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Sample records for cvd-diamond-based position sensitive

  1. Absolute x-ray and neutron calibration of CVD-diamond-based time-of-flight detectors for the National Ignition Facility

    Science.gov (United States)

    Rosenthal, A.; Kabadi, N. V.; Sio, H.; Rinderknecht, H.; Gatu Johnson, M.; Frenje, J. A.; Seguin, F. H.; Petrasso, R. D.; Glebov, V.; Forrest, C.; Knauer, J.

    2016-10-01

    The particle-time-of-flight (pTOF) detector at the National Ignition Facility routinely measures proton and neutron nuclear bang-times in inertial confinement fusion (ICF) implosions. The active detector medium in pTOF is a chemical vapor deposition (CVD) diamond biased to 250 - 1500 V. This work discusses an absolute measurement of CVD diamond sensitivity to continuous neutrons and x-rays. Although the impulse response of the detector is regularly measured on a diagnostic timing shot, absolute sensitivity of the detector's response to neutrons and x-rays has not been fully established. X-ray, DD-n, and DT-n sources at the MIT HEDP Accelerator Facility provide continuous sources for testing. CVD diamond detectors are also fielded on OMEGA experiments to measure sensitivity to impulse DT-n. Implications for absolute neutron yield measurements at the NIF using pTOF detectors will be discussed. This work was supported in part by the U.S. DoE and LLNL.

  2. Position-sensitive superconductor detectors

    Science.gov (United States)

    Kurakado, M.; Taniguchi, K.

    2016-12-01

    Superconducting tunnel junction (STJ) detectors and superconducting transition- edge sensors (TESs) are representative superconductor detectors having energy resolutions much higher than those of semiconductor detectors. STJ detectors are thin, thereby making it suitable for detecting low-energy X rays. The signals of STJ detectors are more than 100 times faster than those of TESs. By contrast, TESs are microcalorimeters that measure the radiation energy from the change in the temperature. Therefore, signals are slow and their time constants are typically several hundreds of μs. However, TESs possess excellent energy resolutions. For example, TESs have a resolution of 1.6 eV for 5.9-keV X rays. An array of STJs or TESs can be used as a pixel detector. Superconducting series-junction detectors (SSJDs) comprise multiple STJs and a single-crystal substrate that acts as a radiation absorber. SSJDs are also position sensitive, and their energy resolutions are higher than those of semiconductor detectors. In this paper, we give an overview of position-sensitive superconductor detectors.

  3. Position sensitive solid state detectors

    Energy Technology Data Exchange (ETDEWEB)

    Schnatterly, S.E.; Husk, D.

    1986-05-15

    Solid state detectors have been used for years as high quantum efficiency detectors for visible light. In this paper the use of PDA and CCD, solid state detectors, in the X-ray region will be discussed. In particular examples of data in the soft X-ray region are presented. Finally the use of phosphor coatings to enhance the sensitivity of solid state detectors is described.

  4. A New Positioning Algorithm for Position-Sensitive Avalanche Photodiodes.

    Science.gov (United States)

    Zhang, Jin; Olcott, Peter D; Levin, Craig S

    2007-06-01

    We are using a novel position sensitive avalanche photodiode (PSAPD) for the construction of a high resolution positron emission tomography (PET) camera. Up to now most researchers working with PSAPDs have been using an Anger-like positioning algorithm involving the four corner readout signals of the PSAPD. This algorithm yields a significant non-linear spatial "pin-cushion" distortion in raw crystal positioning histograms. In this paper, we report an improved positioning algorithm, which combines two diagonal corner signals of the PSAPD followed by a 45° rotation to determine the X or Y position of the interaction. We present flood positioning histogram data generated with the old and new positioning algorithms using a 3 × 4 array of 2 × 2 × 3 mm(3) and a 3 × 8 array of 1 × 1 × 3 mm(3) of LSO crystals coupled to 8 × 8 mm(2) PSAPDs. This new algorithm significantly reduces the pin-cushion distortion in raw flood histogram image.

  5. Signal processors for position-sensitive detectors

    Energy Technology Data Exchange (ETDEWEB)

    Hasegawa, Ken-ichi [Hosei Univ., Koganei, Tokyo (Japan). Coll. of Engineering

    1996-07-01

    Position-sensitive detectors (PSD) are widely used in following various fields: condensed matter studies, material engineering, medical radiology particle physics, astrophysics and industrial applications. X-ray diffraction analysis is one of the field where PSDs are the most important instruments. In this field, many types of PSAs are employed: position-sensitive proportional counters (PSPC), multi-wire proportional chambers (MWPC), imaging plates, image intensifiers combined CCD cameras and semiconductor array devices. Two readout systems used for PSDs, where one is a charge-division type with high stability and the other is an encoder with multiple delay, line readout circuits useful for fast counting, were reported in this paper. The multiple delay line encoding system can be applicable to high counting rate 1D and 2D gas proportional detectors. (G.K.)

  6. Two-dimensional position sensitive neutron detector

    Indian Academy of Sciences (India)

    A M Shaikh; S S Desai; A K Patra

    2004-08-01

    A two-dimensional position sensitive neutron detector has been developed. The detector is a 3He + Kr filled multiwire proportional counter with charge division position readout and has a sensitive area of 345 mm × 345 mm, pixel size 5 mm × 5 mm, active depth 25 mm and is designed for efficiency of 70% for 4 Å neutrons. The detector is tested with 0.5 bar 3He + 1.5 bar krypton gas mixture in active chamber and 2 bar 4He in compensating chamber. The pulse height spectrum recorded at an anode potential of 2000 V shows energy resolution of ∼ 25% for the 764 keV peak. A spatial resolution of 8 mm × 6 mm is achieved. The detector is suitable for SANS studies in the range of 0.02–0.25 Å-1.

  7. A Two-dimension Position Sensitive PPAC

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A two-dimensional position sensitive parauel-plate avalanche counter(PPAC)with a 100 mm×100 mm active area is developed for the Radioactive Ion-Beam Line in Lanzhou(RIBLL).The detector consists of one anode plane and two cathodes wire planes which are strip planes for the PPACs used in RIKEN~[1].The anode is a Mylar foil coated with a thin layer of gold on each side.The cathode planes X and Y are made of gold-

  8. Position-sensitive transition-edge sensors

    Energy Technology Data Exchange (ETDEWEB)

    Iyomoto, N. [NASA/GSFC, Greenbelt, MD 20771 (United States)]. E-mail: iyomoto@milkyway.gsfc.nasa.gov; Bandler, S.R. [NASA/GSFC, Greenbelt, MD 20771 (United States); Brekosky, R.P. [NASA/GSFC, Greenbelt, MD 20771 (United States); Chervenak, J.A. [NASA/GSFC, Greenbelt, MD 20771 (United States); Figueroa-Feliciano, E. [NASA/GSFC, Greenbelt, MD 20771 (United States); Finkbeiner, F.M. [NASA/GSFC, Greenbelt, MD 20771 (United States); Kelley, R.L. [NASA/GSFC, Greenbelt, MD 20771 (United States); Kilbourne, C.A. [NASA/GSFC, Greenbelt, MD 20771 (United States); Lindeman, M.A. [University of Wisconsin, 1150 University Ave, Madison, WI 53706 (United States); Murphy, K. [NASA/GSFC, Greenbelt, MD 20771 (United States); Porter, F.S. [NASA/GSFC, Greenbelt, MD 20771 (United States); Saab, T. [NASA/GSFC, Greenbelt, MD 20771 (United States); Sadleir, J.E. [NASA/GSFC, Greenbelt, MD 20771 (United States); Talley, D.J. [NASA/GSFC, Greenbelt, MD 20771 (United States)

    2006-04-15

    We report the latest results from our development of Position-Sensitive Transition-edge sensors (PoSTs), which are one-dimensional imaging spectrometers. In PoSTs with segmented Au absorbers, we obtained 8eV energy resolution on K K{alpha} lines, which is consistent to the baseline energy resolution and the design values, on all of the nine pixels, by choosing the best combination of the thermal conductance in absorbers and in links that connects the absorbers. The pulse decay time of 193{mu}s is fast enough for our purpose. In a PoST with a continuous Bi/Cu absorber, by dividing the events into 63 effective pixels, we obtained energy resolutions of 16eV at the center 'pixel', which is comparable to the baseline energy resolution, and 33eV at the outer 'pixel'. The degradation of the energy resolution in the outer 'pixel' is due to position dependence, which we can cancel out by dividing the events into smaller 'pixels' when we have sufficient X-ray events.

  9. Salt sensitivity correlates positively with insulin sensitivity in healthy volunteers

    NARCIS (Netherlands)

    ter Maaten, JC; Voordouw, JJ; Bakker, SJL; Gans, ROB

    1999-01-01

    Background The aim of the study was to assess the relationship between insulin sensitivity and salt sensitivity in healthy subjects who display a wide range of insulin sensitivity. As a secondary objective, we assessed the relationship between salt sensitivity and the other characteristics of the in

  10. Practical Considerations for Optimizing Position Sensitivity in Arrays of Position-sensitive TES's

    Science.gov (United States)

    Smith, Stephen J.; Bandler, Simon R.; Figueroa-Feliciano, Encetali; Iyomoto, Naoko; Kelley, Richard L.; Kilbourne, Caroline A.; Porder, Frederick S.; Sadleir, John E.

    2007-01-01

    We are developing Position-Sensitive Transitions-Edge Sensors (PoST's) for future X-ray astronomy missions such as NASA's Constellation-X. The PoST consists of one or more Transitions Edge Sensors (TES's) thermally connected to a large X-ray absorber, which through heat diffusion, gives rise to position dependence. The development of PoST's is motivated by the desire to achieve the largest the focal-plan coverage with the fewest number of readout channels. In order to develop a practical array, consisting of an inner pixellated core with an outer array of large absorber PoST's, we must be able to simultaneously read out all (-1800) channels in the array. This is achievable using time division multiplexing (TDM), but does set stringent slew rate requirements on the array. Typically, we must damp the pulses to reduce the slew rate of the input signal to the TDM. This is achieved by applying a low-pass analog filter with large inductance to the signal. This attenuates the high frequency components of the signal, essential for position discrimination in PoST's, relative to the white noise of the readout chain and degrades the position sensitivity. Using numerically simulated data, we investigate the position sensing ability of typical PoST designs under such high inductance conditions. We investigate signal-processing techniques for optimal determination of the event position and discuss the practical considerations for real-time implementation.

  11. Measurement and Analysis on Neutron Position Sensitive Detector at CARR

    Institute of Scientific and Technical Information of China (English)

    GAO; Jian-bo; HAO; Li-jie; LIU; Xin-zhi; MA; Xiao-bai; LI; Yu-qing

    2013-01-01

    Neutron position sensitive detector is one of the key components for neutron scattering spectrometer.As the eyes of the spectrometer,the detector is mainly used for recording the position and intensity of the neutrons.The 16 linear position sensitive detectors from GE Reuter-Stokes Company have been measured

  12. Position-sensitive CZT detector module

    Science.gov (United States)

    Matteson, James L.; Duttweiler, Fred; Huszar, George L.; Leblanc, Philippe C.; Skelton, Robert E.; Stephan, Edwin A.; Hink, Paul L.; Dowkontt, Paul F.; Slavis, Kimberly R.; Tumer, Tumay O.; Kravis, Scott D.

    1998-07-01

    Coded mask imagers for future high energy x-ray astronomy missions will require detector planes with areas of hundreds to thousands of cm(superscript 2) and position resolutions CZT detector systems with crossed-strip readout to meet these requirements. We report progress on a compact detector module with 41 cm(superscript 2) area and 0.5 mm spatial resolution. The design includes the bias network and ASIC readout electronics, and allows modules to be combined in large area arrays with very high live-area factors. Results from laboratory and balloon flight tests are presented.

  13. Construction and commissioning of a position-sensitive ionization chamber

    Science.gov (United States)

    Kwag, M. S.; Chae, K. Y.; Cha, S. M.; Kim, A.; Kim, M. J.; Lee, E. J.; Lee, J. H.

    2016-05-01

    A position-sensitive ionization chamber has been constructed and commissioned at the Physics Department of Sungkyunkwan University to extract position information on incident charged particles for future nuclear reaction measurements. By utilizing the newly-designed position-sensitive anodes and the previously-commissioned portable gas-filled ionization chamber by Chae et al., position information on incident particles could be obtained. The device was tested with an 241Am α-emitting source, and the standard deviation of the fitted Gaussian distribution was measured to be 1.76 mm when a collimator with a 2 mm hole was used.

  14. Reducing edge effects and improving position resolution in position sensitive NaI(Tl) detectors

    Energy Technology Data Exchange (ETDEWEB)

    Freifelder, R.; Haigh, A.T.; Karp, J.S. (Univ. of Pennsylvania, Philadelphia (United States))

    1993-04-01

    Large two dimensional position sensitive NaI (Tl) crystals used in positron emission tomographs and elsewhere normally have gaps or inactive, unusable areas at the edges. Experiments aimed at reducing these edge effects have been performed. Unencapsulated crystals have been used to test the feasibility of optically coupling crystals together to decrease gap size. Other experiments increased the sampling of the scintillation light at the edges in order to obtain better position sensitivity. Work was also performed to treat the edges to reduce unwanted reflections and increase the position sensitive area. Finally, experiments aimed at improving the position resolution throughout the crystal as well as at the edges were performed.

  15. New test and analysis of position-sensitive-silicon-detector

    Institute of Scientific and Technical Information of China (English)

    FENG Lang; GE Vu-Cheng; WANG He; FAN Feng-Ying; QIAO Rui; LU Fei; SONG Yu-Shou; ZHENG Tao; YE Yan-Lin

    2009-01-01

    We have tested and analyzed the properties of two-dimensional Position-Sensitive-silicon-Detector (PSD) with new integrated preamplifiers.The test demonstrates that the best position resolution for 5.5 MeV α particles is 1.7 mm (FWHM),and the best energy resolution is 2.1%,which are notably better than the previously reported results.A scaling formula is introduced to make the absolute position calibration.

  16. Vantage sensitivity: individual differences in response to positive experiences.

    Science.gov (United States)

    Pluess, Michael; Belsky, Jay

    2013-07-01

    The notion that some people are more vulnerable to adversity as a function of inherent risk characteristics is widely embraced in most fields of psychology. This is reflected in the popularity of the diathesis-stress framework, which has received a vast amount of empirical support over the years. Much less effort has been directed toward the investigation of endogenous factors associated with variability in response to positive influences. One reason for the failure to investigate individual differences in response to positive experiences as a function of endogenous factors may be the absence of adequate theoretical frameworks. According to the differential-susceptibility hypothesis, individuals generally vary in their developmental plasticity regardless of whether they are exposed to negative or positive influences--a notion derived from evolutionary reasoning. On the basis of this now well-supported proposition, we advance herein the new concept of vantage sensitivity, reflecting variation in response to exclusively positive experiences as a function of individual endogenous characteristics. After distinguishing vantage sensitivity from theoretically related concepts of differential-susceptibility and resilience, we review some recent empirical evidence for vantage sensitivity featuring behavioral, physiological, and genetic factors as moderators of a wide range of positive experiences ranging from family environment and psychotherapy to educational intervention. Thereafter, we discuss genetic and environmental factors contributing to individual differences in vantage sensitivity, potential mechanisms underlying vantage sensitivity, and practical implications.

  17. Dual Position Sensitive MWPC for tracking reaction products at VAMOS++

    CERN Document Server

    Vandebrouck, Marine; Rejmund, Maurycy; Fremont, Georges; Pancin, Julien; Navin, Alahari; Michelagnoli, Caterina; Goupil, Johan; Spitaels, Charles; Jacquot, Bertrand

    2015-01-01

    The characteristics and performance of a Dual Position Sensitive Multi-Wire Proportional Counter (DPS-MWPC) used to measure the scattering angle, interaction position on the target and the velocity of reaction products, detected in the VAMOS++ magnetic spectrometer, are reported. The detector consists of a pair of position sensitive low pressure MWPCs and provides both fast timing signals, along with the two-dimensional position coordinates required to define the trajectory of the reaction products. A time-of-flight resolution of 305(11) ps (FWHM) was measured. The measured resolutions (FWHM) were 2.5(3) mrad and 560(70) {\\mu}m for the scattering angle and the interaction point at the target respectively. The subsequent improvement of the Doppler correction of the energy of the gamma-rays, detected in the gamma-ray tracking array AGATA in coincidence with isotopically identified ions in VAMOS++, is also discussed.

  18. Position-sensitive gaseous photomultipliers research and applications

    CERN Document Server

    Francke, Tom; Peskov, Vladimir

    2016-01-01

    Gaseous photomultipliers are defined as gas-filled devices capable of recording single ultraviolet (UV) and visible photons with high position resolution. Used in a variety of research areas, these detectors can be paired with computers to treat and store imaging information of UV-light. Position-Sensitive Gaseous Photomultipliers: Research and Applications explores the advancement of gaseous detectors as applied for single photon detection. Emphasizing emerging perspectives and new ways to apply gaseous detectors across research fields, this research-based publication is an essential reference source for engineers, physicists, graduate-level students, and researchers.

  19. Efficiency of position sensitive PPAC for various ions

    CERN Document Server

    Hua Hui; Li Xiang Qing; Qian Tao; Wu He Yu; JinGenMing; Tan Ji Lian; Zhan Wen Long; Duan Li Min; Xiao Zhi Guang; Guo Zhong Yan; Li Zu Yu; Wang Hong Wei; Wang Shu Fan

    2002-01-01

    The detection efficiencies of a position sensitive parallel plate avalanche counter, measured with 40 MeV/u sup 1 sup 7 N beam bombarding on a 621 mg/cm sup 2 sup 1 sup 9 sup 7 Au target, were observed to be significantly different for different ions from helium to oxygen. Furthermore, for a given type of ion, the efficiency decreases with the increase of the incident energy.

  20. Two-dimensional position sensitive ionization chamber with GEM

    Science.gov (United States)

    Kitamura, Noritaka; Noro, Tetsuo; Sakaguchi, Satoshi; Takao, Hideaki; Nishio, Yasutaka

    2014-09-01

    We have been developing a multi-anode ionization chamber for Accelerator Mass Spectrometry (AMS) at Kyushu University. Furthermore, we are planning to construct a neutron detector with high position resolution by combining the chamber with Gas Electron Multiplier (GEM) and a neutron converter. One of purposes is the measurement of p-> , pn knockout reaction from unstable nuclei. The multi-anode ionization chamber is composed of subdivided multiple anodes, a cathode to produce an uniform electric field, and a Frisch grid. The chamber must have position sensitivity because obtaining a beam profile is required for AMS measurements, where counting loss should be avoided. Also in the case of the neutron detector, it is necessary to measure the position to deduce the scattering angles. We have recently established a two-dimensional position readout system by the following methods: the measurement of horizontal position is enabled by trimming some anodes into wedge-like shape, and vertical position can be determined by the ratio of induced charge on the grid to the total charge on anodes. In addition, improvement of S/N ratio is important for isotope separation and position resolution. We installed a rectangular-shaped GEM and tried improving S/N ratio by electron amplification.

  1. Position Sensitive Detector Used to Detect Beam Profile

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Non-destructive diagnostic methods are very important for beam adjustments and monitors,especially when the beam intensity is less than 10~8 pps during the heavy-ion treatment of cancer.Now the diagnostic devices of HIFRL can’t satisfy the requests,so we decide to construct a detecting system of the residual-gas beam profile~([1,2]).The system uses the Position Sensitive Detector(PSD)~([3,4])based on microchannel plate(MCP)to

  2. Emulation workbench for position sensitive gaseous scintillation detectors

    CERN Document Server

    Pereira, L; Morozov, A; Solovov, V; Fraga, F A F

    2015-01-01

    Position sensitive detectors based on gaseous scintillation proportional counters with Anger-type readout are being used in several research areas such as neutron detection, search for dark matter and neutrinoless double beta decay. Design and optimization of such detectors are complex and time consuming tasks. Simulations, while being a powerful tool, strongly depend on the light transport models and demand accurate knowledge of many parameters, which are often not available. Here we describe an alternative approach based on the experimental evaluation of a detector using an isotropic point-like light source with precisely controllable light emission properties, installed on a 3D positioning system. The results obtained with the developed setup at validation conditions, when the scattered light is strongly suppressed, show good agreement with simulations.

  3. Emulation workbench for position sensitive gaseous scintillation detectors

    Science.gov (United States)

    Pereira, L.; Margato, L. M. S.; Morozov, A.; Solovov, V.; Fraga, F. A. F.

    2015-12-01

    Position sensitive detectors based on gaseous scintillation proportional counters with Anger-type readout are being used in several research areas such as neutron detection, search for dark matter and neutrinoless double beta decay. Design and optimization of such detectors are complex and time consuming tasks. Simulations, while being a powerful tool, strongly depend on the light transfer models and demand accurate knowledge of many parameters, which are often not available. Here we describe an alternative approach based on the experimental evaluation of a detector using an isotropic point-like light source with precisely controllable light emission properties, installed on a 3D positioning system. The results obtained with the developed setup at validation conditions, when the scattered light is strongly suppressed show good agreement with simulations.

  4. First investigation of a novel 2D position-sensitive

    CERN Document Server

    Bassignana, D; Jaramillo, R; Lozano, M; Munoz, F J; Pellegrini, G; Quirion, D; Vila, I

    2012-01-01

    This paper presents a first study of the performance of a novel 2D position-sensitive microstrip detector, where the resistive charge division method was implemented by replacing the metallic electrodes with resistive electrodes made of polycrystalline silicon. A characterization of two proof-of-concept prototypes with different values of the electrode resistivity was carried out using a pulsed Near Infra-Red laser. The experimental data were compared with the electrical simulation of the sensor equivalent circuit coupled to simple electronics readout circuits. The good agreement between experimental and simulation results establishes the soundness of resistive charge division method in silicon microstrip sensors and validates the developed simulation as a tool for the optimization of future sensor prototypes. Spatial resolution in the strip length direction depends on the ionizing event position. The average value obtained from the protype analysis is close to 1.2% of the strip length for a 6 MIP signal.

  5. Position-sensitive transition edge sensor modeling and results

    Energy Technology Data Exchange (ETDEWEB)

    Hammock, Christina E-mail: chammock@milkyway.gsfc.nasa.gov; Figueroa-Feliciano, Enectali; Apodaca, Emmanuel; Bandler, Simon; Boyce, Kevin; Chervenak, Jay; Finkbeiner, Fred; Kelley, Richard; Lindeman, Mark; Porter, Scott; Saab, Tarek; Stahle, Caroline

    2004-03-11

    We report the latest design and experimental results for a Position-Sensitive Transition-Edge Sensor (PoST). The PoST is motivated by the desire to achieve a larger field-of-view without increasing the number of readout channels. A PoST consists of a one-dimensional array of X-ray absorbers connected on each end to a Transition Edge Sensor (TES). Position differentiation is achieved through a comparison of pulses between the two TESs and X-ray energy is inferred from a sum of the two signals. Optimizing such a device involves studying the available parameter space which includes device properties such as heat capacity and thermal conductivity as well as TES read-out circuitry parameters. We present results for different regimes of operation and the effects on energy resolution, throughput, and position differentiation. Results and implications from a non-linear model developed to study the saturation effects unique to PoSTs are also presented.

  6. ASIC for High Rate 3D Position Sensitive Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Vernon, E.; De Geronimo, G.; Ackley, K.; Fried, J.; He, Z.; Herman, C.; Zhang, F.

    2010-06-16

    We report on the development of an application specific integrated circuit (ASIC) for 3D position sensitive detectors (3D PSD). The ASIC is designed to operate with pixelated wide bandgap sensors like Cadmium-Zinc-Telluride (CZT), Mercuric Iodide (Hgl2) and Thallium Bromide (TIBr). It measures the amplitudes and timings associated with an ionizing event on 128 anodes, the anode grid, and the cathode. Each channel provides low-noise charge amplification, high-order shaping with peaking time adjustable from 250 ns to 12 {micro}s, gain adjustable to 20 mV/fC or 120 mV/fC (for a dynamic range of 3.2 MeV and 530 keV in CZT), amplitude discrimination with 5-bit trimming, and positive and negative peak and timing detections. The readout can be full or sparse, based on a flag and single- or multi-cycle token passing. All channels, triggered channels only, or triggered with neighbors can be read out thus increasing the rate capability of the system to more than 10 kcps. The ASIC dissipates 330 mW which corresponds to about 2.5 mW per channel.

  7. New uses of position-sensitive photomultiplier tubes

    Science.gov (United States)

    Gordon, Jeffrey S.; Redus, Robert H.; Nagarkar, Vivek V.; Squillante, Michael R.

    1992-12-01

    Recent advances in photomultiplier tube technology have led to the availability of position sensitive photomultiplier tubes (PSPMTs). These tubes make it possible to build a new generation of imaging instruments for gamma rays and other types of ionizing radiation. We have investigated the use of these tubes for the construction of several prototype instruments. The first application investigated measures the quantity and distribution of radioactive compounds on filter papers used in microbiology research. The intent of this instrument is to replace film autoradiography with an electronic imaging system which can analyze samples 75 to 110 times faster than film. The second application involved the development of an intraoperative imaging probe to help surgeons identify cancerous tissue and ensure its complete removal. This instrument will replace a non-imaging probe now in use at many hospitals. A third prototype instrument under evaluation is an imaging nuclear survey system which obtains both a video and gamma ray image for the purpose of locating and quantifying radioactive materials. This system would be used at nuclear power plants and radioactive materials preparation facilities. A modification of this system could be built into robots used for inspecting and repairing power plants.

  8. Developments of a 2D Position Sensitive Neutron Detector

    CERN Document Server

    Tian, Li-Chao; Wang, Xiao-Hu; Liu, Rong-Guang; Zhang, Jian; Chen, Yuan-Bo; Sun, Zhi-Jia; Xu, Hong; Yang, Gui-An; Zhang, Qiang

    2011-01-01

    Chinese Spallation Neutron Source (CSNS), one project of the 12th five-year-plan scheme of China, is under construction in Guangdong province. Three neutron spectrometers will be installed at the first phase of the project, where two-dimensional position sensitive thermal neutron detectors are required. Before the construction of the neutron detector, a prototype of two-dimensional 200 mmx200 mm Multi-wire Proportional Chamber (MWPC) with the flowing gas of Ar/CO2 (90/10) has been constructed and tested with the 55Fe X-Ray using part of the electronics in 2009, which showed a good performance. Following the test in 2009, the neutron detector has been constructed with the complete electronics and filled with the 6atm.3He + 2.5atm.C3H8 gas mixture in 2010. The neutron detector has been primarily tested with an Am/Be source. In this paper, some new developments of the neutron detector including the design of the high pressure chamber, the optimization of the gas purifying system and the gas filling process will ...

  9. READOUT ASIC FOR 3D POSITION-SENSITIVE DETECTORS.

    Energy Technology Data Exchange (ETDEWEB)

    DE GERONIMO,G.; VERNON, E.; ACKLEY, K.; DRAGONE, A.; FRIED, J.; OCONNOR, P.; HE, Z.; HERMAN, C.; ZHANG, F.

    2007-10-27

    We describe an application specific integrated circuit (ASIC) for 3D position-sensitive detectors. It was optimized for pixelated CZT sensors, and it measures, corresponding to an ionizing event, the energy and timing of signals from 121 anodes and one cathode. Each channel provides low-noise charge amplification, high-order shaping, along with peak- and timing-detection. The cathode's timing can be measured in three different ways: the first is based on multiple thresholds on the charge amplifier's voltage output; the second uses the threshold crossing of a fast-shaped signal; and the third measures the peak amplitude and timing from a bipolar shaper. With its power of 2 mW per channel the ASIC measures, on a CZT sensor Connected and biased, charges up to 100 fC with an electronic resolution better than 200 e{sup -} rms. Our preliminary spectral measurements applying a simple cathode/mode ratio correction demonstrated a single-pixel resolution of 4.8 keV (0.72 %) at 662 keV, with the electronics and leakage current contributing in total with 2.1 keV.

  10. Signal and noise properties of position-sensitive avalanche photodiodes.

    Science.gov (United States)

    Yang, Yongfeng; Wu, Yibao; Farrell, Richard; Dokhale, Purushottam A; Shah, Kanai S; Cherry, Simon R

    2011-10-07

    After many years of development, position-sensitive avalanche photodiodes (PSAPDs) are now being incorporated into a range of scintillation detector systems, including those used in high-resolution small-animal PET and PET/MR scanners. In this work, the signal, noise, signal-to-noise ratio (SNR), flood histogram and timing resolution were measured for lutetium oxyorthosilicate (LSO) scintillator arrays coupled to PSAPDs ranging in size from 10 to 20 mm, and the optimum bias voltage and working temperature were determined. Variations in the SNR performance of PSAPDs with the same dimensions were small, but the SNR decreased significantly with increasing PSAPD size and increasing temperature. Smaller PSAPDs (10 mm and 15 mm in width) produced acceptable flood histograms at 24 °C, and cooling lower than 16 °C produced little improvement. The optimum bias voltage was about 25 V below the break down voltage. The larger 20 mm PSAPDs have lower SNR and require cooling to 0-7 °C for acceptable performance. The optimum bias voltage is also lower (35 V or more below the break down voltage depending on the temperature). Significant changes in the timing resolution were observed as the bias voltage and temperature varied. Higher bias voltages provided better timing resolution. The best timing resolution obtained for individual crystals was 2.8 ns and 3.3 ns for the 10 mm and 15 mm PSAPDs, respectively. The results of this work provide useful guidance for selecting the bias voltage and working temperature for scintillation detectors that incorporate PSAPDs as the photodetector.

  11. Use of Opioid Medications for Employees in Critical Safety or Security Positions and Positions with Safety Sensitive Duties

    Science.gov (United States)

    2017-01-30

    Employees in Critical Safety or Security Positions and Positions with Safety Sensitive Duties . 1. REFERENCES. A. Army Regulation 40-5, Preventive... duties . C. The employee is considered unfit for safety sensitive duties until such a time when he or she is no longer taking opioid pain...Aeromedical Policy Letters, Medication Waivers, January 2002 Revision. 2. BACKGROUND. Employees who work in safety-sensitive occupations or handle

  12. Analytical expression for position sensitivity of linear response beam position monitor having inter-electrode cross talk

    Science.gov (United States)

    Kumar, Mukesh; Ojha, A.; Garg, A. D.; Puntambekar, T. A.; Senecha, V. K.

    2017-02-01

    According to the quasi electrostatic model of linear response capacitive beam position monitor (BPM), the position sensitivity of the device depends only on the aperture of the device and it is independent of processing frequency and load impedance. In practice, however, due to the inter-electrode capacitive coupling (cross talk), the actual position sensitivity of the device decreases with increasing frequency and load impedance. We have taken into account the inter-electrode capacitance to derive and propose a new analytical expression for the position sensitivity as a function of frequency and load impedance. The sensitivity of a linear response shoe-box type BPM has been obtained through simulation using CST Studio Suite to verify and confirm the validity of the new analytical equation. Good agreement between the simulation results and the new analytical expression suggest that this method can be exploited for proper designing of BPM.

  13. Positioning Social Work in a Socially Sensitive Society

    NARCIS (Netherlands)

    Ewijk, H. van

    2010-01-01

    As a practitioner, a manager and a scientist in social work for 40 years, I am still intrigued by the social work positioning and legitimating processes. Its recognition by users and financiers is often diffuse and its fragmentation sometimes hinders effective interventions. In social work itself, w

  14. Positioning Social Work in a Socially Sensitive Society.

    NARCIS (Netherlands)

    Ewijk, Hans van

    2010-01-01

    As a practitioner, a manager and a scientist in social work for 40 years, I am still intrigued by the social work positioning and legitimating processes. Its recognition by users and financiers is often diffuse and its fragmentation sometimes hinders effective interventions. In social work itself, w

  15. Positioning Social Work in a Socially Sensitive Society.

    NARCIS (Netherlands)

    Dr Hans van Ewijk

    2010-01-01

    As a practitioner, a manager and a scientist in social work for 40 years, I am still intrigued by the social work positioning and legitimating processes. Its recognition by users and financiers is often diffuse and its fragmentation sometimes hinders effective interventions. In social work itself,

  16. Positioning Social Work in a Socially Sensitive Society

    NARCIS (Netherlands)

    Ewijk, H. van

    2010-01-01

    As a practitioner, a manager and a scientist in social work for 40 years, I am still intrigued by the social work positioning and legitimating processes. Its recognition by users and financiers is often diffuse and its fragmentation sometimes hinders effective interventions. In social work itself,

  17. Centroid finding method for position-sensitive detectors

    Energy Technology Data Exchange (ETDEWEB)

    Radeka, V.; Boie, R.A.

    1979-10-01

    A new centroid finding method for all detectors where the signal charge is collected or induced on strips of wires, or on subdivided resistive electrodes, is presented. The centroid of charge is determined by convolution of the sequentially switched outputs from these subdivisions or from the strips with a linear centroid finding filter. The position line width is inversely proportional to N/sup 3/2/, where N is the number of subdivisions.

  18. Gamma ray polarimetry using a position sensitive germanium detector

    CERN Document Server

    Kroeger, R A; Kurfess, J D; Phlips, B F

    1999-01-01

    Imaging gamma-ray detectors make sensitive polarimeters in the Compton energy regime by measuring the scatter direction of gamma rays. The principle is to capitalize on the angular dependence of the Compton scattering cross section to polarized gamma rays and measure the distribution of scatter directions within the detector. This technique is effective in a double-sided germanium detector between roughly 50 keV and 1 MeV. This paper reviews device characteristics important to the optimization of a Compton polarimeter, and summarizes measurements we have made using a device with a 5x5 cm active area, 1 cm thickness, and strip-electrodes on a 2 mm pitch.

  19. 2D position sensitive microstrip sensors with charge division along the strip Studies on the position measurement error

    CERN Document Server

    Bassignana, D; Fernandez, M; Jaramillo, R; Lozano, M; Munoz, F.J; Pellegrini, G; Quirion, D; Vila, I; Vitorero, F

    2013-01-01

    Position sensitivity in semiconductor detectors of ionizing radiation is usually achieved by the segmentation of the sensing diode junction in many small sensing elements read out separately as in the case of conventional microstrips and pixel detectors. Alternatively, position sensitivity can be obtained by splitting the ionization signal collected by one single electrode amongst more than one readout channel with the ratio of the collected charges depending on the position where the signal was primary generated. Following this later approach, we implemented the charge division method in a conventional microstrip detector to obtain position sensitivity along the strip. We manufactured a proofof-concept demonstrator where the conventional aluminum electrodes were replaced by slightly resistive electrodes made of strongly doped poly-crystalline silicon and being readout at both strip ends. Here, we partially summarize the laser characterization of this first proof-of-concept demonstrator with special emphasis ...

  20. 2D Position Sensitive Microstrip Sensors with Charge Division Along the Strip: Studies on the position measurement error

    CERN Document Server

    Bassignana, D; Fernandez, M; Jaramillo, R; Lozano, M; Munoz, F J; Pellegrini, G; Quirion, D; Vila, I; Vitorero, F

    2013-01-01

    Position sensitivity in semiconductor detectors of ionizing radiation is usually achieved by the segmentation of the sensing diode junction in many small sensing elements read out separately as in the case of conventional microstrips and pixel detectors. Alternatively, position sensitivity can be obtained by splitting the ionization signal collected by one single electrode amongst more than one readout channel with the ratio of the collected charges depending on the position where the signal was primary generated. Following this later approach, we implemented the charge division method in a conventional microstrip detector to obtain position sensitivity along the strip. We manufactured a proof-of-concept demonstrator where the conventional aluminum electrodes were replaced by slightly resistive electrodes made of strongly doped poly-crystalline silicon and being readout at both strip ends. Here, we partially summarize the laser characterization of this first proof-of-concept demonstrator with special emphas...

  1. Towards a positive and context-sensitive diagnostic practice

    Directory of Open Access Journals (Sweden)

    Susana Verdinelli

    2015-09-01

    Full Text Available The therapists who endorse positive psychology, constructivist theories and strength-based ideas understand how important it is to consider psychological health and adaptation. The people and their relationships, culture, and context shape multiple ways of defining reality. On the contrary, the Diagnostic and Statistical Manual of Mental Disorders (DSM considers human problems as pathological deficits from a single shared reality. The DSM is becoming increasingly the dominant discourse in the treatment of psychological problems. How are these differences negotiated in theory and practice? What is the perspective of the therapist who practices in the light of ideas such as: strength, context, possibility, systems, and power over the role of the DSM in therapy? The collaborative strategies needed to bridge this gap will be presented in this paper. The need to incorporate a diagnosis based on human strength and environmental resources and the importance of including the patient in the diagnostic process will be discussed. 

  2. Cellular automaton-based position sensitive detector equalization

    Energy Technology Data Exchange (ETDEWEB)

    Ferrando, Nestor [Grupo de Diseno de Sistemas Digitales, Instituto de Aplicaciones de las Tecnologias de la Informacion y de las Comunicaciones Avanzadas, Universidad Politecnica de Valencia, Camino de Vera s/n, 46022 Valencia (Spain)], E-mail: nesferjo@upvnet.upv.es; Herrero, V.; Cerda, J.; Lerche, C.W.; Colom, R.J.; Gadea, R.; Martinez, J.D.; Monzo, J.M.; Mateo, F.; Sebastia, A.; Benlloch, J.M. [Grupo de Diseno de Sistemas Digitales, Instituto de Aplicaciones de las Tecnologias de la Informacion y de las Comunicaciones Avanzadas, Universidad Politecnica de Valencia, Camino de Vera s/n, 46022 Valencia (Spain)

    2009-06-01

    Indirect position detectors based on scintillator crystals lack of spacial uniformity in their response. This happens due to crystal inhomogeneities and gain differences among the photomultiplier anodes. In order to solve this, PESIC, an integrated front-end for multianode photomultiplier based nuclear imaging devices was created. One of its main features is the digitally programmable gain adjustment for every photomultiplier output. On another front, cellular automata have been proved to be a useful method for dynamic system modeling. In this paper, a cellular automaton which emulates the behavior of the scintillator crystal, the photomultiplier and the front-end is introduced. Thanks to this model, an automatic energy-based calibration of the detector can be done by configuring the cellular automaton with experimental data and making it evolve up to an stable state. This can be useful as a precalibration method of the detector.

  3. Parasitic mode losses versus signal sensitivity in beam position monitors

    Science.gov (United States)

    Denard, J. C.; Bane, K. L.; Bijleveld, J.; Hutton, A. M.; Pellegrin, J. I.; Rivkin, L.; Wang, P.; Weaver, J. N.

    1985-04-01

    A beam position monitor (BPM) for a storage or damping ring may be subject to heating problems due to the parasitic mode (PM) losses, beam interception and synchrotron radiation interception. In addition, high PM losses can cause beam instabilities under some conditions. Recessing and/or masking the BPM may increase the PM losses in the process of solving the latter two problems. Three complementary methods for estimating the PM losses and for improving the design of a stripline directional coupler type of BPM: bench measurements, computer modeling (TBCI), and an equivalent circuit representation are presented. These methods lead to a decrease in PM losses without significant reduction in output signal for the north Stanford Linear Collider (SLC) damping ring BPMs.

  4. 78 FR 42982 - Submission for Review: Information Collection; Questionnaire for Non-Sensitive Positions (SF 85)

    Science.gov (United States)

    2013-07-18

    ... MANAGEMENT Submission for Review: Information Collection; Questionnaire for Non-Sensitive Positions (SF 85..., Standard Form 85 (SF 85). As required by the Paperwork Reduction Act of 1995, (Pub. L. 104-13, 44 U.S.C...@opm.gov . SUPPLEMENTARY INFORMATION: The Questionnaire for Non-Sensitive Positions, SF 85, housed in...

  5. POSSuMUS: a position sensitive scintillating muon SiPM detector

    CERN Document Server

    Ruschke, Alexander

    The development of a modular designed large scale scintillation detector with a two-dimensional position sensitivity is presented in this thesis. This novel POsition Sensitive Scintillating MUon SiPM Detector is named POSSuMUS. The POSSuMUS detector is capable to determine the particle’s position in two space dimensions with a fast trigger capability. Each module is constructed from two trapezoidal shaped plastic scintillators to form one rectangular shaped detector module. Both trapezoids are optically insulated against each other. In both trapezoids the scintillation light is collected by plastic fibers and guided towards silicon photomultipliers (SiPMs). SiPMs are light sensors which are capable to detect even smallest amounts of light. By combining several detector modules, position sensitive areas from 100 cm2 to few m2 are achievable with few readout channels. Therefore, POSSuMUS provides a cost effective detector concept. The position sensitivity along the trapezoidal geometry of one detector module ...

  6. 2D position sensitive microstrip sensors with charge division along the strip: Studies on the position measurement error

    Energy Technology Data Exchange (ETDEWEB)

    Bassignana, D. [Centro Nacional de Microelectrónica de Barcelona IMB-CNM (CSIC), Campus Univ. Autónoma de Barcelona, 08193 Bellaterra (Spain); Curras, E.; Fernandez, M.; Jaramillo, R. [Instituto de Física de Cantabria IFCA (CSIC-UC), Avd. de los Castros s/n, 39005 Santander (Spain); Lozano, M. [Centro Nacional de Microelectrónica de Barcelona IMB-CNM (CSIC), Campus Univ. Autónoma de Barcelona, 08193 Bellaterra (Spain); Munoz, F.J. [Instituto de Física de Cantabria IFCA (CSIC-UC), Avd. de los Castros s/n, 39005 Santander (Spain); Pellegrini, G.; Quirion, D. [Centro Nacional de Microelectrónica de Barcelona IMB-CNM (CSIC), Campus Univ. Autónoma de Barcelona, 08193 Bellaterra (Spain); Vila, I., E-mail: vila@ifca.unican.es [Instituto de Física de Cantabria IFCA (CSIC-UC), Avd. de los Castros s/n, 39005 Santander (Spain); Vitorero, F. [Instituto de Física de Cantabria IFCA (CSIC-UC), Avd. de los Castros s/n, 39005 Santander (Spain)

    2013-12-21

    Position sensitivity in semiconductor detectors of ionizing radiation is usually achieved by the segmentation of the sensing diode junction in many small sensing elements read out separately as in the case of conventional microstrips and pixel detectors. Alternatively, position sensitivity can be obtained by splitting the ionization signal collected by one single electrode amongst more than one readout channel with the ratio of the collected charges depending on the position where the signal was primary generated. Following this later approach, we implemented the charge division method in a conventional microstrip detector to obtain position sensitivity along the strip. We manufactured a proof-of-concept demonstrator where the conventional aluminum electrodes were replaced by slightly resistive electrodes made of strongly doped poly-crystalline silicon and being readout at both strip ends. Here, we partially summarize the laser characterization of this first proof-of-concept demonstrator with special emphasis on the study on how the different noise sources are affecting the device position error along the strip.

  7. Position-Sensitive Silicon Detector for X-ray Difractometry of Fast Transient Processes

    Directory of Open Access Journals (Sweden)

    Pugatch, V.M.

    2014-03-01

    Full Text Available The results of the development and application of position sensitive microdetectors to study dynamics of fast transient processes in metals and alloys under heating/cooling by means of high-speed radiography are presented.

  8. A large area position sensitive X-ray detector for astrophysical observations

    NARCIS (Netherlands)

    Mels, W.A.; Lowes, P.; Buurmans, H.B.; Brinkman, A.C.; Naber, A.P.; Rook, A.

    1988-01-01

    A large area position sensitive X-ray detector has been developed for use in the coded mask imaging X-ray spectrometer (COMIS) aboard the USSR research module KVANT. The module was launched on March 31, 1987. The detector, having a sensitive area of 256 × 256 mm2, is a sealed multiwire proportional

  9. A large area two-dimensional position sensitive multiwire proportional detector

    CERN Document Server

    Moura, M M D; Souza, F A; Alonso, E E; Fujii, R J; Meyknecht, A B; Added, N; Aissaoui, N; Cardenas, W H Z; Ferraretto, M D; Schnitter, U; Szanto, E M; Szanto de Toledo, A; Yamamura, M S; Carlin, N

    1999-01-01

    Large area two-dimensional position sensitive multiwire proportional detectors were developed to be used in the study of light heavy-ion nuclear reactions at the University of Sao Paulo Pelletron Laboratory. Each detector has a 20x20 cm sup 2 active area and consists of three grids (X-position, anode and Y-position) made of 25 mu m diameter gold plated tungsten wires. The position is determined through resistive divider chains. Results for position resolution, linearity and efficiency as a function of energy and position for different elements are reported.

  10. Sensitivity of Human Choice to Manipulations of Parameters of Positive and Negative Sound Reinforcement

    OpenAIRE

    Lambert, Joseph Michael

    2013-01-01

    The purpose of this study was to determine whether altering parameters of positive and negative reinforcement in identical ways could influence behavior maintained by each in different ways. Three undergraduate students participated in a series of assessments designed to identify preferred and aversive sounds with similar reinforcing values. Following reinforcer identification, we conducted parameter sensitivity assessments for both positive and negative reinforcers. Parameter manipulation...

  11. Neutron beam applications - Development of one dimensional position sensitive neutron detector

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Yun; Kang, Hee Dong; Kim, Wan; Moon, Myung Kook [Kyungpook National University, Taegu (Korea)

    2000-04-01

    This research is sponsored and supported by KAERI as a part of {sup D}evelopment of One Dimensional Position Sensitive Neutron Detector{sup .} To apply residual stress measurement and small angle neutron scattering the one dimensional position sensitive neutron detectors which have wide window and good position resolution were designed and fabricated. The detection area are 200 mm x 100, 120 mm x 80 mm. The thermal neutron detection efficiency are about 60%. The spatial resolution of the detector are less than 2mm. The characteristics of the detectors were studied. Using the detector we could get neutron diffraction patterns from some samples. 19 refs., 103 figs., 4 tabs. (Author)

  12. Development and Improvement of Position Sensitive Parallel Plate Avalanche Counter (PS-PPAC)

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A series of PS-PPAC was developed and the position resolution was successively improved by us in order to meet the need of heavy ion physics research.The PS-PPAC may be divided into two groups.1 PS-PPAC used for stable(ion)bearna)Double grid position sensitive avalanche chamber(DGAC)~[1].DGAC consists of 4 electrodes:anode A,cathode C,grids K and G,which are made of wire planes.The sensitive area was 25×20 cm~2.A position

  13. Design and experimental study of a two-dimensional position sensitive X-ray detector

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A prototype of a two-dimensional position sensitive X-ray detector was designed and constructed for small angle X-ray scattering experiments at BSFR (Beijing Synchrotron Radiation Facility). The detector is based on MWPC with cathode strip readout, and has a sensitive area of 200 mmx200 mm. The spatial resolution (FWHM) of about 210 μm along the anode wire direction was obtained from the 55Fe X-ray test of the detector.

  14. Position-Sensitive Detector with Depth-of-Interaction Determination for Small Animal PET

    CERN Document Server

    Fedorov, A; Kholmetsky, A L; Korzhik, M V; Lecoq, P; Lobko, A S; Missevitch, O V; Tkatchev, A

    2002-01-01

    Crystal arrays made of LSO and LuAP crystals 2x2x10 mm pixels were manufactured for evaluation of detector with depth-of-interaction (DOI) determination capability intended for small animal positron emission tomograph. Position-sensitive LSO/LuAP phoswich DOI detector based on crystal 8x8 arrays and HAMAMATSU R5900-00-M64 position-sensitive multi-anode photomultiplier tube was developed and evaluated. Time resolution was found to be not worse than 1.0 ns FWHM for both layers, and spatial resolution mean value was 1.5 mm FWHM for the center of field-of-view.

  15. Atomic force microscopy: Loading position dependence of cantilever spring constants and detector sensitivity

    Science.gov (United States)

    Vakarelski, Ivan U.; Edwards, Scott A.; Dagastine, Raymond R.; Chan, Derek Y. C.; Stevens, Geoffrey W.; Grieser, Franz

    2007-11-01

    A simple and accurate experimental method is described for determining the effective cantilever spring constant and the detector sensitivity of atomic force microscopy cantilevers on which a colloidal particle is attached. By attaching large (approximately 85μm diameter) latex particles at various positions along the V-shaped cantilevers, we demonstrate how the normal and lateral spring constants as well as the sensitivity vary with loading position. Comparison with an explicit point-load theoretical model has also been used to verify the accuracy of the method.

  16. Numerical modeling of 3-D Position Reconstruction from 3-Axial Planar Spiral Coil Sensor Sensitivity

    CERN Document Server

    Sanjaya, Edi; Viridi, Sparisoma

    2011-01-01

    A sensitivity profile of a planar spiral coil sensor (PSCS) is proposed and use to generate the relation of 3-D position of object observed using three (PSCS)-s, one in each x, y, and z axis to the sensors response. A numerical procedure using self consistent field-like method to reconstruct the real position of observed object from sensor sensitivity is presented and the results are discussed. Unfortunately, the procedure fails to approach the desired results due to the existence of quadratic terms.

  17. Development of 2D-ACAR apparatus using position-sensitive photomultiplier tubes

    Energy Technology Data Exchange (ETDEWEB)

    Nagai, Yasuyoshi; Saito, Haruo; Iwata, Tetsuya; Nagashima, Yasuyuki; Hyodo, Toshio [Tokyo Univ. (Japan). Coll. of Arts and Sciences; Uchida, Hiroshi; Omura, Tomohide

    1997-03-01

    A new two-dimensional angular correlation of annihilation radiation apparatus is described. Position-sensitive photomultiplier tubes coupled with two-dimensional arrays of small BGO scintillator blocks make simple and compact position-sensitive {gamma}-ray detectors. With a sample-detector distance of 5m, an angular resolution of 1.1 mrad FWHM and a coincidence count rate of {approx}2.4 c.p.s. per mCi are obtained. Its performance is demonstrated by the result of a test measurement for KI crystal in which non-localized positronium exists at low temperatures. (author)

  18. A position-sensitive time-of-flight analyser for study of molecular photofragmentation

    CERN Document Server

    Rius-I-Riu, J; Karawajczyk, A; Winiarczyk, P

    2002-01-01

    The basic features of a simple radial position-sensitive detector design, construction and performance, are described in detail in this paper. The electronics and method used to correlate the position information from the spectrum recorded by the detector are presented. Monte Carlo simulations of the performance of the detector embedded in a time of flight analyser show that such an instrument enables kinetic energy and angular distribution measurements and triple coincidence studies of photofragmentation of simple molecules.

