Science.gov

Sample records for activation system s9

  1. Cloning, expression, and biochemical characterization of a cold-active GDSL-esterase of a Pseudomonas sp. S9 isolated from Spitsbergen island soil.

    PubMed

    Wicka, Monika; Wanarska, Marta; Krajewska, Ewelina; Pawlak-Szukalska, Anna; Kur, Józef; Cieśliński, Hubert

    2016-01-01

    An estS9 gene, encoding an esterase of the psychrotolerant bacterium Pseudomonas sp. S9 was cloned and sequenced. The deduced sequence revealed a protein of 636 amino acid residues with a molecular mass of 69 kDa. Further amino acid sequence analysis revealed that the EstS9 enzyme contained a G-D-S-L motif centered at a catalytic serine, an N-terminal catalytic domain and a C-terminal autotransporter domain. Two recombinant E. coli strains for production of EstS9N (a two domain enzyme) and EstS9Δ (a one domain enzyme) proteins were constructed, respectively. Both recombinant proteins were successfully produced as inclusion bodies and then purified under denaturing conditions. However, because of the low enzymatic activity of the refolded EstS9Δ protein, only the EstS9N protein was further characterized. The purified and refolded EstS9N protein was active towards short-chain p-nitrophenyl esters (C2-C8), with optimal activity for the butyrate (C4) ester. With p-nitrophenyl butyrate as the substrate, the enzyme displayed optimal activity at 35°C and pH 9.0. Additionally, the EstS9N esterase retained ~90% of its activity from 25-40°C and ~40% of its activity at 10°C. Moreover, analysis of its kinetic parameters (Km, kcat, kcat/Km) toward p-nitrophenyl butyrate determined at 15°C and 25°C confirmed that the EstS9 enzyme is cold-adapted. To the best of our knowledge, EstS9 is the third characterized cold-active GDSL-esterase and the first one confirmed to contain an autotransporter domain characteristic for enzymes secreted by the type V secretion system. PMID:26824293

  2. Comparison of S9 mix and hepatocytes as external metabolizing systems in mammalian cell cultures: cytogenetic effects of 7,12-dimethylbenzanthracene and aflatoxin B1

    SciTech Connect

    Madle, E.; Tiedemann, G.; Madle, S.; Oett, A.; Kaufmann, G.

    1986-01-01

    Two external metabolizing systems, S9 mix from Aroclor-induced rat livers and freshly isolated hepatocytes, were used for activation in cultures of human lymphocytes and V79 cells. 7, 12-dimethylbenzanthracene (DMBA) and aflatoxin B1 (AFB1) were employed as indirectly acting reference mutagens. Mutagenic effects were measured by induction of sister chromatid exchange (SCE). With DMBA, SCE-inducing effects were found to be quite similar after activation by S9 mix and activation by hepatocytes. In contrast with AFB1, S9 activation led to a stronger SCE induction than hepatocyte activation in both target cells. The induction of chromosomal aberrations by AFB1 after activation by the two metabolizing systems was also analyzed in V79 cells. This experiment again revealed that AFB1 was more efficiently activated by S9 mix than by hepatocytes. The experiments have shown that the suitability of hepatocytes as an activation system is not restricted to microbial or eukaryotic point mutation assays, but that hepatocyte metabolism can also be successfully included in cytogenetic tests with short- and long-term cultures of mammalian target cells.

  3. S9-DEPENDENT ACTIVATION OF 1-NITROPYRENE AND 3-NITROFLUORANTHENE IN BACTERIAL MUTAGENICITY ASSAYS

    EPA Science Inventory

    Nitro-substituted polycyclic aromatic hydrocarbons (N02PAH) such as 1-nitropyrene (NP) and 3-nitrofluoranthene (3-NFA), both widespread environmental mutagens, generally require activation by bacterial nitroreductases for maximal expression of their mutagenicity in the Ames Salmo...

  4. The utility of metabolic activation mixtures containing human hepatic post-mitochondrial supernatant (S9) for in vitro genetic toxicity assessment.

    PubMed

    Cox, Julie A; Fellows, Mick D; Hashizume, Tsuneo; White, Paul A

    2016-03-01

    In vitro genotoxicity assessment routinely employs an exogenous metabolic activation mixture to simulate mammalian metabolism. Activation mixtures commonly contain post-mitochondrial liver supernatant (i.e. S9) from chemically induced Sprague Dawley rats. Although Organization for Economic Cooperation and Development (OECD) test guidelines permit the use of other S9 preparations, assessments rarely employ human-derived S9. The objective of this study is to review and evaluate the use of human-derived S9 for in vitro genetic toxicity assessment. All available published genotoxicity assessments employing human S9 were compiled for analysis. To facilitate comparative analyses, additional matched Ames data using induced rat liver S9 were obtained for certain highly cited chemicals. Historical human and induced rat S9 quality control reports from Moltox were obtained and mined for enzyme activity and mutagenic potency data. Additional in vitro micronucleus data were experimentally generated using human and induced rat S9. The metabolic activity of induced rat S9 was found to be higher than human S9, and linked to high mutagenic potency results. This study revealed that human S9 often yields significantly lower Salmonella mutagenic potency values, especially for polycyclic aromatic hydrocarbons, aflatoxin B1 and heterocyclic amines (~3- to 350-fold). Conversely, assessment with human S9 activation yields higher potency for aromatic amines (~2- to 50-fold). Outliers with extremely high mutagenic potency results were observed in the human S9 data. Similar trends were observed in experimentally generated mammalian micronucleus cell assays, however human S9 elicited potent cytotoxicity L5178Y, CHO and TK6 cell lines. Due to the potential for reduced sensitivity and the absence of a link between enzyme activity levels and mutagenic potency, human liver S9 is not recommended for use alone in in vitro genotoxicity screening assays; however, human S9 may be extremely useful in

  5. S9, a Novel Anticancer Agent, Exerts Its Anti-Proliferative Activity by Interfering with Both PI3K-Akt-mTOR Signaling and Microtubule Cytoskeleton

    PubMed Central

    Yang, Chun-hao; Ding, Hua-sheng; Luo, Cheng; Zhang, Yu; Wu, Mao-jiang; Zhang, Xiong-wen; Shen, Xu; Jiang, Hua-liang; Meng, Ling-hua; Ding, Jian

    2009-01-01

    Background Deregulation of the phosphatidylinositol 3-kinases (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway plays a central role in tumor formation and progression, providing validated targets for cancer therapy. S9, a hybrid of α-methylene-γ-lactone and 2-phenyl indole compound, possessed potent activity against this pathway. Methodology/Principal Findings Effects of S9 on PI3K-Akt-mTOR pathway were determined by Western blot, immunofluorescence staining and in vitro kinas assay. The interactions between tubulin and S9 were investigated by polymerization assay, CD, and SPR assay. The potential binding modes between S9 and PI3K, mTOR or tubulin were analyzed by molecular modeling. Anti-tumor activity of S9 was evaluated in tumor cells and in nude mice bearing human cancer xenografts. S9 abrogated EGF-activated PI3K-Akt-mTOR signaling cascade and Akt translocation to cellular membrane in human tumor cells. S9 possessed inhibitory activity against both PI3K and mTOR with little effect on other tested 30 kinases. S9 also completely impeded hyper-phosphorylation of Akt as a feedback of inhibition of mTOR by rapamycin. S9 unexpectedly arrested cells in M phase other than G1 phase, which was distinct from compounds targeting PI3K-Akt-mTOR pathway. Further study revealed that S9 inhibited tubulin polymerization via binding to colchicine-binding site of tubulin and resulted in microtubule disturbance. Molecular modeling indicated that S9 could potentially bind to the kinase domains of PI3K p110α subunit and mTOR, and shared similar hydrophobic interactions with colchicines in the complex with tubulin. Moreover, S9 induced rapid apoptosis in tumor cell, which might reflect a synergistic cooperation between blockade of both PI3-Akt-mTOR signaling and tubulin cytoskeleton. Finally, S9 displayed potent antiproliferative activity in a panel of tumor cells originated from different tissue types including drug-resistant cells and in nude mice bearing human tumor

  6. Effects of surfactants on visible-light-driven photocatalytic hydrogen evolution activities of AgInZn7S9 nanorods

    NASA Astrophysics Data System (ADS)

    Peng, Yong; Shang, Lu; Cao, Yitao; Wang, Qing; Zhao, Yufei; Zhou, Chao; Bian, Tong; Wu, Li-Zhu; Tung, Chen-Ho; Zhang, Tierui

    2015-12-01

    Hydrophobic quaternary AgInZn7S9 nanorods with good visible-light response prepared via high-temperature pyrolysis method were transferred into aqueous solutions by inserting surfactants into their hydrophobic ligand layer for improved photocatalytic H2 production. Photocatalytic H2 evolution tests of AgInZn7S9 nanorods showed that the surfactants on their surfaces have a significant effect on their H2 evolution activities. Specifically, anionic surfactants can promote H2 evolution by enriching protons on the surface of AgInZn7S9 nanorods.

  7. Comparison of rat liver S-9 activity induced with aroclor-1254 and phenobarbital/{beta}-naphthoflavone in microbial and CHO/HGPRT mutation assays

    SciTech Connect

    Xu, J.; Pant, K.

    1995-11-01

    There is an intense interest in alternatives to Aroclor-1254 (PCB) for induction of S-9. Manufacturers no longer produce PCB, and are selling PCB, in stock, with a 30% increase in price. One substitute, a combination of phenobarbital (PB) and {beta}-naphthoflavone ({beta}-NF), has been suggested to be a suitable replacement for PCB. In order to compare the activity of PB/{beta}-NF-induced S-9 with PCB-induced S-9, the two kinds of S-9 were prepared and tested in both Microbial and CHO/HGPRT Mutation Assays. One group of CD rats was treated with PB at 75 mg/kg by I.P. injection for 4 consecutive days and a single dose of {beta}-NF at 80 mg/kg 2 days prior to sacrifice. A second group of CD rats was treated with a single dose of Aroclor-1254 at 500 mg/kg on Day 1 by I.P. injection. All animals were sacrificed on Day 5. A Plate Incorporation Mutation Assay was performed with five Salmonella typhimurium tester strains and one Escherichia coli tester strain. A single dose of 2-Amino-anthracene (2-AA) at 1.25 {mu}g/plate for the five Salmonella typhimurium tester strains and 10 {mu}g/plate for the WP2uvrA tester stain was used as a positive control. DMSO at 0.1 mL/plate was used as a solvent control. In the CHO/HGPRT Gene Mutation Assay, 7, 12-Dimethylbenz ({alpha})anthra-cene (DMBA) was used at 5.0 {mu}g/mL as a positive control. Acetone at 10 {mu}L/mL was used as a solvent control. The results from the Microbial Assay showed that the increase in mean reversion frequency of 2-AA over that of the corresponding solvent control with the PB/{beta}-NF-induced S-9 was greater than the increase from the PCB-induced S-9 for all of the six tester strains. In the CHO/HGPRT Mutation Assay, the results showed that DMBA gave a similar positive response for both the PCB- and PB/{beta}-NF-induced S-9s. The data obtained from these comparative studies supports the suggestion of the authors listed above that PB/{beta}-NF is a suitable substitute for PCB for induction of S-9.

  8. Isolation of S9 fractions from mouse and rat with increased enzyme activities after repeated administration of cytochrome P-450 and P-448 inducers.

    PubMed

    Paolini, M; Sapigni, E; Hrelia, P; Grilli, S; Cantelli-Forti, G

    1988-05-01

    Cytochrome P-450 (cyt P-450), NADPH cytochrome P-450 reductase and various microsomal monooxygenase activities [e.g. aminopyrine N-demethylase, p-nitroanisole O-demethylase, dinemorphan N-demethylase, ethoxycoumarin O-deethylase and ethoxyresorufin O-deethylase (ERD)], were determined in hepatic post-mitochondrial supernatant from mice and rats. Experiments were performed on male and female animals treated with a combination of sodium phenobarbital and beta-naphthoflavone according to the standard protocol schedule for short-term genotoxicity testing. A second inductive treatment after 2, 3, 4 or 5 weeks was provided. The increase in cyt P-450 and in all enzymatic activities measured was enhanced in both species by a second induction treatment, particularly when given after 4 weeks. ERD activity was the only monooxygenase activity which was sex-dependent, being more active in female than in male animals. To extend the biochemical data, experiments were performed with the proposed S9 fractions on styrene, which previously has proved difficult to detect in short-term in vitro mutagenicity tests. Using the new induction conditions positive results were obtained with the D7 strain of Saccharomyces cerevisiae. It was concluded that a simple pre-induction of the animals 3-4 weeks before the main induction treatment leads to a more active S9 fraction for in vitro genotoxicity studies. PMID:3045486

  9. In Vitro Transformation of Chlorinated Parabens by the Liver S9 Fraction: Kinetics, Metabolite Identification, and Aryl Hydrocarbon Receptor Agonist Activity.

    PubMed

    Terasaki, Masanori; Wada, Takeshi; Nagashima, Satoshi; Makino, Masakazu; Yasukawa, Hiro

    2016-01-01

    We investigated the kinetics of in vitro transformation of a dichlorinated propyl paraben (2-propyl 3,5-dichloro-4-hydroxybenzoate; Cl2PP) by the rat liver S9 fraction and assessed the aryl hydrocarbon receptor (AhR) agonist activity of the metabolite products identified in HPLC and GC/MS analysis and by metabolite syntheses. The results indicated that the chlorination of Cl2PP reduced its degradation rate by approximately 40-fold. Two hydroxylated metabolite products showed AhR agonist activity of up to 39% of that of the parent Cl2PP when assessed in a yeast (YCM3) reporter gene assay. The determination of the metabolic properties of paraben bioaccumulation presented here provides further information on the value of risk assessments of chlorinated parabens as a means to ensure human health and environmental safety. PMID:27250800

  10. Influence of S9 mix composition on the SOS response in Escherichia coli PQ37 by polycyclic aromatic hydrocarbons.

    PubMed

    Mersch-Sundermann, V; Wintermann, F; Kern, S; Hof, H

    1993-02-01

    To investigate the variability in test results obtained with the SOS chromotest (Escherichia coli PQ37 genotoxicity assay) when varying the composition of the exogenous metabolizing system (S9 mix), we examined the influence of different S9 and NADP concentrations, of buffer pH value, of SDS concentrations, the effects of E. coli PQ37 density and centrifugation steps on the expression of beta-galactosidase (beta g) and alkaline phosphatase (ap) activity, the calculated induction factors (IFs) and SOS-inducing potencies (SOSIPs). Additionally we examined the metabolic potency (stability) of S9 mix when stored at 37 degrees C before use. Initially, we used 0-5000 ng (= 0-20 nmole) benzo[a]pyrene (B[a]P) as a reference compound for the test procedure in the presence of standard S9 mix. Subsequently, to evaluate the results of S9 mix variations we examined several polycyclic aromatic hydrocarbons (PAHs) using both the standard and a modified S9 mix composition and test protocol. We observed the highest beta g and ap activities and/or IFs using only 11-27 microliters 9000 x g liver supernatant (S9) from Aroclor 1254-induced rats per assay (20-50% of standard amount) and calibrating the S9 mix Tris buffer to pH 7.8-8.0. 60-300 micrograms NADP/assay (10-50% of standard) was sufficient for optimum activation of PAHs. In contrast to previous investigations about the variability of the SOS chromotest in the absence of a metabolizing system, higher induction factors were obtained when using higher bacterial densities (12-18 x 10(6) cfu/assay). Centrifugation steps as recommended by other investigators were not necessary when using optimum S9 amounts. The metabolic activity of S9 mix remained nearly constant approximately 20 min after preparation, but decreased to 80% of its activity in about 1 h. PMID:7678915

  11. Inhibition of pathogenic bacterial biofilm by biosurfactant produced by Lysinibacillus fusiformis S9.

    PubMed

    Pradhan, Arun Kumar; Pradhan, Nilotpala; Sukla, Lala Behari; Panda, Prasanna Kumar; Mishra, Barda Kanta

    2014-02-01

    A biosurfactant producing microbe isolated from a river bank was identified as Lysinibacillus fusiformis S9. It was identified with help of biochemical tests and 16S rRNA gene phylogenetic analysis. The biosurfactant S9BS produced was purified and characterized as glycolipid. The biosurfactant showed remarkable inhibition of biofilm formation by pathogenic bacteria like Escherichia coli and Streptococcus mutans. It was interesting to note that at concentration of 40 μg ml(-1) the biosurfactant did not show any bactericidal activity but restricted the biofilm formation completely. L. fusiformis is reported for the first time to produce a glycolipid type of biosurfactant capable of inhibiting biofilm formation by pathogenic bacteria. The biosurfactant inhibited bacterial attachment and biofilm formation equally well on hydrophilic as well as hydrophobic surfaces like glass and catheter tubing. This property is significant in many biomedical applications where the molecule should help in preventing biofouling of surfaces without being toxic to biotic system. PMID:23719930

  12. Active optical zoom system

    DOEpatents

    Wick, David V.

    2005-12-20

    An active optical zoom system changes the magnification (or effective focal length) of an optical imaging system by utilizing two or more active optics in a conventional optical system. The system can create relatively large changes in system magnification with very small changes in the focal lengths of individual active elements by leveraging the optical power of the conventional optical elements (e.g., passive lenses and mirrors) surrounding the active optics. The active optics serve primarily as variable focal-length lenses or mirrors, although adding other aberrations enables increased utility. The active optics can either be LC SLMs, used in a transmissive optical zoom system, or DMs, used in a reflective optical zoom system. By appropriately designing the optical system, the variable focal-length lenses or mirrors can provide the flexibility necessary to change the overall system focal length (i.e., effective focal length), and therefore magnification, that is normally accomplished with mechanical motion in conventional zoom lenses. The active optics can provide additional flexibility by allowing magnification to occur anywhere within the FOV of the system, not just on-axis as in a conventional system.

  13. Solar cell activation system

    SciTech Connect

    Apelian, L.

    1983-07-05

    A system for activating solar cells involves the use of phosphorescent paint, the light from which is amplified by a thin magnifying lens and used to activate solar cells. In a typical system, a member painted with phosphorescent paint is mounted adjacent a thin magnifying lens which focuses the light on a predetermined array of sensitive cells such as selenium, cadmium or silicon, mounted on a plastic board. A one-sided mirror is mounted adjacent the cells to reflect the light back onto said cells for purposes of further intensification. The cells may be coupled to rechargeable batteries or used to directly power a small radio or watch.

  14. Production Systems. Laboratory Activities.

    ERIC Educational Resources Information Center

    Gallaway, Ann, Ed.

    This production systems guide provides teachers with learning activities for secondary students. Introductory materials include an instructional planning outline and worksheet, an outline of essential elements, domains and objectives, a course description, and a content outline. The guide contains 30 modules on the following topics: production…

  15. Communication Systems. Laboratory Activities.

    ERIC Educational Resources Information Center

    Sutherland, Barbara, Ed.

    This communication systems guide provides teachers with learning activities for secondary students. Introductory materials include an instructional planning outline and worksheet, an outline of essential elements, a list of objectives, a course description, and a content outline. The guide contains 32 modules on the following topics: story…

  16. ADASY (Active Daylighting System)

    NASA Astrophysics Data System (ADS)

    Vázquez-Moliní, Daniel; González-Montes, Mario; Fernández-Balbuena, Antonio Á.; Bernabéu, Eusebio; García-Botella, Ángel; García-Rodríguez, Lucas; Pohl, Wilfried

    2009-08-01

    The main objective of ADASY (Active Daylighting System) work is to design a façade static daylighting system oriented to office applications, mainly. The goal of the project is to save energy by guiding daylight into a building for lighting purpose. With this approach we can reduce the electrical load for artificial lighting, completing it with sustainable energy. The collector of the system is integrated on a vertical façade and its distribution guide is always horizontal inside of the false ceiling. ADASY is designed with a specific patent pending caption system, a modular light-guide and light extractor luminaire system. Special care has been put on the final cost of the system and its building integration purpose. The current ADASY configuration is able to illuminate 40 m2 area with a 300lx-400lx level in the mid time work hours; furthermore it has a good enough spatial uniformity distribution and a controlled glare. The data presented in this study are the result of simulation models and have been confirmed by a physical scaled prototype. ADASY's main advantages over regular illumination systems are: -Low maintenance; it has not mobile pieces and therefore it lasts for a long time and require little attention once installed. - No energy consumption; solar light continue working even if there has been a power outage. - High quality of light: the colour rendering of light is very high - Psychological benefits: People working with daylight get less stress and more comfort, increasing productivity. - Health benefits

  17. Photoelectric properties and charge dynamics in ZnO nanowires/Cu4Bi4S9 and ZnO nanowires/In2O3/Cu4Bi4S9 heterostructures

    NASA Astrophysics Data System (ADS)

    Liu, Xiangyang; Wang, Shun; Zhang, Jingwei; Zhang, Jiwei; Gu, Yuzong

    2014-12-01

    ZnO nanowires arrays were preformed in a horizontal double-tube system. Two types of heterostructures (ZnO nanowires/Cu4Bi4S9 and ZnO nanowires/In2O3/Cu4Bi4S9) and three-dimensional solar cells were fabricated with ZnO nanowires arrays as working electrode, In2O3 as buffer layer, and Cu4Bi4S9 as inorganic dye and hole collector. It is suggested that two types of heterostructures have the similar absorption properties with single Cu4Bi4S9. However, the results of steady state and electric field-induced surface photovoltage indicate that ZnO nanowires/In2O3/Cu4Bi4S9 exhibits the higher photovoltaic response than ZnO nanowires/Cu4Bi4S9. Using the transient surface photovoltage spectroscopy, we further studied the separation and transport mechanism of photogenerated charges. Furthermore, Cu4Bi4S9/In2O3/ZnO cells presents the better performance than Cu4Bi4S9/ZnO cells and the highest efficiencies are about 6.4% and 5.2%, respectively. It is suggested that direct paths, interface barrier, built-in electric field, and double energy level matchings between conduction bands (Cu4Bi4S9 and In2O3, In2O3 and ZnO) have obvious effect on the separation of photogenerated charges. Then we discussed the synthetic action on the charge dynamics from these factors.

  18. Neutron activation analysis system

    DOEpatents

    Taylor, M.C.; Rhodes, J.R.

    1973-12-25

    A neutron activation analysis system for monitoring a generally fluid media, such as slurries, solutions, and fluidized powders, including two separate conduit loops for circulating fluid samples within the range of radiation sources and detectors is described. Associated with the first loop is a neutron source that emits s high flux of slow and thermal neutrons. The second loop employs a fast neutron source, the flux from which is substantially free of thermal neutrons. Adjacent to both loops are gamma counters for spectrographic determination of the fluid constituents. Other gsmma sources and detectors are arranged across a portion of each loop for deterMining the fluid density. (Official Gazette)

  19. European Neutron Activation System.

    2013-01-11

    Version 03 EASY-2010 (European Activation System) consists of a wide range of codes, data and documentation all aimed at satisfying the objective of calculating the response of materials irradiated in a neutron flux. The main difference from the previous version is the upper energy limit, which has increased from 20 to 60 MeV. It is designed to investigate both fusion devices and accelerator based materials test facilities that will act as intense sources of high-energymore » neutrons causing significant activation of the surrounding materials. The very general nature of the calculational method and the data libraries means that it is applicable (with some reservations) to all situations (e.g. fission reactors or neutron sources) where materials are exposed to neutrons below 60 MeV. EASY can be divided into two parts: data and code development tools and user tools and data. The former are required to develop the latter, but EASY users only need to be able to use the inventory code FISPACT and be aware of the contents of the EAF library (the data source). The complete EASY package contains the FISPACT-2007 inventory code, the EAF-2003, EAF-2005, EAF-2007 and EAF-2010 libraries, and the EASY User Interface for the Window version. The activation package EASY-2010 is the result of significant development to extend the upper energy range from 20 to 60 MeV so that it is capable of being used for IFMIF calculations. The EAF-2010 library contains 66,256 reactions, almost five times more than in EAF-2003 (12,617). Deuteron-induced and proton-induced cross section libraries are also included, and can be used with EASY to enable calculations of the activation due to deuterons and proton [2].« less

  20. Technology Systems. Laboratory Activities.

    ERIC Educational Resources Information Center

    Brame, Ray; And Others

    This guide contains 43 modules of laboratory activities for technology education courses. Each module includes an instructor's resource sheet and the student laboratory activity. Instructor's resource sheets include some or all of the following elements: module number, course title, activity topic, estimated time, essential elements, objectives,…

  1. Portable active interrogation system.

    SciTech Connect

    Moss, C. E.; Brener, M. W.; Hollas, C. L.; Myers, W. L.

    2004-01-01

    The system consists of a pulsed DT neutron generator (5 x 10{sup 7} n/s) and a portable but high intrinsic efficiency, custom-designed, polyethylene-moderated {sup 3}He neutron detector. A multichannel scaler card in a ruggedized laptop computer acquires the data. A user-friendly LabVIEW program analyzes and displays the data. The program displays a warning message when highly enriched uranium or any other fissionable materials is detected at a specified number of sigmas above background in the delayed region between pulses. This report describes the system and gives examples of the response of the system to highly enriched uranium and some other fissionable materials, at several distances and with various shielding materials.

  2. Active Response Gravity Offload System

    NASA Technical Reports Server (NTRS)

    Valle, Paul; Dungan, Larry; Cunningham, Thomas; Lieberman, Asher; Poncia, Dina

    2011-01-01

    The Active Response Gravity Offload System (ARGOS) provides the ability to simulate with one system the gravity effect of planets, moons, comets, asteroids, and microgravity, where the gravity is less than Earth fs gravity. The system works by providing a constant force offload through an overhead hoist system and horizontal motion through a rail and trolley system. The facility covers a 20 by 40-ft (approximately equals 6.1 by 12.2m) horizontal area with 15 ft (approximately equals4.6 m) of lifting vertical range.

  3. In vitro Metabolism of Sodium 9-dehydro-17-hydro-andrographolide-19-yl Sulfate in Rat Liver S9 by Liquid Chromatography–Mass Spectrometry Method

    PubMed Central

    Zheng, Dongkun; Shao, Jun; Chen, Weikang; Luo, Yuehua

    2016-01-01

    Background: Sodium 9-dehydro-17-hydro-andrographolide-19-yl sulfate (DHAS) is the active ingredient of Xiyanping injection, a traditional Chinese medicine in clinical use. However, there has been no report about the metabolic rate and metabolites of DHAS in vitro. Materials and Methods: In this article, DHAS was incubated with rat liver S9, and liquid chromatography/mass spectrometry (LC/MS) was used for the metabolism study. The residual concentrations of substrate were determined by ultra-high-performance liquid chromatography-electrospray ionization–tandem mass spectrometry method for the metabolic rate study of DHAS in liver S9. Metabolites were identified by the (UPLC-TOF-MSE) Ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry method. Results: The calibration curves of DHAS were linear over the concentration range from 0.75 μM to 75.22 μM with correlation coefficients >0.99. The lower limit of quantification was 0.150 μM for DHAS. The determination recoveries of DHAS were in the range of 84.9–90.6%. The t½ and CLint of DHAS in rat liver S9 were 98.6 ± 2.1 min and 3.5 ± 0.1 mL/min/g, respectively. Five metabolites were preliminarily identified based on the high resolution mass spectrum data in comparison with related references. These metabolites were mainly the products of dehydration and hydrogenation of DHAS. Conclusion: The present in vitro metabolic study of DHAS provided valuable information about the metabolic rate and potential metabolites of DHAS, which are important for future in vivo metabolism studies of DHAS and the discovery of more active andrographolide derivatives. SUMMARY In this paper, sodium 9-dehydro-17-hydro-andrographolide-19-yl sulfate (DHAS) metabolism in vitro has been investigated with rat liver S9 using liquid chromatography-mass spectrometry (LC-MS). The result of quantitative analysis showed that DHAS had a long t1/2, which indicated its high metabolic stability. Five metabolites of DHAS

  4. Assessment of metabolic stability using the rainbow trout (Oncorhynchus mykiss) liver S9 fraction

    EPA Science Inventory

    Standard protocols are given for assessing metabolic stability in rainbow trout using the liver S9 fraction. These protocols describe the isolation of S9 fractions from trout livers, evaluation of metabolic stability using a substrate depletion approach, and expression of the res...

  5. The JET Neutron Activation System

    NASA Astrophysics Data System (ADS)

    Roquemore, A. L.; Bertalot, L.; Esposito, B.; Jarvis, O. N.; Loughlin, M. J.; Sadler, G.; van Belle, P.

    1997-11-01

    The JET activation system provides the absolute value of the neutron yields as well as a check on the linearity of other neutron detector systems. The total neutron yield is standardized to one irradiation end reentrant in the top of the vessel, while the results from the other seven irradiation ends are normalized to this standard end and provide redundancy as well as information on the plasma position. A pneumatic transfer system is used to transfer up to five capsules containing elemental foils for a single discharge on JET. Eleven different elemental foils have been utilized to determine the yields from both DD and DT plasmas. By placing several different foils with different activation energy thresholds in a single capsule for one DT discharge, neutron spectral information has been obtained by use of the SAND-II unfolding code. A description of the activation system hardware and calibration of the activation detector system will be presented along with the results from the DT neutron calibration campaign.

  6. Modeling approaches for active systems

    NASA Astrophysics Data System (ADS)

    Herold, Sven; Atzrodt, Heiko; Mayer, Dirk; Thomaier, Martin

    2006-03-01

    To solve a wide range of vibration problems with the active structures technology, different simulation approaches for several models are needed. The selection of an appropriate modeling strategy is depending, amongst others, on the frequency range, the modal density and the control target. An active system consists of several components: the mechanical structure, at least one sensor and actuator, signal conditioning electronics and the controller. For each individual part of the active system the simulation approaches can be different. To integrate the several modeling approaches into an active system simulation and to ensure a highly efficient and accurate calculation, all sub models must harmonize. For this purpose, structural models considered in this article are modal state-space formulations for the lower frequency range and transfer function based models for the higher frequency range. The modal state-space formulations are derived from finite element models and/or experimental modal analyses. Consequently, the structure models which are based on transfer functions are directly derived from measurements. The transfer functions are identified with the Steiglitz-McBride iteration method. To convert them from the z-domain to the s-domain a least squares solution is implemented. An analytical approach is used to derive models of active interfaces. These models are transferred into impedance formulations. To couple mechanical and electrical sub-systems with the active materials, the concept of impedance modeling was successfully tested. The impedance models are enhanced by adapting them to adequate measurements. The controller design strongly depends on the frequency range and the number of modes to be controlled. To control systems with a small number of modes, techniques such as active damping or independent modal space control may be used, whereas in the case of systems with a large number of modes or with modes that are not well separated, other control

  7. The activation system EASY-2007

    NASA Astrophysics Data System (ADS)

    Forrest, R. A.; Kopecky, J.

    2009-04-01

    Safety and waste management of materials for ITER, IFMIF and future power plants require knowledge of the activation caused by irradiation with neutrons, or in the case of IFMIF, deuterons. The European Activation System has been developed for such calculations and a new version was released earlier this year. This contains a large amount of nuclear data in the European Activation File covering neutron-, deuteron- and proton-induced cross sections. These data are input to the FISPACT code for activation calculations. EASY-2007 is being validated using integral and differential measurements. However, only a minority of reactions have experimental support and a statistical method is described that can test the complete library. Importance diagrams are useful in finding the dominant nuclides formed following irradiation and the reactions responsible for their production. These diagrams now cover energies above 20 MeV and examples of new dominant nuclides and reactions relevant to IFMIF are given.

  8. Synthesis, crystal and electronic structure, and optical property of the pentanary chalcohalide Ba3KSb4S9Cl

    NASA Astrophysics Data System (ADS)

    Zhao, Hua-Jun; Liu, Peng-Fei

    2015-12-01

    The pentanary chalcohalide Ba3KSb4S9Cl has been prepared from stoichiometric mixtures of KCl, Ba, Sb, and S in an evacuated silica tube, which is the first example of chalcohalides in the pentanary A/Ae/Sb/Q/X (A=alkali metal; Ae=alkaline-earth metal; Q=S, Se, Te; X=F, Cl, Br, I) system. This material crystallize in the Pnnm space group and its new structure type comprises one-dimensional (1D) [Sb3S7]5- chains running down the [001] direction separated by isolated dimeric Sb2S4 polyhedra, Ba2+, K+, and Cl-, respectively. The optical gap of 1.99 eV for Ba3KSb4S9Cl was deduced from the UV/vis reflectance spectroscopy and DFT study indicates a indirect band gap with an electronic transfer excitation of S 3p to Sb 5p orbital electrons.

  9. Evaluation of 4-methylimidazole, in the Ames/Salmonella test using induced rodent liver and lung S9.

    PubMed

    Beevers, Carol; Adamson, Richard H

    2016-01-01

    4-methylimidazole (4-MeI) is formed by the interaction of ammonia with reducing sugars and low levels have been identified as a by-product in coffee, soy sauce, wine, dark beers, soft drinks, and caramel colors. The 4-MeI has been reported to induce alveolar/bronchiolar tumors in mice but not rats. Its mechanism of action is unlikely to be due to genotoxicity as 4-MeI does not induce mutation in Salmonella typhimurium and does not induce micronuclei in rodent peripheral erythrocytes or bone marrow cells. However, the question of whether genetically reactive intermediates could be formed via lung-specific metabolism has not previously been addressed. The 4-MeI was tested for its ability to induce mutation in five standard Ames strains of S. typhimurium using induced rat (F344/N) and mouse (B6C3F1) liver and lung S9 as a source of exogenous metabolism. The chemicals were tested in an OECD 471-compliant bacterial reverse mutation assay, using both plate-incorporation and pre-incubation methodologies, together with 10% S-9 metabolic activation. No induction of mutation (as measured by an increase in revertant colonies) was observed and it was concluded that 4-MeI was not mutagenic in S. typhimurium using either rodent liver or lung S9 for exogenous metabolism. PMID:26765635

  10. The interaction pattern between a homology model of 40S ribosomal S9 protein of Rhizoctonia solani and 1-hydroxyphenaize by docking study.

    PubMed

    Dharni, Seema; Sanchita; Samad, Abdul; Sharma, Ashok; Patra, Dharani Dhar

    2014-01-01

    1-Hydroxyphenazine (1-OH-PHZ), a natural product from Pseudomonas aeruginosa strain SD12, was earlier reported to have potent antifungal activity against Rhizoctonia solani. In the present work, the antifungal activity of 1-OH-PHZ on 40S ribosomal S9 protein was validated by molecular docking approach. 1-OH-PHZ showed interaction with two polar contacts with residues, Arg69 and Phe19, which inhibits the synthesis of fungal protein. Our study reveals that 1-OH-PHZ can be a potent inhibitor of 40S ribosomal S9 protein of R. solani that may be a promising approach for the management of fungal diseases. PMID:24864254

  11. The Interaction Pattern between a Homology Model of 40S Ribosomal S9 Protein of Rhizoctonia solani and 1-Hydroxyphenaize by Docking Study

    PubMed Central

    Dharni, Seema; Sanchita; Sharma, Ashok; Patra, Dharani Dhar

    2014-01-01

    1-Hydroxyphenazine (1-OH-PHZ), a natural product from Pseudomonas aeruginosa strain SD12, was earlier reported to have potent antifungal activity against Rhizoctonia solani. In the present work, the antifungal activity of 1-OH-PHZ on 40S ribosomal S9 protein was validated by molecular docking approach. 1-OH-PHZ showed interaction with two polar contacts with residues, Arg69 and Phe19, which inhibits the synthesis of fungal protein. Our study reveals that 1-OH-PHZ can be a potent inhibitor of 40S ribosomal S9 protein of R. solani that may be a promising approach for the management of fungal diseases. PMID:24864254

  12. Active thermal control system evolution

    NASA Technical Reports Server (NTRS)

    Petete, Patricia A.; Ames, Brian E.

    1991-01-01

    The 'restructured' baseline of the Space Station Freedom (SSF) has eliminated many of the growth options for the Active Thermal Control System (ATCS). Modular addition of baseline technology to increase heat rejection will be extremely difficult. The system design and the available real estate no longer accommodate this type of growth. As the station matures during its thirty years of operation, a demand of up to 165 kW of heat rejection can be expected. The baseline configuration will be able to provide 82.5 kW at Eight Manned Crew Capability (EMCC). The growth paths necessary to reach 165 kW have been identified. Doubling the heat rejection capability of SSF will require either the modification of existing radiator wings or the attachment of growth structure to the baseline truss for growth radiator wing placement. Radiator performance can be improved by enlarging the surface area or by boosting the operating temperature with a heat pump. The optimal solution will require both modifications. The addition of growth structure would permit the addition of a parallel ATCS using baseline technology. This growth system would simplify integration. The feasibility of incorporating these growth options to improve the heat rejection capacity of SSF is under evaluation.

  13. Method optimization for fathead minnow (Pimephales promelas) liver S9 isolation

    EPA Science Inventory

    Standard protocols have been proposed to assess metabolic stability in rainbow trout liver S9 fractions. Using in vitro substrate depletion assays, in vitro intrinsic clearance rates can be calculated for a variety of study compounds. Existing protocols suggest potential adaptati...

  14. 75 FR 10487 - International Conference on Harmonisation; Guidance on S9 Nonclinical Evaluation for Anticancer...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-08

    ... Federal Register of February 17, 2009 (74 FR 7445), FDA published a notice announcing the availability of... HUMAN SERVICES Food and Drug Administration International Conference on Harmonisation; Guidance on S9 Nonclinical Evaluation for Anticancer Pharmaceuticals; Availability AGENCY: Food and Drug Administration,...

  15. Manually controlled neutron-activation system

    NASA Astrophysics Data System (ADS)

    Johns, R. A.; Carothers, G. A.

    1982-01-01

    A manually controlled neutron activation system, the Manual Reactor Activation System, was designed and built and has been operating at one of the Savannah River Plant's production reactors. With this system, samples can be irradiated for up to 24 hours and pneumatically transferred to a shielded repository for decay until their activity is low enough for them to be handled at a radiobench. The Manual Reactor Activation System was built to provide neutron activation of solid waste forms for the Alternative Waste Forms Leach Testing Program. Neutron activation of the bulk sample prior to leaching permits sensitive multielement radiometric analyses of the leachates.

  16. Wave activated power generation system

    SciTech Connect

    Ono, Y.

    1983-08-09

    A wave activated power generation system of the float type is disclosed, comprising at least one piston-cylinder device having an anchored cylinder and a piston slidable in the cylinder and cooperating with the cylinder to form a pumping chamber above the piston and a low pressure chamber below the piston. The cylinder has an intake port and an exhaust port both formed at an upper port thereof to communicate with the pumping chamber and each provided with a check valve. A float is connected through a cable to the piston of the piston- cylinder device. A pair of fluid storages are connected to the intake port and the exhaust port of the pumping chamber, respectively. A waterwheel generator is driven by the fluid flowing from one of the fluid storages to another. A pressure regulating device is connected to the low pressure chamber so as to maintain the low pressure chamber at a pressure lower than the pressure in the pumping chamber, the difference in pressure ceaselessly applying a downward force on the piston to keep the cable in a tensed condition.

  17. Genome-wide polysomal analysis of a yeast strain with mutated ribosomal protein S9

    PubMed Central

    Pnueli, Lilach; Arava, Yoav

    2007-01-01

    Background The yeast ribosomal protein S9 (S9) is located at the entrance tunnel of the mRNA into the ribosome. It is known to play a role in accurate decoding and its bacterial homolog (S4) has recently been shown to be involved in opening RNA duplexes. Here we examined the effects of changing the C terminus of S9, which is rich in acidic amino acids and extends out of the ribosome surface. Results We performed a genome-wide analysis to reveal effects at the transcription and translation levels of all yeast genes. While negligible relative changes were observed in steady-state mRNA levels, a significant number of mRNAs appeared to have altered ribosomal density. Notably, 40% of the genes having reliable signals changed their ribosomal association by more than one ribosome. Yet, no general correlations with physical or functional features of the mRNA were observed. Ribosome Density Mapping (RDM) along four of the mRNAs with increased association revealed an increase in ribosomal density towards the end of the coding region for at least two of them. Read-through analysis did not reveal any increase in read-through of a premature stop codon by the mutant strain. Conclusion The ribosomal protein rpS9 appears to be involved in the translation of many mRNAs, since altering its C terminus led to a significant change in ribosomal association of many mRNAs. We did not find strong correlations between these changes and several physical features of the mRNA, yet future studies with advanced tools may allow such correlations to be determined. Importantly, our results indicate an accumulation of ribosomes towards the end of the coding regions of some mRNAs. This suggests an involvement of S9 in ribosomal dissociation during translation termination. PMID:17711575

  18. What Is an Activity? Appropriating an Activity-Centric System

    NASA Astrophysics Data System (ADS)

    Yarosh, Svetlana; Matthews, Tara; Moran, Thomas P.; Smith, Barton

    Activity-Centric Computing (ACC) systems seek to address the fragmentation of office work across tools and documents by allowing users to organize work around the computational construct of an Activity. Defining and structuring appropriate Activities within a system poses a challenge for users that must be overcome in order to benefit from ACC support. We know little about how knowledge workers appropriate the Activity construct. To address this, we studied users’ appropriation of a production-quality ACC system, Lotus Activities, for everyday work by employees in a large corporation. We contribute to a better understanding of how users articulate their individual and collaborative work in the system by providing empirical evidence of their patterns of appropriation. We conclude by discussing how our findings can inform the design of other ACC systems for the workplace.

  19. Laboratory measurement of the S(9) pure rotation frequency in H2

    NASA Technical Reports Server (NTRS)

    Jennings, D. E.; Rahn, L. A.; Owyoung, A.

    1985-01-01

    The S(9) J = 11-9 ground-state transition in H2 is investigated experimentally, applying a 514.5-nm 300-mW single-mode CW Ar-ion laser to probe the stimulated Raman emission of a CH4-air flame pumped by a single-frequency electronically scannable dye laser amplified to 2 MW by a 10-Hz frequency-doubled Nd:YAG laser. An H2 Raman spectrum with an S(9) frequency of 2130.102 + or - 0.004/cm is shown, and the results are found to be consistent with the measurements obtained in the Orion molecular cloud by Knacke and Young (1980 and 1981).

  20. Alternatives to Aroclor 1254-induced S9 in in vitro genotoxicity assays.

    PubMed

    Elliott, B M; Combes, R D; Elcombe, C R; Gatehouse, D G; Gibson, G G; Mackay, J M; Wolf, R C

    1992-05-01

    A working party was set up by the UK Environmental Mutagen Society to consider alternatives to Aroclor 1254 (Aroclor)-induced S9 in in vitro genotoxicity assays, with the aims of considering whether a replacement for Aroclor in its role in general screening assays could be readily identified. The working party concluded that there was sufficient support in the literature to justify the use of an appropriate phenobarbital/beta-naphthoflavone regime as an acceptable alternative to Aroclor. PMID:1602970

  1. Impact analysis of ICH S9 on non-clinical development of anticancer drugs.

    PubMed

    Bonelli, Milton; Di Giuseppe, Francesca; Beken, Sonja

    2015-10-01

    Cancer presents a major healthcare challenge worldwide, with several millions new cases a year, and represents a therapeutic area with a high need for new drugs. To respond to this, the parties of the International Conference for Harmonization agreed in 2007 to develop a guideline on nonclinical requirements for oncology therapeutics' development (ICH S9), which came into effect in early 2010. This guideline includes recommendations to facilitate and accelerate the development and marketing of cancer therapeutic agents for serious and life threatening malignancies and aims to address this need through a refinement and a reduction in the use of experimental animals, following the 3Rs principles. To assess the impact of ICH S9 on drug development and reduction of animal use, we performed an analysis of Marketing Authorization Applications at the European Medicines Agency relevant to the period in which the development of the guideline was approaching the final steps and its early implementation period. From the analysis performed, a consistent trend towards a decrease in the average number of non-clinical studies performed (-40.7%) and number of animals used per development program (-58.1%) for new chemical entities has been detected, highlighting increasing compliance by companies to the recommendations of ICH S9. PMID:26232707

  2. Data base management systems activities

    NASA Technical Reports Server (NTRS)

    1983-01-01

    The Data Management System-1100 is designed to operate in conjunction with the UNIVAC 1100 Series Operating System on any 1100 Series computer. DMS-1100 is divided into the following four major software components: (1) Data Definition Languages (DDL); (2) Data Management Routine (DMR); (3) Data Manipulation Languages (DML); and (4) Data Base Utilities (DBU). These software components are described in detail.

  3. Orbiter active thermal control system description

    NASA Technical Reports Server (NTRS)

    Laubach, G. E.

    1975-01-01

    A brief description of the Orbiter Active Thermal Control System (ATCS) including (1) major functional requirements of heat load, temperature control and heat sink utilization, (2) the overall system arrangement, and (3) detailed description of the elements of the ATCS.

  4. Experiment system of LAMOST active optics

    NASA Astrophysics Data System (ADS)

    Cui, Xiangqun; Su, Ding; Li, Guoping; Yao, Zhengqiu; Zhang, Zhengcao; Li, Yeping; Zhang, Yong; Wang, You; Xu, Xinqi; Wang, Hai

    2004-10-01

    Active optics is the most difficult part in LAMOST project. Especially for the segmented reflecting Schmidt plate Ma, in which both segmented mirror active optics and thin mirror (or deformable mirror) active optics are applied. To test and optimize the thin mirror active optics of Ma, and to approach the reality of operating environment of the telescope, an outdoor experiment system has been established. This experiment system is also a `small LAMOST" with one sub-mirror of the primary mirror Mb and one sub-mirror of the Schmidt plate Ma, and with full scale in spacing (40 meters) between Ma and Mb. many parts of LAMOST were tested in the experiment system except segmented mirror active optics. Especially for force actuators, thin mirror support system, friction driving of the alt-azimuth mounting and its control system, wave front test along such a long optical path. This paper presents the experiment system, research and developments, and some experiment results.

  5. Modeling Cytoskeletal Active Matter Systems

    NASA Astrophysics Data System (ADS)

    Blackwell, Robert

    Active networks of filamentous proteins and crosslinking motor proteins play a critical role in many important cellular processes. One of the most important microtubule-motor protein assemblies is the mitotic spindle, a self-organized active liquid-crystalline structure that forms during cell division and that ultimately separates chromosomes into two daughter cells. Although the spindle has been intensively studied for decades, the physical principles that govern its self-organization and function remain mysterious. To evolve a better understanding of spindle formation, structure, and dynamics, I investigate course-grained models of active liquid-crystalline networks composed of microtubules, modeled as hard spherocylinders, in diffusive equilibrium with a reservoir of active crosslinks, modeled as hookean springs that can adsorb to microtubules and and translocate at finite velocity along the microtubule axis. This model is investigated using a combination of brownian dynamics and kinetic monte carlo simulation. I have further refined this model to simulate spindle formation and kinetochore capture in the fission yeast S. pombe. I then make predictions for experimentally realizable perturbations in motor protein presence and function in S. pombe.

  6. High speed hybrid active system

    NASA Astrophysics Data System (ADS)

    Gonzalez, Ignacio F.; Chang, Fu-Kuo; Qing, Peter X.; Kumar, Amrita; Zhang, David

    2005-05-01

    A novel piezoelectric/fiber-optic system is developed for long-term health monitoring of aerospace vehicles and structures. The hybrid diagnostic system uses the piezoelectric actuators to input a controlled excitation to the structure and the fiber optic sensors to capture the corresponding structural response. The aim of the system is to detect changes in structures such as those found in aerospace applications (damage, cracks, aging, etc.). This system involves the use of fiber Bragg gratings, which may be either bonded to the surface of the material or embedded within it in order to detect the linear strain component produced by the excitation waves generate by an arbitrary waveform generator. Interrogation of the Bragg gratings is carried out using a high speed fiber grating demodulation unit and a high speed data acquisition card to provide actuation input. With data collection and information processing; is able to determine the condition of the structure. The demands on a system suitable for detecting ultrasonic acoustic waves are different than for the more common strain and temperature systems. On the one hand, the frequency is much higher, with typical values for ultrasonic frequencies used in non-destructive testing ranging from 100 kHz up to several MHz. On the other hand, the related strain levels are much lower, normally in the μstrain range. Fiber-optic solutions for this problem do exist and are particularly attractive for ultrasonic sensing as the sensors offer broadband detection capability.

  7. First participation by the NMISA in a low-level comparison: CCRI(II)-S9 exercise.

    PubMed

    van Wyngaardt, W M; van Staden, M J; Lubbe, J

    2013-11-01

    The NMISA Radioactivity Standards Laboratory participated in the CCRI(II)-S9 inter-comparison of the measurement of the activity concentration of (137)Cs and (40)K in rice material, piloted by the KRISS. The paper describes the equipment used, the measurement set-up and data analysis. The efficiency of the detector for (137)Cs and (40)K was determined by comparison against a spiked standard solution, and Monte Carlo simulations performed to estimate the difference in γ-ray escape probability between the solution standard and starch (as an approximation for milled rice) due to attenuation disparities. The uncertainty budget was estimated rather conservatively, since these were the first low-level measurements performed by the NMISA using an HPGe detector. PMID:23562433

  8. Stability of drug metabolizing enzymes during the incubation conditions of the liver microsomal assay with non-induced and induced mouse liver S-9 fractions.

    PubMed

    Paolini, M; Tonelli, F; Bauer, C; Corsi, C; Bronzetti, G

    1987-09-01

    The purpose of this work was to study the relative activities and stabilities of phase-I and phase-II drug metabolizing enzymes in incubation mixtures used in vitro genotoxicity testing in order to optimize the conditions of the assay, increase sensitivity and eliminate false negative results. Cytochrome P-450, NADPH-cytochrome P-450 (cytochrome c) reductase activity and various phase-I and phase-II enzyme activities of the drug-metabolizing system were determined in incubation mixtures used in liver microsomal assays. The behaviour of aminopyrine N-demethylase and p-nitroanisole O-demethylase activities as phase-I markers have been reported previously. Other activities measured were glutathione S-transferase, glutathione S-epoxide transferase and epoxide hydrase, and lipid peroxidation (LP) was determined. The experiments were carried out on liver S9 fractions derived from non-induced mice or mice induced with sodium phenobarbital (PB), and/or beta-naphthoflavone (beta-NF). The phase-II enzymes were much more stable (70-90% residual activity) than phase-I enzyme activities (35-60%) in all conditions tested. The residual cytochrome P-450 was approximately 70% stable and the remaining activity of NADPH-cytochrome c-reductase about 80%, indicating that this latter enzyme does not limit the rate of the monoxygenase system in these conditions. Phase-II enzymes were induced to a smaller extent (about 2 times) than in phase-I enzymes (5-6 times) by beta-NF + PB. NADPH-cytochrome c-reductase behaved as phase-II enzymes in this respect as well as for stability. LP was appreciably higher in non-induced than in induced animals. Treatment with the beta-NF + PB mixture, however, showed that induced enzymes were more stable than those obtained by simple induction with either beta-NF or PB alone. These results lead to the conclusion that prolonged incubation times in mutagenicity assays are unnecessary when considering the relative stabilities of the various phase-I and phase

  9. Centrally activated pipe snubbing system

    DOEpatents

    Cawley, William E.

    1985-01-01

    An electromechanical pipe snubbing system and an electromechanical pipe snubber. In the system, each pipe snubber, in a set of pipe snubbers, has an electromechanical mechanism to lock and unlock the snubber. A sensor, such as a seismometer, measures a quantity related to making a snubber locking or unlocking decision. A control device makes an electrical connection between a power supply and each snubber's electromechanical mechanism to simultaneously lock each snubber when the sensor measurement indicates a snubber locking condition. The control device breaks the connection to simultaneously unlock each snubber when the sensor measurement indicates a snubber unlocking condition. In the snubber, one end of the shaft slides within a bore in one end of a housing. The other end of the shaft is rotatably attached to a pipe; the other end of the housing is rotatively attached to a wall. The snubber's electromechanical mechanism locks the slidable end of the shaft to the housing and unlocks that end from the housing. The electromechanical mechanism permits remote testing and lockup status indication for each snubber.

  10. METABOLISM OF BENZ(J)ACEANTHRYLENE (CHOLANTHRYLENE) AND BENZ(L)ACEANTHRYLENE BY INDUCED RAT LIVER S9 (JOURNAL VERSION)

    EPA Science Inventory

    The metabolites of benz(j)aceanthrylene (B(j)A) and benz(l)aceanthrylene (B(l)A) produced by incubation with liver S9 proteins from rats induced with Aroclor-1254 and phenobarbital have been studied. Aroclor-1254 and phenobarbital induced rat liver S9 each metabolized B(j)A to tr...

  11. Active microrheology in active matter systems: Mobility, intermittency, and avalanches.

    PubMed

    Reichhardt, C; Reichhardt, C J Olson

    2015-03-01

    We examine the mobility and velocity fluctuations of a driven particle moving through an active matter bath of self-mobile disks for varied density or area coverage and varied activity. We show that the driven particle mobility can exhibit nonmonotonic behavior that is correlated with distinct changes in the spatiotemporal structures that arise in the active media. We demonstrate that the probe particle velocity distributions exhibit specific features in the different dynamic regimes and identify an activity-induced uniform crystallization that occurs for moderate activity levels and is distinct from the previously observed higher activity cluster phase. The velocity distribution in the cluster phase has telegraph noise characteristics produced when the probe particle moves alternately through high-mobility areas that are in the gas state and low-mobility areas that are in the dense phase. For higher densities and large activities, the system enters what we characterize as an active jamming regime. Here the probe particle moves in intermittent jumps or avalanches that have power-law-distributed sizes that are similar to the avalanche distributions observed for nonactive disk systems near the jamming transition. PMID:25871116

  12. Formation of GSH-trapped reactive metabolites in human liver microsomes, S9 fraction, HepaRG-cells, and human hepatocytes.

    PubMed

    Lassila, Toni; Rousu, Timo; Mattila, Sampo; Chesné, Christophe; Pelkonen, Olavi; Turpeinen, Miia; Tolonen, Ari

    2015-11-10

    The objective was to compare several in vitro human liver-derived subcellular and cellular incubation systems for the formation of GSH-trapped reactive metabolites. Incubations of pooled human liver microsomes, human liver S9 fractions, HepaRG-cells, and human hepatocytes were performed with glutathione as a trapping agent. Experiments with liver S9 were performed under two conditions, using only NADPH and using a full set of cofactors enabling also conjugative metabolism. Ten structurally different compounds were used as a test set, chosen as either "positive" (ciprofloxacin, clozapine, diclofenac, ethinyl estradiol, pulegone, and ticlopidine) or "negative" (caffeine, citalopram, losartan, montelukast) compounds, based on their known adverse reactions on liver or bone marrow. GSH conjugates were observed for seven of the ten compounds; while no conjugates were observed for caffeine, citalopram, or ciprofloxacin. Hepatocyte and HepaRG assays produced a clearly lower number and lower relative abundance of GSH conjugates compared to assays with microsomes and S9 fractions. The major GSH conjugates were different for many compounds in cellular subfractions and cell-based systems. Hepatocytes generally produced a higher number of GSH conjugates than HepaRG cells, although the differences were minor. The results show that the hepatic enzyme system used for screening of GSH-trapped reactive metabolites do have a high impact on the results, and results between different systems are comparable only qualitatively. PMID:26263063

  13. PASS: Creating Physically Active School Systems

    ERIC Educational Resources Information Center

    Ciotto, Carol M.; Fede, Marybeth H.

    2014-01-01

    PASS, a Physically Active School System, is a program by which school districts and schools utilize opportunities for school-based physical activity that enhance overall fitness and cognition, which can be broken down into four integral parts consisting of connecting, communicating, collaborating, and cooperating. There needs to be an…

  14. Active impedance matching of complex structural systems

    NASA Technical Reports Server (NTRS)

    Macmartin, Douglas G.; Miller, David W.; Hall, Steven R.

    1991-01-01

    Viewgraphs on active impedance matching of complex structural systems are presented. Topics covered include: traveling wave model; dereverberated mobility model; computation of dereverberated mobility; control problem: optimal impedance matching; H2 optimal solution; statistical energy analysis (SEA) solution; experimental transfer functions; interferometer actuator and sensor locations; active strut configurations; power dual variables; dereverberation of complex structure; dereverberated transfer function; compensators; and relative power flow.

  15. Atomic and electronic structure of Mo6S9-xIx nanowires

    NASA Astrophysics Data System (ADS)

    Meden, A.; Kodre, A.; Padeznik Gomilsek, J.; Arcon, I.; Vilfan, I.; Vrbanic, D.; Mrzel, A.; Mihailovic, D.

    2005-09-01

    Moybdenum-based subnanometre diameter nanowires are easy to synthesize and disperse, and they exhibit a variety of functional properties in which they are superior to other one-dimensional materials. However, further progress in the understanding of physical properties and the development of new and specific applications have so far been impeded by the fact that their structure was not accurately known. Here we report on a combination of systematic x-ray diffraction and extended x-ray absorption fine structure experiments, and first-principles theoretical structure calculations, which are used to determine the atomic skeletal structure of individual Mo6S9-xIx (MoSIx) nanowires, their packing arrangement within bundles and their electronic band structure. From this work we conclude that the variations in functional properties appear to arise from different stoichiometry, not skeletal structure. A supplementary data file is available from http://stacks.iop.org/0957-4484/16/1578

  16. Phase Transitions in Model Active Systems

    NASA Astrophysics Data System (ADS)

    Redner, Gabriel S.

    The amazing collective behaviors of active systems such as bird flocks, schools of fish, and colonies of microorganisms have long amazed scientists and laypeople alike. Understanding the physics of such systems is challenging due to their far-from-equilibrium dynamics, as well as the extreme diversity in their ingredients, relevant time- and length-scales, and emergent phenomenology. To make progress, one can categorize active systems by the symmetries of their constituent particles, as well as how activity is expressed. In this work, we examine two categories of active systems, and explore their phase behavior in detail. First, we study systems of self-propelled spherical particles moving in two dimensions. Despite the absence of an aligning interaction, this system displays complex emergent dynamics, including phase separation into a dense active solid and dilute gas. Using simulations and analytic modeling, we quantify the phase diagram and separation kinetics. We show that this nonequilibrium phase transition is analogous to an equilibrium vapor-liquid system, with binodal and spinodal curves and a critical point. We also characterize the dense active solid phase, a unique material which exhibits the structural signatures of a crystalline solid near the crystal-hexatic transition point, as well as anomalous dynamics including superdiffusive motion on intermediate timescales. We also explore the role of interparticle attraction in this system. We demonstrate that attraction drastically changes the phase diagram, which contains two distinct phase-separated regions and is reentrant as a function of propulsion speed. We interpret this complex situation with a simple kinetic model, which builds from the observed microdynamics of individual particles to a full description of the macroscopic phase behavior. We also study active nematics, liquid crystals driven out of equilibrium by energy-dissipating active stresses. The equilibrium nematic state is unstable in these

  17. Active imaging system with Faraday filter

    DOEpatents

    Snyder, J.J.

    1993-04-13

    An active imaging system has a low to medium powered laser transmitter and receiver wherein the receiver includes a Faraday filter with an ultranarrow optical bandpass and a bare (nonintensified) CCD camera. The laser is locked in the vicinity of the passband of the Faraday filter. The system has high sensitivity to the laser illumination while eliminating solar background.

  18. Active imaging system with Faraday filter

    DOEpatents

    Snyder, James J.

    1993-01-01

    An active imaging system has a low to medium powered laser transmitter and receiver wherein the receiver includes a Faraday filter with an ultranarrow optical bandpass and a bare (nonintensified) CCD camera. The laser is locked in the vicinity of the passband of the Faraday filter. The system has high sensitivity to the laser illumination while eliminating solar background.

  19. System for objective assessment of fetal activity.

    PubMed

    Kaluzynski, K J; Kret, T; Czajkowski, K; Sieńko, J; Zmigrodzki, J

    2011-07-01

    Fetal activity is an important indicator of fetal well-being. It is proposed to assess this activity using the pulsed wave Doppler method to collect fetal activity data and dedicated software for on-line processing. The system, addressed to 3rd trimester pregnancies, provides information on presence of pseudobreathing, the heart rate trace, the fetal movement trace, the movement velocity spectrogram, histograms of the velocity and acceleration of both the body movements and pseudobreathing, parameters of these histograms (mean values, standard deviations, shape descriptors), and cumulative counts of the velocity histograms. These parameters form the feature vector of the fetal activity. The system was validated by simultaneous echographic and cardiotocographic recordings and during oxytocin challenge tests. Feature vectors obtained from 1h recordings in 61 pregnancies were submitted to multivariate analysis of variance. Activity patterns of physiological cases and "borderline pathologies" were discriminated using reduced feature vectors, containing cumulative counts of velocity histograms. PMID:21277248

  20. Active containment systems incorporating modified pillared clays

    SciTech Connect

    Lundie, P. |; McLeod, N.

    1997-12-31

    The application of treatment technologies in active containment systems provides a more advanced and effective method for the remediation of contaminated sites. These treatment technologies can be applied in permeable reactive walls and/or funnel and gate systems. The application of modified pillared clays in active containment systems provides a mechanism for producing permeable reactive walls with versatile properties. These pillared clays are suitably modified to incorporate reactive intercalatants capable of reacting with both a broad range of organic pollutants of varying molecular size, polarity and reactivity. Heavy metals can be removed from contaminated water by conventional ion-exchange and other reactive processes within the clay structure. Complex contamination problems can be addressed by the application of more than one modified clay on a site specific basis. This paper briefly describes the active containment system and the structure/chemistry of the modified pillared clay technology, illustrating potential applications of the in-situ treatment process for contaminated site remediation.

