36 research outputs found
Evaluación de la calidad de los materiales educativos digitales aplicados a la enseñanza del Inglés como lengua extranjera.
El desarrollo tecnológico de las últimas décadas ha permitido la implementación de dispositivos cada vez más avanzados en los espacios educativos formales. Estos dispositivos se han constituido en una herramienta fértil para potenciar situaciones de aprendizaje. En los últimos años, las tecnologías de la información y de la comunicación (TIC) han atravesado un período de cuestionamiento sobre su rol e impacto en los procesos de enseñanza y de aprendizaje, generando - tanto en los docentes como en los alumnos - reacciones diversas. Sin embrago, en la actualidad, ya han adquirido un sentido dentro de las prácticas pedagógicas a través de la implementación de las aulas virtuales. No obstante, creemos que la presencia de las TIC, por sí sola, no es garantía de mejora de la calidad de los procesos de enseñanza y de aprendizaje, ya que no todos los tecnofactos cumplen los requisitos de aprovechamiento pedagógico. Por lo tanto, es necesario reflexionar sobre la calidad de dichos instrumentos. En este sentido, el objetivo central de esta comunicación es presentar los resultados de un proyecto de investigación llevado a cabo en la Facultad de Lenguas durante el período 2014-2015, entre cuyos objetivos podemos mencionar los siguientes: (i) definir las características generales de los materiales educativos multimedia; (ii) elaborar criterios consensuados de evaluación que contribuyan a mejorar la calidad de las aulas virtuales destinadas a la enseñanza del inglés como lengua extranjera; (iii) aplicar dichos criterios para detectar fortalezas y debilidades; (iv) diseñar estrategias pedagógicas que contribuyan a superar las debilidades que pudieran haberse detectado.Fil: Negrelli, Fabián H. Universidad Nacional de Córdoba. Facultad de Lenguas; Argentina.Fil: Morchio, María José. Universidad Nacional de Córdoba. Facultad de Lenguas; Argentina.Fil: Capell, Martín Salvador. Universidad Nacional de Córdoba. Facultad de Lenguas; Argentina.Fil: Ferreras, Cecilia R. Universidad Nacional de Córdoba. Facultad de Lenguas; Argentina.Otras Lengua y Literatur
IMF - metallicity: a tight local relation revealed by the CALIFA survey
Variations in the stellar initial mass function (IMF) have been invoked to
explain the spectroscopic and dynamical properties of early-type galaxies.
However, no observations have yet been able to disentangle the physical driver.
We analyse here a sample of 24 early-type galaxies drawn from the CALIFA
survey, deriving in a homogeneous way their stellar population and kinematic
properties. We find that the local IMF is tightly related to the local
metallicity, becoming more bottom-heavy towards metal-rich populations. Our
result, combined with the galaxy mass-metallicity relation, naturally explains
previous claims of a galaxy mass-IMF relation, derived from non-IFU spectra. If
we assume that - within the star formation environment of early-type galaxies -
metallicity is the main driver of IMF variations, a significant revision of the
interpretation of galaxy evolution observables is necessary.Comment: Accepted for publication in ApJL. 6 pages, 4 figure
Rapid Intensity Decrease During the Second Half of the First Millennium BCE in Central Asia and Global Implications
Recent paleomagnetic studies have shown that important short-lived intensity fluctuations occurred during the first millennium BCE. However, the knowledge of the spatial and temporal extension of these features is still limited by the scarce availability of robust data. In this study we focus on the study of the intensity decrease that took place in Central Asia during the second half of the 1st millennium BCE after the high intensities that characterized the Levantine Iron Age Anomaly. Since previous archeointensities available for this period and region were obtained without accomplishing modern standards of quality, we present here new archeointensities that are derived from classical Thellier and Thellier experiments, including partial thermoremanent magnetization (pTRM) checks, thermoremanent magnetization (TRM) anisotropy and cooling rate corrections at the specimen level. The new 51 archeointensities, together with previous archeointensities, have been used to present a new local paleosecular variation curve for Central Asia. The results confirm the existence of an important geomagnetic field intensity decrease in South Uzbekistan from the 4th century BCE to the end of the 1st century BCE associated with rates of changes up to −15 μT/century. A critical analysis of the archeointensity global database indicates that this feature was present at continental scale, from Western Europe to Central Asia. However, this trend is not identified in other regions such as Japan or Mexico. Finally, the comparison with the dipole moment derived from recent global geomagnetic field reconstructions suggests a strong influence of non-dipolar sources upon this continental intensity feature.Financial support was given by the Spanish Ministry of Science and Innovation thorough the projects CERAC (HAR2016-75133-C3-1-P), CONCERAC (HAR2016-75133-C3-3-P), SPYKE (CGL2017-87015-P), SÚMATE (PID2020-113316GB-I00) and PULSES 5.K (PID2020-117105RB-I00). R. Bonilla-Alba thanks the FPI fellowship (PRE2018-085949) associated with the SPYKE project. This study has been also funded by the Ramón y Cajal program (contracts of M. Gómez-Paccard and V. Martínez-Ferreras, refs. RYC-2013-14405 and RYC-2014-15789). The authors wish to acknowledge the professional support of the CSIC Interdisciplinary Thematic Platform Open Heritage: Research and Society (PTI-PAIS). E. Beamud thanks the Geomodels Research Institute (UB) and the Grup de Geodinàmica i Anàlisi de Conques-2017SGR596 (Generalitat de Catalunya). A. Palencia-Ortas thanks the PTA contract of the Spanish Ministry of Science and Innovation
