Independent Orbiter Assessment (IOA): Assessment of the data processing system FMEA/CIL

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the Data Processing System (DPS) hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the NASA FMEA/CIL baseline with proposed Post 51-L updates included. A resolution of each discrepancy from the comparison is provided through additional analysis as required. The results of that comparison is documented for the Orbiter DPS hardware

A head restraint device for vestibular studies

Head restraint device based on vacuum bladder technique for use in vestibular studie

Independent Orbiter Assessment (IOA): Analysis of the DPS subsystem

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis/Critical Items List (FMEA/CIL) is presented. The IOA approach features a top-down analysis of the hardware to independently determine failure modes, criticality, and potential critical items. The independent analysis results corresponding to the Orbiter Data Processing System (DPS) hardware are documented. The DPS hardware is required for performing critical functions of data acquisition, data manipulation, data display, and data transfer throughout the Orbiter. Specifically, the DPS hardware consists of the following components: Multiplexer/Demultiplexer (MDM); General Purpose Computer (GPC); Multifunction CRT Display System (MCDS); Data Buses and Data Bus Couplers (DBC); Data Bus Isolation Amplifiers (DBIA); Mass Memory Unit (MMU); and Engine Interface Unit (EIU). The IOA analysis process utilized available DPS hardware drawings and schematics for defining hardware assemblies, components, and hardware items. Each level of hardware was evaluated and analyzed for possible failure modes and effects. Criticality was assigned based upon the severity of the effect for each failure mode. Due to the extensive redundancy built into the DPS the number of critical items are few. Those identified resulted from premature operation and erroneous output of the GPCs

Bone Morphogenetic Protein-Based Therapeutic Approaches.

Bone morphogenetic proteins (BMPs) constitute the largest subdivision of the transforming growth factor (TGF)-β family of ligands and exert most of their effects through the canonical effectors Smad1, 5, and 8. Appropriate regulation of BMP signaling is critical for the development and homeostasis of numerous human organ systems. Aberrations in BMP pathways or their regulation are increasingly associated with diverse human pathologies, and there is an urgent and growing need to develop effective approaches to modulate BMP signaling in the clinic. In this review, we provide a wide perspective on diseases and/or conditions associated with dysregulated BMP signal transduction, outline the current strategies available to modulate BMP pathways, highlight emerging second-generation technologies, and postulate prospective avenues for future investigation

Effects of elevated atmospheric carbon dioxide concentrations on water and acid requirements of soybeans grown in a recirculating hydroponic system

Establishing mass budgets of various crop needs, i.e. water and nutrients, in different environments is essential for the Controlled Ecological Life Support System (CELSS). The effects of CO2 (500 and 1000 umol mol (exp -1)) on water and acid use (for pH control) by soybeans in a recirculating hydroponic system were examined. Plants of cvs. McCall and Pixie were grown for 90 days using the nutrient film technique (NFT) and a nitrate based nutrient solution. System acid use for both CO2 levels peaked near 4 weeks during a phase of rapid vegetative growth, but acid use decreased more rapidly under 500 compared to 1000 umol mol (exp GR) CO2. Total system water use by 500 and 1000 umol mol (exp -1) plants was similar, leaving off at 5 weeks and declining as plants senesced (ca. 9 weeks). However, single leaf transpiration rates were consistently lower at 1000 umol mol (exp -1). The data suggest that high CO2 concentrations increase system acid (and nutrient) use because of increased vegetative growth, which in turn negates the benefit of reduced water use (lower transpiration rates) per unit leaf area

Activin and BMP Signaling Mechanics in Myogenic Cells

The Activin and BMP signaling pathways exert reciprocal effects on myogenesis and skeletal muscle regeneration after injury. Signal transduction in both pathways is mediated by ligand- induced activation of transcriptional regulators called SMAD proteins, with Activins leading to phosphorylation of SMAD2/3 and BMPs leading to phosphorylation of SMAD1/5/8. These ligands bind to their own type I receptors but can also compete for shared type II receptors (ACVR2A and/or ACVR2B). However, it is unclear how these pathways interact in skeletal muscle progenitor cells. To address this deficiency, we investigated the effects of the ligands BMP2 and Activin-A on C2C12 cells, which are an immortalized mouse myoblast cell line with myogenic potential, using a sequence of pre-treatment and co-treatment assays followed by western blot analyses to examine the activation level of their respective SMAD proteins. As expected, treatment with exogenous BMP2 or Activin A led to phosphorylation of SMAD1/5/8 and SMAD2/3, respectively. Moreover, pre-treatment of C2C12 cells with Activin-A before BMP2 delivery resulted in an attenuated phosphorylation of SMAD1/5/8; this effect seems to be specific to Activin ligands, though, since the converse relationship was not observed with respect to phosphorylation of SMAD2/3. Interestingly, seemingly contradictory results were observed when Activin-A and BMP2 were delivered to C2C12 cells simultaneously; this co-treatment scenario results in a higher level of SMAD1/5/8 phosphorylation than delivery of either ligand alone. Ongoing experiments seek to elucidate the mechanism(s) impacting the cellular responses under sequential versus simultaneous activation by Activin and BMP ligands. A better understanding of these mechanisms could lead to novel therapeutic strategies for regeneration of skeletal muscle tissue after injury

New Technologies In Solar Energy Conversion -An Overview

Useful sources of solar energy, besides the direct rays of the sun, include energy stored in the oceans, the winds, elevated waters and biological materials. Systems for putting any of these forms of solar energy to work for us require economical means for 1) energy conversion 2) energy storage and 3) the concentration of energy in space and time to deliver the necessary sustained high power levels required for significant and productive end use. Technological challenges exist in all three of these areas of need. In this paper the authors describe some of the specific needs and review the status of technology in five developing areas of solar conversion: solar thermal, photovoltaic, ocean thermal gradient, wind and the generation of fuels