Lyapunov design of a simple step-size adaptation strategy based on success

A simple success-based step-size adaptation rule for singleparent Evolution Strategies is formulated, and the setting of the corresponding parameters is considered. Theoretical convergence on the class of strictly unimodal functions of one variable that are symmetric around the optimum is investigated using a stochastic Lyapunov function method developed by Semenov and Terkel [5] in the context of martingale theory. General expressions for the conditional expectations of the next values of step size and distance to the optimum under (1 +, λ)-selection are analytically derived, and an appropriate Lyapunov function is constructed. Convergence rate upper bounds, as well as adaptation parameter values, are obtained through numerical optimization for increasing values of λ. By selecting the number of offspring that minimizes the bound on the convergence rate with respect to the number of function evaluations, all strategy parameter values result from the analysis

Preparación, caracterización y estudios texturales de carbones activados obtenidos a partir de yerba mate y su utilización para la remoción de fenol y Cr (III) en solución acuosa

Se sintetizaron carbones activados partiendo de yerba mate con distintos tratamientos químicos y físicos y se los estudió para la remoción de fenol y Cr(III) en soluciones acuosas. Se realizó la caracterización textural de los materiales carbonosos y se calculó área específica BET; volumen, tamaño y distribución tamaños de poros y posibles heterogeneidades de la superficie, empleandoteoría de funcionales de densidad (NL/QSDFT); tipoy cantidad de grupos oxigenados superficiales por el método de Boehm; punto de carga cero; microscopía electrónica de barrido y espectroscopia infrarroja por transformada de Fourier en celda de reflectancia difusa. Los datos experimentales de la adsorción de fenoly Cr(III) en solución acuosa fueron interpretados empleando modelo de Sips. El mayor área superficial corresponde a la muestra CYMFQ con 454 m2.g-1. CYMF resultó ser la más adecuada para la remoción de fenol, con capacidad máxima de 0.0040 mol.g-1. CYMFQ resultó ser la más adecuada para la remoción de cromo con capacidad máxima de 9.66 mg.g-1

Peginterferon alfa-2a (40KD) (PEGASYS®) plus ribavirin (COPEGUS®) in retreatment of chronic hepatitis C patients, nonresponders and relapsers to previous conventional interferon plus ribavirin therapy

Peginterferon alfa plus ribavirin is currently the treatment of choice for chronic hepatitis C. Peginterferon alfa-2a (40KD) plus ribavirin has given an overall sustained virological response of 18% in F3/F4 previous nonresponder US patients. We evaluated the effectiveness of peginterferon alfa-2a (40KD) plus ribavirin in Brazilian patients who were relapsers or nonresponders to previous interferon-based therapy. One-hundred-thirty-four patients with biopsy-proven chronic hepatitis C, HCV RNA positive, elevated ALT and who were either relapsers (n=37) or nonresponders (n=97) to at least 24 weeks of conventional interferon/ribavirin therapy were retreated with peginterferon alfa-2a (40KD) 180mg/qw and ribavirin 800mg bid for 48 weeks. Efficacy was assessed as virological response (defined as undetectable HCV RNA) at the end of treatment (EoT) and at the end of follow-up (SVR - Sustained Virological Response). Safety assessments consisted of clinical and laboratory evaluations. In the patient sample, 72% were genotype 1 and 34% were cirrhotic. In an intention-to-treat analysis, relapser patients showed 78% EoT response and 51% SVR. Nonresponders showed 57% EoT response and 26% SVR. Positive predictive factors of SVR were non-1 genotype and relapser state. Six percent of the patients interrupted treatment because of adverse events and 45% had dose reduction (mainly associated with leucopenia and anemia). Brazilian patient relapsers and nonresponders to conventional interferon and ribavirin treatment can achieve a sustained virological response when retreated with peginterferon alfa-2a (40KD) and ribavirin. The safety profile is similar to that of naive patients.Federal University of São PauloSanta Casa de Misericórdia Gastroenterology ServiceFederal University of ParáFederal University of Juiz de ForaSão Paulo University Medical School of Ribeirão PretoEmílio Ribas InstituteFederal University of Minas GeraisMedical School of São José do Rio PretoFederal University of AlagoasFederal University of Santa CatarinaFederal University of BahiaTropical Medicine FundationOswaldo Cruz HospitalFederal University of ParaíbaRocheUNIFESPSciEL

Magnetic Nanoparticles Hyperthermia in A Non-Adiabatic and Radiating Process

We investigate the magnetic nanoparticles hyperthermia in a non-adiabatic and radiating process through the calorimetric method. Specifically, we propose a theoretical approach to magnetic hyperthermia from a thermodynamic point of view. To test the robustness of the approach, we perform hyperthermia experiments and analyse the thermal behavior of magnetite and magnesium ferrite magnetic nanoparticles dispersed in water submitted to an alternating magnetic field. From our findings, besides estimating the specific loss power value from a non-adiabatic and radiating process, thus enhancing the accuracy in the determination of this quantity, we provide physical meaning to a parameter found in literature that still remained not fully understood, the effective thermal conductance, and bring to light how it can be obtained from experiment. In addition, we show our approach brings a correction to the estimated experimental results for specific loss power and effective thermal conductance, thus demonstrating the importance of the heat loss rate due to the thermal radiation in magnetic hyperthermia