6,342 research outputs found
Poética realista e innovaciones formales en Cuentos de la oficina, de Roberto Mariani
Se realiza lectura analítica de Cuentos de la oficina, de Roberto Mariani, a partir de reparar en las particulares inflexiones de la poética realista entramada en la obra, en función de apropiaciones innovadoras y creativas del realismo europeo y de la presencia de procedimientos vanguardistas. En consecuencia, se polemiza con los lugares comunes de lecturas críticas tradicionales sobre la producción literaria del Grupo de Boedo, en tanto éstas consideran que los textos producidos por el Grupo de Boedo se reducen a ser una ejemplificación de programas ideológicos previos y en donde la poética realista no presenta innovaciones formales de consideració
Existence of global-in-time solutions to a generalized Dirac-Fock type evolution equation
We consider a generalized Dirac-Fock type evolution equation deduced from
no-photon Quantum Electrodynamics, which describes the self-consistent
time-evolution of relativistic electrons, the observable ones as well as those
filling up the Dirac sea. This equation has been originally introduced by Dirac
in 1934 in a simplified form. Since we work in a Hartree-Fock type
approximation, the elements describing the physical state of the electrons are
infinite rank projectors. Using the Bogoliubov-Dirac-Fock formalism, introduced
by Chaix-Iracane ({\it J. Phys. B.}, 22, 3791--3814, 1989), and recently
established by Hainzl-Lewin-Sere, we prove the existence of global-in-time
solutions of the considered evolution equation.Comment: 12 pages; more explanations added, some final (minor) corrections
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Scaling laws of strategic behaviour and size heterogeneity in agent dynamics
The dynamics of many socioeconomic systems is determined by the decision
making process of agents. The decision process depends on agent's
characteristics, such as preferences, risk aversion, behavioral biases, etc..
In addition, in some systems the size of agents can be highly heterogeneous
leading to very different impacts of agents on the system dynamics. The large
size of some agents poses challenging problems to agents who want to control
their impact, either by forcing the system in a given direction or by hiding
their intentionality. Here we consider the financial market as a model system,
and we study empirically how agents strategically adjust the properties of
large orders in order to meet their preference and minimize their impact. We
quantify this strategic behavior by detecting scaling relations of allometric
nature between the variables characterizing the trading activity of different
institutions. We observe power law distributions in the investment time
horizon, in the number of transactions needed to execute a large order and in
the traded value exchanged by large institutions and we show that heterogeneity
of agents is a key ingredient for the emergence of some aggregate properties
characterizing this complex system.Comment: 6 pages, 3 figure
Lipid Raft Size and Lipid Mobility in Non-raft Domains Increase during Aging and Are Exacerbated in APP/PS1 Mice Model of Alzheimer's Disease. Predictions from an Agent-Based Mathematical Model
A connection between lipid rafts and Alzheimer's disease has been studied during the last decades. Mathematical modeling approaches have recently been used to correlate the effects of lipid composition changes in the physicochemical properties of raft-like membranes. Here we propose an agent based model to assess the effect of lipid changes in lipid rafts on the evolution and progression of Alzheimer's disease using lipid profile data obtained in an established model of familial Alzheimer's disease. We have observed that lipid raft size and lipid mobility in non-raft domains are two main factors that increase during age and are accelerated in the transgenic Alzheimer's disease mouse model. The consequences of these changes are discussed in the context of neurotoxic amyloid β production. Our agent based model predicts that increasing sterols (mainly cholesterol) and long-chain polyunsaturated fatty acids (LCPUFA) (mainly DHA, docosahexaenoic acid) proportions in the membrane composition might delay the onset and progression of the disease.This work was funded by research grants from BIO2014-54411-C2-2-R and SAF2014-52582-R from Ministerio de Economía y Competitividad (MINECO, Spain). GSR acknowledges the support of Obra Social La Caixa-Fundación CajaCanarias that granted him a Posgraduate Fellowship at the Universidad de La Laguna.Peer reviewedPeer Reviewe
Properties of the ionized gas in HH202. I: Results from integral field spectroscopy with PMAS
We present results from integral field spectroscopy with the Potsdam
multi-Aperture Spectrograph of the head of the Herbig-Haro object HH 202 with a
spatial sampling of 1"x1". We have obtained maps of different emission lines,
physical conditions --such as electron temperature and density-- and ionic
abundances from recombination and collisionally excited lines. We present the
first map of the Balmer temperature and of the temperature fluctuation
parameter, t^2. We have calculated the t^2 in the plane of the sky, which is
substantially smaller than that determined along the line of sight. We have
mapped the abundance discrepancy factor of O^{2+}, ADF(O^{2+}), finding its
maximum value at the HH 202-S position. We have explored the relations between
the ADF(O^{2+}) and the electron density, the Balmer and [O III] temperatures,
the ionization degree as well as the t^2 parameter. We do not find clear
correlations between these properties and the results seem to support that the
ADF and t^2 are independent phenomena. We have found a weak negative
correlation between the O^{2+} abundance determined from recombination lines
and the temperature, which is the expected behaviour in an ionized nebula,
hence it seems that there is not evidence for the presence of super-metal rich
droplets in H II regions.Comment: 12 pages, 11 figures. Accepted for publication in MNRA
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