Prevalencia de anticuerpos VEE y EEE en población humana y equina de la selva peruana

The Venezuelan Encephalities virus (VEE) complex include 1AB, 1C, 1D, 1E serotypes, but the 1AB and IC serotypes are the only one related to epizooties. In Peru, the epizootic virus appeared in the 30th and the last appearance was in 1973 and the serotype isolated was 1AR In Loreto in the Peruvianjungle was isolated VEE ID serotype from human febrile illness; however, previous surveillance founded VEE antibodies in the same area. In this study we want to know the prevalence of VEE and Eastern Equine Encephalities virus (EEE) antibodies in humans and equines for the jungle area where the equine population were increasing lately. U sing neutralization test by plaque reduction we founded a variety of prevalence. In the human sera the highest prevalence for VEE was 57% in San Martin and for EEE was 62% in Loreto. In equines sera the highest prevalence for VEE was 68% and for EEE was 65% in Loreto.El complejo de virus de encefalitis equina venezolana (VEE) esta integrado por los serotipos antigénicos 1AB, 1C, 1D, 1E de los cuales los únicos relacionados con epizootias son los serotipos 1AB y IC. En el Perú el virus epizoótico ha hecho su aparición esporádica desde la década de los 30, siendo la última incursión epizoodérmica en el año 1973 por el serotipo 1AB. En Loreto, departamento de la Selva peruana, durante 1973 se identificó el serotipo ID enzootico, asociado a cuadros febriles en humanos, sin embargo encuestas serológicas previas muestran anticuerpos VEE, entendiéndose que su presencia tiene una antigüedad pasada no determinada. El estudio tiene la finalidad de comparar la magnitud de la circulación de las cepas selváticas de la VEE en humanos y equinos, principalmente en las áreas tropicales donde hay una significativa población equina, considerándose este hecho de riesgo para la aparición de cepas epizoóticas. Así mismo, se ha considerado también la encefalitis equina del Este (EEE), virus que ha causado epizootia equina en la selva y cuya participación en la patología humana aún no ha sido definida. Los resultados encontrados mediante prueba de neutralización en placa de VEE y EEE en células YERO con sueros humanos muestran una variada prevalencia. Siendo la mas alta para VEE en el departamento de San Martín 57% y EEE en el departamento de Loreto 62% y con relación a equinos VEE 68% y EEE 65% ambos en el departamento de Loreto

Distribution of the S-matrix in chaotic microwave cavities with direct processes and absorption

We quantify the presence of direct processes in the S-matrix of chaotic microwave cavities with absorption in the one-channel case. To this end the full distribution P_S(S) of the S-matrix, i.e. S=\sqrt{R}e^{i\theta}, is studied in cavities with time-reversal symmetry for different antenna coupling strengths T_a or direct processes. The experimental results are compared with random-matrix calculations and with numerical simulations based on the Heidelberg approach including absorption. The theoretical result is a generalization of the Poisson kernel. The experimental and the numerical distributions are in excellent agreement with random-matrix predictions for all cases.Comment: 4 pages, 4 figure

Interactions and star formation activity in Wolf-Rayet galaxies

We present the main results of the PhD Thesis carried out by L\'opez-S\'anchez (2006), in which a detailed morphological, photometrical and spectroscopical analysis of a sample of 20 Wolf-Rayet (WR) galaxies was realized. The main aims are the study of the star formation and O and WR stellar populations in these galaxies and the role that interactions between low surface companion objects have in the triggering of the bursts. We analyze the morphology, stellar populations, physical conditions, chemical abundances and kinematics of the ionized gas, as well as the star-formation activity of each system.Comment: 16 pages, 15 figure

Applications of Direct Injection Soft Chemical Ionisation-Mass Spectrometry for the Detection of Pre-blast Smokeless Powder Organic Additives

Analysis of smokeless powders is of interest from forensics and security perspectives. This article reports the detection of smokeless powder organic additives (in their pre-detonation condition), namely the stabiliser diphenylamine and its derivatives 2-nitrodiphenylamine and 4-nitrodiphenylamine, and the additives (used both as stabilisers and plasticisers) methyl centralite and ethyl centralite, by means of swab sampling followed by thermal desorption and direct injection soft chemical ionisation-mass spectrometry. Investigations on the product ions resulting from the reactions of the reagent ions H3O+ and O2+ with additives as a function of reduced electric field are reported. The method was comprehensively evaluated in terms of linearity, sensitivity and precision. For H3O+, the limits of detection (LoD) are in the range of 41-88 pg of additive, for which the accuracy varied between 1.5 and 3.2%, precision varied between 3.7 and 7.3% and linearity showed R20.9991. For O2+, LoD are in the range of 72 to 1.4 ng, with an accuracy of between 2.8 and 4.9% and a precision between 4.5 and 8.6% and R20.9914. The validated methodology was applied to the analysis of commercial pre-blast gun powders from different manufacturers.(VLID)4826148Accepted versio

La enseñanza de las ciencias mediante proyectos didácticos en la Universidad de los Andes - Venezuela

Los paradigmas de la pedagogía científica incorporan estrategias activas, pero, en el trabajo de aula sigue prevaleciendo el modelo pasivo. En contraposición a esto, el presente ensayo describe la experiencia que hemos acumulado desde 1999 con el desarrollo de una metodología denominada Proyectos Didácticos para la Enseñanza de la Ciencia que tiene por finalidad principal aportar diferentes propuestas metodológicas para abordar el trabajo de aula y fuera de ésta, para el caso especial de la enseñanza de las ciencias. Esta estrategia implica la participación activa del estudiante diseñando propuestas prácticas o juegos para el desarrollo de diversos contenidos típicos de la ciencia en el contexto de la formación inicial de docentes en la Universidad de Los Andes

The Present and Future of Planetary Nebula Research. A White Paper by the IAU Planetary Nebula Working Group

We present a summary of current research on planetary nebulae and their central stars, and related subjects such as atomic processes in ionized nebulae, AGB and post-AGB evolution. Future advances are discussed that will be essential to substantial improvements in our knowledge in the field.Comment: accepted for publication in RMxAA; 37 page