138 research outputs found
New Mass-Conserving Bedrock Topography for Pine Island Glacier Impacts Simulated Decadal Rates of Mass Loss
Published maps of of Antarctic bedrock elevation place Pine Island Glacier's grounding line on a submarine ridge, but observations of ice velocity indicate that the ridge is absent. Constructing a map of bedrock elevation that is compatible with the ice velocity leads to an ice sheet model that quite different dynamic behaviour over the coming decades, and present day behaviour that is in better agreement with observations
Teacher quality in the twenty first century: new lives, old truths
This chapter is based upon a keynote address to the first global teacher education summit, organised by Beijing Normal University in 2011, in which research across the world about influences which affect teachers' sense of professional identity, capacity for compassion, commitment, resilience and effectiveness long after they have graduated from their pre-service education and training programmes in universities and colleges were shared. The findings suggest that teaching pre-service students about how the conditions in which they work may enhance or diminish their capacity to teach to their best and how they might act to mediate these is a key part of the work of all teacher educators and an important focus for the work of educational researchers
Microbial nitrogen cycling on the Greenland Ice Sheet
Nitrogen inputs and microbial nitrogen cycling were investigated along a 79 km transect into the Greenland Ice Sheet (GrIS) during the main ablation season in summer 2010. The depletion of dissolved nitrate and production of ammonium (relative to icemelt) in cryoconite holes on Leverett Glacier, within 7.5 km of the ice sheet margin, suggested microbial uptake and ammonification respectively. Positive in situ acetylene assays indicated nitrogen fixation both in a debris-rich 100 m marginal zone and up to 5.7 km upslope on Leverett Glacier (with rates up to 16.3 Îźmoles C<sub>2</sub>H<sub>4</sub> m<sup>â2</sup> day<sup>â1</sup>). No positive acetylene assays were detected > 5.7 km into the ablation zone of the ice sheet. Potential nitrogen fixation only occurred when concentrations of dissolved and sediment-bound inorganic nitrogen were undetectable. Estimates of nitrogen fluxes onto the transect suggest that nitrogen fixation is likely of minor importance to the overall nitrogen budget of Leverett Glacier and of negligible importance to the nitrogen budget on the main ice sheet itself. Nitrogen fixation is however potentially important as a source of nitrogen to microbial communities in the debris-rich marginal zone close to the terminus of the glacier, where nitrogen fixation may aid the colonization of subglacial and moraine-derived debris
Performativity and primary teacher relations
A performativity discourse currently pervades teachers' work. It is a discourse that relies on teachers and schools instituting self-disciplinary measures to satisfy newly transparent public accountability and it operates alongside a market discourse. The introduction of the performativity discourse has affected teacher relations at three levels of professional work: with students, colleagues and local advisor/inspectors. Ethnographic research with primary teachers - which focused on their experience of Ofsted inspections in six schools over periods of up to four years - is the source of this paper. The paper argues that a humanist discourse prevalent in teacher relations with students, colleagues and advisor/inspectors has been challenged by a performativity discourse that: distances teachers from students and creates a dependency culture in opposition to previous mutual and intimate relations; creates self disciplining teams that marginalize individuality and stratifies collegial relations in opposition to previous relations where primary teachers sought consensus; and creates subjugatory, contrived and de-personalized relations between local advisors/inspectors in preference to previous partnership relations. The paper concludes that the change in relations is an indicator of fundamental change to social relations but that primary teachers are in a good position to influence the performativity discourse, albeit it a struggle, by reconstituting it through the maintenance of humanist relations
Investigating student teachersâ presentations of literacy and literacy pedagogy in a complex context
The field of literacy and primary literacy education is patterned by multiple discourses and this raises challenges for those educating the next generation of primary literacy teachers. In England, the last 15 years have seen considerable levels of prescription in the primary literacy curriculum and compliance by the school and teacher education sectors has been enforced through demanding accountability regimes. In this paper, the authors draw on findings of a small-scale interview study to consider how understandings of literacies associated with different contexts may or may not inflect student teachersâ orientations towards literacy provision in school. The authors explore how five student teachers presented their experiences of literacy within and beyond the classroom and how they seemed to position themselves in relation to literacy pedagogy. The authors focus particularly on continuities and discontinuities between literacies in the student teachersâ personal and professional lives, and on tensions they identified between the teachers they felt they wanted to, and were expected to, become. Reflecting on this work, the authors consider how they can best equip pre-service primary and early years teachers to develop as critical reflective literacy practitioners in the current context
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