On the dynamics of bubbles in boiling water

We investigate the dynamics of many interacting bubbles in boiling water by using a laser scattering experiment. Specifically, we analyze the temporal variations of a laser intensity signal which passed through a sample of boiling water. Our empirical results indicate that the return interval distribution of the laser signal does not follow an exponential distribution; contrariwise, a heavy-tailed distribution has been found. Additionally, we compare the experimental results with those obtained from a minimalist phenomenological model, finding a good agreement.Comment: Accepted for publication in Chaos, Solitons & Fractal

Symbolic Sequences and Tsallis Entropy

We address this work to investigate symbolic sequences with long-range correlations by using computational simulation. We analyze sequences with two, three and four symbols that could be repeated $l$ times, with the probability distribution $p(l)\propto 1/ l^{\mu}$. For these sequences, we verified that the usual entropy increases more slowly when the symbols are correlated and the Tsallis entropy exhibits, for a suitable choice of $q$, a linear behavior. We also study the chain as a random walk-like process and observe a nonusual diffusive behavior depending on the values of the parameter $\mu$.Comment: Published in the Brazilian Journal of Physic

In vivo kinetics of eosinophils and mast cells in experimental murine Schistosomiasis

During the schistosomiasis infection there is a [quot ]dance of the cells[quot ], varying from site to site and related to the time of infection. 1 - Eosinophil levels exhibit a bimodal pattern, with the first peak related to the egg deposition and maturation and increased Kupfferian hyperplasia; the second peak precedes the death of some adult worms; 2 - The peritoneal eosinophilic levels are inversely proportional to the blood eosinophilic levels; 3 - Eosinopoiesis in the bone marrow begins at day 40, reaching the highest levels at day 50 and coincides with hepatic eosinophilic and neutrophilic metaplasia; 4 - Peritoneal mast cell levels present a bimodal pattern similar to the blood eosinophils, and inverse to the peritoneal eosinophils. They also show a cyclic behaviour within the hepatic and intestinal granulomas. Integral analysis of the events related to the eosinophils in the blood, bone marrow, peritoneal cavity and hepatic and intestinal granulomas allows the detection of two important eosinophilic phases: the first is due to mobilization and redistribution of the marginal pool and the second originates from eosinophilic production in the bone marrow and liver. The productive phase is characterized by an increase in the number of eosinophils and monocyte/macrophages, and a decrease in neutrophils and stabilization of megakariocytes and erithroid lineages

Nuclear alpha-clustering, superdeformation, and molecular resonances

Nuclear alpha-clustering has been the subject of intense study since the advent of heavy-ion accelerators. Looking back for more than 40 years we are able today to see the connection between quasimolecular resonances in heavy-ion collisions and extremely deformed states in light nuclei. For example superdeformed bands have been recently discovered in light N=Z nuclei such as $^{36}$Ar, $^{40}$Ca, $^{48}$Cr, and $^{56}$Ni by $\gamma$-ray spectroscopy. The search for strongly deformed shapes in N=Z nuclei is also the domain of charged-particle spectroscopy, and our experimental group at IReS Strasbourg has studied a number of these nuclei with the charged particle multidetector array {\sc Icare} at the {\sc Vivitron} Tandem facility in a systematical manner. Recently the search for $\gamma$-decays in $^{24}$Mg has been undertaken in a range of excitation energies where previously nuclear molecular resonances were found in $^{12}$C+$^{12}$C collisions. The breakup reaction $^{24}$Mg$+^{12}$C has been investigated at E$_{lab}$($^{24}$Mg) = 130 MeV, an energy which corresponds to the appropriate excitation energy in $^{24}$Mg for which the $^{12}$C+$^{12}$C resonance could be related to the breakup resonance. Very exclusive data were collected with the Binary Reaction Spectrometer in coincidence with {\sc Euroball IV} installed at the {\sc Vivitron}.Comment: 10 pages, 4 eps figures included. Invited Talk 10th Nuclear Physics Workshop Marie and Pierre Curie, Kazimierz Dolny Poland, Sep. 24-28, 2003; To be published in International Journal of Modern Physics

Dark matter effects on hybrid star properties

In the present work we investigate the effects of dark matter (DM) on hybrid star properties. We assume that dark matter is mixed with both hadronic and quark matter and interact with them through the exchange of a Higgs boson. The hybrid star properties are obtained from equations of state calculated with a Maxwell prescription. For the hadronic matter we use the NL3* parameter set and for the quark matter, the MIT bag model with a vector interaction. We see that dark matter does not influence the phase transition points (pressure and chemical potential) but shifts the discontinuity on the energy density, which ultimately reduces the minimum mass star that contains a quark core. Moreover, it changes considerably the star family mass-radius diagrams and moves the merger polarizability curves inside the confidence lines. Another interesting feature is the influence of DM in the quark core of the hybrid stars constructed. Our results show an increase of the core radius for higher values of the dark particle Fermi momentum

Milky spots reactions to schistosomal mansoni infection

Milky spots (MS), considered by the authors as a Coelomatic Lympho-myelopoietic Organ (CLMO), present a strong reactivity during experimental schistosomal mansoni infection, characterized by an increase of lymphocytes, macrophages, plasmocytes, mast cells, neutrophils and expression of eosinophil metaplasia. Intraperitoneal injection of purified Schistosoma mansoni (Sm) eggs provoked a rise in the number and size of MS, which developed the sessile marginal and pedunculated types. The authors conclude that egg antigens are, at least partially, responsible for MS reactivity during Sm infection

Anomalous diffusion in a symbolic model

We address this work to investigate some statistical properties of symbolic sequences generated by a numerical procedure in which the symbols are repeated following a power law probability density. In this analysis, we consider that the sum of n symbols represents the position of a particle in erratic movement. This approach revealed a rich diffusive scenario characterized by non-Gaussian distributions and, depending on the power law exponent and also on the procedure used to build the walker, we may have superdiffusion, subdiffusion or usual diffusion. Additionally, we use the continuous-time random walk framework to compare with the numerical data, finding a good agreement. Because of its simplicity and flexibility, this model can be a candidate to describe real systems governed by power laws probabilities densities.Comment: Accepted for publication in Physica Script

effect of continuous heat exposure on sleep during partial sleep deprivation

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Nonlinear equation for anomalous diffusion: unified power-law and stretched exponential exact solution

The nonlinear diffusion equation $\frac{\partial \rho}{\partial t}=D \tilde{\Delta} \rho^\nu$ is analyzed here, where $\tilde{\Delta}\equiv \frac{1}{r^{d-1}}\frac{\partial}{\partial r} r^{d-1-\theta} \frac{\partial}{\partial r}$, and $d$, $\theta$ and $\nu$ are real parameters. This equation unifies the anomalous diffusion equation on fractals ($\nu =1$) and the spherical anomalous diffusion for porous media ($\theta=0$). Exact point-source solution is obtained, enabling us to describe a large class of subdiffusion ($\theta > (1-\nu)d$), normal diffusion ($\theta= (1-\nu)d$) and superdiffusion ($\theta < (1-\nu)d$). Furthermore, a thermostatistical basis for this solution is given from the maximum entropic principle applied to the Tsallis entropy.Comment: 3 pages, 2 eps figure