Analytical study of tunneling times in flat histogram Monte Carlo

We present a model for the dynamics in energy space of multicanonical simulation methods that lends itself to a rather complete analytic characterization. The dynamics is completely determined by the density of states. In the \pm J 2D spin glass the transitions between the ground state level and the first excited one control the long time dynamics. We are able to calculate the distribution of tunneling times and relate it to the equilibration time of a starting probability distribution. In this model, and possibly in any model in which entering and exiting regions with low density of states are the slowest processes in the simulations, tunneling time can be much larger (by a factor of O(N)) than the equilibration time of the probability distribution. We find that these features also hold for the energy projection of single spin flip dynamics.Comment: 7 pages, 4 figures, published in Europhysics Letters (2005

Introducing the Learning Scorecard: a tool to improve the student learning experience

Improving the student learning experience is an essential aspect of teaching. This paper presents the Learning Scorecard (LS), a tool designed to monitor and manage the learning experience of students in a course. The LS has a student view and a faculty (or course coordinator) view. The student view essentially focuses on time management and uses gamification to engage students with the course’s activities. In the faculty view, data is aggregated from the student’s view, enabling the course coordinator to monitor the average progress of students in the different classes of the course he/she is lecturing. The Learning Scorecard has been developed using Business Intelligence and performance management techniques. It includes a Balanced Scorecard and dashboards for the visualization and monitoring of the student learning experience. In this paper the design of the LS will be presented as well as some initial results with an ongoing experiment in a course lectured in different Higher Education programs within the same university.info:eu-repo/semantics/publishedVersio

Introducing the Learning Scorecard: a tool to improve the student learning experience

Improving the student learning experience is an essential aspect of teaching. This paper presents the Learning Scorecard (LS), a tool designed to monitor and manage the learning experience of students in a course. The LS has a student view and a faculty (or course coordinator) view. The student view essentially focuses on time management and uses gamification to engage students with the course’s activities. In the faculty view, data is aggregated from the student’s view, enabling the course coordinator to monitor the average progress of students in the different classes of the course he/she is lecturing. The Learning Scorecard has been developed using Business Intelligence and performance management techniques. It includes a Balanced Scorecard and dashboards for the visualization and monitoring of the student learning experience. In this paper the design of the LS will be presented as well as some initial results with an ongoing experiment in a course lectured in different Higher Education programs within the same university.info:eu-repo/semantics/acceptedVersio

Dialogue between social movement activists and a Master's Program in youth and adult education

This article presents the results of a qualitative study on the relationship between social movements and a Master's Program in youth and adult education in Bahia, Brazil. It pays particular attention to the importance of antiracism in and the decolonization of the program's curriculum

Direct SW aerosol radiative forcing over Portugal

In this work, the evaluation of the aerosol radiative forcing at the top of the atmosphere as well as at the surface over the south of Portugal is made, particularly in the regions of Évora (38°34' N, 7°54' W) and of Cabo da Roca (38°46' N, 9°38' W), during years 2004 and 2005. <br><br> The radiative transfer calculations, using the radiative transfer code Second Simulation of the Satellite Signal in the Solar Spectrum (6S), combine ground-based measurements, from Aerosol Robotic NETwork (AERONET), and satellite measurements, from MODerate Imaging Spectroradiometer (MODIS), to estimate the direct SW aerosol radiative forcing. The method developed to retrieve the surface spectral reflectance is also presented, based on ground-based measurements (AERONET) of the aerosol optical properties combined with the satellite-measured radiances (MODIS). <br><br> The instantaneous direct SW aerosol radiative forcing values obtained at the top of the atmosphere are, in the majority of the cases, negative, indicating a tendency for cooling the Earth at the top of the atmosphere. For Desert Dust aerosols, over the Évora land region, the average forcing efficiency is estimated to be −25 Wm<sup>−2</sup>/AOT<sub>0.55</sub> whereas for the Cabo da Roca area, the average forcing efficiency is −46 Wm<sup>−2</sup>/AOT<sub>0.55</sub>. In the presence of Forest Fire aerosols, both from short and long distances, the average value of forcing efficiency at the top of the atmosphere over Cabo da Roca is found to be −28 Wm<sup>−2</sup>/AOT<sub>0.55</sub> and, over Évora, −27 Wm<sup>−2</sup>/AOT<sub>0.55</sub>. For specific situations, discussed in this work, the average surface direct SW aerosol radiative forcing efficiency due to the Desert Dust aerosols, in Évora region, is −66 Wm<sup>−2</sup>/AOT<sub>0.55</sub>, whereas in Cabo da Roca region, the corresponding average value is −38 Wm<sup>−2</sup>/AOT<sub>0.55</sub>. Considering the Forest Fire aerosols, over Évora region, the average surface direct SW aerosol radiative forcing efficiency can vary between −36 and −113 Wm<sup>−2</sup>/AOT<sub>0.55</sub>, the more negative value corresponding to forest fire aerosols coming only from shorter distances

