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Sample records for gamma system regulates

  1. Regulation of interferon-gamma gene expression.

    PubMed

    Young, H A

    1996-08-01

    Interferon-gamma (IFN-gamma), also known as type II interferon, is an important immunoregulatory gene that has multiple effects on the development, maturation, and function of the immune system. IFN-gamma mRNA and protein are expressed predominantly by T cells and large granular lymphocytes. The IFN-gamma mRNA is induced/inhibited in these cell types by a wide variety of extracellular signals, thus implicating a number of diverse, yet convergent signal transduction pathways in its transcriptional control. In this review, I describe how DNA methylation and specific DNA binding proteins may regulate transcription of the IFN-gamma gene in response to extracellular signals. PMID:8877725

  2. Dictyostelium possesses highly diverged presenilin/gamma-secretase that regulates growth and cell-fate specification and can accurately process human APP: a system for functional studies of the presenilin/gamma-secretase complex.

    PubMed

    McMains, Vanessa C; Myre, Michael; Kreppel, Lisa; Kimmel, Alan R

    2010-01-01

    Presenilin (PS) is the catalytic moiety of the gamma-secretase complex. PS and other gamma-secretase components are well conserved among metazoa, but their presence and function in more-distant species are not resolved. Because inappropriate gamma-secretase processing of amyloid precursor protein (APP) in humans is associated with familial Alzheimer's disease, understanding essential elements within each gamma-secretase component is crucial to functional studies. Diverged proteins have been identified in primitive plants but experiments have failed to demonstrate gamma-secretase activity. We have identified highly diverged orthologs for each gamma-secretase component in the ancient eukaryote Dictyostelium, which lacks equivalents of APP, Notch and other characterized PS/gamma-secretase substrates. We show that wild-type (WT) Dictyostelium is capable of amyloidogenic processing of ectopically expressed human APP to generate amyloid-beta peptides Abeta(40) and Abeta(42); strains deficient in gamma-secretase cannot produce Abeta peptides but accumulate processed intermediates of APP that co-migrate with the C-terminal fragments alpha- and beta-CTF of APP that are found in mammalian cells. We further demonstrate that Dictyostelium requires PS for phagocytosis and cell-fate specification in a cell-autonomous manner, and show that regulation of phagocytosis requires an active gamma-secretase, a pathway suggested, but not proven, to occur in mammalian and Drosophila cells. Our results indicate that PS signaling is an ancient process that arose prior to metazoan radiation, perhaps independently of Notch. Dictyostelium might serve to identify novel PS/gamma-secretase signaling targets and provide a unique system for high-throughput screening of small-molecule libraries to select new therapeutic targets for diseases associated with this pathway. PMID:20699477

  3. Interferon-gamma regulates nucleoside transport systems in macrophages through signal transduction and activator of transduction factor 1 (STAT1)-dependent and -independent signalling pathways.

    PubMed

    Soler, Concepció; Felipe, Antonio; García-Manteiga, José; Serra, Maria; Guillén-Gómez, Elena; Casado, F Javier; MacLeod, Carol; Modolell, Manuel; Pastor-Anglada, Marçal; Celada, Antonio

    2003-11-01

    The expressions of CNT and ENT (concentrative and equilibrative nucleoside transporters) in macrophages are differentially regulated by IFN-gamma (interferon-gamma). This cytokine controls gene expression through STAT1-dependent and/or -independent pathways (where STAT1 stands for signal transduction and activator of transcription 1). In the present study, the role of STAT1 in the response of nucleoside transporters to IFN-gamma was studied using macrophages from STAT1 knockout mice. IFN-gamma triggered an inhibition of ENT1-related nucleoside transport activity through STAT1-dependent mechanisms. Such inhibition of macrophage growth and ENT1 activity by IFN-gamma is required for DNA synthesis. Interestingly, IFN-gamma led to an induction of the CNT1- and CNT2-related nucleoside transport activities independent of STAT1, thus ensuring the supply of extracellular nucleosides for the STAT1-independent RNA synthesis. IFN-gamma up-regulated CNT2 mRNA and CNT1 protein levels and down-regulated ENT1 mRNA in both wild-type and STAT1 knockout macrophages. This is consistent with a STAT1-independent, long-term-mediated, probably transcription-dependent, regulation of nucleoside transporter genes. Moreover, STAT1-dependent post-transcriptional mechanisms are implicated in the regulation of ENT1 activity. Although nitric oxide is involved in the regulation of ENT1 activity in B-cells at a post-transcriptional level, our results show that STAT1-dependent induction of nitric oxide by IFN-gamma is not implicated in the regulation of ENT1 activity in macrophages. Our results indicate that both STAT1-dependent and -independent pathways are involved in the regulation of nucleoside transporters by IFN-gamma in macrophages. PMID:12868960

  4. 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}.

  5. 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.

  6. Portable compton gamma-ray detection system

    DOEpatents

    Rowland, Mark S.; Oldaker, Mark E.

    2008-03-04

    A Compton scattered gamma-ray detector system. The system comprises a gamma-ray spectrometer and an annular array of individual scintillators. The scintillators are positioned so that they are arrayed around the gamma-ray spectrometer. The annular array of individual scintillators includes a first scintillator. A radiation shield is positioned around the first scintillator. A multi-channel analyzer is operatively connected to the gamma-ray spectrometer and the annular array of individual scintillators.

  7. 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.

  8. 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.

  9. 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.

  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. Gamma-ray binaries and related systems

    NASA Astrophysics Data System (ADS)

    Dubus, Guillaume

    2013-08-01

    After initial claims and a long hiatus, it is now established that several binary stars emit high- (0.1-100 GeV) and very high-energy (>100 GeV) gamma rays. A new class has emerged called "gamma-ray binaries", since most of their radiated power is emitted beyond 1 MeV. Accreting X-ray binaries, novae and a colliding wind binary ( η Car) have also been detected—"related systems" that confirm the ubiquity of particle acceleration in astrophysical sources. Do these systems have anything in common? What drives their high-energy emission? How do the processes involved compare to those in other sources of gamma rays: pulsars, active galactic nuclei, supernova remnants? I review the wealth of observational and theoretical work that have followed these detections, with an emphasis on gamma-ray binaries. I present the current evidence that gamma-ray binaries are driven by rotation-powered pulsars. Binaries are laboratories giving access to different vantage points or physical conditions on a regular timescale as the components revolve on their orbit. I explain the basic ingredients that models of gamma-ray binaries use, the challenges that they currently face, and how they can bring insights into the physics of pulsars. I discuss how gamma-ray emission from microquasars provides a window into the connection between accretion-ejection and acceleration, while η Car and novae raise new questions on the physics of these objects—or on the theory of diffusive shock acceleration. Indeed, explaining the gamma-ray emission from binaries strains our theories of high-energy astrophysical processes, by testing them on scales and in environments that were generally not foreseen, and this is how these detections are most valuable.

  12. 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. PMID:10989281

  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. The PIKE Homolog Centaurin gamma Regulates Developmental Timing in Drosophila

    PubMed Central

    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

  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. Peroxisome proliferator-activated receptor-{gamma} as a regulator of lung inflammation and repair.

    PubMed

    Standiford, Theodore J; Keshamouni, Venkateshwar G; Reddy, Raju C

    2005-01-01

    Peroxisome proliferator-activated receptors (PPARs) are members of the nuclear hormone receptor superfamily that regulate the expression of genes involved in a variety of biological processes, including lipid metabolism and insulin sensitivity. Members of the PPAR family-in particular, PPAR-gamma-have more recently been shown to broadly regulate inflammatory and reparative responses. PPAR-gamma is expressed in both alveolar macrophages and neutrophils, and the ligand-dependent activation of this receptor results in suppression of leukocyte effector responses, including cytokine production, the elaboration of reactive oxygen and nitrogen species, and migratory responses. In addition to antiinflammatory effects, PPAR-gamma regulates diverse processes in lung stromal/parenchymal cells, including cell growth, differentiation, and apoptosis. Studies examining in vivo effects of PPAR-gamma have produced complex and at times conflicting results. However, evidence to date generally suggests that PPAR-gamma functions to dampen inflammation and injury in various animal models of acute lung injury. PPAR-gamma may also play an important role in other inflammatory/immune lung diseases, including ischemia-reperfusion injury, allergic airway inflammation, and cancer. The role of PPAR-gamma in human lung diseases, including acute lung injury, requires further study. PMID:16222042

  18. A system for simultaneous beta and gamma spectroscopy

    NASA Astrophysics Data System (ADS)

    Farsoni, A. T.; Hamby, D. M.

    2007-08-01

    A state-of-the-art radiation detection system for real-time and simultaneous spectroscopy of beta-particles and gamma-rays has been developed. The system utilizes a triple-layer phoswich detector and a customized Digital Pulse Processor (DPP) designed and built in our laboratory. The DPP board digitally captures the analog signal pulses and, following several digital preprocessing steps, transfers valid pulses to the host computer for further digital processing. A resolving algorithm also was developed to digitally discriminate beta and gamma events, and reconstruct separate beta and gamma-ray energy spectra with minimal crosstalk. The spectrometer has proven to be an effective tool for recording separate beta and gamma-ray spectra from mixed radiation fields. The system as a beta-gamma spectrometer will have broad-ranging applications in nuclear non-proliferation, radioactive waste management, worker safety, systems reliability, dose assessment, and risk analysis.

  19. 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.

  20. Follistatin-like protein 1 promotes arthritis by up-regulating IFN-gamma.

    PubMed

    Clutter, Suzanne D; Wilson, David C; Marinov, Anthony D; Hirsch, Raphael

    2009-01-01

    Follistatin-like protein-1 (FSTL-1) is a poorly characterized protein that is up-regulated in the early stage of collagen-induced arthritis and that exacerbates arthritis when delivered by gene transfer. The current study was designed to determine the mechanism by which FSTL-1 promotes arthritis. FSTL-1 was injected into mouse paws, resulting in severe paw swelling associated with up-regulation of IFN-gamma transcript and the IFN-gamma-induced chemokine, CXCL10. Mice depleted of T cells were protected. A central role for IFN-gamma was confirmed by the finding that mice deficient in IFN-gamma failed to exhibit paw swelling in response to injection of FSTL-1. Furthermore, IFN-gamma secretion from mouse spleen cells exposed to a weak TCR signal was increased 5-fold in the presence of FSTL-1. FSTL-1 could be induced by innate immune signals, including TLR4 agonists and the arthritogenic cytokine, IL-1beta, via an NFkappaB pathway. Finally, FSTL-1 was found to be overexpressed in human arthritis and its neutralization inhibited murine collagen-induced arthritis and suppressed IFN-gamma and CXCL10 production in arthritic joints. These findings demonstrate that FSTL-1 plays a critical role in arthritis by enhancing IFN-gamma signaling pathways and suggest a mechanism by which FSTL-1 bridges innate and adaptive immune responses. PMID:19109154

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  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. 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.

  8. 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.

  9. 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.

  10. IL-4 acts as a homeostatic regulator of IL-2-induced TNF and IFN-gamma.

    PubMed Central

    Bello-Fernandez, C; Oblakowski, P; Meager, A; Duncombe, A S; Rill, D M; Hoffbrand, A V; Brenner, M K

    1991-01-01

    Interleukin-4 (IL-4) is a cytokine secreted by interleukin-2 (IL-2)-activated lymphocytes. IL-2-stimulated lymphocytes also secrete two cytokines, tumour necrosis factor (TNF) and gamma-interferon (IFN-gamma), which contribute to effector function and which may themselves recruit fresh, cytokine-secreting effector cells. We have now investigated whether the IL-4 induced is able to homeostatically regulate secretion of the TNF and IFN-gamma. Peripheral blood mononuclear cells or lymphocytes from normal donors and from patients with neoplastic disease were cultured in the presence of IL-2 alone, IL-4 alone or with both cytokines. IL-2 induced high levels of TNF and IFN-gamma secretion in both groups. The addition of recombinant IL-4 to these IL-2-stimulated cultures lead to significant inhibition of IFN-gamma and TNF production. IFN-gamma secretion was reduced by 50-99% in normal donors and by between 11% and 99% in patients (P less than 0.001). TNF levels induced by IL-2 were similarly reduced by IL-4 both in normal donors (P less than 0.003) and in patients (P less than 0.01). These inhibitory effects were produced by IL-4 at doses of IL-2 attainable in vivo. Inhibition appears to represent a homeostatic regulatory mechanism which may limit recruitment of fresh activated killer (AK) cells. When endogenous IL-4 activity in IL-2-activated lymphocytes was blocked by anti-IL-4 antibody, significantly higher levels of IFN-gamma and TNF were secreted (P less than 0.05). Since both TNF and IFN-gamma may contribute to the anti-neoplastic action of IL-2, manipulating the level of IL-4 activity in vivo could augment the benefits of IL-2 immunotherapy. PMID:1901829

  11. Calibration of the RLS HPGe spectral gamma ray logging system

    SciTech Connect

    Koizumi, C.J.; Brodeur, J.R.; Ulbricht, W.H.; Price, R.K.

    1991-11-01

    Gamma-ray spectral data have been recorded with the Radionuclide Logging System (RLS) high purity germanium (HPGe) system at (1) the American Petroleum Institute (API) spectral gamma-ray calibration center in Houston, Texas; (2) the US Department of Energy (DOE) spectral gamma-ray field calibration facility in Spokane, Washington; and (3) the DOE spectral gamma-ray primary calibration center in Grand Junction, Colorado. Analyses of the Grand Junction data yielded: calibration constants for the natural gamma-ray sources (potassium, uranium and thorium), energy-dependent borehole diameter corrections for the aid-filled borehole, energy-dependent borehole casing corrections for steel casing over a range of thicknesses from 0 to 79 cm (5/16 in.), a casing index function that varies with casing thickness and provides a method for verifying that the correct casing correction is applied, and an energy-dependent inverse function that is the basis for assessment of subsurface concentrations of man-made gamma-ray emitters such as cesium-137 and cobalt-60.

  12. 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.

  13. 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.

  14. Design of OLED gamma correction system based on the LUT

    NASA Astrophysics Data System (ADS)

    Tai, Yonghang; Yun, Lijun; Shi, Junsheng; Chen, Zaiqing; Li, Qiong

    2011-11-01

    Gamma correction is an important processing in reproduce images information realizing of video source. In order to improve the image sharpness of the OLED micro-display, a Gamma correction system was established to compensate for the gray scale distortion of the micro-display which is caused by the difference between the optical and electrical characteristic property. Based on the North OLEiD Company's 0.5 inch OLED, We proposed a Gamma correction system to converts 8 bits input signal into 9 bits displayed on the OLED. It used Microchip as the MCU and the master of the I2C serial bus, Development of the hardware system measurement verified the correction of VGA and CVBS video input and the picture quality also apparently improved.

  15. 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].

  16. 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

  17. Endocannabinoid Regulation of Neuroendocrine Systems.

    PubMed

    Tasker, Jeffrey G; Chen, Chun; Fisher, Marc O; Fu, Xin; Rainville, Jennifer R; Weiss, Grant L

    2015-01-01

    The hypothalamus is a part of the brain that is critical for sustaining life through its homeostatic control and integrative regulation of the autonomic nervous system and neuroendocrine systems. Neuroendocrine function in mammals is mediated mainly through the control of pituitary hormone secretion by diverse neuroendocrine cell groups in the hypothalamus. Cannabinoid receptors are expressed throughout the hypothalamus, and endocannabinoids have been found to exert pronounced regulatory effects on neuroendocrine function via modulation of the outputs of several neuroendocrine systems. Here, we review the physiological regulation of neuroendocrine function by endocannabinoids, focusing on the role of endocannabinoids in the neuroendocrine regulation of the stress response, food intake, fluid homeostasis, and reproductive function. Cannabis sativa (marijuana) has a long history of recreational and/or medicinal use dating back to ancient times. It was used as an analgesic, anesthetic, and antianxiety herb as early as 2600 B.C. The hedonic, anxiolytic, and mood-elevating properties of cannabis have also been cited in ancient records from different cultures. However, it was not until 1964 that the psychoactive constituent of cannabis, Δ(9)-tetrahydrocannabinol, was isolated and its chemical structure determined (Gaoni & Mechoulam, 1964). PMID:26638767

  18. 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.

  19. Geraniin down regulates gamma radiation-induced apoptosis by suppressing DNA damage.

    PubMed

    Bing, So Jin; Ha, Danbee; Kim, Min Ju; Park, Eunjin; Ahn, Ginnae; Kim, Dae Seung; Ko, Ryeo Kyeong; Park, Jae Woo; Lee, Nam Ho; Jee, Youngheun

    2013-07-01

    Gamma ray irradiation triggers DNA damage and apoptosis of proliferating stem cells and peripheral immune cells, resulting in the destruction of intestinal crypts and lymphoid system. Geraniin is a natural compound extracts from an aquatic plant Nymphaea tetragona and possesses good antioxidant property. In this study, we demonstrate that geraniin rescues radiosensitive splenocytes and jejunal crypt cells from radiation-induced DNA damage and apoptosis. Isolated splenocytes from C57BL/6 mice treated with geraniin were protected against radiation injury of 2 Gy irradiation through the enhancement of the proliferation and attenuation of DNA damage. Also, geraniin inhibited apoptosis in radiosensitive splenocytes by reducing the expression level and immunoreactivity of proapoptotic p53 and Bax and increasing those of anti-apoptotic Bcl-2. In mice exposed to radiation, geraniin treatment protected splenocytes and intestinal crypt cells from radiation-induced cell death. Our results suggest that geraniin presents radioprotective effects by regulating DNA damage on splenocytes, exerting immunostimulatory capacities and inhibiting apoptosis of radiosensitive immune cells and jejunal crypt cells. Therefore, geraniin can be a radioprotective agent against γ-irradiation exposure. PMID:23541438

  20. 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.

  1. 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.

  2. Maximum Power Point Regulator System

    NASA Astrophysics Data System (ADS)

    Simola, J.; Savela, K.; Stenberg, J.; Tonicello, F.

    2011-10-01

    The target of the study done under the ESA contract No.17830/04/NL/EC (GSTP4) for Maximum Power Point Regulator System (MPPRS) was to investigate, design and test a modular power system (a core PCU) fulfilling requirement for maximum power transfer even after a single failure in the Power System by utilising a power concept without any potential and credible single point failure. The studied MPPRS concept is of a modular construction, able to track the MPP individually on each SA sections, maintaining its functionality and full power capability after a loss of a complete MPPR module (by utilizingN+1module).Various add-on DCDC converter topology candidates were investigated and redundancy, failure mechanisms and protection aspects were studied

  3. 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.

  4. 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

  5. The Pulsed Interrogation Neutron and Gamma (PING) inspection system

    SciTech Connect

    Schultz, F.J.; Hensley, D.C.; Coffey, D.E.; Chapman, J.A.; Caylor, B.A.; Bailey, R.D. ); Vourvopoulos, G. ); Kehayias, J. . USDA Human Nutrition Research Center on Aging at Tufts Univ.)

    1991-01-01

    Explosives and chemical warfare (CW) agents possess elements and characteristic elemental ratios not commonly found in significant quantities in other items. These elements include nitrogen, oxygen, fluorine, phosphorus, sulfur, and chlorine. The research described herein discusses the results to date of the development of a pulsed-neutron interrogation and gamma ({gamma})-ray system for detecting concealed explosives and for discriminating munitions containing CW agents and conventional explosives. Preliminary experimental data has suggested that distinct classes of chemical agents could also be distinguished, for example, nerve agents and mustard gases. Based on there results, the system is currently being designed for the detection of explosives concealed, for example, in airline luggage. Nuclear and x-ray technologies possess unique characteristics to quickly and reliably search for explosives. Both oxygen and nitrogen, present in sufficient concentrations, when detected, uniquely determine the presence of explosives. Carbon would be a third element that is common in all explosives, although it does not correlate uniquely with all known explosives. A system which identifies and quantifies all three elements would provide more reliable information about the interrogated material. We have previously demonstrated that the technique described in this paper can identify certain elements through fast- and slow-neutron interrogation and subsequent prompt- and delayed-{gamma}-ray detection. The identification of CW agent elements such as chlorine, phosphorus, sulfur, and fluorine, is also accomplished through the detection of characteristic capture {gamma}-rays. The Pulsed Interrogation Neutron and Gamma (PING) inspection system is based upon technology developed over twelve years for the determination of fissile mass quantities in radioactive waste, for the determination of sulfur in coal, and for in-vivo body composition measurements.

  6. The Pulsed Interrogation Neutron and Gamma (PING) inspection system

    SciTech Connect

    Schultz, F.J.; Hensley, D.C.; Coffey, D.E.; Chapman, J.A.; Caylor, B.A.; Bailey, R.D.; Vourvopoulos, G.; Kehayias, J.

    1991-12-31

    Explosives and chemical warfare (CW) agents possess elements and characteristic elemental ratios not commonly found in significant quantities in other items. These elements include nitrogen, oxygen, fluorine, phosphorus, sulfur, and chlorine. The research described herein discusses the results to date of the development of a pulsed-neutron interrogation and gamma ({gamma})-ray system for detecting concealed explosives and for discriminating munitions containing CW agents and conventional explosives. Preliminary experimental data has suggested that distinct classes of chemical agents could also be distinguished, for example, nerve agents and mustard gases. Based on there results, the system is currently being designed for the detection of explosives concealed, for example, in airline luggage. Nuclear and x-ray technologies possess unique characteristics to quickly and reliably search for explosives. Both oxygen and nitrogen, present in sufficient concentrations, when detected, uniquely determine the presence of explosives. Carbon would be a third element that is common in all explosives, although it does not correlate uniquely with all known explosives. A system which identifies and quantifies all three elements would provide more reliable information about the interrogated material. We have previously demonstrated that the technique described in this paper can identify certain elements through fast- and slow-neutron interrogation and subsequent prompt- and delayed-{gamma}-ray detection. The identification of CW agent elements such as chlorine, phosphorus, sulfur, and fluorine, is also accomplished through the detection of characteristic capture {gamma}-rays. The Pulsed Interrogation Neutron and Gamma (PING) inspection system is based upon technology developed over twelve years for the determination of fissile mass quantities in radioactive waste, for the determination of sulfur in coal, and for in-vivo body composition measurements.

  7. Testing of a gamma ray imaging system at Omega

    NASA Astrophysics Data System (ADS)

    Lemieux, Daniel A.; Barber, H. Bradford; Grim, Gary P.; Clark, David D.; Danly, Christopher R.; Aragonez, Robert; Griego, Jeffrey; Fatherley, Valerie; Fastje, Daivd

    2013-09-01

    Successful images of hard x-rays were taken at the OMEGA Laser at the Laboratory for Laser energetics ant he University of Rochester. This facility served as a surrogate for the National Ignition Facility for which this system was designed. Eleven plastic shells filled with 3He pellets were imploded producing soft and hard x-rays. As the system was designed to image 4.44MeV gammas the hard x-rays were of particular interest. These bremsstrahlung x-rays were emitted for the outer plastic shell and imaged using the gamma ray imaging system 13 meters away. A number of filtering arrangements were used to do transmission radiography of the source providing spectrum information. A 200-micron pinhole aperture was used to image the source. These shots provide information critical in characterizing the performance of the system

  8. 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.

  9. Gamma scintillator system using boron carbide for neutron detection

    NASA Astrophysics Data System (ADS)

    Ben-Galim, Y.; Wengrowicz, U.; Raveh, A.; Orion, I.

    2014-08-01

    A new approach for neutron detection enhancement to scintillator gamma-ray detectors is suggested. By using a scintillator coupled with a boron carbide (B4C) disc, the 478 keV gamma-photon emitted from the excited Li in 94% of the 10B(n,α)7Li interactions was detected. This suggests that the performance of existing gamma detection systems in Homeland security applications can be improved. In this study, a B4C disc (2 in. diameter, 0.125 in. thick) with ~19.8% 10B was used and coupled with a scintillator gamma-ray detector. In addition, the neutron thermalization moderator was studied in order to be able to increase the neutron sensitivity. An improvement in the detector which is easy to assemble, affordable and efficient was demonstrated. Furthermore, a tailored Monte-Carlo code written in MATLAB was developed for validation of the proposed application through efficiency estimation for thermal neutrons. Validation of the code was accomplished by showing that the MATLAB code results were well correlated to a Monte-Carlo MCNP code results. The measured efficiency of the assembled experimental model was observed to be in agreement with both models calculations.

  10. 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.

  11. Synergy between suppressor of Hairless and Notch in regulation of Enhancer of split m gamma and m delta expression.

    PubMed Central

    Eastman, D S; Slee, R; Skoufos, E; Bangalore, L; Bray, S; Delidakis, C

    1997-01-01

    The Notch signaling pathway is known to regulate cell fate decisions in a variety of organisms from worms to humans. Although several components of the pathway have been characterized, the actual mechanism and molecular results of signaling remain elusive. We have examined the role of the Notch signaling pathway in the transcriptional regulation of two Drosophila Enhancer of split [E(spl)] genes, whose gene products have been shown to be downstream players in the pathway. Using a reporter assay system in Drosophila tissue culture cells, we have observed a significant induction of E(spl) m gamma and m delta expression after cotransfection with activated Notch. Characterization of the 5' regulatory regions of these two genes led to the identification of a number of target sites for the Suppressor of Hairless [Su(H)] protein, a transcription factor activated by Notch signaling. We show that Notch-inducible expression of E(spl) m gamma and m delta both in cultured cells and in vivo is dependent on functional Su(H). Although overexpression of Su(H) augments the level of induction of the reporter genes by activated Notch, Su(H) alone is insufficient to produce high levels of transcriptional activation. Despite the synergy observed between activated Notch and Su(H), the former affects neither the nuclear localization nor the DNA binding activity of the latter. PMID:9271437

  12. Negative transcriptional regulation of the interferon-gamma promoter by glucocorticoids and dominant negative mutants of c-Jun.

    PubMed

    Cippitelli, M; Sica, A; Viggiano, V; Ye, J; Ghosh, P; Birrer, M J; Young, H A

    1995-05-26

    Interferon-gamma (IFN-gamma) is an immunoregulatory cytokine expressed in large granular lymphocytes and T cells. However, the molecular mechanisms underlying IFN-gamma gene transcription have not been fully defined. Here, we analyze the mechanisms responsible for the inhibition of IFN-gamma promoter activity by the glucocorticoid hormone dexamethasone. Cotransfection assays performed in Jurkat T cells demonstrated that the activity of the initial 108 base pairs of the IFN-gamma promoter was down-regulated in the presence of dexamethasone. Furthermore, utilizing electrophoretic mobility shift analysis, we identified activator protein 1 AP-1-cAMP response element binding protein-activating transcription factor (CREB-ATF) binding elements situated in positions of the IFN-gamma promoter previously identified as essential for promoter activity. Moreover, dominant negative mutants of the c-Jun proto-oncogene were able to mimic the same down-regulatory effect exerted by dexamethasone, and mutations that abolished the binding of the AP-1 CREB-ATF factors were able to block the glucocorticoid effect. These results suggest a model involving the inhibition of IFN-gamma AP-1 CREB-ATF DNA binding complexes as one of the mechanisms involved in the negative regulatory action of glucocorticoids on IFN-gamma gene expression and support the relevance of AP-1 CREB-ATF binding factors during the transcriptional activation of the IFN-gamma promoter in T cells. PMID:7759501

  13. 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.

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

    SciTech Connect

    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.

  15. 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. PMID:19054575

  16. 21 CFR 862.1360 - Gamma-glutamyl transpeptidase and isoenzymes test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862.1360 Gamma-glutamyl transpeptidase and isoenzymes test system....

  17. 21 CFR 862.1360 - Gamma-glutamyl transpeptidase and isoenzymes test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862.1360 Gamma-glutamyl transpeptidase and isoenzymes test system....

  18. 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.

  19. The gamma-quantum registration system of SVD setup

    NASA Astrophysics Data System (ADS)

    Golovnya, S.

    2014-09-01

    The gamma-quantum registration system is the part of the SVD setup at the U-70 accelerator (IHEP) exposed in experiments: SERP E-184 (An experiment for studying mechanisms of charmed particle production and decays in pA-interactions at 70 GeV/c) and SERP E-190 (production of particles in pp-interactions in high multiplicity events at 50 GeV/c). The system consists of two detectors — the hodoscope detector of 1532 (48 × 32) cherenkov full absorption counters with a lead glass absorber (DEGA) and the soft photons calorimeter of 49 (7 × 7) counters with BGO crystals (SPC). The following subsystems are described: the high-voltage power system, the DEGA platform positioning control system for detector calibration in an electron beam, the DEGA LED monitoring system. The description of the soft photons calorimeter is also provided. This subsystem is focused to detecting the gamma quantum in energy range of tens MeV. The test results of SPC, obtained during its first operation in the accelerator run of 2013 year, are presented, the energy spectrum of photons are given.

  20. 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

  1. Regulation of gamma T-cell antigen receptor expression by intracellular calcium in acute lymphoblastic leukemia cell line DND41.

    PubMed

    Peralta-Zaragoza, O; Martínez-Valdez, H; Madrid-Marina, V

    1996-01-01

    The calcium ionophore, ionomycin, promotes an increase of intracellular calcium and regulates mRNA expression of gamma/delta-TcR gene in human T lymphocytes. The mechanism of this regulation is not yet clear. Thus, the regulation by intracellular calcium requires elucidation. We studied the gamma-TcR gene expression in acute lymphoblastic leukemia cell line DND41 (CD4- CD8-) by Northern blot and flow cytometric analysis. The mRNA levels of gamma-TcR increased by ionomycin, anti-CD3, and with TPA. TPA had an antagonistic effect to both ionomycin and anti-CD3. Also, TPA inhibits the increased intracellular calcium promoted by ionomycin but not the increase promoted by anti-CD3 and ionomycin. Our results suggest that intracellular calcium induces mRNA and protein expression of gamma-TcR chain. This effect is antagonized by protein kinase C-activation. Thus, we conclude that the target cells of the differential regulation on gamma-TcR mRNA expression by intracellular calcium modulators are the CD4- CD8- cells, and this is due to cytosolic calcium mobilization. PMID:8854386

  2. 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

  3. Estrogen-related receptor gamma is a key regulator of muscle mitochondrial activity and oxidative capacity.

    PubMed

    Rangwala, Shamina M; Wang, Xiaomei; Calvo, Jennifer A; Lindsley, Loren; Zhang, Yunyu; Deyneko, Galina; Beaulieu, Valerie; Gao, Jiaping; Turner, Gordon; Markovits, Judit

    2010-07-16

    Estrogen-related receptor gamma (ERRgamma) regulates the perinatal switch to oxidative metabolism in the myocardium. We wanted to understand the significance of induction of ERRgamma expression in skeletal muscle by exercise. Muscle-specific VP16ERRgamma transgenic mice demonstrated an increase in exercise capacity, mitochondrial enzyme activity, and enlarged mitochondria despite lower muscle weights. Furthermore, peak oxidative capacity was higher in the transgenics as compared with control littermates. In contrast, mice lacking one copy of ERRgamma exhibited decreased exercise capacity and muscle mitochondrial function. Interestingly, we observed that increased ERRgamma in muscle generates a gene expression profile that closely overlays that of red oxidative fiber-type muscle. We further demonstrated that a small molecule agonist of ERRbeta/gamma can increase mitochondrial function in mouse myotubes. Our data indicate that ERRgamma plays an important role in causing a shift toward slow twitch muscle type and, concomitantly, a greater capacity for endurance exercise. Thus, the activation of this nuclear receptor provides a potential node for therapeutic intervention for diseases such as obesity, which is associated with reduced oxidative metabolism and a lower type I fiber content in skeletal muscle. PMID:20418374

  4. Transcriptional regulation of the presenilin-1 gene controls gamma-secretase activity.

    PubMed

    Lee, Sebum; Das, Hriday K

    2010-01-01

    Inhibition of basal JNK activity by JNK inhibitor SP600125 or JNK1siRNA repressed presenilin-1 (PS1) expression in SK-N-SH cells by augmenting the level of p53, a repressor of the PS1 gene (1). We now showed that repression of PS1 transcription by JNK inhibitor SP600125 inhibited gamma-secretase mediated processing of amyloid precursor protein (APP) resulting in the accumulation of C99 fragment and the reduction of secreted Abeta40 level without altering the expression of nicastrin (NCT). Co-treatment of cells with SP600125 and p53 inhibitor, pifithrin-alpha, partially nullified the suppressive effects of SP610025 on PS1 expression and secreted Abeta40 level. Suppression of JNK1 by JNK1siRNA also decreased Abeta40 level. Furthermore, overexpression of the repressors p53, ZNF237 and CHD3 of the PS1 gene also suppressed the processing of APP through repression of PS1 transcription by deacetylation of histone at the PS1 promoter. Transcriptional activator Ets2 increased PS1 protein and secreted Abeta40 levels without affecting the expression of NCT by activating PS1 transcription via hyper-acetylation of histone at the PS1 promoter. Therefore, regulation of PS1 transcription modulates gamma-secretase activity. PMID:20036849

  5. 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

  6. Gamma ray attenuation in a developed borate glassy system

    NASA Astrophysics Data System (ADS)

    Saeed, Aly; El shazly, R. M.; Elbashar, Y. H.; Abou El-azm, A. M.; El-Okr, M. M.; Comsan, M. N. H.; Osman, A. M.; Abdal-monem, A. M.; El-Sersy, A. R.

    2014-09-01

    Measurements and calculations of gamma ray attenuation coefficients in glass barriers of xBaO-5ZnO-5MgO-14Na2O--1Li2O-(75-x)B2O3, previously prepared by the melt-quenching technique [1], were performed for γ-ray of energies 121.8, 244.7, 344.14, 661.66, 778.7, 974, 1086.7, 1173.24, 1332.5, and 1407.9 keV; which emitted from 152Eu, 137Cs, and 60Co radioactive gamma ray sources. The transmitted γ-rays were detected by 3″×3″ and 5″×5″ NaI (Tl) scintillation γ-ray spectrometers, and a highly calibrated survey meter. The mass attenuation coefficients of γ-rays (σ(E) were deduced from the attenuation curves, while the WinXCom computer program (version 3.1) was used to calculate the mass attenuation coefficients of γ-rays for such energies at different barium concentrations of a glassy system. A good agreement between both experimental and theoretical results was achieved as well as results obtained by other workers in similar field.

  7. 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.