  19. Performance of high-resolution position-sensitive detectors developed for storage-ring decay experiments

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, T., E-mail: yamaguti@phy.saitama-u.ac.jp [Department of Physics, Saitama University, Saitama 338-8570 (Japan); Suzaki, F. [Department of Physics, Saitama University, Saitama 338-8570 (Japan); Izumikawa, T. [RI Center, Niigata University, Niigata 951-8510 (Japan); Miyazawa, S. [Department of Physics, Saitama University, Saitama 338-8570 (Japan); Morimoto, K. [RIKEN Nishina Center, Wako, Saitama 351-0198 (Japan); Suzuki, T. [Department of Physics, Saitama University, Saitama 338-8570 (Japan); Tokanai, F. [Department of Physics, Yamagata University, Yamagata 990-8560 (Japan); Furuki, H.; Ichihashi, N.; Ichikawa, C. [Department of Physics, Saitama University, Saitama 338-8570 (Japan); Kitagawa, A. [National Institute of Radiological Sciences, Chiba 263-8555 (Japan); Kuboki, T. [Department of Physics, Saitama University, Saitama 338-8570 (Japan); Momota, S. [School of Environmental Science and Engineering, Kochi University of Technology, Kochi 782-8502 (Japan); Nagae, D. [Institute of Physics, University of Tsukuba, Ibaraki 305-8571 (Japan); Nagashima, M.; Nakamura, Y. [Department of Physics, Niigata University, Niigata 950-2181 (Japan); Nishikiori, R.; Niwa, T. [Institute of Physics, University of Tsukuba, Ibaraki 305-8571 (Japan); Ohtsubo, T. [Department of Physics, Niigata University, Niigata 950-2181 (Japan); Ozawa, A. [Institute of Physics, University of Tsukuba, Ibaraki 305-8571 (Japan); and others

    2013-12-15

    Highlights: • Position-sensitive detectors were developed for storage-ring decay spectroscopy. • Fiber scintillation and silicon strip detectors were tested with heavy ion beams. • A new fiber scintillation detector showed an excellent position resolution. • Position and energy detection by silicon strip detectors enable full identification. -- Abstract: As next generation spectroscopic tools, heavy-ion cooler storage rings will be a unique application of highly charged RI beam experiments. Decay spectroscopy of highly charged rare isotopes provides us important information relevant to the stellar conditions, such as for the s- and r-process nucleosynthesis. In-ring decay products of highly charged RI will be momentum-analyzed and reach a position-sensitive detector set-up located outside of the storage orbit. To realize such in-ring decay experiments, we have developed and tested two types of high-resolution position-sensitive detectors: silicon strips and scintillating fibers. The beam test experiments resulted in excellent position resolutions for both detectors, which will be available for future storage-ring experiments.

  20. Implementation of Complex Signal Processing Algorithms for Position-Sensitive Microcalorimeters

    Science.gov (United States)

    Smith, Stephen J.

    2008-01-01

    We have recently reported on a theoretical digital signal-processing algorithm for improved energy and position resolution in position-sensitive, transition-edge sensor (POST) X-ray detectors [Smith et al., Nucl, lnstr and Meth. A 556 (2006) 2371. PoST's consists of one or more transition-edge sensors (TES's) on a large continuous or pixellated X-ray absorber and are under development as an alternative to arrays of single pixel TES's. PoST's provide a means to increase the field-of-view for the fewest number of read-out channels. In this contribution we extend the theoretical correlated energy position optimal filter (CEPOF) algorithm (originally developed for 2-TES continuous absorber PoST's) to investigate the practical implementation on multi-pixel single TES PoST's or Hydras. We use numerically simulated data for a nine absorber device, which includes realistic detector noise, to demonstrate an iterative scheme that enables convergence on the correct photon absorption position and energy without any a priori assumptions. The position sensitivity of the CEPOF implemented on simulated data agrees very well with the theoretically predicted resolution. We discuss practical issues such as the impact of random arrival phase of the measured data on the performance of the CEPOF. The CEPOF algorithm demonstrates that full-width-at- half-maximum energy resolution of < 8 eV coupled with position-sensitivity down to a few 100 eV should be achievable for a fully optimized device.

  1. Measurement and analysis of field-induced crystallographic texture using curved position-sensitive diffraction detectors

    DEFF Research Database (Denmark)

    Simons, Hugh; Daniels, John E.; Studer, Andrew J.;

    2014-01-01

    employing a curved positive sensitive detector. Methodologies are proposed to account for the geometrical effects when vector fields are applied to textured materials with angularly dispersive detector geometries. Representative results are presented for the ferroelectric (Bi1/2Na1/2)TiO3-6%BaTiO3 (BNT-6BT...

  2. Two-dimensional photon counting imaging detector based on a Vernier position sensitive anode readout

    Institute of Scientific and Technical Information of China (English)

    鄢秋荣; 赵宝升; 刘永安; 杨颢; 盛立志; 韦永林

    2011-01-01

    A two-dimensional photon counting imaging detector based on a Vernier position sensitive anode is reported. The decode principle and design of a two-dimensional Vernier anode are introduced in detail. A photon counting imaging system was built based on a

  3. A position sensitive parallel plate avalanche fission detector for use in particle induced fission coincidence measurements

    NARCIS (Netherlands)

    Plicht, J. van der

    1980-01-01

    A parallel plate avalanche detector developed for the detection of fission fragments in particle induced fission reactions is described. The active area is 6 × 10 cm2; it is position sensitive in one dimension with a resolution of 2.5 mm. The detector can withstand a count rate of 25000 fission

  4. Performance studies on high pressure 1-D position sensitive neutron detectors

    Indian Academy of Sciences (India)

    S S Desai; A M Shaikh

    2008-11-01

    The powder diffractometer and Hi-Q diffractometer at Dhruva reactor make use of five identical 1-D position sensitive detectors (PSDs) to scan scattering angles in the range 3° to 140°. In order to improve the overall throughput of these spectrometers, it is planned to install a bank of 15 high-efficiency and high-resolution PSDs arranged in three layers with five PSDs in each layer. With each high pressure PSD (3He 10 bar + Kr 2 bar) showing the efficiency gain of 1.8 at 1.2 Å, detector bank is expected to show overall gain of 5.5 times the present detection efficiency and reduction in data collection time by equivalent factor. The 1-D PSDs are developed in batches of five, and are characterized so that all PSDs operate at uniform parameters such as position resolution, uniformity of efficiency and linearity of response. Position spectrum indicates the differential position resolution to be ∼ 1 mm and integral position resolution to be 3–4 mm. Broadening of position spectrum at the extreme end of sensitive length of PSD is analysed using fine shift of the beam. Dependence of position resolution and dynamic range of output pulse on the input impedance of pre-amplifier is also presented.

  5. Position sensitivity in 3"×3" Spectroscopic LaBr3:Ce Crystals

    Science.gov (United States)

    Blasi, N.; Giaz, A.; Boiano, C.; Brambilla, S.; Camera, F.; Million, B.; Riboldi, S.

    2015-06-01

    The position sensitivity of a thick, cylindrical and continuous 3" × 3" (7.62 cm × 7.62 cm) LaBr3:Ce crystal with diffusive surfaces was investigated. Nuclear physics basic research uses thick LaBr3:Ce crystals (> 3cm) to measure medium or high energy gamma rays (0.5 MeV < Eγ< 20 MeV). In the first measurement the PMT photocathode entrance window was covered by black absorber except for a small window 1 cm × 1cm wide. A complete scan of the detector over a 0.5 cm step grid was performed. The data show that even in a 3" thick LaBr3:Ce crystal with diffusive surfaces the position of the full energy peak centroid depends on the source position. The position of the full energy peak centroids are sufficient to identify the collimated gamma source position. The crystal was then coupled to four Position Sensitive Photomultipliers (PSPMT). We acquired the signals from the 256 segments of the four PSPMTs grouping them into 16 elements. An event by event analysis shows a positon resolution of the order of 2 cm.

  6. Development of a one-dimensional Position Sensitive Detector for tracking applications

    Science.gov (United States)

    Lydecker, Leigh Kent, IV

    Optical Position Sensitive Detectors (PSDs) are a non-contact method of tracking the location of a light spot. Silicon-based versions of such sensors are fabricated with standard CMOS processing, are inexpensive and provide a real-time, analog signal output corresponding to the position of the light spot. Because they are non-contact, they do not degrade over time from surface friction due to repetitive sliding motion associated with standard full contact sliding potentiometers. This results in long, reliable device lifetimes. In this work, an innovative PSD was developed to replace the linear hard contact potentiometer currently being used in a human-computer interface architecture. First, a basic lateral effect PSD was developed to provide real-time positioning of the mouthpiece used in the interface architecture which tracks along a single axis. During the course of this work, multiple device geometries were fabricated and analyzed resulting in a down selection of a final design. This final device design was then characterized in terms of resolution and responsivity and produced in larger quantities as initial prototypes for the test product integration. Finally, an electronic readout circuit was developed in order to interface the dual- line lateral effect PSD developed in this thesis with specifications required for product integration. To simplify position sensing, an innovative type of optical position sensor was developed using a linear photodiodes with back-to-back connections. This so- called Self-Balancing Position Sensitive Detector (SBPSD) requires significantly fewer processing steps than the basic lateral effect position sensitive detector discussed above and eliminates the need for external readout circuitry entirely. Prototype devices were fabricated in this work, and the performance characteristics of these devices were established paving the way for ultimate integration into the target product as well as additional applications.

  7. Characterization of the VEGA ASIC coupled to large area position-sensitive Silicon Drift Detectors

    CERN Document Server

    Campana, R; Fuschino, F; Ahangarianabhari, M; Macera, D; Bertuccio, G; Grassi, M; Labanti, C; Marisaldi, M; Malcovati, P; Rachevski, A; Zampa, G; Zampa, N; Andreani, L; Baldazzi, G; Del Monte, E; Favre, Y; Feroci, M; Muleri, F; Rashevskaya, I; Vacchi, A; Ficorella, F; Giacomini, G; Picciotto, A; Zuffa, M

    2014-01-01

    Low-noise, position-sensitive Silicon Drift Detectors (SDDs) are particularly useful for experiments in which a good energy resolution combined with a large sensitive area is required, as in the case of X-ray astronomy space missions and medical applications. This paper presents the experimental characterization of VEGA, a custom Application Specific Integrated Circuit (ASIC) used as the front-end electronics for XDXL-2, a large-area (30.5 cm^2) SDD prototype. The ASICs were integrated on a specifically developed PCB hosting also the detector. Results on the ASIC noise performances, both stand-alone and bonded to the large area SDD, are presented and discussed.

  8. 2 Dimensional position sensitive XAFS by using in-house X-ray spectrometer

    Science.gov (United States)

    Shinoda, Kozo; Suzuki, Shigeru; Kuribayashi, Masaru; Taguchi, Takeyoshi

    2009-09-01

    Position sensitive XAFS measurements by using the in-house X-ray spectrometer and the position sensitive X-ray detector were attempted. The in-house spectrometer produces monochromized divergent X-ray beam. Therefore, an extended direct-beam image projected on the detector can be taken, and its extension rate is depending on the arrangement of the sample and the detector. A position sensitive XAFS measurement was demonstrated by using Ni metal foil and NiO powder as a model sample. Ge(220) or Si(400) Johansson-type bent single-crystal was used as monochromator, and Mo and LaB6 were used as the target and filament, respectively. Tube voltage and current were operated at 16 kV and 100 mA (1.6 kW). XAFS spectra were measured by transmission-mode with sample set/reset method and required time of each experiment is about 6 hours in total. It was confirmed that metal and oxide spectra with enough quality for structural analysis were clearly separated by each position in the sample.

  9. Combined liver and kidney transplantation in a highly sensitized and positively cross-matched patient

    Directory of Open Access Journals (Sweden)

    Salem Alqurashi

    2011-01-01

    Full Text Available Combined liver kidney transplantation (CLKT has been used on many occasions and proved to be a successful event for both liver and kidney in highly sensitized patients. Our aim was to review the immunological and other laboratory results of a CLKT in a highly sensitized patient. CLKT was used to treat a highly sensitized, 42-year-old female. She was suffering from end-stage liver disease due to hepatitis C virus (HCV infection and renal disease due to diabetic nephropathy. Cross-matching, panel reactive assay (PRA and routine laboratory tests for liver and renal function were carried out before and after the CLKT. Prior to the CLKT, the patient was highly sensitized with human leukocytes antigens (anti-HLA class I antibodies (>90%. Patient was offered CLKT from a deceased donor. She had donor-specific antibodies, class I and II. Both T and B CDC cross-matches (XM were positive pre-transplant and eight hours post-transplant. Both cross-match and PRA results became completely negative six days post CKLT. Almost 30 months post CLKT, her renal function is normal and negative for class I and II PRA. Liver graft appears to be protective for renal graft when they are combined even in highly sensitized patients. CLKT is very useful in overcoming sensitization in addition to treating end-stage liver and renal diseases.

  10. Improving linearity of position-sensitive detector using support vector machines

    Institute of Scientific and Technical Information of China (English)

    Meiying Ye

    2005-01-01

    An intelligent method for improving position linearity of position-sensitive detector (PSD), based on support vector machines (SVMs), is developed. The SVM is established based on the structural risk minimization principle rather than minimizing the empirical error commonly implemented in neural networks.SVM can achieve higher generalization performance. Training SVM is equivalent to solving a linearly constrained quadratic programming problem, thus the solution of SVM is always unique and globally optimal.The improving position linearity procedure has been illustrated using a two-dimensional (2D) PSD. It is pointed out that the position linearity of the measuring system with a proper SVM correction is improved by two orders of magnitude in the measurement range.

  11. Initial characterization of a position-sensitive photodiode/BGO detector for PET (positron emission tomography)

    Energy Technology Data Exchange (ETDEWEB)

    Derenzo, S.E.; Moses, W.W.; Jackson, H.G.; Turko, B.T.; Cahoon, J.L.; Geyer, A.B.; Vuletich, T.

    1988-11-01

    We present initial results of a position-sensitive photodiode/BGO detector for high resolution, multi-layer positron emission tomography (PET). Position sensitivity is achieved by dividing the 3 mm /times/ 20 mm rectangular photosensitive area along the diagonal to form two triangular segments. Each segment was individually connected to a low-noise amplifier. The photodiodes and crystals were cooled to /minus/100/degree/C to reduce dark current and increase the BGO signal. With an amplifier peaking time of 17 ..mu..sec, the sum of the signals (511 keV photopeak) was 3200 electrons with a full width at half maximum (fwhm) of 750 electrons. The ratio of one signal to the sum determined the depth of interaction with a resolution of 11 mm fwhm. 27 refs., 7 figs.

  12. Position sensitivity in large spectroscopic LaBr3:Ce crystals for Doppler broadening correction

    Science.gov (United States)

    Blasi, N.; Giaz, A.; Boiano, C.; Brambilla, S.; Camera, F.; Million, B.; Riboldi, S.

    2016-12-01

    The position sensitivity of a large LaBr3:Ce crystal was investigated with the aim of correcting for the Doppler broadening in nuclear physics experiments. The crystal was cylindrical, 3 in×3 in (7.62 cm x 7.62 cm) and with diffusive surfaces as typically used in nuclear physics basic research to measure medium or high energy gamma rays (0.5 MeVPosition Sensitive Photomultipliers (PSPMT). The signals from the 256 segments of the four PSPMTs were acquired grouping them into 16 elements. An event by event analysis was performed and a positon resolution of the order of 2 cm was found. It was verified that this allows an important reduction of the Doppler broadening induced by relativistic beams in Nuclear Physics experiments.

  13. Ultrafast Readout of Scintillating Fibres Using Upgraded Position-Sensitive Photomultipliers

    CERN Multimedia

    2002-01-01

    % RD-17 \\\\ \\\\To design a high rate topological trigger device for the future DIRAC Experiment at CERN an extensive work is in progress on a scintillating-fibre detector using a position-sensitive photomultiplier. Several detector prototypes with different lengths ($<$~50~cm) of sensitive area have been tested at T7S~PS beam. \\\\ \\\\With 0.5~mm diameter fibres a spatial resolution of $\\sim$125~$\\mu$m was obtained with a detection efficiency higher than 95\\%. The time resolution is $\\sim$600~ps, and the track position is properly digitized in real time (about 10~ns) by multi-channel peak sensing circuit. Based on experimental data simulations were also performed a comparison of different types of front-end electronics for multi-channel readout.

  14. Angle-resolved ion TOF spectrometer with a position sensitive detector

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Norio [Electrotechnical Lab., Tsukuba, Ibaraki (Japan); Heiser, F.; Wieliczec, K.; Becker, U.

    1996-07-01

    A angle-resolved ion time-of-flight mass spectrometer with a position sensitive anode has been investigated. Performance of this spectrometer has been demonstrated by measuring an angular distribution of a fragment ion pair, C{sup +} + O{sup +}, from CO at the photon energy of 287.4 eV. The obtained angular distribution is very close to the theoretically expected one. (author)

  15. Development of Position-sensitive Transition-edge Sensor X-ray Detectors

    Science.gov (United States)

    Smith, S. J.; Bandler, S. R.; Brekosky, R. P.; Brown, A.-D.; Chervenak, J. A.; Eckard, M. E.; Finkbeiner, F. M.; Kelley, R. L.; Kilbourne, C. A.; Porter, F. s.; Sad (eor. K/ E/); Figueroa-Feliciano, E.

    2008-01-01

    We report on the development of position-sensitive transition-edge sensors (PoST's) for future x-ray astronomy missions such as the International X-ray Observatory (IXO), currently under study by NASA and ESA. PoST's consist of multiple absorbers each with a different thermal coupling to one or more transition-edge sensor (TES). This differential thermal coupling between absorbers and TES's results in different characteristic pulse shapes and allows position discrimination between the different pixels. The development of PoST's is motivated by a desire to achieve maximum focal-plane area with the least number of readout channels and as such. PoST's are ideally suited to provide a focal-plane extension to the Constellation-X microcalorimeter array. We report the first experimental results of our latest one and two channel PoST's, which utilize fast thermalizing electroplated Au/Bi absorbers coupled to low noise Mo/Au TES's - a technology already successfully implemented in our arrays of single pixel TES's. We demonstrate 6 eV energy resolution coupled with spatial sensitivity in the keV energy range. We also report on the development of signal processing algorithms to optimize energy and position sensitivity of our detectors.

  16. Fractionating negative and positive affectivity in handedness: Insights from the Reinforcement Sensitivity Theory of personality.

    Science.gov (United States)

    Beaton, Alan A; Mutinelli, Sofia; Corr, Philip J

    2016-07-28

    The Annett Hand Preference Questionnaire (AHPQ), as modified by Briggs and Nebes [(1975). Patterns of hand preference in a student population. Cortex, 11(3), 230-238. doi: 10.1016/s0010-9452(75)80005-0 ], was administered to a sample of 177 participants alongside the Reinforcement Sensitivity Theory of Personality Questionnaire [RST-PQ; Corr, P. J., & Cooper, A. (2016). The Reinforcement Sensitivity Theory of Personality Questionnaire (RST-PQ): Development and validation. Psychological Assessment. doi: 10.1037/pas000 ], which measures two factors of defensive negative emotion, motivation and affectivity-the Behavioural Inhibition System (BIS) and the Fight-Flight-Freeze System (FFFS)-and one positive-approach dimension related to reward sensitivity, persistence and reactivity-the Behavioural Approach System. We sought to clarify the nature of negative, and positive, affectivity in relation to handedness. ANOVAs and multiple regression analyses converged on the following conclusions: left-handers were higher on the BIS, not the FFFS, than right-handers; in right-handers only, strength of hand preference was positively correlated with the FFFS, not the BIS. The original assessment method proposed by Annett was also used to assess handedness, but associations with RST-PQ factors were not found. These findings help us to clarify existing issues in the literature and raise new ones for future research.

  17. DIAGNOSIS OF CULTURE POSITIVE URINARY TRACT INFECTIONS AND THEIR ANTIMICROBIAL SENSITIVITY PROFILE IN TERTIARY CARE CENTRE

    Directory of Open Access Journals (Sweden)

    Prince Sreekumar Pius

    2016-12-01

    Full Text Available BACKGROUND Urinary tract infection is very common all over the world and in India more than 10 million cases are reported per year. It is one of the common infections diagnosed in the outpatients as well as the hospitalised patients. Empirical treatment of community acquired urinary tract infections are determined by the antibiotic sensitivity in a population. This study was conducted to determine the antimicrobial sensitivity amongst the uropathogens to help establish local guidelines on treatment of urinary tract infection. MATERIALS AND METHODS In this study, we collected 1306 samples from patients in whom we suspected to have urinary tract infection based on clinical signs and symptoms (e.g. with fever (greater than 38°C without another explanation or from a patient who had at least one urinary symptom (dysuria, urgency, frequency, or suprapubic pain or tenderness in our hospital during January 2016-June 2016. RESULTS Urine cultures were positive for 18% of the patients. Among these cultures, Klebsiella pneumonia (41%, Escherichia coli (35% and Pseudomonas aeruginosa (7% were the common organisms found. Highest antimicrobial sensitivity amongst these pathogens was found with cefoperazone/sulbactam and amikacin. CONCLUSION Cefoperazone/sulbactam and amikacin were the highly sensitive systemic antibiotics while ciprofloxacin and norfloxacin were the sensitive oral antibiotics in our locality.

  18. Head Position in the MEG Helmet Affects the Sensitivity to Anterior Sources

    Science.gov (United States)

    Marinkovic, K; Cox, B; Reid, K; Halgren, E

    2013-01-01

    Current MEG instruments derive the whole-head coverage by utilizing a helmet-shaped opening at the bottom of the dewar. These helmets, however, are quite a bit larger than most people’s heads so subjects commonly lean against the back wall of the helmet in order to maintain a steady position. In such cases the anterior brain sources may be too distant to be picked up by the sensors reliably. Potential “invisibility” of the frontal and anterior temporal sources may be particularly troublesome for the studies of cognition and language, as they are subserved significantly by these areas. We examined the sensitivity of the distributed anatomically-constrained MEG (aMEG) approach to the head position (“front” vs. “back”) secured within a helmet with custom-tailored bite-bars during a lexical decision task. The anterior head position indeed resulted in much greater sensitivity to language-related activity in frontal and anterior temporal locations. These results emphasize the need to adjust the head position in the helmet in order to maximize the “visibility” of the sources in the anterior brain regions in cognitive and language tasks. PMID:16012659

  19. Sensitivity of reactor multiplication factor to positions of cross-section resonances

    Indian Academy of Sciences (India)

    V GOPALAKRISHNAN; K R VIJAYARAGHAVAN

    2017-09-01

    Neutron–nuclear interaction cross-section is sensitive to neutron kinetic energy and most nuclei exhibit resonance behaviour at specific energies within the resonance energy range, spanning from a fraction of an electron volt to several tens or hundreds of kilo electron volts. The energy positions of these resonances correspond to the excitation energy levels of the compound nucleus that are formed as intermediate states during the interaction. Though these positions, thanks to sophistication in science and technology, are known reasonably precisely for the materials of reactor interest, deviations or spread in this data among different evaluations cannot be ruled out. In this work, the effect of such a spread in the resonance positions of the reactor materials on the multiplication factor of an infinite reactor, is obtained. The study shows that the effect on a thermal reactor is more pronounced than on a fast reactor.

  20. Compton imaging with a highly-segmented, position-sensitive HPGe detector

    Science.gov (United States)

    Steinbach, T.; Hirsch, R.; Reiter, P.; Birkenbach, B.; Bruyneel, B.; Eberth, J.; Gernhäuser, R.; Hess, H.; Lewandowski, L.; Maier, L.; Schlarb, M.; Weiler, B.; Winkel, M.

    2017-02-01

    A Compton camera based on a highly-segmented high-purity germanium (HPGe) detector and a double-sided silicon-strip detector (DSSD) was developed, tested, and put into operation; the origin of γ radiation was determined successfully. The Compton camera is operated in two different modes. Coincidences from Compton-scattered γ-ray events between DSSD and HPGe detector allow for best angular resolution; while the high-efficiency mode takes advantage of the position sensitivity of the highly-segmented HPGe detector. In this mode the setup is sensitive to the whole 4π solid angle. The interaction-point positions in the 36-fold segmented large-volume HPGe detector are determined by pulse-shape analysis (PSA) of all HPGe detector signals. Imaging algorithms were developed for each mode and successfully implemented. The angular resolution sensitively depends on parameters such as geometry, selected multiplicity and interaction-point distances. Best results were obtained taking into account the crosstalk properties, the time alignment of the signals and the distance metric for the PSA for both operation modes. An angular resolution between 13.8° and 19.1°, depending on the minimal interaction-point distance for the high-efficiency mode at an energy of 1275 keV, was achieved. In the coincidence mode, an increased angular resolution of 4.6° was determined for the same γ-ray energy.

  1. The position effect of electron-deficient quinoxaline moiety in porphyrin based sensitizers

    Science.gov (United States)

    Fan, Suhua; Lv, Kai; Sun, Hong; Zhou, Gang; Wang, Zhong-Sheng

    2015-04-01

    An electron-deficient group, 2,3-diphenylquinoxaline (DPQ), is incorporated as an auxiliary acceptor into the different positions of the porphyrin (Por) based donor-π bridge-acceptor (D-π-A) dye (FNE57) to construct D-A‧-Por-π-A (FNE58) and D-Por-A‧-π-A (FNE59) configurations. The incorporation of DPQ unit between the donor and porphyrin unit has negligible influence on the absorption property, whereas the DPQ unit located between the porphyrin unit and acceptor significantly increases the absorbance for the Soret band and the valley between the Soret and Q bands. Theoretical calculation reveals that incorporating the DPQ unit adjacent to the acceptor is more advantageous to delocalize the lowest unoccupied molecular orbital and enhance the electronic asymmetry, which facilitates the intramolecular charge transfer. The effect of DPQ unit and its linkage position on the performance of related quasi-solid-state dye-sensitized solar cells (DSSCs) is systematically investigated. The quasi-solid-state DSSC with sensitizer FNE59 displays a power conversion efficiency of 6.02%, which is 23% and 51% higher than those for FNE57 and FNE58 based DSSCs. Our studies facilitate the understanding of the crucial importance of molecular engineering and pave a new path to design novel porphyrin based sensitizers for highly efficient DSSCs.

  2. Dorsal striatal D2-like receptor availability covaries with sensitivity to positive reinforcement during discrimination learning.

    Science.gov (United States)

    Groman, Stephanie M; Lee, Buyean; London, Edythe D; Mandelkern, Mark A; James, Alex S; Feiler, Karen; Rivera, Ronald; Dahlbom, Magnus; Sossi, Vesna; Vandervoort, Eric; Jentsch, J David

    2011-05-18

    Deviations in reward sensitivity and behavioral flexibility, particularly in the ability to change or stop behaviors in response to changing environmental contingencies, are important phenotypic dimensions of several neuropsychiatric disorders. Neuroimaging evidence suggests that variation in dopamine signaling through dopamine D(2)-like receptors may influence these phenotypes, as well as associated psychiatric conditions, but the specific neurocognitive mechanisms through which this influence is exerted are unknown. To address this question, we examined the relationship between behavioral sensitivity to reinforcement during discrimination learning and D(2)-like receptor availability in vervet monkeys. Monkeys were assessed for their ability to acquire, retain, and reverse three-choice, visual-discrimination problems, and once behavioral performance had stabilized, they received positron emission tomography (PET) scans. D(2)-like receptor availability in dorsal aspects of the striatum was not related to individual differences in the ability to acquire or retain visual discriminations but did relate to the number of trials required to reach criterion in the reversal phase of the task. D(2)-like receptor availability was also strongly correlated with behavioral sensitivity to positive, but not negative, feedback during learning. These results go beyond electrophysiological findings by demonstrating the involvement of a striatal dopaminergic marker in individual differences in feedback sensitivity and behavioral flexibility, providing insight into the neural mechanisms that are affected in neuropsychiatric disorders that feature these deficits.

  3. Development of a simple test device for spindle error measurement using a position sensitive detector

    Science.gov (United States)

    Liu, Chien-Hung; Jywe, Wen-Yuh; Lee, Hau-Wei

    2004-09-01

    A new spindle error measurement system has been developed in this paper. It employs a design development rotational fixture with a built-in laser diode and four batteries to replace a precision reference master ball or cylinder used in the traditional method. Two measuring devices with two position sensitive detectors (one is designed for the measurement of the compound X-axis and Y-axis errors and the other is designed with a lens for the measurement of the tilt angular errors) are fixed on the machine table to detect the laser point position from the laser diode in the rotational fixture. When the spindle rotates, the spindle error changes the direction of the laser beam. The laser beam is then divided into two separated beams by a beam splitter. The two separated beams are projected onto the two measuring devices and are detected by two position sensitive detectors, respectively. Thus, the compound motion errors and the tilt angular errors of the spindle can be obtained. Theoretical analysis and experimental tests are presented in this paper to separate the compound errors into two radial errors and tilt angular errors. This system is proposed as a new instrument and method for spindle metrology.

  4. Role of induced negative and positive emotions in sensitivity to itch and pain in women.

    Science.gov (United States)

    van Laarhoven, A I M; Walker, A L; Wilder-Smith, O H; Kroeze, S; van Riel, P L C M; van de Kerkhof, P C M; Kraaimaat, F W; Evers, A W M

    2012-08-01

    Itch and pain are common symptoms in skin disease. It has been suggested that negative emotions may play a role in itch and pain. To date, however, the role of emotions has only been studied for pain in experimental studies, not yet for itch. To investigate the effects of negative and positive emotions on the sensitivity to itch and pain. Film fragments were used to induce a negative or positive emotional state in healthy women. Itch and pain were induced using the following somatosensory stimuli: electrical stimulation, histamine iontophoresis and the cold pressor test. Results showed that the scores for itch and pain evoked by histamine and the cold pressor test, respectively, were significantly higher in the negative than in the positive emotion condition, whereas tolerance thresholds to electrical stimulation and the cold pressor test, and stimulus unpleasantness scores did not differ between the two conditions. These findings for the first time indicate in an experimental design that emotions play a role in sensitivity to somatosensory sensations of both itch and pain. © 2012 The Authors. BJD © 2012 British Association of Dermatologists.

  5. A large, high performance, curved 2D position-sensitive neutron detector

    CERN Document Server

    Fried, J W; Mahler, G J; Makowiecki, D S; Mead, J A; Radeka, V; Schaknowski, N A; Smith, G C; Yu, B

    2002-01-01

    A new position-sensitive neutron detector has been designed and constructed for a protein crystallography station at LANL's pulsed neutron source. This station will be one of the most advanced instruments at a major neutron user facility for protein crystallography, fiber and membrane diffraction. The detector, based on neutron absorption in sup 3 He, has a large sensitive area of 3000 cm sup 2 , angular coverage of 120 deg. , timing resolution of 1 mu s, rate capability in excess of 10 sup 6 s sup - sup 1 , position resolution of about 1.5 mm FWHM, and efficiency >50% for neutrons of interest in the range 1-10 A. Features that are key to these remarkable specifications are the utilization of eight independently operating segments within a single gas volume, fabrication of the detector vessel and internal segments with a radius of curvature of about 70 cm, optimized position readout based on charge division and signal shaping with gated baseline restoration, and engineering design with high-strength aluminum ...

  6. Adhesion Force Measurements Using an Atomic Force Microscope Upgraded with a Linear Position Sensitive Detector

    Science.gov (United States)

    Pierce, M.; Stuart, J.; Pungor, A.; Dryden, P.

    2012-01-01

    The atomic force microscope (AFM), in addition to providing images on an atomic scale, can be used to measure the forces between surfaces and the AFM probe. The potential uses of mapping the adhesive forces on the surface include a spatial determination of surface energy and a direct identification of surface proteins through specific protein–ligand binding interactions. The capabilities of the AFM to measure adhesive forces can be extended by replacing the four-quadrant photodiode detection sensor with an external linear position sensitive detector and by utilizing a dedicated user-programmable signal generator and acquisiton system. Such an upgrade enables the microscope to measure in the larger dynamic range of adhesion forces, improves the sensitivity and linearity of the measurement, and eliminates the problems inherent to the multiple repetitious contacts between the AFM probe and the specimen surface. PMID:25125792

  7. Array of 12 coils to measure the position, alignment, and sensitivity of magnetic sensors over temperature

    Science.gov (United States)

    Husstedt, Hendrik; Ausserlechner, Udo; Kaltenbacher, Manfred

    2012-04-01

    A measurement setup is presented that allows one to determine the position, alignment, and sensitivity of magnetic sensors over temperature. To this end, an array of 12 coils is used where the number of coils is larger than the number of unknowns to increase accuracy, and to ensure an adequate measurement signal for an arbitrary orientation of the magnetic sensors. With this coil array, a 3D sensing system is analyzed which is used during the testing of automotive magnetic sensors. In particular, the influence of assembly tolerances, and the variation of temperature are examined.

  8. CdZnTe position-sensitive drift detectors with thicknesses up to 5 cm

    Science.gov (United States)

    Bolotnikov, A. E.; Camarda, G. S.; Chen, E.; Cheng, S.; Cui, Y.; Gul, R.; Gallagher, R.; Dedic, V.; De Geronimo, G.; Ocampo Giraldo, L.; Fried, J.; Hossain, A.; MacKenzie, J. M.; Sellin, P.; Taherion, S.; Vernon, E.; Yang, G.; El-hanany, U.; James, R. B.

    2016-02-01

    We investigated the feasibility of long-drift-time CdZnTe (CZT) gamma-ray detectors, fabricated from CZT material produced by Redlen Technologies. CZT crystals with cross-section areas of 5 × 5 mm2 and 6 × 6 mm2 and thicknesses of 20-, 30-, 40-, and 50-mm were configured as 3D position-sensitive drift detectors and were read out using a front-end ASIC. By correcting the electron charge losses caused by defects in the crystals, we demonstrated high performance for relatively thick detectors fabricated from unselected CZT material.

  9. CdZnTe position-sensitive drift detectors with thicknesses up to 5 cm

    OpenAIRE

    Bolotnikov, AE; Camarda, GS; Chen, E.; Cheng, S.; Cui, Y.; Gul, R; Gallagher, R; Dedic, V.; De Geronimo, G.; Giraldo, LO; Fried, J.; Hossain, A; MacKenzie, JM; Sellin, P.; Taherion, S

    2016-01-01

    We investigated the feasibility of long-drift-time CdZnTe (CZT) gamma-ray detectors, fabricated from CZT material produced by Redlen Technologies. CZT crystals with cross-section areas of 5 5 mm2 and 6 6 mm2 and thicknesses of 20-, 30-, 40-, and 50-mm were configured as 3D position-sensitive drift detectors and were read out using a front-end ASIC. By correcting the electron charge losses caused by defects in the crystals, we demonstrated high performance for relatively thick detectors fabric...

  10. Identifying Moderators of the Link Between Parent and Child Anxiety Sensitivity: The Roles of Gender, Positive Parenting, and Corporal Punishment.

    Science.gov (United States)

    Graham, Rebecca A; Weems, Carl F

    2015-07-01

    A substantial body of literature suggests that anxiety sensitivity is a risk factor for the development of anxiety problems and research has now begun to examine the links between parenting, parent anxiety sensitivity and their child's anxiety sensitivity. However, the extant literature has provided mixed findings as to whether parent anxiety sensitivity is associated with child anxiety sensitivity, with some evidence suggesting that other factors may influence the association. Theoretically, specific parenting behaviors may be important to the development of child anxiety sensitivity and also in understanding the association between parent and child anxiety sensitivity. In this study, 191 families (n = 255 children and adolescents aged 6-17 and their parents) completed measures of child anxiety sensitivity (CASI) and parenting (APQ-C), and parents completed measures of their own anxiety sensitivity (ASI) and their parenting (APQ-P). Corporal punishment was associated with child anxiety sensitivity and the child's report of their parent's positive parenting behaviors moderated the association between parent and child anxiety sensitivity. The child's gender was also found to moderate the association between parent and child anxiety sensitivity, such that there was a positive association between girls' and their parents anxiety sensitivity and a negative association in boys. The findings advance the understanding of child anxiety sensitivity by establishing a link with corporal punishment and by showing that the association between parent and child anxiety sensitivity may depend upon the parenting context and child's gender.

  11. Antibiotic sensitivity pattern in blaNDM-1-positive and carbapenemase-producing Enterobacteriaceae.

    Science.gov (United States)

    Mulla, Summaiya; Charan, Jaykaran; Rajdev, Sangita

    2016-01-01

    Some studies published in recent time revealed that many bacteria from Enterobacteriaceae group are multi-antibiotic-resistant because of the production enzymes carbapenemase particularly New Delhi metallo-beta-lactamase encoded by gene called blaNDM-1. Looking at public health importance of this issue there is a need for studies at other centers to confirm or refute published findings. This study was designed with the aim of exploring antibiotic resistance in Enterobacteriaceae group of bacteria and also to explore gene and enzyme responsible for it. Samples of Enterobacteriaceae were collected from wards and outpatient departments. Antibiotic sensitivity was checked by an automated system (VITEK 2 COMPACT). Carbapenemase production was assessed by Modified Hodge Test. Presence of blaNDM-1 was assessed by polymerase chain reaction. Frequency and percentage were used to describe the data. Frequency of sensitivity was compared between carbapenemase producers and noncarbapenemase producers by Fisher's exact test. Forty-seven percent bacteria were found to be producing carbapenemase enzyme. These bacteria were significantly less sensitive to cefoperazone, cefepime, and amikacin. Among carbapenemase-producing organisms, 3% and 6% were resistant to tigecycline and colistin, respectively. Forty percent bacteria were found to be having blaNDM-1 gene. There was a significant difference between blaNDM-1-positive and blaNDM-1-negative for sensitivity toward cefoperazone + sulbactam, imipenem, meropenem, amikacin, tobramycine, ciprofloxacin, and levofloxacin. Presence of carbapenemase enzyme and blaNDM-1 gene is associated with high level of resistance in Enterobacteriaceae group of bacteria and only few antibiotics have good sensitivity for these organisms.

  12. Demonstration of a high sensitivity GNSS software receiver for indoor positioning

    Science.gov (United States)

    Lin, Tao; Ma, Martin; Broumandan, Ali; Lachapelle, Gérard

    2013-03-01

    Advances in signal processing techniques contributed to the significant improvements of GNSS receiver performance in dense multipath environments and created the opportunities for a new category of high-sensitivity GNSS (HS-GNSS) receivers that can provide GNSS location services in indoor environments. The difficulties in improving the availability, reliability, and accuracy of these indoor capable GNSS receivers exceed those of the receivers designed for the most hostile urban canyon environments. The authors of this paper identified the vector tracking schemes, signal propagation statistics, and parallel processing techniques that are critical to a robust HS-GNSS receiver for indoor environments and successfully incorporated them into a fully functional high-sensitivity software receiver. A flexible vector-based receiver architecture is introduced to combine these key indoor signal processing technologies into GSNRx-hs™ - the high sensitivity software navigation receiver developed at the University of Calgary. The resulting receiver can perform multi-mode vector tracking in indoor environment at various levels of location and timing uncertainties. In addition to the obvious improvements in time-to-first-fix (TTFF) and signal sensitivity, the field test results in indoor environments surrounded by wood, glass, and concrete showed that the new techniques effectively improved the performance of indoor GNSS positioning. With fine GNSS timing, the proposed receiver can consistently deliver indoor navigation solution with the horizontal accuracy of 2-15 m depending on the satellite geometry and the indoor environments. If only the coarse GNSS timing is available, the horizontal accuracy of the indoor navigation solution from the proposed receiver is around 30 m depending on the coarse timing accuracy, the satellite geometry, and the indoor environments. From the preliminary field test results, it has been observed that the signal processing sensitivity is the

  13. Time and position sensitive single photon detector for scintillator read-out

    Science.gov (United States)

    Schössler, S.; Bromberger, B.; Brandis, M.; Schmidt, L. Ph H.; Tittelmeier, K.; Czasch, A.; Dangendorf, V.; Jagutzki, O.

    2012-02-01

    We have developed a photon counting detector system for combined neutron and γ radiography which can determine position, time and intensity of a secondary photon flash created by a high-energy particle or photon within a scintillator screen. The system is based on a micro-channel plate photomultiplier concept utilizing image charge coupling to a position- and time-sensitive read-out anode placed outside the vacuum tube in air, aided by a standard photomultiplier and very fast pulse-height analyzing electronics. Due to the low dead time of all system components it can cope with the high throughput demands of a proposed combined fast neutron and dual discrete energy γ radiography method (FNDDER). We show tests with different types of delay-line read-out anodes and present a novel pulse-height-to-time converter circuit with its potential to discriminate γ energies for the projected FNDDER devices for an automated cargo container inspection system (ACCIS).

  14. A two-dimensional position sensitive gas chamber with scanned charge transfer readout

    Science.gov (United States)

    Gómez, F.; Iglesias, A.; Lobato, R.; Mosquera, J.; Pardo, J.; Pena, J.; Pazos, A.; Pombar, M.; Rodríguez, A.

    2003-10-01

    We have constructed and tested a two-dimensional position sensitive parallel-plate gas ionization chamber with scanned charge transfer readout. The scan readout method described here is based on the development of a new position-dependent charge transfer technique. It has been implemented by using gate strips perpendicularly oriented to the collector strips. This solution reduces considerably the number of electronic readout channels needed to cover large detector areas. The use of a 25 μm thick kapton etched circuit allows high charge transfer efficiency with a low gating voltage, consequently needing a very simple commutating circuit. The present prototype covers 8×8 cm2 with a pixel size of 1.27×1.27 mm2. Depending on the intended use and beam characteristics a smaller effective pixel is feasible and larger active areas are possible. This detector can be used for X-ray or other continuous beam intensity profile monitoring.

  15. A diagnostic for micrometer sensitive positioning of solid targets in intense laser-matter interaction

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Prashant Kumar, E-mail: singh01@ibs.re.kr [Center for Relativistic Laser Science, Institute for Basic Science (IBS), Gwangju 500-712 (Korea, Republic of); Kakolee, K.F. [Center for Relativistic Laser Science, Institute for Basic Science (IBS), Gwangju 500-712 (Korea, Republic of); Jeong, T.W. [Center for Relativistic Laser Science, Institute for Basic Science (IBS), Gwangju 500-712 (Korea, Republic of); Department of Physics and Photon Science, GIST, Gwangju 500-712 (Korea, Republic of); Ter-Avetisyan, Sargis, E-mail: sargis@ibs.re.kr [Center for Relativistic Laser Science, Institute for Basic Science (IBS), Gwangju 500-712 (Korea, Republic of); Department of Physics and Photon Science, GIST, Gwangju 500-712 (Korea, Republic of)

    2016-09-01

    A target position monitoring diagnostic, relevant to intense laser-solid interaction, is presented. The alignment system, having a sensitivity of few micrometers, consist of an infinity corrected long working distance objective, a broadband illuminating source and a CCD camera. The imaging system, placed along the axis of incident laser pulse, serves the dual purpose of laser focus diagnosis and precise positioning of the target in three dimension axis. By employing this technique, solid targets with thickness varying from opaque micrometer thick foils to few nanometer thin transparent foils can be aligned precisely. The effectiveness of the entire alignment system is demonstrated in enhanced acceleration of ions in intense laser-matter interaction, with very high reproducibility.

  16. First Investigation on a novel 2D position sensitive semiconductor detector concept

    CERN Document Server

    Bassignana, D; Jaramillo, R; Lozano, M; Munoz, F.J; Pellegrini, G; Quirion, D; Vila, I

    2012-01-01

    This paper presents a first study of the performance of a novel 2D position-sensitive microstrip detector, where the resistive charge division method was implemented by replacing the metallic electrodes with resistive electrodes made of polycrystalline silicon. A characterization of two proof-of-concept prototypes with different values of the electrode resistivity was carried out using a pulsed Near Infra-Red laser. The experimental data were compared with the electrical simulation of the sensor equivalent circuit coupled to simple electronics readout circuits. The good agreement between experimental and simulation results establishes the soundness of resistive charge division method in silicon microstrip sensors and validates the developed simulation as a tool for the optimization of future sensor prototypes. Spatial resolution in the strip length direction depends on the ionizing event position. The average value obtained from the protype analysis is close to 1.2% of the strip length for a 6 MIP signal.

  17. Time and position sensitive single photon detector for scintillator read-out

    CERN Document Server

    Schössler, Sven; Brandis, Michal; Schmidt, Lothar Ph H; Tittelmeier, Kai; Czasch, Achim; Dangendorf, Volker; Jagutzki, Ottmar

    2012-01-01

    We have developed a photon counting detector system for combined neutron and gamma radiography which can determine position, time and intensity of a secondary photon flash created by a high-energy particle or photon within a scintillator screen. The system is based on a micro-channel plate photomultiplier concept utilizing image charge coupling to a position- and time-sensitive read-out anode placed outside the vacuum tube in air, aided by a standard photomultiplier and very fast pulse-height analyzing electronics. Due to the low dead time of all system components it can cope with the high throughput demands of a proposed combined fast neutron and dual discrete energy gamma radiography method (FNDDER). We show tests with different types of delay-line read-out anodes and present a novel pulse-height-to-time converter circuit with its potential to discriminate gamma energies for the projected FNDDER devices for an automated cargo container inspection system (ACCIS).

  18. A multiplexed TOF and DOI capable PET detector using a binary position sensitive network.

    Science.gov (United States)

    Bieniosek, M F; Cates, J W; Levin, C S

    2016-11-07

    Time of flight (TOF) and depth of interaction (DOI) capabilities can significantly enhance the quality and uniformity of positron emission tomography (PET) images. Many proposed TOF/DOI PET detectors require complex readout systems using additional photosensors, active cooling, or waveform sampling. This work describes a high performance, low complexity, room temperature TOF/DOI PET module. The module uses multiplexed timing channels to significantly reduce the electronic readout complexity of the PET detector while maintaining excellent timing, energy, and position resolution. DOI was determined using a two layer light sharing scintillation crystal array with a novel binary position sensitive network. A 20 mm effective thickness LYSO crystal array with four 3 mm  ×  3 mm silicon photomultipliers (SiPM) read out by a single timing channel, one energy channel and two position channels achieved a full width half maximum (FWHM) coincidence time resolution of 180  ±  2 ps with 10 mm of DOI resolution and 11% energy resolution. With sixteen 3 mm  ×  3 mm SiPMs read out by a single timing channel, one energy channel and four position channels a coincidence time resolution 204  ±  1 ps was achieved with 10 mm of DOI resolution and 15% energy resolution. The methods presented here could significantly simplify the construction of high performance TOF/DOI PET detectors.

  19. A multiplexed TOF and DOI capable PET detector using a binary position sensitive network

    Science.gov (United States)

    Bieniosek, M. F.; Cates, J. W.; Levin, C. S.

    2016-11-01

    Time of flight (TOF) and depth of interaction (DOI) capabilities can significantly enhance the quality and uniformity of positron emission tomography (PET) images. Many proposed TOF/DOI PET detectors require complex readout systems using additional photosensors, active cooling, or waveform sampling. This work describes a high performance, low complexity, room temperature TOF/DOI PET module. The module uses multiplexed timing channels to significantly reduce the electronic readout complexity of the PET detector while maintaining excellent timing, energy, and position resolution. DOI was determined using a two layer light sharing scintillation crystal array with a novel binary position sensitive network. A 20 mm effective thickness LYSO crystal array with four 3 mm  ×  3 mm silicon photomultipliers (SiPM) read out by a single timing channel, one energy channel and two position channels achieved a full width half maximum (FWHM) coincidence time resolution of 180  ±  2 ps with 10 mm of DOI resolution and 11% energy resolution. With sixteen 3 mm  ×  3 mm SiPMs read out by a single timing channel, one energy channel and four position channels a coincidence time resolution 204  ±  1 ps was achieved with 10 mm of DOI resolution and 15% energy resolution. The methods presented here could significantly simplify the construction of high performance TOF/DOI PET detectors.

  20. Position-sensitive radiation monitoring (surface contamination monitor). Innovative technology summary report

    Energy Technology Data Exchange (ETDEWEB)

    1999-06-01

    The Shonka Research Associates, Inc. Position-Sensitive Radiation Monitor both detects surface radiation and prepares electronic survey map/survey report of surveyed area automatically. The electronically recorded map can be downloaded to a personal computer for review and a map/report can be generated for inclusion in work packages. Switching from beta-gamma detection to alpha detection is relatively simple and entails moving a switch position to alpha and adjusting the voltage level to an alpha detection level. No field calibration is required when switching from beta-gamma to alpha detection. The system can be used for free-release surveys because it meets the federal detection level sensitivity limits requires for surface survey instrumentation. This technology is superior to traditionally-used floor contamination monitor (FCM) and hand-held survey instrumentation because it can precisely register locations of radioactivity and accurately correlate contamination levels to specific locations. Additionally, it can collect and store continuous radiological data in database format, which can be used to produce real-time imagery as well as automated graphics of survey data. Its flexible design can accommodate a variety of detectors. The cost of the innovative technology is 13% to 57% lower than traditional methods. This technology is suited for radiological surveys of flat surfaces at US Department of Energy (DOE) nuclear facility decontamination and decommissioning (D and D) sites or similar public or commercial sites.

  1. A position-sensitive twin ionization chamber for fission fragment and prompt neutron correlation experiments

    Energy Technology Data Exchange (ETDEWEB)

    Göök, A.; Geerts, W.; Hambsch, F.-J.; Oberstedt, S.; Vidali, M. [European Commission, Joint Research Centre, Institute for Reference Materials and Measurements, Retieseweg 111, B-2440 Geel (Belgium); Zeynalov, Sh. [Joint Institute for Nuclear Research, Joliot-Curie 6, 141980 Dubna, Mosow region (Russian Federation)

    2016-09-11

    A twin position-sensitive Frisch grid ionization chamber, intended as a fission fragment detector in experiments to study prompt fission neutron correlations with fission fragment properties, is presented. Fission fragment mass and energies are determined by means of the double kinetic energy technique, based on conservation of mass and linear momentum. The position sensitivity is achieved by replacing each anode plate in the standard twin ionization chamber by a wire plane and a strip anode, both readout by means of resistive charge division. This provides information about the fission axis orientation, which is necessary to reconstruct the neutron emission process in the fully accelerated fragment rest-frame. The energy resolution compared to the standard twin ionization chamber is found not to be affected by the modification. The angular resolution of the detector relative to an arbitrarily oriented axis is better than 7° FWHM. Results on prompt fission neutron angular distributions in {sup 235}U(n,f) obtained with the detector in combination with an array of neutron scintillation detectors is presented as a proof of principle.

