Variación de las distribuciones espectrales de atmosféricos en función del umbral de recepción y del tiempo

La distribución estadística de las amplitudes espectrales de los atmosféricos puede ser considerada en el lugar de origen, como una logarítná co normal con suficiente aproximación. Por su parte, en una estación rece£ tora, distante de la fuente, aquella distribución se verá modificada en ma yor o menor medida por el camino de propagación, parámetros ionosféricos y terrestres y condiciones de recepción de las señales. En el presente trabajo analizamos la variación de los valores medios de las distribuciones espectrales en función del umbral de recepción de los equipos y del tiempo.The statistic distribution of atmospheric spectral amplitudes can be considered, in the original spot, as a normal logarithmic with sufficient approximation. At the same time, in a receiver station distant from the source, the above mentioned distribution will suffer modification in higher or lower scale depending on way of propagation, ionospheric and terre£ trial parameters and reception conditions of the signals. In this investigation work we analyze the variations of the average power of the spectral distributions regarding the reception threshold of the equipments and time.Asociación Argentina de Geofísicos y Geodesta

Procesado óptico de datos y su aplicación a geofísica

Se presentan los fundamentos del método de computación óptica y se muestran los resultados obtenidos con un sistema óptico preparado al efecto, que utiliza luz láser coherente, el cual se aplica al filtrado de datos sísmicos y fotografías espaciales.The basis of a method of optical computation are presented, and the results obtained with an optical system especially prepared that uses coherent light from a laser are given, applied to sismic data and spacial pictures.Asociación Argentina de Geofísicos y Geodesta

Comparative susceptibility of mosquito populations in North Queensland, Australia to oral infection with dengue virus.

Dengue is the most prevalent arthropod-borne virus, with at least 40% of the world's population at risk of infection each year. In Australia, dengue is not endemic, but viremic travelers trigger outbreaks involving hundreds of cases. We compared the susceptibility of Aedes aegypti mosquitoes from two geographically isolated populations to two strains of dengue virus serotype 2. We found, interestingly, that mosquitoes from a city with no history of dengue were more susceptible to virus than mosquitoes from an outbreak-prone region, particularly with respect to one dengue strain. These findings suggest recent evolution of population-based differences in vector competence or different historical origins. Future genomic comparisons of these populations could reveal the genetic basis of vector competence and the relative role of selection and stochastic processes in shaping their differences. Lastly, we show the novel finding of a correlation between midgut dengue titer and titer in tissues colonized after dissemination

Culex pipiens, an Experimental Efficient Vector of West Nile and Rift Valley Fever Viruses in the Maghreb Region

West Nile fever (WNF) and Rift Valley fever (RVF) are emerging diseases causing epidemics outside their natural range of distribution. West Nile virus (WNV) circulates widely and harmlessly in the old world among birds as amplifying hosts, and horses and humans as accidental dead-end hosts. Rift Valley fever virus (RVFV) re-emerges periodically in Africa causing massive outbreaks. In the Maghreb, eco-climatic and entomologic conditions are favourable for WNV and RVFV emergence. Both viruses are transmitted by mosquitoes belonging to the Culex pipiens complex. We evaluated the ability of different populations of Cx. pipiens from North Africa to transmit WNV and the avirulent RVFV Clone 13 strain. Mosquitoes collected in Algeria, Morocco, and Tunisia during the summer 2010 were experimentally infected with WNV and RVFV Clone 13 strain at titers of 107.8 and 108.5 plaque forming units/mL, respectively. Disseminated infection and transmission rates were estimated 14–21 days following the exposure to the infectious blood-meal. We show that 14 days after exposure to WNV, all mosquito st developed a high disseminated infection and were able to excrete infectious saliva. However, only 69.2% of mosquito strains developed a disseminated infection with RVFV Clone 13 strain, and among them, 77.8% were able to deliver virus through saliva. Thus, Cx. pipiens from the Maghreb are efficient experimental vectors to transmit WNV and to a lesser extent, RVFV Clone 13 strain. The epidemiologic importance of our findings should be considered in the light of other parameters related to mosquito ecology and biology

Erratum to: EuPRAXIA Conceptual Design Report – Eur. Phys. J. Special Topics 229, 3675-4284 (2020), https://doi.org/10.1140/epjst/e2020-000127-8

International audienceThe online version of the original article can be found at http://https://doi.org/10.1140/epjst/e2020-000127-8</A

Análisis comparativo de tres métodos de localización geográfica de las fuentes de atmosféricos

La localización geográfica de las descargas eléctricas en la atmósfera puede ser realizada mediante dos métodos básicos conocidos. Estos son, las triangulación radio-goniométrica y el método hiperbólico. Una tercera posibilidad consiste en implementar un método híbrido en el cual se utilizan simultáneamente los dos anteriores. El objeto de este trabajo consiste en analizar sucesivamente las posibilidades de cada uno de estos métodos, tanto desde el punto de vista de las precisiones alcanzables en la localización del punto de emisión, como de los medios e infraestructura necesarios para su puesta en funcionamiento. En base al análisis anterior, se extraen conclusiones a fin de seleccionar en cada caso la configuración óptima del sistema de localización.Geographic localization of the electric discharges in the atmosphere can be obtained using one of the two basic methods known. These are: radio -gonometric triangulation method or hyperbolic method. A third possibility could be the application of a hybrid method, applying the two above mentioned methods simultaneously. The object of this work consists in the successive analysis of the po ssibilities of these three methods from the point of view of exactness obtained in the localization of the emission, point as well as from the necessary means and organical structure to set each of them going. From the above mentioned analysis determinations can be taken so as to select in each case the most convenient localization system.Asociación Argentina de Geofísicos y Geodesta