Rapid Intensity Decrease During the Second Half of the First Millennium BCE in Central Asia and Global Implications
Recent paleomagnetic studies have shown that important short-lived intensity fluctuations occurred during the first millennium BCE. However, the knowledge of the spatial and temporal extension of these features is still limited by the scarce availability of robust data. In this study we focus on the study of the intensity decrease that took place in Central Asia during the second half of the 1st millennium BCE after the high intensities that characterized the Levantine Iron Age Anomaly. Since previous archeointensities available for this period and region were obtained without accomplishing modern standards of quality, we present here new archeointensities that are derived from classical Thellier and Thellier experiments, including partial thermoremanent magnetization (pTRM) checks, thermoremanent magnetization (TRM) anisotropy and cooling rate corrections at the specimen level. The new 51 archeointensities, together with previous archeointensities, have been used to present a new local paleosecular variation curve for Central Asia. The results confirm the existence of an important geomagnetic field intensity decrease in South Uzbekistan from the 4th century BCE to the end of the 1st century BCE associated with rates of changes up to −15 μT/century. A critical analysis of the archeointensity global database indicates that this feature was present at continental scale, from Western Europe to Central Asia. However, this trend is not identified in other regions such as Japan or Mexico. Finally, the comparison with the dipole moment derived from recent global geomagnetic field reconstructions suggests a strong influence of non-dipolar sources upon this continental intensity feature
Bacteria-instructed B cells cross-prime naïve CD8+ T cells triggering effective cytotoxic responses.
In addition to triggering humoral responses, conventional B cells have been described in vitro to cross-present exogenous antigens activating naïve CD8+ T cells. Nevertheless, the way B cells capture these exogenous antigens and the physiological roles of B cell-mediated cross-presentation remain poorly explored. Here, we show that B cells capture bacteria by trans-phagocytosis from previously infected dendritic cells (DC) when they are in close contact. Bacterial encounter "instructs" the B cells to acquire antigen cross-presentation abilities, in a process that involves autophagy. Bacteria-instructed B cells, henceforth referred to as BacB cells, rapidly degrade phagocytosed bacteria, process bacterial antigens and cross-prime naïve CD8+ T cells which differentiate into specific cytotoxic cells that efficiently control bacterial infections. Moreover, a proof-of-concept experiment shows that BacB cells that have captured bacteria expressing tumor antigens could be useful as novel cellular immunotherapies against cancer.We are grateful to advanced light microscopy and cytometry facilities of CNB
for technical supporting. The research is supported by grants: SAF2017-84091-
R, and PID2020-116393RB-I00/AEI/10.13039/501100011033, financed by MCIN,
BFERO2020.04, financed by FERO foundation and PI20/0036 from ISCIII. RGF is
supported by BES-2016-076526 from the Spanish Ministry of Economy Industry and Competitiveness, JOP is supported by fellowship LCF/BQ/SO16/
52270012 from La Caixa, BHF is supported by FPU18/00895 and AMP by
FPU18/03199 from Ministry of Science, Innovation and Universities. LdC has
been supported by Juan de la Cierva grant IJC2018-035386-I and a contract
associated to SEV-2017-0712. EVC, AMP, AMAM, and NMM belong to the Spanish National Research Council (CSIC)’s Cancer Hub. Synopsis image made with
biorender.com by Eduardo Roman Camacho and Esteban Veiga. We thanks
Prof. Dan Portnoy who kindly provided bacterial strains.S
IMF radial gradients in most massive early-type galaxies
Using new long-slit spectroscopy obtained with X-Shooter at ESO-VLT, we
study, for the first time, radial gradients of optical and Near-Infrared
IMF-sensitive features in a representative sample of galaxies at the very
high-mass end of the galaxy population. The sample consists of seven early-type
galaxies (ETGs) at , with central velocity dispersion in the range
km/s. Using state-of-art stellar population synthesis models,
we fit a number of spectral indices, from different chemical species (including
TiO's and Na indices), to constrain the IMF slope (i.e. the fraction of
low-mass stars), as a function of galactocentric distance, over a radial range
out to kpc. ETGs in our sample show a significant correlation of IMF
slope and surface mass density. The bottom-heavy population (i.e. an excess of
low-mass stars in the IMF) is confined to central galaxy regions with surface
mass density above , or, alternatively, within a
characteristic radius of ~kpc. Radial distance, in physical units, and
surface mass density, are the best correlators to IMF variations, with respect
to other dynamical (e.g. velocity dispersion) and stellar population (e.g.
