Large dynamic range, high resolution optical heterodyne readout for high velocity slip events.

We present a free-space optical displacement sensor for measuring geological slip event displacements within a laboratory setting. This sensor utilizes a fiberized Mach-Zehnder based optical heterodyne system coupled with a digital phase lock loop, providing a large dynamic range (multiple centimeters), high displacement resolution (with an amplitude spectral density of <10-10 m/Hz for frequencies above 100 Hz), and high velocity tracking capabilities (up to 4.96 m/s). This displacement sensor is used to increase the displacement and the time sensitivity for measuring laboratory-scale earthquakes induced in geological samples by using a triaxial compression apparatus. The sensor architecture provides an improved displacement and time resolution for the millisecond-duration slip events, at high containment and loading pressure and high temperatures. Alternatively, the sensor implementation can be used for other non-contact displacement readouts that required high velocity tracking with low noise and large dynamic range sensing. We use 13 high-velocity slip events in Fontainebleau sandstone to show the large dynamic range displacement tracking ability and displacement amplitude spectral densities to demonstrate the optical readout's unique sensing capabilities.

A system to manage records for credentialed providers.

There has been a rapid growth in and evolution of information management to assure appropriate and timely awarding of privileges for credentialed providers. Proprietary software might not meet the needs of a particular facility. In this article, Jackie Walker and William F. Perry describe how, using commercially available database management software, information management can be tailored to the needs of an individual institution and altered as necessary.

Observations on the heat stability and electrophoretic pattern of alkaline phosphatases extracted from various tissues.

Various tissues were extracted with either normal saline or heat inactivated serum (HIS) and the heat stability and electrophoretic migration of the alkaline phosphatase enzymes (AP) of the extracts were compared to the heat stability and electrophoretic properties of serum AP. The electrophoretic pattern of HIS extracts of liver and bone differed from that of saline extracts but the pattern was unaffected if HIS was added to the saline extracts. The heat stabilities of the tissue AP also differed depending on whether they were extracted with saline or HIS. However, serum AP heat stability can help differentiate between liver and bone disease. It is concluded that the comparison of serum and tissue AP heat stabilities or the comparison of serum and tissue AP electrophoretic patterns as criteria for identification of the tissue source of the serum enzyme may be misleading since both these parameters vary, depending on the medium used for extracting the tissue and the extract(s) may contain a mixture of enzymes different from that in serum. It is further concluded from the electrophoretic studies on tissue AP that the increased serum AP in patients with hepatobiliary disease was unlikely to be due to regurgitation of bile but due to increased synthesis and release of alpha 1 and alpha 2 AP isoenzymes from liver, bile ducts or gall bladder. In patients with bone disease the increased serum AP is derived from bone. The source of the serum AP of "normal" subjects may be either liver or vascular tissue or both.

Effectof dialysis on tissue and serum alkaline phosphatase heat stability.

Tissue extracts and serum samples were dialyzed against TRIS buffer and the heat stability of the alkaline phosphatase (AP) was examined before and after dialysis for various periods of time. The effect of adding a mixture of ions or heat inactivated polled serum (HIS) to the dialyzed samples was also investigated. Dialysis of tissue extracts or of serum resulted in an increase in the mean AP heat stability. Addition of the ion mixture to dialyzed bone or liver extracts decreased the AP heat stability. Addition of HIS to these extracts decreased the AP heat stability of dialyzed bone extract but had little effect on dialyzed liver extract. These results are discussed.