1,844 research outputs found
Measuring collaborative emergent behavior in multi-agent reinforcement learning
Multi-agent reinforcement learning (RL) has important implications for the
future of human-agent teaming. We show that improved performance with
multi-agent RL is not a guarantee of the collaborative behavior thought to be
important for solving multi-agent tasks. To address this, we present a novel
approach for quantitatively assessing collaboration in continuous spatial tasks
with multi-agent RL. Such a metric is useful for measuring collaboration
between computational agents and may serve as a training signal for
collaboration in future RL paradigms involving humans.Comment: 1st International Conference on Human Systems Engineering and Design,
6 pages, 2 figures, 1 tabl
Estudio de espectros de una protuberancia solar en extremo ultravioleta
Fil: Rovira, Marta G.. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina
Observed flux density enhancement at submillimeter wavelengths during an X-class flare
We analyse the 30 October, 2004, X1.2/SF solar event that occurred in AR
10691 (N13 W18) at around 11:44 UT. Observations at 212 and 405 GHz of the
Solar Submillimeter Telescope (SST), with high time resolution (5 ms), show an
intense impulsive burst followed by a long-lasting thermal phase. EUV images
from the Extreme Ultraviolet Imaging Telescope (SOHO/EIT) are used to identify
the possible emitting sources. Data from the Radio Solar Telescope Network
(RSTN) complement our spectral observations below 15 GHz. During the impulsive
phase the turnover frequency is above 15.4 GHz. The long-lasting phase is
analysed in terms of thermal emission and compared with GOES observations. From
the ratio between the two GOES soft X-ray bands, we derive the temperature and
emission measure, which is used to estimate the free-free submillimeter flux
density. Good temporal agreement is found between the estimated and observed
profiles, however the former is larger than the latter.Comment: 13 pages, 7 figure
Deposition of composite materials using a wire-bar coater for achieving processability and air-stability in Organic Field-Effect Transistors (OFETs)
Organic thin films based on composite materials of semiconducting dibenzo-tetrathiafulvalene (DB-TTF) and insulating
styrenic matrices (Polystyrene (PS10k) and Poly-alpha methylstyrene (PAMS10k) ) have been fabricated by the wire-bar
coating technique in ambient conditions (air, light, humidity) and contrasted with the ones prepared by thermally
evaporating the organic semiconductor. The transistors fabricated with DB-TTF:PS10k composites show a clear fieldeffect
behavior with p-type characteristics, exhibiting charge carriers mobilities in the range of 0.01 cm2/Vs, fully
comparable with the films obtained by thermal evaporation. However, while the thermally evaporated films show poor
stability in air, the wire-bar coated composites films and devices are highly reproducible and exhibit lower threshold
voltage values. Thus, we demonstrate the suitability of the wire-bar technique for manufacturing large area devices.The authors thank the ERC StG 2012-306826 e-GAMES project, the Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), the DGI (Spain) with project BE-WELL CTQ2013-40480-R, and the Generalitat de Catalunya (2014-SGR-17). F. G. D. P. thanks Universidad Técnica de Ambato and Secretaría de Educación Superior, Ciencia, Tecnología e Innovación for funding through a doctoral scholarship “Convocatoria abierta 2010”.Peer Reviewe
Fundamentos científicos de la rehabilitación tras la sustitución intraarticular del ligamento cruzado anterior
Hay pocos aspectos de la rehabilitación en nuestra especialidad que sean tan
complejos y controvertidos como la rehabilitación después de la sustitución intraarticular del
ligamento cruzado anterior (LCA). La tendencia actual es utilizar protocolos de rehabilitación
acelerada y rápido funcionalismo, todo lo cual está en relación directa con el avance en la investigación
sobre el comportamiento biológico de los implantes, una mayor sofisticación en
la técnica quirúrgica y los adelantos en las técnicas de rehabilitación. El objetivo de este trabajo
es analizar no protocolos concretos, sino los problemas que plantea la cirugía del LCA y
como minimizarlos en la medida de lo posible, protegiendo al mismo tiempo la plastia.There are few aspects of rehabilitation in our speciality which are so complex
and controversial like rehabilitation after intraarticular replacement of the anterior cruciate
ligament (ACL). Nowadays there is a trend to use protocols of accelerated rehabilitation and
rapid functioning, and all this is related to the advances in research on the biological behavior
of the grafts, a major sophistication in surgical technique and advances in rehabilitation techniques.
The objective of this paper is not to analyze concrete protocols but rather the problems
that state the surgery of the ACL, and how to diminish them to maximum, protecting at the
same time the graft
Natural and laboratory mutations in kuzbanian are associated with zinc stress phenotypes in Drosophila melanogaster
Organisms must cope with altered environmental conditions such as high concentrations of heavy metals. Stress response to heavy metals is mediated by the metal-responsive transcription factor 1 (MTF-1), which is conserved from Drosophila to humans. MTF-1 binds to metal response elements (MREs) and changes the expression of target genes. kuzbanian (kuz), a metalloendopeptidase that activates the evolutionary conserved Notch signaling pathway, has been identified as an MTF-1 target gene. We have previously identified a putatively adaptive transposable element in the Drosophila melanogaster genome, named FBti0019170, inserted in a kuz intron. In this work, we investigated whether a laboratory mutant stock overexpressing kuz is associated with zinc stress phenotypes. We found that both embryos and adult flies overexpressing kuz are more tolerant to zinc compared with wild-type flies. On the other hand, we found that the effect of FBti0019170 on zinc stress tolerance depends on developmental stage and genetic background. Moreover, in the majority of the genetic backgrounds analyzed, FBti0019170 has a deleterious effect in unpolluted environments in pre-adult stages. These results highlight the complexity of natural mutations and suggest that besides laboratory mutations, natural mutations should be studied in order to accurately characterize gene function and evolution.H.L.M. was a VAST-CSIC fellow, L.G. was a FI/DGR fellow (2012FI-B-00676) and J.G. is a Ramón y Cajal fellow (RYC-2010-07306). This work was supported by grants from the European Community’s Seven Framework Programme (FP7-PEOPLE-2011-CIG-293860), from the Spanish Government (BFU2011-24397 and BFU2014-57779-P), and from the Generalitat de Catalunya (2014 SGR 201).EUR 1,305 APC fee funded by the EC FP7 Post-Grant Open Access PilotPeer reviewe
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