RISK PREMIUM: INSIGHTS OVER THE THRESHOLD

The aim of this paper is twofold: First to test the adequacy of Pareto distributions to describe the tail of financial returns in emerging and developed markets, and second to study the possible correlation between stock market indices observed returns and return’s extreme distributional characteristics measured by Value at Risk and Expected Shortfall. We test the empirical model using daily data from 41 countries, in the period from 1995 to 2005. The findings support the adequacy of Pareto distributions and the use of a log linear regression estimation of their parameters, as an alternative for the usually employed Hill’s estimator. We also report a significant relationship between extreme distributional characteristics and observed returns, especially for developed countries.

Risk premium: insights over the threshold

The aim of this paper is twofold: First to test the adequacy of Pareto distributions to describe the tail of financial returns in emerging and developed markets, and second to study the possible correlation between stock market indices observed returns and return's extreme distributional characteristics measured by Value at Risk and Expected Shortfall. We test the empirical model using daily data from 41 countries, in the period from 1995 to 2005. The findings support the adequacy of Pareto distributions and the use of a log linear regression estimation of their parameters, as an alternative for the usually employed Hill's estimator. We also report a significant relationship between extreme distributional characteristics and observed returns, especially for developed countries

A Replicative In Vitro Assay for Drug Discovery against Leishmania donovani.

The protozoan parasite Leishmania donovani is the causative agent of visceral leishmaniasis, a disease potentially fatal if not treated. Current available treatments have major limitations, and new and safer drugs are urgently needed. In recent years, advances in high-throughput screening technologies have enabled the screening of millions of compounds to identify new antileishmanial agents. However, most of the compounds identified in vitro did not translate their activities when tested in in vivo models, highlighting the need to develop more predictive in vitro assays. In the present work, we describe the development of a robust replicative, high-content, in vitro intracellular L. donovani assay. Horse serum was included in the assay media to replace standard fetal bovine serum, to completely eliminate the extracellular parasites derived from the infection process. A novel phenotypic in vitro infection model has been developed, complemented with the identification of the proliferation of intracellular amastigotes measured by EdU incorporation. In vitro and in vivo results for miltefosine, amphotericin B, and the selected compound 1 have been included to validate the assay

Propuesta para la utilización de losas de entrepisos prefabricados y su evaluación costo-tiempo.

La innovación tecnológica abarca aspectos como las mejoras en los procesos, los productos y en los servicios, orientados en estas mejoras es que tenemos por finalidad proponer sistemas innovadores de losas de entrepiso más ventajosos que el sistema de losas tradicionales actualmente usada por el sector de la construcción (Ghio, V. & Bascuñan, R. 2006). Es por esta razón que realizamos un estudio para determinar las diferencias entre las  losas aligeradas en una y dos direcciones, losas macizas, losas prefabricadas compuestas con viguetas pretensadas y prefabricadas, losas compuestas con láminas colaborantes y las Prelosas, que en la actualidad se ofrece en la industria de la construcción. Ante un mercado tan exigente y competitivo es conveniente realizar un análisis de las tendencias del uso de losas de entrepisos prefabricadas y un diagnóstico de la evaluación costo y tiempo comparándolas con las losas del sistema tradicional, de esta manera podemos optar por una mejor alternativa de losa de entrepisos de acuerdo al tipo de obra y sus condiciones. En este análisis se demuestra que no siempre se toma una alternativa por su menor costo, sino también por otras ventajas como el tiempo, la calidad del producto, accesibilidad a la zona de trabajo, procesos constructivos seguros, reducción de gastos generales, etc. Proposal to use prefabricated mezzanine slabs and its cost-time evaluationTechnological innovation includes aspects such as improving processes, products and services. With these improvements in mind, we propose that innovative slab systems are more advantageous than the traditional mezzanine slab system currently used by the sector construction in Peru (Ghio & Bascuñan,. 2006). We conducted a study to determine the differences between the lightened slabs in one and two directions; solid slabs; precast slabs made with prestressed and precast joists made with collaborating sheets; and floor slabs slabs, that are currently offered in the Peruvian construction industry.Faced with such a demanding and competitive market, it is useful to analyze trends in the use of prefabricated mezzanine slabs using a cost and time evaluation by comparing them with traditional slabs in order to choose of the best mezzanine for the type of work and conditions. This analysis shows that an alternative is not always chosen for its lower cost, but also for other benefits such as time, product quality, accessibility to the work area, safe construction processes, reducing overhead costs, etc

