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https://www.readbyqxmd.com/read/27910655/a-fast-feedback-controlled-magnetic-drive-for-the-asdex-upgrade-fast-ion-loss-detectors
#1
J Ayllon-Guerola, J Gonzalez-Martin, M Garcia-Munoz, J Rivero-Rodriguez, A Herrmann, S Vorbrugg, P Leitenstern, S Zoletnik, J Galdon, J Garcia Lopez, M Rodriguez-Ramos, L Sanchis-Sanchez, A D Dominguez, M Kocan, J P Gunn, D Garcia-Vallejo, J Dominguez
A magnetically driven fast-ion loss detector system for the ASDEX Upgrade tokamak has been designed and will be presented here. The device is feedback controlled to adapt the detector head position to the heat load and physics requirements. Dynamic simulations have been performed taking into account effects such as friction, coil self-induction, and eddy currents. A real time positioning control algorithm to maximize the detector operational window has been developed. This algorithm considers dynamical behavior and mechanical resistance as well as measured and predicted thermal loads...
November 2016: Review of Scientific Instruments
https://www.readbyqxmd.com/read/27910629/fast-island-phase-identification-for-tearing-mode-feedback-control-on-j-text-tokamak
#2
B Rao, D Li, F R Hu, Y H Ding, Q M Hu, H Jin
A new method to control the tearing mode (TM) in tokamaks has been proposed [Q. Hu and Q. Yu, Nucl. Fusion 56, 034001 (5pp.) (2016)], according to which, the external resonant magnetic perturbation needs to be applied in certain magnetic island phase regions. Therefore, it is very important to identify the helical phase of magnetic islands in real time. The TM in tokamak plasmas is normally rotating and carries magnetic oscillations, which are known as Mirnov oscillations and can be detected by Mirnov probes...
November 2016: Review of Scientific Instruments
https://www.readbyqxmd.com/read/27910494/far-infrared-tangential-interferometer-polarimeter-design-and-installation-for-nstx-u
#3
E R Scott, R Barchfeld, P Riemenschneider, C W Domier, C M Muscatello, M Sohrabi, R Kaita, Y Ren, N C Luhmann
The Far-infrared Tangential Interferometer/Polarimeter (FIReTIP) system has been refurbished and is being reinstalled on the National Spherical Torus Experiment-Upgrade (NSTX-U) to supply real-time line-integrated core electron density measurements for use in the NSTX-U plasma control system (PCS) to facilitate real-time density feedback control of the NSTX-U plasma. Inclusion of a visible light heterodyne interferometer in the FIReTIP system allows for real-time vibration compensation due to movement of an internally mounted retroreflector and the FIReTIP front-end optics...
November 2016: Review of Scientific Instruments
https://www.readbyqxmd.com/read/27910476/operation-results-of-the-kstar-far-infrared-interferometer
#4
June-Woo Juhn, K C Lee, H M Wi, Y S Kim, Y U Nam
The 2015 KSTAR experimental campaign was the first year of routine measurement with a far infrared interferometer (FIRI) utilizing 118.87 μm CH3OH lasers at maximum 200 mW CW beam power. By using rtEFIT reconstruction, the path lengths of interferometers can be calculated and so the line-averaged electron densities n¯e from the FIRI and a millimeter-wave interferometer were in excellent agreement. In this way, the number of successfully diagnosed discharges is counted: 1003 shots or 83.7% of sustained discharges, defined as shots of plasma current IP ≥ 0...
November 2016: Review of Scientific Instruments
https://www.readbyqxmd.com/read/27910462/a-precision-cryostat-design-for-manual-and-semi-automated-cryo-plunge-instruments
#5
Christopher J Russo, Steve Scotcher, Martin Kyte
Here we describe a bench-top cryostat system to control the temperature of liquid ethane in a cryo-plunge apparatus designed for biological specimen preparation for electron cryomicroscopy. It comprises a foam insulated Dewar containing a copper cryostat cup, whose temperature is controlled via an active feedback system to within 0.1 K. The device can easily be incorporated into existing manual and semi-automatic cryo-plunge instruments that are not equipped with cryogenic temperature control. Over the course of normal use, we find that using a cryostat is convenient, fast, and does not require special mixtures of cryogens like ethane/propane...
