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Sample records for gamma system regulates

  1. Regulation of PPAR{gamma} function by TNF-{alpha}

    SciTech Connect

    Ye Jianping

    2008-09-26

    The nuclear receptor PPAR{gamma} is a lipid sensor that regulates lipid metabolism through gene transcription. Inhibition of PPAR{gamma} activity by TNF-{alpha} is involved in pathogenesis of insulin resistance, atherosclerosis, inflammation, and cancer cachexia. PPAR{gamma} activity is regulated by TNF-{alpha} at pre-translational and post-translational levels. Activation of serine kinases including IKK, ERK, JNK, and p38 may be involved in the TNF-regulation of PPAR{gamma}. Of the four kinases, IKK is a dominant signaling molecule in the TNF-regulation of PPAR{gamma}. IKK acts through at least two mechanisms: inhibition of PPAR{gamma} expression and activation of PPAR{gamma} corepressor. In this review article, literature is reviewed with a focus on the mechanisms of PPAR{gamma} inhibition by TNF-{alpha}.

  2. PPAR{gamma} regulates the expression of cholesterol metabolism genes in alveolar macrophages

    SciTech Connect

    Baker, Anna D.; Malur, Anagha; Barna, Barbara P.; Kavuru, Mani S.; Malur, Achut G.; Thomassen, Mary Jane

    2010-03-19

    Peroxisome proliferator-activated receptor-gamma (PPAR{gamma}) is a nuclear transcription factor involved in lipid metabolism that is constitutively expressed in the alveolar macrophages of healthy individuals. PPAR{gamma} has recently been implicated in the catabolism of surfactant by alveolar macrophages, specifically the cholesterol component of surfactant while the mechanism remains unclear. Studies from other tissue macrophages have shown that PPAR{gamma} regulates cholesterol influx, efflux, and metabolism. PPAR{gamma} promotes cholesterol efflux through the liver X receptor-alpha (LXR{alpha}) and ATP-binding cassette G1 (ABCG1). We have recently shown that macrophage-specific PPAR{gamma} knockout (PPAR{gamma} KO) mice accumulate cholesterol-laden alveolar macrophages that exhibit decreased expression of LXR{alpha} and ABCG1 and reduced cholesterol efflux. We hypothesized that in addition to the dysregulation of these cholesterol efflux genes, the expression of genes involved in cholesterol synthesis and influx was also dysregulated and that replacement of PPAR{gamma} would restore regulation of these genes. To investigate this hypothesis, we have utilized a Lentivirus expression system (Lenti-PPAR{gamma}) to restore PPAR{gamma} expression in the alveolar macrophages of PPAR{gamma} KO mice. Our results show that the alveolar macrophages of PPAR{gamma} KO mice have decreased expression of key cholesterol synthesis genes and increased expression of cholesterol receptors CD36 and scavenger receptor A-I (SRA-I). The replacement of PPAR{gamma} (1) induced transcription of LXR{alpha} and ABCG1; (2) corrected suppressed expression of cholesterol synthesis genes; and (3) enhanced the expression of scavenger receptors CD36. These results suggest that PPAR{gamma} regulates cholesterol metabolism in alveolar macrophages.

  3. Scanning Gamma Ray Densitometer System for Detonations.

    DTIC Science & Technology

    in loaded detonators and delays. The 317 KEV gamma rays from an Ir192 source were collimated into a beam of 0.002 by 0.100 inch. A scanning system...minus 3%. With Ir192 , density measurements on NOL-130 were reproduced to plus or minus 5%, and on RDX to plus or minus 16%. Based on gamma ray

  4. Regulation of gamma-Secretase in Alzheimer's Disease

    SciTech Connect

    Zhou, Shuxia; Zhou, Hua; Walian, Peter; Jap, Bing

    2007-02-07

    The {gamma}-secretase complex is an intramembrane aspartyl protease that cleaves its substrates along their transmembrane regions. Sequential proteolytic processing of amyloid precursor protein by {beta}- and {gamma}-secretase produces amyloid {beta}-peptides, which are the major components of amyloid plaques in the brains of Alzheimer's disease patients. The {gamma}-secretase complex is therefore believed to be critical in the pathogenesis of Alzheimer's disease. Here we review the range of factors found to affect the nature and degree of {gamma}-secretase complex activity; these include {gamma}-secretase complex assembly and activation, the integral regulatory subunit CD147, transient or weak binding partners, the levels of cholesterol and sphingolipids in cell membranes, and inflammatory cytokines. Integrated knowledge of the molecular mechanisms supporting the actions of these factors is expected to lead to a comprehensive understanding of the functional regulation of the {gamma}-secretase complex, and this, in turn, should facilitate the development of novel therapeutic strategies for the treatment of Alzheimer's disease.

  5. Gamma beam system at ELI-NP

    SciTech Connect

    Ur, Calin Alexandru

    2015-02-24

    The Gamma Beam System of ELI-NP will produce brilliant, quasi-monochromatic gamma-ray beams via Inverse Compton Scattering of short laser pulses on relativistic electron beam pulses. The scattered radiation is Doppler upshifted by more than 1,000,000 times and is forward focused in a narrow, polarized, tunable, laser-like beam. The gamma-ray beam at ELI-NP will be characterized by large spectral density of about 10{sup 4} photons/s/eV, narrow bandwidth (< 0.5%) and tunable energy from 200 keV up to about 20 MeV. The Gamma Beam System is a state-of-the-art equipment employing techniques and technologies at the limits of the present-day's knowledge.

  6. A Gamma Memory Neural Network for System Identification

    NASA Technical Reports Server (NTRS)

    Motter, Mark A.; Principe, Jose C.

    1992-01-01

    A gamma neural network topology is investigated for a system identification application. A discrete gamma memory structure is used in the input layer, providing delayed values of both the control inputs and the network output to the input layer. The discrete gamma memory structure implements a tapped dispersive delay line, with the amount of dispersion regulated by a single, adaptable parameter. The network is trained using static back propagation, but captures significant features of the system dynamics. The system dynamics identified with the network are the Mach number dynamics of the 16 Foot Transonic Tunnel at NASA Langley Research Center, Hampton, Virginia. The training data spans an operating range of Mach numbers from 0.4 to 1.3.

  7. High resolution gamma spectroscopy well logging system

    SciTech Connect

    Giles, J.R.; Dooley, K.J.

    1997-05-01

    A Gamma Spectroscopy Logging System (GSLS) has been developed to study sub-surface radionuclide contamination. The absolute counting efficiencies of the GSLS detectors were determined using cylindrical reference sources. More complex borehole geometries were modeled using commercially available shielding software and correction factors were developed based on relative gamma-ray fluence rates. Examination of varying porosity and moisture content showed that as porosity increases, and as the formation saturation ratio decreases, relative gamma-ray fluence rates increase linearly for all energies. Correction factors for iron and water cylindrical shields were found to agree well with correction factors determined during previous studies allowing for the development of correction factors for type-304 stainless steel and low-carbon steel casings. Regression analyses of correction factor data produced equations for determining correction factors applicable to spectral gamma-ray well logs acquired under non-standard borehole conditions.

  8. Gamma ray observations of the solar system

    SciTech Connect

    Not Available

    1981-01-01

    Two general categories are discussed concerning the evolution of the solar system: the dualistic view, the planetesimal approach and the monistic view, the nebular hypothesis. The major points of each view are given and the models that are developed from these views are described. Possible applications of gamma ray astronomical observations to the question of the dynamic evolution of the solar system are discussed.

  9. Gamma ray observations of the solar system

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Two general categories are discussed concerning the evolution of the solar system: the dualistic view, the planetesimal approach; and the monistic view, the nebular hypothesis. The major points of each view are given and the models that are developed from these views are described. Possible applications of gamma ray astronomical observations to the question of the dynamic evolution of the solar system are discussed.

  10. Regulation of hepatic PPAR{gamma}2 and lipogenic gene expression by melanocortin

    SciTech Connect

    Poritsanos, Nicole J.; Wong, Davie; Vrontakis, Maria E.; Mizuno, Tooru M.

    2008-11-14

    The central melanocortin system regulates hepatic lipid metabolism. Hepatic lipogenic gene expression is regulated by transcription factors including sterol regulatory element-binding protein 1c (SREBP-1c), carbohydrate responsive element-binding protein (ChREBP), and peroxisome proliferator-activated receptor {gamma}2 (PPAR{gamma}2). However, it is unclear if central melanocortin signaling regulates hepatic lipogenic gene expression through the activation of these transcription factors. To delineate the molecular mechanisms by which the melanocortin system regulates hepatic lipid metabolism, we examined the effect of intracerebroventricular injection of SHU9119, a melanocortin receptor antagonist, on hepatic expression levels of genes involved in lipid metabolism in mice. SHU9119 treatment increased hepatic triglyceride content and mRNA levels of lipogenic genes, SREBP-1c, and PPAR{gamma}2, whereas it did not cause any changes in hepatic ChREBP mRNA levels. These findings suggest that reduced central melanocortin signaling increases hepatic lipid deposition by stimulating hepatic lipogenic gene expression at least partly through the activation of SREBP-1c and PPAR{gamma}2.

  11. Novel regulation of p38gamma by dopamine D2 receptors during hypoxia.

    PubMed

    Conrad, P W; Millhorn, D E; Beitner-Johnson, D

    2000-07-01

    The p38 signalling pathway is part of the MAPK superfamily and is activated by various stressors. Our previous results have shown that two p38 isoforms, p38alpha and p38gamma, are activated by hypoxia in the neural-like PC12 cell line. PC12 cells also synthesize and secrete catecholamines, including dopamine, in response to hypoxia. We have now used this system to study the interaction between D2-dopamine receptor signalling and the p38 stress-activated protein kinases. Our results show that two D2 receptor antagonists, butaclamol and sulpiride, enhance hypoxia-induced phosphorylation of p38gamma, but not p38. This effect persists in protein kinase A (PKA)-deficient PC12 cells, demonstrating that p38gamma modulation by the D2 receptor is independent of the cAMP/PKA signalling system. We further show that removal of extracellular calcium blocks the hypoxia-induced increase in p38gamma activity. These results are the first to demonstrate that p38gamma can be regulated by the D2 receptor and calcium following hypoxic exposure.

  12. Gamma Delta T-Cells Regulate Wound Myeloid Cell Activity After Burn

    DTIC Science & Technology

    2014-03-01

    GAMMA DELTA T CELLS REGULATE WOUND MYELOID CELL ACTIVITY AFTER BURN Meenakshi Rani ,* Qiong Zhang,* and Martin G. Schwacha*† *Department of Surgery...Cell Activity After Burn 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Rani M., Zhang Q., Schwacha M. G., 5d...WT mice. 138 SHOCK VOL. 42, NO. 2 RANI ET AL. Copyright © 2014 by the Shock Society. Unauthorized reproduction of this article is prohibited. systemic

  13. Synchronization system for Gamma-4 electrophysical facility

    NASA Astrophysics Data System (ADS)

    Grishin, A. V.; Nazarenko, S. T.; Kozachek, A. V.; Kalashnikov, D. A.; Glushkov, S. L.; Mironychev, B. P.; Martynov, V. M.; Turutin, V. V.; Kul'dyushov, D. A.; Pavlov, V. S.; Demanov, V. A.; Shikhanova, T. F.; Esaeva, Yu. A.

    2015-01-01

    A synchronization system for the Gamma-4 four-module electrophysical facility has been developed. It has been shown that the synchronization system should provide triggering (with precision not worse than ±3 ns) of the high-voltage gas-filled trigatron-type switches of the facility modules (144 spark gaps with an operating voltage of 1 MV), the pre-pulse switches of the modules (24 spark gaps with an operating voltage of 3 MV) and eight Arkad'ev-Marx generators (40 spark gaps with an operating voltage of 100 kV).

  14. 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

  15. Gamma band activity in the reticular activating system.

    PubMed

    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 pre

  16. The PIKE homolog Centaurin gamma regulates developmental timing in Drosophila.

    PubMed

    Gündner, Anna Lisa; Hahn, Ines; Sendscheid, Oliver; Aberle, Hermann; Hoch, Michael

    2014-01-01

    Phosphoinositide-3-kinase enhancer (PIKE) proteins encoded by the PIKE/CENTG1 gene are members of the gamma subgroup of the Centaurin superfamily of small GTPases. They are characterized by their chimeric protein domain architecture consisting of a pleckstrin homology (PH) domain, a GTPase-activating (GAP) domain, Ankyrin repeats as well as an intrinsic GTPase domain. In mammals, three PIKE isoforms with variations in protein structure and subcellular localization are encoded by the PIKE locus. PIKE inactivation in mice results in a broad range of defects, including neuronal cell death during brain development and misregulation of mammary gland development. PIKE -/- mutant mice are smaller, contain less white adipose tissue, and show insulin resistance due to misregulation of AMP-activated protein kinase (AMPK) and insulin receptor/Akt signaling. here, we have studied the role of PIKE proteins in metabolic regulation in the fly. We show that the Drosophila PIKE homolog, ceng1A, encodes functional GTPases whose internal GAP domains catalyze their GTPase activity. To elucidate the biological function of ceng1A in flies, we introduced a deletion in the ceng1A gene by homologous recombination that removes all predicted functional PIKE domains. We found that homozygous ceng1A mutant animals survive to adulthood. In contrast to PIKE -/- mouse mutants, genetic ablation of Drosophila ceng1A does not result in growth defects or weight reduction. Although metabolic pathways such as insulin signaling, sensitivity towards starvation and mobilization of lipids under high fed conditions are not perturbed in ceng1A mutants, homozygous ceng1A mutants show a prolonged development in second instar larval stage, leading to a late onset of pupariation. In line with these results we found that expression of ecdysone inducible genes is reduced in ceng1A mutants. Together, we propose a novel role for Drosophila Ceng1A in regulating ecdysone signaling-dependent second to third instar

  17. Regulation of the Spectral Peak in Gamma-Ray Bursts

    NASA Astrophysics Data System (ADS)

    Beloborodov, Andrei M.

    2013-02-01

    Observations indicate that the peak of a gamma-ray burst spectrum forms in the opaque region of an ultrarelativistic jet. Recent radiative transfer calculations support this picture and show that the spectral peak is inherited from initially thermal radiation, which is changed by heating into a broad photon distribution with a high-energy tail. We discuss the processes that regulate the observed position of the spectral peak E pk. The opaque jet has three radial zones: (1) the Planck zone r < R P where a blackbody spectrum is enforced; this zone ends where the Thomson optical depth decreases to τ ≈ 105, (2) the Wien zone R P < r < R W with a Kompaneets parameter y Gt 1 where radiation has a Bose-Einstein spectrum, and (3) the Comptonization zone r > R W where the radiation spectrum develops a high-energy tail. Besides the initial jet temperature, an important factor regulating E pk is internal dissipation (of bulk motions and magnetic energy) at large distances from the central engine. Dissipation in the Planck zone reduces E pk, and dissipation in the Wien zone can increase E pk. In jets with subdominant magnetic fields, the predicted E pk varies around 1 MeV up to a maximum value of about 10 MeV. If the jet carries an energetically important magnetic field, E pk can be additionally increased by dissipation of magnetic energy. This increase is suggested by observations, which show E pk up to about 20 MeV. We also consider magnetically dominated jets; then a simple model of magnetic dissipation gives E pk ≈ 30 ΓW keV where ΓW is the jet Lorentz factor at the Wien radius R W.

  18. The Distinctive Features of Anticoincidence Detector System of the GAMMA-400 Gamma-ray Telescope

    NASA Astrophysics Data System (ADS)

    Runtso, M. F.; Arkhangelskiy, A. I.; Arkhangelskaja, I. V.; Galper, A. M.; Kaplin, V. A.; Leonov, A. A.; sNaumov, P. Yu.; Kheimitz, M. D.; Yurkin, Yu. T.; Kushin, V. V.; Lazarev, S. D.; Likhacheva, V. L.; Maklyaev, E. F.; Loginov, V. A.; Manuilova, E. S.; Fedotov, S. N.; Sharapov, M. P.

    Some features of scintillation anticoincidence system (includes ACtop detector section located upper the converter-tracker and four AClat ones placed from its lateral sides) of the GAMMA-400 gamma-ray telescope, related to joint operations with another fast scintillation systems: SDC (scintillation detector system of calorimeter) and TOF (time-of-flight system) are considered. The main problem for high-energy (over 50 GeV) gamma-rays registration by gamma-telescopes is the presence of so-called «backsplash current» (BS) of particles from massive calorimeter when detecting of particles is provided. BS is a set of low energy particles, moving up from the calorimeter and producing triggering of the anticoincidence detectors, imitating detection of a charged particle. As an additional indicator of BS particles presence of in the ACtop detector, we offer the value of energy release in the S3 scintillation detector placing between two parts of the calorimeter (CC1 and CC2). Fast trigger signal in the main aperture for gamma-quanta is composed of analysis of TOF system signal, showing that charged particle or particles move in the direction from up to down, and ACtop energy deposition taking in to account specially designed for GAMMA-400 algorithms of backsplash rejection.

  19. Regulation of CD3-induced phospholipase C-gamma 1 (PLC gamma 1) tyrosine phosphorylation by CD4 and CD45 receptors.

    PubMed Central

    Kanner, S B; Deans, J P; Ledbetter, J A

    1992-01-01

    Stimulation of the signal transduction cascade in T cells through the T-cell receptor (CD3) coincides with activation of the phosphatidylinositol-phospholipase C (PI-PLC) pathway. activation of phospholipase C-gamma 1 (PLC gamma 1) occurs through tyrosine phosphorylation in T cells following surface ligation of CD3 receptors with CD3-specific monoclonal antibodies (mAb). Here we show that cross-linking of CD4 molecules with CD3 augments the tyrosine phosphorylation of PLC gamma 1, while co-ligation of CD3 with CD45 (a receptor tyrosine phosphatase) results in reduced PLC gamma 1 tyrosine phosphorylation. Mobilization of intracellular calcium correlated with the extent of PLC gamma 1 tyrosine phosphorylation, indicating that PLC gamma 1 enzymatic activity in T cells may be regulated by its phosphorylation state. The time-course of PLC gamma 1 tyrosine phosphorylation in cells stimulated by soluble anti-CD3 was transient and closely paralleled that of calcium mobilization, while the kinetics in cells stimulated by immobilized anti-CD3 were prolonged. The PI-PLC pathway in T cells was not stimulated by tyrosine phosphorylation of PLC gamma 2, a homologue of PLC gamma 1, demonstrating the strict regulation of PLC gamma isoform usage in CD3-stimulated T cells. A 35,000/36,000 MW tyrosine phosphorylated protein in T cells formed stable complexes with PLC gamma 1, and its tyrosine phosphorylation was co-regulated with that of PLC gamma 1 by CD4 and CD45 receptors. Enzymatic activation and tyrosine phosphorylation of PLC gamma 1 occurs during growth factor stimulation of fibroblasts, where PLC gamma 1 exists in multi-component complexes. The observation that PLC gamma 1 exists in complexes with unique tyrosine phosphorylated proteins in T cells suggests that haematopoietic lineage-specific proteins associated with PLC gamma 1 may play roles in cellular signalling. Images Figure 1 Figure 4 PMID:1533389

  20. Regulation of interferon gamma signaling by suppressors of cytokine signaling and regulatory T cells.

    PubMed

    Larkin, Joseph; Ahmed, Chulbul M; Wilson, Tenisha D; Johnson, Howard M

    2013-12-18

    Regulatory T cells (Tregs) play an indispensable role in the prevention of autoimmune disease, as interferon gamma (IFNγ) mediated, lethal auto-immunity occurs (in both mice and humans) in their absence. In addition, Tregs have been implicated in preventing the onset of autoimmune and auto-inflammatory conditions associated with aberrant IFNγ signaling such as type 1 diabetes, lupus, and lipopolysaccharide (LPS) mediated endotoxemia. Notably, suppressor of cytokine signaling-1 deficient (SOCS1(-/-)) mice also succumb to a lethal auto-inflammatory disease, dominated by excessive IFNγ signaling and bearing similar disease course kinetics to Treg deficient mice. Moreover SOCS1 deficiency has been implicated in lupus progression, and increased susceptibility to LPS mediated endotoxemia. Although it has been established that Tregs and SOCS1 play a critical role in the regulation of IFNγ signaling, and the prevention of lethal auto-inflammatory disease, the role of Treg/SOCS1 cross-talk in the regulation of IFNγ signaling has been essentially unexplored. This is especially pertinent as recent publications have implicated a role of SOCS1 in the stability of peripheral Tregs. This review will examine the emerging research findings implicating a critical role of the intersection of the SOCS1 and Treg regulatory pathways in the control of IFN gamma signaling and immune system function.

  1. Regulation of Interferon Gamma Signaling by Suppressors of Cytokine Signaling and Regulatory T Cells

    PubMed Central

    Larkin, Joseph; Ahmed, Chulbul M.; Wilson, Tenisha D.; Johnson, Howard M.

    2013-01-01

    Regulatory T cells (Tregs) play an indispensable role in the prevention of autoimmune disease, as interferon gamma (IFNγ) mediated, lethal auto-immunity occurs (in both mice and humans) in their absence. In addition, Tregs have been implicated in preventing the onset of autoimmune and auto-inflammatory conditions associated with aberrant IFNγ signaling such as type 1 diabetes, lupus, and lipopolysaccharide (LPS) mediated endotoxemia. Notably, suppressor of cytokine signaling-1 deficient (SOCS1−/−) mice also succumb to a lethal auto-inflammatory disease, dominated by excessive IFNγ signaling and bearing similar disease course kinetics to Treg deficient mice. Moreover SOCS1 deficiency has been implicated in lupus progression, and increased susceptibility to LPS mediated endotoxemia. Although it has been established that Tregs and SOCS1 play a critical role in the regulation of IFNγ signaling, and the prevention of lethal auto-inflammatory disease, the role of Treg/SOCS1 cross-talk in the regulation of IFNγ signaling has been essentially unexplored. This is especially pertinent as recent publications have implicated a role of SOCS1 in the stability of peripheral Tregs. This review will examine the emerging research findings implicating a critical role of the intersection of the SOCS1 and Treg regulatory pathways in the control of IFN gamma signaling and immune system function. PMID:24391643

  2. Gamma Ray Imaging System (GRIS) GammaCam{trademark}. Final report, January 3, 1994--May 31, 1996

    SciTech Connect

    1996-12-31

    This report describes the activities undertaken during the development of the Gamma Ray Imaging System (GRIS) program now referred to as the GammaCam{trademark}. The purpose of this program is to develop a 2-dimensional imaging system for gamma-ray energy scenes that may be present in nuclear power plants. The report summarizes the overall accomplishments of the program and the most recent GammaCam measurements made at LANL and Estonia. The GammaCam is currently available for sale from AIL Systems as an off-the-shelf instrument.

  3. A brain-computer interface based on self-regulation of gamma-oscillations in the superior parietal cortex

    NASA Astrophysics Data System (ADS)

    Grosse-Wentrup, Moritz; Schölkopf, Bernhard

    2014-10-01

    Objective. Brain-computer interface (BCI) systems are often based on motor- and/or sensory processes that are known to be impaired in late stages of amyotrophic lateral sclerosis (ALS). We propose a novel BCI designed for patients in late stages of ALS that only requires high-level cognitive processes to transmit information from the user to the BCI. Approach. We trained subjects via EEG-based neurofeedback to self-regulate the amplitude of gamma-oscillations in the superior parietal cortex (SPC). We argue that parietal gamma-oscillations are likely to be associated with high-level attentional processes, thereby providing a communication channel that does not rely on the integrity of sensory- and/or motor-pathways impaired in late stages of ALS. Main results. Healthy subjects quickly learned to self-regulate gamma-power in the SPC by alternating between states of focused attention and relaxed wakefulness, resulting in an average decoding accuracy of 70.2%. One locked-in ALS patient (ALS-FRS-R score of zero) achieved an average decoding accuracy significantly above chance-level though insufficient for communication (55.8%). Significance. Self-regulation of gamma-power in the SPC is a feasible paradigm for brain-computer interfacing and may be preserved in late stages of ALS. This provides a novel approach to testing whether completely locked-in ALS patients retain the capacity for goal-directed thinking.

  4. Gamma-ray tracking method for pet systems

    DOEpatents

    Mihailescu, Lucian; Vetter, Kai M.

    2010-06-08

    Gamma-ray tracking methods for use with granular, position sensitive detectors identify the sequence of the interactions taking place in the detector and, hence, the position of the first interaction. The improved position resolution in finding the first interaction in the detection system determines a better definition of the direction of the gamma-ray photon, and hence, a superior source image resolution. A PET system using such a method will have increased efficiency and position resolution.

  5. Pioglitazone reverses down-regulation of cardiac PPAR{gamma} expression in Zucker diabetic fatty rats

    SciTech Connect

    Pelzer, Theo . E-mail: pelzer_t@klinik.uni-wuerzburg.de; Jazbutyte, Virginija; Arias-Loza, Paula Anahi; Segerer, Stephan; Lichtenwald, Margit; Law, Marilyn P.; Schaefers, Michael; Ertl, Georg; Neyses, Ludwig

    2005-04-08

    Peroxisome proliferator-activated receptor-{gamma} (PPAR{gamma}) plays a critical role in peripheral glucose homeostasis and energy metabolism, and inhibits cardiac hypertrophy in non-diabetic animal models. The functional role of PPAR{gamma} in the diabetic heart, however, is not fully understood. Therefore, we analyzed cardiac gene expression, metabolic control, and cardiac glucose uptake in male Zucker diabetic fatty rats (ZDF fa/fa) and lean ZDF rats (+/+) treated with the high affinity PPAR{gamma} agonist pioglitazone or placebo from 12 to 24 weeks of age. Hyperglycemia, hyperinsulinemia, and hypertriglyceridemia as well as lower cardiac PPAR{gamma}, glucose transporter-4 and {alpha}-myosin heavy chain expression levels were detected in diabetic ZDF rats compared to lean animals. Pioglitazone increased body weight and improved metabolic control, cardiac PPAR{gamma}, glut-4, and {alpha}-MHC expression levels in diabetic ZDF rats. Cardiac [{sup 18}F]fluorodeoxyglucose uptake was not detectable by micro-PET studies in untreated and pioglitazone treated ZDF fa/fa rats but was observed after administration of insulin to pioglitazone treated ZDF fa/fa rats. PPAR{gamma} agonists favorably affect cardiac gene expression in type-2 diabetic rats via activation and up-regulation of cardiac PPAR{gamma} expression whereas improvement of impaired cardiac glucose uptake in advanced type-2 diabetes requires co-administration of insulin.

  6. The Advanced Gamma-ray Imaging System (AGIS): Simulation studies

    SciTech Connect

    Maier, G.; Buckley, J.; Bugaev, V.; Fegan, S.; Funk, S.; Konopelko, A.; Vassiliev, V.V.; /UCLA

    2011-06-14

    The Advanced Gamma-ray Imaging System (AGIS) is a next-generation ground-based gamma-ray observatory being planned in the U.S. The anticipated sensitivity of AGIS is about one order of magnitude better than the sensitivity of current observatories, allowing it to measure gamma-ray emission from a large number of Galactic and extra-galactic sources. We present here results of simulation studies of various possible designs for AGIS. The primary characteristics of the array performance - collecting area, angular resolution, background rejection, and sensitivity - are discussed.

  7. Modeling of gamma/gamma-prime phase equilibrium in the nickel-aluminum system

    NASA Technical Reports Server (NTRS)

    Sanchez, J. M.; Barefoot, J. R.; Jarrett, R. N.; Tien, J. K.

    1984-01-01

    A theoretical model is proposed for the determination of phase equilibrium in alloys, taking into consideration dissimilar lattice parameters. Volume-dependent pair interactions are introduced by means of phenomenological Lennard-Jones potentials and the configurational entropy of the system is treated in the tetrahedron approximation of the cluster variation method. The model is applied to the superalloy-relevant, nickel-rich, gamma/gamma-prime phase region of the Ni-Al phase diagram. The model predicts reasonable values for the lattice parameters and the enthalpy of formation as a function of composition, and the calculated phase diagram closely approximates the experimental diagram.

  8. Grb2 negatively regulates epidermal growth factor-induced phospholipase C-gamma1 activity through the direct interaction with tyrosine-phosphorylated phospholipase C-gamma1.

    PubMed

    Choi, Jang Hyun; Hong, Won-Pyo; Yun, Sanguk; Kim, Hyeon Soo; Lee, Jong-Ryul; Park, Jong Bae; Bae, Yun Soo; Ryu, Sung Ho; Suh, Pann-Ghill

    2005-10-01

    Phospholipase C-gamma1 (PLC-gamma1) plays pivotal roles in cellular growth and proliferation. Upon the stimulation of growth factors and hormones, PLC-gamma1 is rapidly phosphorylated at three known sites; Tyr771, Tyr783 and Tyr1254 and its enzymatic activity is up-regulated. In this study, we demonstrate for the first time that Grb2, an adaptor protein, specifically interacts with tyrosine-phosphorylated PLC-gamma1 at Tyr783. The association of Grb2 with PLC-gamma1 was induced by the treatment with epidermal growth factor (EGF). Replacement of Tyr783 with Phe completely blocked EGF-induced interaction of PLC-gamma1 with Grb2, indicating that tyrosine phosphorylation of PLC-gamma1 at Tyr783 is essential for the interaction with Grb2. Interestingly, the depletion of Grb2 from HEK-293 cells by RNA interference significantly enhanced increased EGF-induced PLC-gamma1 enzymatic activity and mobilization of the intracellular Ca2+, while it did not affect EGF-induced tyrosine phosphorylation of PLC-gamma1. Furthermore, overexpression of Grb2 inhibited PLC-gamma1 enzymatic activity. Taken together, these results suggest Grb2, in addition to its key function in signaling through Ras, may have a negatively regulatory role on EGF-induced PLC-gamma1 activation.

  9. Gamma detectors in explosives and narcotics detection systems

    NASA Astrophysics Data System (ADS)

    Bystritsky, V. M.; Zubarev, E. V.; Krasnoperov, A. V.; Porohovoi, S. Yu.; Rapatskii, V. L.; Rogov, Yu. N.; Sadovskii, A. B.; Salamatin, A. V.; Salmin, R. A.; Slepnev, V. M.; Andreev, E. I.

    2013-11-01

    Gamma detectors based on BGO crystals were designed and developed at the Joint Institute for Nuclear Research. These detectors are used in explosives and narcotics detection systems. Key specifications and design features of the detectors are presented. A software temperature-compensation method that makes it possible to stabilize the gamma detector response and operate the detector in a temperature range from -20 to 50°C is described.

  10. Carbonic anhydrase III regulates peroxisome proliferator-activated receptor-{gamma}2

    SciTech Connect

    Mitterberger, Maria C.; Kim, Geumsoo; Rostek, Ursula; Levine, Rodney L.; Zwerschke, Werner

    2012-05-01

    Carbonic anhydrase III (CAIII) is an isoenzyme of the CA family. Because of its low specific anhydrase activity, physiological functions in addition to hydrating CO{sub 2} have been proposed. CAIII expression is highly induced in adipogenesis and CAIII is the most abundant protein in adipose tissues. The function of CAIII in both preadipocytes and adipocytes is however unknown. In the present study we demonstrate that adipogenesis is greatly increased in mouse embryonic fibroblasts (MEFs) from CAIII knockout (KO) mice, as demonstrated by a greater than 10-fold increase in the induction of fatty acid-binding protein-4 (FABP4) and increased triglyceride formation in CAIII{sup -/-} MEFs compared with CAIII{sup +/+} cells. To address the underlying mechanism, we investigated the expression of the two adipogenic key regulators, peroxisome proliferator-activated receptor-{gamma}2 (PPAR{gamma}2) and CCAAT/enhancer binding protein-{alpha}. We found a considerable (approximately 1000-fold) increase in the PPAR{gamma}2 expression in the CAIII{sup -/-} MEFs. Furthermore, RNAi-mediated knockdown of endogenous CAIII in NIH 3T3-L1 preadipocytes resulted in a significant increase in the induction of PPAR{gamma}2 and FABP4. When both CAIII and PPAR{gamma}2 were knocked down, FABP4 was not induced. We conclude that down-regulation of CAIII in preadipocytes enhances adipogenesis and that CAIII is a regulator of adipogenic differentiation which acts at the level of PPAR{gamma}2 gene expression. -- Highlights: Black-Right-Pointing-Pointer We discover a novel function of Carbonic anhydrase III (CAIII). Black-Right-Pointing-Pointer We show that CAIII is a regulator of adipogenesis. Black-Right-Pointing-Pointer We demonstrate that CAIII acts at the level of PPAR{gamma}2 gene expression. Black-Right-Pointing-Pointer Our data contribute to a better understanding of the role of CAIII in fat tissue.

  11. On the capacity of MISO FSO systems over gamma-gamma and misalignment fading channels.

    PubMed

    Boluda-Ruiz, Rubén; García-Zambrana, Antonio; Castillo-Vázquez, Beatriz; Castillo-Vázquez, Carmen

    2015-08-24

    In this work, the ergodic capacity performance for multiple-input/single-output (MISO) free-space optical (FSO) communications system with equal gain combining (EGC) reception is analyzed over gamma-gamma and misalignment fading channels, which are modeled as statistically independent, but not necessarily identically distributed (i.n.i.d.). Novel and analytical closed-form ergodic capacity expression is obtained in terms of H-Fox function by using the well-known inequality between arithmetic and geometric mean of positive random variables (RV) in order to obtain an approximate closed-form expression of the distribution of the sum of M gamma-gamma with pointing errors variates. In addition, we present an asymptotic ergodic capacity expression at high signal-to-noise ratio (SNR) for the ergodic capacity of MISO FSO systems. It can be concluded that the use of MISO technique can significantly reduce the effect of the atmospheric turbulence as well as pointing errors and, hence, provide significant capacity gain over the direct path link (DL). The impact of pointing errors on the MISO FSO system is also analyzed, which only depends on the number of laser sources and pointing error parameters. Moreover, it can be also concluded that the ergodic capacity performance is dramatically reduced as a consequence of the severity of pointing error effects. Simulation results are further demonstrated to confirm the analytical results.

  12. PPAR{gamma} transcriptionally regulates the expression of insulin-degrading enzyme in primary neurons

    SciTech Connect

    Du, Jing; Zhang, Lang; Liu, Shubo; Zhang, Chi; Huang, Xiuqing; Li, Jian; Zhao, Nanming; Wang, Zhao

    2009-06-12

    Insulin-degrading enzyme (IDE) is a protease that has been demonstrated to play a key role in degrading both A{beta} and insulin and deficient in IDE function is associated with Alzheimer's disease (AD) and type 2 diabetes mellitus (DM2) pathology. However, little is known about the cellular and molecular regulation of IDE expression. Here we show IDE levels are markedly decreased in DM2 patients and positively correlated with the peroxisome proliferator-activated receptor {gamma} (PPAR{gamma}) levels. Further studies show that PPAR{gamma} plays an important role in regulating IDE expression in rat primary neurons through binding to a functional peroxisome proliferator-response element (PPRE) in IDE promoter and promoting IDE gene transcription. Finally, we demonstrate that PPAR{gamma} participates in the insulin-induced IDE expression in neurons. These results suggest that PPAR{gamma} transcriptionally induces IDE expression which provides a novel mechanism for the use of PPAR{gamma} agonists in both DM2 and AD therapies.

  13. Overexpression of gamma-sarcoglycan induces severe muscular dystrophy. Implications for the regulation of Sarcoglycan assembly.

    PubMed

    Zhu, X; Hadhazy, M; Groh, M E; Wheeler, M T; Wollmann, R; McNally, E M

    2001-06-15

    The sarcoglycan complex is found normally at the plasma membrane of muscle. Disruption of the sarcoglycan complex, through primary gene mutations in dystrophin or sarcoglycan subunits, produces membrane instability and muscular dystrophy. Restoration of the sarcoglycan complex at the plasma membrane requires reintroduction of the mutant sarcoglycan subunit in a manner that will permit normal assembly of the entire sarcoglycan complex. To study sarcoglycan gene replacement, we introduced transgenes expressing murine gamma-sarcoglycan into muscle of normal mice. Mice expressing high levels of gamma-sarcoglycan, under the control of the muscle-specific creatine kinase promoter, developed a severe muscular dystrophy with greatly reduced muscle mass and early lethality. Marked gamma-sarcoglycan overexpression produced cytoplasmic aggregates that interfered with normal membrane targeting of gamma-sarcoglycan. Overexpression of gamma-sarcoglycan lead to the up-regulation of alpha- and beta-sarcoglycan. These data suggest that increased gamma-sarcoglycan and/or mislocalization of gamma-sarcoglycan to the cytoplasm is sufficient to induce muscle damage and provides a new model of muscular dystrophy that highlights the importance of this protein in the assembly, function, and downstream signaling of the sarcoglycan complex. Most importantly, gene dosage and promoter strength should be given serious consideration in replacement gene therapy to ensure safety in human clinical trials.

  14. SWEPP Gamma-Ray Spectrometer System software design description

    SciTech Connect

    Femec, D.A.; Killian, E.W.

    1994-08-01

    To assist in the characterization of the radiological contents of contract-handled waste containers at the Stored Waste Examination Pilot Plant (SWEPP), the SWEPP Gamma-Ray Spectrometer (SGRS) System has been developed by the Radiation Measurements and Development Unit of the Idaho National Engineering Laboratory. The SGRS system software controls turntable and detector system activities. In addition to determining the concentrations of gamma-ray-emitting radionuclides, this software also calculates attenuation-corrected isotopic mass ratios of-specific interest. This document describes the software design for the data acquisition and analysis software associated with the SGRS system.

  15. Expression of gamma-hemolysin regulated by sae in Staphylococcus aureus strain Smith 5R.

    PubMed

    Yamazaki, Kazuko; Kato, Fuminori; Kamio, Yoshiyuki; Kaneko, Jun

    2006-06-01

    Staphylococcus aureus strain Smith 5R produces a two-component pore-forming toxin and forms a rough-surfaced colony with hemolytic haloes on human red blood cell plates (R[+]). Serial subcultures of the strain in broth caused the appearance of gamma-hemolysin negative variants with a smooth colony shape (S[-]), and the S[-] valiant became predominant in culture. The R[+] strain, in which agrA is naturally disrupted by an insertion of IS1181, produced high levels of gamma-hemolysin. In the S[-] variant, expression of both hlg and lukS-F mRNAs was strongly reduced. Nucleotide sequencing of the sae locus revealed that all isolated S[-] variants had spontaneous mutations in the sae locus. Recovery of gamma-hemolysin productivity in S[-] by transformation of the wild-type sae allele strongly suggested that the expression of gamma-hemolysin is positively regulated by sae in an agr-independent manner.

  16. Magnetostrictive Pressure Regulating System

    NASA Technical Reports Server (NTRS)

    Richard, James A. (Inventor); Pickens, Herman L. (Inventor)

    2013-01-01

    A magnetostrictive pressure regulating system includes a magnetostrictive valve that incorporates a magnetostrictive actuator with at least one current-carrying coil disposed thereabout. A pressure force sensor, in fluid communication with the fluid exiting the valve, includes (i) a magnetostrictive material, (ii) a magnetic field generator in proximity to the magnetostrictive material for inducing a magnetic field in and surrounding the magnetostrictive material wherein lines of magnetic flux passing through the magnetostrictive material are defined, and (iii) a sensor positioned adjacent to the magnetostrictive material and in the magnetic field for measuring changes in at least one of flux angle and flux density when the magnetostrictive material experiences an applied force that is aligned with the lines of magnetic flux. The pressure of the fluid exiting the valve causes the applied force. A controller coupled to the sensor and to the current-carrying coil adjusts a current supplied to the current-carrying coil based on the changes so-measured.

  17. Gamma spectrometry of the minor bodies of the solar system

    SciTech Connect

    Surkov, Yu.A.; Moskaleva, L.P.; Manvelyan, O.S.

    1987-01-01

    The authors investigate the possibility of determining the elemental composition of the surfaces of minor bodies of the solar system (asteroids, the Martian satellites Phobos and Deimos, etc.) using spacecraft-based ..gamma..-spectrometry. The dependence of ..gamma..-photon flux on altitude above the body was calculated for body radii from 13 to 500 km. Estimates were made of the sensitivity of the determination of basic rock-forming elements with respect to changes in geometry of a factor of two, using ..gamma..-spectrometry with a 100 mm by 100 mm crystal of NaI(Tl). Finally, the time required to determine the stipulated characteristic ..gamma..-radiation of surface rocks with the given precision was derived as a function of altitude.

  18. The UCR gamma ray telescope data acquisition system

    NASA Technical Reports Server (NTRS)

    O'Neill, T. J.; Sweeney, W. E.; Tumer, O. T.; Zych, A. D.; White, R. S.

    1988-01-01

    A description is given of an electronics system based on the DEC Falcon SBC-11/23+, which has been designed and built to support a balloon-borne double Compton gamma-ray telescope. The system provides support for commands, data acquisition, data routing and compression, and photomultiplier tube gain control. The software consists of a number of interrupt-driven routines of differing priorities to handle each system task. This includes two circular buffers for onboard processing and bit encoding before transmission of the information to the ground computer. Acquisition of gamma-ray events at rates above the 200-Hz telemetry constraint is easily achieved.

  19. The Counting and Triggers Signals Formation System for Gamma-telescope GAMMA-400

    NASA Astrophysics Data System (ADS)

    Arkhangelskaja, I. V.; Arkhangelskiy, A. I.; Chasovikov, E. N.; Galper, A. M.; Kheymits, M. D.; Murchenko, A. E.; Yurkin, Y. T.

    Gamma-telescope GAMMA-400 consists of anticoincidence system (polyvinylyltoluene BC-408 based top and lateral detector sections, the converter-tracker with thickness of ∼1 X0 (where X0 is radiation length), time-of-flight system (two sections composed of BC-408 detectors with 50 cm distance between), two calorimeters makes of CsI(Tl) crystals (position-sensitive and electromagnetic. Also it includes neutron detector, two BC-408 based scintillation detectors of the calorimeter, and four BC-408 based lateral detectors of the calorimeter. The total calorimeter thickness is 25 X0 or 1.2 λ0 for vertical incident particles registration and 54 X0 or 2.5 λ0 for laterally incident ones (where λ0 is nuclear interaction length). The counting and triggers signals formation system started the data acquisition and provides particle identification. It used 2 pulses types: fast (t≤10 ns) from BC-408 based scintillation detectors and slow (t≤10 ms) from inorganic ones. Also fast pulses (t∼10 ns) from inorganic calorimeters individual detectors amplitude discriminators are included to this system information processing. Only signals from each detectors system individual detecting units without any summation are used for particle identification. The relationship between γ-quanta and relativistic particles (electrons and protons) energy deposition in GAMMA-400 detectors are discussed. The onboard triggers and trigger markers formation algorithms are described jointly with particles identification methods.

  20. Gamma-ray Albedo of Small Solar System Bodies

    SciTech Connect

    Moskalenko, I.V.

    2008-03-25

    We calculate the {gamma}-ray albedo flux from cosmic-ray (CR) interactions with the solid rock and ice in Main Belt asteroids and Kuiper Belt objects (KBOs) using the Moon as a template. We show that the {gamma}-ray albedo for the Main Belt and KBOs strongly depends on the small-body mass spectrum of each system and may be detectable by the forthcoming Gamma Ray Large Area Space Telescope (GLAST). If detected, it can be used to derive the mass spectrum of small bodies in the Main Belt and Kuiper Belt and to probe the spectrum of CR nuclei at close-to-interstellar conditions. The orbits of the Main Belt asteroids and KBOs are distributed near the ecliptic, which passes through the Galactic center and high Galactic latitudes. Therefore, the {gamma}-ray emission by the Main Belt and Kuiper Belt has to be taken into account when analyzing weak {gamma}-ray sources close to the ecliptic. The asteroid albedo spectrum also exhibits a 511 keV line due to secondary positrons annihilating in the rock. This may be an important and previously unrecognized celestial foreground for the INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL) observations of the Galactic 511 keV line emission including the direction of the Galactic center. For details of our calculations and references see [1].

  1. Binding and cross-linking of recombinant mouse interferon-. gamma. to receptors in mouse leukemic L1210 cells; interferon-. gamma. internalization and receptor down-regulation

    SciTech Connect

    Wietzerbin, J.; Gaudelet, C.; Aguet, M.; Falcoff, E.

    1986-04-01

    Recombinant E. coli-derived murine IFN-..gamma.. (Mu-rIFN-..gamma..; 5 x 10/sup 7/ U/mg) was radiolabeled with /sup 125/I by the chloramine-T method without loss of its antiviral activity. The /sup 125/I-Mu-rIFN-..gamma.. showed specific binding to L1210 cells. Scatchard analysis indicates about 4000 binding sites per cell and an apparent Kd of 5 x 10/sup -10/ M. Binding of /sup 125/I-Mu-rIFn-..gamma.. to cells inhibited by both natural (glycosylated) and rIFN-..gamma.., but not by IFN-..gamma../..beta... Receptor-bound /sup 125/I-Mu-rIFN-..gamma.. was rapidly internalized when incubation temperature was raised from 4/sup 0/C to 37/sup 0/C. On internalization, almost no IFN-..gamma.. degradation was observed during 16 hr incubation. /sup 125/I-Mu-rIFN-..gamma.. binding capacity decreased in cells preincubated with low doses of unlabeled Mu-rIFN-..gamma.., but not with IFN-..cap alpha../..beta... This receptor down-regulation was dose-dependent: 90% reduction of /sup 125/I-Mu-rIFN-..gamma.. binding was observed after preincubation with 100 U/ml. After removal of IFN-..gamma.. from the culture medium, the binding capacity increased with time. However, reappearance of receptor was completely blocked by cycloheximide or tunicamycin, suggesting that re-expression of receptors is not due to recycling but to the synthesis of new receptors, and that the receptor is probably a glycoprotein. Cross-linking of /sup 125/I-Mu-rIFN-..gamma.. to surface L1210 cell proteins by using bifunctional agents yielded a predominant complex of m.w. 110,000 +/- 5000. Thus, assuming a bimolecular complex, the m.w. of the receptor or receptor subunit would be close to 95,000 +/- 5000.

  2. Gamma-telescopes Fermi/LAT and GAMMA-400 Trigger Systems Event Recognizing Methods Comparison

    NASA Astrophysics Data System (ADS)

    Arkhangelskaja, I. V.; Murchenko, A. E.; Chasovikov, E. N.; Arkhangelskiy, A. I.; Kheymits, M. D.

    Usually instruments for high-energy γ-quanta registration consists of converter (where γ-quanta produced pairs) and calorimeter for particles energy measurements surrounded by anticoincidence shield used to events identification (whether incident particle was charged or neutral). The influence of pair formation by γ-quanta in shield and the backsplash (moved in the opposite direction particles created due high energy γ-rays interact with calorimeter) should be taken into account. It leads to decrease both effective area and registration efficiency at E>10 GeV. In the presented article the event recognizing methods used in Fermi/LAT trigger system is considered in comparison with the ones applied in counting and triggers signals formation system of gamma-telescope GAMMA-400. The GAMMA-400 (Gamma Astronomical Multifunctional Modular Apparatus) will be the new high-apogee space γ-observatory. The GAMMA-400 consist of converter-tracker based on silicon-strip coordinate detectors interleaved with tungsten foils, imaging calorimeter make of 2 layers of double (x, y) silicon strip coordinate detectors interleaved with planes of CsI(Tl) crystals and the electromagnetic calorimeter CC2 consists only of CsI(Tl) crystals. Several plastics detections systems used as anticoincidence shield, for particles energy and moving direction estimations. The main differences of GAMMA-400 constructions from Fermi/LAT one are using the time-of-flight system with base of 50 cm and double layer structure of plastic detectors provides more effective particles direction definition and backsplash rejection. Also two calorimeters in GAMMA-400 composed the total absorbtion spectrometer with total thickness ∼ 25 X0 or ∼1.2 λ0 for vertical incident particles registration and 54 X0 or 2.5 λ0 for laterally incident ones (where λ0 is nuclear interaction length). It provides energy resolution 1-2% for 10 GeV-3.0×103 GeV events while the Fermi/LAT energy resolution does not reach such a

  3. A large-area gamma-ray imaging telescope system

    NASA Technical Reports Server (NTRS)

    Koch, D. G.

    1983-01-01

    The concept definition of using the External Tank (ET) of the Space Shuttle as the basis for constructing a large area gamma ray imaging telescope in space is detailed. The telescope will be used to locate and study cosmic sources of gamma rays of energy greater than 100 MeV. Both the telescope properties and the means whereby an ET is used for this purpose are described. A parallel is drawn between those systems that would be common to both a Space Station and this ET application. In addition, those systems necessary for support of the telescope can form the basis for using the ET as part of the Space Station. The major conclusions of this concept definition are that the ET is ideal for making into a gamma ray telescope, and that this telescope will provide a substantial increase in collecting area.

  4. Bidirectional Pressure-Regulator System

    NASA Technical Reports Server (NTRS)

    Burke, Kenneth; Miller, John R.

    2008-01-01

    A bidirectional pressure-regulator system has been devised for use in a regenerative fuel cell system. The bidirectional pressure-regulator acts as a back-pressure regulator as gas flows through the bidirectional pressure-regulator in one direction. Later, the flow of gas goes through the regulator in the opposite direction and the bidirectional pressure-regulator operates as a pressure- reducing pressure regulator. In the regenerative fuel cell system, there are two such bidirectional regulators, one for the hydrogen gas and another for the oxygen gas. The flow of gases goes from the regenerative fuel cell system to the gas storage tanks when energy is being stored, and reverses direction, flowing from the storage tanks to the regenerative fuel cell system when the stored energy is being withdrawn from the regenerative fuel cell system. Having a single bidirectional regulator replaces two unidirectional regulators, plumbing, and multiple valves needed to reverse the flow direction. The term "bidirectional" refers to both the bidirectional nature of the gas flows and capability of each pressure regulator to control the pressure on either its upstream or downstream side, regardless of the direction of flow.

  5. Interferon gamma Signaling Positively Regulates Hematopoietic Stem Cell Emergence

    PubMed Central

    Sawamiphak, Suphansa; Kontarakis, Zacharias; Stainier, Didier Y.R.

    2014-01-01

    Summary Vertebrate hematopoietic stem cells (HSCs) emerge in the aorta-gonad-mesonephros (AGM) region from “hemogenic” endothelium. Here we show that the pro-inflammatory cytokine Ifn-γ and its receptor Crfb17 positively regulate HSC development in zebrafish. This regulation does not appear to modulate the proliferation or survival of HSCs or endothelial cells, but rather the endothelial to HSC transition. Notch signaling and blood flow positively regulate the expression of ifng and crfb17 in the AGM. Notably, Ifn-γ overexpression partially rescues the HSC loss observed in the absence of blood flow or Notch signaling. Importantly, Ifn-γ signaling acts cell-autonomously to control the endothelial to HSC transition. Ifn-γ activates Stat3, an atypical transducer of Ifn-γ signaling, in the AGM, and Stat3 inhibition decreases HSC formation. Together, our findings uncover a developmental role for an inflammatory cytokine and place its action downstream of Notch signaling and blood flow to control Stat3 activation and HSC emergence. PMID:25490269

  6. Implementation of Monte Carlo Simulations for the Gamma Knife System

    NASA Astrophysics Data System (ADS)

    Xiong, W.; Huang, D.; Lee, L.; Feng, J.; Morris, K.; Calugaru, E.; Burman, C.; Li, J.; Ma, C.-M.

    2007-06-01

    Currently the Gamma Knife system is accompanied with a treatment planning system, Leksell GammaPlan (LGP) which is a standard, computer-based treatment planning system for Gamma Knife radiosurgery. In LGP, the dose calculation algorithm does not consider the scatter dose contributions and the inhomogeneity effect due to the skull and air cavities. To improve the dose calculation accuracy, Monte Carlo simulations have been implemented for the Gamma Knife planning system. In this work, the 201 Cobalt-60 sources in the Gamma Knife unit are considered to have the same activity. Each Cobalt-60 source is contained in a cylindric stainless steel capsule. The particle phase space information is stored in four beam data files, which are collected in the inner sides of the 4 treatment helmets, after the Cobalt beam passes through the stationary and helmet collimators. Patient geometries are rebuilt from patient CT data. Twenty two Patients are included in the Monte Carlo simulation for this study. The dose is calculated using Monte Carlo in both homogenous and inhomogeneous geometries with identical beam parameters. To investigate the attenuation effect of the skull bone the dose in a 16cm diameter spherical QA phantom is measured with and without a 1.5mm Lead-covering and also simulated using Monte Carlo. The dose ratios with and without the 1.5mm Lead-covering are 89.8% based on measurements and 89.2% according to Monte Carlo for a 18mm-collimator Helmet. For patient geometries, the Monte Carlo results show that although the relative isodose lines remain almost the same with and without inhomogeneity corrections, the difference in the absolute dose is clinically significant. The average inhomogeneity correction is (3.9 ± 0.90) % for the 22 patients investigated. These results suggest that the inhomogeneity effect should be considered in the dose calculation for Gamma Knife treatment planning.

  7. Mini gamma camera, camera system and method of use

    DOEpatents

    Majewski, Stanislaw; Weisenberger, Andrew G.; Wojcik, Randolph F.

    2001-01-01

    A gamma camera comprising essentially and in order from the front outer or gamma ray impinging surface: 1) a collimator, 2) a scintillator layer, 3) a light guide, 4) an array of position sensitive, high resolution photomultiplier tubes, and 5) printed circuitry for receipt of the output of the photomultipliers. There is also described, a system wherein the output supplied by the high resolution, position sensitive photomultipiler tubes is communicated to: a) a digitizer and b) a computer where it is processed using advanced image processing techniques and a specific algorithm to calculate the center of gravity of any abnormality observed during imaging, and c) optional image display and telecommunications ports.

  8. The Advanced Gamma-ray Imaging System (AGIS) - Simulation Studies

    SciTech Connect

    Maier, G.; Buckley, J.; Bugaev, V.; Fegan, S.; Vassiliev, V. V.; Funk, S.; Konopelko, A.

    2008-12-24

    The Advanced Gamma-ray Imaging System (AGIS) is a US-led concept for a next-generation instrument in ground-based very-high-energy gamma-ray astronomy. The most important design requirement for AGIS is a sensitivity of about 10 times greater than current observatories like Veritas, H.E.S.S or MAGIC. We present results of simulation studies of various possible designs for AGIS. The primary characteristics of the array performance, collecting area, angular resolution, background rejection, and sensitivity are discussed.

  9. A gamma-ray verification system for special nuclear material

    SciTech Connect

    Lanier, R.G.; Prindle, A.L.; Friensehner, A.V.; Buckley, W.M.

    1994-07-01

    The Safeguards Technology Program at the Lawrence Livermore National Laboratory (LLNL) has developed a gamma-ray screening system for use by the Materials Management Section of the Engineering Sciences Division at LLNL for verifying the presence or absence of special nuclear material (SNM) in a sample. This system facilitates the measurements required under the ``5610`` series of US Department of Energy orders. MMGAM is an intelligent, menu driven software application that runs on a personal computer and requires a precalibrated multi-channel analyzer and HPGe detector. It provides a very quick and easy-to-use means of determining the presence of SNM in a sample. After guiding the operator through a menu driven set-up procedure, the system provides an on-screen GO/NO-GO indication after determining the system calibration status. This system represents advances over earlier used systems in the areas of ease-of use, operator training requirements, and quality assurance. The system records the gamma radiation from a sample using a sequence of measurements involving a background measurement followed immediately by a measurement of the unknown sample. Both spectra are stored and available for analysis or output. In the current application, the presence of {sup 235}U, {sup 238}U, {sup 239}Pu, and {sup 208}Tl isotopes are indicated by extracting, from the stored spectra, four energy ``windows`` preset around gamma-ray lines characteristic of the radioactive decay of these nuclides. The system is easily extendible to more complicated problems.

  10. Photovoltaic power regulation system

    SciTech Connect

    Jaster, D.R.

    1986-02-18

    This patent describes a multi-solar module direct current battery charging arrangement consisting of: a group of solar cells; a reverse current blocking diode; a first relay having an energizing winding; and a set of contacts; the diode, the energizing winding and the solar module connected across the battery; a second relay having a second set of contacts; the first relay contacts operate upon a predetermined current flow through the first relay winding to close the first relay and contacts to operate the second relay. A voltage regulator has a set of contacts. The regulator contacts operate upon the battery reaching a predetermined state of charge as indicated by the voltage level; solar cells and a third relay having a set of contacts; the second relay make contacts, the voltage regulator make contacts, the third relay and the second group of solar cells connected in series; the third relay operated upon the second relay operating indicating the solar cells are functioning, and the voltage regulator operating its associated contacts indicating the batteries require further charging to operate the third relay; and the third relay operated to close the associated contacts to connect the second plurality of solar cells across the battery.

  11. The nuclear resonance scattering calibration technique for the EuroGammaS gamma characterisation system at ELI-NP-GBS

    NASA Astrophysics Data System (ADS)

    Pellegriti, M. G.; Albergo, S.; Adriani, O.; Andreotti, M.; Berto, D.; Borgheresi, R.; Cappello, G.; Cardarelli, P.; Consoli, E.; Di Domenico, G.; Evangelisti, F.; Gambaccini, M.; Graziani, G.; Lenzi, M.; Marziani, M.; Palumbo, L.; Passaleva, G.; Paternò, G.; Serban, A.; Squerzanti, S.; Starodubtsev, O.; Tricomi, A.; Variola, A.; Veltri, M.; Zerbo, B.

    2017-03-01

    A Gamma Beam System (GBS), designed by the EuroGammaS collaboration, will be implemented for the ELI-NP facility in Magurele, Romania. The facility will deliver an intense gamma beam, obtained by collimatio of the emerging radiation from inverse Compton interaction. Gamma beam energy range will span from 0.2 up to 19.5 MeV with unprecedented performances in terms of brilliance, photon flux and energy bandwidth. For the characterisation of the gamma beam during the commissioning and normal operation, a full detection system has been designed to measure energy spectrum, beam intensity, space and time profiles. The gamma-beam characterisation system consists of four elements: a Compton spectrometer, to measure and monitor the photon energy spectrum, in particular the energy bandwidth; a sampling calorimeter, for a fast combined measurement of the beam average energy and its intensity; a nuclear resonant scattering spectrometer, for absolute beam energy calibration and inter-calibration of the other detector elements; and finally a beam profile imager to be used for alignment and diagnostics purposes. In this paper, a general overview of the ELI-NP gamma characterisation system will be given and the NRSS system will be in particular discussed.

  12. Ubiquitination of the common cytokine receptor {gamma}{sub c} and regulation of expression by an ubiquitination/deubiquitination machinery

    SciTech Connect

    Gesbert, Franck; Malarde, Valerie; Dautry-Varsat, Alice . E-mail: adautry@pasteur.fr

    2005-08-26

    The common cytokine receptor {gamma}{sub c} is shared by the interleukin-2, -4, -7, -9, -15, and -21 receptors, and is essential for lymphocyte proliferation and survival. The regulation of {gamma}{sub c} receptor expression level is therefore critical for the ability of cells to respond to these cytokines. We previously reported that {gamma}{sub c} is efficiently constitutively internalized and addressed towards a degradation endocytic compartment. We show that {gamma}{sub c} is ubiquitinated and also associated to ubiquitinated proteins. We report that the ubiquitin-ligase c-Cbl induces {gamma}{sub c} down-regulation. In addition, the ubiquitin-hydrolase, DUB-2, counteracts the effect of c-Cbl on {gamma}{sub c} expression. We show that an increase in DUB-2 expression correlates with an increased {gamma}{sub c} half-life, resulting in the up-regulation of the receptor. Altogether, we show that {gamma}{sub c} is the target of an ubiquitination mechanism and its expression level can be regulated through the activities of a couple of ubiquitin-ligase/ubiquitin-hydrolase enzymes, namely c-Cbl/DUB-2.

  13. Voltage Regulators for Photovoltaic Systems

    NASA Technical Reports Server (NTRS)

    Delombard, R.

    1986-01-01

    Two simple circuits developed to provide voltage regulation for highvoltage (i.e., is greater than 75 volts) and low-voltage (i.e., is less than 36 volts) photovoltaic/battery power systems. Use of these circuits results in voltage regulator small, low-cost, and reliable, with very low power dissipation. Simple oscillator circuit controls photovoltaic-array current to regulate system voltage and control battery charging. Circuit senses battery (and system) voltage and adjusts array current to keep battery voltage from exceeding maximum voltage.

  14. Comparative studies of transcriptional regulation mechanisms in a group of eight gamma-proteobacterial genomes.

    PubMed

    Espinosa, Vladimir; González, Abel D; Vasconcelos, Ana T; Huerta, Araceli M; Collado-Vides, Julio

    2005-11-18

    Experimental data on the Escherichia coli transcriptional regulation has enabled the construction of statistical models to predict new regulatory elements within its genome. Far less is known about the transcriptional regulatory elements in other gamma-proteobacteria with sequenced genomes, so it is of great interest to conduct comparative genomic studies oriented to extracting biologically relevant information about transcriptional regulation in these less studied organisms using the knowledge from E. coli. In this work, we use the information stored in the TRACTOR_DB database to conduct a comparative study on the mechanisms of transcriptional regulation in eight gamma-proteobacteria and 38 regulons. We assess the conservation of transcription factors binding specificity across all the eight genomes and show a correlation between the conservation of a regulatory site and the structure of the transcription unit it regulates. We also find a marked conservation of site-promoter distances across the eight organisms and a correspondence of the statistical significance of co-occurrence of pairs of transcription factor binding sites in the regulatory regions, which is probably related to a conserved architecture of higher-order regulatory complexes in the organisms studied. The results obtained in this study using the information on transcriptional regulation in E. coli enable us to conclude that not only transcription factor-binding sites are conserved across related species but also several of the transcriptional regulatory mechanisms previously identified in E. coli.

  15. Peroxisome proliferator-activated receptor-gamma agonist rosiglitazone attenuates postincisional pain by regulating macrophage polarization

    SciTech Connect

    Hasegawa-Moriyama, Maiko; Ohnou, Tetsuya; Godai, Kohei; Kurimoto, Tae; Nakama, Mayo; Kanmura, Yuichi

    2012-09-14

    Highlights: Black-Right-Pointing-Pointer Rosiglitazone attenuated postincisional pain. Black-Right-Pointing-Pointer Rosiglitazone alters macrophage polarization to F4/80{sup +}CD206{sup +} M2 macrophages at the incisional sites. Black-Right-Pointing-Pointer Transplantation of rosiglitazone-treated macrophages produced analgesic effects. -- Abstract: Acute inflammation triggered by macrophage infiltration to injured tissue promotes wound repair and may induce pain hypersensitivity. Peroxisome proliferator-activated receptor {gamma} (PPAR){gamma} signaling is known to regulate heterogeneity of macrophages, which are often referred to as classically activated (M1) and alternatively activated (M2) macrophages. M1 macrophages have considerable antimicrobial activity and produce a wide variety of proinflammatory cytokines. In contrast, M2 macrophages are involved in anti-inflammatory and homeostatic functions linked to wound healing and tissue repair. Although it has been suggested that PPAR{gamma} agonists attenuate pain hypersensitivity, the molecular mechanism of macrophage-mediated effects of PPAR{gamma} signaling on pain development has not been explored. In this study, we investigated the link between the phenotype switching of macrophage polarization induced by PPAR{gamma} signaling and the development of acute pain hypersensitivity. Local administration of rosiglitazone significantly ameliorated hypersensitivity to heat and mechanical stimuli, and paw swelling. Consistent with the down-regulation of nuclear factor {kappa}B (NF{kappa}B) phosphorylation by rosiglitazone at the incisional sites, the number of F4/80{sup +}iNOS{sup +} M1 macrophages was decreased whereas numbers of F4/80{sup +}CD206{sup +} M2 macrophages were increased in rosiglitazone-treated incisional sites 24 h after the procedure. In addition, gene induction of anti-inflammatory M2-macrophage-associated markers such as arginase1, FIZZ1 and interleukin (IL)-10 were significantly increased, whereas

  16. Neutron monitoring systems including gamma thermometers and methods of calibrating nuclear instruments using gamma thermometers

    DOEpatents

    Moen, Stephan Craig; Meyers, Craig Glenn; Petzen, John Alexander; Foard, Adam Muhling

    2012-08-07

    A method of calibrating a nuclear instrument using a gamma thermometer may include: measuring, in the instrument, local neutron flux; generating, from the instrument, a first signal proportional to the neutron flux; measuring, in the gamma thermometer, local gamma flux; generating, from the gamma thermometer, a second signal proportional to the gamma flux; compensating the second signal; and calibrating a gain of the instrument based on the compensated second signal. Compensating the second signal may include: calculating selected yield fractions for specific groups of delayed gamma sources; calculating time constants for the specific groups; calculating a third signal that corresponds to delayed local gamma flux based on the selected yield fractions and time constants; and calculating the compensated second signal by subtracting the third signal from the second signal. The specific groups may have decay time constants greater than 5.times.10.sup.-1 seconds and less than 5.times.10.sup.5 seconds.

  17. PI3K{gamma} activation by CXCL12 regulates tumor cell adhesion and invasion

    SciTech Connect

    Monterrubio, Maria; Mellado, Mario; Carrera, Ana C.

    2009-10-16

    Tumor dissemination is a complex process, in which certain steps resemble those in leukocyte homing. Specific chemokine/chemokine receptor pairs have important roles in both processes. CXCL12/CXCR4 is the most commonly expressed chemokine/chemokine receptor pair in human cancers, in which it regulates cell adhesion, extravasation, metastatic colonization, angiogenesis, and proliferation. All of these processes require activation of signaling pathways that include G proteins, phosphatidylinositol-3 kinase (PI3K), JAK kinases, Rho GTPases, and focal adhesion-associated proteins. We analyzed these pathways in a human melanoma cell line in response to CXCL12 stimulation, and found that PI3K{gamma} regulates tumor cell adhesion through mechanisms different from those involved in cell invasion. Our data indicate that, following CXCR4 activation after CXCL12 binding, the invasion and adhesion processes are regulated differently by distinct downstream events in these signaling cascades.

  18. Myocyte-specific M-CAT and MEF-1 elements regulate G-protein gamma 3 gene (gamma3) expression in cardiac myocytes.

    PubMed

    McWhinney, Charlene; Robishaw, Janet D

    2008-07-01

    Little is known regarding the mechanisms that control the expression of G-protein alpha, beta, and gamma subtypes. We have previously shown that the G-protein gamma(3) gene is expressed in the heart, brain, lung, spleen, kidney, muscle, and testis in mice. We have also reported that the G-protein gamma(3) subunit is expressed in rat cardiac myocytes, but not in cardiac fibroblasts. Other studies have shown that the gamma(3) subunit couples to the angiotensin A1A receptor in portal vein myocytes, and has been shown to mediate beta-adrenergic desensitization in cardiac myocytes treated with atorvastatin. In the present study, we evaluated G-protein gamma(3) promoter-luciferase reporter constructs in primary myocytes to identify key regulatory promoter regions. We identified two important regions of the promoter (upstream promoter region [UPR] and downstream promoter region [DPR]), which are required for expression in cardiac myocytes. We observed that removal of 48 bp in the UPR diminished gene transcription by 75%, and that the UPR contains consensus elements for myocyte-specific M-CAT and myocyte enhancer factor 1 (MEF-1) elements. The UPR and DPR share transcription factor elements for myocyte-specific M-CAT element. We observed that cardiac myocyte proteins bind to gamma(3) oligonucleotides containing transcription factor elements for myocyte-specific M-CAT and MEF-1. Myocyte-specific M-CAT proteins were supershifted with transcriptional enhancer factor-1 (TEF-1) antibodies binding to the gamma(3) M-CAT element, which is in agreement with reports showing that the M-CAT element binds the TEF-1 family of transcription factors. The 150 bp DPR contains three M-CAT elements, an INR element, an upstream stimulatory factor 1 element, and the transcription start site. We have shown that myocyte gamma(3) gene expression is regulated by myocyte-specific M-CAT and MEF-1 elements.

  19. Laser System for Livermore's Mono Energetic Gamma-Ray Source

    SciTech Connect

    Gibson, D; Albert, F; Bayramian, A; Marsh, R; Messerly, M; Ebbers, C; Hartemann, F

    2011-03-14

    A Mono-energetic Gamma-ray (MEGa-ray) source, based on Compton scattering of a high-intensity laser beam off a highly relativistic electron beam, requires highly specialized laser systems. To minimize the bandwidth of the {gamma}-ray beam, the scattering laser must have minimal bandwidth, but also match the electron beam depth of focus in length. This requires a {approx}1 J, 10 ps, fourier-transform-limited laser system. Also required is a high-brightness electron beam, best provided by a photoinjector. This electron source requires a second laser system with stringent requirements on the beam including flat transverse and longitudinal profiles and fast rise times. Furthermore, these systems must be synchronized to each other with ps-scale accuracy. Using a novel hyper-dispersion compressor configuration and advanced fiber amplifiers and diode-pumped Nd:YAG amplifiers, we have designed laser systems that meet these challenges for the X-band photoinjector and Compton-scattering source being built at Lawrence Livermore National Laboratory.

  20. syk protein tyrosine kinase regulates Fc receptor gamma-chain-mediated transport to lysosomes.

    PubMed Central

    Bonnerot, C; Briken, V; Brachet, V; Lankar, D; Cassard, S; Jabri, B; Amigorena, S

    1998-01-01

    B- and T-cell receptors, as well as most Fc receptors (FcR), are part of a large family of membrane proteins named immunoreceptors and are expressed on all cells of the immune system. Immunoreceptors' biological functions rely on two of their fundamental attributes: signal transduction and internalization. The signals required for these two functions are present in the chains associated with immunoreceptors, within conserved amino acid motifs called immunoreceptor tyrosine-based activation motifs (ITAMs). We have examined the role of the protein tyrosine kinase (PTK) syk, a critical effector of immunoreceptor-mediated cell signalling through ITAMs, in FcR-associated gamma-chain internalization and lysosomal targeting. A point mutation in the immunoreceptor-associated gamma-chain ITAM affecting syk activation, as well as overexpression of a syk dominant negative mutant, inhibited signal transduction without affecting receptor coated-pit localization or internalization. In contrast, blocking of gamma-chain-mediated syk activation impaired FcR transport from endosomes to lysosomes and selectively inhibited the presentation of certain T-cell epitopes. Therefore, activation of the PTK syk is dispensable for receptor internalization, but necessary for cell signalling and for gamma-chain-mediated FcR delivery to lysosomes. PMID:9707420

  1. Gamma-quanta onboard identification in the GAMMA-400 experiment using the counting and triggers signals formation system.

    NASA Astrophysics Data System (ADS)

    Arkhangelskaja, I. V.; Arkhangelskiy, A. I.; Chasovikov, E. N.; Galper, A. M.; Kheymits, M. D.; Murchenko, A. E.; Yurkin, Y. T.

    2016-02-01

    GAMMA-400 (Gamma Astronomical Multifunctional Modular Apparatus) will be the new generation satellite gamma-observatory. Gamma-telescope GAMMA-400 consists of anticoincidence system (top and lateral sections - ACtop and AClat), the converter-tracker (C), time-of-flight system (2 sections S1 and S2), position-sensitive calorimeter CC1 makes of 2 strips layers and 2 layers of CsI(Tl) detectors, electromagnetic calorimeter CC2 composed of CsI(Tl) crystals, neutron detector ND, scintillation detectors of the calorimeter (S3 and S4) and lateral detectors of the calorimeter (LD). All detector systems ACtop, AClat, S1-S4, LD consist of two BC-408 based sensitive layers of 1 cm thickness each. Three apertures provide events registration both from upper and lateral directions. The main aperture provides the best angular (all strip layers information analysis) and energy (energy deposition in the all detectors studying) resolution. Gamma-telescope GAMMA-400 is optimized for the gamma-quanta and charged particles with energy 100 GeV detection with the best parameters in the main aperture. Triggers in the main aperture will be formed using information about particle direction provided by time of flight system and presence of charged particle or backsplash signal formed according to analysis of energy deposition in combination of both layers anticoincidence systems ACtop and AClat individual detectors. For double-layer ACtop taking into account both amplitude and temporal trigger marker onboard analysis only 2.8% photons will be wrongly recognized as electrons or protons for 100 GeV particles. The part of charged particles mistakenly identified as gammas is ∼10-5 using described algorithms. For E∼3 GeV less than 3% photons will be wrongly recognized as charged particles and fraction of wrongly identified charged particles will be also ∼10-5. In the additional aperture the particles identification is provided by analysis of signals corresponding to energy deposition in the

  2. 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

  3. Positively regulated bacterial expression systems

    PubMed Central

    Brautaset, Trygve; Lale, Rahmi; Valla, Svein

    2009-01-01

    Summary Regulated promoters are useful tools for many aspects related to recombinant gene expression in bacteria, including for high‐level expression of heterologous proteins and for expression at physiological levels in metabolic engineering applications. In general, it is common to express the genes of interest from an inducible promoter controlled either by a positive regulator or by a repressor protein. In this review, we discuss established and potentially useful positively regulated bacterial promoter systems, with a particular emphasis on those that are controlled by the AraC‐XylS family of transcriptional activators. The systems function in a wide range of microorganisms, including enterobacteria, soil bacteria, lactic bacteria and streptomycetes. The available systems that have been applied to express heterologous genes are regulated either by sugars (l‐arabinose, l‐rhamnose, xylose and sucrose), substituted benzenes, cyclohexanone‐related compounds, ε‐caprolactam, propionate, thiostrepton, alkanes or peptides. It is of applied interest that some of the inducers require the presence of transport systems, some are more prone than others to become metabolized by the host and some have been applied mainly in one or a limited number of species. Based on bioinformatics analyses, the AraC‐XylS family of regulators contains a large number of different members (currently over 300), but only a small fraction of these, the XylS/Pm, AraC/PBAD, RhaR‐RhaS/rhaBAD, NitR/PnitA and ChnR/Pb regulator/promoter systems, have so far been explored for biotechnological applications. PMID:21261879

  4. Design and evaluation of an IDM-based MIMO FSO system over Gamma-Gamma turbulence channels

    NASA Astrophysics Data System (ADS)

    Zhang, Chenglei; Zhou, Xiaolin; Zheng, Xiaowei; Du, Jianhong

    2011-12-01

    In this paper, we design an interleave-division-multiplexing (IDM) based multiple-input multiple-output (MIMO) free-space optics (FSO) communication system. The system overcomes problems harassing conventional optical MIMO systems such as restrictions of antenna number and high complexity in receiver. An iterative on-off keying (OOK) modulated IDM MIMO detection algorithm is developed. Expression of an upper bound of frame-error-rate (FER) is derived. In addition, we evaluate the BER performance of the proposed optical MIMO scheme in various FSO scenarios. Simulations confirm that the proposed scheme can effectively increase the feasibility of FSO communications over Gamma-Gamma turbulence-induced fading channels.