  2. A position-sensitive twin ionization chamber for fission fragment and prompt neutron correlation experiments

    Science.gov (United States)

    Göök, A.; Geerts, W.; Hambsch, F.-J.; Oberstedt, S.; Vidali, M.; Zeynalov, Sh.

    2016-09-01

    A twin position-sensitive Frisch grid ionization chamber, intended as a fission fragment detector in experiments to study prompt fission neutron correlations with fission fragment properties, is presented. Fission fragment mass and energies are determined by means of the double kinetic energy technique, based on conservation of mass and linear momentum. The position sensitivity is achieved by replacing each anode plate in the standard twin ionization chamber by a wire plane and a strip anode, both readout by means of resistive charge division. This provides information about the fission axis orientation, which is necessary to reconstruct the neutron emission process in the fully accelerated fragment rest-frame. The energy resolution compared to the standard twin ionization chamber is found not to be affected by the modification. The angular resolution of the detector relative to an arbitrarily oriented axis is better than 7° FWHM. Results on prompt fission neutron angular distributions in 235U(n,f) obtained with the detector in combination with an array of neutron scintillation detectors is presented as a proof of principle.

  3. A Study of Position-Sensitive Solid-State Photomultiplier Signal Properties.

    Science.gov (United States)

    Schmall, Jeffrey P; Du, Junwei; Judenhofer, Martin S; Dokhale, Purushottam; Christian, James; McClish, Mickel; Shah, Kanai S; Cherry, Simon R

    2014-06-12

    We present an analysis of the signal properties of a position-sensitive solid-state photomultiplier (PS-SSPM) that has an integrated resistive network for position sensing. Attractive features of PS-SSPMs are their large area and ability to resolve small scintillator crystals. However, the large area leads to a high detector capacitance, and in order to achieve high spatial resolution a large network resistor value is required. These inevitably create a low-pass filter that drastically slows what would be a fast micro-cell discharge pulse. Significant changes in the signal shape of the PS-SSPM cathode output as a function of position are observed, which result in a position-dependent time delay when using traditional time pick-off methods such as leading edge discrimination and constant fraction discrimination. The timing resolution and time delay, as a function of position, were characterized for two different PS-SSPM designs, a continuous 10 mm × 10 mm PS-SSPM and a tiled 2 × 2 array of 5 mm × 5 mm PS-SSPMs. After time delay correction, the block timing resolution, measured with a 6 × 6 array of 1.3 × 1.3 × 20 mm(3) LSO crystals, was 8.6 ns and 8.5 ns, with the 10 mm PS-SSPM and 5 mm PS-SSPM respectively. The effect of crystal size on timing resolution was also studied, and contrary to expectation, a small improvement was measured when reducing the crystal size from 1.3 mm to 0.5 mm. Digital timing methods were studied and showed great promise for allowing accurate timing by implementation of a leading edge time pick-off. Position-dependent changes in signal shape on the anode side also are present, which complicates peak height data acquisition methods used for positioning. We studied the effect of trigger position on signal amplitude, flood histogram quality, and depth-of-interaction resolution in a dual-ended readout detector configuration. We conclude that detector timing and positioning can be significantly improved by implementation of digital timing

  4. An animal PET scanner using flat-panel position-sensitive PMTs.

    Science.gov (United States)

    Okamoto, Takashi; Ote, Kibou; Sakai, Koichi; Noda, Akihiro; Shimizu, Keiji; Masuda, Keisuke; Ohmura, Tomohide; Watanabe, Mitsuo

    2014-01-01

    To design, build, and evaluate an animal PET scanner, which can be used with non-human primates under conscious condition, incorporating flat-panel position-sensitive photomultiplier tubes (PS-PMTs). The system contains 30 detector modules, each having two PS-PMTs and 16×18 lutetium–yttrium oxyortho-silicate scintillation crystal arrays. The system has 17,280 crystals (480 per ring) arranged in 36 rings, with a diameter of 508 mm and axial extent of 108 mm. The gantry tilt mechanism enables PET studies to be performed on a monkey in the sitting position. Data can be acquired in either the 2D or 3D mode, with the slice collimators being retracted in the 3D mode. At the center of the field-of-view, radial resolution is 2.7 mm full width at half maximum (FWHM) and tangential resolution is 2.4 mm FWHM, while axial resolution is 2.5 mm FWHM for direct slices and 2.7 mm FWHM for cross slices. Scatter fraction, count rate capability, and sensitivity were evaluated using a cylindrical phantom 10 cm in diameter. The noise equivalent count rate in the 3D mode is equivalent to that in the 2D mode at a three times higher radioactivity level. Total system sensitivity is 1.3 kcps/(kBq/mL) in 2D mode and 7.4 kcps/(kBq/mL) in the 3D mode. Animal studies with a monkey were performed to evaluate the imaging capabilities of the scanner. The new PET scanner will be a useful research tool with non-human primates for pre-clinical drug development.

  5. Preliminary Study of Position-Sensitive Large-Area Radiation Portal Monitor

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Chang Hwy; Kim, Hyunok; Moon, Myung Kook [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Kim, Jongyul [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Park, Jong Won; Lim, Yong Kon [Korea Institute of Ocean Science and Technology, Daejeon (Korea, Republic of)

    2013-10-15

    An RPM, which is a passive inspection method, is a system for monitoring the movement of radioactive materials at an airport, seaport, border, etc. To detect a γ-ray, an RPM using the plastic scintillator is generally used. The method of γ-ray detection using an RPM with a plastic scintillator is to measure lights generated by an incident γ-ray in the scintillator. Generally, a large-area RPM uses one or two photomultiplier tubes (PMT) for light collection. However, in this study, we developed a 4-ch RPM that can measure the radiation signal using 4 PMTs. The reason for using 4 PMTs is to calculate the position of the radiation source. In addition, we developed an electric device for acquisition of a 4-ch output signal at the same time. To estimate the performance of the developed RPM, we performed an RPM test using a {sup 60}Co γ-ray check source. In this study, we performed the development of a 4-ch RPM. The major function of the typical RPM is to measure the radiation. However, we developed a position-sensitive 4-ch RPM, which can be used to measure the location of the radiation source, as well as the radiation measurement, at the same time. In the future, we plan to develop an algorithm for a position detection of the radiation. In addition, an algorithm will be applied to an RPM.

  6. Development of Position-Sensitive Magnetic Calorimeters for X-Ray Astronomy

    Science.gov (United States)

    Bandler, SImon; Stevenson, Thomas; Hsieh, Wen-Ting

    2011-01-01

    Metallic magnetic calorimeters (MMC) are one of the most promising devices to provide very high energy resolution needed for future astronomical x-ray spectroscopy. MMC detectors can be built to large detector arrays having thousands of pixels. Position-sensitive magnetic (PoSM) microcalorimeters consist of multiple absorbers thermally coupled to one magnetic micro calorimeter. Each absorber element has a different thermal coupling to the MMC, resulting in a distribution of different pulse shapes and enabling position discrimination between the absorber elements. PoSMs therefore achieve the large focal plane area with fewer number of readout channels without compromising spatial sampling. Excellent performance of PoSMs was achieved by optimizing the designs of key parameters such as the thermal conductance among the absorbers, magnetic sensor, and heat sink, as well as the absorber heat capacities. Micro fab ri - cation techniques were developed to construct four-absorber PoSMs, in which each absorber consists of a two-layer composite of bismuth and gold. The energy resolution (FWHM full width at half maximum) was measured to be better than 5 eV at 6 keV x-rays for all four absorbers. Position determination was demonstrated with pulse-shape discrimination, as well as with pulse rise time. X-ray microcalorimeters are usually designed to thermalize as quickly as possible to avoid degradation in energy resolution from position dependence to the pulse shapes. Each pixel consists of an absorber and a temperature sensor, both decoupled from the cold bath through a weak thermal link. Each pixel requires a separate readout channel; for instance, with a SQUID (superconducting quantum interference device). For future astronomy missions where thousands to millions of resolution elements are required, having an individual SQUID readout channel for each pixel becomes difficult. One route to attaining these goals is a position-sensitive detector in which a large continuous or

  7. Position-sensitive detection of ultracold neutrons with an imaging camera and its implications to spectroscopy

    CERN Document Server

    Wei, Wanchun; Hoffbauer, M A; Makela, M; Morris, C L; Tang, Z; Adamek, E R; Callahan, N B; Clayton, S M; Cude-Woods, C; Currie, S; Dees, E B; Ding, X; Geltenbort, P; Hickerson, K P; Holley, A T; Ito, T M; Leung, K K; Liu, C -Y; Morley, D J; Ramsey, J C; Pattie,, R W; Salvat, D J; Saunders, A; Seestrom, S J; Sharapov, E I; Sjue, S K; Wexler, J; Womack, T L; Young, A R; Zeck, B A; Wang, Zhehui

    2016-01-01

    Position-sensitive detection of ultracold neutrons (UCNs) is demonstrated using an imaging charge-coupled device (CCD) camera. A spatial resolution less than 15 $\\mu$m has been achieved, which through the relation $\\delta E = m_0g \\delta x$, converts to UCN energy resolution below 2 pico-electron volts. The symbols $\\delta E$, $\\delta x$, $m_0$ and $g$ are for energy resolution, spatial resolution, the neutron rest mass and gravitational acceleration respectively. A multilayer surface convertor described previously is used to capture UCNs and emits visible light for CCD imaging. Particle identification and noise rejection are discussed through light intensity profile analysis. This method allows new types of UCN spectroscopy and various applications.

  8. Simulation and optimisation of a position sensitive scintillation detector with wavelength shifting fibers for thermal neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Herzkamp, Matthias; Engels, Ralf; Kemmerling, Guenter [ZEA-2, Forschungszentrum Juelich (Germany); Brueckel, Thomas [JCNS, Forschungszentrum Juelich (Germany); Stahl, Achim [III. Physikalisches Institut B, RWTH Aachen (Germany); Waasen, Stefan van [ZEA-2, Forschungszentrum Juelich (Germany); Faculty of Engineering, University of Duisburg-Essen (Germany)

    2015-07-01

    In neutron scattering experiments it is important to have position sensitive large scale detectors for thermal neutrons. A detector based on a neutron scintillator with wave length shifting fibers is a new kind of such a detector. We present the simulation of the detector based on the microscopic structure of the scintillation material of the mentioned detector. It consists of a converter and a scintillation powder bound in a matrix. The converter in our case is lithium fluoride with enriched lithium 6, to convert thermal neutrons into high energetic alpha and triton particles. The scintillation material is silver doped zinc sulfide. We show that pulse height spectra obtained by these scintillators can be be explained by the simple model of randomly distributed spheres of zinc sulfide and lithium fluoride. With this model, it is possible to optimise the mass ratio of zinc sulfide to lithium fluoride with respect to detection efficiency and/or energy deposition in zinc sulfide.

  9. Application of 2-D Position Sensitive Detector in Spatial Straightness Measurement of Guide Rails

    Institute of Scientific and Technical Information of China (English)

    GUO Lifeng; ZHANG Guoxiong; GONG Qiang; ZHENG Qi

    2005-01-01

    A laser collimating system based on 2-D position sensitive detector (PSD) is presented in this paper. The working principle of PSD is depicted in detail. A calibration device was developed to check the nonlinearity errors of PSD and a multilayer feedforward neural network based on error back-propagation algorithm was used to compensate errors. With the aid of computer-based data acquisition system, an automatic dynamic measuring process was realized. A series of experiments, including comparison tests with laser interferometer, were done to evaluate the performance of the measuring system. The experimental results show that the spatial straightness errors of guide rails can be measured with high accuracy. The maximum differences between the device and laser interferometer are 0.027 mm in Y direction, and 0.053 mm in X direction in the measuring distance of 6 m.

  10. A large area position-sensitive ionization chamber for heavy-ion-induced reaction studies

    Energy Technology Data Exchange (ETDEWEB)

    Pant, L.M. E-mail: lalit.pant@exp2.physik.uni-giessen.de; Biswas, D.C.; Dinesh, B.V.; Thomas, R.G.; Saxena, A.; Sawant, Y.S.; Choudhury, R.K

    2002-12-11

    A large area position-sensitive ionization chamber with a wide dynamic range has been developed to measure the mass, charge and energy of the heavy ions and the fission fragments produced in heavy-ion-induced reactions. The split anode geometry of the detector makes it suitable for both particle identification and energy measurements for heavy ions and fission fragments. The detector has been tested with {alpha} particles from {sup 241}Am-{sup 239}Pu source, fission fragments from {sup 252}Cf and the heavy-ion beams from the 14UD Mumbai Pelletron accelerator facility. Using this detector, measurements on mass and total kinetic energy distributions in heavy-ion-induced fusion-fission reactions have been carried out for a wide range of excitation energies. Results on deep inelastic collisions and mass-energy correlations on different systems using this detector setup are discussed.

  11. A position-sensitive detector with lithium glass and MaPMT

    Institute of Scientific and Technical Information of China (English)

    FU Zai-Wei; LIU Shu-Dong; LEI Xiang-Cui; HUANG Guo-Rui; JIA Ru; HENG Yue-Kun; QI Ming; HUANG Chang-Hao; LIU Shu-Lin; QIAN Sen; LI Shao-Li; CHEN Xiao-Hui

    2012-01-01

    A position-sensitive detector is designed for neutron detection.It uses a single continuous screen of a self-made lithium glass scintillator,rather than discrete crystal implementations,coupling with a multianode PMT (MaPMT).The scintillator is fast and efficient; with a decay time of 34 ns and thermal neutron detection efficiency of around 95.8% for the 3 mm thick screen,and its light yield is around 5670 photons per neutron and 3768 photons per MeV γrays deposition.The spatial resolution is around 1.6 mm (FWHM) with the energy resolution around 34.7% by using α (5.2 MeV) rays test.

  12. Development of an optical lens based alpha-particle imaging system using position sensitive photomultiplier tube

    Science.gov (United States)

    Ando, Koki; Oka, Miki; Yamamoto, Seiichi

    2017-02-01

    We developed an optical lens based alpha-particle imaging system using position sensitive photomultiplier tube (PSPMT). The alpha-particle imaging system consists of an optical lens, an extension tube and a 1 in. square high quantum efficiency (HQE) type PSPMT. After a ZnS(Ag) is attached to subject, the scintillation image of ZnS(Ag) is focused on the photocathode of the PSPMT by the use of the optical lens. With this configuration we could image the alpha particle distribution with energy information without contacting to the subject. The spatial resolution and energy resolution were 0.8 mm FWHM and 50% FWHM at 5 mm from the optical lens, respectively. We could successfully image the alpha particle distribution in uranium ore. The developed alpha-particle imaging system will be a new tool for imaging alpha emitters with energy information without contacting the subject.

  13. A large area position-sensitive ionization chamber for heavy-ion-induced reaction studies

    CERN Document Server

    Pant, L M; Dinesh, B V; Thomas, R G; Saxena, A; Sawant, Y S; Choudhury, R K

    2002-01-01

    A large area position-sensitive ionization chamber with a wide dynamic range has been developed to measure the mass, charge and energy of the heavy ions and the fission fragments produced in heavy-ion-induced reactions. The split anode geometry of the detector makes it suitable for both particle identification and energy measurements for heavy ions and fission fragments. The detector has been tested with alpha particles from sup 2 sup 4 sup 1 Am- sup 2 sup 3 sup 9 Pu source, fission fragments from sup 2 sup 5 sup 2 Cf and the heavy-ion beams from the 14UD Mumbai Pelletron accelerator facility. Using this detector, measurements on mass and total kinetic energy distributions in heavy-ion-induced fusion-fission reactions have been carried out for a wide range of excitation energies. Results on deep inelastic collisions and mass-energy correlations on different systems using this detector setup are discussed.

  14. Development of a novel 2D position-sensitive semiconductor detector concept

    CERN Document Server

    Bassignana, D; Jaramillo, R; Lozano, M; Munoz, F.J; Pellegrini, G; Quirion, D; Vila, I

    2012-01-01

    A novel 2D position-sensitive semiconductor detector concept has been developed employing resistive electrodes in a single-sided silicon microstrip sensor. The resistive charge division method has been implemented reading out each strip at both ends, in order to get the second coordinate of an ionizing event along the strips length. Two generations of prototypes, with different layout, have been produced and characterized using a pulsed near infra-red laser. The feasibility of the resistive charge division method in silicon microstrip detectors has been demonstrated and the possibility of single-chip readout of the device has been investigated. Experimental data were compared with the theoretical expectations and the electrical simulation of the sensor equivalent circuit coupled to simple electronics readout circuits. The agreement between experimental and simulation results validates the developed simulation as a tool for the optimization of future sensor prototypes.

  15. Two-dimensional photon counting imaging detector based on a Vernier position sensitive anode readout

    Institute of Scientific and Technical Information of China (English)

    YAN Qiu-Rong; ZHAO Bao-Sheng; LIU Yong-An; YANG Hao; SHENG Li-Zhi; WEI Yong-Lin

    2011-01-01

    A two-dimensional photon counting imaging detector based on a Vernier position sensitive anode is reported. The decode principle and design of a two-dimensionai Vernier anode axe introduced in detail. A photon counting imaging system was built based on a Vernier anode. The image of very weak optical radiation can be reconstructed by image processing in a period of integration time. The resolution is superior to 100 μm according to the resolution test. The detector may realize the imaging of very weak particle flow of high- energy photons, electrons and ions, so it can be used for high-energy physics, deep space exploration, spectral measurement and bio-luminescence detection.

  16. A position sensitive silicon detector for AEgIS (Antimatter Experiment: Gravity, Interferometry, Spectroscopy)

    CERN Multimedia

    Gligorova, A

    2014-01-01

    The AEḡIS experiment (Antimatter Experiment: Gravity, Interferometry, Spectroscopy) is located at the Antiproton Decelerator (AD) at CERN and studies antimatter. The main goal of the AEḡIS experiment is to carry out the first measurement of the gravitational acceleration for antimatter in Earth’s gravitational field to a 1% relative precision. Such a measurement would test the Weak Equivalence Principle (WEP) of Einstein’s General Relativity. The gravitational acceleration for antihydrogen will be determined using a set of gravity measurement gratings (Moiré deflectometer) and a position sensitive detector. The vertical shift due to gravity of the falling antihydrogen atoms will be detected with a silicon strip detector, where the annihilation of antihydrogen will take place. This poster presents part of the development process of this detector.

  17. Imaging, Detection, and Identification Algorithms for Position-Sensitive Gamma-Ray Detectors

    Science.gov (United States)

    Wahl, Christopher G.

    Three-dimensional-position-sensitive semiconductors record both the locations and energies of gamma-ray interactions with high resolution, enabling spectroscopy and imaging of gamma-ray-emitting materials. Imaging enables the detection of point sources of gamma rays in an otherwise extended-source background, even when the background spectrum is unknown and may share the point source's spectrum. The generalized likelihood ratio test (GLRT) and source-intensity test (SIT) are applied to this situation to detect one-or-more unshielded point sources from a library of isotopes in a spectrally unknown or known background when the background intensity varies spatially by a factor of two or less. In addition to estimating the number of sources present, their activities, isotopes, and directions from the detector are estimated. Experimental and some simulated results are presented for a single detector and an 18-detector array of 2 cm by 2 cm by 1.5 cm CdZnTe crystals and compared with the performance of spectral-only detection when the background and source are assumed to be spectrally different. Furthermore, the expected detection performance of the 18-detector array system is investigated statistically using experimental data in the case where the background is distinct spectrally from the point source and the possible source location and isotopic identity are known. Including imaging gave at least 7% higher SNR compared to ignoring the image dimension. Also, imaging methods based on the maximum-likelihood, expectation-maximization method are introduced to determine the spatial distribution of isotopes and to find the activity distributions within targets moving with known motion through a radioactive background. Software has also been developed to support the analysis of the data from 3D-position-sensitive spectroscopic systems, for a range of detector designs and applications. The software design and unique features that allow fast multidimensional data analysis are

  18. Computational design and characterization of a temperature-sensitive plasmid replicon for gram positive thermophiles

    Directory of Open Access Journals (Sweden)

    Olson Daniel G

    2012-05-01

    Full Text Available Abstract Background Temperature-sensitive (Ts plasmids are useful tools for genetic engineering, but there are currently none compatible with the gram positive, thermophilic, obligate anaerobe, Clostridium thermocellum. Traditional mutagenesis techniques yield Ts mutants at a low frequency, and therefore requires the development of high-throughput screening protocols, which are also not available for this organism. Recently there has been progress in the development of computer algorithms which can predict Ts mutations. Most plasmids currently used for genetic modification of C. thermocellum are based on the replicon of plasmid pNW33N, which replicates using the RepB replication protein. To address this problem, we set out to create a Ts plasmid by mutating the gene coding for the RepB replication protein using an algorithm designed by Varadarajan et al. (1996 for predicting Ts mutants based on the amino-acid sequence of the protein. Results A library of 34 mutant plasmids was designed, synthesized and screened, resulting in 6 mutants which exhibited a Ts phenotype. Of these 6, the one with the most temperature-sensitive phenotype (M166A was compared with the original plasmid. It exhibited lower stability at 48°C and was completely unable to replicate at 55°C. Conclusions The plasmid described in this work could be useful in future efforts to genetically engineer C. thermocellum, and the method used to generate this plasmid may be useful for others trying to make Ts plasmids.

  19. New Developments in the Position Sensitive Detectors Based on Microchannel Plates

    Science.gov (United States)

    Tremsin, A. S.; Siegmund, O. H. W.

    2002-11-01

    We report on the latest developments in position sensitive photon counting detectors based on microchannel plates. Substantial improvement of the spatial resolution was achieved with introduction of new readout technology, namely crossed strip (XS) anode, and corresponding processing electronics. The spatial resolution of XS readout appeared to be as small as ~3-4 μm FWHM. Reduction of the total detector gain (down to 106 and potentially lower) without compromising the spatial accuracy allows detector operation at much higher local and global counting rates since the microchannel recharge time becomes smaller. Recent developments of novel microchannel plate technologies provide basis for substantial increase of the spectral sensitivity and quantum efficiency of MCP detectors. We have tested a number of new Silicon micromachined MCPs The new MCP technologies should allow deposition of completely new photocathode materials directly on the front surface of microchannel plates (opaque photocathodes). Opposite to standard glass MCPs new Silicon MCPs can sustain high temperatures (-800 C°) required for the photocathode deposition and activation processes.

  20. A two-dimensional position sensitive gas chamber with scanned charge transfer readout

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, F. E-mail: faustgr@usc.es; Iglesias, A.; Lobato, R.; Mosquera, J.; Pardo, J.; Pena, J.; Pazos, A.; Pombar, M.; Rodriguez, A

    2003-10-21

    We have constructed and tested a two-dimensional position sensitive parallel-plate gas ionization chamber with scanned charge transfer readout. The scan readout method described here is based on the development of a new position-dependent charge transfer technique. It has been implemented by using gate strips perpendicularly oriented to the collector strips. This solution reduces considerably the number of electronic readout channels needed to cover large detector areas. The use of a 25 {mu}m thick kapton etched circuit allows high charge transfer efficiency with a low gating voltage, consequently needing a very simple commutating circuit. The present prototype covers 8x8 cm{sup 2} with a pixel size of 1.27x1.27 mm{sup 2}. Depending on the intended use and beam characteristics a smaller effective pixel is feasible and larger active areas are possible. This detector can be used for X-ray or other continuous beam intensity profile monitoring.

  1. Estimation of Compton imager using single 3D position-sensitive LYSO scintillator: Monte Carlo simulation

    Science.gov (United States)

    Lee, Taewoong; Lee, Hyounggun; Kim, Younghak; Lee, Wonho

    2017-07-01

    The performance of a Compton imager using a single three-dimensional position-sensitive LYSO scintillator detector was estimated using a Monte Carlo simulation. The Compton imager consisted of a single LYSO scintillator with a pixelized structure. The size of the scintillator and each pixel were 1.3 × 1.3 × 1.3 cm3 and 0.3 × 0.3 × 0.3 cm3, respectively. The order of γ-ray interactions was determined based on the deposited energies in each detector. After the determination of the interaction sequence, various types of reconstruction algorithms such as simple back-projection, filtered back-projection, and list-mode maximum-likelihood expectation maximization (LM-MLEM) were applied and compared with each other in terms of their angular resolution and signal-to-noise ratio (SNR) for several γ-ray energies. The LM-MLEM reconstruction algorithm exhibited the best performance for Compton imaging in maintaining high angular resolution and SNR. The two sources of 137Cs (662 keV) could be distinguishable if they were more than 17° apart. The reconstructed Compton images showed the precise position and distribution of various radiation isotopes, which demonstrated the feasibility of the monitoring of nuclear materials in homeland security and radioactive waste management applications.

  2. Design and performance of a 2-D multi-wire position sensitive X-ray detector

    Indian Academy of Sciences (India)

    S S Desai; J N Joshi; A M Shaikh

    2002-10-01

    A 2-D multi-wire position sensitive detector for X-ray diffraction and small angle X-ray scattering studies is described. The detector has an active area of 100 mm × 100 mm and consists of an anode plane with 10 m SS wires at 3 mm spacing and a pair of orthogonal cathode readout planes with 25 m SS wires placed at 1.5 mm spacing. The position information is obtained using charge division method and recorded using a laboratory built data acquisition system. The resolution and gas gain was measured for 5.9 keV X-rays (55Fe-source) as a function of the anode wire voltage and gas pressure. It was observed that the proportional region of the PSD at 100 kPa pressure extended up to a high voltage value of around 1.5 kV and it shifted to high values up to 2 kV for gas pressure of 300 kPa. The energy resolution improved from 18% (FWHM) to 12% with increase in pressure. The spatial resolution of the PSD also showed improvement, with a value of 1.2 mm × 1.4 mm at 300 kPa gas pressure. A maximum gain of 5 × 104 is obtained.

  3. Development of large area and of position-sensitive timing RPCs

    CERN Document Server

    Blanco, A; Finck, C; Fonte, Paulo J R; Gobbi, A; Mendiratta, S K; Monteiro, J; Policarpo, Armando; Rozas, M

    2002-01-01

    Resistive Plate Chambers (RPC) made with glass and metal electrodes forming accurately spaced gas gaps of a few hundred micrometers have reached timing accuracies below 50 ps sigma with efficiencies above 99% for MIPs. This type of detector, operating at atmospheric pressure with non-flammable gases, seems well suited for large TOF systems, providing performances comparable to the scintillator-based TOF technology with significantly lower price per channel and being compatible with magnetic fields. In this work, we report recent developments of the timing RPC technology, including a large area counter (0.16 m sup 2) and smaller, position-sensitive, single-gap counters. The latter devices are aimed to be applied in small and accurate TOF systems using a multilayer structure. The large counter has shown a timing resolution between 50 and 75 ps sigma over the whole active area, with 96% efficiency and very small timing tails, along with a longitudinal position-resolution of 1.2 cm sigma. The single-gap counters ...

  4. Free recall of pleasant words from recency positions is especially sensitive to acute administration of cortisol.

    Science.gov (United States)

    Tops, M; van der Pompe, G; Wijers, A A; Den Boer, J A; Meijman, T F; Korf, J

    2004-04-01

    In a recent study we investigated the acute effects of cortisol administration in healthy male volunteers on free recall of pleasant, unpleasant, and neutral nouns using a between-subjects double-blind placebo-controlled design. The volunteers were administered 10 mg of hydrocortisone or placebo between 9:00 and 10:30. Two hours after administration of cortisol a decline in recall of neutral and pleasant words was found, while recall of unpleasant words did not change. These results are consistent with a possible inhibitory influence of cortisol on a prefrontal dopaminergic mechanism involved in approach and positivity bias. In this paper we first explain why this interpretation would predict recall of pleasant words from recency positions to be especially sensitive to cortisol administration. Comparing primacy and recency recall of pleasant and unpleasant words, there proved to be a selective decline in recall of pleasant recency words. These results did not appear to stem from differences in recall strategies between our groups of volunteers.

  5. The residual stress instrument with optimized Si(220) monochromator and position-sensitive detector at HANARO

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Chang-Hee [Korea Atomic Energy Research Institute, Yusung, Daejon 305-600 (Korea, Republic of); Moon, Myung-Kook [Korea Atomic Energy Research Institute, Yusung, Daejon 305-600 (Korea, Republic of)]. E-mail: moonmk@kaeri.re.kr; Em, Vyacheslav T. [Korea Atomic Energy Research Institute, Yusung, Daejon 305-600 (Korea, Republic of); Choi, Young-Hyun [Korea Atomic Energy Research Institute, Yusung, Daejon 305-600 (Korea, Republic of); Cheon, Jong-Kyu [Korea Atomic Energy Research Institute, Yusung, Daejon 305-600 (Korea, Republic of); Nam, Uk-Won [Korea Astronomy Observatory, Yusung, Daejon 305-348 (Korea, Republic of); Kong, Kyung-Nam [Korea Astronomy Observatory, Yusung, Daejon 305-348 (Korea, Republic of)

    2005-06-11

    An upgraded residual stress instrument at the HANARO reactor of the KAERI is described. A horizontally focusing bent perfect crystal Si(220) monochromator (instead of a mosaic vertical focusing Ge monochromator) is installed in a drum with a tunable (2{theta}{sub M}=0-60{sup o}) take-off angle/wavelength. A specially designed position-sensitive detector (60% efficiency for {lambda}=1.8A) with 200mm (instead of 100mm) high-active area is used. There are no Soller type collimators in the instrument. The minimum possible monochromator to sample distance, L{sub MS}=2m, and sample to detector distance, L{sub SD}=1.2m, were found to be optimal. The new PSD and bent Si(220) monochromator combined with the possibility of selecting an appropriate wavelength resulted in about a ten-fold gain in data collection rate. The optimal reflections of austenitic and ferritic steels, aluminum and nickel for stress measurements with a Si(220) monochromator were chosen experimentally. The ability of the instrument to make strain measurements deep inside the austenitic and ferritic steels has been tested. For the chosen reflections and wavelengths, no shift of peak position (apparent strain) was observed up to 56mm length of path.

  6. A study of the timing properties of position-sensitive avalanche photodiodes.

    Science.gov (United States)

    Wu, Yibao; Ng, Thomas S C; Yang, Yongfeng; Shah, Kanai; Farrell, Richard; Cherry, Simon R

    2009-09-07

    In this paper, we study position-dependent timing shifts and timing resolution in position sensitive avalanche photodiodes (PSAPDs) and their effects on the coincidence window used in positron emission tomography (PET) systems using these devices. There is a delay in PSAPD signals that increases as the excitation position moves from the corner to the center of the device and the timing resolution concurrently worsens. The difference in timing between the center and the corner can be up to 30.7 ns for a 14 x 14 mm(2) area PSAPD. This means that a PSAPD-based PET system could require a very wide coincidence timing window (>60 ns) if this effect is not corrected, although the individual crystal pairs still have full-width half-maximum (FWHM) timing resolutions better than 7.4 ns. In addition to characterizing the timing properties of PSAPDs, two correction methods were developed and applied to data from a pair of PSAPD detectors. These two timing offset corrections reduced the timing shift of a crystal pair from 52.4 ns to 9.7 ns or 1.3 ns, improved the FWHM timing resolution of the detector pair from 24.6 ns to 9.5 ns or 6.0 ns and reduced the timing window (sufficient to cover at least twice the FWHM for all crystal pairs) from 65.1 ns to 22.0 ns or 15.2 ns, respectively. A two-step timing alignment method is proposed for a PET system consisting of multiple PSAPDs. Lastly, the effect of PSAPD size on the timing performance was also evaluated.

  7. Coexistence of positive and negative refractive index sensitivity in the liquid-core photonic crystal fiber based plasmonic sensor.

    Science.gov (United States)

    Shuai, Binbin; Xia, Li; Liu, Deming

    2012-11-05

    We present and numerically characterize a liquid-core photonic crystal fiber based plasmonic sensor. The coupling properties and sensing performance are investigated by the finite element method. It is found that not only the plasmonic mode dispersion relation but also the fundamental mode dispersion relation is rather sensitive to the analyte refractive index (RI). The positive and negative RI sensitivity coexist in the proposed design. It features a positive RI sensitivity when the increment of the SPP mode effective index is larger than that of the fundamental mode, but the sensor shows a negative RI sensitivity once the increment of the fundamental mode gets larger. A maximum negative RI sensitivity of -5500nm/RIU (Refractive Index Unit) is achieved in the sensing range of 1.50-1.53. The effects of the structural parameters on the plasmonic excitations are also studied, with a view of tuning and optimizing the resonant spectrum.

  8. Theory and Development of Position-Sensitive Quantum Calorimeters. Degree awarded by Stanford Univ.

    Science.gov (United States)

    Figueroa-Feliciano, Enectali; White, Nicholas E. (Technical Monitor)

    2001-01-01

    Quantum calorimeters are being developed as imaging spectrometers for future X-ray astrophysics observatories. Much of the science to be done by these instruments could benefit greatly from larger focal-plane coverage of the detector (without increasing pixel size). An order of magnitude more area will greatly increase the science throughput of these future instruments. One of the main deterrents to achieving this goal is the complexity of the readout schemes involved. We have devised a way to increase the number of pixels from the current baseline designs by an order of magnitude without increasing the number of channels required for readout. The instrument is a high energy resolution, distributed-readout imaging spectrometer called a Position-Sensitive Transition-Edge Sensor (POST). A POST is a quantum calorimeter consisting of two Transition-Edge Sensors (TESS) on the ends of a long absorber capable of one-dimensional imaging spectroscopy. Comparing rise time and energy information from the two TESS, the position of the event in the POST is determined. The energy of the event is inferred from the sum of the two pulses. We have developed a generalized theoretical formalism for distributed-readout calorimeters and apply it to our devices. We derive the noise theory and calculate the theoretical energy resolution of a POST. Our calculations show that a 7-pixel POST with 6 keV saturation energy can achieve 2.3 eV resolution, making this a competitive design for future quantum calorimeter instruments. For this thesis we fabricated 7- and 15-pixel POSTS using Mo/Au TESs and gold absorbers, and moved from concept drawings on scraps of napkins to a 32 eV energy resolution at 1.5 keV, 7-pixel POST calorimeter.

  9. SA-I Mechanoreceptor Position in Fingertip Skin May Impact Sensitivity to Edge Stimuli

    Directory of Open Access Journals (Sweden)

    Gregory J. Gerling

    2010-01-01

    Full Text Available Background: The skin plays a role in conditioning mechanical indentation into distributions of stress/strain that mechanoreceptors convert into neural signals. Solid mechanics methods have modelled the skin to predict the in vivo neural response from mechanoreceptors. Despite their promise, current models cannot explain the role that anatomical positioning and receptor organ morphology play in producing differences in neural response. This work hypothesises that the skin's intermediate ridges may help explain, in part, the sensitivity of slowly adapting type I (SA-I mechanoreceptors to edge stimuli. Method: Two finite-element models of the fingertip were built, validated and used to analyse the functionality of the intermediate ridges. One of the two-dimensional, cross-sectional models included intermediate ridges, while the other did not. The analysis sought to determine if intermediate ridges (1 increase the magnitude of strain energy density (SED near the SA-I location and (2 help differentiate one 2.0-mm indenter from two 0.5-mm wide indenters with a 1.0-mm gap. Results: Higher concentrations of SED were found near the tips of the intermediate ridges, the anatomical location that coincides with the SA-I receptors. This first result suggested that the location of the SA-Is in the stiffer epidermal tissue helps magnify their response to edge stimuli. The second result was that both models were equally capable of predicting the spatial structure within the in vivo neural responses, and therefore the addition of intermediate ridges did not help in differentiating the indenters. Conclusion: The finding, a 15%–35% increase in response when the sampling point lies within the stiffer tissue at the same depth, seeks to inform the positioning of force sensors in robotic skin substrates.

  10. Performance of resistive-charge position sensitive detectors for RBS/Channeling applications

    Energy Technology Data Exchange (ETDEWEB)

    Miranda, P.A., E-mail: pjmirand@gmail.com [Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, 2696-953 Sacavém (Portugal); Wahl, U. [Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, 2696-953 Sacavém (Portugal); Catarino, N. [Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 2696-953 Sacavém (Portugal); Ribeiro da Silva, M. [Centro de Física Nuclear da Universidade de Lisboa, Avenida Prof. Gama Pinto 2, 1649-003 Lisboa (Portugal); Alves, E. [Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 2696-953 Sacavém (Portugal)

    2014-10-01

    The performance of two types of 1×1 cm{sup 2} photodiode position sensitive detectors (PSDs) based on resistive charge division was evaluated for their use in Rutherford Backscattering/Channeling (RBS/C) experiments in blocking geometry. Their energy resolution was first determined for ∼5.5MeV alpha particles from a radioactive sources, and values of full width half maximum (FWHM) of 22 keV and 33 keV were achieved using a shaping time constant of τ=2.0μs. Additional tests were performed using backscattered {sup 4}He particles from the 2.0 MeV beam of a Van de Graaff accelerator. While the 22 keV FWHM detector failed after exposure to less than 5×10{sup 6} cm{sup −24}He particles, the other did not show any noticeable deterioration due to radiation damage for a fluence of 4×10{sup 8} cm{sup −2}. For this type of PSD position resolution (τ=0.5μs) standard deviations of ΔL=0.072mm at ∼5.5MeV and ΔL=0.247mm at 1.1 MeV were achieved. RBS/Channeling experiments using PSD were performed on several crystalline samples, showing that this setup seems suitable for lattice location studies, particularly for heavy ions implantation (D≳10{sup 15}at/cm{sup 2}) on light substrates like Si, SiC, and AlN.

  11. A position-sensitive neutron spectrometer/dosimeter based on pressurized superheated drop (bubble) detectors

    Science.gov (United States)

    d'Errico, F.; Nath, R.; Holland, S. K.; Lamba, M.; Patz, S.; Rivard, M. J.

    2002-01-01

    A position-sensitive, superheated emulsion chamber (SEC) is introduced for three-dimensional (3D) spectrometry and dosimetry of fast neutrons. The detector is based on a fine suspension of octafluorocyclobutane droplets emulsified in a tissue-equivalent gel. This gel is highly viscous and immobilizes the bubbles at the location of their formation. At an operating temperature of 35°C, the droplets are moderately superheated and their evaporation is nucleated by the densely ionizing products of fast neutron interactions, with no response to sparsely ionizing radiations. Thus, when a neutron emitter such as a 252Cf brachytherapy source is inserted in the SEC, a bubble distribution forms around the source and makes the neutron field visible. The SEC is operated at different externally applied pressures that correspond to different response thresholds. These responses form a virtually orthogonal matrix which is suitable for spectrometry and allows the use of effective few channel unfolding procedures, yielding the spatial dependence of absorbed dose and neutron energy spectra in-tissue. Bubble spatial distributions in the chamber can be determined through optical tomography or magnetic resonance imaging (MRI). A 3D, steady-state MRI method has proven particularly effective for this purpose. After the imaging, the SEC can be pressurized above the halocarbon vapor tension in order to recondense the bubbles to the liquid phase. Within a few minutes, the device is annealed and ready to be used again for repeated measurements improving the bubble counting statistics.

  12. The particle background of the Rosat PSPC. [Position Sensitive Proportional Counter

    Science.gov (United States)

    Snowden, S. L.; Plucinsky, P. P.; Briel, U.; Hasinger, G.; Pfeffermann, E.

    1992-01-01

    In order to permit quantitative studies of the diffuse cosmic X-ray background and of extended X-ray sources, the particle induced background of the Roentgen Satellite, Rosat, Position Sensitive Proportional Counter (PSPC) is parameterized. Data collected during 210,000 s of PSPC operation have been analyzed and the temporal, spectral, and spatial distributions investigated. About 77 percent of the residual events originate within the detector while the remainder enter through the counter window. During typical conditions, the count rate of the residual events is well correlated with the Master Veto (MV) count rate. The spectrum of these events is well described by a flat component plus a soft power law and an Al K-alpha line at 1.5 keV. Also during typical conditions, the ratio between the power law and flat components remains constant to +/- 4 while the relative Al K-alpha contribution increases with increasing MV count rate. The distribution of the counts over the field of view is uniform except for a slight radial dependence and shadowing caused by blockage of the externally produced component by the window support structure.

  13. High-energy resolution μ-XRF analysis by position sensitive spectrometer

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    With a high-energy resolution micro-X-ray fluorescence (μ-XRF) analysis setup, which basically consists of an X-ray microbeam formed by an X-ray focusing lens combined with an X-ray apparatus and a wavelength dispersive position sensitive spectrometer with a flat crystal (PSS), preliminary results have been obtained. The counting rate of the analyzed element linearly increased with the power of X-ray apparatus, and the energy resolution, full width of half maximum (FWHM) of Ka lines of Ti and Cr reached 16.6 and 23.6 eV, respectively. The Cr Kb and Mn Ka lines in a sample of stainless steel could clearly be resolved. The above-mentioned results are also compared with those obtained by synchrotron radiation light microbeam combined with the PSS. The facts show that the high-energy resolution element analysis is feasible by using the setup. Moreover, problems for the setup and the ways to resolve them are discussed as well.

  14. Depth of interaction detection with enhanced position-sensitive proportional resistor network

    Energy Technology Data Exchange (ETDEWEB)

    Lerche, Ch.W. [Instituto de Fisisca Corpuscular (CSIC-UV), Apdo. 22085, 46071 Valencia (Spain)]. E-mail: lerche@ific.uv.es; Benlloch, J.M. [Instituto de Fisisca Corpuscular (CSIC-UV), Apdo. 22085, 46071 Valencia (Spain); Sanchez, F. [Instituto de Fisisca Corpuscular (CSIC-UV), Apdo. 22085, 46071 Valencia (Spain); Pavon, N. [Instituto de Fisisca Corpuscular (CSIC-UV), Apdo. 22085, 46071 Valencia (Spain); Gimenez, N. [Instituto de Fisisca Corpuscular (CSIC-UV), Apdo. 22085, 46071 Valencia (Spain); Fernandez, M. [Instituto de Fisisca Corpuscular (CSIC-UV), Apdo. 22085, 46071 Valencia (Spain); Gimenez, M. [Instituto de Fisisca Corpuscular (CSIC-UV), Apdo. 22085, 46071 Valencia (Spain); Sebastia, A. [Universidad Politecnica de Valencia, Valencia (Spain); Martinez, J. [Universidad Politecnica de Valencia, Valencia (Spain); Mora, F.J. [Universidad Politecnica de Valencia, Valencia (Spain)

    2005-01-21

    A new method of determining the depth of interaction of {gamma}-rays in thick inorganic scintillation crystals was tested experimentally. The method uses the strong correlation between the width of the scintillation light distribution within large continuous crystals and the {gamma}-ray's interaction depth. This behavior was successfully reproduced by a theoretical model distribution based on the inverse square law. For the determination of the distribution's width, its standard deviation {sigma} is computed using an enhanced position-sensitive proportional resistor network which is often used in {gamma}-ray-imaging devices. Minor changes of this known resistor network allow the analog and real-time determination of the light distribution's 2nd moment without impairing the measurement of the energy and centroid. First experimental results are presented that confirm that the described method works correctly. Since only some cheap electronic components, but no additional detectors or crystals are required, the main advantage of this method is its low cost.

  15. Development of position-sensitive time-of-flight spectrometer for fission fragment research

    CERN Document Server

    Arnold, C W; Meierbachtol, K; Bredeweg, T; Jandel, M; Jorgenson, H J; Laptev, A; Rusev, G; Shields, D W; White, M; Blakeley, R E; Mader, D M; Hecht, A A

    2014-01-01

    A position-sensitive, high-resolution time-of-flight detector for fission fragments has been developed. The SPectrometer for Ion DEterminiation in fission Research (SPIDER) is a $2E-2v$ spectrometer designed to measure the mass of light fission fragments to a single mass unit. The time pick-off detector pairs to be used in SPIDER have been tested with $\\alpha$-particles from $^{229}$Th and its decay chain and $\\alpha$-particles and spontaneous fission fragments from $^{252}$Cf. Each detector module is comprised of a thin electron conversion foil, electrostatic mirror, microchannel plates, and delay-line anodes. Particle trajectories on the order of 700 mm are determined accurately to within 0.7 mm. Flight times on the order of 70 ns were measured with 200 ps resolution FWHM. Computed particle velocities are accurate to within 0.06 mm/ns corresponding to precision of 0.5%. An ionization chamber capable of 400 keV energy resolution coupled with the velocity measurements described here will pave the way for mode...

  16. A position-sensitive neutron spectrometer/dosimeter based on pressurized superheated drop (bubble) detectors

    Energy Technology Data Exchange (ETDEWEB)

    D' Errico, F. E-mail: francesco.derrico@yale.edu; Nath, R.; Holland, S.K.; Lamba, M.; Patz, S.; Rivard, M.J

    2002-01-01

    A position-sensitive, superheated emulsion chamber (SEC) is introduced for three-dimensional (3D) spectrometry and dosimetry of fast neutrons. The detector is based on a fine suspension of octafluorocyclobutane droplets emulsified in a tissue-equivalent gel. This gel is highly viscous and immobilizes the bubbles at the location of their formation. At an operating temperature of 35 deg.C, the droplets are moderately superheated and their evaporation is nucleated by the densely ionizing products of fast neutron interactions, with no response to sparsely ionizing radiations. Thus, when a neutron emitter such as a {sup 252}Cf brachytherapy source is inserted in the SEC, a bubble distribution forms around the source and makes the neutron field visible. The SEC is operated at different externally applied pressures that correspond to different response thresholds. These responses form a virtually orthogonal matrix which is suitable for spectrometry and allows the use of effective few channel unfolding procedures, yielding the spatial dependence of absorbed dose and neutron energy spectra in-tissue. Bubble spatial distributions in the chamber can be determined through optical tomography or magnetic resonance imaging (MRI). A 3D, steady-state MRI method has proven particularly effective for this purpose. After the imaging, the SEC can be pressurized above the halocarbon vapor tension in order to recondense the bubbles to the liquid phase. Within a few minutes, the device is annealed and ready to be used again for repeated measurements improving the bubble counting statistics.

  17. Depth of interaction resolution measurements for a high resolution PET detector using position sensitive avalanche photodiodes.

    Science.gov (United States)

    Yang, Yongfeng; Dokhale, Purushottam A; Silverman, Robert W; Shah, Kanai S; McClish, Mickel A; Farrell, Richard; Entine, Gerald; Cherry, Simon R

    2006-05-07

    We explore dual-ended read out of LSO arrays with two position sensitive avalanche photodiodes (PSAPDs) as a high resolution, high efficiency depth-encoding detector for PET applications. Flood histograms, energy resolution and depth of interaction (DOI) resolution were measured for unpolished LSO arrays with individual crystal sizes of 1.0, 1.3 and 1.5 mm, and for a polished LSO array with 1.3 mm pixels. The thickness of the crystal arrays was 20 mm. Good flood histograms were obtained for all four arrays, and crystals in all four arrays can be clearly resolved. Although the amplitude of each PSAPD signal decreases as the interaction depth moves further from the PSAPD, the sum of the two PSAPD signals is essentially constant with irradiation depth for all four arrays. The energy resolutions were similar for all four arrays, ranging from 14.7% to 15.4%. A DOI resolution of 3-4 mm (including the width of the irradiation band which is approximately 2 mm) was obtained for all the unpolished arrays. The best DOI resolution was achieved with the unpolished 1 mm array (average 3.5 mm). The DOI resolution for the 1.3 mm and 1.5 mm unpolished arrays was 3.7 and 4.0 mm respectively. For the polished array, the DOI resolution was only 16.5 mm. Summing the DOI profiles across all crystals for the 1 mm array only degraded the DOI resolution from 3.5 mm to 3.9 mm, indicating that it may not be necessary to calibrate the DOI response separately for each crystal within an array. The DOI response of individual crystals in the array confirms this finding. These results provide a detailed characterization of the DOI response of these PSAPD-based PET detectors which will be important in the design and calibration of a PET scanner making use of this detector approach.

  18. Evaluation of human skin tests for potential dermal irritant and contact sensitizing products: a position paper

    NARCIS (Netherlands)

    Loveren H van; Jong WH de; Garssen J; LPI

    1998-01-01

    Prediction of human cutaneous irritation and sensitization in view of hazard identification has primarily relied on the use of laboratory animals. Such studies in laboratory animals have been very instrumental in the detection of potential contact sensitizing agents. There are however many uncertain

  19. Positional cloning of the human quantitative trait locus underlying taste sensitivity to phenylthiocarbamide.

    Science.gov (United States)

    Kim, Un-kyung; Jorgenson, Eric; Coon, Hilary; Leppert, Mark; Risch, Neil; Drayna, Dennis

    2003-02-21

    The ability to taste the substance phenylthiocarbamide (PTC) has been widely used for genetic and anthropological studies, but genetic studies have produced conflicting results and demonstrated complex inheritance for this trait. We have identified a small region on chromosome 7q that shows strong linkage disequilibrium between single-nucleotide polymorphism (SNP) markers and PTC taste sensitivity in unrelated subjects. This region contains a single gene that encodes a member of the TAS2R bitter taste receptor family. We identified three coding SNPs giving rise to five haplotypes in this gene worldwide. These haplotypes completely explain the bimodal distribution of PTC taste sensitivity, thus accounting for the inheritance of the classically defined taste insensitivity and for 55 to 85% of the variance in PTC sensitivity. Distinct phenotypes were associated with specific haplotypes, which demonstrates that this gene has a direct influence on PTC taste sensitivity and that sequence variants at different sites interact with each other within the encoded gene product.

  20. Proportional counter for X-ray analysis of lunar and planetary surfaces. [a position sensitive scintillating imaging proportional counter

    Science.gov (United States)

    1979-01-01

    A position sensitive proportional scintillation detector was developed and evaluated for use in applications involving X-ray imaging as well as spectroscopy. Topics covered include limitations of the proportional scintillation counter for use in space; purification of the xenon gas in the detector, and the operation of the detector system. Results show that the light signal in a proportional scintillation detector remains well localized. With modest electric fields in xenon, the primary electrons from a photoelectric absorption of an X-ray can be brought a distance of a few millimeters to a higher field region without spreading more than a millimeter or so. Therefore, it is possible to make a proportional scintillation detector with good position sensitivity that could be used to calibrate out the difference in light collection over its sensitive volume.

