1,108 research outputs found
Comparing the performance of two structural indicators for different water models while seeking for connections between structure and dynamics in the glassy regime
In this work, we compare the performance of two structural indicators based on the degree of translational order up to the second coordination shell in three water models: SPC/E, TIP4P/2005, and TIP5P. Beyond directly contrasting their distributions for different temperatures to evidence their usefulness in estimating the fraction of structured and unstructured molecules and, when possible, their classification capability, we also correlate them with an indirect measure of structural constraint: the dynamic propensity. Furthermore, this procedure enables us to show the existence of evident correlations between structural and dynamical information. More specifically, we find that locally structured molecules display a preference for low dynamic propensity values and, more conspicuously, that locally unstructured molecules are extremely subject to high dynamic propensity. This result is particularly relevant for the supercooled regime where the establishment of firm links between the structure and dynamics has remained rather elusive since the occurrence of dynamics that vary in orders of magnitude upon supercooling usually contrast with barely noticeable overall structural changes.Fil: Verde, Alejandro Raúl. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; ArgentinaFil: Montes de Oca, Joan Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; ArgentinaFil: Accordino, Sebastián R.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; ArgentinaFil: Alarcón, Laureano M.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; ArgentinaFil: Appignanesi, Gustavo Adrian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; Argentin
\pi N scattering in relativistic baryon chiral perturbation theory revisited
We have analyzed pion-nucleon scattering using the manifestly relativistic
covariant framework of Infrared Regularization up to {\cal O}(q^3) in the
chiral expansion, where q is a generic small momentum. We describe the
low-energy phase shifts with a similar quality as previously achieved with
Heavy Baryon Chiral Perturbation Theory, \sqrt{s}\lesssim1.14 GeV. New values
are provided for the {\cal O}(q^2) and {\cal O}(q^3) low-energy constants,
which are compared with previous determinations. This is also the case for the
scattering lengths and volumes. Finally, we have unitarized the previous
amplitudes and as a result the energy range where data are reproduced increases
significantly.Comment: 26 pages, 5 figures, 5 table
El aceite de oliva extra virgen y su fracción polifenólica previenen la respuesta inflamatoria y el daño articular en un modelo de artritis experimental en murino
The consumption of EVOO in Mediterranean countries has shown beneficial effects. A wide range of evidence indicates that the phenolic compounds present in EVOO are endowed with anti-inflammatory properties. In this work, we evaluated the effects of dietary EVOO and treatment with its phenolic extract (PE) in a model of RA, the collagen-induced arthritis (CIA) in mice. On day 0, DBA-1/J mice were immunized with bovine collagen type II (CII). On day 21, the mice received a booster injection. We have demonstrated that EVOO and its PE decreases joint edema, cell migration, cartilage degradation and bone erosion. Our data indicate that dietary EVOO and PE treatment inhibit JNK, p38 and signal transducer and STAT-3. In addition, both EVOO and PE decrease NF-κB translocation leading to the down-regulation of the arthritic process. These results support the interest of natural diet components in the development of therapeutic products for arthritic conditions.El consumo de Aceite de oliva virgen extra (AOVE) en los países mediterráneos ha demostrado tener efectos beneficiosos. Una amplia gama de pruebas indica que los compuestos fenólicos presentes en el AOVE tienen propiedades anti-inflamatorias. En este trabajo, se evaluaron los efectos de AOVE y el tratamiento en dieta de su fracción polifenólica (FP) en un modelo de la artritis reumatoide inducida por colágeno (CIA) en ratones. En el día 0, los ratones DBA-1/J se inmunizaron con colágeno bovino tipo II (CII). En el día 21, los ratones recibieron una inyección de refuerzo. Hemos demostrado que el AOVE y su FP disminuyen conjuntamente el edema, la migración celular, la degradación del cartílago y erosión ósea. Nuestros datos indican que la dieta con AOVE y el tratamiento con FP inhiben JNK, p38 y el transductor de señal y activador de la transcripción 3 (STAT-3). Además, tanto el AOVE como la FP disminuyen la translocación NF-κB que conduce a la mejora del proceso artrítico. Estos resultados apoyan el interés de una dieta con componentes naturales y el desarrollo de productos terapéuticos para desordenes artríticos
Sobolev spaces of vector-valued functions
We are concerned here with Sobolev-type spaces of vector-valued functions.