  5. IFN-gamma expression is up-regulated by peripheral blood mononuclear cells (PBMC) from non-exposed dogs upon Leishmania chagasi promastigote stimulation in vitro.

    PubMed

    Rodrigues, Cleusa Alves Theodore; Batista, Luís Fábio da Silva; Filho, Roberto Santos Teixeira; Santos, Claire da Silva; Pinheiro, Cristiane Garboggini; Almeida, Taís Fontoura de; Freitas, Luiz Antônio Rodrigues de; Veras, Patrícia Sampaio Tavares

    2009-02-15

    While the response to Leishmania spp. is well characterized in mice and humans, much less is known concerning the canine immune response, particularly soon after exposure to the parasite. Early events are considered to be a determinant of infection outcome. To investigate the dog's early immune response to L. chagasi, an in vitro priming system (PIV) using dog naïve PBMC was established. Until now, dog PIV immune response to L. chagasi has not been assessed. We co-cultivated PBMC primarily stimulated with L. chagasi in vitro with autologous infected macrophages and found that IFN-gamma mRNA is up-regulated in these cells compared to control unstimulated cells. IL-4 and IL-10 mRNA expression by L. chagasi-stimulated PBMC was similar to control unstimulated PBMC when incubated with infected macrophages. Surprisingly, correlation studies showed that a lower IFN-gamma/IL-4 expression ratio correlated with a lower percentage of infection. We propose that the direct correlation between IFN-gamma/IL-4 ratio and parasite load is dependent on the higher correlation of both IFN-gamma and IL-4 expression with lower parasite infection. This PIV system was shown to be useful in evaluating the dog immune response to L. chagasi, and results indicate that a balance between IFN-gamma and IL-4 is associated with control of parasite infection in vitro.

  6. Photomultiplier tube gain regulating system

    DOEpatents

    Johnson, Wayne F.

    1976-01-01

    This invention relates to an improved system for regulating the gain of a photomultiplier tube, and was designed for use with the photomultiplier tubes of a GeMSAEC fast analyzers. It has the following advantages over the prior system: noise is virtually eliminated; sample analysis can begin after 3 to 4 revolutions of the rotor; fluorescent and light scattering solutions can be used as a reference; and the reference solution can be in any cuvette on the rotor.

  7. Selective regulation of long-form calcium-permeable AMPA receptors by an atypical TARP, gamma-5.

    PubMed

    Soto, David; Coombs, Ian D; Renzi, Massimiliano; Zonouzi, Marzieh; Farrant, Mark; Cull-Candy, Stuart G

    2009-03-01

    Although the properties and trafficking of AMPA-type glutamate receptors (AMPARs) depend critically on associated transmembrane AMPAR regulatory proteins (TARPs) such as stargazin (gamma-2), no TARP has been described that can specifically regulate the important class of calcium-permeable (CP-) AMPARs. We examined the stargazin-related protein gamma-5, which is highly expressed in Bergmann glia, a cell type possessing only CP-AMPARs. gamma-5 was previously thought not to be a TARP, and it has been widely used as a negative control. Here we find that, contrary to expectation, gamma-5 acts as a TARP and serves this role in Bergmann glia. Whereas gamma-5 interacts with all AMPAR subunits, and modifies their behavior to varying extents, its main effect is to regulate the function of AMPAR subunit combinations that lack short-form subunits, which constitute predominantly CP-AMPARs. Our results suggest an important role for gamma-5 in regulating the functional contribution of CP-AMPARs.

  8. Inverse Fourier Transform in the Gamma Coordinate System

    PubMed Central

    Wei, Yuchuan; Yu, Hengyong; Wang, Ge

    2011-01-01

    This paper provides auxiliary results for our general scheme of computed tomography. In 3D parallel-beam geometry, we first demonstrate that the inverse Fourier transform in different coordinate systems leads to different reconstruction formulas and explain why the Radon formula cannot directly work with truncated projection data. Also, we introduce a gamma coordinate system, analyze its properties, compute the Jacobian of the coordinate transform, and define weight functions for the inverse Fourier transform assuming a simple scanning model. Then, we generate Orlov's theorem and a weighted Radon formula from the inverse Fourier transform in the new system. Furthermore, we present the motion equation of the frequency plane and the conditions for sharp points of the instantaneous rotation axis. Our analysis on the motion of the frequency plane is related to the Frenet-Serret theorem in the differential geometry. PMID:21076520

  9. Gamma-quanta and charged particles recognition by the counting and triggers signals formation system of GAMMA-400 space gamma-telescope

    NASA Astrophysics Data System (ADS)

    Arkhangelskaja, I. V.; Arkhangelskiy, A. I.; Chasovikov, E. N.; Kheymits, M. D.; Yurkin, Y. T.; Galper, A. M.; Suchkov, S. I.; Topchiev, N. P.; Murchenko, A. E.

    2017-01-01

    Registered events identification procedures details in three apertures of gamma-telescope GAMMA-400 are discussed in the presented article for gammas, electrons/positrons and protons both in low and high energy bands. Gamma-telescope GAMMA-400 consists of the converter-tracker (C) surrounded by anticoincidence system, time-of-flight system (2 sections S1 and S2) and calorimeter. Anticoincidence system will make of top and lateral sections - ACtop and AClat, time-of-flight system TOF contain 2 segments S1 and S2. Calorimeter consists of position-sensitive calorimeter CC1 makes of 2 strips layers and 2 layers of CsI(Tl) detectors and electromagnetic calorimeter CC2 composed of CsI(Tl) crystals surrounded by plastic lateral detectors LD. Scintillation detectors of the calorimeter S3 and S4 placed correspondingly between CC1 and CC2 and after electromagnetic calorimeter. All segments of detector systems ACtop, AClat, S1-S4, LD composed of two BC-408 based sensitive layers thickness of 1 cm each. Events registration both from upper and lateral directions provides due three apertures: main, additional and lateral. GAMMA-400 parameters are optimized for detection of gamma-quanta with the energy ∼ 100 GeV in the main aperture. Gammas, electrons/positrons and protons recognition in main aperture provides due energy deposition analysis in individual detectors of ACtop, AClat, S1-S3 and CC1 individual scintillator detectors discriminators. Particles identification in the additional aperture supplied by study of energy deposition in the individual detectors S2, S3 and position-sensitive calorimeter individual scintillator detectors discriminators. In the lateral aperture low energy (0.2 - 100 MeV) photons classified by using simple anticoincidence signals from the individual detectors of LD and CC2. Higher energies γ-quanta (E>100 MeV) recognized using energy deposition analysis in the individual detectors of S3, S4, LD and CC2.

  10. A Mobile Automated Tomographic Gamma Scanning System - 13231

    SciTech Connect

    Kirkpatrick, J.M.; LeBlanc, P.J.; Nakazawa, D.; Petroka, D.L.; Kane Smith, S.; Venkataraman, R.; Villani, M.

    2013-07-01

    Canberra Industries have recently designed and built a new automated Tomographic Gamma Scanning (TGS) system for mobile deployment. The TGS technique combines high-resolution gamma spectroscopy with low spatial resolution 3-dimensional image reconstruction to provide increased accuracy over traditional approaches for the assay of non-uniform source distributions in low-to medium-density, non-heterogeneous matrices. Originally pioneered by R. Estep at Los Alamos National Laboratory (LANL), the TGS method has been further developed and commercialized by Canberra Industries in recent years. The present system advances the state of the art on several fronts: it is designed to be housed in a standard cargo transport container for ease of transport, allowing waste characterization at multiple facilities under the purview of a single operator. Conveyor feed, drum rotator, and detector and collimator positioning mechanisms operated by programmable logic control (PLC) allow automated batch mode operation. The variable geometry settings can accommodate a wide range of waste packaging, including but not limited to standard 220 liter drums, 380 liter overpack drums, and smaller 20 liter cans. A 20 mCi Eu-152 transmission source provides attenuation corrections for drum matrices up to 1 g/cm{sup 3} in TGS mode; the system can be operated in Segmented Gamma Scanning (SGS) mode to measure higher density drums. To support TGS assays at higher densities, the source shield is sufficient to house an alternate Co-60 transmission source of higher activity, up to 250 mCi. An automated shutter and attenuator assembly is provided for operating the system with a dual intensity transmission source. The system's 1500 kg capacity rotator turntable can handle heavy containers such as concrete lined 380 liter overpack drums. Finally, data acquisition utilizes Canberra's Broad Energy Germanium (BEGE) detector and Lynx MCA, with 32 k channels, providing better than 0.1 keV/channel resolution to

  11. Software for Control and Measuring Instrumentation of the GAMMA-400 Gamma-telescope Fast Scintillator Detector System

    NASA Astrophysics Data System (ADS)

    Naumov, P. P.; Naumov, P. Yu.; Runtso, M. F.; Solodovnikov, A. A.

    Currently, the final stage of the ground tests for the technological detector of the high-energy gamma-ray telescope (GRT) GAMMA-400 are finished. The new space GRT will accept the gamma-rays with energy more than 400 MeV and is aimed to open our eyes for so-called "dark matter" problem in the Universe. The high-speed scintillation detectors system (SDS) is used one of the main GRT particle detectors and the good ground test measurements will let the future space mission to get the reliable data. This paper describes the software and hardware of the laboratory control and calibration systems for physical measurements of GRT STDS properties.

  12. Comparative genomic analysis of regulation of anaerobic respiration in ten genomes from three families of gamma-proteobacteria (Enterobacteriaceae, Pasteurellaceae, Vibrionaceae)

    PubMed Central

    Ravcheev, Dmitry A; Gerasimova, Anna V; Mironov, Andrey A; Gelfand, Mikhail S

    2007-01-01

    Background Gamma-proteobacteria, such as Escherichia coli, can use a variety of respiratory substrates employing numerous aerobic and anaerobic respiratory systems controlled by multiple transcription regulators. Thus, in E. coli, global control of respiration is mediated by four transcription factors, Fnr, ArcA, NarL and NarP. However, in other Gamma-proteobacteria the composition of global respiration regulators may be different. Results In this study we applied a comparative genomic approach to the analysis of three global regulatory systems, Fnr, ArcA and NarP. These systems were studied in available genomes containing these three regulators, but lacking NarL. So, we considered several representatives of Pasteurellaceae, Vibrionaceae and Yersinia spp. As a result, we identified new regulon members, functioning in respiration, central metabolism (glycolysis, gluconeogenesis, pentose phosphate pathway, citrate cicle, metabolism of pyruvate and lactate), metabolism of carbohydrates and fatty acids, transcriptional regulation and transport, in particular: the ATP synthase operon atpIBEFHAGCD, Na+-exporting NADH dehydrogenase operon nqrABCDEF, the D-amino acids dehydrogenase operon dadAX. Using an extension of the comparative technique, we demonstrated taxon-specific changes in regulatory interactions and predicted taxon-specific regulatory cascades. Conclusion A comparative genomic technique was applied to the analysis of global regulation of respiration in ten gamma-proteobacterial genomes. Three structurally different but functionally related regulatory systems were described. A correlation between the regulon size and the position of a transcription factor in regulatory cascades was observed: regulators with larger regulons tend to occupy top positions in the cascades. On the other hand, there is no obvious link to differences in the species' lifestyles and metabolic capabilities. PMID:17313674

  13. Method and System for Gamma-Ray Localization Induced Spacecraft Navigation Using Celestial Gamma-Ray Sources

    NASA Technical Reports Server (NTRS)

    Sheikh, Suneel I. (Inventor); Hisamoto, Chuck (Inventor); Arzoumanian, Zaven (Inventor)

    2015-01-01

    A method and system for spacecraft navigation using distant celestial gamma-ray bursts which offer detectable, bright, high-energy events that provide well-defined characteristics conducive to accurate time-alignment among spatially separated spacecraft. Utilizing assemblages of photons from distant gamma-ray bursts, relative range between two spacecraft can be accurately computed along the direction to each burst's source based upon the difference in arrival time of the burst emission at each spacecraft's location. Correlation methods used to time-align the high-energy burst profiles are provided. The spacecraft navigation may be carried out autonomously or in a central control mode of operation.

  14. The structure, logic of operation and distinctive features of the system of triggers and counting signals formation for gamma-telescope GAMMA-400

    NASA Astrophysics Data System (ADS)

    Topchiev, N. P.; Galper, A. M.; Arkhangelskiy, A. I.; Arkhangelskaja, I. V.; Kheymits, M. D.; Suchkov, S. I.; Yurkin, Y. T.

    2017-01-01

    Scientific project GAMMA-400 (Gamma Astronomical Multifunctional Modular Apparatus) relates to the new generation of space observatories intended to perform an indirect search for signatures of dark matter in the cosmic-ray fluxes, measurements of characteristics of diffuse gamma-ray emission and gamma-rays from the Sun during periods of solar activity, gamma-ray bursts, extended and point gamma-ray sources, electron/positron and cosmic-ray nuclei fluxes up to TeV energy region by means of the GAMMA-400 gamma-ray telescope represents the core of the scientific complex. The system of triggers and counting signals formation of the GAMMA-400 gamma-ray telescope constitutes the pipelined processor structure which collects data from the gamma-ray telescope subsystems and produces summary information used in forming the trigger decision for each event. The system design is based on the use of state-of-the-art reconfigurable logic devices and fast data links. The basic structure, logic of operation and distinctive features of the system are presented.

  15. The agile alert system for gamma-ray transients

    SciTech Connect

    Bulgarelli, A.; Trifoglio, M.; Gianotti, F.; Fioretti, V.; Chen, A. W.; Pittori, C.; Verrecchia, F.; Lucarelli, F.; Santolamazza, P.; Fanari, G.; Giommi, P.; Pellizzoni, A.; and others

    2014-01-20

    In recent years, a new generation of space missions has offered great opportunities for discovery in high-energy astrophysics. In this article we focus on the scientific operations of the Gamma-Ray Imaging Detector (GRID) on board the AGILE space mission. AGILE-GRID, sensitive in the energy range of 30 MeV-30 GeV, has detected many γ-ray transients of both galactic and extragalactic origin. This work presents the AGILE innovative approach to fast γ-ray transient detection, which is a challenging task and a crucial part of the AGILE scientific program. The goals are to describe (1) the AGILE Gamma-Ray Alert System, (2) a new algorithm for blind search identification of transients within a short processing time, (3) the AGILE procedure for γ-ray transient alert management, and (4) the likelihood of ratio tests that are necessary to evaluate the post-trial statistical significance of the results. Special algorithms and an optimized sequence of tasks are necessary to reach our goal. Data are automatically analyzed at every orbital downlink by an alert pipeline operating on different timescales. As proper flux thresholds are exceeded, alerts are automatically generated and sent as SMS messages to cellular telephones, via e-mail, and via push notifications from an application for smartphones and tablets. These alerts are crosschecked with the results of two pipelines, and a manual analysis is performed. Being a small scientific-class mission, AGILE is characterized by optimization of both scientific analysis and ground-segment resources. The system is capable of generating alerts within two to three hours of a data downlink, an unprecedented reaction time in γ-ray astrophysics.

  16. The AGILE Alert System for Gamma-Ray Transients

    NASA Astrophysics Data System (ADS)

    Bulgarelli, A.; Trifoglio, M.; Gianotti, F.; Tavani, M.; Parmiggiani, N.; Fioretti, V.; Chen, A. W.; Vercellone, S.; Pittori, C.; Verrecchia, F.; Lucarelli, F.; Santolamazza, P.; Fanari, G.; Giommi, P.; Beneventano, D.; Argan, A.; Trois, A.; Scalise, E.; Longo, F.; Pellizzoni, A.; Pucella, G.; Colafrancesco, S.; Conforti, V.; Tempesta, P.; Cerone, M.; Sabatini, P.; Annoni, G.; Valentini, G.; Salotti, L.

    2014-01-01

    In recent years, a new generation of space missions has offered great opportunities for discovery in high-energy astrophysics. In this article we focus on the scientific operations of the Gamma-Ray Imaging Detector (GRID) on board the AGILE space mission. AGILE-GRID, sensitive in the energy range of 30 MeV-30 GeV, has detected many γ-ray transients of both galactic and extragalactic origin. This work presents the AGILE innovative approach to fast γ-ray transient detection, which is a challenging task and a crucial part of the AGILE scientific program. The goals are to describe (1) the AGILE Gamma-Ray Alert System, (2) a new algorithm for blind search identification of transients within a short processing time, (3) the AGILE procedure for γ-ray transient alert management, and (4) the likelihood of ratio tests that are necessary to evaluate the post-trial statistical significance of the results. Special algorithms and an optimized sequence of tasks are necessary to reach our goal. Data are automatically analyzed at every orbital downlink by an alert pipeline operating on different timescales. As proper flux thresholds are exceeded, alerts are automatically generated and sent as SMS messages to cellular telephones, via e-mail, and via push notifications from an application for smartphones and tablets. These alerts are crosschecked with the results of two pipelines, and a manual analysis is performed. Being a small scientific-class mission, AGILE is characterized by optimization of both scientific analysis and ground-segment resources. The system is capable of generating alerts within two to three hours of a data downlink, an unprecedented reaction time in γ-ray astrophysics.

  17. Instructions for calibrating gamma detectors using the Canberra-Nuclear Data Genie Gamma Spectroscopy System

    SciTech Connect

    Brunk, J.L.

    1995-09-01

    A straight forward protocol provides a way to guide the calibration of a gamma detector for a particular geometry and material. Several programs have used the Low Level Gamma Counting Facility of the Health and Ecological Assessment Division of the Lawrence Livermore National Laboratory to count a variety of large environmental samples contained in several unique geometries. The equipment and calibration requirements needed to analyze these types of samples are explained. This document describes the calibration protocol that has been developed and describes how it is used to calibrate the detectors.

  18. The Advanced Gamma-Ray Imaging System (AGIS): Science Highlights

    SciTech Connect

    Buckley, J.; Coppi, P.; Digel, S.; Funk, S.; Krawczynski, H.; Krennrich, F.; Pohl, M.; Romani, R.; Vassiliev, V.; /UCLA

    2011-11-21

    The Advanced Gamma-ray Imaging System (AGIS), a future gamma-ray telescope consisting of an array of {approx}50 atmospheric Cherenkov telescopes distributed over an area of {approx}1 km{sup 2}, will provide a powerful new tool for exploring the high-energy universe. The order-of-magnitude increase in sensitivity and improved angular resolution could provide the first detailed images of {gamma}-ray emission from other nearby galaxies or galaxy clusters. The large effective area will provide unprecedented sensitivity to short transients (such as flares from AGNs and GRBs) probing both intrinsic spectral variability (revealing the details of the acceleration mechanism and geometry) as well as constraining the high-energy dispersion in the velocity of light (probing the structure of spacetime and Lorentz invariance). A wide field of view ({approx}4 times that of current instruments) and excellent angular resolution (several times better than current instruments) will allow for an unprecedented survey of the Galactic plane, providing a deep unobscured survey of SNRs, X-ray binaries, pulsar-wind nebulae, molecular cloud complexes and other sources. The differential flux sensitivity of {approx}10{sup -13} erg cm{sup -2} sec{sup -1} will rival the most sensitive X-ray instruments for these extended Galactic sources. The excellent capabilities of AGIS at energies below 100 GeV will provide sensitivity to AGN and GRBs out to cosmological redshifts, increasing the number of AGNs detected at high energies from about 20 to more than 100, permitting population studies that will provide valuable insights into both a unified model for AGN and a detailed measurement of the effects of intergalactic absorption from the diffuse extragalactic background light. A new instrument with fast-slewing wide-field telescopes could provide detections of a number of long-duration GRBs providing important physical constraints from this new spectral component. The new array will also have excellent

  19. Demonstration of lightweight gamma spectrometry systems in urban environments.

    PubMed

    Cresswell, A J; Sanderson, D C W; Harrold, M; Kirley, B; Mitchell, C; Weir, A

    2013-10-01

    Urban areas present highly complex radiation environments; with small scale features resulting from different construction materials, topographic effects and potential anthropogenic inputs from past industrial activity or other sources. Mapping of the radiation fields in urban areas allows a detailed assessment of exposure pathways for the people who live and work there, as well as locating discrete sources of activity that may warrant removal to mitigate dose to the general public. These areas also present access difficulties for radiometric mapping using vehicles or aircraft. A lightweight portable gamma spectrometry system has been used to survey sites in the vicinity of Glasgow to demonstrate the possibilities of radiometric mapping of urban areas, and to investigate the complex radiometric features such areas present. Variations in natural activity due to construction materials have been described, the presence of (137)Cs used to identify relatively undisturbed ground, and a previously unknown NORM feature identified. The effect of topographic enclosure on measurements of activity concentration has been quantified. The portable system is compared with the outputs that might be expected from larger vehicular or airborne systems. For large areas airborne surveys are the most cost effective approach, but provide limited spatial resolution, vehicular surveys can provide sparse exploratory data rapidly or detailed mapping of open areas where off-road access is possible. Backpack systems are ideally suited to detailed surveys of small areas, especially where vehicular access is difficult.

  20. A Case Study Correlating Innovative Gamma Ray Scanning Detection Systems Data to Surface Soil Gamma Spectrometry Results - 13580

    SciTech Connect

    Thompson, Shannon; Rodriguez, Rene; Billock, Paul; Lit, Peter

    2013-07-01

    HydroGeoLogic (HGL), Inc. completed a United States Environmental Protection Agency (USEPA) study to characterize radiological contamination at a site near Canoga Park, California. The characterized area contained 470 acres including the site of a prototype commercial nuclear reactor and other nuclear design, testing, and support operations from the 1950's until 1988 [1]. The site history included radiological releases during operation followed by D and D activities. The characterization was conducted under an accelerated schedule and the results will support the project remediation. The project has a rigorous cleanup to background agenda and does not allow for comparison to risk-based guidelines. To target soil sample locations, multiple lines of evidence were evaluated including a gamma radiation survey, geophysical surveys, historical site assessment, aerial photographs, and former worker interviews. Due to the time since production and decay, the primary gamma emitting radionuclide remaining is cesium-137 (Cs-137). The gamma ray survey covered diverse, rugged terrain using custom designed sodium iodide thallium-activated (NaI(Tl)) scintillation detection systems. The survey goals included attaining 100% ground surface coverage and detecting gamma radiation as sensitively as possible. The effectiveness of innovative gamma ray detection systems was tested by correlating field Cs-137 static count ratios to Cs-137 laboratory gamma spectrometry results. As a case study, the area encompassing the former location of the first nuclear power station in the U. S. was scanned, and second by second global positioning system (GPS)-linked gamma spectral data were evaluated by examining total count rate and nuclide-specific regions of interest. To compensate for Compton scattering from higher energy naturally occurring radionuclides (U-238, Th-232 and their progeny, and K-40), count rate ratios of anthropogenic nuclide-specific regions of interest to the total count rate were

  1. [Cannabinoid system and feeding regulation].

    PubMed

    Arias Horcajadas, Francisco

    2008-01-01

    There is increasing evidence to suggest that the cannabinoid system is a crucial mechanism in the regulation of feeding and metabolism. It is against this background that a cannabinoid antagonist, rimonabant, is about to come onto the market for the treatment of obesity. Moreover, in addition to weight-loss effect, this drug has a beneficial effect on the so-called metabolic syndrome, with changes in the lipid and glucidic metabolism not observed for other anti-obesity drugs currently available. We present a review of current knowledge in this field and data from our own studies: genetic studies of this system in eating disorders and in obesity and studies of localization of cannabinoid receptors at sites related to feeding. These studies support a state of cannabinoid hyperactivity in obesity; furthermore, such hyperactivity can constitute a prognostic factor.

  2. 5-HT3a Receptors Modulate Hippocampal Gamma Oscillations by Regulating Synchrony of Parvalbumin-Positive Interneurons.

    PubMed

    Huang, Ying; Yoon, Kristopher; Ko, Ho; Jiao, Song; Ito, Wataru; Wu, Jian-Young; Yung, Wing-Ho; Lu, Bai; Morozov, Alexei

    2016-02-01

    Gamma-frequency oscillatory activity plays an important role in information integration across brain areas. Disruption in gamma oscillations is implicated in cognitive impairments in psychiatric disorders, and 5-HT3 receptors (5-HT3Rs) are suggested as therapeutic targets for cognitive dysfunction in psychiatric disorders. Using a 5-HT3aR-EGFP transgenic mouse line and inducing gamma oscillations by carbachol in hippocampal slices, we show that activation of 5-HT3aRs, which are exclusively expressed in cholecystokinin (CCK)-containing interneurons, selectively suppressed and desynchronized firings in these interneurons by enhancing spike-frequency accommodation in a small conductance potassium (SK)-channel-dependent manner. Parvalbumin-positive interneurons therefore received diminished inhibitory input leading to increased but desynchronized firings of PV cells. As a consequence, the firing of pyramidal neurons was desynchronized and gamma oscillations were impaired. These effects were independent of 5-HT3aR-mediated CCK release. Our results therefore revealed an important role of 5-HT3aRs in gamma oscillations and identified a novel crosstalk among different types of interneurons for regulation of network oscillations. The functional link between 5-HT3aR and gamma oscillations may have implications for understanding the cognitive impairments in psychiatric disorders.

  3. Gamma-ray imaging system. Innovative technology summary report

    SciTech Connect

    1998-11-01

    The RadScan 600 gamma-ray imaging system is designed to survey large surface areas for radiological contamination with accuracy and efficiency. The resulting survey data are clear, concise, and precise in describing how much contamination is present at exact locations. Data can be permanently stored electronically and on video tape, making storage and retrieval economical and efficient. This technology can perform accurate measurements in high radiation contamination areas while minimizing worker exposure. The RadScan 600 system is a safe and effective alternative to hand-held radiation detection devices. Performance data of the demonstrated survey area of the RadScan 600 system versus the baseline, which is the hand-held radiation detection devices (RO-2 and RO-7) for a given survey, production rate is 72% of the baseline. It should be noted that the innovative technology provides 100% coverage at a unit cost of $8.64/m{sup 2} versus a static measurement of a unit cost of $1.61/m{sup 2} for the baseline.

  4. T Cell Mineralocorticoid Receptor Controls Blood Pressure by Regulating Interferon Gamma.

    PubMed

    Sun, Xue Nan; Li, Chao; Liu, Yuan; Du, Lin-Juan; Zeng, Meng-Ru; Zheng, Xiao Jun; Zhang, Wu Chang; Liu, Yan; Zhu, Mingjiang; Kong, Deping; Zhou, Li; Lu, Limin; Shen, Zhu-Xia; Yi, Yi; Du, Lili; Qin, Mu; Liu, Xu; Hua, Zichun; Sun, Shuyang; Yin, Huiyong; Zhou, Bin; Yu, Ying; Zhang, Zhiyuan; Duan, Sheng-Zhong

    2017-03-15

    Rationale: Hypertension remains to be a global public health burden and demands novel intervention strategies such as targeting T cells and T cell-derived cytokines. Mineralocorticoid receptor (MR) antagonists have been clinically used to treat hypertension. However, the function of T cell MR in blood pressure (BP) regulation has not been elucidated. Objective: We aim to determine the role of T cell MR in BP regulation and to explore the mechanism. Methods and Results: Using T cell MR knockout (TMRKO) mouse in combination with angiotensin II (AngII)-induced hypertensive mouse model, we demonstrated that MR deficiency in T cells strikingly decreased both systolic and diastolic BP, and attenuated renal and vascular damage. Flow cytometric analysis showed that TMRKO mitigated AngII-induced accumulation of interferon-gamma (IFNγ)-producing T cells, particularly CD8(+) population, in both kidneys and aortas. Similarly, eplerenone attenuated AngII-induced elevation of BP and accumulation of IFNγ-producing T cells in wild type mice. In cultured CD8(+) T cells, TMRKO suppressed IFNγ expression whereas T cell MR overexpression and aldosterone both enhanced IFNγ expression. At the molecular level, MR interacted with nuclear factor of activated T-cells 1 (NFAT1) and activator protein-1 (AP-1) in T cells. Finally, T cell MR overexpressing mice manifested more elevated BP compared to control mice after AngII infusion and such difference was abolished by IFNγ-neutralizing antibodies. Conclusions: MR may interact with NFAT1 and AP-1 to control IFNγ in T cells, and to regulate target organ damage and ultimately BP. Targeting MR in T cells specifically may be an effective novel approach for hypertension treatment.

  5. SER Analysis of MPPM-Coded MIMO-FSO System over Uncorrelated and Correlated Gamma-Gamma Atmospheric Turbulence Channels

    NASA Astrophysics Data System (ADS)

    Khallaf, Haitham S.; Garrido-Balsells, José M.; Shalaby, Hossam M. H.; Sampei, Seiichi

    2015-12-01

    The performance of multiple-input multiple-output free space optical (MIMO-FSO) communication systems, that adopt multipulse pulse position modulation (MPPM) techniques, is analyzed. Both exact and approximate symbol-error rates (SERs) are derived for both cases of uncorrelated and correlated channels. The effects of background noise, receiver shot-noise, and atmospheric turbulence are taken into consideration in our analysis. The random fluctuations of the received optical irradiance, produced by the atmospheric turbulence, is modeled by the widely used gamma-gamma statistical distribution. Uncorrelated MIMO channels are modeled by the α-μ distribution. A closed-form expression for the probability density function of the optical received irradiance is derived for the case of correlated MIMO channels. Using our analytical expressions, the degradation of the system performance with the increment of the correlation coefficients between MIMO channels is corroborated.

  6. Bacterial expression system with tightly regulated gene expression and plasmid copy number.

    PubMed

    Bowers, Lisa M; Lapoint, Kathleen; Anthony, Larry; Pluciennik, Anna; Filutowicz, Marcin

    2004-09-29

    A new Escherichia coli host/vector system has been engineered to allow tight and uniform modulation of gene expression and gamma origin (ori) plasmid copy number. Regulation of gamma ori plasmid copy number is achieved through arabinose-inducible expression of the necessary Rep protein, pi, whose gene was integrated into the chromosome of the host strain under control of the P(BAD) promoter. gamma ori replication can be uniformly modulated over 100-fold by changing the concentration of l-arabinose in the growth medium. This strain avoids the problem of all-or-nothing induction of P(BAD) because it is deficient in both arabinose uptake and degradation genes. Arabinose enters the cell by a mutant LacY transporter, LacYA177C, which is expressed from the host chromosome. Although this strain could be compatible with any gamma ori plasmid, we describe the utility of a gamma ori expression vector that allows especially tight regulation of gene expression. With this host/vector system, it is possible to independently modulate gene expression and gene dosage, facilitating the cloning and overproduction of toxic gene products. We describe the successful use of this system for cloning a highly potent toxin, Colicin E3, in the absence of its cognate immunity protein. This system could be useful for cloning genes encoding other potent toxins, screening libraries for potential toxins, and maintaining any gamma ori vector at precise copy levels in a cell.

  7. Experimental study of the vidicon system for information recording using the wide-gap spark chamber of gamma - telescope gamma-I

    NASA Technical Reports Server (NTRS)

    Akimov, V. V.; Bazer-Bashv, R.; Voronov, S. A.; Galper, A. M.; Gro, M.; Kalinkin, L. F.; Kerl, P.; Kozlov, V. D.; Koten, F.; Kretol, D.

    1979-01-01

    The development of the gamma ray telescope is investigated. The wide gap spark chambers, used to identify the gamma quanta and to determine the directions of their arrival, are examined. Two systems of information recording with the spark chambers photographic and vidicon system are compared.

  8. Shunt regulation electric power system

    NASA Technical Reports Server (NTRS)

    Wright, W. H.; Bless, J. J. (Inventor)

    1971-01-01

    A regulated electric power system having load and return bus lines is described. A plurality of solar cells interconnected in a power supplying relationship and having a power shunt tap point electrically spaced from the bus lines is provided. A power dissipator is connected to the shunt tap point and provides for a controllable dissipation of excess energy supplied by the solar cells. A dissipation driver is coupled to the power dissipator and controls its conductance and dissipation and is also connected to the solar cells in a power taping relationship to derive operating power therefrom. An error signal generator is coupled to the load bus and to a reference signal generator to provide an error output signal which is representative of the difference between the electric parameters existing at the load bus and the reference signal generator. An error amplifier is coupled to the error signal generator and the dissipation driver to provide the driver with controlling signals.

  9. Innovative Gamma Ray Spectrometer Detection Systems for Conducting Scanning Surveys on Challenging Terrain - 13583

    SciTech Connect

    Palladino, Carl; Mason, Bryan; Engle, Matt; LeVangie, James; Dempsey, Gregg; Klemovich, Ron

    2013-07-01

    The Santa Susana Field Laboratory located near Simi Valley, California was investigated to determine the nature and extent of gamma radiation anomalies. The primary objective was to conduct gamma scanning surveys over 100 percent of the approximately 1,906,000 square meters (471 acre) project site with the most sensitive detection system possible. The site had challenging topography that was not conducive to traditional gamma scanning detection systems. Terrain slope varied from horizontal to 48 degrees and the ground surface ranged from flat, grassy meadows to steep, rocky hillsides. In addition, the site was home to many protected endangered plant and animal species, and archaeologically significant sites that required minimal to no disturbance of the ground surface. Therefore, four innovative and unique gamma ray spectrometer detection systems were designed and constructed to successfully conduct gamma scanning surveys of approximately 1,076,000 square meters (266 acres) of the site. (authors)

  10. Neutron interrogation system using high gamma ray signature to detect contraband special nuclear materials in cargo

    DOEpatents

    Slaughter, Dennis R.; Pohl, Bertram A.; Dougan, Arden D.; Bernstein, Adam; Prussin, Stanley G.; Norman, Eric B.

    2008-04-15

    A system for inspecting cargo for the presence of special nuclear material. The cargo is irradiated with neutrons. The neutrons produce fission products in the special nuclear material which generate gamma rays. The gamma rays are detecting indicating the presence of the special nuclear material.

  11. Performance analysis of free space optical system with spatial modulation and diversity combiners over the Gamma Gamma atmospheric turbulence

    NASA Astrophysics Data System (ADS)

    Odeyemi, Kehinde O.; Owolawi, Pius A.; Srivastava, Viranjay M.

    2017-01-01

    Atmospheric turbulence is a major impairment that degrades the performance of free space optical (FSO) communication systems. Spatial modulation (SM) with receive spatial diversity is considered as a powerful technique to mitigate the fading effect induced by atmospheric turbulence. In this paper, the performance of free space optical spatial modulation (FSO-SM) system under Gamma-Gamma atmospheric turbulence is presented. We studied the Average Bit Error Rate (ABER) for the system by employing spatial diversity combiners such Maximum Ratio Combining (MRC) and Equal Gain Combining (EGC) at the receiving end. In particular, we provide a theoretical framework for the system error by deriving Average Pairwise Error Probability (APEP) expression using a generalized infinite power series expansion approach and union bounding technique is applied to obtain the ABER for each combiner. Based on this study, it was found that spatial diversity combiner significantly improved the system error rate where MRC outperforms the EGC. The performance of this system is also compared with other well established diversity combiner systems. The proposed system performance is further improved by convolutional coding technique and our analysis confirmed that the system performance of MRC coded system is enhanced by approximately 20 dB while EGC falls within 17 dB.

  12. Impact of gamma rays exposure and growth regulators on Oryza sativa L. c.v MR269 callus induction

    NASA Astrophysics Data System (ADS)

    Kadhimi, Ahsan A.; Zain, Che Radziah Che Mohd; Alhasnawi, Arshad Naji; Isahak, Anizan; Ashraf, Mehdi Farshad; Mohamad, Azhar; Doni, Febri; Yusoff, Wan Mohtar Wan

    2016-11-01

    The study is aimed to evaluate in vitro somatic embryogenesis to gamma ray exposure and the use of growth regulators to mature embryos explants for rice callus induction. Seeds of local rice genotype (MR269) were exposed to gamma rays at 350 Gy (Source: Caesium-137). Matured embryos were cultured to induce callus on Murashige and Skoog (MS) supplemented at different concentrations of 1.0, 2.0, 3.0 mg/L 2.4-D and 0.1 and 0.2 mg/L Kinetin for 4 weeks. Callus induction and callus fresh weight were decreased after exposure to gamma ray. The most efficient response to callus induction and callus fresh weight was found at 3 mg/L 2,4-D and 0.1 mg/L kinetin.

  13. Human IFN-gamma up-regulates IL-2 receptors in mitogen-activated T lymphocytes.

    PubMed Central

    Rodriguez, M A; De Sanctis, J B; Blasini, A M; Leon-Ponte, M; Abadi, I

    1990-01-01

    This study examined the role of human recombinant interferon-gamma (rIFN-gamma) in the expression of interleukin-2 receptors (IL-2R) by human T lymphocytes. rIFN-gamma enhanced total numbers of IL-2R in mitogen-activated but not resting T cells. Scatchard plot analysis indicated that rIFN-gamma increased both high- and low-affinity receptors, with a predominant effect on the latter. Phytohaemagglutinin (PHA)-activated T cells treated with IFN-gamma showed higher IL-2 binding and greater IL-2 internalization and degradation than cells treated with PHA alone. There was a corresponding increase of mitogen-driven proliferative responses, indicating an increase of functional receptors in IFN-treated cultures. IFN-gamma may influence T-cell activation and proliferation by enhancing expression of IL-2R and promoting IL-2 uptake by mitogen-activated lymphocytes. PMID:2110548

  14. Networked gamma radiation detection system for tactical deployment

    NASA Astrophysics Data System (ADS)

    Mukhopadhyay, Sanjoy; Maurer, Richard; Wolff, Ronald; Smith, Ethan; Guss, Paul; Mitchell, Stephen

    2015-08-01

    A networked gamma radiation detection system with directional sensitivity and energy spectral data acquisition capability is being developed by the National Security Technologies, LLC, Remote Sensing Laboratory to support the close and intense tactical engagement of law enforcement who carry out counterterrorism missions. In the proposed design, three clusters of 2″ × 4″ × 16″ sodium iodide crystals (4 each) with digiBASE-E (for list mode data collection) would be placed on the passenger side of a minivan. To enhance localization and facilitate rapid identification of isotopes, advanced smart real-time localization and radioisotope identification algorithms like WAVRAD (wavelet-assisted variance reduction for anomaly detection) and NSCRAD (nuisance-rejection spectral comparison ratio anomaly detection) will be incorporated. We will test a collection of algorithms and analysis that centers on the problem of radiation detection with a distributed sensor network. We will study the basic characteristics of a radiation sensor network and focus on the trade-offs between false positive alarm rates, true positive alarm rates, and time to detect multiple radiation sources in a large area. Empirical and simulation analyses of critical system parameters, such as number of sensors, sensor placement, and sensor response functions, will be examined. This networked system will provide an integrated radiation detection architecture and framework with (i) a large nationally recognized search database equivalent that would help generate a common operational picture in a major radiological crisis; (ii) a robust reach back connectivity for search data to be evaluated by home teams; and, finally, (iii) a possibility of integrating search data from multi-agency responders.

  15. Peroxisome proliferator-activated receptor gamma regulates expression of signal transducer and activator of transcription 5A

    SciTech Connect

    Olsen, Hanne; Haldosen, Lars-Arne . E-mail: Lars-Arne.Haldosen@mednut.ki.se

    2006-05-01

    Signal transducer and activator of transcription 5A (STAT5A) has been shown to be important for terminal differentiation of mammary epithelial cells. In order to understand regulation of expression of STAT5A, the 5' end of the mouse Stat5a gene was isolated. Putative regulatory elements was searched for and several peroxisome proliferator response elements (PPREs) were found, one with high (12/13 nucleotides) and three with less (8-10/13) similarity to the reported consensus sequence. Mouse mammary epithelial HC11 cells were treated with peroxisome proliferator-activated receptor {gamma} (PPAR{gamma}) ligand, the thiazolidinedione (TZD) troglitazone, and an increase in STAT5A protein expression was seen. The 5' flank of Stat5a gene was cloned in a luciferase reporter vector. A concentration dependent activation of the STAT5A-luciferase reporter was detected, when transiently transfected HC11 cells were treated with TZD. The activation could be inhibited by treatment with a PPAR{gamma} antagonist. It has earlier been shown that epidermal growth factor (EGF) induces MAPK phosphorylation of PPAR{gamma} resulting in a less transcriptionally active receptor. In HC11 cells, EGF inhibited TZD induced STAT5A-reporter activity suggesting that our previously reported EGF-mediated suppression of STAT5A expression is mediated in all or partly through inhibition of PPAR{gamma} activity. Furthermore, the MEK inhibitor PD98059 inhibited the EGF effect. All together, data presented suggest that PPAR{gamma} participates in regulation of STAT5A expression.

  16. Soluble common gamma chain exacerbates COPD progress through the regulation of inflammatory T cell response in mice

    PubMed Central

    Lee, Byunghyuk; Ko, Eunhee; Lee, Jiyeon; Jo, Yuna; Hwang, Hyunju; Goh, Tae Sik; Joo, Myungsoo; Hong, Changwan

    2017-01-01

    Cigarette smoking (CS) is a major cause of considerable morbidity and mortality by inducing lung cancer and COPD. COPD, a smoking-related disorder, is closely related to the alteration of immune system and inflammatory processes that are specifically mediated by T cells. Soluble common gamma chain (sγc) has recently been identified as a critical regulator of the development and differentiation of T cells. We examined the effects of sγc in a cigarette smoke extract (CSE) mouse model. The sγc level in CSE mice serum is significantly downregulated, and the cellularity of lymph node (LN) is systemically reduced in the CSE group. Overexpression of sγc enhances the cellularity and IFNγ production of CD8 T cells in LN and also enhances Th1 and Th17 differentiation of CD4 T cells in the respiratory tract. Mechanistically, the downregulation of sγc expression mediated by CSE is required to prevent excessive inflammatory T cell responses. Therefore, our data suggest that sγc may be one of the target molecules for the control of immunopathogenic progresses in COPD. PMID:28331303

  17. A system for the measurement of delayed neutrons and gammas from special nuclear materials

    DOE PAGES

    Andrews, M. T.; Corcoran, E. C.; Goorley, J. T.; ...

    2014-11-27

    The delayed neutron counting (DNC) system at the Royal Military College of Canada has been upgraded to accommodate concurrent delayed neutron and gamma measurements. This delayed neutron and gamma counting (DNGC) system uses a SLOWPOKE-2 reactor to irradiate fissile materials before their transfer to a counting arrangement consisting of six ³He and one HPGe detector. The application of this system is demonstrated in an example where delayed neutron and gamma emissions are used in complement to examine ²³³U content and determine fissile mass with an average relative error and accuracy of -2.2 and 1.5 %, respectively.

  18. Statins enhance peroxisome proliferator-activated receptor gamma coactivator-1alpha activity to regulate energy metabolism.

    PubMed

    Wang, Wenxian; Wong, Chi-Wai

    2010-03-01

    Peroxisome proliferator-activated receptor gamma coactivator-1alpha (PGC-1alpha) serves as an inducible coactivator for a number of transcription factors to control energy metabolism. Insulin signaling through Akt kinase has been demonstrated to phosphorylate PGC-1alpha at serine 571 and downregulate its activity in the liver. Statins are 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors that reduce cholesterol synthesis in the liver. In this study, we found that statins reduced the active form of Akt and enhanced PGC-1alpha activity. Specifically, statins failed to activate an S571A mutant of PGC-1alpha. The activation of PGC-1alpha by statins selectively enhanced the expression of energy metabolizing enzymes and regulators including peroxisome proliferator-activated receptor alpha, acyl-CoA oxidase, carnitine palmitoyl transferase-1A, and pyruvate dehydrogenase kinase 4. Importantly, a constitutively active form of Akt partially reduced the statin-enhanced gene expression. Our study thus provides a plausible mechanistic explanation for the hypolipidemic effect of statin through elevating the rate of beta-oxidation and mitochondrial Kreb's cycle capacity to enhance fatty acid utilization while reducing the rate of glycolysis.

  19. Adipogenesis and insulin sensitivity in obesity are regulated by retinoid-related orphan receptor gamma

    PubMed Central

    Meissburger, Bettina; Ukropec, Jozef; Roeder, Eva; Beaton, Nigel; Geiger, Matthias; Teupser, Daniel; Civan, Burcak; Langhans, Wolfgang; Nawroth, Peter P; Gasperikova, Daniela; Rudofsky, Gottfried; Wolfrum, Christian

    2011-01-01

    Obesity is a well-known risk factor for the development of secondary complications such as type 2 diabetes. However, only a part of the obese population develops secondary metabolic disorders. Here, we identify the transcription factor retinoid-related orphan receptor gamma (RORγ) as a negative regulator of adipocyte differentiation through expression of its newly identified target gene matrix metalloproteinase 3. In vivo differentiation of adipocyte progenitor cells from Rorγ-deficient mice is enhanced and obese Rorγ−/− mice show decreased adipocyte sizes. These small adipocytes are highly insulin sensitive, leading to an improved control of circulating free fatty acids. Ultimately, Rorγ−/− mice are protected from hyperglycemia and insulin resistance in the state of obesity. In adipose stromal-vascular fraction from obese human subjects, Rorγ expression is correlated with adipocyte size and negatively correlated with adipogenesis and insulin sensitivity. Taken together, our findings identify RORγ as a factor, which controls adipogenesis as well as adipocyte size and modulates insulin sensitivity in obesity. RORγ might therefore serve as a novel pharmaceutical target to treat obesity-associated insulin resistance. PMID:21853531

  20. Dehydroepiandrosterone down-regulates the expression of peroxisome proliferator-activated receptor gamma in adipocytes.

    PubMed

    Kajita, Kazuo; Ishizuka, Tatsuo; Mune, Tomoatsu; Miura, Atsushi; Ishizawa, Masayoshi; Kanoh, Yoshinori; Kawai, Yasunori; Natsume, Yoshiyuki; Yasuda, Keigo

    2003-01-01

    Dehydroepiandrosterone (DHEA) is expected to have a weight-reducing effect. In this study, we evaluated the effect of DHEA on genetically obese Otsuka Long Evans Fatty rats (OLETF) compared with Long-Evans Tokushima rats (LETO) as control. Feeding with 0.4% DHEA-containing food for 2 wk reduced the weight of sc, epididymal, and perirenal adipose tissue in association with decreased plasma leptin levels in OLETF. Adipose tissue from OLETF showed increased expression of peroxisome proliferator-activated receptor gamma (PPARgamma) protein, which was prevented by DHEA treatment. Further, we examined the effect of DHEA on PPARgamma in primary cultured adipocytes and monolayer adipocytes differentiated from rat preadipocytes. PPARgamma protein level was decreased in a time- and concentration-dependent manner, and DHEA significantly reduced mRNA levels of PPARgamma, adipocyte lipid-binding protein, and sterol regulatory element-binding protein, but not CCAAT/enhancer binding protein alpha. DHEA-sulfate also reduced the PPARgamma protein, but dexamethasone, testosterone, or androstenedione did not alter its expression. In addition, treatment with DHEA for 5 d reduced the triglyceride content in monolayer adipocytes. These results suggest that DHEA down-regulates adiposity through the reduction of PPARgamma in adipocytes.

  1. Operational Management System for Regulated Water Systems

    NASA Astrophysics Data System (ADS)

    van Loenen, A.; van Dijk, M.; van Verseveld, W.; Berger, H.

    2012-04-01

    Most of the Dutch large rivers, canals and lakes are controlled by the Dutch water authorities. The main reasons concern safety, navigation and fresh water supply. Historically the separate water bodies have been controlled locally. For optimizating management of these water systems an integrated approach was required. Presented is a platform which integrates data from all control objects for monitoring and control purposes. The Operational Management System for Regulated Water Systems (IWP) is an implementation of Delft-FEWS which supports operational control of water systems and actively gives advice. One of the main characteristics of IWP is that is real-time collects, transforms and presents different types of data, which all add to the operational water management. Next to that, hydrodynamic models and intelligent decision support tools are added to support the water managers during their daily control activities. An important advantage of IWP is that it uses the Delft-FEWS framework, therefore processes like central data collection, transformations, data processing and presentation are simply configured. At all control locations the same information is readily available. The operational water management itself gains from this information, but it can also contribute to cost efficiency (no unnecessary pumping), better use of available storage and advise during (water polution) calamities.

  2. Olfactory system gamma oscillations: the physiological dissection of a cognitive neural system

    PubMed Central

    Rojas-Líbano, Daniel

    2008-01-01

    Oscillatory phenomena have been a focus of dynamical systems research since the time of the classical studies on the pendulum by Galileo. Fast cortical oscillations also have a long and storied history in neurophysiology, and olfactory oscillations have led the way with a depth of explanation not present in the literature of most other cortical systems. From the earliest studies of odor-evoked oscillations by Adrian, many reports have focused on mechanisms and functional associations of these oscillations, in particular for the so-called gamma oscillations. As a result, much information is now available regarding the biophysical mechanisms that underlie the oscillations in the mammalian olfactory system. Recent studies have expanded on these and addressed functionality directly in mammals and in the analogous insect system. Sub-bands within the rodent gamma oscillatory band associated with specific behavioral and cognitive states have also been identified. All this makes oscillatory neuronal networks a unique interdisciplinary platform from which to study neurocognitive and dynamical phenomena in intact, freely behaving animals. We present here a summary of what has been learned about the functional role and mechanisms of gamma oscillations in the olfactory system as a guide for similar studies in other cortical systems. PMID:19003484

  3. Development of gamma-photon/Cerenkov-light hybrid system for simultaneous imaging of I-131 radionuclide

    NASA Astrophysics Data System (ADS)

    Yamamoto, Seiichi; Suzuki, Mayumi; Kato, Katsuhiko; Watabe, Tadashi; Ikeda, Hayato; Kanai, Yasukazu; Ogata, Yoshimune; Hatazawa, Jun

    2016-09-01

    Although iodine 131 (I-131) is used for radionuclide therapy, high resolution images are difficult to obtain with conventional gamma cameras because of the high energy of I-131 gamma photons (364 keV). Cerenkov-light imaging is a possible method for beta emitting radionuclides, and I-131 (606 MeV maximum beta energy) is a candidate to obtain high resolution images. We developed a high energy gamma camera system for I-131 radionuclide and combined it with a Cerenkov-light imaging system to form a gamma-photon/Cerenkov-light hybrid imaging system to compare the simultaneously measured images of these two modalities. The high energy gamma imaging detector used 0.85-mm×0.85-mm×10-mm thick GAGG scintillator pixels arranged in a 44×44 matrix with a 0.1-mm thick reflector and optical coupled to a Hamamatsu 2 in. square position sensitive photomultiplier tube (PSPMT: H12700 MOD). The gamma imaging detector was encased in a 2 cm thick tungsten shield, and a pinhole collimator was mounted on its top to form a gamma camera system. The Cerenkov-light imaging system was made of a high sensitivity cooled CCD camera. The Cerenkov-light imaging system was combined with the gamma camera using optical mirrors to image the same area of the subject. With this configuration, we simultaneously imaged the gamma photons and the Cerenkov-light from I-131 in the subjects. The spatial resolution and sensitivity of the gamma camera system for I-131 were respectively 3 mm FWHM and 10 cps/MBq for the high sensitivity collimator at 10 cm from the collimator surface. The spatial resolution of the Cerenkov-light imaging system was 0.64 mm FWHM at 10 cm from the system surface. Thyroid phantom and rat images were successfully obtained with the developed gamma-photon/Cerenkov-light hybrid imaging system, allowing direct comparison of these two modalities. Our developed gamma-photon/Cerenkov-light hybrid imaging system will be useful to evaluate the advantages and disadvantages of these two

  4. In vivo regulation of gene transcription by alpha- and gamma-Tocopherol in murine T lymphocytes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Of the 8 different analogues (alpha-, beta-, gamma-, delta-tocopherols and tocotrienols) designated as vitamin E, alpha-tocopherol (a-T) has been mostly studied, together with gamma-tocopherol (g-T) which is abundant in the US diet. We compared the effect of dietary supplementation with adequate or ...

  5. Multi-gamma-source CT imaging system: a feasibility study with the Poisson noise

    NASA Astrophysics Data System (ADS)

    Wi, Sunhee; Cho, Seungryong

    2016-03-01

    This study was performed to test the feasibility of multi-gamma-source CT imaging system. Gamma-source CT employs radioisotopes that emit monochromatic energy gamma-rays. The advantages of gamma-source CT include its immunity to beam hardening artifacts, its capacity of quantitative CT imaging, and its higher performance in low contrast imaging compared to the conventional x-ray CT. Radioisotope should be shielded by use of a pin-hole collimator so as to make a fine focal spot. Due to its low gamma-ray flux in general, the reconstructed image from a single gamma-source CT would suffer from high noise in data. To address this problem, we proposed a multi-gamma source CT imaging system and developed an iterative image reconstruction algorithm accordingly in this work. Conventional imaging model assumes a single linear imaging system typically represented by Mf = g. In a multi-gamma-source CT system however, the inversion problem is not any more based on a single linear system since one cannot separate a detector pixel value into multiple ones that are corresponding to each rays from the sources. Instead, the imaging model can be constructed by a set of linear system models each of which assumes an estimated measurement g. Based on this model, the proposed algorithm has a weighting step which distributes each projection data into multiple estimated measurements. We used two gamma sources at various positions and with varying intensities in this numerical study to demonstrate its feasibility. Therefore, the measured projection data(g) is separated into each estimated projection data(g1, g2) in this study. The proposed imaging protocol is believed to contribute to both medical and industrial applications.

  6. Determination of the optimal positions for installing gamma ray detection systems at Tehran Research Reactor

    NASA Astrophysics Data System (ADS)

    Sayyah, A.; Rahmani, F.; Khalafi, H.

    2015-09-01

    Dosimetric instruments must constantly monitor radiation dose levels in different areas of nuclear reactor. Tehran Research Reactor (TRR) has seven beam tubes for different research purposes. All the beam tubes extend from the reactor core to Beam Port Floor (BPF) of the reactor facility. During the reactor operation, the gamma rays exiting from each beam tube outlet produce a specific gamma dose rate field in the space of the BPF. To effectively monitor the gamma dose rates on the BPF, gamma ray detection systems must be installed in optimal positions. The selection of optimal positions is a compromise between two requirements. First, the installation positions must possess largest gamma dose rates and second, gamma ray detectors must not be saturated in these positions. In this study, calculations and experimental measurements have been carried out to identify the optimal positions of the gamma ray detection systems. Eight three dimensional models of the reactor core and related facilities corresponding to eight scenarios have been simulated using MCNPX Monte Carlo code to calculate the gamma dose equivalent rate field in the space of the BPF. These facilities are beam tubes, thermal column, pool, BPF space filled with air, facilities such as neutron radiography facility, neutron powder diffraction facility embedded in the beam tubes as well as biological shields inserted into the unused beam tubes. According to the analysis results of the combined gamma dose rate field, three positions on the north side and two positions on the south side of the BPF have been recognized as optimal positions for installing the gamma ray detection systems. To ensure the consistency of the simulation data, experimental measurements were conducted using TLDs (600 and 700) pairs during the reactor operation at 4.5 MW.

  7. Real time method and computer system for identifying radioactive materials from HPGe gamma-ray spectroscopy

    DOEpatents

    Rowland, Mark S.; Howard, Douglas E.; Wong, James L.; Jessup, James L.; Bianchini, Greg M.; Miller, Wayne O.

    2007-10-23

    A real-time method and computer system for identifying radioactive materials which collects gamma count rates from a HPGe gamma-radiation detector to produce a high-resolution gamma-ray energy spectrum. A library of nuclear material definitions ("library definitions") is provided, with each uniquely associated with a nuclide or isotope material and each comprising at least one logic condition associated with a spectral parameter of a gamma-ray energy spectrum. The method determines whether the spectral parameters of said high-resolution gamma-ray energy spectrum satisfy all the logic conditions of any one of the library definitions, and subsequently uniquely identifies the material type as that nuclide or isotope material associated with the satisfied library definition. The method is iteratively repeated to update the spectrum and identification in real time.

  8. Measurements of gamma-ray production cross sections for shielding materials of space nuclear systems

    NASA Technical Reports Server (NTRS)

    Orphan, V. J.; John, J.; Hoot, C. G.

    1972-01-01

    Measurements of secondary gamma ray production from neutron interactions have been made over the entire energy range of interest in shielding applications. The epithermal capture gamma ray yields for both resolved gamma ray lines and continuum have been measured from thermal energies to 100 KeV for natural tungsten and U-238, two important candidate shield materials in SNAP reactor systems. Data are presented to illustrate the variation of epithermal capture gamma ray yields with neutron energy. The gamma ray production cross sections from (n,xy) reactions have been measured for Fe and Al from the threshold energies for inelastic scattering to approximately 16 MeV. Typical Fe and Al cross sections obtained with high-neutron energy resolution and averaged over broad neutron-energy groups are presented.

  9. Inhibition of murine renal carcinoma pulmonary metastases by systemic administration of interferon gamma: mechanism of action and potential for combination with interleukin 4.

    PubMed

    Hillman, G G; Younes, E; Visscher, D; Hamzavi, F; Kim, S; Lam, J S; Montecillo, E J; Ali, E; Pontes, J E; Puri, R K; Haas, G P

    1997-10-01

    We have previously demonstrated that IFN-gamma causes cell growth inhibition and up-regulation of MHC antigens in human renal cell carcinoma cell lines. In this study, we have investigated the therapeutic potential of IFN-gamma for the treatment of 5-day established pulmonary metastases induced by i.v. injection of Renca cells, a murine renal adenocarcinoma. We found that systemic injections of IFN-gamma significantly reduced the number of lung metastases in a dose-dependent manner and increased mouse survival. Histological evaluation of IFN-gamma-treated lungs showed residual small tumor nodules containing extensive necrosis and mononuclear infiltrates. Immunohistochemistry studies on lung sections showed macrophage infiltration into tumor nodules, and in vivo depletion of macrophages partially inhibited IFN-gamma antitumor effect, suggesting a role for the macrophages in tumor destruction. Lymphocyte depletion of either natural killer (NK) cells or CD4+ or CD8+ T-cell subsets or both T-cell subsets did not affect the IFN-gamma effect, whereas depletion of both NK and T cells decreased the antitumor activity of IFN-gamma. These data indicate that neither T cells nor NK cells are essential for this activity but that either lymphocyte population can contribute to the IFN-gamma effect. An optimal dose of IFN-gamma inhibited by 60% the growth of Renca cells treated for 3 days in vitro, but this effect was transient and less pronounced in a long-term colony assay, suggesting that IFN-gamma direct growth inhibition may play a role but may not be sufficient to mediate its antitumor effect in vivo. In vitro, IFN-gamma caused up-regulation of class I MHC antigens and induction of class II antigen expression in Renca cells, an effect that may enhance Renca immunogenicity but may be relevant only when a T-cell response is elicited. A sequential administration of IFN-gamma followed by interleukin 4 was therapeutically better than IFN-gamma alone for the treatment of advanced

  10. The Role of PPAR Gamma in Systemic Sclerosis

    PubMed Central

    Dantas, Andréa Tavares; Pereira, Michelly Cristiny; de Melo Rego, Moacyr Jesus Barreto; da Rocha, Laurindo Ferreira; Pitta, Ivan da Rocha; Marques, Cláudia Diniz Lopes; Duarte, Angela Luzia Branco Pinto; Pitta, Maira Galdino da Rocha

    2015-01-01

    Fibrosis is recognized as an important feature of many chronic diseases, such as systemic sclerosis (SSc), an autoimmune disease of unknown etiology, characterized by immune dysregulation and vascular injury, followed by progressive fibrosis affecting the skin and multiple internal organs. SSc has a poor prognosis because no therapy has been shown to reverse or arrest the progression of fibrosis, representing a major unmet medical need. Recently, antifibrotic effects of PPARγ ligands have been studied in vitro and in vivo and some theories have emerged leading to new insights. Aberrant PPARγ function seems to be implicated in pathological fibrosis in the skin and lungs. This antifibrotic effect is mainly related to the inhibition of TGF-β/Smad signal transduction but other pathways can be involved. This review focused on recent studies that identified PPARγ as an important novel pathway with critical roles in regulating connective tissue homeostasis, with emphasis on skin and lung fibrosis and its role on systemic sclerosis. PMID:26064084

  11. Code System for Isotope Identification by Gamma-Ray Analysis

    SciTech Connect

    1996-01-01

    For a set of a priori given nuclides taken from a work library, DIMEN uses median estimates of the peak areas and estimates of their errors to produce a list of possible nuclides matching a gamma-ray line and some measure of the reliability of this assignment.

  12. Autocrine regulation of interferon gamma in mesenchymal stem cells plays a role in early osteoblastogenesis.

    PubMed

    Duque, Gustavo; Huang, Dao Chao; Macoritto, Michael; Rivas, Daniel; Yang, Xian Fang; Ste-Marie, Louis Georges; Kremer, Richard

    2009-03-01

    Interferon (IFN)gamma is a strong inhibitor of osteoclast differentiation and activity. However, its role in osteoblastogenesis has not been carefully examined. Using microarray expression analysis, we found that several IFNgamma-inducible genes were upregulated during early phases of osteoblast differentiation of human mesenchymal stem cells (hMSCs). We therefore hypothesized that IFNgamma may play a role in this process. We first observed a strong and transient increase in IFNgamma production following hMSC induction to differentiate into osteoblasts. We next blocked this endogenous production using a knockdown approach with small interfering RNA and observed a strong inhibition of hMSC differentiation into osteoblasts with a concomitant decrease in Runx2, a factor indispensable for osteoblast development. Additionally, exogenous addition of IFNgamma accelerated hMSC differentiation into osteoblasts in a dose-dependent manner and induced higher levels of Runx2 expression during the early phase of differentiation. We next examined IFNgamma signaling in vivo in IFNgamma receptor 1 knockout (IFNgammaR1(-/-)) mice. Compared with their wild-type littermates, IFNgammaR1(-/-) mice exhibited a reduction in bone mineral density. As in the in vitro experiments, MSCs obtained from IFNgammaR1(-/-) mice showed a lower capacity to differentiate into osteoblasts. In summary, we demonstrate that the presence of IFNgamma plays an important role during the commitment of MSCs into the osteoblastic lineage both in vitro and in vivo, and that this process can be accelerated by exogenous addition of IFNgamma. These data therefore support a new role for IFNgamma as an autocrine regulator of hMSC differentiation and as a potential new target of bone-forming cells in vivo.

  13. Organization of the sural cutaneous input regulating the discharge of triceps surae gamma-motoneurones in the cat.

    PubMed

    Ellaway, P H; Davey, N J; Ljubisavljevic, M

    1997-01-01

    The organization of the cutaneous afferent influence on the discharge of gamma-motoneurones has been investigated in the decerebrated, spinal cat. gamma-Motoneurone discharges were recorded from cut nerve filaments. Time and frequency domain analyses were used to reveal the strength of coupling between gamma-motoneurone discharge and cutaneous afferents excited by natural skin stimulation. Time domain analysis (cross-correlation) was also used to reveal the sigh (facilitation or inhibition) and time course of the cutaneous influence on individual gamma-motoneurones. Mechanical stimulation of discrete areas of skin within the sural nerve field caused facilitation or inhibition of individual gamma-motoneurones supplying the gastrocnemius and soleus muscles. In a few cases, a gamma-motoneurone facilitated by stimulation at one site could be inhibited from another location. The effect of cutaneous afferent stimulation was not evident in the decerebrated cat with intact spinal cord. The intensity of facilitation and inhibition was mapped for the sural nerve field. Facilitation had focus of highest intensity to stimulation applied between the calcaneum and lateral malleolus. The focus for inhibition was either the same as for facilitation or, more frequently, tended to be lateral and dorsal to the calcaneum at the edge of the sural field. Cutaneous stimulation at the edge of the sural field could also reduce the coherence between the discharges of gamma-motoneurones, particularly at low frequencies of association (1-5 Hz), indicating disfacilitation of other sources of afferent input. The results reveal a detailed pattern of cutaneous inputs to the fusimotor system that could participate in a wide range of behavioural adjustments to stretch or contact of the skin at the heel.

  14. Development of a high resolution gamma camera system using finely grooved GAGG scintillator

    NASA Astrophysics Data System (ADS)

    Yamamoto, Seiichi; Kataoka, Jun; Oshima, Tsubasa; Ogata, Yoshimune; Watabe, Tadashi; Ikeda, Hayato; Kanai, Yasukazu; Hatazawa, Jun

    2016-06-01

    High resolution gamma cameras require small pixel scintillator blocks with high light output. However, manufacturing a small pixel scintillator block is difficult when the pixel size becomes small. To solve this limitation, we developed a high resolution gamma camera system using a finely grooved Ce-doped Gd3Al2Ga3O12 (GAGG) plate. Our gamma camera's detector consists of a 1-mm-thick finely grooved GAGG plate that is optically coupled to a 1-in. position sensitive photomultiplier tube (PSPMT). The grooved GAGG plate has 0.2×0.2 mm pixels with 0.05-mm wide slits (between the pixels) that were manufactured using a dicing saw. We used a Hamamatsu PSPMT with a 1-in. square high quantum efficiency (HQE) PSPMT (R8900-100-C12). The energy resolution for the Co-57 gamma photons (122 keV) was 18.5% FWHM. The intrinsic spatial resolution was estimated to be 0.7-mm FWHM. With a 0.5-mm diameter pinhole collimator mounted to its front, we achieved a high resolution, small field-of-view gamma camera. The system spatial resolution for the Co-57 gamma photons was 1.0-mm FWHM, and the sensitivity was 0.0025%, 10 mm from the collimator surface. The Tc-99m HMDP administered mouse images showed the fine structures of the mouse body's parts. Our developed high resolution small pixel GAGG gamma camera is promising for such small animal imaging.

  15. Gamma interferon expression during acute and latent nervous system infection by herpes simplex virus type 1.

    PubMed Central

    Cantin, E M; Hinton, D R; Chen, J; Openshaw, H

    1995-01-01

    This study was initiated to evaluate a role for gamma interferon (IFN-gamma) in herpes simplex virus type 1 (HSV-1) infection. At the acute stage of infection in mice, HSV-1 replication in trigeminal ganglia and brain stem tissue was modestly but consistently enhanced in mice from which IFN-gamma was by ablated monoclonal antibody treatment and in mice genetically lacking the IFN-gamma receptor (Rgko mice). As determined by reverse transcriptase PCR, IFN-gamma and tumor necrosis factor alpha transcripts were present in trigeminal ganglia during both acute and latent HSV-1 infection. CD4+ and CD8+ T cells were detected initially in trigeminal ganglia at day 5 after HSV-1 inoculation, and these cells persisted for 6 months into latency. The T cells were focused around morphologically normal neurons that showed no signs of active infection, but many of which expressed HSV-1 latency-associated transcripts. Secreted IFN-gamma was present up to 6 months into latency in areas of the T-cell infiltration. By 9 months into latency, both the T-cell infiltrate and IFN-gamma expression had cleared, although there remained a slight increase in macrophage levels in trigeminal ganglia. In HSV-1-infected brain stem tissue, T cells and IFN-gamma expression were present at 1 month but were gone by 6 months after infection. Our hypothesis is that the persistence of T cells and the sustained IFN-gamma expression occur in response to an HSV-1 antigen(s) in the nervous system. This hypothesis is consistent with a new model of HSV-1 latency which suggests that limited HSV-1 antigen expression occurs during latency (M. Kosz-Vnenchak, J. Jacobson, D.M. Coen, and D.M. Knipe, J. Virol. 67:5383-5393, 1993). We speculate that prolonged secretion of IFN-gamma during latency may modulate a reactivated HSV-1 infection. PMID:7609058

  16. Shaped scintillation detector systems for measurements of gamma ray flux anisotropy

    NASA Technical Reports Server (NTRS)

    Trombka, J. I.; Vette, J. I.; Stecker, F. W.; Eller, E. L.; Wildes, W. T.

    1973-01-01

    The detection efficiencies of cylindrical detectors for various gamma ray photon angular distributions were studied in the energy range from .10 Mev to 15 Mev. These studies indicate that simple detector systems on small satellites can be used to measure flux anisotropy of cosmic gamma rays and the angular distribution of albedo gamma rays produced in planetary atmospheres. The results indicate that flat cylindrical detectors are most suitable for measuring flux anisotropy because of their angular response function. A general method for calculating detection efficiencies for such detectors is presented.

  17. An alpha–gamma coincidence spectrometer based on the Photon–Electron Rejecting Alpha Liquid Scintillation (PERALS®) system

    DOE PAGES

    Cadieux, J. R.; Fugate, G. A.; King, III, G. S.

    2015-02-07

    Here, an alpha–gamma coincidence spectrometer has been developed for the measurement of selected actinide isotopes in the presence of high beta/gamma fields. The system is based on a PERALS® liquid scintillation counter for beta/alpha discrimination and was successfully tested with both high purity germanium and bismuth germanate, gamma-ray detectors using conventional analog electronics.

  18. Environmental Protection Agency (EPA) airborne gamma spectrometry system for environmental and emergency response surveys

    NASA Astrophysics Data System (ADS)

    Cardarelli, John, II; Thomas, Mark; Curry, Timothy

    2010-08-01

    The EPA Airborne Spectral Photometric Environmental Collection Technology (ASPECT) Program provides airborne ortho-rectified imagery, video, chemical and now radiological information directly to emergency response personnel via a commercial satellite link onboard the aircraft. EPA initiated the ASPECT Gamma Emergency Mapper GEM Project in 2008 to improve its airborne gamma-screening and mapping capability for monitoring any ground-based gamma contamination. This paper will provide an overview of the system, which can be configured to carry six 2"x4"x16" NaI(Tl) detectors and two 3"x3" LaBr3(Ce) detectors or eight 2"x4"x16" NaI(Tl) detectors. The paper will provide an overview of the analysis of gamma radiation spectra, system limitations, and emergency response applications.

  19. Radiation detection system for portable gamma-ray spectroscopy

    DOEpatents

    Rowland, Mark S.; Howard, Douglas E.; Wong, James L.; Jessup, James L.; Bianchini, Greg M.; Miller, Wayne O.

    2006-06-20

    A portable gamma ray detection apparatus having a gamma ray detector encapsulated by a compact isolation structure having at least two volumetrically-nested enclosures where at least one is a thermal shield. The enclosures are suspension-mounted to each other to successively encapsulate the detector without structural penetrations through the thermal shields. A low power cooler is also provided capable of cooling the detector to cryogenic temperatures without consuming cryogens, due to the heat load reduction by the isolation structure and the reduction in the power requirements of the cooler. The apparatus also includes a lightweight portable power source for supplying power to the apparatus, including to the cooler and the processing means, and reducing the weight of the apparatus to enable handheld operation or toting on a user's person.

  20. Specifying dual-detector gamma cameras and associated computer systems.

    PubMed

    Tindale, W B

    1995-07-01

    Increasingly, dual-detector gamma cameras are being purchased as replacements for single-headed cameras. The improvement in sensitivity offered by a dual-detector device can be used in several ways: to shorten acquisition times, to improve signal-to-noise ratios, or to reduce administered doses. This paper focuses on the practical aspects of dual-headed devices and aims to provide some guidance for potential purchasers in the drawing up of an equipment specification.

  1. P-selectin suppresses hepatic inflammation and fibrosis in mice by regulating interferon gamma and the IL-13 decoy receptor.

    PubMed

    Wynn, Thomas A; Hesse, Matthias; Sandler, Netanya G; Kaviratne, Mallika; Hoffmann, Karl F; Chiaramonte, Monica G; Reiman, Rachael; Cheever, Allen W; Sypek, Joseph P; Mentink-Kane, Margaret M

    2004-03-01

    The selectin family of cell adhesion molecules is widely thought to promote inflammatory reactions by facilitating leukocyte recruitment. However, it was unexpectedly found that mice with targeted deletion of the P-selectin gene (PsKO mice) developed unpolarized type 1/type 2 cytokine responses and severely aggravated liver pathology following infection with the type 2-promoting pathogen Schistosoma mansoni. In fact, liver fibrosis, which is dependent on interleukin 13 (IL-13), increased by a factor of more than 6, despite simultaneous induction of the antifibrotic cytokine interferon gamma (IFN-gamma). Inflammation, as measured by granuloma size, also increased significantly in the absence of P-selectin. When infected PsKO mice were treated with neutralizing anti-IFN-gamma monoclonal antibodies, however, granuloma size was restored to wild-type levels; this finding revealed the potent proinflammatory role of IFN-gamma when expressed concomitantly with IL-13. Untreated PsKO mice also exhibited a significant (sixfold) reduction in decoy IL-13 receptor (IL-13 receptor alpha-2) expression when compared with infected wild-type animals. It is noteworthy, however, that when decoy receptor activity was restored in PsKO mice by treatment with soluble IL-13 receptor alpha-2-Fc, the exacerbated fibrotic response was completely inhibited. Thus, reduced expression of the decoy IL-13 receptor mediated by the elevated type 1 cytokine response probably accounts for the enhanced activity of IL-13 in PsKO mice and for the resultant increase in collagen deposition. In conclusion, the current study has revealed the critical role of P-selectin in the progression of chronic liver disease caused by schistosome parasites. By suppressing IFN-gamma and up-regulating the decoy IL-13 receptor, P-selectin dramatically inhibits the pathologic tissue remodeling that results from chronic type 2 cytokine-mediated inflammation.

  2. PDCD10/CCM3 acts downstream of {gamma}-protocadherins to regulate neuronal survival.

    PubMed

    Lin, Chengyi; Meng, Shuxia; Zhu, Tina; Wang, Xiaozhong

    2010-12-31

    γ-Protocadherins (PCDH-γ) regulate neuronal survival in the vertebrate central nervous system. The molecular mechanisms of how PCDH-γ mediates this function are still not understood. In this study, we show that through their common cytoplasmic domain, different PCDH-γ isoforms interact with an intracellular adaptor protein named PDCD10 (programmed cell death 10). PDCD10 is also known as CCM3, a causative genetic defect for cerebral cavernous malformations in humans. Using RNAi-mediated knockdown, we demonstrate that PDCD10 is required for the occurrence of apoptosis upon PCDH-γ depletion in developing chicken spinal neurons. Moreover, overexpression of PDCD10 is sufficient to induce neuronal apoptosis. Taken together, our data reveal a novel function for PDCD10/CCM3, acting as a critical regulator of neuronal survival during development.