  1. Musical training and empathy positively impact adults’ sensitivity to infant distress

    Directory of Open Access Journals (Sweden)

    Christine E Parsons

    2014-12-01

    Full Text Available Crying is the most powerful auditory signal of infant need. Adults’ ability to perceive and respond to crying is important for infant survival and in the provision of care. This study investigated a number of listener variables that might impact on adults’ perception of infant cry distress, namely parental status, musical training and empathy. Sensitivity to infant distress was tested using a previously validated task, which experimentally manipulated distress by varying the pitch of infant cries. Parents with musical training showed a significant advantage on this task when compared with parents without. The extent of the advantage was correlated with the amount of self-reported musical training. For non-parents, individual differences in empathy were associated with task performance, with higher empathy scores corresponding to greater sensitivity to infant distress. We suggest that sensitivity to infant distress can be impacted by a number of listener variables, and may be amenable to training.

  2. Deficits of hot executive function in developmental coordination disorder: Sensitivity to positive social cues

    NARCIS (Netherlands)

    Rahimi-Golkhandan, S.; Steenbergen, B.; Piek, J.P.; Wilson, P.H.

    2014-01-01

    Recent research shows that children with motor coordination problems (or developmental coordination disorder – DCD) show deficits in not only cool executive function (EF), but also hot EF. We aimed to determine whether this deficit of hot EF is due to heightened sensitivity to rewarding stimuli, spe

  3. Deficits of hot executive function in developmental coordination disorder: Sensitivity to positive social cues

    NARCIS (Netherlands)

    Rahimi-Golkhandan, S.; Steenbergen, B.; Piek, J.P.; Wilson, P.H.

    2014-01-01

    Recent research shows that children with motor coordination problems (or developmental coordination disorder - DCD) show deficits in not only cool executive function (EF), but also hot EF. We aimed to determine whether this deficit of hot EF is due to heightened sensitivity to rewarding stimuli, spe

  4. Net positive charge of HIV-1 CRF01_AE V3 sequence regulates viral sensitivity to humoral immunity.

    Directory of Open Access Journals (Sweden)

    Satoshi Naganawa

    Full Text Available The third variable region (V3 of the human immunodeficiency virus type 1 (HIV-1 envelope gp120 subunit participates in determination of viral infection coreceptor tropism and host humoral immune responses. Positive charge of the V3 plays a key role in determining viral coreceptor tropism. Here, we examined by bioinformatics, experimental, and protein modelling approaches whether the net positive charge of V3 sequence regulates viral sensitivity to humoral immunity. We chose HIV-1 CRF01_AE strain as a model virus to address the question. Diversity analyses using CRF01_AE V3 sequences from 37 countries during 1984 and 2005 (n = 1361 revealed that reduction in the V3's net positive charge makes V3 less variable due to limited positive selection. Consistently, neutralization assay using CRF01_AE V3 recombinant viruses (n = 30 showed that the reduction in the V3's net positive charge rendered HIV-1 less sensitive to neutralization by the blood anti-V3 antibodies. The especially neutralization resistant V3 sequences were the particular subset of the CCR5-tropic V3 sequences with net positive charges of +2 to +4. Molecular dynamics simulation of the gp120 monomers showed that the V3's net positive charge regulates the V3 configuration. This and reported gp120 structural data predict a less-exposed V3 with a reduced net positive charge in the native gp120 trimer context. Taken together, these data suggest a key role of the V3's net positive charge in the immunological escape and coreceptor tropism evolution of HIV-1 CRF01_AE in vivo. The findings have molecular implications for the adaptive evolution and vaccine design of HIV-1.

  5. Sensitivity Analysis for Reactor Period Induced by Positive Reactivity Using One-point Adjoint Kinetic Equation

    Science.gov (United States)

    Chiba, G.; Tsuji, M.; Narabayashi, T.

    2014-04-01

    In order to better predict a kinetic behavior of a nuclear fission reactor, an improvement of the delayed neutron parameters is essential. The present paper specifies important nuclear data for a reactor kinetics: Fission yield and decay constant data of 86Ge, some bromine isotopes, 94Rb, 98mY and some iodine isotopes. Their importance is quantified as sensitivities with a help of the adjoint kinetic equation, and it is found that they are dependent on an inserted reactivity (or a reactor period). Moreover, dependence of sensitivities on nuclear data files is also quantified using the latest files. Even though the currently evaluated data are used, there are large differences among different data files from a view point of the delayed neutrons.

  6. Study of performance of small gamma camera consisting of crystal pixel array and position sensitive photomultiplier tube

    Institute of Scientific and Technical Information of China (English)

    ZHU Jie; LIU Shi-Tao; LEI Xiao-Wen; YAN Tian-Xin; XU Zi-Zong; WANG Zhao-Min

    2005-01-01

    The performance of gamma camera with NaI(T1) array coupled with position sensitive photomultiplier tube (PSPMT) R2486 has been studied. The pixel size of NaI(T1) crystal is 2mm×2mm and the overall dimension of the array is 48.2mm×48.2mm×5mm. There are 484 pixels in a 22×22 matrix. Because each pixel can produce a much focused light spot and restrict the spread of photons, position resolution of the gamma camera is mainly determined by pixel size. It is shown that crystal array pixel can reduce shrinkage effect and improve intrinsic position resolution greatly via restricting the spread of photons. Experimental results demonstrate that its position resolution and linearity are much improved comparing with the gamma camera using planar crystals coupled with PSPMT.

  7. Bridging particle and wave sensitivity in a configurable detector of positive operator-valued measures.

    Science.gov (United States)

    Puentes, Graciana; Lundeen, Jeff S; Branderhorst, Matthijs P A; Coldenstrodt-Ronge, Hendrik B; Smith, Brian J; Walmsley, Ian A

    2009-02-27

    We report an optical detector with tunable positive operator-valued measures. The device is based on a combination of weak-field homodyne techniques and photon-number-resolving detection. The resulting positive operator-valued measures can be continuously tuned from Fock-state projectors to a variety of phase-dependent quantum-state measurements by adjusting different system parameters such as local oscillator coupling, amplitude, and phase, allowing thus not only detection but also preparation of exotic quantum states. Experimental tomographic reconstructions of classical benchmark states are presented as a demonstration of the detector capabilities.

  8. Extensive simulation studies on the reconstructed image resolution of a position sensitive detector based on pixelated CdTe crystals

    CERN Document Server

    Zachariadou, K; Kaissas, I; Seferlis, S; Lambropoulos, C; Loukas, D; Potiriadis, C

    2011-01-01

    We present results on the reconstructed image resolution of a position sensitive radiation instrument (COCAE) based on extensive simulation studies. The reconstructed image resolution has been investigated in a wide range of incident photon energies emitted by point-like sources located at different source-to-detector distances on and off the detector's symmetry axis. The ability of the detector to distinguish multiple radioactive sources observed simultaneously is investigating by simulating point-like sources of different energies located on and off the detector's symmetry axis and at different positions

  9. Sensitivity of Human Choice to Manipulations of Parameters of Positive and Negative Sound Reinforcement

    Science.gov (United States)

    Lambert, Joseph M.

    2013-01-01

    The purpose of this study was to determine whether altering parameters of positive and negative reinforcement in identical ways could influence behavior maintained by each in different ways. Three undergraduate students participated in a series of assessments designed to identify preferred and aversive sounds with similar reinforcing values.…

  10. Reprint of "Deficits of hot executive function in developmental coordination disorder: Sensitivity to positive social cues".

    Science.gov (United States)

    Rahimi-Golkhandan, Shahin; Steenbergen, Bert; Piek, Jan; Wilson, Peter

    2015-08-01

    Recent research shows that children with motor coordination problems (or developmental coordination disorder--DCD) show deficits in not only cool executive function (EF), but also hot EF. We aimed to determine whether this deficit of hot EF is due to heightened sensitivity to rewarding stimuli, specifically, or to a general deficit of cognitive control, like inhibition. Using two versions of a go/no-go task, one with neutral facial expressions and the other with happy and fearful faces, we compared 12 children with DCD with 28 typically-developing children, aged 7-12 years. Like earlier studies, children responded faster to happy faces. Both groups showed comparable accuracy in response to go targets, and also had similar commission errors, except when the no-go stimulus was a happy face. Importantly, the DCD group made significantly more commission errors to happy faces failing to suppress their response on more than half of the no-go trials. These results suggest a heightened sensitivity to emotionally significant distractors in DCD; this type of impulsivity may undermine self-regulation in DCD, with possible implications for adaptive function and emotional well-being. We argue that the interaction of cognitive control and emotion processing networks may be disrupted in DCD or delayed in development.

  11. Deficits of hot executive function in developmental coordination disorder: sensitivity to positive social cues.

    Science.gov (United States)

    Rahimi-Golkhandan, S; Steenbergen, B; Piek, J P; Wilson, P H

    2014-12-01

    Recent research shows that children with motor coordination problems (or developmental coordination disorder - DCD) show deficits in not only cool executive function (EF), but also hot EF. We aimed to determine whether this deficit of hot EF is due to heightened sensitivity to rewarding stimuli, specifically, or to a general deficit of cognitive control, like inhibition. Using two versions of a go/no-go task, one with neutral facial expressions and the other with happy and fearful faces, we compared 12 children with DCD with 28 typically-developing children, aged 7-12 years. Like earlier studies, children responded faster to happy faces. Both groups showed comparable accuracy in response to go targets, and also had similar commission errors, except when the no-go stimulus was a happy face. Importantly, the DCD group made significantly more commission errors to happy faces failing to suppress their response on more than half of the no-go trials. These results suggest a heightened sensitivity to emotionally significant distractors in DCD; this type of impulsivity may undermine self-regulation in DCD, with possible implications for adaptive function and emotional well-being. We argue that the interaction of cognitive control and emotion processing networks may be disrupted in DCD or delayed in development.

  12. Organic Position-Sensitive Detectors Based on ZnO:Al and CuPc:C60.

    Science.gov (United States)

    Morimune, Taichiro; Kajii, Hirotake; Nishimaru, Hiroki; Ono, Shinji

    2016-04-01

    Organic position-sensitive detector (OPSD) based on copper phthalocyanine CuPc:fullerene C60 bulk-heterojunction with an inverted structure have been fabricated using aluminum doped ZnO (ZnO:Al) as a resistive layer, which is prepared by sol-gel method. The resistance length of the one-dimensional PSD is fixed at 5 mm, and the Ag common electrode is fabricated by vacuum evaporation within the 100-µm width. The current density-voltage characteristics with different structures of photodetector, the influence of ZnO:Al resistivity on the thickness and the position characteristics of PSDs are investigated. The experimental results indicate that the architecture, which uses an inverted structure, increases sensitivity under red light illumination compared to the conventional structure. In addition, the thickness of the ZnO:Al has influence on the position characteristics. The resistivity of ZnO:A film with Al doping concentration of 2 mol% prepared in this study is around 150 Ωcm and it increases from less than approximately 400 nm-thickness. These characteristics seem to be correlated with the properties of ZnO:AI resistive layer. For a device with a 620 nm-thick ZnO:Al layer, the measured position values obtained from the output photocurrent agree with the actual position values under red laser light illumination. CuPc:C60 OPSD with an inverted structure exhibits red light sensitivity, high incident-photon-to-current conversion efficiency of above 80% at -3 V and linearity error of 5.9% at -2 V.

  13. Sensitivity analysis of ordinary kriging to sampling and positional errors and applications in quality control

    Directory of Open Access Journals (Sweden)

    Victor Miguel Silva

    Full Text Available Abstract Data quality control programs used in the mineral industry normally define tolerance limits based on values considered as good practice or those that have previously been applied to similar deposits, although the precision and accuracy of estimates depend on a combination of geological characteristics, estimation parameters, sample spacing and data quality. This study investigates how the sample quality limits affect the estimates results. The proposed methodology is based on a series of metrics used to compare the impact on the estimates using a synthetic database with an increasing amount of error added to the original sample grades or positions, emulating different levels of precision. The proposed approach results lead to tolerance limits for the grades similar to those recommended in literature. The influence of the positional uncertainty on model estimates is at a minimum, because of the accuracy of current surveying methods that have a deviation in the order of millimeters, so its impact can be considered negligible.

  14. Sensitivity of the late positive potentials evoked by emotional pictures to neuroticism during the menstrual cycle.

    Science.gov (United States)

    Zhang, Wenjuan; Zhou, Renlai; Wang, Qingguo; Zhao, Yan; Liu, Yanfeng

    2013-10-11

    The present event-related potentials (ERPs) study set out to investigate the effect of neuroticism on emotion evaluation during the menstrual cycle, with high and low neuroticism females viewing and evaluating valence and arousal of emotional pictures in the menstruation, late follicular and luteal phases. Behavioral results revealed no group or phase effect. ERPs data showed modulations of the menstrual cycle and neuroticism on the late positive potential (LPP), with the larger LPP (300-1000 ms post-stimulus) during the late follicular phase than that during the luteal phase and larger LPP (1000-3000 ms post-stimulus) in the high neuroticism group than that in the low neuroticism group. Furthermore, significant positive correlations between the LPP amplitudes and valence and arousal evaluations were observed mainly in the high neuroticism group. The present study provides electrophysiological evidences that the LPP evoked by emotional pictures are modulated both by the menstrual cycle and neuroticism.

  15. Two-dimensional position-sensitive detectors for small-angle neutron scattering

    Energy Technology Data Exchange (ETDEWEB)

    McElhaney, S.A.; Vandermolen, R.I.

    1990-05-01

    In this paper, various detectors available for small angle neutron scattering (SANS) are discussed, along with some current developments being actively pursued. A section has been included to outline the various methodologies of position encoding/decoding with discussions on trends and limitations. Computer software/hardware vary greatly from institute and experiment and only a general discussion is given to this area. 85 refs., 33 figs.

  16. Application of a One-Dimensional Position Sensitive Chamber on Synchrotron Radiation

    Science.gov (United States)

    Qi, Huirong; Liu, Mei

    2014-02-01

    In the last few years, wire chambers have been frequently used for X-ray detection because of their low cost, large area and reliability. X-ray diffraction is an irreplaceable method for powder crystal lattice measurements. A one-dimensional single-wire chamber has been developed in our lab to provide high position resolution for powder diffraction experiments using synchrotron radiation. There are 200 readout strips of 0.5 mm width with a pitch of 1.0 mm in the X direction, and the working gas is a mixture of Ar and CO2 (90/10). The one-dimensional position of the original ionization point is determined by the adjacent strip's distribution information using the center of gravity method. Recently, a study of the detector's performance and diffraction image was completed at the 1W1B laboratory of the Beijing Synchrotron Radiation Facility (BSRF) using a sample of SiO2. Most of the relative errors between the measured values of diffraction angles and existing data were less than 1%. The best position resolution achieved for the detector in the test was 71 μm (σ value) with a 20 μm slit collimator. Finally, by changing the detector height in incremental distances from the center of the sample, the one-dimensional detector achieved a two-dimensional diffraction imaging function, and the results are in good agreement with standard data.

  17. Gram positive and Gram negative bacteria differ in their sensitivity to cold plasma

    Science.gov (United States)

    Mai-Prochnow, Anne; Clauson, Maryse; Hong, Jungmi; Murphy, Anthony B.

    2016-12-01

    Cold atmospheric-pressure plasma (CAP) is a relatively new method being investigated for antimicrobial activity. However, the exact mode of action is still being explored. Here we report that CAP efficacy is directly correlated to bacterial cell wall thickness in several species. Biofilms of Gram positive Bacillus subtilis, possessing a 55.4 nm cell wall, showed the highest resistance to CAP, with less than one log10 reduction after 10 min treatment. In contrast, biofilms of Gram negative Pseudomonas aeruginosa, possessing only a 2.4 nm cell wall, were almost completely eradicated using the same treatment conditions. Planktonic cultures of Gram negative Pseudomonas libanensis also had a higher log10 reduction than Gram positive Staphylococcus epidermidis. Mixed species biofilms of P. aeruginosa and S. epidermidis showed a similar trend of Gram positive bacteria being more resistant to CAP treatment. However, when grown in co-culture, Gram negative P. aeruginosa was more resistant to CAP overall than as a mono-species biofilm. Emission spectra indicated OH and O, capable of structural cell wall bond breakage, were present in the plasma. This study indicates that cell wall thickness correlates with CAP inactivation times of bacteria, but cell membranes and biofilm matrix are also likely to play a role.

  18. Nck adaptors are positive regulators of the size and sensitivity of the T-cell repertoire.

    Science.gov (United States)

    Roy, Edwige; Togbe, Dieudonnée; Holdorf, Amy D; Trubetskoy, Dmitry; Nabti, Sabrina; Küblbeck, Günter; Klevenz, Alexandra; Kopp-Schneider, Annette; Leithäuser, Frank; Möller, Peter; Bladt, Friedhelm; Hämmerling, Günter; Arnold, Bernd; Pawson, Tony; Tafuri, Anna

    2010-08-31

    The size and sensitivity of the T-cell repertoire governs the effectiveness of immune responses against invading pathogens. Both are modulated by T-cell receptor (TCR) activity through molecular mechanisms, which remain unclear. Here, we provide genetic evidence that the SH2/SH3 domain containing proteins Nck lower the threshold of T-cell responsiveness. The hallmarks of Nck deletion were T-cell lymphopenia and hyporeactivity to TCR-mediated stimulation. In the absence of the Nck adaptors, peripheral T cells expressing a TCR with low avidity for self-antigens were strongly reduced, whereas an overall impairment of T-cell activation by weak antigenic stimulation was observed. Mechanistically, Nck deletion resulted in a significant decrease in calcium mobilization and ERK phosphorylation upon TCR engagement. Taken together, our findings unveil a crucial role for the Nck adaptors in shaping the T-cell repertoire to ensure maximal antigenic coverage and optimal T cell excitability.

  19. Thermal Neutron Imaging Using A New Pad-Based Position Sensitive Neutron Detector

    Energy Technology Data Exchange (ETDEWEB)

    Dioszegi I.; Vanier P.E.; Salwen C.; Chichester D.L.; Watson S.M.

    2016-10-29

    Thermal neutrons (with mean energy of 25 meV) have a scattering mean free path of about 20 m in air. Therefore it is feasible to find localized thermal neutron sources up to ~30 m standoff distance using thermal neutron imaging. Coded aperture thermal neutron imaging was developed in our laboratory in the nineties, using He-3 filled wire chambers. Recently a new generation of coded-aperture neutron imagers has been developed. In the new design the ionization chamber has anode and cathode planes, where the anode is composed of an array of individual pads. The charge is collected on each of the individual 5x5 mm2 anode pads, (48x48 in total, corresponding to 24x24 cm2 sensitive area) and read out by application specific integrated circuits (ASICs). The high sensitivity of the ASICs allows unity gain operation mode. The new design has several advantages for field deployable imaging applications, compared to the previous generation of wire-grid based neutron detectors. Among these are the rugged design, lighter weight and use of non-flammable stopping gas. For standoff localization of thermalized neutron sources a low resolution (11x11 pixel) coded aperture mask has been fabricated. Using the new larger area detector and the coarse resolution mask we performed several standoff experiments using moderated californium and plutonium sources at Idaho National Laboratory. In this paper we will report on the development and performance of the new pad-based neutron camera, and present long range coded-aperture images of various thermalized neutron sources.

  20. An improved method of angle measurement with a position sensitive detector

    Institute of Scientific and Technical Information of China (English)

    Defeng Zheng; Xiangzhao Wang; Feng Tang

    2007-01-01

    @@ An improved method of angle measurement is proposed based on a parallel plate interferometer. A position detection system is incorporated into a parallel plate interferometer in order to realize large deflection angle measurement. A reflecting mirror is introduced for increasing the measurement resolution. In experiments,a deflection angle of a measured target was measured within ~ 3° with high accuracy. And as a phase modulating interferometer, it was used to measure a small angular displacement with a repeatability of 5.5 × 10-8 rad.

  1. Beam test of a one-dimensional position sensitive chamber on synchrotron radiation

    CERN Document Server

    Mei, Liu; Hui-Rong, Qi; Bao-An, Zhuang; Jian, Zhang; Rong-Guang, Liu; Qi-Ming, Zhu; Qun, Ouyang; Yuan-Bo, Chen; Xiao-Shan, Jiang; Ya-Jie, Wang; Peng, Liu; Guang-Cai, Chang

    2013-01-01

    One-dimensional single-wire chamber was developed to provide high position resolution for powder diffraction experiments with synchrotron radiation. A diffraction test using the sample of SiO2 has been accomplished at 1W2B laboratory of Beijing Synchrotron Radiation Source. The data of beam test were analyzed and some diffraction angles were obtained. The experimental results were in good agreement with standard data from ICDD powder diffraction file. The precision of diffraction angles was 1% to 4.7%. Most of relative errors between measured values of diffraction angles and existing data were less than 1%. As for the detector, the best position resolution in the test was 138 um (sigma value) with an X-ray tube. Finally, discussions of the results were given. The major factor that affected the precision of measurement was deviation from the flat structure of detector. The effect was analyzed and it came to a conclusion that it would be the optimal measurement scheme when the distance between the powder sample...

  2. Current status and requirements for position-sensitive detectors in medicine

    CERN Document Server

    Speller, R

    2002-01-01

    This review considers the current status of detector developments for medical imaging using ionising radiation. This field is divided into two major areas; the use of X-rays for transmission imaging and the use of radioactive tracers in emission imaging (nuclear medicine). Until recently, most detector developments were for applications in nuclear medicine. However, in the past 5 years new developments in large area, X-ray-sensitive detectors have meant that both application domains are equally served. In X-ray imaging, work in CT and mammography are chosen as examples of sensor developments. Photodiode arrays in multi-slice spiral CT acquisitions are described and for mammography the use of amorphous silicon flat panel arrays is considered. The latter is an excellent example where new detector developments have required a re-think of traditional imaging methods. In gamma-ray imaging the recent developments in small area, task-specific cameras are described. Their limitations and current proposals to overcome...

  3. A general technique for characterizing x-ray position sensitive arrays

    Energy Technology Data Exchange (ETDEWEB)

    Dufresne, E.; Bruning, R.; Sutton, M. [McGill Univ., Montreal, PQ (Canada). Dept. of Physics; Rodricks, B. [Argonne National Lab., IL (United States); Stephenson, G.B. [International Business Machines Corp., Yorktown Heights, NY (United States). Thomas J. Watson Research Center

    1994-03-01

    We present a general statistical technique for characterizing x-ray sensitive linear diode arrays and CCD arrays. We apply this technique to characterize the response of a linear diode array, Princeton Instrument model X-PDA, and a virtual phase CCD array, TI 4849, to direct illumination by x-rays. We find that the response of the linear array is linearly proportional to the incident intensity and uniform over its length to within 2 %. Its quantum efficiency is 38 % for Cu K{sub {alpha}} x-rays. The resolution function is evaluated from the spatial autocorrelation function and falls to 10 % of its peak value after one pixel. On the other hand, the response of the CCD detecting system to direct x-ray exposure is non-linear. To properly quantify the scattered x-rays, one must correct for the non- linearity. The resolution is two pixels along the serial transfer direction. We characterize the noise of the CCD and propose a model that takes into account the non-linearity and the resolution function to estimate the quantum efficiency of the detector. The quantum efficiency is 20 %.

  4. Large angle solid state position sensitive x-ray detector system

    Science.gov (United States)

    Kurtz, D.S.; Ruud, C.O.

    1998-03-03

    A method and apparatus for x-ray measurement of certain properties of a solid material are disclosed. In distinction to known methods and apparatus, this invention employs a specific fiber-optic bundle configuration, termed a reorganizer, itself known for other uses, for coherently transmitting visible light originating from the scintillation of diffracted x-radiation from the solid material gathered along a substantially one dimensional linear arc, to a two-dimensional photo-sensor array. The two-dimensional photodetector array, with its many closely packed light sensitive pixels, is employed to process the information contained in the diffracted radiation and present the information in the form of a conventional x-ray diffraction spectrum. By this arrangement, the angular range of the combined detector faces may be increased without loss of angular resolution. Further, the prohibitively expensive coupling together of a large number of individual linear diode photodetectors, which would be required to process signals generated by the diffracted radiation, is avoided. 7 figs.

  5. Amazingly resilient Indigenous people! Using transformative learning to facilitate positive student engagement with sensitive material.

    Science.gov (United States)

    Jackson, Debra; Power, Tamara; Sherwood, Juanita; Geia, Lynore

    2013-12-01

    If health professionals are to effectively contribute to improving the health of Indigenous people, understanding of the historical, political, and social disadvantage that has lead to health disparity is essential. This paper describes a teaching and learning experience in which four Australian Indigenous academics in collaboration with a non-Indigenous colleague delivered an intensive workshop for masters level post-graduate students. Drawing upon the paedagogy of Transformative Learning, the objectives of the day included facilitating students to explore their existing understandings of Indigenous people, the impact of ongoing colonisation, the diversity of Australia's Indigenous people, and developing respect for alternative worldviews. Drawing on a range of resources including personal stories, autobiography, film and interactive sessions, students were challenged intellectually and emotionally by the content. Students experienced the workshop as a significant educational event, and described feeling transformed by the content, better informed, more appreciative of other worldviews and Indigenous resilience and better equipped to contribute in a more meaningful way to improving the quality of health care for Indigenous people. Where this workshop differs from other Indigenous classes was in the involvement of an Indigenous teaching team. Rather than a lone academic who can often feel vulnerable teaching a large cohort of non-Indigenous students, an Indigenous teaching team reinforced Indigenous authority and created an emotionally and culturally safe space within which students were allowed to confront and explore difficult truths. Findings support the value of multiple teaching strategies underpinned by the theory of transformational learning, and the potential benefits of facilitating emotional as well as intellectual student engagement when presenting sensitive material.

  6. Two-dimensional position-sensitive gaseous detectors for high-resolution neutron and X-ray diffraction

    CERN Document Server

    Marmotti, M; Kampmann, R

    2002-01-01

    Two-dimensional position-sensitive gaseous detectors have been developed at the Geesthacht Neutron Facility (GeNF) for high-resolution neutron and X-ray diffractometry. They are multi-wire proportional counters with delay-line readout and sensitive areas of 300 mm x 300 mm or 500 mm x 500 mm. For detecting X-rays, neutrons and hard X-rays the counters are filled with Ar/CO sub 2 , sup 3 He/CF sub 4 and Xe/CO sub 2 , respectively. One neutron detector is used at the ARES diffractometer at GKSS, which is dedicated to the analysis of residual stresses. Further ones are used for analysing textures and residual stresses at the hard-X-ray beamline PETRA-2 at HASYLAB, and one detector is being developed for the neutron reflectometer REFSANS at the research reactor FRM-II in Munich, Germany. (orig.)

  7. Measurements of the position-dependent photo-detection sensitivity of the Hamamatsu R11410 and R8520 photomultiplier tubes

    CERN Document Server

    Baudis, L; Kessler, G; Kish, A; Wulf, J

    2015-01-01

    The Hamamatsu R11410 and R8520 photomultipliers (PMTs) are designed for applications in xenon-based dark matter detectors, featuring sensitivity to VUV light and stable operability at cryogenic temperatures. For eleven R11410 and seven R8520 PMTs, the relative photo-detection sensitivity at 470 nm was measured as a function of the position of the incident light on the photocathode. Typical non-uniformity values, considering 80 % of the photocathode surfaces, are 5 % - 10 % and 25 % - 30 % for the R11410 and R8520 types, respectively. It was found that the non-uniformity in the inner region of the photocathode is dominated by light reflections on the inner parts of the photosensors and the border regions contribute most to the observed non-uniformity.

  8. Biological Tissue Imaging with a Position and Time Sensitive Pixelated Detector

    CERN Document Server

    Jungmann, Julia H; MacAleese, Luke; Klinkert, Ivo; Visser, Jan; Heeren, Ron M A

    2013-01-01

    We demonstrate the capabilities of a highly parallel, active pixel detector for large-area, mass spectrometric imaging of biological tissue sections. A bare Timepix assembly (512x512 pixels) is combined with chevron microchannel plates on an ion microscope matrix-assisted laser desorption time-of-flight mass spectrometer (MALDI TOF-MS). The detector assembly registers position- and time-resolved images of multiple m/z species in every measurement frame. We prove the applicability of the detection system to bio-molecular mass spectrometry imaging on biologically relevant samples by mass-resolved images from Timepix measurements of a peptide-grid benchmark sample and mouse testis tissue slices. Mass-spectral and localization information of analytes at physiological concentrations are measured in MALDI-TOF-MS imaging experiments. We show a high spatial resolution (pixel size down to 740x740 nm2 on the sample surface) and a spatial resolving power of 6 {\\mu}m with a microscope mode laser field of view of 100-335 ...

  9. Phylogenetic position of the acariform mites: sensitivity to homology assessment under total evidence

    Directory of Open Access Journals (Sweden)

    Pepato Almir R

    2010-08-01

    Full Text Available Abstract Background Mites (Acari have traditionally been treated as monophyletic, albeit composed of two major lineages: Acariformes and Parasitiformes. Yet recent studies based on morphology, molecular data, or combinations thereof, have increasingly drawn their monophyly into question. Furthermore, the usually basal (molecular position of one or both mite lineages among the chelicerates is in conflict to their morphology, and to the widely accepted view that mites are close relatives of Ricinulei. Results The phylogenetic position of the acariform mites is examined through employing SSU, partial LSU sequences, and morphology from 91 chelicerate extant terminals (forty Acariformes. In a static homology framework, molecular sequences were aligned using their secondary structure as guide, whereby regions of ambiguous alignment were discarded, and pre-aligned sequences analyzed under parsimony and different mixed models in a Bayesian inference. Parsimony and Bayesian analyses led to trees largely congruent concerning infra-ordinal, well-supported branches, but with low support for inter-ordinal relationships. An exception is Solifugae + Acariformes (P. P = 100%, J. = 0.91. In a dynamic homology framework, two analyses were run: a standard POY analysis and an analysis constrained by secondary structure. Both analyses led to largely congruent trees; supporting a (Palpigradi (Solifugae Acariformes clade and Ricinulei as sister group of Tetrapulmonata with the topology (Ricinulei (Amblypygi (Uropygi Araneae. Combined analysis with two different morphological data matrices were run in order to evaluate the impact of constraining the analysis on the recovered topology when employing secondary structure as a guide for homology establishment. The constrained combined analysis yielded two topologies similar to the exclusively molecular analysis for both morphological matrices, except for the recovery of Pedipalpi instead of the (Uropygi Araneae clade. The

  10. Simple technique for measuring the Goos-Hänchen effect with polarization modulation and a position-sensitive detector.

    Science.gov (United States)

    Gilles, Hervé; Girard, Sylvain; Hamel, Joseph

    2002-08-15

    An original approach to directly measuring the Goos-Hänchen longitudinal shift between TE and TM polarization states during a total internal reflection is introduced. The technique is based on the modulation of the polarization state of a laser by an electro-optic modulator combined with a precise measurement of the resulting spatial displacement with a position-sensitive detector. This method presents many advantages over other techniques and allows measurements at different wavelengths over a broad range for the incident angle.

  11. The sensitivity of soil O2 and redox biogeochemistry to landscape position and climate

    Science.gov (United States)

    Silver, W. L.; Ruan, L.; O'Connell, C.; Gutiérrez del Arroyo, O.

    2015-12-01

    Soil oxygen (O2) availability and associated redox dynamics are key drivers of carbon and nitrogen cycling and greenhouse gas emissions in terrestrial ecosystems. However, few studies have measured soil O2 availability, and even fewer have related this to biogeochemical cycling over space and time. Redox dynamics are likely to play a particularly important role in humid tropical forests characterized by high rainfall, near constant warm temperatures, high biological activity, and finely textured soils, all of which contribute to periodic O2 depletion throughout the soil profile. These ecosystems exhibit rapid C turnover and are a globally important source of the major greenhouse gases. We report on an extensive network of galvanic O2 sensors and time-domain reflectometry along topographic gradients in a lower montane wet tropical forest in Puerto Rico (n = 105 sensors). Within the sensor field we also installed three automated surface flux chambers in each topographic zone (ridge, slope and valley). A Cavity Ring-Down Spectroscopy (CRDS) gas analyzer was used to measure pseudo-continuous fluxes of CO2, N2O, and CH4. Soil O2 concentrations decrease nonlinearly from ridges to valleys along topographic gradients. Soil moisture was the best single predictor of soil O2 concentrations explaining over 50% of the variability in the data, even in these well-drained soils. Drought conditions dramatically altered soil O2 dynamics in both time and space, and showed that redox drivers differed by topographic position. Both ridges and slopes produced higher CO2 fluxes than valleys. Daily CH4 emissions went up to ~2000 g CH4 ha-1d-1 for valleys (hot spots and hot moments). Soil O2 dynamics also helped explain patterns in reactive Fe species and C storage, as well as pH along the catena. Our results highlight the potential for soil O2 concentrations as an integrator of biogeochemical dynamics in variable redox environments. They also provide a mechanism for identifying and

  12. Increased sensitivity in PCR detection of tdh-positive Vibrio parahaemolyticus in seafood with purified template DNA.

    Science.gov (United States)

    Hara-Kudo, Y; Kasuga, Y; Kiuchi, A; Horisaka, T; Kawasumi, T; Kumagai, S

    2003-09-01

    PCR is an important method for the detection of thermostable direct hemolysin gene (tdh)-positive (pathogenic hemolysin-producing) strains of Vibrio parahaemolyticus in seafood because tdh-negative (nonpathogenic) V. parahaemolyticus strains often contaminate seafood and interfere with the direct isolation of tdh-positive V. parahaemolyticus. In this study, the use of PCR to detect the tdh gene of V. parahaemolyticus in various seafoods artificially contaminated with tdh-positive V. parahaemolyticus was examined. PCR was inhibited by substances in oysters, squid, mackerel, and yellowtail but not by cod, sea bream, scallop, short-necked clam, and shrimp. To improve detection, DNA was purified by either the silica membrane method, the glass fiber method, or the magnetic separation method, and the purified DNA was used as the PCR primer template. For all samples, the use of the silica membrane method and the glass fiber method increased detection sensitivity. The results of this study demonstrate that the use of properly purified template DNA for PCR markedly increases the effectiveness of the method in detecting pathogenic tdh-positive V. parahaemolyticus in contaminated seafood.

  13. Design of a beam position sensitive cavity as a Schottky noise detector for mass measurements in CR rate at FAIR

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xiangcheng; Huelsmann, Peter; Nolden, Fritz; Steck, Markus [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Sanjari, Shahab [ExtreMe Matter Institute, Darmstadt (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Litvinov, Yuri [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Piotrowski, Jeremi [AGH University of Science and Technology, Krakow (Poland)

    2014-07-01

    Mass is one of fundamental characteristics of a nucleus. It plays an important role in many areas of physics, as well as other science branches. Especially in nuclear astrophysics, the masses of unstable nuclei close to nucleon drip lines are of great interests, since they are indispensable quantities for modelling nucleosynthesis processes in stellar objects. The Facility for Antiproton and Ion Research (FAIR), by providing high-intensity high-energy secondary beams, will enable unprecedented opportunities to investigate such nuclei. In particular, the collector ring (CR) is designed to be operated in the isochronous ion-optical mode as a high precision mass spectrometer. In order to satisfy the stringent requirements on accuracy and sensitivity for the future mass measurements, a non-destructive detector that is sensitive to single ions is being developed. Owing to the position sensitivity, it will be possible to correct for errors originating from different orbit lengths. In this work, we present simulation results of several possible designs of a cavity-based detector and discuss their potential applications as Schottky-noise detectors.

  14. Definition of Sensitive Skin: An Expert Position Paper from the Special Interest Group on Sensitive Skin of the International Forum for the Study of Itch

    NARCIS (Netherlands)

    Misery, L.; Stander, S.; Szepietowski, J.C.; Reich, A.; Wallengren, J.; Evers, A.W.M.; Takamori, K.; Brenaut, E.; Gall-Ianotto, C. Le; Fluhr, J.; Berardesca, E.; Weisshaar, E.

    2017-01-01

    Sensitive skin is a frequent complaint in the general population, in patients, and among subjects suffering from itch. The International Forum for the Study of Itch (IFSI) decided to initiate a special interest group (SIG) on sensitive skin. Using the Delphi method, sensitive skin was defined as "A

  15. BACTERIOLOGICAL STUDY OF COAGULASE-POSITIVE AND COAGULASE-NEGATIVE STAPHYLOCOCCI IN RELATION TO METHICILLIN SENSITIVITY TESTING

    Directory of Open Access Journals (Sweden)

    Padmanabham Yalangi

    2016-10-01

    Full Text Available BACKGROUND Staphylococcus aureus has long been recognised as an important pathogen in human disease. Staphylococci infection occurs regularly in hospitalised patients and has serious consequences despite antibiotic therapy. Shortly after introduction of methicillin after clinical use Methicillin-Resistant Staphylococcus Aureus (MRSA were identified in many countries and become one of the most common causes of nosocomial infections. The aim of the study is to know the methicillin sensitivity of both coagulase-negative and coagulase-positive staphylococci isolated from various samples. MATERIALS AND METHODS 100 strains of staphylococci both coagulase positive and coagulase negative were isolated in the Department of Microbiology from various clinical samples. They were confirmed by morphology, staining methods and by using standard bacteriological procedures and biochemical reactions. Antibiotic susceptibility testing was performed by Kirby Bauer disc diffusion test. RESULTS Predominant species from pus were S. epidermidis (42.42% and from sputum S. haemolyticus (31.81% from blood S. haemolyticus (53.33%. 53% of strains produced beta-lactamase. Majority 47.22% by S. epidermidis from pus followed by S. haemolyticus 23.33% from pus. Beta-lactamase production was least from throat swab (5.55%. Out of 32 coagulase-positive staphylococci tested to methicillin 15 (46.87% were found to be sensitive, 17 (53.13% were found to be resistant. Out of 68 coagulase-negative staphylococci tested, 13 (19.11% were found to sensitive and 55 (80.88% were found to be resistant. 72% of strains were sensitive to novobiocin and 28% resistant to novobiocin. 43% showed drug resistance to 2 drugs. 14% to 3 drugs and 5 drugs. 6% of staphylococci sensitive to all the 10 drugs. CONCLUSION MRSA is a type of bacteria that is resistant to a number of widely used antibiotics. This means MRSA infections can be more difficult to treat than other bacterial infections. In recent years

  16. Polarization analysis for the 2D position-sensitive detector of the HADAS reflectometer in Jülich

    Science.gov (United States)

    Rücker, U.; Bergs, W.; Alefeld, B.; Kentzinger, E.; Brückel, Th.

    2001-03-01

    A neutron reflectometer with polarization analysis is being built on the basis of the HADAS spectrometer in the neutron guide hall at the research reactor FRJ-2 (DIDO) in Jülich. The new instrument is optimized for reflectivity and diffuse scattering measurements under grazing incidence on layered magnetic structures with thicknesses in the nm range. In order to measure diffuse scattering with polarization analysis, the 2D position-sensitive detector has been equipped with a polarization analyser that consists of a stack of supermirrors parallel to the scattering plane. First tests have revealed that the resolution of the instrument is not reduced by the polarization analyser. A flipping ratio of 20 has been achieved already during the first experiment.

  17. Influence of multiple sclerosis, age and degree of disability, in the position of the contrast sensitivity curve peak

    Science.gov (United States)

    Nunes, A F; Monteiro, P M L; Pato, M Vaz

    2014-01-01

    Context: Contrast sensitivity (CS) function is one of the most important tests available for evaluating visual impairment. Multiple sclerosis (MS) can produce highly selective losses in visual function and psychophysical studies have demonstrated CS deficits for some spatial frequencies. Aims: This work studies the differences in CS between a group of controls and a group of MS patients, focusing on the location of the maximum sensitivity peak, shape of the curve, and determination of the most affected spatial frequencies. Materials and Methods: Using a sinusoidal stimulus the authors assessed CS function in 28 subjects with definitive relapsing remitting MS, and in 50 controls with acuities of 20/25 or better. The peaks of the CS curves were studied by fitting third degree polynomials to individual sets of data. Results: Compared with the control group, the CS function curve for MS subjects showed more deficits in extreme points (low- and high-spatial frequencies). Our results display significant CS losses, at the high-frequencies band level, in the beginning of the disease. When the disease progresses and the disabilities appear, there are greater losses at the low-frequencies band level. In average, the CS curve peaks for the MS group were shifted in relation to the control group. Conclusions: CS losses in the MS group suggest an association with ageing and disability level in the expanded disability status scale. The position of the CS function peak is influenced by MS, age, and degree of disability. PMID:24008796

  18. Position-independent geometric error identification and global sensitivity analysis for the rotary axes of five-axis machine tools

    Science.gov (United States)

    Guo, Shijie; Jiang, Gedong; Zhang, Dongsheng; Mei, Xuesong

    2017-04-01

    Position-independent geometric errors (PIGEs) are the fundamental errors of a five-axis machine tool. In this paper, to identify ten PIGEs peculiar to the rotary axes of five-axis machine tools with a tilting head, the mathematic model of the ten PIGEs is deduced and four measuring patterns are proposed. The measuring patterns and identifying method are validated on a five-axis machine tool with a tilting head, and the ten PIGEs of the machine tool are obtained. The sensitivities of the four adjustable PIGEs of the machine tool in different measuring patterns are analyzed by the Morris global sensitivity analysis method and the modifying method, and the procedure of the four adjustable PIGEs of the machine tool is given accordingly. Experimental results show that after and before modifying the four adjustable PIGEs, the average compensate rate reached 52.7%. It is proved that the proposed measuring, identifying, analyzing and modifying method are effective for error measurement and precision improvement of the five-axis machine tool.

  19. Influence of multiple sclerosis, age and degree of disability, in the position of the contrast sensitivity curve peak

    Directory of Open Access Journals (Sweden)

    A F Nunes

    2014-01-01

    Full Text Available Context: Contrast sensitivity (CS function is one of the most important tests available for evaluating visual impairment. Multiple sclerosis (MS can produce highly selective losses in visual function and psychophysical studies have demonstrated CS deficits for some spatial frequencies. Aims: This work studies the differences in CS between a group of controls and a group of MS patients, focusing on the location of the maximum sensitivity peak, shape of the curve, and determination of the most affected spatial frequencies. Materials and Methods: Using a sinusoidal stimulus the authors assessed CS function in 28 subjects with definitive relapsing remitting MS, and in 50 controls with acuities of 20/25 or better. The peaks of the CS curves were studied by fitting third degree polynomials to individual sets of data. Results: Compared with the control group, the CS function curve for MS subjects showed more deficits in extreme points (low- and high-spatial frequencies. Our results display significant CS losses, at the high-frequencies band level, in the beginning of the disease. When the disease progresses and the disabilities appear, there are greater losses at the low-frequencies band level. In average, the CS curve peaks for the MS group were shifted in relation to the control group. Conclusions: CS losses in the MS group suggest an association with ageing and disability level in the expanded disability status scale. The position of the CS function peak is influenced by MS, age, and degree of disability.

  20. Measurement and analysis of neutron flux distribution of STACY heterogeneous core by position sensitive proportional counter. Contract research

    CERN Document Server

    Murazaki, M; Uno, Y

    2003-01-01

    We have measured neutron flux distribution around the core tank of STACY heterogeneous core by position sensitive proportional counter (PSPC) to develop the method to measure reactivity for subcritical systems. The neutron flux distribution data in the position accuracy of +-13 mm have been obtained in the range of uranium concentration of 50g/L to 210g/L both in critical and in subcritical state. The prompt neutron decay constant, alpha, was evaluated from the measurement data of pulsed neutron source experiments. We also calculated distribution of neutron flux and sup 3 He reaction rates at the location of PSPC by using continuous energy Monte Carlo code MCNP. The measurement data was compared with the calculation results. As results of comparison, calculated values agreed generally with measurement data of PSPC with Cd cover in the region above half of solution height, but the difference between calculated value and measurement data was large in the region below half of solution height. On the other hand, ...

  1. Measurement and analysis of neutron flux distribution of STACY heterogeneous core by position sensitive proportional counter. Contract research

    Energy Technology Data Exchange (ETDEWEB)

    Murazaki, Minoru; Uno, Yuichi; Miyoshi, Yoshinori [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2003-03-01

    We have measured neutron flux distribution around the core tank of STACY heterogeneous core by position sensitive proportional counter (PSPC) to develop the method to measure reactivity for subcritical systems. The neutron flux distribution data in the position accuracy of {+-}13 mm have been obtained in the range of uranium concentration of 50g/L to 210g/L both in critical and in subcritical state. The prompt neutron decay constant, {alpha}, was evaluated from the measurement data of pulsed neutron source experiments. We also calculated distribution of neutron flux and {sup 3}He reaction rates at the location of PSPC by using continuous energy Monte Carlo code MCNP. The measurement data was compared with the calculation results. As results of comparison, calculated values agreed generally with measurement data of PSPC with Cd cover in the region above half of solution height, but the difference between calculated value and measurement data was large in the region below half of solution height. On the other hand, calculated value agreed well with measurement data of PSPC without Cd cover. (author)

  2. Advanced pulse-shape analysis and implementation of gamma-ray tracking in a position-sensitive coaxial HPGe detector

    Energy Technology Data Exchange (ETDEWEB)

    Kuhn, Austin Lee [Univ. of California, Berkeley, CA (United States)

    2002-11-12

    A new concept in g-radiation detection utilizing highly segmented positionsensitive germanium detectors is currently being developed. Through pulse-shape analysis these detectors will provide the three-dimensional position and energy of individual γ-ray interactions and allow the full-energy and direction vectors of the incident radiation to be reconstructed in a process termed tracking. Here, a prototype segmented detector has been utilized in the assessment of theoretically modeled pulse shapes to gain insight into the factors that effect their agreement with those experimentally measured. It was found that simple modeling of the charge-collection process would provide fair agreement between calculated and experimental pulse shapes. However, in some cases significant deviations between the two were present. This was a result of insufficient modeling of all the processes involved in pulse-shape formation. Factors contributing to this include the three-dimensional spatial distribution of the charge carriers, the path of the primary electron, and fluctuations in the electric fields near electrode surfaces and due to variations in impurity concentrations. Additionally, the sensitivity of pulse shapes to changes in the interaction location has been studied. The results indicate that single interactions with energy deposition of 662 keV can potentially be localized to better than the desired position resolution of 2 mm. However, when the study was extended to two interactions totaling 662 keV a different conclusion was reached. It was shown that the pulse shapes resulting from two interactions were ambiguous with that of pulse shapes from single interactions over dimensions greater than 2 mm in the larger detector segments. The size of these segments in future detectors must be reduced in order to increase their sensitivity. Ultimately, a signal decomposition algorithm was developed and implemented to extract the position and energy of γ-ray interactions, occurring

  3. Evaluation of moderately cooled pure NaI as a scintillator for position-sensitive PET detectors

    Energy Technology Data Exchange (ETDEWEB)

    Wear, J.A.; Karp, J.S.; Haigh, A.T.; Freifelder, R. [Univ. of Pennsylvania, Philadelphia, PA (United States). Dept. of Radiology

    1996-06-01

    A new evaluation of pure NaI has been performed to determine if moderate cooling would lead to better performance than that of existing, activated NaI(Tl) position-sensitive detectors, particularly at high countrates. Using a freezer, an initial effort was performed to cool the crystal assembly to {minus}90 C (183 K). At this temperature, pure NaI has a decay constant of 35 nsec, a light output which is about 20% that of room temperature NaI(Tl), and an energy resolution of 15%. For the PET applications the signal of room temperature (25 C) NaI(Tl) is normally pulse clipped, reducing the light output to 40% of the unclipped signal and yielding an energy resolution of 10.5%. Since the long decay of NaI(Tl) causes it to suffer more significantly than pure NaI from pre-pulse pileup, the difference in energy resolution between the two crystals at high countrates will be reduced. Also, a significantly shorter trigger deadtime with pure NaI will lead to a reduction in coincidence deadtime losses in PET. Computer simulations of large-area crystals operating at high countrates have been performed to quantify their trigger deadtime behavior and position resolution as a function of light output and pulse decay time. Having gained experience with the practical issues of cooling large crystals, measurements of position resolution have been performed with a NaI bar detector of similar geometry to the NaI(Tl) detectors in use in the PENN-PET scanner.

  4. Spatial distortion correction and crystal identification for MRI-compatible position-sensitive avalanche photodiode-based PET scanners.

    Science.gov (United States)

    Chaudhari, Abhijit J; Joshi, Anand A; Wu, Yibao; Leahy, Richard M; Cherry, Simon R; Badawi, Ramsey D

    2009-06-01

    Position-sensitive avalanche photodiodes (PSAPDs) are gaining widespread acceptance in modern PET scanner designs, and owing to their relative insensitivity to magnetic fields, especially in those that are MRI-compatible. Flood histograms in PET scanners are used to determine the crystal of annihilation photon interaction and hence, for detector characterization and routine quality control. For PET detectors that use PSAPDs, flood histograms show a characteristic pincushion distortion when Anger logic is used for event positioning. A small rotation in the flood histogram is also observed when the detectors are placed in a magnetic field. We first present a general purpose automatic method for spatial distortion correction for flood histograms of PSAPD-based PET detectors when placed both inside and outside a MRI scanner. Analytical formulae derived for this scheme are based on a hybrid approach that combines desirable properties from two existing event positioning schemes. The rotation of the flood histogram due to the magnetic field is determined iteratively and is accounted for in the scheme. We then provide implementation details of a method for crystal identification we have previously proposed and evaluate it for cases when the PET detectors are both outside and in a magnetic field. In this scheme, Fourier analysis is used to generate a lower-order spatial approximation of the distortion-corrected PSAPD flood histogram, which we call the 'template'. The template is then registered to the flood histogram using a diffeomorphic iterative intensity-based warping scheme. The calculated deformation field is then applied to the segmentation of the template to obtain a segmentation of the flood histogram. A manual correction tool is also developed for exceptional cases. We present a quantitative assessment of the proposed distortion correction scheme and crystal identification method against conventional methods. Our results indicate that our proposed methods lead to

  5. Race-based rejection sensitivity partially accounts for the relationship between racial discrimination and distressing attenuated positive psychotic symptoms.

