81 research outputs found
Do optional activities matter in virtual learning environments?
Virtual Learning Environments (VLEs) provide students with activi-ties to improve their learning (e.g., reading texts, watching videos or solving exercises). But VLEs usually also provide optional activities (e.g., changing an avatar profile or setting goals). Some of these have a connection with the learn-ing process, but are not directly devoted to learning concepts (e.g., setting goals). Few works have dealt with the use of optional activities and the relation-ships between these activities and other metrics in VLEs. This paper analyzes the use of optional activities at different levels in a specific case study with 291 students from three courses (physics, chemistry and mathematics) using the Khan Academy platform. The level of use of the different types of optional ac-tivities is analyzed and compared to that of learning activities. In addition, the relationship between the usage of optional activities and different student be-haviors and learning metrics is presented
Guiding principles for identification, evaluation and conservation of Vitis vinifera L. subsp. sylvestris
Conservation of grapevine genetic resources is an important and long lasting task. Here, partners of the InWiGrape Activity of the European Cooperative Programme for Plant Genetic Resources have proposed a set of descriptors that will assist in identification, conservation and study of genetic resources of Vitis vinifera L. subsp. sylvestris. A distribution map of Vitis vinifera L. subsp. sylvestris populations in Europe was produced, with on-line access through the European Vitis Database. The several different aspects of conservation of Vitis vinifera L. subsp. sylvestris including bibliographical references, identification in the wild, in situ and ex situ conservation have been discussed. The descriptors and the map will assist different stakeholders, working on biodiversity and ecosystems in more effective conservation of wild grapevine genetic resources
Gradient, UC3M
En este artículo se presenta un resumen de las líneas de investigación que se realizan en el Laboratorio Gradient perteneciente al Grupo GAST (Grupo de Aplicaciones y Servicios Telemáticos) del Departamento de Ingeniería Telemática de la Universidad Carlos III de Madrid. La temática principal de investigación es la aplicación de tecnologías para la mejora de la enseñanza y el aprendizaje. El resumen se centra en tres líneas: Personalización del aprendizaje, uso de dispositivos móviles con fines educativos y aplicaciones de Realidad Virtual y Realidad Aumentada en educación.En este artículo se presenta un resumen de las líneas de investigación que se realizan en el Laboratorio Gradient perteneciente al Grupo GAST (Grupo de Aplicaciones y Servicios Telemáticos) del Departamento de Ingeniería Telemática de la Universidad Carlos III de Madrid. La temática principal de investigación es la aplicación de tecnologías para la mejora de la enseñanza y el aprendizaje. El resumen se centra en tres líneas: Personalización del aprendizaje, uso de dispositivos móviles con fines educativos y aplicaciones de Realidad Virtual y Realidad Aumentada en educación.Publicad
The stellar occultation by Makemake on 2011 April 23
We have taken advantage of a stellar occultation by the dwarf planet Makemake on 2011 April 23, to determine several of its main physical properties. We present results from a multisite campaign with 8 positive occultation detections from 5 different sites, including data from the 8-m VLT and 3.5-m NTT telescopes in Chile, which have very high temporal resolution. Because the star was significantly fainter than Makemake (setting a record in the magnitude of a star whose occultation has been detected), the occultation resulted in a drop of just ~0.3 mag in the lightcurves. From the lightcurves we have been able to determine the size and shape of the body, its geometric albedo and constraints on its atmosphere
Description of the vitis vinifera L. Phenotypic variability in eno-carpological traits by a Euro-Asiatic collaborative network among ampelographic collections
The grapevine intra-specific variability captured an increasing interest during the last decades, as demonstrated by the number of recently funded European projects focused on the grapevine biodiversity preservation. However, nowadays, crop plants are mainly characterized by genotyping methods. The present work summarizes the phenotype data collected among 20 ampelographic collections spread over 15 countries, covering most of the viticultural areas in the Euro-Asiatic region: from Portugal to Armenia and from Cyprus to Luxembourg. Together with agro-climatic characterization of the experimental site, over two years about 2,400 accessions were described. A common experimental protocol mainly focused on the carpological and oe-nological traits was followed, obtaining a general overview of the distribution of the considered phenotypic traits in the cultivated Vitis vinifera species. The most replicated cultivars were selected and, for the subset of these reference cultivars, their behavior in the different environmental conditions over sites and years was described by ANOVA methods
Description of the Vitis vinifera L. phenotypic variability in eno-carpological traits by a Euro-Asiatic collaborative network among ampelographic collections