metallicity) properties. Our results for the most massive galaxies suggest that
there is no single parameter} that fully explains variations in the stellar
IMF, but IMF radial profiles at z0 rather result from the complex
formation and mass accretion history of galaxy inner and outer regions.Comment: 23 pages, 13 figures, accepted for publication in MNRA
An optimized MNK1b aptamer, apMNKQ2, and its potential use as a therapeutic agent in breast cancer
16 pags., 8 figs.Breast cancer is the most commonly diagnosed and leading cause of cancer death among women worldwide. Mitogen-activated protein kinase-interacting kinases (MNKs) promote the expression of several oncogenic proteins and are overexpressed in several types of cancer. In human cells, there are four isoforms of MNKs. The truncated isoform MNK1b, first described in our laboratory, has a higher basal activity and is constitutively active. Aptamers are emerging in recent years as potential therapeutic agents that show significant advantages over drugs of other nature. We have previously obtained and characterized a highly specific aptamer against MNK1b, named apMNK2F, with a dissociation constant in the nanomolar range, which produces significant inhibition of proliferation, migration, and colony formation in breast cancer cells. Furthermore, its sequence analysis predicted two G-quadruplex structures. In this work, we show the optimization process of the aptamer to reduce its size, improving its stability. The obtained aptamer, named apMNKQ2, is able to inhibit proliferation, colony formation, migration, and invasion in breast cancer cells. In murine models of breast cancer, apMNKQ2 has demonstrated its efficacy in reducing tumor volume and the number of metastases. In conclusion, apMNKQ2 could be used as an anti-tumor drug in the future.C.P.-D. was supported by grant RTC-2014-1986-1 from the Ministry of Economy and Competitiveness (Spain). R.F.-M... by predoctoral contract (PEJD-2018-BMD-4416) from the Community of Madrid (Spain) and FPU19/02929 from the Ministry of Science, Innovation and Universities (Spain). R.C.-B. for predoctoral contracts (PEJD 2016-BMD-2145 and 2018-BMD-9201) from the Community of Madrid and grant RTC2019-07227-1. M. EM., and V.M.G. are researchers at FIBio-HRC.
Supported by grants RTC2019-07227-1, PID2020-116620GB-T.I.00, and PID2019-105417RB-I00, funded by MCIN/ AEI /10.13039/501100011033 (Ministry of Economy and Competitiveness, Spain).Peer reviewe
Females know better : Sex-biased habitat selection by the European wildcat
Altres ajuts: FCT/UID/BIA/50027/2013Altres ajuts: POCI/01-0145-FEDER-006821The interactions between animals and their environment vary across species, regions, but also with gender. Sex-specific relations between individuals and the ecosystem may entail different behavioral choices and be expressed through different patterns of habitat use. Regardless, only rarely sex-specific traits are addressed in ecological modeling approaches. The European wildcat (Felis silvestris silvestris) is a species of conservation concern in Europe, with a highly fragmented and declining distribution across most of its range. We assessed sex-specific habitat selection patterns for the European wildcat, at the landscape and home range levels, across its Iberian biogeographic distribution using a multipopulation approach. We developed resource selection functions in a use-availability framework using radio-telemetry data from five wildcat populations. At the landscape level, we observed that, while both genders preferentially established home ranges in areas close to broadleaf forests and far from humanized areas, females selected mid-range elevation areas with some topographic complexity, whereas males used lowland areas. At the home range level, both females and males selected areas dominated by scrublands or broadleaf forests, but habitat features were less important at this level. The strength of association to habitat features was higher for females at both spatial levels, suggesting a tendency to select habitats with higher quality that can grant them enhanced access to shelter and feeding resources. Based on our results, we hypothesize that sex-biased behavioral patterns may contribute to the resilience of wildcats' genetic integrity through influencing the directionality of hybridization with domestic cats. Our study provides information about European wildcats' habitat use in an Iberian context, relevant for the implementation of conservation plans, and highlights the ecological relevance of considering sex-related differences in environmental preferences
Ecological traits and the spatial structure of competitive coexistence among carnivores
