Preservation of glaciochemical time-series in snow and ice from the Penny Ice Cap, Baffin Island

A detailed investigation of major ion concentrations of snow and ice in the summit region of Penny Ice Cap (PIC) was performed to determine the effects of summer melt on the glaciochemical time-series. While ion migration due to meltwater percolation makes it difficult to confidently count annual layers in the glaciochemical profiles, time-series of these parameters do show good structure and a strong one year spectral component, suggesting that annual to biannual signals are preserved in PIC glaciochemical records

Interview with Jason Grumet by Brien Williams

Biographical NoteJason S. Grumet was born February 25, 1967, in Rochester, New York, to Gerald and Madeleine Grumet. After high school, he spent a year traveling North America through a program with the National Audubon Society Expedition Institute. He received an environmental studies degree from Brown University and then worked for the New York State Department of Environmental Conservation. He attended Harvard Law School and ran an organization that worked for the Northeast State Air Pollution Control officials. At the time of this interview, he was president of the Bipartisan Policy Center. SummaryInterview includes discussion of: Mitchell and the Clean Air Act of 1990; Mitchell and the National Commission on Energy Policy; the Clinton Global Initiative; purpose of the National Commission on Energy Policy; bipartisanship; how Senators Mitchell, Daschle, Dole, and Baker interacted on the bipartisan health care commission; how the challenges with Clinton health care influenced the commission; reaction to the report from the commission; Chris Jennings and Mark McClellan; working with the law firms of former senators; lack of bipartisan energy on health care; the Obama administration’s role; how the projects are organized; Senator Mitchell and bipartisan leadership; and Mitchell’s legacy

Meridional transport in the Indian Ocean traced by coral radiocarbon

Ocean circulation in the Indian Ocean is predominantly driven by the monsoon and is responsible for convergence along the equator. As a result, upwelling is primarily restricted to the western boundary where surface waters are anomalously depleted in 14C. Here, we describe aspects of western boundary upwelling based on insights derived from the first coral radiocarbon time-series in the Indian Ocean. The absence of a distinct subannual pre-bomb Δ14C signal suggests that open and coastal upwelling are negligible off the coast of Kenya. Instead, our results suggest that upwelling from the coast of Somalia and possibly Oman are the sources of the depleted seasonal Δ14C signal. In contrast, the southern hemisphere subtropical gyre provides water enriched in 14C. We demonstrate that the coral Δ14C time-series is a tracer for meridional transport in the Indian Ocean. The Indian Ocean exhibits a shallow cross-equatorial overturning circulation cell. Our results demonstrate that the Kenyan coral radiocarbon record is responding to a western boundary limb of this cell, similar to that observed in other subtropical oceans. Therefore, while the majority of cross-equatorial transport is in the interior and eastern basin of the Indian Ocean, our results argue that the Somali Current is a distinct pathway for inter-hemispheric water mass exchange

Curriculum Making as the Enactment of Dwelling in Places

This article uses an account of dwelling to interrogate the concept of curriculum making. Tim Ingold's use of dwelling to understand culture is productive here because of his implicit and explicit interest in intergenerational learning. His account of dwelling rests on a foundational ontological claim-that mental construction and representation are not the basis upon which we live in the world-which is very challenging for the kinds of curriculum making with which many educators are now familiar. It undermines assumptions of propositional knowledge and of the use of mental schemas to communicate and share. At the level of critique, then, dwelling destabilizes contemporary ideas of curriculum as textual, pre-specified content for transmission or pre-defined objectives or standardized activity. The positive claims of dwelling are equally challenging, for these are that the world is a domain of relational entanglement in which an organism can be no more than a point of growth for an emergent ‘environment', and meaning only inheres in these relations. The paper articulates how differentiation (of learner, salient meanings, knowledge, skill and place) are possible in such an ontology, and how curriculum making can be understood from this perspective as being the remaking of relationships between these

Remembrances of Steve Ellmann, Still Present

In Memoriam: Steven Ellman

Nitration of Hsp90 induces cell death

Oxidative stress is a widely recognized cause of cell death associated with neurodegeneration, inflammation, and aging. Tyrosine nitration in these conditions has been reported extensively, but whether tyrosine nitration is a marker or plays a role in the cell-death processes was unknown. Here, we show that nitration of a single tyrosine residue on a small proportion of 90-kDa heat-shock protein (Hsp90), is sufficient to induce motor neuron death by the P2X7 receptor-dependent activation of the Fas pathway. Nitrotyrosine at position 33 or 56 stimulates a toxic gain of function that turns Hsp90 into a toxic protein. Using an antibody that recognizes the nitrated Hsp90, we found immunoreactivity in motor neurons of patients with amyotrophic lateral sclerosis, in an animal model of amyotrophic lateral sclerosis, and after experimental spinal cord injury. Our findings reveal that cell death can be triggered by nitration of a single protein and highlight nitrated Hsp90 as a potential target for the development of effective therapies for a large number of pathologies