BH3-only Protein Noxa Is a Mediator of Hypoxic Cell Death Induced by Hypoxia-inducible Factor 1α

Hypoxia is a common cause of cell death and is implicated in many disease processes including stroke and chronic degenerative disorders. In response to hypoxia, cells express a variety of genes, which allow adaptation to altered metabolic demands, decreased oxygen demands, and the removal of irreversibly damaged cells. Using polymerase chain reaction–based suppression subtractive hybridization to find genes that are differentially expressed in hypoxia, we identified the BH3-only Bcl-2 family protein Noxa. Noxa is a candidate molecule mediating p53-induced apoptosis. We show that Noxa promoter responds directly to hypoxia via hypoxia-inducible factor (HIF)-1α. Suppression of Noxa expression by antisense oligonucleotides rescued cells from hypoxia-induced cell death and decreased infarction volumes in an animal model of ischemia. Further, we show that reactive oxygen species and resultant cytochrome c release participate in Noxa-mediated hypoxic cell death. Altogether, our results show that Noxa is induced by HIF-1α and mediates hypoxic cell death

A study of the causal relationship between IT governance inhibitors and its success in Korea enterprises

노트 : Proceedings of the 41st Hawaii International Conference on System Sciences - 2008 행사명 : 41st Hawaii International Conference on System Sc

A New Practical Identity-Based Encryption System

We present a new practical Identity-Based Encryption (IBE) system that can be another candidate for standard IBE techniques. Our construction is based on a new framework for realizing an IBE trapdoor from pairing-based groups, which is motivated from the `two equation\u27 revocation technique suggested by Lewko, Sahai, and Waters. The new framework enables our IBE system to achieve a tight security reduction to the Decision Bilinear Diffie-Hellman assumption. Due to its the tightness, our system can take as input the shorter size of security parameters than the previous practical BF, SK, and BB$_{1}$ systems, which provides better efficiency to our system in terms of computational cost. With appropriate parametrization at 80-bit security level (considering security loss), our IBE system can obtain 11 times faster decryption than the previous ones and 77 times faster encryption than the BF system. We prove that our system is fully secure against chosen ciphertext attacks in the random oracle model. From computational variant of Naor\u27s observation, we can also suggest a new signature scheme that features a tight security reduction to the Computational Diffie-Hellman assumption and provides strong unforgeability simultaneously

The Analysis of Antecedents for the Video Telephony Service Adoption: From the Value-Based Perspective

Korean Telecommunications Industry has a large scale market and boasts on high service quality and high technologies enough to provide the Video Telephony Service (VTS) satisfactorily. For many years, Korean telephone companies have been investing enormous sums to advertise their services widely and to allow their customers to change their cell phones for the third-generation (3G) devices indispensable for the service. However, despite their efforts, the VTS adoption rate in Korea is very low and it seems that customers seldom feel the necessity to use. From this viewpoint, it becomes necessary to find the antecedents influencing the intention to use for the VTS empirically. For this purpose, we proposed several hypotheses from the perspective of the Value-based Adoption Model (VAM). VAM is a conceptual model suggested to overcome some limitations of the Technology Acceptance Model (TAM) in explaining the adoption of new Information and Communication Technology (ICT) such as Mobile Internet where customers play the role of service consumer rather than simply technology users. We conducted a survey on 125 samples and found that customers perceive the value of VTS when they can recognize the service is functionally useful (Perceived Usefulness) and when they feel they can put themselves forward by using it (Self-Expression). On the other hand, the other factors including Technical Complexity, Privacy Concern and Perceived Price (Fee) don’t have statistically significant influences on the Perceived Value of VTS