Axial quasinormal modes of Einstein-Gauss-Bonnet-dilaton neutron stars

We investigate axial quasinormal modes of realistic neutron stars in Einstein-Gauss-Bonnet-dilaton gravity. We consider eight realistic equations of state containing nuclear, hyperonic, and hybrid matter. We focus on the fundamental curvature mode and compare the results with those of pure Einstein theory. We observe that the frequency of the modes is increased by the presence of the Gauss-Bonnet-dilaton, while the impact on the damping time is typically smaller. Interestingly, we obtain that universal relations valid in pure Einstein theory still hold for Einstein-Gauss-Bonnet-dilaton gravity, and we propose a method to use these phenomenological relations to constrain the value of the Gauss-Bonnet coupling

Spatiotemporal variations of organochlorine pesticides in an apex predator: Influence of government regulations and farming practices

Background: Intensification of agricultural practices has caused several negative effects to the environment. The use of fertilizers and pesticides may alter geochemical cycles or cause direct wildlife intoxication. Detrimental effects of organochlorine pesticides (OCPs) have forced the authorities to ban or restrict its use. This study evaluates the variation in levels of OCPs in a sentinel species in relation to changes in government regulations and the spatial configuration of agricultural practices around the nests. Methods: Between 2003 and 2007, we analysed OCP levels in 256 blood samples of Eurasian Eagle-owl (Bubo bubo) chicks nesting in area of intensive commercial agriculture with historical frequent use of pesticides, in South-eastern Spain. We studied year-to-year variations in OCP concentrations and their relation with land use configuration around raptor nests by Generalized Linear Mixed Models (GLMM). Results: OCPs were detected in 100% samples surveyed in 2003 and 2004, while dropped to 27% in 2005, 6.8% in 2006 and 6.3% in 2007, coinciding with the ban of OCPs. The presence of the main OCPs was related to agricultural practices. In particular, endosulfan and lindane were related to irrigated crops and urban areas, while DDT-related compounds and dieldrin were associated with dry land farming. Conclusions: OCP concentrations in blood samples of Eurasian Eagle-owls may respond quickly to the implementations of new regulations about the use of agricultural products. This raptor was confirmed as a good sentinel species allowing rapid detection of changes in pesticides use

Epidemiology of meningococcal disease in Colombia

Objetivos: Describir la situación epidemiológica de la enfermedad meningocócica en Colombia. Material y métodos: Estudio descriptivo que recopiló información de diferentes fuentes pertenecientes al Sistema Nacional de Vigilancia en Salud Pública. Las variables fueron analizadas de forma descriptiva y se calcularon las tasas de incidencia cuando los datos requeridos estuvieron disponibles. Resultados: Durante el periodo 2005-2011 se notificaron 1.065 casos, lo que representó un promedio anual de incidencia de 0,36/100.000 habitantes. De estos, se confirmaron tan solo el 46%, lo que apunta a la existencia de una importante brecha de notificación y confirmación. La mayor incidencia se encontró en menores de un año (5,4-6,9/100.000 habitantes) y el 50% de los casos se presentaron en menores de 10 años. Discusión: La Neisseria meningitidis serogrupo B representó la mayor proporción de los aislamientos; sin embargo, en los últimos años los serogrupos Y y C han tenido un repunte importante. Los síntomas fueron en general inespecíficos, el curso de la enfermedad fue rápido y la letalidad fue alta (13,3%). Conclusiones: Existe la necesidad de mejorar las herramientas disponibles para la vigilancia. Las acciones preventivas deben estar dirigidas a lactantes y niños, con protección contra los serogrupos Y y C. Es necesaria la investigación de estrategias contra el serogrupo B.Objectives: The purpose of this paper was to describe the epidemiology of meningococcal disease in Colombia. Materials and methods: This was a descriptive study based on data from various sources in the National Surveillance System. The variables were analysed descriptively and the incidence rates were estimated when the required data were available. Results: During the 2005-2011 period, 1,065 cases were reported, which represented an annual mean incidence of 0.36/100.000 inhabitants. Of these, only 46% were confirmed, which reveals a gap between reporting and confirmation. The greatest incidence was observed in infants younger than one year (5.4-6.9/100,000) and 50% of the cases occurred in children under 10 years of age. Discussion: Neisseria meningitidis serogroup B represented the greatest proportion of isolates; however, serogroups Y and C have been increasing recently. The symptoms were non-specific, the course of the disease was rapid and the lethality high (13.3%). Conclusions: There is a need to improve the available tools for diagnosis and surveillance. Prevention must be oriented toward infants, toddlers and children including protection against serogroups C and Y. Research into strategies for prevention against serogroup B is also necessary

A laser spectroscopy system with combined absorption, polarization rotation and fluorescence detection to study two photon transitions in atomic rubidium

AbstractThe design and construction of an experimental system for studying two photon spectroscopy processes in atomic rubidium is presented. It is designed to measure absorption and polarization rotation induced by any of the two laser beams and also the visible fluorescence that results from decay of the excited states. Two home-built diode lasers are used to produce the optical fields that later interact with room temperature rubidium atoms. Using counterpropagating beams allows velocity selection of the groups of atoms that interact with both laser beams. The system was tested in the 5 S→5 P3/2→5 Dj ladder energy level configuration of atomic rubidium. Blue fluorescence (420nm) that results from decay of the intermediate 6Pj states is filtered and then measured with a photomultiplier tube. Absorption and fluorescence spectra provide mutually complementary information about the interaction between the rubidium atoms and the two optical fields