International external quality control assessment for the serological diagnosis of dengue infections

Background: Dengue is endemic to the tropics and subtropics, and the most frequent of arthropod-borne viral diseases. Reliable diagnosis of dengue infection is important not only in clinical care but also in disease surveillance, the control of outbreaks, and the development of new vaccines. The diagnosis of dengue infection is usually established by a variety of commercial or in-house serological protocols. The European Network for the Diagnostics of Imported Viral Diseases (ENIVD) recognized the need to survey the accuracy of dengue serological diagnostics in current use, and organized an external quality assurance (EQA) study of dengue serological practice in diagnostic laboratories. Methods: A 15-sample panel, consisting of sera reactive against dengue plus specificity and negative controls, was sent to 48 laboratories for serological testing. The results returned by the participating laboratories were anonymized, scored, and subjected to comparison and statistical analysis. Results: Ten laboratories rated all samples correctly with regard to IgM, and only three achieved the full score for IgG detection. The main handicaps in assay performance were suboptimal sensitivity of in-house IgM detection protocols by comparison with better-performing commercial ELISA tests, and the presence of IgG cross-reactivity with heterologous flaviviruses. Differences of detail in the methodology of dengue IgG antibody detection appear to underlie the disparities in accuracy observed between laboratories. Conclusion: This EQA study demonstrates that there is room for many laboratories to improve sensitivity in the detection of anti-dengue virus IgM antibodies, against the benchmark set by commercial antibody capture ELISA tests. The EQA shows also that cross-reactivity is a continuing issue, and IgG detection protocols must be optimized to increase their specificity

2D MODELLING OF THE SEISMIC RESPONSE FOR BARQUISIMETO AND CABUDARE CITIES FOR MICROZONATION STUDIES

Se presentan los resultados preliminares del modelado numérico de las ondas sísmicas superficiales a lo largo de cuatro perfiles en las ciudades de Barquisimeto y Cabudare. Este modelado 2D se llevó a cabo usando una técnica que combina un método analítico (suma modal) con un método numérico (diferencias finitas) para obtener la respuesta sísmica en términos de la generación de sismogramas sintéticos. Se emplearon dos eventos sísmicos escenarios de magnitudes 6,0 y 7,0 Mw. Las razones de los espectros de respuesta 2D/1D muestran que la componente vertical sufre amplificaciones de hasta un factor 6, para frecuencias alrededor de 2Hz, mientras que las componentes horizontales amplifican hasta un factor de 2 para frecuencias alrededor de 1Hz. Adicionalmente, se observaron aumentos en la amplitud y duración de la señal sísmica en los bordes de la cuenca sedimentaria.The preliminary results of the 2D superficial seismic wave modeling along four cross sections through the Barquisimeto and Cabudare cities are presented. The 2D modeling was done using a technique that combines an analytical method (modal summation) with a numerical method (finite difference) in order to obtain the seismic response in terms of synthetic seismograms generation. We used two seismic scenarios with magnitude 6.0 and 7.0 Mw. The 2D/1D spectra ratio shows the vertical component of the acceleration with an amplification factor 6, around 2 Hz; whereas the horizontal components have amplification of factor 2, around 1 Hz. We also observed an increase in amplitude and duration of the seismic signal at the edge of the sedimentary basin

Do business customers perceive what salespeople believe? Perceptions of salesperson adoption of innovations

A salesperson's commitment and effort toward an innovation can determine whether the customer agrees to buy it, such that customers' perceptions of such commitment and effort are critical. But these perceptions also might differ fundamentally from the salesperson's self-perceptions of commitment and effort. Therefore, this paper presents a theoretical framework of the relation between salesperson-perceived and customer-perceived commitment and effort, as exhibited by the salesperson while selling an innovation, which represents salesperson adoption. In the framework, job satisfaction factors also exert contingent, moderating effects. The authors gather unique, dyadic data from surveys of salespeople and their (potential) business customers during visits to sell a conventional, incremental innovation, complemented by objective purchase data gathered from company records. Three key insights emerge fromt this study. First, salespeople's own perceptions of their commitment and effort have only moderate influences on customers' perceptions of salespeople's commitment and effort. Second, customers seem to recognize salesperson effort more readily than salesperson commitment, although salesperson commitment has a higher sales performance impact than salesperson effort. Thus, sales managers should seek to encourage and support both the commitment of salespeople and also perceptions of that commitment among customers. Third, while a higher organizational support or job autonomy strengthens customers' perceptions of salesperson adoption, a higher pay satisfaction diminishes it. Thus, firms might need to find ways to increase the support for the salespeople and their autonomy and to reduce salespeople's satisfaction with their (direct) payments. In total, these findings suggest significant scientific and managerial implications

