Ten Year Performance Evaluation of a Field-Scale Zero-Valent Iron Permeable Reactive Barrier Installed to Remediate Trichloroethene Contaminated Groundwater

The Monkstown Fe0 PRB, Europe’s oldest commercially installed PRB, had been treating trichloroethene (TCE) contaminated groundwater for about 10 years on the Nortel Network site in Northern Ireland when cores were collected in December, 2006. Groundwater data from 2001-2006 indicated that TCE is being remediated to below detection limits as the contaminated groundwater flows through the PRB, Ca and Fe carbonates, crystalline and amorphous FeS, and Fe (oxy)hydroxides precipitates are present in the Fe0 filing material within the PRB. A greater variety of minerals are associated with a 1 cm thick slightly cemented crust at the entrance of the Fe0 section of the reactive vessel and the discontinuous cemented Fe0 material directly below it. Also, a greater presence of microbial communities occurred in the upper portion of the PRB compared to the lower section which might be due to less favourable conditions (i.e. high pH, low oxygen) for microbial growth in the lower section of the PRB. Visual estimation suggests that the Fe0 filings in the effluent section of the PRB have life-span of 10+ years compared to the Fe0 filings in the thin influent section of the PRB which may have a life span of only ~2-5 more years. Multi-tracer tests indicated that preferential pathways have formed in this PRB over the 10 years of operation.

Ten years of protein kinase B signalling: a hard Akt to follow

It is ten years since the publication of three papers describing the cloning of a new proto-oncogene serine/threonine kinase termed protein kinase B (PKB)/Akt. Key roles for this protein kinase in cellular processes such as glucose metabolism, cell proliferation, apoptosis, transcription and cell migration are now well established. The explosion of publications involving PKB/Akt in the past three years emphasizes the high level of current interest in this signalling molecule. This review focuses on tracing the characterization of this kinase, through the elucidation of its mechanism of regulation, to its role in regulating physiological and pathophysiological processes,to our current understanding of the biology of PKB/Akt, and prospects for the future.