tanto de interés deterministas; modelos de tantos de interésindependientes; modelos de tanto de interés dependientes; modelos estocásticos.ABSTARCT The purpose of this work is to develop a general methodology of the variation ofinterest rates, in many of which play an important role in the valuation of actuarialfunctions. It extends the unrealistic traditional theory of deterministics interest ratesand generally constant, to the theory that considers different models of variability in theinterest rates: models of deterministics interest rates; models of independent interest rates;models of dependent interest rates; stochastic models
¿Por qué hay tantos festivales en España?
No full textLos festivales artísticos son una excelente plataforma de difusión, una ventana a través de la que, de una manera excepcional y singular, descubrir y disfrutar de nuevas o consolidadas propuestas y tendencias artísticas
Demonstratives, word order and the DP between syntax and semantics: crosslinguistic remarks
No full textThe contribution discusses instances of word order variation within nominal structures (DPs), with specific focus on the position of demonstrative elements, and proposes an attempt of a crosslinguistic analysis in a parametric perspective. After the inspection of relevant data collected on purpose, the hypothesis that both cross- and intra- linguistic differences depend on a cluster of features associated to the representation of definiteness in the DP will be explored. Demonstratives are described as merging in a “low” portion of the DP and thereafter attracted to the D-area by virtue of their (gradable) semantic properties related to the definiteness sphere, with variable effects on the surface string. When attracted to the D-area, they manifest D-properties (across different degrees, according to the features they share with the D-area itself) while they exhibit a more “adjectival” behavior when surfacing lower
Effect of vibrational degrees of freedom on the heat transfer in polyatomic gases confined between parallel plates
No full textConductive stationary heat transfer through rarefied nonpolar polyatomic gases, confined between parallel plates maintained at different temperatures, is investigated. It is assumed that gas molecules possess both rotational and vibrational degrees of freedom, described by the classical rigid rotator and quantum harmonic oscillator models, respectively. The flow structure is computed by the Holway kinetic model and the Direct Simulation Monte Carlo method. In both approaches the total collision frequency is computed according to the Inverse Power Law intermolecular potential. Inelastic collisions in DSMC simulations are based on the quantum version of the Borgnakke–Larsen collision model. Results are presented for N2, O2, CO2, CH4 and SF6 representing diatomic as well as linear and nonlinear polyatomic molecules with 1 up to 15 vibrational modes. The translational, rotational, vibrational and total temperatures and heat fluxes are computed in a wide range of the rarefaction parameter and for various ratios of the hot over the cold plate temperatures. Very good agreement, between the Holway and DSMC results is observed as well as with experiments. The effect of the vibrational degrees of freedom is demonstrated. In diatomic gases the vibrational heat flux varies from 5% up to 25% of the total one. Corresponding results in polyatomic gases with a higher number of vibrational modes show that even at low reference temperatures the contribution of the vibrational heat flux may be considerably higher. For example in the case of SF6 at 300 K and 500 K the vibrational heat flux is about 67% and 76% respectively of the total heat flux. Furthermore, it is numerically proved that the computed solutions are in agreement with the Chapman–Enskog approximation in a central strip of the computational domain even at moderately large values of the rarefaction parameter, as found in previous investigations. This property has been used to compute the gas thermal conductivity predicted by the adopted models
Comentario: A uno de tantos: El mundo quiere ser engañado
No full textPapel. - Artículo titulado COMENTARIO: A UNO DE TANTOS: EL MUNDO QUIERE SER ENGAÑADO publicado en AHORA (MADRID). - Procedencia: fondo Miguel de Unamuno. - Conservación: Buena
Structural disorder and local order of hNopp140
No full textHuman nucleolar phosphoprotein p140 (hNopp 140) is a highly phosphorylated protein inhibitor of casein kinase 2 (CK2). As in the case of many kinase-inhibitor systems, the inhibitor has been described to belong to the family of intrinsically disordered proteins (IDPs), which often utilize transient structural elements to bind their cognate enzyme. Here we investigated the structural status of this protein both to provide distinct lines of evidence for its disorder and to point out its transient structure potentially involved in interactions and also its tendency to aggregate. Structural disorder of hNopp140 is apparent by its anomalous electrophoretic mobility, protease sensitivity, heat stability, hydrodynamic behavior on size-exclusion chromatography, 1H NMR spectrum and differential scanning calorimetry scan. hNopp140 has a significant tendency to aggregate and the change of its circular dichroism spectrum in the presence of 0-80% TFE suggests a tendency to form local helical structures. Wide-line NMR measurements suggest the overall disordered character of the protein. In all, our data suggest that this protein falls into the pre-molten globule state of IDPs, with a significant tendency to become ordered in the presence of its partner as demonstrated in the presence of transcription factor IIB (TFIIB).open
EDITORIAL - Publicar a Educar em Revista em meio a tantos solavancos e retrocessos
No full textDepois de tantos meses e um longo período de pandemia no mundo, imaginávamos que o editorial de 2021 pudesse assumir outra perspectiva, mais alentadora e esperançosa. De certo modo, chegamos ao final deste ano com prospectiva positiva de uma moderada transição de tempos de isolamento para novas práticas de convívio social, devido ao avanço no processo de vacinação contra a Covid19. Entretanto, no Brasil, as dificuldades não se referem apenas à dimensão sanitária (o que já seria grave o suficiente), mas têm relação com aspectos da vida política, econômica, cultural, educativa e também acadêmica. Em poucas linhas, não será possível aqui sintetizar, tantos retrocessos sofridos por nós brasileiros, mas destacar alguns temas que nos afetam diretamente na condição de um periódico educacional.
Polyatomic thermal creep flows through long microchannels at large temperature ratios
No full textRarefied polyatomic gas flows through long microchannels of circular cross section due to small temperature and pressure gradients have been studied on the basis of the Rykov model in a wide range of the gas rarefaction and for various values of the reference flow temperature. Results are presented for N2, CO2, CH4, and SF6 representing linear and nonlinear polyatomic gas molecules. The present numerical results for N2 and CO2 are in good agreement with the corresponding results of previous studies. In addition, a simple method of calculation of the thermal creep under large temperature differences, which has been proposed in previous studies for monatomic gases, is extended in the present work in the case of polyatomic gases. The results based on the polyatomic modeling differ significantly from the corresponding monatomic ones and the differences depend on the gas rarefaction, the working gas, and the flow temperature. Special attention is also given to the computation of the thermomolecular pressure effect in the case of polyatomic gases under large temperature ratios. Furthermore, the dependence of both the thermal creep and the thermomolecular pressure effect on the viscosity variation with temperature along the microchannel is pointed out. Finally, the numerical data are provided as supplementary material for modeling any polyatomic gas flow in a wide range of the gas rarefaction and flow temperatures. © 2019 Author(s)
MARCELO BACKES. A arte do combate. A literatura alemã em cento e poucas chispas poéticas e outros tantos comentários
No full textMichael J. MARCELO BACKES. A arte do combate. A literatura alemã em cento e poucas chispas poéticas e outros tantos comentários. Margem esquerda. 2004;4:219-221
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