142 research outputs found
Evolution of a long-lived volcanic complex: the Chachani case study (south Peru)
The study of numerous individual volcanoes carried out in the Central Andean Volcanic Zone over the past 20 years has provided information to better understand active volcanism in the Peruvian Andes. However, large-sized, dormant volcanic complexes remain much less understood due to their complexity or because the impact of individual active volcanoes on populated areas has led researchers to prioritize their study on the most recent composite cones. Large, long-lived volcanic complexes have not yet been considered in volcanological studies in Peru, although they belie a rich history of eruptive activity that may be more recent than previously thought. The Chachani Volcanic Complex (CVC) is one of the few Andean volcanic complexes in which the relationships between stratigraphy, chronology and compositional changes are considered to understand the compositional evolution of a long-lived magmatic system
Electrophysiology Model for a Human Heart with Ischemic Scar and Realistic Purkinje Network
The role of Purkinje fibres in the onset of arrhythmias is controversial and computer simulations may shed light on possible arrhythmic mechanisms involving the Purkinje fibres. However, few computational modelling studies currently include a detailed Purkinje network as part of the model. We present a coupled Purkinje-myocardium electrophysiology model that includes an explicit model for the ischemic scar plus a detailed Purkinje network, and compare simulated activation times to those obtained by electro-anatomical mapping in vivo during sinus rhythm pacing. The results illustrate the importance of using sufficiently dense Purkinje networks in patient-specific studies to capture correctly the myocardial early activation that may be influenced by surviving Purkinje fibres in the infarct region
Why do semi-analytic models predict higher scatter in the stellar mass-halo mass relation than cosmological hydrodynamic simulations?
Semi-analytic models (SAMs) systematically predict higher stellar-mass
scatter at a given halo mass than hydrodynamical simulations and most empirical
models. Our goal is to investigate the physical origin of this scatter by
exploring modifications to the physics in the SAM Dark Sage. We design two
black hole formation models that approximate results from the IllustrisTNG
300-1 hydrodynamical simulation. In the first model, we assign a fixed black
hole mass of to every halo that reaches
. In the second model, we disregard any black
hole growth as implemented in the standard Dark Sage model. Instead, we force
all black hole masses to follow the median black hole mass-halo mass relation
in IllustrisTNG 300-1 with a fixed scatter. We find that each model on its own
does not significantly reduce the scatter in stellar mass. To do this, we
replace the native Dark Sage AGN feedback model with a simple model where we
turn off cooling for galaxies with black hole masses above . With this additional modification, the SMBH seeding and
fixed conditional distribution models find a significant reduction in the
scatter in stellar mass at halo masses between . These results suggest that AGN feedback in SAMs acts in a
qualitatively different way than feedback implemented in cosmological
simulations. Either or both may require substantial modification to match the
empirically inferred scatter in the Stellar Mass Halo Mass Relation (SMHMR).Comment: 21 pages, 16 figure
Neutron capture and total cross-section measurements on 94,95,96Mo at n_TOF and GELINA
This work was supported by the EUFRAT open-access project of the JRC Geel and received funding from the Euratom research and training programme 2014-2018 under grant agreement No 847594 (ARIEL).Capture and total cross section measurements for 94'95'96 MO have been performed at the neutron time -of-flight facilities, n_TOF at CERN and GELINA at JRC-Geel. The measurements were performed using isotopically enriched samples with an enrichment above 95% for each of the (94'95'96)M0 isotopes. The capture measurements were performed at n_TOF using C6D6 detectors and a new sTED detector. The transmission measurements were performed at a 10 m station of GELINA using a Li-6 glass neutron detector. Preliminary results of these measurements are presented.EUFRAT open-access project of the JRC GeelEuratom
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Implicancias de los sistemas de fallas regionales en el magmatismo del sur del Perú: estratigrafía del Complejo Volcánico Chachani
La mayoría de los arcos magmáticos continentales ocurren en contextos convergentes oblicuos y muestran movimientos de rumbo dentro del arco magmático o adyacentes a estos (Saint Blanquat et al., 1998). El volcanismo tiende a estar asociado con ambientes transtensionales porque estos ofrecen zonas con menor resistencia como fracturas subverticales o fallas por las cuales el magma sale hacia la superficie (Acocella et al., 1999). El complejo volcánico Chachani, ubicado a 22 km aprox. al NNE de la ciudad de Arequipa (del centro de la ciudad a la cumbre del complejo); es uno de los más grandes centros eruptivos de la Zona Volcánica de los Andes Centrales (ZVC) en el Sur del Perú, la cual está relacionada al proceso de subducción. El Chachani es un conjunto de domos y estrato volcanes de composición andesítica principalmente (Suaña, 2011) y tiene como basamento a depósitos de flujos piroclásticos y depósitos volcanoclásticos atribuidos a unidades conocidas como Tufo de Yura, Ignimbrita del Aeropuerto e Ignimbrita del Rió Chili (Paquereau et al., 2006, 2008). Tiene aproximadamente un área de 526.6 Km2 y un volumen 864 Km3