  1. Protection of Active Distribution Systems with DGs

    NASA Astrophysics Data System (ADS)

    Akila, Abdelrahman Ahmed; Helal, Ahmed; Eldesouki, Hussein

    2015-10-01

    Distribution systems are traditionally designed as radial passive systems fed from a single source. Protection coordination of such systems has been easily established assuming the system radiality. Insertion of distributed generators (DGs) into distribution systems makes the distribution system to be more active which causes redistribution of fault currents magnitudes and directions. This causes negative impacts on the original protection system coordination, since the distribution system losses its radiality and passiveness. Recently protection coordination in the presence of distributed generation has been paid a great attention. Researchers proposed various solutions to solve the protection coordination problem caused by adding DG into the distribution network. In this paper, the proposed solutions for the protection coordination problem considering the DG insertion will be illustrated, classified, and criticized.

  2. Aging assessment for active fire protection systems

    SciTech Connect

    Ross, S.B.; Nowlen, S.P.; Tanaka, T.

    1995-06-01

    This study assessed the impact of aging on the performance and reliability of active fire protection systems including both fixed fire suppression and fixed fire detection systems. The experience base shows that most nuclear power plants have an aggressive maintenance and testing program and are finding degraded fire protection system components before a failure occurs. Also, from the data reviewed it is clear that the risk impact of fire protection system aging is low. However, it is assumed that a more aggressive maintenance and testing program involving preventive diagnostics may reduce the risk impact even further.

  3. Active Displacement Control of Active Magnetic Bearing System

    NASA Astrophysics Data System (ADS)

    Kertész, Milan; Kozakovič, Radko; Magdolen, Luboš; Masaryk, Michal

    2014-12-01

    The worldwide energy production nowadays is over 3400 GW while storage systems have a capacity of only 90 GW [1]. There is a good solution for additional storage capacity in flywheel energy storage systems (FES). The main advantage of FES is its relatively high efficiency especially with using the active magnetic bearing system. Therefore there exist good reasons for appropriate simulations and for creating a suitable magneto-structural control system. The magnetic bearing, including actuation, is simulated in the ANSYS parametric design language (APDL). APDL is used to create the loops of transient simulations where boundary conditions (BC) are updated based upon a "gap sensor" which controls the nodal position values of the centroid of the shaft and the current density inputs onto the copper windings.

  4. Gamma Band Activity in the Reticular Activating System

    PubMed Central

    Urbano, Francisco J.; Kezunovic, Nebojsa; Hyde, James; Simon, Christen; Beck, Paige; Garcia-Rill, Edgar

    2012-01-01

    This review considers recent evidence showing that cells in three regions of the reticular activating system (RAS) exhibit gamma band activity, and describes the mechanisms behind such manifestation. Specifically, we discuss how cells in the mesopontine pedunculopontine nucleus (PPN), intralaminar parafascicular nucleus (Pf), and pontine subcoeruleus nucleus dorsalis (SubCD) all fire in the beta/gamma band range when maximally activated, but no higher. The mechanisms behind this ceiling effect have been recently elucidated. We describe recent findings showing that every cell in the PPN have high-threshold, voltage-dependent P/Q-type calcium channels that are essential, while N-type calcium channels are permissive, to gamma band activity. Every cell in the Pf also showed that P/Q-type and N-type calcium channels are responsible for this activity. On the other hand, every SubCD cell exhibited sodium-dependent subthreshold oscillations. A novel mechanism for sleep–wake control based on well-known transmitter interactions, electrical coupling, and gamma band activity is described. The data presented here on inherent gamma band activity demonstrates the global nature of sleep–wake oscillation that is orchestrated by brainstem–thalamic mechanism, and questions the undue importance given to the hypothalamus for regulation of sleep–wakefulness. The discovery of gamma band activity in the RAS follows recent reports of such activity in other subcortical regions like the hippocampus and cerebellum. We hypothesize that, rather than participating in the temporal binding of sensory events as seen in the cortex, gamma band activity manifested in the RAS may help stabilize coherence related to arousal, providing a stable activation state during waking and paradoxical sleep. Most of our thoughts and actions are driven by pre-conscious processes. We speculate that continuous sensory input will induce gamma band activity in the RAS that could participate in the processes of

  5. Traveling and Resting Crystals in Active Systems

    NASA Astrophysics Data System (ADS)

    Menzel, Andreas M.; Löwen, Hartmut

    2013-02-01

    A microscopic field theory for crystallization in active systems is proposed which unifies the phase-field-crystal model of freezing with the Toner—Tu theory for self-propelled particles. A wealth of different active crystalline states are predicted and characterized. In particular, for increasing strength of self-propulsion, a transition from a resting crystal to a traveling crystalline state is found where the particles migrate collectively while keeping their crystalline order. Our predictions, which are verifiable in experiments and in particle-resolved computer simulations, provide a starting point for the design of new active materials.

  6. Application of the TGx-28.65 transcriptomic biomarker to classify genotoxic and non-genotoxic chemicals in human TK6 cells in the presence of rat liver S9.

    PubMed

    Yauk, Carole L; Buick, Julie K; Williams, Andrew; Swartz, Carol D; Recio, Leslie; Li, Heng-Hong; Fornace, Albert J; Thomson, Errol M; Aubrecht, Jiri

    2016-05-01

    In vitro transcriptional signatures that predict toxicities can facilitate chemical screening. We previously developed a transcriptomic biomarker (known as TGx-28.65) for classifying agents as genotoxic (DNA damaging) and non-genotoxic in human lymphoblastoid TK6 cells. Because TK6 cells do not express cytochrome P450s, we confirmed accurate classification by the biomarker in cells co-exposed to 1% 5,6 benzoflavone/phenobarbital-induced rat liver S9 for metabolic activation. However, chemicals may require different types of S9 for activation. Here we investigated the response of TK6 cells to higher percentages of Aroclor-, benzoflavone/phenobarbital-, or ethanol-induced rat liver S9 to expand TGx-28.65 biomarker applicability. Transcriptional profiles were derived 3 to 4 hr following a 4 hr co-exposure of TK6 cells to test chemicals and S9. Preliminary studies established that 10% Aroclor- and 5% ethanol-induced S9 alone did not induce the TGx-28.65 biomarker genes. Seven genotoxic and two non-genotoxic chemicals (and concurrent solvent and positive controls) were then tested with one of the S9s (selected based on cell survival and micronucleus induction). Relative survival and micronucleus frequency was assessed by flow cytometry in cells 20 hr post-exposure. Genotoxic/non-genotoxic chemicals were accurately classified using the different S9s. One technical replicate of cells co-treated with dexamethasone and 10% Aroclor-induced S9 was falsely classified as genotoxic, suggesting caution in using high S9 concentrations. Even low concentrations of genotoxic chemicals (those not causing cytotoxicity) were correctly classified, demonstrating that TGx-28.65 is a sensitive biomarker of genotoxicity. A meta-analysis of datasets from 13 chemicals supports that different S9s can be used in TK6 cells, without impairing classification using the TGx-28.65 biomarker. Environ. Mol. Mutagen. 57:243-260, 2016. © 2016 Her Majesty the Queen in Right of Canada. Environmental and

  7. Liver S9 Fraction-Derived Metabolites of Curcumin Analogue UBS109

    PubMed Central

    2014-01-01

    To address the shortcomings of the natural product curcumin, many groups have created analogues that share similar structural features while displaying superior properties, particularly in anticancer drug discovery. Relatively unexplored have been the mechanisms by which such compounds are metabolized. A comprehensive in vitro study of a curcumin analogue (UBS109) in liver S9 fractions from five different species is presented. Further, we examine the cell-based bioactivity of the major metabolites. In spite of the fact that UBS109 reduces tumor growth in mice, it is quickly metabolized in vitro and 94% protein bound in mouse plasma. The primary monounsaturated metabolite is only modestly bioactive against MDA-MB-231 breast cancer cells. These observations suggest that while the α,β-unsaturated ketone common to curcumin analogues is important for bioactivity, protein binding and tissue distribution may serve to protect UBS109 from full metabolism in vivo while allowing it to exert a pharmacological effect by means of slow drug release. PMID:24900828

  8. Distributed control system for active mirrors

    NASA Astrophysics Data System (ADS)

    Rodriguez-Ramos, Luis F.; Williams, Mark R.; Castro, Javier; Cruz, A.; Gonzalez, Juan C.; Mack, Brian; Martin, Carlos; Pescador, German; Sanchez, Vicente; Sosa, Nicolas A.

    1994-06-01

    This paper presents the IAC (Instituto de Astrofisica de Canaries, Spain) proposal of a distributed control system intended for the active support of a 8 m mirror. The system incorporates a large number of compact `smart' force actuators, six force definers, and a mirror support computer (MSC) for interfacing with the telescope control system and for general housekeeping. We propose the use of a network for the interconnection of the actuators, definers and the MSC, which will minimize the physical complexity of the interface between the mirror support system and the MSC. The force actuator control electronics are described in detail, as is the system software architecture of the actuator and the MSC. As the network is a key point for the system, we also detail the evaluation of three candidates, before electing the CAN bus.

  9. Modular System to Enable Extravehicular Activity

    NASA Technical Reports Server (NTRS)

    Sargusingh, Miriam J.

    2011-01-01

    The ability to perform extravehicular activity (EVA), both human and robotic, has been identified as a key component to space missions to support such operations as assembly and maintenance of space system (e.g. construction and maintenance of the International Space Station), and unscheduled activities to repair an element of the transportation and habitation systems that can only be accessed externally and via unpressurized areas. In order to make human transportation beyond lower earth orbit (BLEO) practical, efficiencies must be incorporated into the integrated transportation systems to reduce system mass and operational complexity. Affordability is also a key aspect to be considered in space system development; this could be achieved through commonality, modularity and component reuse. Another key aspect identified for the EVA system was the ability to produce flight worthy hardware quickly to support early missions and near Earth technology demonstrations. This paper details a conceptual architecture for a modular extravehicular activity system (MEVAS) that would meet these stated needs for EVA capability that is affordable, and that could be produced relatively quickly. Operational concepts were developed to elaborate on the defined needs and define the key capabilities, operational and design constraints, and general timelines. The operational concept lead to a high level design concept for a module that interfaces with various space transportation elements and contains the hardware and systems required to support human and telerobotic EVA; the module would not be self-propelled and would rely on an interfacing element for consumable resources. The conceptual architecture was then compared to EVA Systems used in the Shuttle Orbiter, on the International Space Station to develop high level design concepts that incorporate opportunities for cost savings through hardware reuse, and quick production through the use of existing technologies and hardware designs

  10. Active Annuloplasty System for Mitral Valve Insufficiency

    NASA Astrophysics Data System (ADS)

    Díaz Lantada, Andrés; Lafont, Pilar; Rada, Ignacio; Jiménez, Antonio; Hernández, José Luis; Lorenzo-Yustos, Héctor; Muñoz-García, Julio

    Active materials are capable of responding in a controlled way to different external physical or chemical stimuli by changing some of their properties. These materials can be used to design and develop sensors, actuators and multifunctional systems with a large number of applications for developing medical devices.

  11. METALS DISTRIBUTIONS IN ACTIVATED SLUDGE SYSTEMS

    EPA Science Inventory

    This project developed models to predict the distribution of metals in activated sludge system process streams. The data used to develop the models were obtained through extended pilot studies from a previous project. The objectives of the study were to evaluate the effects of wa...

  12. Supporting Classroom Activities with the BSUL System

    ERIC Educational Resources Information Center

    Ogata, Hiroaki; Saito, Nobuji A.; Paredes J., Rosa G.; San Martin, Gerardo Ayala; Yano, Yoneo

    2008-01-01

    This paper presents the integration of ubiquitous computing systems into classroom settings, in order to provide basic support for classrooms and field activities. We have developed web application components using Java technology and configured a classroom with wireless network access and a web camera for our purposes. In this classroom, the…

  13. Design of nutrient removal activated sludge systems.

    PubMed

    Manga, J; Ferrer, J; Seco, A; Garcia-Usach, F

    2003-01-01

    A mechanistic mathematical model for nutrient and organic matter removal was used to describe the behavior of a nitrification denitrification enhanced biological phosphorus removal (NDEBPR) system. This model was implemented in a user-friendly software DESASS (design and simulation of activated sludge systems). A 484-L pilot plant was operated to verify the model results. The pilot plant was operated for three years over three different sludge ages. The validity of the model was confirmed with data from the pilot plant. Also, the utility of DESASS as a valuable tool for designing NDEBPR systems was confirmed. PMID:12906279

  14. Targeted activation in deterministic and stochastic systems

    NASA Astrophysics Data System (ADS)

    Eisenhower, Bryan; Mezić, Igor

    2010-02-01

    Metastable escape is ubiquitous in many physical systems and is becoming a concern in engineering design as these designs (e.g., swarms of vehicles, coupled building energetics, nanoengineering, etc.) become more inspired by dynamics of biological, molecular and other natural systems. In light of this, we study a chain of coupled bistable oscillators which has two global conformations and we investigate how specialized or targeted disturbance is funneled in an inverse energy cascade and ultimately influences the transition process between the conformations. We derive a multiphase averaged approximation to these dynamics which illustrates the influence of actions in modal coordinates on the coarse behavior of this process. An activation condition that predicts how the disturbance influences the rate of transition is then derived. The prediction tools are derived for deterministic dynamics and we also present analogous behavior in the stochastic setting and show a divergence from Kramers activation behavior under targeted activation conditions.

  15. Green Bank Telescope active surface system

    NASA Astrophysics Data System (ADS)

    Lacasse, Richard J.

    1998-05-01

    During the design phase of the Green Bank Telescope (GBT), various means of providing an accurate surface on a large aperture paraboloid, were considered. Automated jacks supporting the primary reflector were selected as the appropriate technology since they promised greater performance and potentially lower costs than a homologous or carbon fiber design, and had certain advantages over an active secondary. The design of the active surface has presented many challenges. Since the actuators are mounted on a tipping structure, it was required that they support a significant side-load. Such devices were not readily available commercially so they had to be developed. Additional actuator requirements include low backlash, repeatable positioning, and an operational life of at least 230 years. Similarly, no control system capable of controlling the 2209 actuators was commercially available. Again a prime requirement was reliability. Maintaining was also a very important consideration. The system architecture is tree-like. An active surface 'master-computer' controls interaction with the telescope control system, and controls ancillary equipment such as power supplies and temperature monitors. Two slave computers interface with the master- computer, and each closes approximately 1100 position loops. For simplicity, the servo is an 'on/off' type, yet achieves a positioning resolution of 25 microns. Each slave computer interfaces with 4 VME I/O cards, which in turn communicate with 140 control modules. The control modules read out the positions of the actuators every 0.1 sec and control the actuators' DC motors. Initial control of the active surface will be based on an elevation dependant structural model. Later, the model will be improved by holographic observations.Surface accuracy will be improved further by using laser ranging system which will actively measure the surface figure. Several tests have been conducted to assure that the system will perform as desired when

  16. Active gated imaging in driver assistance system

    NASA Astrophysics Data System (ADS)

    Grauer, Yoav

    2014-04-01

    In this paper, we shall present the active gated imaging system (AGIS) in relation to the automotive field. AGIS is based on a fast-gated camera and pulsed illuminator, synchronized in the time domain to record images of a certain range of interest. A dedicated gated CMOS imager sensor and near infra-red (NIR) pulsed laser illuminator, is presented in this paper to provide active gated technology. In recent years, we have developed these key components and learned the system parameters, which are most beneficial to nighttime (in all weather conditions) driving in terms of field of view, illumination profile, resolution, and processing power. We shall present our approach of a camera-based advanced driver assistance systems (ADAS) named BrightEye™, which makes use of the AGIS technology in the automotive field.

  17. Modular System to Enable Extravehicular Activity

    NASA Technical Reports Server (NTRS)

    Sargusingh, Miriam J.

    2012-01-01

    The ability to perform extravehicular activity (EVA), both human and robotic, has been identified as a key component to space missions to support such operations as assembly and maintenance of space systems (e.g. construction and maintenance of the International Space Station), and unscheduled activities to repair an element of the transportation and habitation systems that can only be accessed externally and via unpressurized areas. In order to make human transportation beyond lower Earth orbit (LEO) practical, efficiencies must be incorporated into the integrated transportation systems to reduce system mass and operational complexity. Affordability is also a key aspect to be considered in space system development; this could be achieved through commonality, modularity and component reuse. Another key aspect identified for the EVA system was the ability to produce flight worthy hardware quickly to support early missions and near Earth technology demonstrations. This paper details a conceptual architecture for a modular EVA system that would meet these stated needs for EVA capability that is affordable, and that could be produced relatively quickly. Operational concepts were developed to elaborate on the defined needs, and to define the key capabilities, operational and design constraints, and general timelines. The operational concept lead to a high level design concept for a module that interfaces with various space transportation elements and contains the hardware and systems required to support human and telerobotic EVA; the module would not be self-propelled and would rely on an interfacing element for consumable resources. The conceptual architecture was then compared to EVA Systems used in the Space Shuttle Orbiter, on the International Space Station to develop high level design concepts that incorporate opportunities for cost savings through hardware reuse, and quick production through the use of existing technologies and hardware designs. An upgrade option

  18. Optically Active Porphyrin and Phthalocyanine Systems.

    PubMed

    Lu, Hua; Kobayashi, Nagao

    2016-05-25

    This review highlights and summarizes various optically active porphyrin and phthalocyanine molecules prepared using a wide range of structural modification methods to improve the design of novel structures and their applications. The induced chirality of some illustrative achiral bis-porphyrins with a chiral guest molecule is introduced because these systems are ideal for the identification and separation of chiral biologically active substrates. In addition, the relationship between CD signal and the absolute configuration of the molecule is analyzed through an analysis of the results of molecular modeling calculations. Possible future research directions are also discussed. PMID:27186902

  19. Control Systems Cyber Security Standards Support Activities

    SciTech Connect

    Robert Evans

    2009-01-01

    The Department of Homeland Security’s Control Systems Security Program (CSSP) is working with industry to secure critical infrastructure sectors from cyber intrusions that could compromise control systems. This document describes CSSP’s current activities with industry organizations in developing cyber security standards for control systems. In addition, it summarizes the standards work being conducted by organizations within the sector and provides a brief listing of sector meetings and conferences that might be of interest for each sector. Control systems cyber security standards are part of a rapidly changing environment. The participation of CSSP in the development effort for these standards has provided consistency in the technical content of the standards while ensuring that information developed by CSSP is included.

  20. Advanced extravehicular activity systems requirements definition study

    NASA Technical Reports Server (NTRS)

    1988-01-01

    A study to define the requirements for advanced extravehicular activities (AEVA) was conducted. The purpose of the study was to develop an understanding of the EVA technology requirements and to map a pathway from existing or developing technologies to an AEVA system capable of supporting long-duration missions on the lunar surface. The parameters of an AEVA system which must sustain the crewmembers and permit productive work for long periods in the lunar environment were examined. A design reference mission (DRM) was formulated and used as a tool to develop and analyze the EVA systems technology aspects. Many operational and infrastructure design issues which have a significant influence on the EVA system are identified.

  1. Active State Model for Autonomous Systems

    NASA Technical Reports Server (NTRS)

    Park, Han; Chien, Steve; Zak, Michail; James, Mark; Mackey, Ryan; Fisher, Forest

    2003-01-01

    The concept of the active state model (ASM) is an architecture for the development of advanced integrated fault-detection-and-isolation (FDI) systems for robotic land vehicles, pilotless aircraft, exploratory spacecraft, or other complex engineering systems that will be capable of autonomous operation. An FDI system based on the ASM concept would not only provide traditional diagnostic capabilities, but also integrate the FDI system under a unified framework and provide mechanism for sharing of information between FDI subsystems to fully assess the overall health of the system. The ASM concept begins with definitions borrowed from psychology, wherein a system is regarded as active when it possesses self-image, self-awareness, and an ability to make decisions itself, such that it is able to perform purposeful motions and other transitions with some degree of autonomy from the environment. For an engineering system, self-image would manifest itself as the ability to determine nominal values of sensor data by use of a mathematical model of itself, and selfawareness would manifest itself as the ability to relate sensor data to their nominal values. The ASM for such a system may start with the closed-loop control dynamics that describe the evolution of state variables. As soon as this model was supplemented with nominal values of sensor data, it would possess self-image. The ability to process the current sensor data and compare them with the nominal values would represent self-awareness. On the basis of self-image and self-awareness, the ASM provides the capability for self-identification, detection of abnormalities, and self-diagnosis.

  2. Research on an Active Seat Belt System

    NASA Astrophysics Data System (ADS)

    Kawashima, Takeshi

    In a car crash, permanent injury can be avoided if deformation of an occupant's rib cage is maintained within the allowable value. In order to realize this condition, the occupant's seat belt tension must be instantaneously adjusted by a feedback control system. In this study, a seat belt tension control system based on the active shock control system is proposed. The semi-active control law used is derived from the sliding mode control method. One advantage of this proposed system is that it does not require a large power actuator because the seat belt tension is controlled by a brake mechanism. The effectiveness is confirmed by numerical simulation using general parameters of a human thorax and a passenger car in a collision scenario with a wall at a velocity of 100 km/h. The feasibility is then confirmed with a control experiment using a scale model of about 1/10 scale. The relative displacement of the thorax model approaches the allowable value smoothly along the control reference and settles near this value. Thus, the proposed seat belt tension control system design is established.

  3. Multipurpose active/passive motion compensation system

    SciTech Connect

    Sullivan, R.A.; Clements, R.E.; Davenport, M.R.

    1984-05-01

    A microprocessor-controlled active/passive motion compensation system has been developed for deploying a variety of geotechnical in-situ testing devices with mobile drilling rigs from low-cost service vessels. The light-weight rotary heave compensator incorporates a hydraulic motor as the compensator actuator and a servo-controlled closed loop pump to reduce the air storage and power requirements. Unique features of the system are the use of inertial sensors to measure three components of boat motion, the ability to run the system in active/passive or passive modes, and the ability to automatically lower the drillstring at a constant velocity while maintaining motion compensation. Quantitative measurements made during sea trials offshore California yielded motion compensation accuracy approaching 98 percent which is much better than the compensation achieved with passive systems. Results are presented from offshore in-situ testing with a cone penetrometer, a vane shear device, and a suspension PS logger. The system can also be used for other offshore applications.

  4. Active laser system for sea ice control

    NASA Astrophysics Data System (ADS)

    Evtikhiev, Nickolay N.; Gaponov, Alexandr E.; Kuluba, Yury N.; Matous, Vladislav I.; Radominov, Oleg E.; Tuzikov, Vladimir Z.; Vargaftic, Vasiliy N.

    1997-01-01

    The airborne systems are used for complex investigations of coastline very successfully, for example it can be used to measure the depth of the sea, to discover the reefs and so on. Such information may be used in navigation too. The specific conditions of navigation in the North and Pole seas defines the necessity of exact knowledge about the ice cracks in order to find the possible direction of the ship movement. The active optical system, working in the near IR region, has many advantages before the passive one, especially if it is necessary to work during the polar night and at bad weather conditions. In this article we discuss the demands to the laser active airborne systems, that given the accurate picture of the ice with high resolution in the daytime and nighttime conditions. Such system based on the laser, mechanical scanner and avalanche photodiode is very compact, reliable and informative. The picture of the ice surface can be shown on the TV monitor, can be written to the memory and can be delivered to the processing center by the radiochannel. The experimental results are shown together with results of this system probing in the conditions of the North Pole Ocean.

  5. PCM Passive Cooling System Containing Active Subsystems

    NASA Technical Reports Server (NTRS)

    Blanding, David E.; Bass, David I.

    2005-01-01

    A multistage system has been proposed for cooling a circulating fluid that is subject to intermittent intense heating. The system would be both flexible and redundant in that it could operate in a basic passive mode, either sequentially or simultaneously with operation of a first, active cooling subsystem, and either sequentially or simultaneously with a second cooling subsystem that could be active, passive, or a combination of both. This flexibility and redundancy, in combination with the passive nature of at least one of the modes of operation, would make the system more reliable, relative to a conventional cooling system. The system would include a tube-in-shell heat exchanger, within which the space between the tubes would be filled with a phase-change material (PCM). The circulating hot fluid would flow along the tubes in the heat exchanger. In the basic passive mode of operation, heat would be conducted from the hot fluid into the PCM, wherein the heat would be stored temporarily by virtue of the phase change.

  6. Active Aircraft Pylon Noise Control System

    NASA Technical Reports Server (NTRS)

    Thomas, Russell H. (Inventor); Czech, Michael J (Inventor); Elmiligui, Alaa A. (Inventor)

    2015-01-01

    An active pylon noise control system for an aircraft includes a pylon structure connecting an engine system with an airframe surface of the aircraft and having at least one aperture to supply a gas or fluid therethrough, an intake portion attached to the pylon structure to intake a gas or fluid, a regulator connected with the intake portion via a plurality of pipes, to regulate a pressure of the gas or fluid, a plenum chamber formed within the pylon structure and connected with the regulator, and configured to receive the gas or fluid as regulated by the regulator, and a plurality of injectors in communication with the plenum chamber to actively inject the gas or fluid through the plurality of apertures of the pylon structure.

  7. Spontaneous activity in the developing auditory system.

    PubMed

    Wang, Han Chin; Bergles, Dwight E

    2015-07-01

    Spontaneous electrical activity is a common feature of sensory systems during early development. This sensory-independent neuronal activity has been implicated in promoting their survival and maturation, as well as growth and refinement of their projections to yield circuits that can rapidly extract information about the external world. Periodic bursts of action potentials occur in auditory neurons of mammals before hearing onset. This activity is induced by inner hair cells (IHCs) within the developing cochlea, which establish functional connections with spiral ganglion neurons (SGNs) several weeks before they are capable of detecting external sounds. During this pre-hearing period, IHCs fire periodic bursts of Ca(2+) action potentials that excite SGNs, triggering brief but intense periods of activity that pass through auditory centers of the brain. Although spontaneous activity requires input from IHCs, there is ongoing debate about whether IHCs are intrinsically active and their firing periodically interrupted by external inhibitory input (IHC-inhibition model), or are intrinsically silent and their firing periodically promoted by an external excitatory stimulus (IHC-excitation model). There is accumulating evidence that inner supporting cells in Kölliker's organ spontaneously release ATP during this time, which can induce bursts of Ca(2+) spikes in IHCs that recapitulate many features of auditory neuron activity observed in vivo. Nevertheless, the role of supporting cells in this process remains to be established in vivo. A greater understanding of the molecular mechanisms responsible for generating IHC activity in the developing cochlea will help reveal how these events contribute to the maturation of nascent auditory circuits. PMID:25296716

  8. Voice activity detection for speaker verification systems

    NASA Astrophysics Data System (ADS)

    Borowski, Filip

    2008-01-01

    Complex algorithm for speech activity detection was presented in this article. It is based on speech enhancement, features extraction and final detection algorithm. The first one was published in ETSI standard as a module of "Advanced front-end feature extraction algorithm" in distributed speech recognition system. It consists of two main parts, noise estimatiom and Wiener filtering. For the final detection modified linear prediction coefficients and spectral entropy features are extracted form denoised signal.

  9. Light and immune systems: activation of immunological activities

    NASA Astrophysics Data System (ADS)

    Huang, Zheng; Liu, Hong; Chen, Wei R.

    2006-02-01

    Light has been used to treat diseases for hundreds of years. Convenient and powerful light sources such as lasers make photomedicine a major branch in diseases treatment and detection. Originally, light was often used for local treatment, using photomechanical, photochemical, photothermal reactions and photomodulation as the major mechanisms. More and more investigators have become interested in the systemic effects of light, particularly in its effects on immune systems. Much work has been done to activate and/or enhance the host immune system to combat cancer, either using light as a direct tool or as an adjuvant method. Light has long been used for assisting disease detection and diagnosis. Advances in light technology have made photo-diagnostics ever more precise spatially and temporally. Many techniques facilitate observation of bio-molecule interactions and other biological processes at the cellular level, hence providing opportunities to detect and monitor immune activities. This manuscript will review recent photo-immunological research in treatment of cancer. The recent development of combination therapies involving lasers will be presented. Specifically, the results of cancer treatment using laser photothermal interaction, either with or without additional immunological stimulation will be discussed. The immunological effects of photodynamic therapy (PDT), and of its combination with immunotherapy in cancer treatment will also be discussed. Much interest has been recently concentrated in the immunological responses after laser treatment. Such responses at cellular and molecular levels will be discussed. The effect of these treatment modalities on the distant metastases also showed promise of light induced antitumor immunity. The combination therapy and induced immunological responses appear to be the key for long-term control of tumors.

  10. Active polarimeter optical system laser hazard analysis.

    SciTech Connect

    Augustoni, Arnold L.

    2005-07-01

    A laser hazard analysis was performed for the SNL Active Polarimeter Optical System based on the ANSI Standard Z136.1-2000, American National Standard for Safe Use of Lasers and the ANSI Standard Z136.6-2000, American National Standard for Safe Use of Lasers Outdoors. The Active Polarimeter Optical System (APOS) uses a pulsed, near-infrared, chromium doped lithium strontium aluminum fluoride (Cr:LiSAF) crystal laser in conjunction with a holographic diffuser and lens to illuminate a scene of interest. The APOS is intended for outdoor operations. The system is mounted on a height adjustable platform (6 feet to 40 feet) and sits atop a tripod that points the beam downward. The beam can be pointed from nadir to as much as 60 degrees off of nadir producing an illuminating spot geometry that can vary from circular (at nadir) to elliptical in shape (off of nadir). The JP Innovations crystal Cr:LiSAF laser parameters are presented in section II. The illuminating laser spot size is variable and can be adjusted by adjusting the separation distance between the lens and the holographic diffuser. The system is adjusted while platform is at the lowest level. The laser spot is adjusted for a particular spot size at a particular distance (elevation) from the laser by adjusting the separation distance (d{sub diffuser}) to predetermined values. The downward pointing angle is also adjusted before the platform is raised to the selected operation elevation.

  11. Global Positioning System Synchronized Active Light Autonomous Docking System

    NASA Technical Reports Server (NTRS)

    Howard, Richard T. (Inventor); Book, Michael L. (Inventor); Bryan, Thomas C. (Inventor); Bell, Joseph L. (Inventor)

    1996-01-01

    A Global Positioning System Synchronized Active Light Autonomous Docking System (GPSSALADS) for automatically docking a chase vehicle with a target vehicle comprising at least one active light emitting target which is operatively attached to the target vehicle. The target includes a three-dimensional array of concomitantly flashing lights which flash at a controlled common frequency. The GPSSALADS further comprises a visual tracking sensor operatively attached to the chase vehicle for detecting and tracking the target vehicle. Its performance is synchronized with the flash frequency of the lights by a synchronization means which is comprised of first and second internal clocks operatively connected to the active light target and visual tracking sensor, respectively, for providing timing control signals thereto, respectively. The synchronization means further includes first and second Global Positioning System receivers operatively connected to the first and second internal clocks, respectively, for repeatedly providing simultaneous synchronization pulses to the internal clocks, respectively. In addition, the GPSSALADS includes a docking process controller means which is operatively attached to the chase vehicle and is responsive to the visual tracking sensor for producing commands for the guidance and propulsion system of the chase vehicle.

  12. Global Positioning System Synchronized Active Light Autonomous Docking System

    NASA Technical Reports Server (NTRS)

    Howard, Richard (Inventor)

    1994-01-01

    A Global Positioning System Synchronized Active Light Autonomous Docking System (GPSSALADS) for automatically docking a chase vehicle with a target vehicle comprises at least one active light emitting target which is operatively attached to the target vehicle. The target includes a three-dimensional array of concomitantly flashing lights which flash at a controlled common frequency. The GPSSALADS further comprises a visual tracking sensor operatively attached to the chase vehicle for detecting and tracking the target vehicle. Its performance is synchronized with the flash frequency of the lights by a synchronization means which is comprised of first and second internal clocks operatively connected to the active light target and visual tracking sensor, respectively, for providing timing control signals thereto, respectively. The synchronization means further includes first and second Global Positioning System receivers operatively connected to the first and second internal clocks, respectively, for repeatedly providing simultaneous synchronization pulses to the internal clocks, respectively. In addition, the GPSSALADS includes a docking process controller means which is operatively attached to the chase vehicle and is responsive to the visual tracking sensor for producing commands for the guidance and propulsion system of the chase vehicle.

  13. Dislocation boundaries and active slip systems

    SciTech Connect

    Wert, J.A.; Hansen, N.

    1995-11-01

    Part of the dislocations which have participated in the plastic deformation of a polycrystalline metal are stored in dislocation boundaries in a two- or three-dimensional arrangement. The dislocation in such boundaries can be analyzed by determining the misorientation between neighboring crystallites and the boundary orientation. Information about the dislocations in the boundaries can also be obtained by an analysis of active slip systems based on the crystallite orientation and the imposed stress or strain state in combination with appropriate constraint conditions. In the present paper an analysis of the boundary dislocation structure and of the slip systems has been conducted for pure aluminium cold-rolled to a von Mises strain of 0.41. The results show that a substantial majority of dislocations in different types of dislocation boundaries are from the primary and conjugate slip system in the adjoining crystallites. A basis is therefore provided for integrating deformation structure observations with plastic deformation behavior.

  14. Extravehicular Activity (EVA) 101: Constellation EVA Systems

    NASA Technical Reports Server (NTRS)

    Jordan, Nicole C.

    2007-01-01

    A viewgraph presentation on Extravehicular Activity (EVA) Systems is shown. The topics include: 1) Why do we need space suits? 2) Protection From the Environment; 3) Primary Life Support System (PLSS); 4) Thermal Control; 5) Communications; 6) Helmet and Extravehicular Visor Assy; 7) Hard Upper Torso (HUT) and Arm Assy; 8) Display and Controls Module (DCM); 9) Gloves; 10) Lower Torso Assembly (LTA); 11) What Size Do You Need?; 12) Boot and Sizing Insert; 13) Boot Heel Clip and Foot Restraint; 14) Advanced and Crew Escape Suit; 15) Nominal & Off-Nominal Landing; 16) Gemini Program (mid-1960s); 17) Apollo EVA on Service Module; 18) A Bold Vision for Space Exploration, Authorized by Congress; 19) EVA System Missions; 20) Configurations; 21) Reduced Gravity Program; and 22) Other Opportunities.

  15. The synchronous active neutron detection assay system

    SciTech Connect

    Pickrell, M.M.; Kendall, P.K.

    1994-08-01

    We have begun to develop a novel technique for active neutron assay of fissile material in spent nuclear fuel. This approach will exploit a 14-MeV neutron generator developed by Schlumberger. The technique, termed synchronous active neutron detection (SAND), follows a method used routinely in other branches of physics to detect very small signals in presence of large backgrounds. Synchronous detection instruments are widely available commercially and are termed ``lock-in`` amplifiers. We have implemented a digital lock-in amplifier in conjunction with the Schlumberger neutron generator to explore the possibility of synchronous detection with active neutrons. The Schlumberger system can operate at up to a 50% duty factor, in effect, a square wave of neutron yield. Results are preliminary but promising. The system is capable of resolving the fissile material contained in a small fraction of the fuel rods in a cold fuel assembly; it also appears resilient to background neutron interference. The interrogating neutrons appear to be non-thermal and penetrating. Work remains to fully explore relevant physics and optimize instrument design.

  16. Active Thermal Control System Development for Exploration

    NASA Technical Reports Server (NTRS)

    Westheimer, David

    2007-01-01

    All space vehicles or habitats require thermal management to maintain a safe and operational environment for both crew and hardware. Active Thermal Control Systems (ATCS) perform the functions of acquiring heat from both crew and hardware within a vehicle, transporting that heat throughout the vehicle, and finally rejecting that energy into space. Almost all of the energy used in a space vehicle eventually turns into heat, which must be rejected in order to maintain an energy balance and temperature control of the vehicle. For crewed vehicles, Active Thermal Control Systems are pumped fluid loops that are made up of components designed to perform these functions. NASA has been actively developing technologies that will enable future missions or will provide significant improvements over the state of the art technologies. These technologies have are targeted for application on the Crew Exploration Vehicle (CEV), or Orion, and a Lunar Surface Access Module (LSAM). The technologies that have been selected and are currently under development include: fluids that enable single loop ATCS architectures, a gravity insensitive vapor compression cycle heat pump, a sublimator with reduced sensitivity to feedwater contamination, an evaporative heat sink that can operate in multiple ambient pressure environments, a compact spray evaporator, and lightweight radiators that take advantage of carbon composites and advanced optical coatings.

  17. Advanced Active Thermal Control Systems Architecture Study

    NASA Technical Reports Server (NTRS)

    Hanford, Anthony J.; Ewert, Michael K.

    1996-01-01

    The Johnson Space Center (JSC) initiated a dynamic study to determine possible improvements available through advanced technologies (not used on previous or current human vehicles), identify promising development initiatives for advanced active thermal control systems (ATCS's), and help prioritize funding and personnel distribution among many research projects by providing a common basis to compare several diverse technologies. Some technologies included were two-phase thermal control systems, light-weight radiators, phase-change thermal storage, rotary fluid coupler, and heat pumps. JSC designed the study to estimate potential benefits from these various proposed and under-development thermal control technologies for five possible human missions early in the next century. The study compared all the technologies to a baseline mission using mass as a basis. Each baseline mission assumed an internal thermal control system; an external thermal control system; and aluminum, flow-through radiators. Solar vapor compression heat pumps and light-weight radiators showed the greatest promise as general advanced thermal technologies which can be applied across a range of missions. This initial study identified several other promising ATCS technologies which offer mass savings and other savings compared to traditional thermal control systems. Because the study format compares various architectures with a commonly defined baseline, it is versatile and expandable, and is expected to be updated as needed.

  18. Noninvasive ambulatory measurement system of cardiac activity.

    PubMed

    Pino, Esteban J; Chavez, Javier A P; Aqueveque, Pablo

    2015-08-01

    This work implements a noninvasive system that measures the movements caused by cardiac activity. It uses unobtrusive Electro-Mechanical Films (EMFi) on the seat and on the backrest of a regular chair. The system detects ballistocardiogram (BCG) and respiration movements. Real data was obtained from 54 volunteers. 19 of them were measured in the laboratory and 35 in a hospital waiting room. Using a BIOPAC acquisition system, the ECG was measured simultaneously to the BCG for comparison. Wavelet Transform (WT) is a better option than Empirical Mode Decomposition (EMD) for signal extraction and produces higher effective measurement time. In the laboratory, the best results are obtained on the seat. The correlation index was 0.9800 and the Bland-Altman limits of agreement were 0.7136 ± 4.3673 [BPM]. In the hospital waiting room, the best results are also from the seat sensor. The correlation index was 0.9840, and the limits of agreement were 0.4386 ± 3.5884 [BPM]. The system is able to measure BCG in an unobtrusive way and determine the cardiac frequency with high precision. It is simple to use, which means the system can easily be used in non-standard settings: resting in a chair or couch, at the gym, schools or in a hospital waiting room, as shown. PMID:26738057

  19. Velocity distribution in active particles systems

    PubMed Central

    Marconi, Umberto Marini Bettolo; Gnan, Nicoletta; Paoluzzi, Matteo; Maggi, Claudio; Di Leonardo, Roberto

    2016-01-01

    We derive an analytic expression for the distribution of velocities of multiple interacting active particles which we test by numerical simulations. In clear contrast with equilibrium we find that the velocities are coupled to positions. Our model shows that, even for two particles only, the individual velocities display a variance depending on the interparticle separation and the emergence of correlations between the velocities of the particles. When considering systems composed of many particles we find an analytic expression connecting the overall velocity variance to density, at the mean-field level, and to the pair distribution function valid in the limit of small noise correlation times. Finally we discuss the intriguing analogies and main differences between our effective free energy functional and the theoretical scenario proposed so far for phase-separating active particles. PMID:27001289

  20. Velocity distribution in active particles systems

    NASA Astrophysics Data System (ADS)

    Marconi, Umberto Marini Bettolo; Gnan, Nicoletta; Paoluzzi, Matteo; Maggi, Claudio; di Leonardo, Roberto

    2016-03-01

    We derive an analytic expression for the distribution of velocities of multiple interacting active particles which we test by numerical simulations. In clear contrast with equilibrium we find that the velocities are coupled to positions. Our model shows that, even for two particles only, the individual velocities display a variance depending on the interparticle separation and the emergence of correlations between the velocities of the particles. When considering systems composed of many particles we find an analytic expression connecting the overall velocity variance to density, at the mean-field level, and to the pair distribution function valid in the limit of small noise correlation times. Finally we discuss the intriguing analogies and main differences between our effective free energy functional and the theoretical scenario proposed so far for phase-separating active particles.

  1. Stability of microsomal monooxygenases in murine liver S9 fractions derived from phenobarbital and beta-naphthoflavone induced animals under various long-term conditions of storage.

    PubMed

    Bauer, C; Corsi, C; Paolini, M

    1994-01-01

    The aim of this study was to define the long-term stability of metabolizing enzymes in activating preparations for short-term genotoxicity bioassays under various storage conditions. Expressions of cytochrome P450 content, NADPH-cytochrome (P450) c-reductase activity, and of the several monooxygenases, such as aminopyrine N-demethylase (class IIIA P450), p-nitroanisole O-demethylase (mixed), dinemorphan N-demethylase (IIB1), ethoxyresorufin O-deethylase (IA1), ethoxycoumarin O-deethylase (mixed), and pentoxyresorufin O-dealkylase (IIB1), were examined in S9 fractions derived from Na-phenobarbital (PB) plus beta-naphthoflavone (beta-NF) induced male and female mice, stored at -80 degrees C, or lyophilized and stored at -20 degrees C. Lipid peroxidation was also determined. Cytochrome P450 and the associated activities were decreased by 30-82% within 9 months of storage. The pattern and degree of relative stabilities were different for the various isoforms. The IA1-like activity, for example, was much more stable (approximately 49% loss) than IIB1-like activities (up to 82% loss). In general, lyophilized enzymes were less stable than directly frozen preparations. In addition, immediately after freeze-drying (lyophilization), a marked decrease in activity of up to 35% was observed. On the contrary, demethylation of aminopyrine and p-nitroanisole remains almost constant over 6 months storage at -196 degrees C. The results obtained indicate that either fresh, daily made S9 fractions or, alternatively, fractions stored in liquid nitrogen (up to 6 months) are recommended for mutagenesis studies. PMID:7910416

  2. A Group Recommender System for Tourist Activities

    NASA Astrophysics Data System (ADS)

    Garcia, Inma; Sebastia, Laura; Onaindia, Eva; Guzman, Cesar

    This paper introduces a method for giving recommendations of tourist activities to a group of users. This method makes recommendations based on the group tastes, their demographic classification and the places visited by the users in former trips. The group recommendation is computed from individual personal recommendations through the use of techniques such as aggregation, intersection or incremental intersection. This method is implemented as an extension of the e-Tourism tool, which is a user-adapted tourism and leisure application, whose main component is the Generalist Recommender System Kernel (GRSK), a domain-independent taxonomy-driven search engine that manages the group recommendation.

  3. Influenza virus activation of the interferon system

    PubMed Central

    Killip, Marian J.; Fodor, Ervin; Randall, Richard E.

    2015-01-01

    The host interferon (IFN) response represents one of the first barriers that influenza viruses must surmount in order to establish an infection. Many advances have been made in recent years in understanding the interactions between influenza viruses and the interferon system. In this review, we summarise recent work regarding activation of the type I IFN response by influenza viruses, including attempts to identify the viral RNA responsible for IFN induction, the stage of the virus life cycle at which it is generated and the role of defective viruses in this process. PMID:25678267

  4. System and method for monitoring cellular activity

    NASA Technical Reports Server (NTRS)

    Bearman, Gregory H. (Inventor); Fraser, Scott E. (Inventor); Lansford, Russell D. (Inventor)

    2002-01-01

    A system and method for monitoring cellular activity in a cellular specimen. According to one embodiment, a plurality of excitable markers are applied to the specimen. A multi-photon laser microscope is provided to excite a region of the specimen and cause fluorescence to be radiated from the region. The radiating fluorescence is processed by a spectral analyzer to separate the fluorescence into respective wavelength bands. The respective bands of fluorescence are then collected by an array of detectors, with each detector receiving a corresponding one of the wavelength bands.

  5. LDEF active optical system components experiment

    NASA Technical Reports Server (NTRS)

    Blue, M. D.

    1991-01-01

    A preliminary report on the Active Optical System Components Experiment is presented. This experiment contained 136 components in a six-inch deep tray including lasers, infrared detectors and arrays, ultraviolet light detectors, light-emitting diodes, a light modulator, flash lamps, optical filters, glasses, and samples of surface finishes. The experimental results for those component characteristics appear as much related to the passage of time as to the effects of the space environment, but organic materials and extreme-infrared reflectivity of black paints show unexpected changes.

  6. LDEF active optical system components experiment

    NASA Technical Reports Server (NTRS)

    Blue, M. D.

    1992-01-01

    A preliminary report on the Active Optical System Components Experiment is presented. This experiment contained 136 components in a six inch deep tray including lasers, infrared detectors and arrays, ultraviolet light detectors, light-emitting diodes, a light modulator, flash lamps, optical filters, glasses, and samples of surface finishes. Thermal, mechanical, and structural considerations leading to the design of the tray hardware are discussed. In general, changes in the retested component characteristics appear as much related to the passage of time as to the effects of the space environment, but organic materials, multilayer optical interference filters, and extreme-infrared reflectivity of black paints show unexpected changes.

  7. System and method for monitoring cellular activity

    NASA Technical Reports Server (NTRS)

    Bearman, Gregory H. (Inventor); Fraser, Scott E. (Inventor); Lansford, Russell D. (Inventor)

    2004-01-01

    A system and method for monitoring cellular activity in a cellular specimen. According to one embodiment, a plurality of excitable markers are applied to the specimen. A multi-photon laser microscope is provided to excite a region of the specimen and cause fluorescence to be radiated from the region. The radiating fluorescence is processed by a spectral analyzer to separate the fluorescence into respective wavelength bands. The respective bands of fluorescence are then collected by an array of detectors, with each detector receiving a corresponding one of the wavelength bands.

  8. Analog VLSI system for active drag reduction

    SciTech Connect

    Gupta, B.; Goodman, R.; Jiang, F.; Tai, Y.C.; Tung, S.; Ho, C.M.

    1996-10-01

    In today`s cost-conscious air transportation industry, fuel costs are a substantial economic concern. Drag reduction is an important way to reduce costs. Even a 5% reduction in drag translates into estimated savings of millions of dollars in fuel costs. Drawing inspiration from the structure of shark skin, the authors are building a system to reduce drag along a surface. Our analog VLSI system interfaces with microfabricated, constant-temperature shear stress sensors. It detects regions of high shear stress and outputs a control signal to activate a microactuator. We are in the process of verifying the actual drag reduction by controlling microactuators in wind tunnel experiments. We are encouraged that an approach similar to one that biology employs provides a very useful contribution to the problem of drag reduction. 9 refs., 21 figs.

  9. Spontaneous Oscillations in an Active Matter System

    NASA Astrophysics Data System (ADS)

    Hayes, Robert; Tsang, Boyce; Granick, Steve

    Active matter (which consumes energy to move about) can organize into dynamic structures more interesting than those possible at steady-state. Here we show spontaneous periodic self-assembly in a simple three-component system of water, oil phase, and surfactant at constant room temperature, with emphasis on one model system. Benchtop experiments show that liquid crystal oil droplets spontaneously and collectively oscillate like a `beating heart' for several hours; contract, relax, and subsequently re-contract in a petri dish at a rate of a few `beats' per minute. These oscillations, emergent from the cooperative interaction of the three components, are driven by the competition between positive and negative feedback processes. This illustration of feedback in action reveals a new way to program self-assembled structures to vary with time.

  10. Actively controlled vibration welding system and method

    SciTech Connect

    Cai, Wayne W.; Kang, Bongsu; Tan, Chin-An

    2013-04-02

    A vibration welding system includes a controller, welding horn, an active material element, and anvil assembly. The assembly may include an anvil body connected to a back plate and support member. The element, e.g., a piezoelectric stack or shape memory alloy, is positioned with respect to the assembly. The horn vibrates in a desirable first direction to form a weld on a work piece. The element controls any vibrations in a second direction by applying calibrated response to the anvil body in the second direction. A method for controlling undesirable vibrations in the system includes positioning the element with respect to the anvil assembly, connecting the anvil body to the support member through the back plate, vibrating the horn in a desirable first direction, and transmitting an input signal to the element to control vibration in an undesirable second direction.

  11. Active alignment/contact verification system

    DOEpatents

    Greenbaum, William M.

    2000-01-01

    A system involving an active (i.e. electrical) technique for the verification of: 1) close tolerance mechanical alignment between two component, and 2) electrical contact between mating through an elastomeric interface. For example, the two components may be an alumina carrier and a printed circuit board, two mating parts that are extremely small, high density parts and require alignment within a fraction of a mil, as well as a specified interface point of engagement between the parts. The system comprises pairs of conductive structures defined in the surfaces layers of the alumina carrier and the printed circuit board, for example. The first pair of conductive structures relate to item (1) above and permit alignment verification between mating parts. The second pair of conductive structures relate to item (2) above and permit verification of electrical contact between mating parts.

  12. Active balance system and vibration balanced machine

    NASA Technical Reports Server (NTRS)

    Qiu, Songgang (Inventor); Augenblick, John E. (Inventor); Peterson, Allen A. (Inventor); White, Maurice A. (Inventor)

    2005-01-01

    An active balance system is provided for counterbalancing vibrations of an axially reciprocating machine. The balance system includes a support member, a flexure assembly, a counterbalance mass, and a linear motor or an actuator. The support member is configured for attachment to the machine. The flexure assembly includes at least one flat spring having connections along a central portion and an outer peripheral portion. One of the central portion and the outer peripheral portion is fixedly mounted to the support member. The counterbalance mass is fixedly carried by the flexure assembly along another of the central portion and the outer peripheral portion. The linear motor has one of a stator and a mover fixedly mounted to the support member and another of the stator and the mover fixedly mounted to the counterbalance mass. The linear motor is operative to axially reciprocate the counterbalance mass.

  13. Next Generation Active Buffet Suppression System

    NASA Technical Reports Server (NTRS)

    Galea, Stephen C.; Ryall, Thomas G.; Henderson, Douglas A.; Moses, Robert W.; White, Edward V.; Zimcik, David G.

    2003-01-01

    Buffeting is an aeroelastic phenomenon that is common to high performance aircraft, especially those with twin vertical tails like the F/A-18, at high angles of attack. These loads result in significant random stresses, which may cause fatigue damage leading to restricted capabilities and availability of the aircraft. This paper describes an international collaborative research activity among Australia, Canada and the United States involving the use of active structural control to alleviate the damaging structural response to these loads. The research program is being co-ordinated by the Air Force Research Laboratory (AFRL) and is being conducted under the auspices of The Technical Cooperative Program (TTCP). This truly unique collaborative program has been developed to enable each participating country to contribute resources toward a program that coalesces a broad range of technical knowledge and expertise into a single investigation. This collaborative program is directed toward a full-scale test of an F/A-18 empennage, which is an extension of an earlier initial test. The current program aims at applying advanced directional piezoactuators, the aircraft rudder, switch mode amplifiers and advanced control strategies on a full-scale structure to demonstrate the enhanced performance and capability of the advanced active BLA control system in preparation for a flight test demonstration.

  14. The synchronous active neutron detection assay system

    SciTech Connect

    Pickrell, M.M.; Kendall, P.K.

    1994-09-01

    The authors have begun to develop a novel technique for active neutron assay of fissile material in spent nuclear fuel. They are using a Schlumberger neutron generator for the direct measurement of the fissile material content in spent fuel, in place of the indirect measures used at present. The technique they are investigating is termed synchronous active neutron detection (SAND). It closely follows a method that has been used routinely in other branches of physics for the detection of very small signals in the presence of large backgrounds. Synchronous detection instruments are widely available commercially and are termed ``lock-in`` amplifiers. They have implemented a digital lock-in amplifier in conjunction with the Schlumberger neutron generator to explore the possibility of synchronous detection with active neutrons. The results to data are preliminary but quite promising. The system is capable of resolving the fissile material contained in a small fraction of the fuel rods in a cold fuel assembly. It also appears to be quite resilient to background neutron interference.

  15. Identification of (3S, 9R)- and (3S, 9S)-megastigma-6,7-dien-3,5,9-triol 9-O-beta-D-glucopyranosides as damascenone progenitors in the flowers of Rosa damascena Mill.

    PubMed

    Suzuki, Masayuki; Matsumoto, Shigetaka; Mizoguchi, Masaya; Hirata, Satoshi; Takagi, Kazuteru; Hashimoto, Ikue; Yamano, Yumiko; Ito, Masayoshi; Fleischmann, Peter; Winterhalter, Peter; Morita, Tetuichiro; Watanabe, Naoharu

    2002-12-01

    The progenitors of damascenone (1), the most intensive C13-norisoprenoid volatile aroma constituent of rose essential oil, were surveyed in the flowers of Rosa damascena Mill. Besides 9-O-beta-D-glucopyranosyl-3-hydroxy-7,8-didehydro-beta-ionol (4b), a stable progenitor already isolated from the residual water after steam distillation of flowers of R. damascena Mill., two labile progenitors were identified to be (3S, 9R)- and (3S, 9S)-megastigma-6,7-dien-3,5,9-triol 9-O-beta-D-glucopyranosides (2b) based on their synthesis and HPLC-MS analytical data. Compound 2b gave damascenone (1), 3-hydroxy-beta-damascone (3) and 4b upon heating under acidic conditions. PMID:12596869

  16. Systemic lupus erythematosus activity. An operational definition.

    PubMed

    Liang, M H; Stern, S; Esdaile, J M

    1988-04-01

    Improved diagnosis and treatment have reduced mortality from SLE and present us with an opportunity to consider SLE in finer distinctions than alive or dead. Although much has been learned about SLE without a gold standard of disease activity or a universally agreed-upon definition of SLE activity, standardization of one or more measures would greatly enhance our ability to compare results from different centers and to communicate more precisely. It is unlikely that any of the existing measures or any ones to be developed will completely satisfy everyone's needs but it is pointless to proliferate new ones without testing their metric properties. Some differences in concept are desirable, particularly for investigators who have specialized interests or insights, but each should meet criteria of reliability and validity and have explicit definitions of terms, rules for their ascertainment, and the time period covered. Moreover, agreement on minimum essential elements of any SLE activity measure and their operational definitions would be a boon. SLE activity is one dimension in the disease pathway of lupus and implies a continuous phenomena that is potentially reversible. Organ damage, another point in the path of causation, connotes irreversible disease. We recommend that minimum essential elements be based on their frequency of occurrence, biological sensibleness, and the likelihood that degrees of activity can be rated reliably to show a change in a clinical state. The rating should be independent of whether a therapy is employed. Since activity is always considered with severity, the two dimensions could be recognized in the scale. Severity can be used to expand a scale's gradations if a symptom or sign is present. Severity could be rated by the need to treat with immunosuppressive agents, the need to follow the patient more closely, or the functional or prognostic consequences of the manifestation. For every organ system clinical judgment should be used to decide

  17. A new melanoma diagnosis active support system.

    PubMed

    Fiorini, R A; Dacquino, G; Laguteta, G

    2004-01-01

    The aim of this paper is to present the operational performance of a new MDASS (Melanoma Diagnosis Active Support System) prototype able to distil optimal knowledge from acquired data to automatically capture and reliably discriminate and quantify the stage of disease evolution. Automated classification dermatoscopical parameters can be divided into two main classes: Size Descriptor (point size, local, and global) and Intrinsic Descriptor (morphological, geometrical, chromatic, others). Usually elementary geometric shape robust and effective characterization, invariant to environment and optical geometry transformations, on a rigorous mathematical level is a key and computational intensive problem. MDASS uses GEOGINE (GEOmetrical enGINE), a state-of-the-art OMG (Ontological Model Generator) based on n-D Tensor Moment Invariants for shape/texture effective description. MDASS main results show robust disease classification procedure with distillation of minimal reference grids for pathological cases and they ultimately achieve effective early diagnosis of melanocytic lesion. System results are validated by carefully designed experiments with certified clinical reference database. Overall system operational performance is presented. Finally, MDASS error analysis and computational complexity are addressed and discussed. PMID:17270962

  18. Activity systems in the inquiry classroom

    NASA Astrophysics Data System (ADS)

    Wortham, Donald William

    Inquiry science, as called for by reform-minded organizations such as the National Research Council (1996), offers a platform with the potential for introducing all students to the practice of science while maintaining focus on key concepts and theories. This project followed two small groups as they completed an inquiry unit on genetics at a Midwestern high school. I investigated whether levels of student-to-teacher, student-to-student, student-apparatus, and student-concept connections were approximately equal across all students in each of the two groups. I found differences among students in levels of student-to-teacher, student-to-student, and student-concept connections. From a situated idiopathic perspective, these differences may indicate different levels of opportunity-to-learn. At a more abstract (nomothetic) level, these differences may be due to emergent divisions of labor (roles) within the two groups. From the perspective of Activity Theory (Leont'ev, 1978; Engestrom, 1987), roles serve as important mediators that simultaneously allow the social unit to accomplish its objectives, while shaping the development of participants. I describe three roles that capture modes of participation for students interacting in the small groups, and that may contribute to what Engestrom (2001) calls subject-producing activity systems: networked contributor, social member, and isolate. This paper also describes tools for teachers and researchers to use in identifying levels of mediation and roles as they occur in small groups.

  19. ROVER: A prototype active vision system

    NASA Astrophysics Data System (ADS)

    Coombs, David J.; Marsh, Brian D.

    1987-08-01

    The Roving Eyes project is an experiment in active vision. We present the design and implementation of a prototype that tracks colored balls in images from an on-line charge coupled device (CCD) camera. Rover is designed to keep up with its rapidly changing environment by handling best and average case conditions and ignoring the worst case. This allows Rover's techniques to be less sophisticated and consequently faster. Each of Rover's major functional units is relatively isolated from the others, and an executive which knows all the functional units directs the computation by deciding which jobs would be most effective to run. This organization is realized with a priority queue of jobs and their arguments. Rover's structure not only allows it to adapt its strategy to the environment, but also makes the system extensible. A capability can be added to the system by adding a functional module with a well defined interface and by modifying the executive to make use of the new module. The current implementation is discussed in the appendices.

  20. Preliminary design activities for solar heating and cooling systems

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Information on the development of solar heating and cooling systems is presented. The major emphasis is placed on program organization, system size definition, site identification, system approaches, heat pump and equipment design, collector procurement, and other preliminary design activities.

  1. Activity Systems and Moral Reasoning: An Intervention Study

    ERIC Educational Resources Information Center

    Wardi, Eva; Helkama, Klaus

    2015-01-01

    Seventeen social educator students were taught to analyze their work activity by means of a Vygotsky-inspired method, drawing on Engeström's notion of an activity system. The method aimed at increasing the consciousness of the students of the structure of work activity system. The participants wrote two accounts of their field-work practice…

  2. New approaches to enhance active steering system functionalities: preliminary results

    NASA Astrophysics Data System (ADS)

    Serarslan, Benan

    2014-09-01

    An important development of the steering systems in general is active steering systems like active front steering and steer-by-wire systems. In this paper the current functional possibilities in application of active steering systems are explored. A new approach and additional functionalities are presented that can be implemented to the active steering systems without additional hardware such as new sensors and electronic control units. Commercial active steering systems are controlling the steering angle depending on the driving situation only. This paper introduce methods for enhancing active steering system functionalities depending not only on the driving situation but also vehicle parameters like vehicle mass, tyre and road condition. In this regard, adaptation of the steering ratio as a function of above mentioned vehicle parameters is presented with examples. With some selected vehicle parameter changes, the reduction of the undesired influences on vehicle dynamics of these parameter changes has been demonstrated theoretically with simulations and with real-time driving measurements.

  3. Process of activation of a palladium catalyst system

    DOEpatents

    Sobolevskiy, Anatoly; Rossin, Joseph A.; Knapke, Michael J.

    2011-08-02

    Improved processes for activating a catalyst system used for the reduction of nitrogen oxides are provided. In one embodiment, the catalyst system is activated by passing an activation gas stream having an amount of each of oxygen, water vapor, nitrogen oxides, and hydrogen over the catalyst system and increasing a temperature of the catalyst system to a temperature of at least 180.degree. C. at a heating rate of from 1-20.degree./min. Use of activation processes described herein leads to a catalyst system with superior NOx reduction capabilities.

  4. Student Activity Funds: Creating a System of Controls That Work.

    ERIC Educational Resources Information Center

    Cuzzetto, Charles

    1995-01-01

    Although student-activity funds usually represent a small portion of school-system monies, their very nature makes them a high risk. Outlines three steps for maintaining an efficient and effective system of controls over student-activity funds: (1) identifying control issues; (2) designing a control system; and (3) using checks and balances.…

  5. Active fluidization in dense glassy systems.

    PubMed

    Mandal, Rituparno; Bhuyan, Pranab Jyoti; Rao, Madan; Dasgupta, Chandan

    2016-07-20

    Dense soft glasses show strong collective caging behavior at sufficiently low temperatures. Using molecular dynamics simulations of a model glass former, we show that the incorporation of activity or self-propulsion, f0, can induce cage breaking and fluidization, resulting in the disappearance of the glassy phase beyond a critical f0. The diffusion coefficient crosses over from being strongly to weakly temperature dependent as f0 is increased. In addition, we demonstrate that activity induces a crossover from a fragile to a strong glass and a tendency of active particles to cluster. Our results are of direct relevance to the collective dynamics of dense active colloidal glasses and to recent experiments on tagged particle diffusion in living cells. PMID:27380935

  6. Active vibration control of lightweight floor systems

    NASA Astrophysics Data System (ADS)

    Baader, J.; Fontana, M.