  3. REBOCOL (Robotic Calorimetry): An automated NDA (Nondestructive assay) calorimetry and gamma isotopic system

    SciTech Connect

    Hurd, J.R.; Bonner, C.A.; Ostenak, C.A.; Phelan, P.F.; Powell, W.D.; Sheer, N.L.; Schneider, D.N.; Staley, H.C.

    1989-01-01

    ROBOCAL, which is presently being developed and tested at Los Alamos National Laboratory, is a full-scale, prototypical robotic system, for remote calorimetric and gamma-ray analysis of special nuclear materials. It integrates a fully automated, multi-drawer, vertical stacker-retriever system for staging unmeasured nuclear materials, and a fully automated gantry robot for computer-based selection and transfer of nuclear materials to calorimetric and gamma-ray measurement stations. Since ROBOCAL is designed for minimal operator intervention, a completely programmed user interface and data-base system are provided to interact with the automated mechanical and assay systems. The assay system is designed to completely integrate calorimetric and gamma-ray data acquisition and to perform state-of-the-art analyses on both homogeneous and heterogeneous distributions of nuclear materials in a wide variety of matrices. 10 refs., 10 figs., 4 tabs.

  4. Estimability And Regulability Of Linear Systems

    NASA Technical Reports Server (NTRS)

    Baram, Yoram; Kailath, Thomas

    1990-01-01

    Report presents two new properties of systems characterized by linear state space models (e.g., dynamical systems and associated control systems): estimability and regulability. Provides criteria for reductions of errors and cost functions in control systems. Useful in design of optimal controllers and estimators.

  5. The time-of-flight system on the Goddard medium energy gamma-ray telescope

    NASA Technical Reports Server (NTRS)

    Ross, R. W.; Chesney, J. R.

    1979-01-01

    A scintillation counter time of flight system, incorporated into the Goddard 50 cm by 50 cm spark chamber gamma ray telescope is described. The system, which utilizes constant fractions timing and particle position compensation and digitizes up to 10 ns time differences to six bit accuracy in less than 500 ns is analyzed. The performance of this system during balloon flight is discussed.

  6. GammaScorpion: mobile gamma-ray tomography system for early detection of basal stem rot in oil palm plantations

    NASA Astrophysics Data System (ADS)

    Abdullah, Jaafar; Hassan, Hearie; Shari, Mohamad Rabaie; Mohd, Salzali; Mustapha, Mahadi; Mahmood, Airwan Affendi; Jamaludin, Shahrizan; Ngah, Mohd Rosdi; Hamid, Noor Hisham

    2013-03-01

    Detection of the oil palm stem rot disease Ganoderma is a major issue in estate management and production in Malaysia. Conventional diagnostic techniques are difficult and time consuming when using visual inspection, and destructive and expensive when based on the chemical analysis of root or stem tissue. As an alternative, a transportable gamma-ray computed tomography system for the early detection of basal stem rot (BSR) of oil palms due to Ganoderma was developed locally at the Malaysian Nuclear Agency, Kajang, Malaysia. This system produces high quality tomographic images that clearly differentiate between healthy and Ganoderma infected oil palm stems. It has been successfully tested and used to detect the extent of BSR damage in oil palm plantations in Malaysia without the need to cut down the trees. This method offers promise for in situ inspection of oil palm stem diseases compared to the more conventional methods.

  7. Implementation of gamma-ray instrumentation for solid solar system bodies using neutron activation method

    NASA Astrophysics Data System (ADS)

    Litvak, M. L.; Golovin, D. V.; Jun, I.; Kozyrev, A. S.; Mitrofanov, I. G.; Sanin, A. B.; Shvetsov, V. N.; Timoshenko, G. N.; Zontikov, A.

    2016-06-01

    In this paper we present the results of ground tests performed with a flight model and with industry prototypes of passive and active gamma ray spectrometers with the objective of understanding their capability to distinguish the elemental composition of planetary bodies in the solar system. The gamma instrumentation, which was developed for future space missions was used in the measurements at a special ground test facility where a simulant of planetary material was fabricated with a martian-like composition. In this study, a special attention was paid to the gamma lines from activation reaction products generated by a pulsed neutron generator. The instrumentation was able to detect and identify gamma lines attributed to O, Na, Mg, Al, Si, K, Ca and Fe.

  8. Detection system for high-resolution gamma radiation spectroscopy with neutron time-of-flight filtering

    DOEpatents

    Dioszegi, Istvan; Salwen, Cynthia; Vanier, Peter

    2014-12-30

    A .gamma.-radiation detection system that includes at least one semiconductor detector such as HPGe-Detector, a position-sensitive .alpha.-Detector, a TOF Controller, and a Digitizer/Integrator. The Digitizer/Integrator starts to process the energy signals of a .gamma.-radiation sent from the HPGe-Detector instantly when the HPGe-Detector detects the .gamma.-radiation. Subsequently, it is determined whether a coincidence exists between the .alpha.-particles and .gamma.-radiation signal, based on a determination of the time-of-flight of neutrons obtained from the .alpha.-Detector and the HPGe-Detector. If it is determined that the time-of-flight falls within a predetermined coincidence window, the Digitizer/Integrator is allowed to continue and complete the energy signal processing. If, however, there is no coincidence, the Digitizer/Integrator is instructed to be clear and reset its operation instantly.

  9. System to quantify gamma-ray radial energy deposition in semiconductor detectors

    DOEpatents

    Kammeraad, Judith E.; Blair, Jerome J.

    2001-01-01

    A system for measuring gamma-ray radial energy deposition is provided for use in conjunction with a semiconductor detector. The detector comprises two electrodes and a detector material, and defines a plurality of zones within the detecting material in parallel with the two electrodes. The detector produces a charge signal E(t) when a gamma-ray interacts with the detector. Digitizing means are provided for converting the charge signal E(t) into a digitized signal. A computational means receives the digitized signal and calculates in which of the plurality of zones the gamma-ray deposited energy when interacting with the detector. The computational means produces an output indicating the amount of energy deposited by the gamma-ray in each of the plurality of zones.

  10. Interferon gamma regulates antigen-induced eosinophil recruitment into the mouse airways by inhibiting the infiltration of CD4+ T cells

    PubMed Central

    1993-01-01

    We have previously shown that antigen-induced eosinophil recruitment into the tissue of sensitized mice is mediated by CD4+ T cells and interleukin 5. To determine whether interferon gamma (IFN-gamma) regulates antigen-induced eosinophil recruitment into the tissue, we studied the effect of recombinant (r) murine IFN-gamma and of anti-IFN- gamma monoclonal antibody (mAb) on the eosinophil infiltration of the trachea induced by antigen inhalation in mice. The intraperitoneal administration of rIFN-gamma prevented antigen-induced eosinophil infiltration in the trachea of sensitized mice. The administration of rIFN-gamma also decreased antigen-induced CD4+ T cell but not CD8+ T cell infiltration in the trachea. On the other hand, pretreatment with anti-IFN-gamma mAb enhanced antigen-induced eosinophil and CD4+ T cell infiltration in the trachea. These results indicate that IFN-gamma regulates antigen-induced eosinophil recruitment into the tissue by inhibiting CD4+ T cell infiltration. PMID:8093895

  11. Effects of 900-MHz microwave radiation on gamma-ray-induced damage to mouse hematopoietic system.

    PubMed

    Cao, Yi; Xu, Qian; Jin, Zong-Da; Zhang, Jun; Lu, Min-Xia; Nie, Ji-Hua; Tong, Jian

    2010-01-01

    Exposure of humans simultaneously to microwave and gamma-ray irradiation may be a commonly encountered phenomenon. In a previous study data showed that low-dose microwave radiation increased the survival rate of mice irradiated with 8Gy gamma-ray; however, the mechanisms underlying these findings remain unclear. Consequently, studies were undertaken to examine the effects of microwave exposure on hematopoietic system adversely altered by gamma-ray irradiation in mice. Preexposure to low-dose microwaves attenuated the damage produced by gamma-ray irradiation as evidenced by less severe pathological alterations in bone marrow and spleen. The protective effects of microwaves were postulated to be due to up-expression of some hematopoietic growth factors, stimulation of proliferation of the granulocyte-macrophages in bone marrow, and inhibition of the gamma-ray induced suppression of hematopoietic stem cells/hematopoietic progenitor cells. Data thus indicate that prior exposure to microwaves may be beneficial in providing protection against injuries produced by gamma-ray on the hematopoietic system in mice.

  12. Improved readout system for multi-crystal gamma cameras

    DOEpatents

    Derenzo, S.E.

    1985-08-21

    A radioisotope camera having an array of scintillation crystals arranged in N rows and M columns and adapted to be struck by gamma-rays from a subject, a separate solid state photodetector optically coupled to each crystal, and N + M amplifiers connected to the photodetectors to distinguish the particular row and column of an activated photodetector. One of the anode or cathode leads of each photodetector is coupled to the row amplifier associated with the row containing that photodetector while the other of the two leads is coupled to the column amplifier associated with the column containing that photodetector.

  13. A simultaneous beta and coincidence-gamma imaging system for plant leaves

    NASA Astrophysics Data System (ADS)

    Ranjbar, Homayoon; Wen, Jie; Mathews, Aswin J.; Komarov, Sergey; Wang, Qiang; Li, Ke; O'Sullivan, Joseph A.; Tai, Yuan-Chuan

    2016-05-01

    Positron emitting isotopes, such as 11C, 13N, and 18F, can be used to label molecules. The tracers, such as 11CO2, are delivered to plants to study their biological processes, particularly metabolism and photosynthesis, which may contribute to the development of plants that have a higher yield of crops and biomass. Measurements and resulting images from PET scanners are not quantitative in young plant structures or in plant leaves due to poor positron annihilation in thin objects. To address this problem we have designed, assembled, modeled, and tested a nuclear imaging system (simultaneous beta-gamma imager). The imager can simultaneously detect positrons ({β+} ) and coincidence-gamma rays (γ). The imaging system employs two planar detectors; one is a regular gamma detector which has a LYSO crystal array, and the other is a phoswich detector which has an additional BC-404 plastic scintillator for beta detection. A forward model for positrons is proposed along with a joint image reconstruction formulation to utilize the beta and coincidence-gamma measurements for estimating radioactivity distribution in plant leaves. The joint reconstruction algorithm first reconstructs beta and gamma images independently to estimate the thickness component of the beta forward model and afterward jointly estimates the radioactivity distribution in the object. We have validated the physics model and reconstruction framework through a phantom imaging study and imaging a tomato leaf that has absorbed 11CO2. The results demonstrate that the simultaneously acquired beta and coincidence-gamma data, combined with our proposed joint reconstruction algorithm, improved the quantitative accuracy of estimating radioactivity distribution in thin objects such as leaves. We used the structural similarity (SSIM) index for comparing the leaf images from the simultaneous beta-gamma imager with the ground truth image. The jointly reconstructed images yield SSIM indices of 0.69 and 0.63, whereas the

  14. Triple-head gamma camera PET: system overview and performance characteristics.

    PubMed

    Grosev, D; Loncarić, S; Vandenberghe, S; Dodig, D

    2002-08-01

    Positron emission tomography (PET) is currently performed using either a dedicated PET scanner or scintillation gamma camera equipped with electronic circuitry for coincidence detection of 511 keV annihilation quanta (gamma camera PET system). Although the resolution limits of these two instruments are comparable, the sensitivity and count rate performance of the gamma camera PET system are several times lower than that of the PET scanner. Most gamma camera PET systems are manufactured as dual-detector systems capable of performing dual-head coincidence imaging. One possible step towards the improvement of the sensitivity of the gamma camera PET system is to add another detector head. This work investigates the characteristics of one such triple-head gamma camera PET system capable of performing triple-head coincidence imaging. The following performance characteristics of the system were assessed: spatial resolution, sensitivity, count rate performance. The spatial resolution, expressed as the full width at half-maximum (FWHM), at 1 cm radius is 5.9 mm; at 10 cm radius, the transverse radial resolution is 5.3 mm, whilst the transverse tangential and axial resolutions are 8.9 mm and 13.3 mm, respectively. The sensitivity for a standard cylindrical phantom is 255 counts.s(-1).MBq*(-1)), using a 30% width photopeak energy window. An increase of 35% in the PET sensitivity is achievable by opening an additional 30% width energy window in the Compton region. The count rate in coincidence mode, at the upper limit of the systems optimal performance, is 45 kc.s(-1) (kc=kilocounts) using the photopeak energy window only, and increases to 60 kc.s(-1) using the photopeak + Compton windows. Sensitivity results are compared with published data for a similar dual-head detector system.

  15. Bacillus subtilis-specific poly-gamma-glutamic acid regulates development pathways of naive CD4(+) T cells through antigen-presenting cell-dependent and -independent mechanisms.

    PubMed

    Kim, Sunghoon; Yang, Jun Young; Lee, Kyuheon; Oh, Kyu Heon; Gi, Mia; Kim, Jung Mogg; Paik, Doo Jin; Hong, Seokmann; Youn, Jeehee

    2009-08-01

    Peripheral naive CD4(+) T cells selectively differentiate to type 1 T(h), type 2 T(h) and IL-17-producing T(h) (T(h)17) cells, depending on the priming conditions. Since these subsets develop antagonistically to each other to elicit subset-specific adaptive immune responses, balance between these subsets can regulate the susceptibility to diverse immune diseases. The present study was undertaken to determine whether poly-gamma-glutamic acid (gamma-PGA), an edible and safe exopolymer that is generated by microorganisms such as Bacillus subtilis, could modulate the development pathways of T(h) subsets. The presence of gamma-PGA during priming promoted the development of T(h)1 and T(h)17 cells but inhibited development of T(h)2 cells. gamma-PGA up-regulated the expression of T-bet and ROR-gammat, the master genes of T(h)1 and T(h)17 cells, respectively, whereas down-regulating the level of GATA-3, the master gene of T(h)2 cells. gamma-PGA induced the expression of IL-12p40, CD80 and CD86 in dendritic cells (DC) and macrophages in a Toll-like receptor-4-dependent manner, and the effect of gamma-PGA on T(h)1/T(h)2 development was dependent on the presence of antigen-presenting cells (APC). Furthermore, gamma-PGA-stimulated DC favored the polarization of naive CD4(+) T cells toward T(h)1 cells rather than T(h)2 cells. In contrast, gamma-PGA affected T(h)17 cell development, regardless of the presence or absence of APC. Thus, these data demonstrate that gamma-PGA has the potential to regulate the development pathways of naive CD4(+) T cells through APC-dependent and -independent mechanisms and to be applicable to treating T(h)2-dominated diseases.

  16. Performance degradation of QAM based inter-satellite optical communication system under gamma irradiation

    NASA Astrophysics Data System (ADS)

    Liu, Yun; Zhao, Shanghong; Gong, Zizheng; Zhao, Jing; Li, Xuan

    2016-01-01

    Main devices in quadrature amplitude modulation (QAM) based inter-satellite optical communication system were irradiated to a total dose of 20 krad with the dose rate of 5 rad/s using a Co60 radiation source. Gamma irradiation impacts on devices were analyzed and on the basis, system performance degradation was simulated. Variety of system BER along with onboard working time for different inter-satellite links was presented. In addition, some adaption methods were proposed to reduce gamma irradiation induced degradation.

  17. Effective capacity of MIMO free-space optical systems over gamma-gamma turbulence channels

    NASA Astrophysics Data System (ADS)

    Chen, Li; Wang, Weidong

    2017-01-01

    In this paper, we provide the capacity limits of multiple-input multiple-output (MIMO) free-space optical communication (FSO) system in the presence of quality of service (QoS) requirements. Closed-form expression for the effective capacity of MIMO FSO system with equal gain combining (EGC) is derived. In order to provide insights into the impact of various system parameters, asymptotic expressions are further analyzed in the high signal-to-noise ratio (SNR) regime. Special cases are provided according to the derived results at the same time. Numerical results are given to validate all the analytical results, and the influences of QoS requirements and MIMO configurations are also illustrated.

  18. Polo-like kinase 2 gene expression is regulated by the orphan nuclear receptor estrogen receptor-related receptor gamma (ERR{gamma})

    SciTech Connect

    Park, Yun-Yong; Kim, Seok-Ho; Kim, Yong Joo; Kim, Sun Yee; Lee, Tae-Hoon; Lee, In-Kyu; Park, Seung Bum; Choi, Hueng-Sik

    2007-10-12

    Estrogen receptor-related receptor gamma (ERR{gamma}) is a member of the nuclear receptor family of transcriptional activators. To date, the target genes and physiological functions of ERR{gamma} are not well understood. In the current study, we identify that Plk2 is a novel target of ERR{gamma}. Northern blot analysis showed that overexpression of ERR{gamma} induced Plk2 expression in cancer cell lines. ERR{gamma} activated the Plk2 gene promoter, and deletion and mutational analysis of the Plk2 promoter revealed that the ERR{gamma}-response region is located between nucleotides (nt) -2327 and -2229 and -441 and -432 (relative to the transcriptional start site at +1). Electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP) analysis demonstrated that ERR{gamma} binds directly to the Plk2 promoter. Overexpression of ERR{gamma} in the presence of the mitotic inhibitor nocodazole significantly decreased apoptosis, and induced S-phase cell cycle progression through the induction of Plk2 expression. Taken together, these results demonstrated that Plk2 is a novel target of ERR{gamma}, and suggest that this interaction is crucial for cancer cell proliferation.

  19. Reduction in T gamma delta cell numbers and alteration in subset distribution in systemic lupus erythematosus.

    PubMed Central

    Lunardi, C; Marguerie, C; Bowness, P; Walport, M J; So, A K

    1991-01-01

    We have studied the distribution of T gamma delta cells in the peripheral blood of 35 patients with systemic lupus erythematosus (SLE) and 36 age-matched controls. The monoclonal antibodies A13, BB3 and Ti gamma A, which are specific for the V delta 1, V delta 2 and V delta 9 gene products respectively, were used to define T gamma delta cell subsets. A significantly lower frequency of T gamma delta cells was found in peripheral blood lymphocytes of SLE patients compared with normal subjects (3.2% versus 5.9%). There was a marked reduction in the V delta 2+ subset of T gamma delta cells, which resulted in a reversal of the ratio of V delta 2+/V delta 1+ cells from 4.34 to 0.56. No correlation was found with either clinical or laboratory measures of disease activity. These results suggest that the observed changed in T gamma delta subset distribution are related to the SLE itself, and not secondary to changes in disease activity. PMID:1834377

  20. A compact neutron beam generator system designed for prompt gamma nuclear activation analysis.

    PubMed

    Ghassoun, J; Mostacci, D

    2011-08-01

    In this work a compact system was designed for bulk sample analysis using the technique of PGNAA. The system consists of (252)Cf fission neutron source, a moderator/reflector/filter assembly, and a suitable enclosure to delimit the resulting neutron beam. The moderator/reflector/filter arrangement has been optimised to maximise the thermal neutron component useful for samples analysis with a suitably low level of beam contamination. The neutron beam delivered by this compact system is used to irradiate the sample and the prompt gamma rays produced by neutron reactions within the sample elements are detected by appropriate gamma rays detector. Neutron and gamma rays transport calculations have been performed using the Monte Carlo N-Particle transport code (MCNP5).

  1. A Rotating Phantom: Evaluation Of Hard And Software For Gated Gamma Camera Systems In Nuclear Medicine.

    NASA Astrophysics Data System (ADS)

    Vanregemorter, J.; Deconinck, F.; Bossuyt, A.

    1986-06-01

    In this paper we describe a rotating dynamic phantom which allows quality control of hardware and software for gated gamma camera systems in nuclear medicine. The phantom not only allows simulation of a gated heart study but also testing of the response of the whole system to time frequencies.

  2. Readout system for multi-crystal gamma cameras

    DOEpatents

    Derenzo, Stephen E.

    1987-01-01

    A radioisotope camera (10) having an array (12) of scintillation crystals (13) arranged in N rows and M columns and adapted to be struck by gamma-rays from a subject, a separate solid state photodetector (15 ) optically coupled to each crystal (13), and N+M amplifiers (24) connected to the photodetectors (15) to distinguish the particular row and column of an activated photodetector. One of the anode or cathode leads (33 or 34) of each photodetector (15) is coupled to the row amplifier (24) associated with the row containing that photodetector while the other of the two leads (34 or 33) is coupled to the column amplifier (24) associated with the column containing that photodetector.

  3. Development of an all-in-one gamma camera/CCD system for safeguard verification

    NASA Astrophysics Data System (ADS)

    Kim, Hyun-Il; An, Su Jung; Chung, Yong Hyun; Kwak, Sung-Woo

    2014-12-01

    For the purpose of monitoring and verifying efforts at safeguarding radioactive materials in various fields, a new all-in-one gamma camera/charged coupled device (CCD) system was developed. This combined system consists of a gamma camera, which gathers energy and position information on gamma-ray sources, and a CCD camera, which identifies the specific location in a monitored area. Therefore, 2-D image information and quantitative information regarding gamma-ray sources can be obtained using fused images. A gamma camera consists of a diverging collimator, a 22 × 22 array CsI(Na) pixelated scintillation crystal with a pixel size of 2 × 2 × 6 mm3 and Hamamatsu H8500 position-sensitive photomultiplier tube (PSPMT). The Basler scA640-70gc CCD camera, which delivers 70 frames per second at video graphics array (VGA) resolution, was employed. Performance testing was performed using a Co-57 point source 30 cm from the detector. The measured spatial resolution and sensitivity were 4.77 mm full width at half maximum (FWHM) and 7.78 cps/MBq, respectively. The energy resolution was 18% at 122 keV. These results demonstrate that the combined system has considerable potential for radiation monitoring.

  4. SWEPP gamma-ray spectrometer system software user`s guide

    SciTech Connect

    Femec, D.A.

    1994-08-01

    The SWEPP Gamma-Ray Spectrometer (SGRS) System has been developed by the Radiation Measurement and Development Unit of the Idaho National Engineering Laboratory to assist in the characterization of the radiological contents of contact-handled waste containers at the Stored Waste Examination Pilot Plant (SWEPP). In addition to determining the concentrations of gamma-ray-emitting radionuclides, the software also calculates attenuation-corrected isotopic mass ratios of specific interest, and provides controls for SGRS hardware as required. This document serves as a user`s guide for the data acquisition and analysis software associated with the SGRS system.

  5. Photoreceptor System for Melatonin Regulation and Phototherapy

    NASA Technical Reports Server (NTRS)

    Brainard, George (Inventor); Glickman, Gena (Inventor)

    2010-01-01

    The present invention involves a light system for stimulating or regulating neuroendocrine, circadian, and photoneural systems in mammals based upon the discovery of peak sensitivity ranging from 425-505 nm; a light meter system for quantifying light which stimulates or regulates mammalian circadian, photoneural, and neuroendocrine systems. The present invention also relates to translucent and transparent materials, and lamps or other light sources with or without filters capable of stimulating or regulating neuroendocrine, circadian, and photoneural systems in mammals. Additionally, the present invention involves treatment of mammals with a wide variety of disorders or deficits, including light responsive disorders, eating disorders, menstrual cycle disorders, non-specific alerting and performance deficits, hormone-sensitive cancers, and cardiovascular disorders.

  6. Regulated intramembrane proteolysis of the interleukin-1 receptor II by alpha-, beta-, and gamma-secretase.

    PubMed

    Kuhn, Peer-Hendrik; Marjaux, Els; Imhof, Axel; De Strooper, Bart; Haass, Christian; Lichtenthaler, Stefan F

    2007-04-20

    Ectodomain shedding and intramembrane proteolysis of the amyloid precursor protein (APP) by alpha-, beta- and gamma-secretase are involved in the pathogenesis of Alzheimer disease (AD). Increased proteolytic processing and secretion of another membrane protein, the interleukin-1 receptor II (IL-1R2), have also been linked to the pathogenesis of AD. IL-1R2 is a decoy receptor that may limit detrimental effects of IL-1 in the brain. At present, the proteolytic processing of IL-1R2 remains little understood. Here we show that IL-1R2 can be proteolytically processed in a manner similar to APP. IL-1R2 expressed in human embryonic kidney 293 cells first undergoes ectodomain shedding in an alpha-secretase-like manner, resulting in secretion of the IL-1R2 ectodomain and the generation of an IL-1R2 C-terminal fragment. This fragment undergoes further intramembrane proteolysis by gamma-secretase, leading to the generation of the soluble intracellular domain of IL-1R2. Intramembrane cleavage of IL-1R2 was abolished by a highly specific inhibitor of gamma-secretase and was absent in mouse embryonic fibroblasts deficient in gamma-secretase activity. Surprisingly, the beta-secretase BACE1 and its homolog BACE2 increased IL-1R2 secretion resulting in C-terminal fragments nearly identical to the ones generated by the alpha-secretase-like cleavage. This suggests that both proteases may act as alternative alpha-secretase-like proteases. Importantly, BACE1 and BACE2 did not cleave several other membrane proteins, demonstrating that both proteases do not contribute to general membrane protein turnover but only cleave specific proteins. This study reveals a similar proteolytic processing of IL-1R2 and APP and may provide an explanation for the increased IL-1R2 secretion observed in AD.

  7. Regulation of autoimmune arthritis by the pro-inflammatory cytokine interferon-gamma.

    PubMed

    Kim, Eugene Y; Chi, Howard H; Bouziane, Mohammed; Gaur, Amitabh; Moudgil, Kamal D

    2008-04-01

    The pathogenesis of T cell-mediated diseases like rheumatoid arthritis (RA) has typically been explained in the context of the Th1-Th2 paradigm: the initiation/propagation by pro-inflammatory cytokines, and downregulation by Th2 cytokines. However, in our study based on the adjuvant-induced arthritis (AA) model of RA, we observed that Lewis (LEW) (RT.1(l)) rats at the recovery phase of AA showed the highest level of IFN-gamma in recall response to mycobacterial heat-shock protein 65 (Bhsp65), whereas AA-resistant Wistar-Kyoto (WKY) (RT.1(l)) rats secreted high levels of IFN-gamma much earlier following disease induction. However, no significant secretion of IL-10 or TGF-beta was observed in either strain. Furthermore, pre-treatment of LEW rats with a peptide of self (rat) hsp65 (R465), which induced T cells secreting predominantly IFN-gamma, afforded protection against AA and decreased IL-17 expression by the arthritogenic epitope-restimulated T cells. These results provide a novel perspective on the pathogenesis of autoimmune arthritis.

  8. Rotating and static sources for gamma knife radiosurgery systems: Monte Carlo studies.

    PubMed

    Cheung, J Y C; Yu, K N

    2006-07-01

    Rotating gamma systems (RGSs), GammaART-6000, and its Chinese equivalents, such as OUR and MASEP, etc., are new radiosurgery systems that use rotating 60Co sources instead of the 201 static sources (Leksell gamma knife, LGK). The rotating sources of RGSs simulate an infinite number of beams and promote extremely high target to surface dose ratios. However, the results of Monte Carlo in this study shows that RGS variants (modeled as having the same latitude angles, source to focus distance, and the distance from the source to the end of the collimator as the LGK) have smaller beam profile penumbra in the z direction, while LGK has smaller penumbra in the x and y directions. The differences are more significant in using larger collimators.

  9. Rotating and static sources for gamma knife radiosurgery systems: Monte Carlo studies

    SciTech Connect

    Cheung, J. Y. C.; Yu, K. N.

    2006-07-15

    Rotating gamma systems (RGSs), GammaART-6000{sup TM}, and its Chinese equivalents, such as OUR and MASEP, etc., are new radiosurgery systems that use rotating {sup 60}Co sources instead of the 201 static sources (Leksell gamma knife, LGK). The rotating sources of RGSs simulate an infinite number of beams and promote extremely high target to surface dose ratios. However, the results of Monte Carlo in this study shows that RGS variants (modeled as having the same latitude angles, source to focus distance, and the distance from the source to the end of the collimator as the LGK) have smaller beam profile penumbra in the z direction, while LGK has smaller penumbra in the x and y directions. The differences are more significant in using larger collimators.

  10. Analysis of Neutron Induced Gamma Activity in Lowbackground Ge - Spectroscopy Systems

    NASA Astrophysics Data System (ADS)

    Jovančević, Nikola; Krmar, Midrag

    Neutron interactions with materials of Ge-spectroscopy systems are one of the main sources of background radiation in low-level gamma spectroscopy measurements. Because of that detailed analysis of neutron induced gamma activity in low-background Ge-spectroscopy systems was done. Two HPGe detectors which were located in two different passive shields: one in pre-WW II made iron and the second in commercial low background lead were used in the experiment. Gamma lines emitted after neutron capture, as well as after inelastic scattering on the germanium crystal and shield materials (lead, iron, hydrogen, NaI) were detected and then analyzed. The thermal and fast neutron fluxes were calculated and their values were compared for the two different kinds of detector shield. The relative intensities of several gamma lines emitted after the inelastic scattering of neutrons (created by cosmic muons) in 56Fe were report. These relative intensities of detected gamma lines of 56Fe are compared with the results collected in the same iron shield by the use of the 252Cf neutrons.

  11. Estimability and regulability of linear systems

    NASA Technical Reports Server (NTRS)

    Baram, Yoram; Kailath, Thomas

    1987-01-01

    A linear state-space system will be said to be estimable if in estimating its state from its output the posterior error covariance matrix is strictly smaller than the prior covariance matrix. It will be said to be regulable if the quadratic cost of state feedback control is strictly smaller than the cost when no feedback is used. These properties, which are are shown to be dual, are different from the well known observability and controllability properties of linear systems. Necessary and sufficient conditions for estimability and regulability are derived for time variant and time invariant systems, in discrete and continuous time.

  12. Estimability and regulability of linear systems

    NASA Technical Reports Server (NTRS)

    Baram, Yoram; Kailath, Thomas

    1987-01-01

    A linear state-space system will be said to be estimable if in estimating its state from its output the posterior error covariance matrix is strictly smaller than the prior covariance matrix. It will be said to be regulable if the quadratic cost of state feedback control is strictly smaller than the cost when no feedback is used. These properties, which are shown to be dual, are different from the well known observability and controllability properties of linear systems. Necessary and sufficient conditions for estimability and regulability are derived for time variant and time invariant systems, in discrete and continuous time.

  13. System biology of gene regulation.

    PubMed

    Baitaluk, Michael

    2009-01-01

    ) questions of biological relevance. Thus systems biology could be treated as such a socioscientific phenomenon and a new approach to both experiments and theory that is defined by the strategy of pursuing integration of complex data about the interactions in biological systems from diverse experimental sources using interdisciplinary tools and personnel.

  14. The plasminogen activator system: biology and regulation.

    PubMed

    Irigoyen, J P; Muñoz-Cánoves, P; Montero, L; Koziczak, M; Nagamine, Y

    1999-10-01

    The regulation of plasminogen activation involves genes for two plasminogen activators (tissue type and urokinase type), two specific inhibitors (type 1 and type 2), and a membrane-anchored urokinase-type plasminogen-activator-specific receptor. This system plays an important role in various biological processes involving extracellular proteolysis. Recent studies have revealed that the system, through interplay with integrins and the extracellular matrix protein vitronectin, is also involved in the regulation of cell migration and proliferation in a manner independent of proteolytic activity. The genes are expressed in many different cell types and their expression is under the control of diverse extracellular signals. Gene expression reflects the levels of the corresponding mRNA, which should be the net result of synthesis and degradation. Thus, modulation of mRNA stability is an important factor in overall regulation. This review summarizes current understanding of the biology and regulation of genes involved in plasminogen activation at different levels.

  15. Estimability and Regulability of Linear Systems

    NASA Technical Reports Server (NTRS)

    Baram, Yoram; Kailath, Thomas

    1988-01-01

    A linear state-space system will be said to be estimable if in estimating its state from its output the posterior error covariance matrix is strictly smaller than the prior covariance matrix. It will be said to be regulable if the quadratic cost of state feedback control is strictly smaller than the cost when no feedback is used. Estimability and regulability are shown to be dual properties, equivalent to the nonreducibility of the Kalman filter and of the optimal linear quadratic regulator, respectively.

  16. NRF Based Nondestructive Inspection System for SNM by Using Laser-Compton-Backscattering Gamma-Rays

    NASA Astrophysics Data System (ADS)

    Ohgaki, H.; Omer, M.; Negm, H.; Daito, I.; Zen, H.; Kii, T.; Masuda, K.; Hori, T.; Hajima, R.; Hayakawa, T.; Shizuma, T.; Kando, M.

    2015-10-01

    A non-destructive inspection system for special nuclear materials (SNMs) hidden in a sea cargo has been developed. The system consists of a fast screening system using neutron generated by inertial electrostatic confinement (IEC) device and an isotope identification system using nuclear resonance fluorescence (NRF) measurements with laser Compton backscattering (LCS) gamma-rays has been developed. The neutron flux of 108 n/sec has been achieved by the IEC in static mode. We have developed a modified neutron reactor noise analysis method to detect fission neutron in a short time. The LCS gamma-rays has been generated by using a small racetrack microtoron accelerator and an intense sub-nano second laser colliding head-on to the electron beam. The gamma-ray flux has been achieved more than 105 photons/s. The NRF gamma-rays will be measured using LaBr3(Ce) scintillation detector array whose performance has been measured by NRF experiment of U-235 in HIGS facility. The whole inspection system has been designed to satisfy a demand from the sea port.

  17. Image nonlinearity and non-uniformity corrections using Papoulis - Gerchberg algorithm in gamma imaging systems

    NASA Astrophysics Data System (ADS)

    Shemer, A.; Schwarz, A.; Gur, E.; Cohen, E.; Zalevsky, Z.

    2015-04-01

    In this paper, the authors describe a novel technique for image nonlinearity and non-uniformity corrections in imaging systems based on gamma detectors. The limitation of the gamma detector prevents the producing of high quality images due to the radionuclide distribution. This problem causes nonlinearity and non-uniformity distortions in the obtained image. Many techniques have been developed to correct or compensate for these image artifacts using complex calibration processes. The presented method is based on the Papoulis - Gerchberg(PG) iterative algorithm and is obtained without need of detector calibration, tuning process or using any special test phantom.

  18. Low-background gamma-ray spectrometry for the international monitoring system

    DOE PAGES

    Greenwood, L. R.; Cantaloub, M. G.; Burnett, J. L.; ...

    2016-12-28

    PNNL has developed two low-background gamma-ray spectrometers in a new shallow underground laboratory, thereby significantly improving its ability to detect low levels of gamma-ray emitting fission or activation products in airborne particulate in samples from the IMS (International Monitoring System). Furthermore, the combination of cosmic veto panels, dry nitrogen gas to reduce radon and low background shielding results in a reduction of the background count rate by about a factor of 100 compared to detectors operating above ground at our laboratory.

  19. Low-background gamma-ray spectrometry for the international monitoring system.

    PubMed

    Greenwood, L R; Cantaloub, M G; Burnett, J L; Myers, A W; Overman, C T; Forrester, J B; Glasgow, B G; Miley, H S

    2016-12-28

    PNNL has developed two low-background gamma-ray spectrometers in a new shallow underground laboratory, thereby significantly improving its ability to detect low levels of gamma-ray emitting fission or activation products in airborne particulate in samples from the IMS (International Monitoring System). The combination of cosmic veto panels, dry nitrogen gas to reduce radon and low background shielding results in a reduction of the background count rate by about a factor of 100 compared to detectors operating above ground at our laboratory.

  20. Status of the scientific data acquisition system for the GAMMA-400 space telescope mission

    NASA Astrophysics Data System (ADS)

    Bobkov, S. G.; Serdin, O. V.; Gorbunov, M. S.; Bakaldin, A. V.; Timina, A.; Arkhangelskiy, A. I.; Topchiev, N. P.

    2017-01-01

    The present status of scientific data acquisition system (SDAQ) developed by SRISA for the GAMMA-400 space gamma-ray telescope mission is presented. SDAQ provides the collection of the data from telescope detector subsystems (up to 100 GB per day), the preliminary processing of scientific information and its accumulation in mass memory, transferring the information from mass memory to the satellite radio line for its transmission to the ground station, the control and monitoring of the telescope subsystems. SDAQ includes special space qualified chipset designed by SRISA and has scalable modular net structure based on fast and high-reliable SerialRapidIO 1.25 Gbit/s interface.

  1. Monte Carlo simulation of a collimation system for low-energy beamline of ELI-NP Gamma Beam System

    NASA Astrophysics Data System (ADS)

    Cardarelli, P.; Gambaccini, M.; Marziani, M.; Bagli, E.; Petrillo, V.; Bacci, A.; Curatolo, C.; Drebot, I.; Vaccarezza, C.

    2015-07-01

    ELI-nuclear physics (NP) Gamma Beam System (GBS) is an intense and monochromatic gamma beam source based on inverse Compton interaction, currently being built in Bucharest, Romania. The gamma beam produced, with energy ranging from 0.2 to 20 MeV, energy bandwidth 0.5% and flux of about 108photons/s, will be devoted to investigate a broad range of applications such as nuclear physics, astrophysics, material science and life sciences. The radiation produced by an inverse Compton interaction is not intrinsically monochromatic. In fact, the energy of the photons produced is related to the emission angle, therefore the energy bandwidth can be modified adjusting the collimation of the gamma beam. In order to define the optimal layout and evaluate the performance of a collimation system for the ELI-NP-GBS low-energy beamline (0.2-3.5 MeV), a detailed Monte Carlo simulation activity has been carried out. The simulation, using Geant4 and MCNPX codes, included the transport of the gamma beam from the interaction point to the experimental area passing through vacuum pipes, vacuum chambers, collimation system and relative shielding. The effectiveness of the collimation system, in obtaining the required energy distribution and avoiding the contamination due to secondary radiation production, was evaluated. Also, the background radiation generated by collimation and the shielding layout have been studied.

  2. Performance analysis of relay-aided free-space optical communication system over gamma-gamma fading channels with pointing errors

    NASA Astrophysics Data System (ADS)

    Fu, Hui-hua; Wang, Ping; Wang, Ran-ran; Liu, Xiao-xia; Guo, Li-xin; Yang, Yin-tang

    2016-07-01

    The average bit error rate ( ABER) performance of a decode-and-forward (DF) based relay-assisted free-space optical (FSO) communication system over gamma-gamma distribution channels considering the pointing errors is studied. With the help of Meijer's G-function, the probability density function (PDF) and cumulative distribution function (CDF) of the aggregated channel model are derived on the basis of the best path selection scheme. The analytical ABER expression is achieved and the system performance is then investigated with the influence of pointing errors, turbulence strengths and structure parameters. Monte Carlo (MC) simulation is also provided to confirm the analytical ABER expression.

  3. The Advanced Gamma-ray Imaging System (AGIS) Telescope Optical System Designs

    SciTech Connect

    Bugaev, V.; Buckley, J.; Krawczynski, H.; Diegel, S.; Romani, R.; Falcone, A.; Fegan, S.; Vassiliev, V.; Finley, J.; Guarino, V.; Hanna, D.; Kaaret, P.; Konopelko, A.; Ramsey, B.; Weekes, T.

    2008-12-24

    AGIS is a conceptual design for a future ground-based gamma-ray observatory operating in the energy range 25 GeV-100 TeV, which is based on an array of {approx}20-100 imaging atmospheric Cherenkov telescopes (IACTs). The desired improvement in sensitivity, angular resolution, and reliability of operation of AGIS imposes demanding technological and cost requirements on the design of the IACTs. We are considering several options for the optical system (OS) of the AGIS telescopes, which include the traditional Davies-Cotton design as well as novel two-mirror design. Emerging mirror production technologies based on replication processes such as cold and hot glass slumping, cured carbon fiber reinforced plastic (CFRP), and electroforming provide new opportunities for cost-effective solutions for the design of the OS.

  4. Growth and major histocompatibility antigen expression regulation by IL-4, interferon-gamma (IFN-gamma) and tumour necrosis factor-alpha (TNF-alpha) on human renal cell carcinoma.

    PubMed Central

    Hillman, G G; Puri, R K; Kukuruga, M A; Pontes, J E; Haas, G P

    1994-01-01

    We have recently shown that human renal cell carcinoma (RCC) tumour lines express high-affinity IL-4 receptors. Binding of IL-4 to RCC cells induced a growth inhibition in the range of 20-68%. To enhance the growth inhibitory effect of IL-4, we have tested the effects of two additional cytokines capable of directly affecting tumour cell growth. IFN-gamma caused a significant inhibition of RCC tumour cell growth (up to 70%) in a dose-dependent manner, whereas the effect of TNF-alpha was more limited (0-20% inhibition). The addition of IL-4 to IFN-gamma on RCC cells sensitive to IL-4 induced a greater inhibition of cell growth than that seen with each cytokine alone. IL-4 and IFN-gamma rendered RCC cells more responsive to the inhibitory effect mediated by TNF-alpha. The combination of TNF-alpha with IL-4 and IFN-gamma induced an optimal growth inhibition (up to 90-98%) of RCC cells. In addition to a direct anti-proliferative effect, we have demonstrated that these cytokines can also enhance the expression of MHC antigens on the surface of RCC tumour cell lines which may render the cells more immunogenic. All RCC lines tested expressed class I antigens, but not class II antigens. IFN-gamma induced class II expression and up-regulated the expression of class I antigens on RCC cells. Class II antigen expression was detectable following 48 h incubation, and greater after 72 h with IFN-gamma. IL-4 minimally affected class I expression, whereas TNF-alpha up-regulated class I antigen expression. IL-4 or TNF-alpha did not induce class II expression. The combination of the three cytokines slightly augmented the up-regulation of class I and class II antigens observed with IFN-gamma alone. These observations confirm the direct interaction of IL-4, IFN-gamma and TNF-alpha with RCC tumour cells, both at the level of growth regulation and MHC antigen expression, and suggest a therapeutic potential of the combination of the three cytokines for renal cell carcinoma. PMID:8004818

  5. Fc gamma receptors regulate immune activation and susceptibility during Mycobacterium tuberculosis infection.

    PubMed

    Maglione, Paul J; Xu, Jiayong; Casadevall, Arturo; Chan, John

    2008-03-01

    The critical role of cellular immunity during tuberculosis (TB) has been extensively studied, but the impact of Abs upon this infection remains poorly defined. Previously, we demonstrated that B cells are required for optimal protection in Mycobacterium tuberculosis-infected mice. FcgammaR modulate immunity by engaging Igs produced by B cells. We report that C57BL/6 mice deficient in inhibitory FcgammaRIIB (RIIB-/-) manifested enhanced mycobacterial containment and diminished immunopathology compared with wild-type controls. These findings corresponded with enhanced pulmonary Th1 responses, evidenced by increased IFN-gamma-producing CD4+ T cells, and elevated expression of MHC class II and costimulatory molecules B7-1 and B7-2 in the lungs. Upon M. tuberculosis infection and immune complex engagement, RIIB-/- macrophages produced more of the p40 component of the Th1-promoting cytokine IL-12. These data strongly suggest that FcgammaRIIB engagement can dampen the TB Th1 response by attenuating IL-12p40 production or activation of APCs. Conversely, C57BL/6 mice lacking the gamma-chain shared by activating FcgammaR had enhanced susceptibility and exacerbated immunopathology upon M. tuberculosis challenge, associated with increased production of the immunosuppressive cytokine IL-10. Thus, engagement of distinct FcgammaR can divergently affect cytokine production and susceptibility during M. tuberculosis infection.

  6. Regulation of longevity by the reproductive system.

    PubMed

    Antebi, Adam

    2013-07-01

    Pioneering work in model organisms reveals that the reproductive system is involved not only in propagation of the species but also regulates organismal metabolism and longevity. In C. elegans, prevention of germline stem cell proliferation results in a 60% extension of lifespan, termed gonadal longevity. Gonadal longevity relies on the transcriptional activities of steroid nuclear receptor DAF-12, the FOXO transcription factor homolog DAF-16, the FOXA transcription factor homolog PHA-4, and the HNF-4-like nuclear receptor NHR-80. These transcription factors work in an integrated transcriptional network to regulate fatty acid lipolysis, autophagy, stress resistance and other processes, which altogether enhance homeostasis and extend life. Because the reproductive system also regulates longevity in other species, studies in C. elegans may shed light on ancient mechanisms governing reproduction and survival.

  7. The structure of control and data transfer management system for the GAMMA-400 scientific complex

    NASA Astrophysics Data System (ADS)

    Arkhangelskiy, A. I.; Bobkov, S. G.; Serdin, O. V.; Gorbunov, M. S.; Topchiev, N. P.

    2016-02-01

    A description of the control and data transfer management system for scientific instrumentation involved in the GAMMA-400 space project is given. The technical capabilities of all specialized equipment to provide the functioning of the scientific instrumentation and satellite support systems are unified in a single structure. Control of the scientific instruments is maintained using one-time pulse radio commands, as well as program commands in the form of 16-bit code words, which are transmitted via onboard control system and scientific data acquisition system. Up to 100 GByte of data per day can be transferred to the ground segment of the project. The correctness of the proposed and implemented structure, engineering solutions and electronic elemental base selection has been verified by the experimental working-off of the prototype of the GAMMA-400 scientific complex in laboratory conditions.

  8. Design of a {gamma}{sub t}-jump system for Fermilab Main Injector

    SciTech Connect

    Chou, W., Brown, B.C., Fang, S., Leibfritz, J., Ng, K.Y., Pfeffer, H., Terechkine, I.

    1997-06-01

    In order to control the beam emittance and reduce the particle losses during the transition crossing at high intensity, a conceptual design of a {gamma}{sub t}-jump system for the FNAL Main Injector is presented. It is a first-order system employing local dispersion inserts at existing dispersion free straight sections. The goal is to provide a jump of {Delta}{gamma}{sub t} from +1 to -1 within 0.5 ms. The system consists of 8 sets of pulsed quadrupole triplets. These quads have pole tips of the hyperbolic shape and thin laminations. The power supply uses a GTO as the fast switch and a resonant circuit with a 1 kHz resonant frequency. The elliptical beamtube is made of Inconel 718, which has high electrical resistivity and high strength. Details of the lattice layout and sub- systems design are presented.

  9. A new natural gamma radiation measurement system for marine sediment and rock analysis

    NASA Astrophysics Data System (ADS)

    Vasiliev, M. A.; Blum, P.; Chubarian, G.; Olsen, R.; Bennight, C.; Cobine, T.; Fackler, D.; Hastedt, M.; Houpt, D.; Mateo, Z.; Vasilieva, Y. B.

    2011-11-01

    A new high-efficiency and low-background system for the measurement of natural gamma radioactivity in marine sediment and rock cores retrieved from beneath the seabed was designed, built, and installed on the JOIDES Resolution research vessel. The system includes eight large NaI(Tl) detectors that measure adjacent intervals of the core simultaneously, maximizing counting times and minimizing statistical error for the limited measurement times available during drilling expeditions. Effect to background ratio is maximized with passive lead shielding, including both ordinary and low-activity lead. Large-area plastic scintillator active shielding filters background associated with the high-energy part of cosmic radiation. The new system has at least an order of magnitude higher statistical reliability and significantly enhances data quality compared to other offshore natural gamma radiation (NGR) systems designed to measure geological core samples. Reliable correlations and interpretations of cored intervals are possible at rates of a few counts per second.

  10. Radial Electron Temperature and Density Measurements Using Thomson Scattering System in GAMMA 10/PDX

    NASA Astrophysics Data System (ADS)

    Yoshikawa, M.; Ohta, K.; Wang, X.; Chikatsu, M.; Kohagura, J.; Shima, Y.; Sakamoto, M.; Imai, T.; Nakashima, Y.; Yasuhara, R.; Yamada, I.; Funaba, H.; Minami, T.

    2015-11-01

    A Thomson scattering (TS) system in GAMMA 10/PDX has been developed for the measurement of radial profiles of electron temperature and density in a single plasma and laser shot. The TS system has a large solid angle optical collection system and high-sensitivity signal detection system. The TS signals are obtained using four-channel high-speed digital oscilloscopes controlled by a Windows PC. We designed the acquisition program for six oscilloscopes to obtain 10-Hz TS signals in a single plasma shot, following which the time-dependent electron temperatures and densities can be determined. Moreover, in order to obtain larger TS signal intensity in the edge region, we added a second collection mirror. The radial electron temperatures and densities at six radial positions in GAMMA 10/PDX were successfully obtained.

  11. Measures of Autonomic Nervous System Regulation

    DTIC Science & Technology

    2011-04-01

    Cortisol Galvanic Skin Response (GSR) Gastro- intestinal Pupillary Response Respiratory Salivary Amylase Vascular Manipulative Body-Based...Salivary Amylase Galvanic Skin Response Vascular Gastrointestinal The ANS Measures Table in Appendix A provides a summary of over fifty tools...Measures of Autonomic Nervous System Regulation Salivary Amylase Measurement

  12. Intraocular pressure reduction and regulation system

    NASA Technical Reports Server (NTRS)

    Baehr, E. F.; Burnett, J. E.; Felder, S. F.; Mcgannon, W. J.

    1979-01-01

    An intraocular pressure reduction and regulation system is described and data are presented covering performance in: (1) reducing intraocular pressure to a preselected value, (2) maintaining a set minimum intraocular pressure, and (3) reducing the dynamic increases in intraocular pressure resulting from external loads applied to the eye.

  13. Systems for increasing the sensitivity of gamma-ray imagers

    DOEpatents

    Mihailescu, Lucian; Vetter, Kai M.; Chivers, Daniel H.

    2012-12-11

    Systems that increase the position resolution and granularity of double sided segmented semiconductor detectors are provided. These systems increase the imaging resolution capability of such detectors, either used as Compton cameras, or as position sensitive radiation detectors in imagers such as SPECT, PET, coded apertures, multi-pinhole imagers, or other spatial or temporal modulated imagers.

  14. Development of a Portable Gamma-ray Survey System for the Measurement of Air Dose Rates

    NASA Astrophysics Data System (ADS)

    Goto, Jun; Shobugawa, Yugo; Kawano, Yoh; Amaya, Yoshihiro; Izumikawa, Takuji; Katsuragi, Yoshinori; Shiiya, Tomohiro; Suzuki, Tsubasa; Takahashi, Takeshi; Takahashi, Toshihiro; Yoshida, Hidenori; Naito, Makoto

    BIo-Safety Hybrid Automatic MOnitor-Niigata (BISHAMON), a portable gamma-ray survey system, was developed to support victims of the Fukushima Daiichi nuclear disaster. BISHAMON is capable of constructing a map of the distribution of ambient dose equivalent rates using vehicle-mounted or on-foot survey methods. In this study, we give an overview of BISHAMON and its measurement results including a comparison with those of other systems such as KURAMA.

  15. Role of IFN-gamma in regulating T2 immunity and the development of alternatively activated macrophages during allergic bronchopulmonary mycosis.

    PubMed

    Arora, Shikha; Hernandez, Yadira; Erb-Downward, John R; McDonald, Roderick A; Toews, Galen B; Huffnagle, Gary B

    2005-05-15

    Pulmonary Cryptococcus neoformans infection of C57BL/6 mice is an established model of a chronic pulmonary fungal infection accompanied by an "allergic" response (T2) to the infection, i.e., a model of an allergic bronchopulmonary mycosis. Our objective was to determine whether IFN-gamma plays a role in regulating the pulmonary T2 immune response in C. neoformans-infected C57BL/6 mice. Long-term pulmonary fungistasis was lost in IFN-gamma knockout (KO) mice, resulting in an increased pulmonary burden of fungi at wk 3. IFN-gamma was required for the early influx of leukocytes into the lungs but was not required later in the infection. By wk 3, eosinophil and macrophage numbers were elevated in the absence of IFN-gamma. The inducible NO synthase to arginase ratio was lower in the lungs of IFN-gamma KO mice and the macrophages had increased numbers of intracellular cryptococci and YM1 crystals, indicative of alternatively activated macrophages in these mice. There was evidence of pulmonary fibrosis in both wild-type and IFN-gamma KO mice by 5 wk postinfection. IFN-gamma production was not required for the development of T2 cytokine (IL-4, IL-5, IL-13) producing cells in the lungs and lung-associated lymph nodes or induction of an IgE response. At a number of time points, T2 cytokine production was enhanced in IFN-gamma KO mice. Thus, in the absence of IFN-gamma, C57BL/6 mice develop an augmented allergic response to C. neoformans, including enhanced generation of alternatively activated macrophages, which is accompanied by a switch from a chronic to a progressive pulmonary cryptococcal infection.

  16. The PPAR{gamma} ligand ciglitazone regulates androgen receptor activation differently in androgen-dependent versus androgen-independent human prostate cancer cells

    SciTech Connect

    Moss, Patrice E.; Lyles, Besstina E.; Stewart, LaMonica V.

    2010-12-10

    The androgen receptor (AR) regulates growth and progression of androgen-dependent as well as androgen-independent prostate cancer cells. Peroxisome proliferator-activated receptor gamma (PPAR{gamma}) agonists have been reported to reduce AR activation in androgen-dependent LNCaP prostate cancer cells. To determine whether PPAR{gamma} ligands are equally effective at inhibiting AR activity in androgen-independent prostate cancer, we examined the effect of the PPAR{gamma} ligands ciglitazone and rosiglitazone on C4-2 cells, an androgen- independent derivative of the LNCaP cell line. Luciferase-based reporter assays and Western blot analysis demonstrated that PPAR{gamma} ligand reduced dihydrotestosterone (DHT)-induced increases in AR activity in LNCaP cells. However, in C4-2 cells, these compounds increased DHT-induced AR driven luciferase activity. In addition, ciglitazone did not significantly alter DHT-mediated increases in prostate specific antigen (PSA) protein or mRNA levels within C4-2 cells. siRNA-based experiments demonstrated that the ciglitazone-induced regulation of AR activity observed in C4-2 cells was dependent on the presence of PPAR{gamma}. Furthermore, overexpression of the AR corepressor cyclin D1 inhibited the ability of ciglitazone to induce AR luciferase activity in C4-2 cells. Thus, our data suggest that both PPAR{gamma} and cyclin D1 levels influence the ability of ciglitazone to differentially regulate AR signaling in androgen-independent C4-2 prostate cancer cells.

  17. Study of Comet Nucleus Gamma-Ray Spectrometer Penetration System

    NASA Technical Reports Server (NTRS)

    Adams, G. L.; Amundsen, R. J.; Beardsley, R. W.; Cash, R. H.; Clark, B. C.; Knight, T. C. D.; Martin, J. P.; Monti, P.; Outteridge, D. A.; Plaster, W. D.

    1986-01-01

    A penetrator system has been suggested as an approach for making in situ measurements of the composition and physical properties of the nucleus of a comet. This study has examined in detail the feasibility of implementing the penetrator concept. The penetrator system and mission designs have been developed and iterated in sufficient detail to provide a high level of confidence that the concept can be implemented within the constraints of the Mariner Mark 2 spacecraft.

  18. Shigella Iron Acquisition Systems and their Regulation.

    PubMed

    Wei, Yahan; Murphy, Erin R

    2016-01-01

    Survival of Shigella within the host is strictly dependent on the ability of the pathogen to acquire essential nutrients, such as iron. As an innate immune defense against invading pathogens, the level of bio-available iron within the human host is maintained at exceeding low levels, by sequestration of the element within heme and other host iron-binding compounds. In response to sequestration mediated iron limitation, Shigella produce multiple iron-uptake systems that each function to facilitate the utilization of a specific host-associated source of nutrient iron. As a mechanism to balance the essential need for iron and the toxicity of the element when in excess, the production of bacterial iron acquisition systems is tightly regulated by a variety of molecular mechanisms. This review summarizes the current state of knowledge on the iron-uptake systems produced by Shigella species, their distribution within the genus, and the molecular mechanisms that regulate their production.

  19. High-bandwidth multichannel fiber optic system for measuring gamma rays

    SciTech Connect

    Roeske, F.; Smith, D.E.; Pruett, B.L.; Reedy, R.P.

    1984-07-01

    We describe an analog fiber optic gamma-ray diagnostic system that can transmit signals through fiber cables 600 to 700 m long with a system bandwidth exceeding 1 GHz and measure the relative timing between signals to within 0.3 ns. Gamma rays are converted to visible light via the Cerenkov process in a short length of a radiation-resistant optical fiber. A graded-index optical fiber transmits this pulse to a recording station where the broadened pulse is compensated for material dispersion and recorded using a streak camera. The streak camera can simultaneously record 20 to 30 data channels on a single piece of film. The system has been calibrated using electron linear accelerators and fielded on two experiments.

  20. System and method for resolving gamma-ray spectra

    DOEpatents

    Gentile, Charles A.; Perry, Jason; Langish, Stephen W.; Silber, Kenneth; Davis, William M.; Mastrovito, Dana

    2010-05-04

    A system for identifying radionuclide emissions is described. The system includes at least one processor for processing output signals from a radionuclide detecting device, at least one training algorithm run by the at least one processor for analyzing data derived from at least one set of known sample data from the output signals, at least one classification algorithm derived from the training algorithm for classifying unknown sample data, wherein the at least one training algorithm analyzes the at least one sample data set to derive at least one rule used by said classification algorithm for identifying at least one radionuclide emission detected by the detecting device.

  1. Reliable regulation in decentralised control systems

    NASA Astrophysics Data System (ADS)

    Locatelli, Arturo; Schiavoni, Nicola

    2011-03-01

    This article addresses the design of decentralised regulators which supply the control systems with signal tracking and disturbance rejection. This property has to be attained, to the maximum possible extent, even when instrumentation faults occur, thus causing the opening of some feedback loops. The problem is tackled for LTI asymptotically stable plants, subject to perturbations, under the assumption that the Laplace transforms of the exogenous signals have multiple poles on the imaginary axis. The proposed regulator is composed of an LTI nominal controller supervised by a reconfiguration block. Once the actions of the reconfiguration block have been settled, the synthesis of the nominal controller is reformulated as a suitable regulation problem. A constructive sufficient condition for its solvability is established. This condition turns out to be also necessary if the exogenous signals are polynomial in time.

  2. Design of a synchronization system for the “Gamma-4” electrophysical facility

    NASA Astrophysics Data System (ADS)

    Grishin, A. V.; Glushkov, S. L.; Mironychev, B. P.; Kalashnikov, D. A.; Kozachek, A. V.; Martynov, V. M.; Turutin, V. V.; Sokolov, V. V.; Kul'Dushov, D. A.; Nazarenko, S. T.; Pavlov, V. S.; Shikhanova, T. F.

    2014-08-01

    At RFNC-VNIIEF on the basis of a “Gamma-1” high-current pulsed accelerator there is being developed a four-module “Gamma-4” electrophysical facility. A synchronization system of the "Gamma-4" facility is meant for a simultaneous (with precision not worse than ±3 ns) triggering of high-volt gas-filled trigatron type switches of modules' pulse forming systems (144 items, operating voltage ≤ 1 MV), modules' pre-pulse switches (24 items, ≤ 3 MV) and 8 Marx generators (40 items, ≤ 100 kV). The synchronization system comprises 54 pulse generators, involving 25 generators on the basis of water insulated forming lines with distributed parameters and multi-channel gas-filled switches. On matched cable loads with resistances 0.45 Ohm these generators form voltage pulses with amplitudes 100 kV with durations 25 ns. A jitter of switches of these generators does not exceed ± 2 ns. To raise the amplitude of pulse drivers of pulse forming system switches and pre-pulse switches of modules in the facility synchronization system there are used step-up transformers based on pulsed high-voltage cables.

  3. Initial results from a multiple monoenergetic gamma radiography system for nuclear security

    NASA Astrophysics Data System (ADS)

    O'Day, Buckley E.; Hartwig, Zachary S.; Lanza, Richard C.; Danagoulian, Areg

    2016-10-01

    The detection of assembled nuclear devices and concealed special nuclear materials (SNM) such as plutonium or uranium in commercial cargo traffic is a major challenge in mitigating the threat of nuclear terrorism. Currently available radiographic and active interrogation systems use ∼1-10 MeV bremsstrahlung photon beams. Although simple to build and operate, bremsstrahlung-based systems deliver high radiation doses to the cargo and to potential stowaways. To eliminate problematic issues of high dose, we are developing a novel technique known as multiple monoenergetic gamma radiography (MMGR). MMGR uses ion-induced nuclear reactions to produce two monoenergetic gammas for dual-energy radiography. This allows us to image the areal density and effective atomic number (Zeff) of scanned cargo. We present initial results from the proof-of-concept experiment, which was conducted at the MIT Bates Research and Engineering Center. The purpose of the experiment was to assess the capabilities of MMGR to measure areal density and Zeff of container cargo mockups. The experiment used a 3.0 MeV radiofrequency quadrupole accelerator to create sources of 4.44 MeV and 15.11 MeV gammas from the 11B(d,nγ)12C reaction in a thick natural boron target; the gammas are detected by an array of NaI(Tl) detectors after transmission through cargo mockups . The measured fluxes of transmitted 4.44 MeV and 15.11 MeV gammas were used to assess the areal density and Zeff. Initial results show that MMGR is capable of discriminating the presence of high-Z materials concealed in up to 30 cm of iron shielding from low- and mid-Z materials present in the cargo mockup.

  4. Tle4 regulates epigenetic silencing of gamma interferon expression during effector T helper cell tolerance.

    PubMed

    Bandyopadhyay, Sanmay; Valdor, Rut; Macian, Fernando

    2014-01-01

    In response to suboptimal activation, T cells become hyporesponsive, with a severely reduced capacity to proliferate and produce cytokines upon reencounter with antigen. Chromatin analysis of T cells made tolerant by use of different in vitro and in vivo approaches reveals that the expression of gamma interferon (IFN-γ) is epigenetically silenced in anergic effector TH1 cells. In those T cells, calcium signaling triggers the expression of Tle4, a member of the Groucho family of corepressors, which is then recruited to a distal regulatory element in the Ifng locus and causes the establishment of repressive epigenetic marks at the Ifng gene regulatory elements. Consequently, impaired Tle4 activity results in a markedly reduced capacity to inhibit IFN-γ production in tolerized T cells. We propose that Blimp1-dependent recruitment of Tle4 to the Ifng locus causes epigenetic silencing of the expression of the Ifng gene in anergic TH1 cells. These results define a novel function of Groucho family corepressors in peripheral T cells and demonstrate that specific mechanisms are activated in tolerant T helper cells to directly repress expression of effector cytokines, supporting the hypothesis that stable epigenetic imprinting contributes to the maintenance of the tolerance-associated hyporesponsive phenotype in T cells.

  5. Endogenous IL-10 regulates IFN-gamma and IL-5 cytokine production and the granulomatous response in Schistosomiasis mansoni-infected mice.

    PubMed Central

    Boros, D L; Whitfield, J R

    1998-01-01

    In murine Schistosomiasis mansoni circumovum, granuloma formation is regulated by pro- and anti-inflammatory cytokines. Among the latter, interleukin-10 (IL-10) has been shown to regulate the inflammatory response. In this study we examined the role of endogenously produced IL-10 in T-helper 1 (Th1)- and Th2-type cytokine production and granuloma formation. The dynamics of IL-10 production through the course of the infection were different in granuloma versus splenic cells. In the former, production peaked during the early developmental stage (6 weeks of infection) of the granuloma and then declined. In splenocytes production peaked at 12 weeks, before down-modulation of the granuloma response. In the developing granuloma both macrophages and T cells secreted IL-10. In anti-IL-10 monoclonal antibody (mAb)-supplemented granuloma cell cultures endogenous IL-10-mediated regulation of interferon-gamma (IFN-gamma) was manifest only at 6 weeks; that of IL-2 continued throughout the infection (6-20 weeks). IL-4 production was unaffected, but IL-5 production was regulated at the 6 and 8 weeks time point. Splenocytes showed regulation of IFN-gamma and IL-2 production at the peak of the granulomatous response (8 weeks). IL-4 production was not regulated, whereas IL-5 production was regulated only at 6 weeks. Repeated injections of anti-IL-10 mAb given to mice at 6, 12 or 20 weeks of the infection significantly enhanced liver and lung granuloma growth, tissue eosinophilia, and IFN-gamma, IL-5 production at the early developmental phase (6 weeks) of the lesions. Thus, in schistosome-infected mice endogenous IL-10 is shown to regulate Th1- and Th2-type cytokine production and granuloma formation during the early Th0/Th1 phase of the immune response. PMID:9767435

  6. System of Programmed Modules for Measuring Photographs with a Gamma-Telescope

    NASA Technical Reports Server (NTRS)

    Averin, S. A.; Veselova, G. V.; Navasardyan, G. V.

    1978-01-01

    Physical experiments using tracking cameras resulted in hundreds of thousands of stereo photographs of events being received. To process such a large volume of information, automatic and semiautomatic measuring systems are required. At the Institute of Space Research of the Academy of Science of the USSR, a system for processing film information from the spark gamma-telescope was developed. The system is based on a BPS-75 projector in line with the minicomputer Elektronika 1001. The report describes this system. The various computer programs available to the operators are discussed.

  7. Networked alpha and gamma spectral acquisition and analysis system

    SciTech Connect

    Wilcox, C.M.; Gross, J.M.

    1993-10-01

    This manual assumes a knowledge of (terminology used and a working familiarity with) the windowing system and mouse of the Sun computer workstation. See the appropriate Sun manuals for additional information. ALDO, the alpha detector control program, is used to control, monitor, and edit log information associated with the collection of alpha spectra. Actual data collection and control functions are performed by Mizar Real-Time computers for which ALDO acts as a friendly user command interface and status display. It is normally started as part of your login procedure, but may also be started from the ``NETSPEC Utilities`` submenu of the root menu. The root menu is obtained by pushing the right mouse button when the cursor is over the root window (background picture). To become a user of ALDO and the other programs in the NETSPEC system, contact the person who performs systems administration tasks for the Sun computers. Most user interaction with ALDO is by means of mouse manipulation of screen items such as buttons, checkboxes, and sliders. The action of pushing the left mouse button when the cursor is over an item is called selecting that item. The left mouse button is therefore called the select button. The right mouse button is the menu button because a limited number of options may be displayed when that button is pressed when the cursor is over an item with a triangle (inverted delta). In this document, names of selectable items are printed in bold when they are first mentioned or when emphasis is helpful. In general, items which do not apply to the current context are either disabled or made invisible in order to prevent selection.

  8. Measurements with Pinhole and Coded Aperture Gamma-Ray Imaging Systems

    SciTech Connect

    Raffo-Caiado, Ana Claudia; Solodov, Alexander A; Abdul-Jabbar, Najeb M; Hayward, Jason P; Ziock, Klaus-Peter

    2010-01-01

    From a safeguards perspective, gamma-ray imaging has the potential to reduce manpower and cost for effectively locating and monitoring special nuclear material. The purpose of this project was to investigate the performance of pinhole and coded aperture gamma-ray imaging systems at Oak Ridge National Laboratory (ORNL). With the aid of the European Commission Joint Research Centre (JRC), radiometric data will be combined with scans from a three-dimensional design information verification (3D-DIV) system. Measurements were performed at the ORNL Safeguards Laboratory using sources that model holdup in radiological facilities. They showed that for situations with moderate amounts of solid or dense U sources, the coded aperture was able to predict source location and geometry within ~7% of actual values while the pinhole gave a broad representation of source distributions

  9. Gamma ray scanner systems for nondestructive assay of heterogeneous waste barrels

    SciTech Connect

    Martz, H.E.; Roberson, G.P.; Decman, D.J.; Camp, D.C.; Levai, F.

    1997-08-01

    Traditional gamma measurement errors are related to non-uniform measurement responses associated with unknown radioactive source and matrix material distributions. These errors can be reduced by application of tomographic techniques that measure these distributions. LLNL has developed two tomographic-based waste assay systems. They use external radioactive sources and tomography-protocol to map the attenuation within a waste barrel as a function of mono-energetic gamma-ray energy in waste containers. Passive tomography is used to localize and identify specific radioactive waste contents within the same waste containers. Reconstruction of the passive data via the active images allows internal waste radioactivities in a barrel to be corrected for any overlying heterogeneous materials, thus yielding an absolute assay of the waste radioactivities. Calibration of both systems requires only point source measurements and are independent of matrix materials.

  10. Compact high-resolution gamma-ray computed tomography system for multiphase flow studies

    SciTech Connect

    Bieberle, A.; Nehring, H.; Berger, R.; Arlit, M.; Haerting, H.-U.; Schubert, M.; Hampel, U.

    2013-03-15

    In this paper, a compact high-resolution gamma-ray Computed Tomography (CompaCT) measurement system for multiphase flow studies and tomographic imaging of technical objects is presented. Its compact and robust design makes it particularly suitable for studies on industrial facilities and outdoor applications. Special care has been given to thermal ruggedness, shock resistance, and radiation protection. Main components of the system are a collimated {sup 137}Cs isotopic source, a thermally stabilised modular high-resolution gamma-ray detector arc with 112 scintillation detector elements, and a transportable rotary unit. The CompaCT allows full CT scans of objects with a diameter of up to 130 mm and can be operated with any tilting angle from 0 Degree-Sign (horizontal) to 90 Degree-Sign (vertical).

  11. Ultra-wide Range Gamma Detector System for Search and Locate Operations

    SciTech Connect

    Odell, D. Mackenzie Odell; Harpring, Larry J.; Moore, Frank S. Jr.; French, Phillip J.; Gordon, John R.

    2005-10-26

    Collecting debris samples following a nuclear event requires that operations be conducted from a considerable stand-off distance. An ultra-wide range gamma detector system has been constructed to accomplish both long range radiation search and close range hot sample collection functions. Constructed and tested on a REMOTEC Andros platform, the system has demonstrated reliable operation over six orders of magnitude of gamma dose from 100's of uR/hr to over 100 R/hr. Functional elements include a remotely controlled variable collimator assembly, a NaI(Tl)/photomultiplier tube detector, a proprietary digital radiation instrument, a coaxially mounted video camera, a digital compass, and both local and remote control computers with a user interface designed for long range operations. Long range sensitivity and target location, as well as close range sample selection performance are presented.

  12. Gamma rays induce a p53-independent mitochondrial biogenesis that is counter-regulated by HIF1α.

    PubMed

    Bartoletti-Stella, A; Mariani, E; Kurelac, I; Maresca, A; Caratozzolo, M F; Iommarini, L; Carelli, V; Eusebi, L H; Guido, A; Cenacchi, G; Fuccio, L; Rugolo, M; Tullo, A; Porcelli, A M; Gasparre, G

    2013-06-13

    Mitochondrial biogenesis is an orchestrated process that presides to the regulation of the organelles homeostasis within a cell. We show that γ-rays, at doses commonly used in the radiation therapy for cancer treatment, induce an increase in mitochondrial mass and function, in response to a genotoxic stress that pushes cells into senescence, in the presence of a functional p53. Although the main effector of the response to γ-rays is the p53-p21 axis, we demonstrated that mitochondrial biogenesis is only indirectly regulated by p53, whose activation triggers a murine double minute 2 (MDM2)-mediated hypoxia-inducible factor 1α (HIF1α) degradation, leading to the release of peroxisome-proliferator activated receptor gamma co-activator 1β inhibition by HIF1α, thus promoting mitochondrial biogenesis. Mimicking hypoxia by HIF1α stabilization, in fact, blunts the mitochondrial response to γ-rays as well as the induction of p21-mediated cell senescence, indicating prevalence of the hypoxic over the genotoxic response. Finally, we also show in vivo that post-radiotherapy mitochondrial DNA copy number increase well correlates with lack of HIF1α increase in the tissue, concluding this may be a useful molecular tool to infer the trigger of a hypoxic response during radiotherapy, which may lead to failure of activation of cell senescence.

  13. Cortically projecting basal forebrain parvalbumin neurons regulate cortical gamma band oscillations.

    PubMed

    Kim, Tae; Thankachan, Stephen; McKenna, James T; McNally, James M; Yang, Chun; Choi, Jee Hyun; Chen, Lichao; Kocsis, Bernat; Deisseroth, Karl; Strecker, Robert E; Basheer, Radhika; Brown, Ritchie E; McCarley, Robert W

    2015-03-17

    Cortical gamma band oscillations (GBO, 30-80 Hz, typically ∼40 Hz) are involved in higher cognitive functions such as feature binding, attention, and working memory. GBO abnormalities are a feature of several neuropsychiatric disorders associated with dysfunction of cortical fast-spiking interneurons containing the calcium-binding protein parvalbumin (PV). GBO vary according to the state of arousal, are modulated by attention, and are correlated with conscious awareness. However, the subcortical cell types underlying the state-dependent control of GBO are not well understood. Here we tested the role of one cell type in the wakefulness-promoting basal forebrain (BF) region, cortically projecting GABAergic neurons containing PV, whose virally transduced fibers we found apposed cortical PV interneurons involved in generating GBO. Optogenetic stimulation of BF PV neurons in mice preferentially increased cortical GBO power by entraining a cortical oscillator with a resonant frequency of ∼40 Hz, as revealed by analysis of both rhythmic and nonrhythmic BF PV stimulation. Selective saporin lesions of BF cholinergic neurons did not alter the enhancement of cortical GBO power induced by BF PV stimulation. Importantly, bilateral optogenetic inhibition of BF PV neurons decreased the power of the 40-Hz auditory steady-state response, a read-out of the ability of the cortex to generate GBO used in clinical studies. Our results are surprising and novel in indicating that this presumptively inhibitory BF PV input controls cortical GBO, likely by synchronizing the activity of cortical PV interneurons. BF PV neurons may represent a previously unidentified therapeutic target to treat disorders involving abnormal GBO, such as schizophrenia.

