Ventricular systolic reserve in asymptomatic children previously treated with low doses of anthracyclines: A longitudinal, prospective exercise echocardiography study

Background: The time course of mild cardiotoxicity induced by anthracycline remains unknown. The aim of this study was to evaluate the long-term evolution of decreased myocardial reserve in children previously treated with a cumulative dose of anthracycline up to 100mg/m 2. Patients and Methods: Twenty-seven asymptomatic cancer survival patients (25 with lymphoblastic leukemia), in continuous remission and off treatment for >12 months with no alterations in conventional echocardiograms were evaluated by exercise echocardiography at 37±15.4 months (T1) and 101±24 months (T2) after finishing treatment (ADRIA group). This group was compared with 25 healthy individuals (control group) similar to the ADRIA group with respect to age and body surface area (BSA). All individuals underwent treadmill exercise testing according to Bruce protocol. Echocardiograms were performed before and immediately after exercise. Results: The groups were similar regarding cardiac structure and left ventricular (LV) systolic function at rest at T1 and T2. The growth of LV posterior wall thickness related to BSA was lower in the ADRIA group at T2. Post exercise, smaller LV ejection indexes and attenuated changes in the afterload in ADRIA group were observed at T1 and T2. Conclusion: The decreased systolic reserve induced by a low dose of anthracycline in asymptomatic children and adolescents remains unaffected over a 5-year period, suggesting that positive outcomes in chronic cardiotoxicity would be expected in patients with mild impairment after anthracycline treatment. © 2011 Wiley Periodicals, Inc.

Tjon Lines and Scaling Limit in Four-Body Systems

The fixed-slope correlation between tetramer and trimer binding energies, observed by Tjon in the context of nuclear physics, is mainly a manifestation of the dominance of the two-nucleon force in the nuclear potential, which makes the four-body scale on the order of the three-body one. In a more general four-boson case, the correlation between tetramer and trimer binding energies has a non-fixed slope, which expresses the dependence on the new scale. The associated scaling function generates a family of Tjon lines. This conclusion relies on a recent study with weakly-bound four identical bosons, within a renormalized zero-range Faddeev-Yakubovsky formalism. © 2012 Springer-Verlag.

La dinámica de la pobreza y las variables de población en la Argentina: un analisis longitudinal a partir de la encuesta permanente de hogares (1995-2003)

Incluye Bibliografía

Saddle points and rare collisions under scaling approach in a Fermi accelerator with two nonlinear terms

Rare collisions of a classical particle bouncing between two walls are studied. The dynamics is described by a two-dimensional, nonlinear and area-preserving mapping in the variables velocity and time at the instant that the particle collides with the moving wall. The phase space is of mixed type preventing diffusion of the particle to high energy. Successive and therefore rare collisions are shown to have a histogram of frequency which is scaling invariant with respect to the control parameters. The saddle fixed points are studied and shown to be scaling invariant with respect to the control parameters too. © 2012 Elsevier B.V. All rights reserved.

Scaling invariance of the diffusion coefficient in a family of two-dimensional Hamiltonian mappings

We consider a family of two-dimensional nonlinear area-preserving mappings that generalize the Chirikov standard map and model a variety of periodically forced systems. The action variable diffuses in increments whose phase is controlled by a negative power of the action and hence effectively uncorrelated for small actions, leading to a chaotic sea in phase space. For larger values of the action the phase space is mixed and contains a family of elliptic islands centered on periodic orbits and invariant Kolmogorov-Arnold-Moser (KAM) curves. The transport of particles along the phase space is considered by starting an ensemble of particles with a very low action and letting them evolve in the phase until they reach a certain height h. For chaotic orbits below the periodic islands, the survival probability for the particles to reach h is characterized by an exponential function, well modeled by the solution of the diffusion equation. On the other hand, when h reaches the position of periodic islands, the diffusion slows markedly. We show that the diffusion coefficient is scaling invariant with respect to the control parameter of the mapping when h reaches the position of the lowest KAM island. © 2013 American Physical Society.

Scaling attractors in interacting teleparallel dark energy

It has been proposed recently the existence of a non-minimal coupling between a canonical scalar field (quintessence) and gravity in the framework of teleparallel gravity, motivated by similar constructions in the context of General Relativity. The dynamics of the model, known as teleparallel dark energy, has been further developed, but no scaling attractor has been found. Here we consider a model in which the non-minimal coupling is ruled by a dynamically changing coefficient α≡f,φ/(f)1/2, with f(φ) an arbitrary function of the scalar field φ. It is shown that in this case the existence of scaling attractors is possible, which means that the universe will eventually enter these scaling attractors, regardless of the initial conditions. As a consequence, the cosmological coincidence problem could be alleviated without fine-tunings. © 2013 IOP Publishing Ltd and Sissa Medialab srl.

Longitudinal analysis of serological tests officially adopted by the Brazilian Ministry of Health for the diagnosis of canine visceral leishmaniasis in dogs vaccinated with Leishmune®

Development of vaccines against canine visceral leishmaniasis (CVL) may provide a prophylactic barrier, but antibody response detected by standard diagnostic techniques may not separate vaccinated from naturally infected dogs. Moreover, anti-Leishmania antibody levels in vaccinated dogs may be detectable for months. Accordingly, the aim of the present study was to comparatively evaluate an in-house ELISA with three serological tests officially adopted by the Brazilian Ministry of Health for the diagnosis of CVL in dogs vaccinated with Leishmune®. A total of 18 mongrel dogs were submitted to a complete protocol of the vaccine, monitored and evaluated in 5 times (T0-T4) up to 180 days after T0. Twenty-one days after the first dose (T1), 50% of the dogs were seropositive by the in-house ELISA and 5.5% by IFAT, while by the official ELISA and DPP® CVL rapid test all dogs tested negative. At time T2, 42 days after of the first dose, 100%, 83.3%, 11.1%, and 5.5% of the dogs were seropositive by the in-house ELISA, IFAT, official ELISA kit and the DPP® CVL rapid test, respectively. Ninety days after the first dose (T3), 100%, 83.3%, 72.2% and 33.3% of the dogs were seropositive by the in-house ELISA, official ELISA kit, IFAT, and the DPP® CVL rapid test, respectively. Finally, at time T4, 88.8%, 33.3%, 11.1% and 5.5% of the dogs were seropositive by the in-house ELISA, official ELISA kit, DPP® CVL rapid test and IFAT, respectively. In conclusion, dogs vaccinated with Leishmune® cross-react by an in-house ELISA and by the three official Brazilian serological tests for the diagnosis of canine visceral leishmaniasis up to six months after the first vaccine dose, and may be mistakenly diagnosed and removed. © 2013 Elsevier B.V.

Movimentos na escrita inicial de crianças: um estudo longitudinal de hipersegmentações

Pós-graduação em Estudos Linguísticos - IBILCE

Efeito da prematuridade na terefa A não B: um estudo longitudinal

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)