7,827 research outputs found
Toward a social pedagogy of classroom group work
In any classroom, pupils will be drawn together for many purposes and we can refer to such within classroom contexts as 'groupings'. The teacher often creates these, and the way that they are set up, and how they are used for particular learning purposes. If the relationships between grouping size, interaction type and learning tasks in groups are planned strategically then learning experiences will be more effective. However, research suggests that the relationships between these elements are often unplanned and the 'social pedagogic' potential of classroom learning is therefore unrealised. In this paper we explore the notion of social pedagogy in relation to group work. It is argued that research and theory relevant to group work in classrooms is limited, and that a new approach, sensitive to group work under everyday classroom conditions is required. This paper identifies key features of a social pedagogy of classroom group work, which can inform effective group work in classrooms. It also describes the background to a current large scale UK project which has been set up to design with teachers a programme of high quality group work in classrooms at both primary and secondary phases. © 2003 Elsevier Ltd. All rights reserved.link_to_subscribed_fulltex
Magnetic field induced non-Fermi liquid to Fermi liquid crossover at the quantum critical point of YbCuAu
The temperature (T) dependence of the muon and Cu nuclear spin-lattice
relaxation rates in YbCu4.4Au0.6 is reported over nearly four decades.
It is shown that for diverges following the behaviour
predicted by the self-consistent renormalization (SCR) theory developed by
Moriya for a ferromagnetic quantum critical point. On the other hand, the
static uniform susceptibility is observed to diverge as and
, a behaviour which is not accounted for by SCR theory.
The application of a magnetic field is observed to induce a crossover to a
Fermi liquid behaviour and for is found to obey the scaling
law .Comment: 4 pages, 4 figure
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Explicit time-stepping for moving meshes
In order to move the nodes in a moving mesh method a time-stepping scheme is required which is ideally explicit and non-tangling (non-overtaking in one dimension (1-D)). Such a scheme is discussed in this paper, together with its drawbacks, and illustrated in 1-D in the context of a velocity-based Lagrangian conservation method applied to first order and second order examples which exhibit a regime change after node compression. An implementation in multidimensions is also described in some detail
'White knuckle care work' : violence, gender and new public management in the voluntary sector
Drawing on comparative data from Canada and Scotland, this article explores reasons why violence is tolerated in non-profit care settings. This article will provide insights into how workers' orientations to work, the desire to care and the intrinsic rewards from working in a non-profit context interact with the organization of work and managerially constructed workplace norms and cultures (Burawoy, 1979) to offset the tensions in an environment characterized by scarce resources and poor working conditions. This article will also outline how the same environment of scarce resources causes strains in management's efforts to establish such cultures. Working with highly excluded service users with problems that do not respond to easy interventions, workers find themselves working at the edge of their endurance, hanging on by their fingernails, and beginning to participate in various forms of resistance; suggesting that even among the most highly committed, 'white knuckle care' may be unsustainable
On the spectroastrometric separation of binary point-source fluxes
Spectroastrometry is a technique which has the potential to resolve flux
distributions on scales of milliarcseconds. In this study, we examine the
application of spectroastrometry to binary point sources which are spatially
unresolved due to the observational point spread function convolution. The
technique uses measurements with sub-pixel accuracy of the position centroid of
high signal-to-noise long-slit spectrum observations. With the objects in the
binary contributing fractionally more or less at different wavelengths
(particularly across spectral lines), the variation of the position centroid
with wavelength provides some information on the spatial distribution of the
flux. We examine the width of the flux distribution in the spatial direction,
and present its relation to the ratio of the fluxes of the two components of
the binary. Measurement of three observables (total flux, position centroid and
flux distribution width) at each wavelength allows a unique separation of the
total flux into its component parts even though the angular separation of the
binary is smaller than the observations' point-spread function. This is because
we have three relevant observables for three unknowns (the two fluxes, and the
angular separation of the binary), which therefore generates a closed problem.
This is a wholly different technique than conventional deconvolution methods,
which produce information on angular sizes of the sampling scale.