  14. SU-E-T-94: An Advanced Rotating Gamma Ray System for Stereotactic Radiosurgery

    SciTech Connect

    Ma, C; Chibani, O; Li, J; Chen, L; Mora, G

    2015-06-15

    Purpose: Co-60 beams have unique dosimetric properties that are ideally suited for cranial treatments. Co-60 sources with cone-shaped collimators provide conformal dose distributions allowing for ablative treatments with rapid dose falloff to spare nearby critical structures. This work investigates a novel, image-guided, rotational Gamma ray system that provides both superior dose conformity/gradient and accurate stereotaxy for stereotactic radiosurgery (SRS). Methods: The SupeRay system (Cyber Medical Corp., China) consists of a rotating source chamber containing 30 gamma sources focusing at the isocenter with 4 collimators measuring 3, 4, 8 and 16mm in diameter. A novel switch design enables the 30 Gamma sources to be turned off at any arbitrarily selected 60° interval in order to avoid critical structures. The 3D treatment couch provides automatic treatment positioning between individual shots and the kV imaging system provides orthogonal images with a spatial resolution of 0.24mm to facilitate target localization. Monte Carlo simulations were used to compute dose distributions and compare with measurements and other Gamma ray SRS systems. Results: Monte Carlo results confirmed the SupeRay design parameters including output factors and 3D dose distributions. Its beam penumbra/dose gradient is similar to or slightly better than that of the Elekta Gamma Knife. The penumbra in the (x,y,z) direction was (7.38mm,7.38mm,3.86mm) for the 16mm collimator, (4.83mm,4.83mm,3.12mm) for the 8mm collimator, and (3.03mm,3.03mm,2.38mm) for the 4mm collimator, respectively, on the SupeRay system while it was (9.5mm,10.0mm,2.9mm), (4.3mm,4.3mm,2.9mm) and (3.2mm,3.2mm,1.9mm) for the same collimator sizes, respectively, on the Perfexion system. The kV imaging system together with a non-invasive relocatable frame provides accurate target localization (<0.5mm) for cases requiring multiple treatment fractions. Conclusion: Because of the unique dosimetric properties of Co-60 sources

  15. X-ray and gamma ray detector readout system

    DOEpatents

    Tumer, Tumay O; Clajus, Martin; Visser, Gerard

    2010-10-19

    A readout electronics scheme is under development for high resolution, compact PET (positron emission tomography) imagers based on LSO (lutetium ortho-oxysilicate, Lu.sub.2SiO.sub.5) scintillator and avalanche photodiode (APD) arrays. The key is to obtain sufficient timing and energy resolution at a low power level, less than about 30 mW per channel, including all required functions. To this end, a simple leading edge level crossing discriminator is used, in combination with a transimpedance preamplifier. The APD used has a gain of order 1,000, and an output noise current of several pA/ Hz, allowing bipolar technology to be used instead of CMOS, for increased speed and power efficiency. A prototype of the preamplifier and discriminator has been constructed, achieving timing resolution of 1.5 ns FWHM, 2.7 ns full width at one tenth maximum, relative to an LSO/PMT detector, and an energy resolution of 13.6% FWHM at 511 keV, while operating at a power level of 22 mW per channel. Work is in progress towards integration of this preamplifier and discriminator with appropriate coincidence logic and amplitude measurement circuits in an ASIC suitable for a high resolution compact PET instrument. The detector system and/or ASIC can also be used for many other applications for medical to industrial imaging.

  16. Accuracy and stability of positioning in radiosurgery: Long term results of the Gamma Knife system

    SciTech Connect

    Heck, Bernhard; Jess-Hempen, Anja; Kreiner, Hans Juerg; Schoepgens, Hans; Mack, Andreas

    2007-04-15

    The primary aim of this investigation was to determine the long term overall accuracy of an irradiation position of Gamma Knife systems. The mechanical accuracy of the system as well as the overall accuracy of an irradiation position was examined by irradiating radiosensitive films. To measure the mechanical accuracy, the GafChromic registered film was fixed by a special tool at the unit center point (UCP). For overall accuracy the film was mounted inside a phantom at a target position given by a two-dimensional cross. Its position was determined by CT or MRI scans, a treatment was planned to hit this target by use of the standard planning software and the radiation was finally delivered. This procedure is named ''system test'' according to DIN 6875-1 and is equivalent to a treatment simulation. The used GafChromic registered films were evaluated by high resolution densitometric measurements. The Munich Gamma Knife UCP coincided within x;y;z: -0.014{+-}0.09 mm; 0.013{+-}0.09 mm; -0.002{+-}0.06 mm (mean{+-}SD) to the center of dose distribution. There was no trend in the measured data observed over more than ten years. All measured data were within a sphere of 0.2 mm radius. When basing the target definition in the system test on MRI scans, we obtained an overall accuracy of an irradiation position in the x direction of 0.21{+-}0.32 mm and in the y direction 0.15{+-}0.26 mm (mean{+-}SD). When a CT-based target definition was used, we measured distances in x direction 0.06{+-}0.09 mm and in y direction 0.04{+-}0.09 mm (mean{+-}SD), respectively. These results were compared with those obtained with a Gamma Knife equipped with an automatic positioning system (APS) by use of a different phantom. This phantom was found to be slightly less accurate due to its mechanical construction and the soft fixation into the frame. The phantom related position deviation was found to be about {+-}0.2 mm, and therefore the measured accuracy of the APS Gamma Knife was evidently less

  17. [Thymus endocrine function and the immune system indices of cancer patients after neutron and gamma therapy].

    PubMed

    Grinevich, Iu A; Martynenko, S V; Baraboĭ, V A; Monich, A Iu; Tolstopiatov, B A; Konovalenko, V F; Protsyk, V S

    1992-01-01

    Patients with head and neck and locomotor system tumors received neutron therapy in the total doses of 4-8 and 12-14 Gy which was followed by a pronounced dose-dependent decrease in the serum thymus factor and total blood-lymphocyte levels. The latter changes were predominantly due to a decrease in the non-T-non-B cell concentration. Following the treatment, a rise in the level of circulating immune complexes and those of IgA and IgG was observed. Changes in the immune system proved less apparent in patients with locomotor system cancer who had been given 20 Gy of gamma-ray radiation.

  18. The scientific data acquisition system of the GAMMA-400 space project

    NASA Astrophysics Data System (ADS)

    Bobkov, S. G.; Serdin, O. V.; Gorbunov, M. S.; Arkhangelskiy, A. I.; Topchiev, N. P.

    2016-02-01

    The description of scientific data acquisition system (SDAS) designed by SRISA for the GAMMA-400 space project is presented. We consider the problem of different level electronics unification: the set of reliable fault-tolerant integrated circuits fabricated on Silicon-on-Insulator 0.25 mkm CMOS technology and the high-speed interfaces and reliable modules used in the space instruments. The characteristics of reliable fault-tolerant very large scale integration (VLSI) technology designed by SRISA for the developing of computation systems for space applications are considered. The scalable net structure of SDAS based on Serial RapidIO interface including real-time operating system BAGET is described too.

  19. Verification of Gamma Knife extend system based fractionated treatment planning using EBT2 film

    SciTech Connect

    Natanasabapathi, Gopishankar; Bisht, Raj Kishor

    2013-12-15

    Purpose: This paper presents EBT2 film verification of fractionated treatment planning with the Gamma Knife (GK) extend system, a relocatable frame system for multiple-fraction or serial multiple-session radiosurgery.Methods: A human head shaped phantom simulated the verification process for fractionated Gamma Knife treatment. Phantom preparation for Extend Frame based treatment planning involved creating a dental impression, fitting the phantom to the frame system, and acquiring a stereotactic computed tomography (CT) scan. A CT scan (Siemens, Emotion 6) of the phantom was obtained with following parameters: Tube voltage—110 kV, tube current—280 mA, pixel size—0.5 × 0.5 and 1 mm slice thickness. A treatment plan with two 8 mm collimator shots and three sectors blocking in each shot was made. Dose prescription of 4 Gy at 100% was delivered for the first fraction out of the two fractions planned. Gafchromic EBT2 film (ISP Wayne, NJ) was used as 2D verification dosimeter in this process. Films were cut and placed inside the film insert of the phantom for treatment dose delivery. Meanwhile a set of films from the same batch were exposed from 0 to 12 Gy doses for calibration purposes. An EPSON (Expression 10000 XL) scanner was used for scanning the exposed films in transparency mode. Scanned films were analyzed with inhouse written MATLAB codes.Results: Gamma index analysis of film measurement in comparison with TPS calculated dose resulted in high pass rates >90% for tolerance criteria of 1%/1 mm. The isodose overlay and linear dose profiles of film measured and computed dose distribution on sagittal and coronal plane were in close agreement.Conclusions: Through this study, the authors propose treatment verification QA method for Extend frame based fractionated Gamma Knife radiosurgery using EBT2 film.

  20. First clinical experience with the automatic positioning system and Leksell gamma knife Model C. Technical note.

    PubMed

    Horstmann, G A; Schöpgens, H; van Eck, A T; Kreiner, H J; Herz, W

    2000-12-01

    In May of 1999, the first Leksell Model C gamma knife was installed at the Gamma Knife Zentrum in Krefeld, Germany. The authors recount their experience with this latest technical gamma knife development. Until the end of 1999, extensive physical and technical tests were performed and the system's hardware and software were continuously improved and adapted to the user's needs. By the end of 1999, 163 GKSs had been performed using the new functionality of the Model C in manual or "trunnion" mode. The trunnions, the two parts of the system that fix the patient headframe to the gamma knife when the isocenter positions, are checked manually. During the same period the new automatic positioning system (APS) was extensively tested and refined so that the first APS treatment could be performed in January 2000. Fifty GKSs have been performed with the APS capability of the Model C. It was possible to use APS alone in 74% of surgeries whereas in 14% some shots were given with APS and some with trunnions. In 12%, GKS was scheduled and planned for APS, but due to unexpected technical (6%) or mechanical (6%) reasons the treatment had to be performed manually. At present there are some spatial restrictions with Model C in APS mode when compared with the Model B. The most significant restriction is the narrow space for the patient's shoulders, especially when deep-seated lesions are treated. Through mechanical changes of the APS motor housing and some modifications of and to the motor driven couch adjustment, these limitations will be reduced in the future. The APS treatment runs smoothly and fast. In no case did any relevant safety error occur during GKS. The more stringent mechanical limitations of the APS compared with the Model B means that frame placement on the head is more critical than before.

  1. Hormonal and systemic regulation of sclerostin.

    PubMed

    Drake, Matthew T; Khosla, Sundeep

    2017-03-01

    The Wnt/β-catenin signaling pathway plays an essential role in osteoblast biology. Sclerostin is a soluble antagonist of Wnt/β-catenin signaling secreted primarily by osteocytes. Current evidence indicates that sclerostin likely functions as a local/paracrine regulator of bone metabolism rather than as an endocrine hormone. Nonetheless, circulating sclerostin levels in humans often reflect changes in the bone microenvironment, although there may be exceptions to this observation. Using existing assays, circulating sclerostin levels have been shown to be altered in response to both hormonal stimuli and across a variety of normal physiological and pathophysiological conditions. In both rodents and humans, parathyroid hormone provided either intermittently or continuously suppresses sclerostin levels. Likewise, most evidence from both human and animal studies supports a suppressive effect of estrogen on sclerostin levels. Efforts to examine non-hormonal/systemic regulation of sclerostin have in general shown less consistent findings or have provided associations rather than direct interventional information, with the exception of mechanosensory studies which have consistently demonstrated increased sclerostin levels with skeletal unloading, and conversely decreases in sclerostin with enhanced skeletal loading. Herein, we will review the existent literature on both hormonal and non-hormonal/systemic factors which have been studied for their impact on sclerostin regulation.

  2. Magnetic field regulation control system analysis

    SciTech Connect

    Badelt, Steven W.

    1996-05-01

    This study comprises (1) an analytical characterization of the Cameca ion microscope`s magnetic field regulation circuitry and (2) comparisons between the analytical predictions and the measured performance of the control system. It is the first step in a project to achieve routine field regulation better than 10ppm. The control loop was decomposed into functional subcircuits and simulated in SPICE to determine DC, AC, and transient response. Transfer functions were extracted from SPICE, simplified, and analyzed in MATLAB. Both SPICE and MATLAB simulations were calculated for step inputs, and these results were compared to actual measurements. Magnetic field fluctuations were measured at high mass resolving power. The frequency spectrum of the fluctuations was analyzed by FFT. Difficulties encountered and implications for future work are discussed.

  3. Imaging system for cardiac planar imaging using a dedicated dual-head gamma camera

    DOEpatents

    Majewski, Stanislaw; Umeno, Marc M.

    2011-09-13

    A cardiac imaging system employing dual gamma imaging heads co-registered with one another to provide two dynamic simultaneous views of the heart sector of a patient torso. A first gamma imaging head is positioned in a first orientation with respect to the heart sector and a second gamma imaging head is positioned in a second orientation with respect to the heart sector. An adjustment arrangement is capable of adjusting the distance between the separate imaging heads and the angle between the heads. With the angle between the imaging heads set to 180 degrees and operating in a range of 140-159 keV and at a rate of up to 500kHz, the imaging heads are co-registered to produce simultaneous dynamic recording of two stereotactic views of the heart. The use of co-registered imaging heads maximizes the uniformity of detection sensitivity of blood flow in and around the heart over the whole heart volume and minimizes radiation absorption effects. A normalization/image fusion technique is implemented pixel-by-corresponding pixel to increase signal for any cardiac region viewed in two images obtained from the two opposed detector heads for the same time bin. The imaging system is capable of producing enhanced first pass studies, bloodpool studies including planar, gated and non-gated EKG studies, planar EKG perfusion studies, and planar hot spot imaging.

  4. Regulation of retinoid X receptor gamma expression by fed state in mouse liver

    SciTech Connect

    Park, Sangkyu; Lee, Yoo Jeong; Ko, Eun Hee; Kim, Jae-woo

    2015-02-27

    Glucose metabolism is balanced by glycolysis and gluconeogenesis with precise control in the liver. The expression of genes related to glucose metabolism is regulated primarily by glucose and insulin at transcriptional level. Nuclear receptors play important roles in regulating the gene expression of glucose metabolism at transcriptional level. Some of these nuclear receptors form heterodimers with RXRs to bind to their specific regulatory elements on the target promoters. To date, three isotypes of RXRs have been identified; RXRα, RXRβ and RXRγ. However, their involvement in the interactions with other nuclear receptors in the liver remains unclear. In this study, we found RXRγ is rapidly induced after feeding in the mouse liver, indicating a potential role of RXRγ in controlling glucose or lipid metabolism in the fasting–feeding cycle. In addition, RXRγ expression was upregulated by glucose in primary hepatocytes. This implies that glucose metabolism governed by RXRγ in conjunction with other nuclear receptors. The luciferase reporter assay showed that RXRγ as well as RXRα increased SREBP-1c promoter activity in hepatocytes. These results suggest that RXRγ may play an important role in tight control of glucose metabolism in the fasting–feeding cycle. - Highlights: • Refeeding increases the RXRγ expression level in mouse liver. • RXRγ expression is induced by high glucose condition in primary hepatocytes. • RXRγ and LXRα have synergistic effect on SREBP-1c promoter activity. • RXRγ binds to LXRE(-299/-280) located within SREBP-1c promoter region and interacts with LXRα.

  5. Regulation of retinoid X receptor gamma expression by fed state in mouse liver.

    PubMed

    Park, Sangkyu; Lee, Yoo Jeong; Ko, Eun Hee; Kim, Jae-Woo

    2015-02-27

    Glucose metabolism is balanced by glycolysis and gluconeogenesis with precise control in the liver. The expression of genes related to glucose metabolism is regulated primarily by glucose and insulin at transcriptional level. Nuclear receptors play important roles in regulating the gene expression of glucose metabolism at transcriptional level. Some of these nuclear receptors form heterodimers with RXRs to bind to their specific regulatory elements on the target promoters. To date, three isotypes of RXRs have been identified; RXRα, RXRβ and RXRγ. However, their involvement in the interactions with other nuclear receptors in the liver remains unclear. In this study, we found RXRγ is rapidly induced after feeding in the mouse liver, indicating a potential role of RXRγ in controlling glucose or lipid metabolism in the fasting-feeding cycle. In addition, RXRγ expression was upregulated by glucose in primary hepatocytes. This implies that glucose metabolism governed by RXRγ in conjunction with other nuclear receptors. The luciferase reporter assay showed that RXRγ as well as RXRα increased SREBP-1c promoter activity in hepatocytes. These results suggest that RXRγ may play an important role in tight control of glucose metabolism in the fasting-feeding cycle.

  6. Measured Activities of Al and Ni in gamma-(Ni) and gamma'-(Ni)3Al in the Ni-Al-Pt System

    NASA Technical Reports Server (NTRS)

    Copland, Evan

    2007-01-01

    Adding Pt to Ni-Al coatings is critical to achieving the required oxidation protection of Ni-based superalloys, but the nature of the Pt effect remains unresolved. This research provides a fundamental part of the answer by measuring the influence of Pt on the activities of Al and Ni in gamma-(Ni), gamma prime-(Ni)3Al and liquid in the Ni-Al-Pt system. Measurements have been made at 25 compositions in the Ni-rich corner over the temperature range, T = 1400-1750 K, by the vapor pressure technique with a multiple effusion-cell mass spectrometer (multi-cell KEMS). These measurements clearly show adding Pt (for X(sub Pt) less than 0.25) decreases a(Al) while increasing a(Ni). This solution behavior supports the idea that Pt increases Al transport to an alloy / Al2O3 interface and also limits the interaction between the coating and substrate alloys in the gamma-(Ni) + gamma prime-(Ni)3Al region. This presentation will review the progress of this study.

  7. The effect of gamma keratose on cell viability in vitro after thermal stress and the regulation of cell death pathway-specific gene expression.

    PubMed

    Poranki, Deepika R; Van Dyke, Mark E

    2014-05-01

    When skin is thermally burned, transfer of heat energy into the skin results in the destruction of cells. Some of these cells are damaged but may be capable of self-repair and survival, thereby contributing to spontaneous healing of the wound. Keratin protein-based biomaterials have been suggested as potential treatments for burn injury. Isolation of cortical proteins from hair fibers results in an acid soluble fraction of keratin proteins referred to as "gamma" keratose. In the present study, treatment with this fraction dissolved in media was able to maintain cell viability after thermal stress in an in vitro model using primary mouse dermal fibroblasts. PCR array analysis demonstrated that gamma keratose treatment may assist in the survival and salvage of thermally stressed cells by maintaining their viability through regulation of cell death pathway-related genes. Gamma keratose may be a promising biomaterial for burn treatment that aids in spontaneous wound healing from viable tissue surrounding the burn.

  8. First results of electron temperature measurements by the use of multi-pass Thomson scattering system in GAMMA 10

    SciTech Connect

    Yoshikawa, M. Nagasu, K.; Shimamura, Y.; Shima, Y.; Kohagura, J.; Sakamoto, M.; Nakashima, Y.; Imai, T.; Ichimura, M.; Yasuhara, R.; Yamada, I.; Funaba, H.; Kawahata, K.; Minami, T.

    2014-11-15

    A multi-pass Thomson scattering (TS) has the advantage of enhancing scattered signals. We constructed a multi-pass TS system for a polarisation-based system and an image relaying system modelled on the GAMMA 10 TS system. We undertook Raman scattering experiments both for the multi-pass setting and for checking the optical components. Moreover, we applied the system to the electron temperature measurements in the GAMMA 10 plasma for the first time. The integrated scattering signal was magnified by approximately three times by using the multi-pass TS system with four passes. The electron temperature measurement accuracy is improved by using this multi-pass system.

  9. First results of electron temperature measurements by the use of multi-pass Thomson scattering system in GAMMA 10

    NASA Astrophysics Data System (ADS)

    Yoshikawa, M.; Yasuhara, R.; Nagasu, K.; Shimamura, Y.; Shima, Y.; Kohagura, J.; Sakamoto, M.; Nakashima, Y.; Imai, T.; Ichimura, M.; Yamada, I.; Funaba, H.; Kawahata, K.; Minami, T.

    2014-11-01

    A multi-pass Thomson scattering (TS) has the advantage of enhancing scattered signals. We constructed a multi-pass TS system for a polarisation-based system and an image relaying system modelled on the GAMMA 10 TS system. We undertook Raman scattering experiments both for the multi-pass setting and for checking the optical components. Moreover, we applied the system to the electron temperature measurements in the GAMMA 10 plasma for the first time. The integrated scattering signal was magnified by approximately three times by using the multi-pass TS system with four passes. The electron temperature measurement accuracy is improved by using this multi-pass system.

  10. MODULAR CAUSTIC SIDE SOLVENT EXTRACTION UNIT (MCU) GAMMA MONITORS SYSTEM FINAL REPORT

    SciTech Connect

    Casella, V

    2005-12-15

    The Department of Energy (DOE) selected Caustic-Side Solvent Extraction (CSSX) as the preferred technology for the removal of radioactive cesium from High-Level Waste (HLW) at the Savannah River Site (SRS). Before the full-scale Salt Waste Processing Facility (SWPF) becomes operational, the Closure Business Unit (CBU) plans to process a portion of dissolved saltcake waste through a Modular CSSX Unit (MCU). This work was derived from Technical Task Request SP-TTR-2004-00013, ''Gamma Monitor for MCU''. The deliverables for this task are the hardware and software for the gamma monitors and a report summarizing the testing and acceptance of this equipment for use in the MCU. Gamma-ray monitors are required to: (1) Measure the Cs-137 concentration in the decontaminated salt solution before entering the DSS (Decontaminated Salt Solution) Hold Tank, (2) Measure the Cs-137 concentration in the strip effluent before entering the Strip Effluent Hold Tank, (3) Verify proper operation of the solvent extraction system by verifying material balance within the process (The DSS Hold Tank Cs-137 concentration will be very low and the Cs-137 concentration in the Strip Effluent Hold Tank will be fifteen times higher than the Cs-137 concentration in the Feed Tank.) Sodium iodide monitors are used to measure the Cs-137 concentration in the piping before the DSS Hold tank, while GM monitors are used for Cs-137 measurements before the Strip Effluent Hold Tank. Tungsten shields were designed using Monte Carlo calculations and fabricated to reduce the process background radiation at the detector positions. These monitors were calibrated with NIST traceable standards that were specially made to be the same as the piping being monitored. Since this gamma ray monitoring system is unique, specially designed software was written and acceptance tested by Savannah River National Laboratory personnel. The software is a LabView-based application that serves as a unified interface for controlling

  11. A Single Tower Configuration of the Modular Gamma Box Counter System - 13392

    SciTech Connect

    Morris, K.; Nakazawa, D.; Francalangia, J.; Gonzalez, H.

    2013-07-01

    Canberra's Standard Gamma Box Counter System is designed to perform accurate quantitative assays of gamma emitting nuclides for a wide range of large containers including B-25 crates and ISO shipping containers. Using a modular building-block approach, the system offers tremendous flexibility for a variety of measurement situations with wide ranges of sample activities and throughput requirements, as well as the opportunity to modify the configuration for other applications at a later date. The typical configuration consists of two opposing towers each equipped with two high purity germanium detectors, and an automated container trolley. This paper presents a modified configuration, consisting of a single tower placed inside a measurement trailer with three detector assemblies, allowing for additional vertical segmentation as well as a viewing a container outside the trailer through the trailer wall. An automatic liquid nitrogen fill system is supplied for each of the detectors. The use of a forklift to move the container for horizontal segmentation is accommodated by creating an additional operational and calibration set-up in the NDA 2000 software to allow for the operator to rotate the container and assay the opposite side, achieving the same sensitivity as a comparable two-tower system. This Segmented Gamma Box Counter System retains the core technologies and design features of the standard configuration. The detector assemblies are shielded to minimize interference from environmental and plant background, and are collimated to provide segmentation of the container. The assembly positions can also be modified in height and distance from the container. The ISOCS calibration software provides for a flexible approach to providing the calibrations for a variety of measurement geometries. The NDA 2000 software provides seamless operation with the current configuration, handling the data acquisition and analysis. In this paper, an overview of this system is discussed

  12. High and low energy gamma beam dump designs for the gamma beam delivery system at ELI-NP

    NASA Astrophysics Data System (ADS)

    Yasin, Zafar; Matei, Catalin; Ur, Calin A.; Mitu, Iani-Octavian; Udup, Emil; Petcu, Cristian

    2016-03-01

    The Extreme Light Infrastructure - Nuclear Physics (ELI-NP) is under construction in Magurele, Bucharest, Romania. The facility will use two 10 PW lasers and a high intensity, narrow bandwidth gamma beam for stand-alone and combined laser-gamma experiments. The accurate estimation of particle doses and their restriction within the limits for both personel and general public is very important in the design phase of any nuclear facility. In the present work, Monte Carlo simulations are performed using FLUKA and MCNPX to design 19.4 and 4 MeV gamma beam dumps along with shielding of experimental areas. Dose rate contour plots from both FLUKA and MCNPX along with numerical values of doses in experimental area E8 of the facility are performed. The calculated doses are within the permissible limits. Furthermore, a reasonable agreement between both codes enhances our confidence in using one or both of them for future calculations in beam dump designs, radiation shielding, radioactive inventory, and other calculations releated to radiation protection. Residual dose rates and residual activity calculations are also performed for high-energy beam dump and their effect is negligible in comparison to contributions from prompt radiation.

  13. Computer Assisted Gamma and X-Ray Tomography: Applications to Multiphase Flow Systems.

    SciTech Connect

    Kumar, Sailesh B.; Dudukovic, Milorad P.; Toseland, Bernard A.

    1997-03-01

    The application of X-ray and gamma ray transmission tomography to the study of process engineering systems is reviewed. The fundamental principles of tomography, the algorithms for image reconstruction, the measurement method and the possible sources of error are discussed in detail. A case study highlights the methodology involved in designing a scanning system for the study of a given process unit, e.g., reactor, separations column etc. Results obtained in the authors` laboratory for the gas holdup distribution in bubble columns are also presented. Recommendations are made for the Advanced Fuels Development Unit (AFDU) in LaPorte, TX.

  14. The TRANSFAC system on gene expression regulation.

    PubMed

    Wingender, E; Chen, X; Fricke, E; Geffers, R; Hehl, R; Liebich, I; Krull, M; Matys, V; Michael, H; Ohnhäuser, R; Prüss, M; Schacherer, F; Thiele, S; Urbach, S

    2001-01-01

    The TRANSFAC database on transcription factors and their DNA-binding sites and profiles (http://www.gene-regulation.de/) has been quantitatively extended and supplemented by a number of modules. These modules give information about pathologically relevant mutations in regulatory regions and transcription factor genes (PathoDB), scaffold/matrix attached regions (S/MARt DB), signal transduction (TRANSPATH) and gene expression sources (CYTOMER). Altogether, these distinct database modules constitute the TRANSFAC system. They are accompanied by a number of program routines for identifying potential transcription factor binding sites or for localizing individual components in the regulatory network of a cell.

  15. Design of suboptimal regulators for nonlinear systems

    NASA Technical Reports Server (NTRS)

    Balaram, J.; Saridis, G. N.

    1985-01-01

    An optimal feedback control law is preferred for the regulation of a deterministic nonlinear system. In this paper, a practical, iterative design method leading to a sequence of suboptimal control laws with successively improved performance is presented. The design method requires the determination of an upper bound to the performance of each successive control law. This is obtained by solving a partial differential inequality by means of a linear programming technique. Robustness properties and the application of the design method to the control of a robot manipulator arm are also presented.

  16. The Vitamin E Analog Gamma-Tocotrienol (GT3) and Statins Synergistically Up-Regulate Endothelial Thrombomodulin (TM)

    PubMed Central

    Pathak, Rupak; Ghosh, Sanchita P.; Zhou, Daohong; Hauer-Jensen, Martin

    2016-01-01

    Statins; a class of routinely prescribed cholesterol-lowering drugs; inhibit 3-hydroxy-3-methylglutaryl-coenzymeA reductase (HMGCR) and strongly induce endothelial thrombomodulin (TM); which is known to have anti-inflammatory; anti-coagulation; anti-oxidant; and radioprotective properties. However; high-dose toxicity limits the clinical use of statins. The vitamin E family member gamma-tocotrienol (GT3) also suppresses HMGCR activity and induces TM expression without causing significant adverse side effects; even at high concentrations. To investigate the synergistic effect of statins and GT3 on TM; a low dose of atorvastatin and GT3 was used to treat human primary endothelial cells. Protein-level TM expression was measured by flow cytometry. TM functional activity was determined by activated protein C (APC) generation assay. Expression of Kruppel-like factor 2 (KLF2), one of the key transcription factors of TM, was measured by quantitative reverse transcription polymerase chain reaction (qRT-PCR). TM expression increased in a dose-dependent manner after both atorvastatin and GT3 treatment. A combined treatment of a low-dose of atorvastatin and GT3 synergistically up-regulated TM expression and functional activity. Finally; atorvastatin and GT3 synergistically increased KLF2 expression. These findings suggest that combined treatment of statins with GT3 may provide significant health benefits in treating a number of pathophysiological conditions; including inflammatory and cardiovascular diseases. PMID:27869747

  17. Antiepileptic potential of matrine via regulation the levels of gamma-aminobutyric acid and glutamic acid in the brain.

    PubMed

    Xiang, Jun; Jiang, Yugang

    2013-12-05

    Our present study aimed to determine the antiepileptic activity of matrine, and explore the possible molecular mechanism. To evaluate the antiepileptic activity of matrine, seizures in mice induced by PTZ and MES were established, then the pentobarbital sodium-induced anaesthetizing time and locomotor activity tests in mice were also carried out. For the molecular mechanism investigations, contents of aspartic acid (Asp), gamma-aminobutyric acid (GABA), glutamic acid (Glu), glycine (Gly) in seizures mice were determined; then, the chronic seizures rats induced by PTZ were prepared, and western blotting was used to determine the expressions of GAD 65, GABAA and GABAB in the brains. In the results, matrine showed significant antiepileptic effects on seizures mice induced by MES and PTZ. Moreover, the pentobarbital sodium-induced anaesthetizing time and locomotor activity tests were also demonstrated that matrine had obvious antiepileptic effects. Additionally, our results revealed that after treatment with matrine, contents of GABA can be elevated, and the contents of Glu were obviously decreased. Furthermore, western blotting revealed that the mechanism regarding the antiepileptic effect of may be related to the up-regulations of GAD 65 and GABAA in the brain. Collectively, we suggested that matrine can be developed as an effective antiseptic drug.

  18. Electron temperature measurements by the use of multi-pass Thomson scattering system in GAMMA 10/PDX

    NASA Astrophysics Data System (ADS)

    Yoshikawa, M.; Ohta, K.; Wang, X.; Morishita, M.; Chikatsu, M.; Shima, Y.; Kohagura, J.; Yasuhara, R.; Sakamoto, M.; Nakashima, Y.; Imai, T.; Ichimura, M.; Yamada, I.; Funaba, H.; Kawataha, K.; Minami, T.

    2015-08-01

    A multi-pass (MP) Thomson scattering (TS) system modeled on the GAMMA 10/PDX TS system was constructed for enhancing the Thomson scattered signals. The MPTS system has a polarization-based configuration with an image relaying system. The former MPTS system in GAMMA 10/PDX can measure only four passing signals. We changed the larger aperture polarization control device for improving the MP laser confinement and obtaining the over four passing MPTS signals. The integrated MPTS signals increased about 1.2 times larger than that in the former system.

  19. MODULAR CAUSTIC SIDE SOLVENT EXTRACTION UNIT GAMMA MONITORS SYSTEM FINAL REPORT

    SciTech Connect

    Casella, V

    2007-06-25

    The Department of Energy (DOE) selected Caustic-Side Solvent Extraction (CSSX) as the preferred technology for the removal of radioactive cesium from High-Level Waste (HLW) at the Savannah River Site (SRS). Before the full-scale Salt Waste Processing Facility (SWPF) becomes operational, the liquid Waste Organization (LWO) plans to process a portion of dissolved saltcake waste through a Modular CSSX Unit (MCU). This work was derived from Technical Task Request SP-TTR-2004-00013, ''Gamma Monitor for MCU.'' The deliverables for this task are the hardware and software for the gamma monitors and a report summarizing the testing and acceptance of this equipment for use in the MCU. Revision of this report is a deliverable in Technical Task Report SP-TTR-2006-00010, ''NaI Shield Box Testing.'' Gamma-ray monitors were developed to: {lg_bullet} Measure the Cs-137 concentration in the decontaminated salt solution before entering the DSS (Decontaminated Salt Solution) Hold Tank, {lg_bullet} Measure the Cs-137 concentration in the strip effluent before entering the Strip Effluent Hold Tank, {lg_bullet} Verify proper operation of the solvent extraction system by verifying material balance within the process (The DSS Hold Tank Cs-137 concentration will be very low and the Cs-137 concentration in the Strip Effluent Hold Tank will be approximately fifteen times higher than the Cs-137 concentration in the Feed Tank.)

  20. Rab20 regulates phagosome maturation in RAW264 macrophages during Fc gamma receptor-mediated phagocytosis.

    PubMed

    Egami, Youhei; Araki, Nobukazu

    2012-01-01

    Rab20, a member of the Rab GTPase family, is known to be involved in membrane trafficking, however its implication in FcγR-mediated phagocytosis is unclear. We examined the spatiotemporal localization of Rab20 during phagocytosis of IgG-opsonized erythrocytes (IgG-Es) in RAW264 macrophages. By the live-cell imaging of fluorescent protein-fused Rab20, it was shown that Rab20 was transiently associated with the phagosomal membranes. During the early stage of phagosome formation, Rab20 was not localized on the membranes of phagocytic cups, but was gradually recruited to the newly formed phagosomes. Although Rab20 was colocalized with Rab5 to some extent, the association of Rab20 with the phagosomes persisted even after the loss of Rab5 from the phagosomal membranes. Then, Rab20 was colocalized with Rab7 and Lamp1, late endosomal/lysosomal markers, on the internalized phagosomes. Moreover, our analysis of Rab20 mutant expression revealed that the maturation of phagosomes was significantly delayed in cells expressing the GDP-bound mutant Rab20-T19N. These data suggest that Rab20 is an important component of phagosome and regulates the phagosome maturation during FcγR-mediated phagocytosis.

  1. Differential regulation by leukotrienes and calcium of Fc gamma receptor-induced phagocytosis and Syk activation in dendritic cells versus macrophages.

    PubMed

    Canetti, Claudio; Aronoff, David M; Choe, Mun; Flamand, Nicolas; Wettlaufer, Scott; Toews, Galen B; Chen, Gwo-Hsiao; Peters-Golden, Marc

    2006-06-01

    Macrophage (MØ) phagocytosis via the Fc receptor for immunoglobulin G (Fc gammaR) requires the spleen tyrosine kinase (Syk) and serves an important antimicrobial function. We have reported previously that Fc gammaR-mediated ingestion and Syk activation in MØ are amplified by and depend on the proinflammatory lipid mediator leukotriene B4 (LTB4). Although Fc gammaR-mediated ingestion is also important for antigen uptake, there is no information about LTB4 regulation of these processes in dendritic cells (DCs). In this study, we compared murine bone marrow (BM)-derived DCs to MØ from BM, peritoneum, and the pulmonary alveolar space. Neither phagocytosis nor Syk activation in DCs was influenced by exogenous LTB4. Unlike the various MØ populations, Syk activation in DCs was likewise unaffected by pharmacologic or genetic strategies to inhibit endogenous LTB4 synthesis or to block the high-affinity LTB4 receptor BLT1. DCs were refractory to regulation by LTB4 despite the fact that they expressed BLT1 and mobilized intracellular calcium in response to its ligation. This resistance to LTB4 in DCs instead reflected the fact that in contrast to MØ, Syk activation in DCs was itself entirely independent of calcium. These results identify a fundamental difference in Fc gammaR signaling between DCs and MØ, which may relate to the divergent, functional consequences of target ingestion in the two cell types.

  2. Performance tests on PNL`s transportable neutron/gamma waste assay system

    SciTech Connect

    Haggard, D.L.; Davidson, D.; Lemons, C.J.

    1995-12-31

    Battelle Pacific Northwest Laboratory, in conjunction with Canberra Industries, has implemented a 55-gallon drum waste assay system. The single system unit consists of a combined segmented gamma assay system and a neutron assay system. The unit is designed to function either in the laboratory or in a mobile trailer. The system is on wheels and can be moved through standard double doors. The gamma system uses an HPGe detector with a Se-75 source for transmission corrections. The neutron detector uses 40 He-3 detectors connected to a JSR-12 neutron coincidence counter. The system`s software is unique and is interactive with the user; it features a menu driven operator screen from which all functions regarding operations and calibrations can be selected. Single or combined assays with various setups, including containers smaller than 55 gallons, may be performed. The software and analysis is designed for unknown waste contents, but allows input of waste stream information prior to assay. The system was originally designed for safeguards` MC&A requirements and has enough sensitivity to determine whether a drum is TRU or LLW in one assay pass. Typical counting times are approximately 1800 seconds for a dual pass. Preliminary testing of the system with the available Pu standards has shown the system will perform to the required levels stated in the Data Quality Objectives of the WIPP Performance Demonstration program. An overall study of the system is underway to determine the lower limit of detection (LLD) for different isotopes, to best utilize the combined assay results, and to apply the appropriate data corrections for more complete answers, such as corrections for the end effects. Results from these developments will be presented at the conference.

  3. Gadolinium-doped water cerenkov-based neutron and high energy gamma-ray detector and radiation portal monitoring system

    DOEpatents

    Dazeley, Steven A; Svoboda, Robert C; Bernstein, Adam; Bowden, Nathaniel

    2013-02-12

    A water Cerenkov-based neutron and high energy gamma ray detector and radiation portal monitoring system using water doped with a Gadolinium (Gd)-based compound as the Cerenkov radiator. An optically opaque enclosure is provided surrounding a detection chamber filled with the Cerenkov radiator, and photomultipliers are optically connected to the detect Cerenkov radiation generated by the Cerenkov radiator from incident high energy gamma rays or gamma rays induced by neutron capture on the Gd of incident neutrons from a fission source. The PMT signals are then used to determine time correlations indicative of neutron multiplicity events characteristic of a fission source.

  4. A technical review of the SWEPP gamma-ray spectrometer system

    SciTech Connect

    Hartwell, J.K.

    1996-03-01

    The SWEPP Gamma-ray Spectrometer (SGRS) was developed by INEL researchers as a nonintrusive method of determining the isotopic ratios of TRU and U materials in a 208-liter waste drums. The SGRS has been in use at SWEPP since mid-1994. Enough questions have been raised regarding the system reliability and technical capabilities, that, coupled with a desire to procure an additional gamma-ray spectroscopy system in order to increase the drum throughput of SWEPP, have prompted an independent technical review of the SGRS. The author was chosen as the reviewer, and this report documents the results of the review. While the SGRS is accurate in its isotopic ratio results, the system is not calculationally robust. The primary reason for this lack of calculational reliability is the implementation of the attenuation corrections. Suggested changes may improve the system reliability dramatically. The SGRS is a multiple detector spectrometry system. Tests were conducted on various methods for combining the four detector results into a single drum representative value. No clear solution was reached for the cases in which the isotopic ratios are vertically segregated; however, some methods showed promise. These should be investigated further. 14 refs. , 15 figs., 23 tabs.

  5. Cholinergic regulation of the vasopressin neuroendocrine system

    SciTech Connect

    Michels, K.M.

    1987-01-01

    To clarify the physical and functional relationship between the cholinergic system, and the neurodocrine cells of the supraoptic nucleus, a combination of experiments on receptor binding, localization and function were carried out. The putative nicotinic receptor probe (/sup 125/I)alpha bungarotoxin ((/sup 125/I)alpha BTX) bound with high affinity and specificity to the vasopressin and oxytocin magnocellular neurons of the supraoptic nucleus, nucleus circularis, and paraventricular nucleus. Binding of (/sup 125/I)alpha BTX within the neural lobe was very low. In contrast, the muscarinic cholinergic receptor probe (/sup 3/H)quinuclidinylbenzilate ((/sup 3/H)QNB) did not bind to magnocellular vasopressin and oxytocin cell groups. The median eminence, which contains the neurosecretory axons, and the neural lobe of the pituitary contain low levels of (/sup 3/H)QNB binding. The physiological significance of these cholinergic receptors in regulation of vasopressin release was tested using an in vitro preparation of the supraoptic - neural lobe system.

  6. System and method for regulating resonant inverters

    DOEpatents

    Stevanovic, Ljubisa Dragoljub; Zane, Regan Andrew

    2007-08-28

    A technique is provided for direct digital phase control of resonant inverters based on sensing of one or more parameters of the resonant inverter. The resonant inverter control system includes a switching circuit for applying power signals to the resonant inverter and a sensor for sensing one or more parameters of the resonant inverter. The one or more parameters are representative of a phase angle. The resonant inverter control system also includes a comparator for comparing the one or more parameters to a reference value and a digital controller for determining timing of the one or more parameters and for regulating operation of the switching circuit based upon the timing of the one or more parameters.

  7. SYSTEMS MODELING OF PROSTATE REGULATION AND ...

    EPA Pesticide Factsheets

    The prostate is an androgen-dependent tissue that is an important site of disease in human males as well as an important indicator of androgen status in animals. The rat prostate is used for studying antiandrogenic drugs as well as for evaluation of endocrine disruption (e.g., Hershberger Assay). Pubertal changes in the prostate have been observed to be as sensitive to environmental antiandrogens as in utero effects. The goal of this research is to model the biology of prostate androgen function on a systems level to determine the factors responsible for the dose-response observable with androgens and antiandrogens in the male rat. This includes investigation of the roles of positive and negative feedback loops in prostatic response following castration and dosing with testosterone and/or antiandrogens. A biologically-based, systems-level model will be developed describing the regulation of the prostate by androgens. The model will extend an existing model for the male rat central axis, which describes feedback between luteinizing hormone and testosterone production in the testes, to include the prostate and conversion of testosterone to dihydrotestosterone (DHT). The prostate model will describe binding of androgens to the androgen receptor, 5α-reductase catalyzed production of DHT, and gene regulation affecting cell proliferation, apoptosis, and prostatic fluid production. The model will combine pharmacokinetic models for endogenous hormones (i.e., testost

  8. A clinical gamma camera-based pinhole collimated system for high resolution small animal SPECT imaging.

    PubMed

    Mejia, J; Galvis-Alonso, O Y; Castro, A A de; Braga, J; Leite, J P; Simões, M V

    2010-12-01

    The main objective of the present study was to upgrade a clinical gamma camera to obtain high resolution tomographic images of small animal organs. The system is based on a clinical gamma camera to which we have adapted a special-purpose pinhole collimator and a device for positioning and rotating the target based on a computer-controlled step motor. We developed a software tool to reconstruct the target's three-dimensional distribution of emission from a set of planar projections, based on the maximum likelihood algorithm. We present details on the hardware and software implementation. We imaged phantoms and heart and kidneys of rats. When using pinhole collimators, the spatial resolution and sensitivity of the imaging system depend on parameters such as the detector-to-collimator and detector-to-target distances and pinhole diameter. In this study, we reached an object voxel size of 0.6 mm and spatial resolution better than 2.4 and 1.7 mm full width at half maximum when 1.5- and 1.0-mm diameter pinholes were used, respectively. Appropriate sensitivity to study the target of interest was attained in both cases. Additionally, we show that as few as 12 projections are sufficient to attain good quality reconstructions, a result that implies a significant reduction of acquisition time and opens the possibility for radiotracer dynamic studies. In conclusion, a high resolution single photon emission computed tomography (SPECT) system was developed using a commercial clinical gamma camera, allowing the acquisition of detailed volumetric images of small animal organs. This type of system has important implications for research areas such as Cardiology, Neurology or Oncology.

  9. Gamma-glutamyltransferase activity in mammary gland of pregnant rats and its regulation by ovarian hormones, prolactin and placental lactogen.

    PubMed Central

    Bussmann, L E; Deis, R P

    1984-01-01

    Ovariectomy and ovariectomy plus hysterectomy on day 18 of pregnancy increased gamma-glutamyltransferase activity in the mammary gland. The withdrawal of progesterone and the subsequent release of prolactin are responsible for the rise in enzyme activity. Rat placental lactogen in the absence of prolactin and progesterone is able to induce gamma-glutamyltransferase activity. PMID:6149746

  10. The AMPK gamma1 R70Q mutant regulates multiple metabolic and growth pathways in neonatal cardiac myocytes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although mutations in the gamma-subunit of AMP-activated protein kinase (AMPK) can result in excessive glycogen accumulation and cardiac hypertrophy, the mechanisms by which this occurs have not been well defined. Because >65% of cardiac AMPK activity is associated with the gamma1-subunit of AMPK, w...

  11. Induced ICER I{gamma} down-regulates cyclin A expression and cell proliferation in insulin-producing {beta} cells

    SciTech Connect

    Inada, Akari; Weir, Gordon C.; Bonner-Weir, Susan . E-mail: susan.bonner-weir@joslin.harvard.edu

    2005-04-15

    We have previously found that cyclin A expression is markedly reduced in pancreatic {beta}-cells by cell-specific overexpression of repressor inducible cyclic AMP early repressor (ICER I{gamma}) in transgenic mice. Here we further examined regulatory effects of ICER I{gamma} on cyclin A gene expression using Min6 cells, an insulin-producing cell line. The cyclin A promoter luciferase assay showed that ICER I{gamma} directly repressed cyclin A gene transcription. In addition, upon ICER I{gamma} overexpression, cyclin A mRNA levels markedly decreased, thereby confirming an inhibitory effect of ICER I{gamma} on cyclin A expression. Suppression of cyclin A results in inhibition of BrdU incorporation. Under normal culture conditions endogenous cyclin A is abundant in these cells, whereas ICER is hardly detectable. However, serum starvation of Min6 cells induces ICER I{gamma} expression with a concomitant very low expression level of cyclin A. Cyclin A protein is not expressed unless the cells are in active DNA replication. These results indicate a potentially important anti-proliferative effect of ICER I{gamma} in pancreatic {beta} cells. Since ICER I{gamma} is greatly increased in diabetes as well as in FFA- or high glucose-treated islets, this effect may in part exacerbate diabetes by limiting {beta}-cell proliferation.

  12. Calibration Report for the WRAP Facility Gamma Energy Analysis System [104-ND-06-102A

    SciTech Connect

    WILLS, C.E.

    2000-02-15

    The Waste Receiving And Processing facility (WRAP) adheres to providing gamma-ray spectroscopy instrument calibrations traceable to the National Institute for Standards and Technology (NIST) standards. The detectors are used to produce quantitative results for the Waste Isolation Pilot Plant (WIPP) and must meet calibration programmatic calibration goals. Instruments must meet portions of ANSI N42.14, 1978 guide for Germanium detectors. The Non-Destructive Assay (NDA) Gamma Energy Analysis (GEA) utilizes NIST traceable line source standards for the detector system calibrations. The counting configuration is a series of drums containing the line sources and different density filler matrices. The drums are used to develop system efficiencies with respect to density. The efficiency and density correction factors are required for the processing of drummed waste materials of similar densities. The calibration verification is carried out after the calibration is deemed final, by counting a second drum of NIST traceable sources. Three in-depth calibrations have been completed on one of the two systems to date, the first being the system acceptance plan. This report has a secondary function; that being the development of the instrument calibration errors which are to be folded into the Total Instrument Uncertainty document, HNF-4050.

  13. Calibration Report for the WRAP Facility Gamma Energy Analysis System (104-ND-06-102A)

    SciTech Connect

    WILLS, C.E.

    2000-03-13

    The Waste Receiving And Processing facility (WRAP) adheres to providing gamma-ray spectroscopy instrument calibrations traceable to the National Institute for Standards and Technology (NIST) standard{sup (4)}. The detectors are used to produce quantitative results for the Waste Isolation Pilot Plant (WIPP) and must meet calibration programmatic calibration goals. Instruments must meet portions of ANSI N42.14, 1978 guide for Germanium detectors. The Non-Destructive Assay (NDA) Gamma Energy Analysis (GEA) utilizes NIST traceable line source standards for the detector system calibrations. The counting configuration is a series of drums containing the line sources and different density filler matrices. The drums are used to develop system efficiencies with respect to density. The efficiency and density correction factors are required for the processing of drummed waste materials of similar densities. The calibration verification is carried out after the calibration is deemed final, by counting a second drum of NIST traceable sources. Three in-depth calibrations have been completed on one of the two systems to date, the first being the system acceptance plan. This report has a secondary function; that being the development of the instrument calibration errors which are to be folded into the Total Instrument Uncertainty document, HNF-4050.

  14. Construction and testing of a neutron and gamma spectrometry system using pulse shape discrimination with an organic scintillator

    NASA Astrophysics Data System (ADS)

    Pope, Robert S.

    1993-03-01

    The goal of this thesis was to construct and test a neutron detector to measure the energy spectrum of 1 to 14-MeV neutrons in the presence of gammas. A spectrometer based on the process of pulse shape discrimination (PSD) was constructed, in which the scintillator NE-213 was used. The primary neutron/gamma sources used were 78-mCi and 4.7-Ci Pu-239Be sources, while 4.7-micro-Ci and 97.6-micro-Ci Na-22 gamma sources were used for energy calibration and additional testing of the detector. Proton recoil spectra and Compton electron spectra were unfolded with the neutron and gamma unfolding code FORIST to generate the incident neutron and gamma spectra, respectively. FORIST, which was written for a CDC computer, was modified to run on a VAX 6420. The experimental spectra were compared to those in the literature. The locations of the peaks in the Pu-239Be spectrum agreed with the literature to within 8.3%, the Pu-239Be gamma spectrum agreed to within 0.7%, while the Na-22 gamma spectrum agreed exactly. Uncertainties in the detection system and unfolding procedure are on the order of 5-10%. This thesis is intended to be a summary of the relevant literature and a user's guide to the PSD spectrometer.

  15. Synthesis of a dextran based thermo-sensitive drug delivery system by gamma irradiation.

    PubMed

    Almeida, J F; Ferreira, P; Alves, P; Lopes, A; Gil, M H

    2013-10-01

    Gamma radiation was used as the initiator/crosslinker agent for the synthesis of thermo-sensitive hydrogel networks, under the form of membranes, using dextran and N-isopropylacrylamide. The prepared membranes were loaded with Ondansetron™, a potent antiemetic drug and tested as drug delivery systems. The characterization of the materials was accomplished by: Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy, elemental analysis, lower critical solution temperature (LCST) determination, swelling behaviour evaluation, determination of surface energy by contact angle measurement and drug delivery kinetics studies. Also, the influence of irradiation time and temperature on the materials properties was evaluated.

  16. Automatic and Interactive Analysis Software for Beta-Gamma Coincidence Systems Used in CTBT Monitoring

    DTIC Science & Technology

    2000-09-01

    publication in the Journal of Radioanalytical and Nuclear Chemistry , April 2000. [2] Biegalski, K.M.F. and Biegalski, S. “Determining Minimum Detectable... Radioanalytical and Nuclear Chemistry , April 2000. [3] Reeder, P.L., Bowyer, T.W., and Perkins, R.W. “Analysis of Beta-Gamma Spectra for the PNNL ARSA and...DTRA01-99-C-0031 ABSTRACT A suite of software has been developed by Veridian Systems as part of the Prototype International Data Center (PIDC) to assist

  17. Quality assurance for gamma knives

    SciTech Connect

    Jones, E.D.; Banks, W.W.; Fischer, L.E.

    1995-09-01

    This report describes and summarizes the results of a quality assurance (QA) study of the Gamma Knife, a nuclear medical device used for the gamma irradiation of intracranial lesions. Focus was on the physical aspects of QA and did not address issues that are essentially medical, such as patient selection or prescription of dose. A risk-based QA assessment approach was used. Sample programs for quality control and assurance are included. The use of the Gamma Knife was found to conform to existing standards and guidelines concerning radiation safety and quality control of external beam therapies (shielding, safety reviews, radiation surveys, interlock systems, exposure monitoring, good medical physics practices, etc.) and to be compliant with NRC teletherapy regulations. There are, however, current practices for the Gamma Knife not covered by existing, formalized regulations, standards, or guidelines. These practices have been adopted by Gamma Knife users and continue to be developed with further experience. Some of these have appeared in publications or presentations and are slowly finding their way into recommendations of professional organizations.

  18. Activation of p38 mitogen-activated protein kinase by celecoxib oppositely regulates survivin and gamma-H2AX in human colorectal cancer cells

    SciTech Connect

    Hsiao, P.-W.; Chang, C.-C.; Liu, H.-F.; Tsai, C.-M.; Chiu, Ted H.; Chao, J.-I . E-mail: chaoji@mail.tcu.edu.tw

    2007-07-01

    Cancer cells express survivin that facilitates tumorigenesis. Celecoxib has been shown to reduce human colorectal cancers. However, the role and regulation of survivin by celecoxib in colorectal carcinoma cells remain unclear. Treatment with 40-80 {mu}M celecoxib for 24 h induced cytotoxicity and proliferation inhibition via a concentration-dependent manner in RKO colorectal carcinoma cells. Celecoxib blocked the survivin protein expression and increased the phosphorylation of H2AX at serine-193 ({gamma}-H2AX). The survivin gene knockdown by transfection with a survivin siRNA revealed that the loss of survivin correlated with the expression of {gamma}-H2AX. Meanwhile, celecoxib increased caspase-3 activation and apoptosis. Celecoxib activated the phosphorylation of p38 mitogen-activated protein (MAP) kinase. The phosphorylated proteins of p38 MAP kinase and {gamma}-H2AX were observed in the apoptotic cells. SB203580, a specific p38 MAP kinase inhibitor, protected the survivin protein expression and decreased the levels of {gamma}-H2AX and apoptosis in the celecoxib-exposed cells. The blockade of survivin expression increased the celecoxib-induced cytotoxicity; conversely, overexpression of survivin by transfection with a survivin-expressing vector raised the cancer cell proliferation and resisted the celecoxib-induced cell death. Our results provide for the first time that p38 MAP kinase participates in the down-regulation of survivin and subsequently induces the activation of {gamma}-H2AX for mediating apoptosis following treatment with celecoxib in human colorectal cancer cells.

  19. Rehabilitation of gamma

    NASA Astrophysics Data System (ADS)

    Poynton, Charles A.

    1998-07-01

    Gamma characterizes the reproduction of tone scale in an imaging system. Gamma summarizes, in a single numerical parameter, the nonlinear relationship between code value--in an 8-bit system, from 0 through 255--and physical intensity. Nearly all image coding systems are nonlinear, and so involve values of gamma different from unity. Owing to poor understanding of tone scale reproduction, and to misconceptions about nonlinear coding, gamma has acquired a terrible reputation in computer graphics and image processing. In addition, the world-wide web suffers from poor reproduction of grayscale and color images, due to poor handling of nonlinear image coding. This paper aims to make gamma respectable again.

  20. 78 FR 18083 - Regulation Systems Compliance and Integrity

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-25

    ...The Securities and Exchange Commission (``Commission'') is proposing Regulation Systems Compliance and Integrity (``Regulation SCI'') under the Securities Exchange Act of 1934 (``Exchange Act'') and conforming amendments to Regulation ATS under the Exchange Act. Proposed Regulation SCI would apply to certain self-regulatory organizations (including registered clearing agencies), alternative......

  1. NADP Regulates the Yeast GAL Induction System

    SciTech Connect

    Kumar,P.; Yao, Y.; Sternglanz, R.; Johnston, S.; Joshua-Tor, L.

    2008-01-01

    Transcriptional regulation of the galactose-metabolizing genes in Saccharomyces cerevisiae depends on three core proteins: Gal4p, the transcriptional activator that binds to upstream activating DNA sequences (UASGAL); Gal80p, a repressor that binds to the carboxyl terminus of Gal4p and inhibits transcription; and Gal3p, a cytoplasmic transducer that, upon binding galactose and adenosine 5'-triphosphate, relieves Gal80p repression. The current model of induction relies on Gal3p sequestering Gal80p in the cytoplasm. However, the rapid induction of this system implies that there is a missing factor. Our structure of Gal80p in complex with a peptide from the carboxyl-terminal activation domain of Gal4p reveals the existence of a dinucleotide that mediates the interaction between the two. Biochemical and in vivo experiments suggests that nicotinamide adenine dinucleotide phosphate (NADP) plays a key role in the initial induction event.

  2. Load-dependent regulation of neuromuscular system

    NASA Technical Reports Server (NTRS)

    Ohira, Yoshinobu; Kawano, Fuminori; Stevens, James L.; Wang, Xiao D.; Ishihara, Akihiko

    2004-01-01

    Roles of gravitational loading, sarcomere length, and/or tension development on the electromyogram (EMG) of soleus and afferent neurogram recorded at the L5 segmental level of spinal cord were investigated during parabolic flight of a jet airplane or hindlimb suspension in conscious rats. Both EMG and neurogram levels were increased when the gravity levels were elevated from 1-G to 2-G during the parabolic flight. They were decreased when the hindlimbs were unloaded by exposure to actual microgravity or by suspension. These phenomena were related to passive shortening of muscle fibers and/or sarcomeres. Unloading-related decrease in sarcomere length was greater at the central rather than the proximal and distal regions of fibers. These activities and tension development were not detected when the mean sarcomere length was less than 2.03 micrometers. It is suggested that load-dependent regulation of neuromuscular system is related to the tension development which is influenced by sarcomere length.

  3. Regulation of Trypanosoma cruzi infection in mice by gamma interferon and interleukin 10: role of NK cells.

    PubMed Central

    Cardillo, F; Voltarelli, J C; Reed, S G; Silva, J S

    1996-01-01

    Gamma interferon (IFN-gamma) plays an important role in experimental Trypanosoma cruzi infections, presumably by controlling the early replication of parasites in host macrophages. In this work, we show that NK cells represent an important cell type responsible for the production of most of the IFN-gamma in the early stage of T. cruzi infection and that the in vivo treatment of mice with anti-NK1.1 monoclonal antibody made resistant animals susceptible to the infection. Through in vitro experiments, we demonstrate that normal splenocytes from euthymic or athymic nude mice cultivated for 48 h with live T. cruzi trypomastigotes produced elevated levels of IFN-gamma. In addition, NK-depleted splenocytes show a drastic reduction of IFN-gamma production in response to live T. cruzi trypomastigotes. We also demonstrated that IFN-gamma production is dependent on a factor secreted by adherent cells. Supernatants of spleen cells from athymic nude mice are able to induce IFN-gamma production by normal splenocytes when cultured with trypomastigotes. The addition of anti-interleukin-10 to these cultures resulted in a marked increase in IFN-gamma production. On the other hand, the absence of NK cells led to an increased secretion of interleukin-10 upon in vitro stimulation with T. cruzi. Taken together, these results suggest that NK cells are the major source of IFN-gamma that could be involved in limiting the replication of T. cruzi in host macrophages during the early acute phase of the infection. PMID:8557330

  4. Gamma radiation impact on performance of OOK, DPSK and homodyne BPSK based optical inter-satellite communication system

    NASA Astrophysics Data System (ADS)

    Liu, Yun; Zhao, Shanghong; Gong, Zizheng; Hou, Rui; Qiang, Ruoxin

    2015-09-01

    Performance of optical inter-satellite communication system is influenced by the harsh space radiation environment. Gamma radiation effects on main devices of communication system are analyzed and on the basis of existing experimental data, performance degradation of on off keying (OOK), differential phase shift keying (DPSK) and homodyne binary phase shift keying (BPSK) based system under 1 kGy gamma irradiation is simulated. Variation of Q factors and bit error ratio of these systems with different radiation position are achieved and discussed. The result shows that it is more urgent to improve the radiation hardness of transmitter, and the introduction of local laser is a considerable method to reduce gamma radiation impact on system performance.

  5. A Topological Array Trigger for AGIS, the Advanced Gamma ray Imaging System

    SciTech Connect

    Krennrich, F.; Anderson, J.; Byrum, K.; Dawson, J.; Drake, G.; Haberichter, W.; Kreps, A.; Smith, A.; Buckley, J.; Krawczynski, H.; Imran, A.; Schroedter, M.

    2008-12-24

    Next generation ground based {gamma}-ray observatories such as AGIS{sup 1} and CTA{sup 2} are expected to cover a 1 km{sup 2} area with 50-100 imaging atmospheric Cherenkov telescopes. The stereoscopic view ol air showers using multiple view points raises the possibility to use a topological array trigger that adds substantial flexibility, new background suppression capabilities and a reduced energy threshold. In this paper we report on the concept and technical implementation of a fast topological trigger system, that makes use of real time image processing of individual camera patterns and their combination in a stereoscopic array analysis. A prototype system is currently under construction and we discuss the design and hardware of this topological array trigger system.

  6. Measurement of beta-gamma coincidence with a multi-parameter analyzer system

    NASA Astrophysics Data System (ADS)

    Yazdanpanah-Kejani, M.; Abbasi, F.; Lamehi-Rachti, M.; Doost-Mohammadi, V.

    2017-01-01

    A new version of the Iranian Noble Gas Analyzing System (INGAS) has been improved to facilitate measurement of beta-gamma coincidence events. It employs a new prototype list-mode multi-parameter data analyzer system, MPA4300. In order to test the new version performance, it has used to obtain energy spectra from radioxenon isotopes using the detector assembly of the Iranian Noble Gas Analyzing System. The MPA4300 is able to set the coinciding parameters, extract the corresponding spectrum, and through the use of event by event list file, can replay the measurement in offline mode. A great novelty of this work is the use of internal timing circuit in MPA4300 instead of using standard pick up time modules to identify coincidence events of detectors. A detailed description of the measuring 222Rn and 131mXe is presented.

  7. Evidence for an Inducible Repair-Recombination System in the Female Germ Line of Drosophila Melanogaster. II. Differential Sensitivity to Gamma Rays

    PubMed Central

    Laurencon, A.; Bregliano, J. C.

    1995-01-01

    In a previous paper, we reported that the reactivity level, which regulates the frequency of transposition of I factor, a LINE element-like retrotransposon, is enhanced by the same agents that induce the SOS response in Escherichia coli. In this report, we describe experimental evidence that, for identical genotypes, the reactivity levels correlate with the sensitivity of oogenesis to gamma rays, measured by the number of eggs laid and by frequency of dominant lethals. This strongly supports the hypothesis that the reactivity level is one manifestation of an inducible DNA repair system taking place in the female germ line of Drosophila melanogaster. The implications of this finding for the understanding of the regulation of I factor are discussed and some other possible biological roles of this system are outlined. PMID:8647394

  8. Remote Gamma Scanning System for Characterization of BWR and PWR Fuel Rod Sections

    SciTech Connect

    Crowell, Shannon L.; Alzheimer, James M.

    2011-08-08

    Sometimes challenges with the design and deployment of automated equipment in remote environments deals more with the constraints imposed by the remote environment than it does with the details of the automation. This paper discusses the development of a scanning system used to provide gamma radiation profiles of irradiated fuel rod segments. The system needed the capability to provide axial scans of cut segments of BWR and PWR fuel rods. The scanning location is A-Cell at the Radiochemical Processing Laboratory (RPL) at the Hanford site in Washington State. The criteria for the scanning equipment included axial scanning increments of a tenth of an inch or less, ability to scan fuel rods with diameters ranging from 3/8 inch to 5/8 inch in diameter, and fuel rod segments up to seven feet in length. Constraints imposed by the environment included having the gamma detector and operator controls on the outside of the hot cell and the scanning hardware on the inside of the hot cell. This entailed getting a narrow, collimated beam of radiation from the fuel rod to the detector on the outside of the hot cell while minimizing the radiation exposure caused by openings for the wires and cables traversing the hot cell walls. Setup and operation of all of the in-cell hardware needed to accommodate limited access ports and use of hot cell manipulators. The radiation levels inside the cell also imposed constraints on the materials used.

  9. Suitability of gamma irradiated chitosan based membranes as matrix in drug release system.

    PubMed

    Casimiro, M H; Gil, M H; Leal, J P

    2010-08-16

    To test the possibility of obtain a material simultaneously biocompatible and microbiologically safe to be used as wound dressing material and as a matrix for drug release system, membranes with different initial contents in chitosan and 2-hydroxyethyl methacrylate (HEMA) have been prepared by gamma irradiation from a (60)Co source. The antimicrobial activity of obtained membranes against several reference strains was evaluated after inoculation. Sub-lethal gamma radiation doses were also applied in artificially contaminated membranes and the D(values) of microorganisms in use were determined in order to predict which radiation dose could guarantee membranes microbiological safety. In vitro haemolysis tests were also performed using drug loaded membranes irradiated at different doses. Results point out that those membranes naturally exhibit antimicrobial properties. Also show that, over the studied range values, drug loaded irradiated membranes display a non-significant level of haemolysis. These features show that the application of prepared membranes as a transdermal drug release system "ready to use" is viable.

  10. Effect of gamma radiation on chlorobutyl rubber vulcanized by three different crosslinking systems

    NASA Astrophysics Data System (ADS)

    Scagliusi, Sandra R.; Cardoso, Elisabeth L. C.; Lugao, Ademar B.

    2012-09-01

    The development of halogenated butyl rubber (chlorobutyl) in the 1950s and 1960s greatly extended the usefulness of butyl. Their properties allowed the development of more durable tubeless tires with the air retaining innerliner, chemically bonded to the body of the tire. Tire innerliners are by far the largest application for halobutyl. When polymers are subjected to high energy radiation, a number of chemical reactions may occur following the initial ionization and excitation events. These reactions lead to changes in the molecular weight of the polymer through scission (S) and crosslinking (X) of the molecules and affect the physical and mechanical properties. In the halobutyl rubbers the chain scission may predominate. This work aims to show effects of gamma radiation in properties of chlorobutyl rubbers vulcanized with sulfur, sulfur donor and phenolic resin. The butyl rubber has been already studied by us previously. The samples were characterized before and after irradiation. Gamma radiation doses used were: 25 kGy, 50 kGy, 100 kGy, 150 kGy and 200 kGy, in order to identify which cure system is the most stable under irradiation. In this study we observed that the properties of all samples were affected irrespective of the vulcanization system.

  11. Magnetic levitation self-regulating systems

    SciTech Connect

    Tozoni, O.

    1993-06-08

    A magnet levitation self-regulating system is described comprising monotypic magnetic devices combined together by rigid nonmagnetic couplers; said magnetic device comprising two cylindrical parts extended along a cylinder generatrix: a. an iron core having a symmetrical C-shaped cross section and an air gap between its core shoes; and b. a permanent magnet having a rectangular cross-section disposed in said air gap; wherein all the iron cores of said magnetic devices are fixed on a common foundation by a first plurality of rigid nonmagnetic couplers and formed a stator assembly; all the permanent magnets of said magnetic devices are connected together by a second plurality of rigid non-magnetic couplers and form a levitator assembly; said permanent magnets of said levitator generate an original magnetic field and magnetize the stator cores; said stator cores create a secondary magnetic field; both said original and secondary magnetic fields create a magnetic levitation force that provides a stable hovering of said levitator in a resulting magnetic field of said system.

  12. Regulation of Bacterial Drug Export Systems

    PubMed Central

    Grkovic, Steve; Brown, Melissa H.; Skurray, Ronald A.

    2002-01-01

    The active transport of toxic compounds by membrane-bound efflux proteins is becoming an increasingly frequent mechanism by which cells exhibit resistance to therapeutic drugs. This review examines the regulation of bacterial drug efflux systems, which occurs primarily at the level of transcription. Investigations into these regulatory networks have yielded a substantial volume of information that has either not been forthcoming from or complements that obtained by analysis of the transport proteins themselves. Several local regulatory proteins, including the activator BmrR from Bacillus subtilis and the repressors QacR from Staphylococcus aureus and TetR and EmrR from Escherichia coli, have been shown to mediate increases in the expression of drug efflux genes by directly sensing the presence of the toxic substrates exported by their cognate pump. This ability to bind transporter substrates has permitted detailed structural information to be gathered on protein-antimicrobial agent-ligand interactions. In addition, bacterial multidrug efflux determinants are frequently controlled at a global level and may belong to stress response regulons such as E. coli mar, expression of which is controlled by the MarA and MarR proteins. However, many regulatory systems are ill-adapted for detecting the presence of toxic pump substrates and instead are likely to respond to alternative signals related to unidentified physiological roles of the transporter. Hence, in a number of important pathogens, regulatory mutations that result in drug transporter overexpression and concomitant elevated antimicrobial resistance are often observed. PMID:12456787

  13. Distribution System Voltage Regulation by Distributed Energy Resources

    SciTech Connect

    Ceylan, Oguzhan; Liu, Guodong; Xu, Yan; Tomsovic, Kevin

    2014-01-01

    This paper proposes a control method to regulate voltages in 3 phase unbalanced electrical distribution systems. A constrained optimization problem to minimize voltage deviations and maximize distributed energy resource (DER) active power output is solved by harmony search algorithm. IEEE 13 Bus Distribution Test System was modified to test three different cases: a) only voltage regulator controlled system b) only DER controlled system and c) both voltage regulator and DER controlled system. The simulation results show that systems with both voltage regulators and DER control provide better voltage profile.

  14. Detection of multiple terrestrial gamma-ray flashes from thunderstorm systems

    NASA Astrophysics Data System (ADS)

    Ursi, A.; Marisaldi, M.; Tavani, M.; Casella, D.; Sanò, P.; Dietrich, S.

    2016-11-01

    Since their discovery, Terrestrial Gamma ray Flashes (TGFs) exhibited an evident correlation with thunderstorms and lightning activity. The fleeting nature of these events and the heavy absorption of gamma rays in the lowest atmospheric layers severely hamper the observation of this phenomenon, making us reveal just a small fraction of a probably much wider population. As each thunderstorm produces a large amount of lightning discharges during its lifetime, it is reasonable that even a large amount of TGFs are produced during the same event. However, detection of multiple TGFs coming from the same storm is difficult to perform, as it requires the constant monitoring of a spatially limited geographic region: this is not an easy task to perform for satellites on high-inclination orbits that make them experience nonnegligible latitudinal shifts at each orbital passage over a certain region, preventing the monitoring of a limited geographic region throughout successive overpasses. In this perspective, the quasi-equatorial (2.5°) orbit of the Astrorivelatore Gamma ad Immagini LEggero (AGILE) satellite ensures a minimal latitudinal shift when flying over the same region at successive passages, allowing for the follow-up of thunderstorms in time. We exploit this feature of the AGILE satellite to search for multiple TGFs coming from the same geographic region and, in particular, from the same thunderstorm. We carry out this search on the AGILE TGF database (2009-2016), ending up with a sample of 79 systems producing more than one TGF, both during the same overpass and up to four overpasses after. Data acquired by geostationary meteorological satellites and cross correlation with radio sferics detected by World Wide Lightning Location Network are used to support this investigation. The AGILE satellite for the first time clearly establishes the multiple occurrences of TGFs from convective thunderstorms, both on timescales of minutes to several hours.

  15. Role of the duplicated CCAAT box region in gamma-globin gene regulation and hereditary persistence of fetal haemoglobin.

    PubMed Central

    Ronchi, A; Berry, M; Raguz, S; Imam, A; Yannoutsos, N; Ottolenghi, S; Grosveld, F; Dillon, N

    1996-01-01

    Hereditary persistence of fetal haemoglobin (HPFH) is a clinically important condition in which a change in the developmental specificity of the gamma-globin genes results in varying levels of expression of fetal haemoglobin in the adult. The condition is benign and can significantly alleviate the symptoms of thalassaemia or sickle cell anaemia when co-inherited with these disorders. We have examined structure-function relationships in the -117 HPFH gamma promoter by analysing the effect of mutating specific promoter elements on the functioning of the wild-type and HPFH promoters. We find that CCAAT box mutants dramatically affect expression from the HPFH promoter in adult blood but have little effect on embryonic/fetal expression from the wild-type promoter. Our results suggest that there are substantial differences in the structure of the wild-type gamma promoter expressed early in development and the adult HPFH promoter. Together with previous results, this suggests that gamma silencing is a complex multifactorial phenomenon rather than being the result of a simple repressor binding to the promoter. We present a model for gamma-globin gene silencing that has significant implications for attempts to reactivate the gamma promoters in human adults by pharmacological means. Images PMID:8598197

  16. Anticipatory regulation of complex power systems

    NASA Astrophysics Data System (ADS)

    Fieno, Thomas Edward

    Electric generation control is performed in a distributed manner to supply power to geographically defined control areas. The goal of generation control is to keep the inadvertent flow of power across a control area's boundary as small as possible. If a difference exists between the power supplied and the power demanded in a control area, the load deficit or surplus would be either borrowed from or stored as the kinetic energy in rotating machines on the grid. This thesis addresses the challenge of matching the power demand of a local area grid with the power delivered by a coal-fired power plant. An anticipatory controller for a model power plant is presented to prescribe the power output into the grid. The control system forecasts what the future demand of the power customers in a control area is likely to be and modifies the fuel input to the power generation facility in order to match the predicted demand. A neural network was found to be an adaptable and robust prediction mechanism for the highly nonlinear data found in the power consumption patterns in a residential area of the Commonwealth Edison grid. The corresponding control schedule of the power plant was tuned to match the anticipated demand using an iterative neural network approach. The use of neural networks and an iterative scheme allows the controller design in this research to be applied to a broad range of control problems. The control methodology presented takes into account limits in the magnitude and rate of control actions. Simulations show that this implementation of anticipatory control of electric power demand is effective and especially well suited to dynamic systems that include a dead time or control limitations. The response of the anticipatory neural network control system was shown to be more energy efficient than feedback control for a typical thermal power regulation facility and to have a much smoother, reduced control effort.

  17. Integrated Operation of the GАММА-400 Gamma-Ray Telescope Scintillation Detector Systems

    NASA Astrophysics Data System (ADS)

    Runtso, Mikhail

    In this paper the question of integrated operation of scintillation detector systems AC (anticoincidence system) and SDC (scintillation detector system of calorimeter) in the GАММА-400 gamma-ray telescope is discussed. The main problem is the presence of so-called «backsplash current» (BSC) of particles from massive telescope calorimeter when detecting of very high-energy gamma-rays is provided. BSC is a low energy particle flux, moving up from the calorimeter and producing triggering of the AC detector, imitating detection of a charged particle. It is offered to record all events accompanied by BSC that should not result in to overload of the gamma-ray telescope in frequency of triggering. As an indicator to the number of BSC particles in the AC detector we offer the value of energy release in the C3 scintillation detector placing between two parts of the calorimeter (KK1 and KK2). Using mathematical simulation, the threshold on energy release in the C3 detector equal to 280 GeV was determined, at which the losses of gamma-quanta number in events with BSC do not exceed 10%. When detecting protons there are also events with BSC, which will be accompanied by exceeding of the indicated threshold of energy release in the С3 detector for proton energies above 30 GeV. However, counting rate for such protons will not exceed 200 Hz, that is reasonable for the GAMMA-400 data acquisition system.

  18. Gamma II

    NASA Astrophysics Data System (ADS)

    Barker, Thurburn; Castelaz, M.; Cline, J.; Owen, L.; Boehme, J.; Rottler, L.; Whitworth, C.; Clavier, D.

    2011-05-01

    GAMMA II is the Guide Star Automatic Measuring MAchine relocated from STScI to the Astronomical Photographic Data Archive (APDA) at the Pisgah Astronomical Research Institute (PARI). GAMMA II is a multi-channel laser-scanning microdensitometer that was used to measure POSS and SERC plates to create the Guide Star Catalog and the Digital Sky Survey. The microdensitometer is designed with submicron accuracy in x and y measurements using a HP 5507 laser interferometer, 15 micron sampling, and the capability to measure plates as large as 0.5-m across. GAMMA II is a vital instrument for the success of digitizing the direct, objective prism, and spectra photographic plate collections in APDA for research. We plan several targeted projects. One is a collaboration with Drs. P.D. Hemenway and R. L. Duncombe who plan to scan 1000 plates of 34 minor planets to identify systematic errors in the Fundamental System of celestial coordinates. Another is a collaboration with Dr. R. Hudec (Astronomical Institute, Academy of Sciences of the Czech Republic) who is working within the Gaia Variability Unit CU7 to digitize objective prism spectra on the Henize plates and Burrell-Schmidt plates located in APDA. These low dispersion spectral plates provide optical counterparts of celestial high-energy sources and cataclysmic variables enabling the simulation of Gaia BP/RP outputs. The astronomical community is invited to explore the more than 140,000 plates from 20 observatories now archived in APDA, and use GAMMA II. The process of relocating GAMMA to APDA, re-commissioning, and starting up the production scan programs will be described. Also, we will present planned research and future upgrades to GAMMA II.

