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Individuals with Prader-Willi syndrome (PWS) have a significant reduction in the number of oxytocin-producing neurons (42%) in the hypothalamic paraventricular nucleus. A number of animal studies and observations of humans show that lesions in this region can produce PWS-like symptoms. Given the evidence for potential oxytocin deficiency, we tested the effects of a course of intranasal oxytocin on PWS symptoms. Thirty individuals with PWS aged 12-30 years participated in an 18-week randomized double-blind placebo-controlled crossover trial. Participants received 8 weeks of oxytocin and 8 weeks of placebo with a minimum 2-week washout period. The first 11 participants received the following oxytocin doses: 24 IU (twice daily) B.I.D for participants 16 years and over and 18 IU B.I.D for participants 13-15 years. The dose was increased for the remaining 18 participants to 40 IU B.I.D for participants 16 years and over and 32 IU B.I.D for 13-15 years. Measures used to assess changes were standardized well-accepted measures, including the Developmental Behavior Checklist-Monitor, Parent, Teacher, and Adult; The Yale-Brown Obsessive Compulsive Scale; The Dykens Hyperphagia questionnaire; Reading The Mind in the Eyes Test; Epworth Sleepiness Scale and the Movie Stills. Oxytocin had little impact on any measure. The only significant difference found between the baseline, oxytocin, and placebo measures was an increase in temper outbursts (P = 0.023) with higher dose oxytocin. The lack of effect of oxytocin nasal spray may reflect the importance of endogenous release of oxytocin in response to exogenous oxytocin.

We present a comprehensive methodology for the simulation of astronomical images from optical survey telescopes. We use a photon Monte Carlo approach to construct images by sampling photons from models of astronomical source populations, and then simulating those photons through the system as they interact with the atmosphere, telescope, and camera. We demonstrate that all physical effects for optical light that determine the shapes, locations, and brightnesses of individual stars and galaxies can be accurately represented in this formalism. By using large scale grid computing, modern processors, and an efficient implementation that can produce 400,000 photons/second, we demonstrate that even very large optical surveys can be now be simulated. We demonstrate that we are able to: 1) construct kilometer scale phase screens necessary for wide-field telescopes, 2) reproduce atmospheric point-spread-function moments using a fast novel hybrid geometric/Fourier technique for non-diffraction limited telescopes, 3) accurately reproduce the expected spot diagrams for complex aspheric optical designs, and 4) recover system effective area predicted from analytic photometry integrals. This new code, the photon simulator (PhoSim), is publicly available. We have implemented the Large Synoptic Survey Telescope (LSST) design, and it can be extended to other telescopes. We expect that because of the comprehensive physics implemented in PhoSim, it will be used by the community to plan future observations, interpret detailed existing observations, and quantify systematics related to various astronomical measurements. Future development and validation by comparisons with real data will continue to improve the fidelity and usability of the code., Comment: Accepted for publication in ApJS; 34 pages, 15 figures

Compressive deformation of isotropic and magnetically wetoriented stoichiometric BaO-6Fe2O3 was studied in creep and press forging modes in the temperature range 1000° to 1200°C at stresses to 6000 psi. Texture development was followed by electron microscopy and measured quantitatively by X-ray diffraction. Magnetic properties of the deformation-textured materials were correlated with changes in texture and grain morphology.

Research work on hydrostatic extrusion at N.E.L. (National Engineering Laboratory) has led to the development of a new process for producing wire. A detailed account is given of machines specially designed to exploit this process of hydrostatic extrusion–drawing mainly on the production of fine copper wire. A small-scale machine was built to confirm the design and for experimental investigations. The success of this preliminary work has led to the construction of a large prototype production machine for commercial applications. The operation and performance of both machines is described and some experimental results given.

Recently many researchers, doctors and instrument companies have begun developing fiber optic laser power delivery systems to accomplish less traumatic surgery or localized irradiation treatment(1). With high power levels, particularly in short bursts, large core fibers are needed to keep the power densities from approaching the damage threshold of silica. Among the many advantages of using optical fibers in laser surgery are the following: microsurgery can be employed, trauma is reduced, access to interior through catheter introduction into vascular, gastrointestinal or respiratory tracts, accurate application of laser power through a flexible lightweight medium to provide localized irradiation as well as surgical removal, and the devices are sterilizable and of moderate cost permitting one-time use (disposable) probes. To achieve these wonderful gains in surgical procedures, the optical fibers must satisfy many optical and mechanical requirements. In use the optical fibers are often required to bend around curves or obstructions to reach the desired application area. Large tensile stresses can occur on the outer radius of the bent fiber, especially with large core fibers, thus high strength fibers are needed. Furthermore, since body fluids are primarily water, stress corrosion and fatigue(2-6) will occur. Therefore, the fibers should have excellent fatigue resistance as well as high strength. This paper further describes these requirements and presents details about an optical fiber which meets these requirements and provides additional very useful properties. These fibers with pure silica cores are called Hard Clad Silica, HCS*, fibers because of their hard bonded cladding over silica structure.

Glass optical fibers have high strengths but under tensile stress and in the presence of aqueous media their strength diminishes through fatigue. Analogous to the semiconductor field, where the electronic properties of chips are protected by passivating coatings, optical fiber strength can be protected by passivating the glass surface. Optical fibers have been developed with such a primary coating/cladding, namely HCSR fibers. These fibers not only have high initial strength but also have excellent fatigue resistance. Their stability to environmental exposure is demonstrated by comparing static fatigue results for exposure to hot water, to boiling water, to steam and to acid/base solutions ranging from 10 M acid to 10 M base to results obtained in ambient water. HCS fibers maintain high static fatigue parameters at elevated temperatures and exposure to these temperatures under low stress does not change their fatigue behavior. Except at the extremes in pH, the static fatigue behavior is unchanged across the acid/base spectrum. This insensitivity to environmental changes and the good fit of the data to the power law model permits the prediction of lifetimes for long term exposure to aqueous environments.© (1987) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Fiber optic devices such as endoscopes have been in general use in the medical field for some time. More recently many doctors and instrument companies have begun developing fiber optic sensing systems and fiber optic laser power delivery systems to accomplish less traumatic surgery or localized irradiation treatment. These new systems are primarily single fibers rather than the coherent fiber bundles used in endoscopes, and thus the effects of the environments the fiber will encounter during fabrication/preparation, and during storage and use, must be considered more thoroughly. The changes arising from sterilization procedures and power delivery, specifically those associated with the fiber's strength and some of the effects related to optical degradation, will be discussed. Often the fiber must meet unique strength, fatigue and optical criteria to provide satisfactory performance in the particular medical application.

Compressive deformation of isotropic and magnetically wetoriented stoichiometric BaO-6Fe2O3 was studied in creep and press forging modes in the temperature range 1000° to 1200°C at stresses to 6000 psi. Texture development was followed by electron microscopy and measured quantitatively by X-ray diffraction. Magnetic properties of the deformation-textured materials were correlated with changes in texture and grain morphology.