Seismic anisotropy in the upper mantle beneath continental interiors is generally complicated, with contributions from both the lithosphere and the asthenosphere. Previous studies of SKS splitting beneath the eastern United States have yielded evidence for complex and laterally variable anisotropy, but until the recent arrival of the USArray Transportable Array (TA) the station coverage has been sparse. Here we present SKS splitting measurements at TA stations in eastern North America and compare the measured fast directions with indicators such as absolute plate motion, surface geology, and magnetic lineations. We find few correlations between fast directions and absolute plate motion, except in the northeastern U.S. and southern Canada, where some stations exhibit variations in apparent splitting with backazimuth that would suggest multiple layers of anisotropy. A region of the southeastern U.S. is dominated by null SKS arrivals over a range of backazimuths, consistent with previous work. We document a pattern of fast directions parallel to the Appalachian mountain chain, suggesting a contribution from lithospheric deformation associated with Appalachian orogenesis. Overall, our measurements suggest that upper mantle anisotropy beneath the eastern United States is complex, with likely contributions from both asthenospheric and lithospheric anisotropy in many regions.
No standardised endpoint definitions exist to aid the design of trials that compare antibiotic therapies for bloodstream infection (BSI). We reviewed endpoints used in contemporary BSI studies and defined consensus endpoints using a modified Delphi process. Prospective studies, randomised trials or registered protocols comparing antibiotic therapies for BSI, published from 2005 to 2016, were reviewed. Different primary and secondary endpoints were defined for pilot (small-scale studies designed to evaluate protocol design, feasibility and implementation) and definitive trials (larger-scale studies designed to test hypotheses and influence clinical practice), as well as for Staphylococcus aureus and Gram-negative BSI. For pilot studies of S.
Bloodstream infection was associated with poor long-term outcome measured at one year when compared to matched controls. More evidence is needed to determine if this association is causative.
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