    2016-04-01

    Wide-span and lightweight floors are often prone to structural vibrations due to their low resonance frequency and poor material damping. Their dynamic behaviour can be improved using passive, semi-active or active vibration control devices. The following article proposes a novel method for the controller synthesis for active vibration control. An existing passive TMD (tuned mass damper) is modelled and equipped with an actuator in order to provide more efficient damping. Using an iterative optimization approach under constraints, an optimal controller is found which minimizes a quadratic cost function in frequency domain. A simulation of an existing test bench shows that the active vibration control device is able to provide increased damping compared to the passive TMD.

  7. Power System Considerations and Test Activities

    NASA Technical Reports Server (NTRS)

    Miller, J.

    1983-01-01

    The potential benefits of an IPACS system compared to NiCd and/or Regen Fuel Cell systems are summarized. The benefits are: (1) significant life cycle cost savings; (2) total weight to orbit savings (30 yrs) as much as 10 times; (3) end to end efficiency increase results in approximately 10 kW reduction in array size(6%); (4) motor/generator controller regulation during discharge simplifies distribution system; and (5) momentum stored for attitude control increased by 4 times.

  8. Gender-related differences in the formation of skatole metabolites by specific CYP450 in porcine hepatic S9 fractions.

    PubMed

    Borrisser-Pairó, F; Rasmussen, M K; Ekstrand, B; Zamaratskaia, G

    2015-04-01

    Higher accumulation of skatole in the fat of male pigs compared with female pigs might be due to gender-related differences in the rate of skatole degradation. In the present study, skatole metabolites and cytochrome P450 (CYP450) isoforms involved in skatole metabolism were for the first time investigated in hepatic S9 fractions from six male and four female pigs (crossbred Landrace×Yorkshire dams and Duroc boar). Surprisingly, the rates of production of major skatole metabolites were similar in male and female pigs. The most abundant metabolite of skatole was 3-hydroxy-3-methyloxindole (HMOI) followed by 3-methyloxindole and indole-3-carbinol in both male and female S9 fractions. Concentrations of formed HMOI and 3-methyloxindole did not differ between the genders (P=0.124 for HMOI, and P=0.575 for 3-methyloxindole). Indole-3-carbinol formation was higher in S9 fractions from the females compared with male pigs (P=0.0001). Enzyme kinetic parameters were similar for both genders (P>0.05). In both male and female pigs, ellipticine, diallyl sulphide (DAS) and quercetin inhibited HMOI formation, confirming the involvement of CYP1A1 and CYP2E1. The formation of 3-methyloxindole was reduced in the presence of the CYP2E1 inhibitor DAS, and formation of indole-3-carbinol was reduced in the presence of CYP1A1 and CYP2A19 inhibitors. We found only minor differences in skatole metabolism between male and female pigs, particularly the involvement of CYP2C and CYP3A in indole-3-carbinol formation in female but not in male pigs. This is a very essential finding, suggesting the involvement of larger number of CYP450 isoforms in female pigs. On the other hand, indole-3-carbinol is a minor skatole metabolite, and the physiological significance of CYP2C and CYP3A involvement in its formation in female pigs, but not in male pigs, needs to be elucidated. Our results, however, should be interpreted with caution because of the low number of animals and possibility of breed and age

  9. Description of data base management systems activities

    NASA Technical Reports Server (NTRS)

    1983-01-01

    One of the major responsibilities of the JPL Computing and Information Services Office is to develop and maintain a JPL plan for providing computing services to the JPL management and administrative community that will lead to improved productivity. The CISO plan to accomplish this objective has been titled 'Management and Administrative Support Systems' (MASS). The MASS plan is based on the continued use of JPL's IBM 3032 Computer system for administrative computing and for the MASS functions. The current candidate administrative Data Base Management Systems required to support the MASS include ADABASE, Cullinane IDMS and TOTAL. Previous uses of administrative Data Base Systems have been applied to specific local functions rather than in a centralized manner with elements common to the many user groups. Limited capacity data base systems have been installed in microprocessor based office automation systems in a few Project and Management Offices using Ashton-Tate dBASE II. These experiences plus some other localized in house DBMS uses have provided an excellent background for developing user and system requirements for a single DBMS to support the MASS program.

  10. Hybrid energy storage systems utilizing redox active organic compounds

    DOEpatents

    Wang, Wei; Xu, Wu; Li, Liyu; Yang, Zhenguo

    2015-09-08

    Redox flow batteries (RFB) have attracted considerable interest due to their ability to store large amounts of power and energy. Non-aqueous energy storage systems that utilize at least some aspects of RFB systems are attractive because they can offer an expansion of the operating potential window, which can improve on the system energy and power densities. One example of such systems has a separator separating first and second electrodes. The first electrode includes a first current collector and volume containing a first active material. The second electrode includes a second current collector and volume containing a second active material. During operation, the first source provides a flow of first active material to the first volume. The first active material includes a redox active organic compound dissolved in a non-aqueous, liquid electrolyte and the second active material includes a redox active metal.

  11. Experimental acquisition system for impedance tomography with active electrode approach.

    PubMed

    Rigaud, B; Shi, Y; Chauveau, N; Morucci, J P

    1993-11-01

    An experimental system for impedance tomography has been constructed. The acquisition system uses 16 multifunctional active electrodes, each including a current source and a voltage buffer. Images of active and reactive parts of different target impedances in a phantom filled with liquid have been obtained. The system performance has been compared with those of other systems using either a mesh phantom or rods as point sources used for the determination of the modulation transfer function. PMID:8145585

  12. Practical engineering: control of active systems using the stagnation temperature

    SciTech Connect

    Lunde, P.J.

    1982-04-01

    Solar active systems with flat plate collectors are discussed with reference to the temperature at which the system should be activated. It is concluded that the system should be activated when the stagnation temperature (temperature under the absorber plate when no fluid is circulating) equals the temperature of the fluid in storage. A thermistor Wheatstone bridge control system is described which will eliminate pump relay chatter and the permissible control differential is calculated from the collector efficiency curve. To avoid dedication of an entire collector to house the control system, a method is described for determining the stagnation temperature using a portion of an active collector. For an active solar hot water system, a calculation is carried out to show that a 2/sup 0/F temperature differential (stagnation temperature-storage temperature) is satisfactory. (MJJ)

  13. Electricity/Electronics Systems. Laboratory Activities.

    ERIC Educational Resources Information Center

    Sutherland, Barbara, Ed.

    This electricity/electronics guide provides teachers with learning activities for secondary students. Introductory materials include an instructional planning outline and worksheet, an outline of essential elements, a list of objectives, a course description, and a content outline. The guide contains 35 modules on the following topics: electrical…

  14. MARS PATHFINDER PYRO SYSTEMS SWITCHING ACTIVITY

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The Mars Pathfinder lander is subjected to electrical and functional tests of its pyrotechic petal deployer system by Jet Propulsion Laboratory (JPL) engineers and technicians in KSC's Spacecraft Assembly and Encapsulation Facility (SAEF-2). When the lander touches down on the surface of Mars next year, the pyrotechnic system will deploy its three petals open like a flower and allow the Sojourner autonomous rover to explore the Martian surface. The Mars Pathfinder is scheduled for launch aboard a Delta II expendable launch vehicle on Dec. 2, the beginning of a 24-day launch period. JPL is managing the Mars Pathfinder project for NASA.

  15. PEGASUS: Designing a System for Supporting Group Activity

    ERIC Educational Resources Information Center

    Kyprianidou, Maria; Demetriadis, Stavros; Pombortsis, Andreas; Karatasios, George

    2009-01-01

    Purpose: The purpose of this paper is to present the design and first results of the integration of a web-based system person-centred group-activity support system (PEGASUS) in university instruction, as a means for advancing person-centred learning by supporting group activity. The PEGASUS is expected to help students and teachers in two distinct…

  16. Applying an Activity System to Online Collaborative Group Work Analysis

    ERIC Educational Resources Information Center

    Choi, Hyungshin; Kang, Myunghee

    2010-01-01

    This study determines whether an activity system provides a systematic framework to analyse collaborative group work. Using an activity system as a unit of analysis, the research examined learner behaviours, conflicting factors and facilitating factors while students engaged in collaborative work via asynchronous computer-mediated communication.…

  17. Entry-Level Activities in System Consultation

    ERIC Educational Resources Information Center

    Hylander, Ingrid

    2014-01-01

    System-level consultation or organizational development in schools is an area in great need of theoretical models and definitions. The three articles in this special issue provide a unique learning opportunity not only for consultation across borders but also for consultation within the same nation. In my commentary, I limit my remarks to a few…

  18. Methodology for the systems engineering process. Volume 1: System functional activities

    NASA Technical Reports Server (NTRS)

    Nelson, J. H.

    1972-01-01

    Systems engineering is examined in terms of functional activities that are performed in the conduct of a system definition/design, and system development is described in a parametric analysis that combines functions, performance, and design variables. Emphasis is placed on identification of activities performed by design organizations, design specialty groups, as well as a central systems engineering organizational element. Identification of specific roles and responsibilities for doing functions, and monitoring and controlling activities within the system development operation are also emphasized.

  19. A microscopic field theoretical approach for active systems

    NASA Astrophysics Data System (ADS)

    Alaimo, F.; Praetorius, S.; Voigt, A.

    2016-08-01

    We consider a microscopic modeling approach for active systems. The approach extends the phase field crystal (PFC) model and allows us to describe generic properties of active systems within a continuum model. The approach is validated by reproducing results obtained with corresponding agent-based and microscopic phase field models. We consider binary collisions, collective motion and vortex formation. For larger numbers of particles we analyze the coarsening process in active crystals and identify giant number fluctuation in a cluster formation process.

  20. Motor Cortex Activity Organizes the Developing Rubrospinal System

    PubMed Central

    Williams, Preston T.J.A.

    2015-01-01

    The corticospinal and rubrospinal systems function in skilled movement control. A key question is how do these systems develop the capacity to coordinate their motor functions and, in turn, if the red nucleus/rubrospinal tract (RN/RST) compensates for developmental corticospinal injury? We used the cat to investigate whether the developing rubrospinal system is shaped by activity-dependent interactions with the developing corticospinal system. We unilaterally inactivated M1 by muscimol microinfusion between postnatal weeks 5 and 7 to examine activity-dependent interactions and whether the RN/RST compensates for corticospinal tract (CST) developmental motor impairments and CST misprojections after M1 inactivation. We examined the RN motor map and RST cervical projections at 7 weeks of age, while the corticospinal system was inactivated, and at 14 weeks, after activity returned. During M1 inactivation, the RN on the same side showed normal RST projections and reduced motor thresholds, suggestive of precocious development. By contrast, the RN on the untreated/active M1 side showed sparse RST projections and an immature motor map. After M1 activity returned later in adolescent cat development, RN on the active M1/CST side continued to show a substantial loss of spinal terminations and an impaired motor map. RN/RST on the inactivated side regressed to a smaller map and fewer axons. Our findings suggest that the developing rubrospinal system is under activity-dependent regulation by the corticospinal system for establishing mature RST connections and RN motor map. The lack of RS compensation on the non-inactivated side can be explained by development of ipsilateral misprojections from the active M1 that outcompete the RST. SIGNIFICANCE STATEMENT Skilled movements reflect the activity of multiple descending motor systems and their interactions with spinal motor circuits. Currently, there is little insight into whether motor systems interact during development to

  1. MARS PATHFINDER PYRO SYSTEMS SWITCHING ACTIVITY

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The Mars Pathfinder lander is subjected to a electrical and functional tests of its pyrotechic petal deployer system by Jet Propulsion Laboratory (JPL) engineers and technicians in KSC's Spacecraft Assembly and Encapsulation Facility (SAEF-2). In the background is the Pathfinder cruise stage, which the lander will be mated to once its functional tests are complete. The lander will remain attached to this stage during its six-to-seven-month journey to Mars. When the lander touches down on the surface of Mars next year, the pyrotechnic system will deploy its three petals open like a flower and allow the Sojourner autonomous rover to explore the Martian surface. The Mars Pathfinder is scheduled for launch aboard a Delta II expendable launch vehicle on Dec. 2, the beginning of a 24-day launch period. JPL is managing the Mars Pathfinder project for NASA.

  2. MARS PATHFINDER PYRO SYSTEMS SWITCHING ACTIVITY

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The Mars Pathfinder lander is subjected to a electrical test of its pyrotechnic system by Jet Propulsion Laboratory (JPL) engineers Lorraine Garcia (foreground) and Linda Robeck in KSC's Spacecraft Assembly and Encapsulation Facility (SAEF-2). A wheel of the Sojourner autonomous rover, which is attached to one of the lander's petals, can be seen behind the lander. When the lander touches down on the surface of Mars next year, the pyrotechnic system will deploy its three petals open like a flower and allow the rover to explore the Martian surface. The Mars Pathfinder is scheduled for launch aboard a Delta II expendable launch vehicle on Dec. 2, the beginning of a 24-day launch period. JPL is managing the Mars Pathfinder project for NASA.

  3. MARS PATHFINDER PYRO SYSTEMS SWITCHING ACTIVITY

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The Mars Pathfinder lander is subjected to a test of its pyrotechnic system by Jet Propulsion Laboratory (JPL) engineer Jerry Gutierrez in KSC's Spacecraft Assembly and Encapsulation Facility (SAEF-2). A wheel of the Sojourner autonomous rover, which is attached to one of the lander's petals, can be seen behind the lander. When the lander touches down on the surface of Mars next year, the pyrotechnic system will deploy its three petals open like a flower and allow the rover to explore the Martian surface. The Mars Pathfinder is scheduled for launch aboard a Delta II expendable launch vehicle on Dec. 2, the beginning of a 24-day launch period. JPL is managing the Mars Pathfinder project for NASA.

  4. A fuselage/tank structure study for actively cooled hypersonic cruise vehicles: Active cooling system analysis

    NASA Technical Reports Server (NTRS)

    Stone, J. E.

    1975-01-01

    The effects of fuselage cross section and structural arrangement on the performance of actively cooled hypersonic cruise vehicles are investigated. An active cooling system which maintains the aircraft's entire surface area at temperatures below 394 K at Mach 6 is developed along with a hydrogen fuel tankage thermal protection system. Thermodynamic characteristics of the actively cooled thermal protection systems established are summarized. Design heat loads and coolant flowrate requirements are defined for each major structural section and for the total system. Cooling system weights are summarized at the major component level. Conclusions and recommendations are included.

  5. Active and intelligent packaging systems for a modern society.

    PubMed

    Realini, Carolina E; Marcos, Begonya

    2014-11-01

    Active and intelligent packaging systems are continuously evolving in response to growing challenges from a modern society. This article reviews: (1) the different categories of active and intelligent packaging concepts and currently available commercial applications, (2) latest packaging research trends and innovations, and (3) the growth perspectives of the active and intelligent packaging market. Active packaging aiming at extending shelf life or improving safety while maintaining quality is progressing towards the incorporation of natural active agents into more sustainable packaging materials. Intelligent packaging systems which monitor the condition of the packed food or its environment are progressing towards more cost-effective, convenient and integrated systems to provide innovative packaging solutions. Market growth is expected for active packaging with leading shares for moisture absorbers, oxygen scavengers, microwave susceptors and antimicrobial packaging. The market for intelligent packaging is also promising with strong gains for time-temperature indicator labels and advancements in the integration of intelligent concepts into packaging materials. PMID:25034453

  6. Active synchronization between two different chaotic dynamical system

    SciTech Connect

    Maheri, M.; Arifin, N. Md; Ismail, F.

    2015-05-15

    In this paper we investigate on the synchronization problem between two different chaotic dynamical system based on the Lyapunov stability theorem by using nonlinear control functions. Active control schemes are used for synchronization Liu system as drive and Rossler system as response. Numerical simulation by using Maple software are used to show effectiveness of the proposed schemes.

  7. Active synchronization between two different chaotic dynamical system

    NASA Astrophysics Data System (ADS)

    Maheri, M.; Arifin, N. Md; Ismail, F.

    2015-05-01

    In this paper we investigate on the synchronization problem between two different chaotic dynamical system based on the Lyapunov stability theorem by using nonlinear control functions. Active control schemes are used for synchronization Liu system as drive and Rossler system as response. Numerical simulation by using Maple software are used to show effectiveness of the proposed schemes.

  8. NASA's UAS [Unmanned Aircraft Systems] Related Activities

    NASA Technical Reports Server (NTRS)

    Bauer, Jeffrey

    2012-01-01

    NASA continues to operate all sizes of UAS in all classes of airspace both domestically and internationally. Missions range from highly complex operations in coordination with piloted aircraft, ground, and space systems in support of science objectives to single aircraft operations in support of aeronautics research. One such example is a scaled commercial transport aircraft being used to study recovery techniques due to large upsets. NASA's efforts to support routine UAS operations continued on several fronts last year. At the national level in the United States (U.S.), NASA continued its support of the UAS Executive Committee (ExCom) comprised of the Federal Aviation Administration (FAA), Department of Defense (DoD), Department of Homeland Security (DHS), and NASA. The committee was formed in recognition of the need of UAS operated by these agencies to access to the National Airspace System (NAS) to support operational, training, development and research requirements. Recommendations were received on how to operate both manned and unmanned aircraft in class D airspace and plans are being developed to validate and implement those recommendations. In addition the UAS ExCom has begun developing recommendations for how to achieve routine operations in remote areas as well as for small UAS operations in class G airspace. As well as supporting the UAS ExCom, NASA is a participant in the recently formed Aviation Rule Making Committee for UAS. This committee, established by the FAA, is intended to propose regulatory guidance which would enable routine civil UAS operations. As that effort matures NASA stands ready to supply the necessary technical expertise to help that committee achieve its objectives. By supporting both the UAS ExCom and UAS ARC, NASA is positioned to provide its technical expertise across the full spectrum of UAS airspace access related topic areas. The UAS NAS Access Project got underway this past year under the leadership of NASA s Aeronautics

  9. Retinal waves coordinate patterned activity throughout the developing visual system

    PubMed Central

    Ackman, James B.; Burbridge, Timothy J.; Crair, Michael C.

    2014-01-01

    Summary The morphologic and functional development of the vertebrate nervous system is initially governed by genetic factors and subsequently refined by neuronal activity. However, fundamental features of the nervous system emerge before sensory experience is possible. Thus, activity-dependent development occurring before the onset of experience must be driven by spontaneous activity, but the origin and nature of activity in vivo remains largely untested. Here we use optical methods to demonstrate in live neonatal mice that waves of spontaneous retinal activity are present and propagate throughout the entire visual system before eye opening. This patterned activity encompassed the visual field, relied on cholinergic neurotransmission, preferentially initiated in the binocular retina, and exhibited spatiotemporal correlations between the two hemispheres. Retinal waves were the primary source of activity in the midbrain and primary visual cortex, but only modulated ongoing activity in secondary visual areas. Thus, spontaneous retinal activity is transmitted through the entire visual system and carries patterned information capable of guiding the activity-dependent development of complex intra- and inter- hemispheric circuits before the onset of vision. PMID:23060192

  10. Active Venting System Offshore Northern Norway

    NASA Astrophysics Data System (ADS)

    Chand, Shyam; Rise, Leif; Bellec, Valérie; Dolan, Margaret; Bøe, Reidulv; Thorsnes, Terje; Buhl-Mortensen, Pål; Buhl-Mortensen, Lene

    2008-07-01

    A combined sediment-sampling, high-resolution seismic, multiple echo sounder, and video survey was conducted offshore Vesterålen, northern Norway, in October 2007 as part of the ongoing Marine Area Database for Norwegian Coast and Oceanic Regions (MAREANO) program. MAREANO is a multidisciplinary seabed mapping program conducting physical, biological, and environmental mapping in the Lofoten/southern Barents Sea area. Data and analysis arising from this program will provide the basis for ecosystem-based management of Norway's coastal and offshore regions. The survey used multicorer, box corer, and grab samplers; a TOPAS parametric subbottom profiler; 18-, 38-, 70-, 120-, 200-, and 400-kilohertz echo sounders; and a CAMPOD camera system with two video cameras and lights mounted on an aluminum frame.

  11. Correlated Rotational Noise in Active Brownian Systems

    NASA Astrophysics Data System (ADS)

    Wagner, Caleb; Baskaran, Aparna

    We consider a system of self-propelled particles in a viscous medium for which the angle parametrizing the direction of particle propulsion is subject to correlated noise. The physics involved in the correlated noise is explored by deriving a modified Smoluchowski equation that governs the evolution of the probability distribution for particle positions and orientations. More precisely, given noise correlations that decay exponentially in time with decay constant ν, we give the modified Smoluchowski equation as a perturbative expansion in ν. While the physical origins of correlated noise may be diverse, we give one interpretation of the resulting dynamics in terms of inertial effects that are absent from the usual overdamped description of self-propelled particles in a viscous medium.

  12. Active control system for high speed windmills

    DOEpatents

    Avery, D.E.

    1988-01-12

    A pump stroke is matched to the operating speed of a high speed windmill. The windmill drives a hydraulic pump for a control. Changes in speed of a wind driven shaft open supply and exhaust valves to opposite ends of a hydraulic actuator to lengthen and shorten an oscillating arm thereby lengthening and shortening the stroke of an output pump. Diminishing wind to a stall speed causes the valves to operate the hydraulic cylinder to shorten the oscillating arm to zero. A pressure accumulator in the hydraulic system provides the force necessary to supply the hydraulic fluid under pressure to drive the actuator into and out of the zero position in response to the windmill shaft speed approaching and exceeding windmill stall speed. 4 figs.

  13. Active control system for high speed windmills

    DOEpatents

    Avery, Don E.

    1988-01-01

    A pump stroke is matched to the operating speed of a high speed windmill. The windmill drives a hydraulic pump for a control. Changes in speed of a wind driven shaft open supply and exhaust valves to opposite ends of a hydraulic actuator to lengthen and shorten an oscillating arm thereby lengthening and shortening the stroke of an output pump. Diminishing wind to a stall speed causes the valves to operate the hydraulic cylinder to shorten the oscillating arm to zero. A pressure accumulator in the hydraulic system provides the force necessary to supply the hydraulic fluid under pressure to drive the actuator into and out of the zero position in response to the windmill shaft speed approaching and exceeding windmill stall speed.

  14. An Active RFID Accountability System (RAS) for Constrained Wireless Environments

    SciTech Connect

    Barker, Alan M; Hanson, Gregory R; Sexton, Angela Kay; Jones Jr, J P; Freer, Eva B; Sjoreen, Andrea L

    2011-01-01

    A team from Oak Ridge National Laboratory (ORNL) has developed an RFID Accountability System (RAS) that allows items with active RFID tags to be tracked in environments where tags may not be able to transmit their location continuously. The system uses activators that transmit a short range signal. Active RFID tags are in a sleep state until they encounter an activator. Then they transmit a signal that is picked up by the antennas installed throughout the building. This paper presents the theory of operation, application areas, lessons learned, and key features developed over the course of seven years of development and use.

  15. [Activities of System Studies and Simulation, Inc.

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Contents include the following: 1. Launch Vehicle Interface Work Performed: a. S3 provided to KSC the new launch inclination targets needed for the April '04 launch date. 2. Prelaunch operations work performed: a. S3 updated the staffing plan for MSFC on-console personnel\\during the Final Countdown prior to launch. 3. Software Assessment Work Performed: a. S3 evaluated and recommended approval for Program Control Board (PCB) proposed change 649 for ground software changes, as well as change 650 and 650A for Stored Program Commands. 4. Education and Public Outreach Work Performed: a. S3 continues to coordinate the effort for the design and fabrication of scale models of the GP-3 for use at the launch site, education forums, and management/technical briefings. S3 also prepared a Change Request for additional funds needed for fabrication of additional scale models. S3 drafted the planned uses of these models, including the possibility of participation in the Boston, MA showings of the traveling Einstein Exhibit. 5. Program Management Support Work Performed: a. S3 prepared the input for and closed three MSFC Centerwide Action Item Tracking Systems (CAITS) actions during this period.

  16. Comparative study between two different active flutter suppression systems

    NASA Technical Reports Server (NTRS)

    Nissim, E.

    1978-01-01

    An activated leading-edge (LE)-tailing-edge (TE) control system is applied to a drone aircraft with the objective of enabling the drone to fly subsonically at dynamic pressures which are 44% above the open-loop flutter dynamic pressure. The control synthesis approach is based on the aerodynamic energy concept and it incorporates recent developments in this area. A comparison is made between the performance of the activated LE-TE control system and the performance of a TE control system, analyzed in a previous work. The results obtained indicate that although all the control systems achieve the flutter suppression objectives, the TE control system appears to be somewhat superior to the LE-TE control system, in this specific application. This superiority is manifested through reduced values of control surface activity over a wide range of flight conditions.

  17. Concentration dependence of biotransformation in fish liver S9: Optimizing substrate concentrations to estimate hepatic clearance for bioaccumulation assessment.

    PubMed

    Lo, Justin C; Allard, Gayatri N; Otton, S Victoria; Campbell, David A; Gobas, Frank A P C

    2015-12-01

    In vitro bioassays to estimate biotransformation rate constants of contaminants in fish are currently being investigated to improve bioaccumulation assessments of hydrophobic contaminants. The present study investigates the relationship between chemical substrate concentration and in vitro biotransformation rate of 4 environmental contaminants (9-methylanthracene, pyrene, chrysene, and benzo[a]pyrene) in rainbow trout (Oncorhynchus mykiss) liver S9 fractions and methods to determine maximum first-order biotransformation rate constants. Substrate depletion experiments using a series of initial substrate concentrations showed that in vitro biotransformation rates exhibit strong concentration dependence, consistent with a Michaelis-Menten kinetic model. The results indicate that depletion rate constants measured at initial substrate concentrations of 1 μM (a current convention) could underestimate the in vitro biotransformation potential and may cause bioconcentration factors to be overestimated if in vitro biotransformation rates are used to assess bioconcentration factors in fish. Depletion rate constants measured using thin-film sorbent dosing experiments were not statistically different from the maximum depletion rate constants derived using a series of solvent delivery-based depletion experiments for 3 of the 4 test chemicals. Multiple solvent delivery-based depletion experiments at a range of initial concentrations are recommended for determining the concentration dependence of in vitro biotransformation rates in fish liver fractions, whereas a single sorbent phase dosing experiment may be able to provide reasonable approximations of maximum depletion rates of very hydrophobic substances. PMID:26077187

  18. Space Activism as an Epiphanic Belief System

    NASA Technical Reports Server (NTRS)

    Mendell, Wendell

    2006-01-01

    Years of interaction with young people in the space industry and in space activists groups led to my observation that many such individuals can cite a quite specific life event that triggered a life-long interest in or commitment to creating a space future. I am particularly intrigued by parallels between such experiences and the phenomenon of epiphanic experiences among committed Christians. I see analogies between the puzzlement among space activists and among Christian groups as to the reasons for so many people being "unbelievers." At a small international meeting on lunar exploration in 2003, I heard two separate lunch speakers cite such personal experiences. At the beginning of a break in that meeting, I grabbed the microphone from the chairman and asked each person to write down on a pad by his chair whether or not he (or she) had experienced a specific event that led to their involvement in space. If the answer was positive, I asked for a brief narrative, for their age at the time, and for their current age. I received 53 submissions, 20% of which simply stated that their involvement in space exploration was happenstance. (Apollo astronaut John Young was among these.) The other 80% of the submissions had specific stories. The ages at the time of the epiphany ranged from 4 to 47; and their current ages ranged from 22 to 78. I will present a high-level characterization of these inputs. Interest in space exploration as a form of belief system is consistent with choosing NASA goals for the purpose of inspiration and with phenomena such as the "Overview Effect". More research might explore what form the transcendent experience takes and whether it might be associated with feelings of universal connection such as the noosphere or "The Force". From a pragmatic point of view, outreach strategies for exploration should focus on giving individuals access to personal, potentially transformational experiences as opposed to astronaut talks at civic clubs.

  19. Active Storage Processing in a Parallel File System

    SciTech Connect

    Felix, Evan J.; Fox, Kevin M.; Regimbal, Kevin M.; Nieplocha, Jarek

    2006-01-01

    By creating a processing system within a parallel file system one can harness the power of unused processing power on servers that have very fast access to the disks they are serving. By inserting a module the Lustre file system the Active Storage Concept is able to perform processing with the file system architecture. Results of using this technology are presented as the results of the Supercomputing StorCloud Challenge Application are reviewed.

  20. Bactericidal activity of metal-mediated peroxide-ascorbate systems.

    PubMed

    Drath, D B; Karnovsky, M L

    1974-11-01

    Model systems containing ascorbate, hydrogen peroxide, and divalent copper or cobalt have been shown to possess marked bactericidal activity. At equivalent concentrations, copper-containing systems were more bactericidal than the corresponding mixtures containing cobalt. Cobalt at concentrations below 10(-4) M did not appreciably augment microbicidal activity, whereas systems containing copper at concentrations as low as 5 x 10(-6) M were still capable of causing some bacterial death. Manganese was inactive. None of these systems was as potent as the well known myeloperoxidase-peroxide-halide system. The mechanisms of action of these systems are not as yet clear. The possibility that they function through the generation of superoxide (O(2) (-)), hydroxyl radical (OH.), or other free radicals was explored through the use of superoxide dismutase and several free radical scavengers. It seems likely at present that the two active metal-mediated systems function via separate mechanisms. The copper system acts with dehydroascorbate, whereas the cobalt system does not. Activity in the cobalt system appears to depend upon the generation of free radicals. PMID:16558093

  1. Complement profile and activation mechanisms by different LDL apheresis systems.

    PubMed

    Hovland, Anders; Hardersen, Randolf; Nielsen, Erik Waage; Enebakk, Terje; Christiansen, Dorte; Ludviksen, Judith Krey; Mollnes, Tom Eirik; Lappegård, Knut Tore

    2012-07-01

    Extracorporeal removal of low-density lipoprotein (LDL) cholesterol by means of selective LDL apheresis is indicated in otherwise uncontrolled familial hypercholesterolemia. During blood-biomaterial interaction other constituents than the LDL particles are affected, including the complement system. We set up an ex vivo model in which human whole blood was passed through an LDL apheresis system with one of three different apheresis columns: whole blood adsorption, plasma adsorption and plasma filtration. The concentrations of complement activation products revealed distinctly different patterns of activation and adsorption by the different systems. Evaluated as the final common terminal complement complex (TCC) the whole blood system was inert, in contrast to the plasma systems, which generated substantial and equal amounts of TCC. Initial classical pathway activation was revealed equally for both plasma systems as increases in the C1rs-C1inh complex and C4d. Alternative pathway activation (Bb) was most pronounced for the plasma adsorption system. Although the anaphylatoxins (C3a and C5a) were equally generated by the two plasma separation systems, they were efficiently adsorbed to the plasma adsorption column before the "outlet", whereas they were left free in the plasma in the filtration system. Consequently, during blood-biomaterial interaction in LDL apheresis the complement system is modulated in different manners depending on the device composition. PMID:22373816

  2. Dual-Actuator Active Vibration-Control System

    NASA Technical Reports Server (NTRS)

    Kascak, Albert F.; Kiraly, Louis J.; Montague, Gerald T.; Palazzolo, Alan B.; Manchala, Daniel

    1994-01-01

    Dual-actuator active vibration-control (DAAVC) system is developmental system of type described in "Active Vibration Dampers for Rotating Machinery" (LEW-15427). System features sensors and actuators positioned and oriented at bearings to measure and counteract vibrations of shaft along either of two axes perpendicular to axis of rotation. Effective in damping vibrations of helicopter-engine test stand, making it safer to operate engine at speeds near and above first resonance of engine/test-stand system. Opens new opportunities for engine designers to draw more power from engine, and concept applicable to other rotating machines.

  3. Activity-Based Costing Systems for Higher Education.

    ERIC Educational Resources Information Center

    Day, Dennis H.

    1993-01-01

    Examines traditional costing models utilized in higher education and pinpoints shortcomings related to proper identification of costs. Describes activity-based costing systems as a superior alternative for cost identification, measurement, and allocation. (MLF)

  4. Active mirror alignment control system for the MACE telescope

    NASA Astrophysics Data System (ADS)

    Kulgod, S. V.; Pious, Lizy; Chadda, V. K.; Kaul, S. R.; Yadav, K. K.; Koul, R.

    2002-03-01

    The conceptual design of an active mirror contol system for the MACE telescope, being set up by the Bhabha Atomic Research Centre at Mt. Abu, is described. Preliminary results obtained from recent laboratory trials are also described.

  5. A Survey of Active Vibration Isolation Systems for Microgravity Applications

    NASA Technical Reports Server (NTRS)

    Grodsinsky, Carlos M.; Whorton, Mark S.

    2000-01-01

    In view of the utility of space vehicles as orbiting science laboratories, the need for vibration isolation systems for acceleration sensitive experiments has gained increasing visibility. To date, three active microgravity vibration isolation systems have successfully been demonstrated in flight. This paper provides a tutorial discussion of the microgravity vibration isolation problem including a description of the acceleration environment of the International Space Station and attenuation requirements as well as a comparison of the dynamics of passive isolation, active rack-level isolation, and active payload-level isolation. This paper also surveys the flight test results of the three demonstrated systems: Suppression of Transient Accelerations By Levitation (STABLE); the Microgravity Vibration Isolation Mount (MIM); and the Active Rack Isolation System (ARIS).

  6. Survey of Active Vibration Isolation Systems for Microgravity Applications

    NASA Technical Reports Server (NTRS)

    Grodsinsky, Carlos M.; Whorton, Mark S.

    2000-01-01

    In view of the utility of space vehicles as orbiting science laboratories, the need for vibration isolation systems for acceleration-sensitive experiments has gained increasing visibility. To date, three active microgravity vibration isolation systems have successfully been demonstrated in flight. A tutorial discussion of the microgravity vibration isolation problem, including a description of the acceleration environment of the International Space Station and attenuation requirements, as well as a comparison or the dynamics of passive isolation, active rack-level isolation, and active payload-level isolation is provided. The flight test results of the three demonstrated systems: suppression of transient accelerations by levitation, the microgravity vibration isolation mount, and the active rack isolation system are surveyed.

  7. Activity Theory in Information Systems Research and Practice: Theoretical Underpinnings for an Information Systems Development Model

    ERIC Educational Resources Information Center

    Mursu, Anja; Luukkonen, Irmeli; Toivanen, Marika; Korpela, Mikko

    2007-01-01

    Introduction: The purpose of information systems is to facilitate work activities: here we consider how Activity Theory can be applied in information systems development. Method. The requirements for an analytical model for emancipatory, work-oriented information systems research and practice are specified. Previous research work in Activity…

  8. Overview of coupled bunch active damper systems at FNAL

    SciTech Connect

    Steimel, J.; Crisp, J.; Ma, Hengjie; Marriner, J.; McGinnis, D.

    1996-05-01

    Beam intensities in all of the accelerators at Fermilab will increase significantly when the Main Injector becomes operational and will cause unstable oscillations in transverse position and energy. Places where the coupled bunch oscillations could dilute emittances include the Booster, Main Injector, and Tevatron. This paper provides an overview of the active feedback system upgrades which will be used to counteract the problem. It will explain the similarities between all the systems and will also explain design differences between longitudinal and transverse systems, fast sweeping systems, and systems for partially filled machines. Results from operational systems will also be shown. 7 refs., 4 figs., 1 tab.

  9. Overview of coupled-bunch active damper systems at FNAL

    SciTech Connect

    Steimel, J.; Crisp, J.; Ma, H.; Marriner, J.; McGinnis, D.

    1997-01-01

    Beam intensities in all of the accelerators at Fermilab will increase significantly when the Main Injector becomes operational and will cause unstable oscillations in transverse position and energy. Places where the coupled bunch oscillations could dilute emittances include the Booster, Main Injector, and Tevatron. This paper provides an overview of the active feedback system upgrades which will be used to counteract the problem. It will explain the similarities between all the systems and will also explain design differences between longitudinal and transverse systems, fast sweeping systems, and systems for partially filled machines. Results from operational systems will also be shown. {copyright} {ital 1997 American Institute of Physics.}

  10. Understanding Tensions: Activity Systems Analysis of Cross-Continental Collaboration

    ERIC Educational Resources Information Center

    Ryder, LanHui Zhang; Yamagata-Lynch, Lisa

    2014-01-01

    Using the lens of Vygotsky's sociocultural theory, activity theory, and Engeström's activity systems analysis, this qualitative study explores students' experiences in the context of a sixteen-week transpacific collaboration between seven students at Northern Illinois University (NIU) and seven students from Shandong Normal…

  11. World Energy Projection System Plus (WEPS ): Global Activity Module

    EIA Publications

    2013-01-01

    World Energy Projection System Plus Model Documentation: Global Activity Module Documents the objectives, analytical approach, and development of the World Energy Projection Plus (WEPS ) Global Activity Module (GAM) used to develop the International Energy Outlook for 2013 (IEO2013). The report catalogues and describes the module assumptions, computations, methodology, parameter estimation techniques, and mainframe source code.

  12. Disorder-mediated crowd control in an active matter system

    PubMed Central

    Pinçe, Erçağ; Velu, Sabareesh K. P.; Callegari, Agnese; Elahi, Parviz; Gigan, Sylvain; Volpe, Giovanni; Volpe, Giorgio

    2016-01-01

    Living active matter systems such as bacterial colonies, schools of fish and human crowds, display a wealth of emerging collective and dynamic behaviours as a result of far-from-equilibrium interactions. The dynamics of these systems are better understood and controlled considering their interaction with the environment, which for realistic systems is often highly heterogeneous and disordered. Here, we demonstrate that the presence of spatial disorder can alter the long-term dynamics in a colloidal active matter system, making it switch between gathering and dispersal of individuals. At equilibrium, colloidal particles always gather at the bottom of any attractive potential; however, under non-equilibrium driving forces in a bacterial bath, the colloids disperse if disorder is added to the potential. The depth of the local roughness in the environment regulates the transition between gathering and dispersal of individuals in the active matter system, thus inspiring novel routes for controlling emerging behaviours far from equilibrium. PMID:26956085

  13. Disorder-mediated crowd control in an active matter system

    NASA Astrophysics Data System (ADS)

    Pinçe, Erçağ; Velu, Sabareesh K. P.; Callegari, Agnese; Elahi, Parviz; Gigan, Sylvain; Volpe, Giovanni; Volpe, Giorgio

    2016-03-01

    Living active matter systems such as bacterial colonies, schools of fish and human crowds, display a wealth of emerging collective and dynamic behaviours as a result of far-from-equilibrium interactions. The dynamics of these systems are better understood and controlled considering their interaction with the environment, which for realistic systems is often highly heterogeneous and disordered. Here, we demonstrate that the presence of spatial disorder can alter the long-term dynamics in a colloidal active matter system, making it switch between gathering and dispersal of individuals. At equilibrium, colloidal particles always gather at the bottom of any attractive potential; however, under non-equilibrium driving forces in a bacterial bath, the colloids disperse if disorder is added to the potential. The depth of the local roughness in the environment regulates the transition between gathering and dispersal of individuals in the active matter system, thus inspiring novel routes for controlling emerging behaviours far from equilibrium.

  14. Perceiving active listening activates the reward system and improves the impression of relevant experiences

    PubMed Central

    Kawamichi, Hiroaki; Yoshihara, Kazufumi; Sasaki, Akihiro T.; Sugawara, Sho K.; Tanabe, Hiroki C.; Shinohara, Ryoji; Sugisawa, Yuka; Tokutake, Kentaro; Mochizuki, Yukiko; Anme, Tokie; Sadato, Norihiro

    2015-01-01

    Although active listening is an influential behavior, which can affect the social responses of others, the neural correlates underlying its perception have remained unclear. Sensing active listening in social interactions is accompanied by an improvement in the recollected impressions of relevant experiences and is thought to arouse positive feelings. We therefore hypothesized that the recognition of active listening activates the reward system, and that the emotional appraisal of experiences that had been subject to active listening would be improved. To test these hypotheses, we conducted functional magnetic resonance imaging (fMRI) on participants viewing assessments of their own personal experiences made by evaluators with or without active listening attitude. Subjects rated evaluators who showed active listening more positively. Furthermore, they rated episodes more positively when they were evaluated by individuals showing active listening. Neural activation in the ventral striatum was enhanced by perceiving active listening, suggesting that this was processed as rewarding. It also activated the right anterior insula, representing positive emotional reappraisal processes. Furthermore, the mentalizing network was activated when participants were being evaluated, irrespective of active listening behavior. Therefore, perceiving active listening appeared to result in positive emotional appraisal and to invoke mental state attribution to the active listener. PMID:25188354

  15. Perceiving active listening activates the reward system and improves the impression of relevant experiences.

    PubMed

    Kawamichi, Hiroaki; Yoshihara, Kazufumi; Sasaki, Akihiro T; Sugawara, Sho K; Tanabe, Hiroki C; Shinohara, Ryoji; Sugisawa, Yuka; Tokutake, Kentaro; Mochizuki, Yukiko; Anme, Tokie; Sadato, Norihiro

    2015-01-01

    Although active listening is an influential behavior, which can affect the social responses of others, the neural correlates underlying its perception have remained unclear. Sensing active listening in social interactions is accompanied by an improvement in the recollected impressions of relevant experiences and is thought to arouse positive feelings. We therefore hypothesized that the recognition of active listening activates the reward system, and that the emotional appraisal of experiences that had been subject to active listening would be improved. To test these hypotheses, we conducted functional magnetic resonance imaging (fMRI) on participants viewing assessments of their own personal experiences made by evaluators with or without active listening attitude. Subjects rated evaluators who showed active listening more positively. Furthermore, they rated episodes more positively when they were evaluated by individuals showing active listening. Neural activation in the ventral striatum was enhanced by perceiving active listening, suggesting that this was processed as rewarding. It also activated the right anterior insula, representing positive emotional reappraisal processes. Furthermore, the mentalizing network was activated when participants were being evaluated, irrespective of active listening behavior. Therefore, perceiving active listening appeared to result in positive emotional appraisal and to invoke mental state attribution to the active listener. PMID:25188354

  16. γH2AX and p53 responses in TK6 cells discriminate promutagens and nongenotoxicants in the presence of rat liver S9.

    PubMed

    Bernacki, Derek T; Bryce, Steven M; Bemis, Jeffrey C; Kirkland, David; Dertinger, Stephen D

    2016-08-01

    Previous work with a diverse set of reference chemicals suggests that an in vitro multiplexed flow cytometry-based assay (MultiFlow™ DNA Damage Kit-p53, γH2AX, Phospho-Histone H3) can distinguish direct-acting clastogens and aneugens from nongenotoxicants (Bryce SM et al. []: Environ Mol Mutagen 57:171-189). This work extends this line of investigation to include compounds that require metabolic activation to form reactive electrophiles. For these experiments, TK6 cells were exposed to 11 promutagens and 37 presumed nongenotoxicants in 96 well plates. Unless precipitation or foreknowledge about cytotoxicity suggested otherwise, the highest concentration was 1 mM. Exposure occurred for 4 hr after which time cells were washed to remove S9 and test article. Immediately following the wash and again at 24 hr, cell aliquots were added to wells of a microtiter plate containing the working detergent/stain/antibody cocktail. After a brief incubation, robotic sampling was employed for walk-away flow cytometric data acquisition. Univariate logistic regression analyses indicated that γH2AX induction and p53 activation provide the greatest degree of discrimination between clastogens and nongenotoxicants. Multivariate prediction algorithms that incorporated both of these endpoints, in each combination of time points, were evaluated. The best performing models correctly predicted 9 clastogens out of 11 and 36 nongenotoxicants out of 37. These results are encouraging as they suggest that an efficient and highly scalable multiplexed assay can effectively identify clastogenic chemicals that require bioactivation. More work is planned with a broader range of chemicals, additional cell lines, and other laboratories to further evaluate the merits and limitations of this approach. Environ. Mol. Mutagen. 57:546-558, 2016. © 2016 Wiley Periodicals, Inc. PMID:27364561

  17. Human activity recognition based on Evolving Fuzzy Systems.

    PubMed

    Iglesias, Jose Antonio; Angelov, Plamen; Ledezma, Agapito; Sanchis, Araceli

    2010-10-01

    Environments equipped with intelligent sensors can be of much help if they can recognize the actions or activities of their users. If this activity recognition is done automatically, it can be very useful for different tasks such as future action prediction, remote health monitoring, or interventions. Although there are several approaches for recognizing activities, most of them do not consider the changes in how a human performs a specific activity. We present an automated approach to recognize daily activities from the sensor readings of an intelligent home environment. However, as the way to perform an activity is usually not fixed but it changes and evolves, we propose an activity recognition method based on Evolving Fuzzy Systems. PMID:20945515

  18. THE STATE TOBACCO ACTIVITIES TRACKING AND EVALUATION (STATE) SYSTEM

    EPA Science Inventory

    The State Tobacco Activities Tracking and Evaluation (STATE) System is an electronic data warehouse containing up-to-date and historical state-level data on tobacco use prevention and control. The STATE System is designed to integrate many data sources to provide comprehensive su...

  19. PILOT PLANT EVALUATION OF ALTERNATIVE ACTIVATED SLUDGE SYSTEMS

    EPA Science Inventory

    Step feed, plug flow and complete mix activated sludge systems were compared on a pilot plant scale under similar operating conditions with the same municipal wastewater. The process loading to each system was varied over a wide range during the course of the investigation. Exten...

  20. Emergent Ultra-Long-Range Interactions Between Active Particles in Hybrid Active-Inactive Systems

    NASA Astrophysics Data System (ADS)

    Steimel, Joshua; Aragones, Juan; Hu, Helen; Qureshi, Naser; Alexander-Katz, Alfredo

    Particle-particle interactions determine the state of a system. Control over the range and magnitude of such interactions has been an active area of research for decades due to the fundamental challenges it poses in science and technology. Effective interactions between active particles have gathered much attention as they can lead to out-of-equilibrium cooperative states such as flocking. Inspired by nature, where active living cells coexist with lifeless, immobile objects and structures, here we study the effective interactions that appear in systems composed of active and passive mixtures of colloids. Our system is a two dimensional colloidal monolayer composed primarily of passive (inactive) colloids and a very small fraction of active (sinning) ferromagnetic colloids. We find an emergent ultra-long-range attractive interaction between active particles induced by the activity of the spinning particles and mediated by the elasticity of the passive medium. Interestingly, the appearance of such interaction depends on the spinning protocol and has a minimum actuation time scale below which no attraction is observed. Overall, these results clearly show that in the presence of elastic components, active particles can interact across very long distances without any chemical modification of the environment. Such a mechanism might potentially be important for some biological systems and can be harnessed for newer developments in synthetic active soft materials.

  1. Activation of the reward system boosts innate and adaptive immunity.

    PubMed

    Ben-Shaanan, Tamar L; Azulay-Debby, Hilla; Dubovik, Tania; Starosvetsky, Elina; Korin, Ben; Schiller, Maya; Green, Nathaniel L; Admon, Yasmin; Hakim, Fahed; Shen-Orr, Shai S; Rolls, Asya

    2016-08-01

    Positive expectations contribute to the clinical benefits of the placebo effect. Such positive expectations are mediated by the brain's reward system; however, it remains unknown whether and how reward system activation affects the body's physiology and, specifically, immunity. Here we show that activation of the ventral tegmental area (VTA), a key component of the reward system, strengthens immunological host defense. We used 'designer receptors exclusively activated by designer drugs' (DREADDs) to directly activate dopaminergic neurons in the mouse VTA and characterized the subsequent immune response after exposure to bacteria (Escherichia coli), using time-of-flight mass cytometry (CyTOF) and functional assays. We found an increase in innate and adaptive immune responses that were manifested by enhanced antibacterial activity of monocytes and macrophages, reduced in vivo bacterial load and a heightened T cell response in the mouse model of delayed-type hypersensitivity. By chemically ablating the sympathetic nervous system (SNS), we showed that the reward system's effects on immunity are, at least partly, mediated by the SNS. Thus, our findings establish a causal relationship between the activity of the VTA and the immune response to bacterial infection. PMID:27376577

  2. Advanced Active-Magnetic-Bearing Thrust-Measurement System

    NASA Technical Reports Server (NTRS)

    Imlach, Joseph; Kasarda, Mary; Blumber, Eric

    2008-01-01

    An advanced thrust-measurement system utilizes active magnetic bearings to both (1) levitate a floating frame in all six degrees of freedom and (2) measure the levitation forces between the floating frame and a grounded frame. This system was developed for original use in measuring the thrust exerted by a rocket engine mounted on the floating frame, but can just as well be used in other force-measurement applications. This system offers several advantages over prior thrust-measurement systems based on mechanical support by flexures and/or load cells: The system includes multiple active magnetic bearings for each degree of freedom, so that by selective use of one, some, or all of these bearings, it is possible to test a given article over a wide force range in the same fixture, eliminating the need to transfer the article to different test fixtures to obtain the benefit of full-scale accuracy of different force-measurement devices for different force ranges. Like other active magnetic bearings, the active magnetic bearings of this system include closed-loop control subsystems, through which the stiffness and damping characteristics of the magnetic bearings can be modified electronically. The design of the system minimizes or eliminates cross-axis force-measurement errors. The active magnetic bearings are configured to provide support against movement along all three orthogonal Cartesian axes, and such that the support along a given axis does not produce force along any other axis. Moreover, by eliminating the need for such mechanical connections as flexures used in prior thrust-measurement systems, magnetic levitation of the floating frame eliminates what would otherwise be major sources of cross-axis forces and the associated measurement errors. Overall, relative to prior mechanical-support thrust-measurement systems, this system offers greater versatility for adaptation to a variety of test conditions and requirements. The basic idea of most prior active

  3. Low Energy Physical Activity Recognition System on Smartphones

    PubMed Central

    Morillo, Luis Miguel Soria; Gonzalez-Abril, Luis; Ramirez, Juan Antonio Ortega; de la Concepcion, Miguel Angel Alvarez

    2015-01-01

    An innovative approach to physical activity recognition based on the use of discrete variables obtained from accelerometer sensors is presented. The system first performs a discretization process for each variable, which allows efficient recognition of activities performed by users using as little energy as possible. To this end, an innovative discretization and classification technique is presented based on the χ2 distribution. Furthermore, the entire recognition process is executed on the smartphone, which determines not only the activity performed, but also the frequency at which it is carried out. These techniques and the new classification system presented reduce energy consumption caused by the activity monitoring system. The energy saved increases smartphone usage time to more than 27 h without recharging while maintaining accuracy. PMID:25742171

  4. Active Beam Shaping System and Method Using Sequential Deformable Mirrors

    NASA Technical Reports Server (NTRS)

    Norman, Colin A. (Inventor); Pueyo, Laurent A. (Inventor)

    2015-01-01

    An active optical beam shaping system includes a first deformable mirror arranged to at least partially intercept an entrance beam of light and to provide a first reflected beam of light, a second deformable mirror arranged to at least partially intercept the first reflected beam of light from the first deformable mirror and to provide a second reflected beam of light, and a signal processing and control system configured to communicate with the first and second deformable mirrors. The first deformable mirror, the second deformable mirror and the signal processing and control system together provide a large amplitude light modulation range to provide an actively shaped optical beam.

  5. Individual popularity and activity in online social systems

    NASA Astrophysics Data System (ADS)

    Hu, Haibo; Han, Dingyi; Wang, Xiaofan

    2010-03-01

    We propose a stochastic model of web user behaviors in online social systems, and study the influence of the attraction kernel on the statistical property of user or item occurrence. Combining the different growth patterns of new entities and attraction patterns of old ones, different heavy-tailed distributions for popularity and activity which have been observed in real life, can be obtained. From a broader perspective, we explore the underlying principle governing the statistical feature of individual popularity and activity in online social systems and point out the potential simple mechanism underlying the complex dynamics of the systems.

  6. Vehicle dynamics control using an active third-axle system

    NASA Astrophysics Data System (ADS)

    Soltani, Amir; Goodarzi, Avesta; Hassan Shojaeefard, Mohammad; Khajepour, Amir

    2014-11-01

    This paper introduces the active third-axle system as an innovative vehicle dynamic control method. This method can be applicable for different kinds of three-axle vehicles such as buses, trucks, or even three-axle passenger cars. In this system, an actuator on the middle axle actively applies an independent force on the suspension to improve the handling characteristics, and hence, its technology is similar to slow-active suspension systems. This system can change the inherent vehicle dynamic characteristics, such as under/over steering behaviour, in the linear handling region, as well as vehicle stability in the nonlinear, limit handling region. In this paper, our main focus is to show the potential capabilities of this method in enhancing vehicle dynamic performance. For this purpose, as the first step, the proposed method in both linear and nonlinear vehicle handling regions is studied mathematically. Next, a comprehensive, nonlinear, 10 degrees of freedom vehicle model with a fuzzy control strategy is used to evaluate the effectiveness of this system. The dynamic behaviour of a vehicle, when either uncontrolled or equipped with the active third axle is then compared. Simulation results show that this active system can be considered as an innovative method for vehicle dynamic control.

  7. Narrowband system activities in the NASA communications program

    NASA Technical Reports Server (NTRS)

    Durrani, S. H.

    1979-01-01

    The objective of NASA's narrowband system activities is to identify, develop, and test the technology needed for future commercial satellite-aided mobile communications systems. Desired characteristics include low service cost, efficient spectrum utilization, and compatibility with terrestrial systems. Ongoing effort includes system concept definition and market analysis. A typical system would need a large spaceborne antenna with 50 to 100 beams, each 0.5 to 0.7 degree wide, onboard switching and processing, linear solid-state amplifiers, and low-cost user terminals. The paper describes current studies and discusses future NASA plans in this field.

  8. Fault detection and isolation for an active wheelset control system

    NASA Astrophysics Data System (ADS)

    Mirzapour, Mohammad; Mei, T. X.; Xuesong, Jin

    2014-05-01

    Active control for railway wheelsets in the primary suspension has been shown to offer a number of performance gains, and especially it can be used to stabilise the wheelsets without compromising the vehicle's performance on curves. However, the use of actuators, sensors and data processors to replace the traditional passive suspension raises the issue of system safety in the event of a failure of the active control, which could result in the loss of stability (i.e. wheelset hunting), and in more severe cases, derailment. This paper studies the key issue of condition monitoring for an actively controlled railway system, with a focus on actuator failures to detect and isolate failure modes in such a system. It seeks to establish the necessary basis for fault detection to ensure system reliability in the event of malfunction in one of the two actuators. Computer simulations are used to demonstrate the effectiveness of the method.

  9. Activator-inhibitor systems on heterogeneous ecological networks

    NASA Astrophysics Data System (ADS)

    Nicolaides, C.; Cueto-Felgueroso, L.; Juanes, R.

    2012-12-01

    The consideration of activator-inhibitor systems as complex networks has broadened our knowledge of non-equilibrium reaction-diffusion processes in heterogeneous systems. For example, the Turing mechanism represents a classical model for the formation of self-organized spatial structures in non-equilibrium activator-inhibitor systems. The study of Turing patterns in networks with heterogeneous connectivity has revealed that, contrary to other models and systems, the segregation process takes place mainly in vertices of low degree. In this paper, we study the formation of vegetation patterns in semiarid ecosystems from the perspective of a heterogeneous interacting ecological network. The structure of ecological networks yields fundamental insight into the ecosystem self-organization. Using simple rules for the short-range activation and global inhibition, we reconstruct the observed power-law distribution of vegetation patch size that has been observed in semiarid ecosystems like the Kalahari transect.

  10. Adaptive control model of an active automobile suspension system

    NASA Astrophysics Data System (ADS)

    Fritz, Matthew; Wunsch, Donald C., II; Mitra, Sunanda

    1993-12-01

    The suspension system of a passenger car provides isolation between the occupants in the car and the road surface. The three goals of the suspension system are to provide ride isolation from vibration, limit suspension travel, and maintain road holding characteristics. Each of these three goals conflicts with the others. Thus, the controller must be designed to attain each goal to some extent. This paper proposes the use of a linear quadratic regulator and a fuzzy controller to maintain the ride isolation of a loosely sprung, lightly damped passive suspension while improving the handling characteristics of the vehicle. The suspension performance as pertains to ride isolation can be studied using a simple quarter car model of a suspension system. However, the handling characteristics and the coupling between each quarter of the suspension system must be studied using a full car model. Thus, this paper uses both a quarter car and a full car model to study the performance of suspension systems. The performance of the suspension systems is evaluated by running simulations of the systems subjected to both discrete and random road inputs. This paper shows that an active suspension using a linear full state feedback controller performs better than a passively suspended vehicle. The optimally controlled active suspension system is also compared to a fuzzy controlled active suspension system and the results are discussed.

  11. Macrophages require different nucleoside transport systems for proliferation and activation.

    PubMed

    Soler, C; García-Manteiga, J; Valdés, R; Xaus, J; Comalada, M; Casado, F J; Pastor-Anglada, M; Celada, A; Felipe, A

    2001-09-01

    To evaluate the mechanisms involved in macrophage proliferation and activation, we studied the regulation of the nucleoside transport systems. In murine bone marrow-derived macrophages, the nucleosides required for DNA and RNA synthesis are recruited from the extracellular medium. M-CSF induced macrophage proliferation and DNA and RNA synthesis, whereas interferon gamma (IFN-gamma) led to activation, blocked proliferation, and induced only RNA synthesis. Macrophages express at least the concentrative systems N1 and N2 (CNT2 and CNT1 genes, respectively) and the equilibrative systems es and ei (ENT1 and ENT2 genes, respectively). Incubation with M-CSF only up-regulated the equilibrative system es. Inhibition of this transport system blocked M-CSF-dependent proliferation. Treatment with IFN-gamma only induced the concentrative N1 and N2 systems. IFN-gamma also down-regulated the increased expression of the es equilibrative system induced by M-CSF. Thus, macrophage proliferation and activation require selective regulation of nucleoside transporters and may respond to specific requirements for DNA and RNA synthesis. This report also shows that the nucleoside transporters are critical for macrophage proliferation and activation. PMID:11532978

  12. Active infrared systems: possible roles in ballistic missile defense?

    NASA Astrophysics Data System (ADS)

    Paleologue, A.

    2006-05-01

    Active Infra-Red (IR) systems developed in the past ten years are now available for missile defense applications. The main purpose of this paper is to describe the advantages an active IR system could offer to a ballistic missile defense (BMD). The active IR system considered in this paper is a LIDAR (LIght Detection And Ranging) system. Historically, the Lincoln Laboratory in the USA began using lasers in the early 1960's. The initial applications included the development of a LIDAR system enabling the measurement of the distance between the earth and the moon in 1962. Satellite tracking using LIDAR began early in 1973. Today, technological developments, with the miniaturization of systems and increased performance levels, have enabled new ambitious projects such as the Discrimination Interceptor Technology Program (DITP) program started in 1998 and the use of LIDAR to help in the discrimination of future exo-atmospheric interceptors within the framework of BMD. The first part of this paper presents the possible contribution of LIDAR to BMD: the main roles, objectives, and strategic advantages. The second part gives a brief overview of the technological features of a generic LIDAR instrument, rapidly addressing laser sources, detectors, optics and electronics. Finally, a modeling of an IR LIDAR system, limited solely to direct detection, and an estimation of performance levels will be presented. A list of possible IR active discriminators will be then presented on the basis of the previous analysis and proposed as new constraints in the design of discrete objects.

  13. THE EFFECT OF POWERED ACTIVATED CARBON IN A PETROLEUM REFINERY ACTIVATED SLUDGE TREATMENT SYSTEM

    EPA Science Inventory

    The purpose of this research program was to determine the effect of the addition of powdered activated carbon (PAC) to refinery activated sludge systems. Bench-scale and full-scale tests were performed. A wide range of PAC concentrations and sludge ages were evaluated. Bench-scal...

  14. EVALUATION OF FULL SCALE ACTIVATED SLUDGE SYSTEMS UTILIZING POWDERED ACTIVATED CARBON ADDITION WITH WET AIR REGENERATION

    EPA Science Inventory

    The addition of powdered activated carbon (PAC) to activated sludge systems is a proven method of wastewater treatment. Of eleven POTWs in the U.S. that were designed for PAC use, ten included wet air regeneration (WAR) for the destruction of secondary sludge solids and recovery ...

  15. Emergent ultra-long-range interactions between active particles in hybrid active-inactive systems.

    PubMed

    Steimel, Joshua P; Aragones, Juan L; Hu, Helen; Qureshi, Naser; Alexander-Katz, Alfredo

    2016-04-26

    Particle-particle interactions determine the state of a system. Control over the range of such interactions as well as their magnitude has been an active area of research for decades due to the fundamental challenges it poses in science and technology. Very recently, effective interactions between active particles have gathered much attention as they can lead to out-of-equilibrium cooperative states such as flocking. Inspired by nature, where active living cells coexist with lifeless objects and structures, here we study the effective interactions that appear in systems composed of active and passive mixtures of colloids. Our systems are 2D colloidal monolayers composed primarily of passive (inactive) colloids, and a very small fraction of active (spinning) ferromagnetic colloids. We find an emergent ultra-long-range attractive interaction induced by the activity of the spinning particles and mediated by the elasticity of the passive medium. Interestingly, the appearance of such interaction depends on the spinning protocol and has a minimum actuation timescale below which no attraction is observed. Overall, these results clearly show that, in the presence of elastic components, active particles can interact across very long distances without any chemical modification of the environment. Such a mechanism might potentially be important for some biological systems and can be harnessed for newer developments in synthetic active soft materials. PMID:27071096

  16. JPL Activated Carbon Treatment System (ACTS) for sewage

    NASA Technical Reports Server (NTRS)

    1976-01-01

    An Activated Carbon Treatment System (ACTS) was developed for sewage treatment and is being applied to a one-million gallon per day sewage treatment pilot plant in Orange County California. Activities reported include pyrolysis and activation of carbon-sewage sludge, and activated carbon treatment of sewage to meet ocean discharge standards. The ACTS Sewage treatment operations include carbon-sewage treatment, primary and secondary clarifiers, gravity (multi-media) filter, filter press dewatering, flash drying of carbon-sewage filter cake, and sludge pyrolysis and activation. Tests were conducted on a laboratory scale, 10,000 gallon per day demonstration plant and pilot test equipment. Preliminary economic studies are favorable to the ACTS process relative to activated sludge treatment for a 175,000,000 gallon per day sewage treatment plant.