  8. Peroxisome proliferator-activated receptor-gamma (PPARgamma) modulates hypothalamic Trh regulation in vivo.

    PubMed

    Kouidhi, Soumaya; Seugnet, Isabelle; Decherf, Stéphanie; Guissouma, Hajer; Elgaaied, Amel Benammar; Demeneix, Barbara; Clerget-Froidevaux, Marie-Stéphanie

    2010-04-12

    Thyroid hormone receptor (TR) and peroxisome proliferator-activated receptor gamma (PPARgamma) co-regulate numerous peripheral metabolic responses. To examine potential crosstalk between PPARgamma and TRbeta in the hypothalamus, thyrotropin-releasing hormone (Trh) regulation in the newborn mouse hypothalamus was followed. QPCR showed PPARgamma to be expressed in the hypothalamus at this developmental stage. Intracerebral injection of PPARgamma agonists modified transcription from a TRH-luc construct introduced into the hypothalamus and increased serum thyroxine levels. Furthermore, shRNA-based in vivo PPARgamma knockdown amplified T(3)-independent transcription and PPARgamma overexpression dose-dependently abrogated T(3)-dependent Trh repression. Overexpression of retinoid X receptor-alpha (RXRalpha), the common heterodimeric partner of PPARgamma and TRbeta, rescued PPARgamma abrogation of T(3)-dependent repression. Thus, competition for RXR could represent one mechanism underlying this hypothalamic crosstalk between PPARgamma and TRbeta. These demonstrations of PPARgamma effects on hypothalamic Trh transcription in vivo consolidate the role of the TRH neuron as a central integrator of energy homeostasis. PMID:19900503

  9. Gamma-aminobutyric acid acts as a specific virulence regulator in Pseudomonas aeruginosa.

    PubMed

    Dagorn, Audrey; Hillion, Mélanie; Chapalain, Annelise; Lesouhaitier, Olivier; Duclairoir Poc, Cécile; Vieillard, Julien; Chevalier, Sylvie; Taupin, Laure; Le Derf, Franck; Feuilloley, Marc G J

    2013-02-01

    Gamma-aminobutyric acid (GABA) is widespread in the environment and can be used by animal and plants as a communication molecule. Pseudomonas species, in particular fluorescent ones, synthesize GABA and express GABA-binding proteins. In this study, we investigated the effects of GABA on the virulence of Pseudomonas aeruginosa. While exposure to GABA (10 µM) did not modify either the growth kinetics or the motility of the bacterium, its cytotoxicity and virulence were strongly increased. The Caenorhabditis elegans 'fast killing test' model revealed that GABA acts essentially through an increase in diffusible toxin(s). GABA also modulates the biofilm formation activity and adhesion properties of PAO1. GABA has no effect on cell surface polarity, biosurfactant secretion or on the lipopolysaccharide structure. The production of several exo-enzymes, pyoverdin and exotoxin A is not modified by GABA but we observed an increase in cyanogenesis which, by itself, could explain the effect of GABA on P. aeruginosa virulence. This mechanism appears to be regulated by quorum sensing. A proteomic analysis revealed that the effect of GABA on cyanogenesis is correlated with a reduction of oxygen accessibility and an over-expression of oxygen-scavenging proteins. GABA also promotes specific changes in the expression of thermostable and unstable elongation factors Tuf/Ts involved in the interaction of the bacterium with the host proteins. Taken together, these results suggest that GABA is a physiological regulator of P. aeruginosa virulence. PMID:23154974

  10. The importance of glutamate, glycine, and {gamma}-aminobutyric acid transport and regulation in manganese, mercury and lead neurotoxicity

    SciTech Connect

    Fitsanakis, Vanessa A.; Aschner, Michael . E-mail: michael.aschner@vanderbilt.edu

    2005-05-01

    Historically, amino acids were studied in the context of their importance in protein synthesis. In the 1950s, the focus of research shifted as amino acids were recognized as putative neurotransmitters. Today, many amino acids are considered important neurochemicals. Although many amino acids play a role in neurotransmission, glutamate (Glu), glycine (Gly), and {gamma}-aminobutyric acid (GABA) are among the more prevalent and better understood. Glu, the major excitatory neurotransmitter, and Gly and GABA, the major inhibitory neurotransmitters, in the central nervous system, are known to be tightly regulated. Prolonged exposure to environmental toxicants, such as manganese (Mn), mercury (Hg), or lead (Pb), however, can lead to dysregulation of these neurochemicals and subsequent neurotoxicity. While the ability of these metals to disrupt the regulation of Glu, Gly and GABA have been studied, few articles have examined the collective role of these amino acids in the respective metal's mechanism of toxicity. For each of the neurotransmitters above, we will provide a brief synopsis of their regulatory function, including the importance of transport and re-uptake in maintaining their optimal function. Additionally, the review will address the hypothesis that aberrant homeostasis of any of these amino acids, or a combination of the three, plays a role in the neurotoxicity of Mn, Hg, or Pb.

  11. Up-regulation of gamma-glutamyl transpeptidase (GGT) activity in growth perturbed C6 astrocytes.

    PubMed

    Mares, V; Malík, R; Lisá, V; Sedo, A

    2005-05-20

    Activity of gamma-glutamyl transpeptidase (GGT) was studied in astrocyte-like C6 glial cells modulated in growth and maturation by different concentration of serum and dibutyryl cyclic AMP (Db-cAMP) supplement in culture medium. After reduction of serum concentration from 10% to 0.1%, the number of GGT positive cells determined histochemically increased 3.1 times and the GGT activity/mg protein in whole cell lysates was 5.1 times higher. In cultures with 0.1% serum + Db-cAMP, the histochemically and biochemically assayed GGT activity exceeded 5.1 and 7.9 times the values measured in control 10% serum cultures, respectively. The up-regulation of GGT was accompanied by an inhibition of proliferation, enhanced differentiation and hypertrophy of cells. In addition, the process of metabolic perturbation and/or cellular stress was revealed in these cultures by the (i) growth-support release followed by shrinkage and death of a small number of cells and (ii) higher oxidation of 2'7'dichlorofluorescein diacetate to its fluorescent form in the adherent/viable cells. The observed up-regulation of GGT is considered to primarily reflect increased metabolism of glutathione and/or the maintenance of the redox potential in cells stressed by sub-optimal concentration of serum and Db-cAMP supplement. The concomitant cellular hypertrophy and differentiation and their relationship to increased activity of GGT await further investigation. The study suggests that up-regulation of GGT can contribute to adaptation of astrocytic cells to metabolic and/or oxidative perturbances occurring under various pathological conditions, including radiation- and drug-induced toxicity. PMID:15893589

  12. Recent developments in the VACIS gamma radiography systems

    NASA Astrophysics Data System (ADS)

    Verbinski, Victor V.; Payne, Jay; Snell, Michael

    1998-12-01

    The VACIS-I prototype system, which has been used at U.S.- Mexico POEs for cargo truck and railroad freight-car inspections, has served as a seedbed for other vehicle inspection systems that are cost-effective, transportable, high- speed, reliable, and utilize very low level radiation exposure. The STAR (stolen automobile recovery) system has been developed and successfully tested at Miami, Florida. Its status and further developmental possibilities are discussed. VACIS-II, the high-resolution (0.5 inches versus 2 inches for VACIS-I) system that scans the entire cargo truck, including the van, is capable of conducting normal as well as oblique scans in 1 1/2 minutes. Railroad VACIS, dubbed SENTINEL, which will scan railroad cars entering the U.S. at about 5 mph is now under development. It has the option of utilizing a Co-60 source for inspecting heavier cargoes. In addition, MOBILE VACIS is in the planning stage. As presently envisioned, it will be mounted on a small vehicle with an extendable detector tower and deployable gamma-ray source to scan a suspect vehicle, either a passenger car or cargo truck, for contraband. The state of development of these systems, as well as some of the options and concerns, are presented.

  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 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.

  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. Up-regulation of keratin 17 expression in human HaCaT keratinocytes by interferon-gamma.

    PubMed

    Bonnekoh, B; Huerkamp, C; Wevers, A; Geisel, J; Sebök, B; Bange, F C; Greenhalgh, D A; Böttger, E C; Krieg, T; Mahrle, G

    1995-01-01

    The immortalized human keratinocyte cell line HaCaT was used to assess the effect of interferon-gamma (IFN-gamma) on expression of keratin K17. Both IFN-gamma and K17 have been implicated in the pathophysiology of psoriasis. Western and quantitative enzyme-linked immunosorbent assay analyses demonstrated increasing induction of K17 protein by 48 h exposure to IFN-gamma at concentrations of 10, 50, and 250 U/ml. At 50 U/ml IFN-gamma, immunohistochemical analysis revealed numerous K17-positive foci, whereas in situ hybridization demonstrated K17 message in the majority of cells. In addition, at low (5 U/ml) concentrations of IFN-gamma, cell proliferation and protein synthesis decreased, as determined by 3H-thymidine labeling and 14C-amino acid uptake. These data suggest that aberrant K17 expression observed in psoriatic lesions may be a consequence of IFN-gamma overexpression, and that the HaCaT cell line may be a useful in vitro model system to elucidate the underlying mechanisms. PMID:7528246

  17. 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

  18. Estrogen-related receptor gamma regulates dopaminergic neuronal phenotype by activating GSK3β/NFAT signaling in SH-SY5Y cells.

    PubMed

    Lim, Juhee; Choi, Hueng-Sik; Choi, Hyun Jin

    2015-05-01

    The orphan nuclear receptor estrogen-related receptor gamma (ERRγ) is highly expressed in the nervous system during embryogenesis and in adult brains, but its physiological role in neuronal development remains unknown. In this study, we evaluated the relevance of ERRγ in regulating dopaminergic (DAergic) phenotype and the corresponding signaling pathway. We used retinoic acid (RA) to differentiate human neuroblastoma SH-SY5Y cells. RA induced neurite outgrowth of SH-SY5Y cells with an increase in DAergic neuron-like properties, including up-regulation of tyrosine hydroxylase, dopamine transporter, and vesicular monoamine transporter 2. ERRγ, but not ERRα, was up-regulated by RA, and participated in RA effect on SH-SY5Y cells. ERRγ over-expression enhanced mature DAergic neuronal phenotype with neurite outgrowth as with RA treatment; and RA-induced increase in DAergic phenotype was attenuated by silencing ERRγ expression. ERRγ appears to have a crucial role in morphological and functional regulation of cells that is selective for DAergic neurons. Polo-like kinase 2 was up-regulated in ERRγ-over-expressing SH-SY5Y cells, which was involved in phosphorylation of glycogen synthase kinase 3β and resulting downstream activation of nuclear factor of activated T cells. The likely involvement of ERRγ in regulating the DAergic neuronal phenotype makes this orphan nuclear receptor a novel target for understanding DAergic neuronal differentiation. We propose the relevance of estrogen-related receptor gamma (ERRγ) in regulating dopaminergic neuronal phenotype: ERRγ is up-regulated by retinoic acid in SH-SY5Y cells, and enhances dopaminergic phenotypes and induces neurite outgrowth; Polo-like kinase 2 (PLK2) and glycogen synthase kinase 3 beta/nuclear factor of activated T cells (GSK3β/NFAT) signaling are responsible for the ERRγ effect. Our findings provide the first insights into the role of ERRγ in the brain, as a novel approach toward understanding

  19. 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.

  20. 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.

  1. 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.

  2. PET imaging using gamma camera systems: a review.

    PubMed

    Jarritt, P H; Acton, P D

    1996-09-01

    Optimized positron emission tomographs have begun to demonstrate an ever widening range of clinical applications for positron labelled pharmaceuticals. This potential has led to a renewed interest in the use of the more widely available Anger gamma camera detectors for imaging the 511 keV photons from the positron decay process. Two forms of detection can be considered: either the detection of the 511 keV photons as single events or the detection of coincidence events from the opposed pair annihilation photons. The widespread availability of dual, opposed-pair, large field-of-view detectors has promoted the development of coincidence detection without collimation. With detector rotation, positron emission tomography (PET) can be performed. An alternative and lower cost option has been the universal development of ultra high-energy collimators to perform single photon emission tomography (SPET) with 511 keV photons. This review outlines the currently available performance characteristics of these two approaches and compares them with those from two- and three-dimensional PET optimized systems. The limitations on the development of these systems is discussed through the analysis of the principles underlying both single photon and coincidence detection. Preliminary clinical experience indicates that limitations in the performance characteristics of these systems has implications for their potential role, although applications in cardiology and oncology are being pursued. PMID:8895903

  3. [Role of the fusimotor system in regulating shivering].

    PubMed

    Lupandin, Iu V

    1979-10-01

    Spontaneously active gamma-motoneurons were found in muscles of the cat during shivering. The activity of these gamma-motoneurons could be increased by stimulation of thermoreceptors of the subcutaneous vessels and nociceptors. Administration of oxotremorine, nicotin, phentolamine, isoprenaline, and seduxene into the 3rd brain ventricle suppressed the shivering but did not change the firing rate of the gamma-motoneurons. The fusomotor system seems to participate in the segmentary activation of shivering, but not in its supraspinal control. PMID:228996

  4. 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

  5. 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. PMID:19623486

  6. Granule cell excitability regulates gamma and beta oscillations in a model of the olfactory bulb dendrodendritic microcircuit.

    PubMed

    Osinski, Bolesław L; Kay, Leslie M

    2016-08-01

    Odors evoke gamma (40-100 Hz) and beta (20-30 Hz) oscillations in the local field potential (LFP) of the mammalian olfactory bulb (OB). Gamma (and possibly beta) oscillations arise from interactions in the dendrodendritic microcircuit between excitatory mitral cells (MCs) and inhibitory granule cells (GCs). When cortical descending inputs to the OB are blocked, beta oscillations are extinguished whereas gamma oscillations become larger. Much of this centrifugal input targets inhibitory interneurons in the GC layer and regulates the excitability of GCs, which suggests a causal link between the emergence of beta oscillations and GC excitability. We investigate the effect that GC excitability has on network oscillations in a computational model of the MC-GC dendrodendritic network with Ca(2+)-dependent graded inhibition. Results from our model suggest that when GC excitability is low, the graded inhibitory current mediated by NMDA channels and voltage-dependent Ca(2+) channels (VDCCs) is also low, allowing MC populations to fire in the gamma frequency range. When GC excitability is increased, the activation of NMDA receptors and other VDCCs is also increased, allowing the slow decay time constants of these channels to sustain beta-frequency oscillations. Our model argues that Ca(2+) flow through VDCCs alone could sustain beta oscillations and that the switch between gamma and beta oscillations can be triggered by an increase in the excitability state of a subpopulation of GCs. PMID:27121582

  7. The linear regulator problem for parabolic systems

    NASA Technical Reports Server (NTRS)

    Banks, H. T.; Kunisch, K.

    1983-01-01

    An approximation framework is presented for computation (in finite imensional spaces) of Riccati operators that can be guaranteed to converge to the Riccati operator in feedback controls for abstract evolution systems in a Hilbert space. It is shown how these results may be used in the linear optimal regulator problem for a large class of parabolic systems.

  8. 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 ...

  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. 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.

  12. Phosphorylation-dependent sumoylation regulates estrogen-related receptor-alpha and -gamma transcriptional activity through a synergy control motif.

    PubMed

    Tremblay, Annie M; Wilson, Brian J; Yang, Xiang-Jiao; Giguère, Vincent

    2008-03-01

    Interplay between different posttranslational modifications of transcription factors is an important mechanism to achieve an integrated regulation of gene expression. For the estrogen-related receptors (ERRs) alpha and gamma, regulation by posttranslational modifications is still poorly documented. Here we show that transcriptional repression associated with the ERR amino-terminal domains is mediated through sumoylation at a conserved phospho-sumoyl switch, psiKxEPxSP, that exists within a larger synergy control motif. Arginine substitution of the sumoylatable lysine residue or alanine substitution of a nearby phosphorylatable serine residue (serine 19 in ERRalpha) increased the transcriptional activity of both ERRalpha and -gamma. In addition, phospho-mimetic substitution of the serine residue with aspartate restored the sumoylation and transcriptional repression activity. The increased transcriptional activity of the sumoylation-deficient mutants was more pronounced in the presence of multiple adjacent ERR response elements. We also identified protein inhibitor of activated signal transducer and activator of transcription y as an interacting partner and a small ubiquitin-related modifier E3 ligase for ERRalpha. Importantly, analysis with a phospho-specific antibody revealed that sumoylation of ERRalpha in mouse liver requires phosphorylation of serine 19. Taken together, these results show that the interplay of phosphorylation and sumoylation in the amino-terminal domain provides an additional mechanism to regulate the transcriptional activity of ERRalpha and -gamma. PMID:18063693

  13. 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.

  14. 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.

  15. 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

  16. 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. PMID:23063987

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

    SciTech Connect

    Andrews, M. T.; Corcoran, E. C.; Goorley, J. T.; Kelly, D. G.

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

    DOE PAGESBeta

    Andrews, M. T.; Corcoran, E. C.; Goorley, J. T.; Kelly, D. G.

    2015-03-01

    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.

  19. 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.

  20. 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

  1. A Common Variant in the Adaptor Mal Regulates Interferon Gamma Signaling.

    PubMed

    Ní Cheallaigh, Clíona; Sheedy, Frederick J; Harris, James; Muñoz-Wolf, Natalia; Lee, Jinhee; West, Kim; McDermott, Eva Palsson; Smyth, Alicia; Gleeson, Laura E; Coleman, Michelle; Martinez, Nuria; Hearnden, Claire H A; Tynan, Graham A; Carroll, Elizabeth C; Jones, Sarah A; Corr, Sinéad C; Bernard, Nicholas J; Hughes, Mark M; Corcoran, Sarah E; O'Sullivan, Mary; Fallon, Ciara M; Kornfeld, Hardy; Golenbock, Douglas; Gordon, Stephen V; O'Neill, Luke A J; Lavelle, Ed C; Keane, Joseph

    2016-02-16

    Humans that are heterozygous for the common S180L polymorphism in the Toll-like receptor (TLR) adaptor Mal (encoded by TIRAP) are protected from a number of infectious diseases, including tuberculosis (TB), whereas those homozygous for the allele are at increased risk. The reason for this difference in susceptibility is not clear. We report that Mal has a TLR-independent role in interferon-gamma (IFN-γ) receptor signaling. Mal-dependent IFN-γ receptor (IFNGR) signaling led to mitogen-activated protein kinase (MAPK) p38 phosphorylation and autophagy. IFN-γ signaling via Mal was required for phagosome maturation and killing of intracellular Mycobacterium tuberculosis (Mtb). The S180L polymorphism, and its murine equivalent S200L, reduced the affinity of Mal for the IFNGR, thereby compromising IFNGR signaling in macrophages and impairing responses to TB. Our findings highlight a role for Mal outside the TLR system and imply that genetic variation in TIRAP may be linked to other IFN-γ-related diseases including autoimmunity and cancer. PMID:26885859

  2. A Common Variant in the Adaptor Mal Regulates Interferon Gamma Signaling

    PubMed Central

    Ní Cheallaigh, Clíona; Sheedy, Frederick J.; Harris, James; Muñoz-Wolf, Natalia; Lee, Jinhee; West, Kim; McDermott, Eva Palsson; Smyth, Alicia; Gleeson, Laura E.; Coleman, Michelle; Martinez, Nuria; Hearnden, Claire H.A.; Tynan, Graham A.; Carroll, Elizabeth C.; Jones, Sarah A.; Corr, Sinéad C.; Bernard, Nicholas J.; Hughes, Mark M.; Corcoran, Sarah E.; O’Sullivan, Mary; Fallon, Ciara M.; Kornfeld, Hardy; Golenbock, Douglas; Gordon, Stephen V.; O’Neill, Luke A.J.; Lavelle, Ed C.; Keane, Joseph

    2016-01-01

    Summary Humans that are heterozygous for the common S180L polymorphism in the Toll-like receptor (TLR) adaptor Mal (encoded by TIRAP) are protected from a number of infectious diseases, including tuberculosis (TB), whereas those homozygous for the allele are at increased risk. The reason for this difference in susceptibility is not clear. We report that Mal has a TLR-independent role in interferon-gamma (IFN-γ) receptor signaling. Mal-dependent IFN-γ receptor (IFNGR) signaling led to mitogen-activated protein kinase (MAPK) p38 phosphorylation and autophagy. IFN-γ signaling via Mal was required for phagosome maturation and killing of intracellular Mycobacterium tuberculosis (Mtb). The S180L polymorphism, and its murine equivalent S200L, reduced the affinity of Mal for the IFNGR, thereby compromising IFNGR signaling in macrophages and impairing responses to TB. Our findings highlight a role for Mal outside the TLR system and imply that genetic variation in TIRAP may be linked to other IFN-γ-related diseases including autoimmunity and cancer. PMID:26885859

  3. Evaluation of 3D Gamma index calculation implemented in two commercial dosimetry systems

    NASA Astrophysics Data System (ADS)

    Xing, Aitang; Arumugam, Sankar; Deshpande, Shrikant; George, Armia; Vial, Philip; Holloway, Lois; Goozee, Gary

    2015-01-01

    3D Gamma index is one of the metrics which have been widely used for clinical routine patient specific quality assurance for IMRT, Tomotherapy and VMAT. The algorithms for calculating the 3D Gamma index using global and local methods implemented in two software tools: PTW- VeriSoft® as a part of OCTIVIUS 4D dosimeter systems and 3DVHTM from Sun Nuclear were assessed. The Gamma index calculated by the two systems was compared with manual calculated for one data set. The Gamma pass rate calculated by the two systems was compared using 3%/3mm, 2%/2mm, 3%/2mm and 2%/3mm for two additional data sets. The Gamma indexes calculated by the two systems were accurate, but Gamma pass rates calculated by the two software tools for same data set with the same dose threshold were different due to the different interpolation of raw dose data by the two systems and different implementation of Gamma index calculation and other modules in the two software tools. The mean difference was -1.3%±3.38 (1SD) with a maximum difference of 11.7%.

  4. AZ-101 Mixer Pump Demonstration Data Acquisition System and Gamma Cart Data Acquisition Control System Software Configuration Management Plan

    SciTech Connect

    WHITE, D.A.

    1999-12-29

    This Software Configuration Management Plan (SCMP) provides the instructions for change control of the AZ1101 Mixer Pump Demonstration Data Acquisition System (DAS) and the Sludge Mobilization Cart (Gamma Cart) Data Acquisition and Control System (DACS).

  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. The Role of PPAR Gamma in Systemic Sclerosis.

    PubMed

    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

  7. 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

  8. 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.

  9. Shigella Iron Acquisition Systems and their Regulation

    PubMed Central

    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. PMID:26904516

  10. Development of transportable gamma-ray tomographic system for industrial application

    NASA Astrophysics Data System (ADS)

    Kim, Jongbum; Jung, Sung-hee; Moon, Jinho; Guen Park, Jang; Jin, Joonha; Cho, Gyuseong

    2012-11-01

    This paper introduces a gamma-ray tomographic system which is transportable and can be used for on-line systems such as a pipeline operation. In a previous study, a feasibility study on a gamma-ray tomographic system with a scanning geometry of Electron Beam CT was carried out by Monte Carlo simulation. This paper contains a successive work on a previous study by developing and evaluating a real system. To construct a gamma-ray CT, 137Cs was used as a gamma-ray source and radiation measurement system with 72 channel CsI detectors whose crystal is a 12 mm×12 mm×20 mm rectangular parallelepiped was developed to operate jointly with a motion control system. ML-EM algorithm was used for image reconstruction of experimental data. Using the developed transportable gamma-ray system, laboratory and field experiments were carried out successfully. The field experiment results show that a gamma-ray CT with an Electron Beam CT scanning geometry can be a transportable gantry for objects which are parts of processes.

  11. 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.

  12. 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.

  13. Gamma(2)-melanocyte-stimulating hormone suppression of systemic inflammatory responses to endotoxin is associated with modulation of central autonomic and neuroendocrine activities.

    PubMed

    Xia, Y; Wikberg, J E; Krukoff, T L

    2001-11-01

    Central autonomic and neuroendocrine activities are important components of the host response to bacterial inflammation. We demonstrate that intravenous infusion of gamma(2)-melanocyte-stimulating hormone (gamma(2)-MSH), a potent autonomic regulating peptide, prevents lipopolysaccharide (LPS)-induced hypotension and tachycardia, and modulates the ACTH response to endotoxin. In the hypothalamic paraventricular nucleus, a major neuroendocrine and autonomic center, gamma(2)-MSH inhibits LPS-induced increases in CRF mRNA levels, but does not suppress LPS-augmented arginine vasopressin heteronuclear RNA expression. In the locus coeruleus, a brainstem noradrenergic center, gamma(2)-MSH inhibits LPS-induced increases in tyrosine hydroxylase mRNA levels. Gamma(2)-MSH inhibits LPS-induced IL-1beta gene expression in the brain, pituitary and thymus, and prevents increases in plasma NO levels. These findings reveal that gamma(2)-MSH attenuates systemic inflammatory responses to endotoxin and suggest that modulation of central autonomic and neuroendocrine activities by gamma(2)-MSH contributes to its anti-inflammatory effects. PMID:11694321

  14. Up-regulation of gamma-aminobutyric acid transporter I mediates ethanol sensitivity in mice.

    PubMed

    Hu, J-H; Ma, Y-H; Yang, N; Mei, Z-T; Zhang, M-H; Fei, J; Guo, L-H

    2004-01-01

    Ethanol is among the most widely abused drugs in the world. Chronic ethanol consumption leads to ethanol tolerance and addiction, and impairs learning and memory. Na+/Cl- dependent GABA transporters play an important role in controlling the concentration of GABA in the synaptic cleft, and thus they control the intensity and duration of synaptic transmission of GABA. It has been suggested that GABAergic system is involved in ethanol consumption, tolerance and addiction, because chronic ethanol consumption alters the expression of GABAA receptors and drugs on GABA receptors affect ethanol actions. The results of the present study reveal that that activity of GABA transporters in mouse brain after 15-min acute ethanol injection or after chronic ethanol consumption is increased. Moreover, mice pre-injected with a competitive or a noncompetitive antagonist of gamma-aminobutyric acid transporter subtype 1 (GAT1) showed high sensitivity to the sedative/hypnotic effects of ethanol. In contrast, transgenic mice overexpressing GAT1 displayed low sensitivity to ethanol, as shown by the righting reflex test. Mice overexpressing GAT1 survived a lethal dose of ethanol (9 g/kg, i.p.) longer, maintained locomotor activity longer after a sub-lethal dose (1.75 g/kg, i.p.) and exhibited a higher median lethal dose than wild-type littermates. These results suggest that GAT1 plays an important role in sensitivity to ethanol, and might be a therapeutic target for alcoholism prevention and treatment. Acute and chronic ethanol administration resulted in the increase of GABA transporter function. Use of GAT1 selective inhibitors and GAT1 overexpressing mice thus demonstrate that GAT1 should be an important protein mediating sensitivity to ethanol in mice. PMID:14751274

  15. Monte Carlo simulation of pulse pile-up effect in gamma spectrum of a PGNAA system

    NASA Astrophysics Data System (ADS)

    Mowlavi, Ali Asghar; Hadizadeh Yazdi, Mohammad Hadi

    2011-12-01

    We have applied a pile-up Monte Carlo simulation code on gamma spectrum of a prompt gamma neutron activation analysis (PGNAA) system. The code has been run in nonparalyzable mode for a specific geometry of a PGNAA system with 241Am-9Be source and NaI(Tl) detector to obtain the distortion due to “pile-up” in the pulse height of gamma spectrum. The results show that the main background in the nitrogen region of interest (ROI) is due to two pile-ups. We have also evaluated the variation of count rate and total photon sampling over the Monte Carlo spectra. At high count rates, not only the nitrogen ROI but also carbon ROI, and hydrogen peak are disturbed strongly. Comparison between the results of simulations and the experimental spectra has shown a good agreement. The code could be used for other source setups and different gamma detection systems.

  16. Regulation of the phospholipase C-gamma2 pathway in B cells.

    PubMed

    Kurosaki, T; Maeda, A; Ishiai, M; Hashimoto, A; Inabe, K; Takata, M

    2000-08-01

    In B lymphocytes, a signaling complex that contributes to cell fate decisions is the B-cell antigen receptor (BCR), with different extents of receptor engagement leading to such outcomes as cell death, survival, or proliferation. Here, based upon the available genetic and biochemical data of the BCR signal components, we discuss several mechanisms by which BCR signals are propagated and modified, with specific emphasis on the phospholipase C (PLC)-gamma2-calcium pathway Gene-targeting experiments in DT40 chicken B cells highlighted the importance of the intracellular protein tyrosine kinases Syk and Btk in PLC-gamma2 activation. Until recently, the molecular mechanism underlying the double requirement for Syk and Btk in PLC-gamma2 activation remained unclear, but new data suggest that an adapter molecule, B-cell linker protein (alternatively named SLP-65 or BASH), phosphorylated by Syk, provides docking sites for Btk SH2 domain as well as PLC-gamma2 SH2 domains, thus bringing Btk into close proximity with PLC-gamma2. The activated Btk then phosphorylates PLC-gamma2, leading to its activation. The activated PLC-gamma2 converts phosphatidylinositol 4,5-bisphosphate into the second messenger inositol 1,4,5-trisphosphate (IP3), which in turn binds to IP3 receptors located on the endoplasmic reticulum (ER). Binding of IP3 to the IP3 receptors is essential for triggering a calcium release from the ER and subsequent entry of extracellular calcium. Balancing these activation signals in the PLC-gamma2-calcium pathway are the inhibitory receptors expressed on B cells, FcyRII and paired immunoglobin-like receptor (PIR)-B. Although both FcyRII and PIR-B inhibits the BCR-mediated [Ca2+]i increase, the inhibitory mechanisms of these receptors are distinct. The FcyRII-mediated inhibitory signal is dependent on lipid phosphatase SHIP, whereas the PIR-B requires redundant functions of protein phosphatases SHP-1 and SHP-2. Thus, PIR-B and FcgammaRII inhibit calcium signals by

  17. 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.

  18. 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.

  19. An interferon gamma-regulated protein that binds the interferon-inducible enhancer element of major histocompatibility complex class I genes.

    PubMed Central

    Driggers, P H; Ennist, D L; Gleason, S L; Mak, W H; Marks, M S; Levi, B Z; Flanagan, J R; Appella, E; Ozato, K

    1990-01-01

    Interferons (IFNs) induce transcription of major histocompatibility complex (MHC) class I genes through the conserved IFN consensus sequence (ICS) that contains an IFN response motif shared by many IFN-regulated genes. By screening mouse lambda ZAP expression libraries with the ICS as a probe, we isolated a cDNA clone encoding a protein that binds the ICS, designated ICSBP. Protein blot analysis with labeled oligonucleotide probes showed that ICSBP binds not only the MHC class I ICS but also IFN response motifs of many IFN-regulated genes, as well as a virus-inducible element of the IFN-beta gene. The ICSBP cDNA encodes 424 amino acids and a long 3' untranslated sequence. The N-terminal 115 amino acids correspond to a putative DNA-binding domain and show significant sequence similarity with other cloned IFN response factors (IRF-1 and IRF-2). Because of the structural similarity and shared binding specificity, we conclude that ICSBP is a third member of the IRF gene family, presumably playing a role in IFN- and virus-mediated regulation of many genes. Although IRF-1 and IRF-2 share some similarity in their C-terminal regions, ICSBP shows no similarity to IRF-1 or IRF-2 in this region, suggesting that it is more distantly related. We show that ICSBP mRNA is expressed predominantly in lymphoid tissues and is inducible preferentially by IFN-gamma. The induction by IFN-gamma appears to be predominant in lymphocytes and macrophages, implying that ICSBP plays a regulatory role in cells of the immune system. The presence of multiple factors that bind common IFN response motifs may partly account for the complexity and diversity of IFN action as well as IFN-regulated gene expression. Images PMID:2111015

  20. Interferon gamma regulates accumulation of the proteasome activator PA28 and immunoproteasomes at nuclear PML bodies.

    PubMed

    Fabunmi, R P; Wigley, W C; Thomas, P J; DeMartino, G N

    2001-01-01

    PA28 is an interferon (gamma) (IFN(gamma)) inducible proteasome activator required for presentation of certain major histocompatibility (MHC) class I antigens. Under basal conditions in HeLa and Hep2 cells, a portion of nuclear PA28 is concentrated at promyelocytic leukemia oncoprotein (PML)-containing bodies also commonly known as PODs or ND10. IFN(gamma) treatment greatly increased the number and size of the PA28- and PML-containing bodies, and the effect was further enhanced in serum-deprived cells. PML bodies are disrupted in response to certain viral infections and in diseases such as acute promyelocytic leukemia (APL). Like PML, PA28 was delocalized from PML bodies by expression of the cytomegalovirus protein, IE1, and in NB4 cells, an APL model line. Moreover, retinoic acid treatment, which causes remission of APL in patients and reformation of PML-containing bodies in NB4 cells, relocalized PA28 to this site. In contrast, the proteasome, the functional target of PA28, was not detected at PML bodies under basal conditions in HeLa and Hep2 cells, but IFN(gamma) promoted accumulation of 'immunoproteasomes' at this site. These results establish PA28 as a novel component of nuclear PML bodies, and suggest that PA28 may assemble or activate immunoproteasomes at this site as part of its role in proteasome-dependent MHC class I antigen presentation. PMID:11112687

  1. 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.

  2. Experimental approaches for the development of gamma spectroscopy well logging system

    SciTech Connect

    Shin, Jehyun; Hwang, Seho; Kim, Jongman; Won, Byeongho

    2015-03-10

    This article discusses experimental approaches for the development of gamma spectroscopy well logging system. Considering the size of borehole sonde, we customize 2 x 2 inches inorganic scintillators and the system including high voltage, preamplifier, amplifier and multichannel analyzer (MCA). The calibration chart is made by test using standard radioactive sources so that the measured count rates are expressed by energy spectrum. Optimum high-voltage supplies and the measurement parameters of each detector are set up by experimental investigation. Also, the responses of scintillation detectors have been examined by analysis according to the distance between source and detector. Because gamma spectroscopy well logging needs broad spectrum, high sensitivity and resolution, the energy resolution and sensitivity as a function of gamma ray energy are investigated by analyzing the gamma ray activities of the radioactive sources.

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

    DOE PAGESBeta

    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.

  4. Regulation of DTH and IgE responses by IL-4 and IFN-gamma in immunized mice given pertussis toxin.

    PubMed Central

    Mu, H H; Sewell, W A

    1994-01-01

    Interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) are cytokines with important functions in regulating immune responses. IFN-gamma may be produced by cells responsible for delayed-type hypersensitivity (DTH), whereas IL-4 is essential for IgE production. Pertussis toxin (PT) from Bordetella pertussis enhances both DTH and IgE responses, and causes enhancement of both IFN-gamma and IL-4 secretion in immunized mice. In the present study, the effects of neutralizing monoclonal antibodies against IFN-gamma or IL-4 on DTH, serum IgE and cytokine production were assessed. Treatment with a monoclonal anti-IL-4 antibody at the time of immunization caused a striking increase in DTH responses, and elicited enhanced IFN-gamma expression, while inhibition of the production of IL-4 and IgE was observed. By contrast, injection of a monoclonal anti-IFN-gamma antibody was followed by significant but not complete suppression of DTH reactions. IFN-gamma secretion was also inhibited, whereas IL-4 production and serum IgE were increased. Thus antibodies to IL-4 and IFN-gamma, given at the time of immunization, can profoundly influence the nature of short-term immune responses elicited by PT in immunized mice. Images Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 PMID:7875744

  5. 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.

  6. Structural shielding design for a gamma ray stereotactic body radiotherapy system.

    PubMed

    Xie, Xiangdong; Yang, Guoshan; Zhou, Hongmei; Qu, Decheng

    2006-09-01

    An OUR-QGD gamma ray stereotactic body radiotherapy system (body knife), made in China, is described. According to its structure and the principle of gamma radiation revolved on a focus, the energy distribution of scattered radiation in its treatment room is calculated. The structural shielding of the wall, roof, and door for a certain treatment room is calculated according to the local radiation protection law. PMID:16926472

  7. System Would Regulate Low Gas Pressure

    NASA Technical Reports Server (NTRS)

    Frazer, Robert E.

    1994-01-01

    System intended to maintain gases in containers at pressures near atmospheric. Includes ballast volume in form of underinflated balloon that communicates with working volume. Balloon housed in rigid chamber not subjected to extremes of temperature of working volume. Pressure in chamber surrounding balloon regulated at ambient atmospheric pressure or at constant small differential pressure above or below ambient. Expansion and contraction of balloon accommodates expansion or contraction of gas during operational heating or cooling in working volume, maintaining pressure in working volume at ambient or constant differential above or below ambient. Gas lost from system due to leakage or diffusion, low-pressure sensor responds, signaling valve actuators to supply more gas to working volume. If pressure rises too high, overpressure relief valve opens before excessive pressure damages system.

  8. 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.

  9. 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.

  10. Peroxisome proliferator-activated receptor gamma and the regulation of adipocyte function: lessons from human genetic studies.

    PubMed

    Gurnell, Mark

    2005-12-01

    In recent years, the thiazolidinediones (e.g. rosiglitazone, pioglitazone) have emerged as an exciting novel class of therapeutic agent for the treatment of type 2 diabetes mellitus and the human metabolic syndrome. At first glance, the use of these high-affinity peroxisome proliferator-activated receptor gamma (PPARgamma) agonists, that promote adipogenesis, to treat a group of disorders that typically have their origins in obesity seems counter-intuitive. However, to view PPARgamma simply as a regulator of fat mass, and adipocytes themselves as passive vessels for energy storage, is to ignore an extensive body of data that speaks of the diverse roles of both this receptor and adipose tissue in the maintenance of normal metabolic homeostasis. This article highlights the important clinical and laboratory observations made in human subjects harbouring genetic variations in PPARgamma that have confirmed its pivotal role in the regulation of adipocyte endocrine function, and thus our metabolic response to the environment. PMID:16311214

  11. Pneumatic well casing pressure regulating system

    SciTech Connect

    Flohr, M.C.