Competition is a widespread interaction among carnivores, ultimately manifested through one or more dimensions of the species' ecological niche. One of the most explicit manifestations of competitive interactions regards spatial displacement. Its interpretation under a theoretical context provides an important tool to deepen our understanding of biological systems and communities, but also for wildlife management and conservation. We used Bayesian multispecies occupancy models on camera‐trapping data from multiple sites in Southwestern Europe (SWE) to investigate competitive interactions within a carnivore guild, and to evaluate how species' ecological traits are shaping coexistence patterns. Seventeen out of 26 pairwise interactions departed from a hypothesis of independent occurrence, with spatial association being twice as frequent as avoidance. Association behaviors were only detected among mesocarnivores, while avoidance mainly involved mesocarnivores avoiding the apex predator (n = 4) and mesocarnivore‐only interactions (n = 2). Body mass ratios, defined as the dominant over the subordinate species body mass, revealed an important negative effect ( βˆ=−0.38;CI95=−0.81−0.06 ) on co‐occurrence probability, and support that spatially explicit competitive interactions are mostly expressed by larger species able to dominate over smaller ones, with a threshold in body mass ratios of ~4, above which local‐scale intraguild coexistence is unlikely. We found a weak relationship between pairwise trophic niche overlap and the probability of coexistence ( βˆ=−0.19;CI95=−0.580.21 ), suggesting that competition for feeding resources may not be a key driver of competition, at least at the scale of our analysis. Despite local‐scale avoidance, regional‐scale coexistence appears to be maintained by the spatial structuring of the competitive environment. We provide evidence that SWE ecosystems consist of spatially structured competitive environments, and propose that coexistence among near‐sized species is likely achieved through the interplay of “facultative” and “behavioral” character displacements. Factors influencing carnivore coexistence likely include context‐dependent density and trait‐mediated effects, which should be carefully considered for a sound understanding of the mechanisms regulating these communities.This study was funded by research projects CGL2009‐10741, funded by the Spanish Ministry of Science and Innovation and EU‐FEDER, and OAPN 352/2011, funded by the Spanish Organismo Autónomo Parques Nacionales. P. Monterroso enjoyed a Ph.D. grant from the Fundação para a Ciência e a Tecnologia (FCT) (ref: SFRH/BD/37795/2007) and a postdoctoral fellowship by EU‐FEDER funds through the Operational Programme for Competitiveness Factors—COMPETE and by National Funds through FCT—Foundation for Science and Technology (ref: UID/BIA/50027/2013, POCI‐01‐0145‐FEDER‐006821). F. Díaz‐Ruiz enjoyed a research contract “Juan de la Cierva” (ref: FJCI‐2015‐24949) from the Spanish Ministry of Economy, Industry, and Competitiveness.Peer reviewe
An optimized MNK1b aptamer, apMNKQ2, and its potential use as a therapeutic agent in breast cancer
Breast cancer is the most commonly diagnosed and leading cause of cancer death among women worldwide. Mitogen-activated protein kinase-interacting kinases (MNKs) promote the expression of several oncogenic proteins and are overexpressed in several types of cancer. In human cells, there are four isoforms of MNKs. The truncated isoform MNK1b, first described in our laboratory, has a higher basal activity and is constitutively active. Aptamers are emerging in recent years as potential therapeutic agents that show significant advantages over drugs of other nature. We have previously obtained and characterized a highly specific aptamer against MNK1b, named apMNK2F, with a dissociation constant in the nanomolar range, which produces significant inhibition of proliferation, migration, and colony formation in breast cancer cells. Furthermore, its sequence analysis predicted two G-quadruplex structures. In this work, we show the optimization process of the aptamer to reduce its size, improving its stability. The obtained aptamer, named apMNKQ2, is able to inhibit proliferation, colony formation, migration, and invasion in breast cancer cells. In murine models of breast cancer, apMNKQ2 has demonstrated its efficacy in reducing tumor volume and the number of metastases. In conclusion, apMNKQ2 could be used as an anti-tumor drug in the future.Ministerio de Economía y CompetitividadMinisterio de Ciencia, Innovación y UniversidadesMinisterio de Ciencia e Innovación (MCIN) / AEI /10.13039/501100011033Comunidad de MadridDepto. de Bioquímica y Biología MolecularFac. de Ciencias BiológicasFac. de Ciencias QuímicasTRUEpu