Recent studies of the phenylalkylamine binding site in the ␣ 1C subunit of L-type Ca 2؉ channels have revealed three amino acid residues in transmembrane segment IVS6 that are critical for high affinity block and are unique to L-type channels. We have extended this analysis of the phenylalkylamine binding site to amino acid residues in transmembrane segment IIIS6 and the pore region. Twenty-two consecutive amino acid residues in segment IIIS6 were mutated to alanine and the conserved Glu residues in the pore region of each homologous domain were mutated to Gln. Mutant channels were expressed in tsA-201 cells along with the ␤ 1b and ␣ 2 ␦ auxiliary subunits. Assay for block of Ba

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In this paper, agri-food systems are discussed in the context of a set of sociotechnical transitions principles, with a focus on energy, materials and practice elements that have the potential to promote sustainable outcomes across the system. This paper aims to develop an integrated approach for regime analysis, informed by emerging knowledge on socio-technical transitions. The application of the multi-level perspective (MLP) as a heuristic framework to structure descriptions of the multi-dimensional transition contexts of contemporary agri-food regimes is explored. To do this, the paper aims to elaborate the MLP by proposing an integrated means through which complex transition dynamics can be mapped across: (a) energy and material flows and (b) social practices which shape, direct and determine these energy and material flows. This approach is labelled strategic regime mapping (SRM). The paper forwards insights from the development of SRM and discusses the role of strategic mapping of key points across the regime. By combining insight on the conceptualization of dynamic and globally interconnected socio-technical systems with specific observations on contemporary agri-food systems, the paper provides insight into the mapping of transition capacity across agri-food systems, as well as highlighting the significant challenges associated with such an undertaking.

The international radiation biodosimetry community has recently been engaged in activities focused on establishing cooperative networks for biodosimetric triage for radiation emergency scenarios involving mass casualties. To this end, there have been several recent publications in the literature regarding the potential for shared scoring in such an accident or incident. We present details from a medical irradiation case where two independently validated laboratories found very different yields of dicentric chromosome aberrations. The potential reasons for this disparity are discussed, and the actual reason is identified as being the partial-body nature of the radiation exposure combined with differing criteria for metaphase selection. In the context of the recent networking activity, this report is intended to highlight the fact that shared scoring may produce inconsistencies and that further validation of the scoring protocols and experimental techniques may be required before the networks are prepared to deal satisfactorily with a radiological or nuclear emergency. Also, the findings presented here clearly demonstrate the limitations of the dicentric assay for estimating radiation doses after partial-body exposures and bring into question the usefulness of rapid "triage mode" scoring in such exposure scenarios.