    1987-10-20

    A pneumatic well casing pressure regulating system is described comprising: a hydraulically actuated choke for relieving well casing pressure; a continually running source of pneumatic pressure pulses; first means for applying pulses of hydraulic fluid corresponding to the pneumatic pressure pulses to the choke for opening the choke one step for each pulse of hydraulic fluid when actual casing pressure is higher than a desired casing pressure; and second means for applying pulses of hydraulic fluid corresponding to the pneumatic pressure pulses to the choke for closing the choke one step for each pulse of hydraulic fluid when actual casing pressure is less than a desired casing pressure.

  12. 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.

  13. 21 CFR 870.5900 - Thermal regulating system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Thermal regulating system. 870.5900 Section 870...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Therapeutic Devices § 870.5900 Thermal regulating system. (a) Identification. A thermal regulating system is an external system consisting of a device...

  14. 21 CFR 870.5900 - Thermal regulating system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Thermal regulating system. 870.5900 Section 870...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Therapeutic Devices § 870.5900 Thermal regulating system. (a) Identification. A thermal regulating system is an external system consisting of a device...

  15. 21 CFR 870.5900 - Thermal regulating system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Thermal regulating system. 870.5900 Section 870...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Therapeutic Devices § 870.5900 Thermal regulating system. (a) Identification. A thermal regulating system is an external system consisting of a device...

  16. 21 CFR 870.5900 - Thermal regulating system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Thermal regulating system. 870.5900 Section 870...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Therapeutic Devices § 870.5900 Thermal regulating system. (a) Identification. A thermal regulating system is an external system consisting of a device...

  17. 21 CFR 870.5900 - Thermal regulating system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Thermal regulating system. 870.5900 Section 870...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Therapeutic Devices § 870.5900 Thermal regulating system. (a) Identification. A thermal regulating system is an external system consisting of a device...

  18. EBT-P gamma-ray shielding system

    SciTech Connect

    Gohar, Y.

    1981-12-01

    An elaborate study was carried out for the coil and biological shield of the ELMO Bumpy Torus proof-of-principle (EBT-P) device. A three-dimensional scoping study for the coil shield was performed for four different shielding options to define the heat load for each component and check the compliance with the design criterion of 10 watts maximum heat per coil from the gamma ray sources. Also, a detailed biological dose survey was performed which included: (a) the dose equivalent inside and outside the building, (b) the dose equivalent from the two mazes of the machine room, and (c) the skyshine contribution to the dose equivalent.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. Hybrid System Reduction Method using Reduced System Regulator

    NASA Astrophysics Data System (ADS)

    Kuroda, Eisuke; Tsuji, Takao; Oyama, Tsutomu

    In order to analyze transient stability of large-scale power systems, it is advantageous to apply system reduction method to external systems. Short-circuit current method is one of the typical engineering reduction techniques. However, the dominant eigenvalues are not necessarily conserved in the reduced system. Therefore, the hybrid reduction method in which controller parameters are adjusted to conserve the dominant eigenvalues was proposed. Automatic voltage regulator (AVR) and power system stabilizer (PSS) have been used for parameters adjustment so far. However, since there are many parameters in AVR and PSS, complicated procedures are required to adjust them. Therefore, in this paper, the reduced system regulator (RSR) is proposed for hybrid system reduction method. The RSR has only two parameters for adjustment. It is easier to adjust the RSR than AVR/PSS. In addition, the initial gains of the RSR are set zero so that dynamic behavior of the system is not influenced before the adjustment. The effect and the accuracy of the hybrid system reduction method with RSR are examined using a typical longitudinal power system, IEEJ WEST 10-machine system model.

  5. HtrA3 is regulated by 15-deoxy-{Delta}12,14-prostaglandin J2 independently of PPAR{gamma} in clear cell renal cell carcinomas

    SciTech Connect

    Theoleyre, Sandrine; Mottier, Stephanie; Masson, Damien; Denis, Marc G.

    2010-04-09

    Peroxisome proliferator-activated receptor gamma (PPAR{gamma}) ligands have been shown to possess anti-proliferative effects in many types of cancer. In clear cell renal cell carcinoma (CCRCC), the targets involved in these effects are not known. In this study, we demonstrated that, in CCRCC cell lines, the endogenous PPAR{gamma} ligand 15-deoxy-{Delta}12,14-prostaglandin J2 (15dPGJ2) induces the expression, both at the mRNA and the protein levels, of the HtrA3 gene. This gene belongs to the High-Temperature Requirement Factor A family of serine proteases that repress signaling by TGF-{beta} family members and inhibit cell migration. Rosiglitazone or ciglitazone, synthetic PPAR{gamma} agonists, did not induce HtrA3 expression, and the PPAR{gamma} antagonist GW9662 did not prevent 15dPGJ2 induction, suggesting that the up-regulation of HtrA3 by 15dPGJ2 is independent of PPAR{gamma}. The MEK/ERK inhibitor PD98059 dramatically repressed HtrA3 induction. Altogether, these data indicate that 15dPGJ2 is able to stimulate the expression of HtrA3 through an indirect mechanism involving the MEK/ERK pathway but independent of PPAR{gamma}. Our results provide a better understanding of the mechanisms involved in the regulation of HtrA3, a potential tumor suppressor gene.

  6. Gamma-ray and neutron radiography as part of a pulsed fast neutron analysis inspection system

    NASA Astrophysics Data System (ADS)

    Rynes, J.; Bendahan, J.; Gozani, T.; Loveman, R.; Stevenson, J.; Bell, C.

    1999-02-01

    A gamma-ray and neutron radiography system has been developed to provide useful supplemental information for a Pulsed Fast Neutron Analysis (PFNA) cargo inspection system. PFNA uses a collimated beam of pulsed neutrons to interrogate cargoes using (n, γx) reactions. The PFNA source produces both gamma rays as well as neutrons. The transmission of both species through the cargo is measured with an array of plastic scintillators. Since the neutron and gamma-ray signals are easily separated by arrival time a separate image can be made for both species. The radiography measurement is taken simultaneously with the PFNA measurement turning PFNA into an emission and transmission imaging system, thus enhancing the PFNA radiography system.

  7. 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

  8. 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.

  9. Tetracycline Regulated Systems in Functional Oncogenomics

    PubMed Central

    Welman, Arkadiusz; Barraclough, Jane; Dive, Caroline

    2007-01-01

    The increasing number of proteomic and DNA-microarray studies is continually providing a steady acquisition of data on the molecular abnormalities associated with human tumors. Rapid translation of this accumulating biological information into better diagnostics and more effective cancer therapeutics in the clinic depends on the use of robust function-testing strategies. Such strategies should allow identification of molecular lesions that are essential for the maintenance of the transformed phenotype and enable validation of potential drug-targets. The tetracycline regulated gene expression/ suppression systems (Tet-systems) developed and optimized by bioengineers over recent years seem to be very well suited for the function-testing purposes in cancer research. We review the history and latest improvements in Tet-technology in the context of functional oncogenomics. PMID:23645981

  10. 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.

  11. 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.

  12. 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). PMID:21129990

  13. A coded aperture imaging system optimized for hard X-ray and gamma ray astronomy

    NASA Technical Reports Server (NTRS)

    Gehrels, N.; Cline, T. L.; Huters, A. F.; Leventhal, M.; Maccallum, C. J.; Reber, J. D.; Stang, P. D.; Teegarden, B. J.; Tueller, J.

    1985-01-01

    A coded aperture imaging system was designed for the Gamma-Ray imaging spectrometer (GRIS). The system is optimized for imaging 511 keV positron-annihilation photons. For a galactic center 511-keV source strength of 0.001 sq/s, the source location accuracy is expected to be + or - 0.2 deg.

  14. 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.

  15. Driving force for {gamma} {yields} {var{underscore}epsilon} martensitic transformation and stacking fault energy of {gamma} in Fe-Mn binary system

    SciTech Connect

    Lee, Y.K.; Choi, C.S.

    2000-02-01

    A regular solution model for the difference of the chemical free energy between {gamma} and {var{underscore}epsilon} phases during {gamma} {yields} {var{underscore}epsilon} martensitic transformation in the Fe-Mn binary system has been reexamined and partly modified based on many articles concerning the M{sub s} and A{sub s} temperatures of Fe-Mn alloys. Using the regular solution model, the measured M{sub s} temperatures, and a thermodynamic model for the stacking fault energy (SFE) of austenite ({gamma}), the driving force for {gamma} {yields} {epsilon} martensitic transformation, and the SFE of {gamma} have been calculated. The driving force for {gamma} {yields} {epsilon} martensitic transformation increases linearly from {minus}68 to {minus}120 J/mole with increasing Mn content from 16 to 24 wt pct. The SFE of {gamma} decreases to approximately 13 at. pct Mn and then increases with increasing Mn content, which is in better agreement with Schumann's result rather than Volosevich et al.'s result.

  16. Bone tissue as a systemic endocrine regulator.

    PubMed

    Zofkova, I

    2015-01-01

    Bone is a target tissue for hormones, such as the sex steroids, parathormon, vitamin D, calcitonin, glucocorticoids, and thyroid hormones. In the last decade, other "non-classic" hormones that modulate the bone tissue have been identified. While incretins (GIP and GLP-1) inhibit bone remodeling, angiotensin acts to promote remodeling. Bone morphogenetic protein (BMP) has also been found to have anabolic effects on the skeleton by activating bone formation during embryonic development, as well as in the postnatal period of life. Bone has also been identified as an endocrine tissue that produces a number of hormones, that bind to and modulate extra-skeletal receptors. Osteocalcin occupies a central position in this context. It can increase insulin secretion, insulin sensitivity and regulate metabolism of fatty acids. Moreover, osteocalcin also influences phosphate metabolism via osteocyte-derived FGF23 (which targets the kidneys and parathyroid glands to control phosphate reabsorption and metabolism of vitamin D). Finally, osteocalcin stimulates testosterone synthesis in Leydig cells and thus may play some role in male fertility. Further studies are necessary to confirm clinically important roles for skeletal tissue in systemic regulations. PMID:25470522

  17. 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.

  18. 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.

  19. 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.

  20. Dissection of the interferon gamma-MHC class II signal transduction pathway reveals that type I and type II interferon systems share common signalling component(s).

    PubMed Central

    Loh, J E; Chang, C H; Fodor, W L; Flavell, R A

    1992-01-01

    We have used a herpes virus thymidine kinase (HSV-TK) based metabolic selection system to isolate mutants defective in the interferon gamma mediated induction of the MHC class II promoter. All the mutations act in trans and result in no detectable induction of MHC and invariant chain (Ii) gene expression. Scatchard analysis indicates that the mutants have a normal number of surface IFN gamma receptors with the same affinity constant. The mutants fall into two broad categories. One class of mutants is still able to induce MHC class I, IRF-1, 9-27, 1-8 and GBP genes by IFN gamma. A second class of mutants is defective for the IFN gamma induction of all the genes tested; surprisingly, the IFN alpha/beta induction of MHC class I, 9-27, ISG54 and ISG15 genes is also defective in these mutants, although different members of this class can be discriminated by the response of the GBP and IRF-1 genes to type I interferons. These data demonstrate that the signalling pathways of both type I and type II interferon systems share common signal transduction component(s). These mutants will be useful for the study of IFN gamma regulation of class II genes and Ii chain, and to elucidate molecular components of type I and type II interferon signal transduction. Images PMID:1314162

  1. Interactions of IFN-gamma with IL-3 and IL-4 in the regulation of serotonin and arachidonate release from mouse peritoneal mast cells.

    PubMed Central

    Holliday, M R; Banks, E M; Dearman, R J; Kimber, I; Coleman, J W

    1994-01-01

    We have examined the interactions between interferon-gamma (IFN-gamma), interleukin-3 (IL-3) and interleukin-4 (IL-4) in the regulation of IgE/antigen-induced secretory responses of mouse peritoneal mast cells. The cytokines were added either alone or in various combinations to cultured mast cells sensitized passively with IgE antibody. In experiments with unfractionated peritoneal cells (containing approx. 1% mast cells), IL-3 and IL-4 enhanced in an additive manner antigen-induced release of serotonin (5-HT), while IFN-gamma inhibited release regardless of whether IL-3 and/or IL-4 were present. In experiments employing mast cells purified to > 90%, IL-3 and IL-4 retained their enhancing activities whereas the inhibitory effect of IFN-gamma was considerably diminished. Nevertheless, IFN-gamma still inhibited significantly IL-4-enhanced secretion. The effects of IL-3 and IL-4 +/- IFN-gamma on arachidonate release were identical to those seen for 5-HT release, indicating that the secretion of both preformed mediators and newly synthesized eicosanoids is regulated in a similar way by these cytokines. PMID:8045595

  2. Development of polarization-controlled multi-pass Thomson scattering system in the GAMMA 10 tandem mirror

    SciTech Connect

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

    2012-10-15

    In the GAMMA 10 tandem mirror, the typical electron density is comparable to that of the peripheral plasma of torus-type fusion devices. Therefore, an effective method to increase Thomson scattering (TS) signals is required in order to improve signal quality. In GAMMA 10, the yttrium-aluminum-garnet (YAG)-TS system comprises a laser, incident optics, light collection optics, signal detection electronics, and a data recording system. We have been developing a multi-pass TS method for a polarization-based system based on the GAMMA 10 YAG TS. To evaluate the effectiveness of the polarization-based configuration, the multi-pass system was installed in the GAMMA 10 YAG-TS system, which is capable of double-pass scattering. We carried out a Rayleigh scattering experiment and applied this double-pass scattering system to the GAMMA 10 plasma. The integrated scattering signal was made about twice as large by the double-pass system.

  3. Total Measurement Uncertainty for the Plutonium Finishing Plant (PFP) Segmented Gamma Scan Assay System

    SciTech Connect

    WESTSIK, G.A.

    2001-06-06

    This report presents the results of an evaluation of the Total Measurement Uncertainty (TMU) for the Canberra manufactured Segmented Gamma Scanner Assay System (SGSAS) as employed at the Hanford Plutonium Finishing Plant (PFP). In this document, TMU embodies the combined uncertainties due to all of the individual random and systematic sources of measurement uncertainty. It includes uncertainties arising from corrections and factors applied to the analysis of transuranic waste to compensate for inhomogeneities and interferences from the waste matrix and radioactive components. These include uncertainty components for any assumptions contained in the calibration of the system or computation of the data. Uncertainties are propagated at 1 sigma. The final total measurement uncertainty value is reported at the 95% confidence level. The SGSAS is a gamma assay system that is used to assay plutonium and uranium waste. The SGSAS system can be used in a stand-alone mode to perform the NDA characterization of a container, particularly for low to medium density (0-2.5 g/cc) container matrices. The SGSAS system provides a full gamma characterization of the container content. This document is an edited version of the Rocky Flats TMU Report for the Can Scan Segment Gamma Scanners, which are in use for the plutonium residues projects at the Rocky Flats plant. The can scan segmented gamma scanners at Rocky Flats are the same design as the PFP SGSAS system and use the same software (with the exception of the plutonium isotopics software). Therefore, all performance characteristics are expected to be similar. Modifications in this document reflect minor differences in the system configuration, container packaging, calibration technique, etc. These results are supported by the Quality Assurance Objective (QAO) counts, safeguards test data, calibration data, etc. for the PFP SGSAS system. Other parts of the TMU analysis utilize various modeling techniques such as Monte Carlo N

  4. Kernel Integration Code System--Multigroup Gamma-Ray Scattering.

    Energy Science and Technology Software Center (ESTSC)

    1988-02-15

    GGG (G3) is the generic designation for a series of computer programs that enable the user to estimate gamma-ray scattering from a point source to a series of point detectors. Program output includes detector response due to each source energy, as well as a grouping by scattered energy in addition to a simple, unscattered beam result. Although G3 is basically a single-scatter program, it also includes a correction for multiple scattering by applying a buildupmore » factor for the path segment between the point of scatter and the detector point. Results are recorded with and without the buildup factor. Surfaces, defined by quadratic equations, are used to provide for a full three-dimensional description of the physical geometry. G3 evaluates scattering effects in those situations where more exact techniques are not economical. G3 was revised by Bettis and the name was changed to indicate that it was no longer identical to the G3 program. The name S3 was chosen since the scattering calculation has three steps: calculation of the flux arriving at the scatterer from the point source, calculation of the differential scattering cross section, and calculation of the scattered flux arriving at the detector.« less

  5. 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.

  6. 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.

  7. 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.

  8. CREB, ATF, and AP-1 transcription factors regulate IFN-gamma secretion by human T cells in response to mycobacterial antigen.

    PubMed

    Samten, Buka; Townsend, James C; Weis, Steven E; Bhoumik, Anindita; Klucar, Peter; Shams, Homayoun; Barnes, Peter F

    2008-08-01

    IFN-gamma production by T cells is pivotal for defense against many pathogens, and the proximal promoter of IFN-gamma, -73 to -48 bp upstream of the transcription start site, is essential for its expression. However, transcriptional regulation mechanisms through this promoter in primary human cells remain unclear. We studied the effects of cAMP response element binding protein/activating transcription factor (CREB/ATF) and AP-1 transcription factors on the proximal promoter of IFN-gamma in human T cells stimulated with Mycobacterium tuberculosis. Using EMSA, supershift assays, and promoter pulldown assays, we demonstrated that CREB, ATF-2, and c-Jun, but not cyclic AMP response element modulator, ATF-1, or c-Fos, bind to the proximal promoter of IFN-gamma upon stimulation, and coimmunoprecipitation indicated the possibility of interaction among these transcription factors. Chromatin immunoprecipitation confirmed the recruitment of these transcription factors to the IFN-gamma proximal promoter in live Ag-activated T cells. Inhibition of ATF-2 activity in T cells with a dominant-negative ATF-2 peptide or with small interfering RNA markedly reduced the expression of IFN-gamma and decreased the expression of CREB and c-Jun. These findings suggest that CREB, ATF-2, and c-Jun are recruited to the IFN-gamma proximal promoter and that they up-regulate IFN-gamma transcription in response to microbial Ag. Additionally, ATF-2 controls expression of CREB and c-Jun during T cell activation. PMID:18641343

  9. Operability test procedure for the TK-900 beta/gamma liquid effluent monitoring system

    SciTech Connect

    Weissenfels, R.D.

    1995-02-24

    This operability test procedure will verify that the 221-B beta/gamma liquid effluent monitoring system, installed near the east end of the six inch chemical sewer header, functions as intended by design. An off-line, skid mounted, beta/gamma radiation monitor and pH monitor was installed near stairwell three in the 221-B electrical gallery by Project W-007H. The skid mounted monitoring system includes two radiation detectors and a pH meter, both with local digital displays. Output signals from each monitor are also received and displayed by the Facility Process Monitor and Control System (FPMCS). Pumps, motors, gauges, valves and transport lines complement the skid monitoring system. The system is part of BAT/AKART for the BCE liquid effluent system.

  10. Operability test report for the TK-900 beta/gamma liquid effluent monitoring system

    SciTech Connect

    Weissenfels, R.D.

    1995-04-10

    This operability test report will verify that the 221-B beta/gamma liquid effluent monitoring system installed near the east end of the six inch chemical sewer header, functions as intended by design. An off-line, skid mounted, beta/gamma radiation monitor and pH monitor was installed near stairwell three in the 221-B electrical gallery by Project W-007H. The skid mounted monitoring system includes two radiation detectors and a pH meter, both with local digital displays. Output signals from each monitor are also received and displayed by the Facility Process Monitor and Control System (FPMCS). Pumps, motors, gauges, valves and transport lines complement the skid monitoring system. The system is part of BAT/AKART for the BCE liquid effluent system.

  11. 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.

  12. 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.

  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. Documentation of the data analysis system for the gamma ray monitor aboard OSO-H

    NASA Technical Reports Server (NTRS)

    Croteau, S.; Buck, A.; Higbie, P.; Kantauskis, J.; Foss, S.; Chupp, D.; Forrest, D. J.; Suri, A.; Gleske, I.

    1973-01-01

    The programming system is presented which was developed to prepare the data from the gamma ray monitor on OSO-7 for scientific analysis. The detector, data, and objectives are described in detail. Programs presented include; FEEDER, PASS-1, CAL1, CAL2, PASS-3, Van Allen Belt Predict Program, Computation Center Plot Routine, and Response Function Programs.

  15. System gamma as a function of image- and monitor-dynamic range.

    PubMed

    Kane, David; Bertalmío, Marcelo

    2016-04-01

    System gamma is the end-to-end exponent that describes the relationship between the relative luminance values at capture and the reproduced image. The system gamma preferred by subjects is known to vary with the background luminance condition and the image in question. We confirm the previous two findings using an image database with both high and low dynamic range images (from 102 to 107), but also find that the preferred system gamma varies with the dynamic range of the monitor (CRT, LCD, or OLED). We find that the preferred system gamma can be predicted in all conditions and for all images by a simple model that searches for the value that best flattens the lightness distribution, where lightness is modeled as a power law of onscreen luminance. To account for the data, the exponent must vary with the viewing conditions. The method presented allows the inference of lightness perception in natural scenes without direct measurement and makes testable predictions for how lightness perception varies with the viewing condition and the distribution of luminance values in a scene. The data from this paper has been made available online. PMID:27271806

  16. Shuttle flight test of an advanced gamma-ray detection system

    NASA Astrophysics Data System (ADS)

    Rester, Alfred C., Jr.

    1988-06-01

    The Gamma-Ray Advanced Detector (GRAD) is a gamma-ray detector system consisting of a large-volume, n-type germanium detector with active shielding of bismuth germanate and plastic scintillators. It was diverted from the AFP-675 program to a balloon flight over Antarctica following the Challenger Disaster and the discovery the following year of the supernova 1987A. The present report outlines activities leading to and following the decision to go to Antarctica and summarizes the basic technological results from the project.

  17. The electronic systems for the Gamma Ray Experiment for the Solar Maximum Mission

    NASA Technical Reports Server (NTRS)

    Staples, M.; Gleske, I.; Kubierschky, K.

    1980-01-01

    The Gamma Ray Experiment (GRE) is one of the seven instruments on the Solar Maximum Mission. The scientific objective of the GRE is to study solar gamma ray emissions expected during, and, according to some solar models, prior to solar flares. The instrument consists of a detector assembly and a remote electronic assembly. The latter includes redundant low-voltage power supplies and the remaining command, data handling, and ancillary electronic subsystems of the instrument. The electronic systems and subsystems of the instrument are described in some detail.

  18. Comparisons between digital gamma-ray spectrometer (DSPec) and standard nuclear instrumentation methods (NIM) systems

    SciTech Connect

    Vo, D.T.; Russo, P.A.; Sampson, T.E.

    1998-03-01

    Safeguards isotopic measurements require the best spectrometer systems with excellent resolution, stability and throughput. Up until about a year ago, gamma ray spectroscopy has always been done using the analog amplifier, which processes the pulses from the preamplifier to remove the noise, reject the pile up signals, and shape the signals into some desirable form before sending them to the analog to digital converter (ADC) to be digitized. In late 1996, EG and G Ortec introduced a digital gamma ray spectrometer (DSPec) which uses digital technology to analyze the preamplifiers` pulses from all types of germanium and silicon detectors. Considering its performance, digital based spectroscopy may become the way of future gamma ray spectroscopy.

  19. 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.

  20. The orphan nuclear receptor estrogen receptor-related receptor gamma negatively regulates BMP2-induced osteoblast differentiation and bone formation.

    PubMed

    Jeong, Byung-Chul; Lee, Yong-Soo; Park, Yun-Yong; Bae, In-Ho; Kim, Don-Kyu; Koo, Seung-Hoi; Choi, Hong-Ran; Kim, Sun-Hun; Franceschi, Renny T; Koh, Jeong-Tae; Choi, Hueng-Sik

    2009-05-22

    Estrogen receptor-related receptor gamma (ERRgamma/ERR3/NR3B3) is a member of the orphan nuclear receptor with important functions in development and homeostasis. Recently it has been reported that ERRalpha is involved in osteoblast differentiation and bone formation. In the present study we examined the role of ERRgamma in osteoblast differentiation. Here, we showed that ERRgamma is expressed in osteoblast progenitors and primary osteoblasts, and its expression is increased temporarily by BMP2. Overexpression of ERRgamma reduced BMP2-induced alkaline phosphatase activity and osteocalcin production as well as calcified nodule formation, whereas inhibition of ERRgamma expression significantly enhanced BMP2-induced osteogenic differentiation and mineralization, suggesting that endogenous ERRgamma plays an important role in osteoblast differentiation. In addition, ERRgamma significantly repressed Runx2 transactivity on osteocalcin and bone sialoprotein promoters. We also observed that ERRgamma physically interacts with Runx2 in vitro and in vivo and competes with p300 to repress Runx2 transactivity. Notably, intramuscular injection of ERRgamma strongly inhibited BMP2-induced ectopic bone formation in a dose-dependent manner. Taken together, these results suggest that ERRgamma is a novel negative regulator of osteoblast differentiation and bone formation via its regulation of Runx2 transactivity. PMID:19324883

  1. Fish oil regulates adiponectin secretion by a peroxisome proliferator-activated receptor-gamma-dependent mechanism in mice.

    PubMed

    Neschen, Susanne; Morino, Katsutaro; Rossbacher, Jörg C; Pongratz, Rebecca L; Cline, Gary W; Sono, Saki; Gillum, Matthew; Shulman, Gerald I

    2006-04-01

    Adiponectin has insulin-sensitizing, antiatherogenic, and anti-inflammatory properties, but little is known about factors that regulate its secretion. To examine the effect of fish oil on adiponectin secretion, mice were fed either a control diet or isocaloric diets containing 27% safflower oil or 27, 13.5, and 8% menhaden fish oil. Within 15 days, fish oil feeding raised plasma adiponectin concentrations two- to threefold in a dose-dependent manner, and the concentrations remained approximately twofold higher for 7 days when the fish oil diet was replaced by the safflower oil diet. Within 24 h, fish oil markedly induced transcription of the adiponectin gene in epididymal adipose tissue but not in subcutaneous fat. The increase of plasma adiponectin by fish oil was completely blocked by administration of the peroxisome proliferator-activated receptor (PPAR)gamma inhibitor bisphenol-A-diglycidyl ether. In contrast, there was no effect of fish oil feeding on adiponectin secretion in PPARalpha-null mice. These data suggest that fish oil is a naturally occurring potent regulator of adiponectin secretion in vivo and that it does so through a PPARgamma-dependent and PPARalpha-independent manner in epididymal fat. PMID:16567512

  2. 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.

  3. 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.

  4. 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.

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

    PubMed

    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 (11)C, (13)N, and (18)F, can be used to label molecules. The tracers, such as (11)CO2, 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 ([Formula: see text]) 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 (11)CO2. 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

  6. 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.

  7. Analysis of a parallel-arrayed power regulating system

    NASA Technical Reports Server (NTRS)

    Colburn, B. K.; Horton, H. M.; Honnell, M. A.

    1979-01-01

    A power regulation system incorporating n-parallel power supplies employing PWM switching regulators is studied. Analysis of individual unit operation and coupled-system parameter sensitivity is considered from an operations viewpoint. A detailed example is included to illustrate parallel system operation for 18 such units powered by solar-cell banks.

  8. A General-Purpose Monte Carlo Gamma-Ray Transport Code System for Minicomputers.

    Energy Science and Technology Software Center (ESTSC)

    1981-08-27

    Version 00 The OGRE code system was designed to calculate, by Monte Carlo methods, any quantity related to gamma-ray transport. The system is represented by two codes which treat slab geometry. OGRE-P1 computes the dose on one side of a slab for a source on the other side, and HOTONE computes energy deposition in addition. The source may be monodirectional, isotropic, or cosine distributed.

  9. The chemokine system -- a major regulator of angiogenesis in health and disease.

    PubMed

    Rosenkilde, Mette M; Schwartz, Thue W

    2004-01-01

    The chemokine system controls leukocyte trafficking during homeostasis as well as during inflammation and is necessary for the linkage between innate and adaptive immunity. Tissue regulation outside the hematopoietic compartment, for instance, angiogenesis, organogenesis and tumor development, growth and metastasis, is another important function of the chemokine system. The chemokine-mediated regulation of angiogenesis is highly sophisticated and fine tuned, and involves pro-angiogenic chemokines, for instance, CXCL8/IL8 interacting with the CXCR2 receptor, and anti-angiogenic (i.e. angiostatic) chemokines, for instance, CXCL10/IP10 interacting with the CXCR3 receptor. Chemokines also regulate angiogenesis in a receptor-independent manner by means of a perturbation of bFGF and VEGF function. The current review focuses on the influence of the chemokine system in angiogenesis. Examples of the delicate angiogenesis regulation by the chemokine system in, for instance, wound healing and of the dysregulation in, for instance, tumor development are provided along with the interesting phenomenon of molecular piracy of host-encoded genes within the chemokine system. This phenomenon is a general strategy to circumvent and exploit the immune system -- and thereby improve survival -- for many viruses. Yet, a certain group of herpesviruses -- the gamma2-herpesviruses -- encode a functional CXCR2 receptor homolog that is activated by angiogenic chemokines and antagonized by angiostatic chemokines, and this particular gene seems to cause the development of a vascular tumor -- Kaposi's sarcoma -- in the host. PMID:15563311

  10. Feasibility tests of a dual modality system for imaging using gamma rays and NIR light

    NASA Astrophysics Data System (ADS)

    Uzunov, Nikolay; Atroshchenko, Kostiantyn; Baneva, Yanka; Bello, Michele; De Rosa, Matteo; Fontana, Cristiano Lino; Moschini, Giuliano; Rossi, Paolo

    2013-04-01

    We are developing a dual system for small-animal imaging in multimodality studies, which consists of a highspatial resolution gamma-camera and a scanner for Near-Infra-Red (NIR) light. The gamma-camera is assembled from a position-sensitive photomultiplier and a scintillation-crystal with parallel-hole collimator. On the other hand, the NIR imaging is designed for near-object scanning, and features two operational modes: Transmission and Fluorescence. In the Transmission mode, the NIR light, coming from five different wavelength LEDs, crosses the sample and is subsequently measured by an array sensor. In the Fluorescence mode, the emission from nanoparticles, such as singlewalled carbon nanotubes (SWCNTs) administered in the imaged object, is excited using the laser. The gamma-camera energy and spatial resolutions have been measured. This latter has been assessed by using specially-designed phantoms like capillary tubes or volumes with cavities filled with a radioactive solution. The NIR-scanner spatial resolution has been determined along two perpendicular directions using standards, placed at different distances from the sensor. The results show that both the NIR scanning-system and the gamma-camera feature good imaging-parameters and can be applied to multimodality studies.

  11. Combined Gamma-Ray Spectrometer and Pulsed Neutron Generator System for In-Situ Planetary Geochemical Analysis

    SciTech Connect

    Starr, R. D.; Evans, L. G.; Parsons, A. M.; Akkurt, Hatice; Floyd, H.; Wraight, P.; Ziegler, W.; Schweitzer, J.

    2007-01-01

    A combined pulsed neutron/gamma-ray system can be used on planetary surfaces to provide valuable geochemical analysis of surface materials to depths of {approx}1 m. We describe experimental results that demonstrate the capabilities of such a system.

  12. Neurochemical and electrophysiological evidence for the existence of a functional gamma-hydroxybutyrate system in NCB-20 neurons.

    PubMed

    Kemmel, V; Taleb, O; Perard, A; Andriamampandry, C; Siffert, J C; Mark, J; Maitre, M

    1998-10-01

    Clonal neurohybridoma NCB-20 cells express a valproate-insensitive succinic semialdehyde reductase activity that transforms succinic semialdehyde into gamma-hydroxybutyrate. This activity (1.14+/-0.16 nmol/min/mg protein) was similar to the lowest activity existing in adult rat brain. [3H]gamma-Hydroxybutyrate labels a homogeneous population of sites on NCB-20 cell membranes (Kd=250+/-44.4nM, Bmax=180+/-16.2fmol/mg protein) that apparently represents specific gamma-hydroxybutyrate binding sites characterized previously on brain cell membranes. Finally, an Na+-dependent uptake of [3H]gamma-hydroxybutyrate was expressed in NCB-20 cells with a Km of 35+21.1 microM and a Vmax of 80+/-14.2 pmol/min/mg protein. A three-day treatment with 1 mM dibutyryl-cyclic-AMP induced a three-fold increase in the cellular succinic semialdehyde reductase activity. In parallel, a K+-evoked release of [3H]gamma-hydroxybutyrate occurred. This release was Ca2+ dependent and was not present in undifferentiated cells. Cyclic-AMP treatment induced a decrease of [3H]gamma-hydroxybutyrate binding sites, which could be due to spontaneous gamma-hydroxybutyrate release. Patch-clamp experiments carried out on differentiated NCB-20 cells revealed the presence of Ca2+ conductances which were partially inhibited by 50 microM gamma-hydroxybutyrate. This gamma-hydroxybutyrate-induced effect was blocked by the gamma-hydroxybutyrate receptor antagonist NCS-382, but not by the GABA(B) antagonist CGP-55845. These results demonstrate the presence of an active gamma-hydroxybutyratergic system in NCB-20 cells which possesses the ability to release gamma-hydroxybutyrate. These cells express specific gamma-hydroxybutyrate receptors which modulate Ca2+ currents independently of GABA(B) receptors. PMID:9692734

  13. 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.

  14. Low cost FPGA based data acquisition system for a gamma imaging probe

    NASA Astrophysics Data System (ADS)

    Fysikopoulos, E.; Georgiou, M.; Loudos, G.; Matsopoulos, G.

    2013-11-01

    We present the development of a low cost field programmable gate arrays (FPGA) based data acquisition system for a gamma imaging probe proposed for sentinel lymph node (SLN) mapping. Radioguided surgery using a gamma probe is an established practice and has been widely introduced in SLN biopsies. For such applications, imaging systems require compact readout electronics and flexibility. Embedded systems implemented in the FPGA technology offer new possibilities in data acquisition for nuclear medicine imagers. FPGAs are inexpensive compared to application specific integrated circuits (ASICs), usually used for the readout electronics of dedicated gamma cameras and their size is rather small. In this study, cost effective analog to digital converters (ADCs) were used and signal processing algorithms were implemented in the FPGA to extract the energy and position information. The analog front-end electronics were carefully designed taking into account the low sampling rate of the ADCs. The reference gamma probe has a small field of view (2.5 cm × 2.5 cm) and is based on the R8900U-00-C12 position sensitive photomultiplier tube (PSPMT) coupled to a pixellated CsI(Na) scintillator with 1 mm × 1 mm × 5 mm crystal element size. Measurements were carried out using a general purpose collimator and 99mTc sources emitted at 140 keV. Performance parameters for the imaging gamma probe were compared with those obtained when data were acquired using the standard NIM (Nuclear Instrumentation Modules) electronics and found to be in very good agreement, which demonstrates the efficiency of the proposed implementation.

  15. 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. PMID:25637539

  16. 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.

  17. 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.

  18. 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.

  19. DEVELOPMENT OF DEPOSIT DETECTION SYSTEM IN PIPELINES OF THE STEELWORKS USING CS-137 GAMMA-RAY

    SciTech Connect

    Song, Won-Joon; Lee, Seung-Hee; Jeong, Hee-Dong

    2008-02-28

    The deposit is built up in the pipeline of the steelworks by the chemical reaction among COG (coke oven gas), BFG (blast furnace gas), moisture, and steel in the high temperature environment and obstructs the smooth gas flow. In this study a gamma-ray system is developed to detect the deposit accumulated in pipelines and calculate the accumulation rate with respect to the cross section area of pipes. Cs-137 is used as the gamma-ray source and the system is designed to apply to pipes of various diameters. This system also includes the DB for storage and display of the measurement results so that it can be used for the efficient management of the pipelines.

  20. Development of Deposit Detection System in Pipelines of the Steelworks Using CS-137 Gamma-Ray

    NASA Astrophysics Data System (ADS)

    Song, Won-Joon; Lee, Seung-Hee; Jeong, Hee-Dong

    2008-02-01

    The deposit is built up in the pipeline of the steelworks by the chemical reaction among COG (coke oven gas), BFG (blast furnace gas), moisture, and steel in the high temperature environment and obstructs the smooth gas flow. In this study a gamma-ray system is developed to detect the deposit accumulated in pipelines and calculate the accumulation rate with respect to the cross section area of pipes. Cs-137 is used as the gamma-ray source and the system is designed to apply to pipes of various diameters. This system also includes the DB for storage and display of the measurement results so that it can be used for the efficient management of the pipelines.