The grapevine intra-specific variability captured an increasing interest during the last decades, as demonstrated by the number of recently funded European projects focused on the grapevine biodiversity preservation. However, nowadays, crop plants are mainly characterized by genotyping methods. The present work summarizes the phenotype data collected among 20 ampelographic collections spread in 15 countries, covering mostly of the viticultural areas in the Euro-Asiatic range: from Portugal to Armenia and from Cyprus to Luxembourg. Together with agro-climatic characterization of the experimental site, in two years, about 2400 accessions were described, following a common experimental protocol mainly focused on the carpological and oenological traits, obtaining a general overview of the distribution of the considered phenotypic traits in the cultivated Vitis vinifera species. The most replicated cultivars were selected and, for the subset of these reference cultivars, their behavior in the different environmental conditions over sites and years was described by ANOVA methods
The 2017 May 20 stellar occultation by the elongated centaur (95626) 2002 GZ
We predicted a stellar occultation of the bright star Gaia DR1
4332852996360346368 (UCAC4 385-75921) (m= 14.0 mag) by the centaur
2002 GZ for 2017 May 20. Our latest shadow path prediction
was favourable to a large region in Europe. Observations were arranged in a
broad region inside the nominal shadow path. Series of images were obtained
with 29 telescopes throughout Europe and from six of them (five in Spain and
one in Greece) we detected the occultation. This is the fourth centaur, besides
Chariklo, Chiron and Bienor, for which a multi-chord stellar occultation is
reported. By means of an elliptical fit to the occultation chords we obtained
the limb of 2002 GZ during the occultation, resulting in an ellipse with
axes of 305 17 km 146 8 km. From this limb, thanks to a
rotational light curve obtained shortly after the occultation, we derived the
geometric albedo of 2002 GZ ( = 0.043 0.007) and a 3-D
ellipsoidal shape with axes 366 km 306 km 120 km. This shape
is not fully consistent with a homogeneous body in hydrostatic equilibrium for
the known rotation period of 2002 GZ. The size (albedo) obtained from
the occultation is respectively smaller (greater) than that derived from the
radiometric technique but compatible within error bars. No rings or debris
around 2002 GZ were detected from the occultation, but narrow and thin
rings cannot be discarded.Comment: Accepted for publication in MNRAS (8-Dec.-2020), 15 pages, 9 figure
The European Vitis Database (www.eu-vitis.de) – a technical innovation through an online uploading and interactive modification system
The objective of the European Vitis Database is to safeguard and enhance germplasm by monitoring its preservation. Two issues are strongly related to that purpose: (1) participation of collections covering almost all grape biodiversity and (2) assessment of accessions trueness to type. In the scope of the European project GrapeGen06 efforts have been made towards both objectives. The 35 participating grape germplasm repositories are found between the Iberian Peninsula and Transcaucasia, thus covering a broad range of grape diversity. Altogether they maintain 32,410 accessions. However with respect to biodiversity, gaps are still evident and further collections need to be included and trueness to type assessment absolutely needs to be pursued to organize duplication of endangered genotypes. Within the GrapeGen06 project focus was laid on the establishment of a database conferring the collection holders a high degree of responsibility and independence. Hence for the first time in a European Central Crop Database an on-line uploading application and an interactive modification system for data administration was implemented. These innovations disburden the database manager and offer the curators of collections more flexibility. Prerequisites for data import, descriptors applied, access levels, database contents, uploading, export and search functions are described
Constraints on the structure and seasonal variations of Triton's atmosphere from the 5 October 2017 stellar occultation and previous observations
CONTEXT: A stellar occultation by Neptune’s main satellite, Triton, was observed on 5 October 2017 from Europe, North Africa, and the USA. We derived 90 light curves from this event, 42 of which yielded a central flash detection. AIMS: We aimed at constraining Triton’s atmospheric structure and the seasonal variations of its atmospheric pressure since the Voyager 2 epoch (1989). We also derived the shape of the lower atmosphere from central flash analysis. METHODS: We used Abel inversions and direct ray-tracing code to provide the density, pressure, and temperature profiles in the altitude range ~8 km to ~190 km, corresponding to pressure levels from 9 µbar down to a few nanobars. RESULTS: A pressure of 1.18 ± 0.03 µbar is found at a reference radius of 1400 km (47 km altitude). (ii) A new analysis of the Voyager 2 radio science occultation shows that this is consistent with an extrapolation of pressure down to the surface pressure obtained in 1989. (iii) A survey of occultations obtained between 1989 and 2017 suggests that an enhancement in surface pressure as reported during the 1990s might be real, but debatable, due to very few high S/N light curves and data accessible for reanalysis. The volatile transport model analysed supports a moderate increase in surface pressure, with a maximum value around 2005-2015 no higher than 23 µbar. The pressures observed in 1995-1997 and 2017 appear mutually inconsistent with the volatile transport model presented here. (iv) The central flash structure does not show evidence of an atmospheric distortion. We find an upper limit of 0.0011 for the apparent oblateness of the atmosphere near the 8 km altitude
Constraints on the structure and seasonal variations of Triton's atmosphere from the 5 October 2017 stellar occultation and previous observations
Context. A stellar occultation by Neptune's main satellite, Triton, was observed on 5 October 2017 from Europe, North Africa, and the USA. We derived 90 light curves from this event, 42 of which yielded a central flash detection.