    Science.gov (United States)

    Anglin, Deidre M; Greenspoon, Michelle; Lighty, Quenesha; Ellman, Lauren M

    2016-10-01

    Self-reported experiences of racial discrimination have been associated with a continuum of psychotic experiences in racial and ethnic minority populations; however, the underlying mechanisms of this relationship are not yet clear. Race-based rejection sensitivity (RS-race) has been associated with thought intrusions about being the target of racial discrimination; therefore, the present study aimed to determine whether RS-race accounts for the relationship between racial discrimination and psychotic-like experiences in racial and ethnic minority populations. A sample of 644 young adults from a US urban, predominantly immigrant, and racial and ethnic minority population was administered a self-report inventory of psychosis risk (i.e. Prodromal Questionnaire (PQ) ), providing a dimensional assessment of the total number of attenuated positive psychotic symptoms experienced as distressing (APPS-distress). Participants also completed the Experiences of Discrimination Questionnaire and the Rejection Sensitivity Questionnaire-Race. Hierarchical linear regression analyses revealed that RS-race and racial discrimination were both significantly related to higher levels of APPS-distress. Bootstrapping analyses of indirect effects indicated that RS-race partially accounted for the relationship between racial discrimination and APPS-distress. Although the cross-sectional nature of the data limits conclusions about causal inference, our findings do suggest that racial discrimination and RS-race may both be important for understanding risk for distress in the psychotic spectrum among racial and ethnic minority young adults. Some individuals who report racial discrimination may be more vulnerable to APPS-distress in part because they are anxiously anticipating being racially slighted, and this should be explored further in prospective clinical high-risk studies. © 2014 Wiley Publishing Asia Pty Ltd.

  6. Performance of a position sensitive low-pressure wire chamber (LPWC) having position readout from a separate sense wire plane a critical analysis

    CERN Document Server

    Basu, C; Roy, S; Basu, P; Majumdar, H; Chatterjee, M L

    2002-01-01

    The paper describes the operation of a simple one-dimensional LPWC from a completely different standpoint. The position output is derived from a separate position plane, where discrete resistances are soldered between two adjacent wires. Theoretical formulations for the position extraction are derived where the role of various detector parameters are dealt with. Position spectrum is shown for various choices of resistances varying from 50 OMEGA to 220 k OMEGA. Best position resolution and linearity is obtained for 33 k OMEGA though it violates the existing hypothesis.

  7. Performance measurements of a depth-encoding PET detector module based on position-sensitive avalanche photodiode read-out.

    Science.gov (United States)

    Dokhale, P A; Silverman, R W; Shah, K S; Grazioso, R; Farrell, R; Glodo, J; McClish, M A; Entine, G; Tran, V H; Cherry, S R

    2004-09-21

    We are developing a high-resolution, high-efficiency positron emission tomography (PET) detector module with depth of interaction (DOI) capability based on a lutetium oxyorthosilicate (LSO) scintillator array coupled at both ends to position-sensitive avalanche photodiodes (PSAPDs). In this paper we present the DOI resolution, energy resolution and timing resolution results for complete detector modules. The detector module consists of a 7 x 7 matrix of LSO scintillator crystals (1 x 1 x 20 mm3 in dimension) coupled to 8 x 8 mm2 PSAPDs at both ends. Flood histograms were acquired and used to generate crystal look-up tables. The DOI resolution was measured for individual crystals within the array by using the ratio of the signal amplitudes from the two PSAPDs on an event-by-event basis. A measure of the total scintillation light produced was obtained by summing the signal amplitudes from the two PSAPDs. This summed signal was used to measure the energy resolution. The DOI resolution was measured to be 3-4 mm FWHM irrespective of the position of the crystal within the array, or the interaction location along the length of the crystal. The total light signal and energy resolution was almost independent of the depth of interaction. The measured energy resolution averaged 14% FWHM. The coincidence timing resolution measured using a pair of identical detector modules was 4.5 ns FWHM. These results are consistent with the design goals and the performance required of a compact, high-resolution and high-efficiency PET detector module for small animal and breast imaging applications.

  8. High-Efficiency CdZnTe Position-Sensitive VFG Gamma-Ray Detectors for Safeguards Applications

    Energy Technology Data Exchange (ETDEWEB)

    Bolotnikov, Aleksey E. [Brookhaven National Lab. (BNL), Upton, NY (United States); James, Ralph B. [Brookhaven National Lab. (BNL), Upton, NY (United States); Cui, Y. [Brookhaven National Lab. (BNL), Upton, NY (United States); De Geronimo, G. [Brookhaven National Lab. (BNL), Upton, NY (United States); Vernon, E. [Brookhaven National Lab. (BNL), Upton, NY (United States); Camarda, G. S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Hossain, A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Yang, G. [Brookhaven National Lab. (BNL), Upton, NY (United States); Indusi, J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Boyer, Brian [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-09-30

    The goal of this project is to incorporate a Cadmium-Zinc-Telluride (CdZnTe or CZT) detector (with 1% or better resolution) into a bench-top prototype for isotope identification and related safeguards applications. The bench-top system is based on a 2x2 array of 6x6x20 mm3 position-sensitive virtual Frisch-grid (VFG) CZT detectors. The key features of the array are that it allows for the use of average-grade CZT material with a moderate content of defects, and yet it provides high energy resolution, 1% FWHM at 662 keV, large effective area, and low-power consumption. The development of this type of 3D detector and new instruments incorporating them is motivated by the high cost and low availability of large, > 1 cm3, CZT crystals suitable for making multi-pixel detectors with acceptable energy resolution and efficiency.

  9. High-Efficiency CdZnTe Position-Sensitive VFG Gamma-Ray Detectors for Safeguards Applications

    Energy Technology Data Exchange (ETDEWEB)

    Bolotnikov, Aleksey E. [Brookhaven National Lab. (BNL), Upton, NY (United States); James, Ralph B. [Brookhaven National Lab. (BNL), Upton, NY (United States); Cui, Y. [Brookhaven National Lab. (BNL), Upton, NY (United States); De Geronimo, G. [Brookhaven National Lab. (BNL), Upton, NY (United States); Vernon, E. [Brookhaven National Lab. (BNL), Upton, NY (United States); Camarda, G. S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Hossain, A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Yang, G. [Brookhaven National Lab. (BNL), Upton, NY (United States); Indusi, J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Boyer, Brian [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-09-30

    The goal of this project is to incorporate a Cadmium-Zinc-Telluride (CdZnTe or CZT) detector (with 1% or better resolution) into a bench-top prototype for isotope identification and related safeguards applications. The bench-top system is based on a 2x2 array of 6x6x20 mm3 position-sensitive virtual Frisch-grid (VFG) CZT detectors. The key features of the array are that it allows for the use of average-grade CZT material with a moderate content of defects, and yet it provides high-energy resolution, 1% FWHM at 662 keV, large effective area, and low-power consumption. The development of this type of 3D detector and new instruments incorporating them is motivated by the high cost and low availability of large, > 1 cm3, CZT crystals suitable for making multi-pixel detectors with acceptable energy resolution and efficiency.

  10. Low incidence of minor BRAF V600 mutation-positive subclones in primary and metastatic melanoma determined by sensitive and quantitative real-time PCR

    DEFF Research Database (Denmark)

    Kielsgaard Kristensen, Thomas; Clemmensen, Ole; Hoejberg, Lise

    2013-01-01

    BRAF V600 mutation is an important biological marker for therapeutic guidance in melanoma, where mutation-positive cases are candidates for therapy targeting mutant B-Raf. Recent studies showing intratumor variation in BRAF mutation status have caused concern that sensitive mutation analysis can...... lead to mutation-positive results in patients with melanomas with small subsets of mutation-positive cells who may not benefit from therapy targeting mutant B-Raf. Mutation analysis with high analytical sensitivity is generally preferred, to reduce the risk of false-negative results. In this study......, sensitive and quantitative BRAF V600E and V600K mutation-specific real-time quantitative PCR was used to study the occurrence of small subsets of mutation-positive cells in primary melanomas and melanoma metastases. The BRAF V600E mutation was detected in 39 of 82 melanoma patients. We observed a highly...

  11. Reduced sensitivity to both positive and negative reinforcement in mice over-expressing the 5-hydroxytryptamine transporter.

    Science.gov (United States)

    Line, Samantha J; Barkus, Chris; Rawlings, Nancy; Jennings, Katie; McHugh, Stephen; Sharp, Trevor; Bannerman, David M

    2014-12-01

    The 5-hydroxytryptamine (5-HT) transporter (5-HTT) is believed to play a key role in both normal and pathological psychological states. Much previous data suggest that the s allele of the polymorphic regulatory region of the 5-HTT gene promoter is associated with reduced 5-HTT expression and vulnerability to psychiatric disorders, including anxiety and depression. In comparison, the l allele, which increases 5-HTT expression, is generally considered protective. However, recent data link this allele to both abnormal 5-HT signalling and psychopathic traits. Here, we studied the processing of aversive and rewarding cues in transgenic mice that over-express the 5-HTT (5-HTTOE mice). Compared with wild-type mice, 5-HTTOE mice froze less in response to both a tone that had previously been paired with footshock, and the conditioning context. In addition, on a decision-making T-maze task, 5-HTTOE mice displayed reduced preference for a larger, delayed reward and increased preference for a smaller, immediate reward, suggesting increased impulsiveness compared with wild-type mice. However, further inspection of the data revealed that 5-HTTOE mice displayed a relative insensitivity to reward magnitude, irrespective of delay. In contrast, 5-HTTOE mice appeared normal on tests of spatial working and reference memory, which required an absolute choice between options associated with either reward or no reward. Overall, the present findings suggest that 5-HTT over-expression results in a reduced sensitivity to both positive and negative reinforcers. Thus, these data show that increased 5-HTT expression has some maladaptive effects, supporting recent suggestions that l allele homozygosity may be a potential risk factor for disabling psychiatric traits.

  12. A data acquisition system for two-dimensional position sensitive micropattern gas detectors with delay-line readout

    Energy Technology Data Exchange (ETDEWEB)

    Hanu, A.R., E-mail: hanua@mcmaster.ca [Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario, Canada L8S 4K1 (Canada); NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Prestwich, W.V.; Byun, S.H. [Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario, Canada L8S 4K1 (Canada)

    2015-04-21

    We present a data acquisition (DAQ) system for two-dimensional position sensitive micropattern gas detectors using the delay-line method for readout. The DAQ system consists of a field programmable gate array (FPGA) as the main data processor and our time-to-digital (TDC) mezzanine card for making time measurements. We developed the TDC mezzanine card around the Acam TDC-GPX ASIC and it features four independent stop channels referenced to a common start, a typical timing resolution of ~81 ps, and a 17-bit measurement range, and is compliant with the VITA 57.1 standard. For our DAQ system, we have chosen the Xilinx SP601 development kit which features a single Spartan 6 FPGA, 128 MB of DDR2 memory, and a serial USB interface for communication. Output images consist of 1024×1024 square pixels, where each pixel has a 32-bit depth and corresponds to a time difference of 162 ps relative to its neighbours. When configured for a 250 ns acquisition window, the DAQ can resolve periodic event rates up to 1.8×10{sup 6} Hz without any loses and will report a maximum event rate of 6.11×10{sup 5} Hz for events whose arrival times follow Poisson statistics. The integral and differential non-linearities have also been measured and are better than 0.1% and 1.5%, respectively. Unlike commercial units, our DAQ system implements the delay-line image reconstruction algorithm entirely in hardware and is particularly attractive for its modularity, low cost, ease of integration, excellent linearity, and high throughput rate.

  13. Sensitivity and specificity of CT colonography for the detection of colonic neoplasia after positive faecal occult blood testing: systematic review and meta-analysis

    Energy Technology Data Exchange (ETDEWEB)

    Plumb, Andrew A.; Pendse, Douglas A.; Taylor, Stuart A. [University College London, Centre for Medical Imaging, London (United Kingdom); Halligan, Steve [University College London, Centre for Medical Imaging, London (United Kingdom); University College London, University College Hospital, Centre for Medical Imaging, Podium Level 2, London (United Kingdom); Mallett, Susan [University of Oxford, Department of Primary Care Health Sciences, Oxford (United Kingdom)

    2014-05-15

    CT colonography (CTC) is recommended after positive faecal occult blood testing (FOBt) when colonoscopy is incomplete or infeasible. We aimed to estimate the sensitivity and specificity of CTC for colorectal cancer and adenomatous polyps following positive FOBt via systematic review. The MEDLINE, EMBASE, AMED and Cochrane Library databases were searched for CTC studies reporting sensitivity and specificity for colorectal cancer and adenomatous polyps. Included subjects had tested FOBt-positive by guaiac or immunochemical methods. Per-patient detection rates were summarized via forest plots. Meta-analysis of sensitivity and specificity was conducted using a bivariate random effects model and the average operating point calculated. Of 538 articles considered, 5 met inclusion criteria, describing results from 622 patients. Research study quality was good. CTC had a high per-patient average sensitivity of 88.8 % (95 % CI 83.6 to 92.5 %) for ≥6 mm adenomas or colorectal cancer, with low between-study heterogeneity. Specificity was both more heterogeneous and lower, at an average of 75.4 % (95 % CI 58.6 to 86.8 %). Few studies have investigated CTC in FOBt-positive individuals. CTC is sensitive at a ≥6 mm threshold but specificity is lower and variable. Despite the limited data, these results suggest that CTC may adequately substitute for colonoscopy when the latter is undesirable. (orig.)

  14. Nano-thermometers with thermo-sensitive polymer grafted USPIOs behaving as positive contrast agents in low-field MRI

    Science.gov (United States)

    Hannecart, Adeline; Stanicki, Dimitri; Vander Elst, Luce; Muller, Robert N.; Lecommandoux, Sébastien; Thévenot, Julie; Bonduelle, Colin; Trotier, Aurélien; Massot, Philippe; Miraux, Sylvain; Sandre, Olivier; Laurent, Sophie

    2015-02-01

    Two commercial statistical copolymers of ethylene oxide and propylene oxide, Jeffamine® M-2005 (PEO5-st-PPO37) and M-2070 (PEO46-st-PPO13), exhibiting lower critical solution temperature (LCST) in water, were grafted onto the surface of ultra-small superparamagnetic iron oxide nanoparticles (USPIOs) using silanization and amide-bond coupling reactions. The LCSTs of the polymers in solution were measured by dynamic light scattering (DLS) and nuclear magnetic resonance (NMR). In accordance with the compositions of EO vs. PO, the transition temperature was measured to be 22 +/- 2 °C for M-2005 by both DLS and NMR, while the LCST was much higher, 52 +/- 2 °C, for M-2070 (a second transition was also detected above 80 °C by NMR in that case, ascribed to the full dehydration of chains at the molecular level). The resulting polymer-grafted USPIOs exhibit a temperature-responsive colloidal behaviour, their surface reversibly changing from hydrophilic below LCST to hydrophobic above it. This phenomenon was utilised to design thermo-sensitive contrast agents for MRI. Transverse relaxivities (r2) of the USPIO@PEO5-st-PPO37 core-shell nanoparticles were measured at 8.25, 20, 60, and 300 MHz. Nuclear magnetic resonance dispersion (NMRD) profiles, giving longitudinal relaxivities (r1) between 0.01 and 60 MHz, were acquired at temperatures ranging from 15 to 50 °C. For all tested frequencies except 300 MHz, both r1 and r2 decrease with temperature and show an inflection point at 25 °C, near the LCST. To illustrate the interest of such polymer-coated USPIOs for MRI thermometry, sample tubes were imaged on both low-field (8.25 MHz/0.194 Tesla) and high-field (300 MHz/7.05 Tesla) MRI scanners with either T1- or T2*-weighted spin echo sequences. The positive contrast on low-field MR images and the perfect linearity of the signal with a T2*-weighted sequence over the entire temperature range 15-50 °C render these LCST polymer coated USPIOs interesting positive contrast agents

  15. Reflexive Positioning in a Politically Sensitive Situation: Dealing with the Threats of Researching the West Bank Settler Experience

    Science.gov (United States)

    Possick, Chaya

    2009-01-01

    For the past 7 years, the author has conducted qualitative research projects revolving around the experiences of West Bank settlers. The political situation in Israel in general, and the West Bank in particular, has undergone rapid and dramatic political, military, and social changes during this period. In highly politically sensitive situations…

  16. 231 Pattern of Positive Sensitization in Patient with Asthma and Rhinitis to 3600 MSNM (La Paz, Bolivia)

    OpenAIRE

    Moncada Alcon, Abel Marcelo; Rios Mora, Roxana Ivon

    2012-01-01

    Background In the high altitude exists very few studies about allergies, we seek to give to know our sensitization in population with breathing problems (asthma and Allergic Rhinitis). Methods They were carried out allergy tests to 94 patients between 6 and 13 years with breathing symptoms predominantly allergic rhinitis and asthma. They were carried out allergy tests to foods like peanut, wheat, almond, tomato, milk, fish, soya, nuts, corn egg, chocolate, dog epithelia, cat, rabbit, feathers...

  17. Different co-sensitizations could determine different risk assessment in peach allergy? Evaluation of an anaphylactic biomarker in Pru p 3 positive patients.

    Science.gov (United States)

    Uasuf, Carina Gabriela; Villalta, Danilo; Conte, Maria Elisabetta; Di Sano, Caterina; Barrale, Maria; Cantisano, Vincenzo; Pace, Elisabetta; Gjomarkaj, Mark; Gangemi, Sebastiano; Brusca, Ignazio

    2015-01-01

    In Italy, the nsLTP (Pru p 3) has been identified as the most frequent cause of food allergy and anaphylaxis. In order to estimate the risk assessment in peach allergy, we investigated the presence of correlations between the levels of sIgE to Pru p 3 with the severity of the clinical symptoms in two Pru p 3 positive populations from two different areas of Italy. 133 consecutively Pru p 3 positive patients were recruited from South Italy, where the prevalence of PR-10 and profilin sensitization is low, and from North-East Italy, where the sensitization to pathogenesis related protein -10 (PR-10) and profilin is higher. Skin prick test (SPT) to peach extract and sIgE to peach panallergens were performed. All 133 patients were positive to SPT to peach extract and to sIgE to Pru p 3. The North-East population was simultaneously positive to Pru p 1 (42.8 %) and Pru p 4 (12.7 %), while no Southern patients were positive to PR-10 or to profilin. A significant difference in the levels of sIgE to Pru p 3 was found only in South Italy Pru p 3 + patients vs. asymptomatic patients (p = 0.01) and in mild reactions vs. severe reactions (p = 0.0008). In South Italy patients, it was also found a significant correlation between the severity of the clinical reaction and the levels of sIgE to Pru p 3 (p = 0.001). Level of sIgE to Pru p 3 indicates the possibility of development a severe food allergic reaction. Pru p 3 positive patients from different geographical areas and with different co-sensitizations to Pru p 1 and/or Pru p 4 could have a different risk assessment in peach allergy.

  18. Neutral vs positive oral contrast in diagnosing acute appendicitis with contrast-enhanced CT: sensitivity, specificity, reader confidence and interpretation time

    Science.gov (United States)

    Naeger, D M; Chang, S D; Kolli, P; Shah, V; Huang, W; Thoeni, R F

    2011-01-01

    Objective The study compared the sensitivity, specificity, confidence and interpretation time of readers of differing experience in diagnosing acute appendicitis with contrast-enhanced CT using neutral vs positive oral contrast agents. Methods Contrast-enhanced CT for right lower quadrant or right flank pain was performed in 200 patients with neutral and 200 with positive oral contrast including 199 with proven acute appendicitis and 201 with other diagnoses. Test set disease prevalence was 50%. Two experienced gastrointestinal radiologists, one fellow and two first-year residents blindly assessed all studies for appendicitis (2000 readings) and assigned confidence scores (1=poor to 4=excellent). Receiver operating characteristic (ROC) curves were generated. Total interpretation time was recorded. Each reader's interpretation with the two agents was compared using standard statistical methods. Results Average reader sensitivity was found to be 96% (range 91–99%) with positive and 95% (89–98%) with neutral oral contrast; specificity was 96% (92–98%) and 94% (90–97%). For each reader, no statistically significant difference was found between the two agents (sensitivities p-values >0.6; specificities p-values>0.08), in the area under the ROC curve (range 0.95–0.99) or in average interpretation times. In cases without appendicitis, positive oral contrast demonstrated improved appendix identification (average 90% vs 78%) and higher confidence scores for three readers. Average interpretation times showed no statistically significant differences between the agents. Conclusion Neutral vs positive oral contrast does not affect the accuracy of contrast-enhanced CT for diagnosing acute appendicitis. Although positive oral contrast might help to identify normal appendices, we continue to use neutral oral contrast given its other potential benefits. PMID:20959365

  19. Note: A two-dimensional position-sensitive micro-channel plate detector with a cross-connected-pixels resistive anode and integrated spectroscopy amplifiers.

    Science.gov (United States)

    Yang, Liping; Liu, Junliang; Zhang, Yuezhao; Wang, Wei; Yu, Deyang; Li, Xiaoxiao; Li, Xin; Zheng, Min; Ding, Baowei; Cai, Xiaohong

    2017-08-01

    Based on the charge-division method, a compact detector system for charged particles is constructed. The system consists of a pair of micro-channel plates, a novel two-dimensional position-sensitive cross-connected-pixels resistive anode, and specially designed front-end electronics that can directly drive analog-to-digital converters. The detector is tested with an (241)Am α-source. A position resolution of better than 0.3 mm and a maximum distortion within 0.5 mm in the active dimensions of 100 mm diameter are achieved.

  20. Note: A two-dimensional position-sensitive micro-channel plate detector with a cross-connected-pixels resistive anode and integrated spectroscopy amplifiers

    Science.gov (United States)

    Yang, Liping; Liu, Junliang; Zhang, Yuezhao; Wang, Wei; Yu, Deyang; Li, Xiaoxiao; Li, Xin; Zheng, Min; Ding, Baowei; Cai, Xiaohong

    2017-08-01

    Based on the charge-division method, a compact detector system for charged particles is constructed. The system consists of a pair of micro-channel plates, a novel two-dimensional position-sensitive cross-connected-pixels resistive anode, and specially designed front-end electronics that can directly drive analog-to-digital converters. The detector is tested with an 241Am α-source. A position resolution of better than 0.3 mm and a maximum distortion within 0.5 mm in the active dimensions of 100 mm diameter are achieved.

  1. Count rate studies of a box-shaped PET breast imaging system comprised of position sensitive avalanche photodiodes utilizing monte carlo simulation.

    Science.gov (United States)

    Foudray, Angela M K; Habte, Frezghi; Chinn, Garry; Zhang, Jin; Levin, Craig S

    2006-01-01

    We are investigating a high-sensitivity, high-resolution positron emission tomography (PET) system for clinical use in the detection, diagnosis and staging of breast cancer. Using conventional figures of merit, design parameters were evaluated for count rate performance, module dead time, and construction complexity. The detector system modeled comprises extremely thin position-sensitive avalanche photodiodes coupled to lutetium oxy-orthosilicate scintillation crystals. Previous investigations of detector geometries with Monte Carlo indicated that one of the largest impacts on sensitivity is local scintillation crystal density when considering systems having the same average scintillation crystal densities (same crystal packing fraction and system solid-angle coverage). Our results show the system has very good scatter and randoms rejection at clinical activity ranges ( approximately 200 muCi).

  2. Identification of hazelnut major allergens in sensitive patients with positive double-blind, placebo-controlled food challenge results

    DEFF Research Database (Denmark)

    Pastorello, Elide A; Vieths, Stefan; Pravettoni, Valerio

    2002-01-01

    The hazelnut major allergens identified to date are an 18-kd protein homologous to Bet v 1 and a 14-kd allergen homologous to Bet v 2. No studies have reported hazelnut allergens recognized in patients with positive double-blind, placebo-controlled food challenge (DBPCFC) results or in patients...... allergic to hazelnut but not to birch....

  3. Rotor Position Sensorless Control and Its Parameter Sensitivity of Permanent Magnet Motor Based on Model Reference Adaptive System

    Science.gov (United States)

    Ohara, Masaki; Noguchi, Toshihiko

    This paper describes a new method for a rotor position sensorless control of a surface permanent magnet synchronous motor based on a model reference adaptive system (MRAS). This method features the MRAS in a current control loop to estimate a rotor speed and position by using only current sensors. This method as well as almost all the conventional methods incorporates a mathematical model of the motor, which consists of parameters such as winding resistances, inductances, and an induced voltage constant. Hence, the important thing is to investigate how the deviation of these parameters affects the estimated rotor position. First, this paper proposes a structure of the sensorless control applied in the current control loop. Next, it proves the stability of the proposed method when motor parameters deviate from the nominal values, and derives the relationship between the estimated position and the deviation of the parameters in a steady state. Finally, some experimental results are presented to show performance and effectiveness of the proposed method.

  4. Endocrine sensitivity of the receptor-positive T61 human breast carcinoma serially grown in nude mice

    DEFF Research Database (Denmark)

    Brünner, N; Spang-Thomsen, M; Skovgaard Poulsen, H;

    1985-01-01

    A study was made on the effect of ovariectomy, 17 beta-oestradiol, and tamoxifen on the oestrogen and progesterone receptor-positive T61 human breast carcinoma grown in nude mice. The effect of the treatment was evaluated by the specific growth delay calculated on the basis of Gompertz growth...

  5. Sensitivity of the corneal-plane refractive compensation to change in power and axial position of an intraocular lens

    Directory of Open Access Journals (Sweden)

    W. F. Harris

    2009-12-01

    Full Text Available If an intraocular lens is displaced or if its power is changed what are the consequences for the refractive compensation of the eye?  Gaussian optics is used to obtain explicit formulae for the sensitivityof the corneal-plane refractive compensation (also called the refraction, refractive state, etc to change in power and axial displacement of a thin intraocular lens implanted in a simple eye.  In particular, for a pseudophakic Gullstrand simplified eye with intraocular lens placed 5 mm behind the cornea the sensitivity to errors in the power of the intraocular lens is about  71 . 0 − 71 for an intraocular lens of power   for an intraocular lens of power 20 D, that is, the refractive compensation decreases by about 0.71 dioptres per dioptre increase in the power of the intraocular lens.  More generally the sensitivity is approximately  ( m   0037 . 0 63 . 0 F − − 0.63 ( 003 . 0 63 . 0 − − (0.0037mF where FI is the power of the intraocular lens.  Also for Gullstrand’s simplified eye the sensitivity of refractive compensation to axial displacement of the intraocular lens is approximately linear in FI about  (64D FI, in fact.  That is, for each dioptre of the power of the intraocular lens the refractive compensation increases by about 0.064 dioptres per millimetre of axial displacement towards the retina. 

  6. Genetic and environmental causes of individual differences in daily life positive affect and reward experience and its overlap with stress-sensitivity.

    Science.gov (United States)

    Menne-Lothmann, Claudia; Jacobs, Nele; Derom, Catherine; Thiery, Evert; van Os, Jim; Wichers, Marieke

    2012-09-01

    Momentary positive affect (PA) and reward experience may underlie subjective wellbeing, and index mental health resilience. This study examines their underlying sources of variation and the covariation with stress-sensitivity. The experience sampling method was used to collect multiple appraisals of mood and daily life events in 520 female twins. Structural equation model fitting was employed to determine sources of variation of PA, reward experience, and the association between reward experience and stress-sensitivity. PA was best explained by shared and non-shared environmental factors, and reward experience by non-shared environmental factors only, although the evidence was also suggestive of a small genetic contribution. Reward experience and stress-sensitivity showed no association. PA was not heritable. Most-if not all-variance of reward experience was explained by environmental influences. Stress-sensitivity, indexing depression vulnerability, and reward experience were non-overlapping, suggesting that resilience traits are independent from stress-sensitivity levels in a general population sample.

  7. Plastic scintillators utilization in position sensitive detection systems; Uitilizacao de cintiladores plasticos em sistemas de deteccao sensiveis a posicao

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Marcelo Bernardes; Soares, Adalberto Jose; Baptista Filho, Benedito Dias [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)

    2002-07-01

    This paper shows the viability of using a plastic scintillator detector to determine the one dimension position of a radioactive source. The experiments were performed using collimated {sup 99m} Tc sources of several activities supplied by the Centro de Radiofarmacia (from IPEN), and a 15 cm long plastic scintillator with diameter 5,08 cm, produced by the Centro de Tecnologia das Radiacoes (also from IPEN). The spectrum was obtained using the Genie 2000 software, and the results processed using a neural network specially developed for the proposed application. The final results demonstrate the viability of the proposed application. (author)

  8. Note: A large open ratio, time, and position sensitive detector for time of flight measurements in UHV

    Energy Technology Data Exchange (ETDEWEB)

    Lupone, S.; Damoy, S.; Husseen, A.; Briand, N.; Debiossac, M.; Tall, S.; Roncin, P. [Institut des Sciences Moléculaires d’Orsay (ISMO), CNRS, Univ. Paris-Sud, Université Paris-Saclay, Orsay F-91405 (France)

    2015-12-15

    We report on the construction of an UHV compatible 40 mm active diameter detector based on micro channel plates and assembled directly on the feed-throughs of a DN63CF flange. It is based on the charge division technique and uses a standard 2 inch Si wafer as a collector. The front end electronic is placed directly on the air side of the flange allowing excellent immunity to noise and a very good timing signal with reduced ringing. The important aberrations are corrected empirically providing an absolute positioning accuracy of 500 μm while a 150 μm resolution is measured in the center.

  9. Investigation on gamma-ray position sensitivity at 662 keV in a spectroscopic 3” x 3” LaBr{sub 3}:Ce scintillator

    Energy Technology Data Exchange (ETDEWEB)

    Giaz, A., E-mail: agnese.giaz@mi.infn.it [INFN Milano, Via Celoria 16, 20133 Milano (Italy); Camera, F.; Birocchi, F. [INFN Milano, Via Celoria 16, 20133 Milano (Italy); Università degli Studi di Milano, Physics Dept., Via Celoria 16, 20133 Milano (Italy); Blasi, N.; Boiano, C.; Brambilla, S.; Coelli, S. [INFN Milano, Via Celoria 16, 20133 Milano (Italy); Fiorini, C. [INFN Milano, Via Celoria 16, 20133 Milano (Italy); Politecnico di Milano, Dipartimento di Elettronica, Informazione e Bioingegneria, Via Golgi 40, 20133, Milano (Italy); Marone, A. [Politecnico di Milano, Dipartimento di Elettronica, Informazione e Bioingegneria, Via Golgi 40, 20133, Milano (Italy); Million, B. [INFN Milano, Via Celoria 16, 20133 Milano (Italy); Riboldi, S. [INFN Milano, Via Celoria 16, 20133 Milano (Italy); Università degli Studi di Milano, Physics Dept., Via Celoria 16, 20133 Milano (Italy); Wieland, O. [INFN Milano, Via Celoria 16, 20133 Milano (Italy)

    2015-02-01

    The position sensitivity of a thick, cylindrical and continuous 3” x 3” (7.62 cm x 7.62 cm) LaBr{sub 3}:Ce crystal was studied using a 1 mm collimated beam of 662 keV gamma rays from a 400 MBq intense {sup 137}Cs source and a spectroscopic photomultiplier (PMT) (HAMAMATSU R6233-100SEL). The PMT entrance window was covered by black absorber except for a small window 1 cm x 1 cm wide. A complete scan of the detector over a 0.5 cm step grid was performed for three positions of the 1 cm x 1 cm window. For each configuration the energy spectrum was measured and the peak centroid, the FWHM, the area and peak asymmetry of the 662 keV gamma transition were analyzed. The data show that, even in a 3” thick LaBr{sub 3}:Ce crystal with diffusive surfaces the position of the full energy peak centroid depends on the source position. We verified that, on average, the position of the full energy peak centroids measured in the three 1 cm x 1 cm window configurations is sufficient for the correct identification of the collimated gamma source position.

  10. Investigation on gamma-ray position sensitivity at 662 keV in a spectroscopic 3' x 3' LaBr3:Ce scintillator

    Science.gov (United States)

    Giaz, A.; Camera, F.; Birocchi, F.; Blasi, N.; Boiano, C.; Brambilla, S.; Coelli, S.; Fiorini, C.; Marone, A.; Million, B.; Riboldi, S.; Wieland, O.

    2015-02-01

    The position sensitivity of a thick, cylindrical and continuous 3" x 3" (7.62 cm x 7.62 cm) LaBr3:Ce crystal was studied using a 1 mm collimated beam of 662 keV gamma rays from a 400 MBq intense 137Cs source and a spectroscopic photomultiplier (PMT) (HAMAMATSU R6233-100SEL). The PMT entrance window was covered by black absorber except for a small window 1 cm x 1 cm wide. A complete scan of the detector over a 0.5 cm step grid was performed for three positions of the 1 cm x 1 cm window. For each configuration the energy spectrum was measured and the peak centroid, the FWHM, the area and peak asymmetry of the 662 keV gamma transition were analyzed. The data show that, even in a 3" thick LaBr3:Ce crystal with diffusive surfaces the position of the full energy peak centroid depends on the source position. We verified that, on average, the position of the full energy peak centroids measured in the three 1 cm x 1 cm window configurations is sufficient for the correct identification of the collimated gamma source position.

  11. Toral lateral line units of goldfish, Carassius auratus, are sensitive to the position and vibration direction of a vibrating sphere.

    Science.gov (United States)

    Meyer, Gunnar; Klein, Adrian; Mogdans, Joachim; Bleckmann, Horst

    2012-09-01

    We recorded the responses of lateral line units in the midbrain torus semicircularis of goldfish, Carassius auratus, to a 50-Hz vibrating sphere and determined the unit's spatial receptive fields for various distances between fish and sphere and for different directions of sphere vibration. All but one unit responded to the vibrating sphere with an increase in discharge rate. Only a proportion (25%) of the units exhibited phase-locked responses. Receptive fields were narrow or broad and contained one, two or more areas of increased discharge rate. The data show that the receptive fields of toral lateral line units are in many respects similar to those of brainstem units but differ from those of afferent nerve fibres. The responses of primary afferents represent the pressure gradient pattern generated by a vibrating sphere and provide information about sphere location and vibration direction. Across the array of lateral line neuromasts, the fish brain in principle can derive this information. Nevertheless, toral units tuned to a distinct sphere location or sensitive to a distinct sphere vibration direction were not found. Therefore, it is conceivable that the torus semicircularis uses a population code to determine spatial location and vibration direction of a vibrating sphere.

  12. Enriched Boron-Doped Amorphous Selenium Based Position-Sensitive Solid-State Thermal Neutron Detector for MPACT Applications

    Energy Technology Data Exchange (ETDEWEB)

    Mandal, Krishna [Univ. of South Carolina, Columbia, SC (United States)

    2017-09-29

    High-efficiency thermal neutron detectors with compact size, low power-rating and high spatial, temporal and energy resolution are essential to execute non-proliferation and safeguard protocols. The demands of such detector are not fully covered by the current detection system such as gas proportional counters or scintillator-photomultiplier tube combinations, which are limited by their detection efficiency, stability of response, speed of operation, and physical size. Furthermore, world-wide shortage of 3He gas, required for widely used gas detection method, has further prompted to design an alternative system. Therefore, a solid-state neutron detection system without the requirement of 3He will be very desirable. To address the above technology gap, we had proposed to develop new room temperature solidstate thermal neutron detectors based on enriched boron (10B) and enriched lithium (6Li) doped amorphous Se (As- 0.52%, Cl 5 ppm) semiconductor for MPACT applications. The proposed alloy materials have been identified for its many favorable characteristics - a wide bandgap (~2.2 eV at 300 K) for room temperature operation, high glass transition temperature (tg ~85°C), a high thermal neutron cross-section (for boron ~ 3840 barns, for lithium ~ 940 barns, 1 barn = 10-24 cm2), low effective atomic number of Se for small gamma ray sensitivity, and high radiation tolerance due to its amorphous structure

  13. Low Temperature-Induced 30 (LTI30 positively regulates drought stress resistance in Arabidopsis: effect on abscisic acid sensitivity and hydrogen peroxide accumulation

    Directory of Open Access Journals (Sweden)

    Haitao eShi

    2015-10-01

    Full Text Available As a dehydrin belonging to group II late embryogenesis abundant protein (LEA family, Arabidopsis Low Temperature-Induced 30 (LTI30/XERO2 has been shown to be involved in plant freezing stress resistance. However, the other roles of AtLTI30 remain unknown. In this study, we found that the expression of AtLTI30 was largely induced by drought stress and abscisic acid (ABA treatments. Thereafter, AtLTI30 knockout mutants and overexpressing plants were isolated to investigate the possible involvement of AtLTI30 in ABA and drought stress responses. AtLTI30 knockout mutants were less sensitive to ABA-mediated seed germination, while AtLTI30 overexpressing plants were more sensitive to ABA compared with wild type (WT. Consistently, the AtLTI30 knockout mutants displayed decreased drought stress resistance, while the AtLTI30 overexpressing plants showed improved drought stress resistance compared with WT, as evidenced by a higher survival rate and lower leaf water loss than WT after drought stress. Moreover, manipulation of AtLTI30 expression positively regulated the activities of catalases (CATs and endogenous proline content, as a result, negatively regulated drought stress-triggered hydrogen peroxide (H2O2 accumulation. All these results indicate that AtLTI30 is a positive regulator of plant drought stress resistance, partially through the modulation of ABA sensitivity, H2O2 and proline accumulation.

  14. Comparison of two position sensitive gamma-ray detectors based on continuous YAP and pixellated NaI(TI) for nuclear medical imaging applications

    Science.gov (United States)

    Zhu, Jie; Ma, Hong-Guang; Ma, Wen-Yan; Zeng, Hui; Wang, Zhao-Min; Xu, Zi-Zhong

    2008-11-01

    Dedicated position sensitive gamma-ray detectors based on position sensitive photomultiplier tubes (PSPMTs) coupled to scintillation crystals, have been used for the construction of compact gamma-ray imaging systems, suitable for nuclear medical imaging applications such as small animal imaging and single organ imaging and scintimammography. In this work, the performance of two gamma-ray detectors: a continuous YAP scintillation crystal coupled to a Hamamastu R2486 PSPMT and a pixellated NaI(TI) scintillation array crystal coupled to the same PSPMT, is compared. The results show that the gamma-ray detector based on a pixellated NaI(TI) scintillation array crystal is a promising candidate for nuclear medical imaging applications, since their performance in terms of position linearity, spatial resolution and effective field of view (FOV) is superior than that of the gamma-ray detector based on a continuous YAP scintillation crystal. However, a better photodetector (Hamamatau H8500 Flat Panel PMT, for example) coupled to the continuous crystal is also likely a good selection for nuclear medicine imaging applications. Supported by National Nature Science Foundation of China (10275063)

  15. Comparison of two position sensitive gamma-ray detectors based on continuous YAP and pixellated NaI(TI) for nuclear medical imaging applications

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Dedicated position sensitive gamma-ray detectors based on position sensitive photomultiplier tubes (PSPMTs) coupled to scintillation crystals, have been used for the construction of compact gamma-ray imaging systems, suitable for nuclear medical imaging applications such as small animal imaging and single organ imaging and scintimammography. In this work, the performance of two gamma-ray detectors: a continuous YAP scintillation crystal coupled to a Hamamastu R2486 PSPMT and a pixellated NaI(TI) scintillation array crystal coupled to the same PSPMT, is compared. The results show that the gamma-ray detector based on a pixellated NaI(TI) scintillation array crystal is a promising candidate for nuclear medical imaging applications,since their performance in terms of position linearity, spatial resolution and effective field of view (FOV) is superior than that of the gamma-ray detector based on a continuous YAP scintillation crystal. However, a better photodetector (Hamamatau H8500 Flat Panel PMT, for example) coupled to the continuous crystal is also likely a good selection for nuclear medicine imaging applications.

  16. Numerical modeling of percutaneous auricular vagus nerve stimulation: a realistic 3D model to evaluate sensitivity of neural activation to electrode position.

    Science.gov (United States)

    Samoudi, Amine M; Kampusch, Stefan; Tanghe, Emmeric; Széles, Jozsef C; Martens, Luc; Kaniusas, Eugenijus; Joseph, Wout

    2017-02-13

    Percutaneous stimulation of the auricular branch of the vagus nerve (pVNS) by miniaturized needle electrodes in the auricle gained importance as a treatment for acute and chronic pain. The objective is to establish a realistic numerical model of pVNS and investigate the effects of stimulation waveform, electrodes' depth, and electrodes' position on nerve excitation threshold and the percentage of stimulated nerves. Simulations were performed with Sim4Life. An electrostatic solver and neural tissue models were combined for electromagnetic and neural simulation. The numerical model consisted of a realistic high-resolution model of a human ear, blood vessels, nerves, and three needle electrodes. A novel 3D ear model was established, including blood vessels and nerves. The electric field distribution was extracted and evaluated. Maximum sensitivity to needles' depth and displacement was evaluated to be 9.8 and 15.5% per 0.1 mm, respectively. Stimulation was most effective using biphasic compared to mono-phasic pulses. The established model allows easy and quantitative evaluation of various stimulation setups, enabling optimization of pVNS in experimental settings. Results suggest a high sensitivity of pVNS to the electrodes' position and depth, implying the need for precise electrode positioning. Validation of the model needs to be performed.

  17. Gas-filled position-sensitive detectors of thermal neutrons at the Konstantinov Petersburg Nuclear Physics Institute of the Russian Academy of Sciences

    Science.gov (United States)

    Andreev, V. A.; Ganzha, G. A.; Ivanov, E. A.; Ilyin, D. S.; Kovalenko, S. N.; Kolkhidashvili, M. R.; Krivshich, A. G.; Nadtochy, A. V.; Runov, V. V.; Soloveĭ, V. A.; Shabanov, G. D.

    2010-05-01

    The manufacturing line for the development and fabrication of position-sensitive detectors of thermal neutrons has been organized at the Petersburg Nuclear Physics Institute of the Russian Academy of Sciences. Three detectors with sensitive regions 300 × 170 (prototype), 200 × 200, and 300 × 300 mm in size have been constructed to date. The detectors represent multiwire proportional chambers with cathode data readout to a delay line. The devices are filled with the 3He/CF4 gas mixture. These detectors are intended for modernizing the detector systems of the Vector and Membrana-2 diffractometers (VVR-M reactor, Konstantinov Petersburg Nuclear Physics Institute of the Russian Academy of Sciences, Gatchina, Russia).

  18. Lateral photovoltaic effect in flexible free-standing reduced graphene oxide film for self-powered position-sensitive detection

    Science.gov (United States)

    Moon, In Kyu; Ki, Bugeun; Yoon, Seonno; Oh, Jungwoo

    2016-09-01

    Lightweight, simple and flexible self-powered photodetectors are urgently required for the development and application of advanced optical systems for the future of wearable electronic technology. Here, using a low-temperature reduction process, we report a chemical approach for producing freestanding monolithic reduced graphene oxide papers with different gradients of the carbon/oxygen concentration ratio. We also demonstrate a novel type of freestanding monolithic reduced graphene oxide self-powered photodetector based on a symmetrical metal–semiconductor–metal structure. Upon illumination by a 633-nm continuous wave laser, the lateral photovoltage is observed to vary linfearly with the laser position between two electrodes on the reduced graphene oxide surface. This result may suggest that the lateral photovoltaic effect in the reduced graphene oxide film originates from the built-in electric field by the combination of both the photothermal electric effect and the gradient of the oxygen-to-carbon composition. These results represent substantial progress toward novel, chemically synthesized graphene-based photosensors and suggest one-step integration of graphene-based optoelectronics in the future.

  19. Lateral photovoltaic effect in flexible free-standing reduced graphene oxide film for self-powered position-sensitive detection.

    Science.gov (United States)

    Moon, In Kyu; Ki, Bugeun; Yoon, Seonno; Oh, Jungwoo

    2016-09-16

    Lightweight, simple and flexible self-powered photodetectors are urgently required for the development and application of advanced optical systems for the future of wearable electronic technology. Here, using a low-temperature reduction process, we report a chemical approach for producing freestanding monolithic reduced graphene oxide papers with different gradients of the carbon/oxygen concentration ratio. We also demonstrate a novel type of freestanding monolithic reduced graphene oxide self-powered photodetector based on a symmetrical metal-semiconductor-metal structure. Upon illumination by a 633-nm continuous wave laser, the lateral photovoltage is observed to vary linfearly with the laser position between two electrodes on the reduced graphene oxide surface. This result may suggest that the lateral photovoltaic effect in the reduced graphene oxide film originates from the built-in electric field by the combination of both the photothermal electric effect and the gradient of the oxygen-to-carbon composition. These results represent substantial progress toward novel, chemically synthesized graphene-based photosensors and suggest one-step integration of graphene-based optoelectronics in the future.

  20. The anti-malarial chloroquine overcomes Primary resistance and restores sensitivity to Trastuzumab in HER2-positive breast cancer

    Science.gov (United States)

    Cufí, Sílvia; Vazquez-Martin, Alejandro; Oliveras-Ferraros, Cristina; Corominas-Faja, Bruna; Cuyàs, Elisabet; López-Bonet, Eugeni; Martin-Castillo, Begoña; Joven, Jorge; Menendez, Javier A.

    2013-01-01

    Autophagy may control the de novo refractoriness of HER2 gene-amplified breast carcinomas to the monoclonal antibody trastuzumab (Herceptin). Tumor cells originally obtained from a patient who rapidly progressed on trastuzumab ab initio display increased cellular levels of the LC3-II protein—a finding that correlates with increased numbers of autophagosomes—and decreased levels of the autophagy receptor p62/SQSTM1, a protein selectively degraded by autophagy. Trastuzumab-refractory cells are in a state of “autophagy addiction” because genetic ablation of autophagy-specific genes (ATG8, ATG5, ATG12) notably reduces intrinsic refractoriness to trastuzumab. When the anti-malarial lysosomotropic drug chloroquine impedes autophagic resolution of the accumulation of autophagolysosomes formed in the presence of trastuzumab, cells commit to die by apoptosis. Accordingly, combination treatment with trastuzumab and chloroquine radically suppresses tumor growth by > 90% in a tumor xenograft completely refractory to trastuzumab. Adding chloroquine to trastuzumab-based regimens may therefore improve outcomes among women with autophagy-addicted HER2-positive breast cancer. PMID:23965851

  1. Blocking the NOTCH pathway can inhibit the growth of CD133-positive A549 cells and sensitize to chemotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Juntao; Mao, Zhangfan; Huang, Jie; Xie, Songping; Liu, Tianshu; Mao, Zhifu, E-mail: 48151660@qq.com

    2014-02-21

    Highlights: • Notch signaling pathway members are expressed lower levels in CD133+ cells. • CD133+ cells are not as sensitive as CD133− cells to chemotherapy. • GSI could inhibit the growth of both CD133+ and CD133− cells. • Blockade of Notch signaling pathway enhanced the effect of chemotherapy with CDDP. • DAPT/CDDP co-therapy caused G2/M arrest and elimination in CD133+ cells. - Abstract: Cancer stem cells (CSCs) are believed to play an important role in tumor growth and recurrence. These cells exhibit self-renewal and proliferation properties. CSCs also exhibit significant drug resistance compared with normal tumor cells. Finding new treatments that target CSCs could significantly enhance the effect of chemotherapy and improve patient survival. Notch signaling is known to regulate the development of the lungs by controlling the cell-fate determination of normal stem cells. In this study, we isolated CSCs from the human lung adenocarcinoma cell line A549. CD133 was used as a stem cell marker for fluorescence-activated cell sorting (FACS). We compared the expression of Notch signaling in both CD133+ and CD133− cells and blocked Notch signaling using the γ-secretase inhibitor DAPT (GSI-IX). The effect of combining GSI and cisplatin (CDDP) was also examined in these two types of cells. We observed that both CD133+ and CD133− cells proliferated at similar rates, but the cells exhibited distinctive differences in cell cycle progression. Few CD133+ cells were observed in the G{sub 2}/M phase, and there were half as many cells in S phase compared with the CD133− cells. Furthermore, CD133+ cells exhibited significant resistance to chemotherapy when treated with CDDP. The expression of Notch signaling pathway members, such as Notch1, Notch2 and Hes1, was lower in CD133+ cells. GSI slightly inhibited the proliferation of both cell types and exhibited little effect on the cell cycle. The inhibitory effects of DPP on these two types of cells were

  2. Analysis of Sensitivity, Specificity, and Positive and Negative Predictive Values of Smear and Colposcopy in Diagnosis of Premalignant and Malignant Cervical Lesions.

    Science.gov (United States)

    Barut, Mert Ulaş; Kale, Ahmet; Kuyumcuoğlu, Umur; Bozkurt, Murat; Ağaçayak, Elif; Özekinci, Server; Gül, Talip

    2015-12-10

    BACKGROUND This study aimed to examine the positive and negative predictive value in the diagnosis of premalignant and malignant lesions of cervical colposcopy, the sensitivity and specificity of smear, and to evaluate the correlation with histopathology of abnormal cytology and colposcopy. MATERIAL AND METHODS The criteria for inclusion of patients with unhealthy cervix in the study were: Erosion, Chronic cervicitis, and Healed lacerations, Hypertrophied cervix, bleeding on touch, suspicious growth/ulcer/polyp on the cervix, and abnormal discharges from the cervix. Women with frank carcinoma cervix, pregnant females, patients with bleeding per vaginum at the time of examination, and those who had used vaginal medications, vaginal contraceptives or douches in the last 48 h of examination were excluded from the study. Demographic analysis was performed for 450 patients who were admitted to the clinic. Sensitivity, specificity, positive predictive value and negative predictive values of patients to identify cervical pathologies of smear and colposcopy were histopathologically calculated. The statistical software package SPSS 15.0 (SPSS Inc., Chicago, IL, USA) and Spearman's and Chi-Square tests were used for statistical analysis. RESULTS Sensitivity, specificity, PPD and NDP of smear were 0.57%, 0.76%, 0.26%, 0.92% respectively. Sensitivity, specificity, PPD and NDP of colposcopy were 0.92%, 0.67%, 0.52%, 0.96% respectively. A statistically significant correlation was found between abnormal cytology and histopathology, and abnormal colposcopy finding and histopathology. CONCLUSIONS Women with clinical diagnosis of unhealthy cervix should be evaluated by cytology to detect any premalignant or malignant lesions. It was concluded that Pap smear, colposcopy and histopathology should be collectively evaluated to evaluate cervical findings in low socio-economic regions.