For an open subset and a Banach space , we
compare the classical Sobolev space with the so-called
Sobolev-Reshetnyak space . We see that, in general,
is a closed subspace of . As a main
result, we obtain that if, and only if,
the Banach space has the Radon-Nikod\'ym propert
The effects of intrinsic noise on the behaviour of bistable cell regulatory systems under quasi-steady state conditions
We analyse the effect of intrinsic fluctuations on the properties of bistable
stochastic systems with time scale separation operating under1 quasi-steady
state conditions. We first formulate a stochastic generalisation of the
quasi-steady state approximation based on the semi-classical approximation of
the partial differential equation for the generating function associated with
the Chemical Master Equation. Such approximation proceeds by optimising an
action functional whose associated set of Euler-Lagrange (Hamilton) equations
provide the most likely fluctuation path. We show that, under appropriate
conditions granting time scale separation, the Hamiltonian can be re-scaled so
that the set of Hamilton equations splits up into slow and fast variables,
whereby the quasi-steady state approximation can be applied. We analyse two
particular examples of systems whose mean-field limit has been shown to exhibit
bi-stability: an enzyme-catalysed system of two mutually-inhibitory proteins
and a gene regulatory circuit with self-activation. Our theory establishes that
the number of molecules of the conserved species are order parameters whose
variation regulates bistable behaviour in the associated systems beyond the
predictions of the mean-field theory. This prediction is fully confirmed by
direct numerical simulations using the stochastic simulation algorithm. This
result allows us to propose strategies whereby, by varying the number of
molecules of the three conserved chemical species, cell properties associated
to bistable behaviour (phenotype, cell-cycle status, etc.) can be controlled.Comment: 33 pages, 9 figures, accepted for publication in the Journal of
Chemical Physic
Spectral-analysis-surface-waves-method in ground characterization
The prediction of train induced vibration levels in structures close to railway tracks before track construction starts is important in order to avoid having to implement costly mitigation measures afterwards. The used models require an accurate characterization of the propagation medium i.e. the soil layers. To this end the spectral analysis of surface waves (SASW) method has been chosen among the active surface waves techniques available. As dynamic source a modal sledge hammer has been used. The generated vibrations have been measured at known offsets by means of several accelerometers. There are many parameters involved in estimating the experimental dispersion curve and, later on, thickness and propagation velocities of the different layers. Tests have been carried out at the Segovia railway station. Its main building covers some of the railway tracks and vibration problems in the building should be avoided. In the paper these tests as well as the influence of several parameters on the estimated soil profile will be detailed
A multiscale model of epigenetic heterogeneity-driven cell fate decision-making
Altres ajuts: Obra Social La Caixa Foundation on Collaborative Mathematics awarded to the Centre de Recerca MatemàticaAltres ajuts: CERCA Programme/Generalitat de CatalunyaThe inherent capacity of somatic cells to switch their phenotypic status in response to damage stimuli in vivo might have a pivotal role in ageing and cancer. However, how the entryexit mechanisms of phenotype reprogramming are established remains poorly understood. In an attempt to elucidate such mechanisms, we herein introduce a stochastic model of combined epigenetic regulation (ER)-gene regulatory network (GRN) to study the plastic phenotypic behaviours driven by ER heterogeneity. To deal with such complex system, we additionally formulate a multiscale asymptotic method for stochastic model reduction, from which we derive an efficient hybrid simulation scheme. Our analysis of the coupled system reveals a regime of tristability in which pluripotent stem-like and differentiated steady-states coexist with a third indecisive state, with ER driving transitions between these