4,652 research outputs found
Critical dynamics of the Potts model: short-time Monte Carlo simulations
We calculate the new dinamic exponent of the 4-state Potts model,
using short-time simulations. Our estimates and obtained by following the behavior of the
magnetization or measuring the evolution of the time correlation function of
the magnetization corroborate the conjecture by Okano et. al. In addition,
these values agree with previous estimate of the same dynamic exponent for the
two-dimensional Ising model with three-spin interactions in one direction, that
is known to belong to the same universality class as the 4-state Potts model.
The anomalous dimension of initial magnetization
is calculated by an alternative way that mixes two different initial
conditions. We have also estimated the values of the static exponents
and . They are in complete agreement with the pertinent results of the
literature.Comment: 12 pages, 7 figure
Transport coefficients and nonextensive statistics
We discuss the basic transport phenomena in gases and plasmas obeying the
-nonextensive velocity distribution (power-law). Analytical expressions for
the thermal conductivity () and viscosity () are derived by
solving the Boltzmann equation in the relaxation-time approximation. The
available experimental results to the ratio {}/ constrains the
-parameter on the interval . In the extensive limiting
case, the standard transport coefficients based on the local Gaussian
distribution are recovered, and due to a surprising cancellation, the electric
conductivity of a neutral plasma is not modified.Comment: 14 pages, 3 figures, REVTEX, submitted to PR
Damageable contact between an elastic body and a rigid foundation
AbstractIn this work, the contact problem between an elastic body and a rigid obstacle is studied, including the development of material damage which results from internal compression or tension. The variational problem is formulated as a first-kind variational inequality for the displacements coupled with a parabolic partial differential equation for the damage field. The existence of a unique local weak solution is stated. Then, a fully discrete scheme is introduced using the finite element method to approximate the spatial variable and an Euler scheme to discretize the time derivatives. Error estimates are derived on the approximate solutions, from which the linear convergence of the algorithm is deduced under suitable regularity conditions. Finally, three two-dimensional numerical simulations are performed to demonstrate the accuracy and the behaviour of the scheme
Criteria For Analyzing The Quality Estimate Shake Using Two Different Impellers, "rushton Turbine" And "pbt 45"
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)The Computational Fluid Dynamics (CFD) is used to numerically simulate the behavior of fluid flow, and all the laws that rule the study of fluids, both the energy and mass transfer, chemical reactions, hydraulic behavior, and other applications. Among these innumerable applications, the local behavior of a mixing tank can be estimated using the CFD techniques. In order to follow-up studies in the literature giving them increased credibility, this project aimed to determine whether both the scheduling Potency/Volume and Torque/Volume maintain the necessary level of agitation in the mix tank to extrapolate the volume 10 times and 100 times, using an axial impeller blades inclined at 45 degrees type (PBT 45), and a radial impeller (Rushton turbine) with the use of the CFD. With the results, was analyzed if a criterion is superior to the other in terms of maintaining the level of agitation in scheduling. The case study made it possible to achieve the main objective, deepen studies in Computational Fluid Dynamics. Therefore, managed to the largest domain in tools offered by CFX-ANSYS 14.0 software, allowing future work to be conducted. © Published under licence by IOP Publishing Ltd.73812012/12296-9, FAPESP, Fundação de Amparo à Pesquisa do Estado de São Paulo2012/12298-1, FAPESP, Fundação de Amparo à Pesquisa do Estado de São PauloFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)5th International Conference on Mathematical Modeling in Physical Sciences, IC-MSquare 201623 May 2016 through 26 May 201612370
Results of the MRI substudy of the intravenous magnesium efficacy in stroke trial
<p><b>Background and Purpose:</b>Although magnesium is neuroprotective in animal stroke models, no clinical benefit was confirmed in the Intravenous Magnesium Efficacy in Stroke (IMAGES) trial of acute stroke patients. The Magnetic
Resonance in IMAGES (MR IMAGES) substudy investigated the effects of magnesium on the imaging surrogate
outcome of infarct growth.</p>