Aims. We aimed at constraining Triton's atmospheric structure and the seasonal variations of its atmospheric pressure since the Voyager 2 epoch (1989). We also derived the shape of the lower atmosphere from central flash analysis.
Methods. We used Abel inversions and direct ray-tracing code to provide the density, pressure, and temperature profiles in the altitude range similar to 8 km to similar to 190 km, corresponding to pressure levels from 9 mu bar down to a few nanobars.
Results. (i) A pressure of 1.18 +/- 0.03 mu bar is found at a reference radius of 1400 km (47 km altitude). (ii) A new analysis of the Voyager 2 radio science occultation shows that this is consistent with an extrapolation of pressure down to the surface pressure obtained in 1989. (iii) A survey of occultations obtained between 1989 and 2017 suggests that an enhancement in surface pressure as reported during the 1990s might be real, but debatable, due to very few high S/N light curves and data accessible for reanalysis. The volatile transport model analysed supports a moderate increase in surface pressure, with a maximum value around 2005-2015 no higher than 23 mu bar. The pressures observed in 1995-1997 and 2017 appear mutually inconsistent with the volatile transport model presented here. (iv) The central flash structure does not show evidence of an atmospheric distortion. We find an upper limit of 0.0011 for the apparent oblateness of the atmosphere near the 8 km altitude.J.M.O. acknowledges financial support from the Portuguese Foundation for Science and Technology (FCT) and the European Social Fund (ESF) through the PhD grant SFRH/BD/131700/2017. The work leading to these results has received funding from the European Research Council under the European Community's H2020 2014-2021 ERC grant Agreement nffi 669416 "Lucky Star". We thank S. Para who supported some travels to observe the 5 October 2017 occultation. T.B. was supported for this research by an appointment to the National Aeronautics and Space Administration (NASA) Post-Doctoral Program at the Ames Research Center administered by Universities Space Research Association (USRA) through a contract with NASA. We acknowledge useful exchanges with Mark Gurwell on the ALMA CO observations. This work has made use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, https://www.cosmos.esa.int/web/gaia/dpac/consortium).Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. J.L.O., P.S.-S., N.M. and R.D. acknowledge financial support from the State Agency for Research of the Spanish MCIU through the "Center of Excellence Severo Ochoa" award to the Instituto de Astrofisica de Andalucia (SEV-2017-0709), they also acknowledge the financial support by the Spanish grant AYA-2017-84637-R and the Proyecto de Excelencia de la Junta de Andalucia J.A. 2012-FQM1776. The research leading to these results has received funding from the European Union's Horizon 2020 Research and Innovation Programme, under Grant Agreement no. 687378, as part of the project "Small Bodies Near and Far" (SBNAF). P.S.-S. acknowledges financial support by the Spanish grant AYA-RTI2018-098657-J-I00 "LEO-SBNAF". The work was partially based on observations made at the Laboratorio Nacional de Astrofisica (LNA), Itajuba-MG, Brazil. The following authors acknowledge the respective CNPq grants: F.B.-R. 309578/2017-5; R.V.-M. 304544/2017-5, 401903/2016-8; J.I.B.C. 308150/2016-3 and 305917/2019-6; M.A. 427700/20183, 310683/2017-3, 473002/2013-2. This study was financed in part by the Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior -Brasil (CAPES) -Finance Code 001 and the National Institute of Science and Technology of the e-Universe project (INCT do e-Universo, CNPq grant 465376/2014-2). G.B.R. acknowledges CAPES-FAPERJ/PAPDRJ grant E26/203.173/2016 and CAPES-PRINT/UNESP grant 88887.571156/2020-00, M.A. FAPERJ grant E26/111.488/2013 and A.R.G.Jr. FAPESP grant 2018/11239-8. B.E.M. thanks CNPq 150612/2020-6 and CAPES/Cofecub-394/2016-05 grants. Part of the photometric data used in this study were collected in the frame of the photometric observations with the robotic and remotely controlled telescope at the University of Athens Observatory (UOAO; Gazeas 2016). The 2.3 m Aristarchos telescope is operated on Helmos Observatory by the Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing of the National Observatory of Athens. Observations with the 2.3 m Aristarchos telescope were carried out under OPTICON programme. This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 730890. This material reflects only the authors views and the Commission is not liable for any use that may be made of the information contained therein. The 1.