November 2016: Review of Scientific Instruments
https://www.readbyqxmd.com/read/27910446/self-calibration-method-of-the-bias-of-a-space-electrostatic-accelerometer
#6
Shao-Bo Qu, Xiao-Mei Xia, Yan-Zheng Bai, Shu-Chao Wu, Ze-Bing Zhou
The high precision space electrostatic accelerometer is an instrument to measure the non-gravitational forces acting on a spacecraft. It is one of the key payloads for satellite gravity measurements and space fundamental physics experiments. The measurement error of the accelerometer directly affects the precision of gravity field recovery for the earth. This paper analyzes the sources of the bias according to the operating principle and structural constitution of the space electrostatic accelerometer. Models of bias due to the asymmetry of the displacement sensing system, including the mechanical sensor head and the capacitance sensing circuit, and the asymmetry of the feedback control actuator circuit are described separately...
November 2016: Review of Scientific Instruments
https://www.readbyqxmd.com/read/27910392/real-time-radiative-divertor-feedback-control-development-for-the-nstx-u-tokamak-using-a-vacuum-ultraviolet-spectrometer
#7
V A Soukhanovskii, R Kaita, B Stratton
A radiative divertor technique is planned for the NSTX-U tokamak to prevent excessive erosion and thermal damage of divertor plasma-facing components in H-mode plasma discharges with auxiliary heating up to 12 MW. In the radiative (partially detached) divertor, extrinsically seeded deuterium or impurity gases are used to increase plasma volumetric power and momentum losses. A real-time feedback control of the gas seeding rate is planned for discharges of up to 5 s duration. The outer divertor leg plasma electron temperature Te estimated spectroscopically in real time will be used as a control parameter...
November 2016: Review of Scientific Instruments
https://www.readbyqxmd.com/read/27909841/the-shaping-of-intrinsic-membrane-potential-oscillations-positive-negative-feedback-ionic-resonance-amplification-nonlinearities-and-time-scales
#8
Horacio G Rotstein
The generation of intrinsic subthreshold (membrane potential) oscillations (STOs) in neuronal models requires the interaction between two processes: a relatively fast positive feedback that favors changes in voltage and a slower negative feedback that opposes these changes. These are provided by the so-called resonant and amplifying gating variables associated to the participating ionic currents. We investigate both the biophysical and dynamic mechanisms of generation of STOs and how their attributes (frequency and amplitude) depend on the model parameters for biophysical (conductance-based) models having qualitatively different types of resonant currents (activating and inactivating) and an amplifying current...
December 1, 2016: Journal of Computational Neuroscience
https://www.readbyqxmd.com/read/27908896/depression-screening-with-patient-targeted-feedback-in-cardiology-depscreen-info-randomised-clinical-trial
#9
Bernd Löwe, Stefan Blankenberg, Karl Wegscheider, Hans-Helmut König, Dirk Walter, Alexandra M Murray, Benjamin Gierk, Sebastian Kohlmann
BACKGROUND: International guidelines advocate depression screening in patients with coronary heart disease (CHD) and other chronic illnesses, but evidence is lacking. AIMS: To test the differential efficacy of written patient-targeted feedback v. no written patient feedback after depression screening. METHOD: Patients with CHD or hypertension from three cardiology settings were randomised and screened for depression (ClinicalTrials.gov Identifier: NCT01879111)...
December 1, 2016: British Journal of Psychiatry: the Journal of Mental Science
https://www.readbyqxmd.com/read/27908846/the-effectiveness-of-web-based-asthma-self-management-system-my-asthma-portal-map-a-pilot-randomized-controlled-trial
#10
Sara Ahmed, Pierre Ernst, Susan J Bartlett, Marie-France Valois, Tasneem Zaihra, Guy Paré, Roland Grad, Owis Eilayyan, Robert Perreault, Robyn Tamblyn
BACKGROUND: Whether Web-based technologies can improve disease self-management is uncertain. My Asthma Portal (MAP) is a Web-based self-management support system that couples evidence-based behavioral change components (self-monitoring of symptoms, physical activity, and medication adherence) with real-time monitoring, feedback, and support from a nurse case manager. OBJECTIVE: The aim of this study was to compare the impact of access to a Web-based asthma self-management patient portal linked to a case-management system (MAP) over 6 months compared with usual care on asthma control and quality of life...
