Nancy A. Willing to \u27Dear Senator,\u27 17 April 1978

Typed letter signed dated 17 April 1978 from Nancy A. Willing, Director of White House Visitors Office, to Dear Senator, re: policies of White House Visitors Office. Attached: typed manuscript entitled Sample of Card the Way It Is to Be Filled Out to Send to the Visitors Office; 2 pages.https://egrove.olemiss.edu/joecorr_h/1094/thumbnail.jp

Axisymmetric pulse recycling and motion in bulk semiconductors

The Kroemer model for the Gunn effect in a circular geometry (Corbino disks) has been numerically solved. The results have been interpreted by means of asymptotic calculations. Above a certain onset dc voltage bias, axisymmetric pulses of the electric field are periodically shed by an inner circular cathode. These pulses decay as they move towards the outer anode, which they may not reach. As a pulse advances, the external current increases continuously until a new pulse is generated. Then the current abruptly decreases, in agreement with existing experimental results. Depending on the bias, more complex patterns with multiple pulse shedding are possible.Comment: 8 pages, 15 figure

An In Vitro Study of the Role of Implant Positioning on Ulnohumeral Articular Contact in Distal Humeral Hemiarthroplasty

© 2017 American Society for Surgery of the Hand Purpose To investigate the effect of implant positioning on ulnohumeral contact using patient-specific distal humeral (DH) implants. Methods Seven reverse-engineered DH implants were manufactured based on computed tomography scans of their osseous geometry. Native ulnae were paired with corresponding native humeri and custom DH implants in a loading apparatus. The ulna was set at 90° of flexion and the humeral component (either native bone or reverse-engineered implant) was positioned from 5° varus to 5° valgus in 2.5° increments under a 100-N compressive load. Contact with the ulna was measured with both the native distal humerus and the reverse-engineered DH implant at all varus-valgus (VV) angles, using a joint casting method. Contact patches were digitized and analyzed in 4 ulnar quadrants. Output variables were contact area and contact pattern. Results Mean contact area of the native articulation was significantly greater than with the distal humeral hemiarthroplasty (DHH) implants across all VV positions. Within the native condition, contact area did not significantly change owing to VV angulation. Within the DHH condition, contact area also did not significantly change owing to VV angulation. Conversely, in the DHH condition, contact pattern did significantly change. Medial ulnar contact pattern was significantly affected by VV angulation. Lateral ulnar contact was variably affected, but generally decreased as well. Conclusions Ulnar contact patterns were changed as a result of VV implant positioning using reverse-engineered DH implants, most notably on the medial aspect of the joint. Implant positioning plays a crucial role in producing contact patterns more like those observed in the native joint. Clinical relevance Recent clinical evidence reports nonsymmetrical ulnar wear after DHH. This work suggests that implant positioning is likely a contributing factor and that more exact implant positioning may lead to better clinical outcomes

New Zealand marine biosecurity: delivering outcomes in a fluid environment

Marine biosecurity, the protection of the marine environment from impacts of non-indigenous species, has a high profile in New Zealand largely associated with a dependence on shipping. The Ministry of Fisheries is the lead agency for marine biosecurity and is tasked with managing the risks posed by pests and non-indigenous marine species. Much like the terrestrial environment, multiple pathways provide ample opportunities for new species to arrive. The Marine Biosecurity Team was established in 1998, and under the Biodiversity package delivered by government, has undertaken an ambitious programme to deliver biosecurity outcomes by reducing the knowledge gaps and establishing management frameworks. A Risk Management Framework aids decision-making and operational planning. Despite significant progress, a number of gaps have been identified in our knowledge base, capability, and capacity that require attention

Evaluation of a computational model to predict elbow range of motion

© 2014 The Author(s). Computer models capable of predicting elbow flexion and extension range of motion (ROM) limits would be useful for assisting surgeons in improving the outcomes of surgical treatment of patients with elbow contractures. A simple and robust computer-based model was developed that predicts elbow joint ROM using bone geometries calculated from computed tomography image data. The model assumes a hinge-like flexion-extension axis, and that elbow passive ROM limits can be based on terminal bony impingement. The model was validated against experimental results with a cadaveric specimen, and was able to predict the flexion and extension limits of the intact joint to 0° and 3°, respectively. The model was also able to predict the flexion and extension limits to 1° and 2°, respectively, when simulated osteophytes were inserted into the joint. Future studies based on this approach will be used for the prediction of elbow flexion-extension ROM in patients with primary osteoarthritis to help identify motion-limiting hypertrophic osteophytes, and will eventually permit real-time computer-assisted navigated excisions