  1. 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.

  2. An automated system for gamma radiation field mapping

    NASA Astrophysics Data System (ADS)

    Gould, Robert; Tarpinian, James E.; Kenney, Edward S.

    1990-12-01

    Remote radiation survey equipment was sorely needed at Chernobyl but adequate systems did not exist. The current state of the art still consists of a survey meter mounted on a robotic carriage, which scans an area at many points on a grid. This process is both time consuming and somewhat inaccurate. The system we have developed will overcome these limitations, and would provide significant savings in man-hours and man-rem over manual survey techniques. The system we have developed consists of a collimated ionization chamber mounted in a scanning head. The measurement process is similar to that used in medical computed tomography (CT) imaging and consists of a series of collimator rotations and translations. The key to this work is the use of a collimator to provide position information with a position insensitive detector. In addition, an inverse filter image reconstruction technique has been used to reduce the distortion effects due to the scanner and scanning process in the resulting maps. This technique models the distortion as a linear, space invariant degrading function which is removed in a deconvolution process. We have constructed first- and second-generation prototype scanners, and developed software to produce three-dimensional radiation field "iso-dose" maps. The iso-dose maps will be superimposed on three-dimensional computer-aided design and drafting (CADD) drawings of the radiation area, aiding in the characterization of the source of radiation.

  3. 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.

  4. 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.

  5. Lymphoproliferative and Gamma Interferon Responses to Stress-Regulated Mycobacterium avium subsp. paratuberculosis Recombinant Proteins

    PubMed Central

    Gurung, Ratna B.; Begg, Douglas J.; Purdie, Auriol C.; de Silva, Kumudika; Bannantine, John P.

    2014-01-01

    Johne's disease in ruminants is a chronic infection of the intestines caused by Mycobacterium avium subsp. paratuberculosis. An important strategy to control disease is early detection, and a potentially efficient method for early detection is measurement of cell-mediated immune responses developed by the host in response to exposure or infection. One method is to measure lymphoproliferation and cytokine release from the host cells when exposed to the organism or parts of the organism. In this study, 10 recombinant M. avium subsp. paratuberculosis proteins known to be upregulated under in vitro stress conditions were evaluated by examining their ability to evoke memory as a result of exposure by vaccination or oral challenge with live Mycobacterium avium subsp. paratuberculosis. Out of 10 proteins, MAP2698c was found to induce higher cell-mediated immune responses in vaccinated and challenged sheep in comparison to healthy controls. The findings suggest that not all stress-regulated proteins have the diagnostic potential to detect cell-mediated immune responses in ovine paratuberculosis. PMID:24695774

  6. 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…

  7. 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.

  8. 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).

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

    NASA Astrophysics Data System (ADS)

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

    2013-03-01

    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 137Cs 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° (horizontal) to 90° (vertical).

  10. 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

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

    PubMed

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

    2013-03-01

    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 (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° (horizontal) to 90° (vertical). PMID:23556806

  12. Antiepileptic Potential of Matrine via Regulation the Levels of Gamma-Aminobutyric Acid and Glutamic Acid in the Brain

    PubMed Central

    Xiang, Jun; Jiang, Yugang

    2013-01-01

    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. PMID:24317434

  13. Portable LN 2 gamma-ray spectrometer system

    NASA Astrophysics Data System (ADS)

    McElhaney, S. A.; Brogle, R.; Guim, A.; Gerrish, A. M.; Lasché, G. P.; Nobel, J.; Pauly, S.

    1999-02-01

    The purpose of this program is to design and demonstrate a highly sensitive, portable spectrometer for detecting and identifying trace amounts of nuclear materials in a broad range of nonproliferation scenarios. A high-efficiency 100% n-type germanium (Ge) detector is combined with a special liquid nitrogen dewar designed to accommodate an active Compton suppression shield. The added collimation capability is required in order to be able to identify localized sources that may be obscured by background radiation. These components are complemented by the addition of a newly developed state-of-the-art multichannel analyzer (MCA) capable of 64×16 000 channel acquisition and electronic Compton suppression. The entire system fits into a watertight case that could be stored below the seat of commercial airliners. The unit has 2.74 keV resolution at 1.33 MeV, 8.5° angular resolution, low-power, >25 h full-time battery life, and operations between 35 keV< E<3 MeV.

  14. 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.

  15. Regulation of macrophage alpha 2-macroglobulin receptor/low density lipoprotein receptor-related protein by lipopolysaccharide and interferon-gamma.

    PubMed Central

    LaMarre, J; Wolf, B B; Kittler, E L; Quesenberry, P J; Gonias, S L

    1993-01-01

    alpha 2-Macroglobulin receptor/low density lipoprotein receptor-related protein (alpha 2M-R/LRP) is a broad specificity receptor that may function in lipoprotein metabolism, proteinase regulation, and growth factor regulation. In this study, we demonstrated that alpha 2M-R/LRP expression in macrophages can be markedly decreased by LPS and by IFN-gamma. Regulation of alpha 2M-R/LRP in RAW 264.7 cells was demonstrated at the mRNA, antigen, and receptor-function levels. In receptor-function studies, the decrease in alpha 2M-R/LRP expression was detected as a 90% decrease in the Bmax or maximum receptor binding capacity for activated alpha 2M after treatment with LPS or IFN-gamma. Western blot analysis of whole cell lysates demonstrated significant loss of alpha 2M-R/LRP heavy-chain. Northern blot analysis of poly(A)+ RNA revealed a marked decrease in alpha 2M-R/LRP mRNA after treatment with LPS (79% decrease) or IFN-gamma (70% decrease). Other cytokines, including tumor necrosis factor-alpha, transforming growth factor-beta-1, and interleukin-6 did not regulate alpha 2M-R/LRP. The ability of LPS and IFN-gamma to regulate alpha 2M-R/LRP was confirmed in experiments with primary cultures of murine bone marrow macrophages. These studies demonstrate that macrophage alpha 2M-R/LRP is subject to significant downregulation by physiologically significant cytokines and signaling macromolecules. Images PMID:7680664

  16. Low gamma counting for measuring NORM/TENORM with a radon reducing system

    NASA Astrophysics Data System (ADS)

    Paschoa, Anselmo S.

    2001-06-01

    A detection system for counting low levels of gamma radiation was built by upgrading an existing rectangular chamber made of 18 metric tonne of steel fabricated before World War II. The internal walls, the ceiling, and the floor of the chamber are covered with copper sheets. The new detection system consists of a stainless steel hollow cylinder with variable circular apertures in the cylindrical wall and in the base, to allow introduction of a NaI (Tl) crystal, or alternatively, a HPGe detector in its interior. This counting system is mounted inside the larger chamber, which in turn is located in a subsurface air-conditioned room. The access to the subsurface room is made from a larger entrance room through a tunnel plus a glass anteroom to decrease the air-exchange rate. Both sample and detector are housed inside the stainless steel cylinder. This cylinder is filled with hyper pure nitrogen gas, before counting a sample, to prevent radon coming into contact with the detector surface. As a consequence, the contribution of the 214Bi photopeaks to the background gamma spectra is minimized. The reduction of the gamma radiation background near the detector facilitates measurement of naturally occurring radioactive materials (NORM), and/or technologically enhanced NORM (TENORM), which are usually at concentration levels only slightly higher than those typically found in the natural radioactive background.

  17. Solidification Behavior of gamma'-Ni3Al Containing Alloys in the Ni-Al-O System

    NASA Technical Reports Server (NTRS)

    Copland, Evan

    2007-01-01

    The chemical activities of Al and Ni in gamma(prime)-Ni3Al-containing systems were measured using the multi-cell Knudsen effusion-cell mass spectrometry technique (multi-cell KEMS), over the composition range 8 - 32 at.%Al and temperature range T = 1400 - 1750 K. From these measurements a better understanding of the equilibrium solidification behaviour of gamma(prime)-Ni3Al-containing alloys in the Ni-Al-O system was established. Specifically, these measurements revealed that (1) gamma(prime)-Ni3Al forms via the peritectiod reaction, gamma + Beta (+ A12O3) = gamma (prime) (+ Al2O3), at 1633 +/- 1 K, (2) the {gamma + Beta + Al2O3} phase field is stable over the temperature range 1633 through 1640 K, and (3) equilibrium solidification occurs by the eutectic reaction, L (+ Al2O3) = gamma + Beta (+ Al2O3), at 1640 +/- 1 K and a liquid composition of 24.8 +/- 0.2 at.%Al (at an unknown oxygen content). When projected onto the Ni-Al binary, this behaviour is inconsistent with the current Ni-Al phase diagram and a new diagram is proposed. This new Ni-Al phase diagram explains a number of unusual steady-state solidification structures reported previously and provides a much simpler reaction scheme in the vicinity of the gamma(prime)-Ni3Al phase field.

  18. An end-to-end data system for the Gamma-Ray Observatory

    NASA Astrophysics Data System (ADS)

    Hrastar, J.

    A data system, which includes parts in the orbiting Gamma-Ray Observatory and in its associated ground system, has been designed to rapidly deliver autonomous, packeted data to the science users. Data autonomy means all of the data, including auxiliary data, necessary for processing is included in the data packet that leaves the spacecraft. The data packets leaving the spacecraft remain unopened until they reach the user. Handling the data on a packet rather than a byte level allows simpler and generic software. The data goes through the system more quickly. This in turn reduces cost.

  19. An end-to-end data system for the Gamma-Ray Observatory

    NASA Technical Reports Server (NTRS)

    Hrastar, J.

    1983-01-01

    A data system, which includes parts in the orbiting Gamma-Ray Observatory and in its associated ground system, has been designed to rapidly deliver autonomous, packeted data to the science users. Data autonomy means all of the data, including auxiliary data, necessary for processing is included in the data packet that leaves the spacecraft. The data packets leaving the spacecraft remain unopened until they reach the user. Handling the data on a packet rather than a byte level allows simpler and generic software. The data goes through the system more quickly. This in turn reduces cost.

  20. Accuracy and stability of positioning in radiosurgery: long-term results of the Gamma Knife system.

    PubMed

    Heck, Bernhard; Jess-Hempen, Anja; Kreiner, Hans Jürg; Schöpgens, Hans; Mack, Andreas

    2007-04-01

    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 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 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 precise by

  1. 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.

  2. 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.

  3. 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.

  4. 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

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

    SciTech Connect

    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.

  6. Regulation of Obesity and Metabolic Complications by Gamma and Delta Tocotrienols.

    PubMed

    Zhao, Lu; Fang, Xiefan; Marshall, Maurice R; Chung, Soonkyu

    2016-01-01

    Tocotrienols (T3s) are a subclass of unsaturated vitamin E that have been extensively studied for their anti-proliferative, anti-oxidative and anti-inflammatory properties in numerous cancer studies. Recently, T3s have received increasing attention due to their previously unrecognized property to attenuate obesity and its associated metabolic complications. In this review, we comprehensively evaluated the recent published scientific literature about the influence of T3s on obesity, with a particular emphasis on the signaling pathways involved. T3s have been demonstrated in animal models or human subjects to reduce fat mass, body weight, plasma concentrations of free fatty acid, triglycerides and cholesterol, as well as to improve glucose and insulin tolerance. Their mechanisms of action in adipose tissue mainly include (1) modulation of fat cell adipogenesis and differentiation; (2) modulation of energy sensing; (3) induction of apoptosis in preadipocytes and (4) modulation of inflammation. Studies have also been conducted to investigate the effects of T3s on other targets, e.g., the immune system, liver, muscle, pancreas and bone. Since δT3 and γT3 are regarded as the most active isomers among T3s, their clinical relevance to reduce obesity should be investigated in human trials. PMID:26978344

  7. 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.

  8. 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

  9. 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

  10. Calibration of low-level beta-gamma coincidence detector systems for xenon isotope detection.

    PubMed

    Khrustalev, K; Wieslander, J S E; Auer, M; Gheddou, A

    2016-03-01

    The beta-gamma coincidence detector systems used for the measurement of the CTBT-relevant xenon isotopes (Xe-131m, Xe-133m, Xe-133 and Xe-135) in the International Monitoring System network and in the On-Site Inspection are reviewed. These detectors typically consist of a well-type or bore-through NaI crystal into which a measurement cell, serving also as a sample container, is inserted. This work describes the current calibration procedure for energy, resolution and efficiency, implementation challenges, availability and uncertainties of the specific nuclear decay data and the path forward to full calibration validation using GEANT4. PMID:26702548

  11. 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.

  12. 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.

  13. Monte Carlo modeling of neutron and gamma-ray imaging systems

    NASA Astrophysics Data System (ADS)

    Hall, James M.

    1997-02-01

    Detailed numerical prototypes are essential to the design of efficient and cost-effective neutron and gamma-ray imaging systems. We have exploited the unique capabilities of an LLNL-developed radiation transport code (COG) to develop code modules capable of simulating the performance of neutron and gamma-ray imaging systems over a wide range of source energies. COG allows us to simulate complex, energy-, angle-, and time-dependent radiation sources, model 3D system geometries with 'real world' complexity, specify detailed elemental and isotopic distributions and predict the responses of various types of imaging detectors with full Monte Carlo accuracy. COG references detailed, evaluated nuclear interaction databases allowing users to account for multiple scattering, energy straggling, and secondary particle production phenomena which may significantly effect the performance of an imaging system but may be difficult or even impossible to estimate using simple analytical models. In this work we will present examples illustrating the use of these routines in the analysis of industrial radiographic systems for thick target inspection, non-intrusive luggage and cargo scanning systems, and international treaty verification.

  14. Monte Carlo modeling of neutron and gamma-ray imaging systems

    SciTech Connect

    Hall, J.

    1996-04-01

    Detailed numerical prototypes are essential to design of efficient and cost-effective neutron and gamma-ray imaging systems. We have exploited the unique capabilities of an LLNL-developed radiation transport code (COG) to develop code modules capable of simulating the performance of neutron and gamma-ray imaging systems over a wide range of source energies. COG allows us to simulate complex, energy-, angle-, and time-dependent radiation sources, model 3-dimensional system geometries with ``real world`` complexity, specify detailed elemental and isotopic distributions and predict the responses of various types of imaging detectors with full Monte Carlo accuray. COG references detailed, evaluated nuclear interaction databases allowingusers to account for multiple scattering, energy straggling, and secondary particle production phenomena which may significantly effect the performance of an imaging system by may be difficult or even impossible to estimate using simple analytical models. This work presents examples illustrating the use of these routines in the analysis of industrial radiographic systems for thick target inspection, nonintrusive luggage and cargoscanning systems, and international treaty verification.

  15. The MEGA (Muon decays into an Electron and a GAmma ray) hardware trigger system

    SciTech Connect

    Szymanski, J.J.; Amann, J.F.; Black, J.K.; Cooper, M.D.; Wright, S.C.; Crocker, J.; Sanders, H.

    1988-01-01

    The MEGA experiment is designed to search for the rare decay ..mu.. ..-->.. e ..gamma.. with a branching ratio sensitivity of /approximately/10/sup -13/. As is typical of rare-decay experiments, extensive, online filtering of the data is required for MEGA. The MEGA experiment uses a hardware pattern-recognition system based on Programmable Array Logic (PAL) devices. Additional events are eliminated in an online ACP system before data are written to tape. The MEGA trigger system is generally applicable where high-rate, short-propagation-delay trigger systems are required. This report contains an introduction to the MEGA experiment, a discussion of the MEGA hardware trigger system and a discussion of the system's measured performance. 4 refs., 3 figs.

  16. 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.

  17. 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.)

  18. Primary central nervous system gamma delta cytotoxic T-cell lymphoma.

    PubMed

    Mooney, Kelly L; Choy, Winward; Woodard, Joslyn; Xian, Rena R; Deal, Taylor M; Kendle, Ryan F; Said, Jonathan; Grody, Wayne; Yang, Isaac

    2016-04-01

    Primary T-cell lymphomas of the central nervous system (CNS) are uncommon, but aggressive and increasing in incidence. We describe a rare case of T-cell lymphoma in a cerebellar location, to our knowledge the first reported case demonstrating gamma/delta receptor expression. Additionally, we elaborate on key diagnostic features and review all nine patients with primary CNS lymphoma of cytotoxic T-cell phenotype reported in the literature. A 26-year-old female medical student presented with a 6week history of nausea, vomiting and dizziness. MRI revealed a 2cm cerebellar mass. The tumor was subtotally resected, and pathologic examination of a subtotal resection specimen demonstrated peripheral T-cell lymphoma, not otherwise specified, with a gamma/delta cytotoxic T-cell phenotype. She subsequently started high dose methotrexate and cytarabine. We report a unique case of primary CNS gamma delta CD8+ T-cell lymphoma lineage in a young female patient. While these are rare entities, it is an important differential diagnosis to consider. Therapy should be tailored to the patient, and involves resection with adjuvant chemotherapy, radiotherapy or autologous stem-cell based treatments. PMID:26804925

  19. 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.

  20. Selective activation of p38alpha and p38gamma by hypoxia. Role in regulation of cyclin D1 by hypoxia in PC12 cells.

    PubMed

    Conrad, P W; Rust, R T; Han, J; Millhorn, D E; Beitner-Johnson, D

    1999-08-13

    Hypoxic/ischemic trauma is a primary factor in the pathology of a multitude of disease states. The effects of hypoxia on the stress- and mitogen-activated protein kinase signaling pathways were studied in PC12 cells. Exposure to moderate hypoxia (5% O(2)) progressively stimulated phosphorylation and activation of p38gamma in particular, and also p38alpha, two stress-activated protein kinases. In contrast, hypoxia had no effect on enzyme activity of p38beta, p38beta(2), p38delta, or on c-Jun N-terminal kinase, another stress-activated protein kinase. Prolonged hypoxia also induced phosphorylation and activation of p42/p44 mitogen-activated protein kinase, although this activation was modest compared with nerve growth factor- and ultraviolet light-induced activation. Hypoxia also dramatically down-regulated immunoreactivity of cyclin D1, a gene that is known to be regulated negatively by p38 at the level of gene expression (Lavoie, J. N., L'Allemain, G., Brunet, A., Muller, R., and Pouyssegur, J. (1996) J. Biol. Chem. 271, 20608-20616). This effect was partially blocked by SB203580, an inhibitor of p38alpha but not p38gamma. Overexpression of a kinase-inactive form of p38gamma was also able to reverse in part the effect of hypoxia on cyclin D1 levels, suggesting that p38alpha and p38gamma converge to regulate cyclin D1 during hypoxia. These studies demonstrate that an extremely typical physiological stress (hypoxia) causes selective activation of specific p38 signaling elements; and they also identify a downstream target of these pathways. PMID:10438538

  1. Phospholipase C gamma mediates endogenous brain-derived neurotrophic factor-regulated calcitonin gene-related peptide expression in colitis-induced visceral pain

    PubMed Central

    Hashmi, Fiza; Liu, Miao; Shen, Shanwei

    2016-01-01

    Background Visceral hypersensitivity is a complex pathophysiological paradigm with unclear mechanisms. Primary afferent neuronal plasticity marked by alterations in neuroactive compounds such as calcitonin gene-related peptide is suggested to underlie the heightened sensory responses. Signal transduction that leads to calcitonin gene-related peptide expression thereby sensory neuroplasticity during colitis remains to be elucidated. Results In a rat model with colitis induced by 2,4,6-trinitrobenzene sulfonic acid, we found that endogenously elevated brain-derived neurotrophic factor elicited an up-regulation of calcitonin gene-related peptide in the lumbar L1 dorsal root ganglia. At seven days of colitis, neutralization of brain-derived neurotrophic factor with a specific brain-derived neurotrophic factor antibody reversed calcitonin gene-related peptide up-regulation in the dorsal root ganglia. Colitis-induced calcitonin gene-related peptide transcription was also inhibited by brain-derived neurotrophic factor antibody treatment. Signal transduction studies with dorsal root ganglia explants showed that brain-derived neurotrophic factor-induced calcitonin gene-related peptide expression was mediated by the phospholipase C gamma, but not the phosphatidylinositol 3-kinase/Akt or the mitogen-activated protein kinase/extracellular signal-regulated protein kinase pathway. Application of PLC inhibitor U73122 in vivo confirmed that colitis-induced and brain-derived neurotrophic factor-mediated calcitonin gene-related peptide up-regulation in the dorsal root ganglia was regulated by the phospholipase C gamma pathway. In contrast, suppression of the phosphatidylinositol 3-kinase activity in vivo had no effect on colitis-induced calcitonin gene-related peptide expression. During colitis, calcitonin gene-related peptide also co-expressed with phospholipase C gamma but not with p-Akt. Calcitonin gene-related peptide up-regulation during colitis correlated to the activation

  2. The Endocannabinoid System: Role in Energy Regulation

    PubMed Central

    Gamage, Thomas F.; Lichtman, Aron H.

    2013-01-01

    Cannabis sativa has been used since antiquity to treat many ailments, including eating disorders. The primary psychoactive constituent of this plant, Δ9-tetrahydrocannabinol (THC) is an FDA approved medication to treat nausea and emesis caused by cancer chemotherapeutic agents as well as to stimulate appetite in AIDS patients suffering from cachexia. The effects of THC are mediated through the endocannabinoid system (ECS), which promotes a positive energy balance through stimulation of appetite as well as shifting homeostatic mechanisms toward energy storage. Here we discuss the physiological function of the ECS in energy balance and the therapeutic potential of targeting this system. PMID:22076835

  3. The endocannabinoid system: role in energy regulation.

    PubMed

    Gamage, Thomas F; Lichtman, Aron H

    2012-01-01

    Cannabis sativa has been used since antiquity to treat many ailments, including eating disorders. The primary psychoactive constituent of this plant, Δ(9) -tetrahydrocannabinol (THC) is an FDA approved medication to treat nausea and emesis caused by cancer chemotherapeutic agents as well as to stimulate appetite in AIDS patients suffering from cachexia. The effects of THC are mediated through the endocannabinoid system (ECS), which promotes a positive energy balance through stimulation of appetite as well as shifting homeostatic mechanisms toward energy storage. Here we discuss the physiological function of the ECS in energy balance and the therapeutic potential of targeting this system. PMID:22076835

  4. Electrical conduction and photoresponses of gamma-ray-irradiated single-stranded DNA/single-walled carbon nanotube composite systems

    NASA Astrophysics Data System (ADS)

    Hong, W.; Lee, E. M.; Kim, D. W.; Lee, Cheol Eui

    2015-04-01

    Effects of gamma-ray irradiation on the electrical conductivity and photoresponse have been studied for single-stranded DNA (ssDNA)/single-walled carbon nanotube (SWNT) composite films. The temperature-dependent electrical conductivity of the ssDNA/SWNT composite films, well described by a fluctuation-induced tunneling model, indicated modification of the barrier for thermally activated conduction by the gamma-ray irradiation. Besides, the photoresponse measurements indicated modified photoexcited charge carrier generation and oxygen photodesorption in the composite systems due to the gamma-ray irradiation.

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

    SciTech Connect

    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.

  6. Medium-resolution Autonomous in situ Gamma Detection System for Marine and Coastal Waters

    SciTech Connect

    Schwantes, Jon M.; Addleman, Raymond S.; Davidson, Joseph D.; Douglas, Matthew; Meier, David E.; Mullen, O Dennis; Myjak, Mitchell J.; Jones, Mark E.; Woodring, Mitchell L.; Johnson, Bryce; Santschi, Peter H.

    2009-12-01

    We are developing a medium-resolution autonomous in situ gamma detection system for marine and coastal waters. The system is designed to extract and preconcentrate isotopes of interest from natural waters prior to detection in order to eliminate signal attenuation of the gamma rays traveling through water and lower the overall background due to the presence of naturally occurring radioactive isotopes (40K and U/Th series radionuclides). Filtration is used to preconcentrate target isotopes residing on suspended particles, while chemosorption is employed to preferentially extract truly dissolved components from the water column. A variety of commercial and in-house nano-porus chemosorbents have been selected, procured or produced, and tested. Used filter and chemosorbent media are counted autonomously using two LaBr3 detectors in a near 4-pi configuration around the samples. A compact digital pulse processing system developed in-house and capable of running in coincidence mode is used to process the signal from the detectors to a small on-board computer. The entire system is extremely compact (9” dia. x 30” len.) and platform independent, but designed for initial deployment on a research buoy.

  7. A performance study of an electron-tracking Compton camera with a compact system for environmental gamma-ray observation

    NASA Astrophysics Data System (ADS)

    Mizumoto, T.; Tomono, D.; Takada, A.; Tanimori, T.; Komura, S.; Kubo, H.; Matsuoka, Y.; Mizumura, Y.; Nakamura, K.; Nakamura, S.; Oda, M.; Parker, J. D.; Sawano, T.; Bando, N.; Nabetani, A.

    2015-06-01

    An electron-tracking Compton camera (ETCC) is a detector that can determine the arrival direction and energy of incident sub-MeV/MeV gamma-ray events on an event-by-event basis. It is a hybrid detector consisting of a gaseous time projection chamber (TPC), that is the Compton-scattering target and the tracker of recoil electrons, and a position-sensitive scintillation camera that absorbs of the scattered gamma rays, to measure gamma rays in the environment from contaminated soil. To measure of environmental gamma rays from soil contaminated with radioactive cesium (Cs), we developed a portable battery-powered ETCC system with a compact readout circuit and data-acquisition system for the SMILE-II experiment [1,2]. We checked the gamma-ray imaging ability and ETCC performance in the laboratory by using several gamma-ray point sources. The performance test indicates that the field of view (FoV) of the detector is about 1 sr and that the detection efficiency and angular resolution for 662 keV gamma rays from the center of the FoV is (9.31 ± 0.95) × 10-5 and 5.9° ± 0.6°, respectively. Furthermore, the ETCC can detect 0.15 μSv/h from a 137Cs gamma-ray source with a significance of 5σ in 13 min in the laboratory. In this paper, we report the specifications of the ETCC and the results of the performance tests. Furthermore, we discuss its potential use for environmental gamma-ray measurements.

  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. 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.

  10. 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

  11. Force regulation in multiple-manipulator systems

    NASA Technical Reports Server (NTRS)

    Wen, John T.; Murphy, Steve H.

    1992-01-01

    A new intuitively appealing interpretation of the internal force in a multiple-arm system is presented. The static gravity-free case is considered where internal force has a well-founded physical meaning. The case is extended to the general dynamic case by removing the inertial force through balancing it with the minimum amount of contact force. The remaining component in the contact force is considered to be the sole contributor to the inertial force. Existing techniques for force control can be used to obtain various stabilizing force set point control laws. Particular attention is given to the motion control strategy for multiple arm systems. Three types of control laws, feedback linearization, arms-as-actuators, and passive control, are addressed. The first two techniques provide simplified control tuning but require much model information. The latter approach is considered to be very robust with respect to the model, but good transient performance is more challenging to obtain. It is suggested to combine one of the model-based approaches with the passive control approach.

  12. 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.

  13. Gamma-ray and neutron radiography for a pulsed fast- neutron analysis cargo inspection system

    NASA Astrophysics Data System (ADS)

    Rynes, Joel Christian

    1999-11-01

    This dissertation presents the design, optimization, and characterization of a gamma-ray and neutron radiographic subsystem that was developed for the Pulsed Fast Neutron Analysis (PFNA) cargo inspection system. The PFNA inspection system uses nanosecond pulsed neutrons to produce three-dimensional elemental density images of cargo. Contraband in the cargo can be detected by its elemental content. The PFNA neutron source produces gamma rays as well as neutrons. The radiographic subsystem measures these radiations in an array of plastic scintillators to produce gamma-ray and neutron transmission images of the cargo simultaneously with the PFNA measurement. Although the radiographic subsystem improves PFNA performance in many forms of contraband detection, it was specifically designed to detect Special Nuclear Material (SNM) in cargo containers and trucks. A feasibility study, including experiments and modeling, was performed to determine the usefulness of gamma-ray radiography in this application. The study assumed a baseline configuration of the PFNA source, a relatively small rectangular radiation beam, and a plastic detector with a 5.1 cm diameter and a 7.6 cm length. The study showed that the baseline configuration was useful in cargoes up to 144 g/cm2 thick. At this thickness, a signal-to-noise ratio of three was obtainable per pixel. The maximum cargo thickness was later increased to 180 g/cm2 by increasing the detector length to 17.0 cm and by changing the source beam stop from gold to copper. An experiment was then performed that determined a 3.5 cm radiographic resolution was adequate for SNM detection. The detector configuration and the source motion were optimized to obtain a resolution of approximately 3.5 cm using the minimal number of detectors and the maximum detector diameter. The source is moved up and down as the cargo is pulled through the system to irradiate the entire surface of the cargo with the radiation beam. The final design consisted of

  14. An analysis of a spreader bar crane mounted gamma-ray radiation detection system

    NASA Astrophysics Data System (ADS)

    Grypp, Matthew David

    Over 95% of imports entering the United States from outside North America arrive via cargo containers by sea at 329 ports of entry. The current layered approach for the detection only scans 5% of cargo bound for the United States. This is inadequate to protect our country. This research involved the building of a gamma-ray radiation detection system used for cargo scanning. The system was mounted on a spreader bar crane (SBC) at the Port of Tacoma (PoT) and the applicability and capabilities of the system were analyzed. The detection system provided continuous count rate and spectroscopic data among three detectors while operating in an extreme environment. In a separate set of experiments, 60Co and 137Cs sources were positioned inside a cargo container and data were recorded for several count times. The Monte Carlo N-Particle (MCNP) code was used to simulate a radioactive source inside an empty cargo container and the results were compared to experimentally recorded data. The detection system demonstrated the ability to detect 60Co, 137Cs, 192 Ir, highly-enriched uranium (HEU), and weapons-grade plutonium (WGPu) with minimum detectable activities (MDA) of 5.9 +/- 0.4 microcuries (muCi), 19.3 +/- 1.1 muCi, 11.7 +/- 0.6 muCi, 3.5 +/- 0.3 kilograms (kg), and 30.6 +/- 1.3 grams (g), respectively. This system proved strong gamma-ray detection capabilities, but was limited in the detection of fissile materials Additional details of this system are presented and advantages of this approach to cargo scanning over current approaches are discussed.

  15. Development of Automatic Voltage Regulator for Low Voltage Distribution Systems

    NASA Astrophysics Data System (ADS)

    Matsuda, Katsuhiro; Horikoshi, Kazuhiro; Seto, Toshiyuki; Iyama, Osamu; Kobayashi, Hiromu

    This paper presents the development of a new type of voltage regulator that can adequately maintain the voltage supplied to customers, dealing with the problem of voltage control along with the widespread use of photovoltaic power generation systems. The developed equipment is a pole-mounted type voltage regulator consisting of a step-down transformer that converts voltage from high to low and a series transformer for voltage compensation. The demonstration test conducted at the CRIEPI Akagi Test Center confirmed that the voltage control function of the developed voltage regulator is satisfactory based on the proposed control algorism. Also, simulation analysis, on the assumption of the clustered installation of photovoltaic power generation systems, confirmed that the introduction of the developed voltage regulator enables the system voltage to be adequately maintained and full photovoltaic power generation is possible without suppressing the output. It is anticipated that the developed voltage regulator is very effective in adequately regulating the voltage for low voltage distribution systems and gives an effective way for even more widespread photovoltaic power generation.

  16. 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.

  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. A Visualization Code System for Gamma and Neutron Shielding Calculations, Version 2.0

    Energy Science and Technology Software Center (ESTSC)

    2008-08-01

    EASYQAD, Version 2.0, is a standalone Windows XP or Windows 7 code system which facilitates gamma and neutron shielding calculations with user friendly graphical interfaces. It is used to analyze radiation shielding problems and includes: - 8 kinds of geometry types - Various flexible source options - Common material library - Various detector types The update contents of EASYQAD Version 2.0 are below: - Addition of starting option with ‘P-code’ files - Addition of multi-sourcemore » calculation function - Expansion of source geometries - Addition of warning message - Modifications of EASYQAD program errors a. Coordination application problem in source division b. Source position error c. Rotation problem of source geometry d. Program running error in using more than six gamma energy distribution e. EASYQAD display problem of the right elliptic cylinder, ellipsoid and truncated right cone geometries Through intuitive windows and their interactions inside EASYQAD, the user can specify the dimensions of 3D-shapes, their material compositions, their densities, the type of radioactive sources, the locations of the sources, the type and positions of detectors. With the ease of using these sequences, shielding problems will become simpler and more clearly understandable to the analyzer. Furthermore, the error checking system can prevent users from making mistakes by automatically debugging the user inputs and giving modal dialog windows. The included AECL implementation of QAD-CGGP-A, Version 95.2 (C00645MNYCP00), is run from the user interface.« less

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. Abnormal Default System Functioning in Depression: Implications for Emotion Regulation.

    PubMed

    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. 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

  5. Gamma emission tomosynthesis based on an automated slant hole collimation system

    NASA Astrophysics Data System (ADS)

    Pellegrini, R.; Pani, R.; Cinti, M. N.; Longo, M.; Lo Meo, S.; Viviano, M.

    2015-03-01

    The imaging capabilities of radioisotope molecular imaging systems are limited by their ring geometry and by the object-to-detector distance, which impairs spatial resolution, efficiency and image quality. These detection capabilities could be enhanced by performing acquisitions with dedicated gamma cameras placed in close proximity to the object that has to be examined. The main aim of this work is to develop a compact camera suitable for detecting small and low-contrast lesions, with a higher detection efficiency than conventional SPECT, through a gamma emission tomosynthesis method. In this contribution a prototype of a new automated slant hole collimator, coupled to a small Field of View (FoV) gamma camera, is presented. The proposed device is able to acquire planar projection images at different angles without rotating around the patient body; these projection images are then three-dimensional reconstructed. Therefore, in order to perform the volumetric reconstruction of the studied object, the traditional Back Projection (BP) reconstruction is compared with the Shift And Add (SAA) method. In order to verify the effectiveness of the technique and to test the image reconstruction algorithms, a Monte Carlo simulation, based on the GEANT4 code, was implemented. The method was also validated by a set of experimental measurements. The discussed device is designed to work in patient proximity for detecting lesions placed at a distances ranged from 0 to 8 cm, thus allowing few millimeters planar resolutions and sagittal resolution of about 2 cm. The new collimation method implies high-resolution capabilities demonstrated by reconstructing the projection images through the BP and the SAA methods. The latter is simpler than BP and produces comparable spatial resolutions with respect to the traditional tomographic method, while preserving the image counts.

  6. 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. PMID:26462859

  7. [A multi-phase flow detector system based on gamma-ray].

    PubMed

    Ma, Min; Wang, Hua-xiang; Hao, Kui-hong

    2010-07-01

    In the present paper, a gamma-ray based on-line detection system was designed for multi-phase flow measurement, where the complicated fluid property of multi-phase flow can be studied by using the principle of ray transmission. The system is made up of three parts, i. e., the sensing unit, the signal conditioning & processing unit and the computer imaging unit. The sensing unit consists of five 241 Am sources with principal energy of 59.5 keV and five sets of CdZnTe semiconductor detectors by using the Geant 4 simulating software toolkits. The sources and detectors are mounted equally at the cross section of pipeline to detect different phase medium simultaneously. This function of the system guarantees the real-time performance of the on-line detecting. In order to improve the accuracy of the probe, a low noise probe circuit was designed, including a low noise charge-sensitive preamplifier, a low noise amplifier, filter circuit and an eliminated zero-poles circuit. Some of the emitted gamma-ray photons from the radiation sources are detected by the sensing element, where the photo energy is transferred into electrical energy by using CdZnTe semiconductor detectors. The output of the sensing element is sent to the signal conditioning & processing unit, which is amplified and filtered to be a level-discriminated signal. Finally, the output of the signal conditioning & processing unit is sent to the computer imaging unit, in which the 2D images are reconstructed by using a certain reconstruction algorithm. Under the normal temperature, the system performs the test of energy spectrum and then it has better energy resolution about 4.38% for 241 Am 59.5 keV. The result reveals that our system has higher probe accuracy. Using experimental data, the images are reconstructed with Filter back projection (FBP) reconstruction algorithm. Images of high quality are achieved. PMID:20828018

  8. 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.