December 1, 2016: Journal of Medical Internet Research
https://www.readbyqxmd.com/read/27907997/control-of-oscillations-in-vibration-machines-start-up-and-passage-through-resonance
#11
A Fradkov, D Gorlatov, O Tomchina, D Tomchin
Control of oscillations in mechanical systems in the start-up and passage through resonance modes is studied. In both cases, the control algorithm is based on the speed-gradient method with energy-based goal functions. It is shown that for Hamiltonian 1-degree of freedom (DOF) systems, it is generically possible to move the system from any initial state to any final state by means of a controlling force of arbitrarily small intensity. Controlled passage through resonance is studied for a 5-DOF vibration machine taking friction into account...
November 2016: Chaos
https://www.readbyqxmd.com/read/27907994/hopf-bifurcation-control-for-a-class-of-delay-differential-systems-with-discrete-time-delayed-feedback-controller
#12
Huan Su, Xuerong Mao, Wenxue Li
This paper is concerned with the asymptotical stabilization for a class of unstable delay differential equations. Continuous-time delayed feedback controller (C-TDFC) and discrete-time delayed feedback controller (D-TDFC) are presented and studied, respectively. To our best knowledge, applying Hopf bifurcation theory to delay differential equations with D-TDFC is original and meaningful. The difficulty brought by the introduction of sampling period has been overcome. An effective control range which ensures the asymptotical stability of equilibrium for the system with C-TDFC is obtained...
November 2016: Chaos
https://www.readbyqxmd.com/read/27907817/moderators-of-change-in-an-internet-based-intervention-for-eating-disorders-with-different-levels-of-therapist-support-what-works-for-whom
#13
Jiska J Aardoom, Alexandra E Dingemans, Marjolein Fokkema, Philip Spinhoven, Eric F Van Furth
This study investigated moderators of intervention response in a fully automated Internet-based monitoring and feedback intervention ('Featback') with different levels of therapist support for individuals with eating disorder (ED) symptoms. This study was part of a randomized controlled trial comparing four conditions: 1) Featback, 2) Featback with low-intensity (weekly) therapist support, 3) Featback with high-intensity (three times a week) therapist support, and 4) a waiting list. A total of 273 participants completed baseline and post-intervention assessments...
November 22, 2016: Behaviour Research and Therapy
https://www.readbyqxmd.com/read/27906690/the-long-road-to-leptin
#14
Jeffrey Friedman
Leptin is an adipose tissue hormone that functions as an afferent signal in a negative feedback loop that maintains homeostatic control of adipose tissue mass. This endocrine system thus serves a critical evolutionary function by protecting individuals from the risks associated with being too thin (starvation) or too obese (predation and temperature dysregulation). Mutations in leptin or its receptor cause massive obesity in mice and humans, and leptin can effectively treat obesity in leptin-deficient patients...
December 1, 2016: Journal of Clinical Investigation
https://www.readbyqxmd.com/read/27906180/mir-148a-3p-represses-proliferation-and-emt-by-establishing-regulatory-circuits-between-erbb3-akt2-c-myc-and-dnmt1-in-bladder-cancer
#15
Xiao Wang, Zhen Liang, Xin Xu, Jiangfeng Li, Yi Zhu, Shuai Meng, Shiqi Li, Song Wang, Bo Xie, Alin Ji, Ben Liu, Xiangyi Zheng, Liping Xie
miR-148a-3p downregulation has emerged as a critical factor in cancer progression yet, the underlying mechanisms of miR-148a-3p expression pattern and its function in bladder cancer remains to be elucidated. Here, we illustrate that miR-148a-3p is frequently downregulated in bladder cancer and that its expression may be regulated by DNA methylation. DNA methyltransferase 1 (DNMT1) and miR-148a-3p function in a positive feedback loop in bladder cancer. miR-148a-3p overexpression functions as a tumor suppressor in bladder cancer cells...
December 1, 2016: Cell Death & Disease
https://www.readbyqxmd.com/read/27906130/braf-activates-pax3-to-control-muscle-precursor-cell-migration-during-forelimb-muscle-development
#16
Jaeyoung Shin, Shuichi Watanabe, Soraya Hoelper, Marcus Krüger, Sawa Kostin, Jochen Pöling, Thomas Kubin, Thomas Braun
Migration of skeletal muscle precursor cells is a key step during limb muscle development and depends on the activity of PAX3 and MET. Here, we demonstrate that BRAF serves a crucial function in formation of limb skeletal muscles during mouse embryogenesis downstream of MET and acts as a potent inducer of myoblast cell migration. We found that a fraction of BRAF accumulates in the nucleus after activation and endosomal transport to a perinuclear position. Mass spectrometry based screening for potential interaction partners revealed that BRAF interacts and phosphorylates PAX3...