  19. Bixin regulates mRNA expression involved in adipogenesis and enhances insulin sensitivity in 3T3-L1 adipocytes through PPAR{gamma} activation

    SciTech Connect

    Takahashi, Nobuyuki; Goto, Tsuyoshi; Taimatsu, Aki; Egawa, Kahori; Katoh, Sota; Kusudo, Tatsuya; Sakamoto, Tomoya; Ohyane, Chie; Lee, Joo-Young; Kim, Young-il; Uemura, Taku; Hirai, Shizuka; Kawada, Teruo

    2009-12-25

    Insulin resistance is partly due to suppression of insulin-induced glucose uptake into adipocytes. The uptake is dependent on adipocyte differentiation, which is controlled at mRNA transcription level. The peroxisome proliferator-activated receptor (PPAR), a ligand-regulated nuclear receptor, is involved in the differentiation. Many food-derived compounds serve as ligands to activate or inactivate PPAR. In this study, we demonstrated that bixin and norbixin (annatto extracts) activate PPAR{gamma} by luciferase reporter assay using GAL4-PPAR chimera proteins. To examine the effects of bixin on adipocytes, 3T3-L1 adipocytes were treated with bixin or norbixin. The treatment induced mRNA expression of PPAR{gamma} target genes such as adipocyte-specific fatty acid-binding protein (aP2), lipoprotein lipase (LPL), and adiponectin in differentiated 3T3-L1 adipocytes and enhanced insulin-dependent glucose uptake. The observations indicate that bixin acts as an agonist of PPAR{gamma} and enhances insulin sensitivity in 3T3-L1 adipocytes, suggesting that bixin is a valuable food-derived compound as a PPAR ligand to regulate lipid metabolism and to ameliorate metabolic syndrome.

  20. Dosimetry and mechanical accuracy of the first rotating gamma system installed in North America.

    PubMed

    Kubo, Hideo D; Araki, Fujio

    2002-11-01

    The purpose of this paper is to present the dosimetry and mechanical accuracy of the first rotating gamma system (RGS) installed in North America for stereotactic radiosurgery. The data were obtained during the installation, acceptance test procedure, and commissioning of the unit. The RGS unit installed at UC Davis Cancer Center (RGSu) has modifications on the source and collimator bodies from the earlier version of the Chinese RGS (RGSc). The differences between these two RGSs are presented. The absolute dose at the focal point was measured in a 16-cm-diam acrylic phantom using a small volume chamber, which was calibrated at the University of Wisconsin Accredited Dosimetry Calibration Laboratory (UW-ADCL). The dose in acrylic was then converted to a dose in water. A collimator output factor from each of the four different collimator sizes ranging from 4, 8, 14, and 18 mm was measured with (1) a smaller volume chamber and (2) approximately 3.0 mm x 3.0 mm x 1.0 mm TLD chips in the same acrylic phantom. The Gafchromic films were used for the dose profile, collimator output factor, and mechanical/radiation field isocentricity measurements. The TLD chips were processed in-house whereas Gafchromic films were processed both at the UW-ADCL and in-house. The timer error, timer accuracy, and timer linearity were also determined. The dose profiles were found to be similar between RGSc and RGSu. The 4 mm collimator output factor of the RGSu was approximately 0.6, similar to that from RGSc, in comparison to 0.8 in the report for a Leksell Model U Gamma-Knife. The mechanical/radiation field isocentricity for RGSc and RGSu is found to be similar and is within 0.3 mm in both X and Y directions. In the Z direction, the beam center of the RGSu is shifted toward the sources by 0.75 mm from the mechanical isocenter whereas no data are available for RGSc. Little dosimetric difference is found between RGSu and RGSc. It is reported that RGSc has the same dosimetric and mechanical

  1. Ligand-induced IFN gamma receptor tyrosine phosphorylation couples the receptor to its signal transduction system (p91).

    PubMed Central

    Greenlund, A C; Farrar, M A; Viviano, B L; Schreiber, R D

    1994-01-01

    Herein we report that interferon-gamma (IFN gamma) induces the rapid and reversible tyrosine phosphorylation of the IFN gamma receptor. Using a panel of receptor intracellular domain mutants, we show that a membrane-proximal LPKS sequence (residues 266-269) is required for ligand-induced tyrosine kinase activation and/or kinase-receptor association and biological responsiveness, and a functionally critical membrane-distal tyrosine residue (Y440) is a target of the activated enzyme. The biological significance of Y440 phosphorylation was demonstrated by showing that a receptor-derived nonapeptide corresponding to receptor residues 436-444 and containing phosphorylated Y440 bound specifically to p91, blocked p91 phosphorylation and inhibited the generation of an active p91-containing transcription factor complex. In contrast, nonphosphorylated wild-type, phosphorylated mutant, or phosphorylated irrelevant peptides did not. Moreover, the phosphorylated Y440-containing peptide did not interact with a related but distinct latent transcription factor (p113) which is activatible by IFN alpha but not IFN gamma. These results thus document the specific and inducible association of p91 with the phosphorylated IFN gamma receptor and thereby elucidate the mechanism by which ligand couples the IFN gamma receptor to its signal transduction system. Images PMID:8156998

  2. Scientific and Service Data Acquisition System for the GAMMA-400 Apparatus

    NASA Astrophysics Data System (ADS)

    Gorbunov, Maxim

    The data acquisition system for scientific information (ASSI) is the key part of the scientific GAMMA-400 apparatus. The functions of the ASSI are the acquisition of the data and the service information and the space flight control. It consists of 16 SpaceWire data channels for obtaining the data from detectors, the command driving channel (CDC) for transmission commands, the service information and on-board time for detectors, mainframe processing unit (CPU) for the primary data collection. The ASSI is based on 1907VM038, 1907VM014, 1907VM028 microprocessors and 1907KX018 switch, which are designed by Scientific Research Institute of System Analysis, Russian Academy of Sciences (SRISA). These chips are fabricated at scientific 0.25 μm SOI CMOS technology and provide the high level of radiation hardness and fault-tolerance. The high-speed data channels are based on SpaceWire and RapidIO standards.

  3. How the ubiquitin proteasome system regulates the regulators of transcription.

    PubMed

    Ee, Gary; Lehming, Norbert

    2012-01-01

    The ubiquitin proteasome system plays an important role in transcription. Monoubiquitination of activators is believed to aid their function, while the 26S proteasomal degradation of repressors is believed to restrict their function. What remains controversial is the question of whether the degradation of activators aids or restricts their function.

  4. A Model for Short Gamma-Ray Bursts: Heated Neutron Stars in Close Binary Systems

    NASA Astrophysics Data System (ADS)

    Salmonson, Jay D.; Wilson, James R.

    2003-04-01

    In this paper we present a model for the short (< second) population of gamma-ray bursts (GRBs). In this model heated neutron stars in a close binary system near their last stable orbit emit neutrinos at large luminosities (~ 1053 ergs/sec). A fraction of these neutrinos will annihilate to form an e+e- pair plasma wind which will, in turn, expand and recombine to photons which make the gamma-ray burst. We study neutrino annihilation and show that a substantial fraction (~ 1/2) of energy deposited comes from inter-star neutrinos, where each member of the neutrino pair originates from each neutron star. Thus, in addition to the annihilation of neutrinos blowing off of a single star, we have a new source of baryon free energy that is deposited between the stars. To model the e+e- pair plasma wind between stars, we do three-dimensional relativistic numerical hydrodynamic calculations. Preliminary results are also presented of new, fully general relativistic calculations of gravitationally attracting stars falling from infinity with no angular momentum. These simulations exhibit a compression effect.

  5. Observing gamma-ray bursts with the scaler system of the HAWC Observatory

    NASA Astrophysics Data System (ADS)

    Lennarz, Dirk; Taboada, Ignacio

    2014-03-01

    The origin and acceleration mechanisms of gamma-ray bursts (GRBs) are important questions in contemporary astrophysics. Several models are competing to explain the recent observations at higher energies (HE, above ~ 20 MeV). The detection and temporal evolution of GRB emission at the highest energies (>~ 10 GeV) would have important implications for the GRB physics. The High Altitude Water Cherenkov (HAWC) observatory is a new very-high-energy (VHE, > 100 GeV) gamma-ray detector currently under construction at Sierra Negra in Mexico at an altitude of 4100 m above sea level. Unlike Imaging Atmospheric Cherenkov Telescopes, it has a large field of view and near 100% duty cycle that will allow for observations of the prompt GRB phase. HAWC has two data acquisition (DAQ) systems - one reading out full air-shower events (TDC-DAQ) and the other one counting the hits in each photomultiplier tube (scaler DAQ). GRB 130427A was the most energetic GRB so far detected at a redshift z < 0 . 5 . It featured an unprecedented long high-energy emission and the most energetic photon so far detected from a GRB. In this contribution the results of the scaler analysis of GRB 130427A and other GRBs of interest are shown.

  6. Focal Plane Detectors for the Advanced Gamma-Ray Imaging System (AGIS)

    SciTech Connect

    Otte, A. N.; Williams, D. A.; Byrum, K.; Drake, G.; Horan, D.; Smith, A.; Wagner, R. G.; Falcone, A.; Funk, S.; Tajima, H.; Mukherjee, R.

    2008-12-24

    The Advanced Gamma-Ray Imaging System (AGIS) is a concept for the next generation observatory in ground-based very high energy gamma-ray astronomy. Design goals are ten times better sensitivity, higher angular resolution, and a lower energy threshold than existing Cherenkov telescopes. Simulations show that a substantial improvement in angular resolution may be achieved if the pixel diameter is reduced to the order of 0.05 deg, i.e. two to three times smaller than the pixel diameter of current Cherenkov telescope cameras. At these dimensions, photon detectors with smaller physical dimensions can be attractive alternatives to the classical photomultiplier tube (PMT). Furthermore, the operation of an experiment with the size of AGIS requires photon detectors that are among other things more reliable, more durable, and possibly higher efficiency photon detectors. Alternative photon detectors we are considering for AGIS include both silicon photomultipliers (SiPMs) and multi-anode photomultipliers (MAPMTs). Here we present results from laboratory testing of MAPMTs and SiPMs along with results from the first incorporation of these devices into cameras on test bed Cherenkov telescopes.

  7. Is the Stellar System WR 11 a Gamma-Ray Source?

    NASA Astrophysics Data System (ADS)

    Benaglia, Paula

    2016-04-01

    Many early-type stars are in systems; some of them have been indicated as putative high-energy emitters. The radiation would be produced at the region where two stellar winds collide. Compelling evidence of such emission was found only for the colliding-wind binary (CWB) Eta Car, which was associated to a GeV source. Very recently, the closest CWB, WR 11, was proposed as a counterpart of a 6σ emission excess, measured with the Fermi LAT satellite. We sought evidence to support or reject the hypothesis that WR 11 is responsible of the gamma-ray excess. Archive radio interferometric data at 1.4 and 2.5 GHz taken with the Australia Telescope Compact Array along 16 dates were reduced. The sizes of the field-of-view at 2.5 GHz and of the central region of the Fermi LAT excess are alike. We analysed the emission of the WR 11 field, characterised the radio sources detected and derived their spectral indices, to investigate their nature. Eight sources with fluxes above 10 mJy were detected at both frequencies. All but one (WR 11) showed negative spectral indices. Four of them were identified with known objects, including WR 11. A fifth source, labeled here S6, is a promising candidate to produce gamma-ray emission, besides the CWB WR 11.

  8. Data acquisition system and ground calibration of polarized gamma-ray observer (PoGOLite)

    NASA Astrophysics Data System (ADS)

    Takahashi, Hiromitsu; Chauvin, Maxime; Fukazawa, Yasushi; Jackson, Miranda; Kamae, Tuneyoshi; Kawano, Takafumi; Kiss, Mozsi; Kole, Merlin; Mikhalev, Victor; Mizuno, Tsunefumi; Moretti, Elena; Pearce, Mark; Rydström, Stefan

    2014-07-01

    The Polarized Gamma-ray Observer, PoGOLite, is a balloon experiment with the capability of detecting 10% polarization from a 200 mCrab celestial object between the energy-range 25-80 keV in one 6 hour flight. Polarization measurements in soft gamma-rays are expected to provide a powerful probe into high-energy emission mechanisms in/around neutron stars, black holes, supernova remnants, active-galactic nuclei etc. The "pathfinder" flight was performed in July 2013 for 14 days from Sweden to Russia. The polarization is measured using Compton scattering and photoelectric absorption in an array of 61 well-type phoswich detector cells (PDCs) for the pathfinder instrument. The PDCs are surrounded by 30 BGO crystals which form a side anti-coincidence shield (SAS) and passive polyethylene neutron shield. There is a neutron detector consisting of LiCaAlF6 (LiCAF) scintillator covered with BGOs to measure the background contribution of atmospheric neutrons. The data acquisition system treats 92 PMT signals from 61 PDCs + 30 SASs + 1 neutron detector, and it is developed based on SpaceWire spacecraft communication network. Most of the signal processing is done by digital circuits in Field Programmable Gate Arrays (FPGAs). This enables the reduction of the mass, the space and the power consumption. The performance was calibrated before the launch.

  9. Development of a 3-dimensional dosimetry system for Leksell Gamma Knife Perfexion

    NASA Astrophysics Data System (ADS)

    Yoon, KyoungJun; Kwak, JungWon; Lee, DoHeui; Cho, ByungChul; Lee, SangWook; Ahn, SeungDo

    2015-07-01

    The purpose of our study is to develop a new, 3-dimensional dosimetry system to verify the accuracy of dose deliveries in Leksell Gamma Knife Perfexion (LGKP) (Elekta, Norcross, GA, USA). The instrument consists of a moving head phantom, an embedded thin active layer and a CCD camera system and was designed to be mounted to LGKP. As an active material concentrically located in the hemispheric head phantom, we choose Gafchromic EBT3 films and Gd2O2S:Tb phosphor sheets for dosimetric measurements. Also, to compensate for the lack of backscatter, we located a 1-cm-thick poly methyl methacrylate (PMMA) plate downstream of the active layer. The PMMA plate was transparent to scintillation light to reach the CCD with 1200 × 1200 pixels and a 5.2 µm pitch. With this system, 300 images with a 0.2-mm slice gap were acquired under each of three collimator setups, i.e. 4-mm, 8-mm, and 16-mm, respectively. The 2D projected images taken by the CCD camera were compared with the dose distributions measured by the EBT3 films under the same conditions. All 2D distributions were normalized to the maximum values derived by fitting peaks for each collimator setup. The differences in the full widths at half maximum (FWHM) of 2D profiles between CCD images and film doses were measured to be less than 0.3-mm. The scanning task for all peak regions took less than three minutes with the new instrument. So it can be utilized as a QA tool for the Gamma knife radiosurgery system instead of film dosimetry, the use of which requires much more time and many more resources.

  10. Roles of phosphatidylinositol 3-kinase and p38 mitogen-activated protein kinase in the regulation of protein kinase C-alpha activation in interferon-gamma-stimulated macrophages.

    PubMed

    Hardy, Pierre-Olivier; Diallo, Tamsir O; Matte, Christine; Descoteaux, Albert

    2009-09-01

    Members of the protein kinase C (PKC) family are activated by interferon-gamma (IFN-gamma) and modulate IFN-gamma-induced cellular responses by regulating the activity of transcription factors. We previously reported that PKC-alpha enhances the ability of IFN regulatory factor-1 to transactivate the class II transactivator (CIITA) promoter IV in IFN-gamma-stimulated macrophages. In addition, we showed that IFN-gamma induces the nuclear translocation of PKC-alpha but the mechanisms for this remain to be elucidated. In this study, we sought to identify signalling pathways involved in IFN-gamma-induced activation of PKC-alpha and to characterize their potential roles in modulating IFN-gamma-induced responses in macrophages. IFN-gamma-mediated nuclear translocation of PKC-alpha was a Janus activated kinase 2 (JAK2)-independent process, which required phosphatidylinositol 3-kinase (PI3K) and p38 mitogen-activated protein kinase (MAPK). However, PKC-alpha phosphorylation was independent of PI3K and p38 MAPK, indicating that IFN-gamma-induced phosphorylation and nuclear translocation of PKC-alpha are mediated by distinct mechanisms. In addition, inhibition of PI3K, but not of p38 MAPK, strongly impaired IFN-gamma-induced CIITA and MHC II gene expression. Finally, PKC-alpha associated with signal transducer and activator of transcription 1 (STAT1) and was required for the phosphorylation of STAT1 on serine 727 in IFN-gamma-stimulated macrophages. Taken together, our data indicate that PI3K and p38 MAPK modulate IFN-gamma-stimulated PKC-alpha nuclear translocation independently of JAK2 activity and that both PI3K and PKC-alpha are required for type IV CIITA and MHC II gene expression in IFN-gamma-stimulated macrophages.

  11. Interferon gamma regulates platelet endothelial cell adhesion molecule 1 expression and neutrophil infiltration into herpes simplex virus- infected mouse corneas

    PubMed Central

    1996-01-01

    In a mouse model of herpes simplex virus (HSV) 1 corneal infection, tissue destruction results from a CD4+ T cell-mediated chronic inflammation, in which interleukin 2 and interferon (IFN) gamma are requisite inflammatory mediators and polymorphonuclear leukocytes (PMN) are the predominant infiltrating cells. In vivo neutralization of IFN- gamma relieved inflammation at least in part through a specific block of PMN extravasation into HSV-1-infected corneas. Intercellular adhesion molecule (ICAM) 1 and platelet endothelial cell adhesion molecule (PECAM) 1 were upregulated on the vascular endothelium of inflamed corneas. Reduced PMN extravasation in anti-IFN-gamma-treated mice was associated with a dramatic reduction of PECAM-1 but not ICAM-1 expression on vascular endothelium. PMN accumulated in the lumen of corneal vessels after in vivo IFN-gamma neutralization. PECAM-1 was readily detectable on PMN inside the vessels but was not detectable on PMN that extravasated into the infected cornea. Moreover, flow cytometric analysis revealed reduced PECAM-1 expression but elevated major histocompatibility complex class I expression on PMN that recently extravasated into the peritoneal cavity when compared with PMN in the peripheral blood. We conclude that IFN-gamma contributes to HSV- 1-induced corneal inflammation by facilitating PMN infiltration; this appears to be accomplished through upregulation of PECAM-1 expression on the vascular endothelium; and PMN downregulate PECAM-1 expression during the process of extravasation. PMID:8879215

  12. Design, calibration, and application of an airborne gamma spectrometer system in Switzerland

    SciTech Connect

    Schwarz, G.F.; Rybach, L.; Klingele, E.E.

    1997-09-01

    Airborne radiometric surveys are finding increasingly wider application in environmental mapping and monitoring. They are the most efficient tool to delimit surface contamination and to locate lost radioactive sources. To secure radiometric capability in survey and emergency situations, a new sensitive airborne system has been built that includes an airborne spectrometer with 256 channels and a sodium iodide detector with a total volume of 16.8 liters. A rack-mounted PC with memory cards is used for data acquisition, with a GPS satellite navigation system for positioning. The system was calibrated with point sources using a mathematical correction to take into account the effects of gamma-ray scattering in the ground and in the atmosphere. The calibration was complemented by high precision ground gamma spectrometry and laboratory measurements on rock samples. In Switzerland, two major research programs make use of the capabilities of airborne radiometric measurements. The first one concerns nuclear power-plant monitoring. The five Swiss nuclear installations (four power plants and one research facility) and the surrounding regions of each site are surveyed annually. The project goal is to monitor the dose-rate distribution and to provide a documented baseline database. The measurements show that all sites (with the exception of the Goesgen power plant) can be identified clearly on the maps. No artificial radioactivity that could not be explained by the Chernobyl release or earlier nuclear weapons tests was detected outside of the fenced sites of the nuclear installations. The second program aims at a better evaluation of the natural radiation level in Switzerland. The survey focused on the crystalline rocks of the Central Massifs of the Swiss Alps because of their relatively high natural radioactivity and lithological variability.

  13. LYNX: An unattended sensor system for detection of gamma-ray and neutron emissions from special nuclear materials

    SciTech Connect

    Runkle, Robert C.; Myjak, Mitchell J.; Kiff, Scott D.; Sidor, Daniel E.; Morris, Scott J.; Rohrer, John S.; Jarman, Kenneth D.; Pfund, David M.; Todd, Lindsay C.; Bowler, Ryan S.; Mullen, Crystal A.

    2009-01-21

    This manuscript profiles an unattended and fully autonomous detection system sensitive to gamma-ray and neutron emissions from special nuclear material. The LYNX design specifically targets applications that require radiation detection capabilities but possess little or no infrastructure. In these settings, users need the capability to deploy sensors for extended periods of time that analyze whatever signal-starved data can be captured, since little or no control may be exerted over measurement conditions. The fundamental sensing elements of the LYNX system are traditional NaI(Tl) and 3He detectors. The new developments reported here center on two themes: low-power electronics and computationally simple analysis algorithms capable of discriminating gamma-ray signatures indicative of special nuclear materials from those of naturally occurring radioactive material. Incorporating tripwire-detection algorithms based on gamma-ray spectral signatures into a low-power electronics package significantly improves performance in environments where sensors encounter nuisance sources.

  14. Design and operation of gamma scan and fission gas sampling systems for characterization of irradiated commercial nuclear fuel

    SciTech Connect

    Knox, C.A.; Thornhill, R.E.; Mellinger, G.B.

    1989-09-01

    One of the primary objectives of the Materials Characterization Center (MCC) is to acquire and characterize spent fuels used in waste form testing related to nuclear waste disposal. The initial steps in the characterization of a fuel rod consist of gamma scanning the rod and sampling the gas contained in the fuel rod (referred to as fission gas sampling). The gamma scan and fission gas sampling systems used by the MCC are adaptable to a wide range of fuel types and have been successfully used to characterize both boiling water reactor (BWR) and pressurized water reactor (PWR) fuel rods. This report describes the design and operation of systems used to gamma scan and fission gas sample full-length PWR and BWR fuel rods. 1 ref., 10 figs., 1 tab.

  15. Regulation of immune responses in SJL and F1 hybrid mice by gamma-irradiated syngeneic lymphoma cells

    SciTech Connect

    Katz, I.R.; Nagase, F.; Bell, M.K.; Ponzio, N.M.; Thorbecke, G.J.

    1984-01-01

    Syngeneic mixed lymphocyte-stimulating la+ lymphomas of SJL mice (reticulum cell sarcoma(s) (RCS)) were found to modulate immune responses in vivo. Simultaneous injection of 2 X 10(7) gamma-irradiated or glutaraldehyde-fixed RCS cells with the antigen sheep red blood cells (SRBC) or 2,4,6-trinitrophenol (TNP)-Ficoll markedly suppressed the subsequent plaque-forming cell response in the spleen. The suppression of the anti-SRBC response was prevented by pretreatment of the mice with cyclophosphamide, whereas the suppression of the anti-TNP-Ficoll response was not affected. RCS injection induced high interferon serum titers within 24 hours after injection, which were not prevented by pretreatment with cyclophosphamide. Injection of gamma-irradiated RCS cells (gamma-RCS) or RCS cell extract 2 days prior to antigen enhanced the anti-SRBC but markedly suppressed the anti- TNP-Ficoll response. Injection of RCS both on day -2 and day 0 enhanced the anti-SRBC response. SJL mice 8-9 months of age showed much less or no suppression when gamma-RCS cells were injected on day 0. Certain F1 hybrids of SJL also showed the gamma-RCS-induced suppression of the anti-SRBC response. Suppression was seen in SJL X BALB.B but not in SJL X BALB/c mice and in SJL X A.TH but not in SJL X A.TL mice, suggesting an I-region effect. F1 hybrids of SJL by B10 background mice showed no significant suppression. Enhancement of the anti-SRBC response by prior injection of gamma-RCS was seen in all F1 hybrid mice examined.

  16. Mobile neutron/gamma waste assay system for characterization of waste containing transuranics, uranium, and fission/activation products

    SciTech Connect

    Davidson, D.R.; Haggard, D.; Lemons, C.

    1994-12-31

    A new integrated neutron/gamma assay system has been built for measuring 55-gallon drums at Pacific Northwest Laboratory. The system is unique because it allows simultaneous measurement of neutrons and gamma-rays. This technique also allows measurement of transuranics (TRU), uranium, and fission/activation products, screening for shielded Special Nuclear Material prior to disposal, and critically determinations prior to transportation. The new system is positioned on a platform with rollers and installed inside a trailer or large van to allow transportation of the system to the waste site instead of movement of the drums to the scanner. The ability to move the system to the waste drums is particularly useful for drum retrieval programs common to all DOE sites and minimizes transportation problems on the site. For longer campaigns, the system can be moved into a facility. The mobile system consists of two separate subsystems: a passive Segmented Gamma Scanner (SGS) and a {open_quotes}clam-shell{close_quotes} passive neutron counter. The SGS with high purity germanium detector and {sup 75}Se transmission source simultaneously scan the height of the drum allowing identification of unshieled {open_quotes}hot spots{close_quotes} in the drum or segments where the matrix is too dense for the transmission source to penetrate. Dense segments can flag shielding material that could be used to hide plutonium or uranium during the gamma analysis. The passive nuetron counter with JSR-12N Neutron Coincidence Analyzer measures the coincident neutrons from the spontaneous fission of even isotopes of plutonium. Because high-density shielding produces minimal absorption of neutrons, compared to gamma rays, the passive neutron portion of the system can detect shielded SNM. Measurements to evaluate the performance of the system are still underway at Pacific Northwest Laboratory.

  17. A quality survey on different shielding configurations of gamma ray detector used with a portable PGNAA system

    NASA Astrophysics Data System (ADS)

    Bayat, E.; Afarideh, H.; Davani, F. Abbasi; Ghal-Eh, N.

    2016-03-01

    The appropriate gamma-ray detector shielding configuration is critical for a precise prompt gamma neutron activation analysis (PGNAA) measurement. The shielding material has to prevent the radiation damage to the detector crystal and it must produce less activation gamma rays, whether prompt or delayed, which may interfere the gamma ray spectrum of the sample. In this research, using common shielding materials, a number of combinations have been studies to form a 50 cm long shield for portable PGNAA system against both fast and slow neutrons as well as gamma rays emitted by 20Ci Am-Be source. The measurement results show that in contrast with conventional shadow cone in which the shielding material starts with 20 cm heavy metals such as iron and ends with 30 cm polymer materials, in portable PGNAA systems, the shielding material gives better results if it starts with about 40 cm borated polymer material and ends with an appropriate thickness (7 cm to 10 cm) of heavy metal such as tungsten.

  18. Preservation of mucosal and systemic adjuvant properties of ISCOMS in the absence of functional interleukin-4 or interferon-gamma.

    PubMed Central

    Smith, R E; Donachie, A M; McLaren, F H; Mowat, A M

    1998-01-01

    Adjuvants are a critical component of non-viable vaccine vectors, particularly for those to be used via mucosal routes. Although most adjuvants act by inducing local inflammatory responses, the molecular basis of many of these effects is unclear. Here we have investigated whether interleukin-4 (IL-4) and interferon-gamma (IFN-gamma) are required for the induction of local and systemic immune responses by oral and parenteral administration of ovalbumin (OVA) in immune stimulating complexes (ISCOMS), a potent mucosal adjuvant vector. Our results show that after oral or systemic immunization with OVA ISCOMS, IL-4 knockout (IL4KO) and IFN-gamma receptor knockout (IFN-gamma RKO) mice develop an entirely normal range of immune responses including delayed-type hypersensitivity (DTH), serum immunoglobulin G (IgG) antibodies, T-cell proliferation and cytokine production, class I major histocompatibility complex (MHC)-restricted cytotoxic T lymphocyte (CTL) activity and intestinal IgA antibodies. These responses were of a similar magnitude to those found in the wild-type mice, indicating that the immunogenicity of ISCOMS is not influenced by the presence of IL-4 or IFN-gamma and emphasizing the potential of ISCOMS as widely applicable mucosal adjuvants. PMID:9659229

  19. Low-frequency switching voltage regulators for terrestrial photovoltaic systems

    NASA Technical Reports Server (NTRS)

    Delombard, R.

    1984-01-01

    The photovoltaic technology project and the stand alone applications project are discussed. Two types of low frequency switching type regulators were investigated. The design, operating characteristics and field application of these regulators is described. The regulators are small in size, low in cost, very low in power dissipation, reliable and allow considerable flexibility in system design.

  20. Sialyltransferase regulates nervous system function in Drosophila

    PubMed Central

    Repnikova, Elena; Koles, Kate; Nakamura, Michiko; Pitts, Jared; Li, Haiwen; Ambavane, Apoorva; Zoran, Mark J.; Panin, Vladislav M.

    2012-01-01

    In vertebrates, sialylated glycans participate in a wide range of biological processes and affect nervous system’s development and function. While the complexity of glycosylation and the functional redundancy among sialyltransferases provide obstacles for revealing biological roles of sialylation in mammals, Drosophila possesses a sole vertebrate-type sialyltransferase, DSiaT, with significant homology to its mammalian counterparts, suggesting that Drosophila could be a suitable model to investigate the function of sialylation. To explore this possibility and investigate the role of sialylation in Drosophila, we inactivated DSiaT in vivo by gene targeting and analyzed phenotypes of DSiaT mutants using a combination of behavioural, immunolabeling, electrophysiological and pharmacological approaches. Our experiments demonstrated that DSiaT expression is restricted to a subset of CNS neurons throughout development. We found that DSiaT mutations result in significantly decreased life span, locomotor abnormalities, temperature-sensitive paralysis and defects of neuromuscular junctions. Our results indicate that DSiaT regulates neuronal excitability and affects the function of a voltage-gated sodium channel. Finally, we showed that sialyltransferase activity is required for DSiaT function in vivo, which suggests that DSiaT mutant phenotypes result from a defect in sialylation of N-glycans. This work provided the first evidence that sialylation has an important biological function in protostomes, while also revealing a novel, nervous system-specific function of α2,6 sialylation. Thus, our data shed light on one of the most ancient functions of sialic acids in metazoan organisms and suggest a possibility that this function is evolutionarily conserved between flies and mammals. PMID:20445073

  1. Systems analysis evaluation of gamma-ray detectors for remote monitoring applications

    SciTech Connect

    Antolak, A.J.; Lund, J.C.; Lamonds, H.A.; James, R.B.; Hinton, J.; Thomas, G.

    1996-12-31

    Because of the large number of different gamma-ray detectors available, including both scintillation and semiconductor types, extensive analysis may be required to determine which detector system is optimal for a given application. In the selection of detectors for remote monitoring of nuclear materials, a methodology has been developed to assess which detectors are best suited for this application. The analysis provides a numerical ranking of the performance of each detector thereby reducing the large set of all potential detectors to a small tractable set of most promising candidates. The basis for the evaluation will be discussed, along with the application of the methodology to a wide range of scintillator and semiconductor detector materials. The most promising scintillator and semiconductor materials are identified for remote monitoring applications.

  2. MONICA: a compact, portable dual gamma camera system for mouse whole-body imaging

    SciTech Connect

    Xi, Wenze; Seidel, Jurgen; Kakareka, John W.; Pohida, Thomas J.; Milenic, Diane E.; Proffitt, James; Majewski, Stan; Weisenberger, Andrew G.; Green, Michael V.; Choyke, Peter L.

    2010-04-01

    Introduction We describe a compact, portable dual-gamma camera system (named "MONICA" for MObile Nuclear Imaging CAmeras) for visualizing and analyzing the whole-body biodistribution of putative diagnostic and therapeutic single photon emitting radiotracers in animals the size of mice. Methods Two identical, miniature pixelated NaI(Tl) gamma cameras were fabricated and installed ?looking up? through the tabletop of a compact portable cart. Mice are placed directly on the tabletop for imaging. Camera imaging performance was evaluated with phantoms and field performance was evaluated in a weeklong In-111 imaging study performed in a mouse tumor xenograft model. Results Tc-99m performance measurements, using a photopeak energy window of 140 keV?10%, yielded the following results: spatial resolution (FWHM at 1 cm), 2.2 mm; sensitivity, 149 cps (counts per seconds)/MBq (5.5 cps/μCi); energy resolution (FWHM, full width at half maximum), 10.8%; count rate linearity (count rate vs. activity), r2=0.99 for 0?185 MBq (0?5 mCi) in the field of view (FOV); spatial uniformity, <3% count rate variation across the FOV. Tumor and whole-body distributions of the In-111 agent were well visualized in all animals in 5-min images acquired throughout the 168-h study period. Conclusion Performance measurements indicate that MONICA is well suited to whole-body single photon mouse imaging. The field study suggests that inter-device communications and user-oriented interfaces included in the MONICA design facilitate use of the system in practice. We believe that MONICA may be particularly useful early in the (cancer) drug development cycle where basic whole-body biodistribution data can direct future development of the agent under study and where logistical factors, e.g., limited imaging space, portability and, potentially, cost are important.

  3. MONICA: A Compact, Portable Dual Gamma Camera System for Mouse Whole-Body Imaging

    PubMed Central

    Xi, Wenze; Seidel, Jurgen; Karkareka, John W.; Pohida, Thomas J.; Milenic, Diane E.; Proffitt, James; Majewski, Stan; Weisenberger, Andrew G.; Green, Michael V.; Choyke, Peter L.

    2009-01-01

    Introduction We describe a compact, portable dual-gamma camera system (named “MONICA” for MObile Nuclear Imaging CAmeras) for visualizing and analyzing the whole-body biodistribution of putative diagnostic and therapeutic single photon emitting radiotracers in animals the size of mice. Methods Two identical, miniature pixelated NaI(Tl) gamma cameras were fabricated and installed “looking up” through the tabletop of a compact portable cart. Mice are placed directly on the tabletop for imaging. Camera imaging performance was evaluated with phantoms and field performance was evaluated in a weeklong In-111 imaging study performed in a mouse tumor xenograft model. Results Tc-99m performance measurements, using a photopeak energy window of 140 keV ± 10%, yielded the following results: spatial resolution (FWHM at 1-cm), 2.2-mm; sensitivity, 149 cps/MBq (5.5 cps/μCi); energy resolution (FWHM), 10.8%; count rate linearity (count rate vs. activity), r2 = 0.99 for 0–185 MBq (0–5 mCi) in the field-of-view (FOV); spatial uniformity, < 3% count rate variation across the FOV. Tumor and whole-body distributions of the In-111 agent were well visualized in all animals in 5-minute images acquired throughout the 168-hour study period. Conclusion Performance measurements indicate that MONICA is well suited to whole-body single photon mouse imaging. The field study suggests that inter-device communications and user-oriented interfaces included in the MONICA design facilitate use of the system in practice. We believe that MONICA may be particularly useful early in the (cancer) drug development cycle where basic whole-body biodistribution data can direct future development of the agent under study and where logistical factors, e.g. limited imaging space, portability, and, potentially, cost are important. PMID:20346864

  4. Differential expression of key regulators of Toll-like receptors in ulcerative colitis and Crohn's disease: a role for Tollip and peroxisome proliferator-activated receptor gamma?

    PubMed

    Fernandes, P; MacSharry, J; Darby, T; Fanning, A; Shanahan, F; Houston, A; Brint, E

    2016-03-01

    The innate immune system is currently seen as the probable initiator of events which culminate in the development of inflammatory bowel disease (IBD) with Toll-like receptors (TLRs) known to be involved in this disease process. Many regulators of TLRs have been described, and dysregulation of these may also be important in the pathogenesis of IBD. The aim of this study was to perform a co-ordinated analysis of the expression levels of both key intestinal TLRs and their inhibitory proteins in the same IBD cohorts, both ulcerative colitis (UC) and Crohn's disease (CD), in order to evaluate the potential roles of these proteins in the pathogenesis of IBD. Of the six TLRs (TLRs 1, 2, 4, 5, 6 and 9) examined, only TLR-4 was increased significantly in IBD, specifically in active UC. In contrast, differential alterations in expression of TLR inhibitory proteins were observed. A20 and suppressor of cytokine signalling 1 (SOCS1) were increased only in active UC while interleukin-1 receptor-associated kinase 1 (IRAK-m) and B cell lymphoma 3 protein (Bcl-3) were increased in both active UC and CD. In contrast, expression of both peroxisome proliferator-activated receptor gamma (PPARγ) and Toll interacting protein (Tollip) was decreased in both active and inactive UC and CD and at both mRNA and protein levels. In addition, expression of both PPARγ and A20 expression was increased by stimulation of a colonic epithelial cell line Caco-2 with both TLR ligands and commensal bacterial strains. These data suggest that IBD may be associated with distinctive changes in TLR-4 and TLR inhibitory proteins, implying that alterations in these may contribute to the pathogenesis of IBD.

  5. The Advanced Gamma-ray Imaging System (AGIS)--Science Highlights

    SciTech Connect

    Buckley, J.; Krawczynski, H.; Coppi, P.; Digel, S.; Funk, S.; Krennrich, F.; Pohl, M.; Romani, R.; Vassiliev, V.

    2008-12-24

    The Advanced Gamma-ray Imaging System (AGIS), a future gamma-ray telescope consisting of an array of {approx}50 atmospheric Cherenkov telescopes distributed over an area of {approx}1 km{sup 2}, will provide a powerful new tool for exploring the high-energy universe. The order-of-magnitude increase in sensitivity and improved angular resolution could provide the first detailed images of {gamma}-ray emission from other nearby galaxies or galaxy clusters. The large effective area will provide unprecedented sensitivity to short transients (such as flares from AGNs and GRBs) probing both intrinsic spectral variability (revealing the details of the acceleration mechanism and geometry) as well as constraining the high-energy dispersion in the velocity of light (probing the structure of spacetime and Lorentz invariance). A wide field of view ({approx}4 times that of current instruments) and excellent angular resolution (several times better than current instruments) will allow for an unprecedented survey of the Galactic plane, providing a deep unobscured survey of SNRs, X-ray binaries, pulsar-wind nebulae, molecular cloud complexes and other sources. The differential flux sensitivity of {approx}10{sup -13} erg cm{sup -2} sec{sup -1} will rival the most sensitive X-ray instruments for these extended Galactic sources. The excellent capabilities of AGIS at energies below 100 GeV will provide sensitivity to AGN and GRBs out to cosmological redshifts, increasing the number of AGNs detected at high energies from about 20 to more than 100, permitting population studies that will provide valuable insights into both a unified model for AGN and a detailed measurement of the effects of intergalactic absorption from the diffuse extragalactic background light. A new instrument with fast-slewing wide-field telescopes could provide detections of a number of long-duration GRBs providing important physical constraints from this new spectral component. The new array will also have excellent

  6. A transportable high-resolution gamma-ray spectrometer and analysis system applicable to mobile, autonomous or unattended applications

    SciTech Connect

    Buckley, W.M.; Neufeld, K.W.

    1995-07-01

    The Safeguards Technology Program at the Lawrence Livermore National Laboratory is developing systems based on a compact electro-mechanically cooled high-purity germanium (HPGe) detector. This detector system broadens the practicality of performing high- resolution gamma-ray spectrometry in the field. Utilizing portable computers, multi-channel analyzers and software these systems greatly improve the ease of performing mobile high-resolution gamma-ray spectrometry. Using industrial computers, we can construct systems that will run autonomously for extended periods of time without operator input or maintenance. These systems can start or make decisions based on sensor inputs rather than operator interactions. Such systems can provide greater capability for wider domain of safeguards, treaty verification application, and other unattended, autonomous or in-situ applications.

  7. Characterization of HPGe gamma spectrometric detectors systems for Instrumental Neutron Activation Analysis (INAA) at the Colombian Geological Survey

    NASA Astrophysics Data System (ADS)

    Sierra, O.; Parrado, G.; Cañón, Y.; Porras, A.; Alonso, D.; Herrera, D. C.; Peña, M.; Orozco, J.

    2016-07-01

    This paper presents the progress made by the Neutron Activation Analysis (NAA) laboratory at the Colombian Geological Survey (SGC in its Spanish acronym), towards the characterization of its gamma spectrometric systems for Instrumental Neutron Activation Analysis (INAA), with the aim of introducing corrections to the measurements by variations in sample geometry. Characterization includes the empirical determination of the interaction point of gamma radiation inside the Germanium crystal, through the application of a linear model and the use of a fast Monte Carlo N-Particle (MCNP) software to estimate correction factors for differences in counting efficiency that arise from variations in sample density between samples and standards.

  8. Study of scattered photons from the collimator system of Leksell Gamma Knife using the EGS4 Monte Carlo Code

    SciTech Connect

    Cheung, Joel Y.C.; Yu, K.N.

    2006-01-15

    In the algorithm of Leksell GAMMAPLAN (the treatment planning software of Leksell Gamma Knife), scattered photons from the collimator system are presumed to have negligible effects on the Gamma Knife dosimetry. In this study, we used the EGS4 Monte Carlo (MC) technique to study the scattered photons coming out of the single beam channel of Leksell Gamma Knife. The PRESTA (Parameter Reduced Electron-Step Transport Algorithm) version of the EGS4 (Electron Gamma Shower version 4) MC computer code was employed. We simulated the single beam channel of Leksell Gamma Knife with the full geometry. Primary photons were sampled from within the {sup 60}Co source and radiated isotropically in a solid angle of 4{pi}. The percentages of scattered photons within all photons reaching the phantom space using different collimators were calculated with an average value of 15%. However, this significant amount of scattered photons contributes negligible effects to single beam dose profiles for different collimators. Output spectra were calculated for the four different collimators. To increase the efficiency of simulation by decreasing the semiaperture angle of the beam channel or the solid angle of the initial directions of primary photons will underestimate the scattered component of the photon fluence. The generated backscattered photons from within the {sup 60}Co source and the beam channel also contribute to the output spectra.

  9. Small Field of View Scintimammography Gamma Camera Integrated to a Stereotactic Core Biopsy Digital X-ray System

    SciTech Connect

    Andrew Weisenberger; Fernando Barbosa; T. D. Green; R. Hoefer; Cynthia Keppel; Brian Kross; Stanislaw Majewski; Vladimir Popov; Randolph Wojcik

    2002-10-01

    A small field of view gamma camera has been developed for integration with a commercial stereotactic core biopsy system. The goal is to develop and implement a dual-modality imaging system utilizing scintimammography and digital radiography to evaluate the reliability of scintimammography in predicting the malignancy of suspected breast lesions from conventional X-ray mammography. The scintimammography gamma camera is a custom-built mini gamma camera with an active area of 5.3 cm /spl times/ 5.3 cm and is based on a 2 /spl times/ 2 array of Hamamatsu R7600-C8 position-sensitive photomultiplier tubes. The spatial resolution of the gamma camera at the collimator surface is < 4 mm full-width at half-maximum and a sensitivity of /spl sim/ 4000 Hz/mCi. The system is also capable of acquiring dynamic scintimammographic data to allow for dynamic uptake studies. Sample images of preliminary clinical results are presented to demonstrate the performance of the system.

  10. Experimental investigation of silicon photomultipliers as compact light readout systems for gamma-ray spectroscopy applications in fusion plasmas

    SciTech Connect

    Nocente, M. Gorini, G.; Fazzi, A.; Lorenzoli, M.; Pirovano, C.; Tardocchi, M.; Cazzaniga, C.; Rebai, M.; Uboldi, C.; Varoli, V.

    2014-11-15

    A matrix of Silicon Photo Multipliers has been developed for light readout from a large area 1 in. × 1 in. LaBr{sub 3} crystal. The system has been characterized in the laboratory and its performance compared to that of a conventional photo multiplier tube. A pulse duration of 100 ns was achieved, which opens up to spectroscopy applications at high counting rates. The energy resolution measured using radioactive sources extrapolates to 3%–4% in the energy range E{sub γ} = 3–5 MeV, enabling gamma-ray spectroscopy measurements at good energy resolution. The results reported here are of relevance in view of the development of compact gamma-ray detectors with spectroscopy capabilities, such as an enhanced gamma-ray camera for high power fusion plasmas, where the use of photomultiplier is impeded by space limitation and sensitivity to magnetic fields.

  11. Gamma aminobutyric acid B and 5-hydroxy tryptamine 2A receptors functional regulation during enhanced liver cell proliferation by GABA and 5-HT chitosan nanoparticles treatment.

    PubMed

    Shilpa, Joy; Pretty, Mary Abraham; Anitha, Malat; Paulose, Cheramadathikudyil Skaria

    2013-09-05

    Liver is one of the major organs in vertebrates and hepatocytes are damaged by many factors. The liver cell maintenance and multiplication after injury and treatment gained immense interest. The present study investigated the role of Gamma aminobutyric acid (GABA) and serotonin or 5-hydroxytryptamine (5-HT) coupled with chitosan nanoparticles in the functional regulation of Gamma aminobutyric acid B and 5-hydroxy tryptamine 2A receptors mediated cell signaling mechanisms, extend of DNA methylation and superoxide dismutase activity during enhanced liver cell proliferation. Liver injury was achieved by partial hepatectomy of male Wistar rats and the GABA and 5-HT chitosan nanoparticles treatments were given intraperitoneally. The experimental groups were sham operated control (C), partially hepatectomised rats with no treatment (PHNT), partially hepatectomised rats with GABA chitosan nanoparticle (GCNP), 5-HT chitosan nanoparticle (SCNP) and a combination of GABA and 5-HT chitosan nanoparticle (GSCNP) treatments. In GABA and 5-HT chitosan nanoparticle treated group there was a significant decrease (P<0.001) in the receptor expression of Gamma aminobutyric acid B and a significant increase (P<0.001) in the receptor expression of 5-hydroxy tryptamine 2A when compared to PHNT. The cyclic adenosine monophosphate content and its regulatory protein, presence of methylated DNA and superoxide dismutase activity were decreased in GCNP, SCNP and GSCNP when compared to PHNT. The Gamma aminobutyric acid B and 5-hydroxy tryptamine 2A receptors coupled signaling elements played an important role in GABA and 5-HT chitosan nanoparticles induced liver cell proliferation which has therapeutic significance in liver disease management.

  12. Developing Self-Regulated Learners through an Intelligent Tutoring System

    ERIC Educational Resources Information Center

    Kelly, Kim; Heffernan, Neil

    2015-01-01

    Intelligent tutoring systems have been developed to help students learn independently. However, students who are poor self-regulated learners often struggle to use these systems because they lack the skills necessary to learn independently. The field of psychology has extensively studied self-regulated learning and can provide strategies to…

  13. Production and interferon-gamma-mediated regulation of complement component C2 and factors B and D by the astroglioma cell line U105-MG.

    PubMed Central

    Barnum, S R; Ishii, Y; Agrawal, A; Volanakis, J E

    1992-01-01

    In this paper, we demonstrate the synthesis of the complement component C2 and factors B and D by the human astroglioma cell line U105-MG. All three components were structurally and antigenically similar to their serum counterparts, as determined by biosynthetic labelling studies or Western blot analysis. Northern blot analysis demonstrated that the mRNAs of all three components had the same apparent sizes as the equivalent mRNAs from hepatocyte and monocyte cell lines. Interestingly, U105-MG cells produce two C2 transcripts with sizes of approximately 2.8 and 2.3 kb. Interferon-gamma (IFN-gamma) enhanced the expression of C2 and factor B mRNA and protein in a dose- and time-dependent fashion, while factor D expression was refractory to IFN-gamma. IFN-gamma appeared to predominantly enhance the expression of the large (2.8 kb) C2 transcript. Kinetic studies demonstrated peak C2 and factor B expression in 48 h in response to IFN-gamma, similar to the acute-phase response of factor B in serum. These data are the first to demonstrate the synthesis of C2 and factor D by astroglioma cells. Combined with previous reports documenting the synthesis of C3 by astrocytes, our data suggest that endogenous synthesis of complement proteins, and particularly of alternative pathway activation components (C3, factors B and D), may play an important role in host defence in the central nervous system. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 5. Fig. 6. PMID:1445220

  14. Gamma-ray pulse height spectrum analysis on systems with multiple Ge detectors using spectrum summing

    SciTech Connect

    Killian, E.W.

    1997-11-01

    A technique has been developed at the Idaho National Engineering Laboratory to sum high resolution gamma-ray pulse spectra from systems with multiple Ge detectors. Lockheed Martin Idaho Technologies Company operates a multi-detector spectrometer configuration at the Stored Waste Examination Pilot Plant facility which is used to characterize the radionuclide contents in waste drums destined for shipment to Waste Isolation Pilot Plant. This summing technique was developed to increase the sensitivity of the system, reduce the count times required to properly quantify the radio-nuclides and provide a more consistent methodology for combining data collected from multiple detectors. In spectrometer systems with multiple detectors looking at non homogeneous waste forms it is often difficult to combine individual spectrum analysis results from each detector to obtain a meaningful result for the total waste container. This is particularly true when the counting statistics in each individual spectrum are poor. The spectrum summing technique adds the spectra collected by each detector into a single spectrum which has better counting statistics than each individual spectrum. A normal spectral analysis program can then be used to analyze the sum spectrum to obtain radio-nuclide values which have smaller errors and do not have to be further manipulated to obtain results for the total waste container. 2 refs., 2 figs.

  15. Analysis of effective capacity for free-space optical communication systems over gamma-gamma turbulence channels with pointing errors

    NASA Astrophysics Data System (ADS)

    Yang, You-quan; Chi, Xue-fen; Shi, Jia-lin; Zhao, Lin-lin

    2015-05-01

    To facilitate the efficient support of quality-of-service (QoS) for promising free-space optical (FSO) communication systems, it is essential to model and analyze FSO channels in terms of delay QoS. However, most existing works focus on the average capacity and outage capacity for FSO, which are not enough to characterize the effective transmission data rate when delay-sensitive service is applied. In this paper, the effective capacity of FSO communication systems under statistical QoS provisioning constraints is investigated to meet heterogeneous traffic demands. A novel closed-form expression for effective capacity is derived under the combined effects of atmospheric turbulence conditions, pointing errors, beam widths, detector sizes and QoS exponents. The obtained results reveal the effects of some significant parameters on effective capacity, which can be used for the design of FSO systems carrying a wide range of services with diverse QoS requirements.

  16. Evidence for an Inducible Repair-Recombination System in the Female Germ Line of Drosophila Melanogaster. I. Induction by Inhibitors of Nucleotide Synthesis and by Gamma Rays

    PubMed Central

    Bregliano, J. C.; Laurencon, A.; Degroote, F.

    1995-01-01

    In the I-R system of hybrid dysgenesis in Drosophila melanogaster, the transposition frequency of I factor, a LINE element-like retrotransposon, is regulated by the reactivity level of the R mother. This reactivity is a cellular state maternally inherited but chromosomally determined, which has been shown to undergo heritable, cumulative and reversible changes with aging and some environmental conditions. We propose the hypothesis that this reactivity level is one manifestation of an inducible repair-recombination system whose biological role might be analogous to the SOS response in bacteria. In this paper, we show that inhibitors of DNA synthesis and gamma rays enhance the reactivity level in a very similar way. This enhancement is heritable, cumulative and reversible. PMID:8647393

  17. Size effects on the open probability of two-state ion channel system in cell membranes using microcanonical formalism based on gamma function

    NASA Astrophysics Data System (ADS)

    Erdem, Riza; Aydiner, Ekrem

    2016-08-01

    Ion channel systems are a class of proteins that reside in the membranes of all biological cells and forms conduction pores that regulate the transport of ions into and out of cells. They can be investigated theoretically in the microcanonical formalism since the number of accessible states can be easily evaluated by using the Stirling approximation to deal with factorials. In this work, we have used gamma function (Γ (n)) to solve the two-state or open-close channel model without any approximation. New values are calculated for the open probability (p0) and the relative error between our numerical results and the approximate one using Stirling formula is presented. This error (p0 app — p0)/p0 is significant for small channel systems.

  18. Up-regulated MHC-class II expression and gamma-IFN and soluble IL-2R in lupus nephritis.

    PubMed

    Yokoyama, H; Takabatake, T; Takaeda, M; Wada, T; Naito, T; Ikeda, K; Goshima, S; Takasawa, K; Tomosugi, N; Kobayashi, K

    1992-09-01

    Expression of MHC-class II molecules (HLA-DR and -DQ), serum gamma-interferon (gamma-IFN) and soluble interleukin-2 receptor (sIL-2R) levels were studied in 35 Japanese patients with lupus nephritis (LN) to clarify intraglomerular cellular activation and cytokine involvement in human LN. In 11 normal kidney specimens, HLA-DR(Ia1) was noted in glomerular tufts, but HLA-DQ was either not or was faintly detected in glomeruli by the indirect immunofluorescence technique. HLA-DR and -DQ were observed mainly on the surface of glomerular endothelial cells in 100% and 50% of 28 lupus kidney specimens except for necrotic or sclerotic lesions. HLA-DQ was expressed in a high incidence of 67%, 86% in patients with proliferative LN (WHO Class III-IV) and active lesions, respectively. Serum gamma-IFN and sIL-2R levels were 1.2 +/- 0.2 U/ml and 190 +/- 24 U/ml (mean +/- SEM; N = 30) in normal controls, and elevated in patients with proliferative LN (4.1 +/- 1.0 U/ml, 383 +/- 81 U/ml, N = 25), especially with active lesions (6.2 +/- 1.5 U/ml, 500 +/- 110 U/ml, N = 14). Overall, glomerular lesions such as HLA-DQ expression, the activity index and leukocyte infiltration correlated positively with serum gamma-IFN levels (r = 0.55; P less than 0.01 for HLA-DQ, r = 0.68; P less than 0.001 for activity index, r = 0.38; P less than 0.05 for leukocyte infiltration), but not with serum sIL-2R levels, anti-DNA antibody titers and CH50 titers.(ABSTRACT TRUNCATED AT 250 WORDS)

  19. Robustness properties of discrete time regulators, LOG regulators and hybrid systems

    NASA Technical Reports Server (NTRS)

    Stein, G.; Athans, M.

    1979-01-01

    Robustness properites of sample-data LQ regulators are derived which show that these regulators have fundamentally inferior uncertainty tolerances when compared to their continuous-time counterparts. Results are also presented in stability theory, multivariable frequency domain analysis, LQG robustness, and mathematical representations of hybrid systems.

  20. A reform in the helium purification system of the HTR-10: gamma dose rate measurement and suggestions for decommissioning

    SciTech Connect

    Feng Xie; Hong Li; Jianzhu Cao; Suyuan Yu; Liguo Zhang; Wenqian Li; Sheng Fang

    2013-07-01

    A reform will be implemented in the helium purification system of the 10 MW High Temperature Gas-cooled Test Reactor (HTR-10) in China. The measurement of the gamma dose rates of facilities, including valves, pipes, dust filter, etc., in the purification system of the HTR-10, has been performed. The results indicated that most radiation nuclides are concentrated in the dust filter and facilities at the entrance of the helium purification system upstream of the dust filter. Other facilities have the same gamma dose rate level as the background. Based on the previous study and experiences in AVR, the measurement results can be understood that the radioactive dust carried by the helium gas was filtered by the dust filter. It provides important insights for the decontamination and decommissioning of facilities in the primary loop, especially in the helium purification system of the HTR-10 as well as the High Temperature Reactor-Pebble bed Modules (HTR-PM). (authors)

  1. Radiation Exposure During Head Repositioning With the Automatic Positioning System for Gamma Knife Radiosurgery

    SciTech Connect

    Watanabe, Yoichi . E-mail: watan016@umn.edu; Gerbi, Bruce J.

    2007-07-15

    Purpose: To measure radiation exposure to a patient during head repositioning with the automatic positioning system (APS) for Gamma Knife radiosurgery. Methods and Materials: A 16-cm diameter spherical solid phantom, provided by the manufacturer, was mounted to the APS unit using a custom-made holder. A small-volume ionization chamber (0.07-cm{sup 3} volume) was placed at the center of the phantom. We recorded the temporal variation of ionization current during the entire treatment. Measurements were made for 3 test cases and 7 clinical cases. Results: The average transit time between successive shots, during which the APS unit was moving the phantom for repositioning the shot coordinates, was 20.5 s for 9 cases. The average dose rate, which was measured at the center of the phantom and at a point outside the shot location, was 0.36 {+-} 0.09 cGy/min when the beam output was approximately 3.03 Gy/min for the 18-mm collimator helmet. Hence, the additional intracranial radiation dose during the APS-driven head repositioning between two successive shots (or APS transit dose) was 0.12 {+-} 0.050 cGy. The APS transit dose was independent of the helmet size and the position of shots within the phantom relative to the measurement point. Conclusion: The head repositioning with the APS system adds a small but not negligible dose to the dose expected for the manual repositioning method.

  2. Reflight of the Gamma-Ray Arcminute Telescope Imaging System (GRATIS) Payload

    NASA Technical Reports Server (NTRS)

    Hailey, Charles J.

    2000-01-01

    The Gamma-Ray Arcminute Telescope Imaging System (GRATIS) balloon payload was prepared for reflight. This involved repair of damage caused in the previous flight to structural members of the payload (the gondola support structure) as well as damage to some of the pointing system elements and electronics modules. This work was successfully completed. An extensive pre-calibration of the CsI(Na) imaging detectors was then done. The plan was to take several months to calibrate the 36 detectors and to compare the results with the post-calibration from the previous flight in Alice Springs Australia. During the course of the pre-calibrations it was noted that the light output of the crystals was severely degraded in more than half the detectors compared to the values recorded 1.5 years earlier. Subsequent investigation revealed that the light yield degradation was not unreasonable. The CsI crystals had in fact performed well past their rated life from hygroscopic contamination. The crystals had spent the majority of their life either in the desert or in the extremely low humidity conditions of Livermore California. where the GRATIS payload had been based prior to transfer to Columbia. The extreme summer humidity of New York simply exacerbated a degradation process that had been artificially delayed by dry conditions. Because such a large part of the detector array had been degraded we did not feel it was appropriate to refly the payload because the scientific performance would have been compromised.

  3. Design And Implementation Of A Fiber-Optic Gamma-Measurement System

    NASA Astrophysics Data System (ADS)

    Reedy, R. P.; Crawford, D. W.; Roeske, F.

    1980-10-01

    The planning of scientific field experiments that use delicate optical instrumentation poses a challenge to the designer. At the U.S. atomic test site in Nevada, many experiments are conducted under the most adverse conditions for instrumentation, including extremes of temperature and dust, while the instruments are being installed, aligned, and tested above ground. They are subjected to mechanical shock while being lowered into place deep underground and during the back-filling process. Before being destroyed by the blast, they then must operate in intense radiation fields long enough to transmit their data to a recording station. In this paper we present the design and implementation of the "downhole" portion of a measuring system for gamma rays. Included are three alternative designs for radiation-resistant collimating and condensing lenses, sample cells, turning mirrors, and fiber-optic termination techniques. Also discussed are mechan-ical mounts and positioners, shielding, alignment, test methods, and field installation. Some general design suggestions for optical systems in adverse environments are also presented.

  4. Gamma-Ray Signal from the Pulsar Wind in the Binary Pulsar System PSR B1259-63/LS 2883

    NASA Astrophysics Data System (ADS)

    Khangulyan, Dmitry; Aharonian, Felix A.; Bogovalov, Sergey V.; Ribó, Marc

    2011-12-01

    Binary pulsar systems emit potentially detectable components of gamma-ray emission due to Comptonization of the optical radiation of the companion star by relativistic electrons of the pulsar wind, both before and after termination of the wind. The recent optical observations of binary pulsar system PSR B1259-63/LS 2883 revealed radiation properties of the companion star which differ significantly from previous measurements. In this paper, we study the implications of these observations for the interaction rate of the unshocked pulsar wind with the stellar photons and the related consequences for fluxes of high energy and very high energy (VHE) gamma rays. We show that the signal should be strong enough to be detected with Fermi close to the periastron passage, unless the pulsar wind is strongly anisotropic or the Lorentz factor of the wind is smaller than 103 or larger than 105. The higher luminosity of the optical star also has two important implications: (1) attenuation of gamma rays due to photon-photon pair production and (2) Compton drag of the unshocked wind. While the first effect has an impact on the light curve of VHE gamma rays, the second effect may significantly decrease the energy available for particle acceleration after termination of the wind.

  5. GAMMA-RAY SIGNAL FROM THE PULSAR WIND IN THE BINARY PULSAR SYSTEM PSR B1259-63/LS 2883

    SciTech Connect

    Khangulyan, Dmitry; Bogovalov, Sergey V.; Ribo, Marc E-mail: felix.aharonian@dias.ie E-mail: mribo@am.ub.es

    2011-12-01

    Binary pulsar systems emit potentially detectable components of gamma-ray emission due to Comptonization of the optical radiation of the companion star by relativistic electrons of the pulsar wind, both before and after termination of the wind. The recent optical observations of binary pulsar system PSR B1259-63/LS 2883 revealed radiation properties of the companion star which differ significantly from previous measurements. In this paper, we study the implications of these observations for the interaction rate of the unshocked pulsar wind with the stellar photons and the related consequences for fluxes of high energy and very high energy (VHE) gamma rays. We show that the signal should be strong enough to be detected with Fermi close to the periastron passage, unless the pulsar wind is strongly anisotropic or the Lorentz factor of the wind is smaller than 10{sup 3} or larger than 10{sup 5}. The higher luminosity of the optical star also has two important implications: (1) attenuation of gamma rays due to photon-photon pair production and (2) Compton drag of the unshocked wind. While the first effect has an impact on the light curve of VHE gamma rays, the second effect may significantly decrease the energy available for particle acceleration after termination of the wind.

  6. Elucidating the regulation of complex signalling systems in plant cells.

    PubMed

    Liu, Junli; Lindsey, Keith; Hussey, Patrick J

    2014-02-01

    The pollen tube represents a model system for the study of tip growth, and the root provides a valuable system to study gene and signalling networks in plants. In the present article, using the two systems as examples, we discuss how to elucidate the regulation of complex signalling systems in plant cells. First, we discuss how hormones and related genes in plant root development form a complex interacting network, and their activities are interdependent. Therefore their roles in root development must be analysed as an integrated system, and elucidation of the regulation of each component requires the adaptation of a novel modelling methodology: regulation analysis. Secondly, hydrodynamics, cell wall and ion dynamics are all important properties that regulate plant cell growth. We discuss how regulation analysis can be applied to study the regulation of hydrodynamics, cell wall and ion dynamics, using pollen tube growth as a model system. Finally, we discuss future prospects for elucidating the regulation of complex signalling systems in plant cells.

  7. Gamma ray transients

    NASA Technical Reports Server (NTRS)

    Cline, Thomas L.

    1987-01-01

    The discovery of cosmic gamma ray bursts was made with systems designed at Los Alamos Laboratory for the detection of nuclear explosions beyond the atmosphere. HELIOS-2 was the first gamma ray burst instrument launched; its initial results in 1976, seemed to deepen the mystery around gamma ray transients. Interplanetary spacecraft data were reviewed in terms of explaining the behavior and source of the transients.

  8. Evaluation of a digital data acquisition system and optimization of n-{gamma} discrimination for a compact neutron spectrometer

    SciTech Connect

    Giacomelli, L.; Zimbal, A.; Reginatto, M.; Tittelmeier, K.

    2011-01-15

    A compact NE213 liquid scintillation neutron spectrometer with a new digital data acquisition (DAQ) system is now in operation at the Physikalisch-Technische Bundesanstalt (PTB). With the DAQ system, developed by ENEA Frascati, neutron spectrometry with high count rates in the order of 5x10{sup 5} s{sup -1} is possible, roughly an order of magnitude higher than with an analog acquisition system. To validate the DAQ system, a new data analysis code was developed and tests were done using measurements with 14-MeV neutrons made at the PTB accelerator. Additional analysis was carried out to optimize the two-gate method used for neutron and gamma (n-{gamma}) discrimination. The best results were obtained with gates of 35 ns and 80 ns. This indicates that the fast and medium decay time components of the NE213 light emission are the ones that are relevant for n-{gamma} discrimination with the digital acquisition system. This differs from what is normally implemented in the analog pulse shape discrimination modules, namely, the fast and long decay emissions of the scintillating light.

  9. Design of Dual-Road Transportable Portal Monitoring System for Visible Light and Gamma-Ray Imaging

    SciTech Connect

    Karnowski, Thomas Paul; Cunningham, Mark F; Goddard Jr, James Samuel; Cheriyadat, Anil M; Hornback, Donald Eric; Fabris, Lorenzo; Kerekes, Ryan A; Ziock, Klaus-Peter; Bradley, Eric Craig; Chesser, Joel B; Marchant, William

    2010-01-01

    The use of radiation sensors as portal monitors is increasing due to heightened concerns over the smuggling of fissile material. Transportable systems that can detect significant quantities of fissile material that might be present in vehicular traffic are of particular interest, especially if they can be rapidly deployed to different locations. To serve this application, we have constructed a rapid-deployment portal monitor that uses visible-light and gamma-ray imaging to allow simultaneous monitoring of multiple lanes of traffic from the side of a roadway. The system operation uses machine vision methods on the visible-light images to detect vehicles as they enter and exit the field of view and to measure their position in each frame. The visible-light and gamma-ray cameras are synchronized which allows the gamma-ray imager to harvest gamma-ray data specific to each vehicle, integrating its radiation signature for the entire time that it is in the field of view. Thus our system creates vehicle-specific radiation signatures and avoids source confusion problems that plague non-imaging approaches to the same problem. Our current prototype instrument was designed for measurement of upto five lanes of freeway traffic with a pair of instruments, one on either side of the roadway. Stereoscopic cameras are used with a third alignment camera for motion compensation and are mounted on a 50 deployable mast. In this paper we discuss the design considerations for the machine-vision system, the algorithms used for vehicle detection and position estimates, and the overall architecture of the system. We also discuss system calibration for rapid deployment. We conclude with notes on preliminary performance and deployment.

  10. PPAR{gamma} activation abolishes LDL-induced proliferation of human aortic smooth muscle cells via SOD-mediated down-regulation of superoxide

    SciTech Connect

    Heo, Kyung-Sun; Kim, Dong-Uk; Ryoo, Sungwoo; Nam, Miyoung; Baek, Seung Tae; Kim, Lila; Park, Song-Kyu; Myung, Chang-Seon; Hoe, Kwang-Lae . E-mail: kwanghoe@kribb.re.kr

    2007-08-10

    Native LDL would be a mitogenic and chemotactic stimulus of VSMC proliferation and differentiation in the atherosclerotic lesion where endothelial disruption occurred. In previous studies, our group investigated the molecular mechanisms by which LDL induces IL-8 production and by which PPAR{alpha} activation abolishes LDL effects in human aortic SMCs (hAoSMCs). Herein is the first report of PPAR{gamma} activation by troglitazone (TG) exerting its inhibitory effects on LDL-induced cell proliferation via generation not of H{sub 2}O{sub 2}, but of O2?-, and the subsequent activation of Erk1/2 in hAoSMCs. Moreover, in this study TG abolished the LDL-accelerated G{sub 1}-S progression to control levels via down-regulation of active cyclinD1/CDK4 and cyclinE/CDK2 complexes and up-regulation of p21{sup Cip1} expression. TG exerted its anti-proliferative effects through the up-regulation of basal superoxide dismutase (SOD) expression. This data suggests that the regulation of O2?- is located at the crossroads between LDL signaling and cell proliferation.

  11. An integrated systems approach for understanding cellular responses to gamma radiation.

    PubMed

    Whitehead, Kenia; Kish, Adrienne; Pan, Min; Kaur, Amardeep; Reiss, David J; King, Nichole; Hohmann, Laura; DiRuggiero, Jocelyne; Baliga, Nitin S

    2006-01-01

    Cellular response to stress entails complex mRNA and protein abundance changes, which translate into physiological adjustments to maintain homeostasis as well as to repair and minimize damage to cellular components. We have characterized the response of the halophilic archaeon Halobacterium salinarum NRC-1 to (60)Co ionizing gamma radiation in an effort to understand the correlation between genetic information processing and physiological change. The physiological response model we have constructed is based on integrated analysis of temporal changes in global mRNA and protein abundance along with protein-DNA interactions and evolutionarily conserved functional associations. This systems view reveals cooperation among several cellular processes including DNA repair, increased protein turnover, apparent shifts in metabolism to favor nucleotide biosynthesis and an overall effort to repair oxidative damage. Further, we demonstrate the importance of time dimension while correlating mRNA and protein levels and suggest that steady-state comparisons may be misleading while assessing dynamics of genetic information processing across transcription and translation.

  12. Computer assisted gamma and X-ray tomography: Applications to multiphase flow systems

    SciTech Connect

    Kumar, S.B.; Dudukovic, M.

    1998-01-01

    In process vessels, involving two or three phases it is often important not only to know the volume fraction (holdup) of each phase but also the spatial distribution of such holdups. This information is needed in control, trouble shooting and assessment of flow patterns and can be observed noninvasively by the application of Computed Tomography (CT). This report presents a complete overview of X-ray and gamma ray transmission tomography principles, equipment design to specific tasks and application in process industry. The fundamental principles of tomography, the algorithms for image reconstruction, the measurement method and the possible sources of error are discussed in detail. A case study highlights the methodology involved in designing a scanning system for the study of a given process unit, e.g., reactor, separations column etc. Results obtained in the authors` laboratory for the gas holdup distribution in bubble columns are also presented. Recommendations are made for the Advanced Fuels Development Unit (AFDU) in LaPorte, TX.

  13. A dual neutron/gamma source for the Fissmat Inspection for Nuclear Detection (FIND) system.

    SciTech Connect

    Doyle, Barney Lee; King, Michael; Rossi, Paolo; McDaniel, Floyd Del; Morse, Daniel Henry; Antolak, Arlyn J.; Provencio, Paula Polyak; Raber, Thomas N.

    2008-12-01

    Shielded special nuclear material (SNM) is very difficult to detect and new technologies are needed to clear alarms and verify the presence of SNM. High-energy photons and neutrons can be used to actively interrogate for heavily shielded SNM, such as highly enriched uranium (HEU), since neutrons can penetrate gamma-ray shielding and gamma-rays can penetrate neutron shielding. Both source particles then induce unique detectable signals from fission. In this LDRD, we explored a new type of interrogation source that uses low-energy proton- or deuteron-induced nuclear reactions to generate high fluxes of mono-energetic gammas or neutrons. Accelerator-based experiments, computational studies, and prototype source tests were performed to obtain a better understanding of (1) the flux requirements, (2) fission-induced signals, background, and interferences, and (3) operational performance of the source. The results of this research led to the development and testing of an axial-type gamma tube source and the design/construction of a high power coaxial-type gamma generator based on the {sup 11}B(p,{gamma}){sup 12}C nuclear reaction.

  14. TNF-alpha, but not IFN-gamma, regulates CCN2 (CTGF), collagen type I, and proliferation in mesangial cells: possible roles in the progression of renal fibrosis.

    PubMed

    Cooker, Laurinda A; Peterson, Darryl; Rambow, Joann; Riser, Melisa L; Riser, Rebecca E; Najmabadi, Feridoon; Brigstock, David; Riser, Bruce L

    2007-07-01

    Connective tissue growth factor (CCN2) is a profibrotic factor acting downstream and independently of TGF-beta to mediate renal fibrosis. Although inflammation is often involved in the initiation and/or progression of fibrosis, the role of inflammatory cytokines in regulation of glomerular CCN2 expression, cellular proliferation, and extracellular matrix accumulation is unknown. We studied two such cytokines, TNF-alpha and IFN-gamma, for their effects on cultured mesangial cells in the presence or absence of TGF-beta, as a model for progressive renal fibrosis. Short-term treatment with TNF-alpha, like TGF-beta, significantly increased secreted CCN2 per cell, but unlike TGF-beta inhibited cellular replication. TNF-alpha combined with TGF-beta further increased CCN2 secretion and mRNA levels and reduced proliferation. Surprisingly, however, TNF-alpha treatment decreased baseline collagen type I protein and mRNA levels and largely blocked their stimulation by TGF-beta. Long-term treatment with TGF-beta or TNF-alpha alone no longer increased CCN2 protein levels. However, the combination synergistically increased CCN2. IFN-gamma had no effect on either CCN2 or collagen activity and produced a mild inhibition of TGF-beta-induced collagen only at a high concentration (500 U/ml). In summary, we report a strong positive regulatory role for TNF-alpha, but not IFN-gamma, in CCN2 production and secretion, including that driven by TGF-beta. The stimulation of CCN2 release by TNF-alpha, unlike TGF-beta, is independent of cellular proliferation and not linked to increased collagen type I accumulation. This suggests that the paradigm of TGF-beta-driven CCN2 with subsequent collagen production may be overridden by an as yet undefined inhibitory mechanism acting either directly or indirectly on matrix metabolism.

  15. HWMA/RCRA Closure Plan for the TRA Fluorinel Dissolution Process Mockup and Gamma Facilities Waste System

    SciTech Connect

    K. Winterholler

    2007-01-31

    This Hazardous Waste Management Act/Resource Conservation and Recovery Act closure plan was developed for the Test Reactor Area Fluorinel Dissolution Process Mockup and Gamma Facilities Waste System, located in Building TRA-641 at the Reactor Technology Complex (RTC), Idaho National Laboratory Site, to meet a further milestone established under the Voluntary Consent Order SITE-TANK-005 Action Plan for Tank System TRA-009. The tank system to be closed is identified as VCO-SITE-TANK-005 Tank System TRA-009. This closure plan presents the closure performance standards and methods for achieving those standards.