2D MODELLING OF THE SEISMIC RESPONSE FOR BARQUISIMETO AND CABUDARE CITIES FOR MICROZONATION STUDIES

Se presentan los resultados preliminares del modelado numérico de las ondas sísmicas superficiales a lo largo de cuatro perfiles en las ciudades de Barquisimeto y Cabudare. Este modelado 2D se llevó a cabo usando una técnica que combina un método analítico (suma modal) con un método numérico (diferencias finitas) para obtener la respuesta sísmica en términos de la generación de sismogramas sintéticos. Se emplearon dos eventos sísmicos escenarios de magnitudes 6,0 y 7,0 Mw. Las razones de los espectros de respuesta 2D/1D muestran que la componente vertical sufre amplificaciones de hasta un factor 6, para frecuencias alrededor de 2Hz, mientras que las componentes horizontales amplifican hasta un factor de 2 para frecuencias alrededor de 1Hz. Adicionalmente, se observaron aumentos en la amplitud y duración de la señal sísmica en los bordes de la cuenca sedimentaria.The preliminary results of the 2D superficial seismic wave modeling along four cross sections through the Barquisimeto and Cabudare cities are presented. The 2D modeling was done using a technique that combines an analytical method (modal summation) with a numerical method (finite difference) in order to obtain the seismic response in terms of synthetic seismograms generation. We used two seismic scenarios with magnitude 6.0 and 7.0 Mw. The 2D/1D spectra ratio shows the vertical component of the acceleration with an amplification factor 6, around 2 Hz; whereas the horizontal components have amplification of factor 2, around 1 Hz. We also observed an increase in amplitude and duration of the seismic signal at the edge of the sedimentary basin

First Outbreak of Callitrichid Hepatitis in Germany: Genetic Characterization of the Causative Lymphocytic Choriomeningitis Virus Strains

AbstractCallitrichid hepatitis (CH) is a highly fatal, rodent-borne zoonosis of New World primates (family Callitrichidae) caused by lymphocytic choriomeningitis virus (LCMV). It is unclear whether virulence in Callitrichidae is associated with specific genetic or phylogenetic markers of the virus as only a partial S RNA sequence of a single CH-associated isolate is known. In a period of 10 months, three pygmy marmosets (Cebuella pygmaea) and one Goeldi's monkey (Callimico goeldii) died from CH in a German zoo. LCMV was most likely transmitted by wild mice. Infection was associated with characteristic histopathological lesions in liver, brain, and lymphoid tissue. Virus sequences from all callitrichids and a captured mouse were ≥99.2% identical. LCMV strains from a pygmy marmoset and the Goeldi's monkey were isolated in cell culture and the 3.4-kb S RNA was completely sequenced. Both strains differed considerably in their genetic and phylogenetic characteristics from known LCMV strains, including the previously described CH-associated strain. These data show that CH is widespread and can be caused by distantly related LCMV strains

Solving Stochastic B\"uchi Games on Infinite Arenas with a Finite Attractor

We consider games played on an infinite probabilistic arena where the first player aims at satisfying generalized B\"uchi objectives almost surely, i.e., with probability one. We provide a fixpoint characterization of the winning sets and associated winning strategies in the case where the arena satisfies the finite-attractor property. From this we directly deduce the decidability of these games on probabilistic lossy channel systems.Comment: In Proceedings QAPL 2013, arXiv:1306.241

SIMULATION OF SEISMIC WAVE PROPAGATION, AND AMPLITUDE AND PERIOD CHARACTERISTICS FOR THE SEISMIC MICROZONING OF GUARENAS AND GUATIRE CITIES

