On the construction of a finite Siegel space

In this note we construct a finite analogue of classical Siegel's Space. Our approach is to look at it as a non commutative Poincare's half plane. The finite Siegel Space is described as the space of Lagrangians of a $2n$ dimensional space over a quadratic extension $E$ of a finite base field $F$. The orbits of the action of the symplectic group $Sp(n,F)$ on Lagrangians are described as homogeneous spaces. Also, Siegel's Space is described as the set of anti-involutions of the symplectic group.2

Rapid kinetics of the interaction between daunomycin and drug-sensitive or drug-resistant P388 leukemia cells

AbstractThe initial stages of the interaction of daunomycin (DNM) with drug-sensitive (P388/S) and drug-resistant (P388/100) cells have been defined by a rapid kinetics stopped-flow procedure. The process can be described by two kinetic components. The faster component accounts for rapid occupation of cell surface sites by DNM, as supported by experiments with liposomes with different surface charge. On the other hand, the effect of verapamil in the assays, suggests that the slower component is involved in the transport of the drug into the cells. Our observations are consistent with a loss in the control of the passive permeability to the drugs in the drug-resistant tumor cells

The 2016 seismic series in the south Alboran Sea: Seismotectonics, Coulomb Failure Stress changes and implications for the active tectonics in the area

The Southern Alboran Sea, particularly the area offshore Al Hoceima Bay, presents moderate but continuous seismic activity since the Mw 6.0 1994 Al Hoceima earthquake. The maximum magnitude occurred in the area was a Mw 6.3 earthquake in the 2004 Al Hoceima – Tamasint seismic series. Since then, the seismicity in the Al Hoceima area has been usual, with maximum seismic magnitudes around 4. An increase in the seismic rate was registered during 2015, especially from May, culminating in the seismic series in January 2016. The mainshock occurred on January 25th 2016 with a magnitude Mw 6.3 and it was preceded by a Mw 5.1 foreshock on January 21st. The seismic series took place at the western end of the Alboran Ridge. Towards the northeast the Alboran Ridge bends, and seems to be connected with the NW-SE right-lateral transtensional Yusuf Fault. The recorded seismicity is mainly located in the Alboran Ridge area and along the N-S Al-Idrisi Fault that seems to continue southwards, towards the Al Hoceima Bay. The focal mechanisms calculated previously in the area showed a leftlateral strike-slip faulting with some normal component in the Alboran Ridge; but always within a complex system of diffuse deformation and high rupture type variability. We have used 41 computed focal mechanisms of this seismic series to analyze its seismotectonics and structural characteristics. To group the focal mechanisms we used a clustering algorithm using the spatial distribution of the events and also the type of rupture mechanism. For each cluster we have obtained the composed focal mechanism, associating it to a particular fault or family of structures. We have tested the mechanical compatibility of these structures by Coulomb Failure Stress transfer modeling. The mainshock of the series occurred in the Al Idrisi Fault intersecting the western Alboran Ridge. This event triggered aftershocks and independent series in left-lateral strike-slip faults associated with the Al Idrisi Fault System towards the south, but also in near pure reverse faults in the fault zone bounding the the Alboran Ridge. Both types of faults and rupture-mechanisms coexist, linked mechanically by stress transfer, being coeval the uplift of the Alboran Ridge and its northwestward displacement due to the left-lateral motion of the Al-Idrisi Fault. It is also discussed how the contrasting faulting processes and seismic ruptures are developed in two differentially oriented fault zones in the context the current NW-SE plate convergence between the African and Eurasian plates in the Westernmost Mediterranean

La producciòn académica como uno de los indicadores del desempeño de las universidades públicas colombianas desde la perspectiva del análisis envolvente de datos

Este articulo compara los resultados obtenidos por un modelo propuesto por la Subcomisión Técnica del Sistema de Universidades Estatales basado en la técnica multivariada “Análisis de Componentes Principales”, combinada con Regresión Lineal, y que fue usado para medir el desempeño en investigación y formación en las universidades publicas Colombianas versus la perspectiva resultante de aplicar a éste mismo problema la técnica del Análisis Envolvente de Datos-DEA. La compresión obtenida mediante la comparación de los dos modelos nos lleva a considerar como mas adecuado el enfoque DEA para valorar las eficiencias de la universidades con respecto al factor de producción

La producciòn académica como uno de los indicadores del desempeño de las universidades públicas colombianas desde la perspectiva del análisis envolvente de datos

Este articulo compara los resultados obtenidos por un modelo propuesto por la Subcomisión Técnica del Sistema de Universidades Estatales basado en la técnica multivariada “Análisis de Componentes Principales”, combinada con Regresión Lineal, y que fue usado para medir el desempeño en investigación y formación en las universidades publicas Colombianas versus la perspectiva resultante de aplicar a éste mismo problema la técnica del Análisis Envolvente de Datos-DEA. La compresión obtenida mediante la comparación de los dos modelos nos lleva a considerar como mas adecuado el enfoque DEA para valorar las eficiencias de la universidades con respecto al factor de producción

献辞

The ability to unveil growing rogue waves in the ocean is essential for safe marine travel in stormy conditions. This vital problem has not been adequately addressed so far. We show that the specific triangular spectra of rogue waves can be detected at early stages of their development in a chaotic wave field. Continuously measuring the spectra of various parts of the wave field allows us to find a rogue wave before the dangerous peak appears. This possibility of early detection is a necessary part of a rogue wave early-warning system.N.A. is a grateful recipient of the Alexander von Humboldt Prize. He acknowledges a grant on Extreme Events from the Volkswagen Foundation. J.M.S.C. acknowledges support from the Spanish Ministerio de Ciencia e Innovación under contract FIS2009-09895. A.A. and N.D. acknowledge the support of the Australian Research Council (Discovery Project DP110102068)

EVALUACIÓN DE RIESGOS FINANCIEROS EN EL MERCADO ELÉCTRICO COLOMBIANO

Este artículo presenta los resultados de adaptar técnicas financieras al cálculo de un portafolio de inversiones en el mercado eléctrico. Al definir políticas de inversión a largo plazo se propone usar los caudales medios de los ríos en el país para pronosticar el precio de la energía eléctrica. Luego un modelo de programación cuadrática con restricciones lineales es aplicado para determinar la estructura óptima del portafolio de inversiones y calculado el denominado “Value at Risk (VaR)”, o valoración del riesgo del mismo. Finalmente se presentan algunas recomendaciones acerca de otras metodologías a analizar en posteriores estudios, para resolver este mismo problema