3,194 research outputs found
Developing educational materials about risks on social network sites: a design based research approach
Nearly all of today’s Western teenagers have a profile on a social network site (SNS). As many risks have been reported, researchers and governments have emphasized the role of school education to teach teenagers how to deal safely with SNSs. However, little is known about the specific characteristics which would make interventions effective. Therefore, the overall objective of this research aims to propose a list of validated theoretical design principles for future development of educational materials about risks on SNSs. This research goal was pursued through a design-based research procedure. Thereby targeting teenagers of secondary education in 8 separate studies, the different steps of the design-based research procedure have iteratively been completed. Firstly, a problem analysis was executed through 3 explorative studies, including an observational study, a theoretical evaluation of existing materials and a survey study. Secondly, initial solutions were developed and evaluated in practice through 5 quasi-experimental intervention studies. Thirdly, we reflected upon all the previous results to produce design principles. Finally, we conclude with an analysis of the design-based research methodology
Topological color codes on Union Jack lattices: A stable implementation of the whole Clifford group
We study the error threshold of topological color codes on Union Jack
lattices that allow for the full implementation of the whole Clifford group of
quantum gates. After mapping the error-correction process onto a statistical
mechanical random 3-body Ising model on a Union Jack lattice, we compute its
phase diagram in the temperature-disorder plane using Monte Carlo simulations.
Surprisingly, topological color codes on Union Jack lattices have similar error
stability than color codes on triangular lattices, as well as the Kitaev toric
code. The enhanced computational capabilities of the topological color codes on
Union Jack lattices with respect to triangular lattices and the toric code
demonstrate the inherent robustness of this implementation.Comment: 8 pages, 4 figures, 1 tabl
Collision of Two Rotating Hayward Black Holes
We investigate the spin interaction and the gravitational radiation thermally
allowed in a head-on collision of two rotating Hayward black holes. The Hayward
black hole is a regular black hole in a modified Einstein equation, and hence
it can be an appropriate model to describe the extent to which the regularity
effect in the near-horizon region affects the interaction and the radiation. If
one black hole is assumed to be considerably smaller than the other, the
potential of the spin interaction can be analytically obtained and is dependent
on the alignment of angular momenta of the black holes. For the collision of
massive black holes, the gravitational radiation is numerically obtained as the
upper bound by using the laws of thermodynamics. The effect of the Hayward
black hole tends to increase the radiation energy, but we can limit the effect
by comparing the radiation energy with the gravitational waves GW150914 and
GW151226.Comment: 25 pages, 43 figures, published version in EPJ
Análisis comparado del aprendizaje aversivo en anfibios
El presente artículo desarrolla con un enfoque comparado una revisión completa y actualizada de los estudios de aprendizaje aversivo en anfibios. La mayoría de ellos utilizaron como estímulo aversivo descargas eléctricas, obteniéndose resultados inconsistentes o negativos. Las investigaciones más recientes mostraron que otra clase de estímulos (soluciones salinas de alta concentración, o aumento de la temperatura del agua) han resultado ser más eficientes para producir modificaciones estables en el comportamiento. Se analizan también algunos aspectos neurofisiológicos relacionados con el aprendizaje aversivo y los miedos aprendidos. Si bien se cuenta con datos comparativos de estudios neurofisiológicos en peces, aún no existen referencias con información funcional sobre las bases neurales del aprendizaje aversivo en anfibios. Sin embargo, sí se conoce en anfibios las regiones cerebrales homólogas a las estructuras que en mamíferos mostraron estar implicadas con dicho aprendizaje (especialmente la amígdala), abriendo así el camino para abordar en el futuro el estudio de esta cuestión.Comparative analysis of aversive learning in amphibians: This article develops with a comparative approach a comprehensive and updated review of studies of aversive learning in amphibians. Most of them used electric shock as aversive stimulus, resulting in inconsistent or negative results. Recent research showed that another class of stimuli (saline solutions highly concentrated or warm water) has been more efficient to produce steady changes in behavior. Some neurophysiological aspects of aversive and fear learning are also discussed. While comparative data from neurophysiological studies in fish is available, there are no references on functional information on the neural basis of aversive learning in amphibians. However, it is known in amphibian homologous brain areas to the mammalian structures shown to be involved with such learning (especially the amygdala), opening the way to address the study of this question in the future.Fil: Puddington, Martin Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biologia y Medicina Experimental (i); Argentina; Universidad de Buenos Aires. Facultad de Psicologia; Argentina;Fil: Muzio, Ruben Nestor. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biologia y Medicina Experimental (i); Argentina; Universidad de Buenos Aires. Facultad de Psicologia; Argentina
Digital-analog co-design of the Harrow-Hassidim-Lloyd algorithm
The Harrow-Hassidim-Lloyd quantum algorithm was proposed to solve linear
systems of equations and it is the core of various
applications. However, there is not an explicit quantum circuit for the
subroutine which maps the inverse of the problem matrix into an ancillary
qubit. This makes challenging the implementation in current quantum devices,
forcing us to use hybrid approaches. Here, we propose a systematic manner to
implement this subroutine, which can be adapted to other functions of
the matrix , we present a co-designed quantum processor which reduces the
depth of the algorithm, and we introduce its digital-analog implementation. The
depth of our proposal scales with the precision as
, which is bounded by the number of samples allowed
for a certain experiment. The co-design of the Harrow-Hassidim-Lloyd algorithm
leads to a "kite-like" architecture, which allows us to reduce the number of
required SWAP gates. Finally, merging a co-design quantum processor
architecture with a digital-analog implementation contributes to the reduction
of noise sources during the experimental realization of the algorithm.Comment: 7 pages, 3 figure
Chemical Abundances of Planetary Nebulae in the Substructures of M31
We present deep spectroscopy of planetary nebulae (PNe) that are associated
with the substructures of the Andromeda Galaxy (M31). The spectra were obtained
with the OSIRIS spectrograph on the 10.4 m GTC. Seven targets were selected for
the observations, three in the Northern Spur and four associated with the Giant
Stream. The most distant target in our sample, with a rectified galactocentric
distance >100 kpc, was the first PN discovered in the outer streams of M31. The
[O III] 4363 auroral line was well detected in the spectra of all targets,
enabling electron temperature determination. Ionic abundances are derived based
on the [O III] temperatures, and elemental abundances of helium, nitrogen,
oxygen, neon, sulfur, and argon are estimated. The relatively low N/O and He/H
ratios as well as abundance ratios of alpha-elements indicate that our target
PNe might belong to populations as old as ~2 Gyr. Our PN sample, including the
current seven and the previous three observed by Fang et al., have rather
homogeneous oxygen abundances. The study of abundances and the spatial and
kinematical properties of our sample leads to the tempting conclusion that
their progenitors might belong to the same stellar population, which hints at a
possibility that the Northern Spur and the Giant Stream have the same origin.
This may be explained by the stellar orbit proposed by Merrett et al. Judging
from the position and kinematics, we emphasize that M32 might be responsible
for the two substructures. Deep spectroscopy of PNe in M32 will help to assess
this hypothesis.Comment: Accepted for publication in the ApJ. 23 pages, including 13 figures
and 7 table
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