Two-flavor condensates in chiral dynamics: temperature and isospin density effects

Isospin density and thermal corrections for several condensates are discussed, at the one-loop level, in the frame of chiral dynamics with pionic degrees of freedom. The evolution of such objects give an additional insight into the condensed-pion phase transition, that occurs basically when |\mui|>m_\pi, being |\mui| the isospin chemical potential. Calculations are done in both phases, showing a good agreement with lattice results for such condensates.Comment: 9 pages, 10 figure

Weinberg power counting and the quark determinant at small chemical potential

We construct an effective action for QCD by expanding the quark determinant in powers of the chemical potential at finite temperature in the case of massless quarks. To cut the infinite series we adopt the Weinberg power counting criteria. We compute the minimal effective action (~p^4), expanding in the external momentum, which implies the use of the hard thermal loop approximation. Our main result is a gauge invariant expression for the phase theta of the functional determinant in QCD, and recovers dimensional reduction in the high-temperature limit. We compute, analytically, in the range of p << 2 pi T, including perturbative and nonperturbative contributions, the latter treated within the mean field approximation. Implications for lattice simulations are briefly discussed.Comment: 5 pages, 2 figures. v2: title changed, expanded discussion and added example (calculation of at high temperature). Published in PR

Caracterización morfológica, fisiológica y patogénica de moniliophthora roreri aislados de cinco provincias de la costa ecuatoriana

The moniliasis of cacao, caused by the fungus Moniliophthora roreri, is the main problem, so is necessary to deepen the knowledge of the agent and the differences between populations of the fungus from various sources. To achieve the objectives of this research was carried out on samples collected in ten cocoa production farms located in five provinces of the Coast, was carried isolates that were evaluated and identified by morphological criteria (diameter, edge, color and texture of colonies; type and size of conidia, etc.), physiological (development at a given temperature, weight of mycelium) and pathogenic (time of onset and severity of symptoms), in order to initiate the characterization of populations of the fungus in the country and have a bank of isolates for further investigation at different levels. We used culture media and liquid to assess the morphological and physiological characteristics of 50 isolates. The pathogenicity was evaluated by inoculating healthy fruit with dry conidia method over a period of fourteen days. No morphological differences were found on the edge and texture of the colonies among isolates studied, but variations in color, with shades of white, cream, light brown to dark brown. Also the size and shape of conidia differences, distinguishing conidia globose, subglobose, elliptical. There were variations in the growth of the colonies and the weight of mycelium in different isolates, regardless of their origin, with the exception of 80% of those from areas of the province of Los Rios, who had a higher growth rate on solid medium