1,078 research outputs found

    Spatio-temporal patterns driven by autocatalytic internal reaction noise

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    The influence that intrinsic local density fluctuations can have on solutions of mean-field reaction-diffusion models is investigated numerically by means of the spatial patterns arising from two species that react and diffuse in the presence of strong internal reaction noise. The dynamics of the Gray-Scott (GS) model with constant external source is first cast in terms of a continuum field theory representing the corresponding master equation. We then derive a Langevin description of the field theory and use these stochastic differential equations in our simulations. The nature of the multiplicative noise is specified exactly without recourse to assumptions and turns out to be of the same order as the reaction itself, and thus cannot be treated as a small perturbation. Many of the complex patterns obtained in the absence of noise for the GS model are completely obliterated by these strong internal fluctuations, but we find novel spatial patterns induced by this reaction noise in regions of parameter space that otherwise correspond to homogeneous solutions when fluctuations are not included.Comment: 12 pages, 18 figure

    Una nueva << Historia de la Iglesia en Hispanoamérica y Filipinas>>

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    Statistical Complexity and Nontrivial Collective Behavior in Electroencephalografic Signals

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    We calculate a measure of statistical complexity from the global dynamics of electroencephalographic (EEG) signals from healthy subjects and epileptic patients, and are able to stablish a criterion to characterize the collective behavior in both groups of individuals. It is found that the collective dynamics of EEG signals possess relative higher values of complexity for healthy subjects in comparison to that for epileptic patients. To interpret these results, we propose a model of a network of coupled chaotic maps where we calculate the complexity as a function of a parameter and relate this measure with the emergence of nontrivial collective behavior in the system. Our results show that the presence of nontrivial collective behavior is associated to high values of complexity; thus suggesting that similar dynamical collective process may take place in the human brain. Our findings also suggest that epilepsy is a degenerative illness related to the loss of complexity in the brain.Comment: 13 pages, 3 figure

    Complex noise in diffusion-limited reactions of replicating and competing species

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    We derive exact Langevin-type equations governing quasispecies dynamics. The inherent multiplicative noise has both real and imaginary parts. The numerical simulation of the underlying complex stochastic partial differential equations is carried out employing the Cholesky decomposition for the noise covariance matrix. This noise produces unavoidable spatio-temporal density fluctuations about the mean field value. In two dimensions, the fluctuations are suppressed only when the diffusion time scale is much smaller than the amplification time scale for the master species.Comment: 10 pages, 2 composite figure

    Health care for people with intellectual disability in Spain

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    We describe the healthcare system for people with intellectual disability (ID) in Spain. First, we provide general population statistics before focusing on the most recent prevalence data related to people with disability in general, and with ID in particular. We also discuss how health care is organized. Most of the Spanish population is covered by the public healthcare system, which is structured into primary care (first-level health services; easily accessible and capable of tackling the most common ailments) and specialized care (second-level health services; comprising the most complex and costly diagnostic and therapeutic resources). We then explain Spain's primary legislation that promotes the rights of people with disabilities, highlighting the importance of the United Nations Convention on the Rights of Persons with Disabilities (CRPD), which is enshrined in the Spanish General Law on the Rights of People with Disabilities and their Social Inclusion (Royal Legislative Decree 1/2013). Second, we describe the organization of Spanish disability support and health services, whose regulation is highly complex given that the autonomous regions set their own rules about coverage, services, and financing. Third, we present some recent studies that allow a better understanding of health care for people with ID in Spain, including a summary of the ongoing #Rights4MeToo project. We report specific data on the right to habilitation/rehabilitation. People with ID and professionals providing them with supports agreed that the most problematic aspects of health care for people with ID were the lack of: coordination across services, user-friendly information to maintain or improve their health, psychological treatments, preventive medical check-ups, and knowledge about disability among health professionals. There is a need to give people with ID priority access to services, reduce waiting times, increase the length of medical appointments, and create protocols and prevention campaigns targeting them

    Large scale emergent properties of an autocatalytic reaction-diffusion model subject to noise

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    The non-equilibrium dynamic fluctuations of a stochastic version of the Gray-Scott (GS) model are studied analytically in leading order in perturbation theory by means of the dynamic renormalization group. There is an attracting stable fixed point at one-loop order, and the asymptotic scaling of the correlation functions is predicted for both spatial and temporally correlated noise sources. New effective three-body reaction terms, not present in the original GS model, are induced by the combined interplay of the fluctuations and nonlinearities.Comment: 13 pages, 2 figure

    In vitro development of murine embryos in presence of Campylobacter fetus

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    Bovine campylobacteriosis caused by Campylobacter fetus is associated with reproductive losses. The knowledge about the mechanisms of bacterial pathogenesis is limited, then a murine experimental model is proposed. BALB/c females and males were used. Two-cell embryos were cultured in Ham-F10 as control group (CG). Treatment groups were constituted by the addition of Cfv 1 and 3, or Cff 2 and 5. Morulae were placed in Ham-F10 (CG); treatment groups were constituted by the addition of Cfv27, CFF (cell- free filtrate) and Brucella broth (BB). Blastocysts were cultured in MEM (CG); challenge group were constituted by the addition of Cfv 27. Differentiation, hatching, hatched, adhesion and expansion were evaluated. Results were analyzed by Chi2 test. In two-cell embryo, the differentiation rate was not modified when the study strains were added (p > 0.05). The differentiation rate at 24 h for embryos at the morula stage was lower for BB, Cfv, and CFF, compared with CG (p 0.05). However, the differentiation rate for the CFF group was lower than for CG (p < 0.05). At 48 and 72 h, the hatching rate was higher in CFF and Cfv groups than in CG (p < 0.05). Differences were not detected in blastocyst cultures. In conclusion, under these experimental conditions, Cf was not detrimental to the development of murine embryos. Efforts will be intensified to establish in vitro infection models that reproduce their pathogenicity.Fil: Catena, María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Tandil. Centro de Investigacion Veterinaria de Tandil; Argentina;Fil: Teruel, Miriam. Universidad Nacional del Centro de la Provincia de Bs.as.. Facultad de Cs.veterinarias. Departamento de Fisiopatologia. Cat. de Reproduccion; Argentina;Fil: Morán, P.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Tandil. Centro de Investigacion Veterinaria de Tandil; Argentina;Fil: Chiapparrone, María Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Tandil. Centro de Investigacion Veterinaria de Tandil; Argentina;Fil: Echeverria, Hernan Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Tandil. Centro de Investigacion Veterinaria de Tandil; Argentina;Fil: Soto, Pedro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Tandil. Centro de Investigacion Veterinaria de Tandil; Argentina

    Information and Communications Technologies (ICTs) for energy efficiency in buildings: Review and analysis of results from EU pilot projects

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    Information and Communications Technologies (ICTs) can play a potential role in improving the energy performance of buildings by the implementation of effective solutions that take advantage of the energy interactions between all the elements included in a building. A revision of the 105 pilots implemented or under implementation in 18 projects in the area of ICTs for energy efficiency in buildings located in 23 European countries, through 88 cities with different types of climates, buildings and technologies have been carried out through documentary and field analysis of the energy, economic and social project results. These results have been extrapolated to assess the potential energy savings which could be expected at the EU level by implementing the solutions proposed by the projects. By the implementation of the different ICT solutions, buildings have achieved more than 20% energy savings. Pilots have demonstrated that the effectiveness of the ICT solution does not depend directly on the different climates where the solutions are implemented, but on several factors, such as the level of motivation, perceived thermal comfort, quality of social interaction and communication and ICT support
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