div class=trans-pagebutton class=gotoPage data-page=1Page 1button div class=trans-imageimg data-url=documentfebruary27-2007-vol-104-no9-pp-3017-3668-proceedings-limiteduapapers07pnas10409coverpdfhtmlpage=1 data-page=1 class=trans-thumb lazyload alt=Page 1: February27 2007 vol 104 no9 pp 3017-3668 Proceedings limiteduAPapers07pnas_104_09_coverpdf · February27 2007 vol 104 no9 pp 3017-3668 Proceedings of the National loading=lazy src=data:imagegifbase64iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mM8Uw8AAh0BTZud3BwAAAAASUVORK5CYII= data-src=https:reader036fdocumentsinreader036viewer20220708025f02da497e708231d40654ffhtml5thumbnails1jpg width=140 height=200 divdiv