47,096 research outputs found
βCaMKII regulates bidirectional long-term plasticity in cerebellar Purkinje cells by a CaMKII/PP2B switch mechanism
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise statedPeer reviewe
Discontinuous Almost Automorphic Functions and Almost Automorphic Solutions of Differential Equations with Piecewise Constant Argument
In this article we introduce a class of discontinuous almost automorphic
functions which appears naturally in the study of almost automorphic solutions
of differential equations with piecewise constant argument. Their fundamental
properties are used to prove the almost automorphicity of bounded solutions of
a system of differential equations with piecewise constant argument. Due to the
strong discrete character of these equations, the existence of a unique
discrete almost automorphic solution of a non-autonomous almost automorphic
difference system is obtained, for which conditions of exponential dichotomy
and discrete Bi-almost automorphicity are fundamental
Effective action in DSR1 quantum field theory
We present the one-loop effective action of a quantum scalar field with DSR1
space-time symmetry as a sum over field modes. The effective action has real
and imaginary parts and manifest charge conjugation asymmetry, which provides
an alternative theoretical setting to the study of the particle-antiparticle
asymmetry in nature.Comment: 8 page
Symmetry Aspects in Nonrelativistic Multi-Scalar Field Models and Application to a Coupled Two-Species Dilute Bose Gas
We discuss unusual aspects of symmetry that can happen due to entropic
effects in the context of multi-scalar field theories at finite temperature. We
present their consequences, in special, for the case of nonrelativistic models
of hard core spheres. We show that for nonrelativistic models phenomena like
inverse symmetry breaking and symmetry non-restoration cannot take place, but a
reentrant phase at high temperatures is shown to be possible for some region of
parameters. We then develop a model of interest in studies of Bose-Einstein
condensation in dilute atomic gases and discuss about its phase transition
patterns. In this application to a Bose-Einstein condensation model, however,
no reentrant phases are found.Comment: 8 pages, 1 eps figure, IOP style. Based on a talk given by R. O.
Ramos at the QFEXT05 workshop, Barcelona, Spain, September 5-9, 2005. One
reference was update
Modelling a layer for real-time management of interactions in web based distance learning
In the last few years, the University of Aveiro, Portugal, has been offering several distance learning courses
over the Web, using e-learning platforms.
Experience showed that different editions of a same course, using the same contents and structure, and having
similar target learners, had different success rates. What would be the reason for that?
A hypothesis was considered: The level of success could be directly related with the remote follow-up of the
learners’ participation in the courses; the best results usually occur when the follow-up is closer.
The existing e-learning platforms offer and the standardization works being developed by organizations and
consortiums like IMS (IMS Global Learning Consortium, Inc), ADL SCORM (Advanced Distributed Learning
Sherable Content Object Reference Model), IEEE LTSC LOM (Institute of Electrical and Electronic Engineers
Learning Technologies Standard Committee Learning Object Metadata), ARIADNE (ARIADNE Foundation
for the European Knowledge Pool), AICC CMI (Aviation Industry CBT Committee Computer Managed
Instruction), etc, don’t cover the course monitorization concerns mentioned. Those projects were focused on
aspects like contents and its delivery in the context of the execution of the courses’ activities. This is even
true in the SCORM project that doesn’t include any reference to the management of the e-learning processes.
Recently, in the context of the IMS Global Consortium, a new project designated IMS LD (Learning Design) is
under development, providing a framework for the description of learning units under a three level model. In
the most recently defined level, the C level, some functionalities related to notifications were proposed,
expressing similar concerns to the ones that triggered our research. However, the extent at which IMS LD
takes the functionalities is, from our point of view, not complete.
This article describes a proposal of a reference model and functionalities towards a specification of a layer for
real-time management of user interactions on LMSs, and its possible integration with the ADL SCORM
standard proposal. The paper includes a discussion of the management metadata model for the LMS
sub-system and how the integration of the management module under SCORM may be achieved
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