969 research outputs found
The Twenty-Fifth Amendment and the Establishment of Medical Impairment Panels: Are the Two Safely Compatible?
At least two proposals have been offered by prominent members of the medical community to establish “Medical Impairment Panels” to monitor the health of Presidents of the United States and to facilitate the implementation of relevant Sections of the Twenty-Fifth Amendment. The first discussed in this Article was made by Dr. Herbert Abrams, a now deceased professor of radiology at Stanford University; the second by Dr. Bert Park, a prominent Missouri neurosurgeon. Dr. Abrams and Dr. Park spoke and wrote about their plans frequently over the years. The objective of each proposal was to ensure that the Vice President, the Cabinet, and Congress are informed as to situations when a President might be seriously impaired in terms of carrying out his or her official responsibilities as President of the United States. This Article assesses each proposal in turn
Parameter and configuration study of the DSS-13 antenna drives
The effects of different elevation and azimuth drive configurations on DSS-13 antenna performance are presented as well as a study of gearbox stiffness and motor inertia. Small motor inertia and rigid gearboxes would improve the pointing accuracy up to a certain limit. The limit is imposed by critical values of gearbox stiffness and motor inertia introduced in the article. The critical values depend on the lowest structural frequency of the rate-loop model. The tracking performance can be improved by raising gearbox stiffness to the critical stiffness and reducing motor inertia to the critical inertia. An azimuth drive configuration with four driven wheels was also investigated. For the four-wheel drive configuration in azimuth, the cross-coupling effects are reduced and wind disturbance rejection properties improved. Pointing is improved substantially in the cross-elevation but is relatively unaffected in the elevation direction. More significant improvements can be achieved through either structural redesign (stiffening the structure) or new control algorithms or control concepts, which would eliminate the effect of flexible deformations on the antenna pointing accuracy. Although the study is performed for the DSS-13 antenna, the results can be extended for other DSN antennas
Pain management following new and long-standing spinal cord injury: A pilot study of changes in pain intensity experienced during the day
The aim of the study was to examine variations in pain intensity during the day experienced by patients with spinal cord injury. Fourteen consecutive patients had clinical and demographic data recorded. Pain intensity was recorded using a Graphic Rating Scale (GRS) at 2-3-h intervals. Patients were grouped according to maximum GRS into mild and severe groups at assessment (T0). Changes of one-third in GRS were deemed clinically significant. Eight men and six women (mean age 53.1; SD 16.5; range 28-75) were studied. Seven patients with mild pain tended to deteriorate and those with severe pain to improve. Eight patients demonstrated clinically significant changes. These findings suggest inadequate pain control early morning for one group and increasing pain during the day for another. Use of such simple scores over time would enhance pain rehabilitation for all spinal cord injury patients. Usual GRS reporting may mask clinically significant, treatable, changes in pain
Eigenvalue distributions from a star product approach
We use the well-known isomorphism between operator algebras and function
spaces equipped with a star product to study the asymptotic properties of
certain matrix sequences in which the matrix dimension tends to infinity.
Our approach is based on the coherent states which allow for a
systematic 1/D expansion of the star product. This produces a trace formula for
functions of the matrix sequence elements in the large- limit which includes
higher order (finite-) corrections. From this a variety of analytic results
pertaining to the asymptotic properties of the density of states, eigenstates
and expectation values associated with the matrix sequence follows. It is shown
how new and existing results in the settings of collective spin systems and
orthogonal polynomial sequences can be readily obtained as special cases. In
particular, this approach allows for the calculation of higher order
corrections to the zero distributions of a large class of orthogonal
polynomials.Comment: 25 pages, 8 figure
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