35,827 research outputs found
Embodied Learning and Multimodality in Science Education: Teachers’ Perceptions of Teaching Electrical Circuits, Their Diagrammatic Symbols, Physical Components and Functions Through Multisensory Approach
This small case-study discusses a specific science teaching strategy that has been developed through a multimodal and socio-semiotic lens while drawing on embodied cognition as a pedagogical tool for designing a learning journey to engage students in learning about electric circuits. I have worked with pre-service teachers (PSTs) to use this strategy in their classroom to allow their students to use different senses and modes of communication to engage in knowledge acquisition. The use of movement, sound, imagery and other resources is then linked with real objects and tasks in the science classroom. This type of pedagogical strategy has potential implications for sciences teaching and learning which are explored in this piece. I draw on self-reported answers and semi-structured interviews with PSTs and other former PSTs from our institution who have used this strategy in real classrooms environments. Results show that this strategy has had important impact on PSTs’ perceptions about teaching and learning and pedagogical understanding, as well as achieving a more meaningful engagement of students during and after the lesson, in particular if the teacher is also actively involved in doing the task with the students
Characterizing the nature of Fossil Groups with XMM
We present an X-ray follow-up, based on XMM plus Chandra, of six Fossil Group
(FG) candidates identified in our previous work using SDSS and RASS data. Four
candidates (out of six) exhibit extended X-ray emission, confirming them as
true FGs. For the other two groups, the RASS emission has its origin as either
an optically dull/X-ray bright AGN, or the blending of distinct X-ray sources.
Using SDSS-DR7 data, we confirm, for all groups, the presence of an r-band
magnitude gap between the seed elliptical and the second-rank galaxy. However,
the gap value depends, up to 0.5mag, on how one estimates the seed galaxy total
flux, which is greatly underestimated when using SDSS (relative to Sersic)
magnitudes. This implies that many FGs may be actually missed when using SDSS
data, a fact that should be carefully taken into account when comparing the
observed number densities of FGs to the expectations from cosmological
simulations. The similarity in the properties of seed--FG and non-fossil
ellipticals, found in our previous study, extends to the sample of X-ray
confirmed FGs, indicating that bright ellipticals in FGs do not represent a
distinct population of galaxies. For one system, we also find that the velocity
distribution of faint galaxies is bimodal, possibly showing that the system
formed through the merging of two groups. This undermines the idea that all
selected FGs form a population of true fossils.Comment: 9 pages, 3 figures. Submitted 01/12/2011 to MNRAS, referee report
received 21/02/2012, accepted 22/02/201
Hybrid Quasicrystals, Transport and Localization in Products of Minimal Sets
We consider convex combinations of finite-valued almost periodic sequences
(mainly substitution sequences) and put them as potentials of one-dimensional
tight-binding models. We prove that these sequences are almost periodic. We
call such combinations {\em hybrid quasicrystals} and these studies are related
to the minimality, under the shift on both coordinates, of the product space of
the respective (minimal) hulls. We observe a rich variety of behaviors on the
quantum dynamical transport ranging from localization to transport.Comment: 3 figures. To appear in Journal of Stat. Physic
Decoherence, pointer engineering and quantum state protection
We present a proposal for protecting states against decoherence, based on the
engineering of pointer states. We apply this procedure to the vibrational
motion of a trapped ion, and show how to protect qubits, squeezed states,
approximate phase eigenstates and superpositions of coherent states.Comment: 1 figur
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