December 1, 2016: ELife
https://www.readbyqxmd.com/read/27906065/dystrophin-deficient-dogs-with-reduced-myostatin-have-unequal-muscle-growth-and-greater-joint-contractures
#17
Joe N Kornegay, Daniel J Bogan, Janet R Bogan, Jennifer L Dow, Jiahui Wang, Zheng Fan, Naili Liu, Leigh C Warsing, Robert W Grange, Mihye Ahn, Cynthia J Balog-Alvarez, Steven W Cotten, Monte S Willis, Candice Brinkmeyer-Langford, Hongtu Zhu, Joe Palandra, Carl A Morris, Martin A Styner, Kathryn R Wagner
BACKGROUND: Myostatin (Mstn) is a negative regulator of muscle growth whose inhibition promotes muscle growth and regeneration. Dystrophin-deficient mdx mice in which myostatin is knocked out or inhibited postnatally have a less severe phenotype with greater total mass and strength and less fibrosis and fatty replacement of muscles than mdx mice with wild-type myostatin expression. Dogs with golden retriever muscular dystrophy (GRMD) have previously been noted to have increased muscle mass and reduced fibrosis after systemic postnatal myostatin inhibition...
April 4, 2016: Skeletal Muscle
https://www.readbyqxmd.com/read/27905558/microrna-mir-34-provides-robustness-to-environmental-stress-response-via-the-daf-16-network-in-c-elegans
#18
Meltem Isik, T Keith Blackwell, Eugene Berezikov
Diverse stresses and aging alter expression levels of microRNAs, suggesting a role for these posttranscriptional regulators of gene expression in stress modulation and longevity. Earlier studies demonstrated a central role for the miR-34 family in promoting cell cycle arrest and cell death following stress in human cells. However, the biological significance of this response was unclear. Here we show that in C. elegans mir-34 upregulation is necessary for developmental arrest, correct morphogenesis, and adaptation to a lower metabolic state to protect animals against stress-related damage...
December 1, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27903487/disturbed-p53-mdm2-feedback-loop-contributes-to-thoracic-aortic-dissection-formation-and-may-be-a-result-of-trim-25-overexpression
#19
Bin Gong, Zhiwei Wang, Min Zhang, Zhipeng Hu, Zongli Ren, Zheng Tang, Wanli Jiang, Lianghao Cheng, Jun Huang, Wei Ren, Qingtao Wang
BACKGROUND: The development of thoracic aortic dissection (TAD) is attributed to a broad range of degenerative, genetic, structural, oxidative, apoptotic, and acquired disease states. In this study, we examined the role of the disturbed p53-MDM2 feed-back loop in the formation of TAD, and one of a potential feed-back loop regulator, TRIM-25. METHODS: Surgical specimens of the aorta from TAD patients (n=10) and controls (n=10) were tested for α-smooth muscle actin (α-SMA),p53,murine double minute2(MDM2) and tripartite motif protein-25(TRIM-25) by western blot, immunohistochemical staining and quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) , respectively...
November 26, 2016: Annals of Vascular Surgery
https://www.readbyqxmd.com/read/27902328/hepatitis-c-virus-core-activates-proteasomal-activator-28-gamma-expression-via-upregulation-of-p53-levels-to-control-virus-propagation
#20
Juri Kwak, Indira Tiwari, Kyung Lib Jang
The proteasomal activator PA28γ, frequently overexpressed in hepatocellular carcinoma (HCC), is believed to play several important roles in hepatitis C virus (HCV) replication and viral pathogenesis. However, the underlying mechanism for PA28γ overexpression in HCC and its role during HCV replication are still unclear. In the present study, we found that HCV Core derived from either ectopic expression or HCV infection upregulates PA28γ levels in p53-positive human hepatocytes. For this effect, HCV Core sequentially activated ataxia telangiectasia mutated and checkpoint kinase 2 via phosphorylation at Ser-1981 and Thr-68 residues, respectively, resulting in stabilization of p53 via phosphorylation at Ser-15 and Ser-20 residues and subsequent transcriptional activation of PA28γ expression...
November 11, 2016: Journal of General Virology
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