2m Kryoneri telescope is operated by the Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing of the National Observatory of Athens. The Astronomical Observatory of the Autonomous Region of the Aosta Valley (OAVdA) is managed by the Fondazione Clement Fillietroz-ONLUS, which is supported by the Regional Government of the Aosta Valley, the Town Municipality of Nus and the "Unite des Communes valdotaines Mont-Emilius". The 0.81 m Main Telescope at the OAVdA was upgraded thanks to a Shoemaker NEO Grant 2013 from The Planetary Society. D.C. and J.M.C. acknowledge funds from a 2017 'Research and Education' grant from Fondazione CRT-Cassa di Risparmio di Torino. P.M. acknowledges support from the Portuguese Fundacao para a Ciencia e a Tecnologia ref. PTDC/FISAST/29942/2017 through national funds and by FEDER through COMPETE 2020 (ref. POCI010145 FEDER007672). F.J. acknowledges Jean Luc Plouvier for his help. S.J.F. and C.A. would like to thank the UCL student support observers: Helen Dai, Elise Darragh-Ford, Ross Dobson, Max Hipperson, Edward Kerr-Dineen, Isaac Langley, Emese Meder, Roman Gerasimov, Javier Sanjuan, and Manasvee Saraf. We are grateful to the CAHA, OSN and La Hita Observatory staffs. This research is partially based on observations collected at Centro Astronomico HispanoAleman (CAHA) at Calar Alto, operated jointly by Junta de Andalucia and Consejo Superior de Investigaciones Cientificas (IAA-CSIC). This research was also partially based on observation carried out at the Observatorio de Sierra Nevada (OSN) operated by Instituto de Astrofisica de Andalucia (CSIC). This article is also based on observations made with the Liverpool Telescope operated on the island of La Palma by Liverpool John Moores University in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias with financial support from the UK Science and Technology Facilities Council. Partially based on observations made with the Tx40 and Excalibur telescopes at the Observatorio Astrofisico de Javalambre in Teruel, a Spanish Infraestructura Cientifico-Tecnica Singular (ICTS) owned, managed and operated by the Centro de Estudios de Fisica del Cosmos de Aragon (CEFCA). Tx40 and Excalibur are funded with the Fondos de Inversiones de Teruel (FITE). A.R.R. would like to thank Gustavo Roman for the mechanical adaptation of the camera to the telescope to allow for the observation to be recorded. R.H., J.F.R., S.P.H. and A.S.L. have been supported by the Spanish projects AYA2015-65041P and PID2019-109467GB-100 (MINECO/FEDER, UE) and Grupos Gobierno Vasco IT1366-19. Our great thanks to Omar Hila and their collaborators in Atlas Golf Marrakech Observatory for providing access to the T60cm telescope. TRAPPIST is a project funded by the Belgian Fonds (National) de la Recherche Scientifique (F.R.S.-FNRS) under grant PDR T.0120.21. TRAPPIST-North is a project funded by the University of Liege, and performed in collaboration with Cadi Ayyad University of Marrakesh. E.J. is a FNRS Senior Research Associate
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