218 research outputs found
A Review of the "Digital Turn" in the New Literacy Studies
Digital communication has transformed literacy practices and assumed great importance in the functioning of workplace, recreational, and community contexts. This article reviews a decade of empirical work of the New Literacy Studies, identifying the shift toward research of digital literacy applications. The article engages with the central theoretical, methodological, and pragmatic challenges in the tradition of New Literacy Studies, while highlighting the distinctive trends in the digital strand. It identifies common patterns across new literacy practices through cross-comparisons of ethnographic research in digital media environments. It examines ways in which this research is taking into account power and pedagogy in normative contexts of literacy learning using the new media. Recommendations are given to strengthen the links between New Literacy Studies research and literacy curriculum, assessment, and accountability in the 21st century
Internal alignments of red versus blue discs in dark matter haloes
Large surveys have shown that red galaxies are preferentially aligned with their haloes, while blue galaxies have a more isotropic distribution. Since haloes generally align with their filaments, this introduces a bias in the measurement of the cosmic shear from weak lensing. It is therefore vitally important to understand why this difference arises. We explore the stability of different disc orientations within triaxial haloes. We show that, in the absence of gas, the disc orientation is most stable when its spin is along the minor axis of the halo. Instead when gas cools on to a disc, it is able to form in almost arbitrary orientation, including off the main planes of the halo (but avoiding an orientation perpendicular to the halo's intermediate axis). Substructure helps gasless galaxies reach alignment with the halo faster, but has less effect on galaxies when gas is cooling on to the disc. Our results provide a novel and natural interpretation for why red, gas poor galaxies are preferentially aligned with their halo, while blue, star-forming, galaxies have nearly random orientations, without requiring a connection between galaxies' current star formation rate and their merger history
A Study of the Orbits of the Logarithmic Potential for Galaxies
The logarithmic potential is of great interest and relevance in the study of
the dynamics of galaxies. Some small corrections to the work of Contopoulos &
Seimenis (1990) who used the method of Prendergast (1982) to find periodic
orbits and bifurcations within such a potential are presented. The solution of
the orbital radial equation for the purely radial logarithmic potential is then
considered using the p-ellipse (precessing ellipse) method pioneered by Struck
(2006). This differential orbital equation is a special case of the generalized
Burgers equation. The apsidal angle is also determined, both numerically as
well as analytically by means of the Lambert W and the Polylogarithm functions.
The use of these functions in computing the gravitational lensing produced by
logarithmic potentials is discussed.Comment: 12 pages, 4 figures. Accepted by MNRAS Sept 6 201
Drinking patterns among medical in-patients with reference to MAST categories: a comparative study.
The aim of the study was to describe the drinking patterns and alcohol consumption of patients screened by the Michigan Alcoholism Screening Test (MAST) in a sample of medical patients from a general hospital of a French-speaking, wine-drinking country. Data were recorded using a structured interview administered to 103 consecutively admitted 20-75-year-old MAST-positive patients and 103 age-matched and sex-matched MAST-negative controls admitted to the same ward. Relevant differences between MAST-positive and MAST-negative patients included the frequent report of recent and total abstinence in MAST-positive patients (23% versus 4% in controls), their tendency to drink alone, and less often during mealtimes, at home, or with family or friends than MAST-negative patients. Alcohol consumption was significantly higher in MAST-positive patients of both sexes with 250 and 270 g per week being the optimal discriminative cut-off level of consumption for men and women, respectively (kappa coefficient, 0.70 and 0.81, respectively). Regular drinking was the predominant drinking status of both MAST-positive and MAST-negative patients. This study suggests that a screening test such as the MAST, developed in an English-speaking country may be useful in a French-speaking, wine-drinking country. The test identified patients with drinking patterns that are culturally abnormal, yet in certain respects similar to those of alcoholic patients from other drinking cultures. These findings therefore emphasize the worldwide relevance of the concept of the alcohol dependence syndrome in addition to the transcultural usefulness of alcoholism screening tests
Ranger, an Example of Integration of Robotics into the Home Ecosystem
This paper presents the concept and an example of robject, a robotic entity embedded in an everyday object. Robjects use the affordance of the original object to ensure an efficient interaction and a high acceptance. The example of the ranger robot shows that this approach can be applied to the domestic environment. We explore the integration of a robot (robject) into a family household, by regarding the home as a ecosystem, which consists of people, parts, products, activities, and interactions. A test of the ranger robot in families validates this holistic approach and shows the impact of this type of design in respect to the complexity of the robotic system
Application of new dynamical spectra of orbits in Hamiltonian systems
In the present article, we investigate the properties of motion in
Hamiltonian systems of two and three degrees of freedom, using the distribution
of the values of two new dynamical parameters. The distribution functions of
the new parameters, define the S(g) and the S(w) dynamical spectra. The first
spectrum definition, that is the S(g) spectrum, will be applied in a
Hamiltonian system of two degrees of freedom (2D), while the S(w) dynamical
spectrum will be deployed in a Hamiltonian system of three degrees of freedom
(3D). Both Hamiltonian systems, describe a very interesting dynamical system
which displays a large variety of resonant orbits, different chaotic components
and also several sticky regions. We test and prove the efficiency and the
reliability of these new dynamical spectra, in detecting tiny ordered domains
embedded in the chaotic sea, corresponding to complicated resonant orbits of
higher multiplicity. The results of our extensive numerical calculations,
suggest that both dynamical spectra are fast and reliable discriminants between
different types of orbits in Hamiltonian systems, while requiring very short
computation time in order to provide solid and conclusive evidence regarding
the nature of an orbit. Furthermore, we establish numerical criteria in order
to quantify the results obtained from our new dynamical spectra. A comparison
to other previously used dynamical indicators, reveals the leading role of the
new spectra.Comment: Published in Nonlinear Dynamics (NODY) journal. arXiv admin note:
text overlap with arXiv:1009.1993 by other author
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