Developing Students’ Communication in Technical English with Project Based Learning Methodology
Technical communication is an extremely important soft skill for civil engineers at the
workplace. Due to globalization trends this technical communication often should be
performed in English. If we join the fact that undergraduate engineering programs in Spain
have been taught exclusively in Spanish, with which in addition, in rare cases those
programs provide intentionally placed discipline-specific technical communication
experiences, this all amounts to a major problem, regarded as an obstacle that limit
undergraduates’ opportunities to work abroad. Aware of this problem, some schools
provide their students with a brief course on “Technical English”. However, this course does
not cover all the skills that the student would need in the labour market, such as speaking
and listening abilities.
This paper promotes an innovative teaching methodology that allows Spanish Civil
Engineering students to hone English communication skills through “Lunch&Movies”
sessions. In each session a documentary about technical Civil Engineering topics is shown.
After the screening, students work in small inter-cohort groups with a guiding lecturer.
These groups debate on different questions related to the video, encouraging participation,
and fostering their self-confidence to talk about technical English topics in public. Different
surveys were developed to demonstrate the students’ interest in learning technical English,
and to evaluate the benefit for the attendees and their achievements. The results show that
the students are conscious of the importance of technical English for their future careers,
and most of them improved their initial level as the sessions progressed and they gained
confidence in the foreign language. Also, through a pilot subject in English, it was
demonstrated that the participants of the “Lunch&Movies” sessions obtained better oral
qualifications than those who did not participate. In fact, the overall results indicated that
Lunch & Movie sessions can improve students' technical oral skills as well as their own
perceptions of their abilities
Economía y finanzas sociales: avances en la investigación
Esta obra colectiva propone un cambio de paradigma en la investigación científica, financiera y económica, cuyo centro de atención es reducir las desigualdades sociales y económicas, mejorar la sostenibilidad ambiental y la creación eficiente de valor económico. Desde un punto de vista crítico y mediante diversos enfoques teóricos, metodológicos y disciplinares, los autores analizan el esquema financiero predominante en las economías de mercado, al tiempo que abordan temas como la inclusión financiera, la banca ética o las experiencias e intervenciones en y sobre la economía social.ITESO, A.C
Development of a Panel of Genome-Wide Ancestry Informative Markers to Study Admixture Throughout the Americas
Most individuals throughout the Americas are admixed descendants of Native American, European, and African ancestors. Complex historical factors have resulted in varying proportions of ancestral contributions between individuals within and among ethnic groups. We developed a panel of 446 ancestry informative markers (AIMs) optimized to estimate ancestral proportions in individuals and populations throughout Latin America. We used genome-wide data from 953 individuals from diverse African, European, and Native American populations to select AIMs optimized for each of the three main continental populations that form the basis of modern Latin American populations. We selected markers on the basis of locus-specific branch length to be informative, well distributed throughout the genome, capable of being genotyped on widely available commercial platforms, and applicable throughout the Americas by minimizing within-continent heterogeneity. We then validated the panel in samples from four admixed populations by comparing ancestry estimates based on the AIMs panel to estimates based on genome-wide association study (GWAS) data. The panel provided balanced discriminatory power among the three ancestral populations and accurate estimates of individual ancestry proportions (R2>0.9 for ancestral components with significant between-subject variance). Finally, we genotyped samples from 18 populations from Latin America using the AIMs panel and estimated variability in ancestry within and between these populations. This panel and its reference genotype information will be useful resources to explore population history of admixture in Latin America and to correct for the potential effects of population stratification in admixed samples in the region
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