states. Crucially, ER heterogeneity of differentiation genes is for the most part responsible for conferring abnormal robustness to pluripotent stem-like states. We formulate epigenetic heterogeneity-based strategies capable of unlocking and facilitating the transit from differentiation- refractory (stem-like) to differentiation-primed epistates. The application of the hybrid numerical method validates the likelihood of such switching involving solely kinetic changes in epigenetic factors. Our results suggest that epigenetic heterogeneity regulates the mechanisms and kinetics of phenotypic robustness of cell fate reprogramming. The occurrence of tunable switches capable of modifying the nature of cell fate reprogramming might pave the way for new therapeutic strategies to regulate reparative reprogramming in ageing and cancer
Effects of irrigation and shoot thinning on the size and phenolics content of developing grape berries (Vitis vinifera L. cv. Tempranillo)
Aim of study: The concentration of phenolics in the grape berries can be influenced by cultural practices such as irrigation or thinning. The main objective of the present study was to evaluate the effect of combinations of these practices on grape size and phenolics content. Area of study: The trial was carried out in an experimental cv. Tempranillo vineyard located in Extremadura, Spain. Material and methods: Two irrigation regimes were considered: rainfed vines (non-irrigated, NIr), and 100% ETc irrigated vines (Ir). For each irrigation treatment, two cropping levels were studied: low shoot-thinning (LT) vs high shoot-thinning (HT) implemented in winter and spring, respectively. Berry weight, and total phenolics, proanthocyanidin, and anthocyanin concentrations were determined at eight stages of berry development in three consecutive years (2014, 2015, and 2016). Main results: Specific weather conditions of each year affected phenolics accumulation differently. In 2014, where maximum temperatures were low and an important rainfall occurred at Stage II, both the NIr-LT and NIr-HT treatments led to the greatest concentrations of total phenolics, proanthocyanidins, and anthocyanins. In 2015, where a little rainfall was registered at Stage II, the berries from the NIr-HT and Ir-HT treatments accumulated the greatest total phenolics and proanthocyanidin contents, but the NIr-LT and NIr-HT treatments led to the greatest accumulation of anthocyanins. Finally, in 2016, where high maximum temperatures and scarce rainfall were registered, the Ir-LT and Ir-HT treatments presented the greatest concentrations of total phenolics, proanthocyanidins, and anthocyanins. Research highlights: A significant effect of irrigation and thinning was observed on berry size and phenolic content, as well as year × thinning interaction
Evaluación de las asociaciones público privadas en el área metropolitana de Monterrey: Nivel de satisfacción en la prestación del servicio a los usuarios
La competitividad de los países en los diferentes ámbitos de la vida pública no se alcanza tan solo con el desempeño del sector privado, se requiere contar con un gobierno con estas mismas condiciones con las que se participa en lo privado, además de un alto desempeño. Sin embargo, cuando la administración pública no está en condiciones de ofrecer un servicio de calidad, este sedera dicho servicio a una concesión quien genere las condiciones para llevar con eficiencia y eficacia el servicio público municipal. Por otra parte los grandes cambios que se han estado dando en la prestación del servicio en la Administración Pública, han sigo generales en un contexto global, los países, incluyendo a México han iniciado procesos enfocados a reformas y modernización de la administración pública orientados a
adecuarse a las nuevas demandas de la ciudadanía.
Es necesario renovar los mecanismos y procesos de las instituciones de Gobierno con el fin de permitir que la administración pública responda con éxito a las exigencias de la sociedad. Contar con una modernización administrativa no solo exige desarrollar instituciones que promuevan el mejor desempeño de los funcionarios y permitan racionalizar el gasto, sino también crear procesos que hagan más flexible y legitimen la relación entre Gobierno y ciudadano
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