  3. Computed tomography with thermal neutrons and gaseous position sensitive detector; Tomografia computadorizada com neutrons termicos e detetor a gas sensivel a posicao

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Maria Ines Silvani

    2001-12-01

    A third generation tomographic system using a parallel thermal neutron beam and gaseous position sensitive detector has been developed along three discrete phases. At the first one, X-ray tomographic images of several objects, using a position sensitive detector designed and constructed for this purpose have been obtained. The second phase involved the conversion of that detector for thermal neutron detection, by using materials capable to convert neutrons into detectable charged particles, testing afterwards its performance in a tomographic system by evaluation the quality of the image arising from several test-objects containing materials applicable in the engineering field. High enriched {sup 3} He, replacing the argon-methane otherwise used as filling gas for the X-ray detection, as well as, a gadolinium foil, have been utilized as converters. Besides the pure enriched {sup 3} He, its mixture with argon-methane and later on with propane, have been also tested, in order to evaluate the detector efficiency and resolution. After each gas change, the overall performance of the tomographic system using the modified detector, has been analyzed through measurements of the related parameters. This was done by analyzing the images produced by test-objects containing several materials having well known attenuation coefficients for both thermal neutrons and X-rays. In order to compare the performance of the position sensitive detector as modified to detect thermal neutrons, with that of a conventional BF{sub 3} detector, additional tomographs have been conducted using the last one. The results have been compared in terms of advantages, handicaps and complementary aspects for different kinds of radiation and materials. (author)

  4. Comparison of multi-pole shaping and delay line clipping pre-amplifiers for position sensitive NaI(Tl) detectors

    Energy Technology Data Exchange (ETDEWEB)

    Freifelder, R.; Karp, J.S.; Wear, J.A.; Lockyer, N.S.; Newcomer, F.M.; Surti, S.; Berg, R. van [Univ. of Pennsylvania, Philadelphia, PA (United States)

    1998-06-01

    NaI(Tl) position sensitive detectors have been used in medical imaging for many years. For PET applications without collimators, the high counting rates place severe demands on such large area detectors. The NaI(Tl) detectors in the PENN-PET scanners are read-out via photomultiplier tubes and preamplifiers. Those preamplifiers use a delay-line clipping technique to shorten the characteristic 240 ns fall time of the NaI(Tl) signal. As an alternative, the authors have investigated a pole-zero network to shorten the signal followed by a multi-pole shaper to produce a symmetric signal suitable for high counting rates. This has been compared to the current design by measuring the energy and spatial resolution of a single detector as a function of different preamplifier designs. Data were taken over a range of ADC integration times and countrates. The new design shows improved energy resolution with short integration times. Effects on spatial resolution and deadtime are reported for large position sensitive detectors at different countrates.

  5. Highly sensitive derivatization reagents possessing positively charged structures for the determination of oligosaccharides in glycoproteins by high-performance liquid chromatography electrospray ionization tandem mass spectrometry.

    Science.gov (United States)

    Min, Jun Zhe; Nagai, Keisuke; Shi, Qing; Zhou, Wenjun; Todoroki, Kenichiro; Inoue, Koichi; Lee, Yong-Ill; Toyo'oka, Toshimasa

    2016-09-23

    We have developed three kinds of novel derivatization reagents (4-CEBTPP, 4-CBBTPP, 5-COTPP) with triphenylphosphine (TPP) as a basic structure carrying a permanent positive charge for resolution of the oligosaccharides in glycoprotein using high-performance liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). The synthesized reagents reacted with the sialylglycosylamine of the sialylglycopeptide after treatment by PNGase F. The final derivatives were analyzed by ESI-MS and sensitively detected in the selected reaction monitoring (SRM) mode. Furthermore, the limits of detection (S/N=3) on the SRM chromatograms were at the fmol level (30fmol). Therefore, we used the limit of detection of the reagent products detected by the SRM and evaluated the utility of each reagent. Among the reagents, the positively charged 4-CEBTPP derivative's peak area was the highest; 4-CEBTPP with a positively charged structure showed about a 20 times greater sensitivity for the glycosylamine of the SGP product compared to the conventional fluorescence reagent, Fmoc-Cl. In addition, various fragment ions based on the carbohydrate units also appeared in the MS/MS spectra. Among the fragment ions, m/z 627.37 (CE=40eV) corresponding to 4-CEBTPP-GlcNAc and m/z 120.09 (CE=100eV) corresponding to 4-CEBTPP are the most important ones for identifying the oligosaccharide. 4-CEBTPP-SGA was easily identified by the selected-ion chromatogram in the product ion scan (m/z 120.09) and in the precursor ion scan (m/z 627.37) by MS/MS detection. The derivatized analytes have a high ionization efficiency and they are detected with a high sensitivity in the electrospray ionization. The novel derivatization reagent with a multi-function provided a higher sensitivity for the oligosaccharide analysis, as well as a better specificity and feasibility. Furthermore, several oligosaccharides in fetuin and ribonuclease B were successfully identified by the proposed procedure.

  6. 位敏型探测器数字法读出研究%Digital Readout Method for Position Sensitive Detectors

    Institute of Scientific and Technical Information of China (English)

    田立朝; 孙志嘉; 祁辉荣; 唐彬; 吕新宇; 陈元柏; 欧阳群

    2013-01-01

    Efficient thermal neutron detectors with large area,two-dimensional position sensitive,high counting rate high detection efficiency and low gamma sensitivity are required to satisfy the demands for the China Spallation Neutron Source (CSNS).Compared with the traditional analog readout method,the digital readout method has the advantages of higher counting rate,smaller quantity of data transmission,simpler readout system and higher signal to noise ratio.The theoretical analysis of the digital readout method is reported in this paper.Used the raw data of GEM detector,the relationship between the position resolution and the width of the readout strip was studied.The results indicate that the digital readout method could be a good choice for the large area position sensitive detector where the requirement of position resolution is less than 4 mm,e.g.the detector of Small-Angle Neutron Scattering (SANS) ditfractometer of CSNS.%中国散裂中子源(CSNS)的建造对中子探测器提出了非常高的要求,如更大的有效面积、二维位置灵敏、高计数率、高探测效率和低的y,灵敏度等.与传统的模拟读出方法相比,数字法读出具有更高的计数率,更小的数据传输量,更简单的电子学设计以及更高的信噪比.对数字法读出进行了理论计算,利用GEM探测器的原始数据分析了数字法读出的位置分辨率与读出条宽度的关系.结果表明,数字法读出对于位置分辨要求较低(小于4mm)的大面积位置灵敏探测器是一种较好的选择,如CSNS小角谱仪探测器.

  7. Effects of number and position of meta and para carboxyphenyl groups of zinc porphyrins in dye-sensitized solar cells: structure-performance relationship.

    Science.gov (United States)

    Ambre, Ram B; Mane, Sandeep B; Chang, Gao-Fong; Hung, Chen-Hsiung

    2015-01-28

    Porphyrin sensitizers containing meta- and para-carboxyphenyl groups in their meso positions have been synthesized and investigated for their performance in dye-sensitized solar cells (DSSCs). The superior performance of para-derivative compared to meta-derivative porphyrins was revealed by optical spectroscopy, electrochemical property measurements, density functional theory (DFT) calculations, attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, incident photon-to-current conversion efficiency (IPCE), electrochemical impedance spectroscopy (EIS), and stability performance. Absorption spectra of para-carboxyphenyl-substituted porphyrins on TiO2 show a broader Soret band compared to meta-carboxyphenyl-substituted porphyrins. ATR-FTIR spectra of the studied porphyrins on TiO2 were applied to investigate the number and mode of carboxyl groups attached to TiO2. The VOC, JSC, and IPCE values of para-series porphyrins were distinctly superior to those of meta-series porphyrins. The Nyquist plots of the studied porphyrins show that charge injection in para-series porphyrins is superior to that in meta-series porphyrins. The orthogonally positioned para derivatives have more efficient charge injection and charge transfer over charge recombination, whereas the efficiencies of flat-oriented meta derivatives are retarded by rapid charge recombination. Photovoltaic measurements of the studied meta- and para-carboxyphenyl-functionalized porphyrins show that the number and position of carboxyphenyl groups play a crucial role in the performance of the DSSC. Our results indicate that para-carboxyphenyl derivatives outperform meta-carboxyphenyl derivatives to give better device performance. This study will serve as a guideline for the design and development of organic, porphyrin, and ruthenium dyes in DSSCs.

  8. MRI compatibility of position-sensitive photomultiplier depth-of-interaction PET detectors modules for in-line multimodality preclinical studies

    Energy Technology Data Exchange (ETDEWEB)

    Vaquero, J.J., E-mail: juanjose.vaquero@uc3m.es [Universidad Carlos III de Madrid, Departamento de Bioingeniería e Ingeniería Aeroespacial, Avda. de la Universidad 30 Leganés, 28911 Madrid (Spain); Instituto de Investigación Sanitaria Gregorio Marañón, Madrid (Spain); Sánchez, J.J. [Instituto de Investigación Sanitaria Gregorio Marañón, Madrid (Spain); Udías, J.M.; Cal-González, J. [Grupo de Física Nuclear, Departamento de Física Atómica, Molecular y Nuclear, Universidad Complutense de Madrid, CEI Moncloa, Madrid (Spain); Desco, M. [Universidad Carlos III de Madrid, Departamento de Bioingeniería e Ingeniería Aeroespacial, Avda. de la Universidad 30 Leganés, 28911 Madrid (Spain); Instituto de Investigación Sanitaria Gregorio Marañón, Madrid (Spain)

    2013-02-21

    This work addresses the feasibility of a small-animal, in-line PET/MR system based on Position-Sensitive Photo Multiplier Tubes (PS-PMTs). To this end, we measured the effects of static magnetic fields on the PS-PMTs performance in order to explore the minimal tandem separation between the PET and MR subsystems to preserve their respective performances. We concluded that it is possible to achieve minimal degradation of the PET scanner performance (after a system recalibration) if the magnetic field strength influencing the PET detectors is less than 1 mT and if it is oriented perpendicularly to the longitudinal axis of the tube. Therefore, we predict that it will be possible to maintain the PET image quality if it is placed outside the 1 mT line.

  9. De-Li-DAQ-2D - a new data acquisition system for position-sensitive neutron detectors with delay-line readout

    Science.gov (United States)

    Levchanovskiy, F. V.; Murashkevich, S. M.

    2016-09-01

    Software for a data acquisition system of modern one- and two-dimensional position-sensitive detectors with delay-line readout, which includes a software interface to a new electronic module De-Li-DAQ-2D with a USB interface, is presented. The new system after successful tests on the stand and on several spectrometers of the IBR-2 reactor has been integrated into the software complex SONIX+ [1]. The De-Li- DAQ-2D module [2] contains an 8-channel time-code converter (TDC-GPX) with a time resolution of 80 ps, field programmable gate array (FPGA), 1 Gbyte histogram memory and high-speed interface with a fiber-optic communication line. A real count rate is no less than 106 events/s. The De-Li-DAQ-2D module is implemented in the NIM standard. The De-Li-DAQ-2D module can operate in two modes: histogram mode and list mode.

  10. Comparisons of LET distributions measured in low-earth orbit using tissue-equivalent proportional counters and the position-sensitive silicon-detector telescope (RRMD-III).

    Science.gov (United States)

    Doke, T; Hayashi, T; Borak, T B

    2001-09-01

    Determinations of the LET distribution, phi(L), of charged particles within a spacecraft in low-Earth orbit have been made. One method used a cylindrical tissue-equivalent proportional counter (TEPC), with the assumption that for each measured event, lineal energy, y, is equal to LET and thus phi(L) = phi(y). The other was based on the direct measurement of LETs for individual particles using a charged-particle telescope consisting of position-sensitive silicon detectors called RRMD-III. There were differences of up to a factor of 10 between estimates of phi(L) using the two methods on the same mission. This caused estimates of quality factor to vary by a factor of two between the two methods.

  11. PKA-induced phosphorylation of ERα at serine 305 and high PAK1 levels is associated with sensitivity to tamoxifen in ER-positive breast cancer.

    Science.gov (United States)

    Kok, Marleen; Zwart, Wilbert; Holm, Caroline; Fles, Renske; Hauptmann, Michael; Van't Veer, Laura J; Wessels, Lodewyk F A; Neefjes, Jacques; Stål, Olle; Linn, Sabine C; Landberg, Göran; Michalides, Rob

    2011-01-01

    Phosphorylation of estrogen receptor α at serine 305 (ERαS305-P) by protein kinase A (PKA) or p21-activated kinase 1 (PAK1) has experimentally been associated with tamoxifen sensitivity. Here, we investigated the clinical application of this knowledge to predict tamoxifen resistance in ER-positive breast cancer patients. Using immunohistochemistry, a score including PAK1 and co-expression of PKA and ERαS305-P (PKA/ERαS305-P) was developed on a training set consisting of 103 patients treated with tamoxifen for metastatic disease, and validated on 231 patients randomized between adjuvant tamoxifen or no treatment. In the training set, PAK1 levels were associated with tumor progression after tamoxifen (HR 1.57, 95% CI 0.99-2.48), as was co-expression of PKA and ERαS305-P (HR 2.00, 95% CI 1.14-3.52). In the validation set, a significant tamoxifen benefit was found among the 73% patients negative for PAK1 and PKA/ERαS305-P (HR 0.54, 95% CI 0.34-0.87), while others (27%) were likely to have no benefit from tamoxifen (HR 0.88, 95% 0.42-1.82). The test for interaction showed a significant difference in recurrence-free survival between groups defined by PAK1 and PKA/ERαS305-P (P = 0.037). Elevated PAK1 and PKA/ERαS305-P appeared to influence tamoxifen sensitivity. Both PAK1 and PKA/ERαS305-P levels were associated with sensitivity to tamoxifen in breast tumors and the combination of these variables should be considered in predicting tamoxifen benefit.

  12. Evolutionary Analysis Predicts Sensitive Positions of MMP20 and Validates Newly- and Previously-Identified MMP20 Mutations Causing Amelogenesis Imperfecta

    Directory of Open Access Journals (Sweden)

    Barbara Gasse

    2017-06-01

    Full Text Available Amelogenesis imperfecta (AI designates a group of genetic diseases characterized by a large range of enamel disorders causing important social and health problems. These defects can result from mutations in enamel matrix proteins or protease encoding genes. A range of mutations in the enamel cleavage enzyme matrix metalloproteinase-20 gene (MMP20 produce enamel defects of varying severity. To address how various alterations produce a range of AI phenotypes, we performed a targeted analysis to find MMP20 mutations in French patients diagnosed with non-syndromic AI. Genomic DNA was isolated from saliva and MMP20 exons and exon-intron boundaries sequenced. We identified several homozygous or heterozygous mutations, putatively involved in the AI phenotypes. To validate missense mutations and predict sensitive positions in the MMP20 sequence, we evolutionarily compared 75 sequences extracted from the public databases using the Datamonkey webserver. These sequences were representative of mammalian lineages, covering more than 150 million years of evolution. This analysis allowed us to find 324 sensitive positions (out of the 483 MMP20 residues, pinpoint functionally important domains, and build an evolutionary chart of important conserved MMP20 regions. This is an efficient tool to identify new- and previously-identified mutations. We thus identified six functional MMP20 mutations in unrelated families, finding two novel mutated sites. The genotypes and phenotypes of these six mutations are described and compared. To date, 13 MMP20 mutations causing AI have been reported, making these genotypes and associated hypomature enamel phenotypes the most frequent in AI.

  13. Therapy-refractory Panton Valentine Leukocidin-positive community-acquired methicillin-sensitive Staphylococcus aureus sepsis with progressive metastatic soft tissue infection: a case report

    Directory of Open Access Journals (Sweden)

    Schefold Joerg C

    2007-12-01

    Full Text Available Abstract We report a case of fulminant multiple organ failure including the Acute Respiratory Distress Syndrome (ARDS, haemodynamic, and renal failure due to community-acquired methicillin-sensitive Panton Valentine Leukocidin (PVL positive spa-type 284 (ST121 Staphylococcus aureus septic shock. The patient's first clinical symptom was necrotizing pneumonia. Despite organism-sensitive triple antibiotic therapy with linezolid, imipenem and clindamycin from the first day of treatment, progressive abscess formation in multiple skeletal muscles was observed. As a result, repeated surgical interventions became necessary. Due to progressive soft tissue infection, the anti-microbial therapy was changed to a combination of clindamycin and daptomycin. Continued surgical and antimicrobial therapy finally led to a stabilisation of the patients' condition. The clinical course of our patient underlines the existence of a "PVL-syndrome" which is independent of in vitro Staphylococcus aureus susceptibility. The PVL-syndrome should not only be considered in patients with soft tissue or bone infection, but also in patients with pneumonia. Such a condition, which may easily be mistaken for uncomplicated pneumonia, should be treated early, aggressively and over a long period of time in order to avoid relapsing infection.

  14. CD4 criteria improves the sensitivity of a clinical algorithm developed to identify viral failure in HIV-positive patients on antiretroviral therapy

    Directory of Open Access Journals (Sweden)

    Denise H Evans

    2014-09-01

    Full Text Available Introduction: Several studies from resource-limited settings have demonstrated that clinical and immunologic criteria are poor predictors of virologic failure, confirming the need for viral load monitoring or at least an algorithm to target viral load testing. We used data from an electronic patient management system to develop an algorithm to identify patients at risk of viral failure using a combination of accessible and inexpensive markers. Methods: We analyzed data from HIV-positive adults initiated on antiretroviral therapy (ART in Johannesburg, South Africa, between April 2004 and February 2010. Viral failure was defined as ≥2 consecutive HIV-RNA viral loads >400 copies/ml following suppression ≤400 copies/ml. We used Cox-proportional hazards models to calculate hazard ratios (HR and 95% confidence intervals (CI. Weights for each predictor associated with virologic failure were created as the sum of the natural logarithm of the adjusted HR and dichotomized with the optimal cut-off at the point with the highest sensitivity and specificity (i.e. ≤4 vs. >4. We assessed the diagnostic accuracy of predictor scores cut-offs, with and without CD4 criteria (CD4 30% drop in CD4, by calculating the proportion with the outcome and the observed sensitivity, specificity, positive and negative predictive value of the predictor score compared to the gold standard of virologic failure. Results: We matched 919 patients with virologic failure (1:3 to 2756 patients without. Our predictor score included variables at ART initiation (i.e. gender, age, CD4 count <100 cells/mm3, WHO stage III/IV and albumin and laboratory and clinical follow-up data (drop in haemoglobin, mean cell volume (MCV <100 fl, CD4 count <200 cells/mm3, new or recurrent WHO stage III/IV condition, diagnosis of new condition or symptom and regimen change. Overall, 51.4% had a score 51.4% had a score ≥4 and 48.6% had a score <4. A predictor score including CD4 criteria performed

  15. Combination of bortezomib and mitotic inhibitors down-modulate Bcr-Abl and efficiently eliminates tyrosine-kinase inhibitor sensitive and resistant Bcr-Abl-positive leukemic cells.

    Science.gov (United States)

    Bucur, Octavian; Stancu, Andreea Lucia; Goganau, Ioana; Petrescu, Stefana Maria; Pennarun, Bodvael; Bertomeu, Thierry; Dewar, Rajan; Khosravi-Far, Roya

    2013-01-01

    Emergence of resistance to Tyrosine-Kinase Inhibitors (TKIs), such as imatinib, dasatinib and nilotinib, in Chronic Myelogenous Leukemia (CML) demands new therapeutic strategies. We and others have previously established bortezomib, a selective proteasome inhibitor, as an important potential treatment in CML. Here we show that the combined regimens of bortezomib with mitotic inhibitors, such as the microtubule-stabilizing agent Paclitaxel and the PLK1 inhibitor BI2536, efficiently kill TKIs-resistant and -sensitive Bcr-Abl-positive leukemic cells. Combined treatment activates caspases 8, 9 and 3, which correlate with caspase-induced PARP cleavage. These effects are associated with a marked increase in activation of the stress-related MAP kinases p38MAPK and JNK. Interestingly, combined treatment induces a marked decrease in the total and phosphorylated Bcr-Abl protein levels, and inhibits signaling pathways downstream of Bcr-Abl: downregulation of STAT3 and STAT5 phosphorylation and/or total levels and a decrease in phosphorylation of the Bcr-Abl-associated proteins CrkL and Lyn. Moreover, we found that other mitotic inhibitors (Vincristine and Docetaxel), in combination with bortezomib, also suppress the Bcr-Abl-induced pro-survival signals and result in caspase 3 activation. These results open novel possibilities for the treatment of Bcr-Abl-positive leukemias, especially in the imatinib, dasatinib and nilotinib-resistant CML cases.

  16. High Dynamics and Precision Optical Measurement Using a Position Sensitive Detector (PSD in Reflection-Mode: Application to 2D Object Tracking over a Smart Surface

    Directory of Open Access Journals (Sweden)

    Ioan Alexandru Ivan

    2012-12-01

    Full Text Available When related to a single and good contrast object or a laser spot, position sensing, or sensitive, detectors (PSDs have a series of advantages over the classical camera sensors, including a good positioning accuracy for a fast response time and very simple signal conditioning circuits. To test the performance of this kind of sensor for microrobotics, we have made a comparative analysis between a precise but slow video camera and a custom-made fast PSD system applied to the tracking of a diffuse-reflectivity object transported by a pneumatic microconveyor called Smart-Surface. Until now, the fast system dynamics prevented the full control of the smart surface by visual servoing, unless using a very expensive high frame rate camera. We have built and tested a custom and low cost PSD-based embedded circuit, optically connected with a camera to a single objective by means of a beam splitter. A stroboscopic light source enhanced the resolution. The obtained results showed a good linearity and a fast (over 500 frames per second response time which will enable future closed-loop control by using PSD.

  17. High dynamics and precision optical measurement using a position sensitive detector (PSD) in reflection-mode: application to 2D object tracking over a Smart Surface.

    Science.gov (United States)

    Ivan, Ioan Alexandru; Ardeleanu, Mihai; Laurent, Guillaume J

    2012-12-06

    When related to a single and good contrast object or a laser spot, position sensing, or sensitive, detectors (PSDs) have a series of advantages over the classical camera sensors, including a good positioning accuracy for a fast response time and very simple signal conditioning circuits. To test the performance of this kind of sensor for microrobotics, we have made a comparative analysis between a precise but slow video camera and a custom-made fast PSD system applied to the tracking of a diffuse-reflectivity object transported by a pneumatic microconveyor called Smart-Surface. Until now, the fast system dynamics prevented the full control of the smart surface by visual servoing, unless using a very expensive high frame rate camera. We have built and tested a custom and low cost PSD-based embedded circuit, optically connected with a camera to a single objective by means of a beam splitter. A stroboscopic light source enhanced the resolution. The obtained results showed a good linearity and a fast (over 500 frames per second) response time which will enable future closed-loop control by using PSD.

  18. A combination of positive dielectrophoresis driven on-line enrichment and aptamer-fluorescent silica nanoparticle label for rapid and sensitive detection of Staphylococcus aureus.

    Science.gov (United States)

    Shangguan, Jingfang; Li, Yuhong; He, Dinggeng; He, Xiaoxiao; Wang, Kemin; Zou, Zhen; Shi, Hui

    2015-07-07

    Staphylococcus aureus (S. aureus) is an important human pathogen that causes several diseases ranging from superficial skin infections to life-threatening diseases. Here, a method combining positive dielectrophoresis (pDEP) driven on-line enrichment and aptamer-fluorescent silica nanoparticle label has been developed for the rapid and sensitive detection of S. aureus in microfluidic channels. An aptamer, having high affinity to S. aureus, is used as the molecular recognition tool and immobilized onto chloropropyl functionalized fluorescent silica nanoparticles through a click chemistry approach to obtain S. aureus aptamer-nanoparticle bioconjugates (Apt(S.aureus)/FNPs). The pDEP driven on-line enrichment technology was used for accumulating the Apt(S.aureus)/FNP labeled S. aureus. After incubating with S. aureus, the mixture of Apt(S.aureus)/FNP labeled S. aureus and Apt(S.aureus)/FNPs was directly introduced into the pDEP-based microfluidic system. By applying an AC voltage in a pDEP frequency region, the Apt(S.aureus)/FNP labelled S. aureus moved to the electrodes and accumulated in the electrode gap, while the free Apt(S.aureus)/FNPs flowed away. The signal that came from the Apt(S.aureus)/FNP labelled S. aureus in the focused detection areas was then detected. Profiting from the specificity of aptamer, signal amplification of FNP label and pDEP on-line enrichment, this assay can detect as low as 93 and 270 cfu mL(-1)S. aureus in deionized water and spiked water samples, respectively, with higher sensitivities than our previously reported Apt(S.aureus)/FNP based flow cytometry. Moreover, without the need for separation and washing steps usually required for FNP label involved bioassays, the total assay time including sample pretreatment was within 2 h.

  19. Inhibition of miR-146b expression increases radioiodine-sensitivity in poorly differential thyroid carcinoma via positively regulating NIS expression

    Energy Technology Data Exchange (ETDEWEB)

    Li, Luchuan; Lv, Bin; Chen, Bo [Department of General Surgery, Shandong University Qilu Hospital, Jinan, Shandong 250012 (China); Guan, Ming [Department of General Surgery, Qihe People' s Hospital, Qihe, Shandong 251100 (China); Sun, Yongfeng [Department of General Surgery, Licheng District People' s Hospital, Jinan, Shandong 250115 (China); Li, Haipeng [Department of General Surgery, Caoxian People' s Hospital, Caoxian, Shandong 274400 (China); Zhang, Binbin; Ding, Changyuan; He, Shan [Department of General Surgery, Shandong University Qilu Hospital, Jinan, Shandong 250012 (China); Zeng, Qingdong, E-mail: qingdz0201@163.com [Department of General Surgery, Shandong University Qilu Hospital, Jinan, Shandong 250012 (China)

    2015-07-10

    Dedifferentiated thyroid carcinoma (DTC) with the loss of radioiodine uptake (RAIU) is often observed in clinical practice under radioiodine therapy, indicating the challenge for poor prognosis. MicroRNA (miRNA) has emerged as a promising therapeutic target in many diseases; yet, the role of miRNAs in RAIU has not been generally investigated. Based on recent studies about miRNA expression in papillary or follicular thyroid carcinomas, the expression profiles of several thyroid relative miRNAs were investigated in one DTC cell line, derived from normal DTC cells by radioiodine treatment. The top candidate miR-146b, with the most significant overexpression profiles in dedifferentiated cells, was picked up. Further research found that miR-146b could be negatively regulated by histone deacetylase 3 (HDAC3) in normal cells, indicating the correlation between miR-146b and Na{sup +}/I{sup −} symporter (NIS)-mediated RAIU. Fortunately, it was confirmed that miR-146b could regulate NIS expression/activity; what is more important, miR-146b interference would contribute to the recovery of radioiodine-sensitivity in dedifferentiated cells via positively regulating NIS. In the present study, it was concluded that NIS-mediated RAIU could be modulated by miR-146b; accordingly, miR-146b might serve as one of targets to enhance efficacy of radioactive therapy against poorly differential thyroid carcinoma (PDTC). - Highlights: • Significant upregulated miR-146b was picked up from thyroid relative miRNAs in DTC. • MiR-146b was negatively regulated by HDAC3 in normal thyroid carcinoma cells. • NIS activity and expression could be regulated by miR-146b in thyroid carcinoma. • MiR-146b inhibition could recover the decreased radioiodine-sensitivity of DTC cells.

  20. A sensitive one-step real-time PCR for detection of avian influenza viruses using a MGB probe and an internal positive control

    Directory of Open Access Journals (Sweden)

    Delogu Mauro

    2006-05-01

    Full Text Available Abstract Background Avian influenza viruses (AIVs are endemic in wild birds and their introduction and conversion to highly pathogenic avian influenza virus in domestic poultry is a cause of serious economic losses as well as a risk for potential transmission to humans. The ability to rapidly recognise AIVs in biological specimens is critical for limiting further spread of the disease in poultry. The advent of molecular methods such as real time polymerase chain reaction has allowed improvement of detection methods currently used in laboratories, although not all of these methods include an Internal Positive Control (IPC to monitor for false negative results. Therefore we developed a one-step reverse transcription real time PCR (RRT-PCR with a Minor Groove Binder (MGB probe for the detection of different subtypes of AIVs. This technique also includes an IPC. Methods RRT-PCR was developed using an improved TaqMan technology with a MGB probe to detect AI from reference viruses. Primers and probe were designed based on the matrix gene sequences from most animal and human A influenza virus subtypes. The specificity of RRT-PCR was assessed by detecting influenza A virus isolates belonging to subtypes from H1–H13 isolated in avian, human, swine and equine hosts. The analytical sensitivity of the RRT-PCR assay was determined using serial dilutions of in vitro transcribed matrix gene RNA. The use of a rodent RNA as an IPC in order not to reduce the efficiency of the assay was adopted. Results The RRT-PCR assay is capable to detect all tested influenza A viruses. The detection limit of the assay was shown to be between 5 and 50 RNA copies per reaction and the standard curve demonstrated a linear range from 5 to 5 × 108 copies as well as excellent reproducibility. The analytical sensitivity of the assay is 10–100 times higher than conventional RT-PCR. Conclusion The high sensitivity, rapidity, reproducibility and specificity of the AIV RRT-PCR with

  1. Effect of Continuous Positive Airway Pressure Therapy on Glycemic Excursions and Insulin Sensitivity in Patients with Obstructive Sleep Apnea-hypopnea Syndrome and Type 2 Diabetes

    Institute of Scientific and Technical Information of China (English)

    Li-Xin Guo; Xin Zhao; Qi Pan; Xue Sun; Hui Li; Xiao-Xia Wang; Li-Na Zhang

    2015-01-01

    Background:For patients with obstructive sleep apnea-hypopnea syndrome (OSAHS) and type 2 diabetes mellitus (T2DM),the night sleep interruption and intermittent hypoxia due to apnea or hypopnea may induce glycemic excursions and reduce insulin sensitivity.This study aimed to investigate the effect of continuous positive airway pressure (CPAP) therapy in patients with OSAHS and T2DM.Methods:Continuous glucose monitoring system (CGMS) was used in 40 patients with T2DM and newly diagnosed OSAHS.The measurements were repeated after 30 days of CPAP treatment.Subsequently,insulin sensitivity and glycohemoglobin (HbA1c) were measured and compared to the pretreatment data.Results:After CPAP therapy,the CGMS indicators showed that the 24-h mean blood glucose (MBG) and the night time MBG were significantly reduced (P < 0.05 and P =0.03,respectively).The mean ambulatory glucose excursions (MAGEs) and the mean of daily differences were also significantly reduced (P < 0.05 and P =0.002,respectively) compared to pretreatment levels.During the night,MAGE also significantly decreased (P =0.049).The differences between the highest and lowest levels of blood glucose over 24 h and during the night were significantly lower than prior to CPAP treatment (P < 0.05 and P =0.024,respectively).The 24 h and night time durations of high blood glucose (>7.8 mmol/L and > 11.1 mmol/L) decreased (P < 0.05 and P < 0.05,respectively) after the treatment.Inaddition,HbA1c levels were also lower than those before treatment (P < 0.05),and the homeostasis model assessment index of insulin resistance was also significantly lower than before CPAP treatment (P =0.034).Conclusions:CPAP therapy may have a beneficial effect on improving not only blood glucose but also upon insulin sensitivity in T2DM patients with OSAHS.This suggests that CPAP may be an effective treatment for T2DM in addition to intensive diabetes management.

  2. Towards red-edge positions less sensitive to canopy biophysical parameters for leaf chlorophyll estimation using properties optique spectrales des feuilles (PROSPECT) and scattering by arbitrarily inclined leaves (SAILH) simulated data

    NARCIS (Netherlands)

    Cho, M.A.; Skidmore, A.K.; Atzberger, C.

    2008-01-01

    Several methods for extracting the chlorophyll sensitive red-edge position (REP) from hyperspectral data are reported in literature. This study is a continuation of a recent paper published as 'A new technique for extracting the red edge position from hyperspectral data: the linear extrapolation met

  3. Balancing activity and tolerability of neoadjuvant paclitaxel- and docetaxel-based chemotherapy for HER2-positive early stage breast cancer: sensitivity analysis of randomized trials.

    Science.gov (United States)

    Carbognin, Luisa; Sperduti, Isabella; Nortilli, Rolando; Brunelli, Matteo; Vicentini, Cecilia; Pellini, Francesca; Pollini, Giovanni Paolo; Giannarelli, Diana; Tortora, Giampaolo; Bria, Emilio

    2015-03-01

    Paclitaxel and docetaxel represent the most adopted taxanes in the neoadjuvant treatment of HER2-positive breast cancer. Questions still remain with regard to their difference in terms of activity and tolerability. Events for pathological complete response (pCR), severe and febrile neutropenia (FN), and severe neurotoxicity were pooled by adopting a fixed- and random-effect model. A sensitivity analysis to test for the interaction between paclitaxel and docetaxel was accomplished. Absolute differences with 95% confidence intervals (CIs) and the number of patients needed to treat/harm (NNT/NNH) were calculated to derive the Likelihood of being Helped or Harmed (LHH). Data from 15 trials (3601 patients) were included. Paclitaxel significantly increases pCR rate by 6.8% in comparison with docetaxel (43.4%, 95% CI 41.1-45.7% versus 36.6%, 95% CI 34.3-39.0%, p=0.0001), regardless of the chemotherapy backbone, with an absolute difference of 9% and 9.2% for anthracycline-based or free-regimens. Paclitaxel significantly improves pCR versus docetaxel with a single HER2-inhibition by 6.7% (p=0.0012), with no difference if combined with a dual HER2-inhibition. Severe neutropenia and FN are significantly lower with paclitaxel, with an absolute difference of 32.4% (p<0.0001) and 2.5% (p=0.0059), respectively. Conversely, severe neurotoxicity is slightly higher with paclitaxel (3%, p=0.0001). The LHH ratio calculated for pCR and severe neutropenia is 2.0 and 0.7 for paclitaxel and docetaxel. Although the activity of neoadjuvant paclitaxel and docetaxel HER2-positive breast cancer is considered similar, the slight advantage in pCR, the significantly lower neutropenia and FN, do favor paclitaxel (in the weekly fashion) over docetaxel, despite the slightly worst neurotoxicity.

  4. Genistein sensitizes inhibitory effect of tamoxifen on the growth of estrogen receptor-positive and HER2-overexpressing human breast cancer cells.

    Science.gov (United States)

    Mai, Zhiming; Blackburn, George L; Zhou, Jin-Rong

    2007-07-01

    Although tamoxifen (TAM) is used for the front-line treatment and prevention of estrogen receptor-positive (ER+) breast tumors, nearly 40% of estrogen-dependent breast tumors do not respond to TAM treatment. Moreover, the positive response is usually of short duration, and most tumors eventually develop TAM-resistance. Overexpression of HER2 gene is associated with TAM-resistance of breast tumor, and suppression of HER2 expression enhances the TAM activity. Soy isoflavone genistein has been shown to have anti-cancer activities and suppress expression of HER2 and ERalpha. The objective of this study was to test the hypothesis that genistein may sensitize the response of ER+ and HER2-overexpressing breast cancer cells to TAM treatment. The combination treatment of TAM and genistein inhibited the growth of ER+/HER2-overexpressing BT-474 human breast cancer cells in a synergistic manner in vitro. Determination of cellular markers indicated that this synergistic inhibitory effect might be contributed in part from combined effects on cell-cycle arrest at G(1) phase and on induction of apoptosis. Further determination of the molecular markers showed that TAM and genistein combination synergistically induced BT-474 cell apoptosis in part by synergistic downregulation of the expression of survivin, one of the apoptotic effectors, and downregulation of EGFR, HER2, and ERalpha expression. Our research may provide a novel approach for the prevention and/or treatment of TAM insensitive/resistant human breast cancer, and warrants further in vivo studies to verify the efficacy of genistein and TAM combination on the growth of ER+/HER2-overexpressing breast tumors and to elucidate the in vivo mechanisms of synergistic actions. (c) 2007 Wiley-Liss, Inc.

  5. Effect of Out-of-Plane Alkyl Group's Position in Dye-Sensitized Solar Cell Efficiency: A Structure-Property Relationship Utilizing Indoline-Based Unsymmetrical Squaraine Dyes.

    Science.gov (United States)

    Alagumalai, Ananthan; M K, Munavvar Fairoos; Vellimalai, Punitharasu; Sil, Manik Chandra; Nithyanandhan, Jayaraj

    2016-12-28

    Squaraine dyes are promising chromophores to harvest visible and near-infrared (NIR) photons. A series of indoline-based unsymmetrical squaraine (SQ) dyes that contain alkyl chains at sp(3) C- and N- atoms of indoline moieties with a carboxylic acid anchoring group were synthesized. The optical and electrochemical properties of the SQ dyes in solution were nearly identical as there was no change in the D-A-D SQ framework; however, remarkable changes with respect to the power conversion efficiencies (PCE) were observed depending upon the position of alkyl groups in the dye. Introduction of alkyl groups to the indoline unit that was away from anchoring unit were helped in more dye loading with controlled organization of dyes on surface, increased charge transfer resistance, long electron lifetime, and hence higher PCE than that of the corresponding isomer in which the alkyl groups funtionalized indoline unit contains the carboxylic acid anchoring group. Careful analysis of incident photon-to-current conversion efficiency (IPCE) profiles indicated the presence of aggregated structure on the TiO2 surface that contributes to the charge injection in the presence of a coadsorbent. A dye-sensitized solar cell (DSSC) device made out of SQ5 was achieved an efficiency of 9.0%, with an open-circuit potential (Voc) of 660 mV and short-circuit current density (Jsc) of 19.82 mA/cm(2), under simulated AM 1.5G illumination (100 mW/cm(2)). The IPCE profile of SQ5 shows an onset near to 750 nm with a good quantum efficiency (>80%) in the range of 550-700 nm, indicating the importance of self-organization of dyes on the TiO2 surface for an efficient charge injection. This present investigation revealed the importance of position of alkyl groups in the squaraine-based dyes for the better PCE.

  6. Characterization of a sub-assembly of 3D position sensitive cadmium zinc telluride detectors and electronics from a sub-millimeter resolution PET system

    Science.gov (United States)

    Abbaszadeh, Shiva; Gu, Yi; Reynolds, Paul D.; Levin, Craig S.

    2016-09-01

    Cadmium zinc telluride (CZT) offers key advantages for small animal positron emission tomography (PET), including high spatial and energy resolution and simple metal deposition for fabrication of very small pixel arrays. Previous studies have investigated the intrinsic spatial, energy, and timing resolution of an individual sub-millimeter resolution CZT detector. In this work we present the first characterization results of a system of these detectors. The 3D position sensitive dual-CZT detector module and readout electronics developed in our lab was scaled up to complete a significant portion of the final PET system. This sub-system was configured as two opposing detection panels containing a total of twelve 40~\\text{mm}× 40~\\text{mm}× 5 mm monolithic CZT crystals for proof of concept. System-level characterization studies, including optimizing the trigger threshold of each channel’s comparators, were performed. 68Ge and 137Cs radioactive isotopes were used to characterize the energy resolution of all 468 anode channels in the sub-system. The mean measured global 511 keV photopeak energy resolution over all anodes was found to be 7.35+/- 1.75 % FWHM after correction for photon interaction depth-dependent signal variation. The measured global time resolution was 37 ns FWHM, a parameter to be further optimized, and the intrinsic spatial resolution was 0.76 mm FWHM.

  7. In the Blink of an Eye: Relating Positive-Feedback Sensitivity to Striatal Dopamine D2-Like Receptors through Blink Rate

    Science.gov (United States)

    Groman, Stephanie M.; James, Alex S.; Seu, Emanuele; Tran, Steven; Clark, Taylor A.; Harpster, Sandra N.; Crawford, Maverick; Burtner, Joanna Lee; Feiler, Karen; Roth, Robert H.; Elsworth, John D.; London, Edythe D.

    2014-01-01

    For >30 years, positron emission tomography (PET) has proven to be a powerful approach for measuring aspects of dopaminergic transmission in the living human brain; this technique has revealed important relationships between dopamine D2-like receptors and dimensions of normal behavior, such as human impulsivity, and psychopathology, particularly behavioral addictions. Nevertheless, PET is an indirect estimate that lacks cellular and functional resolution and, in some cases, is not entirely pharmacologically specific. To identify the relationships between PET estimates of D2-like receptor availability and direct in vitro measures of receptor number, affinity, and function, we conducted neuroimaging and behavioral and molecular pharmacological assessments in a group of adult male vervet monkeys. Data gathered from these studies indicate that variation in D2-like receptor PET measurements is related to reversal-learning performance and sensitivity to positive feedback and is associated with in vitro estimates of the density of functional dopamine D2-like receptors. Furthermore, we report that a simple behavioral measure, eyeblink rate, reveals novel and crucial links between neuroimaging assessments and in vitro measures of dopamine D2 receptors. PMID:25339755

  8. In the blink of an eye: relating positive-feedback sensitivity to striatal dopamine D2-like receptors through blink rate.

    Science.gov (United States)

    Groman, Stephanie M; James, Alex S; Seu, Emanuele; Tran, Steven; Clark, Taylor A; Harpster, Sandra N; Crawford, Maverick; Burtner, Joanna Lee; Feiler, Karen; Roth, Robert H; Elsworth, John D; London, Edythe D; Jentsch, James David

    2014-10-22

    For >30 years, positron emission tomography (PET) has proven to be a powerful approach for measuring aspects of dopaminergic transmission in the living human brain; this technique has revealed important relationships between dopamine D2-like receptors and dimensions of normal behavior, such as human impulsivity, and psychopathology, particularly behavioral addictions. Nevertheless, PET is an indirect estimate that lacks cellular and functional resolution and, in some cases, is not entirely pharmacologically specific. To identify the relationships between PET estimates of D2-like receptor availability and direct in vitro measures of receptor number, affinity, and function, we conducted neuroimaging and behavioral and molecular pharmacological assessments in a group of adult male vervet monkeys. Data gathered from these studies indicate that variation in D2-like receptor PET measurements is related to reversal-learning performance and sensitivity to positive feedback and is associated with in vitro estimates of the density of functional dopamine D2-like receptors. Furthermore, we report that a simple behavioral measure, eyeblink rate, reveals novel and crucial links between neuroimaging assessments and in vitro measures of dopamine D2 receptors.

  9. Development of a sensitive and false-positive free PMA-qPCR viability assay to quantify VBNC Escherichia coli and evaluate disinfection performance in wastewater effluent.

    Science.gov (United States)

    Kibbee, Richard J; Örmeci, Banu

    2017-01-01

    The detection and quantification of viable Escherichia coli cells in wastewater treatment plant effluent is very important as it is the main disinfection efficacy parameter for assessing its public health risk and environmental impact. The aim of this study was to develop a sensitive and false-positive free propidium monoazide-quantitative polymerase chain reaction (PMA-qPCR) assay to quantify the viable but non-culturable (VBNC) E. coli present in secondary wastewater effluent after chlorine disinfection. The qPCR target was the E. coli uidA gene, and native Taq was used to eliminate false positives caused by the presence of contaminant E. coli DNA in recombinant Taq polymerase reagents. Due to issues with qPCR inhibitors in wastewater, this study explored several pre-DNA extraction treatment methods for qPCR inhibitor removal. PMA-qPCR validation was done using salmon testes DNA (Sketa DNA) as an exogenous control added directly to the wastewater samples and amplified using a separate qPCR assay. After disinfection of secondary effluent with 2ppm chlorine at the plant, the mean Log10 CFU reduction in E. coli was 2.85 from a mean CFU of 3.48/10mL compared to 0.21 Log10 CCE mean reduction of the uidA gene from a mean CCE of 3.16/10mL. The VBNC cell concentrations were calculated as 2.32 Log10/10mL by subtracting the colony forming units (CFU) obtained from membrane filtration from the calculated CFU equivalent (CCE) values obtained from PMA-qPCR. These results demonstrate the effective use of a PMA-qPCR method for the quantification of the E. coli uidA gene and indicate there are high numbers (2.01×10(3)CCE/100mL) of VBNC E. coli cells leaving the wastewater treatment plant in the final effluent after chlorine treatment. VBNC bacterial cells are of concern as they have the potential to resuscitate and grow, regain virulence, affect natural microbiome in the discharge sites, and pass on antimicrobial resistant genes to other microorganisms. Copyright © 2016

  10. On accelerator-based neutron sources and neutron field characterization with low energy neutron spectrometer based on position sensitive 3He counter.

    Science.gov (United States)

    Murata, I; Miyamaru, H; Kato, I; Mori, Y

    2009-07-01

    The development of new neutron sources for BNCT applications, based on particle accelerators is currently underway all over the world. Though nuclear reactors were used for a long time as the only neutron source available having the requested flux levels, the accelerator-based ones have recently been investigated on the other hand due to its easy-to-use and acceptable performances. However, when using an accelerator, various secondary particles would be emitted which forms a troublesome background. Moreover, the neutrons produced have usually an energy spectrum somewhat different from the requested one and thus should be largely moderated. An additional issue to be taken into account is the patient positioning, which should be close to the neutron source, in order to take advantage of a neutron flux level high enough to limit the BNCT treatment time within 1h. This implies that, inside a relatively narrow space, neutrons should be moderated, while unnecessary secondary particles should be shielded. Considering that a background-free neutron field from an accelerator-driven neutron source dedicated to BNCT application is generally difficult to be provided, the characterization of such a neutron field will have to be clearly assessed. In the present study, a low energy neutron spectrometer has been thus designed and is now being developed to measure the accelerator-based neutron source performance. The presently proposed spectrometer is based on a (3)He proportional counter, which is 50 cm long and 5 cm in diameter, with a gas pressure of 0.5 MPa. It is quite unique that the spectrometer is set up in parallel with the incident neutron beam and a reaction depth distribution is measured by it as a position sensitive detector. Recently, a prototype detector has been developed and the signal test is now underway. In this paper, the feature of the accelerator-based neutron sources is outlined and importance of neutron field characterization is discussed. And the developed

  11. Researcher positioning

    DEFF Research Database (Denmark)

    Mørck, Line Lerche; Khawaja, Iram

    2009-01-01

    abstract  This article focuses on the complex and multi-layered process of researcher positioning, specifically in relation to the politically sensitive study of marginalised and ‘othered' groups such as Muslims living in Denmark. We discuss the impact of different ethnic, religious and racial...... political and personal involvement by the researcher, which challenges traditional perspectives on research and researcher positioning. A key point in this regard is the importance of constant awareness of and reflection on the multiple ways in which one's positioning as a researcher influences the research...

  12. Protein tyrosine phosphatase SHP-1 sensitizes EGFR/HER-2 positive breast cancer cells to trastuzumab through modulating phosphorylation of EGFR and HER-2

    Directory of Open Access Journals (Sweden)

    Wu YF

    2015-09-01

    Full Text Available Yifen Wu,1,2,* Rong Li,3,* Junyi Zhang,4 Gang Wang,5 Bin Liu,6 Xiaofang Huang,7 Tao Zhang,7 Rongcheng Luo8 1Traditional Chinese Medicine-Integrated Hospital, Southern Medical University, Guangzhou, 2Department of Oncology, Dongguan People’s Hospital, Dongguan, 3Department of Oncology, Nanfang Hospital, 4Department of Oncology, Traditional Chinese Medicine-Integrated Hospital, Southern Medical University, Guangzhou, 5Department of Radiology, Dongguan People’s Hospital, Dongguan, 6Second Affiliated Hospital of Guangzhou Medical College, 7College of Traditional Chinese medicine, Southern Medical University, 8Cancer Center, Traditional Chinese Medicine-Integrated Hospital, Southern Medical University, Guangzhou, Guangdong, People’s Republic of China *These authors contributed equally to this work Background: Trastuzumab resistance in HER-2 positive breast cancer cells is closely related to overexpression of both epidermal growth factor receptor (EGFR and human epidermal receptor (HER-2. SHP-1 has been demonstrated to downregulate tyrosine kinase activity including EGFR via its phosphatase function, but its effect on HER-2 activity is still unknown. Here, we examined the hypothesis that SHP-1 enhances the anticancer efficacy of trastuzumab in EGFR/HER-2 positive breast cancer cells through combining dual inhibition of EGFR and HER-2.Methods: Trastuzumab-resistant breast cancer SKBr-3 cells were generated by long-term in vitro culture of SKBr-3cells in the presence of trastuzumab. The SHP-1 was ectopically expressed by stable transfection. The activity and expression of EGFR, HER-2, and downstream signaling pathways were tested by Western blot. Cell viability was examined by the 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay, and apoptosis was examined by flow cytometry. The binding between SHP-1 and EGFR/HER-2 was evaluated by immunoprecipitation assay and bimolecular fluorescence complementation. The effects of SHP-1

  13. Impact and sensitivity of parameters in debris flow models: A Monte Carlo simulation on fluid rheology, geometry and position of release areas

    Science.gov (United States)

    Robl, Jörg; Hergarten, Stefan

    2015-04-01

    along the flow path by more than one order of magnitude and beyond. We should be are aware that even state of the art models provide only a crude numerical description of the debris flow dynamics and forthcoming hazardous events may significantly deviate from predictions based on numerical models. This may be caused by limitations of the numerical models itself, by not fully appropriate flow resistance laws or by large uncertainties regarding involved masses, their release position and initial geometry and rheological parameters. Therefore, it is essential that beside of all these uncertainties we have a clear understanding of impact and sensitivity of these parameters on numerical model results that are commonly used for the delineation of hazard zone and the development of mitigation strategies against natural hazards.

  14. Climate Sensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Lindzen, Richard [M.I.T.

    2011-11-09

    Warming observed thus far is entirely consistent with low climate sensitivity. However, the result is ambiguous because the sources of climate change are numerous and poorly specified. Model predictions of substantial warming aredependent on positive feedbacks associated with upper level water vapor and clouds, but models are notably inadequate in dealing with clouds and the impacts of clouds and water vapor are intimately intertwined. Various approaches to measuring sensitivity based on the physics of the feedbacks will be described. The results thus far point to negative feedbacks. Problems with these approaches as well as problems with the concept of climate sensitivity will be described.

