23,382 research outputs found
E-learning in mixed reality landscape: emerging issues and key trends in scientific research
E-Learning aims to apply information and communications technology to enhance and support the learning process and is a popular mode of delivering educational materials in universities throughout the world. Recently, due to the advancements of Augmented Reality (AR) and Virtual reality (VR), the E-learning process has great challenges and opportunities ahead. This study intends to explore the current trends in the field of AR/VR applied to distance education research. Using bibliographic data extracted from the Scopus® database and social network analysis techniques were able to analyse author keyword toward the identification of major trends. For the analysis, we collected keywords from research papers published in international journals related to E-learning, AR and VR, between 2006 and 2017, and constructed a co-word network, and then conducted the keywords network analysis. Retrieving the "E-learning" ego-network we could find some clusters that define major trends like virtual environments or evaluations process. The study reveals that E-learning process fits better in AR than VR research. The findings obtained in this study may be useful in the exploration of potential research areas in the field of distance education.info:eu-repo/semantics/acceptedVersio
Diluted antiferromagnet in a ferromagnetic enviroment
The question of robustness of a network under random ``attacks'' is treated
in the framework of critical phenomena. The persistence of spontaneous
magnetization of a ferromagnetic system to the random inclusion of
antiferromagnetic interactions is investigated. After examing the static
properties of the quenched version (in respect to the random antiferromagnetic
interactions) of the model, the persistence of the magnetization is analysed
also in the annealed approximation, and the difference in the results are
discussed
Diagnostic tools to detect pathogens causing tuberculosis in cattle and prevent their transmission through dairy products to humans.
Measuring The Co2 Flux At The Air/water Interface In Lakes Using Flow Injection Analysis.
The carbon dioxide flux at the air/water interface in lakes was calculated after the determination of H2CO3* (free CO2) and atmospheric CO2 using flow injection analysis (FIA) coupled to a conductometric detector. The method is based on the diffusion of CO2 through a hydrophobic membrane into a flow of deionized water, generating a gradient of conductivity proportional to the concentration of CO2 in the sample. Using one experimental set-up, the speciation of the inorganic carbon (H2CO3* and dissolved inorganic carbon) was accomplished by simply adjusting the sample pH. The determination of CO2 in the atmosphere was carried out by direct injection of the gaseous samples. The FIA apparatus was taken into the field and CO2 fluxes were evaluated in several Brazilian lakes. In these lakes, representing different eutrophic stages, the CO2 flux varied from -242 (invasive) up to 3227 (evasive) mumol CO2 m-2 h-1.3317-2
Digital image processing and enhancement of gravity data as an aid to the definition of the structural framework of the north Tucano-Jatobá basins, Northeastern Brazil
Técnicas de processamento digital de imagens foram aplicadas a dados gravimétricos visando melhorar definição das principais feições estruturais na porção norte do Rift Recôncavo-Tucano-Jatobá. Os processamentos utilizados incluíram: (a) conversão de dados Bouguer e residual-Bouguer, no formato de grids, em imagens realçadas; (b) geração de composições falsa cor híbridas e (c) geração de modelos de elevação digital com visão em perspectiva. A análise integrada desse conjunto de dados permitiu reconhecer feições lineares e sutis variações espaciais nos dados gravimétricos, as quais foram associadas a unidades tectónicas no contexto do rift, tais como: plataformas em rampa, baixos e altos estruturais, horsts, grabens e falhas de borda.Digitally processed and enhanced gravity data in raster format were used to improve the definition of the main structural features in the northern part of the Reconcavo-Tucano-Jatoba Rift. Image processing techniques included: (a) conversion of Bouguer and residual-Bouguer gridded data into contrast-enhanced gray-level images; (b) generation of enhanced hybrid pseudo-color composites; and (c) generation of a gravity digital elevation model in perspective views. The integrated analysis of this dataset permitted the recognition of subtle trends and intensity-related spatial variations in gravity data, tentatively related to the following tectonic units of the RTJ Rift: ramp platforms, structural lows and highs, along-length horsts, grabens, faulted borders and extensional faults
Occupational Health and Its Influence on Job (Dis)Satisfaction
info:eu-repo/semantics/publishedVersio
Specific configuration of dendritic degeneration in pyramidal neurons of the medial prefrontal cortex induced by differing corticosteroid regimens
We previously demonstrated that hypercorticalism induces pronounced
volumetric reductions in the rat medial prefrontal cortex
(mPFC) and that these structural changes correlate with deficits in
executive function. By applying 3-dimensional analysis of Golgi-
Cox--stained material, we now demonstrate that corticosteroids
can exert differential effects on dendritic arborizations of pyramidal
neurons in lamina II/III of the mPFC. Treatment with the glucocorticoid
receptor--selective agonist dexamethasone and with the
natural adrenosteroid, corticosterone (CORT), results in significant
reductions in the total length of apical dendrites in the pyramidal
neurons in lamina II/III of the anterior cingulate/prelimbic and
infralimbic cortices. Interestingly, although these treatments do not
affect the number of dendritic branches, they are associated with
impoverished arborizations in their distal portions and, in CORTtreated
animals, with increased branching in the middle portions of
the apical dendritic tree. Deprivation of corticosteroids by adrenalectomy
leads to decreases in total apical dendritic length and spine
number, but in this case, dendritic impoverishment was restricted
to the middle/proximal segments of the dendritic trees. None of
the treatments influenced the architecture of the basal dendrites.
These results add to our knowledge of the morphological substrates
through which corticosteroids may disrupt mPFC-dependent
behaviors
Generalized Euler-Lagrange equations for variational problems with scale derivatives
We obtain several Euler-Lagrange equations for variational functionals
defined on a set of H\"older curves. The cases when the Lagrangian contains
multiple scale derivatives, depends on a parameter, or contains higher-order
scale derivatives are considered.Comment: Submitted on 03-Aug-2009; accepted for publication 16-March-2010; in
"Letters in Mathematical Physics"
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