A smart adaptive tutoring system considering learning styles

This document presents the multi-agent system (PLANG) developed to transform the virtual educational environment of the USD ("Unit of Support to Teaching") in an adaptive hypermedia system taking into account learning styles The techniques of adaptation are directed to the personalized selection of teaching materials, navigation tools and navigation strategies of the educational environment according to the learning style of the student.For the modeling of the student we use techniques of Artificial Intelligence as Reasoning Based on Cases and Fuzzy Logic, the system is able to categorize students according to their ability to process, perceive, receive, organize and understand information.We use intelligent agents to examine opportunities for improvement in teaching and to motivate students to Learn according to your preferences in a friendly and bad environment S close to your learning style. The MASPLANG has been built under the central concept of an intelligent agent known as a software entity that acts intelligently and semiautonomously in representation and benefit of the student.En este documento sepresenta el sistema multiagenteMAS-PLANG (MultiAgent System - PLANG)desarrollado para transformar el entorno educativo virtual de las USD ("Unitats de Suport a laDocencia '') en un sistema hipermedia adaptativo teniendo en cuenta estilos de aprendizaje. Lastécnicas de adaptación están dirigidas a la selección personalizada de los materiales didácticos,las herramientas de navegación y las estrategias de navegación del entorno educativo de acuerdoal estilo de aprendizaje del estudiante. Para el modelado del estudiante utilizamos técnicas deInteligencia Artificial COmo el Razonamiento Basado en Casos y la Lógica Difusa. El sistema estáen capacidad de categorizar estudiantes de acuerdo a su habilidad para procesar, percibir,recibir organizar y entender la información. Utilizamos agentes inteligentes para examinar oportunidades de mejora de la enseñanza y para motivar los estudiantes a aprender según suspreferencias en un entorno amigable y lo más cercano posible a su estilo de aprendizaje. El MASPLANGse ha construido bajo el concepto central de un agente inteligente conocido como unaentidad software que actúa en forma inteligente y semiautónoma en representación y beneficiodel estudiante

A low-mass planet candidate orbiting Proxima Centauri at a distance of 1.5 AU

Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC).Our nearest neighbor, Proxima Centauri, hosts a temperate terrestrial planet. We detected in radial velocities evidence of a possible second planet with minimum mass m c sin i c = 5.8 ± 1.9 M ⊕ and orbital period P c = 5.21 - 0.22 + 0.26 years. The analysis of photometric data and spectro-scopic activity diagnostics does not explain the signal in terms of a stellar activity cycle, but follow-up is required in the coming years for confirming its planetary origin. We show that the existence of the planet can be ascertained, and its true mass can be determined with high accuracy, by combining Gaia astrometry and radial velocities. Proxima c could become a prime target for follow-up and characterization with next-generation direct imaging instrumentation due to the large maximum angular separation of ~1 arc second from the parent star. The candidate planet represents a challenge for the models of super-Earth formation and evolution.Peer reviewedFinal Published versio

Carbon remineralization by small mesopelagic and bathypelagic Stomiiforms in the Northeast Atlantic Ocean

The organic carbon resulting from photosynthesis in the upper ocean is transferred downward through the passive sinking of organic particles, physical mixing of particulate and dissolved organic carbon as well as active flux transported by zooplanktonic and micronektonic migrants. Several meso- and bathypelagic organisms feed in shallower layers during the nighttime and respire, defecate, excrete and die at depth. Recent studies suggest that migrant micronekton transport similar amounts of carbon to migrant zooplankton. However, there is scarce information about biomass and carbon flux by non-migratory species in the mesopelagic and bathypelagic zones. The non-migratory bristlemouth fishes (Cyclothone spp.) and partial migrator (A. hemigymnus) remineralise organic carbon at depth, and knowledge about this process by this fauna is lacking despite them having been referred to as the most abundant vertebrates on Earth. Here we show the vertical distribution of biomass and respiration of non-migratory mesopelagic fishes, during day and night, using the enzymatic activity of the electron transfer system (ETS) as a proxy for respiration rates. The study is focused on five Cyclothone species (C. braueri, C. pseudopallida, C. pallida, C. livida and C. microdon) and Argyropelecus hemigymnus. The samples were taken on a transect from the oceanic upwelling off Northwest Africa (20° N, 20° W) to the south of Iceland (60° N, 20° W). Cyclothone spp. showed, by far, the largest biomass (126.90 ± 86.20 mg C·m⁻²) compared to A. hemigymnus (0.54 ± 0.44 mg C·m⁻²). The highest concentrations of Cyclothone spp. in the water column were observed between 400 and 600 m and from 1000 to 1500 m depths, both during day and night. For the different species analysed, ETS activity did not show significant differences between diurnal and nocturnal periods. The total average specific respiration of Cyclothone spp. (0.02 ± 0.01 d⁻¹) was lower than that observed for A. hemigymnus (0.05±0.02 d⁻¹). The average carbon respiration of Cyclothone spp. was 2.22 ± 0.81 mg C·m⁻²·d⁻¹, while it was much lower for A. hemigymnus (0.04 ± 0.03 mg C·m⁻²·d⁻¹). The respiration of Cyclothone spp. was lower in the bathypelagic than in the mesopelagic zone (0.84 ± 0.48 vs 1.36 ± 1.01 mg C·m⁻²·d⁻¹, respectively). These results, to our knowledge, provide the first account of remineralisation by this community in the meso and bathypelagic zones of the ocean.En prens

