Tax-induced recruitment of TORC family coactivators is required for transcriptional activation of HTLV-I LTR (Young Scientists Award-winning presentation)

Ultrasonic transducers are electromechanical devices that covert electrical inputs (voltage, current) into mechanical outputs (force, velocity) and vice-versa. To completely characterize the relationship between these four parameters in general requires knowledge of all the elements of a 2×2 complex-valued “transduction” matrix as a function of frequency. In the literature it has typically been assumed that to obtain all the elements of this transduction matrix it is necessary to perform a combination of both electrical and mechanical measurements (see Sachse and Hsu [1], for example), which makes such a complete characterization rather difficult and expensive. Here, we will show that, by using an electroacoustic measurement model that completely characterizes an entire ultrasonic measurement system, it is possible in principle to set up a practical measurement method where the complete transduction matrix can be obtained by purely electrical measurements at the electrical port of the transducer. Having a practical procedure to completely characterize an ultrasonic transducer is important since it will allow one to make quantitative estimates of the influence of the transducer properties on an ultrasonic measurement process