Apparatus for assembling space structure

An apparatus for producing a structure in outer space from rolls of prepunched ribbon or sheet material that are transported from the earth to the apparatus located in outer space is described. The apparatus spins the space structure similar to a spider spinning a web utilizing the prepunched ribbon material. The prepunched ribbon material is fed through the apparatus and is shaped into a predetermined channel-shaped configuration. Trusses are punched out of the ribbon and are bent downwardly and attached to a track which normally is a previously laid sheet of material. The size of the overall space structure may be increased by merely attaching an additional roll of sheet material to the apparatus

Structural Framework for Flight: NASA's Role in Development of Advanced Composite Materials for Aircraft and Space Structures

This serves as a source of collated information on Composite Research over the past four decades at NASA Langley Research Center, and is a key reference for readers wishing to grasp the underlying principles and challenges associated with developing and applying advanced composite materials to new aerospace vehicle concepts. Second, it identifies the major obstacles encountered in developing and applying composites on advanced flight vehicles, as well as lessons learned in overcoming these obstacles. Third, it points out current barriers and challenges to further application of composites on future vehicles. This is extremely valuable for steering research in the future, when new breakthroughs in materials or processing science may eliminate/minimize some of the barriers that have traditionally blocked the expanded application of composite to new structural or revolutionary vehicle concepts. Finally, a review of past work and identification of future challenges will hopefully inspire new research opportunities and development of revolutionary materials and structural concepts to revolutionize future flight vehicles

Molecular Beams

Contains reports on four research projects.Lincoln Laboratory, Purchase Order DDL BB-107U. S. Air Force under Contract AF 19(628)-50

Molecular Beams

Contains research objectives and reports on six research projects

An Improved Photometric Calibration of the Sloan Digital Sky Survey Imaging Data

We present an algorithm to photometrically calibrate wide field optical imaging surveys, that simultaneously solves for the calibration parameters and relative stellar fluxes using overlapping observations. The algorithm decouples the problem of "relative" calibrations, from that of "absolute" calibrations; the absolute calibration is reduced to determining a few numbers for the entire survey. We pay special attention to the spatial structure of the calibration errors, allowing one to isolate particular error modes in downstream analyses. Applying this to the Sloan Digital Sky Survey imaging data, we achieve ~1% relative calibration errors across 8500 sq.deg. in griz; the errors are ~2% for the u band. These errors are dominated by unmodelled atmospheric variations at Apache Point Observatory. These calibrations, dubbed "ubercalibration", are now public with SDSS Data Release 6, and will be a part of subsequent SDSS data releases.Comment: 16 pages, 17 figures, matches version accepted in ApJ. These calibrations are available at http://www.sdss.org/dr

Stress in nurses : stress-related affect and its determinants examined over the nursing day

Peer reviewedPostprin

A prospective, randomized trial to compare tacrolimus and prednisone with and without mycophenolate mofetil in patients undergoing renal transplantation: first report.

PURPOSE: Between September 20, 1995 and September 20, 1996, 120 patients were entered into a prospective, randomized trial comparing tacrolimus and prednisone with (61) and without (59) 2 gm. mycophenolate mofetil daily to determine whether mycophenolate mofetil was associated with a lower incidence of rejection. MATERIALS AND METHODS: Mean recipient age plus or minus standard deviation was 50.8+/-14.1 years (range 18.8 to 84.1). Mean donor age was 34.3+/-21.7 years (range 0.01 to 76). Of the donors 18 (15%) were older than 60 years. Mean cold ischemia time was 30.9+/-8.4 hours (range 14.2 to 49). Median followup was 8.6+/-0.5 months. RESULTS: The 6-month actuarial patient survival was 95%, 92% in the double therapy group and 98% in the triple therapy group (not significant). The 6-month actuarial graft survival was 88%, 84% in the double therapy group and 92% in the triple therapy group (not significant). The overall incidence of rejection and steroid resistant rejection was 34.2 and 4.2%, respectively. There was a strong trend toward less rejection in the mycophenolate mofetil group than in the double therapy group (26.2 versus 42.4%). Crossover was common, and was 42.6% from triple to double therapy and 18.6% from double to triple therapy. The reasons for discontinuation of mycophenolate mofetil were gastrointestinal toxicity, primarily diarrhea, or less commonly hematological toxicity, primarily neutropenia or thrombocytopenia. Gastrointestinal toxicity was ameliorated by separating the doses of tacrolimus and mycophenolate mofetil by 2 to 4 hours, and reducing the dose to 1 gm. daily. CONCLUSIONS: Mycophenolate mofetil appears to be a useful third agent with tacrolimus in patients undergoing renal transplantation, and is associated with a reduction in the rate of rejection and a low incidence of steroid resistant rejection. There is a high incidence of gastrointestinal toxicity associated with the 2 gm. daily dose but this complication is relatively straightforward to manage

Evidence of a metabolic memory to early-life dietary restriction in male C57BL/6 mice

<p>Background: Dietary restriction (DR) extends lifespan and induces beneficial metabolic effects in many animals. What is far less clear is whether animals retain a metabolic memory to previous DR exposure, that is, can early-life DR preserve beneficial metabolic effects later in life even after the resumption of ad libitum (AL) feeding. We examined a range of metabolic parameters (body mass, body composition (lean and fat mass), glucose tolerance, fed blood glucose, fasting plasma insulin and insulin-like growth factor 1 (IGF-1), insulin sensitivity) in male C57BL/6 mice dietary switched from DR to AL (DR-AL) at 11 months of age (mid life). The converse switch (AL-DR) was also undertaken at this time. We then compared metabolic parameters of the switched mice to one another and to age-matched mice maintained exclusively on an AL or DR diet from early life (3 months of age) at 1 month, 6 months or 10 months post switch.</p> <p>Results: Male mice dietary switched from AL-DR in mid life adopted the metabolic phenotype of mice exposed to DR from early life, so by the 10-month timepoint the AL-DR mice overlapped significantly with the DR mice in terms of their metabolic phenotype. Those animals switched from DR-AL in mid life showed clear evidence of a glycemic memory, with significantly improved glucose tolerance relative to mice maintained exclusively on AL feeding from early life. This difference in glucose tolerance was still apparent 10 months after the dietary switch, despite body mass, fasting insulin levels and insulin sensitivity all being similar to AL mice at this time.</p> <p>Conclusions: Male C57BL/6 mice retain a long-term glycemic memory of early-life DR, in that glucose tolerance is enhanced in mice switched from DR-AL in mid life, relative to AL mice, even 10 months following the dietary switch. These data therefore indicate that the phenotypic benefits of DR are not completely dissipated following a return to AL feeding. The challenge now is to understand the molecular mechanisms underlying these effects, the time course of these effects and whether similar interventions can confer comparable benefits in humans.</p&gt

Structural Framework for Flight I: NASAs Role in Development of Advanced Composite Materials for Aircraft and Space Structures

This monograph is organized to look at: the successful application of composites on aircraft and space launch vehicles, the role of NASA in enabling these applications for each different class of flight vehicles, and a discussion of the major advancements made in discipline areas of research. In each section, key personnel and selected references are included. These references are intended to provide additional information for technical specialists and others who desire a more in-depth discussion of the contributions. Also in each section, lessons learned and future challenges are highlighted to help guide technical personnel either in the conduct or management of current and future research projects related to advanced composite materials