The S3 symmetric model with a dark scalar

We study the S3 symmetric extension of the Standard Model in which all the irreducible representations of the permutation group are occupied by SU(2) scalar doublets, one of which is taken as inert and can lead to dark matter candidates. We perform a scan over parameter space probing points against physical constraints ranging from unitarity tests to experimental Higgs searches limits. We find that the latter constraints severely restrict the parameter space of the model. For acceptable points we compute the value of the relic density of the dark scalar candidates and find that it has a region for low dark matter masses which complies with the Higgs searches bounds and lies within the experimental Planck limit. For masses ≳80 GeV the value of the relic density is below the Planck bound, and it reaches values close to it for very heavy masses ∼5 TeV. In this heavy mass region, this opens the interesting possibility of extending the dark sector of the model with additional particles. Keywords: Dark matter, Multi-Higgs model, S3 symmetric mode

An Inert Scalar In The S3 Symmetric Model

International audienceWe consider the S3 symmetric extension of the Standard Model in which all the irreducible representations of the permutation group are occupied by SU(2) scalar doublets, one of which is taken as inert. We study the parameter space of the model probing points against physical constraints ranging from unitarity tests to experimental Higgs searches limits. We find that the latter constraints severely restrict the parameter space of the model, and that the relic density of the dark matter candidates lies below the Planck bound for a large portion of the probed regions

Sistema de monitoreo para los ambientes arrecifales en Colombia y evaluación de agentes de mortalidad coralina

IP 2105-09-327-97v.1. Informe final. -- v.2. Evaluacion preliminar de algunos indicadores de contaminacion de origen terrestre en areas coralinas de la region de Santa Marta,CaribeColombiano. -- v.3. Sistema nacional de monitoreo de arrecifes coralinos en Colombia.LIBRO(S): Caribbean coral reef, seagrass and mangrove sites /edited by Bjorn Kjerfve. -- Francia : UNESCO;'-- CAPITULO(S) en LIBRO: Assessing and monitoring Coral Reef Condition inColombia During the Last Decade / J.;Garzon Ferreira and J.M. Diaz. -- En: Information, Managementand decisionsupport for marine biodiversity;protection and human welfare: coral reefs / Australian instituteof marinescience. -- Australia: National;library of Australia cataloguin-in-publication data : Australianinstituteof marine science. Workshop (1999 :;Townsville, Qld.); p. 51-58 -- ISBN 0642322015. -- ARTICULO(S)EN REVISTA: Evaluacion rapida de estructura y;salud de las formaciones coralinas de la isla de Malpelo (Pacifico Colombiano) / Jaime Garzon Ferreira y Jorge;H. Pinzon. -- En: Boletin de investigaciones Marinas y costeras.-- No. 28(1999); p. 137-154. -- ISSN;01229761. -- Another unknown caribbean coral phenomenon? /J.Garzon Ferreira, D.L. Gil. -- En: Reef;encounter. -- No. 24 (1998); p. 10. -- ISSN 02552787. -- SIMAC:a new program to monitor coral reef condition;Regional Sector sur de America Tropical (1 : 2000 jun. 6: SanJose, Costa Rica);informe / Jaime Garzon Ferreira. -- En: Reunion Red Mundial deMonitoreo de Arrecifes Coralinos (GCRMN) : Nodo;PONENCIA(S) EN CONGRESO: Problematica ambiental en los mares colombianos /Jaime Garzon Ferreira. -- En:;Expolisboa 98 (1998) -- Cinco años de monitoreo Caricomp en Colombia / Jaime Garzon Ferreira y Alberto;Rodriguez Ramirez. -- En: Seminario Nacional de Politica,Ciencias y Tecnologias del Mar (11 : 1998 oct. 26-30;: Santafe de Bogotá) -- Caracteristicas, incidencia y distribucion de la enfermedad de lunares oscuros en;corales petreos del parque nacional natural Tayrona, Caribe Colombiano / D.L. Gil Agudelo, J. Garzon Ferreira.; En: Seminario Nacional de Politica, Ciencias y Tecnologiasdel Mar (11: 1998 oct. 26-30 : Santafe de;Bogotá) -- Launching SIMAC : the national monitoring system forthe coralreefs of Colombia / J. Garzon;Ferreira ... [et.al]. -- En: International Conference on Scientific Aspects of Coral Reef Assessment,;Monitoringm and Restoration (1999 Apr. 14 : Florida, USA)-- Caricomp y SIMAC: monitoreo de ecosistemas;marinos costeros en Colombia / Jaime Garzon Ferreira, AlbertoRodriguez Ramirez. -- En: Taller de;Investigaciones Ecologicas a Largo Plazo (1 : 1999 ago. 26-28:Villa de Leyva, Colombia) -- Caricomp y SIMAC:;monitoreo de ecosistemas marinos costeros en Colombia / JaimeGarzon Ferreira, Alberto Rodriguez Ramirez. --;En: Seminario-taller Nacional sobre los Efectos del Fenomeno ElNiño enColombia (1 : 1999 nov. 10-11 :;Santiago de Cali, Colombia) -- Patterns of change in coralreef,seagrassande mangrove communities from;Chengue bay Caricomp site (Colombia) over the last seven years/Jaime Garzon Ferreira, Alberto Rodrigez;Ramirez. -- En: Caricomp site Directors Workshop (8 : 2000Jun1-5 : San Jose, Costa Rica) -- Monitoring and;status of coral reefs in southern tropical America / J. GarzonFerreira ..[et.al]. -- En: International Coral;Reef Symposium (9 : 2000 Oct. 23-27 : Bali, Indonesia) --NodoRegional Sector sur de America tropical :;in Colombia / J. Garzon Ferreira, Jorge H. Pinzon C. -- En: ReefEncounter. -- No. 25 (Jul. 1999); p. 14-15.; ISSN 02552787. -- Rapid assesment of coral communitiesof Malpelo island (Colombian Pacific) / J. Garzon;Ferreira, Jorge H. Pinzon. -- En: Reef encounter -- No. 26(Dec.1999); p.12-13. -- ISNN 02552787. -