Se presentan los resultados de la simulación de la propagación de las ondas sísmicas en la cuenca Guarenas Guatire, estimando la respuesta sísmica 2D del suelo mediante la generación de sismogramas sintéticos. Esta simulación corresponde a la propagación a lo largo de secciones 2D de la cuenca preparadas a partir de la información geológica y geofísica local y regional. Se empleó la técnica denominada método híbrido, que utiliza los métodos analítico (suma modal de ondas superficiales) y numérico (diferencias finitas), para obtener los sismogramas sintéticos hasta una frecuencia de 10 Hz a lo largo de ocho perfiles de dirección norte-sur y sur-norte y tres perfiles oeste-este de la cuenca sedimentaria de Guarenas-Guatire. Se escogieron tres eventos escenarios, ubicados en: La Falla San Sebastián, la Falla Pichao (sist. La Victoria) y la Falla Tacagua, con magnitudes de 7, 6 y 5 Mw, respectivamente. Se obtuvieron los siguientes parámetros en superficie: relación 2D/1D espectral de las componentes horizontales y verticales H/V de la aceleración, y relación 2D/1D del espectro de respuesta de aceleración, para las componentes transversal, radial y vertical. Se elaboraron espectros de respuesta de aceleración horizontal para la superficie a partir de las relaciones promedios de espectros de respuesta (consideradas como funciones de transferencia) y el espectro de respuesta de roca obtenido de un estudio de amenaza sísmica regional.We present the results of the simulation of seismic wave propagation in complex geological media through numerical calculation, estimating the 2D/1D seismic soil response by generating synthetic seismograms. This simulation corresponds to the propagation along 2D sections of the basin prepared by using local and regional geological and geophysical information. The hybrid methods technique was applied, that uses analytical (modal summation of surface waves) and numerical (finite differences) methods to obtain synthetic seismograms up to a frequency of 10 Hz, along 8 north-south and south-north profiles, and 3 east-west profiles crossing the sedimentary basin of Guarenas-Guatire. Three scenario earthquake were chosen, located along: San Sebastian, Pichao (system La Victoria) and Tacagua Faults, with magnitudes of 7, 6 and 5 Mw, respectively. The following ground motion parameters were obtained : 2D/1D spectral ratio of the horizontal and vertical components H/V, and 2D/1D acceleration response spectrum ratio for the transverse, radial and vertical components. Response spectra of horizontal acceleration for the ground surface were developed from averages relations of response spectra (considered as transfer functions) and response spectrum at bedrock obtained from a regional seismic hazard study

SIMULATION OF SEISMIC WAVE PROPAGATION, AND AMPLITUDE AND PERIOD CHARACTERISTICS FOR THE SEISMIC MICROZONING OF GUARENAS AND GUATIRE CITIES

Se presentan los resultados de la simulación de la propagación de las ondas sísmicas en la cuenca Guarenas Guatire, estimando la respuesta sísmica 2D del suelo mediante la generación de sismogramas sintéticos. Esta simulación corresponde a la propagación a lo largo de secciones 2D de la cuenca preparadas a partir de la información geológica y geofísica local y regional. Se empleó la técnica denominada método híbrido, que utiliza los métodos analítico (suma modal de ondas superficiales) y numérico (diferencias finitas), para obtener los sismogramas sintéticos hasta una frecuencia de 10 Hz a lo largo de ocho perfiles de dirección norte-sur y sur-norte y tres perfiles oeste-este de la cuenca sedimentaria de Guarenas-Guatire. Se escogieron tres eventos escenarios, ubicados en: La Falla San Sebastián, la Falla Pichao (sist. La Victoria) y la Falla Tacagua, con magnitudes de 7, 6 y 5 Mw, respectivamente. Se obtuvieron los siguientes parámetros en superficie: relación 2D/1D espectral de las componentes horizontales y verticales H/V de la aceleración, y relación 2D/1D del espectro de respuesta de aceleración, para las componentes transversal, radial y vertical. Se elaboraron espectros de respuesta de aceleración horizontal para la superficie a partir de las relaciones promedios de espectros de respuesta (consideradas como funciones de transferencia) y el espectro de respuesta de roca obtenido de un estudio de amenaza sísmica regional.We present the results of the simulation of seismic wave propagation in complex geological media through numerical calculation, estimating the 2D/1D seismic soil response by generating synthetic seismograms. This simulation corresponds to the propagation along 2D sections of the basin prepared by using local and regional geological and geophysical information. The hybrid methods technique was applied, that uses analytical (modal summation of surface waves) and numerical (finite differences) methods to obtain synthetic seismograms up to a frequency of 10 Hz, along 8 north-south and south-north profiles, and 3 east-west profiles crossing the sedimentary basin of Guarenas-Guatire. Three scenario earthquake were chosen, located along: San Sebastian, Pichao (system La Victoria) and Tacagua Faults, with magnitudes of 7, 6 and 5 Mw, respectively. The following ground motion parameters were obtained : 2D/1D spectral ratio of the horizontal and vertical components H/V, and 2D/1D acceleration response spectrum ratio for the transverse, radial and vertical components. Response spectra of horizontal acceleration for the ground surface were developed from averages relations of response spectra (considered as transfer functions) and response spectrum at bedrock obtained from a regional seismic hazard study