<p><b>Methods:</b> IMAGES trial patients in participating centers were randomized to receive either intravenous magnesium or placebo within 12 hours of stroke onset. Infarct growth was defined as volume difference between baseline diffusion-weighted imaging and day 90 fluid-attenuated inversion recovery image lesions. Patients who died were imputed the largest infarct growth observed.</p>
<p><b>Results:</b> Among the 90 patients included in the primary analysis, there was no difference in infarct growth (median absolute growth, P=0.639; median percentage growth, P=0.616; proportion with any growth, P=0.212) between the
46 treated with magnesium and 44 with placebo. Infarct growth correlated with NIHSS score change from baseline to
day 90. There was a trend showing baseline serum glucose correlated with infarct growth with magnesium treatment,
but not in the placebo group. The mismatch frequency was reduced from 73% to 47% by increasing the mismatch
threshold from >20% to >100% of core volume.</p>
<p><b>Conclusions:</b> Infarct growth, confirmed here as a surrogate for clinical progression, was similar between magnesium and placebo treatment, paralleling the main IMAGES trial clinical outcomes. Glucose was a covariate for infarct growth with magnesium treatment. A more stringent mismatch threshold to define penumbra more appropriately would have
excluded half of the patients in this 12-hour time window stroke study.</p>
Non-hormonal male contraception: A review and development of an Eppin based contraceptive
Developing a non-hormonal male contraceptive requires identifying and characterizing an appropriate target and demonstrating its essential role in reproduction. Here we review the development of male contraceptive targets and the current therapeutic agents under consideration. In addition, the development of EPPIN as a target for contraception is reviewed. EPPIN is a well characterized surface protein on human spermatozoa that has an essential function in primate reproduction. EPPIN is discussed as an example of target development, testing in non-human primates, and the search for small organic compounds that mimic contraceptive antibodies; binding EPPIN and blocking sperm motility. Although many hurdles remain before the success of a non-hormonal male contraceptive, continued persistence should yield a marketable product
Cytokines and chemokines production by mononuclear cells from parturient women after stimulation with live Toxoplasma gondii
AbstractToxoplasma gondii is an obligate intracellular parasite that can cause variable clinical symptoms or can even be asymptomatic in immunocompetent individuals. More severe symptoms are observed in immunocompromised patients and congenital transmission of the parasite has been reported. The objective of this study was to evaluate the response of peripheral blood mononuclear cells (PBMC) in parturient and non-pregnant women exposed to live tachyzoites of T. gondii strain RH or ME49. PBMC were isolated from parturient and non-pregnant women with negative or positive serology for toxoplasmosis and cultured with live tachyzoites of the two T. gondii strains for 24 h. Next, the cell culture supernatants were collected and levels of CCL2, CCL5, IL-6, IL-10, IL-12, and TNF-α produced by PBMC after tachyzoite exposure were measured. Live tachyzoite forms of T. gondii significantly inhibited the synthesis of CCL2 in seropositive parturient women, whereas a stimulatory effect on CCL5 was observed in seronegative parturient women. Cells from T. gondii-seronegative non-pregnant women produced significantly higher levels of TNF-α and IL-12, demonstrating the proinflammatory profile induced by the presence of the parasite in culture. The results suggest that the immunomodulation seen during pregnancy contributes to the development of an environment that facilitates escape of the parasite from the immune response
An alternative order parameter for the 4-state Potts model
We have investigated the dynamic critical behavior of the two-dimensional
4-state Potts model using an alternative order parameter first used by
Vanderzande [J. Phys. A: Math. Gen. \textbf{20}, L549 (1987)] in the study of
the Z(5) model. We have estimated the global persistence exponent by
following the time evolution of the probability that the considered
order parameter does not change its sign up to time . We have also obtained
the critical exponents , , , and using this alternative
definition of the order parameter and our results are in complete agreement
with available values found in literature.Comment: 6 pages, 6 figure
VINHOS QUE PENSAM - parte III|III GESTÃO NUTRICIONAL DA VINHA: SENSORES MULTIESPECTRAIS ATIVOS PRÓXIMOS
Os objetivos do presente
trabalho:
• caracterizar a concentração de N,
P, K, Ca, Mg, Zn, Mn, e Fe da copa
da vinha, baseada em observações
multiespectrais e análises de
plantas;
• avaliar a possibilidade de utilização
de sensores multiespectrais
ativos próximos na gestão nutricional
da vinha
- …