4,199 research outputs found
Ligand-biased ensemble receptor docking (LigBEnD): a hybrid ligand/receptor structure-based approach.
Ligand docking to flexible protein molecules can be efficiently carried out through ensemble docking to multiple protein conformations, either from experimental X-ray structures or from in silico simulations. The success of ensemble docking often requires the careful selection of complementary protein conformations, through docking and scoring of known co-crystallized ligands. False positives, in which a ligand in a wrong pose achieves a better docking score than that of native pose, arise as additional protein conformations are added. In the current study, we developed a new ligand-biased ensemble receptor docking method and composite scoring function which combine the use of ligand-based atomic property field (APF) method with receptor structure-based docking. This method helps us to correctly dock 30 out of 36 ligands presented by the D3R docking challenge. For the six mis-docked ligands, the cognate receptor structures prove to be too different from the 40 available experimental Pocketome conformations used for docking and could be identified only by receptor sampling beyond experimentally explored conformational subspace
Luxury branding e design gráfico : os elementos de comunicação das marcas de luxo
A gerência de uma marca de luxo é complexa e exige uma comunicação consistente e coerente ao longo do tempo. As marcas que participam desse setor da economia desenvolvem uma proposta que vai além da oferta produtos de qualidade, de alto desempenho e de autenticidade: implica na sintonia entre valor de marca e de vida do potencial cliente. Para a consolidação e manutenção de uma marca de luxo, as empresas precisam de ações estratégicas que as diferenciem criando o reconhecimento de uma identidade única na mente do consumidor. Este artigo analisa os elementos através dos quais as marcas de luxo se expressam e se comunicam para criar e manter esse reconhecimento. Metodologicamente, utiliza-se de pesquisa exploratória e descritiva através da técnica de levantamento bibliográfico e a observação direta. Deste ponto de partida, são abordados assuntos como a marca e as suas expressões, procurando identificar e compreender os seus elementos de expressão e expor a participação do Design Gráfico através das ações de luxury branding
Statistical analysis of entropy correction from topological defects in Loop Black Holes
In this paper we discuss the entropy of quantum black holes in the LQG
formalism when the number of punctures on the horizon is treated as a quantum
hair, that is we compute the black hole entropy in the grand canonical (area)
ensemble. The entropy is a function of both the average area and the average
number of punctures and bears little resemblance to the Bekenstein-Hawking
entropy. In the thermodynamic limit, both the "temperature" and the chemical
potential can be shown to be functions only of the average area per puncture.
At a fixed temperature, the average number of punctures becomes proportional to
the average area and we recover the Bekenstein-Hawking area-entropy law to
leading order provided that the Barbero-Immirzi parameter, , is
appropriately fixed. This also relates the chemical potential to . We
obtain a sub-leading correction, which differs in signature from that obtained
in the microcanonical and canonical ensembles in its sign but agrees with
earlier results in the grand canonical ensemble.Comment: 12 pages, no figures. Version to appear in Phys. Rev.
Caractéristiques biochimiques des acides humiques des sols tropicaux du Brésil : distinction fondamentale entre les sols équatoriaux et les sols des régions à climat tropical contrasté
Dynamics for a 2-vertex Quantum Gravity Model
We use the recently introduced U(N) framework for loop quantum gravity to
study the dynamics of spin network states on the simplest class of graphs: two
vertices linked with an arbitrary number N of edges. Such graphs represent two
regions, in and out, separated by a boundary surface. We study the algebraic
structure of the Hilbert space of spin networks from the U(N) perspective. In
particular, we describe the algebra of operators acting on that space and
discuss their relation to the standard holonomy operator of loop quantum
gravity. Furthermore, we show that it is possible to make the restriction to
the isotropic/homogeneous sector of the model by imposing the invariance under
a global U(N) symmetry. We then propose a U(N) invariant Hamiltonian operator
and study the induced dynamics. Finally, we explore the analogies between this
model and loop quantum cosmology and sketch some possible generalizations of
it.Comment: 28 pages, v2: typos correcte
Topographic effects on solar radiation distribution in mountainous watersheds and their influence on reference evapotranspiration estimates at watershed scale
Distributed energy and water balance models require time-series surfaces of the climatological variables involved in hydrological processes. Among them, solar radiation constitutes a key variable to the circulation of water in the atmosphere. Most of the hydrological GIS-based models apply simple interpolation techniques to data measured at few weather stations disregarding topographic effects. Here, a topographic solar radiation algorithm has been included for the generation of detailed time-series solar radiation surfaces using limited data and simple methods in a mountainous watershed in southern Spain. The results show the major role of topography in local values and differences between the topographic approximation and the direct interpolation to measured data (IDW) of up to +42% and −1800% in the estimated daily values. Also, the comparison of the predicted values with experimental data proves the usefulness of the algorithm for the estimation of spatially-distributed radiation values in a complex terrain, with a good fit for daily values (<i>R</i><sup>2</sup> = 0.93) and the best fits under cloudless skies at hourly time steps. Finally, evapotranspiration fields estimated through the ASCE-Penman-Monteith equation using both corrected and non-corrected radiation values address the hydrologic importance of using topographically-corrected solar radiation fields as inputs to the equation over uniform values with mean differences in the watershed of 61 mm/year and 142 mm/year of standard deviation. High speed computations in a 1300 km<sup>2</sup> watershed in the south of Spain with up to a one-hour time scale in 30 × 30 m<sup>2</sup> cells can be easily carried out on a desktop PC
A territorial view of the Chilean university system. The case of the regional University of Aysén (UAY)
Indexación: Scopus; Scielo.El análisis del caso de la Universidad de Aysén, que presenta este trabajo, permite describir y comprender algunas de las dificultades que muestran las universidades regionales en Chile para vincularse con su territorio e impactar en el desarrollo local. Este problema, que evidencia una arista de desigualdad y debilidad del sistema de educación chileno, es una constante en las diferentes evaluaciones nacionales e internacionales. Nuestra tesis es que estas dificultades son una de las tantas expresiones de la persistencia de un clivaje centro-periferia, que se manifiesta en una insensibilidad territorial o paradigma centralista de las políticas públicas en Chile, que con independencia de la orientación política del gobierno (democrática o autoritaria) o la preeminencia de la planificación estatal o del mercado como regulador del sistema, ha tendido a respuestas homogéneas y centralistas para enfrentar realidades y necesidades territoriales diversas.The analysis of the case of the University of Aysén presented in this work allows us to describe and understand
some of the difficulties that regional universities in Chile have in relation with their territory and their impact on
local development. This problem, which shows the inequality and weakness of the Chilean education system,
appears continually in various national and international assessments. Our thesis is that these difficulties are one
of the many expressions of the persistence of a center-periphery cleavage manifested in a territorial insensitivity
or centralist paradigm in public policies in Chile, which have been oriented towards homogeneous and centralist
responses in response to different needs and territorial realities. This situation happens regardless of the political
orientation of the government (democratic or authoritarian) or the pre-eminence of state or market planning as a
regulator of the system.https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0718-07052018000100427&lng=en&nrm=iso&tlng=e
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