A Systematic Investigation of Light Heavy-Ion Reactions

We introduce a novel coupling potential for the scattering of deformed light heavy-ion reactions. This new approach is based on replacing the usual first-derivative coupling potential by a new, second derivative coupling potential in the coupled-channels formalism. The new approach has been successfully applied to the study of the $^{12}$C+$^{12}$C, $^{12}$C+$^{24}$Mg, $^{16}$O+$^{28}$Si and $^{16}$O+$^{24}$Mg systems and made major improvements over all the previous coupled-channels calculations for these systems. This paper also shows the limitations of the standard coupled-channels theory and presents a global solution to the problems faced in the previous theoretical accounts of these reactions.Comment: 7 pages with 4 figure

New Results in the Analysis of the 16^{16}O+28^{28}Si Elastic Scattering by Modifying the Optical Potential

The elastic scattering of the $^{16}$O+$^{28}$Si system has been analyzed with a modified potential within the framework of the optical model over a wide energy range in the laboratory system from 29.0 to 142.5 MeV. This system has been extensively studied over the years and a number of serious problems has remained unsolved: The explanation of the anomalous large angle scattering data; the out-of-phase problem between theoretical predictions and experimental data; the reproduction of the oscillatory structure near the Coulomb barrier; the consistent description of angular distributions together with the excitation functions data are just some of these problems. We propose the use of a modified potential method to explain these problems over this wide energy range. This new method consistently improves the agreement with the experimental data and achieves a major improvement on all the previous Optical model calculations for this system.Comment: 19 pages with 8 figure

A Global Potential Analysis of the 16^{16}O+28^{28}Si Reaction Using a New Type of Coupling Potential

A new approach has been used to explain the experimental data for the $^{16}$O+$^{28}$Si system over a wide energy range in the laboratory system from 29.0 to 142.5 MeV. A number of serious problems has continued to plague the study of this system for a couple of decades. The explanation of anomalous large angle scattering data; the reproduction of the oscillatory structure near the Coulomb barrier; the out-of-phase problem between theoretical predictions and experimental data; the consistent description of angular distributions together with excitation functions data are just some of these problems. These are long standing problems that have persisted over the years and do represent a challenge calling for a consistent framework to resolve these difficulties within a unified approach. Traditional frameworks have failed to describe these phenomena within a single model and have so far only offered different approaches where these difficulties are investigated separately from one another. The present work offers a plausible framework where all these difficulties are investigated and answered. Not only it improves the simultaneous fits to the data of these diverse observables, achieving this within a unified approach over a wide energy range, but it departs for its coupling potential from the standard formulation. This new feature is shown to improve consistently the agreement with the experimental data and has made major improvement on all the previous coupled-channels calculations for this system.Comment: 21 pages with 12 figure

Understanding toxicological implications of accidents with caterpillars Megalopyge lanata and Podalia orsilochus (Lepidoptera: Megalopygidae)

Dermal contact with Lepidoptera specimens at their larval stage (caterpillar) commonly causes local envenomation. Although the megalopygids Megalopyge lanata and Podalia orsilochus are common causative agents of accidents in the Misiones province, Northeastern Argentina, there is very little information about their venoms and their toxicological implications on human health. Thus, we employed proteomic techniques and biological assays to characterize venoms (bristle extracts) from caterpillars of both species collected from Misiones, Argentina. The electrophoretic profile of both venoms were substantially different, although proteins related to coagulation disturbance have been identified in both venoms. However, P. orsilochus venom exhibited higher caseinolytic activity than M. lanata venom, agreeing with the fact that only P. orsilochus venom hydrolyzed human fibrin(ogen). While the venom of M. lanata induced a mild inflammatory lesion in mouse skin, P. orsilochus venom caused prominent necrosis, inflammatory infiltration and hemorrhage at the site of venom injection. Altogether, this study provides relevant information about the pathophysiological mechanisms whereby both caterpillars can induce toxicity on human beings, and paves the way for novel discovery of naturally occurring bioactive compounds.Fil: Sanchez, Matias Nicolas. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; Argentina. Ministerio de Salud. Instituto Nacional de Medicina Tropical; ArgentinaFil: Mozer Sciani, Juiana. Universidade São Francisco; BrasilFil: Quintana, María Agustina. Ministerio de Salud. Instituto Nacional de Medicina Tropical; ArgentinaFil: Martínez, María Mercedes. Ministerio de Salud. Instituto Nacional de Medicina Tropical; ArgentinaFil: Tavares, Flávio Luiz. Universidade Federal da Integração Latinoamericana; BrasilFil: Gritti, Micaela Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; Argentina. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias; ArgentinaFil: Fan, Hui W.. Governo do Estado de Sao Paulo. Secretaria da Saude. Instituto Butantan; BrasilFil: Teibler, Gladys Pamela. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias; ArgentinaFil: Peichoto, María Elisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; Argentina. Ministerio de Salud. Instituto Nacional de Medicina Tropical; Argentin