Late Quaternary tephrostratigraphy, Ahklun Mountains, SW Alaska

Radiocarbon-dated sediment cores from six lakes in the Ahklun Mountains, south-western Alaska, were used to interpolate the ages of late Quaternary tephra beds ranging in age from 25.4 to 0.4ka. The lakes are located downwind of the Aleutian Arc and Alaska Peninsula volcanoes in the northern Bristol Bay area between 159° and 161°W at around 60°N. Sedimentation-rate age models for each lake were based on a published spline-fit procedure that uses Monte Carlo simulation to determine age model uncertainty. In all, 62 C ages were used to construct the six age models, including 23 ages presented here for the first time. The age model from Lone Spruce Pond is based on 18 ages, and is currently the best-resolved Holocene age model available from the region, with an average 2s age uncertainty of about±109 years over the past 14.5ka. The sedimentary sequence from Lone Spruce Pond contains seven tephra beds, more than previously found in any other lake in the area. Of the 26 radiocarbon-dated tephra beds at the six lakes and from a soil pit, seven are correlated between two or more sites based on their ages. The major-element geochemistry of glass shards from most of these tephra beds supports the age-based correlations. The remaining tephra beds appear to be present at only one site based on their unique geochemistry or age. The 5.8ka tephra is similar to the widespread Aniakchak tephra [3.7±0.2 (1s) ka], but can be distinguished conclusively based on its trace-element geochemistry. The 3.1 and 0.4ka tephras have glass major- and trace-element geochemical compositions indistinguishable from prominent Aniakchak tephra, and might represent redeposited beds. Only two tephra beds are found in all lakes: the Aniakchak tephra (3.7±0.2ka) and Tephra B (6.1±0.3ka). The tephra beds can be used as chronostratigraphic markers for other sedimentary sequences in the region, including cores from Cascade and Sunday lakes, which were previously undated and were analyzed in this study to correlate with the new regional tephrostratigraphy. © 2012 John Wiley & Sons, Ltd.

Genome-wide association analysis identifies 13 new risk loci for schizophrenia

Schizophrenia is an idiopathic mental disorder with a heritable component and a substantial public health impact. We conducted a multi-stage genome-wide association study (GWAS) for schizophrenia beginning with a Swedish national sample (5,001 cases and 6,243 controls) followed by meta-analysis with previous schizophrenia GWAS (8,832 cases and 12,067 controls) and finally by replication of SNPs in 168 genomic regions in independent samples (7,413 cases, 19,762 controls and 581 parent-offspring trios). We identified 22 loci associated at genome-wide significance; 13 of these are new, and 1 was previously implicated in bipolar disorder. Examination of candidate genes at these loci suggests the involvement of neuronal calcium signaling. We estimate that 8,300 independent, mostly common SNPs (95% credible interval of 6,300-10,200 SNPs) contribute to risk for schizophrenia and that these collectively account for at least 32% of the variance in liability. Common genetic variation has an important role in the etiology of schizophrenia, and larger studies will allow more detailed understanding of this disorder.

John Rich as Opera Patron

This article traces the sustained support that theatre manager John Rich offered to operatic endeavours in 18th-century London. Rich effectively entered the contemporary discourse regarding the valid definition of opera through the kinds of works he supported, and also through the prefatory comments to two works staged at his theatre.

Development and assessment of a robust optimization metric for WAMPAC modeling

A PMU based WAMS is to be placed on a weakly coupled section of distribution grid, with high levels of distributed generation. In anticipation of PMU data a Siemens PSS/E model of the electrical environment has been used to return similar data to that expected from the WAMS. This data is then used to create a metric that reflects optimization, control and protection in the region. System states are iterated through with the most desirable one returning the lowest optimization metric, this state is assessed against the one returned by PSS/E under normal circumstances. This paper investigates the circumstances that trigger SPS in the region, through varying generation between 0 and 110% and compromising the network through line loss under summer minimum and winter maximum conditions. It is found that the optimized state can generally tolerate an additional 2 MW of generation (3% of total) before encroaching the same thresholds and in one instance moves the triggering to 100% of generation output.

Race, space and politics in Mid-Victorian Ireland: the ethnologies of Abraham Hume and John McElheran

There has been much scholarly debate about the significance and influence of racialist thinking in the political and cultural history of nineteenth-century Ireland. With reference to that ongoing historiographical discussion, this paper considers the racial geographies and opposing political motivations of two Irish ethnologists, Abraham Hume and John McElheran, using their racialist regimes to query some of the common assumptions that have informed disagreements over the role and reach of racial typecasting in mid-nineteenth-century Ireland. As well as examining in detail the racial imaginaries promulgated by Hume and McElheran, the paper also argues for the importance of situating racialist discourse in the spaces in which it was communicated and contested. Further, in highlighting the ways in which Hume and McElheran collapsed together race, class and religion, the paper troubles the utility of a crisp analytical distinction between those disputed categories.