  17. Turing pattern formation in fractional activator-inhibitor systems.

    PubMed

    Henry, B I; Langlands, T A M; Wearne, S L

    2005-08-01

    Activator-inhibitor systems of reaction-diffusion equations have been used to describe pattern formation in numerous applications in biology, chemistry, and physics. The rate of diffusion in these applications is manifest in the single parameter of the diffusion constant, and stationary Turing patterns occur above a critical value of d representing the ratio of the diffusion constants of the inhibitor to the activator. Here we consider activator-inhibitor systems in which the diffusion is anomalous subdiffusion; the diffusion rates are manifest in both a diffusion constant and a diffusion exponent. A consideration of this problem in terms of continuous-time random walks with sources and sinks leads to a reaction-diffusion system with fractional order temporal derivatives operating on the spatial Laplacian. We have carried out an algebraic stability analysis of the homogeneous steady-state solution in fractional activator-inhibitor systems, with Gierer-Meinhardt reaction kinetics and with Brusselator reaction kinetics. For each class of reaction kinetics we identify a Turing instability bifurcation curve in the two-dimensional diffusion parameter space. The critical value of d , for Turing instabilities, decreases monotonically with the anomalous diffusion exponent between unity (standard diffusion) and zero (extreme subdiffusion). We have also carried out numerical simulations of the governing fractional activator-inhibitor equations and we show that the Turing instability precipitates the formation of complex spatiotemporal patterns. If the diffusion of the activator and inhibitor have the same anomalous scaling properties, then the surface profiles of these patterns for values of d slightly above the critical value varies from smooth stationary patterns to increasingly rough and nonstationary patterns as the anomalous diffusion exponent varies from unity towards zero. If the diffusion of the activator is anomalous subdiffusion but the diffusion of the inhibitor

  18. EURAMET.M.P-S9: comparison in the negative gauge pressure range ‑950 to 0 hPa

    NASA Astrophysics Data System (ADS)

    Saxholm, S.; Otal, P.; AltintaS, A.; Bermanec, L. G.; Durgut, Y.; Hanrahan, R.; Kocas, I.; Lefkopoulos, A.; Pražák, D.; Sandu, I.; Åetina, J.; Spohr, I.; Steindl, D.; Tammik, K.; Testa, N.

    2016-01-01

    comparison is registered as EURAMET project no. 1170 and as a supplementary comparison EURAMET.M.P-S9 in the BIPM key comparison database. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  19. Fault analysis and detection in large active optical systems

    NASA Astrophysics Data System (ADS)

    Cox, Charles D.; Furber, Mark E.; Jordan, David C.; Blaszak, David D.

    1995-05-01

    Active optical systems are complex systems that may be expected to operate in hostile environments such as space. The ability of such a system either to tolerate failures of components or to reconfigure to accommodate failed components could significantly increase the useful lifetime of the system. Active optical systems often contain hundreds of actuators and sensor channels but have an inherent redundancy, i.e., more actuators or sensor channels than the minimum needed to achieve the required performance. A failure detection and isolation system can be used to find and accommodate failures. One type of failure is the failure of an actuator. The effect of actuator failure on the ability of a deformable mirror to correct aberrations is analyzed using a finite-element model of the deformable mirror, and a general analytical procedure for determining the effect of actuator failures on system performance is given. The application of model-based failure detection, isolation and identification algorithms to active optical systems is outlined.

  20. Evaluation of phenobarbital/beta-naphthoflavone as an alternative S9-induction regime to Aroclor 1254 in the rat for use in in vitro genotoxicity assays.

    PubMed

    Callander, R D; Mackay, J M; Clay, P; Elcombe, C R; Elliott, B M

    1995-11-01

    A series of bacterial mutation, mammalian cell (L5178Y) gene mutation and in vitro cytogenetic assays were performed to compare the efficacy of using S9 fractions prepared from rats induced with a combination of phenobarbital (PB) and beta-naphthoflavone (beta NF), with S9 fractions from rats treated with the general enzyme inducer Aroclor 1254. Although some quantitative differences in the magnitudes of the mutagenic/clastogenic effects were observed between the two induction regimes, no qualitative differences were observed. The use of a combined PB/beta NF induction regime using oral dosing is therefore considered to be a suitable substitute for Aroclor 1254. PMID:8596471

  1. Active Sensing System with In Situ Adjustable Sensor Morphology

    PubMed Central

    Nurzaman, Surya G.; Culha, Utku; Brodbeck, Luzius; Wang, Liyu; Iida, Fumiya

    2013-01-01

    Background Despite the widespread use of sensors in engineering systems like robots and automation systems, the common paradigm is to have fixed sensor morphology tailored to fulfill a specific application. On the other hand, robotic systems are expected to operate in ever more uncertain environments. In order to cope with the challenge, it is worthy of note that biological systems show the importance of suitable sensor morphology and active sensing capability to handle different kinds of sensing tasks with particular requirements. Methodology This paper presents a robotics active sensing system which is able to adjust its sensor morphology in situ in order to sense different physical quantities with desirable sensing characteristics. The approach taken is to use thermoplastic adhesive material, i.e. Hot Melt Adhesive (HMA). It will be shown that the thermoplastic and thermoadhesive nature of HMA enables the system to repeatedly fabricate, attach and detach mechanical structures with a variety of shape and size to the robot end effector for sensing purposes. Via active sensing capability, the robotic system utilizes the structure to physically probe an unknown target object with suitable motion and transduce the arising physical stimuli into information usable by a camera as its only built-in sensor. Conclusions/Significance The efficacy of the proposed system is verified based on two results. Firstly, it is confirmed that suitable sensor morphology and active sensing capability enables the system to sense different physical quantities, i.e. softness and temperature, with desirable sensing characteristics. Secondly, given tasks of discriminating two visually indistinguishable objects with respect to softness and temperature, it is confirmed that the proposed robotic system is able to autonomously accomplish them. The way the results motivate new research directions which focus on in situ adjustment of sensor morphology will also be discussed. PMID:24416094

  2. Numerical evaluation of the performance of active noise control systems

    NASA Technical Reports Server (NTRS)

    Mollo, C. G.; Bernhard, R. J.

    1990-01-01

    This paper presents a generalized numerical technique for evaluating the optimal performance of active noise controllers. In this technique, the indirect BEM numerical procedures are used to derive the active noise controllers for optimal control of enclosed harmonic sound fields where the strength of the noise sources or the description of the enclosure boundary may not be known. The performance prediction for a single-input single-output system is presented, together with the analysis of the stability and observability of an active noise-control system employing detectors. The numerical procedures presented can be used for the design of both the physical configuration and the electronic components of the optimal active noise controller.

  3. Modeling the target acquisition performance of active imaging systems.

    PubMed

    Espinola, Richard L; Jacobs, Eddie L; Halford, Carl E; Vollmerhausen, Richard; Tofsted, David H

    2007-04-01

    Recent development of active imaging system technology in the defense and security community have driven the need for a theoretical understanding of its operation and performance in military applications such as target acquisition. In this paper, the modeling of active imaging systems, developed at the U.S. Army RDECOM CERDEC Night Vision & Electronic Sensors Directorate, is presented with particular emphasis on the impact of coherent effects such as speckle and atmospheric scintillation. Experimental results from human perception tests are in good agreement with the model results, validating the modeling of coherent effects as additional noise sources. Example trade studies on the design of a conceptual active imaging system to mitigate deleterious coherent effects are shown. PMID:19532626

  4. Modeling the target acquisition performance of active imaging systems

    NASA Astrophysics Data System (ADS)

    Espinola, Richard L.; Jacobs, Eddie L.; Halford, Carl E.; Vollmerhausen, Richard; Tofsted, David H.

    2007-04-01

    Recent development of active imaging system technology in the defense and security community have driven the need for a theoretical understanding of its operation and performance in military applications such as target acquisition. In this paper, the modeling of active imaging systems, developed at the U.S. Army RDECOM CERDEC Night Vision & Electronic Sensors Directorate, is presented with particular emphasis on the impact of coherent effects such as speckle and atmospheric scintillation. Experimental results from human perception tests are in good agreement with the model results, validating the modeling of coherent effects as additional noise sources. Example trade studies on the design of a conceptual active imaging system to mitigate deleterious coherent effects are shown.

  5. Bioorthogonal Chemical Activation of Kinases in Living Systems

    PubMed Central

    2016-01-01

    Selective manipulation of protein kinases under living conditions is highly desirable yet extremely challenging, particularly in a gain-of-function fashion. Here we employ our recently developed bioorthogonal cleavage reaction as a general strategy for intracellular activation of individual kinases. Site-specific incorporation of trans-cyclooctene-caged lysine in place of the conserved catalytic lysine, in conjunction with the cleavage partner dimethyl-tetrazine, allowed efficient lysine decaging with the kinase activity chemically rescued in living systems. PMID:27280167

  6. Active vibration damping of the Space Shuttle remote manipulator system

    NASA Technical Reports Server (NTRS)

    Scott, Michael A.; Gilbert, Michael G.; Demeo, Martha E.

    1991-01-01

    The feasibility of providing active damping augmentation of the Space Shuttle Remote Manipulator System (RMS) following normal payload handling operations is investigated. The approach used in the analysis is described, and the results for both linear and nonlinear performance analysis of candidate laws are presented, demonstrating that significant improvement in the RMS dynamic response can be achieved through active control using measured RMS tip acceleration data for feedback.

  7. Coincident Helminth Infection Modulates Systemic Inflammation and Immune Activation in Active Pulmonary Tuberculosis

    PubMed Central

    George, Parakkal Jovvian; Kumar, Nathella Pavan; Sridhar, Rathinam; Hanna, Luke E.; Nair, Dina; Banurekha, Vaithilingam V.; Nutman, Thomas B.; Babu, Subash

    2014-01-01

    Background Helminth infections are known to modulate innate and adaptive immune responses in active and latent tuberculosis (TB). However, the role of helminth infections in modulating responses associated with inflammation and immune activation (reflecting disease activity and/or severity) in TB is not known. Methodology We measured markers of inflammation and immune activation in active pulmonary TB individuals (ATB) with co-incidental Strongyloides stercoralis (Ss) infection. These included systemic levels of acute phase proteins, matrix metalloproteinases and their endogenous inhibitors and immune activation markers. As a control, we measured the systemic levels of the same molecules in TB-uninfected individuals (NTB) with or without Ss infection. Principal Findings Our data confirm that ATB is associated with elevated levels of the various measured molecules when compared to those seen in NTB. Our data also reveal that co-incident Ss infection in ATB individuals is associated with significantly decreased circulating levels of acute phase proteins, matrix metalloproteinases, tissue inhibitors of matrix metalloproteinases as well as the systemic immune activation markers, sCD14 and sCD163. These changes are specific to ATB since they are absent in NTB individuals with Ss infection. Conclusions Our data therefore reveal a profound effect of Ss infection on the markers associated with TB disease activity and severity and indicate that co-incidental helminth infections might dampen the severity of TB disease. PMID:25375117

  8. Activity Management System user reference manual. Revision 1

    SciTech Connect

    Gates, T.A.; Burdick, M.B.

    1994-09-22

    The Activity Management System (AMS) was developed in response to the need for a simple-to-use, low-cost, user interface system for collecting and logging Hanford Waste Vitrification Plant Project (HWVP) activities. This system needed to run on user workstations and provide common user access to a database stored on a local network file server. Most important, users wanted a system that provided a management tool that supported their individual process for completing activities. Existing system treated the performer as a tool of the system. All AMS data is maintained in encrypted format. Users can feel confident that any activities they have entered into the database are private and that, as the originator, they retain sole control over who can see them. Once entered into the AMS database, the activities cannot be accessed by anyone other than the originator, the designated agent, or by authorized viewers who have been explicitly granted the right to look at specific activities by the originator. This user guide is intended to assist new AMS users in learning how to use the application and, after the initial learning process, will serve as an ongoing reference for experienced users in performing infrequently used functions. Online help screens provide reference to some of the key information in this manual. Additional help screens, encompassing all the applicable material in this manual, will be incorporated into future AMS revisions. A third, and most important, source of help is the AMS administrator(s). This guide describes the initial production version of AMS, which has been designated Revision 1.0.

  9. Evaluation of an Active Clearance Control System Concept

    NASA Technical Reports Server (NTRS)

    Steinetz, Bruce M.; Lattime, Scott B.; Taylor, Shawn; DeCastro, Jonathan A.; Oswald, Jay; Melcher, Kevin J.

    2005-01-01

    Reducing blade tip clearances through active tip clearance control in the high pressure turbine can lead to significant reductions in emissions and specific fuel consumption as well as dramatic improvements in operating efficiency and increased service life. Current engines employ scheduled cooling of the outer case flanges to reduce high pressure turbine tip clearances during cruise conditions. These systems have relatively slow response and do not use clearance measurement, thereby forcing cold build clearances to set the minimum clearances at extreme operating conditions (e.g., takeoff, reburst) and not allowing cruise clearances to be minimized due to the possibility of throttle transients (e.g., step change in altitude). In an effort to improve upon current thermal methods, a first generation mechanically-actuated active clearance control (ACC) system has been designed and fabricated. The system utilizes independent actuators, a segmented shroud structure, and clearance measurement feedback to provide fast and precise active clearance control throughout engine operation. Ambient temperature performance tests of this first generation ACC system assessed individual seal component leakage rates and both static and dynamic overall system leakage rates. The ability of the nine electric stepper motors to control the position of the seal carriers in both open- and closed-loop control modes for single and multiple cycles was investigated. The ability of the system to follow simulated engine clearance transients in closed-loop mode showed the system was able to track clearances to within a tight tolerance ( 0.001 in. error).

  10. Evaluation of an Active Clearance Control System Concept

    NASA Technical Reports Server (NTRS)

    Steinetz, Bruce M.; Lattime, Scott B.; DeCastro, Jonathan A.; Oswald, Jay; Melcher, Kevin J.

    2005-01-01

    Reducing blade tip clearances through active tip clearance control in the high pressure turbine can lead to significant reductions in emissions and specific fuel consumption as well as dramatic improvements in operating efficiency and increased service life. Current engines employ scheduled cooling of the outer case flanges to reduce high pressure turbine tip clearances during cruise conditions. These systems have relatively slow response and do not use clearance measurement, thereby forcing cold build clearances to set the minimum clearances at extreme operating conditions (e.g., takeoff, reburst) and not allowing cruise clearances to be minimized due to the possibility of throttle transients (e.g., step change in altitude). In an effort to improve upon current thermal methods, a first generation mechanically-actuated active clearance control (ACC) system has been designed and fabricated. The system utilizes independent actuators, a segmented shroud structure, and clearance measurement feedback to provide fast and precise active clearance control throughout engine operation. Ambient temperature performance tests of this first generation ACC system assessed individual seal component leakage rates and both static and dynamic overall system leakage rates. The ability of the nine electric stepper motors to control the position of the seal carriers in both open- and closed-loop control modes for single and multiple cycles was investigated. The ability of the system to follow simulated engine clearance transients in closed-loop mode showed the system was able to track clearances to within a tight tolerance (0.001 in. error).

  11. Game-Based Virtual Worlds as Decentralized Virtual Activity Systems

    NASA Astrophysics Data System (ADS)

    Scacchi, Walt

    There is widespread interest in the development and use of decentralized systems and virtual world environments as possible new places for engaging in collaborative work activities. Similarly, there is widespread interest in stimulating new technological innovations that enable people to come together through social networking, file/media sharing, and networked multi-player computer game play. A decentralized virtual activity system (DVAS) is a networked computer supported work/play system whose elements and social activities can be both virtual and decentralized (Scacchi et al. 2008b). Massively multi-player online games (MMOGs) such as World of Warcraft and online virtual worlds such as Second Life are each popular examples of a DVAS. Furthermore, these systems are beginning to be used for research, deve-lopment, and education activities in different science, technology, and engineering domains (Bainbridge 2007, Bohannon et al. 2009; Rieber 2005; Scacchi and Adams 2007; Shaffer 2006), which are also of interest here. This chapter explores two case studies of DVASs developed at the University of California at Irvine that employ game-based virtual worlds to support collaborative work/play activities in different settings. The settings include those that model and simulate practical or imaginative physical worlds in different domains of science, technology, or engineering through alternative virtual worlds where players/workers engage in different kinds of quests or quest-like workflows (Jakobsson 2006).

  12. Virial pressure in systems of spherical active Brownian particles.

    PubMed

    Winkler, Roland G; Wysocki, Adam; Gompper, Gerhard

    2015-09-01

    The pressure of suspensions of self-propelled objects is studied theoretically and by simulation of spherical active Brownian particles (ABPs). We show that for certain geometries, the mechanical pressure as force/area of confined systems can be equally expressed by bulk properties, which implies the existence of a nonequilibrium equation of state. Exploiting the virial theorem, we derive expressions for the pressure of ABPs confined by solid walls or exposed to periodic boundary conditions. In both cases, the pressure comprises three contributions: the ideal-gas pressure due to white-noise random forces, an activity-induced pressure ("swim pressure"), which can be expressed in terms of a product of the bare and a mean effective particle velocity, and the contribution by interparticle forces. We find that the pressure of spherical ABPs in confined systems explicitly depends on the presence of the confining walls and the particle-wall interactions, which has no correspondence in systems with periodic boundary conditions. Our simulations of three-dimensional ABPs in systems with periodic boundary conditions reveal a pressure-concentration dependence that becomes increasingly nonmonotonic with increasing activity. Above a critical activity and ABP concentration, a phase transition occurs, which is reflected in a rapid and steep change of the pressure. We present and discuss the pressure for various activities and analyse the contributions of the individual pressure components. PMID:26221908

  13. Retrofitting activated sludge systems to intermittent aeration for nitrogen removal.

    PubMed

    Hanhan, O; Artan, N; Orhon, D

    2002-01-01

    The paper provides the basis and the conceptual approach of applying process kinetics and modelling to the design of alternating activated sludge systems for retrofitting existing activated sludge plants to intermittent aeration for nitrogen removal. It shows the significant role of the two specific parameters, namely, the aerated fraction and the cycle time ratio on process performance through model simulations and proposes a way to incorporate them into a design procedure using process stoichiometry and mass balance. It illustrates the effect of these parameters, together with the sludge age, in establishing the balance between the denitrification potential and the available nitrogen created in the anoxic/aerobic sequences of system operation. PMID:12420968

  14. Implementation study of wearable sensors for activity recognition systems

    PubMed Central

    Ghassemian, Mona

    2015-01-01

    This Letter investigates and reports on a number of activity recognition methods for a wearable sensor system. The authors apply three methods for data transmission, namely ‘stream-based’, ‘feature-based’ and ‘threshold-based’ scenarios to study the accuracy against energy efficiency of transmission and processing power that affects the mote's battery lifetime. They also report on the impact of variation of sampling frequency and data transmission rate on energy consumption of motes for each method. This study leads us to propose a cross-layer optimisation of an activity recognition system for provisioning acceptable levels of accuracy and energy efficiency. PMID:26609413

  15. Control surface spanwise placement in active flutter suppression systems

    NASA Technical Reports Server (NTRS)

    Nissim, E.; Burken, John J.

    1988-01-01

    A method is developed that determines the placement of an active control surface for maximum effectiveness in suppressing flutter. No specific control law is required by this method which is based on the aerodynamic energy concept. It is argued that the spanwise placement of the active controls should coincide with the locations where maximum energy per unit span is fed into the system. The method enables one to determine the distribution, over the different surfaces of the aircraft, of the energy input into the system as a result of the unstable fluttering mode. The method is illustrated using three numerical examples.

  16. Benfotiamine upregulates antioxidative system in activated BV-2 microglia cells

    PubMed Central

    Bozic, Iva; Savic, Danijela; Stevanovic, Ivana; Pekovic, Sanja; Nedeljkovic, Nadezda; Lavrnja, Irena

    2015-01-01

    Chronic microglial activation and resulting sustained neuroinflammatory reaction are generally associated with neurodegeneration. Activated microglia acquires proinflammatory cellular profile that generates oxidative burst. Their persistent activation exacerbates inflammation, which damages healthy neurons via cytotoxic mediators, such as superoxide radical anion and nitric oxide. In our recent study, we have shown that benfotiamine (S-benzoylthiamine O-monophosphate) possesses anti-inflammatory effects. Here, the effects of benfotiamine on the pro-oxidative component of activity of LPS-stimulated BV-2 cells were investigated. The activation of microglia was accompanied by upregulation of intracellular antioxidative defense, which was further promoted in the presence of benfotiamine. Namely, activated microglia exposed to non-cytotoxic doses of benfotiamine showed increased levels and activities of hydrogen peroxide- and superoxide-removing enzymes—catalase and glutathione system, and superoxide dismutase. In addition, benfotiamine showed the capacity to directly scavenge superoxide radical anion. As a consequence, benfotiamine suppressed the activation of microglia and provoked a decrease in NO and ·O−2 production and lipid peroxidation. In conclusion, benfotiamine might silence pro-oxidative activity of microglia to alleviate/prevent oxidative damage of neighboring CNS cells. PMID:26388737

  17. Characterizing wind turbine system response to lightning activity

    SciTech Connect

    McNiff, B.; LaWhite, N.; Muljadi, E.

    1998-07-01

    A lightning protection research program was instituted by National Renewable Energy Laboratory to minimize lightning damage to wind turbines and to further the understanding of effective damage mitigation techniques. To that end, a test program is under way to observe lightning activity, protection system response, and damage at a wind power plant in the Department of Energy (DOE) and Electric Power Research Institute (EPRI) Turbine Verification Program. The authors installed Lightning activated surveillance cameras along with a special storm tracking device to observe the activity in the wind plant area. They instrumented the turbines with lightning and ground current detection devices to log direct and indirect strike activity at each unit. They installed a surge monitor on the utility interface to track incoming activity from the transmission lines. Maintenance logs are used to verify damage and determine downtime and repair costs. Actual strikes to turbines were recorded on video and ancillary devices. The test setup and some results are discussed in this paper.

  18. Active imaging system performance model for target acquisition

    NASA Astrophysics Data System (ADS)

    Espinola, Richard L.; Teaney, Brian; Nguyen, Quang; Jacobs, Eddie L.; Halford, Carl E.; Tofsted, David H.

    2007-04-01

    The U.S. Army RDECOM CERDEC Night Vision & Electronic Sensors Directorate has developed a laser-range-gated imaging system performance model for the detection, recognition, and identification of vehicle targets. The model is based on the established US Army RDECOM CERDEC NVESD sensor performance models of the human system response through an imaging system. The Java-based model, called NVLRG, accounts for the effect of active illumination, atmospheric attenuation, and turbulence effects relevant to LRG imagers, such as speckle and scintillation, and for the critical sensor and display components. This model can be used to assess the performance of recently proposed active SWIR systems through various trade studies. This paper will describe the NVLRG model in detail, discuss the validation of recent model components, present initial trade study results, and outline plans to validate and calibrate the end-to-end model with field data through human perception testing.

  19. Design and Implementation of an Active Video Distribution System

    NASA Astrophysics Data System (ADS)

    Neogi, Anindya; Chiueh, Tzi-cker

    2003-01-01

    The temporal ordering and the spatial viewpoints of video frames in conventional digital video content are completely determined at the time of authoring. Because of the lack of runtime navigation flexibility in the content, traditional video-on-demand systems have very limited navigation controls, such as fast-forward/rewind etc. In contrast, we have developed a new form of interactive video content called active video, which supports hyper-linking among related video sequences for temporal navigation and interpolation among stored video sequences, that simultaneously capture a dynamic scene, for spatial navigation. Thus active video enables the end user to choose the temporal frame sequencing and the viewing angle (even virtual ones) during playback. This additional navigation flexibility cannot be supported by traditional video distribution systems. The storage and playback of active video poses unique design challenges. Active video delivery requires computation support on the data path, between the storage and the playback application, to interpolate new views based on stored views. Since active video is only a specific instance of a broad class of interactive media, that require computation support on the server, the new distribution system designed for active video should also be programmable and extensible to store and perform runtime processing of other forms of interactive media. A software architecture of the shared programmable computation framework also needs to address performance and data isolation issues. We have designed and implemented a comprehensive active video authoring, compression, storage, and playback system called Memphis. In this paper, we describe the design and implementation of the storage and playback components which address the above design issues.

  20. Active cooling for downhole instrumentation: Preliminary analysis and system selection

    SciTech Connect

    Bennett, G.A.

    1988-03-01

    A feasibility study and a series of preliminary designs and analyses were done to identify candidate processes or cycles for use in active cooling systems for downhole electronic instruments. A matrix of energy types and their possible combinations was developed and the energy conversion process for each pari was identified. The feasibility study revealed conventional as well as unconventional processes and possible refrigerants and identified parameters needing further clarifications. A conceptual design or series od oesigns for each system was formulated and a preliminary analysis of each design was completed. The resulting coefficient of performance for each system was compared with the Carnot COP and all systems were ranked by decreasing COP. The system showing the best combination of COP, exchangeability to other operating conditions, failure mode, and system serviceability is chosen for use as a downhole refrigerator. 85 refs., 48 figs., 33 tabs.

  1. Integrated active sensor system for real time vibration monitoring

    NASA Astrophysics Data System (ADS)

    Liang, Qijie; Yan, Xiaoqin; Liao, Xinqin; Cao, Shiyao; Lu, Shengnan; Zheng, Xin; Zhang, Yue

    2015-11-01

    We report a self-powered, lightweight and cost-effective active sensor system for vibration monitoring with multiplexed operation based on contact electrification between sensor and detected objects. The as-fabricated sensor matrix is capable of monitoring and mapping the vibration state of large amounts of units. The monitoring contents include: on-off state, vibration frequency and vibration amplitude of each unit. The active sensor system delivers a detection range of 0-60 Hz, high accuracy (relative error below 0.42%), long-term stability (10000 cycles). On the time dimension, the sensor can provide the vibration process memory by recording the outputs of the sensor system in an extend period of time. Besides, the developed sensor system can realize detection under contact mode and non-contact mode. Its high performance is not sensitive to the shape or the conductivity of the detected object. With these features, the active sensor system has great potential in automatic control, remote operation, surveillance and security systems.

  2. The Solar System Ballet: A Kinesthetic Spatial Astronomy Activity

    NASA Astrophysics Data System (ADS)

    Heyer, Inge; Slater, T. F.; Slater, S. J.; Astronomy, Center; Education ResearchCAPER, Physics

    2011-05-01

    The Solar System Ballet was developed in order for students of all ages to learn about the planets, their motions, their distances, and their individual characteristics. To teach people about the structure of our Solar System can be revealing and rewarding, for students and teachers. Little ones (and some bigger ones, too) often cannot yet grasp theoretical and spatial ideas purely with their minds. Showing a video is better, but being able to learn with their bodies, essentially being what they learn about, will help them understand and remember difficult concepts much more easily. There are three segments to this activity, which can be done together or separately, depending on time limits and age of the students. Part one involves a short introductory discussion about what students know about the planets. Then students will act out the orbital motions of the planets (and also moons for the older ones) while holding a physical model. During the second phase we look at the structure of the Solar System as well as the relative distances of the planets from the Sun, first by sketching it on paper, then by recreating a scaled version in the class room. Again the students act out the parts of the Solar System bodies with their models. The third segment concentrates on recreating historical measurements of Earth-Moon-Sun system. The Solar System Ballet activity is suitable for grades K-12+ as well as general public informal learning activities.

  3. Integrated active sensor system for real time vibration monitoring

    PubMed Central

    Liang, Qijie; Yan, Xiaoqin; Liao, Xinqin; Cao, Shiyao; Lu, Shengnan; Zheng, Xin; Zhang, Yue

    2015-01-01

    We report a self-powered, lightweight and cost-effective active sensor system for vibration monitoring with multiplexed operation based on contact electrification between sensor and detected objects. The as-fabricated sensor matrix is capable of monitoring and mapping the vibration state of large amounts of units. The monitoring contents include: on-off state, vibration frequency and vibration amplitude of each unit. The active sensor system delivers a detection range of 0–60 Hz, high accuracy (relative error below 0.42%), long-term stability (10000 cycles). On the time dimension, the sensor can provide the vibration process memory by recording the outputs of the sensor system in an extend period of time. Besides, the developed sensor system can realize detection under contact mode and non-contact mode. Its high performance is not sensitive to the shape or the conductivity of the detected object. With these features, the active sensor system has great potential in automatic control, remote operation, surveillance and security systems. PMID:26538293

  4. Integrated active sensor system for real time vibration monitoring.

    PubMed

    Liang, Qijie; Yan, Xiaoqin; Liao, Xinqin; Cao, Shiyao; Lu, Shengnan; Zheng, Xin; Zhang, Yue

    2015-01-01

    We report a self-powered, lightweight and cost-effective active sensor system for vibration monitoring with multiplexed operation based on contact electrification between sensor and detected objects. The as-fabricated sensor matrix is capable of monitoring and mapping the vibration state of large amounts of units. The monitoring contents include: on-off state, vibration frequency and vibration amplitude of each unit. The active sensor system delivers a detection range of 0-60 Hz, high accuracy (relative error below 0.42%), long-term stability (10000 cycles). On the time dimension, the sensor can provide the vibration process memory by recording the outputs of the sensor system in an extend period of time. Besides, the developed sensor system can realize detection under contact mode and non-contact mode. Its high performance is not sensitive to the shape or the conductivity of the detected object. With these features, the active sensor system has great potential in automatic control, remote operation, surveillance and security systems. PMID:26538293

  5. The immune system as a regulator of thyroid hormone activity.

    PubMed

    Klein, John R

    2006-03-01

    It has been known for decades that the neuroendocrine system can both directly and indirectly influence the developmental and functional activity of the immune system. In contrast, far less is known about the extent to which the immune system collaborates in the regulation of endocrine activity. This is particularly true for immune-endocrine interactions of the hypothalamus-pituitary-thyroid axis. Although thyroid-stimulating hormone (TSH) can be produced by many types of extra-pituitary cells--including T cells, B cells, splenic dendritic cells, bone marrow hematopoietic cells, intestinal epithelial cells, and lymphocytes--the functional significance of those TSH pathways remains elusive and historically has been largely ignored from a research perspective. There is now, however, evidence linking cells of the immune system to the regulation of thyroid hormone activity in normal physiological conditions as well as during times of immunological stress. Although the mechanisms behind this are poorly understood, they appear to reflect a process of local intrathyroidal synthesis of TSH mediated by a population of bone marrow cells that traffic to the thyroid. This hitherto undescribed cell population has the potential to microregulate thyroid hormone secretion leading to critical alterations in metabolic activity independent of pituitary TSH output, and it has expansive implications for understanding mechanisms by which the immune system may act to modulate neuroendocrine function during times of host stress. In this article, the basic underpinnings of the hematopoietic-thyroid connection are described, and a model is presented in which the immune system participates in the regulation of thyroid hormone activity during acute infection. PMID:16514168

  6. Specification for installation of the crew activity planning system coaxial cable communication system

    NASA Technical Reports Server (NTRS)

    Allen, M. A.; Roman, G. S.

    1979-01-01

    The specification used to install a broadband coaxial cable communication system to support remote terminal operations on the Crew Activity Planning system at the Lyndon B. Johnson Space Center are reported. The system supports high speed communications between a Harris Slash 8 computer and one or more Sanders Graphic 7 displays.

  7. Electromechanical Simulation of Actively Controlled Rotordynamic Systems with Piezoelectric Actuators

    NASA Technical Reports Server (NTRS)

    Lin, Reng Rong; Palazzolo, A. B.; Kascak, A. F.; Montague, G.

    1991-01-01

    Theories and tests for incorporating piezoelectric pushers as actuator devices for active vibration control are discussed. It started from a simple model with the assumption of ideal pusher characteristics and progressed to electromechanical models with nonideal pushers. Effects on system stability due to the nonideal characteristics of piezoelectric pushers and other elements in the control loop were investigated.

  8. SAFETY ASPECTS OF OXYGEN AERATION ACTIVATED SLUDGE SYSTEMS

    EPA Science Inventory

    This project was carried out to assess the impact of the use of oxygen and oxygen-enriched air for aeration of activated sludge systems on the safety of municipal waste-water treatment plants and their personnel. The tasks included (1) determination of oxygen combustion hazards f...

  9. Diet Modifies the Neuroimmune System by Influencing Macrophage Activation

    ERIC Educational Resources Information Center

    Sherry, Christina Lynn

    2009-01-01

    It has long been appreciated that adequate nutrition is required for proper immune function and it is now recognized that dietary components contribute to modulation of immune cells, subsequently impacting the whole body's response during an immune challenge. Macrophage activation plays a critical role in the immune system and directs the…

  10. Moodog: Tracking Student Activity in Online Course Management Systems

    ERIC Educational Resources Information Center

    Zhang, Hangjin; Almeroth, Kevin

    2010-01-01

    Many universities are currently using Course Management Systems (CMSes) to conduct online learning, for example, by distributing course materials or submitting homework assignments. However, most CMSes do not include comprehensive activity tracking and analysis capabilities. This paper describes a method to track students' online learning…

  11. Active coatings technologies for tailorable military coating systems

    NASA Astrophysics Data System (ADS)

    Zunino, J. L., III

    2007-04-01

    The main objective of the U.S. Army's Active Coatings Technologies Program is to develop technologies that can be used in combination to tailor coatings for utilization on Army Materiel. The Active Coatings Technologies Program, ACT, is divided into several thrusts, including the Smart Coatings Materiel Program, Munitions Coatings Technologies, Active Sensor packages, Systems Health Monitoring, Novel Technology Development, as well as other advanced technologies. The goal of the ACT Program is to conduct research leading to the development of multiple coatings systems for use on various military platforms, incorporating unique properties such as self repair, selective removal, corrosion resistance, sensing, ability to modify coatings' physical properties, colorizing, and alerting logistics staff when tanks or weaponry require more extensive repair. A partnership between the U.S. Army Corrosion Office at Picatinny Arsenal, NJ along with researchers at the New Jersey Institute of Technology, NJ, Clemson University, SC, University of New Hampshire, NH, and University of Massachusetts (Lowell), MA, are developing the next generation of Smart Coatings Materiel via novel technologies such as nanotechnology, Micro-electromechanical Systems (MEMS), meta-materials, flexible electronics, electrochromics, electroluminescence, etc. This paper will provide the reader with an overview of the Active Coatings Technologies Program, including an update of the on-going Smart Coatings Materiel Program, its progress thus far, description of the prototype Smart Coatings Systems and research tasks as well as future nanotechnology concepts, and applications for the Department of Defense.

  12. Multi-carrier mobile TDMA system with active array antenna

    NASA Technical Reports Server (NTRS)

    Suzuki, Ryutaro; Matsumoto, Yasushi; Hamamoto, Naokazu

    1990-01-01

    A multi-carrier time division multiple access (TDMA) is proposed for the future mobile satellite communications systems that include a multi-satellite system. This TDMA system employs the active array antenna in which the digital beam forming technique is adopted to control the antenna beam direction. The antenna beam forming is carried out at the base band frequency by using the digital signal processing technique. The time division duplex technique is applied for the TDM/TDMA burst format, in order not to overlap transmit and receive timing.

  13. Dynamic positioning system based on active disturbance rejection technology

    NASA Astrophysics Data System (ADS)

    Lei, Zhengling; Guo, Chen; Fan, Yunsheng

    2015-08-01

    A dynamically positioned vessel, by the International Maritime Organization (IMO) and the certifying class societies (DNV, ABS, LR, etc.), is defined as a vessel that maintains its position and heading (fixed location or pre-determined track) exclusively by means of active thrusters. The development of control technology promotes the upgrading of dynamic positioning (DP) systems. Today there are two different DP systems solutions available on the market: DP system based on PID regulator and that based on model-based control. Both systems have limited disturbance rejection capability due to their design principle. In this paper, a new DP system solution is proposed based on Active Disturbance Rejection Control (ADRC) technology. This technology is composed of Tracking-Differentiator (TD), Extended State Observer (ESO) and Nonlinear Feedback Combination. On one hand, both TD and ESO can act as filters and can be used in place of conventional filters; on the other hand, the total disturbance of the system can be estimated and compensated by ESO, which therefore enhances the system's disturbance rejection capability. This technology's advantages over other methods lie in two aspects: 1) This method itself can not only achieve control objectives but also filter noisy measurements without other specialized filters; 2) This method offers a new useful approach to suppress the ocean disturbance. The simulation results demonstrate the effectiveness of the proposed method.

  14. Automated system for analyzing the activity of individual neurons

    NASA Technical Reports Server (NTRS)

    Bankman, Isaac N.; Johnson, Kenneth O.; Menkes, Alex M.; Diamond, Steve D.; Oshaughnessy, David M.

    1993-01-01

    This paper presents a signal processing system that: (1) provides an efficient and reliable instrument for investigating the activity of neuronal assemblies in the brain; and (2) demonstrates the feasibility of generating the command signals of prostheses using the activity of relevant neurons in disabled subjects. The system operates online, in a fully automated manner and can recognize the transient waveforms of several neurons in extracellular neurophysiological recordings. Optimal algorithms for detection, classification, and resolution of overlapping waveforms are developed and evaluated. Full automation is made possible by an algorithm that can set appropriate decision thresholds and an algorithm that can generate templates on-line. The system is implemented with a fast IBM PC compatible processor board that allows on-line operation.

  15. Active and passive calcium transport systems in plant cells

    SciTech Connect

    Sze, H.

    1990-01-01

    The ability to change cytoplasmic Ca{sup 2+} levels ((Ca{sup 2+})) by cells has made this cation a key regulator of many biological processes. Cytoplasmic (Ca{sup 2+}) is determined by the coordination of passive Ca{sup 2+} fluxes which increase cytosolic (Ca{sup 2+}) and active Ca{sup 2+} transport systems that lower cytosolic (Ca{sup 2+}). The mechanisms by which plant cells achieve this is poorly understood. We have initially used isolated vesicles from the plasma membrane or organellar membranes to study Ca{sup 2+} transport systems in oat roots (a monocot) and carrot suspension cells (a dicot). The objectives of the proposal were to identify and characterize active (energy-dependent) and passive calcium transport systems that work together to regulate calcium levels in the cytoplasm of plant cells. 10 figs., 2 tabs.

  16. Active and passive calcium transport systems in plant cells

    SciTech Connect

    Sze, H.

    1991-01-01

    The ability to change cytoplasmic Ca{sup 2+} levels ((Ca{sup 2+})) by cells has made this cation a key regulator of many biological processes. Cytoplasmic (Ca{sup 2+}) is determined by the coordination of passive Ca{sup 2+} fluxes which increase cytosolic (Ca{sup 2+}) and active Ca{sup 2+} transport systems that lower cytosolic (Ca{sup 2+}). The mechanisms by which plant cells achieve this is poorly understood. We have initially used isolated vesicles from the plasma membrane or organellar membranes to study Ca{sup 2+} transport systems in oat roots (a monocot) and carrot suspension cells (a dicot). The objectives of the proposal were to identify and characterize active (energy-dependent) and passive calcium transport systems that work together to regulate calcium levels in the cytoplasm of plant cells.

  17. Active control technique of fractional-order chaotic complex systems

    NASA Astrophysics Data System (ADS)

    Mahmoud, Gamal M.; Ahmed, Mansour E.; Abed-Elhameed, Tarek M.

    2016-06-01

    Several kinds of synchronization of fractional-order chaotic complex systems are challenging research topics of current interest since they appear in many applications in applied sciences. Our main goal in this paper is to introduce the definition of modified projective combination-combination synchronization (MPCCS) of some fractional-order chaotic complex systems. We show that our systems are chaotic by calculating their Lyapunov exponents. The fractional Lyapunov dimension of the chaotic solutions of these systems is computed. A scheme is introduced to calculate MPCCS of four different (or identical) chaotic complex systems using the active control technique. Special cases of this type, which are projective and anti C-C synchronization, are discussed. Some figures are plotted to show that MPCCS is achieved and its errors approach zero.

  18. Toxin activity assays, devices, methods and systems therefor

    DOEpatents

    Koh, Chung-Yan; Schaff, Ulrich Y.; Sommer, Gregory Jon

    2016-04-05

    Embodiments of the present invention are directed toward devices, system and method for conducting toxin activity assay using sedimentation. The toxin activity assay may include generating complexes which bind to a plurality of beads in a fluid sample. The complexes may include a target toxin and a labeling agent, or may be generated due to presence of active target toxin and/or labeling agent designed to be incorporated into complexes responsive to the presence of target active toxin. The plurality of beads including the complexes may be transported through a density media, wherein the density media has a lower density than a density of the beads and higher than a density of the fluid sample, and wherein the transporting occurs, at least in part, by sedimentation. Signal may be detected from the labeling agents of the complexes.

  19. [The influence of aging on autonomic nervous system activity and gastric myoelectric activity in humans].

    PubMed

    Thor, P J; Kolasińska-Kloch, W; Pitala, A; Janik, A; Kopp, B; Sibiga, W

    1999-01-01

    The study was performed on 84 healthy volunteers (33 women, 52 men) of age 20-71 years with no history of the circulatory or gastrointestinal system disease. The gastric myoelectrical activity (EGG) was recorded with the cutaneous electrodes--electrogastrography Synectics (Sweden). The activity of the cardiac autonomic nervous system was measured by HRV (heart rate variability) recorded with EGG and computer assisted programme Proster (Poland). Subject were divided into 5 groups according to the decade of age (20-70). Percentage of basal electrical rhythm (BER) dysrhythmias increased (1.9 +/- 0.5% vs 21.1 +/- 3.2% in fasting and 2.4 +/- 1.2% vs 24.6 +/- 5% postprandially but decrease of the EGG amplitude after the meal was observed (270 +/- 20% vs 90 +/- 7%) in youngest and oldest group respectively. With the ageing the cardiac sympathetic and parasympathetic activity (LF and HF) decreased in first and last group respectively. In the forth decade in man and women the sympathetic activity system prevalence expressed by the LF/HF rate increased (1.09 +/- 0.2 vs. 2.14 +/- 0.5) (p < 0.05). The results of our study suggest the deleterious influence of the ageing on the of autonomic system activity as shown by changes in HRV and dysrhythmia of the gastric slow waves in EGG. PMID:10909474

  20. Symmetric Active/Active Metadata Service for High Availability Parallel File Systems

    SciTech Connect

    He, X.; Ou, Li; Engelmann, Christian; Chen, Xin; Scott, Stephen L

    2009-01-01

    High availability data storage systems are critical for many applications as research and business become more data-driven. Since metadata management is essential to system availability, multiple metadata services are used to improve the availability of distributed storage systems. Past research focused on the active/standby model, where each active service has at least one redundant idle backup. However, interruption of service and even some loss of service state may occur during a fail-over depending on the used replication technique. In addition, the replication overhead for multiple metadata services can be very high. The research in this paper targets the symmetric active/active replication model, which uses multiple redundant service nodes running in virtual synchrony. In this model, service node failures do not cause a fail-over to a backup and there is no disruption of service or loss of service state. We further discuss a fast delivery protocol to reduce the latency of the needed total order broadcast. Our prototype implementation shows that metadata service high availability can be achieved with an acceptable performance trade-off using our symmetric active/active metadata service solution.

  1. Active stabilization to prevent surge in centrifugal compression systems

    NASA Technical Reports Server (NTRS)

    Epstein, Alan H.; Greitzer, Edward M.; Simon, Jon S.; Valavani, Lena

    1993-01-01

    This report documents an experimental and analytical study of the active stabilization of surge in a centrifugal engine. The aims of the research were to extend the operating range of a compressor as far as possible and to establish the theoretical framework for the active stabilization of surge from both an aerodynamic stability and a control theoretic perspective. In particular, much attention was paid to understanding the physical limitations of active stabilization and how they are influenced by control system design parameters. Previously developed linear models of actively stabilized compressors were extended to include such nonlinear phenomena as bounded actuation, bandwidth limits, and robustness criteria. This model was then used to systematically quantify the influence of sensor-actuator selection on system performance. Five different actuation schemes were considered along with four different sensors. Sensor-actuator choice was shown to have a profound effect on the performance of the stabilized compressor. The optimum choice was not unique, but rather shown to be a strong function of some of the non-dimensional parameters which characterize the compression system dynamics. Specifically, the utility of the concepts were shown to depend on the system compliance to inertia ratio ('B' parameter) and the local slope of the compressor speedline. In general, the most effective arrangements are ones in which the actuator is most closely coupled to the compressor, such as a close-coupled bleed valve inlet jet, rather than elsewhere in the flow train, such as a fuel flow modulator. The analytical model was used to explore the influence of control system bandwidth on control effectiveness. The relevant reference frequency was shown to be the compression system's Helmholtz frequency rather than the surge frequency. The analysis shows that control bandwidths of three to ten times the Helmholtz frequency are required for larger increases in the compressor flow range

  2. Streptococcal Surface Proteins Activate the Contact System and Control Its Antibacterial Activity*

    PubMed Central

    Wollein Waldetoft, Kristofer; Svensson, Lisbeth; Mörgelin, Matthias; Olin, Anders I.; Nitsche-Schmitz, D. Patric; Björck, Lars; Frick, Inga-Maria

    2012-01-01

    Group G streptococci (GGS) are important bacterial pathogens in humans. Here, we investigated the interactions between GGS and the contact system, a procoagulant and proinflammatory proteolytic cascade that, upon activation, also generates antibacterial peptides. Two surface proteins of GGS, protein FOG and protein G (PG), were found to bind contact system proteins. Experiments utilizing contact protein-deficient human plasma and isogenic GGS mutant strains lacking FOG or PG showed that FOG and PG both activate the procoagulant branch of the contact system. In contrast, only FOG induced cleavage of high molecular weight kininogen, generating the proinflammatory bradykinin peptide and additional high molecular weight kininogen fragments containing the antimicrobial peptide NAT-26. On the other hand, PG protected the bacteria against the antibacterial effect of NAT-26. These findings underline the significance of the contact system in innate immunity and demonstrate that GGS have evolved surface proteins to exploit and modulate its effects. PMID:22648411

  3. Inhibition of the central melanocortin system decreases brown adipose tissue activity[S

    PubMed Central

    Kooijman, Sander; Boon, Mariëtte R.; Parlevliet, Edwin T.; Geerling, Janine J.; van de Pol, Vera; Romijn, Johannes A.; Havekes, Louis M.; Meurs, Illiana; Rensen, Patrick C. N.

    2014-01-01

    The melanocortin system is an important regulator of energy balance, and melanocortin 4 receptor (MC4R) deficiency is the most common monogenic cause of obesity. We investigated whether the relationship between melanocortin system activity and energy expenditure (EE) is mediated by brown adipose tissue (BAT) activity. Therefore, female APOE*3-Leiden.CETP transgenic mice were fed a Western-type diet for 4 weeks and infused intracerebroventricularly with the melanocortin 3/4 receptor (MC3/4R) antagonist SHU9119 or vehicle for 2 weeks. SHU9119 increased food intake (+30%) and body fat (+50%) and decreased EE by reduction in fat oxidation (−42%). In addition, SHU9119 impaired the uptake of VLDL-TG by BAT. In line with this, SHU9119 decreased uncoupling protein-1 levels in BAT (−60%) and induced large intracellular lipid droplets, indicative of severely disturbed BAT activity. Finally, SHU9119-treated mice pair-fed to the vehicle-treated group still exhibited these effects, indicating that MC4R inhibition impairs BAT activity independent of food intake. These effects were not specific to the APOE*3-Leiden.CETP background as SHU9119 also inhibited BAT activity in wild-type mice. We conclude that inhibition of central MC3/4R signaling impairs BAT function, which is accompanied by reduced EE, thereby promoting adiposity. We anticipate that activation of MC4R is a promising strategy to combat obesity by increasing BAT activity. PMID:25016380

  4. Smart interactive electronic system for monitoring the electromagnetic activities of biological systems

    NASA Astrophysics Data System (ADS)

    Popa, Sorin G.; Shahinpoor, Mohsen

    2001-08-01

    A novel electronic device capable of sensing and monitoring the myoelectric, polarization wave and electromagnetic activities of the biological systems and in particular the human body is presented. It is known that all the physical and chemical processes within biological systems are associated with polarization, depolarization waves from the brain, neural signals and myoelectric processes that manifest themselves in ionic and dipole motion. The technology developed in our laboratory is based on certain charge motion sensitive electronics. The electronic system developed is capable of sensing the electromagnetic activities of biological systems. The information obtained is then processed by specialized software in order to interpret it from physical and chemical point of view.

  5. Active system area networks for data intensive computations. Final report

    SciTech Connect

    2002-04-01

    The goal of the Active System Area Networks (ASAN) project is to develop hardware and software technologies for the implementation of active system area networks (ASANs). The use of the term ''active'' refers to the ability of the network interfaces to perform application-specific as well as system level computations in addition to their traditional role of data transfer. This project adopts the view that the network infrastructure should be an active computational entity capable of supporting certain classes of computations that would otherwise be performed on the host CPUs. The result is a unique network-wide programming model where computations are dynamically placed within the host CPUs or the NIs depending upon the quality of service demands and network/CPU resource availability. The projects seeks to demonstrate that such an approach is a better match for data intensive network-based applications and that the advent of low-cost powerful embedded processors and configurable hardware makes such an approach economically viable and desirable.

  6. Augmented reality to enhance an active telepresence system

    NASA Astrophysics Data System (ADS)

    Wheeler, Alison; Pretlove, John R. G.; Parker, Graham A.

    1996-12-01

    Tasks carried out remotely via a telerobotic system are typically complex, occur in hazardous environments and require fine control of the robot's movements. Telepresence systems provide the teleoperator with a feeling of being physically present at the remote site. Stereoscopic video has been successfully applied to telepresence vision systems to increase the operator's perception of depth in the remote scene and this sense of presence can be further enhanced using computer generated stereo graphics to augment the visual information presented to the operator. The Mechatronic Systems and Robotics Research Group have over seven years developed a number of high performance active stereo vision systems culminating in the latest, a four degree-of-freedom stereohead. This carries two miniature color cameras and is controlled in real time by the motion of the operator's head, who views the stereoscopic video images on an immersive head mounted display or stereo monitor. The stereohead is mounted on a mobile robot, the movement of which is controlled by a joystick interface. This paper describes the active telepresence system and the development of a prototype augmented reality (AR) application to enhance the operator's sense of presence at the remote site. The initial enhancements are a virtual map and compass to aid navigation in degraded visual conditions and a virtual cursor that provides a means for the operator to interact with the remote environment. The results of preliminary experiments using the initial enhancements are presented.

  7. Extravehicular Activity System Sizing Analysis Tool (EVAS_SAT)

    NASA Technical Reports Server (NTRS)

    Brown, Cheryl B.; Conger, Bruce C.; Miranda, Bruno M.; Bue, Grant C.; Rouen, Michael N.

    2007-01-01

    An effort was initiated by NASA/JSC in 2001 to develop an Extravehicular Activity System Sizing Analysis Tool (EVAS_SAT) for the sizing of Extravehicular Activity System (EVAS) architecture and studies. Its intent was to support space suit development efforts and to aid in conceptual designs for future human exploration missions. Its basis was the Life Support Options Performance Program (LSOPP), a spacesuit and portable life support system (PLSS) sizing program developed for NASA/JSC circa 1990. EVAS_SAT estimates the mass, power, and volume characteristics for user-defined EVAS architectures, including Suit Systems, Airlock Systems, Tools and Translation Aids, and Vehicle Support equipment. The tool has undergone annual changes and has been updated as new data have become available. Certain sizing algorithms have been developed based on industry standards, while others are based on the LSOPP sizing routines. The sizing algorithms used by EVAS_SAT are preliminary. Because EVAS_SAT was designed for use by members of the EVA community, subsystem familiarity on the part of the intended user group and in the analysis of results is assumed. The current EVAS_SAT is operated within Microsoft Excel 2003 using a Visual Basic interface system.

  8. Biomining active cellulases from a mining bioremediation system.

    PubMed

    Mewis, Keith; Armstrong, Zachary; Song, Young C; Baldwin, Susan A; Withers, Stephen G; Hallam, Steven J

    2013-09-20

    Functional metagenomics has emerged as a powerful method for gene model validation and enzyme discovery from natural and human engineered ecosystems. Here we report development of a high-throughput functional metagenomic screen incorporating bioinformatic and biochemical analyses features. A fosmid library containing 6144 clones sourced from a mining bioremediation system was screened for cellulase activity using 2,4-dinitrophenyl β-cellobioside, a previously proven cellulose model substrate. Fifteen active clones were recovered and fully sequenced revealing 9 unique clones with the ability to hydrolyse 1,4-β-D-glucosidic linkages. Transposon mutagenesis identified genes belonging to glycoside hydrolase (GH) 1, 3, or 5 as necessary for mediating this activity. Reference trees for GH 1, 3, and 5 families were generated from sequences in the CAZy database for automated phylogenetic analysis of fosmid end and active clone sequences revealing known and novel cellulase encoding genes. Active cellulase genes recovered in functional screens were subcloned into inducible high copy plasmids, expressed and purified to determine enzymatic properties including thermostability, pH optima, and substrate specificity. The workflow described here provides a general paradigm for recovery and characterization of microbially derived genes and gene products based on genetic logic and contemporary screening technologies developed for model organismal systems. PMID:23906845

  9. Optically powered active sensing system for Internet Of Things

    NASA Astrophysics Data System (ADS)

    Gao, Chen; Wang, Jin; Yin, Long; Yang, Jing; Jiang, Jian; Wan, Hongdan

    2014-10-01

    Internet Of Things (IOT) drives a significant increase in the extent and type of sensing technology and equipment. Sensors, instrumentation, control electronics, data logging and transmission units comprising such sensing systems will all require to be powered. Conventionally, electrical powering is supplied by batteries or/and electric power cables. The power supply by batteries usually has a limited lifetime, while the electric power cables are susceptible to electromagnetic interference. In fact, the electromagnetic interference is the key issue limiting the power supply in the strong electromagnetic radiation area and other extreme environments. The novel alternative method of power supply is power over fiber (PoF) technique. As fibers are used as power supply lines instead, the delivery of the power is inherently immune to electromagnetic radiation, and avoids cumbersome shielding of power lines. Such a safer power supply mode would be a promising candidate for applications in IOT. In this work, we built up optically powered active sensing system, supplying uninterrupted power for the remote active sensors and communication modules. Also, we proposed a novel maximum power point tracking technique for photovoltaic power convertors. In our system, the actual output efficiency greater than 40% within 1W laser power. After 1km fiber transmission and opto-electric power conversion, a stable electric power of 210mW was obtained, which is sufficient for operating an active sensing system.

  10. Active other worlds in the Solar System and beyond

    NASA Astrophysics Data System (ADS)

    Forget, François

    2016-04-01

    Over the past decades, space exploration has moved planetology from the field of astronomy to the disciplines of geosciences. A fleet of spacecrafts have discovered and study tens of worlds in our solar system and beyond. Everywhere, we have been surprised by the diversity and the vigour of the geophysical activity, from volcanic eruptions to plasma waves... Every scientists present at EGU could -and should- be interested in the extraterrestrial processes that are discovered and analyzed elsewhere. In our solar system, a variety of clouds and fluid dynamical phenomena can be studied in six terrestrial atmospheres and on four giant planets. Active glaciers are found on Mars and Pluto. Rivers and lakes have sculpted the surface of Titan and Mars. Sometime, we can even study geophysical activity with no equivalent on our planet: ice caps made of frozen atmosphere that erupt in geysers, hazes formed by organic polymers which can completely shroud a moon, etc. We study these active worlds because we are curious and wish to understand our universe and our origins. However, more than ever, two specific motivations drive solar system geosciences in 2016: Firstly, as we become more and more familiar with the other worlds around us, we can use them to better understand our own planet. Throughout the solar system, we can access to data that are simply not available on the Earth, or study active processes that are subtle on Earth but of greater importance elsewhere, so that we can better understand them. Many geophysical concepts and tools developed for the Earth can also be tested on other planets. For instance the numerical Climate Models used to assess Earth's future climate change are applied to other planets. Much is learned from such experiments. Secondly, the time has come to generalize the fundamental lessons that we have learned from the examples in the solar system (including the Earth) to address the countless scientific questions that are -and will be- raised by

  11. Blogs and Social Network Sites as Activity Systems: Exploring Adult Informal Learning Process through Activity Theory Framework

    ERIC Educational Resources Information Center

    Heo, Gyeong Mi; Lee, Romee

    2013-01-01

    This paper uses an Activity Theory framework to explore adult user activities and informal learning processes as reflected in their blogs and social network sites (SNS). Using the assumption that a web-based space is an activity system in which learning occurs, typical features of the components were investigated and each activity system then…

  12. Bilateral Activity-Dependent Interactions in the Developing Corticospinal System

    PubMed Central

    Friel, Kathleen M.; Martin, John H.

    2009-01-01

    Activity-dependent competition between the corticospinal (CS) systems in each hemisphere drives postnatal development of motor skills and stable CS tract connections with contralateral spinal motor circuits. Unilateral restriction of motor cortex (M1) activity during an early postnatal critical period impairs contralateral visually guided movements later in development and in maturity. Silenced M1 develops aberrant connections with the contralateral spinal cord whereas the initially active M1, in the other hemisphere, develops bilateral connections. In this study, we determined whether the aberrant pattern of CS tract terminations and motor impairments produced by early postnatal M1 activity restriction could be abrogated by reducing activity-dependent synaptic competition from the initially active M1 later in development. We first inactivated M1 unilaterally between postnatal weeks 5–7. We next inactivated M1 on the other side from weeks 7–11 (alternate inactivation), to reduce the competitive advantage that this side may have over the initially inactivated side. Alternate inactivation redirected aberrant contralateral CS tract terminations from the initially silenced M1 to their normal spinal territories and reduced the density of aberrant ipsilateral terminations from the initially active side. Normal movement endpoint control during visually guided locomotion was fully restored. This reorganization of CS terminals reveals an unsuspected late plasticity after the critical period for establishing the pattern of CS terminations in the spinal cord. Our findings show that robust bilateral interactions between the developing CS systems on each side are important for achieving balance between contralateral and ipsilateral CS tract connections and visuomotor control. PMID:17928450

  13. Advanced extravehicular activity systems requirements definition study. Phase 2: Extravehicular activity at a lunar base

    NASA Technical Reports Server (NTRS)

    Neal, Valerie; Shields, Nicholas, Jr.; Carr, Gerald P.; Pogue, William; Schmitt, Harrison H.; Schulze, Arthur E.

    1988-01-01

    The focus is on Extravehicular Activity (EVA) systems requirements definition for an advanced space mission: remote-from-main base EVA on the Moon. The lunar environment, biomedical considerations, appropriate hardware design criteria, hardware and interface requirements, and key technical issues for advanced lunar EVA were examined. Six remote EVA scenarios (three nominal operations and three contingency situations) were developed in considerable detail.

  14. Usability engineering: domain analysis activities for augmented-reality systems

    NASA Astrophysics Data System (ADS)

    Gabbard, Joseph; Swan, J. E., II; Hix, Deborah; Lanzagorta, Marco O.; Livingston, Mark; Brown, Dennis B.; Julier, Simon J.

    2002-05-01

    This paper discusses our usability engineering process for the Battlefield Augmented Reality System (BARS). Usability engineering is a structured, iterative, stepwise development process. Like the related disciplines of software and systems engineering, usability engineering is a combination of management principals and techniques, formal and semi- formal evaluation techniques, and computerized tools. BARS is an outdoor augmented reality system that displays heads- up battlefield intelligence information to a dismounted warrior. The paper discusses our general usability engineering process. We originally developed the process in the context of virtual reality applications, but in this work we are adapting the procedures to an augmented reality system. The focus of this paper is our work on domain analysis, the first activity of the usability engineering process. We describe our plans for and our progress to date on our domain analysis for BARS. We give results in terms of a specific urban battlefield use case we have designed.

  15. Theory of activated transport in bilayer quantum Hall systems.

    PubMed

    Roostaei, B; Mullen, K J; Fertig, H A; Simon, S H

    2008-07-25

    We analyze the transport properties of bilayer quantum Hall systems at total filling factor nu=1 in drag geometries as a function of interlayer bias, in the limit where the disorder is sufficiently strong to unbind meron-antimeron pairs, the charged topological defects of the system. We compute the typical energy barrier for these objects to cross incompressible regions within the disordered system using a Hartree-Fock approach, and show how this leads to multiple activation energies when the system is biased. We then demonstrate using a bosonic Chern-Simons theory that in drag geometries current in a single layer directly leads to forces on only two of the four types of merons, inducing dissipation only in the drive layer. Dissipation in the drag layer results from interactions among the merons, resulting in very different temperature dependences for the drag and drive layers, in qualitative agreement with experiment. PMID:18764355

  16. Theory of Activated Transport in Bilayer Quantum Hall Systems

    NASA Astrophysics Data System (ADS)

    Roostaei, Bahman; Fertig, Herbert; Mullen, Kieran; Simon, Steven

    2008-03-01

    We analyze the transport properties of bilayer quantum Hall systems at total filling factor ν= 1 in drag geometries as a function of interlayer bias, in the limit where the disorder is sufficiently strong to unbind meron-antimeron pairs, the charged topological defects of the system. We compute the typical energy barrier for these objects to cross incompressible regions within the disordered system using a Hartree-Fock approach, and show how this leads to multiple activation energies when the system is biased. We then demonstrate using a bosonic Chern- Simons theory that in drag geometries, current in a single layer directly leads to forces on only two of the four types of merons, inducing dissipation only in the drive layer. Dissipation in the drag layer results from interactions among the merons, resulting in very different temperature dependences for the drag and drive layers, in qualitative agreement with experiment. We conclude with predictions for future experiments.