  9. The mouse CCR2 gene is regulated by two promoters that are responsive to plasma cholesterol and peroxisome proliferator-activated receptor {gamma} ligands

    SciTech Connect

    Chen Yiming; Green, Simone R.; Ho, Jessica; Li, Andrew; Almazan, Felizidad; Quehenberger, Oswald . E-mail: oquehenberger@ucsd.edu

    2005-06-24

    We have previously shown that the expression of monocyte CCR2, the receptor for monocyte chemoattractant protein-1, is induced by plasma cholesterol. The present study examines the mechanisms that regulate monocyte CCR2 expression in hypercholesterolemia using a mouse model. Our data demonstrate that in the mouse, CCR2 expression in circulating monocytes is controlled by two promoters P1 and P2. The two distinct transcripts, which encode the same protein, are produced by alternative splicing in the 5'-untranslated region. Both promoters are constitutively active, but only P2 is stimulated by cholesterol. However, both promoters are repressed by peroxisome proliferator-activated receptor {gamma}.

  10. BER estimation for multi-hop RoFSO QAM or PSK OFDM communication systems over gamma gamma or exponentially modeled turbulence channels

    NASA Astrophysics Data System (ADS)

    Nistazakis, H. E.; Stassinakis, A. N.; Sheikh Muhammad, S.; Tombras, G. S.

    2014-12-01

    The optical wireless and in particular the radio-on-free-space-optical (RoFSO) communication systems are gaining popularity due to their high date rates, license free spectrum and adequate reliability at installation and operational costs which are much lower than comparable technologies. One significant disadvantage of these systems concerns the randomly time varying characteristics of the propagation path mainly caused by the atmospheric turbulence. In this work, we study the BER performance of a multi-hop RoFSO system which is using an orthogonal frequency division multiplexing (OFDM) scheme, with either quadrature amplitude modulation (QAM) or phase shift keying format (PSK), over atmospheric turbulence channels modeled with the gamma gamma or the negative exponential distribution. The individual RoFSO parts of the whole optical link are connected to each other by using regenerators relay nodes. The dominant impairments which are the most significant and have been taken into account are the atmospheric turbulence, the path losses, the nonlinear responsivity of the laser diode and the inter-modulation distortion effect. For this setup, we derive closed form mathematical expressions for the estimation of the BER performance for each individual OFDM RoFSO link and for the whole relayed optical communication system, as well. Finally, the corresponding numerical results, for common link's parameters, are presented.

  11. Recent Developments: The Gamma Ray Imager/Polarimeter for Solar Flares (GRIPS) Imaging and Detector systems

    NASA Astrophysics Data System (ADS)

    Duncan, Nicole; Shih, A. Y.; Hurford, G. J.; Saint-Hilaire, P.; Bain, H.; Zoglauer, A.; Lin, R. P.; Boggs, S. E.

    2013-07-01

    In two of the best-observed flares of the last cycle, the Reuven Ramaty High-Energy Solar Spectroscopic Imager (RHESSI) satellite found the centroids of ion and relativistic electron emission to have a significant displacement. This result is surprising; co-spatially accelerated ions and electrons are thought to be transported along the same field lines, implying they would enter the chromosphere together and have similar emission locations. The Gamma-Ray Imager/Polarimeter for Solar Flares (GRIPS) balloon instrument will investigate particle transport in solar flares by providing enhanced imaging, spectroscopy and polarimetry of gamma/HXR flare emission (20keV - 10MeV). GRIPS’ key technological improvements over the solar state of the art in HXR/gamma ray energies (RHESSI) include three-dimensional position-sensitive germanium detectors (3D-GeDs) and a single-grid modulating collimator, the multi-pitch rotating modulator (MPRM). The 3D-GeDs allow GRIPS to Compton track energy deposition within the crystal. This capability (1) enables the MPRM design by acting as a second modulation grid, (2) provides significant background rejection and (3) makes solar polarization measurements possible. The MPRM imager provides quasi-continuous resolution from 12.5 - 162 arcsecs with 2x the throughput of a dual grid collimator system like RHESSI. This spatial resolution can resolve the separate footpoints of many flare sizes. In comparison, RHESSI images with a minimum of 35 arcsecs for gamma-rays, making these footpoints resolvable in only the largest flares. Here, we present the intial calibration of GRIPS’ 3D-GED detectors using laboratory radioactive sources. We evaluate charge sharing between adjacent strips, the detection of coincidences and preliminary depth measurements. The detectors have been shown to have a linear response and resolve line emission. The MPRM modulation grid is constructed and we present initial results from calibration. GRIPS is scheduled for a

  12. [Adeno-associated virus mediated T-bet gene transfer into SGC-7901 cell to regulate IFN-gamma production].

    PubMed

    Qiu, Gufeng; Wang, Suoying; Wang, Shengjun; Shao, Qixiang; Ma, Jie; Yang, Ming; Xu, Xiaopeng; Mao, Chaoming; Su, Zhaoliang; Huang, Xinxiang; Xu, Huaxi

    2009-06-01

    In order to investigate the effect of T-bet on malignant cells, we selected SGC-7901, a kind of human gastric carcinoma cell line, and used gene clone technique and adeno-associated virus (AAV) packing technology, thus obtaining a recombinant rAAV-eGFP-T-bet and T-bet gene-transfected SGC-7901 cells. Then the function of T-bet gene-infected SGC-7901 cells was researched by detecting the levels of IFN-gamma and T-bet production. The results showed: (1) It was verified that rAAV-T-bet's packing was completed; (2) After SGC-7901 cells was transfected by rAAV-eGFP-T-bet, a green fluorescence was found in about 30%-40% SGC-7901s, and the gene of 1670 bp (T-bet) and 388 bp (IFN-gamma) were generated from SGC-7901s cells; (3) The proteins of IFN-gamma and T-bet secreted by SGC-7901 cells were also detected. These reveal that SGC-7901 cell is efficiently infected by rAAV encoding T-bet, which can induce transfected cells to secret IFN-gamma. It may be useful in the researches on cancer immune therapy of transfecting T-bet gene. PMID:19634682

  13. Crosstalk between chloroplast thioredoxin systems in regulation of photosynthesis.

    PubMed

    Nikkanen, Lauri; Toivola, Jouni; Rintamäki, Eevi

    2016-08-01

    Thioredoxins (TRXs) mediate light-dependent activation of primary photosynthetic reactions in plant chloroplasts by reducing disulphide bridges in redox-regulated enzymes. Of the two plastid TRX systems, the ferredoxin-TRX system consists of ferredoxin-thioredoxin reductase (FTR) and multiple TRXs, while the NADPH-dependent thioredoxin reductase (NTRC) contains a complete TRX system in a single polypeptide. Using Arabidopsis plants overexpressing or lacking a functional NTRC, we have investigated the redundancy and interaction between the NTRC and Fd-TRX systems in regulation of photosynthesis in vivo. Overexpression of NTRC raised the CO2 fixation rate and lowered non-photochemical quenching and acceptor side limitation of PSI in low light conditions by enhancing the activation of chloroplast ATP synthase and TRX-regulated enzymes in Calvin-Benson cycle (CBC). Overexpression of NTRC with an inactivated NTR or TRX domain partly recovered the phenotype of knockout plants, suggesting crosstalk between the plastid TRX systems. NTRC interacted in planta with fructose-1,6-bisphosphatase, phosphoribulokinase and CF1 γ subunit of the ATP synthase and with several chloroplast TRXs. These findings indicate that NTRC-mediated regulation of the CBC and ATP synthesis occurs both directly and through interaction with the ferredoxin-TRX system and is crucial when availability of light is limiting photosynthesis. PMID:26831830

  14. 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

  15. 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.

  16. 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.

  17. 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

  18. 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.

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

    SciTech Connect

    Salmonson, J.D.; Wilson, J.R.

    2001-12-17

    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 ({approx} 10{sup 53} ergs/sec). A fraction of these neutrinos will annihilate to form an e{sup +}e{sup -} 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 ({approx}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{sup +}e{sup -} 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. Tyk2 negatively regulates adaptive Th1 immunity by mediating IL-10 signaling and promoting IFN-gamma-dependent IL-10 reactivation.

    PubMed

    Shaw, Michael H; Freeman, Gordon J; Scott, Mark F; Fox, Barbara A; Bzik, David J; Belkaid, Yasmine; Yap, George S

    2006-06-15

    The Jak, Tyk2, is activated in response to IL-12 and IFN-alphabeta and promotes IFN-gamma production by Th1-type CD4 cells. Mice deficient in Tyk2 function have been previously shown to be resistant to autoimmune arthritis and septic shock but are acutely susceptible to opportunistic pathogens such as Toxoplasma gondii. In this study, we show that Tyk2, in addition to mediating the biological effects of IL-12 and IFN-alphabeta, is an important regulator for the signaling and expression of the immunosuppressive cytokine IL-10. In the absence of Tyk2, Ag-reactive CD4 cells exhibit impaired IL-10 synthesis following rechallenge of T. gondii vaccine-primed mice. The impaired IL-10 reactivation leads to unopposed antimicrobial effector mechanisms which results in a paradoxically superior protection of immune Tyk2(-/-) mice against virulent T. gondii challenge. We further demonstrate that Tyk2 indirectly controls CD4 IL-10 reactivation by signaling for maximal IFN-gamma secretion. The unexpected role of IFN-gamma in mediating IL-10 reactivation by Th1 cells provides compelling evidence that conditions driving Th1 responses establish a negative feedback loop, which will ultimately lead to its autoregulation. Thus, Tyk2 can be viewed as a dual-function Jak, mediating both pro and anti-inflammatory cytokine responses. PMID:16751369

  5. Gamma Knife

    MedlinePlus

    ... results are sent to the Gamma Knife®'s planning computer system. Together, physicians ( radiation oncologists and neurosurgeons) and medical physicists delineate targets and normal anatomical structures. They use a planning computer program to determine the exact spatial relationship between ...

  6. 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. PMID:26990424

  7. 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.

  8. [Exercise and aging: regulation of mitochondrial function and redox system].

    PubMed

    Sun, Li-Juan; Zhang, Yong; Liu, Jian-Kang

    2014-10-01

    Evidence shows that aging is closely related to mitochondrial decay and redox imbalance. With aging, both mitochondrial content and protein synthesis declined and free radicals, the by-products of mitochondrial metabolism and their oxidation to lipids, proteins and nuclear acids increased. The age-related declines in mitochondrial function and redox imbalance affect physical function, induce insulin resistance and neurodegenerative diseases, such as Alzheimer's and Parkinson's disease, thus, play a major role in regulation of life span. Therefore, mitochondrion may be the most important determinant of life span. Increasing evidence demonstrates that long-term aerobic exercise could prevent age-related diseases and improve life quality of aged people. Exercise may possibly stimulate mitochondrial biogenesis and phase II antioxidant defense system to regulate mitochondrial function and balance of redox system. Therefore, regular aerobic exercise may prevent age-related diseases, increase life quality and prolong life span through regulation of mitochondrial function and redox balance. PMID:25764789

  9. 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.

  10. 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.

  11. 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. PMID:19539166

  12. Molecular mechanisms regulating myelination in the peripheral nervous system.

    PubMed

    Pereira, Jorge A; Lebrun-Julien, Frédéric; Suter, Ueli

    2012-02-01

    Glial cells and neurons are engaged in a continuous and highly regulated bidirectional dialog. A remarkable example is the control of myelination. Oligodendrocytes in the central nervous system (CNS) and Schwann cells (SCs) in the peripheral nervous system (PNS) wrap their plasma membranes around axons to organize myelinated nerve fibers that allow rapid saltatory conduction. The functionality of this system is critical, as revealed by numerous neurological diseases that result from deregulation of the system, including multiple sclerosis and peripheral neuropathies. In this review we focus on PNS myelination and present a conceptual framework that integrates crucial signaling mechanisms with basic SC biology. We will highlight signaling hubs and overarching molecular mechanisms, including genetic, epigenetic, and post-translational controls, which together regulate the interplay between SCs and axons, extracellular signals, and the transcriptional network. PMID:22192173

  13. 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,…

  14. Comparison of thunderstorm systems that produce or lack RHESSI identified terrestrial gamma ray flashes

    NASA Astrophysics Data System (ADS)

    Splitt, M. E.; Barnes, D. E.; Dwyer, J. R.; Rassoul, H.; Lazarus, S. M.; Smith, D. M.; Cramer, E. S.; Schaal, M.; Saleh, Z. H.; Ulrich, W.; Grefenstette, B.; Hazelton, B. J.

    2009-12-01

    Thunderstorms associated with RHESSI-identified terrestrial gamma-ray flashes (TGFs) tend to be tall tropical thunderstorms in regions of significant lower tropospheric convergence. Yet despite the frequent occurrence of thunderstorms with these attributes within the RHESSI footprint, TGF detection is relatively rare. Tropical Rainfall Measuring Mission (TRMM) data that sync, in both space and time, with RHESSI, are used to determine whether there are observable differences between thunderstorm systems in which the RHESSI observes a TGF and those that it does not. In particular, TRMM Lightning Imaging Sensor (LIS) data are used to identify electrically active, but non-TGF producing, thunderstorms within a RHESSI footprint . TRMM precipitation and cloud-derived products from the null events are analyzed and compared to the same products composited from TGF producing storms. In addition, observations collected as part of the recent Airborne Detector for Energetic Lightning Emissions (ADELE) project are analyzed in this context.

  15. A gamma ray observatory ground attitude error analysis study using the generalized calibration system

    NASA Technical Reports Server (NTRS)

    Ketchum, E.

    1988-01-01

    The Goddard Space Flight Center (GSFC) Flight Dynamics Division (FDD) will be responsible for performing ground attitude determination for Gamma Ray Observatory (GRO) support. The study reported in this paper provides the FDD and the GRO project with ground attitude determination error information and illustrates several uses of the Generalized Calibration System (GCS). GCS, an institutional software tool in the FDD, automates the computation of the expected attitude determination uncertainty that a spacecraft will encounter during its mission. The GRO project is particularly interested in the uncertainty in the attitude determination using Sun sensors and a magnetometer when both star trackers are inoperable. In order to examine the expected attitude errors for GRO, a systematic approach was developed including various parametric studies. The approach identifies pertinent parameters and combines them to form a matrix of test runs in GCS. This matrix formed the basis for this study.

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

    PubMed

    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. PMID:25430214

  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. Setup and operation of gamma-ray measurement systems to maximize detector lifetime and stability

    NASA Astrophysics Data System (ADS)

    Penn, David G.; Grodsinsky, Carlos M.

    1999-10-01

    The details for optimizing gamma-ray measurement system for specific applications are not always well understood. The setup and operation of a system plays an important role in performance aspects such as maximizing detector lifetime, stability and minimizing the signal to noise ratio. In addition to system setup and operation, the effects of scintillation detector design and accompanying electronics (PMT) are discussed with respect to both gross counting and spectroscopy measurements in order to obtain reliable results. Data has been taken with various sodium iodide scintillation detectors to study system stability during transient such as power cycling and count rate fluctuations. These fluctuations may introduce substantial measurement uncertainty, and if not accounted for will propagate into an analyses. The above transients can also affect the detector lifetime, and if the system conditions are monitored properly, they can be used as a predictive tool for determining the useful life of a detector. Data is also presented to examine counting statistics in an overlapping spectrum as a function of spectral resolution and count rate. The objective is to determine the optimum counting time for the spectrum to reach a statistically stable shape. The data is reduced by examining the standard deviation of fitted Gaussian curves at ten second intervals. The result is a contour plat showing the time needed to reach stability, which increase with spectral resolution and decrease with a rising count rate.

  19. 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

  20. How gamma radiation processing systems are benefiting from the latest advances in information technology

    NASA Astrophysics Data System (ADS)

    Gibson, Wayne H.; Levesque, Daniel

    2000-03-01

    This paper discusses how gamma irradiation plants are putting the latest advances in computer and information technology to use for better process control, cost savings, and strategic advantages. Some irradiator operations are gaining significant benefits by integrating computer technology and robotics with real-time information processing, multi-user databases, and communication networks. The paper reports on several irradiation facilities that are making good use of client/server LANs, user-friendly graphics interfaces, supervisory control and data acquisition (SCADA) systems, distributed I/O with real-time sensor devices, trending analysis, real-time product tracking, dynamic product scheduling, and automated dosimetry reading. These plants are lowering costs by fast and reliable reconciliation of dosimetry data, easier validation to GMP requirements, optimizing production flow, and faster release of sterilized products to market. There is a trend in the manufacturing sector towards total automation using "predictive process control". Real-time verification of process parameters "on-the-run" allows control parameters to be adjusted appropriately, before the process strays out of limits. Applying this technology to the gamma radiation process, control will be based on monitoring the key parameters such as time, and making adjustments during the process to optimize quality and throughput. Dosimetry results will be used as a quality control measurement rather than as a final monitor for the release of the product. Results are correlated with the irradiation process data to quickly and confidently reconcile variations. Ultimately, a parametric process control system utilizing responsive control, feedback and verification will not only increase productivity and process efficiency, but can also result in operating within tighter dose control set points.

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

    SciTech Connect

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

    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.

  2. 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.

  3. Regulated Expression Systems for Mycobacteria and Their Applications

    PubMed Central

    Schnappinger, Dirk; Ehrt, Sabine

    2014-01-01

    For bacterial model organisms like Escherichia coli and Bacillus subtilis genetic tools to experimentally manipulate the activity of individual genes existed for decades. But for genetically less tractable yet medically important bacteria such as M. tuberculosis such tools have rarely been available. More recently several groups developed genetic switches that function efficiently in M. tuberculosis and other mycobacteria. Together these systems utilize six different transcription factors, eight different regulated promoters, and three different regulatory principles. Here we describe their design features, review their main applications, and discuss advantages and disadvantages of regulating transcription, translation, or protein stability for controlling gene activities in bacteria. PMID:25485177

  4. Lhx2 Regulates the Development of the Forebrain Hem System

    PubMed Central

    Roy, Achira; Gonzalez-Gomez, Miriam; Pierani, Alessandra; Meyer, Gundela; Tole, Shubha

    2014-01-01

    Early brain development is regulated by the coordinated actions of multiple signaling centers at key boundaries between compartments. Three telencephalic midline structures are in a position to play such roles in forebrain patterning: The cortical hem, the septum, and the thalamic eminence at the diencephalic–telencephalic boundary. These structures express unique complements of signaling molecules, and they also produce distinct populations of Cajal–Retzius cells, which are thought to act as “mobile patterning units,” migrating tangentially to cover the telencephalic surface. We show that these 3 structures require the transcription factor Lhx2 to delimit their extent. In the absence of Lhx2 function, all 3 structures are greatly expanded, and the Cajal–Retzius cell population is dramatically increased. We propose that the hem, septum, and thalamic eminence together form a “forebrain hem system” that defines and regulates the formation of the telencephalic midline. Disruptions in the forebrain hem system may be implicated in severe brain malformations such as holoprosencephaly. Lhx2 functions as a central regulator of this system's development. Since all components of the forebrain hem system have been identified across several vertebrate species, the mechanisms that regulate them may have played a fundamental role in driving key aspects of forebrain evolution. PMID:23307637

  5. Gamma irradiated micro system for long-term parenteral contraception: An alternative to synthetic polymers.

    PubMed

    Puthli, S; Vavia, P

    2008-11-15

    An injectable system of levonorgestrel (LNG) was developed using biodegradable polymer of natural origin. The parenteral system was optimized for particle size and higher drug loading. The microparticulate system was characterised by scanning electron microscopy, encapsulation efficiency, moisture content, IR, DSC, XRD, residual solvent content, sterility testing, test of abnormal toxicity and test for pyrogens. The microparticles were sterilised by gamma irradiation (2.5Mrad). The system was injected intramuscularly in rabbits and the blood levels of LNG were determined using radioimmunoassay technique. An optimized drug to polymer ratio of 0.3-1.0 (w/w ratio) gave improved drug loading of about 52%. In vivo studies in rabbits showed that the drug was released in a sustained manner for a period of 1 month. The AUC(0-t) was found to be 9363.6+/-2340pg/mLday(-1) with MRT calculated to be about 16 days and Kel of 0.01day(-1). LNG levels were maintained between 200 and 400pg/mL. In vivo release exhibited an initial burst effect which was not observed in the in vitro dissolution. This promising "Progestin-only" long-term contraceptive with improved user compliance is an alternative to the synthetic expensive polymeric carriers. PMID:18760352

  6. 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

  7. [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. PMID:18592962

  8. Synchronised output regulation of nonlinear multi-agent systems

    NASA Astrophysics Data System (ADS)

    Xiang, Ji; Li, Yanjun; Wei, Wei

    2015-01-01

    This paper considers a synchronised output regulation (SOR) problem of nonlinear multi-agent systems with switching graph. The SOR means that all agents have their outputs synchronised but also ultimately evolve on a manifold determined by a predefined exosystem. Each agent constructs its local copy of the predefined exosystem and exchanges the state information of the local exosystem to realise the synchronisation of local exosystem. A controller based on the nonlinear output regulation theory is then presented to force the agent's output track the output of local exosystem. It is shown that the SOR is solvable under the assumptions same as that for nonlinear output regulation of a single agent, if the switching graph satisfies the bounded interconnectivity times condition. Both state feedback and output feedback are addressed. A numerical simulation is made to show the efficacy of the analytic results.

  9. Regulation of renin release by local and systemic factors.

    PubMed

    Schweda, F; Kurtz, A

    2011-01-01

    The renin-angiotensin system (RAS) is critically involved in the regulation of the salt and volume status of the body and blood pressure. The activity of the RAS is controlled by the protease renin, which is released from the renal juxtaglomerular epithelioid cells into the circulation. Renin release is regulated in negative feedback-loops by blood pressure, salt intake, and angiotensin II. Moreover, sympathetic nerves and renal autacoids such as prostaglandins and nitric oxide stimulate renin secretion. Despite numerous studies there remained substantial gaps in the understanding of the control of renin release at the organ or cellular level. Some of these gaps have been closed in the last years by means of gene-targeted mice and advanced imaging and electrophysiological methods. In our review, we discuss these recent advances together with the relevant previous literature on the regulation of renin release. PMID:22128405

  10. 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.

  11. 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.

  12. Regulation of pathogenic IL-17 responses in collagen-induced arthritis: roles of endogenous interferon-gamma and IL-4

    PubMed Central

    2009-01-01

    Introduction Interleukin (IL)-17 plays an important role in the pathogenesis of rheumatoid arthritis and the mouse model collagen-induced arthritis (CIA). Interferon(IFN)-γ and IL-4 have been shown to suppress Th17 development in vitro, but their potential immunoregulatory roles in vivo are uncertain. The goals of this study were to determine the relationship between Th17 responses and disease severity in CIA and to assess regulation of IL-17 by endogenous IFN-γ and IL-4. Methods DBA1/LacJ mice were immunized with type II collagen in complete Freund's adjuvant (CFA) to induce arthritis, and treated with neutralizing antibody to IFN-γ and/or IL-4. Systemic IL-17, IFN-γ, and IL-4 were measured in serum. At the peak of disease, cytokine production was measured by ELISA of supernatants from spleen, lymph node and paw cultures. Paws were also scored for histologic severity of arthritis. Results Joint inflammation was associated with a higher ratio of systemic IL-17/IFN-γ. Neutralization of IFN-γ accelerated the course of CIA and was associated with increased IL-17 levels in the serum and joints. The IFN-γ/IL-4/IL-17 responses in the lymphoid organ were distinct from such responses in the joints. Neutralization of IL-4 led to increased arthritis only in the absence of IFN-γ and was associated with increased bone and cartilage damage without an increase in the levels of IL-17. Conclusions IL-4 and IFN-γ both play protective roles in CIA, but through different mechanisms. Our data suggests that the absolute level of IL-17 is not the only determinant of joint inflammation. Instead, the balance of Th1, Th2 and Th17 cytokines control the immune events leading to joint inflammation. PMID:19852819

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

    PubMed

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

    2014-11-01

    A matrix of Silicon Photo Multipliers has been developed for light readout from a large area 1 in. × 1 in. LaBr3 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 Eγ = 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. PMID:25430287

  14. 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.

  15. 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.

  16. 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.

  17. Regulation of cadherin expression in nervous system development

    PubMed Central

    Paulson, Alicia F; Prasad, Maneeshi S; Thuringer, Amanda Henke; Manzerra, Pasquale

    2014-01-01

    This review addresses our current understanding of the regulatory mechanisms for classical cadherin expression during development of the vertebrate nervous system. The complexity of the spatial and temporal expression patterns is linked to morphogenic and functional roles in the developing nervous system. While the regulatory networks controlling cadherin expression are not well understood, it is likely that the multiple signaling pathways active in the development of particular domains also regulate the specific cadherins expressed at that time and location. With the growing understanding of the broader roles of cadherins in cell–cell adhesion and non-adhesion processes, it is important to understand both the upstream regulation of cadherin expression and the downstream effects of specific cadherins within their cellular context. PMID:24526207

  18. 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. PMID:17376761

  19. Cooperative Output Regulation of Singular Heterogeneous Multiagent Systems.

    PubMed

    Ma, Qian; Xu, Shengyuan; Lewis, Frank L; Zhang, Baoyong; Zou, Yun

    2016-06-01

    This paper investigates the cooperative output regulation problem of singular heterogeneous multiagent systems. General distributed observers are proposed for every agent obtaining the estimated state of the exosystem. The feedforward control technique and reduced-order approach are used to design distributed singular output feedback controllers and distributed normal output feedback controllers. The proposed cooperative dynamic controller is dependent on the plant parameters and the interaction topologies. A simulation example is provided to demonstrate the effectiveness of the proposed design method. PMID:26173224

  20. Validation of Non-Invasive Waste Assay System (Gamma Box Counter) Performance at AECL Whiteshell Laboratories - 13136

    SciTech Connect

    Attas, E.M.; Bialas, E.; Rhodes, M.J.

    2013-07-01

    Low-level radioactive waste (LLW) in solid form, resulting from decommissioning and operations activities at AECL's Whiteshell Laboratories (WL), is packaged in B-25 and B-1000 standard waste containers and characterized before it is shipped to an on-site interim storage facility, pending AECL decisions on long term management of its LLW. Assay of the waste packages before shipment contributes to an inventory of the interim storage facility and provides data to support acceptance at a future repository. A key characterization step is a gamma spectrometric measurement carried out under standard conditions using an automated, multi-detector Waste Assay System (WAS), purchased from Antech Corporation. A combination of ORTEC gamma acquisition software and custom software is used in this system to incorporate multiple measurements from two collimated high-resolution detectors. The software corrects the intensities of the gamma spectral lines for geometry and attenuation, and generates a table of calculated activities or limits of detection for a user-defined list of radioisotopes that may potentially be present. Validation of WAS performance was a prerequisite to routine operation. Documentation of the validation process provides assurance of the quality of the results produced, which may be needed one or two decades after they were generated. Aspects of the validation included setting up a quality control routine, measurements of standard point sources in reproducible positions, study of the gamma background, optimization of user-selectable software parameters, investigation of the effect of non-uniform distribution of materials and radionuclides, and comparison of results with measurements made using other gamma detector systems designed to assay bulk materials. The following key components of the validation process have been established. A daily quality control routine has been instituted, to verify stability of the gamma detector operation and the background levels

  1. Nesfatin-1 as a New Potent Regulator in Reproductive System

    PubMed Central

    Kim, Jinhee; Yang, Hyunwon

    2012-01-01

    Nesfatin-1 is a recently discovered anorexigenic peptide which is distributed in several brain areas implicated in the feeding and metabolic regulation. Recently, it has been reported that nesfatin-1 is expressed not only in brain, but also in peripheral organs such as digestive organs, adipose tissues, heart, and reproductive organs. Nesfatin-1 is markedly expressed in the pancreas, stomach and duodenum. Eventually, the nesfatin-1 expression in the digestive organs may be regulated by nutritional status, which suggests a regulatory role of peripheral nesfatin-1 in energy homeostasis. Nesfatin-1 is also detected in the adipose tissues of humans and rodents, indicating that nesfatin-1 expression in the fat may regulate food intake independently, rather than relying on leptin. In addition, nesfatin-1 is expressed in the heart as a cardiac peptide. It suggests that nesfatin-1 may regulate cardiac function and encourage clinical potential in the presence of nutrition-dependent physio-pathologic cardiovascular diseases. Currently, only a few studies demonstrate that nesfatin-1 is expressed in the reproductive system. However, it is not clear yet what function of nesfatin-1 is in the reproductive organs. Here, we summarize the expression of nesfatin-1 and its roles in brain and peripheral organs and discuss the possible roles of nesfatin-1 expressed in reproductive organs, including testis, epididymis, ovary, and uterus. We come to the conclusion that nesfatin-1 as a local regulator in male and female reproductive organs may regulate the steroidogenesis in the testis and ovary and the physiological activity in epididymis and uterus. PMID:25949098

  2. 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

  3. 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. PMID:25833324

  4. Code System to Determine Pu Isotope Abundances from Multichannel Analyzer Gamma Spectra.

    Energy Science and Technology Software Center (ESTSC)

    2008-09-26

    Version 00 The MGA (Multiple Group Analysis) program determines the relative abundances of plutonium and other actinide isotopes in different materials. The program analyzes spectra taken of such samples using a 4096-channel germanium (Ge) gamma-ray spectrometer. The code can be run in a one or two detector mode. The first spectrum, which is required and must be taken at a gain of 0.075 Kev/channel with a high resolution planar detector, contains the 0-300Kev energy region.more » The second spectrum, which is optional, must be taken at a gain of 0.25 Kev/channel; it becomes important when analyzing high burnup samples (concentration of Pu241 greater than one percent). Isotopic analysis precisions of one percent or better can be obtained, and no calibrations are required. The system also measures the abundances of U235, U238, Np237, and Am241. A special calibration option is available to perform a one-time peak-shape characterization when first using a new detector system.« less

  5. 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.

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

    PubMed

    Klein, John R

    2006-03-01

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

  7. 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.

  8. Code System to Calculate Neutron and Gamma-Ray Skyshine Doses Using the Integral Line-Beam Method.

    Energy Science and Technology Software Center (ESTSC)

    2000-11-16

    Version 03 This package includes the SKYNEUT 1.1, SKYDOSE 2.3, MCSKY 2.3 and SKYCONES 1.1 codes plus the DLC-188/SKYDATA library to form a comprehensive system for calculating skyshine doses. See the author's web site for related information: http://athena.mne.ksu.edu/~jks/ SKYNEUT evaluates the neutron and neutron-induced secondary gamma-ray skyshine doses from an isotropic, point, neutron source collimated by three simple geometries: an open silo, a vertical black (perfectly absorbing) wall, and a rectangular building. The source maymore » emit monoenergetic neutrons or neutrons with an arbitrary multigroup spectrum of energies. SKYDOSE evaluates the gamma-ray skyshine dose from an isotropic, monoenergetic, point gamma-photon source collimated by three simple geometries: (1) a source in a silo, (2) a source behind an infinitely long, vertical, black wall, and (3) a source in a rectangular building. In all three geometries an optional overhead slab shield may be specified. MCSKY evaluates the gamma-ray skyshine dose from an isotropic, monoenergetic, point gamma-photon source collimated into either a vertical cone (i.e., silo geometry) or into a vertically oriented structure with an N-sided polygon cross section. An overhead laminate shield composed of two different materials is assumed, although shield thicknesses of zero may be specified to model an unshielded SKYSHINE source. SKYCONES evaluates the skyshine doses produced by a point neutron or gamma-photon source emitting, into the atmosphere, radiation that is collimated into an upward conical annulus between two arbitrary polar angles. The source is assumed to be axially (azimuthally) symmetric about a vertical axis through the source and can have an arbitrary polyenergetic spectrum. Nested contiguous annular cones can thus be used to represent the energy and polar-angle dependence of a skyshine source emitting radiation into the atmosphere.« less

  9. Prompt Fission Gamma-ray Spectra and Multiplicities for Various Fissioning Systems

    NASA Astrophysics Data System (ADS)

    Litaize, Olivier; Regnier, David; Serot, Olivier

    The prompt fission gamma spectra (PFGS) and multiplicities (PFGM) are investigated from a Monte Carlo simulation of the fission fragment deexcitation. The fission fragment characteristics are sampled from mass, charge, kinetic energy, spin and parity distributions from experimental data or theoretical models. Initial excitation energy is shared between the two complementary fragments using a mass dependent temperature ratio law and a level density parameter law based on Ignatyuk's prescription. Details can be found elsewhere in the literature. The deexcitation process can be performed with different calculation schemes. The first one is based on a Weisskopf model for neutron evaporation and nuclear transition sampling (from level density and strength function models) for gamma evaporation. In this case, the competition between neutrons and gammas is taken into account by using a spin dependent excitation energy limit under which gamma emission takes place. The second one is based on an Hauser-Feshbach model for neutron/gamma evaporation based on neutron transmission coefficients (from optical model calculations) and the same model as above for gammas. The n/γ competition is then automatically taken into account at the very beginning of the primary fission fragments evaporation process. Fission observables, especially related to prompt fission gammas are presented and discussed for spontaneous fission (252Cf, 240Pu), thermal fission (235U+nth) and fast fission (238U+n1.8MeV). Comparisons with experimental data are shown when available.

  10. 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.

  11. Trithorax regulates systemic signaling during Drosophila imaginal disc regeneration.

    PubMed

    Skinner, Andrea; Khan, Sumbul Jawed; Smith-Bolton, Rachel K

    2015-10-15

    Although tissue regeneration has been studied in a variety of organisms, from Hydra to humans, many of the genes that regulate the ability of each animal to regenerate remain unknown. The larval imaginal discs of the genetically tractable model organism Drosophila melanogaster have complex patterning, well-characterized development and a high regenerative capacity, and are thus an excellent model system for studying mechanisms that regulate regeneration. To identify genes that are important for wound healing and tissue repair, we have carried out a genetic screen for mutations that impair regeneration in the wing imaginal disc. Through this screen we identified the chromatin-modification gene trithorax as a key regeneration gene. Here we show that animals heterozygous for trithorax are unable to maintain activation of a developmental checkpoint that allows regeneration to occur. This defect is likely to be caused by abnormally high expression of puckered, a negative regulator of Jun N-terminal kinase (JNK) signaling, at the wound site. Insufficient JNK signaling leads to insufficient expression of an insulin-like peptide, dILP8, which is required for the developmental checkpoint. Thus, trithorax regulates regeneration signaling and capacity. PMID:26487779

  12. Regulation of System xc− by Pharmacological Manipulation of Cellular Thiols

    PubMed Central

    Albano, Rebecca; Raddatz, Nicholas J.; Hjelmhaug, Julie; Baker, David A.; Lobner, Doug

    2015-01-01

    The cystine/glutamate exchanger (system xc−) mediates the transport of cystine into the cell in exchange for glutamate. By releasing glutamate, system xc− can potentially cause excitotoxicity. However, through providing cystine to the cell, it regulates the levels of cellular glutathione (GSH), the main endogenous intracellular antioxidant, and may protect cells against oxidative stress. We tested two different compounds that deplete primary cortical cultures containing both neurons and astrocytes of intracellular GSH, L-buthionine-sulfoximine (L-BSO), and diethyl maleate (DEM). Both compounds caused significant concentration and time dependent decreases in intracellular GSH levels. However; DEM caused an increase in radiolabeled cystine uptake through system xc−, while unexpectedly BSO caused a decrease in uptake. The compounds caused similar low levels of neurotoxicity, while only BSO caused an increase in oxidative stress. The mechanism of GSH depletion by these two compounds is different, DEM directly conjugates to GSH, while BSO inhibits γ-glutamylcysteine synthetase, a key enzyme in GSH synthesis. As would be expected from these mechanisms of action, DEM caused a decrease in intracellular cysteine, while BSO increased cysteine levels. The results suggest that negative feedback by intracellular cysteine is an important regulator of system xc− in this culture system. PMID:25949770

  13. Regulation of System xc(-) by Pharmacological Manipulation of Cellular Thiols.

    PubMed

    Albano, Rebecca; Raddatz, Nicholas J; Hjelmhaug, Julie; Baker, David A; Lobner, Doug

    2015-01-01

    The cystine/glutamate exchanger (system xc (-)) mediates the transport of cystine into the cell in exchange for glutamate. By releasing glutamate, system xc (-) can potentially cause excitotoxicity. However, through providing cystine to the cell, it regulates the levels of cellular glutathione (GSH), the main endogenous intracellular antioxidant, and may protect cells against oxidative stress. We tested two different compounds that deplete primary cortical cultures containing both neurons and astrocytes of intracellular GSH, L-buthionine-sulfoximine (L-BSO), and diethyl maleate (DEM). Both compounds caused significant concentration and time dependent decreases in intracellular GSH levels. However; DEM caused an increase in radiolabeled cystine uptake through system xc (-), while unexpectedly BSO caused a decrease in uptake. The compounds caused similar low levels of neurotoxicity, while only BSO caused an increase in oxidative stress. The mechanism of GSH depletion by these two compounds is different, DEM directly conjugates to GSH, while BSO inhibits γ-glutamylcysteine synthetase, a key enzyme in GSH synthesis. As would be expected from these mechanisms of action, DEM caused a decrease in intracellular cysteine, while BSO increased cysteine levels. The results suggest that negative feedback by intracellular cysteine is an important regulator of system xc (-) in this culture system. PMID:25949770

  14. Molecular cloning of the mouse proteasome subunits MC14 and MECL-1: reciprocally regulated tissue expression of interferon-gamma-modulated proteasome subunits.