Spectroastrometry can produce information on smaller scales than conventional
deconvolution, and is successful in separating fluxes in a binary object with a
separation of less than one pixel. We present an analysis of the errors
involved in making binary object spectroastrometric measurements and the
separation method, and highlight necessary observing methodology.Comment: 11 pages, 8 figures, accepted for publication in Astronomy and
Astrophysic
Sub-milliarcsecond precision spectro-astrometry of Be stars
The origin of the disks around Be stars is still not known. Further progress
requires a proper parametrization of their structure, both spatially and
kinematically. This is challenging as the disks are very small. Here we assess
whether a novel method is capable of providing these data. We obtained spectro
astrometry around the Pa beta line of two bright Be stars, alpha Col and zeta
Tau, to search for disk signatures. The data, with a pixel to pixel precision
of the centroid position of 0.3..0.4 milliarcsecond is the most accurate such
data to date. Artefacts at the 0.85 mas level are present in the data, but
these are readily identified as they were non-repeatable in our redundant
datasets. This does illustrate the need of taking multiple data to avoid
spurious detections. The data are compared with simple model simulations of the
spectro astrometric signatures due to rotating disks around Be stars. The upper
limits we find for the disk radii correspond to disk sizes of a few dozen
stellar radii if they rotate Keplerian. This is very close to observationally
measured and theoretically expected disk sizes, and this paper therefore
demonstrates that spectro-astrometry, of which we present the first such
attempt, has the potential to resolve the disks around Be stars.Comment: 6 pages, A&A accepte
Regulation of synaptic connectivity: levels of fasciclin II influence synaptic growth in the Drosophila CNS
Much of our understanding of synaptogenesis comes from studies that deal with the development of the neuromuscular junction (NMJ). Although well studied, it is not clear how far the NMJ represents an adequate model for the formation of synapses within the CNS. Here we investigate the role of Fasciclin II (Fas II) in the development of synapses between identified motor neurons and cholinergic interneurons in the CNS of Drosophila. Fas II is a neural cell adhesion molecule homolog that is involved in both target selection and synaptic plasticity at the NMJ in Drosophila. In this study, we show that levels of Fas II are critical determinants of synapse formation and growth in the CNS. The initial establishment of synaptic contacts between these identified neurons is seemingly independent of Fas II. The subsequent proliferation of these synaptic connections that occurs postembryonically is, in contrast, significantly retarded by the absence of Fas II. Although the initial formation of synaptic connectivity between these neurons is seemingly independent of Fas II, we show that their formation is, nevertheless, significantly affected by manipulations that alter the relative balance of Fas II in the presynaptic and postsynaptic neurons. Increasing expression of Fas II in either the presynaptic or postsynaptic neurons, during embryogenesis, is sufficient to disrupt the normal level of synaptic connectivity that occurs between these neurons. This effect of Fas II is isoform specific and, moreover, phenocopies the disruption to synaptic connectivity observed previously after tetanus toxin light chain-dependent blockade of evoked synaptic vesicle release in these neurons
Motherhood and Abjection in Peter Carey's "Jack Maggs"
Jack Maggs is a novel in which maternity plays an important role. The story significantly connects motherhood to the universal notion of Mother Earth in order to criticise the annihilating power that Mother Britain exercised over its people and colonies. Consequently, most mothers are presented as horrible beings who are able to hurt, and even kill, their children. In contrast, the only positive mother of the story turns into a kind of heroine. She does not only help the protagonist, but also becomes Australian, mother of Australians and the protector of the thus far marginalised voice of the colonies.En Jack Maggs la maternidad desempeña un papel importante. La novela conecta maternidad con el concepto universal de Madre Tierra para criticar el poder aniquilador que la Madre Gran Bretaña ejercía sobre su pueblo y colonias. Por consiguiente, la mayoría de las madres son descritas como seres horribles capaces de herir, e incluso matar, a sus hijos. En contraste, la única madre positiva de la historia se convierte en una especie de heroína. Ella no sólo ayuda al protagonista, sino que también se convierte en australiana, madre de australianos y protectora de la hasta ahora marginalizada voz de las colonias
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