  17. Theory of Activated Transport in Bilayer Quantum Hall Systems

    NASA Astrophysics Data System (ADS)

    Roostaei, B.; Mullen, K. J.; Fertig, H. A.; Simon, S. H.

    2008-07-01

    We analyze the transport properties of bilayer quantum Hall systems at total filling factor ν=1 in drag geometries as a function of interlayer bias, in the limit where the disorder is sufficiently strong to unbind meron-antimeron pairs, the charged topological defects of the system. We compute the typical energy barrier for these objects to cross incompressible regions within the disordered system using a Hartree-Fock approach, and show how this leads to multiple activation energies when the system is biased. We then demonstrate using a bosonic Chern-Simons theory that in drag geometries current in a single layer directly leads to forces on only two of the four types of merons, inducing dissipation only in the drive layer. Dissipation in the drag layer results from interactions among the merons, resulting in very different temperature dependences for the drag and drive layers, in qualitative agreement with experiment.

  18. Hypersonic Vehicle Propulsion System Control Model Development Roadmap and Activities

    NASA Technical Reports Server (NTRS)

    Stueber, Thomas J.; Le, Dzu K.; Vrnak, Daniel R.

    2009-01-01

    The NASA Fundamental Aeronautics Program Hypersonic project is directed towards fundamental research for two classes of hypersonic vehicles: highly reliable reusable launch systems (HRRLS) and high-mass Mars entry systems (HMMES). The objective of the hypersonic guidance, navigation, and control (GN&C) discipline team is to develop advanced guidance and control algorithms to enable efficient and effective operation of these challenging vehicles. The ongoing work at the NASA Glenn Research Center supports the hypersonic GN&C effort in developing tools to aid the design of advanced control algorithms that specifically address the propulsion system of the HRRLSclass vehicles. These tools are being developed in conjunction with complementary research and development activities in hypersonic propulsion at Glenn and elsewhere. This report is focused on obtaining control-relevant dynamic models of an HRRLS-type hypersonic vehicle propulsion system.

  19. System design for active vibration control of aerospace structures

    NASA Astrophysics Data System (ADS)

    Shankar, V.; Nagaraja, B. V.; Balasubramaniam, R.; Shree S, Amrutha; Muthaiah, Skanda N.

    2003-10-01

    Instrumentation, electronics, digital signal processing and related software form the basic building blocks of a system for implementation of Active Vibration Control (AVC) for smart aerospace structures. This paper essentially deals with the design, development and implementation of a 4 channel analog input sub-system essentially consisting of charge amplifiers, filters, gain amplifiers & Analog to Digital Converters (ADC), the subsequent Digital Signal Processor (DSP) hardware for implementation of the controller and finally a 4 Channel analog output subsystem consisting of Digital to Analog Converters (DAC), reconstruction filters & high voltage amplifiers. This system essentially interfaces to a structure with piezo-ceramic sensors and actuators for implementation of real time AVC on a smart beam. The paper also highlights some of the new ideas that have been incorporated into the system design.

  20. An analysis of Mars mission activities and the derivation of Extravehicular Activity System design requirements

    NASA Astrophysics Data System (ADS)

    Wells, Peter J.

    1992-07-01

    This paper describes a design process used to develop an extravehicular system suitable for accomplishing a set of specific missions in a Mars environment. The paper first identifies specific candidate geological and operational missions that require direct extravehicular activity action. The tools and procedures necessary to accomplish these missions are identified. The missions are analyzed in order to produce a set of functional and design requirements for the extravehicular system. A preliminary design of an extravehicular system specifically tailored to accomplish the identified missions is presented.

  1. Coherence and frequency in the reticular activating system (RAS)

    PubMed Central

    Garcia-Rill, Edgar; Kezunovic, Nebojsa; Hyde, James; Simon, Christen; Beck, Paige; Urbano, Francisco J.

    2012-01-01

    SUMMARY This review considers recent evidence showing that cells in the reticular activating system (RAS) exhibit 1) electrical coupling mainly in GABAergic cells, and 2) gamma band activity in virtually all of the cells. Specifically, cells in the mesopontine pedunculopontine nucleus (PPN), intralaminar parafascicular nucleus (Pf), and pontine dorsal subcoeruleus nucleus dorsalis (SubCD) 1) show electrical coupling, and 2) all fire in the beta/gamma band range when maximally activated, but no higher. The mechanism behind electrical coupling is important because the stimulant modafinil was shown to increase electrical coupling. We also provide recent findings demonstrating that all cells in the PPN and Pf have high threshold, voltage-dependent P/Q-type calcium channels that are essential to gamma band activity. On the other hand, all SubCD, and some PPN, cells manifested sodium-dependent subthreshold oscillations. A novel mechanism for sleep-wake control based on transmitter interactions, electrical coupling, and gamma band activity is described. We speculate that continuous sensory input will modulate coupling and induce gamma band activity in the RAS that could participate in the processes of preconscious awareness, and provide the essential stream of information for the formulation of many of our actions. PMID:23044219

  2. Behavioral activation system modulation on brain activation during appetitive and aversive stimulus processing.

    PubMed

    Barrós-Loscertales, Alfonso; Ventura-Campos, Noelia; Sanjuán-Tomás, Ana; Belloch, Vicente; Parcet, Maria-Antònia; Avila, César

    2010-03-01

    The reinforcement sensitivity theory (RST) proposed the behavioral activation system (BAS) as a neurobehavioral system that is dependent on dopamine-irrigated structures and that mediates the individual differences in sensitivity and reactivity to appetitive stimuli associated with BAS-related personality traits. Theoretical developments propose that high BAS sensitivity is associated with both enhanced appetitive stimuli processing and the diminished processing of aversive stimuli. The objective of this study was to analyze how individual differences in BAS functioning were associated with brain activation during erotic and aversive picture processing while subjects were involved in a simple goal-directed task. Forty-five male participants took part in this study. The task activation results confirm the activation of the reward and punishment brain-related structures while viewing erotic and aversive pictures, respectively. The SR scores show a positive correlation with activation of the left lateral prefrontal cortex, the mesial prefrontal cortex and the right occipital cortex while viewing erotic pictures, and a negative correlation with the right lateral prefrontal cortex and the left occipital cortex while viewing aversive pictures. In summary, the SR scores modulate the activity of the cortical areas in the prefrontal and the occipital cortices that are proposed to modulate the BAS and the BIS-FFFS. PMID:20147458

  3. Behavioral activation system modulation on brain activation during appetitive and aversive stimulus processing

    PubMed Central

    Ventura-Campos, Noelia; Sanjuán-Tomás, Ana; Belloch, Vicente; Parcet, Maria-Antònia; Ávila, César

    2010-01-01

    The reinforcement sensitivity theory (RST) proposed the behavioral activation system (BAS) as a neurobehavioral system that is dependent on dopamine-irrigated structures and that mediates the individual differences in sensitivity and reactivity to appetitive stimuli associated with BAS-related personality traits. Theoretical developments propose that high BAS sensitivity is associated with both enhanced appetitive stimuli processing and the diminished processing of aversive stimuli. The objective of this study was to analyze how individual differences in BAS functioning were associated with brain activation during erotic and aversive picture processing while subjects were involved in a simple goal-directed task. Forty-five male participants took part in this study. The task activation results confirm the activation of the reward and punishment brain-related structures while viewing erotic and aversive pictures, respectively. The SR scores show a positive correlation with activation of the left lateral prefrontal cortex, the mesial prefrontal cortex and the right occipital cortex while viewing erotic pictures, and a negative correlation with the right lateral prefrontal cortex and the left occipital cortex while viewing aversive pictures. In summary, the SR scores modulate the activity of the cortical areas in the prefrontal and the occipital cortices that are proposed to modulate the BAS and the BIS-FFFS. PMID:20147458

  4. Exploring creative activity: a software environment for multimedia systems

    NASA Astrophysics Data System (ADS)

    Farrett, Peter W.; Jardine, David A.

    1992-03-01

    This paper examines various issues related to the theory, design, and implementation of a system that supports creative activity for a multimedia environment. The system incorporates artificial intelligence notions to acquire concepts of the problem domain. This paper investigates this environment by considering a model that is a basis for a system, which supports a history of user interaction. A multimedia system that supports creative activity is problematic. It must function as a tool allowing users to experiment dynamically with their own creative reasoning process--a very nebulous task environment. It should also support the acquisition of domain knowledge so that empirical observation can be further evaluated. This paper aims to illustrate that via the reuse of domain-specific knowledge, closely related ideas can be quickly developed. This approach is useful in the following sense: Multimedia navigational systems hardcode referential links with respect to a web or network. Although users can access or control navigation in a nonlinear (static) manner, these referential links are 'frozen' and can not capture their creative actions, which are essential in tutoring or learning applications. This paper describes a multimedia assistant based on the notion of knowledge- links, which allows users to navigate through creative information in a nonlinear (dynamic) fashion. A selection of prototype code based on object-oriented techniques and logic programming partially demonstrates this.

  5. SCAR arrow-wing active flutter suppression system

    NASA Technical Reports Server (NTRS)

    Gordon, C. K.; Visor, O. E.

    1977-01-01

    The potential performance and direct operating cost benefits of an active flutter suppression system (FSS) for the NASA arrow-wing supersonic cruise configuration were determined. A FSS designed to increase the flutter speed of the baseline airplane 20 percent. A comparison was made of the performance and direct operating cost between the FSS equipped aircraft and a previously defined configuration with structural modifications to provide the same flutter speed. Control system synthesis and evaluation indicated that a FSS could provide the increase in flutter speed without degrading airplane reliability, safety, handling qualities, or ride quality, and without increasing repeated loads or hydraulic and electrical power capacity requirements.

  6. Digital Signal Processing System for Active Noise Reduction

    NASA Astrophysics Data System (ADS)

    Edmonson, William W.; Tucker, Jerry

    2002-12-01

    Over the years there has been a need to improve the comfort of passengers in flight. One avenue for increasing comfort is to reduce cabin noise that is attributed to the engine and the vibration of fuselage panels that radiate sound. High frequency noise can be abated using sound absorbing material. Though, for low frequency noise the sound absorption material would have to very thick, thereby reducing the cabin size. To reduce these low frequency disturbances, active noise control systems (ANC) is being developed that utilizes feedback for cancellation of the disturbance. The active noise control system must be small in size, be a low power device, and operate in real-time. It must also be numerically stable i.e. insensitive to temperature and pressure variations. The ANC system will be a module that consists of digital signal processor (DSP), analog-digital and digital-analog converters, power converters, an actuator and sensors. The DSP will implement the feedback control algorithm that controls the actuators. This module will be attached to panels on the inside of the fuselage for actively eliminating resonant modes of the structure caused by turbulent flow across the fuselage Skin. A hardware prototype of the ANC system must be able to eliminate broadband noise consisting of a bandwidth between 100 Hz and 1500 Hz, which requires a sample rate of 5000 Hz. The analog/digital converters output accuracy is 16 bits with a 2's-compliment format and a very short acquisition time. This will also yield the appropriate dynamic range. Similar specifications are required of the digital/analog converter. The processor section of the system integrates a digital signal processor (TI TMS320C33) with analog/digital (Burr-Brown ADS8320) and digital/analog signal (DAC853 1) converters. The converters with associated power conditioning circuitry and test points reside on a daughter board that sits on top of a Spectrum Digital evaluation module. This will have the ability to test

  7. Restoration algorithms and system performance evaluation for active imagers

    NASA Astrophysics Data System (ADS)

    Gilles, Jérôme

    2007-10-01

    This paper deals with two fields related to active imaging system. First, we begin to explore image processing algorithms to restore the artefacts like speckle, scintillation and image dancing caused by atmospheric turbulence. Next, we examine how to evaluate the performance of this kind of systems. To do this task, we propose a modified version of the german TRM3 metric which permits to get MTF-like measures. We use the database acquired during NATO-TG40 field trials to make our tests.

  8. Research progress in some traditional and non-traditional medicinal species in the USDA, ARS, PGRCU (S9) germplasm collection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flavonoids and anthocyanins have shown anti-cancer activities in humans. Therefore, fruit and leaves from several accessions of Abutilon theophrasti Medik., and seeds from Desmodium discolor Vogel, D. incanum (G. Mey) D.C., D. intortum (Mill.) Urb., D. sandwicense E. Mey., D. tortuosum (Sw.) D.C., H...

  9. Active Rack Isolation System Program and Technical Status

    NASA Technical Reports Server (NTRS)

    Bushnell, Glenn; Fialho, Ian; Allen, James; Quraishi, Naveed

    2000-01-01

    The Boeing Active Rack Isolation System (ARIS) is one of the means used to isolate acceleration-sensitive scientific experiments from structurally transmitted disturbances aboard the International Space Station. The presentation provides an overview of ARIS and technical issues associated with the development of the active control system. An overview of ARIS analytical models is presented along with recent isolation performance predictions made using these models. Issues associated with commanding and capturing ARIS data are discussed and possible future options based on the ARIS ISS Characterization Experiment (ICE) Payload On-orbit Processor (POP) are outlined. An overview of the ARIS-ICE experiment scheduled to fly on ISS Flight 6A is presented. The presentation concludes with a discussion of recent- developmental work that includes passive rack damping, umbilical redesigns and advanced multivariable control design methods.

  10. Active magnetic radiation shielding system analysis and key technologies

    NASA Astrophysics Data System (ADS)

    Washburn, S. A.; Blattnig, S. R.; Singleterry, R. C.; Westover, S. C.

    2015-01-01

    Many active magnetic shielding designs have been proposed in order to reduce the radiation exposure received by astronauts on long duration, deep space missions. While these designs are promising, they pose significant engineering challenges. This work presents a survey of the major systems required for such unconfined magnetic field design, allowing the identification of key technologies for future development. Basic mass calculations are developed for each system and are used to determine the resulting galactic cosmic radiation exposure for a generic solenoid design, using a range of magnetic field strength and thickness values, allowing some of the basic characteristics of such a design to be observed. This study focuses on a solenoid shaped, active magnetic shield design; however, many of the principles discussed are applicable regardless of the exact design configuration, particularly the key technologies cited.

  11. Reliable and Affordable Control Systems Active Combustor Pattern Factor Control

    NASA Technical Reports Server (NTRS)

    McCarty, Bob; Tomondi, Chris; McGinley, Ray

    2004-01-01

    Active, closed-loop control of combustor pattern factor is a cooperative effort between Honeywell (formerly AlliedSignal) Engines and Systems and the NASA Glenn Research Center to reduce emissions and turbine-stator vane temperature variations, thereby enhancing engine performance and life, and reducing direct operating costs. Total fuel flow supplied to the engine is established by the speed/power control, but the distribution to individual atomizers will be controlled by the Active Combustor Pattern Factor Control (ACPFC). This system consist of three major components: multiple, thin-film sensors located on the turbine-stator vanes; fuel-flow modulators for individual atomizers; and control logic and algorithms within the electronic control.

  12. Active magnetic radiation shielding system analysis and key technologies.

    PubMed

    Washburn, S A; Blattnig, S R; Singleterry, R C; Westover, S C

    2015-01-01

    Many active magnetic shielding designs have been proposed in order to reduce the radiation exposure received by astronauts on long duration, deep space missions. While these designs are promising, they pose significant engineering challenges. This work presents a survey of the major systems required for such unconfined magnetic field design, allowing the identification of key technologies for future development. Basic mass calculations are developed for each system and are used to determine the resulting galactic cosmic radiation exposure for a generic solenoid design, using a range of magnetic field strength and thickness values, allowing some of the basic characteristics of such a design to be observed. This study focuses on a solenoid shaped, active magnetic shield design; however, many of the principles discussed are applicable regardless of the exact design configuration, particularly the key technologies cited. PMID:26177618

  13. Energy monitoring system based on human activity in the workplace

    NASA Astrophysics Data System (ADS)

    Mustafa, Nur Hanim; Husain, Mohd Nor; Aziz, Mohamad Zoinol Abidin Abdul; Othman, Mohd Azlishah; Malek, Fareq

    2015-05-01

    Human behaviors always related to day routine activities in a smart house directly give the significant factor to manage energy usage in human life. An Addition that, the factor will contribute to the best efficiency of the system. This paper will focus on the monitoring efficiency based on duration time in office hours around 8am until 5pm which depend on human behavior at working place. Besides that, the correlation coefficient method is used to show the relation between energy consumption and energy saving based on the total hours of time energy spent. In future, the percentages of energy monitoring system usage will be increase to manage energy saving based on human behaviors. This scenario will help to see the human activity in the workplace in order to get the energy saving and support world green environment.

  14. OCT detection of neural activity in American cockroach nervous system

    NASA Astrophysics Data System (ADS)

    Gorczyńska, Iwona; Wyszkowska, Joanna; Bukowska, Danuta; Ruminski, Daniel; Karnowski, Karol; Stankiewicz, Maria; Wojtkowski, Maciej

    2013-03-01

    We show results of a project which focuses on detection of activity in neural tissue with Optical Coherence Tomography (OCT) methods. Experiments were performed in neural cords dissected from the American cockroach (Periplaneta americana L.). Functional OCT imaging was performed with ultrahigh resolution spectral / Fourier domain OCT system (axial resolution 2.5 μm). Electrical stimulation (voltage pulses) was applied to the sensory cercal nerve of the neural cord. Optical detection of functional activation of the sample was performed in the connective between the terminal abdominal ganglion and the fifth abdominal ganglion. Functional OCT data were collected over time with the OCT beam illuminating selected single point in the connectives (i.e. OCT M-scans were acquired). Phase changes of the OCT signal were analyzed to visualize occurrence of activation in the neural cord. Electrophysiology recordings (microelectrode method) were also performed as a reference method to demonstrate electrical response of the sample to stimulation.

  15. Active damping performance of the KAGRA seismic attenuation system prototype

    NASA Astrophysics Data System (ADS)

    Fujii, Yoshinori; Sekiguchi, Takanori; Takahashi, Ryutaro; Aso, Yoichi; Barton, Mark; Erasmo Peña Arellano, Fabián; Shoda, Ayaka; Akutsu, Tomotada; Miyakawa, Osamu; Kamiizumi, Masahiro; Ishizaki, Hideharu; Tatsumi, Daisuke; Hirata, Naoatsu; Hayama, Kazuhiro; Okutomi, Koki; Miyamoto, Takahiro; Ishizuka, Hideki; DeSalvo, Riccardo; Flaminio, Raffaele

    2016-05-01

    The Large-scale Cryogenic Gravitational wave Telescope (formerly LCGT now KAGRA) is presently under construction in Japan. This May we assembled a prototype of the seismic attenuation system (SAS) for the beam splitter and the signal recycling mirrors of KAGRA, which we call Type-B SAS, and evaluated its performance at NAOJ (Mitaka, Toyko). We investigated its frequency response, active damping performance, vibration isolation performance and long-term stability both in and out of vacuum. From the frequency response test and the active damping performance test, we confirmed that the SAS worked as we designed and that all mechanical resonances which could disturb lock acquisition and observation are damped within 1 minute, which is required for KAGRA, by the active controls.

  16. Activity of respiratory system during laser irradiation of brain structures

    NASA Astrophysics Data System (ADS)

    Merkulova, N. A.; Sergeyeva, L. I.

    1984-06-01

    The performance of one of the principal links of the respiratory system, the respiratory center, was studied as a function of the exposure of the medulla oblongata and the sensomotor zone of the cerebral hemisphere cortex to low level laser irradiation in the red wavelength of the spectrum. Experiments were done on white rats under barbital anesthesia. Under such conditions a substantial effect was observed on the activity of the respiratory center. Laser light may display activating or inhibitory influences, in some cases the bilateral symmetry of the activity of the respiratory center is affected indicating deep changes in the integrative mechanism of the functioning of the right and left sides of the hemispheres. The laser beam effect depends on many factors: specific light properties, duration of the exposure, repetition of exposures, initial functional state of the CNS, etc.

  17. Ionospheric effects in active retrodirective array and mitigating system design

    NASA Technical Reports Server (NTRS)

    Nandi, A. K.; Tomita, C. Y.

    1980-01-01

    The operation of an active retrodirective array (ARA) in an ionospheric environment (that is either stationary or slowly-varying) was examined. The restrictions imposed on the pilot signal structure as a result of such operation were analyzed. A 3 tone pilot beam system was defined which first estimates the total electron content along paths of interest and then utilizes this information to aid the phase conjugator so that correct beam pointing can be achieved.

  18. Indoor Chemistry: Materials, Ventilation Systems, and Occupant Activities

    SciTech Connect

    Morrison, G.C.; Corsi, R.L.; Destaillats, H.; Nazaroff, W.W.; Wells, J.R.

    2006-05-01

    Chemical processes taking place in indoor environments can significantly alter the nature and concentrations of pollutants. Exposure to secondary contaminants generated in these reactions needs to be evaluated in association with many aspects of buildings to minimize their impact on occupant health and well-being. Focusing on indoor ozone chemistry, we describe alternatives for improving indoor air quality by controlling chemical changes related to building materials, ventilation systems, and occupant activities.

  19. Sex Differences in Monocyte Activation in Systemic Lupus Erythematosus (SLE)

    PubMed Central

    Jiang, Wei; Zhang, Lumin; Lang, Ren; Li, Zihai; Gilkeson, Gary

    2014-01-01

    Introduction TLR7/8 and TLR9 signaling pathways have been extensively studied in systemic lupus erythematosus (SLE) as possible mediators of disease. Monocytes are a major source of pro-inflammatory cytokines and are understudied in SLE. In the current project, we investigated sex differences in monocyte activation and its implications in SLE disease pathogenesis. Methods Human blood samples from 27 healthy male controls, 32 healthy female controls, and 25 female patients with SLE matched for age and race were studied. Monocyte activation was tested by flow cytometry and ELISA, including subset proportions, CD14, CD80 and CD86 expression, the percentage of IL-6-producing monocytes, plasma levels of sCD14 and IL-6, and urine levels of creatinine. Results Monocytes were significantly more activated in women compared to men and in patients with SLE compared to controls in vivo. We observed increased proportions of non-classic monocytes, decreased proportions of classic monocytes, elevated levels of plasma sCD14 as well as reduced surface expression of CD14 on monocytes comparing women to men and lupus patients to controls. Plasma levels of IL-6 were positively related to sCD14 and serum creatinine. Conclusion Monocyte activation and TLR4 responsiveness are altered in women compared to men and in patients with SLE compared to controls. These sex differences may allow persistent systemic inflammation and resultant enhanced SLE susceptibility. PMID:25485543

  20. Database mining applied to central nervous system (CNS) activity.

    PubMed

    Pintore, M; Taboureau, O; Ros, F; Chrétien, J R

    2001-04-01

    A data set of 389 compounds, active in the central nervous system (CNS) and divided into eight classes according to the receptor type, was extracted from the RBI database and analyzed by Self-Organizing Maps (SOM), also known as Kohonen Artificial Neural Networks. This method gives a 2D representation of the distribution of the compounds in the hyperspace derived from their molecular descriptors. As SOM belongs to the category of unsupervised techniques, it has to be combined with another method in order to generate classification models with predictive ability. The fuzzy clustering (FC) approach seems to be particularly suitable to delineate clusters in a rational way from SOM and to get an automatic objective map interpretation. Maps derived by SOM showed specific regions associated with a unique receptor type and zones in which two or more activity classes are nested. Then, the modeling ability of the proposed SOM/FC Hybrid System tools applied simultaneously to eight activity classes was validated after dividing the 389 compounds into a training set and a test set, including 259 and 130 molecules, respectively. The proper experimental activity class, among the eight possible ones, was predicted simultaneously and correctly for 81% of the test set compounds. PMID:11461760

  1. Modulation of Erythrocyte Plasma Membrane Redox System Activity by Curcumin

    PubMed Central

    Singh, Prabhakar; Kesharwani, Rajesh Kumar; Misra, Krishna; Rizvi, Syed Ibrahim

    2016-01-01

    Plasma membrane redox system (PMRS) is an electron transport chain system ubiquitously present throughout all cell types. It transfers electron from intracellular substrates to extracellular acceptors for regulation of redox status. Curcumin, isolated from Curcuma longa, has modulatory effects on cellular physiology due to its membrane interaction ability and antioxidant potential. The present study investigates the effect of curcumin on PMRS activity of erythrocytes isolated from Wistar rats in vitro and in vivo and validated through an in silico docking simulation study using Molegro Virtual Docker (MVD). Effects of curcumin were also evaluated on level of glutathione (GSH) and the oxidant potential of plasma measured in terms of plasma ferric equivalent oxidative potentials (PFEOP). Results show that curcumin significantly (p < 0.01) downregulated the PMRS activity in a dose-dependent manner. Molecular docking results suggest that curcumin interacts with amino acids at the active site cavity of cytochrome b5 reductase, a key constituent of PMRS. Curcumin also increased the GSH level in erythrocytes and plasma while simultaneously decreasing the oxidant potential (PFEOP) of plasma. Altered PMRS activity and redox status are associated with the pathophysiology of several health complications including aging and diabetes; hence, the above finding may explain part of the role of curcumin in health beneficial effects. PMID:26904287

  2. Wireless design of a multisensor system for physical activity monitoring.

    PubMed

    Mo, Lingfei; Liu, Shaopeng; Gao, Robert X; John, Dinesh; Staudenmayer, John W; Freedson, Patty S

    2012-11-01

    Real-time monitoring of human physical activity (PA) is important for assessing the intensity of activity and exposure to environmental pollutions. A wireless wearable multisenor integrated measurement system (WIMS) has been designed for real-time measurement of the energy expenditure and breathing volume of human subjects under free-living conditions. To address challenges posted by the limited battery life and data synchronization requirement among multiple sensors in the system, the ZigBee communication platform has been explored for energy-efficient design. Two algorithms have been developed (multiData packaging and slot-data-synchronization) and coded into a microcontroller (MCU)-based sensor circuitry for real-time control of wireless data communication. Experiments have shown that the design enables continued operation of the wearable system for up to 68 h, with the maximum error for data synchronization among the various sensor nodes (SNs) being less than 24 ms. Experiment under free-living conditions have shown that the WIMS is able to correctly recognize the activity intensity level 86% of the time. The results demonstrate the effectiveness of the energy-efficient wireless design for human PA monitoring. PMID:23086196

  3. Visco-elastic Dynamics of an Active Polar Dynamic System

    NASA Astrophysics Data System (ADS)

    Pleiner, Harald; Svensek, Daniel; Brand, Helmut R.

    2015-03-01

    We study the dynamics of systems with a polar dynamic preferred direction that are embedded in visco-elastic media. Examples include the pattern-forming growth of bacteria and molecular motors. Because the ordered state only exists dynamically, but not statically, the macroscopic variable of choice is the velocity of the active units. The passive visco-elastic medium is described by a relaxing strain tensor. We derive the macroscopic equations for such a system and discuss novel static, reversible and irreversible cross-couplings connected to this two-fluid (two-velocity) system. The dynamics is rather different compared to the case of passive, static polar order. In particular, we find a complicated normal mode structure that reflects the broken time-reversal symmetry due to the non-equilibrium situation, anisotropy of first sound and a possible second sound excitation due to the active velocity, and various manifestations of the visco-elastic relaxation. We discuss critically the role of the so-called active term in the stress tensor as well as the thermodynamically correct description of the hydrodynamic transport velocities.

  4. Seal Investigations of an Active Clearance Control System Concept

    NASA Technical Reports Server (NTRS)

    Steinetz, Bruce M.; Taylor, Shawn; Oswald, Jay; DeCastro, Jonathan A.

    2006-01-01

    In an effort to improve upon current thermal active clearance control methods, a first generation, fast-acting mechanically actuated, active clearance control system has been designed and installed into a non-rotating test rig. In order to harvest the benefit of tighter blade tip clearances, low-leakage seals are required for the actuated carrier segments of the seal shroud to prevent excessive leakage of compressor discharge (P3) cooling air. The test rig was designed and fabricated to facilitate the evaluation of these types of seals, identify seal leakage sources, and test other active clearance control system concepts. The objective of this paper is to present both experimental and analytical investigations into the nature of the face-seal to seal-carrier interface. Finite element analyses were used to examine face seal contact pressures and edge-loading under multiple loading conditions, varied E-seal positions and two new face seal heights. The analyses indicated that moving the E-seal inward radially and reducing face seal height would lead to more uniform contact conditions between the face seal and the carriers. Lab testing confirmed that moving the balance diameter inward radially caused a decrease in overall system leakage.

  5. The synchronous active neutron detection system for spent fuel assay

    SciTech Connect

    Pickrell, M.M.; Kendall, P.K.

    1994-10-01

    The authors have begun to develop a novel technique for active neutron assay of fissile material in spent nuclear fuel. This approach will exploit the unique operating features of a 14-MeV neutron generator developed by Schlumberger. This generator and a novel detection system will be applied to the direct measurement of the fissile material content in spent fuel in place of the indirect measures used at present. The technique they are investigating is termed synchronous active neutron detection (SAND). It closely follows a method that has been used routinely in other branches of physics to detect very small signals in the presence of large backgrounds. Synchronous detection instruments are widely available commercially and are termed {open_quotes}lock-in{close_quotes} amplifiers. The authors have implemented a digital lock-in amplifier in conjunction with the Schlumberger neutron generator to explore the possibility of synchronous detection with active neutrons. This approach is possible because the Schlumberger system can operate at up to a 50% duty factor, in effect, a square wave of neutron yield. The results to date are preliminary but quite promising. The system is capable of resolving the fissile material contained in a small fraction of the fuel rods in a cold fuel assembly. It also appears to be quite resilient to background neutron interference. The interrogating neutrons appear to be nonthermal and penetrating. Although a significant amount of work remains to fully explore the relevant physics and optimize the instrument design, the underlying concept appears sound.

  6. A new active visual system for humanoid robots.

    PubMed

    Xu, De; Li, You Fu; Tan, Min; Shen, Yang

    2008-04-01

    In this paper, a new active visual system is developed, which is based on bionic vision and is insensitive to the property of the cameras. The system consists of a mechanical platform and two cameras. The mechanical platform has two degrees of freedom of motion in pitch and yaw, which is equivalent to the neck of a humanoid robot. The cameras are mounted on the platform. The directions of the optical axes of the two cameras can be simultaneously adjusted in opposite directions. With these motions, the object's images can be located at the centers of the image planes of the two cameras. The object's position is determined with the geometry information of the visual system. A more general model for active visual positioning using two cameras without a neck is also investigated. The position of an object can be computed via the active motions. The presented model is less sensitive to the intrinsic parameters of cameras, which promises more flexibility in many applications such as visual tracking with changeable focusing. Experimental results verify the effectiveness of the proposed methods. PMID:18348917

  7. Systemic blood coagulation activation in acute coronary syndromes

    PubMed Central

    Undas, Anetta; Szułdrzyński, Konstanty; Brummel-Ziedins, Kathleen E.; Tracz, Wiesława; Zmudka, Krzysztof

    2009-01-01

    We evaluated systemic alterations to the blood coagulation system that occur during a coronary thrombotic event. Peripheral blood coagulation in patients with acute coronary thrombosis was compared with that in people with stable coronary artery disease (CAD). Blood coagulation and platelet activation at the microvascular injury site were assessed using immunochemistry in 28 non-anticoagulated patients with acute myocardial infarction (AMI) versus 28 stable CAD patients matched for age, sex, risk factors, and medications. AMI was associated with increased maximum rates of thrombin-antithrombin complex generation (by 93.8%; P < .001), thrombin B-chain formation (by 57.1%; P < .001), prothrombin consumption (by 27.9%; P = .012), fibrinogen consumption (by 27.0%; P = .02), factor (f) Va light chain generation (by 44.2%; P = .003), and accelerated fVa inactivation (by 76.1%; P < .001), and with enhanced release of platelet-derived soluble CD40 ligand (by 44.4%; P < .001). FVa heavy chain availability was similar in both groups because of enhanced formation and activated protein C (APC)–mediated destruction. The velocity of coagulant reactions in AMI patients showed positive correlations with interleukin-6. Heparin treatment led to dampening of coagulant reactions with profiles similar to those for stable CAD. AMI-induced systemic activation of blood coagulation markedly modifies the pattern of coagulant reactions at the site of injury in peripheral vessels compared with that in stable CAD patients. PMID:18931343

  8. GT-CATS: Tracking Operator Activities in Complex Systems

    NASA Technical Reports Server (NTRS)

    Callantine, Todd J.; Mitchell, Christine M.; Palmer, Everett A.

    1999-01-01

    Human operators of complex dynamic systems can experience difficulties supervising advanced control automation. One remedy is to develop intelligent aiding systems that can provide operators with context-sensitive advice and reminders. The research reported herein proposes, implements, and evaluates a methodology for activity tracking, a form of intent inferencing that can supply the knowledge required for an intelligent aid by constructing and maintaining a representation of operator activities in real time. The methodology was implemented in the Georgia Tech Crew Activity Tracking System (GT-CATS), which predicts and interprets the actions performed by Boeing 757/767 pilots navigating using autopilot flight modes. This report first describes research on intent inferencing and complex modes of automation. It then provides a detailed description of the GT-CATS methodology, knowledge structures, and processing scheme. The results of an experimental evaluation using airline pilots are given. The results show that GT-CATS was effective in predicting and interpreting pilot actions in real time.

  9. Vector Disparity Sensor with Vergence Control for Active Vision Systems

    PubMed Central

    Barranco, Francisco; Diaz, Javier; Gibaldi, Agostino; Sabatini, Silvio P.; Ros, Eduardo

    2012-01-01

    This paper presents an architecture for computing vector disparity for active vision systems as used on robotics applications. The control of the vergence angle of a binocular system allows us to efficiently explore dynamic environments, but requires a generalization of the disparity computation with respect to a static camera setup, where the disparity is strictly 1-D after the image rectification. The interaction between vision and motor control allows us to develop an active sensor that achieves high accuracy of the disparity computation around the fixation point, and fast reaction time for the vergence control. In this contribution, we address the development of a real-time architecture for vector disparity computation using an FPGA device. We implement the disparity unit and the control module for vergence, version, and tilt to determine the fixation point. In addition, two on-chip different alternatives for the vector disparity engines are discussed based on the luminance (gradient-based) and phase information of the binocular images. The multiscale versions of these engines are able to estimate the vector disparity up to 32 fps on VGA resolution images with very good accuracy as shown using benchmark sequences with known ground-truth. The performances in terms of frame-rate, resource utilization, and accuracy of the presented approaches are discussed. On the basis of these results, our study indicates that the gradient-based approach leads to the best trade-off choice for the integration with the active vision system. PMID:22438737

  10. Active ultrasound pattern injection system (AUSPIS) for interventional tool guidance.

    PubMed

    Guo, Xiaoyu; Kang, Hyun-Jae; Etienne-Cummings, Ralph; Boctor, Emad M

    2014-01-01

    Accurate tool tracking is a crucial task that directly affects the safety and effectiveness of many interventional medical procedures. Compared to CT and MRI, ultrasound-based tool tracking has many advantages, including low cost, safety, mobility and ease of use. However, surgical tools are poorly visualized in conventional ultrasound images, thus preventing effective tool tracking and guidance. Existing tracking methods have not yet provided a solution that effectively solves the tool visualization and mid-plane localization accuracy problem and fully meets the clinical requirements. In this paper, we present an active ultrasound tracking and guiding system for interventional tools. The main principle of this system is to establish a bi-directional ultrasound communication between the interventional tool and US imaging machine within the tissue. This method enables the interventional tool to generate an active ultrasound field over the original imaging ultrasound signals. By controlling the timing and amplitude of the active ultrasound field, a virtual pattern can be directly injected into the US machine B mode display. In this work, we introduce the time and frequency modulation, mid-plane detection, and arbitrary pattern injection methods. The implementation of these methods further improves the target visualization and guiding accuracy, and expands the system application beyond simple tool tracking. We performed ex vitro and in vivo experiments, showing significant improvements of tool visualization and accurate localization using different US imaging platforms. An ultrasound image mid-plane detection accuracy of ±0.3 mm and a detectable tissue depth over 8.5 cm was achieved in the experiment. The system performance is tested under different configurations and system parameters. We also report the first experiment of arbitrary pattern injection to the B mode image and its application in accurate tool tracking. PMID:25337784

  11. The East Pacific Rise: An Active Not Passive Spreading System

    NASA Astrophysics Data System (ADS)

    Rowley, D. B.; Rowan, C. J.; Forte, A. M.; Moucha, R.; Grand, S. P.; Simmons, N. A.

    2011-12-01

    Traditional plate tectonic interpretations of mid-oceanic ridges regard spreading as an entirely passive phenomenon. From this one would assume that the oceanic ridges will move over the mantle in response to the geodynamics of the diverging plates, and do not remain fixed spatially over any protracted period of time. An analysis of the kinematics of ridge motions in the Indo-Atlantic hotspot frame of reference since 83 Ma generally supports this view, with the notable exception of the East Pacific Rise (EPR). The Pacific-Nazca/Farallon segment of the EPR north of Easter Island (27°S) is oriented essentially N-S, and has produced more than 9500km of E-W spreading in the past 80 Ma, making it the dominant ridge in the world's plate system over this interval of time. Yet despite the large amount of E-W divergence, the spreading center has maintained its longitudinal position to within <±250 km of the current ridge axis. Global mantle convective flow modeling indicates that the EPR, unlike any other extensive segment of the mid-oceanic ridge system, is underlain by an active upwelling system extending from the core-mantle boundary to the surface. We suggest that the lack of E-W motion of the EPR apparent from the kinematics is a consequence of these mantle dynamics; this ridge is thus not behaving as a passive plate boundary, but is actively and directly linked to, and controlled by, whole mantle upwelling. This observation overturns the notion that ridges are always entirely passive features of the plate system. Subduction of the northern EPR beneath western North America has thus resulted in the overriding of an active upwelling system that has contributed significantly to the evolution of Basin and Range kinematics and superimposed dynamics, including significant contributions from dynamic topography.

  12. Active Ultrasound Pattern Injection System (AUSPIS) for Interventional Tool Guidance

    PubMed Central

    Guo, Xiaoyu; Kang, Hyun-Jae; Etienne-Cummings, Ralph; Boctor, Emad M.

    2014-01-01

    Accurate tool tracking is a crucial task that directly affects the safety and effectiveness of many interventional medical procedures. Compared to CT and MRI, ultrasound-based tool tracking has many advantages, including low cost, safety, mobility and ease of use. However, surgical tools are poorly visualized in conventional ultrasound images, thus preventing effective tool tracking and guidance. Existing tracking methods have not yet provided a solution that effectively solves the tool visualization and mid-plane localization accuracy problem and fully meets the clinical requirements. In this paper, we present an active ultrasound tracking and guiding system for interventional tools. The main principle of this system is to establish a bi-directional ultrasound communication between the interventional tool and US imaging machine within the tissue. This method enables the interventional tool to generate an active ultrasound field over the original imaging ultrasound signals. By controlling the timing and amplitude of the active ultrasound field, a virtual pattern can be directly injected into the US machine B mode display. In this work, we introduce the time and frequency modulation, mid-plane detection, and arbitrary pattern injection methods. The implementation of these methods further improves the target visualization and guiding accuracy, and expands the system application beyond simple tool tracking. We performed ex vitro and in vivo experiments, showing significant improvements of tool visualization and accurate localization using different US imaging platforms. An ultrasound image mid-plane detection accuracy of ±0.3 mm and a detectable tissue depth over 8.5 cm was achieved in the experiment. The system performance is tested under different configurations and system parameters. We also report the first experiment of arbitrary pattern injection to the B mode image and its application in accurate tool tracking. PMID:25337784

  13. Use of a pendulum magnetometer for measuring the magnetic susceptibility of solids under pressure: The compound V4S9Br4

    NASA Astrophysics Data System (ADS)

    Panfilov, A. S.

    2015-12-01

    The construction and operating principle of a pendulum magnetometer for measuring the magnetic susceptibility of solids under high gas pressures are described. This device is distinctive in having the pendulum mounted directly in the high pressure chamber. Experimental plots of the susceptibility of the compound V4S9Br4 as a function of pressure up to 2 kbar at temperatures of 60-300 K are presented as an example of the use of the magnetometer.

  14. Active Learning for Directed Exploration of Complex Systems

    NASA Technical Reports Server (NTRS)

    Burl, Michael C.; Wang, Esther

    2009-01-01

    Physics-based simulation codes are widely used in science and engineering to model complex systems that would be infeasible to study otherwise. Such codes provide the highest-fidelity representation of system behavior, but are often so slow to run that insight into the system is limited. For example, conducting an exhaustive sweep over a d-dimensional input parameter space with k-steps along each dimension requires k(sup d) simulation trials (translating into k(sup d) CPU-days for one of our current simulations). An alternative is directed exploration in which the next simulation trials are cleverly chosen at each step. Given the results of previous trials, supervised learning techniques (SVM, KDE, GP) are applied to build up simplified predictive models of system behavior. These models are then used within an active learning framework to identify the most valuable trials to run next. Several active learning strategies are examined including a recently-proposed information-theoretic approach. Performance is evaluated on a set of thirteen synthetic oracles, which serve as surrogates for the more expensive simulations and enable the experiments to be replicated by other researchers.

  15. Red wine activates plasma membrane redox system in human erythrocytes.

    PubMed

    Tedesco, Idolo; Moccia, Stefania; Volpe, Silvestro; Alfieri, Giovanna; Strollo, Daniela; Bilotto, Stefania; Spagnuolo, Carmela; Di Renzo, Massimo; Aquino, Rita P; Russo, Gian Luigi

    2016-05-01

    In the present study, we report that polyphenols present in red wine obtained by a controlled microvinification process are able to protect human erythrocytes from oxidative stress and to activate Plasma Membrane Redox System (PMRS). Human plasma obtained from healthy subjects was incubated in the presence of whole red wine at a concentration corresponding to 9.13-73 μg/ml gallic acid equivalents to verify the capacity to protect against hypochlorous acid (HOCl)-induced plasma oxidation and to minimize chloramine formation. Red wine reduced hemolysis and chloramine formation induced by HOCl of 40 and 35%, respectively. PMRS present on human erythrocytes transfers electrons from intracellular molecules to extracellular electron acceptors. We demonstrated that whole red wine activated PMRS activity in human erythrocytes isolated from donors in a dose-dependent manner with a maximum at about 70-100 μg/ml gallic acid equivalents. We also showed that red wine increased glutathione (GSH) levels and erythrocytic antioxidant capacity, measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH) quenching assay. Furthermore, we reported that GSH played a crucial role in regulating PMRS activity in erythrocytes. In fact, the effect of iodoacetamide, an alkylating agent that induces depletion of intracellular GSH, was completely counteracted by red wine. Bioactive compounds present in red wine, such as gallic acid, resveratrol, catechin, and quercetin were unable to activate PMRS when tested at the concentrations normally present in aged red wines. On the contrary, the increase of PMRS activity was associated with the anthocyanin fraction, suggesting the capacity of this class of compounds to positively modulate PMRS enzymatic activity. PMID:26866566

  16. Energy management and control of active distribution systems

    NASA Astrophysics Data System (ADS)

    Shariatzadeh, Farshid

    Advancements in the communication, control, computation and information technologies have driven the transition to the next generation active power distribution systems. Novel control techniques and management strategies are required to achieve the efficient, economic and reliable grid. The focus of this work is energy management and control of active distribution systems (ADS) with integrated renewable energy sources (RESs) and demand response (DR). Here, ADS mean automated distribution system with remotely operated controllers and distributed energy resources (DERs). DER as active part of the next generation future distribution system includes: distributed generations (DGs), RESs, energy storage system (ESS), plug-in hybrid electric vehicles (PHEV) and DR. Integration of DR and RESs into ADS is critical to realize the vision of sustainability. The objective of this dissertation is the development of management architecture to control and operate ADS in the presence of DR and RES. One of the most challenging issues for operating ADS is the inherent uncertainty of DR and RES as well as conflicting objective of DER and electric utilities. ADS can consist of different layers such as system layer and building layer and coordination between these layers is essential. In order to address these challenges, multi-layer energy management and control architecture is proposed with robust algorithms in this work. First layer of proposed multi-layer architecture have been implemented at the system layer. Developed AC optimal power flow (AC-OPF) generates fair price for all DR and non-DR loads which is used as a control signal for second layer. Second layer controls DR load at buildings using a developed look-ahead robust controller. Load aggregator collects information from all buildings and send aggregated load to the system optimizer. Due to the different time scale at these two management layers, time coordination scheme is developed. Robust and deterministic controllers

  17. Engineering intracellular active transport systems as in vivo biomolecular tools.

    SciTech Connect

    Bachand, George David; Carroll-Portillo, Amanda

    2006-11-01

    Active transport systems provide essential functions in terms of cell physiology and metastasis. These systems, however, are also co-opted by invading viruses, enabling directed transport of the virus to and from the cell's nucleus (i.e., the site of virus replication). Based on this concept, fundamentally new approaches for interrogating and manipulating the inner workings of living cells may be achievable by co-opting Nature's active transport systems as an in vivo biomolecular tool. The overall goal of this project was to investigate the ability to engineer kinesin-based transport systems for in vivo applications, specifically the collection of effector proteins (e.g., transcriptional regulators) within single cells. In the first part of this project, a chimeric fusion protein consisting of kinesin and a single chain variable fragment (scFv) of an antibody was successfully produced through a recombinant expression system. The kinesin-scFv retained both catalytic and antigenic functionality, enabling selective capture and transport of target antigens. The incorporation of a rabbit IgG-specific scFv into the kinesin established a generalized system for functionalizing kinesin with a wide range of target-selective antibodies raised in rabbits. The second objective was to develop methods of isolating the intact microtubule network from live cells as a platform for evaluating kinesin-based transport within the cytoskeletal architecture of a cell. Successful isolation of intact microtubule networks from two distinct cell types was demonstrated using glutaraldehyde and methanol fixation methods. This work provides a platform for inferring the ability of kinesin-scFv to function in vivo, and may also serve as a three-dimensional scaffold for evaluating and exploiting kinesin-based transport for nanotechnological applications. Overall, the technology developed in this project represents a first-step in engineering active transport system for in vivo applications. Further

  18. Active wireless temperature sensors for aerospace thermal protection systems

    NASA Astrophysics Data System (ADS)

    Milos, Frank S.; Karunaratne, K. S. G.

    2003-07-01

    Vehicle system health diagnostics is an area where major improvements have been identified for potential implementation into the design of new reusable launch vehicles in order to reduce life-cycle costs, to increase safety margins, and to improve mission reliability. NASA Ames is leading the effort to advance inspection and health management technologies for thermal protection systems. This paper summarizes a joint effort by NASA Ames and Korteks to develop active "wireless" sensors that can be embedded in the thermal protection system to monitor subsurface temperature histories. These devices are thermocouples integrated with radio-frequency identification circuits to enable non-contact communication of temperature data through aerospace thermal protection materials. Two generations of prototype sensors are discussed. The advanced prototype collects data from three type-k thermocouples attached to a 25-mm square integrated circuit and can communicate through 7 to 10 cm thickness of thermal protection materials.

  19. [The NAS system: Nursing Activities Score in mobile technology].

    PubMed

    Catalan, Vanessa Menezes; Silveira, Denise Tolfo; Neutzling, Agnes Ludwig; Martinato, Luísa Helena Machado; Borges, Gilberto Cabral de Mello

    2011-12-01

    The objective of this study was to present the computerized structure that enables the use of the Nursing Activities Score (NAS) in mobile technology. It is a project for the development of technology production based on software engineering, founded on the theory of systems development life cycle. The NAS system was built in two modules: the search module, which is accessed using a personal computer (PC), and Data Collection module, which is accessed through a mobile device (Smartphone). The NAS system was constructed to allow other forms, in addition to the NAS tool, to be included in the future. Thus, it is understood that the development of the NAS will bring nurses closer to mobile technology and facilitate their accessibility to the data of the instrument relating to patients, thus assisting in decision-making and in staffing to provide nursing care. PMID:22241201

  20. Assay of SF/sub 6/ and spark-decomposed SF/sub 6/ for mutagenic activity in the CHO/HGPRT (Chinese hamster ovary/hypoxanthine-guanine phosphoribosyl transferase) mammalian cell system

    SciTech Connect

    Kurka, K.; Griffin, G.D.

    1987-01-01

    The potential mutagenic (and cytotoxic) activity of SF/sub 6/ and spark-decomposed SF/sub 6/ was investigated in an in vitro mammalian cell culture system using Chinese Hamster Ovary (CHO) cells. The CHO cells were exposed to the gases in vacutainer tubes which were constantly rotated. After a 4 h exposure the mutagenic and cytotoxic activity was assayed with the CHO/hypoxanthine-guanine phosphoribosyl transferase (CHO/HGPRT) system. Results indicated that SF/sub 6/ was neither cytotoxic nor mutagenic to CHO cells. Spark-decomposed SF/sub 6/ was found to be strongly cytotoxic (-80% cell death following 4 h exposure to 2 kJ spark discharge in 60 cm/sup 3/ at 1000 torr of SF/sub 6/) but not mutagenic. Increasing spark energy increased cytotoxicity but the spark samples remained nonmutagenic. The CHO/HGPRT system was coupled with a metabolic activation (S9 fraction) system used for detecting promutagens. When exposures were carried out in the presence of S9 fraction, SF/sub 6/ was still neither cytotoxic nor mutagenic; spark-decomposed SF/sub 6/ was again strongly cytotoxic but not mutagenic. It appears that SF/sub 6/ and sparked SF/sub 6/ are neither promutagens nor direct acting mutagens in the CHO/HGPRT system. Studies have begun using a more mutagenically sensitive subclone of the CHO cells known as CHO-AS/sub 52/. The results of initial experiments using the CHO-AS/sub 52/ cells remain unchanged. 9 refs., 1 tab.

  1. A Robotic System for Actively Stiffening Flexible Manipulators

    PubMed Central

    Loschak, Paul M.; Burke, Stephen F.; Zumbro, Emiko; Forelli, Alexandra R.; Howe, Robert D.

    2015-01-01

    A system for actively changing the stiffness of a long, thin, flexible robotic manipulator has been designed for cardiologists to use in a range of diagnosis and treatment procedures. Low-stiffness manipulators, such as catheters, are ideal for steering through vasculature with low risk of tissue injury. However, such instruments are not well-suited for applying force to tissue. The proposed system solves this problem by using a series of bead-shaped vertebrae containing pull wires to actively change the stiffness of the catheter, similar to gooseneck surgical retractors. Individual wires steer the catheter to a desired location. All wires are then tensioned to create friction between each vertebra and prevent sliding, therefore resisting motion. While this design concept has been implemented manually in various settings for decades, fine robotic control of the friction and stiffness of the system relies on a thorough understanding of the friction properties between vertebral segments. We have developed an analytical model to understand the interactions between vertebrae and determine the relationships between system parameters and the overall stiffness of the catheter. Experiments validated the calculations from the model and the functionality of the system by applying known loads to the tip of the catheter and measuring the catheter displacement. The catheter stiffness was measured to range from 100 N/m to 800 N/m, which is sufficient for performing many surgical tasks on tissue. This system can be useful in minimally invasive procedures involving direct instrument contact with tissue by improving accuracy, safety, and work flow. PMID:26709364

  2. Active chatter control system for long-overhang boring bars

    NASA Astrophysics Data System (ADS)

    Browning, Douglas R.; Golioto, Igor; Thompson, Norman B.

    1997-05-01

    Some machining processes, such as boring, have been historically limited by excessive bar vibration, often resulting in poor surface finish and reduced tool life. A unique boring bar system has been developed to suppress bar vibration, or chatter, during machining using active control technology. Metal cutting test programs have shown proven, repeatable performance on hard-to-cut, aircraft industry high-temperature nickel alloys as well as more easily cut carbon steels. Critical bar length-to-diameter (L/D) ratios, depths-of-cuts, feed rates and cutting speeds far exceed those attainable from the best available passively-damped boring bars. This industry-ready system consists of three principle subsystems: active clamp, instrumented bar, and control electronics. The active clamp is a lathe-mountable body capable of supporting bars of varying sizes and articulating them in orthogonal directions from the base of the bar shank. The instrumented bar consists of a steel shank, standard insert head and imbedded accelerometers. Wire harnesses from both the bar and clamp connect to control electronics comprised of highly-efficient switched- capacitor amplifiers that drive the piezoelectric actuators, sensor signal conditioning, a PC-based program manager and two 32-bit floating-point DSPs. The program manager code runs on the host PC and distributes system identification and control functions to the two DSPs. All real-time signal processing is based on the principles of adaptive filter minimization. For the described system, cutting performance has extended existing chatter thresholds (cutting parameter combinations) for nickel alloys by as much as 400% while maintaining precision surface finish on the machined part. Bar L/D ratios as high as 11 have enabled deep boring operations on nickel workpieces that otherwise could not be performed free of chatter.

  3. Antioxidant Activity of Flaxseed Extracts in Lipid Systems.

    PubMed

    Slavova-Kazakova, Adriana; Karamać, Magdalena; Kancheva, Vessela; Amarowicz, Ryszard

    2015-01-01

    The aim of this work was to compare the antioxidant activity of the extract of flaxseed and its alkaline hydrolysate in two model systems: lipid autoxidation of triacylglycerols of sunflower oil (TGSO)-in a homogeneous lipid media and during β-carotene-linoleate emulsion system. In addition, pure lignans were tested. The material was defatted with hexane and then phenolic compounds were extracted using dioxane-ethanol (50:50, v/v) mixture. Carbohydrates were removed from the crude extract using an Amberlite XAD-16 column chromatography. The content of total phenolic compounds in the crude extract and after alkaline hydrolysis was determined using a Folin-Ciocalteu's phenol reagent. Individual phenolic compounds were determined by nordihydroguaiaretic acid (RP-HPLC) method in gradient system. The alkaline hydrolysis increased the content of total phenolics in the extract approximately by 10%. In the extracts of flaxseed, phenolic compounds were present in the form of macromolecular complex. In the alkaline hydrolysate, secoisolariciresinol diglucoside (SDG) was found as the main phenolic compound. Small amounts of p-coumaric and ferulic acids were also determined. SDG and both extracts were not able to inhibit effectively lipid autoxidation. The kinetics of TGSO autoxidation at 80 °C in absence and in presence of the extract before hydrolysis (EBH) and after hydrolysis (EAH) was monitored and compared with known standard antioxidants. Ferulic acid (FA) and butylated hydroxyl toluene (BHT) showed much higher antioxidant efficiency and reactivity than that of both extracts. Secoisolariciresinol (SECO) showed a higher activity in both model systems than SDG. However, the activity of SECO was much lower than that of nordihydroquaiaretic acid (NDGA). PMID:26703558

  4. Photo-active collagen systems with controlled triple helix architecture

    PubMed Central

    Tronci, Giuseppe; Russell, Stephen J.; Wood, David J.

    2016-01-01

    The design of photo-active collagen systems is presented as a basis for establishing biomimetic materials with varied network architecture and programmable macroscopic properties. Following in-house isolation of type I collagen, reaction with vinyl-bearing compounds of varied backbone rigidity, i.e. 4-vinylbenzyl chloride (4VBC) and glycidyl methacrylate (GMA), was carried out. TNBS colorimetric assay, 1H-NMR and ATR-FTIR confirmed covalent and tunable functionalization of collagen lysines. Depending on the type and extent of functionalization, controlled stability and thermal denaturation of triple helices were observed via circular dichroism (CD), whereby the hydrogen-bonding capability of introduced moieties was shown to play a major role. Full gel formation was observed following photo-activation of functionalized collagen solutions. The presence of a covalent network only slightly affected collagen triple helix conformation (as observed by WAXS and ATR-FTIR), confirming the structural organization of functionalized collagen precursors. Photo-activated hydrogels demonstrated an increased denaturation temperature (DSC) with respect to native collagen, suggesting that the formation of the covalent network successfully stabilized collagen triple helices. Moreover, biocompatibility and mechanical competence of obtained hydrogels were successfully demonstrated under physiologically-relevant conditions. These results demonstrate that this novel synthetic approach enabled the formation of biocompatible collagen systems with defined network architecture and programmable macroscopic properties, which can only partially be obtained with current synthetic methods.

  5. Capturing community change: Active Living by Design's progress reporting system.

    PubMed

    Bors, Philip A

    2012-11-01

    The Active Living by Design (ALbD) National Program Office (NPO) developed an evaluation system to track progress of 25 community partnerships, funded by the Robert Wood Johnson Foundation (RWJF). Between June 2004 and October 2008, partnerships documented their actions and accomplishments through ALbD's online Progress Reporting System (PRS) database. All entries were verified and analyzed by the NPO. Results from the PRS suggest that the ALbD partnerships were successful fundraisers, leveraging $256 million from grants, policy decisions, in-kind and direct sources. The partnerships also documented newspaper coverage, TV, and radio air time and they developed physical activity programs such as exercise clubs and "walking school buses." Partnerships were adept at influencing decision makers to create or rewrite policies and improve built environments. Selected policy examples included, but were not limited to, approvals for capital improvements, street design standards, and development ordinances. Partnerships also contributed to the completion and approval of influential planning products, such as comprehensive land use, neighborhood, and roadway corridor plans. The most common built-environment changes were street improvements for safer pedestrian and bicycle travel, including new crosswalks, bicycle facilities, and sidewalks. The ALbD community partnerships' accomplishments and challenges contribute to knowledge and best practices in the active living field. Five years after their grant began, RWJF's initial investment showed substantial and measurable results. PMID:23079260

  6. Target system of IFMIF/EVEDA in Japanese activities

    NASA Astrophysics Data System (ADS)

    Ida, M.; Fukada, S.; Furukawa, T.; Hirakawa, Y.; Horiike, H.; Kanemura, T.; Kondo, H.; Miyashita, M.; Nakamura, H.; Sigiura, H.; Suzuki, A.; Terai, T.; Tsuji, Y.; Ushimaru, H.; Watanabe, K.; Yagi, J.

    2011-10-01

    The Engineering Validation and Engineering Design Activities (EVEDA) of the International Fusion Materials Irradiation Facility (IFMIF) have been started. As Japanese activities for the target system, the EVEDA Lithium (Li) Test Loop to simulate hydraulic and impurity conditions of the IFMIF Li loop is under design. The feasibility of the thermo-mechanical structure of the target assembly and the replaceable back-plate made of F82H and 316L stainless steel is a key research subject. Toward final validation at the EVEDA loop, diagnostics systems applicable to the high-speed free-surface Li flow and hot traps to control nitrogen and hydrogen in Li loop have been investigated. In the remote handling subject of target assemblies and the replaceable back-plates activated by irradiation up to 50 dpa/y, lip welds on 316L-316L by laser and dissimilar metal welds on F82H-316L are necessary. Water experiments and hydraulic/thermo-mechanical analyses of the back-plate are underway.

  7. Turing patterns in network-organized activator-inhibitor systems

    NASA Astrophysics Data System (ADS)

    Nakao, Hiroya; Mikhailov, Alexander S.

    2010-07-01

    Turing instability in activator-inhibitor systems provides a paradigm of non-equilibrium self-organization; it has been extensively investigated for biological and chemical processes. Turing instability should also be possible in networks, and general mathematical methods for its treatment have been formulated previously. However, only examples of regular lattices and small networks were explicitly considered. Here we study Turing patterns in large random networks, which reveal striking differences from the classical behaviour. The initial linear instability leads to spontaneous differentiation of the network nodes into activator-rich and activator-poor groups. The emerging Turing patterns become furthermore strongly reshaped at the subsequent nonlinear stage. Multiple coexisting stationary states and hysteresis effects are observed. This peculiar behaviour can be understood in the framework of a mean-field theory. Our results offer a new perspective on self-organization phenomena in systems organized as complex networks. Potential applications include ecological metapopulations, synthetic ecosystems, cellular networks of early biological morphogenesis, and networks of coupled chemical nanoreactors.

  8. Mucosal and systemic adjuvant activity of alphavirus replicon particles

    NASA Astrophysics Data System (ADS)

    Thompson, Joseph M.; Whitmore, Alan C.; Konopka, Jennifer L.; Collier, Martha L.; Richmond, Erin M. B.; Davis, Nancy L.; Staats, Herman F.; Johnston, Robert E.

