Characterization and use of an optical fiber interferometer for measurement of the electric wind

An optical fiber interferometer of the Mach-Zehnder type has proved to be a convenient and accurate method for measuring the electric wind in the active region of a corona discharge. The technique relies on the cooling effect of the wind on a small heated region of one arm of the interferometer, which has been remotely heated with an infrared CO(2) laser beam. Wind speeds of up to 5.5 m s(-1) have been measured near the generation region, and by the use of a mesh electrode, the wind has been detected on the axis up to 0.5 m away from the gap. A number of characterization experiments that show the interferometer to be a useful diagnostic tool in the quantitative analysis of the CO(2) laser beam have also been carried out, and good agreement between experimental results and theoretical calculations based on a simple heat-power balance equation for the fiber exists.     

Parametric study of the absorption cross section for a moderately conducting thin cylinder

Asystem has been developed to measure the absorption cross section for a single carbon fiber at 35 GHz as a functio of length, orientation, and diameter. Typical lengths of the fibers considered ranged from 1 to 20 mm, and diameters ranged from 3 to 8 μm. The results were compared with the modified integra equation calculations of Waterman and Pedersen that describe the scattering and absorption behavior for a wire of finite length and conductivity. Good agreement was found for all lengths, orientations, and diameters studied.     

Partially coherent image formation with x-ray microscopes

Image formation with partially coherent radiation is evaluated with the Hopkins formula and then applied to x-ray microscopy. Image characteristics expected from instruments with circular and annular pupils in partially coherent conditions are considered for two-point objects and a knife-edge object. The theoretically expected values for image characteristics that are easy accessible by an experiment, such as the width of a knife edge, are given for various x-ray microscopes.     

Fiducial markers for increasing the versatility of optical correlation in the measurement of faults on integrated-circuit wafers

A microscope-coherent optical processor is used for the measurement of the registration errors on integrated-circuit wafers. The measurements are obtained from the optical correlation of wafers with reference wafer patterns by use of matched spatial filters. Previously, the intricate pattern of the active circuit area of wafers has been used in the correlation process, and a new matched spatial filter had to be created for each different integrated circuit. Here, the results of using comparatively plain fiducial markers on a wafer for the registration-error measurement are presented, and these show that the measurements can be made independent of the design of the integrated circuit while maintaining the advantages and accuracy of the optical correlation technique.     

An autonomous module for supporting mice during spaceflight

The Animal Module for Autonomous space Support (A-MASS) was developed to enable 30-day spaceflight for mice on the first Commercial Experiment Transporter mission. Because space hardware did not previously exist to support mice without astronaut intervention, the A-MASS presented considerable technical and animal care challenges. The technical challenges included maintaining a 42.5l payload volume and 20-g structural conformance while providing 30 days of autonomous mouse support. Sensors, video, a pressurized oxygen supply system and an internal data logging system were incorporated. The A-MASS met NIH guidelines for temperature, humidity, food and water access, oxygen supply, air quality and odor control. These technical and animal care challenges, along with power and mass constraints, were addressed using a novel design which ensures a fresh food and water supply, a clean view path into the cage for the camera system, and removal of the wastes from the air supply. The payload was successfully tested in an enclosed chamber and passed animal health, vibrational, mechanical, and electrical tests. The physiological, tactical and animal support information gathered will be applicable to the development of mouse support modules for the Shuttle Middeck and Space Station Freedom Express Rack environments.     

Some mental impediments in the collaboration of social pedagogy and adolescent psychiatry

Different mental attitudes sometimes hinder needed synergy. "Sozialp?dagigik" is based on humanities, unlike psychiatry, which is just as well due to the sciences of neuropsychology, neurology, finally biology. These "induce" their theories from empiricism, those "deduce" from principles. What might stand a good chance for completion, ever so often goes bad to merely distinguishing self-assessment. The author of this contribution is occupied in introducing students of "social-pedagogics" to the problems, and to the ways and difficulties of treatment, especially in child and adolescent psychiatry, showing them at an associate hospital. It seems to be successful and gaining more agreement.     

