15,541 research outputs found
Analysing and controlling the tax evasion dynamics via majority-vote model
Within the context of agent-based Monte-Carlo simulations, we study the
well-known majority-vote model (MVM) with noise applied to tax evasion on
simple square lattices, Voronoi-Delaunay random lattices, Barabasi-Albert
networks, and Erd\"os-R\'enyi random graphs. In the order to analyse and to
control the fluctuations for tax evasion in the economics model proposed by
Zaklan, MVM is applied in the neighborhod of the noise critical . The
Zaklan model had been studied recently using the equilibrium Ising model. Here
we show that the Zaklan model is robust and can be reproduced also through the
nonequilibrium MVM on various topologies.Comment: 18 pages, 7 figures, LAWNP'09, 200
Adiabatic decaying vacuum model for the universe
We study a model that the entropy per particle in the universe is constant.
The sources for the entropy are the particle creation and a lambda decaying
term. We find exact solutions for the Einstein field equations and show the
compatibilty of the model with respect to the age and the acceleration of the
universe.Comment: 10 pages, 2 figure
Processo agroindustrial: obtenção de melão desidratado por associação de osmose e secagem em estufa.
O presente trabalho descreve um processo de obtencao de melao desidratado por osmose seguida de secagem em estufa, como uma forma alternativa de aproveitamento e agregacao de valor ao produto.bitstream/CNPAT-2010/8613/1/Ct-095.pd
Integration of heterogenous pluviometric data for crop forecasts.
Abstract. Crop forecast is an activity practiced by experts in agriculture, based on large data volumes. These data cover climatological information of the most diverse types, concerning a geographic region and the type of culture. Besides volume, another problem to face concerns data heterogeneity. This paper presents a project for development of a data management system for crop forecasts. The paper is centered in the management of pluviometric data, an important factor in crop management. The system is being implanted by Embrapa, the Brazilian Agricultural Research Corporation, and part of it is already available on the Web.Geoinfo 2003
Isolamento, atividade antimicrobiana e identificação de actinobactérias isoladas da rizosfera de Xique-xique (Pilosocereus gounellei) e Oiticica (Licania rigida Benth) da Caatinga.
Human cachexia induces changes in mitochondria, autophagy and apoptosis in the skeletal muscle
Cachexia is a wasting syndrome characterized by the continuous loss of skeletal muscle mass due to imbalance between protein synthesis and degradation, which is related with poor prognosis and compromised quality of life. Dysfunctional mitochondria are associated with lower muscle strength and muscle atrophy in cancer patients, yet poorly described in human cachexia. We herein investigated mitochondrial morphology, autophagy and apoptosis in the skeletal muscle of patients with gastrointestinal cancer-associated cachexia (CC), as compared with a weight-stable cancer group (WSC). CC showed prominent weight loss and increased circulating levels of serum C-reactive protein, lower body mass index and decreased circulating hemoglobin, when compared to WSC. Electron microscopy analysis revealed an increase in intermyofibrillar mitochondrial area in CC, as compared to WSC. Relative gene expression of Fission 1, a protein related to mitochondrial fission, was increased in CC, as compared to WSC. LC3 II, autophagy-related (ATG) 5 and 7 essential proteins for autophagosome formation, presented higher content in the cachectic group. Protein levels of phosphorylated p53 (Ser46), activated caspase 8 (Asp384) and 9 (Asp315) were also increased in the skeletal muscle of CC. Overall, our results demonstrate that human cancer-associated cachexia leads to exacerbated muscle-stress response that may culminate in muscle loss, which is in part due to disruption of mitochondrial morphology, dysfunctional autophagy and increased apoptosis. To the best of our knowledge, this is the first report showing quantitative morphological alterations in skeletal muscle mitochondria in cachectic patients
Search for the gravity functional form via gaussian processes
The gravity models, for which is the Ricci scalar and is the
trace of the energy-momentum tensor, elevate the degrees of freedom of the
renowned theories, by making the Einstein field equations of the theory
to also depend on . While such a dependence can be motivated by quantum
effects, the existence of imperfect or extra fluids, or even a cosmological
``constant'' which effectively depends on , the formalism can truly surpass
some deficiencies of gravity. As the function is arbitrary,
several parametric models have been proposed {\it ad hoc} in the literature and
posteriorly confronted with observational data. In the present article, we use
gaussian process to construct an model. To apply the gaussian
process we use a series of measurements of the Hubble parameter. We then
analytically obtain the functional form of the function. By construction, this
form, which is novel in the literature, is well-adjusted to cosmological data.
In addition, by extrapolating our reconstruction to redshift , we were
able to constrain the Hubble constant value to $\rm \ km \
s^{-1} \ Mpc^{-1}5\%$ precision. Lastly, we encourage the application
of the functional form herewith obtained to other current problems of
observational cosmology and astrophysics, such as the rotation curves of
galaxies
Temperature Evolution Law of Imperfect Relativistic Fluids
The first-order general relativistic theory of a generic dissipative
(heat-conducting, viscous, particle-creating) fluid is rediscussed from a
unified covariant frame-independent point of view. By generalizing some
previous works in the literature, we derive a formula for the temperature
variation rate, which is valid both in Eckart's (particle) and in the
Landau-Lifshitz (energy) frames. Particular attention is paid to the case of
gravitational particle creation and its possible cross-effect with the bulk
viscosity mechanism.Comment: 14 pages, no figure, revte
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