Novel genetic loci associated with hippocampal volume

The hippocampal formation is a brain structure integrally involved in episodic memory, spatial navigation, cognition and stress responsiveness. Structural abnormalities in hippocampal volume and shape are found in several common neuropsychiatric disorders. To identify the genetic underpinnings of hippocampal structure here we perform a genome-wide association study (GWAS) of 33,536 individuals and discover six independent loci significantly associated with hippocampal volume, four of them novel. Of the novel loci, three lie within genes (ASTN2, DPP4 and MAST4) and one is found 200 kb upstream of SHH. A hippocampal subfield analysis shows that a locus within the MSRB3 gene shows evidence of a localized effect along the dentate gyrus, subiculum, CA1 and fissure. Further, we show that genetic variants associated with decreased hippocampal volume are also associated with increased risk for Alzheimer's disease (rg =-0.155). Our findings suggest novel biological pathways through which human genetic variation influences hippocampal volume and risk for neuropsychiatric illness

A Science Plan for a Summer Marginal Ice Zone Experiment in the Fram Strait/Greenland Sea: 1984

This document describes a plan for a mesoscalel experimen to study the physical processes by which ice, water and atmosphere interact in the outermost parts of a polar icefield, the region known as the marginal ice zone (MIZ). During the last two decades a series of large projects culminating in the Arctic lee Dynamics Joint Experiment (AIDJEX, Pritchard 1980) yielded considerable understanding of the growth, motion and decay of sea ice in the interior of the Arctic Ocean. With these experiments concluded, and coupled nonlinear sea ice dynamic- thermodynamic models in hand (Hibler 1979, Coon 1980), attention shifted to the problem of understanding the processes which occur near the open ocean boundaries of polar icefields, and which determine the advance and retreat of the sea ice edge. The exchanges which take place in this zone affect hemispheric climate and have a significant effect on naval operation and commercial fisheries