Laser investigations for payload G-652 prior to filing pre-flight accommodation requirements

In anticipation of presenting the preflight accommodations requirements to NASA for approval, the physics, biology, electronic and chemistry aspects of laser experiments which are most advantageous to the flight are investigated. Preliminary laboratory evaluation was targeted with the realization that future flights of the shuttle may begin in 1988. It is the consensus that during the holding time before the resumption of flights, there is an extra margin of perfection which is possible and that the period prior to flight is advantageous technologically. The problems that can be encountered in space flown laser systems are addressed and the analysis of data is offered as a model for preflight accommodation requirement filing

Exact phase space functional for two-body systems

The determination of the two-body density functional from its one-body density is achieved for Moshinsky's harmonium model, using a phase-space formulation, thereby resolving its phase dilemma. The corresponding sign rules can equivalently be obtained by minimizing the ground-state energy.Comment: Latex, 12 page

Crucifixion and median neuropathy.

Crucifixion as a means of torture and execution was first developed in the 6th century B.C. and remained popular for over 1000 years. Details of the practice, which claimed hundreds of thousands of lives, have intrigued scholars as historical records and archaeological findings from the era are limited. As a result, various aspects of crucifixion, including the type of crosses used, methods of securing victims to crosses, the length of time victims survived on the cross, and the exact mechanisms of death, remain topics of debate. One aspect of crucifixion not previously explored in detail is the characteristic hand posture often depicted in artistic renditions of crucifixion. In this posture, the hand is clenched in a peculiar and characteristic fashion: there is complete failure of flexion of the thumb and index finger with partial failure of flexion of the middle finger. Such a "crucified clench" is depicted across different cultures and from different eras. A review of crucifixion history and techniques, median nerve anatomy and function, and the historical artistic depiction of crucifixion was performed to support the hypothesis that the "crucified clench" results from proximal median neuropathy due to positioning on the cross, rather than from direct trauma of impalement of the hand or wrist

Selection of medication in hospitalised elderly patients with Angina Pectoris

Objective: To evaluate medication changes in hospitalised elderly patients diagnosed with angina pectoris and to compare the selection of medication with evidence-based treatment guidelines. Design: Review of medical notes and patient interview. Setting: St. Luke's Hospital, Malta; January - May 2001. Subjects: 226 patients, aged 60 years or over, with a history of chronic stable angina and a discharge diagnosis of angina. Main outcome measures: Prevalence of use of antiplatelet agents, lipid lowering agents, beta-blockers, calcium channel blockers, nitrates, potassium channel openers and cellular anti-ischaemic agents; presence of co-morbidities, concurrent medication and adverse effects. Results: Prior to discharge, 77% of patients were receiving antiplatelet agents and 27% were receiving lipid lowering agents. The most frequent anti-ischaemic agents used were nitrates (97%) and second-generation dihydropyridine calcium channel blockers (59%). Beta-blockers were used in 31% of patients and non-dihydropyridine calcium channel blockers were used in 4% of patients. Potassium channel openers (nicorandil) and cellular anti-ischaemic agents (trimetazidine) were used in 5% and 19% of patients respectively. Of patients discharged on a single anti-ischaemic agent, 96% were prescribed nitrates, while 64% of those on two agents were prescribed nitrates and dihydropyridine calcium channel blockers. Beta-blockers, nicorandil and trimetazidine were generally used in conjunction with at least two other antiischaemic agents. The major medication changes involved the addition, or increase in dose, of amlodipine and isosorbide dinitrate. The major determinants affecting choice of medication were age and co-morbidities. Conclusion: Medication selection for chronic stable angina was not in accordance with treatment guidelines.peer-reviewe

Development of a linearized unsteady aerodynamic analysis for cascade gust response predictions

A method for predicting the unsteady aerodynamic response of a cascade of airfoils to entropic, vortical, and acoustic gust excitations is being developed. Here, the unsteady flow is regarded as a small perturbation of a nonuniform isentropic and irrotational steady background flow. A splitting technique is used to decompose the linearized unsteady velocity into rotational and irrotational parts leading to equations for the complex amplitudes of the linearized unsteady entropy, rotational velocity, and velocity potential that are coupled only sequentially. The entropic and rotational velocity fluctuations are described by transport equations for which closed-form solutions in terms of the mean-flow drift and stream functions can be determined. The potential fluctuation is described by an inhomogeneous convected wave equation in which the source term depends on the rotational velocity field, and is determined using finite-difference procedures. The analytical and numerical techniques used to determine the linearized unsteady flow are outlined. Results are presented to indicate the status of the solution procedure and to demonstrate the impact of blade geometry and mean blade loading on the aerodynamic response of cascades to vortical gust excitations. The analysis described herein leads to very efficient predictions of cascade unsteady aerodynamic response phenomena making it useful for turbomachinery aeroelastic and aeroacoustic design applications

Single-Step Charge Transport through DNA over Long Distances

Quantum yields for charge transport across adenine tracts of increasing length have been measured by monitoring hole transport in synthetic oligonucleotides between photoexcited 2-aminopurine, a fluorescent analogue of adenine, and N_2-cyclopropyl guanine. Using fluorescence quenching, a measure of hole injection, and hole trapping by the cyclopropyl guanine derivative, we separate the individual contributions of single- and multistep channels to DNA charge transport and find that with 7 or 8 intervening adenines the charge transport is a coherent, single-step process. Moreover, a transition occurs from multistep to single-step charge transport with increasing donor/acceptor separation, opposite to that generally observed in molecular wires. These results establish that coherent transport through DNA occurs preferentially across 10 base pairs, favored by delocalization over a full turn of the helix