  15. High proportions of FOXP3+CD25high T cells in neonates are positively associated with allergic sensitization later in childhood

    Science.gov (United States)

    Strömbeck, A; Rabe, H; Lundell, A-C; Andersson, K; Johansen, S; Adlerberth, I; Wold, A E; Hesselmar, B; Rudin, A

    2014-01-01

    Background The role of FOXP3+ regulatory T cells in the prevention against sensitization and allergy development is controversial. Objective We followed 65 newborn Swedish children from farming and non-farming families from birth to 3 years of age and investigated the relation between CD4+ T cell subsets in blood samples and development of sensitization and allergic disease. Methods The proportions of FOXP3+CD25high, CTLA-4+CD25+, CD45RO+, HLA-DR+, CCR4+ or α4β7+ within the CD4+ T cell population were examined by flow cytometry of blood samples at several time-points. Mononuclear cells were isolated from blood and stimulated with birch allergen, ovalbumin or the mitogen PHA, and the levels of IL-1β, IL-6, TNF, IFN-γ, IL-5 and IL-13 were measured. A clinical evaluation regarding the presence of allergen-specific IgE and allergy was performed at 18 and 36 months of age. Results Multivariate discriminant analysis revealed that children who were sensitized at 18 or 36 months of age had higher proportions of FOXP3+CD25high T cells at birth and at 3 days of life than children who remained non-sensitized, whereas allergy was unrelated to the neonatal proportions of these cells. The proportions of CTLA-4+CD25+ T cells were unrelated to both sensitization and allergy. The association between higher proportions of FOXP3+CD25high T cells and sensitization persisted after exclusion of farmer's children. Finally, a farming environment was associated with lower proportions of FOXP3+CD25high T cells in early infancy and to a more prominent T cell memory conversion and cytokine production. Conclusion & Clinical Relevance Our results indicate that high proportions of FOXP3+CD25high T cells in neonates are not protective against later sensitization or development of allergy. PMID:24528482

  16. Researcher positioning

    DEFF Research Database (Denmark)

    Mørck, Line Lerche; Khawaja, Iram

    2009-01-01

    abstract  This article focuses on the complex and multi-layered process of researcher positioning, specifically in relation to the politically sensitive study of marginalised and ‘othered' groups such as Muslims living in Denmark. We discuss the impact of different ethnic, religious and racial...... political and personal involvement by the researcher, which challenges traditional perspectives on research and researcher positioning. A key point in this regard is the importance of constant awareness of and reflection on the multiple ways in which one's positioning as a researcher influences the research...... process. Studying the other calls for close reflections on one's own position, theoretically, personally, and politically, taking into account one's complicity in either overcoming or reproducing processes of othering and marginalisation. [i] We use the term (ethnic) minoritised, not as a distinction...

  17. Researcher Positioning

    DEFF Research Database (Denmark)

    Khawaja, Iram; Mørck, Line Lerche

    2009-01-01

    This article focuses on the complex and multilayered process of researcher positioning,specifically in relation to the politically sensitive study of marginalised and "othered"groups such as Muslims living in Denmark. We discuss the impact of different ethnic,religious, and racial backgrounds...... involvement by the researcher, which challenges traditional perspectives onresearch and researcher positioning. A key point in this regard is the importance ofconstant awareness of and reflection on the multiple ways in which one's positioningas a researcher influences the research process. Studying the other...

  18. Effect of Continuous Positive Airway Pressure Therapy on Glycemic Excursions and Insulin Sensitivity in Patients with Obstructive Sleep Apnea-hypopnea Syndrome and Type 2 Diabetes

    Directory of Open Access Journals (Sweden)

    Li-Xin Guo

    2015-01-01

    Conclusions: CPAP therapy may have a beneficial effect on improving not only blood glucose but also upon insulin sensitivity in T2DM patients with OSAHS. This suggests that CPAP may be an effective treatment for T2DM in addition to intensive diabetes management.

  19. UV Differentially Induces Oxidative Stress, DNA Damage and Apoptosis in BCR-ABL1-Positive Cells Sensitive and Resistant to Imatinib

    Directory of Open Access Journals (Sweden)

    Ewelina Synowiec

    2015-08-01

    Full Text Available Chronic myeloid leukemia (CML cells express the active BCR-ABL1 protein, which has been targeted by imatinib in CML therapy, but resistance to this drug is an emerging problem. BCR-ABL1 induces endogenous oxidative stress promoting genomic instability and imatinib resistance. In the present work, we investigated the extent of oxidative stress, DNA damage, apoptosis and expression of apoptosis-related genes in BCR-ABL1 cells sensitive and resistant to imatinib. The resistance resulted either from the Y253H mutation in the BCR-ABL1 gene or incubation in increasing concentrations of imatinib (AR. UV irradiation at a dose rate of 0.12 J/(m2·s induced more DNA damage detected by the T4 pyrimidine dimers glycosylase and hOGG1, recognizing oxidative modifications to DNA bases in imatinib-resistant than -sensitive cells. The resistant cells displayed also higher susceptibility to UV-induced apoptosis. These cells had lower native mitochondrial membrane potential than imatinib-sensitive cells, but UV-irradiation reversed that relationship. We observed a significant lowering of the expression of the succinate dehydrogenase (SDHB gene, encoding a component of the complex II of the mitochondrial respiratory chain, which is involved in apoptosis sensing. Although detailed mechanism of imatinib resistance in AR cells in unknown, we detected the presence of the Y253H mutation in a fraction of these cells. In conclusion, imatinib-resistant cells may display a different extent of genome instability than their imatinib-sensitive counterparts, which may follow their different reactions to both endogenous and exogenous DNA-damaging factors, including DNA repair and apoptosis.

  20. Integrative genomic analysis in K562 chronic myelogenous leukemia cells reveals that proximal NCOR1 binding positively regulates genes that govern erythroid differentiation and Imatinib sensitivity.

    Science.gov (United States)

    Long, Mark D; van den Berg, Patrick R; Russell, James L; Singh, Prashant K; Battaglia, Sebastiano; Campbell, Moray J

    2015-09-01

    To define the functions of NCOR1 we developed an integrative analysis that combined ENCODE and NCI-60 data, followed by in vitro validation. NCOR1 and H3K9me3 ChIP-Seq, FAIRE-seq and DNA CpG methylation interactions were related to gene expression using bootstrapping approaches. Most NCOR1 combinations (24/44) were associated with significantly elevated level expression of protein coding genes and only very few combinations related to gene repression. DAVID's biological process annotation revealed that elevated gene expression was uniquely associated with acetylation and ETS binding. A matrix of gene and drug interactions built on NCI-60 data identified that Imatinib significantly targeted the NCOR1 governed transcriptome. Stable knockdown of NCOR1 in K562 cells slowed growth and significantly repressed genes associated with NCOR1 cistrome, again, with the GO terms acetylation and ETS binding, and significantly dampened sensitivity to Imatinib-induced erythroid differentiation. Mining public microarray data revealed that NCOR1-targeted genes were significantly enriched in Imatinib response gene signatures in cell lines and chronic myelogenous leukemia (CML) patients. These approaches integrated cistrome, transcriptome and drug sensitivity relationships to reveal that NCOR1 function is surprisingly most associated with elevated gene expression, and that these targets, both in CML cell lines and patients, associate with sensitivity to Imatinib.

  1. Sensitivity of CIPS-computed PVC location to measurement errors in ECG electrode position: the need for the 3D Camera

    NARCIS (Netherlands)

    Dam, P.M. van; Gordon, J.P.; Laks, M.

    2014-01-01

    BACKGROUND: The Cardiac Isochrone Positioning System (CIPS) is a non-invasive method able to localize the origins of PVCs, VT and WPW from the 12 lead ECG. The CIPS model integrates a standard 12-lead ECG with an MRI derived model of the heart, lungs, and torso in order to compute the precise electr

  2. Comprehensive investigation of the influence of acidic, basic, and organic mobile phase compositions on bioanalytical assay sensitivity in positive ESI mode LC/MS/MS.

    Science.gov (United States)

    Rainville, Paul D; Smith, Norman W; Cowan, David; Plumb, Robert S

    2012-02-05

    The sensitivity and accuracy of a bioanalytical method is critical in defining the pharmacokinetic (PK) parameters of a potential new chemical entity (NCE). Inhaled therapeutics and low dose NCEs present one of the most significant analytical challenges to the bioanalyst, due to their low systemic concentration. The sensitivity of a bioanalytical LC/MS/MS based assay can be influenced by multiple parameters, including: mobile phase composition, extraction efficiency and chromatographic performance. In this work, we discuss the influence of acidic (pH 3), and basic (pH 10) aqueous mobile phases in conjunction with the two most common organic modifiers used in HPLC, acetonitrile and methanol, on the assay sensitivity of twenty-four probe pharmaceuticals in solvent and biological fluid extract. The study showed that when the test probe pharmaceuticals were analyzed with basic aqueous mobile phases compared to standard acidic conditions the following results were observed: increases in chromatographic peak area ranging from 1.2 to 9.6 fold for twenty-one of the test compounds as well as increased signal-to-noise for greater than seventy percent of the compounds. This observed increase in the MS response was not necessarily related to the later elution of the analyte in a higher organic composition under basic conditions. This was demonstrated as seven out of the twenty-four (approximately thirty percent) of the probe pharmaceuticals tested, eluted earlier, or with the same retention time, under basic conditions, and still produced a greater signal-to-noise when analyzed under these basic conditions. Also observed were decreases in chromatographic peak width, and increases in the retention time of very hydrophilic pharmaceutical compounds. The effect of the mobile phase combinations on the retention and MS response of the choline-containing phospholipids present in precipitated plasma was also investigated, as these analytes are a major source of interference when

  3. Towards a deep characterization of a 64-fold-pixelated position sensitive detector for a new {gamma}-scanning system of HPGe segmented detectors

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez-Prieto, A.; Quintana, B. [Laboratorio de Radiaciones Ionizantes, Univ. of Salamanca, 37007 (Spain)

    2011-07-01

    Characterization of the electrical response of the HPGe segmented detectors is one of the current goals for the Nuclear Physics community in order to perform {gamma}-ray tracking or even imaging with these detectors. For this purpose, scanning devices have to be developed to achieve the signal-position association with the highest precision. In this laboratory, a new scanning system, SALSA (Salamanca Lyso-based Scanning Array), consisting on a high spatial resolution {gamma} camera, is a under development. In this work the whole scanning system is presented and first results for the characterization of the {gamma} camera are shown. (authors)

  4. [Consensus on antimicrobial sensitivity tests in gram-positive cocci. Subcommittee on Antimicrobials, SADEBAC (Argentinian Society of Clinical Bacteriology), Argentinian Association of Microbiology].

    Science.gov (United States)

    Famiglietti, A; Quinteros, M; Predari, S C; Corso, A; Lopardo, H; Casellas, J M; Bantar, C; Couto, E; Galas, M; Goldberg, M; Gutkind, G; Kovensky Pupko, J; Marín, M; Nicola, F; Pasterán, F; Radice, M; Soloaga, R

    2003-01-01

    Antimicrobial susceptibility testing is mainly performed in Argentina by disk diffusion method, following National Committee for Clinical Laboratory Standards (NCCLS) recommendations. We worked out new recommendations for the reporting and interpretation of this test when dealing with gram-positive cocci, in accordance to local trends and epidemiology. General considerations for performing the diffusion assay, quality control, and an update on susceptibility testing for gram-positive cocci are reported in this first document. The present update should be considered as a group of recommendations summarized by Argentinean experts and as the result of a consensus meeting coordinated by the Subcomisión de Antimicrobianos of the Sociedad Argentina de Bacteriología Clínica (Asociación Argentina de Microbiología). Experts in antimicrobial agents were convened in order to prepare this final document. These recommendations take into account local needs, affordability and availability to be used in current practice, tending to contribute to the correct antimicrobial treatment election, according to the particular microorganism and the infection sites.

  5. Study on Sensitivity of Isolation Layer Position of Story Isolation%层间隔震结构隔震层位置的敏感性研究

    Institute of Scientific and Technical Information of China (English)

    李振国; 江宜城

    2011-01-01

    To investigate the influence of different isolation layer position on seismic response, a 16-storey office building was built by the software of CSIETABS to do 3-D nonlinear structure analysis. The values of modal quality participate, interlaminar shear, absolute acceleration and envelope diagram of displacement-angle between floors of seismic responses of various isolation layer position. The result shows it could get a better damping effect if we set the isolation layer in the story which has maximum interlaminar shear layer when the structure base-isolated, and restrict lower substructure interlayer shear at the same time.%以一栋16层办公楼为工程背景,研究了层间隔震的不同隔震层位置对其减震效果的影响,使用CSIETABS三维非线性结构分析软件进行分析,得到了各不同隔震层位置对应的隔震后模态质量参与系数以及层间剪力、绝对加速度、层间位移角包络图.发现如果将隔震支座布置在基础隔震时的层间剪力最大层,同时限制住下部子结构层间剪力,将得到比较好的减震效果.

  6. Does the position of the electron-donating nitrogen atom in the ring system influence the efficiency of a dye-sensitized solar cell? A computational study.

    Science.gov (United States)

    Biswas, Abul Kalam; Barik, Sunirmal; Das, Amitava; Ganguly, Bishwajit

    2016-06-01

    We have reported a number of new metal-free organic dyes (2-6) that have cyclic asymmetric benzotripyrrole derivatives as donor groups with peripheral nitrogen atoms in the ring, fluorine and thiophene groups as π-spacers, and a cyanoacrylic acid acceptor group. Density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations were employed to examine the influence of the position of the donor nitrogen atom and π-conjugation on solar cell performance. The calculated electron-injection driving force (ΔG inject), electron-regeneration driving force (ΔG regen), light-harvesting efficiency (LHE), dipole moment (μ normal), and number of electrons transferred (∆q) indicate that dyes 3, 4, and 6 have significantly higher efficiencies than reference dye 1, which exhibits high efficiency. We also extended our comparison to some other reported dyes, 7-9, which have a donor nitrogen atom in the middle of the ring system. The computed results suggest that dye 6 possesses a higher incident photon to current conversion efficiency (IPCE) than reported dyes 7-9. Thus, the use of donor groups with peripheral nitrogen atoms appears to lead to more efficient dyes than those in which the nitrogen atom is present in the middle of the donor ring system. Graphical Abstract The locations of the nitrogen atoms in the donor groups in the designed dye molecules have an important influence on DSSC efficiency.

  7. p185BCR/ABL has a lower sensitivity than p210BCR/ABL to the allosteric inhibitor GNF-2 in Philadelphia chromosome-positive acute lymphatic leukemia

    Science.gov (United States)

    Mian, Afsar A.; Metodieva, Anna; Najajreh, Yousef; Ottmann, Oliver G.; Mahajna, Jamal; Ruthardt, Martin

    2012-01-01

    Background The t(9;22) translocation leads to the formation of the chimeric breakpoint cluster region/c-abl oncogene 1 (BCR/ABL) fusion gene on der22, the Philadelphia chromosome. The p185BCR/ABL or the p210BCR/ABL fusion proteins are encoded as a result of the translocation, depending on whether a “minor” or “major” breakpoint occurs, respectively. Both p185BCR/ABL and p210BCR/ABL exhibit constitutively activated ABL kinase activity. Through fusion to BCR the ABL kinase in p185BCR/ABL and p210BCR/ABL “escapes” the auto-inhibition mechanisms of c-ABL, such as allosteric inhibition. A novel class of compounds including GNF-2 restores allosteric inhibition of the kinase activity and the transformation potential of BCR/ABL. Here we investigated whether there are differences between p185BCR/ABL and p210BCR/ABL regarding their sensitivity towards allosteric inhibition by GNF-2 in models of Philadelphia chromosome-positive acute lymphatic leukemia. Design and Methods We investigated the anti-proliferative activity of GNF-2 in different Philadelphia chromosome-positive acute lymphatic leukemia models, such as cell lines, patient-derived long-term cultures and factor-dependent lymphatic Ba/F3 cells expressing either p185BCR/ABL or p210BCR/ABL and their resistance mutants. Results The inhibitory effects of GNF-2 differed constantly between p185BCR/ABL and p210BCR/ABL expressing cells. In all three Philadelphia chromosome-positive acute lymphatic leukemia models, p210BCR/ABL-transformed cells were more sensitive to GNF-2 than were p185BCR/ABL-positive cells. Similar results were obtained for p185BCR/ABL and the p210BCR/ABL harboring resistance mutations. Conclusions Our data provide the first evidence of a differential response of p185BCR/ABL- and p210BCR/ABL- transformed cells to allosteric inhibition by GNF-2, which is of importance for the treatment of patients with Philadelphia chromosome-positive acute lymphatic leukemia. PMID:22058195

  8. Neutron Position Sensitive Detectors for the ESS

    CERN Document Server

    Kirstein, Oliver; Stefanescu, Irina; Etxegarai, Maddi; Anastasopoulos, Michail; Fissum, Kevin; Gulyachkina, Anna; Höglund, Carina; Imam, Mewlude; Kanaki, Kalliopi; Khaplanov, Anton; Kittelmann, Thomas; Kolya, Scott; Nilsson, Björn; Ortega, Luis; Pfeiffer, Dorothea; Piscitelli, Francesco; Ramos, Judith Freita; Robinson, Linda; Scherzinger, Julius

    2014-01-01

    The European Spallation Source (ESS) in Lund, Sweden will become the world's leading neutron source for the study of materials. The instruments are being selected from conceptual proposals submitted by groups from around Europe. These instruments present numerous challenges for detector technology in the absence of the availability of Helium-3, which is the default choice for detectors for instruments built until today and due to the extreme rates expected across the ESS instrument suite. Additionally a new generation of source requires a new generation of detector technologies to fully exploit the opportunities that this source provides. The detectors will be sourced from partners across Europe through numerous in-kind arrangements; a process that is somewhat novel for the neutron scattering community. This contribution presents briefly the current status of detectors for the ESS, and outlines the timeline to completion. For a conjectured instrument suite based upon instruments recommended for construction, ...

  9. The Positive Psychological Roles of Cultivating College Students’Intercultural Sensitivity%论培养跨文化敏觉力对大学生的积极心理作用

    Institute of Scientific and Technical Information of China (English)

    贾勤; 梅俞杰

    2016-01-01

    Based on the classic theories of the relation between language and culture,this essay explores the affective aspect in the intercultural communication competence-the intercultural sen-sitivity from the perspective of its positive psychological roles of cultivating college students'in-tercultural sensitivity.In the first place,the significance of the cultivation of college students’in-tercultural sensitivity is discussed from its relation with college education and its positive effects on the students’psychological states.Subsequently,the cultivation of the intercultural sensitivity in college students is analyzed as an effective way to enhance learning motivation,to improve English learning outcomes and to build healthy mind for their future life.%从语言文化关系的经典理论出发,结合跨文化交际理论,选取跨文化沟通能力的心理层面——intercul-tural sensitivity为切入点,依据陈国民提出的构成intercultural sensitivity的6个元素,探讨了培养跨文化敏感度对大学生的积极心理作用。根据大学英语的课程教学性质及要求实现的课程教学目标,首先讨论了大学英语教学与培养跨文化敏觉力的关系,指出有意识地培养大学生的跨文化敏觉力是践行“全人教育”的理念;然后,从提升学习动机、改善英语学习效果,塑造大学生健康心灵等方面论述提升跨文化敏觉力对大学生的积极心理作用。

  10. 接收线圈位置对脉冲涡流检测灵敏度的影响%Effect of Receiving Coil Position on Detection Sensitivity in Pulsed Eddy Current Testing

    Institute of Scientific and Technical Information of China (English)

    蔚道祥; 陈定岳; 薛盛龙; 付跃文; 邹国辉

    2015-01-01

    研究了对带包覆层管道的内部腐蚀进行脉冲涡流检测时,接收线圈的位置变化对检测灵敏度的影响,进行了探头置于激励线圈下不同位置的有限元仿真和试验研究。有限元仿真结果表明:在轴向和周向2个方向都是当检测线圈位于激励线圈边缘正下方时检测效果最好,其灵敏度分别为0.61、0.60。验证试验表明:在轴向和周向2个方向上,最佳检测位置都是位于激励线圈边缘正下方,其灵敏度分别为0.26、0.27。试验结果与仿真结果基本一致,表明接收线圈在激励线圈外边缘正下方附近时,检测灵敏度达到最大。研究结果有助于带包覆层管道腐蚀的脉冲涡流检测的传感器设计。%Effect of the detection sensitivity caused by the location change of the receiving coil is studied on the internal corrosion of ferromagnetic pipe under insulation with pulsed eddy current ( PEC ) non-destructive testing. Finite element model was established of ferromagnetic pipe under insulation to analyze the effect of position of receiving coil on the pulsed eddy current testing results. The simulation results show that the sensitivity will reach maximum both axial and circumferencial directions when receiving coil is right under the outer edge of the exciting coil, the sensitivities 0. 61 and 0. 60 respectively. The verification experiment results show that:putting receiving coil right under the outer edge of the exciting coil will get the best test results, the sensitivities 0. 26 and 0. 27 respectively. The experimental results agree well with the simulations and show that the detection sensitivity will reach maximum when receiving coil is right under the outer edge of the exciting coil, which will be of help to probe design in the corrosion detection of the pipe under insulation with PEC.

  11. Differential sensitivity of aerobic gram-positive and gram-negative microorganisms to 2,4,6-trinitrotoluene (TNT) leads to dissimilar growth and TNT transformation: Results of soil and pure culture studies

    Energy Technology Data Exchange (ETDEWEB)

    Fuller, M.E.; Manning, J.F. Jr.

    1996-07-30

    The effects of 2,4,6-trinitrotoluene (TNT) on indigenous soil populations and pure bacterial cultures were examined. The number of colony-forming units (CFU) appearing when TNT-contaminated soil was spread on 0.3% molasses plates decreased by 50% when the agar was amended with 67 {mu}g TNT mL{sup -1}, whereas a 99% reduction was observed when uncontaminated soil was plated. Furthermore, TNT-contaminated soil harbored a greater number of organisms able to grow on plates amended with greater than 10 {mu}g TNT mL{sup -1}. The percentage of gram-positive isolates was markedly less in TNT-contaminated soil (7%; 2 of 30) than in uncontaminated soil (61%; 20 of 33). Pseudomonas aeruginosa, Pseudomonas corrugate, Pseudomonasfluorescens and Alcaligenes xylosoxidans made up the majority of the gram-negative isolates from TNT-contaminated soil. Gram-positive isolates from both soils demonstrated marked growth inhibition when greater than 8-16 {mu}g TNT mL{sup -1} was present in the culture media. Most pure cultures of known aerobic gram-negative organisms readily degraded TNT and evidenced net consumption of reduced metabolites. However, pure cultures of aerobic gram-positive bacteria were sensitive to relatively low concentrations of TNT as indicated by the 50% reduction in growth and TNT transformation which was observed at approximately 10 {mu}g TNT mL{sup -1}. Most non-sporeforming gram-positive organisms incubated in molasses media amended with 80 {mu}g TNT mL{sup -1} or greater became unculturable, whereas all strains tested remained culturable when incubated in mineral media amended with 98 {mu}g TNT mL{sup -1}, indicating that TNT sensitivity is likely linked to cell growth. These results indicate that gram-negative organisms are most likely responsible for any TNT transformation in contaminated soil, due to their relative insensitivity to high TNT concentrations and their ability to transform TNT.

  12. 基于位置敏感探测器的激光位移传感器小波优化方法%Wavelet Optimization Method of Laser Displacement Sensor Based on Position Sensitive Detector

    Institute of Scientific and Technical Information of China (English)

    邾继贵; 陈浩; 薛彬

    2013-01-01

    The laser displacement sensor which uses position sensitive detector (PSD) as position detector can realize the displacement measurement in small space, but the PSD is vulnerable to external environment. Therefore, there are lots of noises in the output signal which severely affect the accuracy of PSD position detection. For the purpose of effectively extracting the useful PSD position signal, this paper presents a wavelet threshold denoising technology to improve the accuracy of position detection of laser displacement sensor based on PSD. Based on the discrete wavelet transform, the original signal of the PSD can be decomposed into multiple scales and then be reconstructed with quantified wavelet coefficients which contain the noise by soft thresholding function. The result of wavelet denoising is evaluated by the experiments such as using different kinds of base wavelet, changing the decomposition scale and considering different amounts of signal samples. The experimental results indicate that, by selecting the appropriate combination algorithm of wavelet denoising, the denoised signal can maintain the mean value of the original signal and the standard deviation can be minimized to 2 μm or below, which significantly improves the position detection accuracy of the sensor and shorten the measurement period.%在激光位移传感器中引入位置敏感探测器(PSD)可在狭小空间内实现测量,但易受外界因素影响使得输出信号中包含大量噪声,严重影响PSD位置检测精度.为在此测量环境下有效提取PSD位置信号,提出一种利用小波阈值去噪技术提高基于PSD的激光位移传感器检测精度的方法.该方法在离散小波变换的基础上,将PSD的原始测量信号进行多尺度小波分解,通过软阈值量化处理含噪声的小波系数后重构测量信号.实验中通过选择不同的基小波、变化分解尺度以及控制信号采样数量等过程评价小波去噪的效果,最终证实:选取

  13. An array of virtual Frisch-grid CdZnTe detectors and a front-end application-specific integrated circuit for large-area position-sensitive gamma-ray cameras

    Energy Technology Data Exchange (ETDEWEB)

    Bolotnikov, A. E., E-mail: bolotnik@bnl.gov; Ackley, K.; Camarda, G. S.; Cherches, C.; Cui, Y.; De Geronimo, G.; Fried, J.; Hossain, A.; Mahler, G.; Maritato, M.; Roy, U.; Salwen, C.; Vernon, E.; Yang, G.; James, R. B. [Brookhaven National Laboratory, Upton, New York 11793 (United States); Hodges, D. [University of Texas at El Paso, El Paso, Texas 79968 (United States); Lee, W. [Korea University, Seoul 136-855 (Korea, Republic of); Petryk, M. [SUNY Binghamton, Vestal, New York 13902 (United States)

    2015-07-15

    We developed a robust and low-cost array of virtual Frisch-grid CdZnTe detectors coupled to a front-end readout application-specific integrated circuit (ASIC) for spectroscopy and imaging of gamma rays. The array operates as a self-reliant detector module. It is comprised of 36 close-packed 6 × 6 × 15 mm{sup 3} detectors grouped into 3 × 3 sub-arrays of 2 × 2 detectors with the common cathodes. The front-end analog ASIC accommodates up to 36 anode and 9 cathode inputs. Several detector modules can be integrated into a single- or multi-layer unit operating as a Compton or a coded-aperture camera. We present the results from testing two fully assembled modules and readout electronics. The further enhancement of the arrays’ performance and reduction of their cost are possible by using position-sensitive virtual Frisch-grid detectors, which allow for accurate corrections of the response of material non-uniformities caused by crystal defects.

  14. An array of virtual Frisch-grid CdZnTe detectors and a front-end application-specific integrated circuit for large-area position-sensitive gamma-ray cameras.

    Science.gov (United States)

    Bolotnikov, A E; Ackley, K; Camarda, G S; Cherches, C; Cui, Y; De Geronimo, G; Fried, J; Hodges, D; Hossain, A; Lee, W; Mahler, G; Maritato, M; Petryk, M; Roy, U; Salwen, C; Vernon, E; Yang, G; James, R B

    2015-07-01

    We developed a robust and low-cost array of virtual Frisch-grid CdZnTe detectors coupled to a front-end readout application-specific integrated circuit (ASIC) for spectroscopy and imaging of gamma rays. The array operates as a self-reliant detector module. It is comprised of 36 close-packed 6 × 6 × 15 mm(3) detectors grouped into 3 × 3 sub-arrays of 2 × 2 detectors with the common cathodes. The front-end analog ASIC accommodates up to 36 anode and 9 cathode inputs. Several detector modules can be integrated into a single- or multi-layer unit operating as a Compton or a coded-aperture camera. We present the results from testing two fully assembled modules and readout electronics. The further enhancement of the arrays' performance and reduction of their cost are possible by using position-sensitive virtual Frisch-grid detectors, which allow for accurate corrections of the response of material non-uniformities caused by crystal defects.

  15. Sensitivity analysis

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003741.htm Sensitivity analysis To use the sharing features on this page, please enable JavaScript. Sensitivity analysis determines the effectiveness of antibiotics against microorganisms (germs) ...

  16. Position Information

    Data.gov (United States)

    Social Security Administration — The Position Information Data Asset provides the ability to search for active SSA position descriptions using various search criteria. An individual may search by PD...

  17. Positive Psychology

    Science.gov (United States)

    Peterson, Christopher

    2009-01-01

    Positive psychology is a deliberate correction to the focus of psychology on problems. Positive psychology does not deny the difficulties that people may experience but does suggest that sole attention to disorder leads to an incomplete view of the human condition. Positive psychologists concern themselves with four major topics: (1) positive…

  18. Ubiquitous positioning

    CERN Document Server

    Mannings, Robin

    2008-01-01

    This groundbreaking resource offers a practical, in-depth understanding of Ubiquitous Positioning - positioning systems that identify the location and position of people, vehicles and objects in time and space in the digitized networked economy. The future and growth of ubiquitous positioning will be fueled by the convergence of many other areas of technology, from mobile telematics, Internet technology, and location systems, to sensing systems, geographic information systems, and the semantic web. This first-of-its-kind volume explores ubiquitous positioning from a convergence perspective, of

  19. Positioning consumption

    DEFF Research Database (Denmark)

    Halkier, Bente; Keller, Margit

    2014-01-01

    positionings emerges based on empirical examples of research in parent–children consumption. Positionings are flexible discursive fixations of the relationship between the performances of the practitioner, other practitioners, media discourse and consumption activities. The basic positioning types...... are the practice maintenance and the practice change position, with different sorts of adapting in between. Media discourse can become a resource for a resistant position against social control or for an appropriating position in favour of space for action. Regardless of the current relation to a particular media...... discourse, practitioners attempt to maintain their self-positioning of competence when performing. This leads us, as researchers, to caution against any a priori anticipation of the anchoring power of media discourses within everyday activities....

  20. A TOUCH-SENSITIVE DEVICE

    DEFF Research Database (Denmark)

    2009-01-01

    propagating towards a specific point of the detector array is prevented from being incident upon the specific point of the detector array when an object contacts a touch-sensitive surface of the touch-sensitive waveguide at a corresponding specific contact point.......The present invention relates to an optical touch-sensitive device and a method of determining a position and determining a position change of an object contacting an optical touch sensitive device. In particular, the present invention relates to an optical touch pad and a method of determining...... a position and determining a position change of an object contacting an optical touch pad. A touch-sensitive device, according to the present invention may comprise a light source, a touch- sensitive waveguide, a detector array, and a first light redirecting member, wherein at least a part of the light...

  1. Cobalt sensitization and dermatitis

    DEFF Research Database (Denmark)

    Thyssen, Jacob P

    2012-01-01

    : This clinical review article presents clinical and scientific data on cobalt sensitization and dermatitis. It is concluded that cobalt despite being a strong sensitizer and a prevalent contact allergen to come up on patch testing should be regarded as a very complex metal to test with. Exposure...... data together with clinical data from metal workers heavily exposed to cobalt suggest that patch-test reactions are sometimes false positive and that patch testers should carefully evaluate their clinical relevance....

  2. Positive Psychotherapy

    Science.gov (United States)

    Seligman, Martin E. P.; Rashid, Tayyab; Parks, Acacia C.

    2006-01-01

    Positive psychotherapy (PPT) contrasts with standard interventions for depression by increasing positive emotion, engagement, and meaning rather than directly targeting depressive symptoms. The authors have tested the effects of these interventions in a variety of settings. In informal student and clinical settings, people not uncommonly reported…

  3. Positioning Agility

    Science.gov (United States)

    Oza, Nilay; Abrahamsson, Pekka; Conboy, Kieran

    Agile methods are increasingly adopted by European companies. Academics too are conducting numerous studies on different tenets of agile methods. Companies often feel proud in marketing themselves as ‘agile’. However, the true notion of ‘being agile’ seems to have been overlooked due to lack of positioning of oneself for agility. This raises a call for more research and interactions between academia and the industry. The proposed workshop refers to this call. It will be highly relevant to participants, interested in positioning their company’s agility from organizational, group or project perspectives. The positioning of agility will help companies to better align their agile practices with stakeholder values. Results of the workshop will be shared across participants and they will also have opportunity to continue their work on agile positioning in their companies. At broader level, the work done in this workshop will contribute towards developing Agile Positioning System.

  4. Proton recoil telescope based on diamond detectors for measurement of fusion neutrons

    CERN Document Server

    Caiffi, B; Ripani, M; Pillon, M; Taiuti, M

    2015-01-01

    Diamonds are very promising candidates for the neutron diagnostics in harsh environments such as fusion reactor. In the first place this is because of their radiation hardness, exceeding that of Silicon by an order of magnitude. Also, in comparison to the standard on-line neutron diagnostics (fission chambers, silicon based detectors, scintillators), diamonds are less sensitive to $\\gamma$ rays, which represent a huge background in fusion devices. Finally, their low leakage current at high temperature suppresses the detector intrinsic noise. In this talk a CVD diamond based detector has been proposed for the measurement of the 14 MeV neutrons from D-T fusion reaction. The detector was arranged in a proton recoil telescope configuration, featuring a plastic converter in front of the sensitive volume in order to induce the (n,p) reaction. The segmentation of the sensitive volume, achieved by using two crystals, allowed to perform measurements in coincidence, which suppressed the neutron elastic scattering backg...

  5. Gluten Sensitivity

    Science.gov (United States)

    Gluten is a protein found in wheat, rye, and barley. It is found mainly in foods but ... products like medicines, vitamins, and supplements. People with gluten sensitivity have problems with gluten. It is different ...

  6. Positional games

    CERN Document Server

    Hefetz, Dan; Stojaković, Miloš; Szabó, Tibor

    2014-01-01

    This text serves as a thorough introduction to the rapidly developing field of positional games. This area constitutes an important branch of combinatorics, whose aim it is to systematically develop an extensive mathematical basis for a variety of two-player perfect information games. These range from such popular games as Tic-Tac-Toe and Hex to purely abstract games played on graphs and hypergraphs. The subject of positional games is strongly related to several other branches of combinatorics such as Ramsey theory, extremal graph and set theory, and the probabilistic method. These notes cover a variety of topics in positional games, including both classical results and recent important developments. They are presented in an accessible way and are accompanied by exercises of varying difficulty, helping the reader to better understand the theory. The text will benefit both researchers and graduate students in combinatorics and adjacent fields.

  7. Positively Adolescent!

    Science.gov (United States)

    Williamson, Sue

    2000-01-01

    Believes that music teachers should reassess their views toward adolescent behavior in the music classroom by learning to see their behavior in a positive light. Describes teaching strategies that build on four adolescent behaviors: (1) desire for peer acceptance; (2) abundant energy; (3) love of fun; and (4) limited time-managing skills. (CMK)

  8. Path Sensitization

    Institute of Scientific and Technical Information of China (English)

    赵著行; 闵应骅; 等

    1997-01-01

    For different delay models,the concept of sensitization can be very different.Traditonal concepts of sensitization cannot precisely describe circuit behavior when the input vectors change very fast.Using Boolean process aporoach,this paper presents a new definition of sensitization for arbitrary input waveforms.By this new concept it is found that if the inputs of a combinational circuit can change at any time,and each gate's delay varies within an interval (bounded gate delay model),then every path,which is not necessarily a single topological path,is sensitizable.From the experimental results it can be seen that,all nonsensitizable paths for traditional concepts actually can propagate transitions along them for some input waveforms.However,specified time between input transitions(STBIT) and minimum permissible pulse width(ε)are two major factors to make some paths non-sensitizable.

  9. Sensitive innovation

    DEFF Research Database (Denmark)

    Søndergaard, Katia Dupret

    Present paper discusses sources of innovation as heterogenic and at times intangible processes. Arguing for heterogeneity and intangibility as sources of innovation originates from a theoretical reading in STS and ANT studies (e.g. Callon 1986, Latour 1996, Mol 2002, Pols 2005) and from field work...... in the area of mental health (Dupret Søndergaard 2009, 2010). The concept of sensitive innovation is developed to capture and conceptualise exactly those heterogenic and intangible processes. Sensitive innovation is therefore primarily a way to understand innovative sources that can be......, but are not necessarily, recognized and acknowledged as such in the outer organisational culture or by management. The added value that qualifies these processes to be defined as “innovative” are thus argued for along different lines than in more traditional innovation studies (e.g. studies that build on the classic...

  10. LIN28A, a sensitive immunohistochemical marker for Embryonal Tumor with Multilayered Rosettes (ETMR), is also positive in a subset of Atypical Teratoid/Rhabdoid Tumor (AT/RT).

    Science.gov (United States)

    Rao, Shilpa; Rajeswarie, R T; Chickabasaviah Yasha, T; Nandeesh, Bevinahalli N; Arivazhagan, Arimappamagan; Santosh, Vani

    2017-07-25

    CNS embryonal tumors comprise a group of highly malignant neoplasms with a wide spectrum of histomorphological entities that includes Medulloblastoma (MB), Atypical Teratoid/Rhabdoid Tumor (AT/RT), Neuroblastoma (NB), Ganglioneuroblastoma (GNB), Embryonal Tumor with Multilayered Rosettes (ETMR), and the embryonal tumor-Not Otherwise Specified (NOS). The entity ETMR includes previously described histopathologic patterns-Embryonal Tumor with Abundant Neuropil and True Rosettes (ETANTR), Ependymoblastoma (EBL), and Medulloepithelioma (MEPL). Based on the histopathological similarities (multilayered rosettes) among ETANTR, EBL, and MEPL, as well as uniform clinical behavior and common molecular genetic characteristics, the WHO revision has created a new entity, "ETMR." Immunoreactivity of LIN28A has been identified as a sensitive tool for the diagnosis of this entity. Since there is a paucity of literature regarding immunoreactivity of LIN28A across all embryonal CNS tumors, the present study was undertaken. During the 5-year study period (2012 to 2016), all the embryonal tumors (MB, AT/RT, other embryonal tumors-ETANTR, MEPL, PNET) that had been earlier diagnosed in the department of neuropathology (cases operated in our institute as well as received as referral) were reviewed. The archived Hematoxylin and Eosin (H&E) and the available immunohistochemistry (IHC) sections were studied. Further, for the other embryonal tumors where the paraffin blocks were available, an extended panel of IHC was performed for confirming the diagnosis of embryonal tumor and only confirmed cases were included in the study. The demographic details of the study cohort were noted. IHC for LIN28A was performed on conventional sections. A total of 396 cases of embryonal tumors including 302 MB, 72 AT/RT, and 22 other embryonal tumors were diagnosed during the study period. Among these, 80 MB, 35 AT/RT, 4 ETANTR, 1 MEPL, 4 NB, 2 GNB, and 1 CNS embryonal tumor-NOS (total-127) were included for

  11. Study of the effect of positive ions impinging sensitive emulsions in mass spectrography; Etude de l'action des ions positifs sur les emulsions sensibles en spectrographie de masse

    Energy Technology Data Exchange (ETDEWEB)

    Cavard, A. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1969-08-01

    Experimental relationships have been established between the blackening of emulsions by impinging ions and the following parameters: number, mass and energy of impinging particles. Mean energy ions (about twenty keV) give rise to a latent image probably made of small specks of metallic silver located at the surface or in the bulk of the silver halide grain. A specific developer for ion sensitive emulsion was perfected. Sensitivity and detection threshold are increased by a factor of two or three, compared with values observed using a classical developer. Low energy particles sputtered from superficial layers of the emulsion by the impinging twenty keV ions, produce a latent image close to the surface of the silver halide grain. An oxidizing process bleaches superficial latent image and then reduces background fog. The improved signal over background ratio allows to observe lines undetectable when the plates are developed by usual process. (author) [French] On a etabli les relations experimentales entre le noircissement resultant de l'action des ions sur l'emulsion sensible et les parametres suivants: nombre de particules incidentes, masse et energie de ces particules. L'effet sur les grains d'halogenure d'argent a ete examine: les ions d'energie moyenne (de l'ordre de 20 keV) creent une image latente vraisemblablement constituee d'argent, situee a la fois a la surface et a l'interieur du grain. Un revelateur specifique pour le developpement des emulsions sensibles exposees aux ions a ete mis au point: il accroit la sensibilite d'un facteur deux a trois et le facteur de contraste par rapport a un revelateur usuel. Les particules de faible energie, emises par pulverisation des couches superficielles de l'emulsion au cours de l'enregistrement des spectres de masse des ions d'energie moyenne, creent essentiellement dans les grains d'halogenure d'argent, une image latente superficielle

  12. Sensitivity, Recalculated

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, J. P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-11-07

    Prior to this study, the sensitivity in nEXO was calculated using an approximate method that does not provide 90% coverage. I find it useful to understand the confidence level of a limit by focusing on the confidence level as a property of the method used to find the limit.A particular method (algorithm,formula) is applied to an experiment to produce a limit. That experiment was conducted in a particular universe with certain values of the physical parameters. We’d like a method than produces a correct limit for 90% of the experiments that could run. We also want that to be true for every universe—that is, regardless of the physical parameter value, the method should still produce a correct limit 90% of the time.

  13. Beyond sensitivity

    DEFF Research Database (Denmark)

    Stott, Iain; Hodgson, David James; Townley, Stuart

    2012-01-01

    1. Perturbation analyses of population models are integral to population management: such analyses evaluate how changes in vital rates of members of the population translate to changes in population dynamics. Sensitivity and elasticity analyses of long-term (asymptotic) growth are popular...... formulae for the transfer function of population inertia, which describes nonlinear perturbation curves of transient population dynamics. The method comfortably fits into wider frameworks for analytical study of transient dynamics, and for perturbation analyses that use the transfer function approach. 3....... We use case studies to illustrate how the transfer function of population inertia may be used in population management. These show that strategies based solely on asymptotic perturbation analyses can cause undesirable transient dynamics and/ or fail to exploit desirable transient dynamics...

  14. Do differences in the American Academy of Pediatrics and the American College of Obstetricians and Gynecologists positions on the ethics of maternal-fetal interventions reflect subtly divergent professional sensitivities to pregnant women and fetuses?

    Science.gov (United States)

    Brown, Stephen D; Truog, Robert D; Johnson, Judith A; Ecker, Jeffrey L

    2006-04-01

    As therapeutic interventions that are designed for the direct benefit of the fetus have evolved, pediatric specialists along with obstetricians have become increasingly engaged in the management of pregnancies that are complicated by fetal disorders. Do the 2 groups of medical specialists hold differing "world views" on the nature of the maternal-fetal relationship that could have an impact on decision-making? A direct comparison of the positions of the ethics committees of the American Academy of Pediatrics and the American College of Obstetricians and Gynecologists concerning maternal-fetal conflicts and fetal therapy reveals subtle but telling differences. Compared with the American College of Obstetricians and Gynecologists policy, the American Academy of Pediatrics statement accords somewhat less weight to maternal decision-making and is more tolerant of overriding maternal refusal of interventions that are recommended for fetal benefit. In doing so, it may oblige pregnant patients to assume greater risk and tolerate diminished autonomy. We urge leaders from both disciplines to meet and seek consensus so that a common approach and language can guide treatment of the patients whom we share.

  15. Positionality at the Center

    Directory of Open Access Journals (Sweden)

    Catherine Vanner

    2015-11-01

    Full Text Available As a Western feminist supporting and researching gender equality in education in postcolonial contexts, I often wonder: Am I doing more harm than good? The privilege of my social location means that my efforts to support education in postcolonial contexts risk being patronizing, insulting, threatening, imperialist, and recolonizing. Yet neglecting and ignoring postcolonial contexts similarly reflects and reproduces a privileged position. I provide a tentative framework designed to address positionality, power, and privilege while creating an ethical research process for working in a postcolonial context. Beginning with an identification of positionality, the objectives of research, and guiding theoretical frameworks to situate the research in relation to the participants and context, I proceed to establish a methodology designed to minimize the negative effects of power and maximize participants’ empowerment. I position myself as a bricoleur, layering feminist standpoint theory and postcolonial theory, and propose the collaborative data collection and analysis techniques, with particular attention to ethical and cultural sensitivity, using a social constructivist approach to grounded theory. This article highlights the need for Western researchers to reflect upon the power dynamics of their research in postcolonial contexts and develop a strategy for conducting empowering research that prevents the misrepresentation and exploitation of participants. Observations from my doctoral thesis data collection provide examples of how these concepts were operationalized in practice as well as reflections on the disconnect between theorizing and conducting ethical research in postcolonial contexts.

  16. Gluten Sensitivity.

    Science.gov (United States)

    Catassi, Carlo

    2015-01-01

    Non-celiac gluten sensitivity (NCGS) is a syndrome characterized by intestinal and extraintestinal symptoms related to the ingestion of gluten-containing food in subjects who are not affected by either celiac disease (CD) or wheat allergy (WA). The prevalence of NCGS is not clearly defined yet. Indirect evidence suggests that NCGS is slightly more common than CD, the latter affecting around 1% of the general population. NCGS has been mostly described in adults, particularly in females in the age group of 30-50 years; however, pediatric case series have also been reported. Since NCGS may be transient, gluten tolerance needs to be reassessed over time in patients with NCGS. NCGS is characterized by symptoms that usually occur soon after gluten ingestion, disappear with gluten withdrawal, and relapse following gluten challenge within hours/days. The 'classical' presentation of NCGS is a combination of irritable bowel syndrome-like symptoms, including abdominal pain, bloating, bowel habit abnormalities (either diarrhea or constipation), and systemic manifestations such as 'foggy mind', headache, fatigue, joint and muscle pain, leg or arm numbness, dermatitis (eczema or skin rash), depression, and anemia. In recent years, several studies explored the relationship between the ingestion of gluten-containing food and the appearance of neurological and psychiatric disorders/symptoms like ataxia, peripheral neuropathy, schizophrenia, autism, depression, anxiety, and hallucinations (so-called gluten psychosis). The diagnosis of NCGS should be considered in patients with persistent intestinal and/or extraintestinal complaints showing a normal result of the CD and WA serological markers on a gluten-containing diet, usually reporting worsening of symptoms after eating gluten-rich food. NCGS should not be an exclusion diagnosis only. Unfortunately, no biomarker is sensitive and specific enough for diagnostic purposes; therefore, the diagnosis of NCGS is currently based on

  17. Sensitivity Analysis of Component Reliability

    Institute of Scientific and Technical Information of China (English)

    ZhenhuaGe

    2004-01-01

    In a system, Every component has its unique position within system and its unique failure characteristics. When a component's reliability is changed, its effect on system reliability is not equal. Component reliability sensitivity is a measure of effect on system reliability while a component's reliability is changed. In this paper, the definition and relative matrix of component reliability sensitivity is proposed, and some of their characteristics are analyzed. All these will help us to analyse or improve the system reliability.

  18. Position-sensitive silicon strip detector characterization using particle beams

    CERN Document Server

    Maenpaeae, Teppo

    2012-01-01

    Silicon strip detectors are fast, cost-effective and have an excellent spatial resolution.They are widely used in many high-energy physics experiments. Modern high energyphysics experiments impose harsh operation conditions on the detectors, e.g., of LHCexperiments. The high radiation doses cause the detectors to eventually fail as a resultof excessive radiation damage. This has led to a need to study radiation tolerance usingvarious techniques. At the same time, a need to operate sensors approaching the endtheir lifetimes has arisen.The goal of this work is to demonstrate that novel detectors can survive the environment that is foreseen for future high-energy physics experiments. To reach this goal,measurement apparatuses are built. The devices are then used to measure the propertiesof irradiated detectors. The measurement data are analyzed, and conclusions are drawn.Three measurement apparatuses built as a part of this work are described: two telescopes measuring the tracks of the beam of a particle acceler...

  19. PICsIT a position sensitive detector for space applications

    CERN Document Server

    Labanti, C; Ferriani, S; Ferro, G; Malaguti, G; Mauri, A; Rossi, E; Schiavone, F; Stephen, J B; Traci, A; Visparelli, D

    2002-01-01

    Pixellated Imaging CsI Telescope (PICsIT) is the high energy detector plane of Imager on Board INTEGRAL Satellite (IBIS), one of the main instruments on board the International Gamma-Ray Astrophysics Laboratory (INTEGRAL) satellite that will be launched in the year 2001. It consists of 4096 CsI(Tl) individual detector elements and operates in the energy range from 120 to 10,000 keV. PICsIT is made up of 8 identical modules, each housing 512 scintillating crystals coupled to PIN photodiodes (PD). Each crystal, 30 mm long and with a cross-section of 8.55x8.55 mm sup 2 , is wrapped with a white diffusing coating and then inserted into an aluminium crate. In order to have a compact design, two electronic boards, mounted directly below the crystal/PD assembly, host both the Analogue and Digital Front-End Electronics (FEE). The behaviour of the read-out FEE has a direct impact on the performance of the whole detector in terms of lower energy threshold, energy resolution and event time tagging. Due to the great numb...

  20. High counting rate, two-dimensional position sensitive timing RPC

    CERN Document Server

    Petrovici, M.; Simion, V; Bartos, D; Caragheorgheopol, G; Deppner, I; Adamczewski-Musch, J; Linev, S; Williams, MCS; Loizeau, P; Herrmann, N; Doroud, K; Radulescu, L; Constantin, F

    2012-01-01

    Resistive Plate Chambers (RPCs) are widely employed as muon trigger systems at the Large Hadron Collider (LHC) experiments. Their large detector volume and the use of a relatively expensive gas mixture make a closed-loop gas circulation unavoidable. The return gas of RPCs operated in conditions similar to the experimental background foreseen at LHC contains large amount of impurities potentially dangerous for long-term operation. Several gas-cleaning agents, characterized during the past years, are currently in use. New test allowed understanding of the properties and performance of a large number of purifiers. On that basis, an optimal combination of different filters consisting of Molecular Sieve (MS) 5Å and 4Å, and a Cu catalyst R11 has been chosen and validated irradiating a set of RPCs at the CERN Gamma Irradiation Facility (GIF) for several years. A very important feature of this new configuration is the increase of the cycle duration for each purifier, which results in better system stabilit...

  1. A Two Dimension Position Sensitive Microchannel Plate Detector

    Institute of Scientific and Technical Information of China (English)

    1995-01-01

    A Two Dimension Position Sensitive Microchannel Plate DetectorATwoDimensionPositionSensitiveMicrochannelPlateDetector¥LinYuan...

  2. Simulated performance of a position sensitive radiation detecting system (COCAE)

    CERN Document Server

    Karafasoulis, K; Seferlis, S; Kaissas, I; Lambropoulos, C; Loukas, D; Poritiriadis, C

    2011-01-01

    Extensive simulations of a portable radiation detecting system have been performed in order to explore important performance parameters. The instrument consists of a stack of ten detecting layers made of pixelated Cadmium Telluride (CdTe) crystals. Its aim is to localize and identify radiation sources, by exploiting the Compton imaging technique. In this paper we present performance parameters based on simulation studies. Specifically the ratio of incompletely absorbed photons, the detector's absolute efficiency as well as its energy and angular resolution are evaluated in a wide range of incident photon energies.

  3. Benign positional vertigo

    Science.gov (United States)

    Vertigo - positional; Benign paroxysmal positional vertigo; BPPV: dizziness- positional ... Benign positional vertigo is also called benign paroxysmal positional vertigo (BPPV). It is caused by a problem in the inner ear. ...

