A review of flip-chip GaAs circuits, models, interconnections and modelling techniques in use at Marconi

Broadband high frequency systems are increasingly utilising MMIC technology to reduce circuit design uncertainties. At frequencies above 6 GHz the MMIC interconnections become critical, bond wire inductances become significant and bond length variations in the assembly process cause significant performance variation. At Marconi Electronic Systems the benefits of solder bump connections to the MMIC are being explored. These benefits include very low inductance, self-alignment and repeatable connections. The technology is also extremely well suited to automatic and semi-automatic production, making multiple channel systems such as phased arrays more cost-effective. This paper is a review of recent work (2-40 GHz) on solder bumped MMIC circuits and covers broadband flip-chip S-parameter circuit interconnect modelling, thermal modelling of HEMT transistors connected by solder bump arrays. Additional layers to the MMT H40 Foundry process have been specially designed to facilitate solder bump connection

FBI-1 Can Stimulate HIV-1 Tat Activity and Is Targeted to a Novel Subnuclear Domain that Includes the Tat-P-TEFb—containing Nuclear Speckles

FBI-1 is a cellular POZ-domain–containing protein that binds to the HIV-1 LTR and associates with the HIV-1 transactivator protein Tat. Here we show that elevated levels of FBI-1 specifically stimulate Tat activity and that this effect is dependent on the same domain of FBI-1 that mediates Tat-FBI-1 association in vivo. FBI-1 also partially colocalizes with Tat and Tat's cellular cofactor, P-TEFb (Cdk9 and cyclin T1), at the splicing-factor–rich nuclear speckle domain. Further, a less-soluble population of FBI-1 distributes in a novel peripheral-speckle pattern of localization as well as in other nuclear regions. This distribution pattern is dependent on the FBI-1 DNA binding domain, on the presence of cellular DNA, and on active transcription. Taken together, these results suggest that FBI-1 is a cellular factor that preferentially associates with active chromatin and that can specifically stimulate Tat-activated HIV-1 transcription

Evolutionary perspectives on salary dispersion within firms

Behavioral economics, Relative fitness, Egalitarianism, Evolutionary psychology, Anthropology, Trans disciplinary, Compensation, Sex differences, Age, Labor unions, J31, D31, M52, Z10,