The Volcker task force on tax reform, part of the President’s Economic Recovery Advisory Board, faces a daunting task that is made materially more difficult by ex ante constraints placed on its purview and recommendations. Broad-based reform proposals seem to be out of the question, and distributional constraints appear to eliminate many serious ideas. Nevertheless, I believe that significant t...

Described is an unusual complication occurring during right-sided cardiac catheterization using a 7F flow-directed balloon catheter. During an attempt to direct the catheter from the main pulmonary artery into the pulmonary wedge position, the tip became entangled in a loop of catheter and knotted. Initially, all attempts to unknot or remove the catheter failed. A movable core guide wire was pa...

During fixation of a femoral neck fracture in a 23-year-old male patient with cannulated screws, a broken guide wire fragment inadvertently advanced through the hip joint and protruded into the pelvis. A second surgical approach was needed to remove the broken fragment from the pelvis. Awareness of such a potentially devastating complication will make surgeons more cautious during implementatio...

The ciliate Paramecium tetraurelia must eliminate approximately 60,000 short sequences from its genome to generate uninterrupted coding sequences in its somatic macronucleus. In this issue of Genes & Development, Baudry and colleagues (pp. 2478-2483) identify the protein that excises these noncoding sequences: a domesticated piggyBac transposase that has been adapted to remove what are likely t...

<p style='text-indent:20px;'>In this article we consider the inverse problem of determining diffusion coefficient heat operator in an unbounded guide using a finite number localized observations. For problem, prove stability estimate any portion adapted Carleman inequality. The measurements are located on boundary larger guide. A special care is required to avoid cross-section boundaries ...

Casual observation suggests that Internet media firms sometimes allow consumers to pay to remove advertisements from a free advertisement-based product. In this paper I characterize when this business model is optimal and analyze its impact on advertising quantity and the distribution of surplus. The optimality of the business model depends on the relation between product quality, the annoyance...