Information technology outsourcing in financial services

Regulatory pressures and strong competitiveness, as well as the need to control costs and remain up to date with information technologies have turned outsourcing into a basic tool at the disposal of financial entities. Our paper has as its aim to show the peculiarities of information technology outsourcing in the financial services industry, additionally suggesting a decision framework which can help firms minimise risks

A brain atlas of axonal and synaptic delays based on modelling of cortico-cortical evoked potentials.

Epilepsy presurgical investigation may include focal intracortical single-pulse electrical stimulations with depth electrodes, which induce cortico-cortical evoked potentials at distant sites because of white matter connectivity. Cortico-cortical evoked potentials provide a unique window on functional brain networks because they contain sufficient information to infer dynamical properties of large-scale brain connectivity, such as preferred directionality and propagation latencies. Here, we developed a biologically informed modelling approach to estimate the neural physiological parameters of brain functional networks from the cortico-cortical evoked potentials recorded in a large multicentric database. Specifically, we considered each cortico-cortical evoked potential as the output of a transient stimulus entering the stimulated region, which directly propagated to the recording region. Both regions were modelled as coupled neural mass models, the parameters of which were estimated from the first cortico-cortical evoked potential component, occurring before 80 ms, using dynamic causal modelling and Bayesian model inversion. This methodology was applied to the data of 780 patients with epilepsy from the F-TRACT database, providing a total of 34 354 bipolar stimulations and 774 445 cortico-cortical evoked potentials. The cortical mapping of the local excitatory and inhibitory synaptic time constants and of the axonal conduction delays between cortical regions was obtained at the population level using anatomy-based averaging procedures, based on the Lausanne2008 and the HCP-MMP1 parcellation schemes, containing 130 and 360 parcels, respectively. To rule out brain maturation effects, a separate analysis was performed for older (>15 years) and younger patients (<15 years). In the group of older subjects, we found that the cortico-cortical axonal conduction delays between parcels were globally short (median = 10.2 ms) and only 16% were larger than 20 ms. This was associated to a median velocity of 3.9 m/s. Although a general lengthening of these delays with the distance between the stimulating and recording contacts was observed across the cortex, some regions were less affected by this rule, such as the insula for which almost all efferent and afferent connections were faster than 10 ms. Synaptic time constants were found to be shorter in the sensorimotor, medial occipital and latero-temporal regions, than in other cortical areas. Finally, we found that axonal conduction delays were significantly larger in the group of subjects younger than 15 years, which corroborates that brain maturation increases the speed of brain dynamics. To our knowledge, this study is the first to provide a local estimation of axonal conduction delays and synaptic time constants across the whole human cortex in vivo, based on intracerebral electrophysiological recordings