    2006-03-01

    Vaccination represents the most effective control measure in the fight against infectious diseases. Local mucosal immune responses are critical for protection from, and resolution of, infection by numerous mucosal pathogens. Antigen processing across mucosal surfaces is the natural route by which mucosal immunity is generated, as peripheral antigen delivery typically fails to induce mucosal immune responses. However, we demonstrate in this article that mucosal immune responses are evident at multiple mucosal surfaces after parenteral delivery of Venezuelan equine encephalitis virus replicon particles (VRP). Moreover, coinoculation of null VRP (not expressing any transgene) with inactivated influenza virions, or ovalbumin, resulted in a significant increase in antigen-specific systemic IgG and fecal IgA antibodies, compared with antigen alone. Pretreatment of VRP with UV light largely abrogated this adjuvant effect. These results demonstrate that alphavirus replicon particles possess intrinsic systemic and mucosal adjuvant activity and suggest that VRP RNA replication is the trigger for this activity. We feel that these observations and the continued experimentation they stimulate will ultimately define the specific components of an alternative pathway for the induction of mucosal immunity, and if the activity is evident in humans, will enable new possibilities for safe and inexpensive subunit and inactivated vaccines. vaccine vector | Venezuelan equine encephalitis virus | viral immunology | RNA virus

  9. Minimum Detectable Activity for Tomographic Gamma Scanning System

    SciTech Connect

    Venkataraman, Ram; Smith, Susan; Kirkpatrick, J. M.; Croft, Stephen

    2015-01-01

    For any radiation measurement system, it is useful to explore and establish the detection limits and a minimum detectable activity (MDA) for the radionuclides of interest, even if the system is to be used at far higher values. The MDA serves as an important figure of merit, and often a system is optimized and configured so that it can meet the MDA requirements of a measurement campaign. The non-destructive assay (NDA) systems based on gamma ray analysis are no exception and well established conventions, such the Currie method, exist for estimating the detection limits and the MDA. However, the Tomographic Gamma Scanning (TGS) technique poses some challenges for the estimation of detection limits and MDAs. The TGS combines high resolution gamma ray spectrometry (HRGS) with low spatial resolution image reconstruction techniques. In non-imaging gamma ray based NDA techniques measured counts in a full energy peak can be used to estimate the activity of a radionuclide, independently of other counting trials. However, in the case of the TGS each “view” is a full spectral grab (each a counting trial), and each scan consists of 150 spectral grabs in the transmission and emission scans per vertical layer of the item. The set of views in a complete scan are then used to solve for the radionuclide activities on a voxel by voxel basis, over 16 layers of a 10x10 voxel grid. Thus, the raw count data are not independent trials any more, but rather constitute input to a matrix solution for the emission image values at the various locations inside the item volume used in the reconstruction. So, the validity of the methods used to estimate MDA for an imaging technique such as TGS warrant a close scrutiny, because the pair-counting concept of Currie is not directly applicable. One can also raise questions as to whether the TGS, along with other image reconstruction techniques which heavily intertwine data, is a suitable method if one expects to measure samples whose activities

  10. The conformationally flexible S9-S10 linker region in the core domain of p53 contains a novel MDM2 binding site whose mutation increases ubiquitination of p53 in vivo.

    PubMed

    Shimizu, Harumi; Burch, Lindsay R; Smith, Amanda J; Dornan, David; Wallace, Maura; Ball, Kathryn L; Hupp, Ted R

    2002-08-01

    Although the N-terminal BOX-I domain of the tumor suppressor protein p53 contains the primary docking site for MDM2, previous studies demonstrated that RNA stabilizes the MDM2.p53 complex using a p53 mutant lacking the BOX-I motif. In vitro assays measuring the specific activity of MDM2 in the ligand-free and RNA-bound state identified a novel MDM2 interaction site in the core domain of p53. As defined using phage-peptide display, the RNA.MDM2 isoform exhibited a notable switch in peptide binding specificity, with enhanced affinity for novel peptide sequences in either p53 or small nuclear ribonucleoprotein-U (snRNP-U) and substantially reduced affinity for the primary p53 binding site in the BOX-I domain. The consensus binding site for the RNA.MDM2 complex within p53 is SGXLLGESXF, which links the S9-S10 beta-sheets flanking the BOX-IV and BOX-V motifs in the core domain and which is a site of reversible conformational flexibility in p53. Mutation of conserved amino acids in the linker at Ser(261) and Leu(264), which bridges the S9-S10 beta-sheets, stimulated p53 activity from reporter templates and increased MDM2-dependent ubiquitination of p53. Furthermore, mutation of the conserved Phe(270) within the S10 beta-sheet resulted in a mutant p53, which binds more stably to RNA.MDM2 complexes in vitro and which is strikingly hyper-ubiquitinated in vivo. Introducing an Ala(19) mutation into the p53(F270A) protein abolished both RNA.MDM2 complex binding and hyper-ubiquitination in vivo, thus indicating that p53(F270A) protein hyper-ubiquitination depends upon MDM2 binding to its primary site in the BOX-I domain. Together, these data identify a novel MDM2 binding interface within the S9-S10 beta-sheet region of p53 that plays a regulatory role in modulating the rate of MDM2-dependent ubiquitination of p53 in cells. PMID:11925449

  11. Activation-induced necroptosis contributes to B-cell lymphopenia in active systemic lupus erythematosus

    PubMed Central

    Fan, H; Liu, F; Dong, G; Ren, D; Xu, Y; Dou, J; Wang, T; Sun, L; Hou, Y

    2014-01-01

    B-cell abnormality including excessive activation and lymphopenia is a central feature of systemic lupus erythematosus (SLE). Although activation threshold, auto-reaction and death of B cells can be affected by intrinsical and/or external signaling, the underlying mechanisms are unclear. Herein, we demonstrate that co-activation of Toll-like receptor 7 (TLR7) and B-cell receptor (BCR) pathways is a core event for the survival/dead states of B cells in SLE. We found that the mortalities of CD19+CD27- and CD19+IgM+ B-cell subsets were increased in the peripheral blood mononuclear cells (PBMCs) of SLE patients. The gene microarray analysis of CD19+ B cells from active SLE patients showed that the differentially expressed genes were closely correlated to TLR7, BCR, apoptosis, necroptosis and immune pathways. We also found that co-activation of TLR7 and BCR could trigger normal B cells to take on SLE-like B-cell characters including the elevated viability, activation and proliferation in the first 3 days and necroptosis in the later days. Moreover, the necroptotic B cells exhibited mitochondrial dysfunction and hypoxia, along with the elevated expression of necroptosis-related genes, consistent with that in both SLE B-cell microarray and real-time PCR verification. Expectedly, pretreatment with the receptor-interacting protein kinase 1 (RIPK1) inhibitor Necrostatin-1, and not the apoptosis inhibitor zVAD, suppressed B-cell death. Importantly, B cells from additional SLE patients also significantly displayed high expression levels of necroptosis-related genes compared with those from healthy donors. These data indicate that co-activation of TLR7 and BCR pathways can promote B cells to hyperactivation and ultimately necroptosis. Our finding provides a new explanation on B-cell lymphopenia in active SLE patients. These data suggest that extrinsic factors may increase the intrinsical abnormality of B cells in SLE patients. PMID:25210799

  12. Combining Users' Activity Survey and Simulators to Evaluate Human Activity Recognition Systems

    PubMed Central

    Azkune, Gorka; Almeida, Aitor; López-de-Ipiña, Diego; Chen, Liming

    2015-01-01

    Evaluating human activity recognition systems usually implies following expensive and time-consuming methodologies, where experiments with humans are run with the consequent ethical and legal issues. We propose a novel evaluation methodology to overcome the enumerated problems, which is based on surveys for users and a synthetic dataset generator tool. Surveys allow capturing how different users perform activities of daily living, while the synthetic dataset generator is used to create properly labelled activity datasets modelled with the information extracted from surveys. Important aspects, such as sensor noise, varying time lapses and user erratic behaviour, can also be simulated using the tool. The proposed methodology is shown to have very important advantages that allow researchers to carry out their work more efficiently. To evaluate the approach, a synthetic dataset generated following the proposed methodology is compared to a real dataset computing the similarity between sensor occurrence frequencies. It is concluded that the similarity between both datasets is more than significant. PMID:25856329

  13. Combining users' activity survey and simulators to evaluate human activity recognition systems.

    PubMed

    Azkune, Gorka; Almeida, Aitor; López-de-Ipiña, Diego; Chen, Liming

    2015-01-01

    Evaluating human activity recognition systems usually implies following expensive and time-consuming methodologies, where experiments with humans are run with the consequent ethical and legal issues. We propose a novel evaluation methodology to overcome the enumerated problems, which is based on surveys for users and a synthetic dataset generator tool. Surveys allow capturing how different users perform activities of daily living, while the synthetic dataset generator is used to create properly labelled activity datasets modelled with the information extracted from surveys. Important aspects, such as sensor noise, varying time lapses and user erratic behaviour, can also be simulated using the tool. The proposed methodology is shown to have very important advantages that allow researchers to carry out their work more efficiently. To evaluate the approach, a synthetic dataset generated following the proposed methodology is compared to a real dataset computing the similarity between sensor occurrence frequencies. It is concluded that the similarity between both datasets is more than significant. PMID:25856329

  14. High-Tc SQUID magnetometer system with active cancellation

    NASA Astrophysics Data System (ADS)

    Kuriki, S.; Oyama, H.; Hayashi, A.; Washio, T.; Fujita, M.; Hirata, Y.

    2002-05-01

    Recent developments of high-Tc SQUIDs have enabled high sensitivity magnetometers to be used in wide range of places, such as laboratory and outdoor fields. At the early stage of developing multichannel system for measurement of magnetocardiogram (MCG) in clinical application, we have fabricated a single channel high-Tc SQUID magnetometer system. The system includes a direct-coupled SQUID with slot structure, a simple magnetically shielded room (MSR), and some active compensation electronics for the purpose of reducing various environmental field noises. A novel active noise cancellation was made by using a combination of a normal conducting detection coil that was horizontally wound in the middle height of the MSR, and two compensation coils that were wound at the top and bottom of the MSR. In addition, adaptive noise cancellation was supplemented by means of adaptive digital filter that was implemented in a digital signal processor. A total noise field attenuation of 50-60 dB was attained at 0.5-100 Hz. Low noise signals from the human heart were measured with a high-Tc SQUID in the noise reduced space in the MSR.

  15. Teaching Systems Biology: An Active-learning Approach

    PubMed Central

    2005-01-01

    With genomics well established in modern molecular biology, recent studies have sought to further the discipline by integrating complementary methodologies into a holistic depiction of the molecular mechanisms underpinning cell function. This genomic subdiscipline, loosely termed “systems biology,” presents the biology educator with both opportunities and obstacles: The benefit of exposing students to this cutting-edge scientific methodology is manifest, yet how does one convey the breadth and advantage of systems biology while still engaging the student? Here, I describe an active-learning approach to the presentation of systems biology. In graduate classes at the University of Michigan, Ann Arbor, I divided students into small groups and asked each group to interpret a sample data set (e.g., microarray data, two-hybrid data, homology-search results) describing a hypothetical signaling pathway. Mimicking realistic experimental results, each data set revealed a portion of this pathway; however, students were only able to reconstruct the full pathway by integrating all data sets, thereby exemplifying the utility in a systems biology approach. Student response to this cooperative exercise was extremely positive. In total, this approach provides an effective introduction to systems biology appropriate for students at both the undergraduate and graduate levels. PMID:16341259

  16. Active phase compensation system for fiber optic holography

    NASA Technical Reports Server (NTRS)

    Mercer, Carolyn R.; Beheim, Glenn

    1989-01-01

    Fiber optic delivery systems promise to extend the application of holography to severe environments by simplifying test configurations and permitting the laser to be remotely placed in a more benign location. However, the introduction of optical fiber leads to phase stability problems. Environmental effects cause the pathlengths of the fibers to change randomly, preventing the formation of stationary interference patterns which are required for holography. An active phase control system has been designed and used with an all-fiber optical system to stabilize the phase difference between light emitted from two fibers, and to step the phase difference by 90 deg without applying any constraints on the placement of the fibers. The accuracy of the phase steps is shown to be better than 0.02 deg., and a stable phase difference can be maintained for 30 min. This system can be applied to both conventional and electro-optic holography, as well as to any system where the maintenance of an accurate phase difference between two coherent beams is required.

  17. Active phase compensation system for fiber optic holography

    NASA Technical Reports Server (NTRS)

    Mercer, Carolyn R.; Beheim, Glenn

    1988-01-01

    Fiber optic delivery systems promise to extend the application of holography to severe environments by simplifying test configurations and permitting the laser to be remotely placed in a more benign location. However, the introduction of optical fiber leads to phase stability problems. Environmental effects cause the pathlengths of the fibers to change randomly, preventing the formation of stationary interference patterns which are required for holography. An active phase control system has been designed and used with an all-fiber optical system to stabilize the phase difference between light emitted from two fibers, and to step the phase difference by 90 deg without applying any constraints on the placement of the fibers. The accuracy of the phase steps is shown to be better than 0.02 deg., and a stable phase difference can be maintained for 30 min. This system can be applied to both conventional and electro-optic holography, as well as to any system where the maintenance of an accurate phase difference between two coherent beams is required.

  18. Activation of a new proline transport system in Salmonella typhimurium.

    PubMed

    Ekena, K; Liao, M K; Maloy, S

    1990-06-01

    Proline uptake can be mediated by three different transport systems in wild-type Salmonella typhimurium: a high-affinity proline transport system encoded by the putP gene and two glycine-betaine transport systems with a low affinity for proline encoded by the proP and proU genes. However, only the PutP permease transports proline well enough t allow growth on proline as a sole carbon or nitrogen source. By selecting for mutations that allow a putP mutant to grow on proline as a sole nitrogen source, we isolated mutants (designated proZ) that appeared to activate a cryptic proline transport system. These mutants enhanced the transport of proline and proline analogs but did not require the function of any of the known proline transport genes. The mutations mapped between 75 and 77.5 min on the S. typhimurium linkage map. Proline transport by the proZ mutants was competitively inhibited by isoleucine and leucine, which suggests that the ProZ phenotype may be due to unusual mutations that alter the substrate specificity of the branched-chain amino acid transport system encoded by the liv genes. PMID:2160931

  19. Orthonormal filters for identification in active control systems

    NASA Astrophysics Data System (ADS)

    Mayer, Dirk

    2015-12-01

    Many active noise and vibration control systems require models of the control paths. When the controlled system changes slightly over time, adaptive digital filters for the identification of the models are useful. This paper aims at the investigation of a special class of adaptive digital filters: orthonormal filter banks possess the robust and simple adaptation of the widely applied finite impulse response (FIR) filters, but at a lower model order, which is important when considering implementation on embedded systems. However, the filter banks require prior knowledge about the resonance frequencies and damping of the structure. This knowledge can be supposed to be of limited precision, since in many practical systems, uncertainties in the structural parameters exist. In this work, a procedure using a number of training systems to find the fixed parameters for the filter banks is applied. The effect of uncertainties in the prior knowledge on the model error is examined both with a basic example and in an experiment. Furthermore, the possibilities to compensate for the imprecise prior knowledge by a higher filter order are investigated. Also comparisons with FIR filters are implemented in order to assess the possible advantages of the orthonormal filter banks. Numerical and experimental investigations show that significantly lower computational effort can be reached by the filter banks under certain conditions.

  20. Maternal Immune Activation Disrupts Dopamine System in the Offspring

    PubMed Central

    Luchicchi, Antonio; Lecca, Salvatore; Melis, Miriam; De Felice, Marta; Cadeddu, Francesca; Frau, Roberto; Muntoni, Anna Lisa; Fadda, Paola; Devoto, Paola

    2016-01-01

    Background: In utero exposure to maternal viral infections is associated with a higher incidence of psychiatric disorders with a supposed neurodevelopmental origin, including schizophrenia. Hence, immune response factors exert a negative impact on brain maturation that predisposes the offspring to the emergence of pathological phenotypes later in life. Although ventral tegmental area dopamine neurons and their target regions play essential roles in the pathophysiology of psychoses, it remains to be fully elucidated how dopamine activity and functionality are disrupted in maternal immune activation models of schizophrenia. Methods: Here, we used an immune-mediated neurodevelopmental disruption model based on prenatal administration of the polyriboinosinic-polyribocytidilic acid in rats, which mimics a viral infection and recapitulates behavioral abnormalities relevant to psychiatric disorders in the offspring. Extracellular dopamine levels were measured by brain microdialysis in both the nucleus accumbens shell and the medial prefrontal cortex, whereas dopamine neurons in ventral tegmental area were studied by in vivo electrophysiology. Results: Polyriboinosinic-polyribocytidilic acid-treated animals, at adulthood, displayed deficits in sensorimotor gating, memory, and social interaction and increased baseline extracellular dopamine levels in the nucleus accumbens, but not in the prefrontal cortex. In polyriboinosinic-polyribocytidilic acid rats, dopamine neurons showed reduced spontaneously firing rate and population activity. Conclusions: These results confirm that maternal immune activation severely impairs dopamine system and that the polyriboinosinic-polyribocytidilic acid model can be considered a proper animal model of a psychiatric condition that fulfills a multidimensional set of validity criteria predictive of a human pathology. PMID:26819283

  1. The contact activation and kallikrein/kinin systems: pathophysiologic and physiologic activities.

    PubMed

    Schmaier, A H

    2016-01-01

    The contact activation system (CAS) and kallikrein/kinin system (KKS) are older recognized biochemical pathways that include several proteins that skirt the fringes of the blood coagulation, fibrinolytic, complement and renin-angiotensin fields. These proteins initially were proposed as part of the hemostatic pathways because their deficiencies are associated with prolonged clinical assays. However, the absence of bleeding states with deficiencies of factor XII (FXII), prekallikrein (PK) and high-molecular-weight kininogen indicates that the CAS and KKS do not contribute to hemostasis. Since the discovery of the Hageman factor 60 years ago much has been learned about the biochemistry, cell biology and animal physiology of these proteins. The CAS is a pathophysiologic surface defense mechanism against foreign proteins, organisms and artificial materials. The KKS is an inflammatory response mechanism. Targeting their activation through FXIIa or plasma kallikrein inhibition when blood interacts with the artificial surfaces of modern interventional medicine or in acute attacks of hereditary angioedema restores vascular homeostasis. FXII/FXIIa and products that arise with PK deficiency also offer novel ways to reduce arterial and venous thrombosis without an effect on hemostasis. In summary, there is revived interest in the CAS and KKS due to better understanding of their activities. The new appreciation of these systems will lead to several new therapies for a variety of medical disorders. PMID:26565070

  2. A "Kanes's Dynamics" Model for the Active Rack Isolation System

    NASA Technical Reports Server (NTRS)

    Hampton, R. David; Beech, Geoffrey

    1999-01-01

    Many microgravity space-science experiments require vibratory acceleration levels unachievable without active isolation. The Boeing Corporation's Active Rack Isolation System (ARIS) employs a novel combination of magnetic actuation and mechanical linkages, to address these isolation requirements on the International Space Station (ISS). ARIS provides isolation at the rack (international Standard Payload Rack, or ISPR) level. Effective model-based vibration isolation requires (1) an appropriate isolation device, (2) an adequate dynamic (i.e., mathematical) model of that isolator, and (3) a suitable, corresponding controller. ARIS provides the ISS response to the first requirement. This paper presents one response to the second, in a state-space framework intended to facilitate an optimal-controls approach to the third. The authors use "Kane's Dynamics" to develop an state-space, analytical (algebraic) set of linearized equations of motion for ARIS.

  3. A "Kane's Dynamics" Model for the Active Rack Isolation System

    NASA Technical Reports Server (NTRS)

    Hampton, R. D.; Beech, G. S.; Rao, N. N. S.; Rupert, J. K.; Kim, Y. K.

    2001-01-01

    Many microgravity space science experiments require vibratory acceleration levels unachievable without active isolation. The Boeing Corporation's Active Rack Isolation System (ARIS) employs a novel combination of magnetic actuation and mechanical linkages to address these isolation requirements on the International Space Station (ISS). ARIS provides isolation at the rack (International Standard Payload Rack (ISPR)) level. Effective model-based vibration isolation requires: (1) an appropriate isolation device, (2) an adequate dynamic (i.e., mathematical) model of that isolator, and (3) a suitable, corresponding controller. ARIS provides the ISS response to the first requirement. This paper presents one response to the second, in a state space framework intended to facilitate an optimal-controls approach to the third. The authors use "Kane's Dynamics" to develop a state-space, analytical (algebraic) set of linearized equations of motion for ARIS.

  4. Comprehensive Design Reliability Activities for Aerospace Propulsion Systems

    NASA Technical Reports Server (NTRS)

    Christenson, R. L.; Whitley, M. R.; Knight, K. C.

    2000-01-01

    This technical publication describes the methodology, model, software tool, input data, and analysis result that support aerospace design reliability studies. The focus of these activities is on propulsion systems mechanical design reliability. The goal of these activities is to support design from a reliability perspective. Paralleling performance analyses in schedule and method, this requires the proper use of metrics in a validated reliability model useful for design, sensitivity, and trade studies. Design reliability analysis in this view is one of several critical design functions. A design reliability method is detailed and two example analyses are provided-one qualitative and the other quantitative. The use of aerospace and commercial data sources for quantification is discussed and sources listed. A tool that was developed to support both types of analyses is presented. Finally, special topics discussed include the development of design criteria, issues of reliability quantification, quality control, and reliability verification.

  5. Enceladus: An Active Ice World in the Saturn System

    NASA Astrophysics Data System (ADS)

    Spencer, John R.; Nimmo, Francis

    2013-05-01

    Enceladus, one of the mid-sized icy moons of Saturn, has an importance to planetary science far greater than its modest 504-km diameter would suggest. Intensive exploration of Enceladus by the Cassini Saturn orbiter has revealed that it is the only known icy world in the solar system with ongoing deep-seated geological activity. Active tectonic fractures at Enceladus's south pole, dubbed “tiger stripes,” warmed by internal tidally generated heat, spew supersonic jets of water vapor, other gases, and ice particles into circum-Saturnian space. A subsurface saltwater sea probably exists under the south pole, between the ice shell and the silicate core. Because of evidence that liquid water is probably present at the jet sources, Enceladus is also of great astrobiological interest as a potential habitat for life.

  6. Active optics system of the VLT Survey Telescope.

    PubMed

    Schipani, Pietro; Noethe, Lothar; Magrin, Demetrio; Kuijken, Konrad; Arcidiacono, Carmelo; Argomedo, Javier; Capaccioli, Massimo; Dall'Ora, Massimo; D'Orsi, Sergio; Farinato, Jacopo; Fierro, Davide; Holzlöhner, Ronald; Marty, Laurent; Molfese, Cesare; Perrotta, Francesco; Ragazzoni, Roberto; Savarese, Salvatore; Rakich, Andrew; Umbriaco, Gabriele

    2016-03-01

    This paper describes the active optics system of the VLT Survey Telescope, the 2.6-m survey telescope designed for visible wavelengths of the European Southern Observatory at Cerro Paranal, in the Atacama desert. The telescope is characterized by a wide field of view (1.42 deg diameter), leading to tighter active optics than in conventional telescopes, in particular for the alignment requirements. We discuss the effects of typical error sources on the image quality and present the specific solutions adopted for wavefront sensing and correction of the aberrations, which are based on the shaping of a monolithic primary mirror and the positioning of the secondary in five degrees of freedom. PMID:26974616

  7. Boswellia carterii liquisolid systems with promoted anti-inflammatory activity.

    PubMed

    Mostafa, Dina Mahmoud; Ammar, Nagwa Mohammed; Abd El-Alim, Sameh Hosam; Kassem, Ahmed Alaa; Hussein, Rehab Ali; Awad, Gamal; El-Awdan, Sally Abdul-Wanees

    2015-01-01

    Boswellia carterii (BC) Birdwood oleogum resin is an ancient remedy of inflammation processes known since Ancient Egyptian time. Of boswellic acids, 3-acetyl-11-keto-β-boswellic acid (AKBA) is the most potent anti-inflammatory active principle. Liquisolid systems of the biologically active fraction of BC oleogum resin were prepared for improving dissolution properties using low dose oral delivery to achieve enhanced anti-inflammatory activity, in comparison with the standard oral anti-inflammatory; Indomethacin. AKBA was assayed, employing an accurate and sensitive HPLC method. Detection was carried out at 210 nm using UV/Vis detector. A solubility study for the bioactive fraction was conducted. Microcrystalline cellulose and Aeroperl®300 Pharma were used as carrier and coating materials. Angle of slide, liquid load factor and Carr's flow index were estimated. Six systems were prepared using polyethylene glycol 400, solvent and two drug loading concentrations; 20 and 40 %. For each concentration, three carrier: coat ratios were dispensed; 20:1, 10:1, and 5:1. Dissolution study was performed and two systems were selected for characterization and in vivo evaluation by investigating upper GIT ulcerogenic effect and anti-inflammatory efficacy in rats. Results indicate absence of ulcers and significantly higher and prolonged anti-inflammatory efficacy for formulations F1 and F2, with carrier: coat ratio, 5:1 and drug loads of 20 and 40 %, respectively, compared with standard oral indomethacin. We conclude higher efficacy of BC bioactive fraction liquisolids compared with Indomethacin with greater safety on GIT, longer duration of action and hence better patient compliance. PMID:25895614

  8. Low-power MOEMS components for active optical systems

    NASA Astrophysics Data System (ADS)

    Castracane, James; Yan, Dong; Madison, Seth; Xu, Bai

    2004-01-01

    The eventual, widespread insertion of Micro-Opto-Electro-Mechanical Systems (MOEMS) into the marketplace rests fundamentally on the ability to produce viable components that maximize optical performance while minimizing power consumption and size. In addition, the incorporation of optical reconfigurability into custom MOEMS devices offers an extra degree of freedom not possible with conventional components. Active control of surface topology allows for one component to perform multiple functions thus reducing cost and complexity. This paper will focus on the current status of the MOEMS research program at the University at Albany Institute for Materials" (UAIM) NanoFab 200 with several examples described to illustrate component and system development. In particular, among the MOEMS research portfolio at UAIM, the development of selected MOEMS-based, active optics will be discussed. This active control of diffraction and reflection forms the basis for the utility of such devices. Leveraging the extensive research expertise on the patented MEMS Compound Grating (MCG), emphasis will be placed on the extension of the approach to novel designs, materials and fabrication methods to yield low power, high performance prototypes. The main focus of this paper is on the development of a polymer version (including sacrificial layer, in some designs) of the MCG which allows for ease of fabrication and a reduced electrostatic actuation voltage. Following a system design effort, several generations of the component were fabricated to optimize the process flow. Component metrology, electromechanical characterization and initial results of optical tests will be reported. A second example presented is the design and prototype fabrication of a spring micrograting using a customized SOI process. This highly flexible component builds on the MCG concept and yields an order of magnitude reduction in actuation voltage. These examples will be presented against a backdrop of the broad UAIM

  9. Placebo-Activated Neural Systems are Linked to Antidepressant Responses

    PubMed Central

    Peciña, Marta; Bohnert, Amy S. B.; Sikora, Magdalena; Avery, Erich T.; Langenecker, Scott A.; Mickey, Brian J.; Zubieta, Jon-Kar

    2016-01-01

    Importance High placebo responses have been observed across a wide range of pathologies, severely impacting drug development. Objective Here we examined neurochemical mechanisms underlying the formation of placebo effects in patients with Major Depressive Disorder (MDD). Participants Thirty-five medication-free MDD patients. Design and Intervention We performed a single-blinded two-week cross-over randomized controlled trial of two identical oral placebos (described as having either “active” or “inactive” fast-acting antidepressant-like effects) followed by a 10-week open-label treatment with a selective serotonin reuptake inhibitor (SSRI) or in some cases, another agent as clinically indicated. The volunteers were studied with PET and the μ-opioid receptor (MOR)-selective radiotracer [11C]carfentanil after each 1-week “inactive” and “active” oral placebo treatment. In addition, 1 mL of isotonic saline was administered intravenously (i.v.) within sight of the volunteer during PET scanning every 4 min over 20 min only after the 1-week active placebo treatment, with instructions that the compound may be associated with the activation of brain systems involved in mood improvement. This challenge stimulus was utilized to test the individual capacity to acutely activate endogenous opioid neurotransmision under expectations of antidepressant effect. Setting A University Health System. Main Outcomes and Measures Changes in depressive symptoms in response to “active” placebo and antidepressant. Baseline and activation measures of MOR binding. Results Higher baseline MOR binding in the nucleus accumbens (NAc) was associated with better response to antidepressant treatment (r=0.48; p=0.02). Reductions in depressive symptoms after 1-week of “active” placebo treatment, compared to the “inactive”, were associated with increased placebo-induced μ-opioid neurotransmission in a network of regions implicated in emotion, stress regulation, and the

  10. Portable Radio System for Automated Meteor Activity Recording

    NASA Astrophysics Data System (ADS)

    Martinez Picar, Antonio

    2010-08-01

    Radio waves that collide with trails of ionized particles generated by the meteoroid entering the Earth's atmosphere undergo a process of electromagnetic scattering. The forward scatter mechanism (or oblique scattering) explains how these meteor trails can be used to establish longrange communication links. This paper describes the design and setup of a portable device that, based on this propagation mechanism, allows the automatic registration of meteor activity from the most appropriate observing location. The results show the feasibility of the system for detecting, recording and adequate storage of the necessary parameters in the study of meteor streams.

  11. New design deforming controlling system of the active stressed lap

    NASA Astrophysics Data System (ADS)

    Ying, Li; Wang, Daxing

    2008-07-01

    A 450mm diameter active stressed lap has been developed in NIAOT by 2003. We design a new lap in 2007. This paper puts on emphases on introducing the new deforming control system of the lap. Aiming at the control characteristic of the lap, a new kind of digital deforming controller is designed. The controller consists of 3 parts: computer signal disposing, motor driving and force sensor signal disposing. Intelligent numeral PID method is applied in the controller instead of traditional PID. In the end, the result of new deformation are given.

  12. IASM: A System for the Intelligent Active Surveillance of Malaria

    PubMed Central

    Yang, Bo; Chen, Hechang; Gu, Xiao; Bai, Yuan

    2016-01-01

    Malaria, a life-threatening infectious disease, spreads rapidly via parasites. Malaria prevention is more effective and efficient than treatment. However, the existing surveillance systems used to prevent malaria are inadequate, especially in areas with limited or no access to medical resources. In this paper, in order to monitor the spreading of malaria, we develop an intelligent surveillance system based on our existing algorithms. First, a visualization function and active surveillance were implemented in order to predict and categorize areas at high risk of infection. Next, socioeconomic and climatological characteristics were applied to the proposed prediction model. Then, the redundancy of the socioeconomic attribute values was reduced using the stepwise regression method to improve the accuracy of the proposed prediction model. The experimental results indicated that the proposed IASM predicted malaria outbreaks more close to the real data and with fewer variables than other models. Furthermore, the proposed model effectively identified areas at high risk of infection. PMID:27563343

  13. IASM: A System for the Intelligent Active Surveillance of Malaria.

    PubMed

    Wang, Xinlei; Yang, Bo; Huang, Jing; Chen, Hechang; Gu, Xiao; Bai, Yuan; Du, Zhanwei

    2016-01-01

    Malaria, a life-threatening infectious disease, spreads rapidly via parasites. Malaria prevention is more effective and efficient than treatment. However, the existing surveillance systems used to prevent malaria are inadequate, especially in areas with limited or no access to medical resources. In this paper, in order to monitor the spreading of malaria, we develop an intelligent surveillance system based on our existing algorithms. First, a visualization function and active surveillance were implemented in order to predict and categorize areas at high risk of infection. Next, socioeconomic and climatological characteristics were applied to the proposed prediction model. Then, the redundancy of the socioeconomic attribute values was reduced using the stepwise regression method to improve the accuracy of the proposed prediction model. The experimental results indicated that the proposed IASM predicted malaria outbreaks more close to the real data and with fewer variables than other models. Furthermore, the proposed model effectively identified areas at high risk of infection. PMID:27563343

  14. Characterization of the airborne activity confinement system prefilter material

    SciTech Connect

    Long, T.A.; Monson, P.R.

    1992-05-01

    A general concern with assessing the effects of postulated severe accidents is predicting and preventing the release of radioactive isotopes to the environment at the Savannah River Site (SRS) reactor. Unless the confinement systems are breached in an accident the Airborne Activity Confinement System forces all of the internal air through the filter compartments. Proper modeling of the radioactivity released to the environment requires knowledge of the filtering characteristics of the demisters, the HEPA`s, and the charcoal beds. An investigation of the mass loading characteristics for a range of particle sizes was performed under the direction of Vince Novick of Argonne National Laboratory (ANL) for the Savannah River Technology Center (SRTC) in connection with the restart of the K reactor. Both solid and liquid aerosols were used to challenge sample prefilter and HEPA filters. The results of the ANL investigation are reported in this document.

  15. Characterization of the airborne activity confinement system prefilter material

    SciTech Connect

    Long, T.A.; Monson, P.R.

    1992-05-01

    A general concern with assessing the effects of postulated severe accidents is predicting and preventing the release of radioactive isotopes to the environment at the Savannah River Site (SRS) reactor. Unless the confinement systems are breached in an accident the Airborne Activity Confinement System forces all of the internal air through the filter compartments. Proper modeling of the radioactivity released to the environment requires knowledge of the filtering characteristics of the demisters, the HEPA's, and the charcoal beds. An investigation of the mass loading characteristics for a range of particle sizes was performed under the direction of Vince Novick of Argonne National Laboratory (ANL) for the Savannah River Technology Center (SRTC) in connection with the restart of the K reactor. Both solid and liquid aerosols were used to challenge sample prefilter and HEPA filters. The results of the ANL investigation are reported in this document.

  16. Design of active orthoses for a robotic gait rehabilitation system

    NASA Astrophysics Data System (ADS)

    Villa-Parra, A. C.; Broche, L.; Delisle-Rodríguez, D.; Sagaró, R.; Bastos, T.; Frizera-Neto, A.

    2015-09-01

    An active orthosis (AO) is a robotic device that assists both human gait and rehabilitation therapy. This work proposes portable AOs, one for the knee joint and another for the ankle joint. Both AOs will be used to complete a robotic system that improves gait rehabilitation. The requirements for actuator selection, the biomechanical considerations during the AO design, the finite element method, and a control approach based on electroencephalographic and surface electromyographic signals are reviewed. This work contributes to the design of AOs for users with foot drop and knee flexion impairment. However, the potential of the proposed AOs to be part of a robotic gait rehabilitation system that improves the quality of life of stroke survivors requires further investigation.

  17. Active Wireless Temperature Sensors for Aerospace Thermal Protection Systems

    NASA Technical Reports Server (NTRS)

    Milos, Frank S.; Karunaratne, K.; Arnold, Jim (Technical Monitor)

    2002-01-01

    Health diagnostics is an area where major improvements have been identified for potential implementation into the design of new reusable launch vehicles in order to reduce life-cycle costs, to increase safety margins, and to improve mission reliability. NASA Ames is leading the effort to advance inspection and health management technologies for thermal protection systems. This paper summarizes a joint project between NASA Ames and Korteks to develop active wireless sensors that can be embedded in the thermal protection system to monitor sub-surface temperature histories. These devices are thermocouples integrated with radio-frequency identification circuitry to enable acquisition and non-contact communication of temperature data through aerospace thermal protection materials. Two generations of prototype sensors are discussed. The advanced prototype collects data from three type-k thermocouples attached to a 2.54-cm square integrated circuit.

  18. A simulation system for Space Station extravehicular activity

    NASA Technical Reports Server (NTRS)

    Marmolejo, Jose A.; Shepherd, Chip

    1993-01-01

    America's next major step into space will be the construction of a permanently manned Space Station which is currently under development and scheduled for full operation in the mid-1990's. Most of the construction of the Space Station will be performed over several flights by suited crew members during an extravehicular activity (EVA) from the Space Shuttle. Once fully operational, EVA's will be performed from the Space Station on a routine basis to provide, among other services, maintenance and repair operations of satellites currently in Earth orbit. Both voice recognition and helmet-mounted display technologies can improve the productivity of workers in space by potentially reducing the time, risk, and cost involved in performing EVA. NASA has recognized this potential and is currently developing a voice-controlled information system for Space Station EVA. Two bench-model helmet-mounted displays and an EVA simulation program have been developed to demonstrate the functionality and practicality of the system.

  19. Robust Kalman filter design for active flutter suppression systems

    NASA Technical Reports Server (NTRS)

    Garrard, W. L.; Mahesh, J. K.; Stone, C. R.; Dunn, H. J.

    1982-01-01

    Additional insight is provided into the use of the Doyle-Stein (1979, 1981) technique in aeroelastic control problems by examining the application of the method to a flutter control problem. The system to be controlled consists of a full-size wind tunnel model of a wing, plus an aileron, an actuator, and an accelerometer used to sense the motion of the wing. A full-state feedback controller was designed using linear optimal control theory, and a Kalman filter was used in the feedback loop for state estimation. The filter design procedure is explained along with that to improve closed-loop properties of the system. The locus of the poles of the filter is examined as a scalar design parameter is varied. The Doyle-Stein design procedure is shown to substantially improve the stability properties of an active flutter controller designed using the linear quadratic Gaussian control theory.

  20. Spiral and never-settling patterns in active systems

    NASA Astrophysics Data System (ADS)

    Yang, X.; Marenduzzo, D.; Marchetti, M. C.

    2014-01-01

    We present a combined numerical and analytical study of pattern formation in an active system where particles align, possess a density-dependent motility, and are subject to a logistic reaction. The model can describe suspensions of reproducing bacteria, as well as polymerizing actomyosin gels in vitro or in vivo. In the disordered phase, we find that motility suppression and growth compete to yield stable or blinking patterns, which, when dense enough, acquire internal orientational ordering to give asters or spirals. We predict these may be observed within chemotactic aggregates in bacterial fluids. In the ordered phase, the reaction term leads to previously unobserved never-settling patterns which can provide a simple framework to understand the formation of motile and spiral patterns in intracellular actin systems.

  1. Spiral and never-settling patterns in active systems.

    PubMed

    Yang, X; Marenduzzo, D; Marchetti, M C

    2014-01-01

    We present a combined numerical and analytical study of pattern formation in an active system where particles align, possess a density-dependent motility, and are subject to a logistic reaction. The model can describe suspensions of reproducing bacteria, as well as polymerizing actomyosin gels in vitro or in vivo. In the disordered phase, we find that motility suppression and growth compete to yield stable or blinking patterns, which, when dense enough, acquire internal orientational ordering to give asters or spirals. We predict these may be observed within chemotactic aggregates in bacterial fluids. In the ordered phase, the reaction term leads to previously unobserved never-settling patterns which can provide a simple framework to understand the formation of motile and spiral patterns in intracellular actin systems. PMID:24580261

  2. Apparatus and method for gas turbine active combustion control system

    NASA Technical Reports Server (NTRS)

    Umeh, Chukwueloka (Inventor); Kammer, Leonardo C. (Inventor); Shah, Minesh (Inventor); Fortin, Jeffrey B. (Inventor); Knobloch, Aaron (Inventor); Myers, William J. (Inventor); Mancini, Alfred Albert (Inventor)

    2011-01-01

    An Active Combustion Control System and method provides for monitoring combustor pressure and modulating fuel to a gas turbine combustor to prevent combustion dynamics and/or flame extinguishments. The system includes an actuator, wherein the actuator periodically injects pulsed fuel into the combustor. The apparatus also includes a sensor connected to the combustion chamber down stream from an inlet, where the sensor generates a signal detecting the pressure oscillations in the combustor. The apparatus controls the actuator in response to the sensor. The apparatus prompts the actuator to periodically inject pulsed fuel into the combustor at a predetermined sympathetic frequency and magnitude, thereby controlling the amplitude of the pressure oscillations in the combustor by modulating the natural oscillations.

  3. Active vibration and balance system for closed cycle thermodynamic machines

    NASA Technical Reports Server (NTRS)

    Qiu, Songgang (Inventor); Augenblick, John E. (Inventor); Peterson, Allen A. (Inventor); White, Maurice A. (Inventor)

    2004-01-01

    An active balance system is provided for counterbalancing vibrations of an axially reciprocating machine. The balance system includes a support member, a flexure assembly, a counterbalance mass, and a linear motor or an actuator. The support member is configured for attachment to the machine. The flexure assembly includes at least one flat spring having connections along a central portion and an outer peripheral portion. One of the central portion and the outer peripheral portion is fixedly mounted to the support member. The counterbalance mass is fixedly carried by the flexure assembly along another of the central portion and the outer peripheral portion. The linear motor has one of a stator and a mover fixedly mounted to the support member and another of the stator and the mover fixedly mounted to the counterbalance mass. The linear motor is operative to axially reciprocate the counterbalance mass. A method is also provided.

  4. New GPS Network on the Active Fault System in Taiwan

    NASA Astrophysics Data System (ADS)

    Hou, C.; Chen, Y.; Hu, J.; Lin, C.; Chen, C.; Wang, J.; Chung, L.; Chung, W.; Hsieh, C.; Chen, Y.

    2004-12-01

    According to the historical records, disastrous earthquakes occurred in Taiwan were caused by reactivations of active faults. In last century, there were five with the surface rupture: 1906 Meishan Eq. (the Meishan F.), 1935 Hsihchu Eq. (the Shihtan and the Tuntzuchiao F.), 1946 Hsinhua Eq. (Hsinhua F.), 1951 Hualien-Taitung Eq. (Longitudinal Valley F.), and 1999 Chi-Chi Eq. (the Chelungpu F.). In order to identify earthquake associated surface rupture and further to mitigate potential hazards, the investigation and monitoring on the active fault system are of great urgency. Central Geological Survey (CGS) of Taiwan is currently executing a 5-year (2002-2006) project, integrating geological and geodetic data to better characterize short-term and long-term spatial and temporal variations in deformation across major already-known active faults of Taiwan. For the former, we use field survey, drilling, geophysical exploration, and trenching to recognize the long-term slip rate and recurrence interval of each fault. For the latter, we deploy near-fault campaign-style GPS and leveling monitoring networks. Here we further combine the result of other GPS networks including continuous-mode. This project is actually concentrated on fault-specific investigation.. Until Dec. 2004, we have set up 756 GPS stations and 27 precise leveling lines including 1024 leveling benchmarks. For the purpose of understanding temporal variability and receive continuous record, the CGS began to deploy 6~10 new GPS stations of continuous mode since 2004. Upon the completion of the geodetic project, we are supposed to provide information on short-term slip rates of major active faults. By integrating other geological datasets we will also evaluate the short-term and long-term behavior of the active faults, and further offer insight into spatial and temporal variability in deformation processes.

  5. Application of electrical propulsion for an active debris removal system: a system engineering approach

    NASA Astrophysics Data System (ADS)

    Covello, Fabio

    2012-10-01

    One of the main challenge in the design of an active removal system for space debris is the high ΔV required both to approach space debris lying in different orbits and to de-orbit/re-orbit them. Indeed if the system does not target a number of objects during its lifetime the cost of the removal will be far too high to be considered as the basis of an economically viable business case. Using a classical chemical propulsion (CP) system, the ΔV is limited by the mass of propellant that the system can carry. This limitation is greatly reduced if electrical propulsion is considered. Electrical propulsion (EP) systems are indeed characterized by low propellant mass requirements, however this comes at the cost of higher electrical power and, typically, higher complexity and mass of the power supply system. Because of this, the use of EP systems has been, therefore, primarily limited to station keeping maneuvers. However in the recent past, the success of missions using EP as primary propulsion (e.g. GOCE, SMART-1, Artemis, Deep Spcae1, Hayabusa) makes this technology a suitable candidate for providing propulsion for an active debris removal system. This study case will provide the analysis of the possible application of electrical propulsion systems in such a context, presenting a number of possible mission profiles. This paper will start with the description of possible mission concepts and the assessment of the EP technology, comparing near-term propulsion options, that best fits the mission. A more detailed analysis follows with the relevant trade-off to define the characteristics of the final system and its size in terms of mass and power required. A survey of available space qualified EP systems will be performed with the selection of the best candidates to be used and/or developed for an active debris removal system. The results of a similar analysis performed for a classical CP system are then presented and the two options are compared in terms of total cost of

  6. Active transmission isolation/rotor loads measurement system

    NASA Technical Reports Server (NTRS)

    Kenigsberg, I. J.; Defelice, J. J.

    1973-01-01

    Modifications were incorporated into a helicopter active transmission isolation system to provide the capability of utilizing the system as a rotor force measuring device. These included; (1) isolator redesign to improve operation and minimize friction, (2) installation of pressure transducers in each isolator, and (3) load cells in series with each torque restraint link. Full scale vibration tests performed during this study on a CH-53A helicopter airframe verified that these modifications do not degrade the systems wide band isolation characteristics. Bench tests performed on each isolator unit indicated that steady and transient loads can be measured to within 1 percent of applied load. Individual isolator vibratory load measurement accuracy was determined to be 4 percent. Load measurement accuracy was found to be independent of variations in all basic isolator operating characteristics. Full scale system load calibration tests on the CH-53A airframe established the feasibility of simultaneously providing wide band vibration isolation and accurate measurement of rotor loads. Principal rotor loads (lift, propulsive force, and torque) were measured to within 2 percent of applied load.

  7. Active smart material system for buffet load alleviation

    NASA Astrophysics Data System (ADS)

    Lazarus, Kenneth B.; Saarmaa, Erik; Agnes, Gregory S.

    1995-05-01

    This paper addressed the feasibility of using an active piezoelectric buffet suppression system to reduce buffet vibrations in vertical tail aircraft. During the assessment, functional requirements were defined, models were developed, and full-scale piezoelectric buffet suppression systems were designed and evaluated. A variety of actuator distributions, sensor locations and controller architectures were examined and it was found that significant performance improvements could be achieved (greater than 70 percent) with minimal weight penalties (less than 8 percent). This work enabled the evaluation of issues such as system performance versus added weight and piezoelectric actuator control authority and power requirements. The study showed that the added performance benefit (in terms of vibration reduction and fatigue life) are far greater than the weight penalty, and that piezoelectric actuators have the control authority required to suppress high energy buffet forces within aircraft geometry, weight, and power constraints. Further, the high performance achieved (much greater than that defined in the functional requirements) suggests that systems can be designed with a much lower weight penalty (1/2 to 1/4) than that assumed in this study.

  8. Obligate symbionts activate immune system development in the tsetse fly

    PubMed Central

    Weiss, Brian L.; Maltz, Michele; Aksoy, Serap

    2012-01-01

    Many insects rely on the presence of symbiotic bacteria for proper immune system function. However, the molecular mechanisms that underlie this phenomenon are poorly understood. Adult tsetse flies (Glossina spp.) house 3 symbiotic bacteria that are vertically transmitted from mother to offspring during this insect's unique viviparous mode of reproduction. Larval tsetse that undergo intrauterine development in the absence of their obligate mutualist, Wigglesworthia, exhibit a compromised immune system during adulthood. In this study we characterize the immune phenotype of tsetse that develop in the absence of all of their endogenous symbiotic microbes. Aposymbiotic tsetse (GmmApo) present a severely compromised immune system that is characterized by the absence of phagocytic hemocytes and atypical expression of immunity-related genes. Correspondingly, these flies quickly succumb to infection with normally non-pathogenic E. coli. The susceptible phenotype exhibited by GmmApo adults can be reversed when they receive hemocytes transplanted from wild-type donor flies prior to infection. Furthermore, the process of immune system development can be restored in intrauterine GmmApo larvae when their moms are fed a diet supplemented with Wigglesworthia cell extracts. Our finding that molecular components of Wigglesworthia exhibit immunostimulatory activity within tsetse is representative of a novel evolutionary adaptation that steadfastly links an obligate symbiont with it's host. PMID:22368278

  9. Active Disaster Response System for a Smart Building

    PubMed Central

    Lin, Chun-Yen; Chu, Edward T.-H; Ku, Lun-Wei; Liu, Jane W. S.

    2014-01-01

    Disaster warning and surveillance systems have been widely applied to help the public be aware of an emergency. However, existing warning systems are unable to cooperate with household appliances or embedded controllers; that is, they cannot provide enough time for preparedness and evacuation, especially for disasters like earthquakes. In addition, the existing warning and surveillance systems are not responsible for collecting sufficient information inside a building for relief workers to conduct a proper rescue action after a disaster happens. In this paper, we describe the design and implementation of a proof of concept prototype, named the active disaster response system (ADRS), which automatically performs emergency tasks when an earthquake happens. ADRS can interpret Common Alerting Protocol (CAP) messages, published by an official agency, and actuate embedded controllers to perform emergency tasks to respond to the alerts. Examples of emergency tasks include opening doors and windows and cutting off power lines and gas valves. In addition, ADRS can maintain a temporary network by utilizing the embedded controllers; hence, victims trapped inside a building are still able to post emergency messages if the original network is disconnected. We conducted a field trial to evaluate the effectiveness of ADRS after an earthquake happened. Our results show that compared to manually operating emergency tasks, ADRS can reduce the operation time by up to 15 s, which is long enough for people to get under sturdy furniture, or to evacuate from the third floor to the first floor, or to run more than 100 m. PMID:25237897

  10. Active disaster response system for a smart building.

    PubMed

    Lin, Chun-Yen; Chu, Edward T-H; Ku, Lun-Wei; Liu, Jane W S

    2014-01-01

    Disaster warning and surveillance systems have been widely applied to help the public be aware of an emergency. However, existing warning systems are unable to cooperate with household appliances or embedded controllers; that is, they cannot provide enough time for preparedness and evacuation, especially for disasters like earthquakes. In addition, the existing warning and surveillance systems are not responsible for collecting sufficient information inside a building for relief workers to conduct a proper rescue action after a disaster happens. In this paper, we describe the design and implementation of a proof of concept prototype, named the active disaster response system (ADRS), which automatically performs emergency tasks when an earthquake happens. ADRS can interpret Common Alerting Protocol (CAP) messages, published by an official agency, and actuate embedded controllers to perform emergency tasks to respond to the alerts. Examples of emergency tasks include opening doors and windows and cutting off power lines and gas valves. In addition, ADRS can maintain a temporary network by utilizing the embedded controllers; hence, victims trapped inside a building are still able to post emergency messages if the original network is disconnected. We conducted a field trial to evaluate the effectiveness of ADRS after an earthquake happened. Our results show that compared to manually operating emergency tasks, ADRS can reduce the operation time by up to 15 s, which is long enough for people to get under sturdy furniture, or to evacuate from the third floor to the first floor, or to run more than 100 m. PMID:25237897

  11. Development of active vibration isolation system for precision machines

    NASA Astrophysics Data System (ADS)

    Li, H. Z.; Lin, W. J.; Yang, G. L.

    2009-12-01

    It is a common understanding by manufacturers of precision machines that vibrations are a potentially disastrous threat to precision and throughput. To satisfy the quest for more stable processes and tighter critical dimension control in the microelectronics manufacturing industry, active vibration control becomes increasingly important for high-precision equipment developers. This paper introduced the development of an active vibration isolation system for precision machines. Innovative mechatronic approaches are investigated that can effectively suppress both environmental and payload-generated vibration. In this system, accelerometers are used as the feedback sensor, voice coil motors are used to generate the counter force, and a TI DSP controller is used to couple sensor measurements to actuator forces via specially designed control algorithms in real-time to counteract the vibration disturbances. Experimental results by using the developed AVI prototype showed promising performance on vibration attenuation. It demonstrated a reduction of the settling time from 2s to 0.1s under impulsive disturbances; and a vibration attenuation level of more than 20dB for harmonic disturbances. The technology can be used to suppress vibration for a wide range of precision machines to achieve fast settling time and higher accuracy.

  12. Development of active vibration isolation system for precision machines

    NASA Astrophysics Data System (ADS)

    Li, H. Z.; Lin, W. J.; Yang, G. L.

    2010-03-01

    It is a common understanding by manufacturers of precision machines that vibrations are a potentially disastrous threat to precision and throughput. To satisfy the quest for more stable processes and tighter critical dimension control in the microelectronics manufacturing industry, active vibration control becomes increasingly important for high-precision equipment developers. This paper introduced the development of an active vibration isolation system for precision machines. Innovative mechatronic approaches are investigated that can effectively suppress both environmental and payload-generated vibration. In this system, accelerometers are used as the feedback sensor, voice coil motors are used to generate the counter force, and a TI DSP controller is used to couple sensor measurements to actuator forces via specially designed control algorithms in real-time to counteract the vibration disturbances. Experimental results by using the developed AVI prototype showed promising performance on vibration attenuation. It demonstrated a reduction of the settling time from 2s to 0.1s under impulsive disturbances; and a vibration attenuation level of more than 20dB for harmonic disturbances. The technology can be used to suppress vibration for a wide range of precision machines to achieve fast settling time and higher accuracy.

  13. Dielectric elastomer vibrissal system for active tactile sensing

    NASA Astrophysics Data System (ADS)

    Conn, Andrew T.; Pearson, Martin J.; Pipe, Anthony G.; Welsby, Jason; Rossiter, Jonathan

    2012-04-01

    Rodents are able to dexterously navigate confined and unlit environments by extracting spatial and textural information with their whiskers (or vibrissae). Vibrissal-based active touch is suited to a variety of applications where vision is occluded, such as search-and-rescue operations in collapsed buildings. In this paper, a compact dielectric elastomer vibrissal system (DEVS) is described that mimics the vibrissal follicle-sinus complex (FSC) found in rodents. Like the vibrissal FSC, the DEVS encapsulates all sensitive mechanoreceptors at the root of a passive whisker within an antagonistic muscular system. Typically, rats actively whisk arrays of macro-vibrissae with amplitudes of up to +/-25°. It is demonstrated that these properties can be replicated by exploiting the characteristic large actuation strains and passive compliance of dielectric elastomers. A prototype DEVS is developed using VHB 4905 and embedded strain gauges bonded to the root of a tapered whisker. The DEVS is demonstrated to produce a maximum rotational output of +/-22.8°. An electro-mechanical model of the DEVS is derived, which incorporates a hyperelastic material model and Euler- Bernoulli beam equations. The model is shown to predict experimental measurements of whisking stroke amplitude and whisker deflection.

  14. The systemic activation of platelets by Dacron grafts.

    PubMed

    Shoenfeld, N A; Connolly, R; Ramberg, K; Valeri, C R; Eldrup-Jorgensen, J; Callow, A D

    1988-05-01

    Dacron (polyester fiber), a stimulus to platelet aggregation in vitro, accumulates platelets to a greater extent in vivo than autogenous artery, polytetrafluoroethylene (PTFE) or human umbilical vein (HUV). We conducted a series of experiments using the ex vivo shunt in the baboon to determine whether or not systemic activation of platelet function was produced by a Dacron graft. Two 5 centimeter segments of 4 millimeter internal diameter graft materials were placed in series in the ex vivo shunt perfused at 25 milliliters per minute flow rate for two and one-half hours. Deposition of autologous Indium 111 labeled platelets was monitored. The ex vivo shunt procedures were divided into two groups, both with PTFE as the proximal graft: one with a distal Dacron graft (n = 21), the second with PTFE or HUV distally (n = 17). In this study, an increase in platelet deposition on the proximal PTFE graft represents systemic platelet activation caused by the distal graft. Increased platelet deposition on PTFE was noted at all time points in the presence of a Dacron graft (p less than 0.05). This property of Dacron has important clinical implications, potentially accelerating the progression of vascular disease, increasing the failure rate of composite grafts and subsequent arterial reconstruction. PMID:2966442

  15. Active immunization therapies for Parkinson's disease and multiple system atrophy.

    PubMed

    Schneeberger, Achim; Tierney, Lanay; Mandler, Markus

    2016-02-01

    Vaccination is increasingly being investigated as a potential treatment for synucleinopathies, a group of neurodegenerative diseases including Parkinson's disease, multiple system atrophy, and dementia with Lewy bodies associated with α-synuclein pathology. All lack a causal therapy. Development of novel, disease-altering treatment strategies is urgently needed. Vaccination has positioned itself as a prime strategy for addressing these diseases because it is broadly applicable, requires infrequent administration, and maintains low production costs for treating a large population or as a preventive measure. Current evidence points to a causal role of misfolded α-synuclein in the development and progression of synucleinopathies. In the past decade, significant progress in active immunization against α-synuclein has been shown both in preclinical animal models and in early clinical development. In this review, we describe the state-of-the-art in active immunization approaches to synucleinopathies, with a focus on advances in Parkinson's disease (PD) and multiple-system atrophy (MSA). We first review preclinical animal models, highlighting their progress in translation to the clinical setting. We then discuss current clinical applications, stressing different approaches taken to address α-synuclein pathology. Finally, we address challenges, trends, and future perspectives of current vaccination programs. PMID:26260853

  16. Active smart material control system for buffet alleviation

    NASA Astrophysics Data System (ADS)

    Sheta, Essam F.; Moses, Robert W.; Huttsell, Lawrence J.

    2006-05-01

    Vertical tail buffeting is a serious multidisciplinary problem that limits the performance and maneuverability of twin-tail fighter aircraft. The buffet problem occurs at high angles of attack when the vortical flow breaks down ahead of the vertical tails resulting in unsteady and unbalanced loads on the tails leading to their premature fatigue failure. An active smart material control system, using distributed piezoelectric (PZT) actuators, is developed for buffet alleviation and is presented. The surfaces of the vertical tail are equipped with PZT actuators to control the buffet responses in the first bending and torsion modes. The electrodynamics of the PZT actuators are modeled using a finite-element model. A single-input/single-output controller is designed to drive the active PZT actuators. High-fidelity analysis modules for the fluid dynamics, structural dynamics, electrodynamics of the PZT actuators, control law, fluid-structure interfacing, and grid motion are integrated into a multidisciplinary computing environment that controls the temporal synchronization of the analysis modules. The results of this study indicate that the actively controlled PZT actuators are an effective tool for buffet alleviation over wide range of angels of attack. Peak values of power spectral density of tail-tip acceleration are reduced by as much as 22% in the first bending mode and by as much as 82% in the first torsion mode. The root mean square values of tail-tip acceleration are reduced by as much as 12%.

  17. Confinement of active systems: trapping, swim pressure, and explosions

    NASA Astrophysics Data System (ADS)

    Takatori, Sho; de Dier, Raf; Vermant, Jan; Brady, John

    2015-11-01

    We analyze the run-and-tumble dynamics and motion of living bacteria and self-propelled Janus motors confined in an acoustic trap. Since standard optical tweezers are far too weak, we developed an acoustic trap strong enough to confine swimmers over distances large compared to the swimmers' size and run length. The external trap behaves as an ``osmotic barrier'' that confines the swimmers inside the trapping region, analogous to semipermeable membranes that confine passive Brownian particles inside a boundary. From the swimmers' restricted motion inside the trap, we calculate the unique swim pressure generated by active systems originating from the force required to confine them by boundaries. We apply a strong trap to collect the swimmers into a close-packed active crystal and then turn off the trap which causes the crystal to ``explode'' due to an imbalance of the active pressure. We corroborate all experimental results with Brownian dynamics simulations and analytical theory. ST is supported by a Gates Millennium Scholars fellowship and a NSF Fellowship No. DGE-1144469. RDD is supported by a doctoral fellowship of the fund for scientific research (FWO-Vlaanderen). This work is also supported by NSF Grant CBET 1437570.

  18. Tractor Mechanics. Maintaining and Servicing the Cooling System, Learning Activity Packages 34-40; Maintaining and Servicing Hydraulic Systems, Learning Activity Packages 41-48.

    ERIC Educational Resources Information Center

    Clemson Univ., SC. Vocational Education Media Center.

    This series of learning activity packages focuses on two areas of tractor mechanics: (1) maintaining and servicing the cooling system and (2) maintaining and servicing hydraulic systems. Each of the fifteen illustrated learning activity packages follows a typical format: introduction, directions, objectives, learning activities, tools and…

  19. A correction factor to f-chart predictions of active solar fraction in active-passive heating systems

    NASA Astrophysics Data System (ADS)

    Evans, B. L.; Beckman, W. A.; Duffie, J. A.; Mitchell, J. W.; Klein, S. A.

    1983-11-01

    The extent to which a passive system degrades the performance of an active solar space heating system was investigated, and a correction factor to account for these interactions was developed. The transient system simulation program TRNSYS is used to simulate the hour-by-hour performance of combined active-passive (hybrid) space heating systems in order to compare the active system performance with simplified design method predictions. The TRNSYS simulations were compared to results obtained using the simplified design calculations of the f-Chart method. Comparisons of TRNSYS and f-Chart were used to establish the accuracy of the f-Charts for active systems. A correlation was then developed to correct the monthly loads input into the f-Chart method to account for controller deadbands in both hybrid and active only buildings. A general correction factor was generated to be applied to the f-Chart method to produce more accurate and useful results for hybrid systems.

  20. Dynamic Docking Test System (DDTS) active table computer program NASA Advanced Docking System (NADS)

    NASA Technical Reports Server (NTRS)

    Gates, R. M.; Jantz, R. E.

    1974-01-01

    A computer program was developed to describe the three-dimensional motion of the Dynamic Docking Test System active table. The input consists of inertia and geometry data, actuator structural data, forcing function data, hydraulics data, servo electronics data, and integration control data. The output consists of table responses, actuator bending responses, and actuator responses.

  1. Shuttle active thermal control system development testing. Volume 5: Integrated radiator/expendable cooling system tests

    NASA Technical Reports Server (NTRS)

    Scheps, P. B.

    1974-01-01

    Tests were conducted to gather data on a space shuttle active control system (ATCS) incorporating both radiators and an expendable cooling device to provide vehicle heat removal. Two systems were tested and design information was provided for both nominal and limit conditions. The tests verified the concept that an integrated radiator/expendable cooling system can adequately maintain desired water quantities while responding to variations in heat loads and environments. In addition, the need for duct heating was demonstrated, while exhaust nozzle heating was also shown to be unnecessary.

  2. Xylazine Activates Adenosine Monophosphate-Activated Protein Kinase Pathway in the Central Nervous System of Rats.

    PubMed

    Shi, Xing-Xing; Yin, Bai-Shuang; Yang, Peng; Chen, Hao; Li, Xin; Su, Li-Xue; Fan, Hong-Gang; Wang, Hong-Bin

    2016-01-01

    Xylazine is a potent analgesic extensively used in veterinary and animal experimentation. Evidence exists that the analgesic effect can be inhibited using adenosine 5'-monophosphate activated protein kinase (AMPK) inhibitors. Considering this idea, the aim of this study was to investigate whether the AMPK signaling pathway is involved in the central analgesic mechanism of xylazine in the rat. Xylazine was administrated via the intraperitoneal route. Sprague-Dawley rats were sacrificed and the cerebral cortex, cerebellum, hippocampus, thalamus and brainstem were collected for determination of liver kinase B1 (LKB1) and AMPKα mRNA expression using quantitative real-time polymerase chain reaction (qPCR), and phosphorylated LKB1 and AMPKα levels using western blot. The results of our study showed that compared with the control group, xylazine induced significant increases in AMPK activity in the cerebral cortex, hippocampus, thalamus and cerebellum after rats received xylazine (P < 0.01). Increased AMPK activities were accompanied with increased phosphorylation levels of LKB1 in corresponding regions of rats. The protein levels of phosphorylated LKB1 and AMPKα in these regions returned or tended to return to control group levels. However, in the brainstem, phosphorylated LKB1 and AMPKα protein levels were decreased by xylazine compared with the control (P < 0.05). In conclusion, our data indicates that xylazine alters the activities of LKB1 and AMPK in the central nervous system of rats, which suggests that xylazine affects the regulatory signaling pathway of the analgesic mechanism in the rat brain. PMID:27049320

  3. Neutron activation system using water flow for ITER

    NASA Astrophysics Data System (ADS)

    Nishitani, T.; Ebisawa, K.; Kasai, S.; Walker, C.