  16. Increased expression of CCL18, CCL19, and CCL17 by dendritic cells from patients with rheumatoid arthritis, and regulation by Fc gamma receptors

    PubMed Central

    Radstake, T; van der Voort, R; ten, B; de Waal, Malefijt M; Looman, M; Figdor, C; van den Berg, W B; Barrera, P; Adema, G

    2005-01-01

    Background: Dendritic cells (DC) have a role in the regulation of immunity and tolerance, attracting inflammatory cells by the production of various chemokines (CK). Fc gamma receptors (FcγR) may be involved in regulation of the DC function. Objective: To assess the expression of CK by immature (iDC) and mature DC (mDC) and its regulation by FcγR in patients with RA and healthy donors (HC). Methods: Expression of CK by DC from patients with RA and from HC was determined by real time quantitative PCR and ELISA. DC were derived from monocytes following standardised protocols. To study the potential regulation by FcγR, iDC were stimulated with immune complexes (IC) during lipopolysaccharide (LPS) induced maturation. The presence of CK was studied in synovial tissue from patients with RA, osteoarthritis, and healthy subjects by RT-PCR and immunohistochemistry. Results: iDC from patients with RA had markedly increased mRNA levels of the CK CCL18 and CXCL8. Upon maturation with LPS, expression of CCL18, CCL19, CXCL8, CCL3, and CCL17 increased dramatically, reaching significantly higher levels in patients with RA. Monocytes failed to express these CK, except for CXCL8 and CCL3. IC-mediated triggering of the FcγR on DC from patients with highly active RA down regulated all CK, whereas the reverse was seen when DC from patients with low disease activity and healthy donors were stimulated. CCL18 was significantly increased in RA synovial tissue. Conclusion: Increased CK expression by DC was found in patients with RA. This expression is partly regulated by FcγR triggering and results in an inhibitory DC subtype in RA upon FcγR-mediated triggering. PMID:15331393

  17. Characterization of system-related geometric distortions in MR images employed in Gamma Knife radiosurgery applications

    NASA Astrophysics Data System (ADS)

    Pappas, E. P.; Seimenis, I.; Moutsatsos, A.; Georgiou, E.; Nomikos, P.; Karaiskos, P.

    2016-10-01

    This work provides characterization of system-related geometric distortions present in MRIs used in Gamma Knife (GK) stereotactic radiosurgery (SRS) treatment planning. A custom-made phantom, compatible with the Leksell stereotactic frame model G and encompassing 947 control points (CPs), was utilized. MR images were obtained with and without the frame, thus allowing discrimination of frame-induced distortions. In the absence of the frame and following compensation for field inhomogeneities, measured average CP disposition owing to gradient nonlinearities was 0.53 mm. In presence of the frame, contrarily, detected distortion was greatly increased (up to about 5 mm) in the vicinity of the frame base due to eddy currents induced in the closed loop of its aluminum material. Frame-related distortion was obliterated at approximately 90 mm from the frame base. Although the region with the maximum observed distortion may not lie within the GK treatable volume, the presence of the frame results in distortion of the order of 1.5 mm at a 7 cm distance from the center of the Leksell space. Additionally, severe distortions observed outside the treatable volume could possibly impinge on the delivery accuracy mainly by adversely affecting the registration process (e.g. the position of the lower part of the N-shaped fiducials used to define the stereotactic space may be miss-registered). Images acquired with a modified version of the frame developed by replacing its front side with an acrylic bar, thus interrupting the closed aluminum loop and reducing the induced eddy currents, were shown to benefit from relatively reduced distortion. System-related distortion was also identified in patient MR images. Using corresponding CT angiography images as a reference, an offset of 1.1 mm was detected for two vessels lying in close proximity to the frame base, while excellent spatial agreement was observed for a vessel far apart from the frame base.

  18. Efficacy of Recombinant Gamma Interferon for Treatment of Systemic Cryptococcosis in SCID Mice

    PubMed Central

    Clemons, Karl V.; Lutz, Jon E.; Stevens, David A.

    2001-01-01

    We have previously shown that gamma interferon (IFN-γ) is a useful adjunct to therapy of experimental systemic cryptococcosis in normal mice. To better emulate AIDS patients, SCID mice were infected intravenously with Cryptococcus neoformans. Mice received no therapy, 3 mg of amphotericin B (AmB) per kg of body weight, or 105 U of IFN-γ alone (prophylactically and therapeutically or only therapeutically) or with AmB. In the first experiment, >75% of the mice survived. Therapy with AmB alone was efficacious compared to no therapy in all organs. Both regimens of IFN-γ alone were efficacious in the brain and lungs, and the combination of AmB and IFN-γ showed significant synergy in the kidneys. AmB alone cured 40% of mice of infection, whereas the combination regimens cured >50% of the mice and 90% of the brain infections. In a second study, IFN-γ again proved efficacious alone, and when given with AmB its efficacy was improved. Therapeutic IFN-γ alone was effective only in the liver compared to no therapy, and the combination regimen, although highly effective, showed no significant synergy. In a third experiment, AmB alone or in combination with IFN-γ prolonged survival compared to no therapy or IFN-γ alone. The combination regimen showed significant synergy over AmB alone in the brain, liver, kidneys, and lungs. AmB alone cured no mice of infections in more than two organs, whereas AmB in combination with IFN-γ cured 55% of infections in three or more organs. These results indicate that IFN-γ has therapeutic efficacy in severely immunodeficient animals, especially in combination with AmB. Significant synergistic activity was noted in all organs except the spleen. Overall, IFN-γ has utility as an adjunctive therapy against systemic cryptococcosis in the severely immunocompromised host. PMID:11181343

  19. Numerical Simulation of Tubular Pumping Systems with Different Regulation Methods

    NASA Astrophysics Data System (ADS)

    Zhu, Honggeng; Zhang, Rentian; Deng, Dongsheng; Feng, Xusong; Yao, Linbi

    2010-06-01

    Since the flow in tubular pumping systems is basically along axial direction and passes symmetrically through the impeller, most satisfying the basic hypotheses in the design of impeller and having higher pumping system efficiency in comparison with vertical pumping system, they are being widely applied to low-head pumping engineering. In a pumping station, the fluctuation of water levels in the sump and discharge pool is most common and at most time the pumping system runs under off-design conditions. Hence, the operation of pump has to be flexibly regulated to meet the needs of flow rates, and the selection of regulation method is as important as that of pump to reduce operation cost and achieve economic operation. In this paper, the three dimensional time-averaged Navier-Stokes equations are closed by RNG κ-ɛ turbulent model, and two tubular pumping systems with different regulation methods, equipped with the same pump model but with different designed system structures, are numerically simulated respectively to predict the pumping system performances and analyze the influence of regulation device and help designers make final decision in the selection of design schemes. The computed results indicate that the pumping system with blade-adjusting device needs longer suction box, and the increased hydraulic loss will lower the pumping system efficiency in the order of 1.5%. The pumping system with permanent magnet motor, by means of variable speed regulation, obtains higher system efficiency partly for shorter suction box and partly for different structure design. Nowadays, the varied speed regulation is realized by varied frequency device, the energy consumption of which is about 3˜4% of output power of the motor. Hence, when the efficiency of variable frequency device is considered, the total pumping system efficiency will probably be lower.

  20. Use of a Shielded High Resolution Gamma Spectrometry System to Segregate LLW from Contact Handleable ILW Containing Plutonium - 13046

    SciTech Connect

    Lester, Rosemary; Wilkins, Colin; Chard, Patrick; Jaederstroem, Henrik; LeBlanc, Paul; Mowry, Rick; MacDonald, Sanders; Gunn, William

    2013-07-01

    Dounreay Site Restoration Limited (DSRL) have a number of drums of solid waste that may contain Plutonium Contaminated Material. These are currently categorised as Contact Handleable Intermediate Level Waste (CHILW). A significant fraction of these drums potentially contain waste that is in the Low Level Waste (LLW) category. A Canberra Q2 shielded high resolution gamma spectrometry system is being used to quantify the total activity of drums that are potentially in the LLW category in order to segregate those that do contain LLW from CHILW drums and thus to minimise the total volume of waste in the higher category. Am-241 is being used as an indicator of the presence of plutonium in the waste from its strong 59.54 keV gamma-ray; a knowledge of the different waste streams from which the material originates allows a pessimistic waste 'fingerprint' to be used in order to determine an upper limit to the activities of the weak and non-gamma-emitting plutonium and associated radionuclides. This paper describes the main features of the high resolution gamma spectrometry system being used by DSRL to perform the segregation of CHILW and LLW and how it was configured and calibrated using the Canberra In-Situ Object Counting System (ISOCS). It also describes how potential LLW drums are selected for assay and how the system uses the existing waste stream fingerprint information to determine a reliable upper limit for the total activity present in each measured drum. Results from the initial on-site commissioning trials and the first measurements of waste drums using the new monitor are presented. (authors)

  1. Clinical research regulation: challenges to the institutional review board system.

    PubMed

    Straight, Timothy M

    2009-01-01

    The system in place to ensure the ethical conduct of human subject research in accordance with federal regulations has drawn great criticism from all sides, to include clinical investigators, administrators, research subjects, and legislators. The administrative requirements associated with clinical trials has changed dramatically in the last several decades, as has the complexity of the science being regulated. The institutional review board (IRB) system, however, appears to be struggling to keep pace, and has even been labeled a "system in jeopardy" by a national committee of experts. This contribution outlines the current obstacles and critique of IRBs, providing a discussion of the structure of the IRB system and strategies to meet these challenges.

  2. Dual-head gamma camera system for intraoperative localization of radioactive seeds

    NASA Astrophysics Data System (ADS)

    Arsenali, B.; de Jong, H. W. A. M.; Viergever, M. A.; Dickerscheid, D. B. M.; Beijst, C.; Gilhuijs, K. G. A.

    2015-10-01

    Breast-conserving surgery is a standard option for the treatment of patients with early-stage breast cancer. This form of surgery may result in incomplete excision of the tumor. Iodine-125 labeled titanium seeds are currently used in clinical practice to reduce the number of incomplete excisions. It seems likely that the number of incomplete excisions can be reduced even further if intraoperative information about the location of the radioactive seed is combined with preoperative information about the extent of the tumor. This can be combined if the location of the radioactive seed is established in a world coordinate system that can be linked to the (preoperative) image coordinate system. With this in mind, we propose a radioactive seed localization system which is composed of two static ceiling-suspended gamma camera heads and two parallel-hole collimators. Physical experiments and computer simulations which mimic realistic clinical situations were performed to estimate the localization accuracy (defined as trueness and precision) of the proposed system with respect to collimator-source distance (ranging between 50 cm and 100 cm) and imaging time (ranging between 1 s and 10 s). The goal of the study was to determine whether or not a trueness of 5 mm can be achieved if a collimator-source distance of 50 cm and imaging time of 5 s are used (these specifications were defined by a group of dedicated breast cancer surgeons). The results from the experiments indicate that the location of the radioactive seed can be established with an accuracy of 1.6 mm  ±  0.6 mm if a collimator-source distance of 50 cm and imaging time of 5 s are used (these experiments were performed with a 4.5 cm thick block phantom). Furthermore, the results from the simulations indicate that a trueness of 3.2 mm or less can be achieved if a collimator-source distance of 50 cm and imaging time of 5 s are used (this trueness was achieved for all 14 breast phantoms which

  3. Derivation of a Multiparameter Gamma Model for Analyzing the Residence-Time Distribution Function for Nonideal Flow Systems as an Alternative to the Advection-Dispersion Equation

    DOE PAGES

    Embry, Irucka; Roland, Victor; Agbaje, Oluropo; ...

    2013-01-01

    A new residence-time distribution (RTD) function has been developed and applied to quantitative dye studies as an alternative to the traditional advection-dispersion equation (AdDE). The new method is based on a jointly combined four-parameter gamma probability density function (PDF). The gamma residence-time distribution (RTD) function and its first and second moments are derived from the individual two-parameter gamma distributions of randomly distributed variables, tracer travel distance, and linear velocity, which are based on their relationship with time. The gamma RTD function was used on a steady-state, nonideal system modeled as a plug-flow reactor (PFR) in the laboratory to validate themore » effectiveness of the model. The normalized forms of the gamma RTD and the advection-dispersion equation RTD were compared with the normalized tracer RTD. The normalized gamma RTD had a lower mean-absolute deviation (MAD) (0.16) than the normalized form of the advection-dispersion equation (0.26) when compared to the normalized tracer RTD. The gamma RTD function is tied back to the actual physical site due to its randomly distributed variables. The results validate using the gamma RTD as a suitable alternative to the advection-dispersion equation for quantitative tracer studies of non-ideal flow systems.« less

  4. Representation of Cognitive Reappraisal Goals in Frontal Gamma Oscillations

    PubMed Central

    Kang, Jae-Hwan; Jeong, Ji Woon; Kim, Hyun Taek; Kim, Sang Hee; Kim, Sung-Phil

    2014-01-01

    Recently, numerous efforts have been made to understand the neural mechanisms underlying cognitive regulation of emotion, such as cognitive reappraisal. Many studies have reported that cognitive control of emotion induces increases in neural activity of the control system, including the prefrontal cortex and the dorsal anterior cingulate cortex, and increases or decreases (depending upon the regulation goal) in neural activity of the appraisal system, including the amygdala and the insula. It has been hypothesized that information about regulation goals needs to be processed through interactions between the control and appraisal systems in order to support cognitive reappraisal. However, how this information is represented in the dynamics of cortical activity remains largely unknown. To address this, we investigated temporal changes in gamma band activity (35–55 Hz) in human electroencephalograms during a cognitive reappraisal task that was comprised of three reappraisal goals: to decease, maintain, or increase emotional responses modulated by affect-laden pictures. We examined how the characteristics of gamma oscillations, such as spectral power and large-scale phase synchronization, represented cognitive reappraisal goals. We found that left frontal gamma power decreased, was sustained, or increased when the participants suppressed, maintained, or amplified their emotions, respectively. This change in left frontal gamma power appeared during an interval of 1926 to 2453 ms after stimulus onset. We also found that the number of phase-synchronized pairs of gamma oscillations over the entire brain increased when participants regulated their emotions compared to when they maintained their emotions. These results suggest that left frontal gamma power may reflect cortical representation of emotional states modulated by cognitive reappraisal goals and gamma phase synchronization across whole brain regions may reflect emotional regulatory efforts to achieve these goals

  5. Regulation of early endocytic vesicle motility and fission in a reconstituted system.

    PubMed

    Bananis, Eustratios; Murray, John W; Stockert, Richard J; Satir, Peter; Wolkoff, Allan W

    2003-07-01

    We previously established conditions to reconstitute kinesin-dependent early endocytic vesicle motility and fission on microtubules in vitro. The present study examined the question whether motility and fission are regulated in this system. Screening for proteins by immunofluorescence microscopy revealed that the small G protein, Rab4, was associated with 80% of hepatocyte-derived early endocytic vesicles that contain the ligand asialoorosomucoid (ASOR). By contrast, other markers for early endocytic vesicles including clathrin, Rab5 and EEA1 were present in the preparation but did not colocalize with the ASOR vesicles. Guanine nucleotides exchanged into the Rab4 present on the vesicles as shown by solubilization of Rab4 by Rab-GDI; solubilization was inhibited by incubation with GTP-gamma-S and promoted by GDP. Pre-incubation of vesicles with GDP increased the number of vesicles moving on microtubules and markedly increased vesicle fission. This increase in motility from GDP was shown to be towards the minus end of microtubules, possibly through activation of the minus-end-directed kinesin, KIFC2. Pre-incubation of vesicles with GTP-gamma-S, by contrast, repressed motility. Addition of exogenous GST-Rab4- GTP-gamma-S led to a further repression of motility and fission. Repression was not seen with addition of GST-Rab4-GDP. Treatment of vesicles with Rab4 antibody also repressed motility, and repression was not seen when vesicles were pre-incubated with GDP. Based on these results we hypothesize that endogenous Rab4-GTP suppresses motility of ASOR-containing vesicles in hepatocytes and that conversion of Rab4-GTP to Rab4-GDP serves as a molecular switch that activates minus-end kinesin-based motility, facilitating early endosome fission and consequent receptor-ligand segregation.

  6. Resonance production in. gamma gamma. collisions

    SciTech Connect

    Renard, F.M.

    1983-04-01

    The processes ..gamma gamma.. ..-->.. hadrons can be depicted as follows. One photon creates a q anti q pair which starts to evolve; the other photon can either (A) make its own q anti q pair and the (q anti q q anti q) system continue to evolve or (B) interact with the quarks of the first pair and lead to a modified (q anti q) system in interaction with C = +1 quantum numbers. A review of the recent theoretical activity concerning resonance production and related problems is given under the following headings: hadronic C = +1 spectroscopy (q anti q, qq anti q anti q, q anti q g, gg, ggg bound states and mixing effects); exclusive ..gamma gamma.. processes (generalities, unitarized Born method, VDM and QCD); total cross section (soft and hard contributions); q/sup 2/ dependence of soft processes (soft/hard separation, 1/sup +- +/ resonances); and polarization effects. (WHK)

  7. SU-E-T-117: Analysis of the ArcCHECK Dosimetry Gamma Failure Using the 3DVH System

    SciTech Connect

    Cho, S; Choi, W; Lee, H; Yoon, J; Lee, E; Park, K; Keum, K

    2015-06-15

    Purpose: To evaluate gamma analysis failure for the VMAT patient specific QA using ArcCHECK cylindrical phantom. The 3DVH system(Sun Nuclear, FL) was used to analyze the dose difference statistic between measured dose and treatment planning system calculated dose. Methods: Four case of gamma analysis failure were selected retrospectively. Our institution gamma analysis indexes were absolute dose, 3%/3mm and 90%pass rate in the ArcCHECK dosimetry. The collapsed cone convolution superposition (CCCS) dose calculation algorithm for VMAT was used. Dose delivery was performed with Elekta Agility. The A1SL(standard imaging, WI) and cavity plug were used for point dose measurement. Delivery QA plans and images were used for 3DVH Reference data instead of patient plan and image. The measured data of ‘.txt’ file was used for comparison at diodes to acquire a global dose level. The,.acml’ file was used for AC-PDP and to calculated point dose. Results: The global dose of 3DVH was calculated as 1.10 Gy, 1.13, 1.01 and 0.2 Gy respectively. The global dose of 0.2 Gy case was induced by distance discrepancy. The TPS calculated point dose of was 2.33 Gy to 2.77 Gy and 3DVH calculated dose was 2.33 Gy to 2.68 Gy. The maximum dose differences were −2.83% and −3.1% for TPS vs. measured dose and TPS vs. 3DVH calculated respectively in the same case. The difference between measured and 3DVH was 0.1% in that case. The 3DVH gamma pass rate was 98% to 99.7%. Conclusion: We found the TPS calculation error by 3DVH calculation using ArcCHECK measured dose. It seemed that our CCCS algorithm RTP system over estimated at the central region and underestimated scattering at the peripheral diode detector point. The relative gamma analysis and point dose measurement would be recommended for VMAT DQA in the gamma failure case of ArcCHECK dosimetry.

  8. Signal regulators of systemic acquired resistance

    PubMed Central

    Gao, Qing-Ming; Zhu, Shifeng; Kachroo, Pradeep; Kachroo, Aardra

    2015-01-01

    Salicylic acid (SA) is an important phytohormone that plays a vital role in a number of physiological responses, including plant defense. The last two decades have witnessed a number of breakthroughs related to biosynthesis, transport, perception and signaling mediated by SA. These findings demonstrate that SA plays a crictical role in both local and systemic defense responses. Systemic acquired resistance (SAR) is one such SA-dependent response. SAR is a long distance signaling mechanism that provides broad spectrum and long-lasting resistance to secondary infections throughout the plant. This unique feature makes SAR a highly desirable trait in crop production. This review summarizes the recent advances in the role of SA in SAR and discusses its relationship to other SAR inducers. PMID:25918514

  9. [Regulation of allergy by innate immune system].

    PubMed

    Kumagai, Yutaro; Akira, Shizuo

    2009-11-01

    Allergy is an immune disease including asthma. Activation of Th2 response, such as production of IL-4, IL-5 and IL-13 from CD4+ T cells and IgG1 or IgE from B cells is responsible for allergy. Activation of acquired immune system requires preceding activation of innate immunity, therefore innate immunity may control Th2 response and allergy. Recent studies revealed that dendritic cells, epithelial cells, and basophils play central roles in the initiation of Th2 response. In this review, we will summarize the current understanding on the control of Th2 and allergic responses by innate immune system, and discuss recent findings on house dust mite-induced allergic response based on these understandings.

  10. The brain endocannabinoid system in the regulation of energy balance.

    PubMed

    Richard, Denis; Guesdon, Benjamin; Timofeeva, Elena

    2009-02-01

    The role played by the endocannabinoid system in the regulation of energy balance is currently generating a great amount of interest among several groups of investigators. This interest in large part comes from the urgent need to develop anti-obesity and anti-cachexia drugs around target systems (such as the endocannabinoid system), which appears to be genuinely involved in energy balance regulation. When activated, the endocannabinoid system favors energy deposition through increasing energy intake and reducing energy expenditure. This system is activated in obesity and following food deprivation, which further supports its authentic function in energy balance regulation. The cannabinoid receptor type 1 (CB1), one of the two identified cannabinoid receptors, is expressed in energy-balance brain structures that are also able to readily produce or inactivate N-arachidonoyl ethanolamine (anandamide) and 2-arachidonoylglycerol (2AG), the most abundantly formed and released endocannabinoids. The brain action of endocannabinoid system on energy balance seems crucial and needs to be delineated in the context of the homeostatic and hedonic controls of food intake and energy expenditure. These controls require the coordinated interaction of the hypothalamus, brainstem and limbic system and it appears imperative to unravel those interplays. It is also critical to investigate the metabolic endocannabinoid system while considering the panoply of functions that the endocannabinoid system fulfills in the brain and other tissues. This article aims at reviewing the potential mechanisms whereby the brain endocannabinoid system influences the regulation energy balance.

  11. [Control of bone remodeling by nervous system. Regulation of bone metabolism by appetite regulating neuropeptides].

    PubMed

    Fukuda, Toru; Takeda, Shu

    2010-12-01

    The traditional view of bone metabolism as a primarily endocrine activity has been expanded in recent years following the identification of nervous system controlling bone metabolism by leptin studies. Especially, hypothalamic appetite regulating-peptides, such as NPY, CART and NMU have been demonstrated to be bone-regulating neuropeptides. Recently, other neuropeptides, such as serotonin and oxytocin, are reported to be associated with bone metabolism.

  12. Gamma Knife

    MedlinePlus

    ... equipment? How is safety ensured? What is this equipment used for? The Gamma Knife® and its associated ... in size. top of page How does the equipment work? The Gamma Knife® utilizes a technique called ...

  13. SU-E-T-104: Development of 3 Dimensional Dosimetry System for Gamma Knife

    SciTech Connect

    Yoon, K; Kwak, J; Cho, B; Lee, D; Ahn, S

    2014-06-01

    Purpose: The aim of this study was to develop a new 3 dimensional dosimetry system to verify the dosimetric accuracy of Leksell Gamma Knife-Perfexion™ (LGK) (Elekta, Norcross, GA). Methods: We designed and manufactured a lightweight dosimetry instrument to be equipped with the head frame to LGK. It consists of a head phantom, a scintillator, a CCD camera and a step motor. The 10×10 cm2 sheet of Gd2O3;Tb phosphor or Gafchromic EBT3 film was located at the center of the 16 cm diameter hemispherical PMMA, the head phantom. The additional backscatter compensating material of 1 cm thick PMMA plate was placed downstream of the phosphor sheet. The backscatter plate was transparent for scintillation lights to reach the CCD camera with 1200×1200 pixels by 5.2 um pitch. With This equipment, 300 images with 0.2 mm of slice gap were acquired under three collimator setups (4mm, 8mm and 16mm), respectively. The 2D projected doses from 3D distributions were compared with the exposured film dose. Results: As all doses normalized by the maximum dose value in 16 mm setup, the relative differences between the equipment dose and film dose were 0.2% for 4mm collimator and 0.5% for 8mm. The acquisition of 300 images by the equipment took less than 3 minutes. Conclusion: The new equipment was verified to be a good substitute to radiochromic film, with which required more time and resources. Especially, the new methods was considered to provide much convenient and faster solution in the 3D dose acquisition for LGK.

  14. Onset and Rapid Increase of Gamma-Ray activity from the Binary System PSR B1259-63 detected by Fermi LAT

    NASA Astrophysics Data System (ADS)

    Wood, K. S.; Caliandro, G. A.; Cheung, C. C.; Li, J.; Torres, D. F.; Fermi LAT Collaboration

    2014-06-01

    The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, is measuring rapid brightening of the binary system PSR B1259-63/SS 2883 in the GeV energy range. ...

  15. Seismic response of a regulator in Memphis gas transmission system

    SciTech Connect

    Lu, C.H.; Hwang, H.H.M.; He, Q.

    1995-12-31

    This paper presents a study of the seismic performance of an above-ground regulator in the Memphis gas transmission system. The objective is to assess the integrity of the regulator in the event of a major earthquake. A finite element model of the regulator is established using the ABAQUS program. Two types of gap elements are used to model the contact conditions among components of the structure. In the analysis, static responses caused by the weight of the regulator and the operating pressure are first calculated. The results then serve as the initial conditions of seismic responses analysis to determine the stresses in pipes and bolts. Results of the finite element calculations indicate that although the supports of the regulatory may involve separation and slipping movements, the regulator remains functional in the event of a severe earthquake.

  16. Identification of transcriptional regulators in the mouse immune system.

    PubMed

    Jojic, Vladimir; Shay, Tal; Sylvia, Katelyn; Zuk, Or; Sun, Xin; Kang, Joonsoo; Regev, Aviv; Koller, Daphne; Best, Adam J; Knell, Jamie; Goldrath, Ananda; Joic, Vladimir; Koller, Daphne; Shay, Tal; Regev, Aviv; Cohen, Nadia; Brennan, Patrick; Brenner, Michael; Kim, Francis; Rao, Tata Nageswara; Wagers, Amy; Heng, Tracy; Ericson, Jeffrey; Rothamel, Katherine; Ortiz-Lopez, Adriana; Mathis, Diane; Benoist, Christophe; Bezman, Natalie A; Sun, Joseph C; Min-Oo, Gundula; Kim, Charlie C; Lanier, Lewis L; Miller, Jennifer; Brown, Brian; Merad, Miriam; Gautier, Emmanuel L; Jakubzick, Claudia; Randolph, Gwendalyn J; Monach, Paul; Blair, David A; Dustin, Michael L; Shinton, Susan A; Hardy, Richard R; Laidlaw, David; Collins, Jim; Gazit, Roi; Rossi, Derrick J; Malhotra, Nidhi; Sylvia, Katelyn; Kang, Joonsoo; Kreslavsky, Taras; Fletcher, Anne; Elpek, Kutlu; Bellemarte-Pelletier, Angelique; Malhotra, Deepali; Turley, Shannon

    2013-06-01

    The differentiation of hematopoietic stem cells into cells of the immune system has been studied extensively in mammals, but the transcriptional circuitry that controls it is still only partially understood. Here, the Immunological Genome Project gene-expression profiles across mouse immune lineages allowed us to systematically analyze these circuits. To analyze this data set we developed Ontogenet, an algorithm for reconstructing lineage-specific regulation from gene-expression profiles across lineages. Using Ontogenet, we found differentiation stage-specific regulators of mouse hematopoiesis and identified many known hematopoietic regulators and 175 previously unknown candidate regulators, as well as their target genes and the cell types in which they act. Among the previously unknown regulators, we emphasize the role of ETV5 in the differentiation of γδ T cells. As the transcriptional programs of human and mouse cells are highly conserved, it is likely that many lessons learned from the mouse model apply to humans.

  17. Feasibility study of a low-energy gamma ray system for measuring quantity and flow rate of slush hydrogen

    NASA Technical Reports Server (NTRS)

    Singh, Jag J.; Shen, Chih-Ping; Sprinkle, Danny R.

    1992-01-01

    As part of a study to demonstrate the suitability of an X-ray or gamma ray probe for monitoring the quality and flow rate of slush hydrogen, mass attenuation coefficients for Cd-109 X- and gamma radiation in five chemical compounds were measured. The Ag-109 K rays were used for water and acetic acid, whereas E3 transition from the first excited state at 87.7 keV in Ag-109 provided the probe radiation for bromobenzene, alpha (exp 2) chloroisodurene, and cetyl bromide. Measurements were made for a single phase (gas, liquid, solid) as well as mixed phases (liquid plus solid) in all cases. It was shown that the mass attenuation coefficient for the selected radiations is independent of the phase of the test fluids or phase ratios in the case of mixed phase fluids. Described here are the procedure and the results for the five fluid systems investigated.

  18. Interpretation of Gravity and Gamma-Ray Spectrometry Data in Low Temperature Hydrothermal Systems, Southeastern Part of Fukuoka, Japan

    NASA Astrophysics Data System (ADS)

    Nishijima, Jun; Fujimitsu, Yasuhiro

    2016-12-01

    The Hakata hot springs area is located in Fukuoka City, which is in the southwestern part of Japan. Gamma-ray and gravity surveys were conducted to understand the relationship between the low-temperature hydrothermal systems and geophysical data of the area. The depth of the reservoir basement, which was derived from gravity data, gradually deepens toward the east; it includes some steep depth gradients in the Hakata hot springs area. High intensities of gamma-rays were detected around these gradients. In addition, higher hot spring temperatures and flow rates can be observed in this area. These results indicate that some part of the level of the basement where the hot springs are concentrated is a part of the Kego Fault and is similar to the fracture zone created by past activities of the fault. Moreover, these steep depth gradients act as a path for hot spring water from the deeper side of the granitic body to the surface.

  19. Two-component systems and toxinogenesis regulation in Clostridium botulinum.

    PubMed

    Connan, Chloé; Popoff, Michel R

    2015-05-01

    Botulinum neurotoxins (BoNTs) are the most potent toxins ever known. They are mostly produced by Clostridium botulinum but also by other clostridia. BoNTs associate with non-toxic proteins (ANTPs) to form complexes of various sizes. Toxin production is highly regulated through complex networks of regulatory systems involving an alternative sigma factor, BotR, and at least 6 recently described two-component systems (TCSs). TCSs allow bacteria to sense environmental changes and to respond to various stimuli by regulating the expression of specific genes at a transcriptional level. Several environmental stimuli have been identified to positively or negatively regulate toxin synthesis; however, the link between environmental stimuli and TCSs is still elusive. This review aims to highlight the role of TCSs as a central point in the regulation of toxin production in C. botulinum.

  20. Functional asymmetry of posture and body system regulation

    NASA Technical Reports Server (NTRS)

    Boloban, V. N.; Otsupok, A. P.

    1980-01-01

    The manifestation of functional asymmetry during the regulation of an athlete's posture and a system of bodies and its effect on the execution of individual and group acrobatic exercises were studied. Functional asymmetry of posture regulation was recorded in acrobats during the execution of individual and group exercises. It was shown that stability is maintained at the expense of bending and twisting motions. It is important to consider whether the functional asymmetry of posture regulation is left or right sided in making up pairs and groups of acrobats.

  1. Advanced helium regulator for a fluorine propellant system

    NASA Technical Reports Server (NTRS)

    Wichmann, H.; Yankura, G.

    1976-01-01

    The space storable propulsion module is an advanced high performance (375 seconds Isp minimum) planetary spacecraft propulsion system with a mission life of 5-10 years. The propellants used are liquid fluorine and amine fuel. This application requires high pressure regulator accuracy to optimize propellant depletion characteristics. An advanced regulator concept was prepared which is compatible with both fuel and oxidizer and which features design concepts such as redundant bellows, all-metallic/ceramic construction, friction-free guidance of moving parts and gas damping. Computer simulation of the propulsion module performance over two mission profiles indicated satisfactory minimization of those propellant residual requirements imposed by regulator performance variables.

  2. 41 CFR 101-1.101 - Federal Property Management Regulations System.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Management Regulations System. 101-1.101 Section 101-1.101 Public Contracts and Property Management Federal Property Management Regulations System FEDERAL PROPERTY MANAGEMENT REGULATIONS GENERAL 1-INTRODUCTION 1.1-Regulation System § 101-1.101 Federal Property Management Regulations System. The Federal Property...

  3. Abnormal Default System Functioning in Depression: Implications for Emotion Regulation

    PubMed Central

    Messina, Irene; Bianco, Francesca; Cusinato, Maria; Calvo, Vincenzo; Sambin, Marco

    2016-01-01

    Depression is widely seen as the result of difficulties in regulating emotions. Based on neuroimaging studies on voluntary emotion regulation, neurobiological models have focused on the concept of cognitive control, considering emotion regulation as a shift toward involving controlled processes associated with activation of the prefrontal and parietal executive areas, instead of responding automatically to emotional stimuli. According to such models, the weaker executive area activation observed in depressed patients is attributable to a lack of cognitive control over negative emotions. Going beyond the concept of cognitive control, psychodynamic models describe the development of individuals’ capacity to regulate their emotional states in mother-infant interactions during childhood, through the construction of the representation of the self, others, and relationships. In this mini-review, we link these psychodynamic models with recent findings regarding the abnormal functioning of the default system in depression. Consistently with psychodynamic models, psychological functions associated with the default system include self-related processing, semantic processes, and implicit forms of emotion regulation. The abnormal activation of the default system observed in depression may explain the dysfunctional aspects of emotion regulation typical of the condition, such as an exaggerated negative self-focus and rumination on self-esteem issues. We also discuss the clinical implications of these findings with reference to the therapeutic relationship as a key tool for revisiting impaired or distorted representations of the self and relational objects. PMID:27375536

  4. High-resolution gamma-ray measurement systems using a compact electro- mechanically cooled detector system and intelligent software

    SciTech Connect

    Buckley, W.M.; Carlson, J.B.; Neufeld, K.W.

    1995-09-27

    Obtaining high-resolution gamma-ray measurements using high-purity germanium (HPGe) detectors in the field has been of limited practicality due to the need to use and maintain a supply of liquid nitrogen (LN{sub 2}). This same constraint limits high-resolution gamma measurements in unattended safeguards or treaty Verification applications. We are developing detectors and software to greatly extend the applicability of high-resolution germanium-based measurements for these situations.

  5. High spatial resolution X-ray and gamma ray imaging system using diffraction crystals

    DOEpatents

    Smither, Robert K.

    2011-05-17

    A method and a device for high spatial resolution imaging of a plurality of sources of x-ray and gamma-ray radiation are provided. The device comprises a plurality of arrays, with each array comprising a plurality of elements comprising a first collimator, a diffracting crystal, a second collimator, and a detector.

  6. Stability evaluation and correction of a pulsed neutron generator prompt gamma activation analysis system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Source output stability is important for accurate measurement in prompt gamma neutron activation. This is especially true when measuring low-concentration elements such as in vivo nitrogen (~2.5% of body weight). We evaluated the stability of the compact DT neutron generator within an in vivo nitrog...

  7. Efficiency calibration and minimum detectable activity concentration of a real-time UAV airborne sensor system with two gamma spectrometers.

    PubMed

    Tang, Xiao-Bin; Meng, Jia; Wang, Peng; Cao, Ye; Huang, Xi; Wen, Liang-Sheng; Chen, Da

    2016-04-01

    A small-sized UAV (NH-UAV) airborne system with two gamma spectrometers (LaBr3 detector and HPGe detector) was developed to monitor activity concentration in serious nuclear accidents, such as the Fukushima nuclear accident. The efficiency calibration and determination of minimum detectable activity concentration (MDAC) of the specific system were studied by MC simulations at different flight altitudes, different horizontal distances from the detection position to the source term center and different source term sizes. Both air and ground radiation were considered in the models. The results obtained may provide instructive suggestions for in-situ radioactivity measurements of NH-UAV.

  8. Mutation in cysteine bridge domain of the gamma-subunit affects light regulation of the ATP synthase in Arabidopsis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The chloroplast ATP synthase functions to synthesize ATP from ADP and free phosphate coupled by the electrochemical potential across the thylakoid membrane in the light. The light-dependent regulation of ATP synthase activity is carried out in part through redox modulation of a cysteine bridge in CF...

  9. Analysis on TeV Gamma-ray Binary Systems and Candidates in the Northern Hemisphere with HAWC

    NASA Astrophysics Data System (ADS)

    Rho, Chang Dong; HAWC Collaboration

    2017-01-01

    Binary systems, which emit high-energy radiation, are natural testbeds for studying astrophysical particle acceleration and the production of Galactic cosmic rays. The emitted radiation may be modulated in time by the orbital period of the system, or may occur in very strong and unpredictable flares. However, while hundreds of binary systems have been observed in X-rays and radio, only a handful has been detected through TeV gamma rays. The High Altitude Water Cherenkov (HAWC) Observatory is a wide-field and high-uptime detector of TeV gamma rays that is particularly well suited to observe transient systems such as TeV binaries. Preliminary measurements of the 3 known TeV binary systems and 28 TeV binary candidates in the Northern Hemisphere were analyzed with HAWC at > 1 TeV using 17 months of data. HAWC does not decisively observe any significant traces of the 31 systems / candidates yet. However, 95% upper limits were successfully assembled for the candidates with significance below 2 sigma.

  10. SU-E-T-442: Geometric Calibration and Verification of a GammaPod Breast SBRT System

    SciTech Connect

    Yu, C; Niu, Y; Maton, P; Hoban, P; Mutaf, Y

    2015-06-15

    Purpose: The first GammaPod™ unit for prone stereotactic treatment of early stage breast cancer has recently been installed and calibrated. Thirty-six rotating circular Co-60 beams focus dose at an isocenter that traverses throughout a breast target via continuous motion of the treatment table. The breast is immobilized and localized using a vacuum-assisted stereotactic cup system that is fixed to the table during treatment. Here we report on system calibration and on verification of geometric and dosimetric accuracy. Methods: Spatial calibration involves setting the origin of each table translational axis within the treatment control system such that the relationship between beam isocenter and table geometry is consistent with that assumed by the treatment planning system. A polyethylene QA breast phantom inserted into an aperture in the patient couch is used for calibration and verification. The comparison is performed via fiducial-based registration of measured single-isocenter dose profiles (radiochromic film) with kernel dose profiles. With the table calibrations applied, measured relative dose distributions were compared with TPS calculations for single-isocenter and dynamic (many-isocenter) treatment plans. Further, table motion accuracy and linearity was tested via comparison of planned control points with independent encoder readouts. Results: After table calibration, comparison of measured and calculated single-isocenter dose profiles show agreement to within 0.5 mm for each axis. Gamma analysis of measured vs calculated profiles with 3%/2mm criteria yields a passing rate of >99% and >98% for single-isocenter and dynamic plans respectively. This also validates the relative dose distributions produced by the TPS. Measured table motion accuracy was within 0.05 mm for all translational axes. Conclusion: GammaPod table coordinate calibration is a straightforward process that yields very good agreement between planned and measured relative dose distributions

  11. Early-time observations of gamma-ray burst error boxes with the Livermore optical transient imaging system

    SciTech Connect

    Williams, G G

    2000-08-01

    Despite the enormous wealth of gamma-ray burst (GRB) data collected over the past several years the physical mechanism which causes these extremely powerful phenomena is still unknown. Simultaneous and early time optical observations of GRBs will likely make an great contribution t o our understanding. LOTIS is a robotic wide field-of-view telescope dedicated to the search for prompt and early-time optical afterglows from gamma-ray bursts. LOTIS began routine operations in October 1996 and since that time has responded to over 145 gamma-ray burst triggers. Although LOTIS has not yet detected prompt optical emission from a GRB its upper limits have provided constraints on the theoretical emission mechanisms. Super-LOTIS, also a robotic wide field-of-view telescope, can detect emission 100 times fainter than LOTIS is capable of detecting. Routine observations from Steward Observatory's Kitt Peak Station will begin in the immediate future. During engineering test runs under bright skies from the grounds of Lawrence Livermore National Laboratory Super-LOTIS provided its first upper limits on the early-time optical afterglow of GRBs. This dissertation provides a summary of the results from LOTIS and Super-LOTIS through the time of writing. Plans for future studies with both systems are also presented.

  12. Individual versus systemic risk and the Regulator's Dilemma

    PubMed Central

    Beale, Nicholas; Rand, David G.; Battey, Heather; Croxson, Karen; May, Robert M.; Nowak, Martin A.

    2011-01-01

    The global financial crisis of 2007–2009 exposed critical weaknesses in the financial system. Many proposals for financial reform address the need for systemic regulation—that is, regulation focused on the soundness of the whole financial system and not just that of individual institutions. In this paper, we study one particular problem faced by a systemic regulator: the tension between the distribution of assets that individual banks would like to hold and the distribution across banks that best supports system stability if greater weight is given to avoiding multiple bank failures. By diversifying its risks, a bank lowers its own probability of failure. However, if many banks diversify their risks in similar ways, then the probability of multiple failures can increase. As more banks fail simultaneously, the economic disruption tends to increase disproportionately. We show that, in model systems, the expected systemic cost of multiple failures can be largely explained by two global parameters of risk exposure and diversity, which can be assessed in terms of the risk exposures of individual actors. This observation hints at the possibility of regulatory intervention to promote systemic stability by incentivizing a more diverse diversification among banks. Such intervention offers the prospect of an additional lever in the armory of regulators, potentially allowing some combination of improved system stability and reduced need for additional capital. PMID:21768387

  13. The cAMP signaling system inhibits the repair of {gamma}-ray-induced DNA damage by promoting Epac1-mediated proteasomal degradation of XRCC1 protein in human lung cancer cells

    SciTech Connect

    Cho, Eun-Ah; Juhnn, Yong-Sung

    2012-06-01

    Highlights: Black-Right-Pointing-Pointer cAMP signaling system inhibits repair of {gamma}-ray-induced DNA damage. Black-Right-Pointing-Pointer cAMP signaling system inhibits DNA damage repair by decreasing XRCC1 expression. Black-Right-Pointing-Pointer cAMP signaling system decreases XRCC1 expression by promoting its proteasomal degradation. Black-Right-Pointing-Pointer The promotion of XRCC1 degradation by cAMP signaling system is mediated by Epac1. -- Abstract: Cyclic AMP is involved in the regulation of metabolism, gene expression, cellular growth and proliferation. Recently, the cAMP signaling system was found to modulate DNA-damaging agent-induced apoptosis by regulating the expression of Bcl-2 family proteins and inhibitors of apoptosis. Thus, we hypothesized that the cAMP signaling may modulate DNA repair activity, and we investigated the effects of the cAMP signaling system on {gamma}-ray-induced DNA damage repair in lung cancer cells. Transient expression of a constitutively active mutant of stimulatory G protein (G{alpha}sQL) or treatment with forskolin, an adenylyl cyclase activator, augmented radiation-induced DNA damage and inhibited repair of the damage in H1299 lung cancer cells. Expression of G{alpha}sQL or treatment with forskolin or isoproterenol inhibited the radiation-induced expression of the XRCC1 protein, and exogenous expression of XRCC1 abolished the DNA repair-inhibiting effect of forskolin. Forskolin treatment promoted the ubiquitin and proteasome-dependent degradation of the XRCC1 protein, resulting in a significant decrease in the half-life of the protein after {gamma}-ray irradiation. The effect of forskolin on XRCC1 expression was not inhibited by PKA inhibitor, but 8-pCPT-2 Prime -O-Me-cAMP, an Epac-selective cAMP analog, increased ubiquitination of XRCC1 protein and decreased XRCC1 expression. Knockdown of Epac1 abolished the effect of 8-pCPT-2 Prime -O-Me-cAMP and restored XRCC1 protein level following {gamma}-ray irradiation. From

  14. Motor Control and Regulation for a Flywheel Energy Storage System

    NASA Technical Reports Server (NTRS)

    Kenny, Barbara; Lyons, Valerie

    2003-01-01

    This talk will focus on the motor control algorithms used to regulate the flywheel system at the NASA Glenn Research Center. First a discussion of the inner loop torque control technique will be given. It is based on the principle of field orientation and is implemented without a position or speed sensor (sensorless control). Then the outer loop charge and discharge algorithm will be presented. This algorithm controls the acceleration of the flywheel during charging and the deceleration while discharging. The algorithm also allows the flywheel system to regulate the DC bus voltage during the discharge cycle.

  15. Sympathetic nervous system regulation of the tumour microenvironment

    PubMed Central

    Cole, Steven W.; Nagaraja, Archana S.; Lutgendorf, Susan K.; Green, Paige A.; Sood, Anil K.

    2016-01-01

    The peripheral autonomic nervous system (ANS) is known to regulate gene expression in primary tumours and their surrounding microenvironment. Activation of the sympathetic division of the ANS in particular modulates gene expression programs that promote metastasis of solid tumours by stimulating macrophage infiltration, inflammation, angiogenesis, epithelial-mesenchymal transition, and tumour invasion, and by inhibiting cellular immune responses and programmed cell death. Haematological cancers are modulated by sympathetic nervous system (SNS) regulation of stem cell biology and hematopoietic differentiation programs. In addition to identifying a molecular basis for physiologic stress effects on cancer, these findings have also identified new pharmacologic strategies to inhibit cancer progression in vivo. PMID:26299593

  16. Sea Buckthorn Leaf Extract Protects Jejunum and Bone Marrow of 60Cobalt-Gamma-Irradiated Mice by Regulating Apoptosis and Tissue Regeneration

    PubMed Central

    Bala, Madhu; Gupta, Manish; Saini, Manu; Abdin, M. Z.; Prasad, Jagdish

    2015-01-01

    A single dose (30 mg/kg body weight) of standardized sea buckthorn leaf extract (SBL-1), administered 30 min before whole body 60Co-gamma-irradiation (lethal dose, 10 Gy), protected >90% of mice population. The purpose of this study was to investigate the mechanism of action of SBL-1 on jejunum and bone marrow, quantify key bioactive compounds, and analyze chemical composition of SBL-1. Study with 9-week-old inbred male Swiss albino Strain ‘A' mice demonstrated that SBL-1 treatment before 60Co-gamma-irradiation (10 Gy) significantly (p < 0.05) countered radiation induced decreases in jejunum crypts (1.27-fold), villi number (1.41-fold), villus height (1.25-fold), villus cellularity (2.27-fold), cryptal Paneth cells (1.89-fold), and Bcl2 level (1.54-fold). It countered radiation induced increases in cryptal apoptotic cells (1.64-fold) and Bax levels (1.88-fold). It also countered radiation (2 Gy and 3 Gy) induced bone marrow apoptosis (1.59-fold and 1.85-fold) and micronuclei frequency (1.72-fold and 2.6-fold). SBL-1 rendered radiation protection by promoting cryptal stem cells proliferation, by regulating apoptosis, and by countering radiation induced chromosomal damage. Quercetin, Ellagic acid, Gallic acid, high contents polyphenols, tannins, and thiols detected in SBL-1 may have contributed to radiation protection by neutralization of radiation induced oxidative species, supporting stem cell proliferation and tissue regeneration. PMID:26421051

  17. Sea Buckthorn Leaf Extract Protects Jejunum and Bone Marrow of (60)Cobalt-Gamma-Irradiated Mice by Regulating Apoptosis and Tissue Regeneration.

    PubMed

    Bala, Madhu; Gupta, Manish; Saini, Manu; Abdin, M Z; Prasad, Jagdish

    2015-01-01

    A single dose (30 mg/kg body weight) of standardized sea buckthorn leaf extract (SBL-1), administered 30 min before whole body (60)Co-gamma-irradiation (lethal dose, 10 Gy), protected >90% of mice population. The purpose of this study was to investigate the mechanism of action of SBL-1 on jejunum and bone marrow, quantify key bioactive compounds, and analyze chemical composition of SBL-1. Study with 9-week-old inbred male Swiss albino Strain 'A' mice demonstrated that SBL-1 treatment before (60)Co-gamma-irradiation (10 Gy) significantly (p < 0.05) countered radiation induced decreases in jejunum crypts (1.27-fold), villi number (1.41-fold), villus height (1.25-fold), villus cellularity (2.27-fold), cryptal Paneth cells (1.89-fold), and Bcl2 level (1.54-fold). It countered radiation induced increases in cryptal apoptotic cells (1.64-fold) and Bax levels (1.88-fold). It also countered radiation (2 Gy and 3 Gy) induced bone marrow apoptosis (1.59-fold and 1.85-fold) and micronuclei frequency (1.72-fold and 2.6-fold). SBL-1 rendered radiation protection by promoting cryptal stem cells proliferation, by regulating apoptosis, and by countering radiation induced chromosomal damage. Quercetin, Ellagic acid, Gallic acid, high contents polyphenols, tannins, and thiols detected in SBL-1 may have contributed to radiation protection by neutralization of radiation induced oxidative species, supporting stem cell proliferation and tissue regeneration.

  18. Approaches Mediating Oxytocin Regulation of the Immune System

    PubMed Central

    Li, Tong; Wang, Ping; Wang, Stephani C.; Wang, Yu-Feng

    2017-01-01

    The hypothalamic neuroendocrine system is mainly composed of the neural structures regulating hormone secretion from the pituitary gland and has been considered as the higher regulatory center of the immune system. Recently, the hypothalamo-neurohypophysial system (HNS) emerged as an important component of neuroendocrine–immune network, wherein the oxytocin (OT)-secreting system (OSS) plays an essential role. The OSS, consisting of OT neurons in the supraoptic nucleus, paraventricular nucleus, their several accessory nuclei and associated structures, can integrate neural, endocrine, metabolic, and immune information and plays a pivotal role in the development and functions of the immune system. The OSS can promote the development of thymus and bone marrow, perform immune surveillance, strengthen immune defense, and maintain immune homeostasis. Correspondingly, OT can inhibit inflammation, exert antibiotic-like effect, promote wound healing and regeneration, and suppress stress-associated immune disorders. In this process, the OSS can release OT to act on immune system directly by activating OT receptors or through modulating activities of other hypothalamic–pituitary–immune axes and autonomic nervous system indirectly. However, our understandings of the role of the OSS in neuroendocrine regulation of immune system are largely incomplete, particularly its relationship with other hypothalamic–pituitary–immune axes and the vasopressin-secreting system that coexists with the OSS in the HNS. In addition, it remains unclear about the relationship between the OSS and peripherally produced OT in immune regulation, particularly intrathymic OT that is known to elicit central immunological self-tolerance of T-cells to hypophysial hormones. In this work, we provide a brief review of current knowledge of the features of OSS regulation of the immune system and of potential approaches that mediate OSS coordination of the activities of entire neuroendocrine

  19. Approaches Mediating Oxytocin Regulation of the Immune System.

    PubMed

    Li, Tong; Wang, Ping; Wang, Stephani C; Wang, Yu-Feng

    2016-01-01

    The hypothalamic neuroendocrine system is mainly composed of the neural structures regulating hormone secretion from the pituitary gland and has been considered as the higher regulatory center of the immune system. Recently, the hypothalamo-neurohypophysial system (HNS) emerged as an important component of neuroendocrine-immune network, wherein the oxytocin (OT)-secreting system (OSS) plays an essential role. The OSS, consisting of OT neurons in the supraoptic nucleus, paraventricular nucleus, their several accessory nuclei and associated structures, can integrate neural, endocrine, metabolic, and immune information and plays a pivotal role in the development and functions of the immune system. The OSS can promote the development of thymus and bone marrow, perform immune surveillance, strengthen immune defense, and maintain immune homeostasis. Correspondingly, OT can inhibit inflammation, exert antibiotic-like effect, promote wound healing and regeneration, and suppress stress-associated immune disorders. In this process, the OSS can release OT to act on immune system directly by activating OT receptors or through modulating activities of other hypothalamic-pituitary-immune axes and autonomic nervous system indirectly. However, our understandings of the role of the OSS in neuroendocrine regulation of immune system are largely incomplete, particularly its relationship with other hypothalamic-pituitary-immune axes and the vasopressin-secreting system that coexists with the OSS in the HNS. In addition, it remains unclear about the relationship between the OSS and peripherally produced OT in immune regulation, particularly intrathymic OT that is known to elicit central immunological self-tolerance of T-cells to hypophysial hormones. In this work, we provide a brief review of current knowledge of the features of OSS regulation of the immune system and of potential approaches that mediate OSS coordination of the activities of entire neuroendocrine-immune network.

  20. Nicotine regulates cocaine-amphetamine-Regulated Transcript (Cart) in the mesocorticolimbic system.

    PubMed

    Kaya, Egemen; Gozen, Oguz; Ugur, Muzeyyen; Koylu, Ersin O; Kanit, Lutfiye; Balkan, Burcu

    2016-07-01

    Cocaine-and-Amphetamine Regulated Transcript (CART) mRNA and peptides are intensely expressed in the brain regions comprising mesocorticolimbic system. Studies suggest that CART peptides may have a role in the regulation of reward circuitry. The present study aimed to examine the effect of nicotine on CART expression in the mesocorticolimbic system. Three different doses of nicotine (0.2, 0.4, 0.6 mg/kg free base) were injected subcutaneously for 5 days, and on day 6, rats were decapitated following a challenge dose. CART mRNA and peptide levels in medial prefrontal cortex (mPFC), nucleus accumbens (NAc), dorsal striatum (DST), amygdala (AMG), lateral hypothalamic area (LHA), and ventral tegmental area (VTA) were measured by quantitative real-time PCR (qPCR) and Western Blot analysis, respectively. In the mPFC, 0.4 and 0.6 mg/kg nicotine, decreased CART peptide levels whereas there was no effect on CART mRNA levels. In the VTA, a down-regulation of CART peptide expression was observed with 0.2 and 0.6 mg/kg nicotine. Conversely, 0.4 and 0.6 mg/kg nicotine increased CART mRNA levels in the AMG without affecting the CART peptide expression. Nicotine did not regulate CART mRNA or CART peptide expression in the NAc, DST, and LHA. We conclude that nicotine regulates CART expression in the mesocorticolimbic system and this regulation may play an important role in nicotine reward. Synapse 70:283-292, 2016. © 2016 Wiley Periodicals, Inc.

  1. High time resolved electron temperature measurements by using the multi-pass Thomson scattering system in GAMMA 10/PDX

    NASA Astrophysics Data System (ADS)

    Yoshikawa, Masayuki; Yasuhara, Ryo; Ohta, Koichi; Chikatsu, Masayuki; Shima, Yoriko; Kohagura, Junko; Sakamoto, Mizuki; Nakashima, Yousuke; Imai, Tsuyoshi; Ichimura, Makoto; Yamada, Ichihiro; Funaba, Hisamichi; Minami, Takashi

    2016-11-01

    High time resolved electron temperature measurements are useful for fluctuation study. A multi-pass Thomson scattering (MPTS) system is proposed for the improvement of both increasing the TS signal intensity and time resolution. The MPTS system in GAMMA 10/PDX has been constructed for enhancing the Thomson scattered signals for the improvement of measurement accuracy. The MPTS system has a polarization-based configuration with an image relaying system. We optimized the image relaying optics for improving the multi-pass laser confinement and obtaining the stable MPTS signals over ten passing TS signals. The integrated MPTS signals increased about five times larger than that in the single pass system. Finally, time dependent electron temperatures were obtained in MHz sampling.

  2. Analysis of gamma-aminobutyric acidB receptor function in the in vitro and in vivo regulation of alpha-melanotropin-stimulating hormone secretion from melanotrope cells of Xenopus laevis.

    PubMed

    De Koning, H P; Jenks, B G; Roubos, E W

    1993-02-01

    The activity of many endocrine cells is regulated by gamma-aminobutyric acid (GABA). The effects of GABA are mediated by GABAA and/or GABAB receptors. While GABAB receptors in the central nervous system have now been extensively characterized, little is known of the function and pharmacology of GABAB receptors on endocrine cells. In the amphibian Xenopus laevis, GABA inhibits the release of alpha MSH from the endocrine melanotrope cells through both GABAA and GABAB receptors. We have investigated the following aspects of the GABAB receptor of the melanotrope cells of X. laevis: 1) the pharmacology of this receptor, using antagonists previously established to demonstrate GABAB receptors in the mammalian central nervous system; 2) the relative contribution to the regulation of hormone secretion by the GABAA and GABAB receptors on melanotrope cells in vitro; and 3) the role of the GABAB receptor with respect to the physiological function of the melanotrope cell in vivo, i.e. regulation of pigment dispersion in skin melanophores in relation to background color. Our results demonstrate that phaclofen, 2-hydroxysaclofen, and 4-aminobutylphosphonic acid dose-dependently blocked the inhibition of alpha MSH release by GABAB receptor activation, but not by GABAA receptor activation. The GABAB receptor antagonist delta-aminovaleric acid appeared to be a selective agonist on the GABAB receptor of melanotrope cells. The inhibitory secretory response to a low dose of GABA (10(-5) M) was not affected by bicuculline, but was significantly reduced by phaclofen, indicating that at a low GABA concentration, the GABAB receptor mechanism would dominate in inhibiting the melanotrope cells. Different thresholds of activation may form the basis for differential action of GABA through both GABA receptor types. The tonic inhibition of alpha MSH release in animals adapted to a white background was not affected by 4-aminobutylphosphonic acid, indicating that the GABAB receptor is not (solely

  3. Estimation of neutron spectrum in the low-level gamma spectroscopy system using unfolding procedure

    NASA Astrophysics Data System (ADS)

    Knežević, D.; Jovančević, N.; Krmar, M.

    2016-03-01

    The radiation resulting from neutron interactions with Ge nuclei in active volume of HPGe detectors is one of the main concerns in low-level gamma spectroscopy measurements [1,2]. It is usually not possible to measure directly spectrum of neutrons which strike detector. This paper explore the possibility of estimation of neutron spectrum using measured activities of certain Ge(n,γ) and Ge(n,n') reactions (obtained from low-level gamma measurements), available ENDF cross section data and unfolding procedures. In this work HPGe detector with passive shield made from commercial low background lead was used for the measurement. The most important objective of this study was to reconstruct muon induced neutron spectrum created in the shield of the HPGe detector. MAXED [3] and GRAVEL [4] algorithms for neutron spectra unfolding were used. The results of those two algorithms were compared and we analyzed the sensitivity of the unfolding procedure to the various input parameters.

  4. A new frequency-multiplied interferometer system in the GAMMA 10 tandem mirror.

    PubMed

    Kohagura, J; Yoshikawa, M; Shima, Y; Morikawa, Y; Yamada, T; Akita, D; Tatebe, K; Ichimura, M; Hirata, M; Ikezoe, R; Yokoyama, T; Imai, T

    2012-10-01

    A new interferometer is installed on the west anchor cell of the GAMMA 10 tandem mirror. In GAMMA 10, we have used a heterodyne-type interferometer with a 70-GHz IMPATT oscillator and a 150-MHz oscillator for frequency modulation. The new interferometer consists of a 17.5-GHz phase locked dielectric resonator oscillator and a 37.5-MHz temperature-compensated crystal oscillator, as well as frequency multipliers. The main motivation for the new interferometer using frequency multipliers is to achieve a stable and cost effective interferometer. Direct anchor heating experiments with new anchor ion cyclotron range of frequency antennas in both the west and the east anchor cells are carried out. Density increases in both anchor cells are clearly observed using the new interferometer.

  5. Development of microwave interferometer system for divertor simulation experiments in GAMMA 10/PDX

    NASA Astrophysics Data System (ADS)

    Kohagura, J.; Wang, X.; Kanno, S.; Yoshikawa, M.; Kuwahara, D.; Nagayama, Y.; Shima, Y.; Chikatsu, M.; Nojiri, K.; Sakamoto, M.; Imai, T.; Nakashima, Y.; Mase, A.

    2015-12-01

    Microwave interferometer has newly been installed on GAMMA 10/PDX for divertor simulation study. A divertor simulation experimental module (D-module) is used to investigate the physics of divertor in the end-cell of GAMMA 10/PDX where an open magnetic field configuration is formed. D-module has a rectangular chamber with an inlet aperture. Two tungsten target plates are mounted in V-shape inside the chamber. In order to develop understandings of divertor simulation experiments the microwave interferometer using heterodyne scheme and a 1D horn-antenna mixer array (HMA) is applied to obtain electron density and density distribution inside the V-shaped target plates. Line-averaged electron density distributions inside D-module are first observed in H2 gas injection experiments.

  6. Small systems and regulator dependence in relativistic hydrodynamics

    NASA Astrophysics Data System (ADS)

    Spaliński, Michał

    2016-10-01

    Consistent theories of hydrodynamics necessarily include nonhydrodynamic modes, which can be viewed as a regulator necessary to ensure causality. Under many circumstances the choice of regulator is not relevant, but this is not always the case. In particular, for sufficiently small systems (such as those arising in pA or pp collisions) such dependence may be inevitable. We address this issue in the context of the modern version of Müller-Israel-Stewart theory of relativistic hydrodynamics. In this case, by demanding that the nonhydrodynamic modes do not dominate, we find that regulator dependence becomes inevitable only for multiplicities d N /d Y of the order of a few. This conclusion supports earlier studies based on hydrodynamic simulations of small systems, at the same time providing a simple physical picture of how hydrodynamics can be reliable even in such seemingly extreme conditions.

  7. Advanced design for a seafloor gamma-measurement data-collection system. Final report for the period July 1, 1988-September 30, 1991. Open File Report

    SciTech Connect

    Noakes, J.E.

    1992-08-28

    The Center for Applied Isotope Studies (CAIS) conducted a three-year program to upgrade and field test the Gamma Isotope Measurement System (GIMS), one of several CAIS systems capable of rapid, remote surveillance and collection of seafloor data. The GIMS is designed specifically for detecting the gamma radiation that is emitted by naturally occurring radioactive minerals on or near the seafloor, which can then be used for the interpretation of seafloor lithology. The GIMS consists of a towed sled containing a gamma radiation detector and a battery pack, connected by signal cable to a shipboard data acquisition system. The system processes the gamma spectrum to identify certain radioactive isotopes, simultaneously measuring four levels of radioactivity. Following the three-year system upgrade program, the operational parameters of the GIMS have been substantially improved from the prototype gamma radiation detection systems first developed in the mid-1970s. Gamma radiation detection sensitivity has been increased fourfold with the inclusion of a larger thallium-activated sodium iodide (NaI(Tl)) crystal detector. The maximum operating depth of the system has been doubled to a capability of 300 feet at a towing speed of 3 knots, allowing access to extensive areas of seafloor that were not previously available for rapid survey investigation. Enhanced data processing, storage, and mapping capabilities now provide user access to gamma spectrum analyses and two- and three-dimensional maps in near real time. In addition to these improvements, computer software now in development at CAIS will be applicable to the GIMS system to permit real time mapping within the next year.

  8. A celestial gamma-ray foreground due to the albedo of small solar system bodies and a remote probe of the interstellar cosmic ray spectrum

    SciTech Connect

    Moskalenko, Igor V.; Porter, Troy A.; Digel, Seth W.; Michelson, Peter F.; Ormes, Jonathan F.

    2007-12-17

    We calculate the {gamma}-ray albedo flux from cosmic-ray (CR) interactions with the solid rock and ice in Main Belt asteroids and Kuiper Belt objects (KBOs) using the Moon as a template. We show that the {gamma}-ray albedo for the Main Belt and Kuiper Belt strongly depends on the small-body mass spectrum of each system and may be detectable by the forthcoming Gamma Ray Large Area Space Telescope (GLAST). The orbits of the Main Belt asteroids and KBOs are distributed near the ecliptic, which passes through the Galactic center and high Galactic latitudes. If detected, the {gamma}-ray emission by the Main Belt and Kuiper Belt has to be taken into account when analyzing weak {gamma}-ray sources close to the ecliptic, especially near the Galactic center and for signals at high Galactic latitudes, such as the extragalactic {gamma}-ray emission. Additionally, it can be used to probe the spectrum of CR nuclei at close-to-interstellar conditions, and the mass spectrum of small bodies in the Main Belt and Kuiper Belt. The asteroid albedo spectrum also exhibits a 511 keV line due to secondary positrons annihilating in the rock. This may be an important and previously unrecognized celestial foreground for the INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL) observations of the Galactic 511 keV line emission including the direction of the Galactic center.

  9. Systemic regulation of photosynthetic function in field-grown sorghum.

    PubMed

    Li, Tao; Liu, Yujun; Shi, Lei; Jiang, Chuangdao

    2015-09-01

    The photosynthetic characteristics of developing leaves of plants grown under artificial conditions are, to some extent, regulated systemically by mature leaves; however, whether systemic regulation of photosynthesis occurs in field-grown crops is unclear. To explore this question, we investigated the effects of planting density on growth characteristics, gas exchange, leaf nitrogen concentration and chlorophyll a fluorescence in field-grown sorghum (Sorghum bicolor L.). Our results showed that close planting resulted in a marked decline in light intensity in lower canopy. Sorghum plants grown at a high planting density had lower net photosynthetic rate (Pn), stomatal conductance (Gs), and transpiration rate (E) than plants grown at a low planting density. Moreover, in the absence of mineral deficiency, close planting induced a slight increase in leaf nitrogen concentration. The decreased photosynthesis in leaves of the lower canopy at high planting density was caused mainly by the low light. However, newly developed leaves exposed to high light in the upper canopy of plants grown at high planting density also exhibited a distinct decline in photosynthesis relative to plants grown at low planting density. Based on these results, the photosynthetic function of the newly developed leaves in the upper canopy was not determined fully by their own high light environment. Accordingly, we suggest that the photosynthetic function of newly developed leaves in the upper canopy of field-grown sorghum plants is regulated systemically by the lower canopy leaves. The differences in systemic regulation of photosynthesis were also discussed between field conditions and artificial conditions.

  10. An International Perspective on Regulated Family Day Care Systems

    ERIC Educational Resources Information Center

    Davis, Elise; Freeman, Ramona; Doherty, Gillian; Karlsson, Malene; Everiss, Liz; Couch, Jane; Foote, Lyn; Murray, Patricia; Modigliani, Kathy; Owen, Sue; Griffin, Sue; Friendly, Martha; McDonald, Grace; Bohanna, India; Corr, Lara; Smyth, Lisa; Morkeseth, Elisabeth Ianke; Morreaunet, Sissel; Ogi, Mari; Fukukawa, Sumi; Hinke-Rahnau, Jutta

    2012-01-01

    Despite emerging evidence of the contributors to high-quality family day care, a comprehensive comparison of international family day care systems has not been undertaken. The aim of this paper is to compare regulated family day care (FDC) in Australia, Canada, England and Wales, Germany, Ireland, Japan, Norway, New Zealand, Sweden, and the USA,…

  11. 75 FR 64148 - General Regulation: National Park System

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-19

    ... 27,000 historic and prehistoric structures. The National Park System also has a physical... for different types of national parks, or prohibiting certain types of public conduct, or drafting distinct regulations for different types of park areas such as wilderness, visitor centers, and...

  12. Comparative study of lead borate and bismuth lead borate glass systems as gamma-radiation shielding materials

    NASA Astrophysics Data System (ADS)

    Singh, Narveer; Singh, Kanwar Jit; Singh, Kulwant; Singh, Harvinder

    2004-09-01

    Gamma-ray mass attenuation coefficients have been measured experimentally and calculated theoretically for PbO-B 2O 3 and Bi 2O 3-PbO-B 2O 3 glass systems using narrow beam transmission method. These values have been used to calculate half value layer (HVL) parameter. These parameters have also been calculated theoretically for some standard radiation shielding concretes at same energies. Effect of replacing lead by bismuth has been analyzed in terms of density, molar volume and mass attenuation coefficient.

  13. Identification of Phospholipase C gamma1 as a Protein Tyrosine Phosphatase mu Substrate that Regulates Cell Migration

    PubMed Central

    Phillips-Mason, Polly J.; Kaur, Harpreet; Burden-Gulley, Susan M.; Craig, Sonya E.L.; Brady-Kalnay, Susann M.

    2010-01-01

    The receptor protein tyrosine phosphatase PTPmu has a cell-adhesion molecule-like extracellular segment and a catalytically active intracellular segment. This structure gives PTPmu the ability to transduce signals in response to cell-cell adhesion. Full-length PTPmu is down-regulated in glioma cells by proteolysis which is linked to increased migration of these cells in the brain. To gain insight into the substrates PTPmu may be dephosphorylating to suppress glioma cell migration, we used a substrate trapping method to identify PTPmu substrates in tumor cell lines. We identified both PKCdelta and PLCgamma1 as PTPmu substrates. As PLCgamma1 activation is linked to increased invasion of cancer cells, we set out to determine whether PTPmu may be upstream of PLCgamma1 in regulating glioma cell migration. We conducted brain slice assays using U87-MG human glioma cells in which PTPmu expression was reduced by shRNA to induce migration. Treatment of the same cells with PTPmu shRNA and a PLCgamma1 inhibitor prevented migration of the cells within the brain slice. These data suggest that PLCgamma1 is downstream of PTPmu and that dephosphorylation of PLCgamma1 is likely to be a major pathway through which PTPmu suppresses glioma cell migration. PMID:20506511

  14. In Search of a Human Self-Regulation System

    PubMed Central

    Kelley, William M.; Wagner, Dylan D.; Heatherton, Todd F.

    2015-01-01

    The capacity for self-regulation allows people to control their thoughts, behaviors, emotions, and desires. In spite of this impressive ability, failures of self-regulation are common and contribute to numerous societal problems, from obesity to drug addiction. Such failures frequently occur following exposure to highly tempting cues, during negative moods, or after self-regulatory resources have been depleted. Here we review the available neuroscientific evidence regarding self-regulation and its failures. At its core, self-regulation involves a critical balance between the strength of an impulse and an individual’s ability to inhibit the desired behavior. Although neuroimaging and patient studies provide consistent evidence regarding the reward aspects of impulses and desires, the neural mechanisms that underlie the capacity for control have eluded consensus, with various executive control regions implicated in different studies. We outline the necessary properties for a self-regulation control system and suggest that the use of resting-state functional connectivity analyses may be useful for understanding how people regulate their behavior and why they sometimes fail in their attempts. PMID:25938728

  15. In search of a human self-regulation system.

    PubMed

    Kelley, William M; Wagner, Dylan D; Heatherton, Todd F

    2015-07-08

    The capacity for self-regulation allows people to control their thoughts, behaviors, emotions, and desires. In spite of this impressive ability, failures of self-regulation are common and contribute to numerous societal problems, from obesity to drug addiction. Such failures frequently occur following exposure to highly tempting cues, during negative moods, or after self-regulatory resources have been depleted. Here we review the available neuroscientific evidence regarding self-regulation and its failures. At its core, self-regulation involves a critical balance between the strength of an impulse and an individual's ability to inhibit the desired behavior. Although neuroimaging and patient studies provide consistent evidence regarding the reward aspects of impulses and desires, the neural mechanisms that underlie the capacity for control have eluded consensus, with various executive control regions implicated in different studies. We outline the necessary properties for a self-regulation control system and suggest that the use of resting-state functional connectivity analyses may be useful for understanding how people regulate their behavior and why they sometimes fail in their attempts.

  16. Signaling Mechanisms Regulating Myelination in the Central Nervous System

    PubMed Central

    AHRENDSEN, Jared T.; MACKLIN, Wendy B.

    2014-01-01

    The precise and coordinated production of myelin is essential for proper development and function of the nervous system. Diseases that disrupt myelin, including multiple sclerosis (MS), cause significant functional disability. Current treatment aims to reduce the inflammatory component of the disease, thereby preventing damage resulting from demyelination. However, therapies are not yet available to improve natural repair processes after damage has already occurred. A thorough understanding of the signaling mechanisms that regulate myelin generation will improve our ability to enhance repair. In this review, we summarize the positive and negative regulators of myelination, focusing primarily on central nervous system myelination. Axon-derived signals, extracellular signals from both diffusible factors and the extracellular matrix, and intracellular signaling pathways within myelinating oligodendrocytes are discussed. Much more is known about the positive regulators that drive myelination, while less is known about the negative regulators that shift active myelination to myelin maintenance at the appropriate time. Therefore, we also provide new data on potential negative regulators of CNS myelination. PMID:23558589

  17. Combining Measurements with Three-Dimensional Laser Scanning System and Coded Aperture Gamma-Ray Imaging Systems for International Safeguards Applications

    SciTech Connect

    Boehnen, Chris Bensing; Bogard, James S; Hayward, Jason P; Raffo-Caiado, Ana Claudia; Smith, Stephen E; Ziock, Klaus-Peter

    2010-01-01

    Being able to verify the operator's declaration in regards to technical design of nuclear facilities is an important aspect of every safeguards approach. In addition to visual observation, it is relevant to know if nuclear material is present or has been present in piping and ducts not declared. The possibility of combining different measurement techniques into one tool should optimize the inspection effort and increase safeguards effectiveness. Oak Ridge National Laboratory (ORNL) is engaged in a technical collaboration project involving two U.S. Department of Energy foreign partners to investigate combining measurements from a three-dimensional (3D) laser scanning system and gamma-ray imaging systems. ORNL conducted simultaneous measurements with a coded-aperture gamma-ray imager and the 3D laser scanner in an operational facility with complex configuration and different enrichment levels and quantities of uranium. This paper describes these measurements and their results.

  18. Fragmentation and Flow Regulation of the World's Large River Systems

    NASA Astrophysics Data System (ADS)

    Reidy, C.; Nilsson, C.; Dynesius, M.; Revenga, C.

    2005-12-01

    Humans have extensively altered river systems through impoundments and diversions to meet their water, energy and transportation needs. Here we present a global overview of flow regulation and channel fragmentation by dams in the world's large river systems (LRSs), which comprise a total virgin mean annual discharge (the discharge before any significant human manipulations) of some 790,000 m3s-1, or 60% of the world's river runoff. Over half of the systems (172 out of 292) are impacted by dams, including the eight most biogeographically diverse. In terms of summed LRS discharge and catchment area, the proportions of impacted rivers are 84% and 88%, respectively. The greatest flow regulation (428%) is reported for the Volta river system in Africa, and regulation is beyond 250% in both the Manicougan and Colorado systems in North and Central America. Dam-impacted catchments experience higher irrigation pressure and about 25 times as much economic activity per unit of water as do unaffected catchments. In view of projected changes in climate, land use and water stress, these findings can be used to identify ecohydrological risks associated with further impacts on large river systems.

  19. Catalytic oxidation of toluene in contaminant emission control systems using Mn-Ce/gamma-Al2O3.

    PubMed

    Kim, H-J; Choi, S-W; Inyang, H I

    2008-05-01

    Toluene, the alkyl benzene, is a common constituent of contaminant streams emitted by hydrocarbon fuel combustion systems. The oxidation of toluene to less toxic compounds can be enhanced through catalysis. The capacity of Mn-Ce/gamma-Al2O3 to catalyze toluene oxidation was investigated using a fixed bed flow reactor, operating within a temperature range of 160-400 degrees C. Mono-metallic catalysts were prepared with the manganese and cerium contents of 1-21 wt% on gamma-Al2O3, support and bi-metallic catalysts were prepared with cerium (0.5-21 wt%/) on 18.2 wt% manganese. The results indicate that the 18.2 wt% Mn-10.0 wt% Ce catalyst combination had the best catalytic efficiency for toluene oxidation. Increase in cerium loading reduces the surface area of catalytic materials measured by BET, but increases catalytic activity. Data obtained through TGA (Thermogravimetric analysis), XRD (X-ray diffraction) and toluene-TPR (Temperature Programmed Reduction) measurements show that the reduction of the catalysts in the process of toluene oxidation is directly proportional to observed weight loss under hydrogen flow. From these results, it is concluded that cerium improves the catalytic role of manganese in toluene oxidation. Oxygen mobility is also promoted in a redox mechanism in which MnO2 serves as the active sites. These results are useful in the development of toluene emission control systems for hydrocarbon fuel combustion systems.

