1,308 research outputs found
Recommended from our members
Angels in the architecture - and devils in the detail: how the learning space impacts on teaching and learning
An innovative classroom design pioneered in the US, which aims to facilitate greater student engagement, has been piloted in a UK University for the first time. This case study reflects on some of the advantages and the challenges of this technology rich learning space and considers its impact on curriculum design in a module which aims to develop academic, research and digital skills in first year students on an undergraduate Health and Social Care course
A common contrast pooling rule for suppression within and between the eyes
Recent work has revealed multiple pathways for cross-orientation suppression in cat and human vision. In particular, ipsiocular and interocular pathways appear to assert their influence before binocular summation in human but have different (1) spatial tuning, (2) temporal dependencies, and (3) adaptation after-effects. Here we use mask components that fall outside the excitatory passband of the detecting mechanism to investigate the rules for pooling multiple mask components within these pathways. We measured psychophysical contrast masking functions for vertical 1 cycle/deg sine-wave gratings in the presence of left or right oblique (645 deg) 3 cycles/deg mask gratings with contrast C%, or a plaid made from their sum, where each component (i) had contrast 0.5Ci%. Masks and targets were presented to two eyes (binocular), one eye (monoptic), or different eyes (dichoptic). Binocular-masking functions superimposed when plotted against C, but in the monoptic and dichoptic conditions, the grating produced slightly more suppression than the plaid when Ci $ 16%. We tested contrast gain control models involving two types of contrast combination on the denominator: (1) spatial pooling of the mask after a local nonlinearity (to calculate either root mean square contrast or energy) and (2) "linear suppression" (Holmes & Meese, 2004, Journal of Vision 4, 1080–1089), involving the linear sum of the mask component contrasts. Monoptic and dichoptic masking were typically better fit by the spatial pooling models, but binocular masking was not: it demanded strict linear summation of the Michelson contrast across mask orientation. Another scheme, in which suppressive pooling followed compressive contrast responses to the mask components (e.g., oriented cortical cells), was ruled out by all of our data. We conclude that the different processes that underlie monoptic and dichoptic masking use the same type of contrast pooling within their respective suppressive fields, but the effects do not sum to predict the binocular case
The development of the reflective practitioner through digital storytelling
This paper presents a multiple case study on the use of digital storytelling to support the development of reflection and digital skills in professional education. Students from two universities, one group studying health and social care, the other training to be teachers, were asked to produce two artefacts, at the beginning and end of their respective modules, in which they reflected on the aspects of professional and personal learning. The artefacts, some of which were produced in groups, others by individual students, were analysed for recurring themes, levels of reflection and digital competence, particularly in the use of open educational resources. Findings from the analysis support the use of digital storytelling methods to develop a range of key skills pertinent to professional education in general but concluded that the deeper levels of reflection may be most evident in individual artefacts produced in the later stages of professional education. The study provides some important insights for teaching and learning in professional education as it suggests that digital storytelling provides a highly engaging way of introducing both reflective and open educational practices
Recommended from our members
Digital artefacts for reflection on identity in the first year of teacher education: the teacher I want to be
This paper presents an analysis of digital reflective narratives of identity constructed by student teachers in their first year in a Spanish University. The literature review demonstrates the multidimensional nature of teacher identity, showing that, during the transition of their first year at University, student teachers’ ideas of identity reflect a highly emotional and committed stance on
childhood and social justice. The innovative approach taken in the current work includes a review of the possibilities of digital artefacts, as OER, for reflection. The conclusion discusses the importance of scaffolding approaches to the development of teacher identity through a reflective methodology
CMB power spectrum parameter degeneracies in the era of precision cosmology
Cosmological parameter constraints from the CMB power spectra alone suffer
several well-known degeneracies. These degeneracies can be broken by numerical
artefacts and also a variety of physical effects that become quantitatively
important with high-accuracy data e.g. from the Planck satellite. We study
degeneracies in models with flat and non-flat spatial sections, non-trivial
dark energy and massive neutrinos, and investigate the importance of various
physical degeneracy-breaking effects. We test the CAMB power spectrum code for
numerical accuracy, and demonstrate that the numerical calculations are
accurate enough for degeneracies to be broken mainly by true physical effects
(the integrated Sachs-Wolfe effect, CMB lensing and geometrical and other
effects through recombination) rather than numerical artefacts. We quantify the
impact of CMB lensing on the power spectra, which inevitably provides
degeneracy-breaking information even without using information in the
non-Gaussianity. Finally we check the numerical accuracy of sample-based
parameter constraints using CAMB and CosmoMC. In an appendix we document recent
changes to CAMB's numerical treatment of massive neutrino perturbations, which
are tested along with other recent improvements by our degeneracy exploration
results.Comment: 27 pages, 28 figures. Latest CAMB version available from
http://camb.info/. Reduced number of figures, plot legend corrected and minor
edits to match published versio
Generation of Curvature Perturbations with Extra Anisotropic Stress
We study the evolution of curvature perturbations and the cosmic microwave
background (CMB) power spectrum in the presence of an hypothesized extra
anisotropic stress which might arise, for example, from the dark radiation term
in brane-world cosmology. We evolve the scalar modes of such perturbations
before and after neutrino decoupling and analyze their effects on the CMB
spectrum. A novel result of this work is that the cancellation of the neutrino
and extra anisotropic stress could lead to a spectrum of residual curvature
perturbations which is similar to the observed CMB power spectrum. This implies
a possible additional consideration in the determination of cosmological
parameters from the CMB analysis.Comment: 13 pages, 2 figures; improved discussio
CMB lensing with shear-only reconstruction on the full sky
Reconstruction of gravitational lensing effects in the CMB from current and
upcoming surveys is still dominated by temperature anisotropies. Extragalactic
foregrounds in temperature maps can induce significant biases in the lensing
power spectrum obtained with the standard quadratic estimators. Techniques such
as masking cannot remove these foregrounds fully, and the residuals can still
lead to large biases if unaccounted for. In this paper, we study the
"shear-only" estimator, an example of a class of geometric methods that
suppress extragalactic foreground contamination while making only minimal
assumptions about foreground properties. The shear-only estimator has only been
formulated in the flat-sky limit and so is not easily applied to wide surveys.
Here, we derive the full-sky version of the shear-only estimator and its
generalisation to an multipole estimator that has improved performance
for lensing reconstruction on smaller scales. The multipole estimator is
generally not separable, and so is expensive to compute. We explore separable
approximations based on a singular-value decomposition, which allow efficient
evaluation of the estimator with real-space methods. Finally, we apply these
estimators to simulations that include extragalactic foregrounds and verify
their efficacy in suppressing foreground biases.Comment: v2 matches with published versio
- …