    2003-03-01

    A neutron activation system with flowing water using the 16O(n,p)16N reaction has been designed for the International Thermonuclear Experimental Reaction (ITER) neutron yield monitor with temporal resolution, based on the experimental results carried out at the fusion neutronics source (FNS) facility of the Japan Atomic Energy Research Institute. On ITER, irradiation ends will be installed in the filler shielding module between the blanket modules at the equatorial ports. The gamma-ray counting stations will be installed on the upstairs of the pit outside the biological shield. BGO (Bi4Ge3O12) scintillation detectors will be employed to measure 6.13 MeV gamma rays emitted from 16N. The distance between the irradiation end and the counting station is ˜20 m. The performance of the neutron activation system has been evaluated by using the neutron Monte Carlo code MCNP-4b with the JENDL 3.2 library. The reaction rate of 16O(n,p)16N was calculated not only at the irradiation end but also along the transfer line, which showed that the temporal resolution would be less than the ITER requirement of 100 ms including turbulent diffusion effects for the flow velocity of 10 m/s. With a flow velocity of 10 m/s, this system can measure the fusion power from 50 kW to 1 GW of the ITER operation by using two gamma-ray detectors; one detector faces the water pipe directly, and another has a collimator for higher-neutron yield. Also the calculation shows that the reaction rate is relatively insensitive to the change of the plasma position.

  4. Antifungal activity of the local complement system in cerebral aspergillosis.

    PubMed

    Rambach, Günter; Hagleitner, Magdalena; Mohsenipour, Iradj; Lass-Flörl, Cornelia; Maier, Hans; Würzner, Reinhard; Dierich, Manfred P; Speth, Cornelia

    2005-10-01

    Dissemination of aspergillosis into the central nervous system is associated with nearly 100% mortality. To study the reasons for the antifungal immune failure we analyzed the efficacy of cerebral complement to combat the fungus Aspergillus. Incubation of Aspergillus in non-inflammatory cerebrospinal fluid (CSF) revealed that complement levels were sufficient to obtain a deposition on the surface, but opsonization was much weaker than in serum. Consequently complement deposition from normal CSF on fungal surface stimulated a very low phagocytic activity of microglia, granulocytes, monocytes and macrophages compared to stimulation by conidia opsonized in serum. Similarly, opsonization of Aspergillus by CSF was not sufficient to induce an oxidative burst in infiltrating granulocytes, whereas conidia opsonized in serum induced a clear respiratory signal. Thus, granulocytes were capable of considerably reducing the viability of serum-opsonized Aspergillus conidia, but not of conidia opsonized in CSF. The limited efficacy of antifungal attack by cerebral complement can be partly compensated by enhanced synthesis, leading to elevated complement concentrations in CSF derived from a patient with cerebral aspergillosis. This inflammatory CSF was able to induce (i) a higher complement deposition on the Aspergillus surface than non-inflammatory CSF, (ii) an accumulation of complement activation products and (iii) an increase in phagocytic and killing activity of infiltrating granulocytes. However, levels and efficacy of the serum-derived complement were not reached. These data indicate that low local complement synthesis and activation may represent a central reason for the insufficient antifungal defense in the brain and the high mortality rate of cerebral aspergillosis. PMID:16027023

  5. Activation of the Peripheral Endocannabinoid System in Human Obesity

    PubMed Central

    Engeli, Stefan; Böhnke, Jana; Feldpausch, Mareike; Gorzelniak, Kerstin; Janke, Jürgen; Bátkai, Sándor; Pacher, Pál; Harvey-White, Judy; Luft, Friedrich C.; Sharma, Arya M.; Jordan, Jens

    2008-01-01

    Obesity is the main risk factor for the development of type 2 diabetes. Activation of the central endocannabinoid system increases food intake and promotes weight gain. Blockade of the cannabinoid type 1 (CB-1) receptor reduces body weight in animals by central and peripheral actions; the role of the peripheral endocannabinoid system in human obesity is now being extensively investigated. We measured circulating endocannabinoid concentrations and studied the expression of CB-1 and the main degrading enzyme, fatty acid amide hydrolase (FAAH), in adipose tissue of lean (n = 20) and obese (n = 20) women and after a 5% weight loss in a second group of women (n = 17). Circulating levels of anandamide and 1/2-arachidonoylglycerol were increased by 35 and 52% in obese compared with lean women (P < 0.05). Adipose tissue mRNA levels were reduced by −34% for CB-1 and −59% for FAAH in obese subjects (P < 0.05). A strong negative correlation was found between FAAH expression in adipose tissue and circulating endocannabinoids. Circulating endocannabinoids and CB-1 or FAAH expression were not affected by 5% weight loss. The expression of CB-1 and FAAH was increased in mature human adipocytes compared with in preadipocytes and was found in several human tissues. Our findings support the presence of a peripheral endocannabinoid system that is upregulated in human obesity. PMID:16186383

  6. Activation of the peripheral endocannabinoid system in human obesity.

    PubMed

    Engeli, Stefan; Böhnke, Jana; Feldpausch, Mareike; Gorzelniak, Kerstin; Janke, Jürgen; Bátkai, Sándor; Pacher, Pál; Harvey-White, Judy; Luft, Friedrich C; Sharma, Arya M; Jordan, Jens

    2005-10-01

    Obesity is the main risk factor for the development of type 2 diabetes. Activation of the central endocannabinoid system increases food intake and promotes weight gain. Blockade of the cannabinoid type 1 (CB-1) receptor reduces body weight in animals by central and peripheral actions; the role of the peripheral endocannabinoid system in human obesity is now being extensively investigated. We measured circulating endocannabinoid concentrations and studied the expression of CB-1 and the main degrading enzyme, fatty acid amide hydrolase (FAAH), in adipose tissue of lean (n = 20) and obese (n = 20) women and after a 5% weight loss in a second group of women (n = 17). Circulating levels of anandamide and 1/2-arachidonoylglycerol were increased by 35 and 52% in obese compared with lean women (P < 0.05). Adipose tissue mRNA levels were reduced by -34% for CB-1 and -59% for FAAH in obese subjects (P < 0.05). A strong negative correlation was found between FAAH expression in adipose tissue and circulating endocannabinoids. Circulating endocannabinoids and CB-1 or FAAH expression were not affected by 5% weight loss. The expression of CB-1 and FAAH was increased in mature human adipocytes compared with in preadipocytes and was found in several human tissues. Our findings support the presence of a peripheral endocannabinoid system that is upregulated in human obesity. PMID:16186383

  7. A distributed architecture for activating the peripheral nervous system.

    PubMed

    Andreu, David; Guiraud, David; Souquet, Guillaume

    2009-04-01

    We present a new system for functional electrical stimulation (FES) applications based on networked stimulation units. They embed an advanced analog circuit, which provides multipolar and multiphasic stimulation profiles, and digital circuits, which ensure safety, locally executed programmed profiles, and communication with the master controller. This architecture is thus based on distributed stimulation units (DSU) that need only a two-wire bus to communicate, regardless of the number of poles of each DSU-driven electrode. This structure minimizes the required bandwidth between master and distributed units, increases the safety and stimulation features and decreases the complexity of the surgical approach. We have successfully tested this network-based stimulation architecture on benchtop stimulators. This original approach allows broad exploration of all possible methods to stimulate peripheral nerves, particularly in the goal of restoring the motor function. It provides a powerful research device to determine the optimal, least aggressive and the most efficient way to activate the peripheral nervous system using an implanted FES system that is less invasive than other existing devices. PMID:19213992

  8. A "Kane's Dynamics" Model for the Active Rack Isolation System

    NASA Astrophysics Data System (ADS)

    Rupert, J. K.; Hampton, R. D.; Beech, G. S.

    2005-02-01

    In the late 1980s, microgravity researchers began to voice their concern that umbilical-transmitted energy could significantly degrade the acceleration environment of microgravity space science experiments onboard manned spacecraft. Since umbilicals are necessary for many experiments, control designers began to seek ways to compensate for these "indirect" disturbances. Hampton, et al., used the Kane s method to develop a model of the active rack isolation system (ARIS) that includes (1) actuator control forces, (2) direct disturbance forces, and (3) indirect, actuator-transmitted disturbances. Their model does not, however, include the indirect, umbilical-transmitted disturbances. Since the umbilical stiffnesses are not negligible, these indirect disturbances must be included in the model. Until the umbilicals have been appropriately included, the model will be incomplete. This Technical Memorandum presents a nonlinear model of ARIS with umbilicals included. Model verification was achieved by utilizing two commercial-off-the-shelf software tools. Various forces and moments were applied to the model to yield simulated responses of the system. Plots of the simulation results show how various critical points on an ARIS-outfitted international standard payload rack behave under the application of direct disturbances, indirect disturbances, and control forces. Simulations also show system response to a variety of initial conditions.

  9. Gold enrichment in active geothermal systems by accumulating colloidal suspensions

    NASA Astrophysics Data System (ADS)

    Hannington, Mark; Harðardóttir, Vigdis; Garbe-Schönberg, Dieter; Brown, Kevin L.

    2016-04-01

    The origins of high-grade hydrothermal ore deposits are debated, but active geothermal systems provide important clues to their formation. The highest concentrations of gold are found in geothermal systems with direct links to island arc magmatism. Yet, similar concentrations have also been found in the absence of any input from arc magmas, for example, in the Reykjanes geothermal field, Iceland. Here we analyse brine samples taken from deep wells at Reykjanes and find that gold concentrations in the reservoir zone have increased over the past seven years from an average of 3 ppb to 14 ppb. The metal concentrations greatly exceed the maximum solubility of gold in the reservoir under saturated conditions and are now nearly two orders of magnitude higher than in mid-ocean ridge black smoker fluids--the direct analogues of Reykjanes deep liquids. We suggest that ongoing extraction of brine, the resulting pressure drop, and increased boiling have caused gold to drop out of solution and become trapped in the reservoir as a colloidal suspension. This process may explain how the stock of metal in the reservoirs of fossil geothermal systems could have increased over time and thus become available for the formation of gold-rich ore deposits.

  10. ISS Internal Active Thermal Control System (IATCS) Coolant Remediation Project

    NASA Technical Reports Server (NTRS)

    Morrison, Russell H.; Holt, Mike

    2005-01-01

    The IATCS coolant has experienced a number of anomalies in the time since the US Lab was first activated on Flight 5A in February 2001. These have included: 1) a decrease in coolant pH, 2) increases in inorganic carbon, 3) a reduction in phosphate buffer concentration, 4) an increase in dissolved nickel and precipitation of nickel salts, and 5) increases in microbial concentration. These anomalies represent some risk to the system, have been implicated in some hardware failures and are suspect in others. The ISS program has conducted extensive investigations of the causes and effects of these anomalies and has developed a comprehensive program to remediate the coolant chemistry of the on-orbit system as well as provide a robust and compatible coolant solution for the hardware yet to be delivered. The remediation steps include changes in the coolant chemistry specification, development of a suite of new antimicrobial additives, and development of devices for the removal of nickel and phosphate ions from the coolant. This paper presents an overview of the anomalies, their known and suspected system effects, their causes, and the actions being taken to remediate the coolant.

  11. P-NITROPHENOL METABOLISM BY JAPANESE MEDAKA (ORYZIAS LATIPES) LIVER MICROSOMES AND S-9 FRACTION: ADDITIONAL EVIDENCE FOR THE EXISTENCE OF A CYP2E1-LIKE ISOFORM IN TELEOSTS

    EPA Science Inventory

    Liver microsomes and S-9 fraction of Japanese medaka (Oryzias latipes) metabolized the CYP2E1 specific substrate, p-nitrophenol (PNP), to a single hydroxylated product, 4-nitrocatechol. The use of liver S-9 fraction proved to be a viable alternative to liver microsomes and allowe...

  12. Thermal neutron activation system for confirmatory nonmetallic land mine detection

    NASA Astrophysics Data System (ADS)

    McFee, John E.; Cousins, Thomas; Jones, Trevor; Brisson, Jean R.; Jamieson, Terry; Waller, Ed; LeMay, Francois; Ing, Harry; Clifford, Edward T. H.; Selkirk, Barkley

    1998-09-01

    To detect and locate buried landmines, the Canadian Department of National Defence (DND) is developing a teleoperated, vehicle-mounted, multisensor system called ILDP. In operation, a suite of 4 detectors scan ahead of the vehicle. Their outputs are combined through data fusion to indicate the possibility of a mine at a particular location, within a 30 cm radius. A thermal neutron activation (TNA) sensor, mounted behind the vehicle, is used to confirm the presence of explosives via detection of the 10.83 MeV gamma-ray associated with neutron capture on 14N. The TNA system developed for this uses a 100 microgram 252Cf neutron source surrounded by four 7.62 cm X 7.62 cm NaI(Tl) detectors. A combination of the use of state-of-the art radiation transport codes for design, judicious choice of specialized shielding materials and development of high-rate, fast pulse processing electronics has led to a system which can; (1) confirm the presence of all surface-laid or shallowly-buried anti-tank mines in a few seconds to a minute (depending on mass of explosive) (2) confirm the presence of anti-tank mines down to 20 cm depth in less than 5 minutes. (3) confirm the presence of large (greater than 100 g Nitrogen) anti-personnel mines in less than five minutes (4) operate in adverse climatic conditions. These results have been verified in field trials using the prototype sensor. Work is now ongoing to miniaturize the electronics, make the system robust and easy to use and investigate the use of an electronic neutron generator expected to enter service by the year 2000.

  13. Active Storage with Analytics Capabilities and I/O Runtime System for Petascale Systems

    SciTech Connect

    Choudhary, Alok

    2015-03-18

    Computational scientists must understand results from experimental, observational and computational simulation generated data to gain insights and perform knowledge discovery. As systems approach the petascale range, problems that were unimaginable a few years ago are within reach. With the increasing volume and complexity of data produced by ultra-scale simulations and high-throughput experiments, understanding the science is largely hampered by the lack of comprehensive I/O, storage, acceleration of data manipulation, analysis, and mining tools. Scientists require techniques, tools and infrastructure to facilitate better understanding of their data, in particular the ability to effectively perform complex data analysis, statistical analysis and knowledge discovery. The goal of this work is to enable more effective analysis of scientific datasets through the integration of enhancements in the I/O stack, from active storage support at the file system layer to MPI-IO and high-level I/O library layers. We propose to provide software components to accelerate data analytics, mining, I/O, and knowledge discovery for large-scale scientific applications, thereby increasing productivity of both scientists and the systems. Our approaches include 1) design the interfaces in high-level I/O libraries, such as parallel netCDF, for applications to activate data mining operations at the lower I/O layers; 2) Enhance MPI-IO runtime systems to incorporate the functionality developed as a part of the runtime system design; 3) Develop parallel data mining programs as part of runtime library for server-side file system in PVFS file system; and 4) Prototype an active storage cluster, which will utilize multicore CPUs, GPUs, and FPGAs to carry out the data mining workload.

  14. An active UHF RFID localization system for fawn saving

    NASA Astrophysics Data System (ADS)

    Eberhardt, M.; Lehner, M.; Ascher, A.; Allwang, M.; Biebl, E. M.

    2015-11-01

    We present a localization concept for active UHF RFID transponders which enables mowing machine drivers to detect and localize marked fawns. The whole system design and experimental results with transponders located near the ground in random orientations in a meadow area are shown. The communication flow between reader and transponders is realized as a dynamic master-slave concept. Multiple marked fawns will be localized by processing detected transponders sequentially. With an eight-channel-receiver with integrated calibration method one can estimate the direction-of-arrival by measuring the phases of the transponder signals up to a range of 50 m in all directions. For further troubleshooting array manifolds have been measured. An additional hand-held receiver with a two-channel receiver allows a guided approaching search without endangering the fawn by the mowing machine.

  15. World Energy Projection System Plus (WEPS ): Global Activity Module

    EIA Publications

    2016-01-01

    The World Energy Projection System Plus (WEPS ) is a comprehensive, mid?term energy forecasting and policy analysis tool used by EIA. WEPS projects energy supply, demand, and prices by country or region, given assumptions about the state of various economies, international energy markets, and energy policies. The Global Activity Module (GLAM) provides projections of economic driver variables for use by the supply, demand, and conversion modules of WEPS . GLAM’s baseline economic projection contains the economic assumptions used in WEPS to help determine energy demand and supply. GLAM can also provide WEPS with alternative economic assumptions representing a range of uncertainty about economic growth. The resulting economic impacts of such assumptions are inputs to the remaining supply and demand modules of WEPS .

  16. Active System for Electromagnetic Perturbation Monitoring in Vehicles

    NASA Astrophysics Data System (ADS)

    Matoi, Adrian Marian; Helerea, Elena

    Nowadays electromagnetic environment is rapidly expanding in frequency domain and wireless services extend in terms of covered area. European electromagnetic compatibility regulations refer to limit values regarding emissions, as well as procedures for determining susceptibility of the vehicle. Approval procedure for a series of cars is based on determining emissions/immunity level for a few vehicles picked randomly from the entire series, supposing that entire vehicle series is compliant. During immunity assessment, the vehicle is not subjected to real perturbation sources, but exposed to electric/magnetic fields generated by laboratory equipment. Since current approach takes into account only partially real situation regarding perturbation sources, this paper proposes an active system for determining electromagnetic parameters of vehicle's environment, that implements a logical diagram for measurement, satisfying the imposed requirements. This new and original solution is useful for EMC assessment of hybrid and electrical vehicles.

  17. Optical ordnance system for use in explosive ordnance disposal activities

    NASA Technical Reports Server (NTRS)

    Merson, J. A.; Salas, F. J.; Helsel, F.M.

    1994-01-01

    A portable hand-held solid state rod laser system and an optically-ignited detonator have been developed for use in explosive ordnance disposal (EOD) activities. Laser prototypes from Whittaker Ordnance and Universal Propulsion have been tested and evaluated. The optical detonator contains 2-(5 cyanotetrazolato) pentaamine cobalt(III) perchlorate (CP) as the DDT column and the explosive Octahydro- 1,3,5,7 - tetrazocine (HMX) as the output charge. The laser is designed to have an output of 150 mJ in a 500 microsecond pulse. This output allows firing through 2000 meters of optical fiber. The detonator can also be ignited with a portable laser diode source through a shorter length of fiber.

  18. Effectiveness of classroom response systems within an active learning environment.

    PubMed

    Welch, Susan

    2013-11-01

    In nursing education, the inclusion of pedagogical tools is necessary to transform Millennial classrooms. One such pedagogical tool currently offered is classroom response systems (CRS). The purpose of this study was to evaluate the effectiveness of CRS as a pedagogical tool in improving nursing students' examination performance within an active learning environment. A pretest-posttest design was used to determine whether there was a relationship between the use of CRS (independent variable) and nursing students' examination performance in a first-year Professional Practice course (dependent variable). Paired t tests revealed no greater improvement in posttest scores. Therefore, the use of CRS technology was not effective in increasing nursing students' examination scores in the Professional Practice course. Additional research is needed to provide adequate understanding of the effectiveness of CRS within the nursing education classroom. PMID:24127175

  19. Optical ordance system for use in explosive ordnance disposal activities

    SciTech Connect

    Merson, J.A.; Salas, F.J.; Helsel, F.M.

    1994-01-01

    A portable hand-held solid state rod laser system and an optically-ignited detonator have been developed for use in explosive ordnance disposal (EOD) activities. Laser prototypes from Whittaker Ordnance and Universal Propulsion have been tested and evaluated. The optical detonator contains 2-(5 cyanotetrazolato) pentaamine cobalt III perchlorate (CP) as the DDT column and the explosive Octahydro 1, 3, 5, 7 -- tetranitro -- 1, 3, 5, 7 -- tetrazocine (HMX) as the output charge. The laser is designed to have an output of 150 mJ in a 500 microsecond pulse. This output allows firing through 2000 meters of optical fiber. The detonator can also be ignited with a portable laser diode source through a shorter length of fiber.

  20. Peroxisome proliferator-activated receptors in the cardiovascular system

    PubMed Central

    Bishop-Bailey, David

    2000-01-01

    Peroxisome proliferator-activated receptor (PPAR)s are a family of three nuclear hormone receptors, PPARα, -δ, and -γ, which are members of the steriod receptor superfamily. The first member of the family (PPARα) was originally discovered as the mediator by which a number of xenobiotic drugs cause peroxisome proliferation in the liver. Defined functions for all these receptors, until recently, mainly concerned their ability to regulate energy balance, with PPARα being involved in β-oxidation pathways, and PPARγ in the differentiation of adipocytes. Little is known about the functions of PPARδ, though it is the most ubiquitously expressed. Since their discovery, PPARs have been shown to be expressed in monocytes/macrophages, the heart, vascular smooth muscle cells, endothelial cells, and in atherosclerotic lesions. Furthermore, PPARs can be activated by a vast number of compounds including synthetic drugs, of the clofibrate, and anti-diabetic thiazoldinedione classes, polyunsaturated fatty acids, and a number of eicosanoids, including prostaglandins, lipoxygenase products, and oxidized low density lipoprotein. This review will aim to introduce the field of PPAR nuclear hormone receptors, and discuss the discovery and actions of PPARs in the cardiovascular system, as well as the source of potential ligands. PMID:10696077

  1. Active impedance of respiratory system in anesthetized cats.

    PubMed

    Zin, W A; Pengelly, L D; Milic-Emili, J

    1982-07-01

    We have assessed the validity of the method of Siafakas et al. (J. Appl. Physiol.: Respirat. Environ. Exercise Physiol. 51: 109-121, 1981) for determining active elastance (E'rs) and flow resistance (R'rs) of the respiratory system. In six cats anesthetized with pentobarbital sodium we have measured flow, volume, and tracheal occlusion pressure during spontaneous breathing. This allowed us to compute E'rs and R'rs. From these data and the occlusion pressure wave we predicted the time course of volume during inspirations with added linear flow resistances (delta R). These were compared to the actual loaded inspirograms. The agreement was generally good, except for small predictable discrepancies with the highest delta R values, which could be attributed to decompression of thoracic gas. These results indicate that the approach of Siakafas et al. to determine E'rs and R'rs is valid. In addition, we have quantified the "terminal inhibition" of inspiratory activity, which occurs toward the end of unoccluded breaths (both loaded and unloaded). PMID:7118628

  2. A latchable thermally activated phase change actuator for microfluidic systems

    NASA Astrophysics Data System (ADS)

    Richter, Christiane; Sachsenheimer, Kai; Rapp, Bastian E.

    2016-03-01

    Complex microfluidic systems often require a high number of individually controllable active components like valves and pumps. In this paper we present the development and optimization of a latchable thermally controlled phase change actuator which uses a solid/liquid phase transition of a phase change medium and the displacement of the liquid phase change medium to change and stabilize the two states of the actuator. Because the phase change is triggered by heat produced with ohmic resistors the used control signal is an electrical signal. In contrast to pneumatically activated membrane valves this concept allows the individual control of several dozen actuators with only two external pressure lines. Within this paper we show the general working principle of the actuator and demonstrate its general function and the scalability of the concept at an example of four actuators. Additionally we present the complete results of our studies to optimize the response behavior of the actuator - the influence of the heating power as well as the used phase change medium on melting and solidifying times.

  3. Calibrating a novel multi-sensor physical activity measurement system

    PubMed Central

    John, D; Liu, S; Sasaki, J E; Howe, C A; Staudenmayer, J; Gao, R X; Freedson, P S

    2011-01-01

    Advancing the field of physical activity (PA) monitoring requires the development of innovative multi-sensor measurement systems that are feasible in the free-living environment. The use of novel analytical techniques to combine and process these multiple sensor signals is equally important. This paper, describes a novel multi-sensor ‘Integrated PA Measurement System’ (IMS), the lab-based methodology used to calibrate the IMS, techniques used to predict multiple variables from the sensor signals, and proposes design changes to improve the feasibility of deploying the IMS in the free-living environment. The IMS consists of hip and wrist acceleration sensors, two piezoelectric respiration sensors on the torso, and an ultraviolet radiation sensor to obtain contextual information (indoors vs. outdoors) of PA. During lab-based calibration of the IMS, data were collected on participants performing a PA routine consisting of seven different ambulatory and free-living activities while wearing a portable metabolic unit (criterion measure) and the IMS. Data analyses on the first 50 adult participants are presented. These analyses were used to determine if the IMS can be used to predict the variables of interest. Finally, physical modifications for the IMS that could enhance feasibility of free-living use are proposed and refinement of the prediction techniques is discussed. PMID:21813941

  4. Activation of the Renin-Angiotensin System Promotes Colitis Development

    PubMed Central

    Shi, Yongyan; Liu, Tianjing; He, Lei; Dougherty, Urszula; Chen, Li; Adhikari, Sarbani; Alpert, Lindsay; Zhou, Guolin; Liu, Weicheng; Wang, Jiaolong; Deb, Dilip K.; Hart, John; Liu, Shu Q.; Kwon, John; Pekow, Joel; Rubin, David T.; Zhao, Qun; Bissonnette, Marc; Li, Yan Chun

    2016-01-01

    The renin-angiotensin system (RAS) plays pathogenic roles in renal and cardiovascular disorders, but whether it is involved in colitis is unclear. Here we show that RenTgMK mice that overexpress active renin from the liver developed more severe colitis than wild-type controls. More than 50% RenTgMK mice died whereas all wild-type mice recovered. RenTgMK mice exhibited more robust mucosal TH17 and TH1/TH17 responses and more profound colonic epithelial cell apoptosis compared to wild-type controls. Treatment with aliskiren (a renin inhibitor), but not hydralazine (a smooth muscle relaxant), ameliorated colitis in RenTgMK mice, although both drugs normalized blood pressure. Chronic infusion of angiotensin II into wild-type mice mimicked the severe colitic phenotype of RenTgMK mice, and treatment with losartan [an angiotensin type 1 receptor blocker (ARB)] ameliorated colitis in wild-type mice, confirming a colitogenic role for the endogenous RAS. In human biopsies, pro-inflammatory cytokines were suppressed in patients with inflammatory bowel disease who were on ARB therapy compared to patients not receiving ARB therapy. These observations demonstrate that activation of the RAS promotes colitis in a blood pressure independent manner. Angiotensin II appears to drive colonic mucosal inflammation by promoting intestinal epithelial cell apoptosis and mucosal TH17 responses in colitis development. PMID:27271344

  5. Anxiety, not anger, induces inflammatory activity: An avoidance/approach model of immune system activation.

    PubMed

    Moons, Wesley G; Shields, Grant S

    2015-08-01

    Psychological stressors reliably trigger systemic inflammatory activity as indexed by levels of proinflammatory cytokines. This experiment demonstrates that one's specific emotional reaction to a stressor may be a significant determinant of whether an inflammatory reaction occurs in response to that stressor. Based on extant correlational evidence and theory, a causal approach was used to determine whether an avoidant emotion (anxiety) triggers more inflammatory activity than an approach emotion (anger). In an experimental design (N = 40), a 3-way Emotion Condition × Time × Analyte interaction revealed that a writing-based anxiety induction, but not a writing-based anger induction, increased mean levels of interferon-γ (IFN- γ) and interleukin-1β (IL-1β), but not interleukin-6 (IL-6) in oral mucous, F(2, 54) = 4.64, p = .01, ηp(²) = .15. Further, self-reported state anxiety predicted elevated levels of proinflammatory cytokines, all ΔR(²) >.06, ps <.04, but self-reported state anger did not. These results constitute the first evidence to our knowledge that specific negative emotions can differentially cause inflammatory activity and support a theoretical model explaining these effects based on the avoidance or approach motivations associated with emotions. PMID:26053247

  6. Assessing Children's Physical Activity in Their Homes: The Observational System for Recording Physical Activity in Children-Home

    ERIC Educational Resources Information Center

    McIver, Kerry L.; Brown, William H.; Pfeiffer, Karin A.; Dowda, Marsha; Pate, Russell R.

    2009-01-01

    The present study describes the development and pilot testing of the Observation System for Recording Physical Activity in Children-Home version. This system was developed to document physical activity and related physical and social contexts while children are at home. An analysis of interobserver agreement and a description of children's…

  7. Activities for a long duration flight system in Japan

    NASA Astrophysics Data System (ADS)

    Nishimura, J.

    The balloon group in the Institute of Space and Astronomical Science (ISAS) has been spending many efforts to long duration balloon flights for scientific observations. One of those achievements is the of Boomerang Balloon system. The system has been successfully applied to many scientific observations in Japan during these 20 years. Recent achievements along this line are ``Satellite linked Boomerang Balloons'' This is to recover the payloads after several days of flights over the Pacific Ocean. ISAS and the Communication Research Laboratory have been conducting this program. The Polar Patrol Balloon at Antarctica has been established already to perform the circumpolar flight at level altitude taking almost 3 weeks. The National Institute for Polar Research and ISAS have been conducting this program. Summarizing those activities, in this paper we mainly refer to some recent results of feasibility studies of the Over Pressurized Pumpkin Shaped Balloons and of the balloons with new possible balloon films (EVAL, Ethylene-Vinyl-Alcohol) of specific IR absorptivity for the long duration flights.

  8. Active-solar-energy-system materials research priorities

    SciTech Connect

    Herzenberg, S.A.; Hien, L.K.; Silberglitt, R.

    1983-01-01

    THis report describes and prioritizes materials research alternatives to improve active solar heating and cooling system cost-effectiveness. Materials research areas analyzed are (polymer) glazings, heat mirrors, (selective) absorber surfaces, absorber adhesives, absorber substrates, fluids, thermal storage materials, and desiccants. Three classes of solar collectors are considered in the cost-effectiveness analysis: medium-temperature flat-plate collectors (operating temperature, 70/sup 0/C); high-temperature flat-plate collectors (operating temperature, 70 to 120/sup 0/C); and evacuated tubes (operating temperature 70 to 230/sup 0/C). We found the highest priority for medium-temperature flat-plate collectors to be research on polymeric materials to improve performance and durability characteristics. For the high-temperature, flat-plate collectors and evacuated tubes, heat mirror and selective absorber research is the highest priority. Research on storage materials, fluids, and desiccants is of relatively low priority for improving cost-effectiveness in all cases. The highest priority materials research areas identified include: optical properties and degradation of transparent conducting oxide heat mirrors and thickness insensitive selective paints; uv and thermal stabilization of polymeric glazing materials; and systems analysis of integrated polymeric collectors.

  9. TERATOGENICITY OF CYCLOPHOSPHAMIDE IN A COUPLED MICROSOMAL ACTIVATING/EMBRYO CULTURE SYSTEM

    EPA Science Inventory

    Using the coupled microsomal activating/embryo culture system, in vitro experiments were performed to establish the role of metabolism in the embryo toxicity and teratogenicity of cyclophosphamide. Cyclophosphamide in the coupled microsomal activating/embryo culture system produc...

  10. Xylazine Activates Adenosine Monophosphate-Activated Protein Kinase Pathway in the Central Nervous System of Rats

    PubMed Central

    Shi, Xing-Xing; Yin, Bai-Shuang; Yang, Peng; Chen, Hao; Li, Xin; Su, Li-Xue; Fan, Hong-Gang; Wang, Hong-Bin

    2016-01-01

    Xylazine is a potent analgesic extensively used in veterinary and animal experimentation. Evidence exists that the analgesic effect can be inhibited using adenosine 5’-monophosphate activated protein kinase (AMPK) inhibitors. Considering this idea, the aim of this study was to investigate whether the AMPK signaling pathway is involved in the central analgesic mechanism of xylazine in the rat. Xylazine was administrated via the intraperitoneal route. Sprague-Dawley rats were sacrificed and the cerebral cortex, cerebellum, hippocampus, thalamus and brainstem were collected for determination of liver kinase B1 (LKB1) and AMPKα mRNA expression using quantitative real-time polymerase chain reaction (qPCR), and phosphorylated LKB1 and AMPKα levels using western blot. The results of our study showed that compared with the control group, xylazine induced significant increases in AMPK activity in the cerebral cortex, hippocampus, thalamus and cerebellum after rats received xylazine (P < 0.01). Increased AMPK activities were accompanied with increased phosphorylation levels of LKB1 in corresponding regions of rats. The protein levels of phosphorylated LKB1 and AMPKα in these regions returned or tended to return to control group levels. However, in the brainstem, phosphorylated LKB1 and AMPKα protein levels were decreased by xylazine compared with the control (P < 0.05). In conclusion, our data indicates that xylazine alters the activities of LKB1 and AMPK in the central nervous system of rats, which suggests that xylazine affects the regulatory signaling pathway of the analgesic mechanism in the rat brain. PMID:27049320

  11. Systemic complement activation, lung injury, and products of lipid peroxidation.

    PubMed Central

    Ward, P A; Till, G O; Hatherill, J R; Annesley, T M; Kunkel, R G

    1985-01-01

    Previously we have demonstrated that systemic activation of the complement system after intravenous injection of cobra venom factor (CVF) results in acute lung injury as reflected by increases in the vascular permeability of the lung as well as by morphologic evidence of damage to lung vascular endothelial cells. In using the vascular permeability of the lung as the reference, the current studies show a quantitative correlation between lung injury and the appearance in plasma of lipid peroxidation products (conjugated dienes) as well as increased concentrations of lactic dehydrogenase (LDH) and one of its isoenzymes (LDH-4). After injection of CVF, extracts of lungs also showed elevated levels of conjugated dienes, whereas no elevations were found in extracts of liver, kidney, and spleen. There was no evidence in CVF-injected rats of renal or hepatic injury as reflected by the lack of development of proteinuria and the failure to detect increased serum levels of liver-related enzymes. Other peroxidation products identified in plasma of CVF-injected rats involved hydroperoxides and fluorescent compounds with features of Schiff bases. Not surprisingly, malondialdehyde was not found to be a reliable plasma indicator of lipid peroxidation associated with oxygen radical-mediated lung vascular injury. In using a model of oxygen radical-independent lung injury induced by oleic acid, although large amounts of LDH and LDH-4 were found in the plasma, no increases in plasma levels of conjugated dienes were detected. In CVF-injected animals treated with interventions protective against lung injury (neutrophil depletion, catalase, hydroxyl radical scavengers, or iron chelators), there were striking reductions in the plasma levels of conjugated dienes, hydroperoxides, and fluorochromic products. Morphometric analysis of lung sections revealed that the protective interventions did not interfere with the accumulation of neutrophils in lung interstitial capillaries after systemic

  12. Active fault database of Japan: Its construction and search system

    NASA Astrophysics Data System (ADS)

    Yoshioka, T.; Miyamoto, F.

    2011-12-01

    The Active fault database of Japan was constructed by the Active Fault and Earthquake Research Center, GSJ/AIST and opened to the public on the Internet from 2005 to make a probabilistic evaluation of the future faulting event and earthquake occurrence on major active faults in Japan. The database consists of three sub-database, 1) sub-database on individual site, which includes long-term slip data and paleoseismicity data with error range and reliability, 2) sub-database on details of paleoseismicity, which includes the excavated geological units and faulting event horizons with age-control, 3) sub-database on characteristics of behavioral segments, which includes the fault-length, long-term slip-rate, recurrence intervals, most-recent-event, slip per event and best-estimate of cascade earthquake. Major seismogenic faults, those are approximately the best-estimate segments of cascade earthquake, each has a length of 20 km or longer and slip-rate of 0.1m/ky or larger and is composed from about two behavioral segments in average, are included in the database. This database contains information of active faults in Japan, sorted by the concept of "behavioral segments" (McCalpin, 1996). Each fault is subdivided into 550 behavioral segments based on surface trace geometry and rupture history revealed by paleoseismic studies. Behavioral segments can be searched on the Google Maps. You can select one behavioral segment directly or search segments in a rectangle area on the map. The result of search is shown on a fixed map or the Google Maps with information of geologic and paleoseismic parameters including slip rate, slip per event, recurrence interval, and calculated rupture probability in the future. Behavioral segments can be searched also by name or combination of fault parameters. All those data are compiled from journal articles, theses, and other documents. We are currently developing a revised edition, which is based on an improved database system. More than ten

  13. A simple wavelength division multiplexing system for active learning teaching

    NASA Astrophysics Data System (ADS)

    Zghal, Mourad; Ghalila, Hassen; Ben Lakhdar, Zohra

    2009-06-01

    The active learning project consists in a series of workshops for educators, researchers and students and promotes an innovative method of teaching physics using simple, inexpensive materials that can be fabricated locally. The objective of the project is to train trainers and inspire students to learn physics. The workshops are based on the use of laboratory work and hands-on activities in the classroom. The interpretation of these experiments is challenging for some students, and the experiments can lead to a significant amount of discussion. The workshops are organized within the framework of the project ``Active Learning in Optics and Photonics" (ALOP) mainly funded by UNESCO, with the support of ICTP (Abdus Salam International Centre for Theoretical Physics) and SPIE. ALOP workshops offer high school, college or university physics teachers the opportunity to improve their conceptual understanding of optics. These workshops usually run for five days and cover several of the topics usually found in any introductory university physics program. Optics and photonics are used as subject matter because it is relevant as well as adaptable to research and educational conditions in many developing countries [1]. In this paper, we will mainly focus on a specific topic of the ALOP workshops, namely optical communications and Wavelength Division Multiplexing technology (WDM). This activity was originally developed by Mazzolini et al [2]. WDM is a technology used in fibre-optic communications for transmitting two or more separate signals over a single fibre optic cable by using a separate wavelength for each signal. Multiple signals are carried together as separate wavelengths of light in a multiplexed signal. Simple and inexpensive WDM system was implemented in our laboratory using light emitting diodes or diode lasers, plastic optical fibres, a set of optical filters and lenses, prism or grating, and photodiodes. Transmission of audio signals using home-made, simple

  14. Active alignment and vibration control system for a large airborne optical system

    NASA Astrophysics Data System (ADS)

    Kienholz, David A.

    2000-04-01

    Airborne optical or electro-optical systems may be too large for all elements to be mounted on a single integrating structure, other than the aircraft fuselage itself. An active system must then be used to maintain the required alignment between elements. However the various smaller integrating structures (benches) must still be isolated from high- frequency airframe disturbances that could excite resonances outside the bandwidth of the alignment control system. The combined active alignment and vibration isolation functions must be performed by flight-weight components, which may have to operate in vacuum. A testbed system developed for the Air Force Airborne Laser program is described. The payload, a full-scale 1650-lb simulated bench, is mounted in six degrees- of-freedom to a vibrating platform by a set of isolator- actuators. The mounts utilize a combination of pneumatics and magnetics to perform the dual functions of low-frequency alignment and high-frequency isolation. Test results are given and future directions for development are described.

  15. Assessing preschool children's physical activity: the Observational System for Recording Physical Activity in children-preschool version.

    PubMed

    Brown, William H; Pfeiffer, Karin A; Mclver, Kerry L; Dowda, Marsha; Almeida, M Joao C A; Pate, Russell R

    2006-06-01

    In this paper we present initial information concerning a new direct observation system-the Observational System for Recording Physical Activity in Children-Preschool Version. The system will allow researchers to record young children's physical activity levels while also coding the topography of their physical activity, as well as detailed indoor and outdoor social and nonsocial contextual information. With respect to interobserver agreement (IOA), the kappa and category-by-category agreement mean of those obtained for the three illustrative preschools were generally above .80. Hence, our IOA data indicated that trained observers in the three preschools frequently agreed on the eight observational categories and accompanying codes. The results for preschoolers' level of physical activity indicated they spent the majority of observational intervals in sedentary activity (i.e., more than 80% intervals) and were observed in moderate to vigorous physical activity much less frequently (i.e., 5% or fewer intervals). For the 15 indoor and 12 outdoor activity contexts, variability across both the activity contexts and the three preschools were evident. Nevertheless, three classroom contexts-transition, snacks, and naptime--accounted for the greatest porportion of coded activity contexts for the children. In the three preschools, 4 of 17 physical activity types--sit and squat, lie down, stand, and walk--accounted for the topography of much of children's physical activity behavior Systematic observation of more representative preschool samples might better inform our present understanding of young children's physical activity in community preschool programs. PMID:16898273

  16. Acoustic challenges of the A400M for active systems

    NASA Astrophysics Data System (ADS)

    Breitbach, Harald; Sachau, Delf; Böhme, Sten

    2006-03-01

    In some types of aircraft tonal interior noise with high sound pressure level (up to 110 dB(A)) occurs at low frequencies (f < 500 Hz). Typical examples are propeller driven aircraft, for which the excitation frequencies are given by the blade passage frequency (BPF) and its higher harmonics. The high tonal noise levels at these frequencies can occur due to the fact that the blades' profiles are only optimized in terms of aerodynamics. The acoustic properties are usually not taken into account. In order to obtain an acceptable interior noise level, and to guarantee both work-safety and comfort in the aircraft interiors, passive methods are commonly used - e.g. adding material with high damping or vibration absorbing qualities. Especially when low frequency noise has to be reduced, adding material results in a lot of unwanted additional weight. In order to avoid this extra weight, the concept of active noise reduction (ANR) and tunable vibration absorber systems (TVA), which focus on the unwanted tonal noise, are a good compromise of treating noise and the amount of additional weight in aircraft design. This paper briefly discusses two different possible methods to reduce the low frequency noise. The noise reduction of tuned vibration absorbers (TVA) mounted on the airframe are nowadays commonly used in propeller driven aircraft and can be predicted by vibroacoustic finite element calculations, which is described in this paper. In order to abide to industrial safety regulations, the noise level inside the semi closed loadmaster area (LMA) must be reduced down to a noise level, which is even 8 dB(A) below the specified cargo hold noise level. The paper describes also the phases of development of an ANR system that could be used to control the sound pressure level inside the LMA. The concept is verified by experimental investigations within a mock up of the LMA.

  17. Changing remuneration systems: effects on activity in general practice.

    PubMed Central

    Krasnik, A; Groenewegen, P P; Pedersen, P A; von Scholten, P; Mooney, G; Gottschau, A; Flierman, H A; Damsgaard, M T

    1990-01-01

    OBJECTIVE--To investigate the effects on general practitioners' activities of a change in their remuneration from a capitation based system to a mixed fee per item and capitation based system. DESIGN--Follow up study with data collected from contact sheets completed by general practitioners in one period before (March 1987) a change in their remuneration system and two periods after (March 1988, November 1988), with a control group of general practitioners with a mixed fee per item and capitation based system throughout. SETTING--General practices in Copenhagen city (index group) and Copenhagen county (control group). SUBJECTS--265 General practitioners in Copenhagen city, of whom 100 were selected randomly from the 130 who agreed to participate (10 exclusions) and 326 general practitioners in Copenhagen county. MAIN OUTCOME MEASURES--Number of consultations (face to face and by telephone) and renewals of prescriptions, diagnostic and curative services, and specialist and hospital referrals per 1000 enlisted patients in one week. RESULTS--Of the 75 general practitioners who completed all three sheets, four were excluded for incomplete data. Total contact rates per 1000 patients listed rose significantly compared with the rates before the change index in the city (100.0 before the change v 111.7 (95% confidence interval 106.4 to 117.4 after the change) and over the same time in the control group (100.0 v 106.0), but within a year these rates fell (to 104.2(99.1 to 109.6) and 104.0 respectively). There was an increase in consultations by telephone initially but not thereafter. Rates of examinations and treatments that attracted specific additional remuneration after the change rose significantly compared with those before (diagnostic services, 138.1 (118.7 to 160.5) and 159.5 (137.8 to 184.7) and curative services 194.6 (152.2 to 248.9) and 194.8(152.3 to 249.2) for second and third data collections respectively) and with the control group (diagnostic services 105

  18. Peripheral Endocannabinoid System Activity in Patients Treated With Sibutramine

    PubMed Central

    Engeli, Stefan; Heusser, Karsten; Janke, Jürgen; Gorzelniak, Kerstin; Bátkai, Sándor; Pacher, Pál; Harvey-White, Judith; Luft, Friedrich C.; Jordan, Jens

    2008-01-01

    Objective The endocannabinoid system (ECS) promotes weight gain and obesity-associated metabolic changes. Weight loss interventions may influence obesity-associated risk indirectly through modulation of the peripheral ECS. We investigated the effect of acute and chronic treatment with sibutramine on components of the peripheral ECS. Methods and Procedures Twenty obese otherwise healthy patients received randomized, double-blind, crossover treatment with placebo and 15 mg/day sibutramine for 5 days each, followed by 12 weeks open-label sibutramine treatment. We determined circulating anandamide and 2-arachidonoylglycerol and expression levels of endocannabinoid genes in subcutaneous abdominal adipose tissue biopsies. Results Body weight was stable during the acute treatment period and decreased by 6.0 ± 0.8 kg in those patients completing 3 months of sibutramine treatment (P < 0.05). Circulating endocannabinoids and the expression of ECS genes did not change with acute or chronic sibutramine treatment. Discussion The ECS is activated in obesity. We did not find any influence of 5% body weight loss induced by sibutramine on circulating levels of endocannabinoids and adipose-tissue expression of endocannabinoid genes in obese subjects. These data confirm our previous findings on dietary weight loss and suggest that the dysregulation of the ECS may be a cause rather than a consequence of obesity. PMID:18356837

  19. Evaluation of an Active Humidification System for Inspired Gas

    PubMed Central

    Roux, Nicolás G.; Villalba, Darío S.; Gogniat, Emiliano; Feld, Vivivana; Ribero Vairo, Noelia; Sartore, Marisa; Bosso, Mauro; Scapellato, José L.; Intile, Dante; Planells, Fernando; Noval, Diego; Buñirigo, Pablo; Jofré, Ricardo; Díaz Nielsen, Ernesto

    2015-01-01

    Objectives The effectiveness of the active humidification systems (AHS) in patients already weaned from mechanical ventilation and with an artificial airway has not been very well described. The objective of this study was to evaluate the performance of an AHS in chronically tracheostomized and spontaneously breathing patients. Methods Measurements were quantified at three levels of temperature (T°) of the AHS: level I, low; level II, middle; and level III, high and at different flow levels (20 to 60 L/minute). Statistical analysis of repeated measurements was performed using analysis of variance and significance was set at a P<0.05. Results While the lowest temperature setting (level I) did not condition gas to the minimum recommended values for any of the flows that were used, the medium temperature setting (level II) only conditioned gas with flows of 20 and 30 L/minute. Finally, at the highest temperature setting (level III), every flow reached the minimum absolute humidity (AH) recommended of 30 mg/L. Conclusion According to our results, to obtain appropiate relative humidity, AH and T° of gas one should have a device that maintains water T° at least at 53℃ for flows between 20 and 30 L/m, or at T° of 61℃ at any flow rate. PMID:25729499

  20. Radiochemical microassay for aspartate aminotransferase activity in the nervous system

    SciTech Connect

    Garrison, D.; Beattie, J.; Namboodiri, M.A.

    1988-07-01

    A radiochemical procedure for measuring aspartate aminotransferase activity in the nervous system is described. The method is based on the exchange of tritium atoms at positions 2 and 3 of L-2,3-(/sup 3/H)aspartate with water when this amino acid is transaminated in the presence of alpha-ketoglutarate to form oxaloacetate. The tritiated water is separated from the radiolabeled aspartate by passing the reaction mixture over a cation exchange column. Confirmation that the radioactivity in the product is associated with water was obtained by separating it by anion exchange HPLC and by evaporation. The product formation is linear with time up to 120 min and with tissue in the 0.05- to 10-micrograms range. The apparent Km for aspartate in the rat brain homogenate is found to be 0.83 mM and that for alpha-ketoglutarate to be 0.12 mM. Methods that further improve the sensitivity of the assay are also discussed.

  1. The virtual microphone technique in active sound field control systems

    NASA Astrophysics Data System (ADS)

    Lampropoulos, Iraklis E.; Shimizu, Yasushi

    2003-04-01

    Active Sound Field Control (AFC) has been proven very useful in reverberation enhancement applications in large rooms. However, feedback control is required in order to eliminate peaks in the frequency response of the system. The present research closely follows the studies of Shimizu in AFC, in which smoothing of the rooms transfer function is achieved by averaging the impulse responses of multiple microphones. ``The virtual or rotating microphone technique'' reduces the number of microphones in the aforementioned AFC technology, while still achieving the same acoustical effects in the room. After the impulse responses at previously specified pairs of microphone positions are measured, the ratio of transfer functions for every pair is calculated, thus yielding a constant K. Next, microphones are removed and their impulse responses are reproduced by processing the incoming signal of each pair through a convolver, where the computed K constants have been previously stored. Band limiting, windowing and time variance effects are critical factors, in order to reduce incoherence effects and yield reliable approximations of inverse filters and consequently calculations of K. The project is implemented in a church lacking low frequency reverberation for music and makes use of 2 physical and 2 virtual microphones.

  2. Active Vision in Marmosets: A Model System for Visual Neuroscience

    PubMed Central

    Reynolds, John H.; Miller, Cory T.

    2014-01-01

    The common marmoset (Callithrix jacchus), a small-bodied New World primate, offers several advantages to complement vision research in larger primates. Studies in the anesthetized marmoset have detailed the anatomy and physiology of their visual system (Rosa et al., 2009) while studies of auditory and vocal processing have established their utility for awake and behaving neurophysiological investigations (Lu et al., 2001a,b; Eliades and Wang, 2008a,b; Osmanski and Wang, 2011; Remington et al., 2012). However, a critical unknown is whether marmosets can perform visual tasks under head restraint. This has been essential for studies in macaques, enabling both accurate eye tracking and head stabilization for neurophysiology. In one set of experiments we compared the free viewing behavior of head-fixed marmosets to that of macaques, and found that their saccadic behavior is comparable across a number of saccade metrics and that saccades target similar regions of interest including faces. In a second set of experiments we applied behavioral conditioning techniques to determine whether the marmoset could control fixation for liquid reward. Two marmosets could fixate a central point and ignore peripheral flashing stimuli, as needed for receptive field mapping. Both marmosets also performed an orientation discrimination task, exhibiting a saturating psychometric function with reliable performance and shorter reaction times for easier discriminations. These data suggest that the marmoset is a viable model for studies of active vision and its underlying neural mechanisms. PMID:24453311

  3. Toward high-dynamic active mirrors for LGS refocusing systems

    NASA Astrophysics Data System (ADS)

    Hugot, Emmanuel; Madec, Fabrice; Vives, Sébastien; Ferrari, Marc; Le Mignant, David; Cuby, Jean Gabriel

    2010-07-01

    In the frame of the E-ELT-EAGLE instrument phase A studies, we designed a convex VCM able to compensate for the focus variation on the Laser Guide Star (LGS) wavefront sensor, due to the elevation of the telescope and the fixed sodium layer altitude. We present an original optical design including this active convex mirror, providing a large sag variation on a spherical surface with a 120mm clear aperture, with an optical quality better than lambda/5 RMS up to 820μm of sag and better than lambda/4 RMS up to 1000μm of sag. Finite element analysis (FEA) allowed an optimisation of the mirror's variable thickness distribution to compensate for geometrical and material non linearity. Preliminary study of the pre-stressing has also been performed by FEA, showing that a permanent deformation remains after removal of the loads. Results and comparison with the FEA are presented in the article of F.Madec et al (AS10-7736-119, this conference), with an emphasis on the system approach.

  4. Development of a Practical Broadband Active Vibration Control System

    NASA Technical Reports Server (NTRS)

    Schiller, Noah H.; Perey, Daniel F.; Cabell, Randolph H.

    2011-01-01

    The goal of this work is to develop robust, lightweight, and low-power control units that can be used to suppress structural vibration in flexible aerospace structures. In particular, this paper focuses on active damping, which is implemented using compact decentralized control units distributed over the structure. Each control unit consists of a diamond-shaped piezoelectric patch actuator, three miniature accelerometers, and analog electronics. The responses from the accelerometers are added together and then integrated to give a signal proportional to velocity. The signal is then inverted, amplified, and applied to the actuator, which generates a control force that is out of phase with the measured velocity. This paper describes the development of the control system, including a detailed description of the control and power electronics. The paper also presents experimental results acquired on a Plexiglas window blank. Five identical control units installed around the perimeter of the window achieved 10 dB peak reductions and a 2.4 dB integrated reduction of the spatially averaged velocity of the window between 500 and 3000 Hz.

  5. Cooperative wireless network control based health and activity monitoring system.

    PubMed

    Prakash, R; Ganesh, A Balaji; Girish, Siva V

    2016-10-01

    A real-time cooperative communication based wireless network is presented for monitoring health and activity of an end-user in their environment. The cooperative communication offers better energy consumption and also an opportunity to aware the current location of a user non-intrusively. The link between mobile sensor node and relay node is dynamically established by using Received Signal Strength Indicator (RSSI) and Link Quality Indicator (LQI) based on adaptive relay selection scheme. The study proposes a Linear Acceleration based Transmission Power Decision Control (LA-TPDC) algorithm to further enhance the energy efficiency of cooperative communication. Further, the occurrences of false alarms are carefully prevented by introducing three stages of sequential warning system. The real-time experiments are carried-out by using the nodes, namely mobile sensor node, relay nodes and a destination node which are indigenously developed by using a CC430 microcontroller integrated with an in-built transceiver at 868 MHz. The wireless node performance characteristics, such as energy consumption, Signal-Noise ratio (SNR), Bit Error Rate (BER), Packet Delivery Ratio (PDR) and transmission offset are evaluated for all the participated nodes. The experimental results observed that the proposed linear acceleration based transmission power decision control algorithm almost doubles the battery life time than energy efficient conventional cooperative communication. PMID:27562484

  6. Neutron Activation Analysis PRognosis and Optimization Code System.

    2004-08-20

    Version 00 NAAPRO predicts the results and main characteristics (detection limits, determination limits, measurement limits and relative precision of the analysis) of neutron activation analysis (instrumental and radiochemical). Gamma-ray dose rates for different points of time after sample irradiation and input count rate of the spectrometry system are also predicted. The code uses standard Windows user interface and extensive graphical tools for the visualization of the spectrometer characteristics (efficiency, response and background) and simulated spectrum.more » Optimization part is not included in the current version of the code. This release is designated NAAPRO, Version 01.beta. The MCNP code was used for generating detector responses. PREPRO-2000 and FCONV programs were used at the preparation of the program nuclear databases. A special program was developed for viewing, editing and updating of the program databases (not included into the present program package). The MCNP, PREPRO-2000 and FCONV software packages are not included in the NAAPRO package.« less

  7. Non-linear dynamics of the complement system activation.

    PubMed

    Korotaevskiy, Andrey A; Hanin, Leonid G; Khanin, Mikhail A

    2009-12-01

    The complement system (CS) plays a prominent role in the immune defense. The goal of this work is to study the dynamics of activation of the classic and alternative CS pathways based on the method of mathematical modeling. The principal difficulty that hinders modeling effort is the absence of the measured values of kinetic constants of many biochemical reactions forming the CS. To surmount this difficulty, an optimization procedure consisting of constrained minimization of the total protein consumption by the CS was designed. The constraints made use of published data on the in vitro kinetics of elimination of the Borrelia burgdorferi bacteria by the CS. Special features of the problem at hand called for a significant modification of the general constrained optimization procedure to include a mathematical model of the bactericidal effect of the CS in the iterative setting. Determination of the unknown kinetic constants of biochemical reactions forming the CS led to a fully specified mathematical model of the dynamics of cell killing induced by the CS. On the basis of the model, effects of the initial concentrations of complements and their inhibitors on the bactericidal action of the CS were studied. Proteins playing a critical role in the regulation of the bactericidal action of the CS were identified. Results obtained in this work serve as an important stepping stone for the study of functioning of the CS as a whole as well as for developing methods for control of pathogenic processes. PMID:19854207

  8. 47 CFR 76.1711 - Emergency alert system (EAS) tests and activation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Emergency alert system (EAS) tests and... § 76.1711 Emergency alert system (EAS) tests and activation. Every cable system of 1,000 or more subscribers shall keep a record of each test and activation of the Emergency Alert System (EAS)...

  9. 47 CFR 76.1711 - Emergency alert system (EAS) tests and activation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 4 2011-10-01 2011-10-01 false Emergency alert system (EAS) tests and... § 76.1711 Emergency alert system (EAS) tests and activation. Every cable system of 1,000 or more subscribers shall keep a record of each test and activation of the Emergency Alert System (EAS)...

  10. 47 CFR 76.1711 - Emergency alert system (EAS) tests and activation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 4 2012-10-01 2012-10-01 false Emergency alert system (EAS) tests and... § 76.1711 Emergency alert system (EAS) tests and activation. Every cable system of 1,000 or more subscribers shall keep a record of each test and activation of the Emergency Alert System (EAS)...

  11. 47 CFR 76.1711 - Emergency alert system (EAS) tests and activation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 4 2014-10-01 2014-10-01 false Emergency alert system (EAS) tests and... § 76.1711 Emergency alert system (EAS) tests and activation. Every cable system of 1,000 or more subscribers shall keep a record of each test and activation of the Emergency Alert System (EAS)...

  12. 47 CFR 76.1711 - Emergency alert system (EAS) tests and activation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 4 2013-10-01 2013-10-01 false Emergency alert system (EAS) tests and... § 76.1711 Emergency alert system (EAS) tests and activation. Every cable system of 1,000 or more subscribers shall keep a record of each test and activation of the Emergency Alert System (EAS)...

  13. The Influence of Climate Change in Active Convergent Systems

    NASA Astrophysics Data System (ADS)

    Scarselli, S.; Simpson, G. H.; Allen, P. A.; Minelli, G.

    2006-12-01

    The link between tectonics, surface erosion, and climate in the evolution of mountain belts has been observed in several natural systems (Sinclair & Allen, 1992; Norris & Cooper, 1997; Pavlis et al., 1997; Willett et al., 2006) and numerous theoretical and applied studies have been carried out in the last several years ( Willett et al., 2002; Simpson, 2004 a, c). This relation is particularly sensitive in active convergent orogenic wedges where the efficiency of surface mass transport and climatic change controls the spatial distribution of deformation and sedimentation and degree of crustal thickening (Beaumont et al., 1992; Willett, 1999; Simpson, 2006). This study focus on the effect of climatic changes, leading to palaeogeographic changes, in an active convergent system. In particular, the effects produced by relative sea-level changes and efficiency of the erosional processes have been tested using a two dimensional mechanical model (Simpson, 2006). The model is suited to study deformation, erosion and sedimentation in fold-thrust belts and foreland basins. Two effects of the relative sea-level changes, and in particular in the case of the relative sea-level drop occurring during deformation, can be potentially important for the mechanical behavior of the surrounding crust. Firstly, gravitational water loads above the deforming rocks could be decreased. Secondly, the replacement of submarine with subaerial conditions could probably increase erosion rates, especially within the river system. Both effects would tend to amplify local deformation rates leading to a major pulse of deformation (Simpson, 2006) and to the formation of complex three dimensional deformation patterns (Simpson, 2004). Finally, this model has been used to evaluate the effect of the Messinian salinity crisis in the Mediterranean basin and in particular in the Northern Apennines evolution (Italy). References: Beaumont, C.; Fullsack, P. & Hamilton J., (1992). In: Thrust Tectonics (Ed by K

  14. Source characterization of nervous system active pharmaceutical ingredients in healthcare wastewaters

    EPA Science Inventory

    Nervous system active pharmaceutical ingredients (APIs), including anti-depressants and opioids, are important clinically administered pharmaceuticals within healthcare facilities. Concentrations and mass loadings of ten nervous system APIs and three nervous system API metaboli...

  15. In vitro evaluation of atmospheric particulate matter and sedimentation particles using yeast bioassay system.

    PubMed

    Mori, Taiki; Inudo, Makiko; Takao, Yuji; Koga, Minoru; Takemasa, Takehiro; Shinohara, Ryota; Arizono, Koji

    2007-01-01

    Little information on the evaluation of airborne particulate matter (APM) and sedimentation particles from subway stations is available. The thermal metamorphism of train wheels generating toxic particles in subway stations is a possibility. In this study, the toxicity and physiological effects of particles from subway stations were evaluated using a yeast bioassay system. Estrogenic and antiestrogenic activities of APM in APM extracts from subway stations were determined. No estrogenic activity was found in the APM fractions and their S9-activated APM samples. Sedimentation dust samples also showed no estrogen activity. In contrast, extracts from sedimentation dust samples showed antiestrogen activity. Marked yeast toxicity was observed in the samples extracted from sedimentation dust. Potent yeast toxicity was also found in the S9-activated extracts from sedimentation dust. The results suggest that sedimentation dust from a semiclosed area of a subway system has antiestrogen activity, although both the origin and generation system of this activity are uncertain. These pollutants in sedimentation dust may change to a more toxic form in vivo by S9 activation. PMID:17762843

  16. HIPPARCOS satellite: Aeritalia involvement and system test activities and results

    NASA Astrophysics Data System (ADS)

    Strim, B.; Cugno, W.; Morsillo, G.