    PubMed

    Stohwasser, R; Standera, S; Peters, I; Kloetzel, P M; Groettrup, M

    1997-05-01

    The primary structures of the interferon-gamma-inducible mouse 20S proteasome subunit MECL-1 and its alternate homolog MC14 were determined. Northern analysis of mouse tissues revealed that MECL-1 mRNA predominantly occurred in thymus, lymph nodes, and spleen, whereas small amounts were detected in non-lymphoid tissues such as kidney, muscle, and testis. Unexpectedly, probing RNA blots with MC14 showed that tissues with high MECL-1 expression contained little MC14 and vice versa. A very similar reciprocal tissue expression was subsequently found for the homologous subunit pairs LMP2 and delta as well as LMP7 and MB1. The subunit protein composition of 20S proteasomes purified from liver, thymus, and lung reflected RNA expression. The impact of a regulated reciprocal tissue expression is discussed with respect to thymic selection and the induction of tolerance in potentially autoreactive T cells. PMID:9174609

  15. Integrin alpha1beta1 regulates epidermal growth factor receptor activation by controlling peroxisome proliferator-activated receptor gamma-dependent caveolin-1 expression.

    PubMed

    Chen, Xiwu; Whiting, Carrie; Borza, Corina; Hu, Wen; Mont, Stacey; Bulus, Nada; Zhang, Ming-Zhi; Harris, Raymond C; Zent, Roy; Pozzi, Ambra

    2010-06-01

    Integrin alpha1beta1 negatively regulates the generation of profibrotic reactive oxygen species (ROS) by inhibiting epidermal growth factor receptor (EGFR) activation; however, the mechanism by which it does this is unknown. In this study, we show that caveolin-1 (Cav-1), a scaffolding protein that binds integrins and controls growth factor receptor signaling, participates in integrin alpha1beta1-mediated EGFR activation. Integrin alpha1-null mesangial cells (MCs) have reduced Cav-1 levels, and reexpression of the integrin alpha1 subunit increases Cav-1 levels, decreases EGFR activation, and reduces ROS production. Downregulation of Cav-1 in wild-type MCs increases EGFR phosphorylation and ROS synthesis, while overexpression of Cav-1 in the integrin alpha1-null MCs decreases EGFR-mediated ROS production. We further show that integrin alpha1-null MCs have increased levels of activated extracellular signal-regulated kinase (ERK), which leads to reduced activation of peroxisome proliferator-activated receptor gamma (PPARgamma), a transcription factor that positively regulates Cav-1 expression. Moreover, activation of PPARgamma or inhibition of ERK increases Cav-1 levels in the integrin alpha1-null MCs. Finally, we show that glomeruli of integrin alpha1-null mice have reduced levels of Cav-1 and activated PPARgamma but increased levels of phosphorylated EGFR both at baseline and following injury. Thus, integrin alpha1beta1 negatively regulates EGFR activation by positively controlling Cav-1 levels, and the ERK/PPARgamma axis plays a key role in regulating integrin alpha1beta1-dependent Cav-1 expression and consequent EGFR-mediated ROS production. PMID:20368353

  16. Differential regulation of the central neural cardiorespiratory system by metabotropic neurotransmitters

    PubMed Central

    Pilowsky, Paul M.; Lung, Mandy S. Y.; Spirovski, Darko; McMullan, Simon

    2009-01-01

    Central neurons in the brainstem and spinal cord are essential for the maintenance of sympathetic tone, the integration of responses to the activation of reflexes and central commands, and the generation of an appropriate respiratory motor output. Here, we will discuss work that aims to understand the role that metabotropic neurotransmitter systems play in central cardiorespiratory mechanisms. It is well known that blockade of glutamatergic, gamma-aminobutyric acidergic and glycinergic pathways causes major or even complete disruption of cardiorespiratory systems, whereas antagonism of other neurotransmitter systems barely affects circulation or ventilation. Despite the lack of an ‘all-or-none’ role for metabotropic neurotransmitters, they are nevertheless significant in modulating the effects of central command and peripheral adaptive reflexes. Finally, we propose that a likely explanation for the plethora of neurotransmitters and their receptors on cardiorespiratory neurons is to enable differential regulation of outputs in response to reflex inputs, while at the same time maintaining a tonic level of sympathetic activity that supports those organs that significantly autoregulate their blood supply, such as the heart, brain, retina and kidney. Such an explanation of the data now available enables the generation of many new testable hypotheses. PMID:19651655

  17. Second biannaul recalibration of two spectral gamma-ray logging systems used for baseline characterization measurements in the Hanford Tank Farms

    SciTech Connect

    Koizumi, C.J.

    1996-08-01

    The U.S. Department of Energy`s (DOE) Grand Junction Projects Office (GJPO) is establishing an initial, or baseline, characterization of gamma-ray-emitting contaminants in the subsurface of the Tank Farms at the DOE Hanford Site in the State of Washington. These baseline data are gathered by logging existing monitoring boreholes with two high-resolution passive spectral gamma-ray logging systems (SGLSs) informally known as Gamma 1 and Gamma 2. Calibration of the logging systems is crucial to the assurance of data quality. The project document Vadose Zone Monitoring Project at the Hanford Tank Farms, Spectral Gamma-Ray Borehole Geophysical Logging Characterization and Baseline Monitoring Plan for the Hanford Single-Shell Tanks specifies that both systems must be recalibrated, using the calibration standards at the Hanford borehole logging calibration center, every 6 months. DOE presents a description of the first recalibrations.

  18. 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

  19. Yersinia Type III Secretion System Master Regulator LcrF.

    PubMed

    Schwiesow, Leah; Lam, Hanh; Dersch, Petra; Auerbuch, Victoria

    2016-02-01

    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

  20. 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

  1. 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.

  2. N-glycosylation in Regulation of the Nervous System

    PubMed Central

    Scott, Hilary; Panin, Vladislav M.

    2015-01-01

    Summary Protein N-glycosylation can influence the nervous system in a variety of ways by affecting functions of glycoproteins involved in nervous system development and physiology. The importance of N-glycans for different aspects of neural development has been well documented. For example, some N-linked carbohydrate structures were found to play key roles in neural cell adhesion and axonal targeting during development. At the same time, the involvement of glycosylation in the regulation of neural physiology remains less understood. Recent studies have implicated N-glycosylation in the regulation of neural transmission, revealing novel roles of glycans in synaptic processes and the control of neural excitability. N-Glycans were found to markedly affect the function of several types of synaptic proteins involved in key steps of synaptic transmission, including neurotransmitter release, reception and uptake. Glycosylation also regulates a number of channel proteins, such as TRP channels that control responses to environmental stimuli and voltage-gated ion channels, the principal determinants of neuronal excitability. Sialylated carbohydrate structures play a particularly prominent part in the modulation of voltage gated ion channels. Sialic acids appear to affect channel functions via several mechanisms, including charge interactions, as well as other interactions that probably engage steric effects and interactions with other molecules. Experiments also indicated that some structural features of glycans can be particularly important for their function. Since glycan structures can vary significantly between different cell types and depends on the metabolic state of the cell, it is important to analyze glycan functions using in vivo approaches. While the complexity of the nervous system and intricacies of glycosylation pathways can create serious obstacles for in vivo experiments in vertebrates, recent studies have indicated that more simple and experimentally

  3. Design of dual-road transportable portal monitoring system for visible light and gamma-ray imaging

    NASA Astrophysics Data System (ADS)

    Karnowski, Thomas P.; Cunningham, Mark F.; Goddard, James S.; Cheriyadat, Anil M.; Hornback, Donald E.; Fabris, Lorenzo; Kerekes, Ryan A.; Ziock, Klaus-Peter; Bradley, E. Craig; Chesser, J.; Marchant, W.

    2010-04-01

    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.

  4. 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.

  5. Two-photon absorption cross section measurement in the gamma band system of nitric oxide

    SciTech Connect

    Burris, J.F. Jr.

    1982-01-01

    A dye laser with a single longitudinal mode and very stable spatial mode structure has been constructed. With this laser system a four-wave mixing experiment was done in the gamma bands of nitric oxide using two photon resonance. Another four-wave mixing experiment was done in nitrogen using coherent anti-Stokes Raman scattering (CARS) and the two signals ratioed. Using accurately known values of the Raman scattering cross section, the third order susceptibility in NO was determined without needing to know the spatial and temporal properties of the dye lasers. From this susceptibility, the two photon absorption cross section was calculated with the explicit dependence of sigma/sup (2)/ upon X/sup (3)/ shown. For the R/sub 22/ + S/sub 12/(J'' = 9 1/2) (A/sup 2/..sigma..+(v' = 0) -- X/sup 2/..pi..(v'' = 0)) line, sigma/sup (2)/ = (1.0 +/- 0.6) x 10/sup -38/cm/sup 4/g(2/sub 1/-Vertical Barsub f/ is the normalized lineshape. Branching ratios for the A/sup 2/..sigma..+(v' = n) ..-->.. X/sup 2/..omega..(v'' = n)(n = o,...9) transitions of NO were also measured, Franck-Condon factors calculated and the lifetime of the A state determined.

  6. Thin film deployable reflector model for ET gamma ray imaging telescope system (ET-GRITS)

    NASA Technical Reports Server (NTRS)

    Huegele, Vinson B.

    1989-01-01

    The Marshall Space Flight Center is developing a thin film reflector for a Gamma Ray Imaging Telescope System (GRITS) using the Shuttle External Tank (ET). The concept is to install an inflatable reflector in the ET that could be transferred from the orbiter in orbit. This is a study of a scale model reflector for the ET GRITS application. The approach is to form 1/2 mil film into a spherical mirror mounted on a seven-foot diameter metal ring. The ring mount is sealed and slightly evacuated to pressurize the film into shape. Several different fabrication techniques were investigated using seamed gore designs to form the reflector. Also studied was casting a film into a seamless circular sheet. The goal for this model was to achieve a one milliradian (rms) surface curvature error over 90 percent of the reflector area. This curvature was measured by a laser scanning instrument. The results show how different reflector designs and fabrication techniques contribute to surface curvature and focusing errors.

  7. Stimulus generation technique for code simulation of FPGA based gamma spectroscopy system

    NASA Astrophysics Data System (ADS)

    Rahman, Nur Aira Abd; Ramli, Abdul Rahman; Lombigit, Lojius; Abdullah, Nor Arymaswati; Khalid, Mohd Ashhar Hj

    2014-02-01

    The aim of this study is to develop a software that can systematically generate stimulus required for code simulation (functional and timing) of new digital processors in gamma spectroscopy system. Software must be able to produce stimulus that emulate ADC data of charge sensitive amplifier (CSA) output signal. Signal parameters such as pulse shape, amplitude, pulse width and count rate should be adjustable while allowing options such as pulse pile-up and random pulse events. To fulfill this objective, a pulse generator software PulseGEN has been developed. The software GUI is designed to operate in two modes, Single/Pile-Up Mode and Continuous Random Mode. Its ADC module simulates real-time ADC sampling. The output can be saved as input stimulus to test various functions of digital processors such as pulse height measurements, pile-up detection and correction, as well as random pulse detection and measurement that is similar to the actual real-time measurement. PulseGEN results have been compared and verified against commercial charge sensitive amplifier with NaI detector and NIM pulser.

  8. 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.

  9. 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.

  10. 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.

  11. 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...

  12. Mechanisms of immune regulation in the peripheral nervous system.

    PubMed

    Gold, R; Archelos, J J; Hartung, H P

    1999-04-01

    The peripheral nervous system (PNS) is a target for heterogenous immune attacks mediated by different components of the systemic immune compartment. T cells, B cells, and macrophages can interact with endogenous, partially immune-competent glial cells and contribute to local inflammation. Cellular and humoral immune functions of Schwann cells have been well characterized in vitro. In addition, the interaction of the humoral and cellular immune system with the cellular and extracellular components in the PNS may determine the extent of tissue inflammation and repair processes such as remyelination and neuronal outgrowth. The animal model experimental autoimmune neuritis (EAN) allows direct monitoring of these immune responses in vivo. In EAN contributions to regulate autoimmunity in the PNS are made by adhesion molecules and by cytokines that orchestrate cellular interactions. The PNS has a significant potential to eliminate T cell inflammation via apoptosis, which is almost lacking in other tissues such as muscle and skin. In vitro experiments suggest different scenarios how specific cellular and humoral elements in the PNS may sensitize autoreactive T cells for apoptosis in vivo. Interestingly several conventional and novel immunotherapeutic approaches like glucocorticosteroids and high-dose antigen therapy induce T cell apoptosis in situ in EAN. A better understanding of immune regulation and its failure in the PNS may help to develop improved, more specific immunotherapies. PMID:10219750

  13. Risk analysis of nuclear safeguards regulations. [Aggregated Systems Model (ASM)

    SciTech Connect

    Al-Ayat, R.A.; Altman, W.D.; Judd, B.R.

    1982-06-01

    The Aggregated Systems Model (ASM), a probabilisitic risk analysis tool for nuclear safeguards, was applied to determine benefits and costs of proposed amendments to NRC regulations governing nuclear material control and accounting systems. The objective of the amendments was to improve the ability to detect insiders attempting to steal large quantities of special nuclear material (SNM). Insider threats range from likely events with minor consequences to unlikely events with catastrophic consequences. Moreover, establishing safeguards regulations is complicated by uncertainties in threats, safeguards performance, and consequences, and by the subjective judgments and difficult trade-offs between risks and safeguards costs. The ASM systematically incorporates these factors in a comprehensive, analytical framework. The ASM was used to evaluate the effectiveness of current safeguards and to quantify the risk of SNM theft. Various modifications designed to meet the objectives of the proposed amendments to reduce that risk were analyzed. Safeguards effectiveness was judged in terms of the probability of detecting and preventing theft, the expected time to detection, and the expected quantity of SNM diverted in a year. Data were gathered in tours and interviews at NRC-licensed facilities. The assessment at each facility was begun by carefully selecting scenarios representing the range of potential insider threats. A team of analysts and facility managers assigned probabilities for detection and prevention events in each scenario. Using the ASM we computed the measures of system effectiveness and identified cost-effective safeguards modifications that met the objectives of the proposed amendments.

  14. Zeb2: A multifunctional regulator of nervous system development.

    PubMed

    Hegarty, Shane V; Sullivan, Aideen M; O'Keeffe, Gerard W

    2015-09-01

    Zinc finger E-box binding homeobox (Zeb) 2 is a transcription factor, identified due its ability to bind Smad proteins, and consists of multiple functional domains which interact with a variety of transcriptional co-effectors. The complex nature of the Zeb2, both at its genetic and protein levels, underlie its multifunctional properties, with Zeb2 capable of acting individually or as part of a transcriptional complex to repress, and occasionally activate, target gene expression. This review introduces Zeb2 as an essential regulator of nervous system development. Zeb2 is expressed in the nervous system throughout its development, indicating its importance in neurogenic and gliogenic processes. Indeed, mutation of Zeb2 has dramatic neurological consequences both in animal models, and in humans with Mowat-Wilson syndrome, which results from heterozygous ZEB2 mutations. The mechanisms by which Zeb2 regulates the induction of the neuroectoderm (CNS primordium) and the neural crest (PNS primordium) are reviewed herein. We then describe how Zeb2 acts to direct the formation, delamination, migration and specification of neural crest cells. Zeb2 regulation of the development of a number of cerebral regions, including the neocortex and hippocampus, are then described. The diverse molecular mechanisms mediating Zeb2-directed development of various neuronal and glial populations are reviewed. The role of Zeb2 in spinal cord and enteric nervous system development is outlined, while its essential function in CNS myelination is also described. Finally, this review discusses how the neurodevelopmental defects of Zeb2 mutant mice delineate the developmental dysfunctions underpinning the multiple neurological defects observed in Mowat-Wilson syndrome patients. PMID:26193487

  15. Output feedback regulator design for jet engine control systems

    NASA Technical Reports Server (NTRS)

    Merrill, W. C.

    1977-01-01

    A multivariable control design procedure based on the output feedback regulator formulation is described and applied to turbofan engine model. Full order model dynamics, were incorporated in the example design. The effect of actuator dynamics on closed loop performance was investigaged. Also, the importance of turbine inlet temperature as an element of the dynamic feedback was studied. Step responses were given to indicate the improvement in system performance with this control. Calculation times for all experiments are given in CPU seconds for comparison purposes.

  16. Output feedback regulator design for jet engine control systems

    NASA Technical Reports Server (NTRS)

    Merrill, W.

    1977-01-01

    A multivariable control design procedure based on the output feedback regulator formulation is described and applied to an F100 turbofan engine model. Full order model dynamics, are incorporated in the example design. The effect of actuator dynamics on closed loop performance is investigated. Also, the importance of turbine inlet temperature as an element of the dynamic feedback is studied. Step responses are given to indicate the improvement in system performance with this control. Calculation times for all experiments are given in CPU seconds for comparison purposes.

  17. Evodiamine inhibits the proliferation of leukemia cell line K562 by regulating peroxisome proliferators-activated receptor gamma (PPARγ) pathway.

    PubMed

    Sun, Chengming; Zhang, Guili; Luan, Shuping; Luan, Caifu; Shao, Huiyuan; Dong, Fei; Liu, Xuena

    2016-08-01

    Evodiamine, a quinolone alkaloid, is one of the major bioactive compounds of Evodia rutaecarpa Bentham (Rutaceae). It exhibits excellent biological activities, especially the anticancer activity. This study aims to investigate the effect of evodiamine on the proliferation of leukemia cell line K562 and to explore the underlying mechanism. The effect of evodiamine on K562 cells proliferation was analyzed by trypan blue dye exclusion assay and MTT assay. The expression levels of peroxisome proliferators-activated receptor gamma (PPARγ), cyclin D1, and p21 were detected by western blot assay. The results demonstrated that evodiamine inhibited the proliferation and decreased the viability of K562 cells in a dose- and time-dependent manner. 2-Chloro-5-nitro-N-phenylbenzamide (GW9662) and/or PPARγ-siRNA pretreatment alleviated the cell growth suppression triggered by evodiamine. Meanwhile, evodiamine intervention elevated the expression of PPARγ in K562 cells, while pretreatment with GW9662 attenuated the enhanced upregulation of PPARγ expression induced by evodiamine. In addition, GW9662 and PPARγ-siRNA pretreatment also significantly attenuated the downregulation of the cell cycle control protein cyclin D1 and the upregulation of cyclin-dependent kinase inhibitor p21 induced by evodiamine. In conclusion, PPARγ signaling pathway may involve in the proliferation inhibition of evodiamine on K562 cells via inhibiting cylcin D1 and stimulating of p21. PMID:26671528

  18. A pulse shape discriminator and an online system for the balloon-borne hard X-ray/gamma-ray detector

    NASA Astrophysics Data System (ADS)

    Takahashi, T.; Kamae, T.; Tanaka, M.; Gunji, S.; Miyazuki, S.; Tamura, T.; Sekimoto, Y.; Yamaoka, N.; Nishimura, J.; Yajima, N.

    Attention is given to a new kind of phoswich counters (the well-type phoswich counter) that will be capable of detecting very low flux hard X-rays/gamma-rays (40-1000 keV) from astronomical objects. A specially designed pulse-shape discriminator (PSD) selects hard X-rays/gamma-rays that has deposited energy only in the detection part. Sixty-four such counters are assembled into an array where each phoswich element acts as an active shield to the neighboring elements too. The ADCs, the TDCs, the hit-pattern latches, and the precision clock are read out by a VME-based online system, stored on an 8-mm video tape, and transmitted to the ground station. The design and performance of the pulse shape discriminator and the online system are described.

  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. 41 CFR 109-1.101 - Federal Property Management Regulations System.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false Federal Property Management Regulations System. 109-1.101 Section 109-1.101 Public Contracts and Property Management Federal Property Management Regulations System (Continued) DEPARTMENT OF ENERGY PROPERTY MANAGEMENT REGULATIONS GENERAL 1-INTRODUCTION 1.1-Regulation...

  1. 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

  2. A photon detector system for the search for the rare muon decay {mu} {yields} e{gamma}

    SciTech Connect

    Van Ausdeln, L.A.

    1993-11-01

    An innovative and state of the art pair spectrometer system to measure the photon component of {mu}{sup +} decay to obtain an improved branching ratio limit for the decay {mu} {yields} e{gamma} is investigated. Analysis algorithms are developed and an experimental inner bremsstrahlung spectrum is obtained and agrees well with Monte Carlo simulations. Background sources are investigated and found to be highly suppressed at various stages of acquisition and analysis.

  3. 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)

  4. 15-Deoxy-{delta}{sup 12,14}-prostaglandin J{sub 2} down-regulates CXCR4 on carcinoma cells through PPAR{gamma}- and NF{kappa}B-mediated pathways

    SciTech Connect

    Richard, Cynthia Lee; Lowthers, Erica Lauren; Blay, Jonathan

    2007-10-01

    The chemokine receptor CXCR4 plays a key role in the metastasis of colorectal cancer and its growth at metastatic sites. Here, we have investigated the mechanisms by which CXCR4 on cancer cells might be regulated by eicosanoids present within the colorectal tumor microenvironment. We show that prostaglandins PGE{sub 2}, PGA{sub 2}, PGD{sub 2}, PGJ{sub 2} and 15dPGJ{sub 2} each down-regulates CXCR4 receptor expression on human colorectal carcinoma cells to differing degrees. The most potent of these were PGD{sub 2} and its metabolites PGJ{sub 2} and 15dPGJ{sub 2}. Down-regulation was most rapid with the end-product 15dPGJ{sub 2} and was accompanied by a marked reduction in CXCR4 mRNA. 15dPGJ{sub 2} is known to be a ligand for the nuclear receptor PPAR{gamma}. Down-regulation of CXCR4 was also observed with the PPAR{gamma} agonist rosiglitazone, while 15dPGJ{sub 2}-induced CXCR4 down-regulation was substantially diminished by the PPAR{gamma} antagonists GW9662 and T0070907. These data support the involvement of PPAR{gamma}. However, the 15dPGJ{sub 2} analogue CAY10410, which can act on PPAR{gamma} but which lacks the intrinsic cyclopentenone structure found in 15dPGJ{sub 2}, down-regulated CXCR4 substantially less potently than 15dPGJ{sub 2}. The cyclopentenone grouping is known to inhibit the activity of NF{kappa}B. Consistent with an additional role for NF{kappa}B, we found that the cyclopentenone prostaglandin PGA{sub 2} and cyclopentenone itself could also down-regulate CXCR4. Immunolocalization studies showed that the cellular context was sufficient to trigger a focal nuclear pattern of NF{kappa}B p50 and that 15dPGJ{sub 2} interfered with this p50 nuclear localization. These data suggest that 15dPGJ{sub 2} can down-regulate CXCR4 on cancer cells through both PPAR{gamma} and NF{kappa}B. 15dPGJ{sub 2}, present within the tumor microenvironment, may act to down-regulate CXCR4 and impact upon the overall process of tumor expansion.

  5. Mycobacterium tuberculosis Phosphate Uptake System Component PstA2 Is Not Required for Gene Regulation or Virulence

    PubMed Central

    Leistikow, Rachel L.; Ramakrishnan, Pavithra; Voskuil, Martin I.; McKinney, John D.

    2016-01-01

    The Mycobacterium tuberculosis genome encodes two complete high-affinity Pst phosphate-specific transporters. We previously demonstrated that a membrane-spanning component of one Pst system, PstA1, was essential both for M. tuberculosis virulence and for regulation of gene expression in response to external phosphate availability. To determine if the alternative Pst system is similarly required for virulence or gene regulation, we constructed a deletion of pstA2. Transcriptome analysis revealed that PstA2 is not required for regulation of gene expression in phosphate-replete growth conditions. PstA2 was also dispensable for replication and virulence of M. tuberculosis in a mouse aerosol infection model. However, a ΔpstA1ΔpstA2 double mutant was attenuated in mice lacking the cytokine interferon-gamma, suggesting that M. tuberculosis requires high-affinity phosphate transport to survive phosphate limitation encountered in the host. Surprisingly, ΔpstA2 bacteria were more resistant to acid stress in vitro. This phenotype is intrinsic to the alternative Pst transporter since a ΔpstS1 mutant exhibited similar acid resistance. Our data indicate that the two M. tuberculosis Pst transporters have distinct physiological functions, with the PstA1 transporter being specifically involved in phosphate sensing and gene regulation while the PstA2 transporter influences survival in acidic conditions. PMID:27557082

  6. Mycobacterium tuberculosis Phosphate Uptake System Component PstA2 Is Not Required for Gene Regulation or Virulence.

    PubMed

    Tischler, Anna D; Leistikow, Rachel L; Ramakrishnan, Pavithra; Voskuil, Martin I; McKinney, John D

    2016-01-01

    The Mycobacterium tuberculosis genome encodes two complete high-affinity Pst phosphate-specific transporters. We previously demonstrated that a membrane-spanning component of one Pst system, PstA1, was essential both for M. tuberculosis virulence and for regulation of gene expression in response to external phosphate availability. To determine if the alternative Pst system is similarly required for virulence or gene regulation, we constructed a deletion of pstA2. Transcriptome analysis revealed that PstA2 is not required for regulation of gene expression in phosphate-replete growth conditions. PstA2 was also dispensable for replication and virulence of M. tuberculosis in a mouse aerosol infection model. However, a ΔpstA1ΔpstA2 double mutant was attenuated in mice lacking the cytokine interferon-gamma, suggesting that M. tuberculosis requires high-affinity phosphate transport to survive phosphate limitation encountered in the host. Surprisingly, ΔpstA2 bacteria were more resistant to acid stress in vitro. This phenotype is intrinsic to the alternative Pst transporter since a ΔpstS1 mutant exhibited similar acid resistance. Our data indicate that the two M. tuberculosis Pst transporters have distinct physiological functions, with the PstA1 transporter being specifically involved in phosphate sensing and gene regulation while the PstA2 transporter influences survival in acidic conditions. PMID:27557082

  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. MicroRNA Regulation in Systemic Lupus Erythematosus Pathogenesis

    PubMed Central

    Yan, Sheng; Yim, Lok Yan; Lu, Liwei; Lau, Chak Sing

    2014-01-01

    MicroRNAs (miRNAs) are endogenous small RNA molecules best known for their function in post-transcriptional gene regulation. Immunologically, miRNA regulates the differentiation and function of immune cells and its malfunction contributes to the development of various autoimmune diseases including systemic lupus erythematosus (SLE). Over the last decade, accumulating researches provide evidence for the connection between dysregulated miRNA network and autoimmunity. Interruption of miRNA biogenesis machinery contributes to the abnormal T and B cell development and particularly a reduced suppressive function of regulatory T cells, leading to systemic autoimmune diseases. Additionally, multiple factors under autoimmune conditions interfere with miRNA generation via key miRNA processing enzymes, thus further skewing the miRNA expression profile. Indeed, several independent miRNA profiling studies reported significant differences between SLE patients and healthy controls. Despite the lack of a consistent expression pattern on individual dysregulated miRNAs in SLE among these studies, the aberrant expression of distinct groups of miRNAs causes overlapping functional outcomes including perturbed type I interferon signalling cascade, DNA hypomethylation and hyperactivation of T and B cells. The impact of specific miRNA-mediated regulation on function of major immune cells in lupus is also discussed. Although research on the clinical application of miRNAs is still immature, through an integrated approach with advances in next generation sequencing, novel tools in bioinformatics database analysis and new in vitro and in vivo models for functional evaluation, the diagnostic and therapeutic potentials of miRNAs may bring to fruition in the future. PMID:24999310

  9. 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 PAGESBeta

    Embry, Irucka; Roland, Victor; Agbaje, Oluropo; Watson, Valetta; Martin, Marquan; Painter, Roger; Byl, Tom; Sharpe, Lonnie

    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

  10. GSH1, which encodes gamma-glutamylcysteine synthetase, is a target gene for yAP-1 transcriptional regulation.

    PubMed Central

    Wu, A L; Moye-Rowley, W S

    1994-01-01

    Changes in gene dosage of the YAP1 gene, encoding the yAP-1 transcriptional regulatory protein, cause profound alterations in cellular drug and metal resistance. Previous studies on yAP-1 action in yeast cells have used the AP-1 response element (ARE) from simian virus 40 as an artificial site for yAP-1-mediated transcriptional activation. No authentic yeast target sites for control of gene expression by yAP-1 are known. Here we show that the GSH1 gene, encoding gamma-glutamylcysteine synthetase, is transcriptionally responsive to the yAP-1 protein. GSH1 encodes the rate-limiting step in yeast glutathione biosynthesis and contains within its promoter region a DNA element that matches the ARE in 11 of 12 positions. The GSH1 yAP-1 response element (YRE) was recognized by yAP-1 protein in vitro. Northern (RNA) blot analysis showed that GSH1 mRNA levels were responsive to YAP1 gene dosage. A site-directed mutation in the YRE that blocked yAP-1 binding in vitro prevented the mutant GSH1 promoter from responding to elevation in YAP1 gene dosage. A delta gsh1 mutant strain was constructed and unable to grow in the absence of exogenous glutathione. A mutant GSH1 gene lacking the YRE was unable to confer normal cadmium tolerance, although other yAP-1-mediated phenotypes remained normal. Thus, GSH1 is one of several genes that are transcriptionally controlled by yAP-1 and influence drug resistance. Images PMID:7915005

  11. 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. Mol. Reprod. Dev. 83: 276-286, 2016. © 2016 Wiley Periodicals, Inc. PMID:26888468

  12. Understanding carbon regulation in aquatic systems - Bacteriophages as a model.

    PubMed

    Sanmukh, Swapnil; Khairnar, Krishna; Paunikar, Waman; Lokhande, Satish

    2015-01-01

    The bacteria and their phages are the most abundant constituents of the aquatic environment, and so represent an ideal model for studying carbon regulation in an aquatic system. The microbe-mediated interconversion of bioavailable organic carbon (OC) into dissolved organic carbon (DOC) by the microbial carbon pump (MCP) has been suggested to have the potential to revolutionize our view of carbon sequestration. It is estimated that DOC is the largest pool of organic matter in the ocean and, though a major component of the global carbon cycle, its source is not yet well understood. A key element of the carbon cycle is the microbial conversion of DOC into inedible forms. The primary aim of this study is to understand the phage conversion from organic to inorganic carbon during phage-host interactions. Time studies of phage-host interactions under controlled conditions reveal their impact on the total carbon content of the samples and their interconversion of organic and inorganic carbon compared to control samples. A total organic carbon (TOC) analysis showed an increase in inorganic carbon content by 15-25 percent in samples with bacteria and phage compared to samples with bacteria alone. Compared to control samples, the increase in inorganic carbon content was 60-70-fold in samples with bacteria and phage, and 50-55-fold for samples with bacteria alone. This study indicates the potential impact of phages in regulating the carbon cycle of aquatic systems. PMID:26213615

  13. Understanding carbon regulation in aquatic systems - Bacteriophages as a model

    PubMed Central

    Sanmukh, Swapnil; Khairnar, Krishna; Paunikar, Waman; Lokhande, Satish

    2015-01-01

    The bacteria and their phages are the most abundant constituents of the aquatic environment, and so represent an ideal model for studying carbon regulation in an aquatic system. The microbe-mediated interconversion of bioavailable organic carbon (OC) into dissolved organic carbon (DOC) by the microbial carbon pump (MCP) has been suggested to have the potential to revolutionize our view of carbon sequestration. It is estimated that DOC is the largest pool of organic matter in the ocean and, though a major component of the global carbon cycle, its source is not yet well understood. A key element of the carbon cycle is the microbial conversion of DOC into inedible forms. The primary aim of this study is to understand the phage conversion from organic to inorganic carbon during phage-host interactions. Time studies of phage-host interactions under controlled conditions reveal their impact on the total carbon content of the samples and their interconversion of organic and inorganic carbon compared to control samples. A total organic carbon (TOC) analysis showed an increase in inorganic carbon content by 15-25 percent in samples with bacteria and phage compared to samples with bacteria alone. Compared to control samples, the increase in inorganic carbon content was 60-70-fold in samples with bacteria and phage, and 50-55-fold for samples with bacteria alone. This study indicates the potential impact of phages in regulating the carbon cycle of aquatic systems. PMID:26213615

  14. 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).

  15. Mutations in GCD11, the structural gene for eIF-2 gamma in yeast, alter translational regulation of GCN4 and the selection of the start site for protein synthesis.

    PubMed Central

    Dorris, D R; Erickson, F L; Hannig, E M

    1995-01-01

    Translation initiation factor 2 (eIF-2) in eukaryotic organisms is composed of three non-identical subunits, alpha, beta and gamma. In a previous report, we identified GCD11 as an essential gene encoding the gamma subunit of eIF-2 in the yeast Saccharomyces cerevisiae. The predicted amino acid sequence of yeast eIF-2 gamma displays remarkable similarity to bacterial elongation factor Tu, including the presence of sequence elements conserved in all known guanine nucleotide binding proteins. We have identified the molecular defects present in seven unique alleles of GCD11 characterized by a partial loss of function. Three of these mutations result in amino acid substitutions within the putative GTP binding domain of eIF-2 gamma. We show that the gcd11 mutations specifically alter regulation of GCN4 expression at the translational level, without altering the scanning mechanism for protein synthesis initiation. Six of the mutant alleles presumably alter the function of eIF-2 gamma, rather than its abundance. A single allele, gcd11-R510H, suppresses a mutant his4 allele that lacks a functional AUG start codon. The latter result indicates that the gamma subunit of eIF-2 participates in recognition of the start site for protein synthesis, a role previously demonstrated in yeast for eIF-2 alpha and eIF-2 beta. Images PMID:7774582

  16. 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

  17. A novel IFN-gamma regulated human melanoma associated antigen gp33-38 defined by monoclonal antibody Me14/D12. I. Identification and immunochemical characterization.