  20. Early peroxisome proliferator-activated receptor gamma regulated genes involved in expansion of pancreatic beta cell mass

    PubMed Central

    2011-01-01

    Background The progression towards type 2 diabetes depends on the allostatic response of pancreatic beta cells to synthesise and secrete enough insulin to compensate for insulin resistance. The endocrine pancreas is a plastic tissue able to expand or regress in response to the requirements imposed by physiological and pathophysiological states associated to insulin resistance such as pregnancy, obesity or ageing, but the mechanisms mediating beta cell mass expansion in these scenarios are not well defined. We have recently shown that ob/ob mice with genetic ablation of PPARγ2, a mouse model known as the POKO mouse failed to expand its beta cell mass. This phenotype contrasted with the appropriate expansion of the beta cell mass observed in their obese littermate ob/ob mice. Thus, comparison of these models islets particularly at early ages could provide some new insights on early PPARγ dependent transcriptional responses involved in the process of beta cell mass expansion Results Here we have investigated PPARγ dependent transcriptional responses occurring during the early stages of beta cell adaptation to insulin resistance in wild type, ob/ob, PPARγ2 KO and POKO mice. We have identified genes known to regulate both the rate of proliferation and the survival signals of beta cells. Moreover we have also identified new pathways induced in ob/ob islets that remained unchanged in POKO islets, suggesting an important role for PPARγ in maintenance/activation of mechanisms essential for the continued function of the beta cell. Conclusions Our data suggest that the expansion of beta cell mass observed in ob/ob islets is associated with the activation of an immune response that fails to occur in POKO islets. We have also indentified other PPARγ dependent differentially regulated pathways including cholesterol biosynthesis, apoptosis through TGF-β signaling and decreased oxidative phosphorylation. PMID:22208362

  1. The teenager's confession: regulating shame in internal family systems therapy.

    PubMed

    Sweezy, Martha

    2011-01-01

    This case study explores the clinical relevance of the differences among shame, guilt that is linked with shame, and pure guilt. Empirical literature on emotion suggests that shame is instrumental in a host of psychiatric symptoms while pure guilt is prosocial and adaptive. Regulating shame and being able to feel pure guilt may be especially important for trauma patients like the one described here, who have transgressors as well as victims. The protocol of internal family systems (IFS), a mode of therapy that utilizes psychic multiplicity and actively recruits internal compassion, is described as a treatment for regulating shame and facilitating adaptive guilt.

  2. Stimulatory heterotrimeric G protein augments gamma ray-induced apoptosis by up-regulation of Bak expression via CREB and AP-1 in H1299 human lung cancer cells.

    PubMed

    Choi, Yoon Jung; Kim, So Young; Oh, Jung Min; Juhnn, Yong Sung

    2009-08-31

    Stimulatory heterotrimeric GTP-binding proteins (Gs protein) stimulate cAMP generation in response to various signals, and modulate various cellular phenomena such as proliferation and apoptosis. This study aimed to investigate the effect of Gs proteins on gamma ray-induced apoptosis of lung cancer cells and its molecular mechanism, as an attempt to develop a new strategy to improve the therapeutic efficacy of gamma radiation. Expression of constitutively active mutant of the alpha subunit of Gs (GalphasQL) augmented gamma ray-induced apoptosis via mitochondrial dependent pathway when assessed by clonogenic assay, FACS analysis of PI stained cells, and western blot analysis of the cytoplasmic translocation of cytochrome C and the cleavage of caspase-3 and ploy(ADP-ribose) polymerase (PARP) in H1299 human lung cancer cells. GalphasQL up-regulated the Bak expression at the levels of protein and mRNA. Treatment with inhibitors of PKA (H89), SP600125 (JNK inhibitor), and a CRE-decoy blocked GalphasQL-stimulated Bak reporter luciferase activity. Expression of GalphasQL increased basal and gamma ray-induced luciferase activity of cAMP response element binding protein (CREB) and AP-1, and the binding of CREB and AP-1 to Bak promoter. Furthermore, prostaglandin E2, a Galphas activating signal, was found to augment gamma ray-induced apoptosis, which was abolished by treatment with a prostanoid receptor antagonist. These results indicate that Galphas augments gamma ray-induced apoptosis by up-regulation of Bak expression via CREB and AP-1 in H1299 lung cancer cells, suggesting that the efficacy of radiotherapy of lung cancer may be improved by modulating Gs signaling pathway.

  3. Combination of PTEN and {gamma}-Ionizing Radiation Enhances Cell Death and G{sub 2}/M Arrest Through Regulation of AKT Activity and p21 Induction in Non-Small-Cell Lung Cancer Cells

    SciTech Connect

    Park, Jong Kuk; Jung, Hae-Yun; Park, Seon Ho; Kang, Seung Yi; Yi, Mi-Rang; Um, Hong Duck; Hong, Sung Hee

    2008-04-01

    Purpose: To identify the role of phosphatase and tensin homolog deleted on chromosome 10 (PTEN) during {gamma}-ionizing radiation ({gamma}-IR) treatment for non-small-cell lung cancer cells. Methods and Materials: Wild-type PTEN or mutant forms of PTEN plasmids were transfected to construct stable transfectants of the NCI-H1299 non-small-cell lung cancer cell line. Combined effects of PTEN expression and IR treatment were tested using immunoblot, clonogenic, and cell-counting assays. Related signaling pathways were studied with immunoblot and kinase assays. Results: At steady state, stable transfectants showed almost the same proliferation rate but had different AKT phosphorylation patterns. When treated with {gamma}-IR, wild-type PTEN transfectants showed higher levels of cell death compared with mock vector or mutant transfectants, and showed increased G{sub 2}/M cell-cycle arrest accompanied by p21 induction and CDK1 inactivation. NCI-H1299 cells were treated with phosphosinositide-3 kinase (PI3K)/AKT pathway inhibitor (LY29002), resulting in reduced AKT phosphorylation levels. Treatment of NCI-H1299 cells with LY29002 and {gamma}-IR resulted in increased cell-cycle arrest and p21 induction. Endogenous wild-type PTEN-containing NCI-H460 cells were treated with PTEN-specific siRNA and then irradiated with {gamma}-IR: however reduced PTEN levels did not induce cell-cycle arrest or p21 expression. Conclusions: Taken together, these findings indicate that PTEN may modulate cell death or the cell cycle via AKT inactivation by PTEN and {gamma}-IR treatment. We also propose that a PTEN-PI3K/AKT-p21-CDK1 pathway could regulate cell death and the cell cycle by {gamma}-IR treatment.

  4. Combining Measurements with Three-Dimensional Laser Scanning System and Coded Aperture Gamma-Ray Imaging System for International Safeguards Applications

    SciTech Connect

    Boehnen, Chris Bensing; Bogard, James S; Hayward, Jason P; Raffo-Caiado, Ana Claudia; Smith, Steven E; Ziock, Klaus-Peter

    2010-01-01

    Being able to verify the operator's declaration in regard to the technical design of nuclear facilities is an important aspect of every safeguards approach. In addition to visual observation, it is necessary to know if nuclear material is present or has been present in undeclared piping and ducts. The possibility of combining the results from different measurement techniques into one easily interpreted product should optimize the inspection effort and increase safeguards effectiveness. A collaborative effort to investigate the possibility of combining measurements from a three-dimensional (3D) laser scanning system and gamma-ray imaging systems is under way. The feasibility of the concept has been previously proven with different laboratory prototypes of gamma-ray imaging systems. Recently, simultaneous measurements were conducted with a new highly portable, mechanically cooled, High Purity Germanium (HPGe), coded-aperture gamma-ray imager and a 3D laser scanner in an operational facility with complex configuration and different enrichment levels and quantities of uranium. With specially designed software, data from both instruments were combined and a 3D model of the facility was generated that also identified locations of radioactive sources. This paper provides an overview of the technology, describes the measurements, discusses the various safeguards scenarios addressed, and presents results of experiments.

  5. Activation of ion transport systems during cell volume regulation

    SciTech Connect

    Eveloff, J.L.; Warnock, D.G.

    1987-01-01

    This review discusses the activation of transport pathways during volume regulation, including their characteristics, the possible biochemical pathways that may mediate the activation of transport pathways, and the relations between volume regulation and transepithelial transport in renal cells. Many cells regulate their volume when exposed to an anisotonic medium. The changes in cell volume are caused by activation of ion transport pathways, plus the accompanying osmotically driven water movement such that cell volume returns toward normal levels. The swelling of hypertonically shrunken cells is termed regulatory volume increase (RVI) and involves an influx of NaCl into the cell via either activation of Na-Cl, Na-K-2Cl cotransport systems, or Na/sup +/-H/sup +/ and Cl/sup -/-HCO/sub 3//sup -/ exchangers. The reshrinking of hypotonically swollen cells is termed regulatory volume decrease (RVD) and involves an efflux of KCl and water from the cell by activation of either separate K/sup +/ and Cl/sup -/ conductances, a K-Cl cotransport system, or parallel K/sup +/-H/sup +/ and Cl/sup -/-HCO/sub 3//sup -/ exchangers. The biochemical mechanisms involved in the activation of transport systems are largely unknown, however, the phosphoinositide pathway may be implicated in RVI; phorbol esters, cGMP, and Ca/sup 2 +/ affect the process of volume regulation. Renal tubular cells, as well as the blood cells that transverse the medulla, are subjected to increasing osmotic gradients from the corticomedullary junction to the papillary tip, as well as changing interstitial and tubule fluid osmolarity, depending on the diuretic state of the animal. Medullary cells from the loop of Henle and the papilla can volume regulate by activating Na-K-2Cl cotransport or Na/sup +/-H/sup +/ and Cl/sup -/-HCO/sub 3//sup -/ exchange systems.

  6. [Psychoneuroimmunology--regulation of immunity at the systemic level].

    PubMed

    Boranić, Milivoj; Sabioncello, Ante; Gabrilovac, Jelka

    2008-01-01

    Innate and acquired immune reactions are controlled by their intrinsic regulatory mechanisms, ie. by an array of cytokines that mediate communication among cells of the immune system itself and with other cells and tissues, e. g. in areas of inflammation. In addition, the immune system is also subjected to systemic regulation by the vegetative and endocrine systems since immune cells express receptors for neurotransmitters and hormones. Neuroendocrine signals may enhance or suppress the immune reaction, accelerate or slow it, but do not affect specificity. Various stressful factors, including the psychosocial ones, affect immunity. In turn, cytokines generated by the immune system influence hormonal secretion and central nervous system, producing specific behavioral changes (the "sickness behavior") accompanying infectious and inflammatory diseases. That includes somnolence, loss of apetite, depression or anxiety and decrease of cognitive abilities, attention and memory. Local immune systems in skin and mucosa are also subjected to systemic neuroendocrine regulation and possess intrinsic neuroregulatory networks as well. These mechanisms render skin and respiratory and digestive tracts responsive to various forms of stress. Examples are neurodermitis, asthma and ulcerative colitis. In children, the immune and the neuroendocrine systems are still developing, particularly in fetal, neonatal and early infant periods, and exposure to stressful experiences at that time may result in late consequences in the form of deficient immunity or greater risks for allergic or autoimmune reactions. Recognition of the participation of neuroendocrine mechanisms in regulation of immunity helps us understand alterations and disturbances of immune reactions under the influence of stressful factors but so far has not produced reliable therapeutic implications. Psychosocial interventions involving the child and its family may be useful.

  7. Differential regulation of expression of the MHC class II molecules RT1.B and RT1.D on rat B lymphocytes: effects of interleukin-4, interleukin-13 and interferon-gamma.

    PubMed Central

    Roos, A; Schilder-Tol, E J; Chand, M A; Claessen, N; Lakkis, F G; Pascual, D W; Weening, J J; Aten, J

    1998-01-01

    Susceptibility to induction of both T helper 1- (Th1) and Th2-mediated autoimmunity is multifactorial and involves genetic linkage to the major histocompatibility complex (MHC) class II haplotype. Brown Norway (BN) rats exposed to mercuric chloride develop a Th2-dependent systemic autoimmunity, whereas Lewis rats, which are highly susceptible to Th1-mediated autoimmunity, develop immune suppression after mercuric chloride exposure. Exposure to mercuric chloride is known to enhance B-lymphocyte expression of the MHC class II molecule RT1.B, predominantly in BN rats. We demonstrate that, in contrast, expression of RT1.D was unmodified on these B cells, whereas both RT1.B and RT1.D were up-regulated on epithelial cells. Regulation of B-cell MHC class II isotype expression was further studied in vitro, using BN rat lymph node (LN) cells. Interleukin-4 (IL-4) strongly enhanced B-cell expression of RT1.B (2.8-fold), whereas RT1.D expression was only slightly, although significantly, modified (1.2-fold). B cells from Lewis rats showed a similar IL-4-induced enhancement of RT1.B expression (2.5-fold), whereas, in contrast, RT1.D expression was unmodified. Exposure of LN cells from BN rats to interferon-gamma induced a moderate increase of B-cell MHC class II expression, predominantly of RT1.B. Strong and rapid enhancement of B-cell RT1.D expression was observed after stimulation by phorbol 12-myristate 13-acetate and ionomycin. Rat IL-13 did not modify B-cell MHC class II expression; however, it induced typical morphological changes in peritoneal macrophages. These experiments demonstrate isotype-specific and strain-dependent regulation of MHC class II expression on rat B lymphocytes, which may be of pathophysiological relevance for the strain-dependent susceptibility for Th1- or Th2-mediated autoimmunity. Images Figure 1 Figure 5 PMID:9536116

  8. Theta, beta and gamma rate modulations in the developing auditory system.

    PubMed

    Vanvooren, Sophie; Hofmann, Michael; Poelmans, Hanne; Ghesquière, Pol; Wouters, Jan

    2015-09-01

    In the brain, the temporal analysis of many important auditory features relies on the synchronized firing of neurons to the auditory input rhythm. These so-called neural oscillations play a crucial role in sensory and cognitive processing and deviances in oscillatory activity have shown to be associated with neurodevelopmental disorders. Given the importance of neural auditory oscillations in normal and impaired sensory and cognitive functioning, there has been growing interest in their developmental trajectory from early childhood on. In the present study, neural auditory processing was investigated in typically developing young children (n = 40) and adults (n = 27). In all participants, auditory evoked theta, beta and gamma responses were recorded. The results of this study show maturational differences between children and adults in neural auditory processing at cortical as well as at brainstem level. Neural background noise at cortical level was shown to be higher in children compared to adults. In addition, higher theta response amplitudes were measured in children compared to adults. For beta and gamma rate modulations, different processing asymmetry patterns were observed between both age groups. The mean response phase was also shown to differ significantly between children and adults for all rates. Results suggest that cortical auditory processing of beta develops from a general processing pattern into a more specialized asymmetric processing preference over age. Moreover, the results indicate an enhancement of bilateral representation of monaural sound input at brainstem with age. A dissimilar efficiency of auditory signal transmission from brainstem to cortex along the auditory pathway between children and adults is suggested. These developmental differences might be due to both functional experience-dependent as well as anatomical changes. The findings of the present study offer important information about maturational differences between children

  9. Differential regulation of serotonin-1A receptor-stimulated [35S]GTP gamma S binding in the dorsal raphe nucleus by citalopram and escitalopram.

    PubMed

    Rossi, Dania V; Burke, Teresa F; Hensler, Julie G

    2008-03-31

    The effect of chronic citalopram or escitalopram administration on 5-HT1A receptor function in the dorsal raphe nucleus was determined by measuring [35S]GTP gamma S binding stimulated by the 5-HT1A receptor agonist (R)-(+)-8-OH-DPAT (1nM-10 microM). Although chronic administration of citalopram or escitalopram has been shown to desensitize somatodendritic 5-HT1A autoreceptors, we found that escitalopram treatment decreased the efficacy of 5-HT1A receptors to activate G proteins, whereas citalopram treatment did not. The binding of [3H]8-OH-DPAT to the coupled, high affinity agonist state of the receptor was not altered by either treatment. Interestingly, escitalopram administration resulted in greater occupancy of serotonin transporter sites as measured by the inhibition of [3H]cyanoimipramine binding. As the binding and action of escitalopram is limited by the inactive enantiomer R-citalopram present in racemic citalopram, we propose that the regulation of 5-HT1A receptor function in the dorsal raphe nucleus at the level of receptor-G protein interaction may be a result of greater inhibition of the serotonin transporter by escitalopram.

  10. Cis-vaccenic acid induces differentiation and up-regulates gamma globin synthesis in K562, JK1 and transgenic mice erythroid progenitor stem cells.

    PubMed

    Aimola, Idowu A; Inuwa, Hajiya M; Nok, Andrew J; Mamman, Aisha I; Bieker, James J

    2016-04-05

    Gamma globin induction remains a promising pharmacological therapeutic treatment mode for sickle cell anemia and beta thalassemia, however Hydroxyurea remains the only FDA approved drug which works via this mechanism. In this regard, we assayed the γ-globin inducing capacity of Cis-vaccenic acid (CVA). CVA induced differentiation of K562, JK1 and transgenic mice primary bone marrow hematopoietic progenitor stem cells. CVA also significantly up-regulated γ-globin gene expression in JK-1 and transgenic mice bone marrow erythroid progenitor stem cells (TMbmEPSCs) but not K562 cells without altering cell viability. Increased γ-globin expression was accompanied by KLF1 suppression in CVA induced JK-1 cells. Erythropoietin induced differentiation of JK-1 cells 24h before CVA induction did not significantly alter CVA induced differentiation and γ-globin expression in JK-1 cells. Inhibition of JK-1 and Transgenic mice bone marrow erythroid progenitor stem cells Fatty acid elongase 5 (Elovl5) and Δ(9) desaturase suppressed the γ-globin inductive effects of CVA. CVA treatment failed to rescue γ-globin expression in Elovl5 and Δ(9)-desaturase inhibited cells 48 h post inhibition in JK-1 cells. The data suggests that CVA directly modulates differentiation of JK-1 and TMbmEPSCs, and indirectly modulates γ-globin gene expression in these cells. Our findings provide important clues for further evaluations of CVA as a potential fetal hemoglobin therapeutic inducer.

  11. Characterization of the androgen-regulated prostate-specific T cell receptor gamma-chain alternate reading frame protein (TARP) promoter.

    PubMed

    Cheng, Wing-Shing; Giandomenico, Valeria; Pastan, Ira; Essand, Magnus

    2003-08-01

    TARP (T cell receptor gamma-chain alternate reading frame protein) is uniquely expressed in males in prostate epithelial cells and prostate cancer cells. Here we demonstrate that TARP expression is regulated by testosterone at the transcriptional level through specific binding of androgen receptor to an androgen response element in the proximal TARP promoter. We further demonstrate that the promoter specifically initiates reporter gene expression in TARP-positive prostate cancer cell lines. To develop a regulatory sequence for prostate-specific gene expression, we constructed a chimeric sequence consisting of the TARP promoter and the prostate-specific antigen (PSA) enhancer. We found that in the prostatic adenocarcinoma cell line LNCaP, the transcriptional activity of the regulatory sequence consisting of a TARP promoter and PSA enhancer is 20 times higher than the activity of a regulatory sequence consisting of the PSA promoter and PSA enhancer. Thus, our studies define a regulatory sequence that may be used to restrict expression of therapeutic genes to prostate cancer cells and may therefore play a role in prostate cancer gene therapy.

  12. A functional assay to measure postsynaptic gamma-aminobutyric acidB responses in cultured spinal cord neurons: Heterologous regulation of the same K+ channel

    SciTech Connect

    Kamatchi, G.L.; Ticku, M.K. )

    1991-02-01

    The stimulation of postsynaptic gamma-aminobutyric acid (GABA)B receptors leads to slow inhibitory postsynaptic potentials due to the influx of K(+)-ions. This was studied biochemically, in vitro in mammalian cultured spinal cord neurons by using 86Rb as a substitute for K+. (-)-Baclofen, a GABAB receptor agonist, produced a concentration-dependent increase in the 86Rb-influx. This effect was stereospecific and blocked by GABAB receptor antagonists like CGP 35 348 (3-aminopropyl-diethoxymethyl-phosphonic acid) and phaclofen. Apart from the GABAB receptors, both adenosine via adenosine1 receptors and 5-hydroxytryptamine (5-HT) via 5-HT1 alpha agonists also increased the 86Rb-influx. These agonists failed to show any additivity between them when they were combined in their maximal concentration. In addition, their effect was antagonized specifically by their respective antagonists without influencing the others. These findings suggest the presence of GABAB, adenosine1 and 5-HT1 alpha receptors in the cultured spinal cord neurons, which exhibit a heterologous regulation of the same K(+)-channel. The effect of these agonists were antagonized by phorbol 12,13-didecanoate, an activator of protein kinase C, and pretreatment with pertussis toxin. This suggests that these agonists by acting on their own receptors converge on the same K(+)-channel through the Gi/Go proteins. In summary, we have developed a biochemical functional assay for studying and characterizing GABAB synaptic pharmacology in vitro, using spinal cord neurons.

  13. Cis-vaccenic acid induces differentiation and up-regulates gamma globin synthesis in K562, JK1 and transgenic mice erythroid progenitor stem cells

    PubMed Central

    Aimola, Idowu A.; Inuwa, Hajiya M.; Nok, Andrew J.; Mamman, Aisha I.; Bieker, James J.

    2017-01-01

    Gamma globin induction remains a promising pharmacological therapeutic treatment mode for sickle cell anemia and beta thalassemia, however Hydroxyurea remains the only FDA approved drug which works via this mechanism. In this regard, we assayed the γ-globin inducing capacity of Cis-vaccenic acid (CVA). CVA induced differentiation of K562, JK1 and transgenic mice primary bone marrow hematopoietic progenitor stem cells. CVA also significantly up-regulated γ-globin gene expression in JK-1 and transgenic mice bone marrow erythroid progenitor stem cells (TMbmEPSCs) but not K562 cells without altering cell viability. Increased γ-globin expression was accompanied by KLF1 suppression in CVA induced JK-1 cells. Erythropoietin induced differentiation of JK-1 cells 24 h before CVA induction did not significantly alter CVA induced differentiation and γ-globin expression in JK-1 cells. Inhibition of JK-1 and Transgenic mice bone marrow erythroid progenitor stem cells Fatty acid elongase 5 (Elovl5) and Δ9 desaturase suppressed the γ-globin inductive effects of CVA. CVA treatment failed to rescue γ-globin expression in Elovl5 and Δ9-desaturase inhibited cells 48 h post inhibition in JK-1 cells. The data suggests that CVA directly modulates differentiation of JK-1 and TMbmEPSCs, and indirectly modulates γ-globin gene expression in these cells. Our findings provide important clues for further evaluations of CVA as a potential fetal hemoglobin therapeutic inducer PMID:26879870

  14. Development and Validation of a Small Animal Immobilizer and Positioning System for the Study of Delivery of Intracranial and Extracranial Radiotherapy Using the Gamma Knife System.

    PubMed

    Awan, Musaddiq J; Dorth, Jennifer; Mani, Arvind; Kim, Haksoo; Zheng, Yiran; Mislmani, Mazen; Welford, Scott; Yuan, Jiankui; Wessels, Barry W; Lo, Simon S; Letterio, John; Machtay, Mitchell; Sloan, Andrew; Sohn, Jason W

    2017-04-01

    The purpose of this research is to establish a process of irradiating mice using the Gamma Knife as a versatile system for small animal irradiation and to validate accurate intracranial and extracranial dose delivery using this system. A stereotactic immobilization device was developed for small animals for the Gamma Knife head frame allowing for isocentric dose delivery. Intercranial positional reproducibility of a reference point from a primary reference animal was verified on an additional mouse. Extracranial positional reproducibility of the mouse aorta was verified using 3 mice. Accurate dose delivery was validated using film and thermoluminescent dosimeter measurements with a solid water phantom. Gamma Knife plans were developed to irradiate intracranial and extracranial targets. Mice were irradiated validating successful targeted radiation dose delivery. Intramouse positional variability of the right mandible reference point across 10 micro-computed tomography scans was 0.65 ± 0.48 mm. Intermouse positional reproducibility across 2 mice at the same reference point was 0.76 ± 0.46 mm. The accuracy of dose delivery was 0.67 ± 0.29 mm and 1.01 ± 0.43 mm in the coronal and sagittal planes, respectively. The planned dose delivered to a mouse phantom was 2 Gy at the 50% isodose with a measured thermoluminescent dosimeter dose of 2.9 ± 0.3 Gy. The phosphorylated form of member X of histone family H2A (γH2AX) staining of irradiated mouse brain and mouse aorta demonstrated adjacent tissue sparing. In conclusion, our system for preclinical studies of small animal irradiation using the Gamma Knife is able to accurately deliver intracranial and extracranial targeted focal radiation allowing for preclinical experiments studying focal radiation.

  15. Regulation of carnitine palmitoyltransferase I (CPT-Iα) gene expression by the peroxisome proliferator activated receptor gamma coactivator (PGC-1) isoforms

    PubMed Central

    Sadana, Prabodh; Zhang, Yi; Song, Shulan; Cook, George A.; Elam, Marshall B.; Park, Edwards A.

    2007-01-01

    Summary The peroxisome proliferator-activated receptor gamma coactivators (PGC-1) have important roles in mitochondrial biogenesis and metabolic control in a variety of tissues. There are multiple isoforms of PGC-1 including PGC-1α and PGC-1β. Both the PGC-1α and β isoforms promote mitochondrial biogenesis and fatty acid oxidation, but only PGC-1α stimulates gluconeogenesis in the liver. Carnitine palmitoyltransferase I (CPT-I) is a key enzyme regulating mitochondrial fatty acid oxidation. In these studies, we determined that PGC-1β stimulated expression of the “liver” isoform of CPT-I (CPT-Iα) but that PGC-1β did not induce pyruvate dehydrogenase kinase 4 (PDK4) which is a regulator of pyruvate metabolism. The CPT-Iα gene is induced by thyroid hormone. We found that T3 increased the expression of PGC-1β and that PGC-1β enhanced the T3 induction of CPT-Iα. The thyroid hormone receptor interacts with PGC-1β in a ligand dependent manner. Unlike PGC-1α, the interaction of PGC-1β and the T3 receptor does not occur exclusively through the leucine-X-X-leucine-leucine motif in PGC-1β. We have found that PGC-1β is associated with the CPT-Iα gene in vivo. Overall, our results demonstrate that PGC-1β is a coactivator in the T3 induction of CPT-Iα and that PGC-1β has similarities and differences with the PGC-1α isoform. PMID:17239528

  16. Peroxisome proliferator-activated receptor gamma (PPARγ) in yellow catfish Pelteobagrus fulvidraco: molecular characterization, mRNA expression and transcriptional regulation by insulin in vivo and in vitro.

    PubMed

    Zheng, Jia-Lang; Zhuo, Mei-Qin; Luo, Zhi; Pan, Ya-Xiong; Song, Yu-Feng; Huang, Chao; Zhu, Qing-Ling; Hu, Wei; Chen, Qi-Liang

    2015-02-01

    Peroxisome proliferator-activated receptor gamma (PPARγ) is ligand-inducible transcription factor and has important roles in lipid metabolism, cell proliferation and inflammation. In the present study, yellow catfish Pelteobagrus fulvidraco PPARγ cDNA was isolated from liver by RT-PCR and RACE, and its molecular characterization and transcriptional regulation by insulin in vivo and in vitro were determined. The generation of PPARγ1 and PPARγ2 was due to alternative promoter of PPARγ gene. PPARγ1 and PPARγ2 mRNA covered 2426 bp and 2537 bp, respectively, with an open reading frame (ORF) of 1584 bp encoding 527 amino acid residues. Yellow catfish PPARγ gene was organized in a manner similar to that of their mammalian homologs, implying a modular organization of the protein's domains. A comparison between the yellow catfish PPARγ amino acid sequence and the correspondent sequences of several other species revealed the identity of 55-76.2%. Two PPARγ transcripts (PPARγ1 and PPARγ2) mRNAs were expressed in a wide range of tissues, but the abundance of each PPARγ mRNA showed the tissue- and developmental stage-dependent expression patterns. Intraperitoneal injection of insulin in vivo significantly stimulated the mRNA expression of total PPARγ and PPARγ1, but not PPARγ2 in the liver of yellow catfish. In contrast, incubation of hepatocytes with insulin in vitro increased the mRNA levels of PPARγ1, PPARγ2 and total PPARγ. To our knowledge, for the first time, the present study provides evidence that PPARγ1 and PPARγ2 are differentially expressed with and among tissues during different developmental stages and also regulated by insulin both in vivo and in vitro, which serves to increase our understanding on PPARγ physiological function in fish.

  17. Development of Gamma-Ray Nondestructive Detection and Assay Systems for Nuclear Safeguards and Security at JAEA

    NASA Astrophysics Data System (ADS)

    Hajima, Ryoichi

    2015-10-01

    Nondestructive detection and assay of nuclide is one of the promising applications of energy-tunable gamma-rays from laser Compton scattering. In JAEA, we are developing technologies relevant to the gamma-ray non-destructive assay, which include a high-brightness gamma-ray source based on advanced laser and accelerator technologies and gamma-ray measurement techniques optimized for highly radioactive samples. In this paper, the status of the above R&D's is reviewed.

  18. On Some Properties of Gamma Matrices

    ERIC Educational Resources Information Center

    Dumais, Jean-Francois

    1977-01-01

    Discusses the problem of the order, reducibility, and equivalence of systems of Dirac gamma matrices. Gives a simple systematic method for finding the matrices connecting different systems of 4 x 4 gamma matrices. (MLH)

  19. Mathematical Investigation of Gamma Ray and Neutron Absorption Grid Patterns for Homeland Defense Related Fourier Imaging Systems

    NASA Technical Reports Server (NTRS)

    Boccio, Dona

    2003-01-01

    Terrorist suitcase nuclear devices typically using converted Soviet tactical nuclear warheads contain several kilograms of plutonium. This quantity of plutonium emits a significant number of gamma rays and neutrons as it undergoes radioactive decay. These gamma rays and neutrons normally penetrate ordinary matter to a significant distance. Unfortunately this penetrating quality of the radiation makes imaging with classical optics impractical. However, this radiation signature emitted by the nuclear source may be sufficient to be imaged from low-flying aerial platforms carrying Fourier imaging systems. The Fourier imaging system uses a pair of co-aligned absorption grids to measure a selected range of spatial frequencies from an object. These grids typically measure the spatial frequency in only one direction at a time. A grid pair that looks in all directions simultaneously would be an improvement over existing technology. A number of grid pairs governed by various parameters were investigated to solve this problem. By examining numerous configurations, it became apparent that an appropriate spiral pattern could be made to work. A set of equations was found to describe a grid pattern that produces straight fringes. Straight fringes represent a Fourier transform of a point source at infinity. An inverse Fourier transform of this fringe pattern would provide an accurate image (location and intensity) of a point source.

  20. Air-flow regulation system for a coal gasifier

    DOEpatents

    Fasching, George E.

    1984-01-01

    An improved air-flow regulator for a fixed-bed coal gasifier is provided which allows close air-flow regulation from a compressor source even though the pressure variations are too rapid for a single primary control loop to respond. The improved system includes a primary controller to control a valve in the main (large) air supply line to regulate large slow changes in flow. A secondary controller is used to control a smaller, faster acting valve in a secondary (small) air supply line parallel to the main line valve to regulate rapid cyclic deviations in air flow. A low-pass filter with a time constant of from 20 to 50 seconds couples the output of the secondary controller to the input of the primary controller so that the primary controller only responds to slow changes in the air-flow rate, the faster, cyclic deviations in flow rate sensed and corrected by the secondary controller loop do not reach the primary controller due to the high frequency rejection provided by the filter. This control arrangement provides at least a factor of 5 improvement in air-flow regulation for a coal gasifier in which air is supplied by a reciprocating compressor through a surge tank.

  1. HNF-1B specifically regulates the transcription of the {gamma}a-subunit of the Na{sup +}/K{sup +}-ATPase

    SciTech Connect

    Ferre, Silvia; Veenstra, Gert Jan C.; Bouwmeester, Rianne; Hoenderop, Joost G.J.; Bindels, Rene J.M.

    2011-01-07

    Research highlights: {yields} Defects in HNF-1B transcription factor affect Mg{sup 2+} handling in the distal kidney. {yields} {gamma}a- and {gamma}b- subunits of the Na{sup +}/K{sup +}-ATPase colocalize in the distal convoluted tubule of the nephron. {yields} HNF-1B specifically activates {gamma}a expression. {yields} HNF-1B mutants have a dominant negative effect on wild type HNF-1B activity. {yields} Defective transcription of {gamma}a may promote renal Mg{sup 2+} wasting. -- Abstract: Hepatocyte nuclear factor-1B (HNF-1B) is a transcription factor involved in embryonic development and tissue-specific gene expression in several organs, including the kidney. Recently heterozygous mutations in the HNF1B gene have been identified in patients with hypomagnesemia due to renal Mg{sup 2+} wasting. Interestingly, ChIP-chip data revealed HNF-1B binding sites in the FXYD2 gene, encoding the {gamma}-subunit of the Na{sup +}/K{sup +}-ATPase. The {gamma}-subunit has been described as one of the molecular players in the renal Mg{sup 2+} reabsorption in the distal convoluted tubule (DCT). Of note, the FXYD2 gene can be alternatively transcribed into two main variants, namely {gamma}a and {gamma}b. In the present study, we demonstrated via two different reporter gene assays that HNF-1B specifically acts as an activator of the {gamma}a-subunit, whereas the {gamma}b-subunit expression was not affected. Moreover, the HNF-1B mutations H69fsdelAC, H324S325fsdelCA, Y352finsA and K156E, previously identified in patients with hypomagnesemia, prevented transcription activation of {gamma}a-subunit via a dominant negative effect on wild type HNF1-B. By immunohistochemistry, it was shown that the {gamma}a- and {gamma}b-subunits colocalize at the basolateral membrane of the DCT segment of mouse kidney. On the basis of these data, we suggest that abnormalities involving the HNF-1B gene may impair the relative abundance of {gamma}a and {gamma}b, thus affecting the transcellular Mg{sup 2

  2. IMPACT OF NEUTRON AND GAMMA RADIATION ON THE DESIGN OF DIAGNOSTICS AND OTHER TARGET-BAY SYSTEMS

    SciTech Connect

    Eder, D C; Song, P M; Latkowski, J F; Reyes, S; O'Brien, D W; Lee, F D; Young, B K; Koch, J A; Watts, P W; Kimbrough, J R; Ng, E W; Landen, O L; MacGowan, B J

    2005-09-01

    The design of a wide range of components in and near the target bay of the National Ignition Facility (NIF) must allow for significant radiation from neutrons and gammas. Detailed 3D Monte Carlo simulations are critical to determine neutron and gamma fluxes for all target-bay components to allow optimization of location and auxiliary shielding. Demonstration of ignition poses unique challenges because of the large range ({approx}3 orders of magnitude) in the yield for any given attempt at ignition. Some diagnostics will provide data independent of yield, while others will provide data for lower yields and only survive high yields with little or no damage. In addition, for a given yield there is a more than 10 orders of magnitude range in neutron and gamma fluxes depending on location in the facility. For example, sensitive components in the diagnostic mezzanines and switchyards require auxiliary shielding for high-yield shots even though they are greater than 17 meters from target chamber center (TCC) and shielded by the 2 m-thick target-bay wall. In contrast, there are components 0.2 to 2 m from TCC with little or no shielding. For these components, particular attention is being made to use low-activation material because of the extremely high neutron loading levels. Many of the components closest to target center are designed to be single use to reduce worker dose from having to refurbish highly activated components. The cryogenic target positioner is an example where activation and ease of component replacement is an important part of the design. We are developing a design process for all target-bay systems that will assure reliable operation for the full range of planned yields.

  3. Neutron and gamma-ray shielding requirements for a below-ground neutrino detector system at the Rutherford Laboratory Spallation Neutron Source

    SciTech Connect

    Gabriel, T.A.; Lillie, R.A.; Childs, R.L.; Wilczynski, J.; Zeitnitz, B.

    1983-03-01

    The neutron and gamma-ray shielding requirements for a proposed neutrino system below the target station at the Rutherford Laboratory Spallation Neutron Source (SNS) are studied. The present shield below the station consists of 2 meters of iron and 1 meter of concrete, below which is chalk (CaCO/sub 3/). An underground bunker housing the neutrino detector system would require additional shielding consisting of 6 meters of the chalk plus approx. 3 meters of iron to reduce the number of high-energy (> approx. 7 MeV) neutrons and gamma rays entering the detector system to an acceptable level of approx. 1 per day.

  4. Roles of PU.1 in monocyte- and mast cell-specific gene regulation: PU.1 transactivates CIITA pIV in cooperation with IFN-gamma.

    PubMed

    Ito, Tomonobu; Nishiyama, Chiharu; Nakano, Nobuhiro; Nishiyama, Makoto; Usui, Yoshihiko; Takeda, Kazuyoshi; Kanada, Shunsuke; Fukuyama, Kanako; Akiba, Hisaya; Tokura, Tomoko; Hara, Mutsuko; Tsuboi, Ryoji; Ogawa, Hideoki; Okumura, Ko

    2009-07-01

    Over-expression of PU.1, a myeloid- and lymphoid-specific transcription factor belonging to the Ets family, induces monocyte-specific gene expression in mast cells. However, the effects of PU.1 on each target gene and the involvement of cytokine signaling in PU.1-mediated gene expression are largely unknown. In the present study, PU.1 was over-expressed in two different types of bone marrow-derived cultured mast cells (BMMCs): BMMCs cultured with IL-3 plus stem cell factor (SCF) and BMMCs cultured with pokeweed mitogen-stimulated spleen-conditioned medium (PWM-SCM). PU.1 over-expression induced expression of MHC class II, CD11b, CD11c and F4/80 on PWM-SCM-cultured BMMCs, whereas IL-3/SCF-cultured BMMCs expressed CD11b and F4/80, but not MHC class II or CD11c. When IFN-gamma was added to the IL-3/SCF-based medium, PU.1 transfectant acquired MHC class II expression, which was abolished by antibody neutralization or in Ifngr(-/-) BMMCs, through the induction of expression of the MHC class II transactivator, CIITA. Real-time PCR detected CIITA mRNA driven by the fourth promoter, pIV, and chromatin immunoprecipitation indicated direct binding of PU.1 to pIV in PU.1-over-expressing BMMCs. PU.1-over-expressing cells showed a marked increase in IL-6 production in response to LPS stimulation in both IL-3/SCF and PWM-SCM cultures. These results suggest that PU.1 overproduction alone is sufficient for both expression of CD11b and F4/80 and for amplification of LPS-induced IL-6 production. However, IFN-gamma stimulation is essential for PU.1-mediated transactivation of CIITA pIV. Reduced expression of mast cell-related molecules and transcription factors GATA-1/2 and up-regulation of C/EBPalpha in PU.1 transfectants indicate that enforced PU.1 suppresses mast cell-specific gene expression through these transcription factors.

  5. Understanding the links between vestibular and limbic systems regulating emotions

    PubMed Central

    Rajagopalan, Archana; Jinu, K. V.; Sailesh, Kumar Sai; Mishra, Soumya; Reddy, Udaya Kumar; Mukkadan, Joseph Kurien

    2017-01-01

    Vestibular system, which consists of structures in the inner ear and brainstem, plays a vital role is body balance and patient well-being. In recent years, modulating this system by vestibular stimulation techniques are reported to be effective in stress relief and possibly patient's emotional well-being. Emotions refer to an aroused state involving intense feeling, autonomic activation, and related change in behavior, which accompany many of our conscious experiences. The limbic system is primarily involved in the regulation of emotions. Considering the extensive networks between vestibular and limbic system, it is likely that vestibular stimulation techniques may be useful in influencing emotions. Hence, we review here, the possible mechanisms through which vestibular system can influence emotions and highlight the necessary knowledge gaps, which warrants further research to develop vestibular stimulation techniques as a means to treat health conditions associated with emotional disturbances. PMID:28250668

  6. Occurrence of regulated and non-regulated disinfection by-products in small drinking water systems.

    PubMed

    Guilherme, Stéphanie; Rodriguez, Manuel J

    2014-12-01

    The occurrence of regulated and non-regulated disinfection by-products (DBPs) was investigated in the drinking water of small systems in two provinces in Canada, Newfoundland and Labrador (NL) and Quebec (QC), through an intensive sampling program. Sixteen DBPs were studied: four trihalomethanes (THMs), five haloacetic acids (HAAs), four haloacetonitriles (HANs), one halonitromethane, chloropikrin (CPK) and two haloketones (HKs). Average measured concentrations of these compounds were much higher than those reported in the literature for medium and large systems. The measured average value for THMs was 75 μg L(-1) (Stdv=69μgL(-1)); HAAs, 77 μg L(-1) (Stdv=75 μg L(-1)); HANs, 2.5 μg L(-1) (Stdv=1.8 μg L(-1)); CPK, 0.4 μg L(-1) (Stdv=0.3 μg L(-1)) and HKs, 6.0 μg L(-1) (Stdv=4.5 μg L(-1)). The gap (some 10 times difference) between the average levels of regulated DBPs (THMs, HAAs) and non-regulated DBPs (HANs, CPK and HKs) is comparable to that observed in large systems where the occurrence of the same compounds has been reported. Generally, investigated DBPs followed a comparable seasonal evolution during the year: they decreased between the fall and winter and then increased to eventually reach a maximum in late summer. This trend was less observable in NL than in QC. However, observed seasonal fluctuations of DBPs were less considerable than those observed in medium and large systems located in similar temperate environments reported in the literature. Spatial variations from the plant to the extremities were high and comparable to those observed in large systems, which is surprising, considering the smaller size of distribution networks supplying small communities. Generally speaking, the results support the premise that problems associated with implementing treatment that removes DBP precursors in water submitted to chlorination can increase population exposure to these contaminants in small systems.

  7. Regulation of Bacterial Virulence by Csr (Rsm) Systems

    PubMed Central

    Vakulskas, Christopher A.; Potts, Anastasia H.; Babitzke, Paul; Ahmer, Brian M. M.

    2015-01-01

    SUMMARY Most bacterial pathogens have the remarkable ability to flourish in the external environment and in specialized host niches. This ability requires their metabolism, physiology, and virulence factors to be responsive to changes in their surroundings. It is no surprise that the underlying genetic circuitry that supports this adaptability is multilayered and exceedingly complex. Studies over the past 2 decades have established that the CsrA/RsmA proteins, global regulators of posttranscriptional gene expression, play important roles in the expression of virulence factors of numerous proteobacterial pathogens. To accomplish these tasks, CsrA binds to the 5′ untranslated and/or early coding regions of mRNAs and alters translation, mRNA turnover, and/or transcript elongation. CsrA activity is regulated by noncoding small RNAs (sRNAs) that contain multiple CsrA binding sites, which permit them to sequester multiple CsrA homodimers away from mRNA targets. Environmental cues sensed by two-component signal transduction systems and other regulatory factors govern the expression of the CsrA-binding sRNAs and, ultimately, the effects of CsrA on secretion systems, surface molecules and biofilm formation, quorum sensing, motility, pigmentation, siderophore production, and phagocytic avoidance. This review presents the workings of the Csr system, the paradigm shift that it generated for understanding posttranscriptional regulation, and its roles in virulence networks of animal and plant pathogens. PMID:25833324

  8. Regulation of bacterial virulence by Csr (Rsm) systems.

    PubMed

    Vakulskas, Christopher A; Potts, Anastasia H; Babitzke, Paul; Ahmer, Brian M M; Romeo, Tony

    2015-06-01

    Most bacterial pathogens have the remarkable ability to flourish in the external environment and in specialized host niches. This ability requires their metabolism, physiology, and virulence factors to be responsive to changes in their surroundings. It is no surprise that the underlying genetic circuitry that supports this adaptability is multilayered and exceedingly complex. Studies over the past 2 decades have established that the CsrA/RsmA proteins, global regulators of posttranscriptional gene expression, play important roles in the expression of virulence factors of numerous proteobacterial pathogens. To accomplish these tasks, CsrA binds to the 5' untranslated and/or early coding regions of mRNAs and alters translation, mRNA turnover, and/or transcript elongation. CsrA activity is regulated by noncoding small RNAs (sRNAs) that contain multiple CsrA binding sites, which permit them to sequester multiple CsrA homodimers away from mRNA targets. Environmental cues sensed by two-component signal transduction systems and other regulatory factors govern the expression of the CsrA-binding sRNAs and, ultimately, the effects of CsrA on secretion systems, surface molecules and biofilm formation, quorum sensing, motility, pigmentation, siderophore production, and phagocytic avoidance. This review presents the workings of the Csr system, the paradigm shift that it generated for understanding posttranscriptional regulation, and its roles in virulence networks of animal and plant pathogens.

  9. Data Processing for the Near Earth Asteroid Rendezvous (NEAR), X-Ray and Gamma-Ray Spectrometer (XRS) Ground System

    NASA Technical Reports Server (NTRS)

    McClanahan, Timothy P.; Mikheeva, I.; Trombka, J. I.; Floyd, S. R.; Boynton, W. V.; Bailey, H.; Bhangoo, J.; Starr, R.; Clark, P. E.; Evans, L. G.

    1999-01-01

    An X-ray and Gamma-ray spectrometer (XGRS) is onboard the Near Earth Asteroid Rendezvous (NEAR) spacecraft to determine the elemental composition of the surface of the asteroid 433Eros. The Eros asteroid is highly non-spherical in physical shape and the development of data management and analysis methodologies are in several areas a divergence from traditional remotely sensed geographical information systems techniques. Field of view and asteroid surface geometry must be derived virtually and then combined with real measurements of solar, spectral and instrument calibration information to derive meaningful scientific results. Spatial resolution of planned geochemical maps will be improved from the initial conditions of low statistical significance per integration by repeated surface flyovers and regional spectral accumulation. This paper describes the results of a collaborative effort of design and development of the NEAR XGRS instrument ground system undertaken by participants at the Goddard Space Flight Center, University of Arizona, Cornell University, Applied Physics Laboratory, and Max Plank institute.

  10. Data Processing for the Near Earth Asteroid Rendezvous (NEAR), X-ray and Gamma-ray Spectrometer (XGRS) Ground System

    NASA Technical Reports Server (NTRS)

    McClanahan, Timothy P.; Mikheeva, I.; Trombka, J. I.; Floyd, S. R.; Boynton, W. V.; Bailey, H.; Bhangoo, J.; Starr, R.; Clark, P. E.; Evans, L. G.

    1999-01-01

    An X-ray and Gamma-ray spectrometer (XGRS) is onboard the Near Earth Asteroid Rendezvous (NEAR) spacecraft to determine the elemental composition of the surface of the asteroid 433Eros. The Eros asteroid is highly non-spherical in physical shape and the development of data management and analysis methodologies are in several areas a divergence from traditional remotely sensed geographical information systems techniques. Field of view and asteroid surface geometry must be derived virtually and then combined with real measurements of solar, spectral and instrument calibration information to derive meaningful scientific results. Spatial resolution of planned geochemical maps will be improved from the initial conditions of low statistical significance per integration by repeated surface flyovers and regional spectral accumulation. This paper describes the results of a collaborative effort of design and development of the NEAR XGRS instrument ground system undertaken by participants at the Goddard Space Flight Center, University of Arizona, Cornell University, Applied Physics Laboratory, and Max Plank institute.

  11. The spectra program library: A PC based system for gamma-ray spectra analysis and INAA data reduction

    USGS Publications Warehouse

    Baedecker, P.A.; Grossman, J.N.

    1995-01-01

    A PC based system has been developed for the analysis of gamma-ray spectra and for the complete reduction of data from INAA experiments, including software to average the results from mulitple lines and multiple countings and to produce a final report of analysis. Graphics algorithms may be called for the analysis of complex spectral features, to compare the data from alternate photopeaks and to evaluate detector performance during a given counting cycle. A database of results for control samples can be used to prepare quality control charts to evaluate long term precision and to search for systemic variations in data on reference samples as a function of time. The entire software library can be accessed through a user-friendly menu interface with internal help.

  12. Dynamic gamma knife radiosurgery

    NASA Astrophysics Data System (ADS)

    Luan, Shuang; Swanson, Nathan; Chen, Zhe; Ma, Lijun

    2009-03-01

    Gamma knife has been the treatment of choice for various brain tumors and functional disorders. Current gamma knife radiosurgery is planned in a 'ball-packing' approach and delivered in a 'step-and-shoot' manner, i.e. it aims to 'pack' the different sized spherical high-dose volumes (called 'shots') into a tumor volume. We have developed a dynamic scheme for gamma knife radiosurgery based on the concept of 'dose-painting' to take advantage of the new robotic patient positioning system on the latest Gamma Knife C™ and Perfexion™ units. In our scheme, the spherical high dose volume created by the gamma knife unit will be viewed as a 3D spherical 'paintbrush', and treatment planning reduces to finding the best route of this 'paintbrush' to 'paint' a 3D tumor volume. Under our dose-painting concept, gamma knife radiosurgery becomes dynamic, where the patient moves continuously under the robotic positioning system. We have implemented a fully automatic dynamic gamma knife radiosurgery treatment planning system, where the inverse planning problem is solved as a traveling salesman problem combined with constrained least-square optimizations. We have also carried out experimental studies of dynamic gamma knife radiosurgery and showed the following. (1) Dynamic gamma knife radiosurgery is ideally suited for fully automatic inverse planning, where high quality radiosurgery plans can be obtained in minutes of computation. (2) Dynamic radiosurgery plans are more conformal than step-and-shoot plans and can maintain a steep dose gradient (around 13% per mm) between the target tumor volume and the surrounding critical structures. (3) It is possible to prescribe multiple isodose lines with dynamic gamma knife radiosurgery, so that the treatment can cover the periphery of the target volume while escalating the dose for high tumor burden regions. (4) With dynamic gamma knife radiosurgery, one can obtain a family of plans representing a tradeoff between the delivery time and the

  13. SU-E-T-594: Out-Of-Field Neutron and Gamma Dose Estimated Using TLD-600/700 Pairs in the Wobbling Proton Therapy System

    SciTech Connect

    Chen, Y; Lin, Y; Tsai, H

    2015-06-15

    Purpose: Secondary fast neutrons and gamma rays are mainly produced due to the interaction of the primary proton beam with the beam delivery nozzle. These secondary radiation dose to patients and radiation workers are unwanted. The purpose of this study is to estimate the neutron and gamma dose equivalent out of the treatment volume during the wobbling proton therapy system. Methods: Two types of thermoluminescent (TL) dosimeters, TLD-600 ({sup 6}LiF: Mg, Ti) and TLD-700 ({sup 7}LiF: Mg, Ti) were used in this study. They were calibrated in the standard neutron and gamma sources at National Standards Laboratory. Annealing procedure is 400°C for 1 hour, 100°C for 2 hours and spontaneously cooling down to the room temperature in a programmable oven. Two-peak method (a kind of glow curve analysis technique) was used to evaluate the TL response corresponding to the neutron and gamma dose. The TLD pairs were placed outside the treatment field at the neutron-gamma mixed field with 190-MeV proton beam produced by the wobbling system through the polyethylene plate phantom. The results of TLD measurement were compared to the Monte Carlo simulation. Results: The initial experiment results of calculated dose equivalents are 0.63, 0.38, 0.21 and 0.13 mSv per Gy outside the field at the distance of 50, 100, 150 and 200 cm. Conclusion: The TLD-600 and TLD-700 pairs are convenient to estimate neutron and gamma dosimetry during proton therapy. However, an accurate and suitable glow curve analysis technique is necessary. During the wobbling system proton therapy, our results showed that the neutron and gamma doses outside the treatment field are noticeable. This study was supported by the grants from the Chang Gung Memorial Hospital (CMRPD1C0682)

  14. Application of the Double-Tangent Construction of Coexisting Phases to Any Type of Phase Equilibrium for Binary Systems Modeled with the Gamma-Phi Approach

    ERIC Educational Resources Information Center

    Jaubert, Jean-Noël; Privat, Romain

    2014-01-01

    The double-tangent construction of coexisting phases is an elegant approach to visualize all the multiphase binary systems that satisfy the equality of chemical potentials and to select the stable state. In this paper, we show how to perform the double-tangent construction of coexisting phases for binary systems modeled with the gamma-phi…

  15. Evaluation of sarcoglycans, vinculin-talin-integrin system and filamin2 in alpha- and gamma-sarcoglycanopathy: an immunohistochemical study.

    PubMed

    Anastasi, Giuseppe; Cutroneo, Giuseppina; Trimarchi, Fabio; Santoro, Giuseppe; Bruschetta, Daniele; Bramanti, Placido; Pisani, Antonina; Favaloro, Angelo

    2004-12-01

    The sarcoglycan subcomplex (SGC) is a well-known system of interaction between extracellular matrix and sarcolemma-associated cytoskeleton in skeletal and cardiac muscle. The SGC is included in the DGC made up of sarcoplasmic subcomplex and a dystroglycan subcomplex. Recent developments in molecular genetics have demonstrated that the mutation of each single sarcoglycan gene, causes a series of recessive autosomal muscular dystrophies, dystrophin-positive, called sarcoglycanopathies or limb girdle muscular dystrophies. Our recent studies have demonstrated that costameres are a proteic machinery made up of DGC and vinculin-talin-integrin system, also revealing the colocalization of sarcoglycans and integrins in adult human skeletal muscle. These results may support the hypothesis of the existence of a bidirectional signalling between sarcoglycans and integrins in cultured L6 myocytes. The hypothesis of bidirectional signalling between sarcoglycans and integrins could be supported by the identification of a skeletal and cardiac muscle filamin2 as a gamma-sarcoglycan, delta-sarcoglycan and, hypothetically, beta1 integrin interacting protein. Our results, acquired with an immunofluorescence study on adult human skeletal muscle affected by LGMD type 2D and 2C, showed that in LGMD2D: a) alpha-sarcoglycan staining is severely reduced; b) the beta-gamma-delta-sarcoglycan subunit and all tested integrins staining are clearly detectable; c) filamin2 is normal and shows a costameric distribution. In LGMD2C: a) alpha-sarcoglycan staining is preserved; b) the beta-gamma-delta-sarcoglycan subunit staining is severely reduced; c) the alpha7B-integrin is slightly reduced and beta1D-integrin is severely reduced; d) filamin2 is severely reduced. Other tested proteins of the two systems show a normal staining pattern in both sarcoglycanopathies. Our study seems to confirm, for the first time on adult human skeletal muscle of subjects affected by LGMDs, the hypo-theses of: a) the

  16. DC Bus Regulation with a Flywheel Energy Storage System

    NASA Technical Reports Server (NTRS)

    Kenny, Barbara H.; Kascak, Peter E.

    2003-01-01

    This paper describes the DC bus regulation control algorithm for the NASA flywheel energy storage system during charge, charge reduction and discharge modes of operation. The algorithm was experimentally verified with results given in a previous paper. This paper presents the necessary models for simulation with detailed block diagrams of the controller algorithm. It is shown that the flywheel system and the controller can be modeled in three levels of detail depending on the type of analysis required. The three models are explained and then compared using simulation results.

  17. GAMMA IRRADIATION TESTING OF MONTAN WAX FOR USE IN WASTE MANAGEMENT SYSTEMS

    SciTech Connect

    SOO,P.; HEISER,J.; HART,A.

    1996-09-08

    A field demonstration was funded by the US Department of Energy (DOE) to quantify the potential use of montan wax as a subsurface barrier material for nuclear waste management applications. As part of that demonstration, a study was completed to address some of the characteristics of the wax. Of particular interest is its resistance to chemical and structural changes that would influence its integrity as a barrier to minimize the migration of contaminants from their storage or disposal locations. Properties that were evaluated included hardness, melting point, molecular weight, and biodegradation as a function of gamma radiation dose. Based on the data obtained to date the wax is extremely resistant to radiation-induced change. Coupled with low permeability, the material shows promise as a subsurface barrier material.

  18. Thermal, mechanical and ionic conductive behaviour of gamma-radiation induced PEO/PVDF(SIN)-LiClO 4 polymer electrolyte system

    NASA Astrophysics Data System (ADS)

    Song, Yongxian; Wu, Shuyun; Jing, Xiabing; Sun, Jiazhen; Chen, Donglin

    1997-05-01

    An effort has been made to modify the mechanical behaviour of our previously reported gel-type gamma-radiation crosslinked polyethylene oxide (PEO)-LiClO 4 polymer electrolyte. A highly polar and gamma-radiation crosslinkable crystalline polymer, polyvinylidene fluoride (PVDF), was selected to blend with PEO and then subjected to gamma-irradiation in order to make an simultaneous interpenetrating network (SIN), which was used as a polymer host to impart stiffness to the plasticized system. Experimental results have shown that the presence of PVDF in the system, through gamma-radiation induced SIN formation, could not only give a rather high mechanical modulus of 10 7 Pa at ambient temperature, but also maintain the room temperature ionic conductivity at a high level (greater than 10 -4 S/cm). DSC, DMA and conductivity measurement techniques were used to examine the effects of blending, gamma-irradiation and plasticization on the variations of glass transition and melting endotherm, on the appearance of high elastic plateau and on the temperature dependence of ionic conductivity. In addition, it was found that, in contrast with the unplasticized system, the ionic conductivity mechanism of this gel-type electrolyte seems to conform to the Arrhenius model, suggesting that, as a result of the high degree of plasticization, the polymer chains act mainly as the skeleton of the networks or polymer cages to immobilize the liquid electrolyte solution, whereas the ionic species migrate as if they were in a liquid medium.

  19. Mobile gamma-ray scanning system for detecting radiation anomalies associated with /sup 226/Ra-bearing materials

    SciTech Connect

    Myrick, T.E.; Blair, M.S.; Doane, R.W.; Goldsmith, W.A.

    1982-11-01

    A mobile gamma-ray scanning system has been developed by Oak Ridge National Laboratory for use in the Department of Energy's remedial action survey programs. The unit consists of a NaI(T1) detection system housed in a specially-equipped van. The system is operator controlled through an on-board mini-computer, with data output provided on the computer video screen, strip chart recorders, and an on-line printer. Data storage is provided by a floppy disk system. Multichannel analysis capabilities are included for qualitative radionuclide identification. A /sup 226/Ra-specific algorithm is employed to identify locations containing residual radium-bearing materials. This report presents the details of the system description, software development, and scanning methods utilized with the ORNL system. Laboratory calibration and field testing have established the system sensitivity, field of view, and other performance characteristics, the results of which are also presented. Documentation of the instrumentation and computer programs are included.

  20. Interferon-gamma and tumor necrosis factor-alpha regulate amyloid-beta plaque deposition and beta-secretase expression in Swedish mutant APP transgenic mice.

    PubMed

    Yamamoto, Masaru; Kiyota, Tomomi; Horiba, Masahide; Buescher, James L; Walsh, Shannon M; Gendelman, Howard E; Ikezu, Tsuneya

    2007-02-01

    Reactive astrocytes and microglia in Alzheimer's disease surround amyloid plaques and secrete proinflammatory cytokines that affect neuronal function. Relationship between cytokine signaling and amyloid-beta peptide (Abeta) accumulation is poorly understood. Thus, we generated a novel Swedish beta-amyloid precursor protein mutant (APP) transgenic mouse in which the interferon (IFN)-gamma receptor type I was knocked out (APP/GRKO). IFN-gamma signaling loss in the APP/GRKO mice reduced gliosis and amyloid plaques at 14 months of age. Aggregated Abeta induced IFN-gamma production from co-culture of astrocytes and microglia, and IFN-gamma elicited tumor necrosis factor (TNF)-alpha secretion in wild type (WT) but not GRKO microglia co-cultured with astrocytes. Both IFN-gamma and TNF-alpha enhanced Abeta production from APP-expressing astrocytes and cortical neurons. TNF-alpha directly stimulated beta-site APP-cleaving enzyme (BACE1) expression and enhanced beta-processing of APP in astrocytes. The numbers of reactive astrocytes expressing BACE1 were increased in APP compared with APP/GRKO mice in both cortex and hippocampus. IFN-gamma and TNF-alpha activation of WT microglia suppressed Abeta degradation, whereas GRKO microglia had no changes. These results support the idea that glial IFN-gamma and TNF-alpha enhance Abeta deposition through BACE1 expression and suppression of Abeta clearance. Taken together, these observations suggest that proinflammatory cytokines are directly linked to Alzheimer's disease pathogenesis.

  1. Role of gamma carboxylated Glu47 in connexin 26 hemichannel regulation by extracellular Ca²⁺: insight from a local quantum chemistry study.

    PubMed

    Zonta, Francesco; Mammano, Fabio; Torsello, Mauro; Fortunati, Nicola; Orian, Laura; Polimeno, Antonino

    2014-02-28

    Connexin hemichannels are regulated by several gating mechanisms, some of which depend critically on the extracellular Ca(2+) concentration ([Ca(2+)]e). It is well established that hemichannel activity is inhibited at normal (∼1 mM) [Ca(2+)]e, whereas lowering [Ca(2+)]e to micromolar levels fosters hemichannel opening. Atomic force microscopy imaging shows significant and reversible changes of pore diameter at the extracellular mouth of Cx26 hemichannels exposed to different [Ca(2+)]e, however, the underlying molecular mechanisms are not fully elucidated. Analysis of the crystal structure of connexin 26 (Cx26) gap junction channels, corroborated by molecular dynamics (MD) simulations, suggests that several negatively charged amino acids create a favorable environment for low-affinity Ca(2+) binding within the extracellular vestibule of the Cx26 hemichannel. In particular a highly conserved glutammic acid, found in position 47 in most connexins, is thought to undergo post translational gamma carboxylation (γGlu47), and is thus likely to play an important role in Ca(2+) coordination. γGlu47 may also form salt bridges with two conserved arginines (Arg75 and Arg184 in Cx26), which are considered important in stabilizing the structure of the extracellular region. Using a combination of quantum chemistry methods, we analyzed the interaction between γGlu47, Arg75 and Arg184 in a Cx26 hemichannel model both in the absence and in the presence of Ca(2+). We show that Ca(2+) imparts significant local structural changes and speculate that these modifications may alter the structure of the extracellular loops in Cx26, and may thus account for the mechanism of hemichannel closure in the presence of mM [Ca(2+)]e.

  2. Down-Regulated Lymphoproliferation Coincides with Parasite Maturation and with the Collapse of Both Gamma Interferon and Interleukin-4 Responses in a Bovine Model of Onchocerciasis†

    PubMed Central

    Graham, Simon P.; Trees, Alexander J.; Collins, Robert A.; Moore, Davina M.; Guy, Francis M.; Taylor, Mark J.; Bianco, Albert E.

    2001-01-01

    Onchocerciasis is a debilitating parasitic infection caused by the filarial nematode Onchocerca volvulus. Infections are chronic, and persistence of the parasites for several years argues for highly adapted mechanisms of immune evasion. Due to the restricted host repertoire of O. volvulus, we have used the cattle parasite Onchocerca ochengi to investigate the nature of immunomodulation underpinning these long-term infections. Cattle were infected with a single inoculation of 350 infective-stage larvae under laboratory conditions (n = 6). Intradermal nodules containing immature adult worms were detected from 110 days postinfection, and microfilariae in skin were detected from day 280 postinfection. Parasite-specific responses during early infection were nonpolarized with respect to the major Th cytokines (interleukin-4 [IL-4], IL-2, and gamma interferon [IFN-γ]) produced by antigen-stimulated peripheral blood mononuclear cells (PBMC) or serum antibody isotypes. Antigen-induced proliferation of PBMC peaked shortly after exposure and remained high during the prepatent infection. As the parasites matured and animals developed patent infections, there was a profound down-regulation of lymphoproliferation, accompanied by sharp falls in the expression of both IL-4 and IFN-γ and a gradual decline in IL-2. Levels of immunoglobulin G2 (IgG2) fell, while those of IgG1 remained high. We conclude that neither a classical Th2 response nor a simple Th1-to-Th2 switch is sufficient to explain the immunomodulation associated with patent Onchocerca infections. Instead, there is an initial Th0 response, which matures into a response with some, but not all of the features of a Th2 response. The natural host-parasite relationship of O. ochengi in cattle may be useful as both a descriptive and predictive tool to test more refined models of immunomodulation in onchocerciasis. PMID:11401968

  3. Metabolic Master Regulators: Sharing Information among Multiple Systems

    PubMed Central

    Corkey, Barbara E.; Shirihai, Orian

    2012-01-01

    Obesity and diabetes are caused by defects in metabolically sensitive tissues. Attention has been paid to insulin resistance as the key relevant pathosis, with a detailed focus on signal transduction pathways in metabolic tissues. Evidence exists to support an important role for each tissue in metabolic homeostasis and a potential causative role in both diabetes and obesity. The redox metabolome, that coordinates tissue responses and reflects shared control and regulation, is our focus. Consideration is given to the possibility that pathosis results from contributions of all relevant tissues, by virtue of a circulating communication system. Validation of this model would support simultaneous regulation of all collaborating metabolic organs through changes in the circulation, regardless of whether change was initiated exogenously or by a single organ. PMID:22939743

  4. Yersinia Type III Secretion System Master Regulator LcrF

    PubMed Central

    Schwiesow, Leah; Lam, Hanh

    2015-01-01

    Many Gram-negative pathogens express a type III secretion (T3SS) system to enable growth and survival within a host. The three human-pathogenic Yersinia species, Y. pestis, Y. pseudotuberculosis, and Y. enterocolitica, encode the Ysc T3SS, whose expression is controlled by an AraC-like master regulator called LcrF. In this review, we discuss LcrF structure and function as well as the environmental cues and pathways known to regulate LcrF expression. Similarities and differences in binding motifs and modes of action between LcrF and the Pseudomonas aeruginosa homolog ExsA are summarized. In addition, we present a new bioinformatics analysis that identifies putative LcrF binding sites within Yersinia target gene promoters. PMID:26644429

  5. Gamma ray shielding and structural properties of Bi2O3-PbO-B2O3-V2O5 glass system

    NASA Astrophysics Data System (ADS)

    Kaur, Kulwinder; Singh, K. J.; Anand, Vikas

    2014-04-01

    The present work has been undertaken to evaluate the applicability of Bi2O3-PbO-B2O3-V2O5 glass system as gamma ray shielding material. Gamma ray mass attenuation coefficient has been determined theoretically using WinXcom computer software developed by National Institute of Standards and Technology. A meaningful comparison of their radiation shielding properties has been made in terms of their half value layer parameter with standard radiation shielding concrete 'barite'. Structural properties of the prepared glass system have been investigated in terms of XRD and FTIR techniques in order to check the possibility of their commercial utility as alternate to conventional concrete for gamma ray shielding applications.

  6. The Gamma-ray Sky with Fermi

    NASA Technical Reports Server (NTRS)

    Thompson, David

    2012-01-01

    Gamma rays reveal extreme, nonthermal conditions in the Universe. The Fermi Gamma-ray Space Telescope has been exploring the gamma-ray sky for more than four years, enabling a search for powerful transients like gamma-ray bursts, novae, solar flares, and flaring active galactic nuclei, as well as long-term studies including pulsars, binary systems, supernova remnants, and searches for predicted sources of gamma rays such as dark matter annihilation. Some results include a stringent limit on Lorentz invariance derived from a gamma-ray burst, unexpected gamma-ray variability from the Crab Nebula, a huge gamma-ray structure associated with the center of our galaxy, surprising behavior from some gamma-ray binary systems, and a possible constraint on some WIMP models for dark matter.

  7. Method and system for the combination of non-thermal plasma and metal/metal oxide doped .gamma.-alumina catalysts for diesel engine exhaust aftertreatment system

    DOEpatents

    Aardahl, Christopher L.; Balmer-Miller, Mari Lou; Chanda, Ashok; Habeger, Craig F.; Koshkarian, Kent A.; Park, Paul W.

    2006-07-25

    The present disclosure pertains to a system and method for treatment of oxygen rich exhaust and more specifically to a method and system that combines non-thermal plasma with a metal doped .gamma.-alumina catalyst. Current catalyst systems for the treatment of oxygen rich exhaust are capable of achieving only approximately 7 to 12% NO.sub.x reduction as a passive system and only 25 40% reduction when a supplemental hydrocarbon reductant is injected into the exhaust stream. It has been found that treatment of an oxygen rich exhaust initially with a non-thermal plasma and followed by subsequent treatment with a metal doped .gamma.-alumina prepared by the sol gel method is capable of increasing the NO.sub.x reduction to a level of approximately 90% in the absence of SO.sub.2 and 80% in the presence of 20 ppm of SO.sub.2. Especially useful metals have been found to be indium, gallium, and tin.

  8. Data management and analysis techniques used in the near X-ray and gamma-ray spectrometer systems

    NASA Astrophysics Data System (ADS)

    McClanahan, T. P.; Trombka, J. I.; Floyd, S. R.; Boynton, W. V.; Mikheeva, I.; Bailey, H.; Liewicki, C.; Bhangoo, J.; Starr, R.; Clark, P. E.; Evans, L. G.; Squyres, S.; McNutt, R.; Brückner, J.

    1999-02-01

    The NEAR Earth Asteroid Rendezvous (NEAR) spacecraft will encounter the 433Eros asteroid for a one year orbital mission in December 1998. Its on-board remote sensing instrumentation includes X-ray and gamma-ray (XGRS) spectrometers. NEAR is an orbital mission and long integrations over spatially specific asteroid regions are generally not possible. A methodology for simulating longer integrations has been developed for XGRS and uses unique management, correlative and analytical ground systems to render mapping data products. Evaluation of the spatial environment is accomplished through virtual renderings of the asteroid surface giving incidence, emission and surface roughness factors. Extended computer plate modeling information is employed to optimize ground computer systems processing time. Interactive visualization systems have been developed to manage close to a million spectra that will be collected during the encounter. Feedback systems are employed to inspect, tag and calibrate spectral data products. Mission planning, systems development and managerial responsibilities have been distributed to cooperating science organizations at The Goddard Space Flight Center, The University of Arizona, Cornell University, The Applied Physics Laboratory and The Max Plank Institute.

  9. High molecular weight poly-gamma-glutamic acid regulates lipid metabolism in rats fed a high-fat diet and humans.

    PubMed

    Park, Ji Ho; Choi, Jae-Chul; Sung, Moon-Hee; Kang, Jae-Heon; Chang, Moon-Jeong

    2011-07-01

    We investigated the effect of high molecular weight polygamma- glutamic acid (hm gamma-PGA) on adiposity and lipid metabolism of rats in the presence of an obesity-inducing diet. Thirty-two Sprague-Dawley rats were fed either a normal-fat (11.4% kcal fat, NFC) or high-fat (51% kcal fat, HFC) diet. After 5 weeks, half of each diet-fed group was treated with hm gamma-PGA (NFP or HFP) for 4 weeks. The HFC group had significantly higher body weight, visceral fat mass, fasting serum levels of total cholesterol, LDL cholesterol, and leptin, and lower serum HDL cholesterol level compared with those of the NFC group (p < 0.05). Treatment with hm gamma-PGA decreased body weight gain and perirenal fat mass (p<0.05), fasting serum total cholesterol, and mRNA expression of glucose-6- phosphate dehydrogenase (G6PD), regardless of dietary fat contents (p < 0.01). However, hm gamma-PGA increased serum HDL cholesterol in the HFC group (p < 0.05). In vitro, 3-hydroxy-3-methylglutaryl coenzyme-A (HMGCoA) reductase activity was suppressed by the addition of hm gamma-PGA. In agreement with observations in animal study, the supplementation of hm gamma-PGA (150 mg/day) to 20 female subjects in an 8-week double-blind, placebocontrolled study resulted in a tendency to decrease total cholesterol and LDL cholesterol concentrations. We thus conclude that dietary supplementation of hm gamma-PGA may act as a hypocholestrolemic agent, secondary to its inhibitor effect on HMG-CoA reductase, and decrease abdominal adiposity by decreasing hepatic lipogenesis. The present study is an important first step in establishing the effect of hm gamma-PGA on cholesterol levels in rats and humans.

  10. Modeling and Investigation of Heavy Oxide and Alkali-Halide Scintillators for Potential Use in Neutron and Gamma Detection Systems

    DTIC Science & Technology

    2015-06-01

    Gamma rays are a form of high energy electromagnetic radiation created in a nuclear process or transition. Gamma radiation from the decay of...fast neutron detection efficiencies well over 40%, were investigated for potential use as highly efficient gamma-neutron radiation detectors. The...Monte Carlo N-Particle radiation transport code (MCNP) was used to characterize the radiation interactions in a candidate set of crystals, including

  11. Study on detecting spatial distribution of neutrons and gamma rays using a multi-imaging plate system.

    PubMed

    Tanaka, Kenichi; Sakurai, Yoshinori; Endo, Satoru; Takada, Jun

    2014-06-01

    In order to measure the spatial distributions of neutrons and gamma rays separately using the imaging plate, the requirement for the converter to enhance specific component was investigated with the PHITS code. Consequently, enhancing fast neutrons using recoil protons from epoxy resin was not effective due to high sensitivity of the imaging plate to gamma rays. However, the converter of epoxy resin doped with (10)B was found to have potential for thermal and epithermal neutrons, and graphite for gamma rays.

  12. REGULATION OF MULTIPLE RENIN-ANGIOTENSIN SYSTEM GENES BY SRY

    PubMed Central

    Milsted, Amy; Underwood, Adam C.; Dunmire, Jeff; DelPuerto, Helen L.; Martins, Almir S.; Ely, Daniel L.; Turner, Monte E.

    2010-01-01

    We demonstrated that the Sry gene complex on the SHR Y chromosome is a candidate locus for hypertension that accounts for the SHR Y chromosome blood pressure effect. All rat strains examined to date share 6 Sry loci, and a seventh Sry locus (Sry3) appears to be unique to SHR males. Previously, we showed that Sry1 increased activity of the tyrosine hydroxylase promoter in transfected PC12 cells, and Sry1 delivered to adrenal gland of WKY rats increased blood pressure and sympathetic nervous system activity. The objective of this study was to determine whether renin-angiotensin system genes participate in Sry-mediated effects. Sry expression vectors were co-transfected into CHO cells with luciferase reporter constructs containing promoters of angiotensinogen (Agt −1430/+22), renin (Ren −1050/−1), ACE (ACE −1677/+21) and ACE2 (ACE2 −1091/+83). Sry1, Sry2 and Sry3 differentially up-regulated activity of the promoters of angiotensinogen, renin and ACE genes, and down-regulated ACE2 promoter activity. The largest effect was seen with Sry3, which increased activity of angiotensinogen promoter by 1.7 fold, renin promoter by 1.3 fold, ACE promoter by 2.6 fold, and decreased activity of ACE2 promoter by 0.5 fold. The effect of Sry1 on promoter activity was significantly less than Sry3. Sry2 activated promoters at a significantly lower level than Sry1. The result of either an additive effect of Sry regulation of multiple genes in the renin-angiotensin system or alterations in expression of a single gene could favor increased levels of Ang II and decreased levels of Ang-(1-7). These actions of Sry could result in increased blood pressure in males and contribute to gender differences in blood pressure. PMID:19809364

  13. Genistein nanoparticles protect mouse hematopoietic system and prevent proinflammatory factors after gamma irradiation.

