IL-21 has been shown to play an important role in the CD8 T cell response during acute and chronic viral infections. However, the role of IL-21 signaling in the CD4 T cell response to viral infection remains incompletely defined. In a model of infection with vaccinia virus, we show that intrinsic IL-21 signaling on CD4 T cells was critical for the formation of memory CD4 T cells in vivo. We fur...

Comparison of human sequences with the DNA of other mammals is an excellent means of identifying functional elements in the human genome. Here we describe the utility of high-density oligonucleotide arrays as a rapid approach for comparing human sequences with the DNA of multiple species whose sequences are not presently available. High-density arrays representing approximately 22.5 Mb of nonre...

The transition to digital in the TV broadcasting industry is already gradually being performed while the complete digital switchover seems now possible to be accomplished within the near future. This article describes and analyses this phenomenon and the role of MPEG-21 may play in it. MPEG-21 is the ISO/IEC standard currently under development in MPEG (ISO/IEC JTC1/SC29/WG11). Unlike preceding...

The visual system adapts to its environment. Some adaptive changes are detrimental-perception is no longer veridical. Others are beneficial-the ability to discriminate two stimuli improves. The latter may reflect the visual system's ability to zoom-in on the currently relevant properties of the environment. We studied the neural basis of adaptive changes in the middle temporal area (MT) of maca...