    PubMed

    Giuffré, L; Isler, P; Mach, J P; Carrel, S

    1988-09-15

    A novel melanoma-associated differentiation Ag whose surface expression can be enhanced or induced by IFN-gamma was identified by mAb Me14/D12. Testing of numerous tumor cell lines and tumor tissue sections showed that Me14/D12-defined Ag was present not only on melanoma but also on other tumor lines of neuroectodermal origin such as gliomas and neuroblastomas and on some lymphoblastic B cell lines, on monocytes and macrophages. Immunoprecipitation by mAb Me14/D12 of lysates from [35S]methionine-labeled melanoma cells analyzed by SDS-PAGE revealed two polypeptide chains of 33 and 38 KDa, both under reducing and nonreducing conditions. Cross-linking experiments indicated that the two chains were present at the cell surface as a dimeric structure. Two-dimensional gel electrophoresis showed that the two chains of 33 and 38 KDa had isoelectric points of 6.2 and 5.7, respectively. Treatment of the melanoma cells with tunicamycin, an inhibitor of N-linked glycosylation, resulted in a reduction of the Mr from 33 to 24 KDa and from 38 to 26 KDa. Peptide maps obtained after Staphylococcus aureus V8 protease digestion showed no shared peptides between the two chains. Although biochemical data indicate that Me14/D12 molecules do not correspond to any known MHC class II Ag, their dimeric structure, tissue distribution, and regulation of IFN-gamma suggest that they could represent a new member of the MHC class II family. PMID:3139751

  18. 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

  19. 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. PMID:26421051

  20. 75 FR 391 - Medical Device Quality System Regulation Educational Forum on Risk Management Through the Product...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-05

    ... From the Federal Register Online via the Government Publishing Office ] DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration Medical Device Quality System Regulation Educational Forum... ``Medical Device Quality System Regulation Educational Forum on Risk Management through the Product...

  1. Gamma ray astronomy in perspective

    NASA Technical Reports Server (NTRS)

    1981-01-01

    A brief overview of the development of gamma ray astronomy is presented. Gamma ray telescopes and other optical measuring instruments are highlighted. Emphasis is placed on findings that were unobtainable before gamma ray astronomy. Information on evolution of the solar system, the relationship of the solar system to the galaxy, and the composition of interstellar matter is discussed.

  2. 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.

  3. 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. PMID:25243199

  4. 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

  5. General Purpose Kernel Integration Shielding Code System-Point and Extended Gamma-Ray Sources.

    Energy Science and Technology Software Center (ESTSC)

    1981-06-11

    PELSHIE3 calculates dose rates from gamma-emitting sources with different source geometries and shielding configurations. Eight source geometries are provided and are called by means of geometry index numbers. Gamma-emission characteristics for 134 isotopes, attenuation coefficients for 57 elements or shielding materials and Berger build-up parameters for 17 shielding materials can be obtained from a direct access data library by specifying only the appropriate library numbers. A different option allows these data to be read frommore » cards. For extended sources, constant source strengths as well as exponential and Bessel function source strength distributions are allowed in most cases.« less

  6. 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.

  7. Simulated weightlessness down-regulated antioxidant defense system in rats

    NASA Astrophysics Data System (ADS)

    Li, Qi; Qu, Lina; Li, Yingxian; Bi, Lei; Huang, Zengming; Wang, Bo

    A variety of experiments suggest that space flight is associated with an increase in oxidative stress in organism The aim of the present study is to investigate whether or not simulated weightlessness by tail-suspension can affect the antioxidant defense system in rats and the possible protection effects of Chinese medicine named Liu Wei Di Huang Wan LWDHW Blood plasma of rats was taken after 21 days - tail-suspension for the assessment of the change of antioxidant defense system The total antioxidant capacity T-AOC was significantly decreased and the content of malondialdehyde MDA was increased after simulated weightlessness Activities of antioxidant enzymes such as superoxide dismutase and catalase were lower than those in the controlled groups However the activity of glutathione peroxidase was increased in comparison with the controlled groups Adequate dosage of LWDHW could inhibit the production of MAD and improve T-AOC in tail-suspension rats These results suggested that tail-suspension might break the oxidative antioxidative balance and down-regulate antioxidant defense system and Chinese medicine LWDHW was shown to protect rats from oxidative damage during simulated weightlessness Key words Simulated weightlessness Tail-suspension Antioxidant defense system Rats

  8. System xc- regulates microglia and macrophage glutamate excitotoxicity in vivo

    PubMed Central

    Kigerl, Kristina A.; Ankeny, Daniel P.; Garg, Sanjay K.; Wei, Ping; Guan, Zhen; Lai, Wenmin; McTigue, Dana M.; Banerjee, Ruma; Popovich, Phillip G.

    2011-01-01

    It is widely believed that microglia and monocyte-derived macrophages (collectively referred to as central nervous system (CNS) macrophages) cause excitotoxicity in the diseased or injured CNS. This view has evolved mostly from in vitro studies showing that neurotoxic concentrations of glutamate are released from CNS macrophages stimulated with lipopolysaccharide (LPS), a potent inflammogen. We hypothesized that excitotoxic killing by CNS macrophages is more rigorously controlled in vivo, requiring both the activation of the glutamate/cystine antiporter (system xc-) and an increase in extracellular cystine, the substrate that drives glutamate release. Here, we show that non-traumatic microinjection of low-dose LPS into spinal cord gray matter activates CNS macrophages but without causing overt neuropathology. In contrast, neurotoxic inflammation occurs when LPS and cystine are co-injected. Simultaneous injection of NBQX, an antagonist of AMPA glutamate receptors, reduces the neurotoxic effects of LPS+cystine, implicating glutamate as a mediator of neuronal cell death in this model. Surprisingly, neither LPS nor LPS+cystine adversely affects survival of oligodendrocytes or oligodendrocyte progenitor cells. Ex vivo analyses show that redox balance in microglia and macrophages is controlled by induction of system xc- and that high GSH:GSSG ratios predict the neurotoxic potential of these cells. Together, these data indicate that modulation of redox balance in CNS macrophages, perhaps through regulating system xc-, could be a novel approach for attenuating injurious neuroinflammatory cascades. PMID:22079587

  9. Gamma Oscillation in Schizophrenia

    PubMed Central

    O'Donnell, Brian F.; Youn, Soyoung; Kwon, Jun Soo

    2011-01-01

    Dysfunctional neural circuitry has been found to be involved in abnormalities of perception and cognition in patients with schizophrenia. Gamma oscillations are essential for integrating information within neural circuits and have therefore been associated with many perceptual and cognitive processes in healthy human subjects and animals. This review presents an overview of the neural basis of gamma oscillations and the abnormalities in the GABAergic interneuronal system thought to be responsible for gamma-range deficits in schizophrenia. We also review studies of gamma activity in sensory and cognitive processes, including auditory steady state response, attention, object representation, and working memory, in animals, healthy humans and patients with schizophrenia. PMID:22216037

  10. NsrR: a key regulator circumventing Salmonella enterica serovar Typhimurium oxidative and nitrosative stress in vitro and in IFN-gamma-stimulated J774.2 macrophages.

    PubMed

    Gilberthorpe, Nicola J; Lee, Margaret E; Stevanin, Tania M; Read, Robert C; Poole, Robert K

    2007-06-01

    Over the past decade, the flavohaemoglobin Hmp has emerged as the most significant nitric oxide (NO)-detoxifying protein in many diverse micro-organisms, particularly pathogenic bacteria. Its expression in enterobacteria is dramatically increased on exposure to NO and other agents of nitrosative stress as a result of transcriptional regulation of hmp gene expression, mediated by (at least) four regulators. One such regulator, NsrR, has recently been shown to be responsible for repression of hmp transcription in the absence of NO in Escherichia coli and Salmonella, but the roles of other members of this regulon in Salmonella, particularly in surviving nitrosative stresses in vitro and in vivo, have not been elucidated. This paper demonstrates that an nsrR mutant of Salmonella enterica Serovar Typhimurium expresses high levels of Hmp both aerobically and anaerobically, exceeding those that can be elicited in vitro by supplementing media with S-nitrosoglutathione (GSNO). Elevated transcription of ytfE, ygbA, hcp and hcp is also observed, but no evidence was obtained for tehAB upregulation. The hyper-resistance to GSNO of an nsrR mutant is attributable solely to Hmp, since an nsrR hmp double mutant has a wild-type phenotype. However, overexpression of NsrR-regulated genes other than hmp confers some resistance of respiratory oxygen consumption to NO. The ability to enhance, by mutating NsrR, Hmp levels without recourse to exposure to nitrosative stress was used to test the hypothesis that control of Hmp levels is required to avoid oxidative stress, Hmp being a potent generator of superoxide. Within IFN-gamma-stimulated J774.2 macrophages, in which high levels of nitrite accumulated (indicative of NO production) an hmp mutant was severely compromised in survival. Surprisingly, under these conditions, an nsrR mutant (as well as an nsrR hmp double mutant) was also disadvantaged relative to the wild-type bacteria, attributable to the combined oxidative effect of the

  11. Pro-apoptotic gene regulation and its activation by gamma-irradiation in the Caribbean fruit fly, Anastrepha suspensa.

    PubMed

    Nirmala, Xavier; Schetelig, Marc F; Zimowska, Grazyna J; Zhou, Lei; Handler, Alfred M

    2015-01-01

    Transcriptional activation of pro-apoptotic genes in response to cytotoxic stimuli is a conserved feature of the cell death pathway in metazoans. However, understanding the extent of this conservation in insects has been limited by the lack of known pro-apoptotic genes in non-drosophilids. Recently, we described the pro-apoptotic genes, Asrpr and Ashid, from the tephritid, Anastrepha suspensa, that now allow us to explore the conservation of pro-apoptotic gene regulation between a tephritid and drosophilids. In this study, we determined the developmental profiles of Asrpr and Ashid transcripts during embryogenesis and in embryos exposed to γ-irradiation. Transcript levels of both genes determined by qRT-PCR were low throughout embryogenesis, with strong Ashid expression occurring during early to mid-embryogenesis and Asrpr expression peaking in late embryogenesis. This correlated to acridine orange stained apoptotic cells first appearing at 17 h and increasing over time. However, when irradiated at 16 h post-oviposition embryos exhibited significant levels of apoptosis consistent with strong induction of Asrpr and Ashid transcript levels by γ-irradiation in young embryos <24 h post-oviposition. Furthermore, embryos irradiated <24 h post-oviposition failed to hatch, those irradiated between 24 and 32 h had increased hatching rates, but between 48 and 72 h irradiation had no effect on egg hatching. This indicates a transition of embryos from an irradiation-sensitive to irradiation-resistance stage between 24 and 48 h. Throughout post-embryonic development, the two pro-apoptotic genes share similar patterns of up-regulated gene expression, which correlate to ecdysone-induced developmental events, especially during metamorphosis. Together these results provide the first direct evidence for a conserved molecular mechanism of the programmed cell death pathway in insects. PMID:25433919

  12. The Catalytic Subunit of Protein Phosphatase 1 Gamma Regulates Thrombin-Induced Murine Platelet αIIbβ3 Function

    PubMed Central

    Gushiken, Francisca C.; Hyojeong, Han; Pradhan, Subhashree; Langlois, Kimberly W.; Alrehani, Nawaf; Cruz, Miguel A.; Rumbaut, Rolando E.; Vijayan, K. Vinod

    2009-01-01

    Background Hemostasis and thrombosis are regulated by agonist-induced activation of platelet integrin αIIbβ3. Integrin activation, in turn is mediated by cellular signaling via protein kinases and protein phosphatases. Although the catalytic subunit of protein phosphatase 1 (PP1c) interacts with αIIbβ3, the role of PP1c in platelet reactivity is unclear. Methodology/Principal Findings Using γ isoform of PP1c deficient mice (PP1cγ−/−), we show that the platelets have moderately decreased soluble fibrinogen binding and aggregation to low concentrations of thrombin or protease-activated receptor 4 (PAR4)-activating peptide but not to adenosine diphosphate (ADP), collagen or collagen-related peptide (CRP). Thrombin-stimulated PP1cγ−/− platelets showed decreased αIIbβ3 activation despite comparable levels of αIIbβ3, PAR3, PAR4 expression and normal granule secretion. Functions regulated by outside-in integrin αIIbβ3 signaling like adhesion to immobilized fibrinogen and clot retraction were not altered in PP1cγ−/− platelets. Thrombus formation induced by a light/dye injury in the cremaster muscle venules was significantly delayed in PP1cγ−/− mice. Phosphorylation of glycogen synthase kinase (GSK3)β-serine 9 that promotes platelet function, was reduced in thrombin-stimulated PP1cγ−/− platelets by an AKT independent mechanism. Inhibition of GSK3β partially abolished the difference in fibrinogen binding between thrombin-stimulated wild type and PP1cγ−/− platelets. Conclusions/Significance These studies illustrate a role for PP1cγ in maintaining GSK3β-serine9 phosphorylation downstream of thrombin signaling and promoting thrombus formation via fibrinogen binding and platelet aggregation. PMID:20016849

  13. 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.

  14. 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...

  15. 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. PMID:26773821

  16. 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

  17. A high speed digital data acquisition system for the Indian National Gamma Array at Tata Institute of Fundamental Research

    NASA Astrophysics Data System (ADS)

    Palit, R.; Saha, S.; Sethi, J.; Trivedi, T.; Sharma, S.; Naidu, B. S.; Jadhav, S.; Donthi, R.; Chavan, P. B.; Tan, H.; Hennig, W.

    2012-07-01

    A digital data acquisition system for the Compton suppressed clover detector array has been implemented at the TIFR-BARC accelerator facility for the high resolution gamma ray spectroscopy using the Pixie-16 Digital Gamma Finder modules by XIA LLC. This system has a provision for simultaneous digitization of 96 preamplifier signals of high purity germanium crystals. The energy and timing characteristics of the clover detectors have been investigated in detail. In-beam data has been collected both in singles and in the coincidence mode. The system has been tested with 64 channels with each of the 64 crystals having an event rate up to 5 kHz and 2-fold clover coincidence rate up to 15 kHz. The use of the digital data acquisition system has improved the high counting rate handling capabilities for the clover array. Conventional systems with analog shaping are being replaced by digital system that provides higher throughput, better energy resolution and better stability for the multi-detector Compton suppressed clover array.

  18. 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

  19. The Zinc Transport Systems and Their Regulation in Pathogenic Fungi

    PubMed Central

    2015-01-01

    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. PMID:26539032

  20. Systemic inflammation regulates microglial responses to tissue damage in vivo.

    PubMed

    Gyoneva, Stefka; Davalos, Dimitrios; Biswas, Dipankar; Swanger, Sharon A; Garnier-Amblard, Ethel; Loth, Francis; Akassoglou, Katerina; Traynelis, Stephen F

    2014-08-01

    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 proinflammatory 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

  1. CRISPR-Cas systems for genome editing, regulation and targeting

    PubMed Central

    Sander, Jeffry D.; Joung, J. Keith

    2014-01-01

    Targeted genome editing using engineered nucleases has rapidly transformed from 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 platform for generating RNA-guided nucleases (RGNs), such as Cas9, with customizable specificities. RGN-mediated genome editing is facile, rapid and has enabled the efficient modification of endogenous genes in a wide variety of biomedically important cell types and novel 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 capabilities 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. PMID:24584096

  2. 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)

  3. Network regulation of the Escherichia coli maltose system.

    PubMed

    Schlegel, Anja; Böhm, Alex; Lee, Sung-Jae; Peist, Ralf; Decker, Katja; Boos, Winfried

    2002-05-01

    The genes of the Escherichia coli maltose regulon are controlled by MalT, the specific transcriptional activator which, together with the inducer maltotriose and ATP, is essential for mal gene transcription. Network regulation in this system affects the function of MalT and occurs on two levels. The first concerns the expression of malT. It has long been known that malT is under catabolite repression and thus under the control of the cAMP/CAP complex. We found that, in addition, the global regulator Mlc is a repressor for malT transcription. The repressor activity of Mlc is controlled by the transport status of the glucose-specific enzyme EIICB of the PTS that causes sequestration (and inactivation as a repressor) of Mlc when glucose is transported. The second level of MalT regulation affects its activity. MalT is activated by maltotriose which is not only formed when the cells are growing on any maltodextrin but also, in low amounts, endogenously when the cells grow on non-maltodextrin carbon sources. Thus, cellular metabolism, for instance degradation of galactose or trehalose, can cause mal gene induction. It was found that unphosphorylated internal glucose takes part in endogenous maltodextrin biosynthesis and is therefore a key element in endogenous mal gene expression. In addition to the maltotriose-dependent activation, MalT can interact with three different enzymes that lead to its inactivation as a transcriptional activator. The first is MaIK, the energy transducing ABC subunit of the maltodextrin transport system. Transport controls the interaction of MalK and MalT thus affecting gene expression. The second enzyme is MalY, a pyridoxal phosphate containing enzyme exhibiting cystathionase activity. The crystal structure of MalY was established and mutations in MalY that reduce mal gene repression map in a hydrophobic MalT interaction patch on the surface of the enzyme. The last enzyme is a soluble esterase of as yet unknown function. When overproduced, this

  4. 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

  5. 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.

  6. 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.

  7. 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

    2016-04-01

    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 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. PMID:26879870

  8. 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

  9. 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. PMID:25637673

  10. CdTe and CdZnTe gamma ray detectors for medical and industrial imaging systems

    NASA Astrophysics Data System (ADS)

    Eisen, Y.; Shor, A.; Mardor, I.

    1999-06-01

    CdTe and CdZnTe X-ray and gamma ray detectors in the form of single elements or as segmented monolithic detectors have been shown to be useful in medical and industrial imaging systems. These detectors possess inherently better energy resolution than scintillators coupled to either photodiodes or photomultipliers, and together with application specific integrated circuits they lead to compact imaging systems of enhanced spatial resolution and better contrast resolution. Photopeak efficiencies of these detectors is greatly affected by a relatively low hole mobility-lifetime product. Utilizing these detectors as highly efficient good spectrometers, demands use of techniques to improve their charge collection properties, i.e., correct for variations in charge losses at different depths of interaction in the detector. The corrections for the large hole trapping are made either by applying electronic techniques or by fabricating detector or electrical contacts configurations which differ from the commonly used planar detectors. The following review paper is divided into three parts: The first part discusses detector contact configurations for enhancing photopeak efficiencies and the single carrier collection approach which leads to improved energy resolutions and photopeak efficiencies at high gamma ray energies. The second part demonstrates excellent spectroscopic results using thick CdZnTe segmented monolithic pad and strip detectors showing energy resolutions less than 2% FWHM at 356 keV gamma rays. The third part discusses advantages and disadvantages of CdTe and CdZnTe detectors in imaging systems and describes new developments for medical diagnostics imaging systems.

  11. 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

  12. 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).

  13. Expression of cassini, a murine gamma-satellite sequence conserved in evolution, is regulated in normal and malignant hematopoietic cells

    PubMed Central

    2012-01-01

    Background Acute lymphoblastic leukemia (ALL) cells treated with drugs can become drug-tolerant if co-cultured with protective stromal mouse embryonic fibroblasts (MEFs). Results We performed transcriptional profiling on these stromal fibroblasts to investigate if they were affected by the presence of drug-treated ALL cells. These mitotically inactivated MEFs showed few changes in gene expression, but a family of sequences of which transcription is significantly increased was identified. A sequence related to this family, which we named cassini, was selected for further characterization. We found that cassini was highly upregulated in drug-treated ALL cells. Analysis of RNAs from different normal mouse tissues showed that cassini expression is highest in spleen and thymus, and can be further enhanced in these organs by exposure of mice to bacterial endotoxin. Heat shock, but not other types of stress, significantly induced the transcription of this locus in ALL cells. Transient overexpression of cassini in human 293 embryonic kidney cells did not increase the cytotoxic or cytostatic effects of chemotherapeutic drugs but provided some protection. Database searches revealed that sequences highly homologous to cassini are present in rodents, apicomplexans, flatworms and primates, indicating that they are conserved in evolution. Moreover, CASSINI RNA was induced in human ALL cells treated with vincristine. Surprisingly, cassini belongs to the previously reported murine family of γ-satellite/major satellite DNA sequences, which were not known to be present in other species. Conclusions Our results show that the transcription of at least one member of these sequences is regulated, suggesting that this has a function in normal and transformed immune cells. Expression of these sequences may protect cells when they are exposed to specific stress stimuli. PMID:22916712

  14. 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.

  15. Extracellular RNAs: A Secret Arm of Immune System Regulation.

    PubMed

    de Candia, Paola; De Rosa, Veronica; Casiraghi, Maurizio; Matarese, Giuseppe

    2016-04-01

    The immune system has evolved to protect multicellular organisms from the attack of a variety of pathogens. To exert this function efficiently, the system has developed the capacity to coordinate the function of different cell types and the ability to down-modulate the response when the foreign attack is over. For decades, immunologists believed that these two characteristics were primarily related to cytokine/chemokine-based communication and cell-to-cell direct contact. More recently, it has been shown that immune cells also communicate by transferring regulatory RNAs, microRNAs in particular, from one cell to the other. Several studies have suggested a functional role of extracellular regulatory RNAs in cell-to-cell communication in different cellular contexts. This minireview focuses on the potential role of extracellular RNA transfer in the regulation of adaptive immune response, also contextualizing it in a broader field of what is known of cell-free RNAs in communication among different organisms in the evolutionary scale. PMID:26887954

  16. 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

  17. Divergent regulation of distinct glucocorticoid systems in alcohol dependence.

    PubMed

    Edwards, Scott; Little, Hilary J; Richardson, Heather N; Vendruscolo, Leandro F

    2015-12-01

    Chronic alcohol consumption disrupts glucocorticoid signaling at multiple physiological levels to interact with several disease-related processes associated with neuroendocrine and psychiatric disorders. Excessive alcohol use produces stress-related neuroadaptations at the level of the hypothalamic-pituitary-adrenal (HPA) axis as well as within central (extra-hypothalamic) neural circuitry, including the central amygdala (CeA) and prefrontal cortex (PFC). Altered glucocorticoid receptor (GR) signaling in these areas following excessive alcohol exposure is postulated to mediate the transition from recreational drinking to dependence, as well as the manifestation of a host of cognitive and neurological deficits. Specifically, a bidirectional regulation of stress systems by glucocorticoids leads to the development of an HPA axis tolerance and a concomitant sensitization of cortical and subcortical circuitries. A greater understanding of how hypothalamic and extra-hypothalamic glucocorticoid systems interact to mediate excessive drinking and related pathologies will lead to more effective therapeutic strategies for alcohol use disorder (AUD) and closely related comorbidities. PMID:26003866

  18. Mechanisms regulating caste differentiation in an aphid social system

    PubMed Central

    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 2nd instar. Aphid density was the proximate cue that acts on 1st instar nymphs and embryos to induce soldier differentiation. The final determination of soldier differentiation occurred postnatally, probably at a late 1st instar stage. Direct contact stimuli from live non-soldier aphids mediated the density effect. While coexisting non-soldiers facilitated soldier differentiation in 1st 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. PMID:20539772

  19. 41 CFR 101-1.101 - Federal Property Management Regulations System.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 41 Public Contracts and Property Management 2 2012-07-01 2012-07-01 false Federal Property 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...

  20. 41 CFR 101-1.101 - Federal Property Management Regulations System.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 41 Public Contracts and Property Management 2 2014-07-01 2012-07-01 true Federal Property 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. 41 CFR 101-1.101 - Federal Property Management Regulations System.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 41 Public Contracts and Property Management 2 2013-07-01 2012-07-01 true Federal Property 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...

  2. 41 CFR 101-1.101 - Federal Property Management Regulations System.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 2 2010-07-01 2010-07-01 true Federal Property 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...

  3. 41 CFR 101-1.101 - Federal Property Management Regulations System.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 41 Public Contracts and Property Management 2 2011-07-01 2007-07-01 true Federal Property 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...

  4. 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...

  5. 75 FR 32635 - Defense Acquisition Regulations System; Defense Federal Acquisition Regulation Supplement...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-08

    ... Regulation Supplement; Balance of Payments Program Exemption for Commercial Information Technology... Defense Federal Acquisition Regulation Supplement (DFARS) to implement the exemption from the Balance of... implement in the clauses at 252.225-7044, Balance of Payments Program--Construction Material, and...

  6. 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.

  7. Multigroup Neutron/Gamma-Ray Direct Integration Transport Code System for Two-Dimensional Cylindrical Geometry.

    Energy Science and Technology Software Center (ESTSC)

    1980-10-15

    Version 00 PALLAS-2DCY-FX is a code for direct integration of the transport equation in two-dimensional (r,z) geometry. It solves the energy and angular-dependent Boltzmann transport equation with general anisotropic scattering in cylindrical geometry. Its principal applications are to neutron or gamma-ray transport problems in the forward mode. The code is particularly designed for and suited to the solution of deep penetration radiation transport problems with an external (fixed) source.

  8. Sesamol ameliorates hypotension by modulating cytokines and PPAR-gamma in systemic inflammatory response

    PubMed Central

    Periasamy, Srinivasan; Chu, Pei-Yi; Li, Ya-Hui; Hsu, Dur-Zong; Liu, Ming-Yie

    2015-01-01

    Sepsis is one of the major causes of death reported in intensive care units. Acute kidney injury (AKI) and hypotension are important in the pathogenesis and mortality of systemic inflammatory response (SIR). Sesamol delays mortality in sepsis; however, its effects on AKI and hypotension and the role of peroxisome proliferator-activated receptor-ɣ (PPAR-γ) activation have not been established. We investigated the effect of sesamol on SIR in cecal ligation and puncture (CLP)-induced acute kidney injury and lipopolysaccharide (LPS)-induced hypotension in rats. Sesamol was subcutaneously injected 1 h after SIR. Renal function (BUN and CRE) and proinflammatory mediators interleukin (IL)-1β and IL-6 were increased after CLP. Tumor necrosis factor (TNF)-α, IL-1β, IL-10, and nitrite production were significantly increased 6 h after LPS-induced hypotension (mean arterial pressure was significantly decreased). Sesamol significantly inhibited BUN, CRE, IL-1β, IL-6, and nitrite after CLP-induced acute renal injury. In addition, sesamol increased mean arterial pressure and IL-10, inhibited TNF-α and IL-1β, but did not affect nitrite production in LPS-induced hypotension. Sesamol increased PPAR-γ in the leucocytes and peritoneal macrophages in LPS-induced SIR. We conclude that sesamol regulates leucocyte and macrophage PPAR-γ-associated systemic cytokines expression, thereby ameliorates acute kidney injury and hypotension in rats. PMID:26839527

  9. 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.

  10. 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.

  11. New hazardous waste management system: regulation of wastes or wasted regulation

    SciTech Connect

    Friedland, S.I.

    1981-01-01

    The unsound management of hazardous wastes, as exemplified by Love Canal, causes a variety of environmental and health problems. A review of present state controls reveals the need for the Federal regulation that was incorporated in the Resource Conservation and Recovery Act of 1976 (RCRA). A detailed description of RCRA, however, faults the Environmental Protection Agency (EPA) for deferring regulation and for its failure to meet deadlines, issue standards, or include many dangerous wastes in the prohibited list. EPA's interim standards of essentially voluntary guidelines will offer little protection from contamination until final permit regulations are established. 326 references. (DCK)

  12. GammaModeler TM 3-D gamma-ray imaging technology

    SciTech Connect

    2000-09-01

    The 3-D GammaModeler{trademark} system was used to survey a portion of the facility and provide 3-D visual and radiation representation of contaminated equipment located within the facility. The 3-D GammaModeler{trademark} system software was used to deconvolve extended sources into a series of point sources, locate the positions of these sources in space and calculate the 30 cm. dose rates for each of these sources. Localization of the sources in three dimensions provides information on source locations interior to the visual objects and provides a better estimate of the source intensities. The three dimensional representation of the objects can be made transparent in order to visualize sources located within the objects. Positional knowledge of all the sources can be used to calculate a map of the radiation in the canyon. The use of 3-D visual and gamma ray information supports improved planning decision-making, and aids in communications with regulators and stakeholders.

  13. Analysis of T cells bearing different isotypic forms of the gamma/delta T cell receptor in patients with systemic autoimmune diseases.

    PubMed

    Gerli, R; Agea, E; Bertotto, A; Tognellini, R; Flenghi, L; Spinozzi, F; Velardi, A; Grignani, F

    1991-10-01

    The expression of gamma/delta T cell receptor (TCR) on peripheral blood CD3+ cells circulating in 74 patients with different systemic autoimmune diseases was evaluated. There was a significant increase in the gamma/delta T cell number only in patients with primary Sjögren's syndrome (SS) and in untreated patients with systemic lupus erythematosus (SLE). Unlike healthy subjects, a subgroup of patients with SLE and SS displayed a marked increase in gamma/delta T cells. Immunosuppressive treatment of patients with active SLE led to a normalization of the gamma/delta T cell number. Analysis of surface phenotype showed that when patient gamma/delta T cells were expanded in the peripheral blood, they were not activated but bore "memory" markers. In addition, they preferentially expressed the disulfide linked form of the TCR, except in progressive systemic sclerosis where the nondisulfide form was displayed. Serial determinations in single patients demonstrated that the gamma/delta T cell increase is a persistent immunological feature in these patient subgroups. PMID:1837314

  14. The Mucosal Immune System and Its Regulation by Autophagy

    PubMed Central

    Kabat, Agnieszka M.; Pott, Johanna; Maloy, Kevin J.

    2016-01-01

    The gastrointestinal tract presents a unique challenge to the mucosal immune system, which has to constantly monitor the vast surface for the presence of pathogens, while at the same time maintaining tolerance to beneficial or innocuous antigens. In the intestinal mucosa, specialized innate and adaptive immune components participate in directing appropriate immune responses toward these diverse challenges. Recent studies provide compelling evidence that the process of autophagy influences several aspects of mucosal immune responses. Initially described as a “self-eating” survival pathway that enables nutrient recycling during starvation, autophagy has now been connected to multiple cellular responses, including several aspects of immunity. Initial links between autophagy and host immunity came from the observations that autophagy can target intracellular bacteria for degradation. However, subsequent studies indicated that autophagy plays a much broader role in immune responses, as it can impact antigen processing, thymic selection, lymphocyte homeostasis, and the regulation of immunoglobulin and cytokine secretion. In this review, we provide a comprehensive overview of mucosal immune cells and discuss how autophagy influences many aspects of their physiology and function. We focus on cell type-specific roles of autophagy in the gut, with a particular emphasis on the effects of autophagy on the intestinal T cell compartment. We also provide a perspective on how manipulation of autophagy may potentially be used to treat mucosal inflammatory disorders. PMID:27446072

  15. Bioelectrical regulation of cell cycle and the planarian model system.

    PubMed

    Barghouth, Paul G; Thiruvalluvan, Manish; Oviedo, Néstor J

    2015-10-01

    Cell cycle regulation through the manipulation of endogenous membrane potentials offers tremendous opportunities to control cellular processes during tissue repair and cancer formation. However, the molecular mechanisms by which biophysical signals modulate the cell cycle remain underappreciated and poorly understood. Cells in complex organisms generate and maintain a constant voltage gradient across the plasma membrane known as the transmembrane potential. This potential, generated through the combined efforts of various ion transporters, pumps and channels, is known to drive a wide range of cellular processes such as cellular proliferation, migration and tissue regeneration while its deregulation can lead to tumorigenesis. These cellular regulatory events, coordinated by ionic flow, correspond to a new and exciting field termed molecular bioelectricity. We aim to present a brief discussion on the biophysical machinery involving membrane potential and the mechanisms mediating cell cycle progression and cancer transformation. Furthermore, we present the planarian Schmidtea mediterranea as a tractable model system for understanding principles behind molecular bioelectricity at both the cellular and organismal level. This article is part of a Special Issue entitled: Membrane channels and transporters in cancers. PMID:25749155

  16. System Regulates the Water Contents of Fuel-Cell Streams

    NASA Technical Reports Server (NTRS)

    Vasquez, Arturo; Lazaroff, Scott

    2005-01-01

    An assembly of devices provides for both humidification of the reactant gas streams of a fuel cell and removal of the product water (the water generated by operation of the fuel cell). The assembly includes externally-sensing forward-pressure regulators that supply reactant gases (fuel and oxygen) at variable pressures to ejector reactant pumps. The ejector supply pressures depend on the consumption flows. The ejectors develop differential pressures approximately proportional to the consumption flow rates at constant system pressure and with constant flow restriction between the mixer-outlet and suction ports of the ejectors. For removal of product water from the circulating oxygen stream, the assembly includes a water/gas separator that contains hydrophobic and hydrophilic membranes. The water separator imposes an approximately constant flow restriction, regardless of the quality of the two-phase flow that enters it from the fuel cell. The gas leaving the water separator is nearly 100 percent humid. This gas is returned to the inlet of the fuel cell along with a quantity of dry incoming oxygen, via the oxygen ejector, thereby providing some humidification.

  17. Risk analysis systems for veterinary biologicals: a regulator's tool box.

    PubMed

    Osborne, C G; McElvaine, M D; Ahl, A S; Glosser, J W

    1995-12-01

    Recent advances in biology and technology have significantly improved our ability to produce veterinary biologicals of high purity, efficacy and safety, virtually anywhere in the world. At the same time, increasing trade and comprehensive trade agreements, such as the Uruguay Round of the General Agreement on Tariffs and Trade (GATT: now the World Trade Organisation [WTO]), have put pressure on governments to use scientific principles in the regulation of trade for a wide range of products, including veterinary biologicals. In many cases, however, nations have been reluctant to allow the movement of veterinary biologicals, due to the perceived threat of importing an exotic disease. This paper discusses the history of risk analysis as a decision support tool and provides examples of how this tool may be used in a science-based regulatory system for veterinary biologicals. A wide variety of tools are described, including qualitative, semi-quantitative and quantitative methods, most with a long history of use in engineering and the health and environmental sciences. PMID:8639961

  18. Medical device data systems and FDA regulation. Should medical device data systems require FDA clearance?

    PubMed

    Kelley, Peter

    2010-01-01

    It is widely understood why medical devices need to be regulated by the FDA and other governing bodies. However medical software does not typically require the same level of regulation. Currently the FDA is investigating whether one type of medical software, Medical Device Data Systems (MDDS), should require FDA clearance because of the potential risk they impose when interconnected with medical devices. Hospitals are looking to implement MDDS because the technology allows nursing staff to spend more time on direct patient care and reduces charting errors. This article will explore the FDA's proposal and will review the possible risks and provide a rationale for why MDDS should be regulated by the FDA and why MDDS vendors should have the right level of quality and risk management procedures in place to ensure that they are developing and bringing to market the safest products possible. PMID:20677470

  19. 75 FR 64148 - General Regulation: National Park System

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-19

    ... park areas for public enjoyment. (48 FR 30252, 30272) Among other things, these two NPS regulations... in 73 FR 46217 (2008), this one year time frame allows applicants to be better able to determine the... definition already provided in the preamble to the 1983 final regulation. 48 FR 30272 (June 30, 1983)....

  20. 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

  1. Gamma-Ray Signatures for State-Of-Health Analysis and Monitoring of Widely-Arrayed Radiation Portal Monitor Systems

    SciTech Connect

    Woodring, Mitchell L.; Ely, James H.; Angel, Linda K.; Wright, Ingrid H.; Eslinger, Melany A.; Pospical, A. Jill; Ellis, John E.

    2008-05-15

    Pacific Northwest National Laboratory (PNNL) has deployed a large array of radiation portal monitors for the Department of Homeland Security U.S. Customs and Border Protection. These portal monitors scan incoming vehicles crossing the U.S. border and shipping containers leaving international ports for radioactive material via gamma-ray and neutron detection. Data produced and captured by these systems are recorded for every vehicle related to radiation signature, sensor/system status, and local background, as well as a host of other variables. Within the Radiation Portal Monitor Project at PNNL, state-of-health observation and analysis for the whole RPM system using these data to determine functionality and performance is being developed. (PIET-43741-TM-492)

  2. Performance of Indian National Gamma Array (INGA) Coupled with a Fast Digital Data Acquisition System for Nuclear Structure Studies

    NASA Astrophysics Data System (ADS)

    Palit, R.; Saha, S.; Sethi, J.; Trivedi, T.; Naidu, B. S.; Chavan, P. B.; Donthi, R.; Jadhav, S.

    2013-03-01

    The Indian National Gamma Array (INGA) is set up at TIFR-BARC accelerator facility, as a part of a national collaboration between different research Institutes and Universities. The array is designed for 24 Compton suppressed clover detectors providing around 5% photo-peak efficiency. Recently, a digital data acquisition system with 96 channels (based on Pixie-16 modules developed by XIA LLC) has been implemented for this Compton suppressed clover array. The digital system provides higher throughput, better energy resolution and better stability for the multi-detector Compton suppressed clover array compared to its previous conventional system with analog shaping. A number of nuclear spectroscopic experiments have been carried out using the array. The results from the initial in-beam experiments of the complete set-up will be discussed in this paper.

  3. 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.

  4. 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.