    PubMed

    Ha, Cam T; Li, Xiang-Hong; Fu, Dadin; Xiao, Mang; Landauer, Michael R

    2013-09-01

    Previous studies demonstrated that genistein protects mice from radiation-induced bone marrow failure. To overcome genistein's extremely low water solubility, a nanoparticle suspension of genistein has been formulated for more rapid dissolution. In the current study, we evaluated the radioprotective effects of a nanoparticle formulation of genistein on survival and hematopoietic recovery in mice exposed to total-body gamma irradiation. A single intramuscular injection of a saline-based genistein nanosuspension (150 mg/kg) administered to CD2F1 mice 24 h before 9.25 Gy (60)Co radiation exposure resulted in a 30-day survival rate of 95% compared to 25% in vehicle-treated animals. In mice irradiated at 7 Gy, the genistein nanosuspension increased mouse bone marrow cellularity from approximately 2.9% (vehicle treated) to 28.3% on day 7 postirradiation. Flow cytometry analysis demonstrated decreased radiation-induced hematopoietic stem and progenitor cell (HSPC, Lineage(-)/cKit(+)) death from 77.0% (vehicle) to 43.9% (genistein nanosuspension) with a significant recovery of clonogenicity 7 days after irradiation. The genistein nanosuspension also attenuated the radiation-induced elevation of proinflammatory factors interleukin 1 beta (IL-1β), IL-6 and cyclooxygenase-2 (COX-2) in mouse bone marrow and spleen, which may contribute to protecting HSPCs.

  14. Macrophage migration inhibitory factor (MIF): a glucocorticoid counter-regulator within the immune system.

    PubMed

    Calandra, T; Bucala, R

    1997-01-01

    Originally described as a T lymphocyte-derived factor that inhibited the random migration of macrophages, the protein known as macrophage migration inhibitory factor (MIF) was an enigmatic cytokine for almost 3 decades. In recent years, the discovery of MIF as a product of the anterior pituitary gland and the cloning and expression of bioactive, recombinant MIF protein have led to the definition of its critical biological role in vivo. MIF has the unique property of being released from macrophages and T lymphocytes that have been stimulated by glucocorticoids. Once released, MIF overcomes the inhibitory effects of glucocorticoids on TNF alpha, IL-1 beta, IL-6, and IL-8 production by LPS-stimulated monocytes in vitro and suppresses the protective effects of steroids against lethal endotoxemia in vivo. MIF also antagonizes glucocorticoid inhibition of T-cell proliferation in vitro by restoring IL-2 and IFN-gamma production. This observation has identified a pivotal role for MIF within the immune system and fills an important gap in our understanding of the control of inflammatory and immune responses. Glucocorticoids have long been considered to be an integral component of the stress response to infection or tissue invasion and serve to modulate inflammatory and immune responses. MIF is the first mediator to be identified that can counter-regulate the inhibitory effects of glucocorticoids and thus plays a critical role in the host control of inflammation and immunity.

  15. Somatostatin system: molecular mechanisms regulating anterior pituitary hormones.

    PubMed

    Eigler, Tamar; Ben-Shlomo, Anat

    2014-08-01

    The somatostatin (SRIF) system, which includes the SRIF ligand and receptors, regulates anterior pituitary gland function, mainly inhibiting hormone secretion and to some extent pituitary tumor cell growth. SRIF-14 via its cognate G-protein-coupled receptors (subtypes 1-5) activates multiple cellular signaling pathways including adenylate cyclase/cAMP, MAPK, ion channel-dependent pathways, and others. In addition, recent data have suggested SRIF-independent constitutive SRIF receptor activity responsible for GH and ACTH inhibition in vitro. This review summarizes current knowledge on ligand-dependent and independent SRIF receptor molecular and functional effects on hormone-secreting cells in the anterior pituitary gland.

  16. Iron acquisition and regulation systems in Streptococcus species.

    PubMed

    Ge, Ruiguang; Sun, Xuesong

    2014-05-01

    Gram-positive Streptococcus species are responsible for millions of cases of meningitis, bacterial pneumonia, endocarditis, erysipelas and necrotizing fasciitis. Iron is essential for the growth and survival of Streptococcus in the host environment. Streptococcus species have developed various mechanisms to uptake iron from an environment with limited available iron. Streptococcus can directly extract iron from host iron-containing proteins such as ferritin, transferrin, lactoferrin and hemoproteins, or indirectly by relying on the employment of specialized secreted hemophores (heme chelators) and small siderophore molecules (high affinity ferric chelators). This review presents the most recent discoveries in the iron acquisition system of Streptococcus species - the transporters as well as the regulators.

  17. Systems analysis of bone remodelling as a homeostatic regulator.

    PubMed

    Chen, A; Hamamura, K; Zhang, P; Chen, Y; Yokota, H

    2010-01-01

    Bone remodelling in adult skeleton is a process of maintaining bone mass through combined activities of bone forming osteoblasts and bone resorbing osteoclasts. Focusing on a molecular pathway mediated by osteoprotegerin, the authors derived a mathematical formulation for molecular interactions and cellular behaviours. The authors also treated this remodelling process as a homeostatic regulator in a framework of linear quadratic problems. A primary question was: does a solution of a matrix Riccati equation provide a guideline for therapeutic interventions for prevention of bone loss? In order to elucidate the systems dynamics, the authors analysed the perturbed set of equations around a stable equilibrium state together with the original equations. The results demonstrate that a homeostatic regulator with the selected control variables effectively reduces bone degradation activities and restore a physiological remodelling process. To partially validate efficacy of the described intervention strategy, biological experiments were conducted with an osteoblast cell line using one of the control variables, salubrinal (chemical agent). The authors observed that administration of salubrinal activated mRNA levels of transcription factors and an osteogenic marker gene as well as enhancement of mineralisation. Taken together, the current study supports a potential usage of control theories in active regulation of bone remodelling homeostasis.

  18. Neutron/gamma coupled library generation and gamma transport calculation with KARMA 1.2

    SciTech Connect

    Hong, S. G.; Kim, K. S.; Cho, J. Y.; Lee, K. H.

    2012-07-01

    KAERI has developed a lattice transport calculation code KARMA and its multi-group cross section library generation system. Recently, the multi-group cross section library generation system has included a gamma cross section generation capability and KARMA also has been improved to include a gamma transport calculation module. This paper addresses the multi-group gamma cross section generation capability for the KARMA 1.2 code and the preliminary test results of the KARMA 1.2 gamma transport calculations. The gamma transport calculation with KARMA 1.2 gives the gamma flux, gamma smeared power, and gamma energy deposition distributions. The results of the KARMA gamma calculations were compared with those of HELIOS and they showed that KARMA 1.2 gives reasonable gamma transport calculation results. (authors)

  19. Self-Regulating Water-Separator System for Fuel Cells

    NASA Technical Reports Server (NTRS)

    Vasquez, Arturo; McCurdy, Kerri; Bradley, Karla F.

    2007-01-01

    proposed system would perform multiple coordinated functions in regulating the pressure of the oxidant gas (usually, pure oxygen) flowing to a fuelcell stack and in removing excess product water that is generated in the normal fuel-cell operation. The system could function in the presence or absence of gravitation, and in any orientation in a gravitational field. Unlike some prior systems for removing product water, the proposed system would not depend on hydrophobicity or hydrophilicity of surfaces that are subject to fouling and, consequently, to gradual deterioration in performance. Also unlike some prior systems, the proposed system would not include actively controlled electric motors for pumping; instead, motive power for separation and pumping away of product water would be derived primarily from the oxidant flow and perhaps secondarily from the fuel flow. The net effect of these and other features would be to make the proposed system more reliable and safer, relative to the prior systems. The proposed system (see figure) would include a pressure regulator and sensor in the oxidant supply just upstream from an ejector reactant pump. The pressure of the oxidant supply would depend on the consumption flow. In one of two control subsystems, the pressure of oxidant flowing from the supply to the ejector would be sensed and used to control the speed of a set of a reciprocating constant-displacement pump so that the volumetric flow of nominally incompressible water away from the system would slightly exceed the rate at which water was produced by the fuel cell(s). The two-phase (gas/liquid water) outlet stream from the fuel cell(s) would enter the water separator, a turbinelike centrifugal separator machine driven primarily by the oxidant gas stream. A second control subsystem would utilize feedback derived from the compressibility of the outlet stream: As the separator was emptied of liquid water, the compressibility of the pumped stream would increase. The

  20. New readout and data-acquisition system in an electron-tracking Compton camera for MeV gamma-ray astronomy (SMILE-II)

    NASA Astrophysics Data System (ADS)

    Mizumoto, T.; Matsuoka, Y.; Mizumura, Y.; Tanimori, T.; Kubo, H.; Takada, A.; Iwaki, S.; Sawano, T.; Nakamura, K.; Komura, S.; Nakamura, S.; Kishimoto, T.; Oda, M.; Miyamoto, S.; Takemura, T.; Parker, J. D.; Tomono, D.; Sonoda, S.; Miuchi, K.; Kurosawa, S.

    2015-11-01

    For MeV gamma-ray astronomy, we have developed an electron-tracking Compton camera (ETCC) as a MeV gamma-ray telescope capable of rejecting the radiation background and attaining the high sensitivity of near 1 mCrab in space. Our ETCC comprises a gaseous time-projection chamber (TPC) with a micro pattern gas detector for tracking recoil electrons and a position-sensitive scintillation camera for detecting scattered gamma rays. After the success of a first balloon experiment in 2006 with a small ETCC (using a 10×10×15 cm3 TPC) for measuring diffuse cosmic and atmospheric sub-MeV gamma rays (Sub-MeV gamma-ray Imaging Loaded-on-balloon Experiment I; SMILE-I), a (30 cm)3 medium-sized ETCC was developed to measure MeV gamma-ray spectra from celestial sources, such as the Crab Nebula, with single-day balloon flights (SMILE-II). To achieve this goal, a 100-times-larger detection area compared with that of SMILE-I is required without changing the weight or power consumption of the detector system. In addition, the event rate is also expected to dramatically increase during observation. Here, we describe both the concept and the performance of the new data-acquisition system with this (30 cm)3 ETCC to manage 100 times more data while satisfying the severe restrictions regarding the weight and power consumption imposed by a balloon-borne observation. In particular, to improve the detection efficiency of the fine tracks in the TPC from 10% to 100%, we introduce a new data-handling algorithm in the TPC. Therefore, for efficient management of such large amounts of data, we developed a data-acquisition system with parallel data flow.

  1. Use of Iqqm For Management of A Regulated River System

    NASA Astrophysics Data System (ADS)

    Hameed, T.; Podger, G.; Harrold, T. I.

    The Integrated Quantity-Quality Model (IQQM) is a modelling tool for the planning and management of water-sharing issues within regulated and unregulated river sys- tems. IQQM represents the major river system processes, including inflows, rainfall and evaporation, infiltration, and flow routing down river channels and floodplains. It is a water balance model that operates on a daily timestep and can represent reser- voirs, wetlands, surface water/groundwater interaction, and soil moisture deficit for irrigation areas, along with many other features of both natural and regulated systems. IQQM can be customised for any river valley, and has proven to be a useful tool for the development, evaluation, and selection of operational rules for complex river systems. The Lachlan catchment lies within Australia's largest river system, the Murray- Darling Basin. Extensive development in the Murray-Darling Basin within the last 100 years has resulted in land degradation, increased salinity, poor water quality, damage to wetlands, and decline in native fish species. In response to these issues, in 1995 the Murray-Darling Basin Commission (MDBC) imposed restrictions on growth in diver- sions (the "MDBC Cap"), and the New South Wales government has more recently applied its own restrictions (the "River Flow Objectives"). To implement the MDBC Cap and the River Flow Objectives, new operational rules were required. This presen- tation describes how IQQM was used to develop and evaluate these rules for the Lach- lan system. In particular, rules for release of environmental flows were developed and evaluated. The model helped identify the flow window that would be most beneficial to the riverine environment, the critical time of year when environmental releases should be made, and resource constraint conditions when environmental releases should not be made. This process also involved intensive consultations with stakeholders. The role of IQQM within this process was to help the

  2. Epigenetic regulation of inducible gene expression in the immune system.

    PubMed

    Lim, Pek Siew; Li, Jasmine; Holloway, Adele F; Rao, Sudha

    2013-07-01

    T cells are exquisitely poised to respond rapidly to pathogens and have proved an instructive model for exploring the regulation of inducible genes. Individual genes respond to antigenic stimulation in different ways, and it has become clear that the interplay between transcription factors and the chromatin platform of individual genes governs these responses. Our understanding of the complexity of the chromatin platform and the epigenetic mechanisms that contribute to transcriptional control has expanded dramatically in recent years. These mechanisms include the presence/absence of histone modification marks, which form an epigenetic signature to mark active or inactive genes. These signatures are dynamically added or removed by epigenetic enzymes, comprising an array of histone-modifying enzymes, including the more recently recognized chromatin-associated signalling kinases. In addition, chromatin-remodelling complexes physically alter the chromatin structure to regulate chromatin accessibility to transcriptional regulatory factors. The advent of genome-wide technologies has enabled characterization of the chromatin landscape of T cells in terms of histone occupancy, histone modification patterns and transcription factor association with specific genomic regulatory regions, generating a picture of the T-cell epigenome. Here, we discuss the multi-layered regulation of inducible gene expression in the immune system, focusing on the interplay between transcription factors, and the T-cell epigenome, including the role played by chromatin remodellers and epigenetic enzymes. We will also use IL2, a key inducible cytokine gene in T cells, as an example of how the different layers of epigenetic mechanisms regulate immune responsive genes during T-cell activation.

  3. The thermal control system of the x-ray telescope eROSITA on Spektrum-Roentgen-Gamma

    NASA Astrophysics Data System (ADS)

    Fürmetz, Maria; Eder, Josef; Pfeffermann, Elmar; Predehl, Peter; Tiedemann, Lars

    2012-09-01

    The X-ray telescope eROSITA is the main instrument besides the Russian ART-XC on the Spektrum-Rontgen-Gamma mission. Starting from 2014, an all-sky survey will be performed in the range between 0.3-10keV, followed by pointed observations. The main objective of thismission is the detection of 100 0000 galaxy clusters in order to constrain cosmological parameters, amongst others the density distribution and evolution of dark energy. Due to the minimum lifetime of seven years the thermal control system has to be completely passive without any consumables. With the ideal operational temperature of the CCD cameras being between 173K and 183K, this requires a very effective heat rejection system, consisting of a complex heat pipe system and a good thermal insulation. Simultaneously, a very sensitive temperature control via variable conductance heat pipes is implemented. For special outgassing requirements at the betinning of the mission these heat pipes are not working after launch but can be switched on any time. On the other hand the mirror moduules have to be tempered at room temperature and more than 200W of the electronics have to be dissipated without affecting the surrounding components or the satellite structure. The thermal control system has to be able to keep up the required temperature range and has to guarantee the optimum working conditions for all parts of the instrument. Calculations and verification tests validated the thermal concept.

  4. Gamma-ray emission from globular clusters. Shock high energy emission from the Be-Star/Pulsar System PSR 1259-63. Echoes in x-ray novae

    NASA Technical Reports Server (NTRS)

    Kaaret, Philip

    1995-01-01

    This grant covers work on the Compton phase 3 investigation, 'Shock High Energy Emission from the Be- Star/Pulsar System PSR 1259-63' and cycle 4 investigations 'Diffuse Gamma-Ray Emission at High Latitudes' and 'Echoes in X-Ray Novae'. Work under the investigation 'Diffuse Gamma-Ray Emission at High Latitudes' has lead to the publication of a paper (attached), describing gamma-ray emissivity variations in the northern galactic hemisphere. Using archival EGRET data, we have found a large irregular region of enhanced gamma-ray emissivity at energies greater 100 MeV. This is the first observation of local structure in the gamma-ray emissivity. Work under the investigation 'Echoes in X-Ray Novae' is proceeding with analysis of data from OSSE from the transient source GRO J1655-40. The outburst of this source last fall triggered this Target of Opportunity investigation. Preliminary spectral analysis shows emission out to 600 keV and a pure power low spectrum with no evidence of an exponential cutoff. Work is complete on the analysis of BATSE data from the Be-Star/Pulsar Sustem PSR 1259-63.

  5. INVESTIGATING THE EFFECT OF GAMMA-RAYS, X-RAYS AND NEUTRONS ON ELECTRIC PROPERTIES OF CDS-SE AND CDSE-SE RECTIFYING SYSTEMS,

    DTIC Science & Technology

    The effects of light, gamma rays, x-rays, and neutrons were studied on semiconducting rectifier systems of selenium doped cadmium sulfied and cadmium ... selenide . The results indicate that quantum energy of radiation is not related to the effects (volt-ampere, volt-ohm, luxampere, etc.) produced.

  6. SU-E-T-335: Dosimetric Investigation of An Advanced Rotating Gamma Ray System for Imaged Guided Radiation Therapy

    SciTech Connect

    Ma, C; Eldib, A; Chibani, O; Li, J; Chen, L; Li, C; Mora, G

    2015-06-15

    Purpose: Co-60 beams have unique dosimetric properties for cranial treatments and thoracic cancers. The conventional concern about the high surface dose is overcome by modern system designs with rotational treatment techniques. This work investigates a novel rotational Gamma ray system for image-guided, external beam radiotherapy. Methods: The CybeRT system (Cyber Medical Corp., China) consists of a ring gantry with either one or two treatment heads containing a Gamma source and a multileaf collimator (MLC). The MLC has 60 paired leaves, and the maximum field size is either 40cmx40cm (40 pairs of 0.5cm central leaves, 20 pairs of 1cm outer leaves), or 22cmx40cm (32 pairs of 0.25cm central leaves, 28 pairs of 0.5cm outer leaves). The treatment head(s) can swing 35° superiorly and 8° inferiorly, allowing a total of 43° non-coplanar beam incident. The treatment couch provides 6-degrees-of-freedom motion compensation and the kV cone-beam CT system has a spatial resolution of 0.4mm. Monte Carlo simulations were used to compute dose distributions and compare with measurements. A retrospective study of 98 previously treated patients was performed to compare CybeRT with existing RT systems. Results: Monte Carlo results confirmed the CybeRT design parameters including output factors and 3D dose distributions. Its beam penumbra/dose gradient was similar to or better than that of 6MV photon beams and its isocenter accuracy is 0.3mm. Co-60 beams produce lower-energy secondary electrons that exhibit better dose properties in low-density lung tissues. Because of their rapid depth dose falloff, Co-60 beams are favorable for peripheral lung tumors with half-arc arrangements to spare the opposite lung and critical structures. Superior dose distributions were obtained for head and neck, breast, spine and lung tumors. Conclusion: Because of its accurate dose delivery and unique dosimetric properties of C-60 sources, CybeRT is ideally suited for advanced SBRT as well as

  7. WE-EF-303-03: A New Aperture-Based Imaging System for Prompt-Gamma Range Verification of Proton Beam Therapy

    SciTech Connect

    Ready, J; Pak, R; Mihailescu, L; Vetter, K

    2015-06-15

    Purpose: To develop and characterize a novel aperture-based imaging system for high-energy gamma-rays. This collimated system will provide 2-dimensional imaging capability for verification of proton beam range and Bragg peak dose via prompt-gamma detection. Methods: A multi-knife-edge slit collimator has been designed, constructed, and characterized via simulations and experimental measurements. The 20×20×7.5 cm{sup 3} tungsten collimator and accompanying LSO scintillation detector were simulated using the TOPAS Geant4 -based Monte Carlo package. Iterative reconstruction methods were combined with point response functions to characterize the imaging performance of the system. The response of the system has begun to be characterized experimentally as well, using 2.6 MeV gamma-rays from Th-228. Results: Both simulation and experimental results indicate that this collimated system provides 2-D imaging capability in the energy range of interest for prompt-gamma dose verification. In the current configuration, with collimator to source distance of 13 cm, image reconstruction of point sources resulted in spatial resolution (FWHM) of approximately 4 mm in both x-and y-directions in the imaging plane. The accuracy of positioning the point sources is less than 1 mm. Conclusion: This work has characterized, via simulation and measurements, a novel multi-knife-edge slit collimator in front of a more conventional position-sensitive LSO scintillator detector. The multi-slit pattern is designed to increase detection efficiency and provide spatial information in 2-dimensions -- an improvement over a single-slit collimator design. The thickness and density of the collimator will allow this detection system to perform well in an environment with high gamma flux, while ultimately providing peak determination accuracy on the order of 1 mm. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number: DE-NA0000979

  8. Roles and regulation of the matrix metalloproteinase system in parturition.

    PubMed

    Geng, Junnan; Huang, Cong; Jiang, Siwen

    2016-04-01

    Significant tissue destruction, repair, and remodeling are involved in parturition, which involves fetal membrane rupture, cervical ripening, and uterine contraction and its subsequent involution. Extracellular matrix degradation and remodeling by proteolytic enzymes, such as matrix metalloproteinases (MMPs), are required for the final steps of parturition. MMPs participate in physiological degradation and remodeling through their proteolytic activities on specific substrates, and are balanced by the action of their inhibitors. Disruption to this balance can result in pathological stress that ends with preterm or post-term birth or pre-eclampsia. In this review, we examine the roles and regulation of the MMP system in physiological and pathological labor, and propose a model that illustrates the mechanisms by which the MMP system contributes to these processes.

  9. Distributed cooperative regulation for multiagent systems and its applications to power systems: a survey.

    PubMed

    Hu, Jianqiang; Li, Yaping; Yong, Taiyou; Cao, Jinde; Yu, Jie; Mao, Wenbo

    2014-01-01

    Cooperative regulation of multiagent systems has become an active research area in the past decade. This paper reviews some recent progress in distributed coordination control for leader-following multiagent systems and its applications in power system and mainly focuses on the cooperative tracking control in terms of consensus tracking control and containment tracking control. Next, methods on how to rank the network nodes are summarized for undirected/directed network, based on which one can determine which follower should be connected to leaders such that partial followers can perceive leaders' information. Furthermore, we present a survey of the most relevant scientific studies investigating the regulation and optimization problems in power systems based on distributed strategies. Finally, some potential applications in the frequency tracking regulation of smart grids are discussed at the end of the paper.

  10. Distributed Cooperative Regulation for Multiagent Systems and Its Applications to Power Systems: A Survey

    PubMed Central

    Li, Yaping; Yong, Taiyou; Yu, Jie; Mao, Wenbo

    2014-01-01

    Cooperative regulation of multiagent systems has become an active research area in the past decade. This paper reviews some recent progress in distributed coordination control for leader-following multiagent systems and its applications in power system and mainly focuses on the cooperative tracking control in terms of consensus tracking control and containment tracking control. Next, methods on how to rank the network nodes are summarized for undirected/directed network, based on which one can determine which follower should be connected to leaders such that partial followers can perceive leaders' information. Furthermore, we present a survey of the most relevant scientific studies investigating the regulation and optimization problems in power systems based on distributed strategies. Finally, some potential applications in the frequency tracking regulation of smart grids are discussed at the end of the paper. PMID:25243199

  11. Regulation of cytokine production by soluble CD23: costimulation of interferon gamma secretion and triggering of tumor necrosis factor alpha release

    PubMed Central

    1994-01-01

    Soluble CD23 (sCD23) has multiple IgE-independent biological activities. In the present study, we examined the regulatory effect of sCD23 on cytokine production by human peripheral blood mononuclear cells (PBMC). We show that sCD23 enhances by about 80-fold the interleukin 2 (IL-2)-induced interferon gamma (IFN-gamma) production and by about 10-fold the response to IL-12. This potentiating activity is time and dose dependent and is not associated with a significant effect on DNA synthesis. The sCD23 costimulatory activity for IFN-gamma synthesis is drastically reduced in monocyte-depleted PBMC, suggesting that monocytes may be the target for sCD23. This hypothesis was supported by the following observations. First, sCD23 alone is a potent inducer of tumor necrosis factor alpha (TNF-alpha) production by PBMC and this effect disappears after monocyte depletion. The triggering of TNF-alpha release is specifically inhibited by neutralizing anti-CD23 monoclonal antibody (mAb). In addition, IL-2 and IL-12 synergize with sCD23 to induce TNF-alpha production. Second, sCD23 triggers the release of other inflammatory mediators such as IL-1 alpha, IL-1 beta, and IL-6. Finally, TNF-alpha production in response to IL-2 and sCD23 precedes IFN-gamma and IFN-gamma secretion is significantly inhibited by anti-TNF-alpha mAb, indicating that the sCD23 costimulatory signal for IFN-gamma production may be partially mediated by TNF-alpha release. It is proposed that sCD23 is a proinflammatory cytokine that, in addition, may play an important role in the control of the immune response via the enhancement of IFN-gamma production. PMID:8064221

  12. SELF-REGULATED SHOCKS IN MASSIVE STAR BINARY SYSTEMS

    SciTech Connect

    Parkin, E. R.; Sim, S. A. E-mail: s.sim@qub.ac.uk

    2013-04-20

    In an early-type, massive star binary system, X-ray bright shocks result from the powerful collision of stellar winds driven by radiation pressure on spectral line transitions. We examine the influence of the X-rays from the wind-wind collision shocks on the radiative driving of the stellar winds using steady-state models that include a parameterized line force with X-ray ionization dependence. Our primary result is that X-ray radiation from the shocks inhibits wind acceleration and can lead to a lower pre-shock velocity, and a correspondingly lower shocked plasma temperature, yet the intrinsic X-ray luminosity of the shocks, L{sub X}, remains largely unaltered, with the exception of a modest increase at small binary separations. Due to the feedback loop between the ionizing X-rays from the shocks and the wind driving, we term this scenario as self-regulated shocks. This effect is found to greatly increase the range of binary separations at which a wind-photosphere collision is likely to occur in systems where the momenta of the two winds are significantly different. Furthermore, the excessive levels of X-ray ionization close to the shocks completely suppress the line force, and we suggest that this may render radiative braking less effective. Comparisons of model results against observations reveal reasonable agreement in terms of log (L{sub X}/L{sub bol}). The inclusion of self-regulated shocks improves the match for kT values in roughly equal wind momenta systems, but there is a systematic offset for systems with unequal wind momenta (if considered to be a wind-photosphere collision).

  13. Emerging role of neurotensin in regulation of the cardiovascular system.

    PubMed

    Osadchii, Oleg E

    2015-09-05

    There is increasing evidence in support of an important role played by neurotensin (NT), a tridecapeptide originally found in bovine hypothalamus, in regulation of cardiovascular system. Elevated systemic levels of NT may contribute to pathogenesis of acute circulatory disoders, and predict the risk for cardiovascular morbidity and mortality in population-based studies. Within cardiovascular system, NT-containing neural fibers are found in close contact with atrial and ventricular cardiac myocytes, cardiac conduction system, intracardiac ganglia, as well as coronary vessels in humans and various animal species. The density of NT-immunoreactive innervation is reduced in cardiac disease. NT produces a variety of cardiovascular actions including effects on heart rate, myocardial contractility, systemic blood pressure, coronary vascular tone, venous smooth muscle tone, and regional blood flow in gastrointestinal tract, cutaneous and adipose tissue. NT could trigger cardiovascular reflexes by stimulating primary visceral afferents synaptically connected with preganglionic sympathetic neurons at the spinal cord. Structural determinants of biological activity of NT reside primarily in the C-terminal portion of its molecule which is responsible for receptor activation. NT effects are mediated via activation of NT receptors, or produced indirectly via stimulation of release of various endogenous neuromodulators/neurotransmitters such as histamine, catecholamines and prostaglandins. Three subtypes of NT receptor (NTS1, NTS2 and NTS3) have been shown to be expressed in the myocardium. NTS1, a high-affinity NT binding site coupled to phospholipase C-inositoltrisphosphate transduction pathway, is thought to mediate NT-induced cardiovascular responses.

  14. Photovoltaic-powered regulated cathodic-protection system

    NASA Astrophysics Data System (ADS)

    Anis, Wagdy R.; Alfons, Hany A.

    The objective of a cathodic protection system is to protect metallic structures against corrosion. To achieve this, a sacrificial anode is connected to the protected structure (which acts as a cathode) through a d.c. power supply. To stop the corrosion, the protected structure requires a constant current. The current is determined by the metal and area of the structure, as well as the surrounding medium. The major difficulty in achieving a constant current is the variation in the resistivity of the surrounding medium that is caused by changes in the climatic conditions. Conventional cathodic-protection systems resolve this problem by manual adjustment of the d.c. voltage periodically to obtain a constant current. Such adjustment depends on the experience of the technician and the accuracy of the measuring equipment. Moreover if the interval between successive adjustments is relative long, the corrosion could become excessive. To overcome such difficulties, an automatically regulated system has been developed. The proposed system senses variations is the resistivity of the surrounding medium and adjusts the d.c. voltage accordingly so that the current is kept constant at the required level. The design of a solar photovoltaic system to supply the required d.c. power is discussed in this communication.

  15. Management of the Spring Snowmelt Recession in Regulated Systems

    NASA Astrophysics Data System (ADS)

    Yarnell, S. M.; Lind, A.; Epke, G.; Viers, J. H.

    2013-12-01

    In unregulated rivers in the Sierra Nevada mountains of California, the spring snowmelt recession links high winter flows to low summer baseflow and is a consistent and predictable portion of the annual hydrograph. Consequently, it is an important resource to both riverine ecosystems and California's water supply. In regulated river systems where the spring snowmelt recession is often captured behind dams or diverted for hydropower, restoration of a more natural spring flow regime can provide distinct ecological benefits, such as breeding and migration cues for native species, increased habitat availability, and greater hydraulic habitat diversity. However, knowledge of how to create and manage an ecologically beneficial spring snowmelt recession in a regulated river system has been lacking. This study defined a methodology by which spring flow regimes can be modeled in regulated systems from the quantifiable characteristics of spring snowmelt recessions in unregulated rivers. Using fundamental flow components such as magnitude, timing, and rate of change, the spring snowmelt recession in eight unregulated rivers across the Sierra Nevada range was quantified to gain a better understanding of the predictability and variability across watersheds. The analysis found that unregulated Sierran systems behaved similarly with respect to seasonal patterns and flow recession shape (i.e., recession limb curvature), and thus flows could be modeled in a manner that mimics those predictable characteristics. Using this methodology that quantifies spring recession flows in terms of a daily percent decrease in flow, a series of flow recession scenarios were then created for application on a regulated Sierran river. Four scenarios, ranging from a slow natural recession to a short fast recession typically observed in regulated rivers following cessation of high flow spills, were evaluated within a 2D hydrodynamic model. The effects of the flows on suitable habitat for Foothill yellow

  16. EVOLUTIONS OF STELLAR-MASS BLACK HOLE HYPERACCRETION SYSTEMS IN THE CENTER OF GAMMA-RAY BURSTS

    SciTech Connect

    Song, Cui-Ying; Liu, Tong; Gu, Wei-Min; Lu, Ju-Fu; Hou, Shu-Jin; Tian, Jian-Xiang E-mail: jxtian@dlut.edu.cn

    2015-12-10

    A neutrino-dominated accretion disk around a stellar-mass black hole (BH) can power a gamma-ray burst (GRB) via annihilation of neutrinos launched from the disk. For the BH hyperaccretion system, high accretion rate should trigger the violent evolution of the BH’s characteristics, which further leads to the evolution of the neutrino annihilation luminosity. In this paper, we consider the evolution of the accretion system to analyze the mean time-dependent neutrino annihilation luminosity with the different mean accretion rates and initial BH parameters. By time-integrating the luminosity, the total neutrino annihilation energy with the reasonable initial disk mass can satisfy most short-duration GRBs and about half of long-duration GRBs. Moreover, the extreme Kerr BH should exist in the cental engines of some high-luminosity GRBs. GRBs with higher energy have to request the alternative magnetohydrodynamics processes in the centers, such as the Blandford–Znajek jet from the accretion system or the millisecond magnetar.

  17. Use of a solid-state multihead gamma counter in a second-generation system for solid-phase immunoassay

    SciTech Connect

    Parsons, G.H. Jr.; Rogers, C.H.; Polsky-Cynkin, R.; Wood, A.M.; Miles, L.E.; Rogers, A.H.

    1983-09-01

    Simultaneous advances in detector technology and solid-phase separation systems, as well as the availability of powerful desktop computers, have made possible the development of ''second-generation'' solid-phase immunoassays. These retain the advantages of classical solid phase while significantly accelerating reaction kinetics. Hapten assays--such as for digoxin, thyroxin, and triiodothyronine uptake--in batches of 48 are processed in about 20 min from reagent introduction until hard-copy printout, with minimal operator involvement. The system also functions as a 48-detector gamma counter, capable of counting and reducing data for any /sup 125/I-based RIA that can be run in a 12 X 75 mm test tube. System control, data management, and computer screen displays of kinetic data are provided by an unmodified Hewlett Packard HP-87XM computer. User-friendly disc-based software facilitates the creation and storage of counting and data reduction protocols for as many as 30 RIAs from various manufacturers as well as up to 30 of our own assays.

  18. Molecular recognition of nitrated fatty acids by PPAR[gamma

    SciTech Connect

    Li, Yong; Zhang, Jifeng; Schopfer, Francisco J.; Martynowski, Dariusz; Garcia-Barrio, Minerva T.; Kovach, Amanda; Suino-Powell, Kelly; Baker, Paul R.S.; Freeman, Bruce A.; Chen, Y. Eugene; Xu, H. Eric

    2010-03-08

    Peroxisome proliferator activated receptor-{gamma} (PPAR{gamma}) regulates metabolic homeostasis and adipocyte differentiation, and it is activated by oxidized and nitrated fatty acids. Here we report the crystal structure of the PPAR{gamma} ligand binding domain bound to nitrated linoleic acid, a potent endogenous ligand of PPAR{gamma}. Structural and functional studies of receptor-ligand interactions reveal the molecular basis of PPAR{gamma} discrimination of various naturally occurring fatty acid derivatives.

  19. Single-dose gamma-irradiation induces up-regulation of chemokine gene expression and recruitment of granulocytes into the portal area but not into other regions of rat hepatic tissue.

    PubMed

    Malik, Ihtzaz Ahmed; Moriconi, Federico; Sheikh, Nadeem; Naz, Naila; Khan, Sajjad; Dudas, Jozsef; Mansuroglu, Tümen; Hess, Clemens Friedrich; Rave-Fränk, Margret; Christiansen, Hans; Ramadori, Giuliano

    2010-04-01

    Liver damage is a serious clinical complication of gamma-irradiation. We therefore exposed rats to single-dose gamma-irradiation (25 Gy) that was focused on the liver. Three to six hours after irradiation, an increased number of neutrophils (but not mononuclear phagocytes) was observed by immunohistochemistry to be attached to portal vessels between and around the portal (myo)fibroblasts (smooth muscle actin and Thy-1(+) cells). MCP-1/CCL2 staining was also detected in the portal vessel walls, including some cells of the portal area. CC-chemokine (MCP-1/CCL2 and MCP-3/CCL7) and CXC-chemokine (KC/CXCL1, MIP-2/CXCL2, and LIX/CXCL5) gene expression was significantly induced in total RNA from irradiated livers. In laser capture microdissected samples, an early (1 to 3 hours) up-regulation of CCL2, CXCL1, CXCL8, and CXCR2 gene expression was detected in the portal area but not in the parenchyma; with the exception of CXCL1 gene expression. In addition, treatment with an antibody against MCP-1/CCL2 before irradiation led to an increase in gene expression of interferon-gamma and IP-10/CXCL10 in liver tissue without influencing the recruitment of granulocytes. Indeed, the CCL2, CXCL1, CXCL2, and CXCL5 genes were strongly expressed and further up-regulated in liver (myo)fibroblasts after irradiation (8 Gy). Taken together, these results suggest that gamma-irradiation of the liver induces a transient accumulation of granulocytes within the portal area and that (myo)fibroblasts of the portal vessels may be one of the major sources of the chemokines involved in neutrophil recruitment. Moreover, inhibition of more than one chemokine (eg, CXCL1 and CXCL8) may be necessary to reduce leukocytes recruitment.

  20. Role of gamma carboxylated Glu47 in connexin 26 hemichannel regulation by extracellular Ca{sup 2+}: Insight from a local quantum chemistry study

    SciTech Connect

    Zonta, Francesco; Mammano, Fabio; Torsello, Mauro; Fortunati, Nicola; Orian, Laura; Polimeno, Antonino

    2014-02-28

    Graphical abstract: - Highlights: • QM calculations show that Ca{sup 2+} binds to γGlu47 in connexin hemichannels. • Molecular models of increasing size are employed in hybrid DFT calculations. • Ca{sup 2+} binding affects the interaction between γGlu47 and Arg75, Arg184. • Ca{sup 2+} binding alters the structure in a critical region of connexin hemichannels. - Abstract: Connexin hemichannels are regulated by several gating mechanisms, some of which depend critically on the extracellular Ca{sup 2+} concentration ([Ca{sup 2+}]{sub e}). It is well established that hemichannel activity is inhibited at normal (∼1 mM) [Ca{sup 2+}]{sub e}, whereas lowering [Ca{sup 2+}]{sub e} to micromolar levels fosters hemichannel opening. Atomic force microscopy imaging shows significant and reversible changes of pore diameter at the extracellular mouth of Cx26 hemichannels exposed to different [Ca{sup 2+}]{sub e}, however, the underlying molecular mechanisms are not fully elucidated. Analysis of the crystal structure of connexin 26 (Cx26) gap junction channels, corroborated by molecular dynamics (MD) simulations, suggests that several negatively charged amino acids create a favorable environment for low-affinity Ca{sup 2+} binding within the extracellular vestibule of the Cx26 hemichannel. In particular a highly conserved glutammic acid, found in position 47 in most connexins, is thought to undergo post translational gamma carboxylation (γGlu47), and is thus likely to play an important role in Ca{sup 2+} coordination. γGlu47 may also form salt bridges with two conserved arginines (Arg75 and Arg184 in Cx26), which are considered important in stabilizing the structure of the extracellular region. Using a combination of quantum chemistry methods, we analyzed the interaction between γGlu47, Arg75 and Arg184 in a Cx26 hemichannel model both in the absence and in the presence of Ca{sup 2+}. We show that Ca{sup 2+} imparts significant local structural changes and speculate

  1. The gamma-chain cytokine/receptor system in fish: more ligands and receptors.

    PubMed

    Wang, Tiehui; Huang, Wenshu; Costa, Maria M; Secombes, Christopher J

    2011-11-01

    The mammalian gamma-chain (γC) cytokine family consists of interleukin (IL)-2, IL-4, IL-7, IL-9, IL-15 and IL-21. They signal through a receptor complex containing the common γC and a private alpha chain, and in the case of IL-2 and IL-15 an additional common IL-2/15Rβ chain. Deficiency of γC signalling in mammals prevents CD4+ T cells from developing effector functions and CD8+ T cells from developing immunological memory. Thus γC cytokines are critical for the generation and peripheral homeostasis of naïve and memory T cells. This review will give an update on the γC ligands and receptor subunits in fish, and also present some new data on the cloning and expression of a second γC and two IL-2Rβ chains in rainbow trout Oncorhynchus mykiss. In recent years, aided by the availability of sequenced fish genomes and expressed sequence tag databases, five of the six mammalian γC cytokines and their cognate receptors have been discovered in fish, with only the IL-9/IL-9R homologues apparently absent. Paralogues have been discovered in diploid fish and all the receptors described in the tetraploid rainbow trout, including γC itself, IL-2Rβ, IL-4Rα, IL-13Rα1, IL-13Rα2 and IL-2/15Rα, have duplicates. As a consequence of the teleost and salmonid whole genome duplications, even more paralogues may yet be discovered. Some of the paralogues have changes in domain structures and show differential expression and modulation, suggesting the potential for a change in function. Functional characterisation of fish γC cytokines is beginning but made more difficult by the co-existence of so many paralogues of the ligands and their receptors. Initial functional studies have shown that fish γC cytokines can modulate the expression of key cytokines (e.g. interferon-γ, IL-10 and IL-22) of the adaptive immune response, and may thus have promise as adjuvants to improve vaccination efficiency in fish.

  2. Development of a pixelated GSO gamma camera system with tungsten parallel hole collimator for single photon imaging

    SciTech Connect

    Yamamoto, S.; Watabe, H.; Kanai, Y.; Shimosegawa, E.; Hatazawa, J.

    2012-02-15

    Purpose: In small animal imaging using a single photon emitting radionuclide, a high resolution gamma camera is required. Recently, position sensitive photomultiplier tubes (PSPMTs) with high quantum efficiency have been developed. By combining these with nonhygroscopic scintillators with a relatively low light output, a high resolution gamma camera can become useful for low energy gamma photons. Therefore, the authors developed a gamma camera by combining a pixelated Ce-doped Gd{sub 2}SiO{sub 5} (GSO) block with a high quantum efficiency PSPMT. Methods: GSO was selected for the scintillator, because it is not hygroscopic and does not contain any natural radioactivity. An array of 1.9 mm x 1.9 mm x 7 mm individual GSO crystal elements was constructed. These GSOs were combined with a 0.1-mm thick reflector to form a 22 x 22 matrix and optically coupled to a high quantum efficiency PSPMT (H8500C-100 MOD8). The GSO gamma camera was encased in a tungsten gamma-ray shield with tungsten pixelated parallel hole collimator, and the basic performance was measured for Co-57 gamma photons (122 keV). Results: In a two-dimensional position histogram, all pixels were clearly resolved. The energy resolution was {approx}15% FWHM. With the 20-mm thick tungsten pixelated collimator, the spatial resolution was 4.4-mm FWHM 40 mm from the collimator surface, and the sensitivity was {approx}0.05%. Phantom and small animal images were successfully obtained with our developed gamma camera. Conclusions: These results confirmed that the developed pixelated GSO gamma camera has potential as an effective instrument for low energy gamma photon imaging.

  3. Molecular Mechanisms of Aging and Immune System Regulation in Drosophila

    PubMed Central

    Eleftherianos, Ioannis; Castillo, Julio Cesar

    2012-01-01

    Aging is a complex process that involves the accumulation of deleterious changes resulting in overall decline in several vital functions, leading to the progressive deterioration in physiological condition of the organism and eventually causing disease and death. The immune system is the most important host-defense mechanism in humans and is also highly conserved in insects. Extensive research in vertebrates has concluded that aging of the immune function results in increased susceptibility to infectious disease and chronic inflammation. Over the years, interest has grown in studying the molecular interaction between aging and the immune response to pathogenic infections. The fruit fly Drosophila melanogaster is an excellent model system for dissecting the genetic and genomic basis of important biological processes, such as aging and the innate immune system, and deciphering parallel mechanisms in vertebrate animals. Here, we review the recent advances in the identification of key players modulating the relationship between molecular aging networks and immune signal transduction pathways in the fly. Understanding the details of the molecular events involved in aging and immune system regulation will potentially lead to the development of strategies for decreasing the impact of age-related diseases, thus improving human health and life span. PMID:22949833

  4. Production of levulinic acid, furfural, and gamma valerolactone from C.sub.5 and C.sub.6 carbohydrates in mono- and biphasic systems using gamma-valerolactone as a solvent

    DOEpatents

    Dumesic, James A.; Alonso, David Martin; Gurbuz, Elif I.; Wettstein, Stephanie G.

    2013-03-19

    A method to make levulinic acid (LA), furfural, or gamma-valerolactone (GVL). React cellulose (and/or other C.sub.6 carbohydrates) or xylose (and/or other C.sub.5 carbohydrates) or combinations thereof in a monophasic reaction medium comprising GVL and an acid; or (ii) a biphasic reaction system comprising an organic layer comprising GVL, and a substantially immiscible aqueous layer. At least a portion of the cellulose (and/or other C.sub.6 carbohydrates), if present, is converted to LA and at least a portion of the xylose (and/or other C.sub.5 carbohydrates), if present, is converted into furfural.

  5. Gamma watermarking

    SciTech Connect

    Ishikawa, Muriel Y.; Wood, Lowell L.; Lougheed, Ronald W.; Moody, Kenton J.; Wang, Tzu-Fang

    2004-05-25

    A covert, gamma-ray "signature" is used as a "watermark" for property identification. This new watermarking technology is based on a unique steganographic or "hidden writing" digital signature, implemented in tiny quantities of gamma-ray-emitting radioisotopic material combinations, generally covertly emplaced on or within an object. This digital signature may be readily recovered at distant future times, by placing a sensitive, high energy-resolution gamma-ray detecting instrument reasonably precisely over the location of the watermark, which location may be known only to the object's owner; however, the signature is concealed from all ordinary detection means because its exceedingly low level of activity is obscured by the natural radiation background (including the gamma radiation naturally emanating from the object itself, from cosmic radiation and material surroundings, from human bodies, etc.). The "watermark" is used in object-tagging for establishing object identity, history or ownership. It thus may serve as an aid to law enforcement officials in identifying stolen property and prosecuting theft thereof. Highly effective, potentially very low cost identification-on demand of items of most all types is thus made possible.

  6. The Gamma-ray Universe through Fermi

    NASA Technical Reports Server (NTRS)

    Thompson, David J.

    2012-01-01

    Gamma rays, the most powerful form of light, reveal extreme conditions in the Universe. The Fermi Gamma-ray Space Telescope and its smaller cousin AGILE have been exploring the gamma-ray sky for several years, enabling a search for powerful transients like gamma-ray bursts, novae, solar flares, and flaring active galactic nuclei, as well as long-term studies including pulsars, binary systems, supernova remnants, and searches for predicted sources of gamma rays such as dark matter annihilation. Some results include a stringent limit on Lorentz invariance derived from a gamma-ray burst, unexpected gamma-ray variability from the Crab Nebula, a huge ga.nuna-ray structure associated with the center of our galaxy, surprising behavior from some gamma-ray binary systems, and a possible constraint on some WIMP models for dark matter.

  7. The Regulation of GluN2A by Endogenous and Exogenous Regulators in the Central Nervous System.

    PubMed

    Sun, Yongjun; Zhan, Liying; Cheng, Xiaokun; Zhang, Linan; Hu, Jie; Gao, Zibin

    2017-04-01

    The NMDA receptor is the most widely studied ionotropic glutamate receptor, and it is central to many physiological and pathophysiological processes in the central nervous system. GluN2A is one of the two main types of GluN2 NMDA receptor subunits in the forebrain. The proper activity of GluN2A is important to brain function, as the abnormal regulation of GluN2A may induce some neuropsychiatric disorders. This review will examine the regulation of GluN2A by endogenous and exogenous regulators in the central nervous system.

  8. Controlled-release systems for the insect growth regulator pyriproxyfen.

    PubMed

    Schwartz, Liliana; Wolf, David; Markus, Arie; Wybraniec, Sławomir; Wiesman, Zeev

    2003-09-24

    A simple technique was developed for the production of controlled-release systems (CRSs) for pyriproxyfen, an insect growth regulator active against the larvae of Culex pipiens, the most common species of mosquito found in developed countries. The CRSs consisted of a spongy core material encapsulated in a coating of a polyurethane or polyurea hydrogel, into which the active ingredient had been incorporated. The coating also included a surfactant to improve the low solubility in water of pyriproxyfen. The light core material enabled the CRS to float on the water surface, where the mosquitoe larvae are found. The type and amount of the polymeric coating and the amount of surfactant influenced the release profiles into water of the active ingredient. The release profiles of the CRSs were adjusted to the life cycle of the C. pipiens mosquito in order to obtain their optimal activity on the eighth day, which corresponds to the time of larval maturity.

  9. The ubiquitin-proteasome system regulates plant hormone signaling

    PubMed Central

    Santner, Aaron; Estelle, Mark

    2011-01-01

    SUMMARY Plants utilize the ubiquitin-proteasome system (UPS) to modulate nearly every aspect of growth and development. Ubiquitin is covalently attached to target proteins through the action of three enzymes known as E1, E2, and E3. The ultimate outcome of this post-translational modification depends on the nature of the ubiquitin linkage and the extent of polyubiquitination. In most cases, ubiquitination results in degradation of the target protein in the 26S proteasome. During the last 10 years it has become clear that the UPS plays a prominent regulatory role in hormone biology. E3 ubiquitin ligases in particular actively participate in hormone perception, de-repression of hormone signaling pathways, degradation of hormone specific transcription factors, and regulation of hormone biosynthesis. It is certain that additional functions will be discovered as more of the nearly 1200 potential E3s in plants are elucidated. PMID:20409276

  10. Rpl13a small nucleolar RNAs regulate systemic glucose metabolism

    PubMed Central

    Lee, Jiyeon; Harris, Alexis N.; Holley, Christopher L.; Mahadevan, Jana; Pyles, Kelly D.; Lavagnino, Zeno; Scherrer, David E.; Fujiwara, Hideji; Sidhu, Rohini; Zhang, Jessie; Huang, Stanley Ching-Cheng; Piston, David W.; Remedi, Maria S.; Urano, Fumihiko; Ory, Daniel S.

    2016-01-01

    Small nucleolar RNAs (snoRNAs) are non-coding RNAs that form ribonucleoproteins to guide covalent modifications of ribosomal and small nuclear RNAs in the nucleus. Recent studies have also uncovered additional non-canonical roles for snoRNAs. However, the physiological contributions of these small RNAs are largely unknown. Here, we selectively deleted four snoRNAs encoded within the introns of the ribosomal protein L13a (Rpl13a) locus in a mouse model. Loss of Rpl13a snoRNAs altered mitochondrial metabolism and lowered reactive oxygen species tone, leading to increased glucose-stimulated insulin secretion from pancreatic islets and enhanced systemic glucose tolerance. Islets from mice lacking Rpl13a snoRNAs demonstrated blunted oxidative stress responses. Furthermore, these mice were protected against diabetogenic stimuli that cause oxidative stress damage to islets. Our study illuminates a previously unrecognized role for snoRNAs in metabolic regulation. PMID:27820699

  11. The Zinc Transport Systems and Their Regulation in Pathogenic Fungi.

    PubMed

    Jung, Won Hee

    2015-09-01

    Zinc is an essential micronutrient required for many enzymes that play essential roles in a cell. It was estimated that approximately 3% of the total cellular proteins are required for zinc for their functions. Zinc has long been considered as one of the key players in host-pathogen interactions. The host sequesters intracellular zinc by utilizing multiple cellular zinc importers and exporters as a means of nutritional immunity. To overcome extreme zinc limitation within the host environment, pathogenic microbes have successfully evolved a number of mechanisms to secure sufficient concentrations of zinc for their survival and pathogenesis. In this review, we briefly discuss the zinc uptake systems and their regulation in the model fungus Saccharomyces cerevisiae and in major human pathogenic fungi such as Aspergillus fumigatus, Candida albicans, and Cryptococcus gattii.

  12. The influence of the gamma system on cross-correlated activity of Ia muscle spindles and its relation to information transmission.

    PubMed

    Inbar, G; Madrid, J; Rudomín, P

    1979-06-01

    In the decerebrate cat during static or slowly varying (less than 0.3 Hz) muscle stretches, the activity of muscle spindle (MS) pairs was poorly correlated and such correlation was not changed after ventral root sectioning. With slightly faster sinusoidal stretches (0.3-20 Hz) activity in pairs of MS was also poorly correlated. However, sectioning of the ventral roots produced preferential firing frequencies in the same muscle spindle pairs and increased their degree of correlation. The increase in correlation between MS activity detected after suppressing the gamma bias appeared to arise from extrinsic 60 Hz power line vibration in the range of micrometers. Nevertheless, activation of the gamma system could suppress such phase locking. When frequencies above 20 Hz were used, the gamma system could not decorrelate the MS pair activity since the two units became locked to their common input signal. It is suggested that decorrelation of MS activity by gamma influence may improve the fidelity of the information transmitted by the Ia MS ensemble by filtering distortion harmonics, as well as damping tremor oscillations in the stretch reflex loop.

  13. Systemic inflammation regulates microglial responses to tissue damage in vivo

    PubMed Central

    Gyoneva, Stefka; Davalos, Dimitrios; Biswas, Dipankar; Swanger, Sharon A.; Garnier-Amblard, Ethel; Loth, Francis; Akassoglou, Katerina; Traynelis, Stephen F.

    2015-01-01

    Microglia, the resident immune cells of the central nervous system, exist in either a “resting” state associated with physiological tissue surveillance or an “activated” state in neuroinflammation. We recently showed that ATP is the primary chemoattractor to tissue damage in vivo and elicits opposite effects on the motility of activated microglia in vitro through activation of adenosine A2A receptors. However, whether systemic inflammation affects microglial responses to tissue damage in vivo remains largely unknown. Using in vivo two-photon imaging of mice, we show that injection of lipopolysaccharide (LPS) at levels that can produce both clear neuroinflammation and some features of sepsis significantly reduced the rate of microglial response to laser-induced ablation injury in vivo. Under pro-inflammatory conditions, microglial processes initially retracted from the ablation site, but subsequently moved toward and engulfed the damaged area. Analyzing the process dynamics in 3D cultures of primary microglia indicated that only A2A, but not A1 or A3 receptors, mediate process retraction in LPS-activated microglia. The A2A receptor antagonists caffeine and preladenant reduced adenosine-mediated process retraction in activated microglia in vitro. Finally, administration of preladenant before induction of laser ablation in vivo accelerated the microglial response to injury following systemic inflammation. The regulation of rapid microglial responses to sites of injury by A2A receptors could have implications for their ability to respond to the neuronal death occurring under conditions of neuroinflammation in neurodegenerative disorders. PMID:24807189

  14. CRISPR-Cas systems for editing, regulating and targeting genomes.

    PubMed

    Sander, Jeffry D; Joung, J Keith

    2014-04-01

    Targeted genome editing using engineered nucleases has rapidly gone from being a niche technology to a mainstream method used by many biological researchers. This widespread adoption has been largely fueled by the emergence of the clustered, regularly interspaced, short palindromic repeat (CRISPR) technology, an important new approach for generating RNA-guided nucleases, such as Cas9, with customizable specificities. Genome editing mediated by these nucleases has been used to rapidly, easily and efficiently modify endogenous genes in a wide variety of biomedically important cell types and in organisms that have traditionally been challenging to manipulate genetically. Furthermore, a modified version of the CRISPR-Cas9 system has been developed to recruit heterologous domains that can regulate endogenous gene expression or label specific genomic loci in living cells. Although the genome-wide specificities of CRISPR-Cas9 systems remain to be fully defined, the power of these systems to perform targeted, highly efficient alterations of genome sequence and gene expression will undoubtedly transform biological research and spur the development of novel molecular therapeutics for human disease.

  15. Stabilization and set-point regulation of underactuated mechanical systems

    NASA Astrophysics Data System (ADS)

    Loccufier, Mia

    2016-09-01

    Mechanical systems are referred to as underactuated if the number of independent actuators are fewer than the number of degrees of freedom, a general encountered problem in engineering applications. The considered mechanical systems belong to the class of Euler- Lagrange systems where both kinetic energy and potential energy are modeled in their most general form and energy dissipation is modeled according to the dissipation function of Rayleigh, i.e. viscous damping forces are assumed. The control objectives are stabilization and set-point regulation. The structure of the controller is a parallel combination of static output feedback with dynamic output feedback where nonlinear amplifiers are included. An energy based approach with Liapunov functions and the Kalman-Yacubovich-Popov main lemma yields alternative stability theorems. A number of conditions are introduced with respect to the controller's structure in order to guarantee stability. However, sufficient design freedom is left to choose a proper tuning principle and obtain the specified control objectives such as fast convergence to a set-point combined with disturbance rejection. A restriction on the control input energy can be incorporated as well. The applicability of the method will be illustrated with planar manipulators. The main contribution is that a methodology is developed which incorporates many controllers and tuning facilities.

  16. Transcriptional regulation of the peripheral nervous system in Ciona intestinalis.

    PubMed

    Joyce Tang, W; Chen, Jerry S; Zeller, Robert W

    2013-06-15

    The formation of the sensory organs and cells that make up the peripheral nervous system (PNS) relies on the activity of transcription factors encoded by proneural genes (PNGs). Although PNGs have been identified in the nervous systems of both vertebrates and invertebrates, the complexity of their interactions has complicated efforts to understand their function in the context of their underlying regulatory networks. To gain insight into the regulatory network of PNG activity in chordates, we investigated the roles played by PNG homologs in regulating PNS development of the invertebrate chordate Ciona intestinalis. We discovered that in Ciona, MyT1, Pou4, Atonal, and NeuroD-like are expressed in a sequential regulatory cascade in the developing epidermal sensory neurons (ESNs) of the PNS and act downstream of Notch signaling, which negatively regulates these genes and the number of ESNs along the tail midlines. Transgenic embryos mis-expressing any of these proneural genes in the epidermis produced ectopic midline ESNs. In transgenic embryos mis-expressing Pou4, and MyT1 to a lesser extent, numerous ESNs were produced outside of the embryonic midlines. In addition we found that the microRNA miR-124, which inhibits Notch signaling in ESNs, is activated downstream of all the proneural factors we tested, suggesting that these genes operate collectively in a regulatory network. Interestingly, these factors are encoded by the same genes that have recently been demonstrated to convert fibroblasts into neurons. Our findings suggest the ascidian PNS can serve as an in vivo model to study the underlying regulatory mechanisms that enable the conversion of cells into sensory neurons.

  17. A state-of-the-art passive gamma-ray assay system

    SciTech Connect

    Sampson, T.E.; Parker, J.L.; Cowder, L.R.; Kern, E.A.; Garcia, D.L.; Ensslin, N.

    1987-01-01

    We report details of the development of a high-accuracy, high-precision system for the non-destructive assay of /sup 235/U in solution. The system can measure samples with concentrations ranging from 0.0001 to 500 g /sup 235/U/l using 200-ml samples at low concentrations, 30-ml samples at high concentrations, and 1000-s measurement times. The accuracy and precision goals of 0.1% were essentially attained for concentrations above 100 g/l. This at-line system, designed for a production plant environment, represents a significant improvement in the state of the art.

  18. An automated microcomputer-controlled system for neutron activation and gamma-ray spectroscopy

    NASA Astrophysics Data System (ADS)

    Edward, J. B.; Beeley, P. A.; Bennett, L. G. I.; Anderson, A.; Burbidge, G. A.

    1990-12-01

    An automated instrumental neutron activation analysis (INAA) system has been constructed at the SLOWPOKE-2 reactor at the Royal Military College of Canada (RMC). Its pneumatic transfer system is controlled by an Apple IIe computer, linked in turn to an MS-DOS-compatible microcomputer which controls data acquisition. Custom software has been created for these computers and for off-line spectral analysis using programs that incorporate either peak boundary or Gaussian peak fitting methods of analysis. This system provides the gamut of INAA techniques for the analyst. The design and performance of the hardware and software are discussed.

  19. Extensional Elastica in large deformation as $Gamma $ Γ -limit of a discrete 1D mechanical system

    NASA Astrophysics Data System (ADS)

    Alibert, Jean-Jacques; Della Corte, Alessandro; Giorgio, Ivan; Battista, Antonio

    2017-04-01

    The present paper deals with the rigorous homogenization of a discrete system consisting of extensible rods linked by rotational springs. Specifically, a Γ -convergence result is proven for a sequence of discrete measure functionals En, describing the energy of the discrete system, toward the continuous energy functional for the extensible Euler beam model ( Elastica) in large deformation regime. A relative compactness result for the sequence En is also proven. Moreover, numerical results are shown on the deformed shape and on the total energy of the system when the number of elements of the discrete system increases. The numerical convergence of the energy to a definite value is shown in two cases. The results provide rigorous justification of a very commonly used algorithm for the discretization of the extensible Euler beam, namely Hencky-type beam model.

  20. Positive feedback regulation between gamma-aminobutyric acid type A (GABA(A)) receptor signaling and brain-derived neurotrophic factor (BDNF) release in developing neurons.

    PubMed

    Porcher, Christophe; Hatchett, Caroline; Longbottom, Rebecca E; McAinch, Kristina; Sihra, Talvinder S; Moss, Stephen J; Thomson, Alex M; Jovanovic, Jasmina N

    2011-06-17

    During the early development of the nervous system, γ-aminobutyric acid (GABA) type A receptor (GABA(A)R)-mediated signaling parallels the neurotrophin/tropomyosin-related kinase (Trk)-dependent signaling in controlling a number of processes from cell proliferation and migration, via dendritic and axonal outgrowth, to synapse formation and plasticity. Here we present the first evidence that these two signaling systems regulate each other through a complex positive feedback mechanism. We first demonstrate that GABA(A)R activation leads to an increase in the cell surface expression of these receptors in cultured embryonic cerebrocortical neurons, specifically at the stage when this activity causes depolarization of the plasma membrane and Ca(2+) influx through L-type voltage-gated Ca(2+) channels. We further demonstrate that GABA(A)R activity triggers release of the brain-derived neurotrophic factor (BDNF), which, in turn by activating TrkB receptors, mediates the observed increase in cell surface expression of GABA(A)Rs. This BDNF/TrkB-dependent increase in surface levels of GABA(A)Rs requires the activity of phosphoinositide 3-kinase (PI3K) and protein kinase C (PKC) and does not involve the extracellular signal-regulated kinase (ERK) 1/2 activity. The increase in GABA(A)R surface levels occurs due to an inhibition of the receptor endocytosis by BDNF, whereas the receptor reinsertion into the plasma membrane remains unaltered. Thus, GABA(A)R activity is a potent regulator of the BDNF release during neuronal development, and at the same time, it is strongly enhanced by the activity of the BDNF/TrkB/PI3K/PKC signaling pathway.

  1. Monte Carlo based calibration of an air monitoring system for gamma and beta+ radiation.

    PubMed

    Sarnelli, A; Negrini, M; D'Errico, V; Bianchini, D; Strigari, L; Mezzenga, E; Menghi, E; Marcocci, F; Benassi, M

    2015-11-01

    Marinelli beaker systems are used to monitor the activity of radioactive samples. These systems are usually calibrated with water solutions and the determination of the activity in gases requires correction coefficients accounting for the different mass-thickness of the sample. For beta+ radionuclides the different distribution of the positrons annihilation points should be also considered. In this work a Monte Carlo simulation based on Geant4 is used to compute correction coefficients for the measurement of the activity of air samples.

  2. Regulation of autonomic nervous system in space and magnetic storms

    NASA Astrophysics Data System (ADS)

    Baevsky, R. M.; Petrov, V. M.; Chernikova, A. G.

    Variations in the earth's magnetic field and magnetic storms are known to be a risk factor for the development of cardiovascular disorders. The main ``targets'' for geomagnetic perturbations are the central nervous system and the neural regulation of vascular tone and heart rate variability. This paper presents the data about effect of geomagnetic fluctuations on human body in space. As a method for research the analysis of heart rate variability was used, which allows evaluating the state of the sympathetic and parasympathetic parts of the autonomic nervous system, vasomotor center and subcortical neural centers activity. Heart rate variability data were analyzed for 30 cosmonauts at the 2-nd day of space flight on transport spaceship Soyuz (32nd orbit). There were formed three groups of cosmonauts: without magnetic storm (n=9), on a day with magnetic storm (n=12) and 1-2 days after magnetic storm (n=9). The present study was the first to demonstrate a specific impact of geomagnetic perturbations on the system of autonomic circulatory control in cosmonauts during space flight. The increasing of highest nervous centers activity was shown for group with magnetic storms, which was more significant on 1-2 days after magnetic storm. The use of discriminate analysis allowed to classify indicated three groups with 88 % precision. Canonical variables are suggested to be used as criterions for evaluation of specific and non-specific components of cardiovascular reactions to geomagnetic perturbations. The applied aspect of the findings from the present study should be emphasized. They show, in particular, the need to supplement the medical monitoring of cosmonauts with predictions of probable geomagnetic perturbations in view of the prevention of unfavorable states appearances if the adverse reactions to geomagnetic perturbations are added to the tension experienced by regulatory systems during various stresses situations (such as work in the open space).

  3. Homeostatic regulation of memory systems and adaptive decisions.

    PubMed

    Mizumori, Sheri J Y; Jo, Yong Sang

    2013-11-01

    While it is clear that many brain areas process mnemonic information, understanding how their interactions result in continuously adaptive behaviors has been a challenge. A homeostatic-regulated prediction model of memory is presented that considers the existence of a single memory system that is based on a multilevel coordinated and integrated network (from cells to neural systems) that determines the extent to which events and outcomes occur as predicted. The "multiple memory systems of the brain" have in common output that signals errors in the prediction of events and/or their outcomes, although these signals differ in terms of what the error signal represents (e.g., hippocampus: context prediction errors vs. midbrain/striatum: reward prediction errors). The prefrontal cortex likely plays a pivotal role in the coordination of prediction analysis within and across prediction brain areas. By virtue of its widespread control and influence, and intrinsic working memory mechanisms. Thus, the prefrontal cortex supports the flexible processing needed to generate adaptive behaviors and predict future outcomes. It is proposed that prefrontal cortex continually and automatically produces adaptive responses according to homeostatic regulatory principles: prefrontal cortex may serve as a controller that is intrinsically driven to maintain in prediction areas an experience-dependent firing rate set point that ensures adaptive temporally and spatially resolved neural responses to future prediction errors. This same drive by prefrontal cortex may also restore set point firing rates after deviations (i.e. prediction errors) are detected. In this way, prefrontal cortex contributes to reducing uncertainty in prediction systems. An emergent outcome of this homeostatic view may be the flexible and adaptive control that prefrontal cortex is known to implement (i.e. working memory) in the most challenging of situations. Compromise to any of the prediction circuits should result in

  4. Homeostatic Regulation of Memory Systems and Adaptive Decisions

    PubMed Central

    Mizumori, Sheri JY; Jo, Yong Sang

    2013-01-01

    While it is clear that many brain areas process mnemonic information, understanding how their interactions result in continuously adaptive behaviors has been a challenge. A homeostatic-regulated prediction model of memory is presented that considers the existence of a single memory system that is based on a multilevel coordinated and integrated network (from cells to neural systems) that determines the extent to which events and outcomes occur as predicted. The “multiple memory systems of the brain” have in common output that signals errors in the prediction of events and/or their outcomes, although these signals differ in terms of what the error signal represents (e.g., hippocampus: context prediction errors vs. midbrain/striatum: reward prediction errors). The prefrontal cortex likely plays a pivotal role in the coordination of prediction analysis within and across prediction brain areas. By virtue of its widespread control and influence, and intrinsic working memory mechanisms. Thus, the prefrontal cortex supports the flexible processing needed to generate adaptive behaviors and predict future outcomes. It is proposed that prefrontal cortex continually and automatically produces adaptive responses according to homeostatic regulatory principles: prefrontal cortex may serve as a controller that is intrinsically driven to maintain in prediction areas an experience-dependent firing rate set point that ensures adaptive temporally and spatially resolved neural responses to future prediction errors. This same drive by prefrontal cortex may also restore set point firing rates after deviations (i.e. prediction errors) are detected. In this way, prefrontal cortex contributes to reducing uncertainty in prediction systems. An emergent outcome of this homeostatic view may be the flexible and adaptive control that prefrontal cortex is known to implement (i.e. working memory) in the most challenging of situations. Compromise to any of the prediction circuits should result

  5. 75 FR 25165 - Defense Federal Acquisition Regulation Supplement; Cost and Software Data Reporting System

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-07

    ... Regulation Supplement; Cost and Software Data Reporting System AGENCY: Defense Acquisition Regulations System... the Defense Federal Acquisition Regulation Supplement (DFARS) to set forth DoD Cost and Software Data... Software Data Reporting (CSDR) process offerors intend to use to satisfy the requirements of the...

  6. {gamma} parameter and Solar System constraint in chameleon-Brans-Dicke theory

    SciTech Connect

    Saaidi, Kh.; Mohammadi, A.; Sheikhahmadi, H.

    2011-05-15

    The post Newtonian parameter is considered in the chameleon-Brans-Dicke model. In the first step, the general form of this parameter and also effective gravitational constant is obtained. An arbitrary function for f({Phi}), which indicates the coupling between matter and scalar field, is introduced to investigate validity of solar system constraint. It is shown that the chameleon-Brans-Dicke model can satisfy the solar system constraint and gives us an {omega} parameter of order 10{sup 4}, which is in comparable to the constraint which has been indicated in [19].

  7. Proficiency test: a quality assurance method for high-purity gamma spectrometry system

    NASA Astrophysics Data System (ADS)

    Radulescu, Ileana; Romeo Calin, Marian

    2014-03-01

    As part of the implementation of the quality system on ISO 17025 and accreditation, SALROM laboratory participated in the last year in intercomparison exercises, national and international, for determination of natural and man-made radionuclides. This paper describes results obtained in intercomparison exercise organized by IAEA in 2011. The reported values were mostly in good agreement with the resulting reference values.

  8. Neuroendocrine mechanisms for immune system regulation during stress in fish.

    PubMed

    Nardocci, Gino; Navarro, Cristina; Cortés, Paula P; Imarai, Mónica; Montoya, Margarita; Valenzuela, Beatriz; Jara, Pablo; Acuña-Castillo, Claudio; Fernández, Ricardo

    2014-10-01

    In the last years, the aquaculture crops have experienced an explosive and intensive growth, because of the high demand for protein. This growth has increased fish susceptibility to diseases and subsequent death. The constant biotic and abiotic changes experienced by fish species in culture are challenges that induce physiological, endocrine and immunological responses. These changes mitigate stress effects at the cellular level to maintain homeostasis. The effects of stress on the immune system have been studied for many years. While acute stress can have beneficial effects, chronic stress inhibits the immune response in mammals and teleost fish. In response to stress, a signaling cascade is triggered by the activation of neural circuits in the central nervous system because the hypothalamus is the central modulator of stress. This leads to the production of catecholamines, corticosteroid-releasing hormone, adrenocorticotropic hormone and glucocorticoids, which are the essential neuroendocrine mediators for this activation. Because stress situations are energetically demanding, the neuroendocrine signals are involved in metabolic support and will suppress the "less important" immune function. Understanding the cellular mechanisms of the neuroendocrine regulation of immunity in fish will allow the development of new pharmaceutical strategies and therapeutics for the prevention and treatment of diseases triggered by stress at all stages of fish cultures for commercial production.

  9. Mechanisms regulating caste differentiation in an aphid social system.

    PubMed

    Shibao, Harunobu; Kutsukake, Mayako; Matsuyama, Shigeru; Fukatsu, Takema; Shimada, Masakazu

    2010-01-01

    For evolution and maintenance of the social systems of insect colonies, caste production should be controlled in response to external cues so that caste ratio in the colony is kept at an optimal range. Recent developments using artificial diet rearing techniques have revealed an underlying mechanism for adaptive control of caste production in a social aphid, Tuberaphis styraci, which has a sterile soldier caste in the 2(nd) instar. Aphid density was the proximate cue that acts on 1(st) instar nymphs and embryos to induce soldier differentiation. The final determination of soldier differentiation occurred postnatally, probably at a late 1(st) instar stage. Direct contact stimuli from live non-soldier aphids mediated the density effect. While coexisting non-soldiers facilitated soldier differentiation in 1(st) instar nymphs, coexisting soldiers acted to suppress such differentiation. These results suggest that caste production in aphid colonies is controlled by positive and negative feedback mechanisms consisting of density-dependent induction and suppression of soldier differentiation. Here, we demonstrate the mechanisms that coordinate aphid society, and provide a striking case of clonal superorganism system where simple responses of colony members to local extrinsic stimuli are integrated into a highly organized regulation of the whole colony.

  10. Systemic regulation of soybean nodulation by acidic growth conditions.

    PubMed

    Lin, Meng-Han; Gresshoff, Peter M; Ferguson, Brett J

    2012-12-01

    Mechanisms inhibiting legume nodulation by low soil pH, although highly prevalent and economically significant, are poorly understood. We addressed this in soybean (Glycine max) using a combination of physiological and genetic approaches. Split-root and grafting studies using an autoregulation-of-nodulation-deficient mutant line, altered in the autoregulation-of-nodulation receptor kinase GmNARK, determined that a systemic, shoot-controlled, and GmNARK-dependent mechanism was critical for facilitating the inhibitory effect. Acid inhibition was independent of aluminum ion concentration and occurred early in nodule development, between 12 and 96 h post inoculation with Bradyrhizobium japonicum. Biological effects were confirmed by measuring transcript numbers of known early nodulation genes. Transcripts decreased on both sides of split-root systems, where only one side was subjected to low-pH conditions. Our findings enhance the present understanding of the innate mechanisms regulating legume nodulation control under acidic conditions, which could benefit future attempts in agriculture to improve nodule development and biological nitrogen fixation in acid-stressed soils.

  11. Modeling Systems-Level Regulation of Host Immune Responses

    PubMed Central

    Thakar, Juilee; Pilione, Mylisa; Kirimanjeswara, Girish; Harvill, Eric T; Albert, Réka

    2007-01-01

    Many pathogens are able to manipulate the signaling pathways responsible for the generation of host immune responses. Here we examine and model a respiratory infection system in which disruption of host immune functions or of bacterial factors changes the dynamics of the infection. We synthesize the network of interactions between host immune components and two closely related bacteria in the genus Bordetellae. We incorporate existing experimental information on the timing of immune regulatory events into a discrete dynamic model, and verify the model by comparing the effects of simulated disruptions to the experimental outcome of knockout mutations. Our model indicates that the infection time course of both Bordetellae can be separated into three distinct phases based on the most active immune processes. We compare and discuss the effect of the species-specific virulence factors on disrupting the immune response during their infection of naive, antibody-treated, diseased, or convalescent hosts. Our model offers predictions regarding cytokine regulation, key immune components, and clearance of secondary infections; we experimentally validate two of these predictions. This type of modeling provides new insights into the virulence, pathogenesis, and host adaptation of disease-causing microorganisms and allows systems-level analysis that is not always possible using traditional methods. PMID:17559300

  12. Effects of Low-Dose-Gamma Rays on the Immune System of Different Animal Models of Disease

    PubMed Central

    Shimura, Noriko; Kojima,