    In 1989 the European Space Agency is scheduled to launch HIPPARCOS on a 2.5-year mission that will revolutionize the state of astronomy. This is the first satellite to be dedicated to astrometry, a branch of astronomy that deals with the position of celestial objects and their motion in space. With an accuracy impossible to achieve from Earth, HIPPARCOS will make position, trigonometric parallax and proper motion measurements of some 100.000 pre-selected stars. The data will be used to calculate each star's distance and motion, providing astronomers with an unprecedented map of the heavens. In the end, the HIPPARCOS mission is expected to reveal surprisingly new insight into theories of stellar evolution, as well as into the nature of our galaxy and the universe. The program has been awarded to the MESH industrial consortium for definition, development and production. The French firm MATRA (prime contractor) and the AERITALIA SPACE SYSTEMS GROUP (major co-contractor) share program responsibility. AERITALIA is in charge of the spacecraft or "service module". This is the structural platform for the telescope payload and provides all subsystem services including thermal control, data handling, telecommunications, electrical power distribution, power generation, attitude and orbit control, and apogee kick motor. AERITALIA is responsible for the procurement of all spacecraft subsystems for which it directs the activities of a multinational team of subcontractors. In addition, it is in charge of the satellite's final assembly, integration and testing, as well as for the procurement of all ground support equipment for satellite testing. HIPPARCOS stands for HIgh Precision PARallax COllecting Satellite. Its name is also intended to honor the Greek astronomer Hipparchus (190-120 BC) who compiled the first star catalog and who first used trigonometric parallax to calculate the distance to the moon. (Parallax is the apparent shift in a celestial body's position in the sky

  17. Active noise canceling system for mechanically cooled germanium radiation detectors

    SciTech Connect

    Nelson, Karl Einar; Burks, Morgan T

    2014-04-22

    A microphonics noise cancellation system and method for improving the energy resolution for mechanically cooled high-purity Germanium (HPGe) detector systems. A classical adaptive noise canceling digital processing system using an adaptive predictor is used in an MCA to attenuate the microphonics noise source making the system more deployable.

  18. Mobility systems activity for lunar rovers at MSFC

    NASA Technical Reports Server (NTRS)

    Jones, C. S., Jr.; Nola, F. J.

    1971-01-01

    The Apollo Lunar Roving Vehicle (LRV) mobility system is described. Special emphasis is given to the redundancy aspects and to the selection of the drive motors. A summary chart of the performance on the lunar surface during the Apollo 15 flight is included. An appendix gives details on some development work on high efficiency drive systems and compares these systems to the selected system.

  19. Tsunamigenic potential of Mediterranean fault systems and active subduction zones

    NASA Astrophysics Data System (ADS)

    Petricca, Patrizio; Babeyko, Andrey

    2016-04-01

    Since the North East Atlantic and Mediterranean Tsunami Warning System (NEAMTWS) is under development by the European scientific community, it becomes necessary to define guidelines for the characterization of the numerous parameters must be taken into account in a fair assessment of the risk. Definition of possible tectonic sources and evaluation of their potential is one of the principal issues. In this study we systematically evaluate tsunamigenic potential of up-to-now known real fault systems and active subduction interfaces in the NEAMTWS region. The task is accomplished by means of numerical modeling of tsunami generation and propagation. We have simulated all possible uniform-slip ruptures populating fault and subduction interfaces with magnitudes ranging from 6.5 up to expected Mmax. A total of 15810 individual ruptures were processed. For each rupture, a tsunami propagation scenario was computed in linear shallow-water approximation on 1-arc minute bathymetric grid (Gebco_08) implying normal reflection boundary conditions. Maximum wave heights at coastal positions (totally - 23236 points of interest) were recorded for four hours of simulation and then classified according to currently adopted warning level thresholds. The resulting dataset allowed us to classify the sources in terms of their tsunamigenic potential as well as to estimate their minimum tsunamigenic magnitude. Our analysis shows that almost every source in the Mediterranean Sea is capable to produce local tsunami at the advisory level (i.e., wave height > 20 cm) starting from magnitude values of Mw=6.6. In respect to the watch level (wave height > 50 cm), the picture is less homogeneous: crustal sources in south-west Mediterranean as well as East-Hellenic arc need larger magnitudes (around Mw=7.0) to trigger watch levels even at the nearby coasts. In the context of the regional warning (i.e., source-to-coast distance > 100 km) faults also behave more heterogeneously in respect to the minimum

  20. Effect of the active damper coil system on the lateral displacement of the magnetically levitated bogie

    SciTech Connect

    Ohashi, S.; Ohsaki, H.; Masada, E.

    1999-09-01

    Numerical simulation of the superconducting magnetically levitated bogie (JR Maglev) has been studied. The active damper coil system is introduced. In this levitation system, the interaction between levitation and guidance is strong. This active damper coil system is designed for reducing the vertical vibration of the bogie. Using the numerical simulation, its effect on the lateral displacement of the bogie is assessed. The active damper coil system for the vertical vibration is shown to works as a passive damper for the lateral vibration.

  1. Microgravity Active Vibration Isolation System on Parabolic Flights

    NASA Astrophysics Data System (ADS)

    Dong, Wenbo; Pletser, Vladimir; Yang, Yang

    2016-07-01

    The Microgravity Active Vibration Isolation System (MAIS) aims at reducing on-orbit vibrations, providing a better controlled lower gravity environment for microgravity physical science experiments. The MAIS will be launched on Tianzhou-1, the first cargo ship of the China Manned Space Program. The principle of the MAIS is to suspend with electro-magnetic actuators a scientific payload, isolating it from the vibrating stator. The MAIS's vibration isolation capability is frequency-dependent and a decrease of vibration of about 40dB can be attained. The MAIS can accommodate 20kg of scientific payload or sample unit, and provide 30W of power and 1Mbps of data transmission. The MAIS is developed to support microgravity scientific experiments on manned platforms in low earth orbit, in order to meet the scientific requirements for fluid physics, materials science, and fundamental physics investigations, which usually need a very quiet environment, increasing their chances of success and their scientific outcomes. The results of scientific experiments and technology tests obtained with the MAIS will be used to improve future space based research. As the suspension force acting on the payload is very small, the MAIS can only be operative and tested in a weightless environment. The 'Deutsches Zentrum für Luft- und Raumfahrt e.V.' (DLR, German Aerospace Centre) granted a flight opportunity to the MAIS experiment to be tested during its 27th parabolic flight campaign of September 2015 performed on the A310 ZERO-G aircraft managed by the French company Novespace, a subsidiary of the 'Centre National d'Etudes Spatiales' (CNES, French Space Agency). The experiment results confirmed that the 6 degrees of freedom motion control technique was effective, and that the vibration isolation performance fulfilled perfectly the expectations based on theoretical analyses and simulations. This paper will present the design of the MAIS and the experiment results obtained during the

  2. Microbial Community Dynamics and Activity Link to Indigo Production from Indole in Bioaugmented Activated Sludge Systems

    PubMed Central

    Deng, Jie; Deng, Ye; Van Nostrand, Joy D.; Wu, Liyou; He, Zhili; Qin, Yujia; Zhou, Jiti; Zhou, Jizhong

    2015-01-01

    Biosynthesis of the popular dyestuff indigo from indole has been comprehensively studied using pure cultures, but less has been done to characterize the indigo production by microbial communities. In our previous studies, a wild strain Comamonas sp. MQ was isolated from activated sludge and the recombinant Escherichia coli nagAc carrying the naphthalene dioxygenase gene (nag) from strain MQ was constructed, both of which were capable of producing indigo from indole. Herein, three activated sludge systems, G1 (non-augmented control), G2 (augmented with Comamonas sp. MQ), and G3 (augmented with recombinant E. coli nagAc), were constructed to investigate indigo production. After 132-day operation, G3 produced the highest yields of indigo (99.5 ± 3.0 mg/l), followed by G2 (27.3 ± 1.3 mg/l) and G1 (19.2 ± 1.2 mg/l). The microbial community dynamics and activities associated with indigo production were analyzed by Illumina Miseq sequencing of 16S rRNA gene amplicons. The inoculated strain MQ survived for at least 30 days, whereas E. coli nagAc was undetectable shortly after inoculation. Quantitative real-time PCR analysis suggested the abundance of naphthalene dioxygenase gene (nagAc) from both inoculated strains was strongly correlated with indigo yields in early stages (0–30 days) (P < 0.001) but not in later stages (30–132 days) (P > 0.10) of operation. Based on detrended correspondence analysis (DCA) and dissimilarity test results, the communities underwent a noticeable shift during the operation. Among the four major genera (> 1% on average), the commonly reported indigo-producing populations Comamonas and Pseudomonas showed no positive relationship with indigo yields (P > 0.05) based on Pearson correlation test, while Alcaligenes and Aquamicrobium, rarely reported for indigo production, were positively correlated with indigo yields (P < 0.05). This study should provide new insights into our understanding of indigo bio-production by microbial communities

  3. Development and Testing of the Observational System for Recording Physical Activity in Children: Elementary School

    ERIC Educational Resources Information Center

    McIver, Kerry L.; Brown, William H.; Pfeiffer, Karin A.; Dowda, Marsha; Pate, Russell R.

    2016-01-01

    Purpose: This study describes the development and pilot testing of the Observational System for Recording Physical Activity-Elementary School (OSRAC-E) Version. Method: This system was developed to observe and document the levels and types of physical activity and physical and social contexts of physical activity in elementary school students…

  4. The Systemic-Structural Theory of Activity: Applications to the Study of Human Work

    ERIC Educational Resources Information Center

    Bedny, Gregory Z.; Harris, Steven Robert

    2005-01-01

    This article offers an introduction to the central concepts and principles of the Systemic-Structural Theory of Activity (SSTA), an activity-theoretical approach specifically tailored to the analysis and design of human work. In activity theory, cognition is understood both as a process and as a structured system of actions. Building on the…

  5. From Concept-to-Flight: An Active Active Fluid Loop Based Thermal Control System for Mars Science Laboratory Rover

    NASA Technical Reports Server (NTRS)

    Birur, Gajanana C.; Bhandari, Pradeep; Bame, David; Karlmann, Paul; Mastropietro, A. J.; Liu, Yuanming; Miller, Jennifer; Pauken, Michael; Lyra, Jacqueline

    2012-01-01

    The Mars Science Laboratory (MSL) rover, Curiosity, which was launched on November 26, 2011, incorporates a novel active thermal control system to keep the sensitive electronics and science instruments at safe operating and survival temperatures. While the diurnal temperature variations on the Mars surface range from -120 C to +30 C, the sensitive equipment are kept within -40 C to +50 C. The active thermal control system is based on a single-phase mechanically pumped fluid loop (MPFL) system which removes or recovers excess waste heat and manages it to maintain the sensitive equipment inside the rover at safe temperatures. This paper will describe the entire process of developing this active thermal control system for the MSL rover from concept to flight implementation. The development of the rover thermal control system during its architecture, design, fabrication, integration, testing, and launch is described.

  6. Continued Development of the Rapid Cycle Amine (RCA) System for Advanced Extravehicular Activity Systems

    NASA Technical Reports Server (NTRS)

    Papale, William; Chullen, Cinda; Campbell, Colin; Conger, Bruce; McMillin, Summer; Jeng, Frank

    2014-01-01

    Development activities related to the Rapid Cycle Amine (RCA) Carbon Dioxide (CO2) and Humidity control system have progressed to the point of integrating the RCA into an advanced Primary Life Support System (PLSS 2.0) to evaluate the interaction of the RCA among other PLSS components in a ground test environment. The RCA 2.0 assembly (integrated into PLSS 2.0) consists of a valve assembly with commercial actuator motor, a sorbent canister, and a field-programmable gate array (FPGA)-based process node controller. Continued design and development activities for RCA 3.0 have been aimed at optimizing the canister size and incorporating greater fidelity in the valve actuator motor and valve position feedback design. Further, the RCA process node controller is envisioned to incorporate a higher degree of functionality to support a distributed PLSS control architecture. This paper will describe the progression of technology readiness levels of RCA 1.0, 2.0 and 3.0 along with a review of the design and manufacturing successes and challenges for 2.0 and 3.0 units. The anticipated interfaces and interactions with the PLSS 2.0/2.5/3.0 assemblies will also be discussed.

  7. Design and Implementation of an Object Oriented Learning Activity System

    ERIC Educational Resources Information Center

    Lin, Huan-Yu; Tseng, Shian-Shyong; Weng, Jui-Feng; Su, Jun-Ming

    2009-01-01

    With the development of e-learning technology, many specifications of instructional design have been proposed to make learning activity sharable and reusable. With the specifications and sufficient learning resources, the researches further focus on how to provide learners more appropriate learning activities to improve their learning performance.…

  8. Midazolam microdose to determine systemic and pre-systemic metabolic CYP3A activity in humans

    PubMed Central

    Hohmann, Nicolas; Kocheise, Franziska; Carls, Alexandra; Burhenne, Jürgen; Haefeli, Walter E; Mikus, Gerd

    2015-01-01

    Aim We aimed to establish a method to assess systemic and pre-systemic cytochrome P450 (CYP) 3A activity using ineffective microgram doses of midazolam. Methods In an open, one sequence, crossover study, 16 healthy participants received intravenous and oral midazolam at microgram (0.001 mg intravenous and 0.003 mg oral) and regular milligram (1 mg intravenous and 3 mg oral) doses to assess the linearity of plasma and urine pharmacokinetics. Results Dose-normalized AUC and Cmax were 37.1 ng ml−1 h [95% CI 35.5, 40.6] and 39.1 ng ml−1 [95% CI 30.4, 50.2] for the microdose and 39.0 ng ml−1 h [95% CI 36.1, 42.1] and 37.1 ng ml−1 [95% CI 26.9, 51.3] for the milligram dose. CLmet was 253 ml min−1 [95% CI 201, 318] vs. 278 ml min−1 [95% CI 248, 311] for intravenous doses and 1880 ml min−1 [95% CI 1590, 2230] vs. 2050 ml min−1 [95% CI 1720, 2450] for oral doses. Oral bioavailability of a midazolam microdose was 23.4% [95% CI 20.0, 27.3] vs. 20.9% [95% CI 17.1, 25.5] after the regular dose. Hepatic and gut extraction ratios for microgram doses were 0.44 [95% CI 0.39, 0.49] and 0.53 [95% CI 0.45, 0.63] and compared well with those for milligram doses (0.43 [95% CI 0.37, 0.49] and 0.61 [95% CI 0.53, 0.70]). Conclusion The pharmacokinetics of an intravenous midazolam microdose is linear to the applied regular doses and can be used to assess safely systemic CYP3A activity and, in combination with oral microdoses, pre-systemic CYP3A activity. PMID:25588320

  9. 77 FR 52317 - Record of Decision for Surveillance Towed Array Sensor System Low Frequency Active Sonar

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-29

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF DEFENSE Department of the Navy Record of Decision for Surveillance Towed Array Sensor System Low Frequency Active... Array Sensor System Low Frequency Active (SURTASS LFA) sonar systems with certain...

  10. Teaching Tip: Using Activity Diagrams to Model Systems Analysis Techniques: Teaching What We Preach

    ERIC Educational Resources Information Center

    Lending, Diane; May, Jeffrey

    2013-01-01

    Activity diagrams are used in Systems Analysis and Design classes as a visual tool to model the business processes of "as-is" and "to-be" systems. This paper presents the idea of using these same activity diagrams in the classroom to model the actual processes (practices and techniques) of Systems Analysis and Design. This tip…

  11. The C-5A active lift distribution control system

    NASA Technical Reports Server (NTRS)

    Hargrove, W. J.

    1976-01-01

    The ALDCS development and design tasks, ALDCS functional configuration, and resulting challenges encountered while accomplishing the first phase of the program are described. These tasks are establishing system requirements and criteria and synthesizing a system mechanization to meet the desired load alleviation, stability margins, flight safety, and flying qualities performance. Results of the ALDCS development and prototype system flight simulation programs, and control law optimization including system stability, handling qualities and structural load analyses are presented, along with concluding remarks relative to the system design integration.

  12. Effect of Knowledge Integration Activities on Students' Perception of the Earth's Crust as a Cyclic System.

    ERIC Educational Resources Information Center

    Kali, Yael; Orion, Nir; Eylon, Bat-Sheva

    2003-01-01

    Characterizes students' understanding of the rock cycle system. Examines effects of a knowledge integration activity on their system thinking. Interprets answers to an open-ended test using a systems thinking continuum ranging from a completely static view of the system to an understanding of the system's cyclic nature. Reports meaningful…

  13. Geomorphological analysis of the drainage system on the active convergent system in Azerbaijan, NW Iran

    NASA Astrophysics Data System (ADS)

    Kaveh Firouz, Amaneh; Burg, Jean-Pierre; Giachetta, Emanuele

    2016-04-01

    profiles are related to active fault systems.

  14. Antioxidant activity of whey protein hydrolysates in milk beverage system.

    PubMed

    Mann, Bimlesh; Kumari, Anuradha; Kumar, Rajesh; Sharma, Rajan; Prajapati, Kishore; Mahboob, Shaik; Athira, S

    2015-06-01

    The aim of the present study was to evaluate the antioxidant activity of flavoured milk enriched with antioxidative whey protein hydrolysates (WPHs) by radical scavenging method. Whey protein concentrate (WPC) was hydrolyzed by using three commercial proteases; flavouzyme, alcalase and corolase PP and these WPHs were analyzed for degree of hydrolysis and antioxidant activity. The antioxidant activities of these WPHs were evaluated using ABTS method. Trolox equivalent antioxidant activity of all the hydrolysates i.e. flavourzyme (0.81 ± 0.04), alcalase (1.16 ± 0.05) and corolase (1.42 ± 0.12) was higher than the WPC (0.19 ± 0.01). Among these, whey protein hydrolysates prepared using corolase showed maximum antioxidant activity. Total 15 β-lactoglobulin, 1 α-lactoalbumin, and 6 β-casein derived peptide fragments were identified in the WPHs by LC-MS/MS. Due to their size and characteristic amino acid composition, all the identified peptides may contribute for the antioxidant activity. The strawberry and chocolate flavoured milk was supplemented with WPC and WPHs and 2 % addition has shown increase in antioxidant activity upto 42 %. The result suggests that WPH could be used as natural biofunctional ingredients in enhancing antioxidant properties of food products. PMID:26028704

  15. Behavioral Inhibition and Activation Systems: Differences in Substance Use Expectancy Organization and Activation in Memory

    PubMed Central

    Simons, Jeffrey S.; Dvorak, Robert D.; Lau-Barraco, Cathy

    2009-01-01

    We used multidimensional scaling to model the semantic network of alcohol and marijuana expectancies (N = 897). Preference mapping was used to estimate vectors representing patterns of activation through the network as a function of levels of behavioral inhibition (BIS) and behavioral activation (BAS). Individuals with low BIS combined with high BAS levels exhibited patterns of activation emphasizing behavioral activation similar to heavier drug users in previous research. High BIS, low BAS individuals exhibited activation patterns with greater emphasis on inhibitory expectancies similar to low-level users. Differences in expectancy activation patterns were maintained after controlling for substance use and gender. Individual differences in BIS/BAS are associated with the organization of semantic networks and patterns of activation of expectancies contributing to differences in substance use behavior. PMID:19586148

  16. [Perfluorocarbon emulsions and other corpuscular systems influence on neutrophil activity].

    PubMed

    Shekhtman, D G; Safronova, V G; Sklifas, A N; Alovskaia, A A; Gapeev, A B; Obraztsov, V V; Chemeris, N K

    1997-01-01

    Influence of perfluorodecalin, perfluoromethilcyclohexylpiperidine, perfluorotributylamine emulsions on active oxygen form (AOF) generation by neutrophils has been studied. All investigated emulsions stabilized both proxanol 268 and egg yolk phospholipids inhibited PMA-stimulated neutrophil activity. Castor oil emulsion also inhibited the neutrophil activity. Neutrophil response for chemotactic peptide, was unchanged in the presence of all tested emulsions. We suppose that fast hydrophobic attachment of inert submicrone emulsion particles to cell surface provokes alteration of neutrophil plasma membrane function resulting in a decrease of AOF generation. PMID:9490112

  17. Control system of a dispersed fringe type sensing system of active optics

    NASA Astrophysics Data System (ADS)

    Zhang, Yajun; Zhang, Zhenchao; Zhang, Yong

    2010-07-01

    Active optics plays an important part in segmented mirrors of astronomy telescopes. A dispersed fringe sensor(DFS) using a broadband point source is an efficient method for cophasing and is also highly automated and robust. DFS can estimate the piston between segments only through the spectrum formed by the transmissive grating's dispersion and therefore can replace the edge sensors. So we build an system in our lab to experiment the DFS method. The whole control system of DFS is put forward, including control of displacement actuators and control of shifting the optical fiber. Control of displacement actuators consists in industry computer, HY-6120 I/O card, six stepper motor and other parts. Some theoretical analysis and experiment tests reveal that the actuator could be controlled to 5nm and without backlash by this control strategy. The optical fiber could be shifted out of optical path or shifted in part or whole of optical path so that the spectrum formed by the transmissive grating's dispersion could alter. When six actuators are moving, the piston is changing, and the spectrum is also moving and altering. And the whole control of DFS system is constructed now and seems well. Further test and experiment will be carry out.

  18. ACTIVELY CONTROLLED VORTEX DISPOSAL SYSTEM FOR SLUDGE WASTES

    EPA Science Inventory

    The development of an advanced sludge treatment concept is under way for applications to sludge wastes. The concept integrates primary treatment of sludge in an advanced vortex containment combustor (VCC) with subsequent post treatment in an actively controlled acoustic afterburn...

  19. ACTIVELY CONTROLLED VORTEX DISPOSAL SYSTEM FOR SLUDGE WASTES

    EPA Science Inventory

    The development of an advanced sludge treatment concept is underway for applications to sludge wastes. The concept integrates primary treatment of sludge in an advanced vortex containment combustor (VCC) with subsequent post treatment in an actively controlled acoustic afterburne...

  20. System and method for collisional activation of charged particles

    DOEpatents

    Ibrahim, Yehia M; Belov, Mikhail E; Prior, David C

    2013-09-24

    A collision cell is disclosed that provides ion activation in various selective modes. Ion activation is performed inside selected segments of a segmented quadrupole that provides maximum optimum capture and collection of fragmentation products. The invention provides collisional cooling of precursor ions as well as product fragments and further allows effective transmission of ions through a high pressure interface into a coupled mass analysis instrument.

  1. MSFC Skylab airlock module, volume 2. [systems design and performance, systems support activity, and reliability and safety programs

    NASA Technical Reports Server (NTRS)

    1974-01-01

    System design and performance of the Skylab Airlock Module and Payload Shroud are presented for the communication and caution and warning systems. Crew station and storage, crew trainers, experiments, ground support equipment, and system support activities are also reviewed. Other areas documented include the reliability and safety programs, test philosophy, engineering project management, and mission operations support.

  2. Phase segregation in a system of active dumbbells

    NASA Astrophysics Data System (ADS)

    Gonnella, Giuseppe; Lamura, Antonio; Suma, Antonio

    2014-04-01

    A systems of self-propelled dumbbells interacting by a Weeks-Chandler-Anderson potential is considered. At sufficiently low temperatures the system phase separates into a dense phase and a gas-like phase. The kinetics of the cluster formation and the growth law for the average cluster size are analyzed.

  3. E-Learning Activity-Based Material Recommendation System

    ERIC Educational Resources Information Center

    Liu, Feng-jung; Shih, Bai-jiun

    2007-01-01

    Purpose: Computer based systems have great potential for delivering learning material. However, problems are encountered, such as: difficulty of Learning resource sharing, high redundancy of learning material, and deficiency of the course brief. In order to solve these problems, this paper aims to propose an automatic inquiring system for learning…

  4. 40 CFR 60.759 - Specifications for active collection systems.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... professional engineer. The following issues shall be addressed in the design: depths of refuse, refuse gas generation rates and flow characteristics, cover properties, gas system expandibility, leachate and... section shall address landfill gas migration issues and augmentation of the collection system through...

  5. 40 CFR 60.759 - Specifications for active collection systems.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... professional engineer. The following issues shall be addressed in the design: depths of refuse, refuse gas generation rates and flow characteristics, cover properties, gas system expandibility, leachate and... section shall address landfill gas migration issues and augmentation of the collection system through...

  6. 40 CFR 60.759 - Specifications for active collection systems.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... generation rates and flow characteristics, cover properties, gas system expandibility, leachate and... section shall address landfill gas migration issues and augmentation of the collection system through the..., parts per million by volume 3.6×10−9 = conversion factor (iii) The values for k and CNMOC determined...

  7. 40 CFR 60.759 - Specifications for active collection systems.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... generation rates and flow characteristics, cover properties, gas system expandibility, leachate and... section shall address landfill gas migration issues and augmentation of the collection system through the..., parts per million by volume 3.6×10−9 = conversion factor (iii) The values for k and CNMOC determined...

  8. 40 CFR 60.759 - Specifications for active collection systems.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... generation rates and flow characteristics, cover properties, gas system expandibility, leachate and... section shall address landfill gas migration issues and augmentation of the collection system through the..., parts per million by volume 3.6×10−9 = conversion factor (iii) The values for k and CNMOC determined...

  9. Outline of the Solar System: Activities for elementary students

    NASA Technical Reports Server (NTRS)

    Hartsfield, J.; Sellers, M.

    1990-01-01

    An introduction to the solar system for the elementary school student is given. The introduction contains historical background, facts, and pertinent symbols concerning the sun, the nine major planets and their moons, and information about comets and asteroids. Aids to teaching are given, including a solar system crossword puzzle with answers.

  10. Towards Next Generation Activity-Based Learning Systems

    ERIC Educational Resources Information Center

    Sampson, Demetrios G.; Karampiperis, Pythagoras

    2006-01-01

    The need for e-learning systems that support a diverse set of pedagogical requirements has been identified as an important issue in web-based education. Until now, significant research and development effort has been devoted to aiming towards web-based educational systems tailored to specific pedagogical approaches. The most advanced of them are…

  11. A mobile system for active otpical pollution monitoring

    NASA Technical Reports Server (NTRS)

    Sunesson, A.; Edner, H.; Svanberg, S.; Uneus, L.; Wendt, W.; Fredriksson, K.

    1986-01-01

    The remote monitoring of atmospheric pollutants can now be performed in several ways. Laser radar techniques have proven their ability to reveal the spatial distribution of different species or particles. Classical optical techniques can also be used, but yield the average concentration over a given path and hence no range resolution. One such technique is Differential Optical Absorption Spectroscopy, DOAS. Such schemes can be used to monitor paths that a preliminary lidar investigation has shown to be of interest. Having previously had access to a mobile lidar system, a new system has been completed. The construction builds on experience from using the other system and it is meant to be more of a mobile optical laboratory than just a lidar system. A complete system description is given along with some preliminary usage. Future uses are contemplated.

  12. Engineering Translational Activators with CRISPR-Cas System.

    PubMed

    Du, Pei; Miao, Chensi; Lou, Qiuli; Wang, Zefeng; Lou, Chunbo

    2016-01-15

    RNA parts often serve as critical components in genetic engineering. Here we report a design of translational activators which is composed of an RNA endoribonuclease (Csy4) and two exchangeable RNA modules. Csy4, a member of Cas endoribonuclease, cleaves at a specific recognition site; this cleavage releases a cis-repressive RNA module (crRNA) from the masked ribosome binding site (RBS), which subsequently allows the downstream translation initiation. Unlike small RNA as a translational activator, the endoribonuclease-based activator is able to efficiently unfold the perfect RBS-crRNA pairing. As an exchangeable module, the crRNA-RBS duplex was forwardly and reversely engineered to modulate the dynamic range of translational activity. We further showed that Csy4 and its recognition site, together as a module, can also be replaced by orthogonal endoribonuclease-recognition site homologues. These modularly structured, high-performance translational activators would endow the programming of gene expression in the translation level with higher feasibility. PMID:26414660

  13. Wounding systemically activates a mitogen-activated protein kinase in forage and turf grasses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Forage and turf grasses are continually cut and grazed by livestock, however very little is known concerning the perception or molecular responses to wounding. Mechanical wounding rapidly activated a 46 kDa and a 44 kDa mitogen-activated protein kinase (MAPK) in six different grass species. In the m...

  14. [Glutamatergic neurotransmitter system in regulation of the gastrointestinal tract motor activity].

    PubMed

    Alekseeva, E V; Popova, T S; Sal'nikov, P S

    2015-01-01

    The review include actual facts, demonstrating high probability of glutamatergic neurotransmitter system role in the regulation of the gastrointestinal tract motor activity. These facts suggest significant role of the glutamatergic neurotransmitter system dysfunction in forming motor activity disorders of the digestive tract, including in patients in critical condition. The analysis is based on results of multiple experimental and clinical researches of glutamic acid and other components of the glutamatergic neurotransmitter system in central nervous system and autonomic nervous system (with the accent on the enteral nervous system) in normal conditions and with functioning changes of the glutamatergic neurotransmitter system in case of inflammation, hupoxia, stress and in critical condition. PMID:26852608

  15. Application of Active Controls Technology to Aircraft Ride Smoothing Systems

    NASA Technical Reports Server (NTRS)

    Lapins, Maris; Jacobson, Ira D.

    1975-01-01

    A critical review of past efforts in the design and testing of ride smoothing and gust alleviation systems is presented. Design trade-offs involving sensor types, choice of feedback loops, human comfort and aircraft handling-qualities criteria are discussed. Synthesis of a system designed to employ direct-lift and side-force producing surfaces is reported. Two STOL-class aircraft and an executive transport are considered. Theoretically-predicted system performance is compared with hybrid simulation and flight test data. Pilot opinion rating, pilot workload, and passenger comfort rating data for the basic and augmented aircraft are included.

  16. Application of active controls technology to aircraft bide smoothing systems

    NASA Technical Reports Server (NTRS)

    Lapins, M.; Jacobson, I. D.

    1975-01-01

    A critical review of past efforts in the design and testing of ride smoothing and gust alleviation systems is presented. Design trade offs involving sensor types, choice of feedback loops, human comfort, and aircraft handling-qualities criteria are discussed. Synthesis of a system designed to employ direct-lift and side-force producing surfaces is reported. Two STOL aircraft and an executive transport are considered. Theoretically predicted system performance is compared with hybrid simulation and flight test data. Pilot opinion rating, pilot workload, and passenger comfort rating data for the basic and augmented aircraft are included.

  17. The crew activity planning system bus interface unit

    NASA Technical Reports Server (NTRS)

    Allen, M. A.

    1979-01-01

    The hardware and software designs used to implement a high speed parallel communications interface to the MITRE 307.2 kilobit/second serial bus communications system are described. The primary topic is the development of the bus interface unit.

  18. Advanced active health monitoring system of liquid rocket engines

    NASA Astrophysics Data System (ADS)

    Qing, Xinlin P.; Wu, Zhanjun; Beard, Shawn; Chang, Fu-Kuo

    2008-11-01

    An advanced SMART TAPE system has been developed for real-time in-situ monitoring and long term tracking of structural integrity of pressure vessels in liquid rocket engines. The practical implementation of the structural health monitoring (SHM) system including distributed sensor network, portable diagnostic hardware and dedicated data analysis software is addressed based on the harsh operating environment. Extensive tests were conducted on a simulated large booster LOX-H2 engine propellant duct to evaluate the survivability and functionality of the system under the operating conditions of typical liquid rocket engines such as cryogenic temperature, vibration loads. The test results demonstrated that the developed SHM system could survive the combined cryogenic temperature and vibration environments and effectively detect cracks as small as 2 mm.

  19. Calc-silicate mineralization in active geothermal systems

    SciTech Connect

    Bird, D.K.; Schiffman, P.; Elders, W.A.; Williams, A.E.; McDowell, S.D.

    1983-01-01

    The detailed study of calc-silicate mineral zones and coexisting phase relations in the Cerro Prieto geothermal system were used as examples for thermodynamic evaluation of phase relations among minerals of variable composition and to calculate the chemical characteristics of hydrothermal solutions compatible with the observed calc-silicate assemblages. In general there is a close correlation between calculated and observed fluid compositions. Calculated fugacities of O{sub 2} at about 320{degrees}C in the Cerro Prieto geothermal system are about five orders of magnitude less than that at the nearby Salton Sea geothermal system. This observation is consistent with the occurrence of Fe{sup 3+} rich epidotes in the latter system and the presence of prehnite at Cerro Prieto.

  20. Coronal temperatures of unusually active K-dwarf binary systems

    NASA Technical Reports Server (NTRS)

    Stern, Robert A.

    1994-01-01

    We report the results of a ROSAT pointed study of 4 BY Dra systems. Good quality pulse-height spectra are available from all four systems. Except for a required interstellar absorption component in HD 319139, the four systems have remarkably similar x-ray spectra; the two systems BD +22deg.669 and BD +23deg.635 look virtually identical in x rays. Analysis of the 4 x-ray spectra reveals that, in all cases, a single-temperature hot plasma (RS or Mewe) spectra is inadequate to fit the data, and two temperatures are required. We present examples of fitted pulse-height spectra and chi squared contours in kT(sub 1)-kT(sub 2) space.

  1. Active waste-injection systems in Florida, 1976

    USGS Publications Warehouse

    Vecchioli, John; McKenzie, D.J.; Pascale, C.A.; Wilson, W.E.

    1979-01-01

    As of the end of 1976, seven systems were injecting liquid wastes into Florida 's subsurface environment at a combined average rate of 15 million gallons per day. This report presents for each of these systems information on the kind and amount of waste injected and type of pretreatment, construction characteristics of the injection and monitor wells, type of test and monitoring data available, and brief discussion of any operational problems experienced. (Kosco-USGS)

  2. Hybrid architecture active wavefront sensing and control system, and method

    NASA Technical Reports Server (NTRS)

    Feinberg, Lee D. (Inventor); Dean, Bruce H. (Inventor); Hyde, Tristram T. (Inventor)

    2011-01-01

    According to various embodiments, provided herein is an optical system and method that can be configured to perform image analysis. The optical system can comprise a telescope assembly and one or more hybrid instruments. The one or more hybrid instruments can be configured to receive image data from the telescope assembly and perform a fine guidance operation and a wavefront sensing operation, simultaneously, on the image data received from the telescope assembly.

  3. Mars Exploration Rover: thermal design is a system engineering activity

    NASA Technical Reports Server (NTRS)

    Tsuyuki, Glenn T.; Avila, Arturo; Awaya, Henry I.; Krylo, Robert; Novak, Keith; Phillips, Charles

    2003-01-01

    The Mars Exploration Rovers (MER), were launched in June and July of 2003, repsectively and successfully landed on Mars in early and late January of 2004, repectively. The flight system architecture implemented many successful features of the Mars Pathfinder (MPF) system: A cruise stage that transported an entry vehicle that housed the Lander, which in turn, used airbags to cushion the Rover during the landing event.

  4. Quantitative structure-activity relationships for fluoroelastomer/chlorofluorocarbon systems

    SciTech Connect

    Paciorek, K.J.L.; Masuda, S.R.; Nakahara, J.H. ); Snyder, C.E. Jr.; Warner, W.M. )

    1991-12-01

    This paper reports on swell, tensile, and modulus data that were determined for a fluoroelastomer after exposure to a series of chlorofluorocarbon model fluids. Quantitative structure-activity relationships (QSAR) were developed for the swell as a function of the number of carbons and chlorines and for tensile strength as a function of carbon number and chlorine positions in the chlorofluorocarbons.

  5. How Activity Systems Evolve: Making / Saving Salmon in British Columbia

    ERIC Educational Resources Information Center

    Lee, Yew-Jin; Roth, Wolff-Michael

    2008-01-01

    The purpose of this article is to describe the history of a state-sponsored salmon enhancement project in British Columbia and to explicate the development of the former using cultural historical activity theory. We make thematic the notion of inner contradictions, which express themselves outwardly as a function of both quantitative and…

  6. Reinforcement active learning in the vibrissae system: optimal object localization.

    PubMed

    Gordon, Goren; Dorfman, Nimrod; Ahissar, Ehud

    2013-01-01

    Rats move their whiskers to acquire information about their environment. It has been observed that they palpate novel objects and objects they are required to localize in space. We analyze whisker-based object localization using two complementary paradigms, namely, active learning and intrinsic-reward reinforcement learning. Active learning algorithms select the next training samples according to the hypothesized solution in order to better discriminate between correct and incorrect labels. Intrinsic-reward reinforcement learning uses prediction errors as the reward to an actor-critic design, such that behavior converges to the one that optimizes the learning process. We show that in the context of object localization, the two paradigms result in palpation whisking as their respective optimal solution. These results suggest that rats may employ principles of active learning and/or intrinsic reward in tactile exploration and can guide future research to seek the underlying neuronal mechanisms that implement them. Furthermore, these paradigms are easily transferable to biomimetic whisker-based artificial sensors and can improve the active exploration of their environment. PMID:22789551

  7. DESIGN AND CONSTRUCTION OF A MOBILE ACTIVATED CARBON REGENERATOR SYSTEM

    EPA Science Inventory

    Activated carbon adsorption has become a standard procedure for the cleanup of contaminated water streams. To facilitate such cleanup at hazardous waste and spill sites, mobile carbon adsorption units have been constructed and are now in use. Their primary drawback is the logisti...

  8. Nitroxide delivery system for Nrf2 activation and skin protection.

    PubMed

    Ben Yehuda Greenwald, Maya; Frušić-Zlotkin, Marina; Soroka, Yoram; Sasson, Shmuel Ben; Bianco-Peled, Havazelet; Bitton, Ronit; Kohen, Ron

    2015-08-01

    Cyclic nitroxides are a large group of compounds composed of diverse stable radicals also known as synthetic antioxidants. Although nitroxides are valuable for use in several skin conditions, in in vivo conditions they have several drawbacks, such as nonspecific dispersion in normal tissue, preferential renal clearance and rapid reduction of the nitroxide to the corresponding hydroxylamine. However, these drawbacks can be easily addressed by encapsulating the nitroxides within microemulsions. This approach would allow nitroxide activity and therefore their valuable effects (e.g. activation of the Keap1-Nrf2-EpRE pathway) to continue. In this work, nitroxides were encapsulated in a microemulsion composed of biocompatible ingredients. The nanometric size and shape of the vehicle microemulsion and nitroxide microemulsion displayed high similarity, indicating that the stability of the microemulsions was preserved. Our studies demonstrated that nitroxide microemulsions were more potent inducers of the Keap1-Nrf2-EpRE pathway than the free nitroxides, causing the activation of phase II enzymes. Moreover, microemulsions containing nitroxides significantly reduced UVB-induced cytotoxicity in the skin. Understanding the mechanism of this improved activity may expand the usage of many other Nrf2 modulating molecules in encapsulated form, as a skin protection strategy against oxidative stress-related conditions. PMID:25986586

  9. Model Activity Systems: Dialogic Teacher Learning for Social Justice Teaching

    ERIC Educational Resources Information Center

    Hoffman-Kipp, Peter

    2003-01-01

    Interest of teacher educators working in the field of social justice focuses on the ways in which teachers learn to inscribe their professional activity within social movements (for progressive change. The community of practice (COP) approach to understanding learning as a social process has a lot of currency right now in teacher education…

  10. Hybrid Active/Passive Jet Engine Noise Suppression System

    NASA Technical Reports Server (NTRS)

    Parente, C. A.; Arcas, N.; Walker, B. E.; Hersh, A. S.; Rice, E. J.

    1999-01-01

    A novel adaptive segmented liner concept has been developed that employs active control elements to modify the in-duct sound field to enhance the tone-suppressing performance of passive liner elements. This could potentially allow engine designs that inherently produce more tone noise but less broadband noise, or could allow passive liner designs to more optimally address high frequency broadband noise. A proof-of-concept validation program was undertaken, consisting of the development of an adaptive segmented liner that would maximize attenuation of two radial modes in a circular or annular duct. The liner consisted of a leading active segment with dual annuli of axially spaced active Helmholtz resonators, followed by an optimized passive liner and then an array of sensing microphones. Three successively complex versions of the adaptive liner were constructed and their performances tested relative to the performance of optimized uniform passive and segmented passive liners. The salient results of the tests were: The adaptive segmented liner performed well in a high flow speed model fan inlet environment, was successfully scaled to a high sound frequency and successfully attenuated three radial modes using sensor and active resonator arrays that were designed for a two mode, lower frequency environment.

  11. PERFORMANCE OF ACTIVATED SLUDGE-POWDERED ACTIVATED CARBON-WET AIR REGENERATION SYSTEMS

    EPA Science Inventory

    The investigation summarized in this report was undertaken to evaluate the performance of powdered activated carbon (PAC) technology used in conjuntion with wet air regeneration (WAR) at municipal wastewater treatment plants. xcessive ash concentrations accumulated in the mixed l...

  12. Development of Active Catheter,Active Guide Wire and Micro Sensor Systems

    PubMed Central

    Haga, Y.; Mineta, T.; Totsu, K.; Makishi, W.; Esashi, M.

    2001-01-01

    Summary Active catheters and active guide wires which move like a snake have been developed for catheter-based minimally invasive diagnosis and therapy. Communication and control IC chips in the active catheter reduce the number of lead wires for control. The active catheter can be not only bent but also torsioned and extended. An ultra minature fiber-optic pressure sensor; a forward-looking ultrasonic probe and a magnetic position and orientation sensor have been developed for catheters and guide wires. These moving mechanisms and several sensors which are fitted near the tip of the catheter and the guide wire will provide detailed information near the tip and enable delicate and effective catheter intervention. PMID:20663389

  13. PERFORMANCE OF ACTIVATED SLUDGE-POWDERED ACTIVATED CARBON-WET AIR REGENERATION SYSTEMS

    EPA Science Inventory

    The investigation summarized in the report was undertaken to evaluate the performance of powdered activated carbon (PAC) technology used in conjunction with wet air regeneration (WAR) at municipal wastewater treatment plants. Excessive ash concentrations accumulated in the mixed ...

  14. Activities of the Pilot Land Data System project

    NASA Technical Reports Server (NTRS)

    Sircar, J. K. (Principal Investigator)

    1985-01-01

    The University of Maryland's Remote Sensing Systems Laboratory submitted to NASA/Goddard an interim progress report on the work being conducted within its Pilot Land Data System IPLDS project. The Remote Sensing Systems Laboratory addressed the following tasks: (1) identify data types and data sources needed to describe the selected test sites in collaboration with Goddard's Hydrological Sciences Branch; (2) define the procedures necessary to access/acquire this data; (3) conduct meetings with the PLDS Systems Engineering Group to identify functional specification priorities for PLDS development; (4) assemble documentation on historical remotely sensed imagery and transfer of such information to the PLDS Data Management Group; (5) collect data identified by Goodard's Hydrological Sciences Branch for data set inventory in PLD; (6) develop a Workstation-PLDS system interface over high speed lines, (7) develop and test through a Phase 1 demonstration of a micro workstation to access PLDS; and (8) establish interdepartmental agreement of development of computer link for electronic access of water resources data from USGS.

  15. Active flutter suppression - Control system design and experimental validation

    NASA Technical Reports Server (NTRS)

    Waszak, Martin R.; Srinathkumar, S.

    1991-01-01

    The synthesis and experimental validation of an active flutter suppression controller for the Active Flexible Wing wind-tunnel model is presented. The design is accomplished with traditional root locus and Nyquist methods using interactive computer graphics tools and with extensive use of simulation-based analysis. The design approach uses a fundamental understanding of the flutter mechanism to formulate a simple controller structure to meet stringent design specifications. Experimentally, the flutter suppression controller succeeded in simultaneous suppression of two flutter modes, significantly increasing the flutter dynamic pressure despite errors in flutter dynamic pressure and flutter frequency in the mathematical model. The flutter suppression controller was also successfully operated in combination with a roll maneuver controller to perform flutter suppression during rapid rolling maneuvers.

  16. Antitussive activity and respiratory system effects of levodropropizine in man.

    PubMed

    Bossi, R; Braga, P C; Centanni, S; Legnani, D; Moavero, N E; Allegra, L

    1988-08-01

    Antitussive activity of the new antitussive drug, levodropropizine (S(-)-3-(4-phenyl-piperazin-1-yl)-propane-1,2-diol, DF 526), was evaluated in healthy volunteers by the classical method of citric acid-induced coughing. Levodropropizine dose-dependently reduced cough frequency. Maximal inhibition was observed at 6 h after administration. Cough intensity was also reduced, as shown by the analysis of cough noise. Levodropropizine, at the dosage of 60 mg t.i.d., had no adverse effects on respiratory function nor on airway clearance mechanisms: in fact, it did not affect spirometric parameters. Levodropropizine had no effects on the rheological properties of mucus nor on ciliary activity of airway epithelium. PMID:3196411

  17. An active target for the accelerator-based transmutation system

    SciTech Connect

    Grebyonkin, K. F.

    1995-09-15

    Consideration is given to the possibility of radical reduction in power requirements to the proton accelerator of the electronuclear reactor due to neutron multiplication both in the blanket and the target of an active material. The target is supposed to have the fast-neutron spectrum, and the blanket--the thermal one. The blanket and the target are separated by the thermal neutrons absorber, which is responsible for the neutron decoupling of the active target and blanket. Also made are preliminary estimations which illustrate that the realization of the idea under consideration can lead to significant reduction in power requirements to the proton beam and, hence considerably improve economic characteristics of the electronuclear reactor.

  18. The effect of different inter-pad distances on the determination of active drag using the Measuring Active Drag system.

    PubMed

    Schreven, S; Toussaint, H M; Smeets, J B J; Beek, P J

    2013-07-26

    The Measuring Active Drag (MAD) system was developed to determine active drag in swimming by measuring the push-off force exerted at fixed pads placed below the waterline. The imposed inter-pad distance, which to date has been kept constant while using the MAD system, could affect the active drag because it requires the use of different stroke frequencies. The aim of the present study was therefore to determine the effect of inter-pad distance on active drag at a given speed. In particular, drag-velocity curves at three different inter-pad distances (1.25m, 1.35m and 1.45m) were determined using the MAD system for eleven competitive swimmers. Variation of 16% in inter-pad distance (14% change in stroke frequency) revealed no significant difference in calculated active drag between different inter-pad distances and a low (<5%) average coefficient of variation over different inter-pad distances was found. In addition, inter-test reliability, which was determined for the two 1.35m conditions only, was high (ICC>0.90) for measurements on two consecutive days. The results suggest that it may not be necessary to adapt the inter-pad distance of the MAD system based on anthropometric characteristics of the subject or the velocity-related stroke length in free swimming. PMID:23791187

  19. Mutagenicity of emissions from eight binder systems used in steel foundries

    SciTech Connect

    Kaiser-Farrell, C.; Sheldrake, C.; McCalla, D.R.; Gibson, E.S.; Kerr, A.A.; Lockington, J.N.

    1986-09-01

    Emissions generated when molten steel was poured into sand molds fabricated with eight different binder systems were collected separately and tested for mutagenic activity using the Ames Salmonella assay. The sampling device consisted of an initial 8 X 10 in. glass fiber filter in a custom fabricated apparatus through which air was drawn using a Hi-Vol motor and fan. A portion of the airstream, which passed this filter, was in turn passed through a smaller glass fiber filter and then into two glass impingers filled with ice-cold methanol. All the binder systems generated material, which induced mutations in the absence of added S-9 extract, and in all emissions a higher level of activity was found when S-9 was added. In the presence of S-9, the shell-core system produced by far the most mutagenic activity followed by the oil-clay-cereal system. The green sand, furan and Kold Set systems produced much lower levels while the two reclaimed sand systems and sodium silicate system were intermediate.

  20. Aerosol identification using a hybrid active/passive system

    NASA Astrophysics Data System (ADS)

    D'Amico, Francis M.; Moon, Raphael P.; Davidson, Charles E.

    2005-08-01

    Recent experimental work has shown that passive systems such as hyperspectral FTIR and frequency-tunable IR cameras have application in detection of biological aerosols. This provided the motivation for a new detection technique, which we call Aerosol Ranging Spectroscopy (ARS), whereby a scattering LIDAR is used to augment passive spectrometer data to determine the location and optical depth of the aerosol plume. When the two systems are co-aligned or boresighted, the hybrid data product provides valuable enhancements for signal exploitation of the passive spectral data. This paper presents the motivation and theoretical basis for the ARS technique. A prototype implementation of an ARS system will also be described, along with preliminary results from recent outdoor field experiments.

  1. Broken detailed balance at mesoscopic scales in active biological systems.

    PubMed

    Battle, Christopher; Broedersz, Chase P; Fakhri, Nikta; Geyer, Veikko F; Howard, Jonathon; Schmidt, Christoph F; MacKintosh, Fred C

    2016-04-29

    Systems in thermodynamic equilibrium are not only characterized by time-independent macroscopic properties, but also satisfy the principle of detailed balance in the transitions between microscopic configurations. Living systems function out of equilibrium and are characterized by directed fluxes through chemical states, which violate detailed balance at the molecular scale. Here we introduce a method to probe for broken detailed balance and demonstrate how such nonequilibrium dynamics are manifest at the mesosopic scale. The periodic beating of an isolated flagellum from Chlamydomonas reinhardtii exhibits probability flux in the phase space of shapes. With a model, we show how the breaking of detailed balance can also be quantified in stationary, nonequilibrium stochastic systems in the absence of periodic motion. We further demonstrate such broken detailed balance in the nonperiodic fluctuations of primary cilia of epithelial cells. Our analysis provides a general tool to identify nonequilibrium dynamics in cells and tissues. PMID:27126047

  2. Image change detection using a SWIR active imaging system

    NASA Astrophysics Data System (ADS)

    Schneider, Armin L.; Monnin, David; Laurenzis, Martin; Christnacher, Frank

    2013-10-01

    We are currently developing a system consisting of a GPS receiver, a three-axis magnetic compass as well as a digital video camera in order to visualize changes occuring along a regularily used itinerary. This is done by comparing actual images with images from the same scene, which have been acquired during a previous measurement. The luminosity of images from two different passages however can be quite different (due to different meteorological conditions). Whereas the global luminosity can be adjusted using non-linear luminosity correction, the treatment of shadows is more di cult. Since meteorological conditions cannot be controlled, we are investigating the possibility of using a Laser Gated Viewing system in the SWIR domain to illuminate the scene. Using appropriate filters for the camera, we are completely independent of natural illumination and in addition, the system can also be used at night.

  3. Layered shielding design for an active neutron interrogation system

    NASA Astrophysics Data System (ADS)

    Whetstone, Zachary D.; Kearfott, Kimberlee J.

    2016-08-01

    The use of source and detector shields in active neutron interrogation can improve detector signal. In simulations, a shielded detector with a source rotated π/3 rad relative to the opening decreased neutron flux roughly three orders of magnitude. Several realistic source and detector shield configurations were simulated. A layered design reduced neutron and secondary photon flux in the detector by approximately one order of magnitude for a deuterium-tritium source. The shield arrangement can be adapted for a portable, modular design.

  4. [Physiopathology of the autonomic nervous system activity during sleep].

    PubMed

    Bersano, C; Revera, M; Vanoli, E

    2001-08-01

    Sleep consists of two phases that periodically alternate: the rapid eye movement (REM) phase and the non-REM phase. The non-REM stage is characterized by wide synchronous waves in the electroencephalogram, by a low heart rate and by a decrease in arterial blood pressure and peripheral resistances. This hemodynamic setting is the consequence of the autonomic balance characterized by high vagal activity and low sympathetic activity. Such an autonomic condition is adequately described by the spectral analysis of heart rate variability documenting a prevalence in the high frequency band (the respiratory vagal band). The REM stage of sleep is characterized by asynchronous waves in the electroencephalogram and it is associated with a further increase in the vagal dominance of the autonomic balance resulting in a lower heart rate and decreased peripheral resistances. The REM phase of sleep is, however, also characterized by hemodynamic instability due to sudden bursts of sympathetic activity, associated with the rapid eye movements. These sympathetic bursts cause sudden changes in heart rate and peripheral resistance and may influence cardiac electrical stability both at the atrial and ventricular levels. Additionally, REM sleep may enhance the risk of anginal attacks in coronary artery disease patients. Analysis of the autonomic balance during the different phases of sleep may also help in the identification of autonomic derangements typically associated with myocardial infarction. PMID:11582715

  5. Proteomics reliability for micropollutants degradation insight into activated sludge systems.

    PubMed

    Buttiglieri, Gianluigi; Collado, Neus; Casas, Nuria; Comas, Joaquim; Rodriguez-Roda, Ignasi

    2015-01-01

    Little information is available on pharmaceutical trace compounds degradation pathways in wastewater. The potential of the proteomics approach has been evaluated to extract information on activated sludge microbial metabolism in degrading a trace concentration of a pharmaceutical compound (ibuprofen). Ibuprofen is one of the most consumed pharmaceuticals, measured in wastewater at very high concentrations and, despite its high removal rates, found in different environmental compartments. Aerated and completely mixed activated sludge batch tests were spiked with ibuprofen at 10 and 1,000 μg L(-1). Ibuprofen concentrations were determined in the liquid phase: 100% removal was observed and the kinetics were estimated. The solid phase was sampled for proteomics purposes. The first objective was to apply proteomics to evaluate protein profile variations in a complex matrix such as activated sludge. The second objective was to determine, at different ibuprofen concentrations, which proteins followed pre-defined trends. No newly expressed proteins were found. Nonetheless, the obtained results suggest that proteomics itself is a promising methodology to be applied in this field. Statistical and comparative studies analyses provided, in fact, useful information on biological reproducibility and permitted us to detect 62 proteins following coherent and plausible expected trends in terms of presence and intensity change. PMID:26360747

  6. Activity, regulation, copy number and function in the glyoxalase system.

    PubMed

    Rabbani, Naila; Xue, Mingzhan; Thornalley, Paul J

    2014-04-01

    Molecular, catalytic and structural properties of glyoxalase pathway enzymes of many species are now known. Current research has focused on the regulation of activity and expression of Glo1 (glyoxalase I) and Glo2 (glyoxalase II) and their role in health and disease. Human GLO1 has MRE (metal-response element), IRE (insulin-response element), E2F4 (early gene 2 factor isoform 4), AP-2α (activating enhancer-binding protein 2α) and ARE (antioxidant response-element) regulatory elements and is a hotspot for copy number variation. The human Glo2 gene, HAGH (hydroxyacylglutathione hydrolase), has a regulatory p53-response element. Glo1 is linked to healthy aging, obesity, diabetes and diabetic complications, chronic renal disease, cardiovascular disease, other disorders and multidrug resistance in cancer chemotherapy. Mathematical modelling of the glyoxalase pathway predicts that pharmacological levels of increased Glo1 activity markedly decrease cellular methylglyoxal and related glycation, and pharmacological Glo1 inhibition markedly increases cellular methylglyoxal and related glycation. Glo1 inducers are in development to sustain healthy aging and for treatment of vascular complications of diabetes and other disorders, and cell-permeant Glo1 inhibitors are in development for treatment of multidrug-resistant tumours, malaria and potentially pathogenic bacteria and fungi. PMID:24646254

  7. The Adipose Renin-Angiotensin System Modulates Systemic Markers of Insulin Sensitivity and Activates the Intrarenal Renin-Angiotensin System

    DOE PAGESBeta

    Kim, Suyeon; Soltani-Bejnood, Morvarid; Quignard-Boulange, Annie; Massiera, Florence; Teboul, Michele; Ailhaud, Gerard; Kim, Jung Han; Moustaid-Moussa, Naima; Voy, Brynn H.

    2006-01-01

    Background . The adipose tissue renin-angiotensin system (RAS) contributes to regulation of fat mass and may also impact systemic functions such as blood pressure and metabolism. Methods and results . A panel of mouse models including mice lacking angiotensinogen, Agt ( Agt -KO), mice expressing Agt solely in adipose tissue (aP2- Agt/Agt -KO), and mice overexpressing Agt in adipose tissue (aP2- Agt ) was studied. Total body weight, epididymal fat pad weight, and circulating levels of leptin, insulin, and resistin were significantly decreased in Agt -KO mice, while plasma adiponectin levels were increased. aP2- Agt mice exhibited increased adipositymore » and plasma leptin and insulin levels compared to wild type (WT) controls. Angiotensinogen and type I Ang II receptor protein levels were also elevated in kidney of aP2- Agt mice. Conclusion . These findings demonstrate that alterations in adipose RAS activity significantly impact both local and systemic physiology in a way that may contribute to the detrimental health effects of obesity.« less

  8. Ultraviolet imaging spectroscopy shows an active saturnian system.

    PubMed

    Esposito, Larry W; Colwell, Joshua E; Larsen, Kristopher; McClintock, William E; Stewart, A Ian F; Hallett, Janet Tew; Shemansky, Donald E; Ajello, Joseph M; Hansen, Candice J; Hendrix, Amanda R; West, Robert A; Keller, H Uwe; Korth, Axel; Pryor, Wayne R; Reulke, Ralf; Yung, Yuk L

    2005-02-25

    Neutral oxygen in the saturnian system shows variability, and the total number of oxygen atoms peaks at 4 x 10(34). Saturn's aurora brightens in response to solar-wind forcing, and the auroral spectrum resembles Jupiter's. Phoebe's surface shows variable water-ice content, and the data indicate it originated in the outer solar system. Saturn's rings also show variable water abundance, with the purest ice in the outermost A ring. This radial variation is consistent with initially pure water ice bombarded by meteors, but smaller radial structures may indicate collisional transport and recent renewal events in the past 10(7) to 10(8) years. PMID:15604361

  9. 78 FR 77649 - Notification of Proposed Production Activity, Xylem Water Systems USA LLC, Subzone 37D...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-24

    ... Foreign-Trade Zones Board Notification of Proposed Production Activity, Xylem Water Systems USA LLC, Subzone 37D, (Centrifugal, Submersible Pumps and Related Components), Auburn, New York Xylem Water Systems USA LLC (Xylem), operator of Subzone 37D, submitted a notification of proposed production activity...

  10. Marital Conflict and Growth in Children's Internalizing Symptoms: The Role of Autonomic Nervous System Activity

    ERIC Educational Resources Information Center

    El-Sheikh, Mona; Keiley, Margaret; Erath, Stephen; Dyer, W. Justin

    2013-01-01

    We assessed trajectories of children's internalizing symptoms, indexed through anxiety and depression, with a focus on the role of interactions between interparental marital conflict, children's sympathetic nervous system activity indexed by skin conductance level (SCL), and parasympathetic nervous system activity indexed by respiratory sinus…

  11. Learning Activity Packets for Auto Mechanics II. Section B--Electrical Systems.

    ERIC Educational Resources Information Center

    Oklahoma State Board of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    Six learning activity packets (LAPs) are provided for the instructional area of electrical systems in the auto mechanics II program. They accompany an instructor's guide available separately. The LAPs outline the study activities and performance tasks for these six units: (1) basic electrical theory, (2) battery service, (3) starting system, (4)…

  12. BEACHES: An Observational System for Assessing Children's Eating and Physical Activity Behaviors and Associated Events.

    ERIC Educational Resources Information Center

    McKenzie, Thomas L.; And Others

    1991-01-01

    The Behaviors of Eating and Activity for Children's Health Evaluation System (BEACHES) codes direct observations of children's dietary and physical activity behaviors and associated environmental events, including physical location, antecedents, and consequences. The system's reliability and validity was assessed in a study of 42 children (ages…

  13. 36 CFR 9.83 - Coordination of AMRAP activities in National Park System units.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false Coordination of AMRAP activities in National Park System units. 9.83 Section 9.83 Parks, Forests, and Public Property NATIONAL PARK... Coordination of AMRAP activities in National Park System units. (a) To facilitate compliance with this...

  14. 36 CFR 9.83 - Coordination of AMRAP activities in National Park System units.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 36 Parks, Forests, and Public Property 1 2014-07-01 2014-07-01 false Coordination of AMRAP activities in National Park System units. 9.83 Section 9.83 Parks, Forests, and Public Property NATIONAL PARK... Coordination of AMRAP activities in National Park System units. (a) To facilitate compliance with this...

  15. 36 CFR 9.83 - Coordination of AMRAP activities in National Park System units.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 1 2012-07-01 2012-07-01 false Coordination of AMRAP activities in National Park System units. 9.83 Section 9.83 Parks, Forests, and Public Property NATIONAL PARK... Coordination of AMRAP activities in National Park System units. (a) To facilitate compliance with this...

  16. 36 CFR 9.83 - Coordination of AMRAP activities in National Park System units.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Coordination of AMRAP activities in National Park System units. 9.83 Section 9.83 Parks, Forests, and Public Property NATIONAL PARK... Coordination of AMRAP activities in National Park System units. (a) To facilitate compliance with this...

  17. 36 CFR 9.83 - Coordination of AMRAP activities in National Park System units.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 1 2013-07-01 2013-07-01 false Coordination of AMRAP activities in National Park System units. 9.83 Section 9.83 Parks, Forests, and Public Property NATIONAL PARK... Coordination of AMRAP activities in National Park System units. (a) To facilitate compliance with this...

  18. A Critical Analysis of Active Learning and an Alternative Pedagogical Framework for Introductory Information Systems Courses

    ERIC Educational Resources Information Center

    Drake, John R.

    2012-01-01

    Active learning has been championed in academic circles as the pedagogical fix to boring lectures typically found in introduction to information systems courses. However, the literature on active learning is mixed. In this paper, we critically examine active learning research and discover a misplaced emphasis leading to paradoxical findings in…

  19. Predicting Classroom Achievement from Active Responding on a Computer-Based Groupware System.

    ERIC Educational Resources Information Center

    Shin, Jongho; Deno, Stanley L.; Robinson, Steven L.; Marston, Douglas

    2000-01-01

    The predictive validity of active responding on a computer-based groupware system was examined with 48 second graders. Results showed that active responding correlated highly with initial and final performance measures and that active responding contributed significantly to predicting final performance when initial performance was controlled.…

  20. Use of an open-loop system to increase physical activity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study evaluated the effectiveness of an open-loop system that reinforces physical activity with TV watching to increase children’s physical activity. Non-overweight, sedentary boys and girls (8-12 y) were randomized to a group that received feedback of activity counts + reinforcement for physic...