  5. Regulation of power pools and system operators: An international comparison

    SciTech Connect

    Barker, J. Jr.; Tenenbaum, B.; Woolf, F.

    1997-12-31

    This paper focuses on the governance and regulation of power pools outside the United States. The current governance and regulatory arrangements for four power pools, as developed in pool documents and government regulations and laws, are compared and contrasted. The power pools analyzed are located in England and Wales, Australia, Canada, and Scandinavia. Topics discussed in relation to these pools are the effects of structure on governance, how each pool has dealt with a number of basic governance decisions, how the pools monitor the markets, ways in which regulators and other institutions control pools, and self-governance issues.

  6. 77 FR 12761 - Special Regulations; Areas of the National Park System, Saguaro National Park, Bicycle Route

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-02

    ... National Park Service 36 CFR Part 7 RIN 1024-AE08 Special Regulations; Areas of the National Park System...) requires promulgation of a special regulation to designate bicycle routes outside of developed areas and... promulgation of special regulations for the designation of bicycle routes outside of developed areas...

  7. Regulation of gene expression in the nervous system

    SciTech Connect

    Stella, A.M.G. ); de Vellis, J. ); Perez-Polo, J.R. 62230.

    1990-01-01

    This book covers subjects under the following topics: Plenary Lecture; Growth factors; Regulation of gene expression in neurons; Cell adhesion molecules and development; Nervous tissue reaction to injury-aging; and Poster presentation.

  8. [The chalone-antichalone system, and mechanisms regulating granulocytopoiesis].

    PubMed

    Bala, Iu M; Sidel'nikova, V I; Lishits, V M

    1988-01-01

    The normal physiological balance between granylocytic chalone and antichalone is shown to be significantly upset where an inflammatory focus is present, with segmented neutrophils activated by cell breakdown products producing, for the most part, a stimulator of cell proliferation. It is also shown that the production of tissue-specific regulators in inflammation depends on the functional state of the entire mature neutrophil pool. The mechanisms of intrasystemic granulocytopoiesis regulation have been unraveled. PMID:2966620

  9. 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.

  10. 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.

  11. Development of the multi-purpose gamma-ray detection system consisting of a double-sided silicon strip detector and a 25-segmented germanium detector

    NASA Astrophysics Data System (ADS)

    Lee, J. H.; Kim, N. Y.; Lee, C. S.; Jang, Z. H.

    2005-07-01

    We developed a position-sensitive gamma-ray detection system consisting of a double-sided silicon strip detector (DSSD) and a 25-segmented germanium detector (25-SEGD). Two major applications of the system are gamma-ray imaging (Compton camera) and linear polarization measurement for gamma rays emitted from oriented nuclei. Customized electronics were developed in order to handle multi-channel signals of both the DSSD and the 25-SEGD. Images for a 133Ba-based compound source in a square shape with areal dimensions of 1.5 × 1.5 mm2 are presented. Comparison between experimental images and a Monte Carlo simulation yielded the overall imaging resolution within 1 cm for the present system.

  12. 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…

  13. The Predator becomes the Prey: Regulating the Ubiquitin System by Ubiquitylation and Degradation

    PubMed Central

    Weissman, Allan M.; Shabek, Nitzan; Ciechanover, Aaron

    2012-01-01

    Ubiquitylation (also known as ubiquitination) regulates essentially all intracellular processes in eukaryotes through highly specific, and often tightly spatially and temporally regulated, modification of numerous cellular proteins. Although most often associated with proteasomal degradation, ubiquitylation frequently serves non-proteolytic functions. In light of its central roles in cellular regulation, it has not been surprising to find that many of the components of the ubiquitin system itself are regulated by ubiquitylation. This observation has broad implications for pathophysiology. PMID:21860393

  14. 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)

  15. 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.

  16. Ultra-low gamma-ray measurement system for neutrinoless double beta decay.

    PubMed

    Kang, W G; Choi, J H; Jeon, E J; Lee, J I; Kim, H J; Kim, S K; Kim, Y D; Lee, J H; Ma, K J; Myung, S S; So, J H

    2013-11-01

    An experiment for the detection of 0νβ(+)/EC and 0νEC/EC in 92Mo nuclei has been carried out with a scintillating crystal, CaMoO4, in coincidence with the HPGe detector. We study the background events inside the event selection window for 0ν β(+)/EC decays of CaMoO4 detector. For 51.2 days of data taking period, we didn't observe any event in the neutrinoless EC/EC decay event window. The (92)Mo 0νβ(+)/EC decay half-life limit was set to 0.61×10(20) years with a 90% confidence by method of Feldman and Cousins. This ultra-low gamma ray measurement utilizing coincidence technique can be used for the resonant EC/EC decay process of some nuclei which is potentially important for neutrinoless double beta decay process. PMID:23726518

  17. Development of an optimized Compton suppression gamma-ray spectrometric system using Monte Carlo simulation.

    PubMed

    Choi, Y; Lee, K B; Kim, K J; Han, J; Yi, E S

    2016-03-01

    We have chosen to establish the Compton Suppression Spectrometer (CSS) for low activity environmental samples with a high purity germanium (HPGe) primary detector and a removable plug-in detector (NaI(Tl)) surrounded with a cylindrical annulus guard detector (NaI(Tl)). Monte Carlo simulation with PENELOPE (PENetration and Energy LOss of Positrons and Electrons) is used to determine the optimal geometry of the CSS. To verify a correlation between experiment and simulation, the energy distribution of (137)Cs and (60)Co point sources is measured and simulated for each condition. The CSS parameters are studied to determine optimal detector geometry and Compton Suppression Factor (CSF). The timing resolution of the CSS was found to be 44ns (FWHM), which is an outstanding result in the semiconductor-based gamma-ray spectrometry. All measured values of CSF agree within 5% with the values obtained from the simulation. The optimum geometry and CSF values are discussed. PMID:26778448

  18. Characterization Studies of Radioactive Waste Drums Using High Resolution Gamma Spectrometric Systems

    SciTech Connect

    Toma, M.; Cristache, C.; Done, L.; Dragolici, F.; Sima, O.

    2010-01-21

    The problem of radioactive waste has become a critical issue in the country and worldwide. The radioactive waste containers, containing different radioactive materials, have to be characterized before their final disposal. Destructive methods, although being the most precise, are also the most expensive and not the easiest ones from the radioprotection point of view. In this situation, high resolution gamma spectrometry proved to be a reliable method for the non destructive assay method. However, the non-homogenous composition of the radioactive waste inside the drum makes the quantitative characterization of the radioactive waste drum a difficult task. Experimental studies and computed results, combined with Monte Carlo simulations using GESPECOR, are presented in this paper as a possibility to achieve this task.

  19. In situ gamma spectrometry of piping in a CANDU heat transport system -- Application during decontamination

    SciTech Connect

    Husain, A.; Breckenridge, C.E.; Storey, D.

    1995-02-01

    An in situ pipe gamma spectrometry technique was applied to determine the activity within piping during various stages of CANDU reactor decontaminations. Measurements were performed in general radiation fields up to {approximately}500 mR/h and required both the detector and the pipe being scanned to be appropriately shielded from other neighboring piping. Measured counts were interpreted using a pipe source efficiency calibration with due regard to its distance dependence. Cobalt-60 was the dominant radionuclide on the piping before the decontamination. Deposition of {sup 124}Sb occurred on out-core piping surfaces during the decontamination. The spectrometry measurements were supplemented with contact radiation field measurements, which were performed using survey detectors housed within specially designed pipe shields. Radiation fields estimated from measured radionuclide activities were compared with the measured radiation fields. On average, the ratio of measured to estimated fields was {approximately}72%. Reasons for this discrepancy are discussed.

  20. Automated 1.3-m near-infrared telescope system triggered by gamma-ray burst

    NASA Astrophysics Data System (ADS)

    Murakami, Toshio; Yonetoku, Daisuke; Kinoshita, Shin; Masui, Hiroki; Okuno, Shinya; Yoshinari, Satoru; Kidamura, Takashi; Tanabe, Sachiko; Yokota, Satoshi; Kobayashi, Yukiyasu; Nakagawa, Takao; Nakamura, Takashi

    2006-06-01

    The design for robotic telescopes to observe Gamma-Ray Burst (GRB) afterglows and the results of observations are presented. Quickly fading bright GRB flashes and afterglows provide a good tool to study an extremely early universe. However, most large ground-based telescopes cannot afford to follow-up the afterglows and flashes quickly within a few hours since a GRB explosion. We re-modeled the existing middle-class 1.3 m ø telescope of the near infrared band at ISAS in Japan to match for the above requirement. We also set a small telescope of 30 cm diameter with a conventional CCD. These telescopes can monitor afterglows quickly within a few minutes in J, H, Ks and R band with a grism spectrometer.

  1. High Precision Grids for Neutron, Hard X-Ray, and Gamma-Ray Imaging Systems

    NASA Technical Reports Server (NTRS)

    Campbell, Jonathan W. (Inventor)

    2002-01-01

    Fourier telescopes permit observations over a very broad band of energy. They generally include synthetic spatial filtering structures, known as multilayer grids or grid pairs consisting of alternate layers of absorbing and transparent materials depending on whether neutrons or photons are being imaged. For hard x-rays and gamma rays high (absorbing) and low (transparent) atomic number elements, termed high-Z and low-Z materials may be used. Fabrication of these multilayer grid structures is not without its difficulties. Herein the alternate layers of the higher material and the lower material are inserted in a polyhedron, transparent to photons of interest, through an open face of the polyhedron. The inserted layers are then uniformly compressed to form a multilayer grid.

  2. Performance evaluation of a small CZT pixelated semiconductor gamma camera system with a newly designed stack-up parallel-hole collimator

    NASA Astrophysics Data System (ADS)

    Lee, Youngjin; Kim, Hee-Joung

    2015-09-01

    Gamma ray imaging techniques that use a cadmium zinc telluride (CZT) or cadmium telluride (CdTe) pixelated semiconductor detectors have rapidly gained popularity as a key tool for nuclear medicine research. By using a pinhole collimator with a pixelated semiconductor gamma camera system, better spatial resolution can be achieved. However, this improvement in spatial resolution is accomplished with a decrease in the sensitivity due to the small collimator hole diameter. Furthermore, few studies have been conducted for novel parallel-hole collimator geometric designs with pixelated semiconductor gamma camera systems. A gamma camera system which combines a CZT pixelated semiconductor detector with a newly designed stack-up parallel-hole collimator was developed and evaluated. The eValuator-2500 CZT pixelated semiconductor detector (eV product, Saxonburg, PA) was selected for the gamma camera system. This detector consisted of a row of four CZT crystals of 12.8 mm in length with 3 mm in thickness. The proposed parallel-hole collimator consists of two layers. The upper layer results in a fourfold increase in hole size compared to a matched square hole parallel-hole collimator with an equal hole and pixel size, while the lower layer also consisted of fourfold holes size and pretty acts as a matched square hole parallel-hole collimator. The overlap ratios of these collimators were 1:1, 1:2, 2:1, 1:5, and 5:1. These collimators were mounted on the eValuator-2500 CZT pixelated semiconductor detector. The basic performance of the imaging system was measured for a 57Co gamma source (122 keV). The measured averages of sensitivity and spatial resolution varied depending on the overlap ratios of the proposed parallel-hole collimator and source-to-collimator distances. One advantage of our system is the use of stacked collimators that can select the best combination of system sensitivity and spatial resolution. With low counts, we can select a high sensitivity collimator with a 1

  3. Phosphorylation of 20S proteasome alpha subunit C8 (alpha7) stabilizes the 26S proteasome and plays a role in the regulation of proteasome complexes by gamma-interferon.

    PubMed Central

    Bose, Suchira; Stratford, Fiona L L; Broadfoot, Kerry I; Mason, Grant G F; Rivett, A Jennifer

    2004-01-01

    In animal cells there are several regulatory complexes which interact with 20S proteasomes and give rise to functionally distinct proteasome complexes. gamma-Interferon upregulates three immuno beta catalytic subunits of the 20S proteasome and the PA28 regulator, and decreases the level of 26S proteasomes. It also decreases the level of phosphorylation of two proteasome alpha subunits, C8 (alpha7) and C9 (alpha3). In the present study we have investigated the role of phosphorylation of C8 by protein kinase CK2 in the formation and stability of 26S proteasomes. An epitope-tagged C8 subunit expressed in mammalian cells was efficiently incorporated into both 20S proteasomes and 26S proteasomes. Investigation of mutants of C8 at the two known CK2 phosphorylation sites demonstrated that these are the two phosphorylation sites of C8 in animal cells. Although phosphorylation of C8 was not absolutely essential for the formation of 26S proteasomes, it did have a substantial effect on their stability. Also, when cells were treated with gamma-interferon, there was a marked decrease in phosphorylation of C8, a decrease in the level of 26S proteasomes, and an increase in immunoproteasomes and PA28 complexes. These results suggest that the down-regulation of 26S proteasomes after gamma-interferon treatment results from the destabilization that occurs after dephosphorylation of the C8 subunit. PMID:14583091

  4. 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.

  5. Methods, systems and apparatus for synchronous current regulation of a five-phase machine

    DOEpatents

    Gallegos-Lopez, Gabriel; Perisic, Milun

    2012-10-09

    Methods, systems and apparatus are provided for controlling operation of and regulating current provided to a five-phase machine when one or more phases has experienced a fault or has failed. In one implementation, the disclosed embodiments can be used to synchronously regulate current in a vector controlled motor drive system that includes a five-phase AC machine, a five-phase inverter module coupled to the five-phase AC machine, and a synchronous current regulator.

  6. System and method for regulating EGR cooling using a rankine cycle

    DOEpatents

    Ernst, Timothy C.; Morris, Dave

    2015-12-22

    This disclosure relates to a waste heat recovery (WHR) system and method for regulating exhaust gas recirculation (EGR) cooling, and more particularly, to a Rankine cycle WHR system and method, including a recuperator bypass arrangement to regulate EGR exhaust gas cooling for engine efficiency improvement and thermal management. This disclosure describes other unique bypass arrangements for increased flexibility in the ability to regulate EGR exhaust gas cooling.

  7. Self-regulating control of parasitic loads in a fuel cell power system

    NASA Technical Reports Server (NTRS)

    Vasquez, Arturo (Inventor)

    2011-01-01

    A fuel cell power system comprises an internal or self-regulating control of a system or device requiring a parasitic load. The internal or self-regulating control utilizes certain components and an interconnection scheme to produce a desirable, variable voltage potential (i.e., power) to a system or device requiring parasitic load in response to varying operating conditions or requirements of an external load that is connected to a primary fuel cell stack of the system. Other embodiments comprise a method of designing such a self-regulated control scheme and a method of operating such a fuel cell power system.

  8. 75 FR 75549 - Defense Federal Acquisition Regulation Supplement; Business Systems-Definition and Administration...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-03

    ...-D038) in the Federal Register on January 15, 2010 (75 FR 2457). The public comment period closed March... Acquisition Regulation Supplement; Business Systems-- Definition and Administration (DFARS Case 2009-D038... RIN 0750-AG58 Defense Federal Acquisition Regulation Supplement; Business Systems--Definition...

  9. The NAD/NARB System: Advertising Self-Regulation at Work.

    ERIC Educational Resources Information Center

    Hays, Robert

    Self-regulation, as defined by the National Advertising Division/National Advertising Review Board (NAD/NARB), is a process whereby the advertising industry regulates itself and turns to the federal government only if the system fails. The NAD/NARB system involves a two-step process: complaints are initially handled by the NAD and then are either…

  10. 41 CFR 109-1.101 - Federal Property Management Regulations System.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 41 Public Contracts and Property Management 3 2011-01-01 2011-01-01 false Federal Property Management Regulations System. 109-1.101 Section 109-1.101 Public Contracts and Property Management Federal Property Management Regulations System (Continued) DEPARTMENT OF ENERGY PROPERTY MANAGEMENT...

  11. 41 CFR 109-1.101 - Federal Property Management Regulations System.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 41 Public Contracts and Property Management 3 2014-01-01 2014-01-01 false Federal Property Management Regulations System. 109-1.101 Section 109-1.101 Public Contracts and Property Management Federal Property Management Regulations System (Continued) DEPARTMENT OF ENERGY PROPERTY MANAGEMENT...

  12. 41 CFR 109-1.101 - Federal Property Management Regulations System.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 41 Public Contracts and Property Management 3 2013-07-01 2013-07-01 false Federal Property Management Regulations System. 109-1.101 Section 109-1.101 Public Contracts and Property Management Federal Property Management Regulations System (Continued) DEPARTMENT OF ENERGY PROPERTY MANAGEMENT...

  13. 41 CFR 109-1.101 - Federal Property Management Regulations System.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 41 Public Contracts and Property Management 3 2012-01-01 2012-01-01 false Federal Property Management Regulations System. 109-1.101 Section 109-1.101 Public Contracts and Property Management Federal Property Management Regulations System (Continued) DEPARTMENT OF ENERGY PROPERTY MANAGEMENT...

  14. 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

  15. A Review of Emotion Regulation in Intelligent Tutoring Systems

    ERIC Educational Resources Information Center

    Malekzadeh, Mehdi; Mustafa, Mumtaz Begum; Lahsasna, Adel

    2015-01-01

    Having improved emotional (affective) state may have several benefits on learners, such as promoting higher cognitive flexibility and opens the learner to discovery of new ideas and possibilities. On other side, negative emotional states like boredom and frustration have been linked with less use of self-regulation and cognitive strategies for…

  16. Optimizing Assurance: The Risk Regulation System in Relationships

    ERIC Educational Resources Information Center

    Murray, Sandra L.; Holmes, John G.; Collins, Nancy L.

    2006-01-01

    A model of risk regulation is proposed to explain how people balance the goal of seeking closeness to a romantic partner against the opposing goal of minimizing the likelihood and pain of rejection. The central premise is that confidence in a partner's positive regard and caring allows people to risk seeking dependence and connectedness. The risk…

  17. 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.

  18. Leakage of radioactive particle systems from a synovial joint studied with a gamma camera. Its application to radiation synovectomy

    SciTech Connect

    Noble, J.; Jones, A.G.; Davies, M.A.; Sledge, C.B.; Kramer, R.I.; Livni, E.

    1983-03-01

    We have determined rates of leakage of radioactivity from a rabbit synovial pouch in vivo for a number of particle systems of varying sizes and differing resistance to degradation. The estimates were made using a gamma scintillation camera and without killing the test animals. The lowest leakage at twenty-four hours was seen with inert carbonized microspheres and the highest rates were seen with surface-labeled particles of biodegradable denatured human serum albumin and with erythrocytes. The carbonized microspheres had no adverse long-term effects on the health of the animals' articular cartilage. Clinical Relevance: Results obtained with inert particles indicate that reducing the biodegradability of the particle or increasing its diameter, or both, reduces radioactivity losses from the knee joint. Large (twenty-five-micrometer-diameter) microspheres of human serum albumin incorporating the radioactivity and carbonized microspheres are suggested as potential carriers of isotopes for human radiation synovectomy.

  19. A murid gamma-herpesviruses exploits normal splenic immune communication routes for systemic spread.

    PubMed

    Frederico, Bruno; Chao, Brittany; May, Janet S; Belz, Gabrielle T; Stevenson, Philip G

    2014-04-01

    Gamma-herpesviruses (γHVs) are widespread oncogenic pathogens that chronically infect circulating lymphocytes. How they subvert the immune check-point function of the spleen to promote persistent infection is not clear. We show that Murid Herpesvirus-4 (MuHV-4) enters the spleen by infecting marginal zone (MZ) macrophages, which provided a conduit to MZ B cells. Relocation of MZ B cells to the white pulp allowed virus transfer to follicular dendritic cells. From here the virus reached germinal center B cells to establish persistent infection. Mice lacking MZ B cells, or treated with a sphingosine-1-phosphate receptor agonist to dislocate them, were protected against MuHV-4 colonization. MuHV-4 lacking ORF27, which encodes a glycoprotein necessary for efficient intercellular spread, could infect MZ macrophages but was impaired in long-term infection. Thus, MuHV-4, a γHV, exploits normal immune communication routes to spread by serial lymphoid/myeloid exchange. PMID:24721574

  20. A system for mutation measurement in mammalian cells: application to gamma-irradiation.

    PubMed

    Puck, T T; Johnson, R; Rasumussen, S

    1997-02-18

    Monitoring of mutagenesis by environmental agents for the purpose of preventing genetic disease including cancer must include quantitation of cell killing, sensitive measurement of mutation production by appropriate doses of each agent, and assessment of mutation repair effects in mammalian cells. A four-step procedure, in the presence and absence of a repair suppressor, is proposed: (i) determination of the survival curve; (ii) measurement of the mitotic index in cells collected after treatment with colcemid; (iii) construction of a mutagenesis yield curve in the presence and absence of a repair suppressor, like caffeine; and (iv) assessment of the effect of test agents on the repair of mutations produced by other mutagens. The procedure is quantitative, reproducible, and reasonably rapid. It involves measurement of mutations causing visible chromosomal aberrations. Numerical parameters are proposed defining quantitatively mutation, cell killing, and mutation repair capacity. The procedure is applied to gamma-irradiation and can detect the effects of doses as low as 2-5 cGy. Theoretical analysis of the underlying processes is presented, using the concept of D(0)E, the effective dose of mutagen after repair mechanisms and neutralizing agents have acted. Microscopically visible chromosome aberrations are due to mutations that distort the process of mitotic chromosome condensation, with or without actual chromosome breakage. PMID:9037033

  1. Effects of traditionally used anxiolytic botanicals on enzymes of the gamma-aminobutyric acid (GABA) system.

    PubMed

    Awad, R; Levac, D; Cybulska, P; Merali, Z; Trudeau, V L; Arnason, J T

    2007-09-01

    In Canada, the use of botanical natural health products (NHPs) for anxiety disorders is on the rise, and a critical evaluation of their safety and efficacy is required. The purpose of this study was to determine whether commercially available botanicals directly affect the primary brain enzymes responsible for gamma-aminobutyric acid (GABA) metabolism. Anxiolytic plants may interact with either glutamic acid decarboxylase (GAD) or GABA transaminase (GABA-T) and ultimately influence brain GABA levels and neurotransmission. Two in vitro rat brain homogenate assays were developed to determine the inhibitory concentrations (IC50) of aqueous and ethanolic plant extracts. Approximately 70% of all extracts that were tested showed little or no inhibitory effect (IC50 values greater than 1 mg/mL) and are therefore unlikely to affect GABA metabolism as tested. The aqueous extract of Melissa officinalis (lemon balm) exhibited the greatest inhibition of GABA-T activity (IC50 = 0.35 mg/mL). Extracts from Centella asiatica (gotu kola) and Valeriana officinalis (valerian) stimulated GAD activity by over 40% at a dose of 1 mg/mL. On the other hand, both Matricaria recutita (German chamomile) and Humulus lupulus (hops) showed significant inhibition of GAD activity (0.11-0.65 mg/mL). Several of these species may therefore warrant further pharmacological investigation. The relation between enzyme activity and possible in vivo mode of action is discussed. PMID:18066140

  2. Flow and pressure regulation in the cardiovascular system. [engineering systems model

    NASA Technical Reports Server (NTRS)

    Iberall, A.

    1974-01-01

    Principles and descriptive fragments which may contribute to a model of the regulating chains in the cardiovascular system are presented. Attention is given to the strain sensitivity of blood vessels, the law of the autonomy of the heart beat oscillator, the law of the encapsulation of body fluids, the law of the conservation of protein, the law of minimum 'arterial' pressure, the design of the 'mammalian' kidney, questions of homeokinetic organization, and the development of self-regulatory chains. Details concerning the development program for the heart muscle are considered along with the speed of response of the breathing rate and the significance of the pulmonary vascular pressure-flow characteristics.

  3. Leptin regulates bone formation via the sympathetic nervous system

    NASA Technical Reports Server (NTRS)

    Takeda, Shu; Elefteriou, Florent; Levasseur, Regis; Liu, Xiuyun; Zhao, Liping; Parker, Keith L.; Armstrong, Dawna; Ducy, Patricia; Karsenty, Gerard

    2002-01-01

    We previously showed that leptin inhibits bone formation by an undefined mechanism. Here, we show that hypothalamic leptin-dependent antiosteogenic and anorexigenic networks differ, and that the peripheral mediators of leptin antiosteogenic function appear to be neuronal. Neuropeptides mediating leptin anorexigenic function do not affect bone formation. Leptin deficiency results in low sympathetic tone, and genetic or pharmacological ablation of adrenergic signaling leads to a leptin-resistant high bone mass. beta-adrenergic receptors on osteoblasts regulate their proliferation, and a beta-adrenergic agonist decreases bone mass in leptin-deficient and wild-type mice while a beta-adrenergic antagonist increases bone mass in wild-type and ovariectomized mice. None of these manipulations affects body weight. This study demonstrates a leptin-dependent neuronal regulation of bone formation with potential therapeutic implications for osteoporosis.

  4. 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

  5. Regulation of Sugar Transport Systems in Fusarium oxysporum var. lini

    PubMed Central

    Brandão, Rogélio L.; Loureiro-Dias, Maria C.

    1990-01-01

    Fusarium oxysporum var. lini (ATCC 10960) formed a facilitated diffusion system for glucose (Ks, about 10 mM) when grown under repressed conditions. Under conditions of derepression, the same system was present together with a high-affinity (Ks, about 40 μM) active system. The maximum velocity of the latter was about 5% of that of the facilitated diffusion system. The high-affinity system was under the control of glucose repression and glucose inactivation. When lactose was the only carbon source in the medium, a facilitated diffusion system for lactose was found (Ks, about 30 mM). PMID:16348256

  6. Central Nervous System Regulation of Brown Adipose Tissue

    PubMed Central

    Morrison, Shaun F.; Madden, Christopher J.

    2015-01-01

    Thermogenesis, the production of heat energy, in brown adipose tissue is a significant component of the homeostatic repertoire to maintain body temperature during the challenge of low environmental temperature in many species from mouse to man and plays a key role in elevating body temperature during the febrile response to infection. The sympathetic neural outflow determining brown adipose tissue (BAT) thermogenesis is regulated by neural networks in the CNS which increase BAT sympathetic nerve activity in response to cutaneous and deep body thermoreceptor signals. Many behavioral states, including wakefulness, immunologic responses, and stress, are characterized by elevations in core body temperature to which central command-driven BAT activation makes a significant contribution. Since energy consumption during BAT thermogenesis involves oxidation of lipid and glucose fuel molecules, the CNS network driving cold-defensive and behavioral state-related BAT activation is strongly influenced by signals reflecting the short and long-term availability of the fuel molecules essential for BAT metabolism and, in turn, the regulation of BAT thermogenesis in response to metabolic signals can contribute to energy balance, regulation of body adipose stores and glucose utilization. This review summarizes our understanding of the functional organization and neurochemical influences within the CNS networks that modulate the level of BAT sympathetic nerve activity to produce the thermoregulatory and metabolic alterations in BAT thermogenesis and BAT energy expenditure that contribute to overall energy homeostasis and the autonomic support of behavior. PMID:25428857

  7. 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.

  8. 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.

  9. Nitrogen-source regulation of yeast gamma-glutamyl transpeptidase synthesis involves the regulatory network including the GATA zinc-finger factors Gln3, Nil1/Gat1 and Gzf3.

    PubMed Central

    Springael, Jean-Yves; Penninckx, Michel J

    2003-01-01

    In Saccharomyces cerevisiae, the CIS2 gene encodes gamma-glutamyl transpeptidase (gamma-GT; EC 2.3.2.2), the main GSH-degrading enzyme. The promoter region of CIS2 contains one stress-response element (CCCCT) and eight GAT(T/A)A core sequences, probably involved in nitrogen-regulated transcription. We show in the present study that expression of CIS2 is indeed regulated according to the nature of the nitrogen source. Expression is highest in cells growing on a poor nitrogen source such as urea. Under these conditions, the GATA zinc-finger transcription factors Nil1 and Gln3 are both required for CIS2 expression, Nil1 appearing as the more important factor. We further show that Gzf3, another GATA zinc-finger protein, acts as a negative regulator in nitrogen-source control of CIS2 expression. During growth on a preferred nitrogen source like NH(4)(+), CIS2 expression is repressed through a mechanism involving (at least) the Gln3-binding protein Ure2/GdhCR. Induction of CIS2 expression during nitrogen starvation is dependent on Gln3 and Nil1. Furthermore, rapamycin causes similar CIS2 activation, indicating that the target of rapamycin signalling pathway controls CIS2 expression via Gln3 and Nil1 in nitrogen-starved cells. Finally, our results show that CIS2 expression is induced mainly by nitrogen starvation but apparently not by other types of stress. PMID:12529169

  10. Vertical organization of gamma-aminobutyric acid-accumulating intrinsic neuronal systems in monkey cerebral cortex

    SciTech Connect

    DeFelipe, J.; Jones, E.G.

    1985-12-01

    Light and electron microscopic methods were used to examine the neurons in the monkey cerebral cortex labeled autoradiographically following the uptake and transport of (/sup 3/H)-gamma-aminobutyric acid (GABA). Nonpyramidal cell somata in the sensory-motor areas and primary visual area (area 17) were labeled close to the injection site and at distances of 1 to 1.5 mm beyond the injection site, indicating labeling by retrograde axoplasmic transport. This labeling occurred preferentially in the vertical dimension of the cortex. Prior injections of colchicine, an inhibitor of axoplasmic transport, abolished all labeling of somata except those within the injection site. In each area, injections of superficial layers (I to III) produced labeling of clusters of cell somata in layer V, and injections of the deep layers (V and VI) produced labeling of clusters of cell somata in layers II and III. In area 17, injections of the superficial layers produced dense retrograde cell labeling in three bands: in layers IVC, VA, and VI. Vertically oriented chains of silver grains linked the injection sites with the resulting labeled cell clusters. In all areas, the labeling of cells in the horizontal dimension was insignificant. Electron microscopic examination of labeled neurons confirms that the neurons labeled at a distance from an injection site are nonpyramidal neurons, many with somata so small that they would be mistaken for neuroglial cells light microscopically. They receive few axosomatic synapses, most of which have symmetric membrane thickenings. The vertical chains of silver grains overlie neuronal processes identifiable as both dendrites and myelinated axons, but unmyelinated axons may also be included. The clusters of (/sup 3/H)GABA-labeled cells are joined to one another and to adjacent unlabeled cells by junctional complexes, including puncta adherentia and multi-lamellar cisternal complexes.

  11. Shuttle-flight test of an advanced gamma-ray detection system. Final report, 1 July 1983-31 July 1987

    SciTech Connect

    Rester, A.C.

    1988-06-30

    The Gamma-Ray Advanced Detector (GRAD) is a gamma-ray detector system consisting of a large-volume, n-type germanium detector with active shielding of bismuth germanate and plastic scintillators. It was diverted from the AFP-675 program to a balloon flight over Antarctica following the Challenger Disaster and the discovery the following year of the supernova 1987A. The present report outlines activities leading to and following the decision to go to Antarctica and summarizes the basic technological results from the project.

  12. 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.

  13. The spleen in local and systemic regulation of immunity

    PubMed Central

    Bronte, Vincenzo; Pittet, Mikael J

    2013-01-01

    Summary The spleen is the main filter for blood-borne pathogens and antigens, as well as a key organ for iron metabolism and erythrocyte homeostasis. However, immune and hematopoietic functions have been recently unveiled for the mouse spleen, suggesting additional roles for this secondary lymphoid organ. Here we discuss the integration of the spleen in the regulation of immune responses locally and in the whole body and present the relevance of findings for our understanding of inflammatory and degenerative diseases and their treatments. We also consider whether equivalent activities in humans are known, as well as initial therapeutic attempts to target the spleen for modulating innate and adaptive immunity. PMID:24238338

  14. Power fluctuations smoothing and regulations in wind turbine generator systems

    NASA Astrophysics Data System (ADS)

    Babazadehrokni, Hamed

    Wind is one of the most popular renewable energy sources and it has the potential to become the biggest energy source in future. Since the wind does not always blow constantly, the output wind power is not constant which may make some problem for the power grid. According to the grid code which is set by independent system operator, ISO, wind turbine generator systems need to follow some standards such as the predetermined acceptable power fluctuations. In order to smooth the output powers, the energy storage system and some power electronics modules are employed. The utilized power electronics modules in the wind turbine system can pursue many different goals, such as maintaining the voltage stability, frequency stability, providing the available and predetermined output active and reactive power. On the other side, the energy storage system can help achieving some of these goals but its main job is to store the extra energy when not needed and release the stored energy when needed. The energy storage system can be designed in different sizes, material and also combination of different energy storage systems (hybrid designs). Combination of power electronics devises and also energy storage system helps the wind turbine systems to smooth the output power according to the provided standards. In addition prediction of wind speed may improve the performance of wind turbine generator systems. In this research study all these three topics are studied and the obtained results are written in 10 papers which 7 of them are published and three of them are under process.

  15. General Purpose Monte Carlo Multigroup Neutron and Gamma-Ray Transport Code System with Array Geometry Capability. We recommend C00474/ALLCP/02 MORSE-CGA.

    Energy Science and Technology Software Center (ESTSC)

    1991-05-01

    Version 00 MORSE-CGA was developed to add the capability of modelling rectangular lattices for nuclear reactor cores or for multipartitioned structures. It thus enhances the capability of the MORSE code system. The MORSE code is a multipurpose neutron and gamma-ray transport Monte Carlo code. It has been designed as a tool for solving most shielding problems. Through the use of multigroup cross sections, the solution of neutron, gamma-ray, or coupled neutron-gamma-ray problems may be obtainedmore » in either the forward or adjoint mode. Time dependence for both shielding and criticality problems is provided. General three-dimensional geometry may be used with an albedo option available at any material surface. Isotropic or anisotropic scattering up to a P16 expansion of the angular distribution is allowed.« less

  16. 75 FR 41097 - Homeland Security Acquisition Regulation; Lead System Integrators [HSAR Case 2009-003

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-15

    ... Acquisition Regulation; Lead System Integrators AGENCY: Office of the Chief Procurement Officer, DHS. ACTION... lead system integrators in the acquisition of DHS major systems if they have direct financial interests... 6 U.S.C. 396; hereinafter ``Section 396''), limits firms that can serve as lead system...

  17. Evolutions of Stellar-mass Black Hole Hyperaccretion Systems in the Center of Gamma-Ray Bursts

    NASA Astrophysics Data System (ADS)

    Song, Cui-Ying; Liu, Tong; Gu, Wei-Min; Hou, Shu-Jin; Tian, Jian-Xiang; Lu, Ju-Fu

    2015-12-01

    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.

  18. Development of a Monte Carlo model for treatment planning dose verification of the Leksell Gamma Knife Perfexion radiosurgery system.

    PubMed

    Yuan, Jiankui; Lo, Simon S; Zheng, Yiran; Sohn, Jason W; Sloan, Andrew E; Ellis, Rodney; Machtay, Mitchell; Wessels, Barry

    2016-01-01

    Detailed Monte Carlo (MC) modeling of the Leksell Gamma Knife (GK) Perfexion (PFX) collimator system is the only accurate ab initio approach appearing in the literature. As a different approach, in this work, we present a MC model based on film measurement. By adjusting the model parameters and fine-tuning the derived fluence map for each individual source to match the manufacturer's ring output factors, we created a reasonable virtual source model for MC simulations to verify treatment planning dose for the GK PFX radiosurgery system. The MC simulation model was commissioned by simple single shots. Dose profiles and both ring and collimator output factors were compared with the treatment planning system (TPS). Good agreement was achieved for dose profiles especially for the region of plateau (< 2%), while larger difference (< 5%) came from the penumbra region. The maximum difference of the calculated output factor was within 0.7%. The model was further validated by a clinical test case. Good agreement was obtained. The DVHs for brainstem and the skull were almost identical and, for the target, the volume covered by the prescription (12.5 Gy to 50% isodose line) was 95.6% from MC calculation versus 100% from the TPS. PMID:27455497

  19. 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.

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

    SciTech Connect

    Killian, E.W.

    1997-05-01

    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 radio nuclide 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 radionuclides and provide a more consistent methodology for combining data collected from multiple detectors. In spectrometer systems with multiple detectors looking at non homogenous 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.