Calculation of Response matrix of a BSS with 6LiI scintillator

The response matrix of a Bonner sphere spectrometer was calculated using MCNP 4C and MCNPX 2.4.0 codes. As thermal neutron detector a 0.4 cm £; 0.4 cm 6LiI which is located at the center of a set of polyethylene spheres. The response was calculated for 0, 2, 3, 5, 8, 10, and 12 inches-diameter polyethylene spheres for neutrons whose energy goes from 2.50E(-8) to 100 MeV. The response matrix was calculated for 23 neutron energies, the response functions were energy-interpolated to 51 neutron energies and were compared with a matrix response reported in the literature, in this comparison both response matrices are in agreement. The main differences were found in the bare detector and are attributed to the irradiation conditions and cross sections, for the other detectors the differences are due to the cross sections libraries

Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

Procesos migratorios en la región centroamericana: Entender lo contemporáneo desde una mirada histórica en la época del bicentenario

Los recientes procesos migratorios en la región centroamericana presentan como principal característica la intensidad, los volúmenes y la orientación hacia afuera de sus territorios. Se debe indicar el funcionamiento de dos zonas geográficas delimitadas mediante las cuales opera el sistema de las migraciones centroamericanas, apuntado su rasgos heterogéneos, sus diversas composiciones, así como las causalidades y efectos diferenciados.The recent migratory processes in the Central American region present as main characteristics the intensity, the volumes and the outward orientation of their territories. The operation of two delimited geographical areas through which the Central American migrations system operates should be indicated, pointing out their heterogeneous features, their various compositions, as well as the differentiated causalities and effects.Decanato Facultad de Ciencias Sociale

Movilidad humana centroamericana y la respuesta ante la vulnerabilidad, discriminación y exclusión

Explica los principales problemas de vulnerabilidad, exclusión y discriminación, hacia aquellas personas centroamericanas, que por diferentes razones, han optado por emigrar hacia otros países, en búsqueda de empleo, que permita mejorar su calidad de vida, a nivel económico y familiar.Universidad Nacional, Costa RicaInstituto de Estudios Sociales en Población (IDESPO

Molecular Epidemiology of Avian Malaria in Wild Breeding Colonies of Humboldt and Magellanic Penguins in South America

Avian malaria is a disease caused by species of the genera Haemoproteus, Leucocytozoon, and Plasmodium. It affects hundreds of bird species, causing varied clinical signs depending on the susceptibility of the host species. Although high mortality has been reported in captive penguins, limited epidemiological studies have been conducted in wild colonies, and isolated records of avian malaria have been reported mostly from individuals referred to rehabilitation centers. For this epidemiological study, we obtained blood samples from 501 adult Humboldt and 360 adult Magellanic penguins from 13 colonies throughout South America. To identify malaria parasitaemia, we amplified the mtDNA cytochrome b for all three parasite genera. Avian malaria was absent in most of the analyzed colonies, with exception of the Punta San Juan Humboldt penguin colony, in Peru, where we detected at least two new Haemoproteus lineages in three positive samples, resulting in a prevalence of 0.6% for the species. The low prevalence of avian malaria detected in wild penguins could be due to two possible causes: A low incidence, with high morbidity and mortality in wild penguins or alternatively, penguins sampled in the chronic stage of the disease (during which parasitaemia in peripheral blood samples is unlikely) would be detected as false negatives.Fil: Sallaberry Pincheira, Nicole. Universidad Católica de Chile; Chile. Pontificia Universidad Católica de Chile; Chile. Universidad Andrés Bello; ChileFil: Gonzalez Acuña, Daniel. Universidad de Concepción; ChileFil: Herrera Tello, Yertiza. Pontificia Universidad Católica de Chile; Chile. Universidad Católica de Chile; ChileFil: Dantas, Gisele P. M.. Pontificia Universidade Catolica de Minas Gerais;Fil: Luna Jorquera, Guillermo. Universidad Catolica del Norte; ChileFil: Frere, Esteban. Universidad Nacional de la Patagonia Austral; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Valdés Velasquez, Armando. Universidad Peruana Cayetano Heredia; PerúFil: Simeone, Alejandro. Universidad Andrés Bello; ChileFil: Vianna, Juliana A.. Pontificia Universidad Católica de Chile; Chile. Universidad Católica de Chile; Chil

Movimiento social afrodescendiente en Centroamérica: institucionalidad y desempeño organizacional

Este libro contiene el resultado de las principales reflexiones del simposio “Movimiento regional afrodescendiente en Centroamérica: institucionalidad y desempeño organizacional”, realizado en la Universidad Nacional, en marzo de 2012. Esta propuesta constituye una oportunidad invalorable para posicionar en la agenda de investigación académica, el tema de las condiciones mediante las cuales las poblaciones afrodescendientes en la región centroamericana resuelven su bienestar material y subjetivo, de qué forman organizan su respuesta frente al estado, y las circunstancias históricas que han determinado procesos de exclusión, así como las consideraciones de carácter teórico-conceptual y metodológico que determinan el abordaje que la masa crítica regional ha hecho sobre esta población en particular.This book contains the results of the main reflections of the symposium "Afro-descendant regional movement in Central America: institutionality and organizational performance", held at the National University in March 2012. This proposal constitutes an invaluable opportunity to position on the academic research agenda, the issue of the conditions through which Afro-descendant populations in the Central American region resolve their material and subjective well-being, how they organize their response to the state, and the historical circumstances that have determined exclusion processes, as well as theoretical considerations -conceptual and methodological that determine the approach that the regional critical mass has made on this particular population.Universidad Nacional, Costa RicaUniversidad Nacional, Costa Ric

Territorios y espacios transfronterizos : una visión desde Centroamérica

Este libro es un esfuerzo conjunto de tres unidades académicas de la Universidad Nacional, Costa Rica: Escuela de Relaciones Internacionales, Instituto de Estudios Sociales en Población (IDESPO), y Sede Regional Chorotega, que le ofrecen a usted, lector un intento por re-pensar los espacios transfronterizos como unidades territoriales con una dinámica propia, que transcienden las divisiones fronterizas entre Estados.This book is a joint effort of three academic units of the National University, Costa Rica: School of International Relations, Institute of Social Studies in Population (IDESPO), and Chorotega Regional Headquarters, which offer you, the reader, an attempt to re- think of cross-border spaces as territorial units with their own dynamics, which transcend border divisions between States.Universidad Nacional, Costa RicaEscuela de Relaciones InternacionalesInstituto de Estudios Sociales en Población (IDESPO

Ciencias Sociales y Relaciones Internacionales : nuevas perspectivas desde América Latina

Esta obra es un modesto intento para situar la disciplina de las Relaciones Internacionales dentro de las Ciencias Sociales, pero con una visión desde América Latina. El conjunto de trabajos, que se solicitaron expresamente a autoras y autores, se agrupa en tres secciones: i) Epistemología e Investigación; ii) Enfoques teóricos y metodológicos y iii) Estudio de casos.This work is a modest attempt to place the discipline of International Relations within the Social Sciences, but with a view from Latin America. The set of works, which is expressly requested from authors, is grouped into three sections: i) Epistemology and Research; ii) Theoretical and methodological approaches and iii) Case studies.Universidad Nacional, Costa RicaIDESPOCLACSOEscuela de Relaciones Internacionale