25,733 research outputs found
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
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
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
VIP: Finding Important People in Images
People preserve memories of events such as birthdays, weddings, or vacations
by capturing photos, often depicting groups of people. Invariably, some
individuals in the image are more important than others given the context of
the event. This paper analyzes the concept of the importance of individuals in
group photographs. We address two specific questions -- Given an image, who are
the most important individuals in it? Given multiple images of a person, which
image depicts the person in the most important role? We introduce a measure of
importance of people in images and investigate the correlation between
importance and visual saliency. We find that not only can we automatically
predict the importance of people from purely visual cues, incorporating this
predicted importance results in significant improvement in applications such as
im2text (generating sentences that describe images of groups of people)
Calculation of complex DNA damage induced by ions
This paper is devoted to the analysis of the complex damage of DNA irradiated
by ions. The analysis and assessment of complex damage is important because
cells in which it occurs are less likely to survive because the DNA repair
mechanisms may not be sufficiently effective. We studied the flux of secondary
electrons through the surface of nucleosomes and calculated the radial dose and
the distribution of clustered damage around the ion's track. The calculated
radial dose distribution is compared to simulations. The radial distribution of
the complex damage is found to be different from that of the dose. Comparison
with experiments may solve the question of what is more lethal for the cell,
damage complexity or absorbed energy. We suggest a way to calculate the
probability of cell death based on the complexity of the damage. This work is
done within the framework of the phenomenon-based multiscale approach to
radiation damage by ions.Comment: 8 pages, 7 figure
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