We investigated the semantic blocking effect in picture naming and word-picture matching for two nonfluent aphasic patients who show evidence of a deficit in inhibiting verbal representations (M.L. and B.Q), one fluent aphasic patient (K.V.), and neurologically intact control participants. In two picture-naming tasks (Experiments 1A and 1B), M.L. and B.Q, relative to controls, showed a greatly ...

We use a regression-discontinuity design to study the effects of double blocking sixth-grade students in reading and mathematics on their achievement across three years of middle school. To identify the effect of the intervention, we use sharp cutoffs in the test scores used to assign students to double blocking. We find large, positive, and persistent effects of double blocking in reading, but...

We study a variety of image deblocking algorithms for improving quality of visual signals degraded by blocking artifacts from compression. The image improvements afforded by these algorithms is measured using the PSNR, PSNR-B, and SSIM. Rather than relying on PSNR, which correlates poorly with subjective judgment, we propose a new Deblocking quality index that is sensitive to blocking artifacts...

We have investigated the role of adenosine diphosphate (ADP) receptors in the adhesion, activation, and aggregation of platelets perfused over immobilized von Willebrand factor (VWF) under high shear stress. Blocking P2Y(1) prevented stable platelet adhesion and aggregation, indicative of a complete inhibition of alpha(IIb)beta(3) activation, and decreased the duration of transient arrests from...