Spatial performance with perspective displays as a function of computer graphics eyepoint elevation and geometric field of view

The purpose of this study was to investigate the effect of varying the elevation of the computer graphics eyepoint and the geometric field of view on judgements of spatial information using a stereoscopic perspective display. Twelve subjects judged the elevation and azimuth angle separating two computer-generated objects viewed using an eyepoint elevation that ranged between -15 degrees and 45 degrees and a geometric field of view that ranged between 40 degrees and 80 degrees. The results of the study indicated that judgements of elevation were affected by the compression of the vertical axis resulting from the raised eyepoint elevation. Furthermore, azimuth judgements were influenced by both the eyepoint elevation and the geometric field of view. Implications of the results for the design of displays and for spatial performance using stereoscopic displays are discussed.     

Effectiveness of slow release L-DOPA/benserazide in treatment of end-of-dose akinesia in Parkinson disease

In an open label study 63 patients with idiopathic Parkinson's disease suffering from end-of-dose akinesia were switched from a treatment with a L-DOPA standard formulation to a combined therapy of L-DOPA standard in the morning and L-DOPA slow release (levodopa, benserazide, Madopar Depot) at the remaining single doses. Substitution of L-DOPA standard by L-DOPA slow release took on average 2-4 weeks. Patients were subsequently treated for 6 months. Due to a lower bioavailability of the slow release formulation--the latter is based on the "hydrodynamically balanced system" (HBS)--, the patients remained initially on their time schedule of drug intake but received a higher dose of L-DOPA slow release compared to the preceding L-DOPA standard therapy. In 20 centers 37 men and 26 women were included into the study. 27 males and 20 females completed the 6 month treatment period. Before switching, the patients received 438 +/- 213 mg a day L-DOPA standard, after conversion, the average dose was 617 +/- 323 mg L-DOPA slow release and 107 +/- 95 mg L-DOPA standard a day. Fluctuations during the day and at night which were rated according to a newly developed clinical 5-point rating scale were significantly improved by the treatment regimen from 2.8 +/- 0.9 to 1.4 +/- 1.2. Additionally, parkinsonian symptoms were significantly reduced during the ON-phase as there was a significant decrease of the Webster rating score from 12.0 +/- 4.6 to 7.1 +/- 4.0. Quality of life as measured by subjective ratings of the patients improved. The tolerability of the new formulation of L-DOPA was rated to be good in 51.1% and very good in 48.9%. The results of this open label study suggest that the combination of L-DOPA standard in the morning and L-DOPA slow release formulation at the following time points can be an efficient therapy in parkinsonian patients who suffer form L-DOPA related end-of-dose motor akinesia.     

New strategies for intraoperative myocardial protection

In the past, most strategies for intraoperative myocardial protection were developed in models using nondiseased adult hearts from various animal species. In the clinical setting, however, myocardial status in cardiac patients may be quite different and there is a need to adapt our current protective strategies to the actual pathophysiological status of the heart. In the immature heart as well as in the senescent heart, current protective techniques have been shown to be deficient and further research is required. New insights have been gained into the pathophysiological processes underlying chronic ischemic left ventricular dysfunction in the "hibernating" myocardium. It has been shown that viability in these hearts is associated with subcellular alterations related to dedifferentiation of the myocytes. This finding explains the delayed recovery in function of these hearts after revascularization and the need for intraoperative protective strategies focusing on the prevention of stunning in the nonhibernating segments. Tepid continuous retrograde blood cardioplegia is suggested as the optimal technique. Unraveling the mechanisms of preconditioning in the heart and understanding endogenous myocardial protection may provide clues for novel cardioprotective techniques. Adenosine itself may be used as an adjunct to cardioplegia, and treatment with adenosine regulating agents or nucleoside transport inhibitors shows promising results. Like adenosine, other hyperpolarizing agents (potassium-channel openers) are suggested for arrest of the heart instead of the depolarizing agents commonly used in cardioplegia. Finally, the role of Na(+)-H+ exchange in the development of ischemic and postischemic injury has become more clear. By the use of a new selective Na(+)-H+ exchange inhibitor, postischemic contracture can be dramatically reduced and contractility improved. This opens prospective approaches in emergency coronary bypass surgery for evolving myocardial infarction.