The transcriptional activation of GRP78, which controls multiple signaling pathways of the unfolded protein response, has been used extensively as an indicator for the onset of endoplasmic reticulum stress in tissue culture systems. Here we investigate the mechanism of Grp78 induction during mouse embryonic development. Our results reveal that in transgenic mouse models, reporter gene activity driven by the Grp78 promoter is strongly activated during early embryonic heart development but subsides in later stages. This activation is strictly dependent on a 100-base pair region of the Grp78 promoter containing the endoplasmic reticulum stress response elements (ERSEs). Previous studies establish that endoplasmic reticulum stress induces in vivo binding of YY1 and the nuclear form of ATF6 to the ERSE. Since the expression of YY1 as well as ATF6 is ubiquitous in the mouse embryo, activation of the Grp78 promoter in the early embryonic heart may involve a specific mechanism. Here we report that GATA-4, a transcription factor essential for heart development, binds to the Grp78 promoter in vivo and activates the ERSE, which does not contain a consensus GATA binding site. GATA-4 cooperatively activates the Grp78 promoter with YY1, and the DNA binding domain of YY1 is necessary and sufficient for this cooperation. In addition, GATA-4 activation of the Grp78 promoter is enhanced by the nuclear form of ATF6, and this synergy is further potentiated by YY1. These results suggest that during early heart organogenesis, Grp78 can be activated through cooperation between the cell type-specific transcription factors and ERSE-binding factors.
Multichip rriodule technology c a n be used t o dramatically increase t h e capability a n d performance of field programmable gate arrays (FPGAs) and t h e field prograiriiriable s y s t e m s (FP,';) t h a t t h e y are a part of. Aft e r a n analysis of t h e k e y advantages t h a t M(:M technology h a s f o r F P G A s , w e present t h e design of o u r first-generation silicon-on-silicon field programmable multi-chip rriodule ( F P M C M ) , analyze its l i m i t a t i o n s , and present s o m e lessons learned in t h e development process. We conclude w i t h a comparison of M C M -C and MCM-I) technology f o r t h i s application and suggest t h a t t h e case f o r M C M -D f o r F P M C M s i s m o s t compelling w h e n MCM-D i s considered a s a doorwayt o active substrate a n d chip-on-chip technologies.
A 1080p high profile H.264 encoder is designed by the robust reusable silicon IP methodology and fabricated in a 0.13μm CMOS technology with an area of 10 mm 2 and 242mW at 145MHz. Compared to the state-of-the-art design targeted at 720p baseline, this design reduces 53.4% power and 46.7% area through parallelism enhanced throughput and cross stage sharing pipeline.
The heavy memory access of motion estimation (ME) execution consumes significant power and could limit ME execution when the available memory bandwidth (BW) is reduced because of access congestion or changes in the dynamics of the power environment of modern mobile devices. In order to adapt to the changing BW while maintaining the rate-distortion (R-D) performance, this article proposes a novel data BW-scalable algorithm for ME with mobile multimedia chips. The available BW is modeled in a R-D sense and allocated to fit the dynamic contents. The simulation result shows 70% BW savings while keeping equivalent R-D performance compared with H.264 reference software for low-motion CIF-sized video. For high-motion sequences, the result shows our algorithm can better use the available BW to save an average bit rate of up to 13% with up to 0.1-dB PSNR increase for similar BW usage.
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