Chronic stress alters neuropeptide Y signaling in the bed nucleus of the stria terminalis in DBA/2J but not C57BL/6J mice

Numerous rodent and human studies have demonstrated that neuropeptide Y (NPY) is involved in the regulation of anxiety-related behaviors. In this study, we examined whether there were differences in NPY signaling between two inbred mouse strains (C57BL/6J and DBA/2J) that exhibit divergent basal and stress-induced anxiety phenotypes. We focused on the bed nucleus of the stria terminals (BNST), a structure in the extended amygdala that is important for the regulation of anxiety-like behavior and contains NPY receptors. While results from whole-cell voltage-clamp recordings and immunofluorescence histochemistry revealed no significant basal differences in NPY signaling or NPY and NPY Y2 receptor (Y2R) expression in the BNST, these measures were differentially altered by chronic restraint stress. Ten days of chronic restraint stress increased basal GABAergic transmission and decreased NPY’s ability to inhibit evoked GABAergic transmission in the dorsolateral BNST (dlBNST) via Y2R in DBA/2J, but not C57BL/6J, mice. Additionally, restraint stress increased NPY and Y2R expression across subregions of the BNST of DBA/2J mice 24 hrs after the last stress exposure, but no changes were observed in C57BL/6J mice. Together, these results suggest that chronic restraint stress engages the NPY system and alters NPY modulation of inhibitory transmission in the dlBNST of DBA/2J mice, but not C57BL/6J mice, which may be related to increased expression of anxiety-related behaviors in this strain

Reversible Dimerization/Polymerization of a Janus Diradical Producing Labile CC Bonds and Giant Chromism

En esta comunicación se presenta el estudio espectroscópico y téorico de la dimerización/oligomerización reversible de un birradical derivado de naftoditiofeno el cual en su forma monomérica presenta una intenso color azul mientras que al agregar se muestra incoloro, siendo éstas formas intercambiables gracias a la aplicación de estímulos débiles como presión o temperatura.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Shoc2/Sur8 protein regulates neurite outgrowth

This is an openaccess article distributed under the terms of the Creative Commons Attribution License.-- et al.The Shoc2 protein has been implicated in the positive regulation of the Ras-ERK pathway by increasing the functional binding interaction between Ras and Raf, leading to increased ERK activity. Here we found that Shoc2 overexpression induced sustained ERK phosphorylation, notably in the case of EGF stimulation, and Shoc2 knockdown inhibited ERK activation. We demonstrate that ectopic overexpression of human Shoc2 in PC12 cells significantly promotes neurite extension in the presence of EGF, a stimulus that induces proliferation rather than differentiation in these cells. Finally, Shoc2 depletion reduces both NGF-induced neurite outgrowth and ERK activation in PC12 cells. Our data indicate that Shoc2 is essential to modulate the Ras-ERK signaling outcome in cell differentiation processes involved in neurite outgrowth.GL, TG and LMD were recipients of fellowships from the Ministerio de Educación y Ciencia (MEC) (to GL, TG), and Fondo de Investigaciones Sanitarias (FIS) (to LMD). LSR held a postdoctoral research contract from CIBERNED. This work was supported by FIS grant (PI10/00815) to JLO; CIBERNED to MC; SAF2008-01951, Comunidad Autónoma de Madrid (CAM) SSAL-0202-2006-01 and Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED) to TI; FIS grant PI12/00775 and ISCIII-RETIC (Red Temática de Investigación Cooperativa en Cáncer) RD12/0036/0027 from the Instituto de Salud Carlos III to PSG; and FIS grants (PI09/0562 and PI13/00703), ISCIIIRETIC (RD06/0020/0003 and RD12/0036/0021), and the Spanish Association Against Cancer (AECC) to JMR.Peer Reviewe