370 research outputs found
Socialization of the elderly in outdoor health circuits
En los parques biosaludables, originalmente concebidos para la población madura y anciana, se encuentran usuarios de diferentes edades y con distintas formas de entender la actividad física. El presente trabajo intenta examinar las relaciones de las personas mayores con el resto de usuarios para determinar en qué medida dichos parques pueden cumplir alguna función social más allá del fomento de hábitos saludables. Para ello se ha llevado a cabo una serie de observaciones, participantes y no participantes, en tres parques de la ciudad de Granada, donde se ha visto que, si bien existe una proporción minoritaria pero importante de usuarios jóvenes (aproximadamente un tercio del total), estos tienden a evitar una interacción que parte de los usuarios de mayor edad buscan expresamente
Prominent effect of soil network heterogeneity on microbial invasion
Using a network representation for real soil samples and mathematical models for microbial spread, we show that the structural heterogeneity of the soil habitat may have a very significant influence on the size of microbial invasions of the soil pore space. In particular, neglecting the soil structural heterogeneity may lead to a substantial underestimation of microbial invasion. Such effects are explained in terms of a crucial interplay between heterogeneity in microbial spread and heterogeneity in the topology of soil networks. The main influence of network topology on invasion is linked to the existence of long channels in soil networks that may act as bridges for transmission of microorganisms between distant parts of soil
PVS: a web server for protein sequence variability analysis tuned to facilitate conserved epitope discovery
We have developed PVS (Protein Variability Server), a web-based tool that uses several variability metrics to compute the absolute site variability in multiple protein-sequence alignments (MSAs). The variability is then assigned to a user-selected reference sequence consisting of either the first sequence in the alignment or a consensus sequence. Subsequently, PVS performs tasks that are relevant for structure-function studies, such as plotting and visualizing the variability in a relevant 3D-structure. Neatly, PVS also implements some other tasks that are thought to facilitate the design of epitope discovery-driven vaccines against pathogens where sequence variability largely contributes to immune evasion. Thus, PVS can return the conserved fragments in the MSA—as defined by a user-provided variability threshold—and locate them in a relevant 3D-structure. Furthermore, PVS can return a variability-masked sequence, which can be directly submitted to the RANKPEP server for the prediction of conserved T-cell epitopes. PVS is freely available at: http://imed.med.ucm.es/PVS/
Modelling avalanches in martensites
Solids subject to continuous changes of temperature or mechanical load often
exhibit discontinuous avalanche-like responses. For instance, avalanche
dynamics have been observed during plastic deformation, fracture, domain
switching in ferroic materials or martensitic transformations. The statistical
analysis of avalanches reveals a very complex scenario with a distinctive lack
of characteristic scales. Much effort has been devoted in the last decades to
understand the origin and ubiquity of scale-free behaviour in solids and many
other systems. This chapter reviews some efforts to understand the
characteristics of avalanches in martensites through mathematical modelling.Comment: Chapter in the book "Avalanches in Functional Materials and
Geophysics", edited by E. K. H. Salje, A. Saxena, and A. Planes. The final
publication is available at Springer via
http://dx.doi.org/10.1007/978-3-319-45612-6_
La socialización de las personas mayores en el parque biosaludable
The outdoor health circuits, originally conceived to be used by the mature and the elderly, is a meeting point for users of different ages and with different conceptions of physical activity. This paper attempts to examine the social relations of the elderly with the rest of users, in order to determine to what extent the health circuits might be fulfilling any other social function beyond encouraging healthy habits. To that end, a series of participant and non-participant observations have been carried in three circuits in Granada, where it has been observed that, while there is a significant minority of young users (approximately a third of the total number of users), these tend to avoid the interactions that some of the elderly users actively try to engage in.En los parques biosaludables, originalmente concebidos para la población madura y anciana, se encuentran usuarios de diferentes edades y con distintas formas de entender la actividad física. El presente trabajo intenta examinar las relaciones de las personas mayores con el resto de usuarios para determinar en qué medida dichos parques pueden cumplir alguna función social más allá del fomento de hábitos saludables. Para ello se ha llevado a cabo una serie de observaciones, participantes y no participantes, en tres parques de la ciudad de Granada, donde se ha visto que, si bien existe una proporción minoritaria pero importante de usuarios jóvenes (aproximadamente un tercio del total), estos tienden a evitar una interacción que parte de los usuarios de mayor edad buscan expresamente.
Reinforcement-Driven Spread of Innovations and Fads
We propose kinetic models for the spread of permanent innovations and
transient fads by the mechanism of social reinforcement. Each individual can be
in one of M+1 states of awareness 0,1,2,...,M, with state M corresponding to
adopting an innovation. An individual with awareness k<M increases to k+1 by
interacting with an adopter. Starting with a single adopter, the time for an
initially unaware population of size N to adopt a permanent innovation grows as
ln(N) for M=1, and as N^{1-1/M} for M>1. The fraction of the population that
remains clueless about a transient fad after it has come and gone changes
discontinuously as a function of the fad abandonment rate lambda for M>1. The
fad dies out completely in a time that varies non-monotonically with lambda.Comment: 4 pages, 2 columns, 5 figures, revtex 4-1 format; revised version has
been expanded and put into iop format, with one figure adde
Epidemics in Networks of Spatially Correlated Three-dimensional Root Branching Structures
Using digitized images of the three-dimensional, branching structures for
root systems of bean seedlings, together with analytical and numerical methods
that map a common 'SIR' epidemiological model onto the bond percolation
problem, we show how the spatially-correlated branching structures of plant
roots affect transmission efficiencies, and hence the invasion criterion, for a
soil-borne pathogen as it spreads through ensembles of morphologically complex
hosts. We conclude that the inherent heterogeneities in transmissibilities
arising from correlations in the degrees of overlap between neighbouring
plants, render a population of root systems less susceptible to epidemic
invasion than a corresponding homogeneous system. Several components of
morphological complexity are analysed that contribute to disorder and
heterogeneities in transmissibility of infection. Anisotropy in root shape is
shown to increase resilience to epidemic invasion, while increasing the degree
of branching enhances the spread of epidemics in the population of roots. Some
extension of the methods for other epidemiological systems are discussed.Comment: 21 pages, 8 figure
On the athermal character of structural phase transitions
The significance of thermal fluctuations on nucleation in structural
first-order phase transitions has been examined. The prototype case of
martensitic transitions has been experimentally investigated by means of
acoustic emission techniques. We propose a model based on the mean
first-passage time to account for the experimental observations. Our study
provides a unified framework to establish the conditions for isothermal and
athermal transitions to be observed.Comment: 5 pages, 4 figures, accepted in Phys. Rev. Let
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