On three-point correlation functions in the gauge/gravity duality

We study the effect of marginal and irrelevant deformations on the renormalization of operators near a CFT fixed point. New divergences in a given operator are determined by its OPE with the operator D that generates the deformation. This provides a scheme to compute the couplings a_DAB between the operator D and two arbitrary operators O_A and O_B. We exemplify for the case of N=4 SYM, considering the simplest case of the exact Lagrangian deformation. In this case the deformed anomalous dimension matrix is determined by the derivative of the anomalous dimension matrix with respect to the coupling. We use integrability techniques to compute the one-loop couplings a_LAB between the Lagrangian and two distinct large operators built with Magnons, in the SU(2) sector of the theory. Then we consider a_DAA at strong coupling, and show how to compute it using the gauge/gravity duality, when D is a chiral operator dual to any supergravity field and O_A is dual to a heavy string state. We exemplify for the Lagrangian and operators O_A dual to heavy string states, showing agreement with the prediction derived from the renormalization group arguments

The recombination dynamics of Staphylococcus aureus inferred from spA gene

BACKGROUND: Given the role of spA as a pivotal virulence factor decisive for Staphylococcus aureus ability to escape from innate and adaptive immune responses, one can consider it as an object subject to adaptive evolution and that variations in spA may uncover pathogenicity variations. RESULTS: The population genetic structure was deduced from the extracellular domains of SpA gene sequence (domains A-E and the X-region) and compared to the MLST-analysis of 41 genetically diverse methicillin-resistant (MRSA) and methicillin-susceptible (MSSA) S. aureus strains. Incongruence between tree topologies was noticeable and in the inferred spA tree most MSSA isolates were clustered in a distinct group. Conversely, the distribution of strains according to their spA-type was not always congruent with the tree inferred from the complete spA gene foreseeing that spA is a mosaic gene composed of different segments exhibiting different evolutionary histories. Evidences of a network-like organization were identified through several conflicting phylogenetic signals and indeed several intragenic recombination events (within subdomains of the gene) were detected within and between CC’s of MRSA strains. The alignment of SpA sequences enabled the clustering of several isoforms as a result of non-randomly distributed amino acid variations, located in two clusters of polymorphic sites in domains D to B and Xr (a). Nevertheless, evidences of cluster specific structural arrangements were detected reflecting alterations on specific residues with potential impact on S. aureus pathogenicity. CONCLUSIONS: The detection of positive selection operating on spA combined with frequent non-synonymous mutations, domain duplication and frequent intragenic recombination events represent important mechanisms acting in the evolutionary adaptive mechanism promoting spA genetic plasticity. These findings argue that crucial allelic forms correlated with pathogenicity can be identified by sequences analysis enabling the design of more robust schemes. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12866-016-0757-9) contains supplementary material, which is available to authorized users