Changes in mineral metabolism with immobilization/space flight

Researchers are still unsure of the accuracy of previous bone density measurements of their significance following a period of weightlessness. Rapid technological advances in the measurement of bone density will enable us now to measure bone density accurately at multiple sites in the skeleton with doses of radiation less than that given by a spine x ray. It may not be possible to obtain this type of information before the next series of space flights take place, although the bed-rest model may provide supporting information. Extensive testing of bone density on every astronaut should be performed before and after the space flight. Prevention and treatment can only be undertaken after gathering sufficient baseline information. The use of exercise in preventing bone loss is still highly speculative, but represents a relatively easy approach to the problem in terms of study

Technique for producing bipolar and MOS field effect transistors on a single chip

Several cycles of photoetching, dopant deposition, and drive-in produce selectively-doped regions and semiconductor junctions within a single chip

Accreditation of practice educators: An expectation too far ?

The successful completion of practice placements is essential to the education of occupational therapists; however, ensuring quality placements is challenging for occupational therapy educators. In 2000, Brunel University introduced a revised system of accreditation of practice educators which involved attendance at a course, the supervision of a student and the submission of an essay to be assessed. An audit revealed that a total of 314 therapists attended 15 courses between 2000 and 2003; of these, 243 (77%) subsequently supervised students and 32 (10%) became accredited. The requirement to accredit practice educators, which is a commendable attempt to ensure quality, may paradoxically have been detrimental in achieving quality. The College of Occupational Therapists’ apparent change of emphasis on this topic is welcome

Conceptual techniques for reducing parasitic current gain of lateral pnp transistors

Two techniques have been conceptually proposed as possible means of reducing parasitic beta in lateral p-n-p transistors. One method uses a degenerate substrate and high concentration P /plus/ guard-ring diffusion, another places the base contact at the center of an annular ring structure

Diffusion technique stabilizes resistor values

Reduction of the contact resistance stabilizes the values, over a broad temperature range, of resistors used in linear integrated circuits. This reduction is accomplished by p-plus diffusion under the alloyed aluminum contacts

Low-pressure, chemical vapor deposition polysilicon

The low-pressure chemical vapor deposition (LPCVD) of polycrystalline silicon was investigted. The physical system was described, as was the controlling process parameters and requirements for producing films for use as an integral portion of the solar cell contact system