  4. Positive maps, positive polynomials and entanglement witnesses

    CERN Document Server

    Skowronek, Lukasz

    2009-01-01

    We link the study of positive quantum maps, block positive operators, and entanglement witnesses with problems related to multivariate polynomials. For instance, we show how indecomposable block positive operators relate to biquadratic forms that are not sums of squares. Although the general problem of describing the set of positive maps remains open, in some particular cases we solve the corresponding polynomial inequalities and obtain explicit conditions for positivity.

  5. Positive maps, positive polynomials and entanglement witnesses

    Energy Technology Data Exchange (ETDEWEB)

    Skowronek, Lukasz; Zyczkowski, Karol [Institute of Physics, Jagiellonian University, Krakow (Poland)], E-mail: lukasz.skowronek@uj.edu.pl, E-mail: karol@tatry.if.uj.edu.pl

    2009-08-14

    We link the study of positive quantum maps, block positive operators and entanglement witnesses with problems related to multivariate polynomials. For instance, we show how indecomposable block positive operators relate to biquadratic forms that are not sums of squares. Although the general problem of describing the set of positive maps remains open, in some particular cases we solve the corresponding polynomial inequalities and obtain explicit conditions for positivity.

  6. Navicular bone position determined by positional MRI

    DEFF Research Database (Denmark)

    Hansen, Philip; Johannsen, Finn E; Hangaard, Stine

    2016-01-01

    OBJECTIVE: To examine intraobserver, interobserver and between-day reproducibility of positional MRI for evaluation of navicular bone height (NVH) and medial navicular position (MNP). MATERIALS AND METHODS: Positional MRI (pMRI) of the foot was performed on ten healthy participants (0.25 T G......: Navicular height and medial navicular position can be measured by pMRI in a very reproducible manner within and between observers. Increased measurement variation is observed between-days in supine position, which may be due to small positional differences or other unknown biomechanical factors....

  7. Sensitivity of 96 and 120-hour Numerical Model Tropical Cyclone Position Forecasts to Initial Position Errors

    Science.gov (United States)

    2014-03-27

    to thank my Lord and Savior Jesus Christ who has graciously granted me the opportunities in this life. Secondly, to my beautiful wife, I am indebted... original Matrix Laboratory (MATLAB R©) software routine performed numerical computations using JTWC best track data, JTWC warning bulletins, and GFS...weighting function and the model parameter values at the model’s original grid resolution, but regardless of the ultimate grid resolution, the vortex

  8. Diclofenac derivatives with insulin-sensitizing activity

    Institute of Scientific and Technical Information of China (English)

    Jian Ta Wang; Ying Wang; Ji Quan Zhang; Xing Cui; Yi Zhang; Gao Feng Zhu; Lei Tang

    2011-01-01

    A series of diclofenac derivatives were synthesized. The insulin-sensitizing activity of 28 new compounds was evaluated in 3T3-L1 cells. The compounds 10a and 10f exhibited similar insulin-sensitizing activity with positive drag rosiglitazone.

  9. Climate sensitivity in the Anthropocene

    Directory of Open Access Journals (Sweden)

    M. Previdi

    2011-09-01

    Full Text Available Understanding the sensitivity of Earth's climate to an imposed external forcing is one of the great challenges in science and a critical component of efforts to avoid dangerous anthropogenic interference with the climate system. Climate sensitivity (or equilibrium global surface warming to a doubling of atmospheric CO2 has long been estimated to be about 3 °C, considering only fast climate feedbacks associated with increases in water vapor, decreases in sea ice, and changes in clouds. However, evidence from Earth's history suggests that slower surface albedo feedbacks due to vegetation change and melting of Greenland and Antarctica can come into play on the timescales of interest to humans, which could increase the sensitivity to significantly higher values, as much as 6 °C. Even higher sensitivity may result as present-day land and ocean carbon sinks begin to lose their ability to sequester anthropogenic CO2 in the coming decades. The evolving view of climate sensitivity in the Anthropocene is therefore one in which a wider array of Earth system feedbacks are recognized as important. Since these feedbacks are overwhelmingly positive, the sensitivity is likely to be higher than has traditionally been assumed.

  10. Positive clinical neuroscience: explorations in positive neurology.

    Science.gov (United States)

    Kapur, Narinder; Cole, Jonathan; Manly, Tom; Viskontas, Indre; Ninteman, Aafke; Hasher, Lynn; Pascual-Leone, Alvaro

    2013-08-01

    Disorders of the brain and its sensory organs have traditionally been associated with deficits in movement, perception, cognition, emotion, and behavior. It is increasingly evident, however, that positive phenomena may also occur in such conditions, with implications for the individual, science, medicine, and for society. This article provides a selective review of such positive phenomena--enhanced function after brain lesions, better-than-normal performance in people with sensory loss, creativity associated with neurological disease, and enhanced performance associated with aging. We propose that, akin to the well-established field of positive psychology and the emerging field of positive clinical psychology, the nascent fields of positive neurology and positive neuropsychology offer new avenues to understand brain-behavior relationships, with both theoretical and therapeutic implications.

  11. Positive Psychology: Positive Emotions and Emotional Intelegence

    OpenAIRE

    2008-01-01

    The paper focuses on the and emotional intelligence. We try to answer on some questions regarding the role which positive emotions have in our life’s. The broaden-and-build theory (Fredrickson, 1998; 2001) predicts that positive emotions are useful in several ways. They guide present behavior, by broadening one’s attention and cognition, setting the stage for creative, explorative, and innovative pursuits. As well, positive emotions build personal and social resources to help individuals achi...

  12. Serum level of high-sensitivity C-reactive protein in a rabbit model of atherosclerosis following repeated long-term exposure to positive acceleration%重复长时间正加速度暴露动脉粥样硬化家兔模型血清超敏C-反应蛋白的变化

    Institute of Scientific and Technical Information of China (English)

    罗慧兰; 陈勇胜

    2012-01-01

    BACKGROUND: Serum levels of high-sensitivity C-reactive protein (hs-CRP) can be used to predict cardiovascular injury.OBJECTIVE: To investigate the serum levels of hs-CRP in a rabbit model of atherosclerosis following repeated long-termexposure to positive acceleration and to predict the risk of cardiovascular injury.METHODS: Twenty-four New Zealand purebred rabbits were randomly divided into a positive acceleration group and a controlgroup. Rabbits in the positive acceleration group were exposed to +4 g rotation for 20 seconds with an acceleration of 1 g/s. Therotation interval was 5 minutes and totally three rotations were daily performed for 3 days per week. 0.5 g rotation was addedevery week, and by week 4, +6 g rotation was added, and the exposure lasted for 40 seconds.RESULTS AND CONCLUSION: Exposure to positive acceleration yielded significant effects on serum level of hs-CRP in rabbitswith atherosclerosis compared with before exposure (P 0.05). The interaction between exposure to positive acceleration and exposure time also did not produce significanteffects on serum level of hs-CRP (P > 0.05). Hyperplastic foam cells in the aortic tunica intima and the superficial layer of mediaincreased with the prolongation of exposure to positive acceleration. Repeated long-term exposure to positive acceleration maylead to a long-term high serum level of hs-CRP in rabbits.%背景:血清超敏C-反应蛋白的水平能够预测心血管损伤.目的:探讨重复正加速度暴露时动脉粥样硬化模型家兔血清超敏C-反应蛋白的变化与心血管损伤的风险预测.方法:将24 只新西兰纯种兔随机等分为正加速度组和对照组.正加速度组兔先在+4 g 水平(持续20 s,增长率为1 g/s)下暴露,旋转间隔时间为5 min,连续旋转3 次,每周3 d.每周增加0.5 g,至第4 周时增加至+6 g,持续暴露40 s.差异也无显著性意义(P > 0.05).兔主动脉内膜下及中膜浅层增生的泡沫细胞量随正加速度暴露的延长

  13. Associations between sensitivity to punishment, sensitivity to reward, and gambling.

    Science.gov (United States)

    Gaher, Raluca M; Hahn, Austin M; Shishido, Hanako; Simons, Jeffrey S; Gaster, Sam

    2015-03-01

    The majority of individuals gamble during their lifetime; however only a subset of these individuals develops problematic gambling. Gray's Reinforcement Sensitivity Theory may be relevant to understanding gambling problems. Differences in sensitivity to punishments and rewards can influence an individual's behavior and may be pertinent to the development of gambling problems. This study examined the functional associations between sensitivity to punishment (SP), sensitivity to reward (SR), and gambling problems in a sample of 2254 college students. Zero-inflated negative binomial regression was used to predict gambling problems as well as the absence of gambling problems. Gambling problems were hypothesized to be positively associated with SR and inversely associated with SP. In addition, SP was hypothesized to moderate the association between SR and gambling problems, attenuating the strength of the association. As hypothesized, SR was positively associated with gambling problems. However, SP did not moderate the relationship between SR and gambling problems. SP did, however, moderate the relationship between SR and the likelihood of never experiencing gambling problems. The results demonstrate that individual differences in SP and SR are functionally associated with gambling problems.

  14. Benign positional vertigo - aftercare

    Science.gov (United States)

    Vertigo - positional - aftercare; Benign paroxysmal positional vertigo - aftercare; BPPV - aftercare; Dizziness - positional vertigo ... Your health care provider may have treated your vertigo with the Epley maneuver . These are head movements ...

  15. Want Positive Behavior? Use Positive Language

    Science.gov (United States)

    Wood, Chip; Freeman-Loftis, Babs

    2012-01-01

    Positive adult language is the professional use of words and tone of voice to enable students to learn in an engaged, active way. This includes learning social skills. To guide children toward choosing and maintaining positive behaviors, adults need to carefully choose the words and tone of voice used when speaking to them. Learning to use…

  16. Positive Education: Positive Psychology and Classroom Interventions

    Science.gov (United States)

    Seligman, Martin E. P.; Ernst, Randal M.; Gillham, Jane; Reivich, Karen; Linkins, Mark

    2009-01-01

    Positive education is defined as education for both traditional skills and for happiness. The high prevalence worldwide of depression among young people, the small rise in life satisfaction, and the synergy between learning and positive emotion all argue that the skills for happiness should be taught in school. There is substantial evidence from…

  17. A study of an optimal technological solution for the electronics of particle position sensitive gas detectors (multiwire proportional chambers); Etude d`une solution technologique optimale pour l`electronique de localisation des particules avec des detecteurs a gaz (chambre proportionelle multifils)

    Energy Technology Data Exchange (ETDEWEB)

    Zojceski, Z. [Institut de Physique Nucleaire, CNRS - IN2P3 Universite Paris Sud, 91406 Orsay Cedex (France)

    1997-12-31

    This work aims at optimizing the electronics for position sensitive gas detectors. The first part is a review of proportional chamber operation principles and presents the different possibilities for the architecture of the electronics. The second part involves electronic signal processing for best signal-to-noise ratio. We present a time-variant filter based on a second order base line restorer.It allows a simple pole-zero and tail cancellation at high counting rates. Also, various interpolating algorithms for cathode strip chambers have been studied. The last part reports the development of a complete electronic system, from the preamplifiers up to the readout and control interface, for the cathode strip chambers in the focal plane of the BBS Spectrometer at KVI, Holland. The system is based on application specific D-size VXI modules. In all modules, the 16-bit ADCs and FIFO memory are followed by a Digital Signal Processor, which performs data filtering and cathode induced charge interpolation. Very good analog noise performance is obtained in a multi-processor environment. (author). 127 refs.

  18. A study of an optimal technological solution for the electronics of particle position sensitive gas detectors (multiwire proportional chambers); Etude d`une solution technologique optimale pour l`electronique de localisation des particules avec des detecteurs a gaz (chambre proportionelle multifils)

    Energy Technology Data Exchange (ETDEWEB)

    Zojceski, Z. [Institut de Physique Nucleaire, CNRS - IN2P3 Universite Paris Sud, 91406 Orsay Cedex (France)

    1997-12-31

    This work aims at optimizing the electronics for position sensitive gas detectors. The first part is a review of proportional chamber operation principles and presents the different possibilities for the architecture of the electronics. The second part involves electronic signal processing for best signal-to-noise ratio. We present a time-variant filter based on a second order base line restorer.It allows a simple pole-zero and tail cancellation at high counting rates. Also, various interpolating algorithms for cathode strip chambers have been studied. The last part reports the development of a complete electronic system, from the preamplifiers up to the readout and control interface, for the cathode strip chambers in the focal plane of the BBS Spectrometer at KVI, Holland. The system is based on application specific D-size VXI modules. In all modules, the 16-bit ADCs and FIFO memory are followed by a Digital Signal Processor, which performs data filtering and cathode induced charge interpolation. Very good analog noise performance is obtained in a multi-processor environment. (author). 127 refs.

  19. 容积调强旋转放疗的计划验证通过率对多叶准直器位置误差的灵敏度%The sensitivity of patient-specific VMAT QA to MLC positioning errors

    Institute of Scientific and Technical Information of China (English)

    王清鑫; 戴建荣; 张可; 杨昕

    2013-01-01

    Objective To evaluate the sensitivity of patient-specific volumetric-modulated arc therapy (VMAT) quality assurance (QA) to minor multileaf collimator (M LC) positioning errors.Methods Systematic multileaf collimator (MLC) positioning errors (+0.5 mm,+ 1 mm and +2 mm) were introduced into the clinical VMAT patient plans with 2 types of MLC positioning errors:systematic MLC gap width errors and systematic MLC shift errors for 6 cases,including 3 cases with prostatic cancer and 3 cases with nasopharyngeal cancer.The planar dose distributions of the original and modified plans were measured using ArcCheck array.The coincidence between the measured results and the calculated results was evaluated using both absolute distance-to-agreement (AD-DTA) analysis with 3%/3 mm and 2%/2 mm criteria.Results The average passing rate of the 6 original VMAT plans was 96.0% with the ADDTA criteria of 3%/3 mm which was commonly adopted in clinical practice.For the MLC gap width errors of + 1 mm,+2 mm,and-2 mm and the MLC shift errors of 2 mm,the drop levels in average passing rate with the AD-DTA criteria of 3%/3 mm were 8.8%,15.5%,6.1% and 7.9%,respectively.The + 2 mm MLC positioning errors and + 1 mm MLC gap width errors could be detected by the patient-specific VMAT QA procedure.The AD-DTA criteria of 2%/2 mm was more sensitive compared with the criteria of 3%/3 mm.Conclusions Patient-specific VMAT QA is not sensitive enough to detect the systematic MLC positioning errors within 1 mm.Additional MLC QA is needed to guarantee the accuracy of VMAT delivery.%目的 针对容积调强旋转放疗技术(VMAT),分析患者计划验证通过率对多叶准直器(MLC)位置误差的灵敏度.方法 选取6例双弧VMAT计划,引入MLC位置误差(±0.5 mm、±1 mm和±2 mm),模拟VMAT执行过程中MLC可能出现的系统误差,包括MLC射野宽度误差和MLC整体偏向一侧的误差.每个病例有10个计划,1个原计划和9个带有误差的新计划.利用

  20. The Contrast Sensitivity Function in Low Vision

    Institute of Scientific and Technical Information of China (English)

    1992-01-01

    The contrast sensitivity of 51 low vision patients (95 eyes) showed a substantial decrease in all spatial frequencies. The peak contrast sensitivity was shifted to 1 C/D from the normal 3-4 C/D. The high-frequency cut off is correlated to the visual acuity positively. Of the 33 patients, the preferred eye was the eye with better peak sensitivity in 28 patients (84%), while the preferred eye was the eye with better visual acuity in 22 patients (66%). It seems that the peak sensitivity is more important t...

  1. Non Celiac Gluten Sensitivity.

    Science.gov (United States)

    Bardella, Maria Teresa; Elli, Luca; Ferretti, Francesca

    2016-12-01

    A new syndrome responding to gluten-free diet and defined non-celiac gluten sensitivity entered the spectrum of gluten-related disorders, together with celiac disease and wheat allergy. However, its definition, prevalence, diagnosis, pathogenesis, treatment, and follow up are still controversial. The purpose of the review is to summarize the evidence and problems emerging from the current literature. Direct implication of gluten in the onset of symptoms is often unproved as a low fermentable oligo-, di- and mono-saccharides and polyols diet or other components of cereals as wheat amylase trypsin inhibitor could be similarly involved. To date, no specific biomarkers or histological abnormalities confirm diagnosis, and only the self-reported response to gluten-free diet as well as a positive double blind placebo-gluten challenge characterizes these non-celiac, non-wheat allergic patients. Critical revision of published studies can offer practical indications in approaching this clinical topic and useful suggestions to standardize scientific researches.

  2. How sensitizing is chlorocresol?

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner; Hamann, K

    1984-01-01

    Chlorocresol is a biocide with widespread use in industry and pharmaceutical products. It is an occasional human contact sensitizer. The sensitizing potential of chlorocresol was judged strong using the guinea pig maximization test (GPMT) and doubtful in the less sensitive open epicutaneous test ...

  3. Tooth sensitivity and whitening.

    Science.gov (United States)

    Swift, Edward J

    2005-09-01

    This article presents a review of the basic concepts of tooth sensitivity and how those concepts apply to cervical dentin hypersensitivity and the sensitivity frequently associated with tooth whitening. The etiology and treatment of cervical dentin hypersensitivity are described. The clinical presentation, incidence, and predisposing factors for sensitivity associated with tooth whitening also are discussed.

  4. B-type natriuretic peptide is a long-term predictor of all-cause mortality, whereas high-sensitive C-reactive protein predicts recurrent short-term troponin T positive cardiac events in chest pain patients: a prognostic study

    Directory of Open Access Journals (Sweden)

    Staines Harry

    2008-11-01

    Full Text Available Abstract Background Few studies have addressed whether the combined use of B-type natriuretic peptide (BNP and high-sensitive C-reactive protein (hsCRP improves risk stratification for mortality and cardiovascular events in a population with chest pain and suspected acute coronary syndromes (ACS. Therefore, we wanted to assess the incremental prognostic value of these biomarkers with respect to long-term all-cause mortality and recurrent troponin T (TnT positive cardiac events in 871 patients admitted to the emergency department. Methods Blood samples were obtained immediately following admission. Results After a follow-up period of 24 months, 129 patients had died. The BNP levels were significantly higher among patients dying than in long-term survivors (401 (145–736 versus 75 (29–235 pq/mL [median, 25 and 75% percentiles], p = 0.000. In a multivariable Cox regression model for death within 2 years, the hazard ratio (HR for BNP in the highest quartile (Q4 was 5.13 (95% confidence interval (CI, 1.97–13.38 compared to the lowest quartile (Q1 and was associated with all-cause mortality above and beyond age, congestive heart failure and the index diagnosis ST-segment elevation myocardial infarction. HsCRP rendered no prognostic information for all-cause mortality. However, within 30 days, the adjusted HR for patients with recurrent TnT cardiac positive events hsCRP in Q4 was 14.79 (95% CI, 1.89–115.63 compared with Q1 and was associated with recurrent ischemic events above and beyond age, hypercholesterolemia and TnT values at admission. Conclusion BNP may act as a clinically useful biomarker when obtained at admission in an unselected patient population following hospitalization with chest pain and potential ACS, and may provide complementary prognostic information to established risk determinants at long-term follow-up. Our data do not support the hypothesis that the additional assessment of hsCRP will lead to better risk stratification

  5. Multi-technology positioning

    CERN Document Server

    Lohan, Elena-Simona; Wymeersch, Henk; Seco-Granados, Gonzalo; Nykänen, Ossi

    2017-01-01

    This book provides an overview of positioning technologies, applications and services in a format accessible to a wide variety of readers. Readers who have always wanted to understand how satellite-based positioning, wireless network positioning, inertial navigation, and their combinations work will find great value in this book. Readers will also learn about the advantages and disadvantages of different positioning methods, their limitations and challenges. Cognitive positioning, adding the brain to determine which technologies to use at device runtime, is introduced as well. Coverage also includes the use of position information for Location Based Services (LBS), as well as context-aware positioning services, designed for better user experience. • Brings understanding of positioning technology to readers from a variety of disciplines • Reviews multiple techniques, providing insight on the pros, cons and challenges related to each • Designed to be a tutorial on basic principles, avoiding unnecessary de...

  6. Positive Deviance: Learning from Positive Anomalies

    Science.gov (United States)

    LeMahieu, Paul G.; Nordstrum, Lee E.; Gale, Dick

    2017-01-01

    Purpose: This paper is one of seven in this volume, each elaborating different approaches to quality improvement in education. The purpose of this paper is to delineate a methodology called positive deviance. Design/methodology/approach: The paper presents the origins, theoretical foundations, core principles and a case study demonstrating an…

  7. Perception of eye positions

    NARCIS (Netherlands)

    Lorteije, J.A.M.; Wezel, R.J.A. van; Lankheet, M.J.M.

    2002-01-01

    In a two-alternative forced-choice psychophysical test human subjects were tested for their ability to perceive their own viewing direction. A small red flash was presented at different horizontal positions left or right from the subjects' eye position on the screen. Eye positions were recorded with

  8. Non-coeliac gluten sensitivity.

    Science.gov (United States)

    Gibson, Peter R; Skodje, Gry I; Lundin, Knut E A

    2017-03-01

    Irritable bowel syndrome-like symptoms in response to wheat ingestion is common and well described, but whether the reaction is due to gluten (i.e., non-coeliac gluten sensitivity), other wheat proteins, or FODMAPs (mostly fructans) alone or in combinations has not been clearly defined. Exclusion of coeliac disease in the presence of negative serology, and normal villous architecture but increased density of intraepithelial lymphocytes on duodenal biopsies, is difficult. Furthermore, the confidence by which a positive diagnosis is made or non-coeliac gluten sensitivity is excluded by blinded placebo-controlled rechallenge with wheat protein is reduced by strong nocebo responses generally found in patients with self-reported non-coeliac gluten sensitivity. The absence of a clear biological mechanism of action and difficulties with the design and interpretation of research studies have plunged this entity into even deeper controversy. In the absence of clarity in its diagnosis, the epidemiology, prognosis, and therapeutic approaches to a patient who may be gluten sensitive remain to be determined. Adequate understanding of the issues surrounding the controversy and further research will slowly unravel the truth behind the problem. © 2017 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.

  9. Contextual sensitivity in scientific reproducibility.

    Science.gov (United States)

    Van Bavel, Jay J; Mende-Siedlecki, Peter; Brady, William J; Reinero, Diego A

    2016-06-07

    In recent years, scientists have paid increasing attention to reproducibility. For example, the Reproducibility Project, a large-scale replication attempt of 100 studies published in top psychology journals found that only 39% could be unambiguously reproduced. There is a growing consensus among scientists that the lack of reproducibility in psychology and other fields stems from various methodological factors, including low statistical power, researcher's degrees of freedom, and an emphasis on publishing surprising positive results. However, there is a contentious debate about the extent to which failures to reproduce certain results might also reflect contextual differences (often termed "hidden moderators") between the original research and the replication attempt. Although psychologists have found extensive evidence that contextual factors alter behavior, some have argued that context is unlikely to influence the results of direct replications precisely because these studies use the same methods as those used in the original research. To help resolve this debate, we recoded the 100 original studies from the Reproducibility Project on the extent to which the research topic of each study was contextually sensitive. Results suggested that the contextual sensitivity of the research topic was associated with replication success, even after statistically adjusting for several methodological characteristics (e.g., statistical power, effect size). The association between contextual sensitivity and replication success did not differ across psychological subdisciplines. These results suggest that researchers, replicators, and consumers should be mindful of contextual factors that might influence a psychological process. We offer several guidelines for dealing with contextual sensitivity in reproducibility.

  10. Pretty Easy Pervasive Positioning

    DEFF Research Database (Denmark)

    Hansen, Rene; Wind, Rico; Jensen, Christian Søndergaard;

    2009-01-01

    With the increasing availability of positioning based on GPS, Wi-Fi, and cellular technologies and the proliferation of mobile devices with GPS, Wi-Fi and cellular connectivity, ubiquitous positioning is becoming a reality. While offerings by companies such as Google, Skyhook, and Spotigo render...... positioning possible in outdoor settings, including urban environments with limited GPS coverage, they remain unable to offer accurate indoor positioning. We will demonstrate a software infrastructure that makes it easy for anybody to build support for accurate Wi-Fi based positioning in buildings. All...... that is needed is a building with Wi-Fi coverage, access to the building, a floor plan of the building, and a Wi-Fi enabled device. Specifically, we will explain the software infrastructure and the steps that must be completed to obtain support for positioning. And we will demonstrate the positioning obtained...

  11. Self-compassion and rejection sensitivity

    OpenAIRE

    Hakan Saricam, Enes Ergun, Halis Sakiz

    2012-01-01

    Objectives: The purpose of this study is to examine the relationships between self-compassion and rejection sensitivity. Design: Self-compassion and are current concepts in social psychology and positive psychology. Preliminary evidence suggests that self-compassion is related to cognitive based social personality traits such as extraversion, social connectedness, self-determination, and feeling interpersonally connected to others. Also, rejection sensitivity is very important factor for inte...

  12. Perceived positions determine crowding.

    Science.gov (United States)

    Maus, Gerrit W; Fischer, Jason; Whitney, David

    2011-01-01

    Crowding is a fundamental bottleneck in object recognition. In crowding, an object in the periphery becomes unrecognizable when surrounded by clutter or distractor objects. Crowding depends on the positions of target and distractors, both their eccentricity and their relative spacing. In all previous studies, position has been expressed in terms of retinal position. However, in a number of situations retinal and perceived positions can be dissociated. Does retinal or perceived position determine the magnitude of crowding? Here observers performed an orientation judgment on a target Gabor patch surrounded by distractors that drifted toward or away from the target, causing an illusory motion-induced position shift. Distractors in identical physical positions led to worse performance when they drifted towards the target (appearing closer) versus away from the target (appearing further). This difference in crowding corresponded to the difference in perceived positions. Further, the perceptual mislocalization was necessary for the change in crowding, and both the mislocalization and crowding scaled with drift speed. The results show that crowding occurs after perceived positions have been assigned by the visual system. Crowding does not operate in a purely retinal coordinate system; perceived positions need to be taken into account.

  13. Perceived positions determine crowding.

    Directory of Open Access Journals (Sweden)

    Gerrit W Maus

    Full Text Available Crowding is a fundamental bottleneck in object recognition. In crowding, an object in the periphery becomes unrecognizable when surrounded by clutter or distractor objects. Crowding depends on the positions of target and distractors, both their eccentricity and their relative spacing. In all previous studies, position has been expressed in terms of retinal position. However, in a number of situations retinal and perceived positions can be dissociated. Does retinal or perceived position determine the magnitude of crowding? Here observers performed an orientation judgment on a target Gabor patch surrounded by distractors that drifted toward or away from the target, causing an illusory motion-induced position shift. Distractors in identical physical positions led to worse performance when they drifted towards the target (appearing closer versus away from the target (appearing further. This difference in crowding corresponded to the difference in perceived positions. Further, the perceptual mislocalization was necessary for the change in crowding, and both the mislocalization and crowding scaled with drift speed. The results show that crowding occurs after perceived positions have been assigned by the visual system. Crowding does not operate in a purely retinal coordinate system; perceived positions need to be taken into account.

  14. Sensitivity and uncertainty analysis

    CERN Document Server

    Cacuci, Dan G; Navon, Ionel Michael

    2005-01-01

    As computer-assisted modeling and analysis of physical processes have continued to grow and diversify, sensitivity and uncertainty analyses have become indispensable scientific tools. Sensitivity and Uncertainty Analysis. Volume I: Theory focused on the mathematical underpinnings of two important methods for such analyses: the Adjoint Sensitivity Analysis Procedure and the Global Adjoint Sensitivity Analysis Procedure. This volume concentrates on the practical aspects of performing these analyses for large-scale systems. The applications addressed include two-phase flow problems, a radiative c

  15. Allergic sensitization: screening methods

    DEFF Research Database (Denmark)

    Ladics, Gregory S.; Fry, Jeremy; Goodman, Richard

    2014-01-01

    Experimental in silico, in vitro, and rodent models for screening and predicting protein sensitizing potential are discussed, including whether there is evidence of new sensitizations and allergies since the introduction of genetically modified crops in 1996, the importance of linear versus...... of infection; (f) role of the gut microbiota; (g) influence of the structure and physicochemical properties of the protein; and (h) the genetic background and physiology of consumers. The consensus view is that sensitization screening models are not yet validated to definitively predict the de novo sensitizing...

  16. Positive criminology in practice.

    Science.gov (United States)

    Ronel, Natti; Segev, Dana

    2014-11-01

    The discourse regarding offender rehabilitation has been criticized by various scholars who have claimed that reducing negative causes and managing risk will not automatically prompt positive human development and elements that are associated with desistance. Positive criminology is an innovative concept that challenges the common preoccupation with negative elements, by placing emphasis on human encounters and forces of inclusion that are experienced positively by target individuals and that can promote crime desistance. However, as the concept is relatively new, there are still no guiding principles for the practice of positive criminology that could direct research and the criminal justice system. This article attempts to fill that gap by providing principles that could be practiced by criminal justice personnel and examples of different interventions that reflect positive criminology. The article also provides ideological explanations for adopting the concept of positive criminology in practice.

  17. Position detection with the use of MAGFETs

    DEFF Research Database (Denmark)

    Kaulberg, Thomas; Bogason, Gudmundur

    1995-01-01

    An angle detector with a digital output is described. The component is meant as an alternative to the traditional slide potentiometer used as volume control in many hearing aid applications. The component is based on the use of magnetic field sensitive MOSFETs (MAGFETs) detecting the position...

  18. Standardization of positive controls in diagnostic immunohistochemistry

    DEFF Research Database (Denmark)

    Torlakovic, Emina E; Nielsen, Søren; Francis, Glenn

    2015-01-01

    controls that are intended to facilitate methodology transfer and harmonization in dIHC. Furthermore, the committee has clarified definitions of IHC assay sensitivity and specificity, with special emphasis on how these definitions apply to positive controls. Recommendations for "best laboratory practice...

  19. Positioning magnetorheological actuator

    Energy Technology Data Exchange (ETDEWEB)

    Mikhailov, Valery; Bazinenkov, Alexey; Akimov, Igor [Bauman Moscow State Technical University, 2-nd Baumanskaia st. 5, MT-11, 105005, Moscow (Russian Federation); Borin, Dmitry [Technische Universitaet Dresden, Chair of Magnetofluiddynamics, 01062, Dresden (Germany)], E-mail: mikhailov@bmstu.ru

    2009-02-01

    In this work we consider a construction of a positioning magnetorheological actuator based on bellow units, as well as dynamical model, which include such elements as a magnetically hysteresis, pressure loses in hydraulic system, nonlinearity of rheological behaviour of working fluid. Two operating modes of positioning actuator are taken into account and transients are presented. Dynamical modelling shows possibility for the improvement of a real control system and ensure of submicron precision of positioning with millisecond time of response.

  20. Logotherapy and positive psychology

    OpenAIRE

    Oscar R. Oro

    2015-01-01

    Psychology omitted to approach, during almost a century, the positive aspects from persons, like creativity, humor, optimism, hope, forgiveness, life meaning, and happiness. These themes are approached by Positive Psychology, with Seligman like the principal exponent. Psychology was dedicated to explore the negative aspects from human beings improving human health. Nevertheless, this pathogenic model could not prevent mental disease. Concepts of Positive Psychology have a solid antecedent in ...

  1. Reflection Positive Doubles

    CERN Document Server

    Jaffe, Arthur

    2016-01-01

    Here we introduce reflection positive doubles, a general framework for reflection positivity, covering a wide variety of systems in statistical physics and quantum field theory. These systems may be bosonic, fermionic, or parafermionic in nature. Within the framework of reflection positive doubles, we give necessary and sufficient conditions for reflection positivity. We use a reflection-invariant cone to implement our construction. Our characterization allows for a direct interpretation in terms of coupling constants, making it easy to check in concrete situations. We illustrate our methods with numerous examples.

  2. Contact sensitivity and bioavailability of chlorocresol

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner; Carlsen, L; Egsgaard, Helge

    1985-01-01

    Chlorocresol sensitization from 5 topical preparations was determined in guinea pigs using the cumulative contact enhancement test. Chlorocresol 5% in olive oil/acetone (4/1), and 5% in aqueous suspension stabilized with carbomer 941 were more sensitizing (55% and 60% of the animals positive......% of the chlorocresol in aqueous suspension permeated the skin in contrast to 34% and 35% of the chlorocresol in olive oil/acetone (4/1) and propylene glycol, respectively. In spite of the same amount of chlorocresol absorption from the 2 latter preparations, they showed a significant difference in sensitizing capacity...

  3. Contact Sensitivity and Bioavailability of Chlorocresol

    DEFF Research Database (Denmark)

    Egsgaard, Helge; Larsen, Elfinn; Carlsen, Lars

    1985-01-01

    Chlorocresol sensitization from 5 topical preparations was determined in guinea pigs using the cumulative contact enhancement test. Chlorocresol 5% in olive oil/acetone (4/1), and 5% in aqueous suspension stabilized with carbomer 941 were more sensitizing (55% and 60% of the animals positive......% of the chlorocresol in aqueous suspension permeated the skin in contrast to 34% and 35% of the chlorocresol in olive oil/acetone (4/1) and propylene glycol, respectively. In spite of the same amount of chlorocresol absorption from the 2 latter preparations, they showed a significant difference in sensitizing capacity...

  4. High Sensitivity deflection detection of nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Sanii, Babak; Ashby, Paul

    2009-10-28

    A critical limitation of nanoelectromechanical systems (NEMS) is the lack of a high-sensitivity position detection mechanism. We introduce a noninterferometric optical approach to determine the position of nanowires with a high sensitivity and bandwidth. Its physical origins and limitations are determined by Mie scattering analysis. This enables a dramatic miniaturization of detectable cantilevers, with attendant reductions to the fundamental minimum force noise in highly damping environments. We measure the force noise of an 81{+-}9??nm radius Ag{sub 2}Ga nanowire cantilever in water at 6{+-}3??fN/{radical}Hz.

  5. Are Psychopaths Morally Sensitive?

    Science.gov (United States)

    Maxwell, Bruce; Le Sage, Leonie

    2009-01-01

    Philosophical and psychological opinion is divided over whether moral sensitivity, understood as the ability to pick out a situation's morally salient features, necessarily involves emotional engagement. This paper seeks to offer insight into this question. It reasons that if moral sensitivity does draw significantly on affective capacities of…

  6. Tuned cavity magnetometer sensitivity.

    Energy Technology Data Exchange (ETDEWEB)

    Okandan, Murat; Schwindt, Peter

    2009-09-01

    We have developed a high sensitivity (sensitivity levels.

  7. Assessing Sensitiveness to Transport

    DEFF Research Database (Denmark)

    Lieb, Christoph; Suter, Stefan; Sánchez, Alfredo

    Summary The EU-project ASSET (ASessing SEnsitiveness to Transport) aims at developing and implementing a concise concept to assess transport sensitive areas (TSA) in a European context, i.e. areas in which transport leads to more serious impacts than in other areas. The aim of work package 2 (WP2...

  8. Structure sensitivity in adsorption

    DEFF Research Database (Denmark)

    Hammer, Bjørk; Nielsen, Ole Holm; Nørskov, Jens Kehlet

    1997-01-01

    The structure sensitivity of CO adsorption on different flat, stepped, kinked and reconstructed Pt surfaces is studied using large-scale density-functional calculations. We find an extremely strong structure sensitivity in the adsorption energy with variations up to 1 eV (or 100%) from one...

  9. Mixed sensitivity design

    NARCIS (Netherlands)

    Kwakernaak, Huibert; Camacho, E.F.; Basanez, L.; Puente, de la J.A.

    2002-01-01

    Mixed sensitivity design of a linear multivariable control system amounts toshaping its sensitivity functions to achieve the design targets of closed-loop system performance and robustness. Both H∞ and H2 optimization may be used to this end. Various tools are available, in particular low and high f

  10. Pathogen distribution of 188 cases for positive infective endocarditis blood cultures and the drug sensitivity analysis%188例感染性心内膜炎血培养阳性的病原菌分布及药敏分析

    Institute of Scientific and Technical Information of China (English)

    曾卫强; 曲云婷

    2012-01-01

    目的 考查本地区近五年来感染性心内膜炎(infective endocarditis,IE)的致病菌分布特点及药敏情况,为临床选择抗菌药物提供参考.方法 通过医院电子病历系统筛选我院自2007年1月至2011年12月确诊为IE并经血培养阳性的病例,对其致病菌及药敏结果进行回顾性分析.结果 革兰氏阳性菌占IE致病菌的82.4%,其中链球菌40.4%、葡萄球菌24.4%、肠球菌10.6%;革兰氏阴性菌占10.1%,主要是肺炎克雷伯菌3.19%、大肠埃希菌2.12%和铜绿假单胞菌2.12%;真菌占7.4%,主要是念珠菌感染3.19%;药敏结果:链球菌对青霉素敏感率为96.1%,对红霉素和四环素耐药率分别38.2%和45.7%;金黄色葡萄球菌对青霉素耐药率为93.1%,耐甲氧西林金黄色葡萄球菌(methicillin resistant staphylococcusanrens,MRSA)20.7%;均无发现对万古霉素、替考拉宁和利奈唑胺耐药菌株;大肠埃希菌和铜绿假单胞菌对三代头孢耐药率分别为50%和100%.结论 链球菌依然是感染IE最常见的致病菌,其次是葡萄球菌和肠球菌;青霉素仍然是链球菌感染IE的首选药物,而金黄色葡萄球菌感染则应避免使用青霉素,但对氧氟沙星、利福平、氨基苷类仍保持有较高的敏感率.链球菌对红霉素和四环素、大肠埃希菌和铜绿假单胞菌对三代头孢的耐药情况应引起重视.%Objective To get clinical references for selection of antibiotics by examining the character of pathogen distribution and drug resistances of infective endocarditis (IE) in this region nearly five years. Methods The pathogens and drug susceptibility of IE and blood culture positive cases in the electronic medical records of our hospital were analyzed retrospectively from January 2007 to December 2011. Results 82. 4% of IE pathogens were Gram-positive bacteria,of which were Streptococcus (40. 4% ) .Staphylococ-cus aureus (24. 4% ) and Enterococci (10. 6% ); 10. 1

  11. An Inexpensive Position Transducer.

    Science.gov (United States)

    Fox, J.; And Others

    1989-01-01

    Described is a position transducer used to convert the position of an object into a voltage read by a computer with use of an interface board. The arrangement of the apparatus, electronic circuit, and typical graph displays are presented. Discussed is the instructional use of the transducer. (YP)

  12. Den positive psykologis metoder

    DEFF Research Database (Denmark)

    Andersen, Frans Ørsted; Mørck, Line Lerche; Nissen, Poul Erik

    En antologi der giver en introduktion til en række af de metoder der anvendes til forskning, assessment, test, udviklingsarbejde og intervention indenfor den positive psykologi.......En antologi der giver en introduktion til en række af de metoder der anvendes til forskning, assessment, test, udviklingsarbejde og intervention indenfor den positive psykologi....

  13. Insulin sensitivity and albuminuria

    DEFF Research Database (Denmark)

    Pilz, Stefan; Rutters, Femke; Nijpels, Giel

    2014-01-01

    OBJECTIVE: Accumulating evidence suggests an association between insulin sensitivity and albuminuria, which, even in the normal range, is a risk factor for cardiovascular diseases. We evaluated whether insulin sensitivity is associated with albuminuria in healthy subjects. RESEARCH DESIGN...... AND METHODS: We investigated 1,415 healthy, nondiabetic participants (mean age 43.9 ± 8.3 years; 54.3% women) from the RISC (Relationship between Insulin Sensitivity and Cardiovascular Disease) study, of whom 852 participated in a follow-up examination after 3 years. At baseline, insulin sensitivity...... was assessed by hyperinsulinemic-euglycemic clamps, expressed as the M/I value. Oral glucose tolerance test-based insulin sensitivity (OGIS), homeostasis model assessment of insulin resistance (HOMA-IR), and urinary albumin-to-creatinine ratio (UACR) were determined at baseline and follow-up. RESULTS...

  14. POSITIONING STRATEGIES DEVELOPMENT

    Directory of Open Access Journals (Sweden)

    Shakhshir Ghassan

    2014-07-01

    Full Text Available The positioning strategy has suffered serious changes in the last few decades, being influenced by the rapid development of competition and the growing focus on specific traits belonging to the market, to the consumer or to the product. The purpose of this paper is to present the developments of theoretical positioning strategies and the orientation from more simple, product oriented strategies, to ones more oriented towards the client and with a briefer period of time. The world is moving in a much faster pace than in the past, thanks to communication development so companies are obliged to adopt more specific strategies in order for them to be effective. This essay represents a literary review presenting a documentary research within the scientific articles and strategy and positioning books. The paper begins with the analysis of company strategies and the marketing strategies in general. The first author to group the product positioning strategies is Porter with his three generic strategies. Following the development of brands and because of the lack of competitiveness in the simple generic positioning strategies, this paper has also presented the newer positioning strategies proposed by Kotler, Treacy & Wiersema, and also more complex ones such as Bowman's Strategy Clock and Blankson and Kalafatis positioning strategy based on the type of the consumer. The fast expansion of local brands in all categories has led to mistakes in positioning strategies, categories also presented in the current essay. The results of this study show that new positioning strategies are more and more based on the consumer and market segments and on the product specification - which have also evolved in the last decades. Adaptability to fast changes in the competitive market will represent the future positioning strategies.

  15. Positional Concerns and Institutions

    DEFF Research Database (Denmark)

    Landes, Xavier

    2013-01-01

    their implications for economics, positional concerns imply important normative dimensions. There have been presumed to be a symptom of envy, reduce people’s happiness, and create problems of social interaction or economic inefficiencies. Individuals are, for instance, prone to pick states of the world that improve...... that invoking envy or subjective well-being is not fully satisfying for regulating positional concerns. More compelling reasons seem, in complement with efficiency, to be related to considerations for equality. In other words, if institutions could have strong reasons to pay attention to and regulate positional...

  16. Clinical Positioning Space

    DEFF Research Database (Denmark)

    Williams, Lars Peter Hedegaard; Christensen, Mette Krogh; Rytter, Carsten

    2014-01-01

    In this article, we present a case study of residents’ clinical experiences and communication in outpatient oncology consultations. We apply positioning theory, a dynamic alternative to role theory, to investigate how oncology residents and patients situate themselves as persons with rights...... establish acts and positions and narratively frame what participants can expect from a medical consultation viewed as a social episode; and (c) the positioning of rights and duties can lead to misunderstandings and frustrations. We conclude that residents and patients locate themselves in outpatient...

  17. Position Resolution in DROIDs

    Science.gov (United States)

    Samedov, Victor V.

    2008-04-01

    Since the very beginning, Distributed Read-Out Imaging Devices (DROIDs) were proposed to achieve both good position and energy resolutions. In DROIDs, the absorption of primary particle energy occurs in a long superconductive strip. Quasiparticles produced in the absorber diffuse along the strip and counted by the superconductive tunnel junctions positioned at the two ends of the strip. In this paper the formula for estimation DROID’s position resolution from experimental data was derived. This formula takes into account correlation between fluctuations of signals of DROID’s detectors.

  18. Positional Concerns and Institutions

    DEFF Research Database (Denmark)

    Landes, Xavier

    2013-01-01

    that invoking envy or subjective well-being is not fully satisfying for regulating positional concerns. More compelling reasons seem, in complement with efficiency, to be related to considerations for equality. In other words, if institutions could have strong reasons to pay attention to and regulate positional...... their implications for economics, positional concerns imply important normative dimensions. There have been presumed to be a symptom of envy, reduce people’s happiness, and create problems of social interaction or economic inefficiencies. Individuals are, for instance, prone to pick states of the world that improve...

  19. Stress Management: Positive Thinking

    Science.gov (United States)

    Healthy Lifestyle Stress management Positive thinking helps with stress management and can even improve your health. Practice overcoming negative self-talk ... with optimism is a key part of effective stress management. And effective stress management is associated with ...

  20. What controls nucleosome positions?

    Science.gov (United States)

    Segal, Eran; Widom, Jonathan

    2009-08-01

    The DNA of eukaryotic genomes is wrapped in nucleosomes, which strongly distort and occlude the DNA from access to most DNA-binding proteins. An understanding of the mechanisms that control nucleosome positioning along the DNA is thus essential to understanding the binding and action of proteins that carry out essential genetic functions. New genome-wide data on in vivo and in vitro nucleosome positioning greatly advance our understanding of several factors that can influence nucleosome positioning, including DNA sequence preferences, DNA methylation, histone variants and post-translational modifications, higher order chromatin structure, and the actions of transcription factors, chromatin remodelers and other DNA-binding proteins. We discuss how these factors function and ways in which they might be integrated into a unified framework that accounts for both the preservation of nucleosome positioning and the dynamic nucleosome repositioning that occur across biological conditions, cell types, developmental processes and disease.

  1. Optimal Centroid Position Estimation

    Energy Technology Data Exchange (ETDEWEB)

    Candy, J V; McClay, W A; Awwal, A S; Ferguson, S W

    2004-07-23

    The alignment of high energy laser beams for potential fusion experiments demand high precision and accuracy by the underlying positioning algorithms. This paper discusses the feasibility of employing online optimal position estimators in the form of model-based processors to achieve the desired results. Here we discuss the modeling, development, implementation and processing of model-based processors applied to both simulated and actual beam line data.

  2. Positive emotions in education

    OpenAIRE

    Pekrun, Reinhard; Götz, Thomas; Titz, Wolfram; Perry, Raymond P.

    2002-01-01

    In this chapter, we focus on the student side of educational settings. More specifically, we give an overview of our research addressing students' academic emotions, that is, their emotions relating to learning, instruction, and achievement in academic settings associate with attending class, studying, and taking tests and exams. In so doing, we address the following problems in turn: (1) How frequently are positive emotions experienced by students at school and university, and which positive...

  3. Spontaneous baroreflex sensitivity

    DEFF Research Database (Denmark)

    Barthel, Petra; Bauer, Axel; Müller, Alexander;

    2012-01-01

    Low baroreflex sensitivity (BRS) indicates poor prognosis after acute myocardial infarction. Noninvasive BRS assessment is complicated by nonstationarities and noise in electrocardiogram and pressure signals. Phase-rectified signal averaging is a novel signal processing technology overcoming...

  4. Developing cultural sensitivity

    DEFF Research Database (Denmark)

    Ruddock, Heidi; Turner, deSalle

    2007-01-01

    . Background. Many countries are becoming culturally diverse, but healthcare systems and nursing education often remain mono-cultural and focused on the norms and needs of the majority culture. To meet the needs of all members of multicultural societies, nurses need to develop cultural sensitivity......Title. Developing cultural sensitivity: nursing students’ experiences of a study abroad programme Aim. This paper is a report of a study to explore whether having an international learning experience as part of a nursing education programme promoted cultural sensitivity in nursing students...... and incorporate this into caregiving. Method. A Gadamerian hermeneutic phenomenological approach was adopted. Data were collected in 2004 by using in-depth conversational interviews and analysed using the Turner method. Findings. Developing cultural sensitivity involves a complex interplay between becoming...

  5. Parametric sensitivity and runaway in tubular reactors

    Energy Technology Data Exchange (ETDEWEB)

    Morbidelli, M.; Varma, A.

    1982-09-01

    Parametric sensitivity of tubular reactors is analyzed to provide critical values of the heat of reaction and heat transfer parameters defining runaway and stable operations for all positive-order exothermic reactions with finite activation energies, and for all reactor inlet temperatures. Evaluation of the critical values does not involve any trial and error.

  6. The Neopuff's PEEP valve is flow sensitive.

    LENUS (Irish Health Repository)

    Hawkes, Colin Patrick

    2011-03-01

    The current recommendation in setting up the Neopuff is to use a gas flow of 5-15 L\\/min. We investigated if the sensitivity of the positive end expiratory pressure (PEEP) valve varies at different flow rates within this range.

  7. Charge-sensitive amplifier

    Directory of Open Access Journals (Sweden)

    Startsev V. I.

    2008-02-01

    Full Text Available The authors consider design and circuit design techniques of reduction of the influence of the pyroelectric effect on operation of the charge sensitive amplifiers. The presented experimental results confirm the validity of the measures taken to reduce the impact of pyroelectric currents. Pyroelectric currents are caused by the influence of the temperature gradient on the piezoelectric sensor and on the output voltage of charge sensitive amplifiers.

  8. Local positioning system

    Energy Technology Data Exchange (ETDEWEB)

    Kyker, R.

    1995-07-25

    Navigation systems have been vital to transportation ever since man took to the air and sea. Early navigation systems utilized the sextant to navigate by starlight as well as the magnetic needle compass. As electronics and communication technologies improved, inertial navigation systems were developed for use in ships and missile delivery. These systems consisted of electronic compasses, gyro-compasses, accelerometers, and various other sensors. Recently, systems such as LORAN and the Global Positioning System (GPS) have utilized the properties of radio wave propagation to triangulate position. The Local Positioning System (LPS), described in this paper, is an implementation of a limited inertial navigation system designed to be used on a bicycle. LPS displays a cyclist`s current position relative to a starting location. This information is displayed in Cartesian-like coordinates. To accomplish this, LPS relies upon two sensors, an electronic compass sensor and a distance sensor. The compass sensor provides directional information while the distance sensor provides the distance traveled. This information yields a distance vector for each point in time which when summed produces the cyclist`s current position. LPS is microprocessor controlled and is designed for a range of less than 90 miles.

  9. Nucleosome Positioning and Epigenetics

    Science.gov (United States)

    Schwab, David; Bruinsma, Robijn

    2008-03-01

    The role of chromatin structure in gene regulation has recently taken center stage in the field of epigenetics, phenomena that change the phenotype without changing the DNA sequence. Recent work has also shown that nucleosomes, a complex of DNA wrapped around a histone octamer, experience a sequence dependent energy landscape due to the variation in DNA bend stiffness with sequence composition. In this talk, we consider the role nucleosome positioning might play in the formation of heterochromatin, a compact form of DNA generically responsible for gene silencing. In particular, we discuss how different patterns of nucleosome positions, periodic or random, could either facilitate or suppress heterochromatin stability and formation.

  10. Positioning for Competition.

    Science.gov (United States)

    Lapovsky, Lucie; Hubbell, Loren Loomis

    2000-01-01

    Analyzes results of the 1999 National Association of College and Business Officers tuition discounting survey and identifies trends. Finds colleges and universities are reactively responding to market pressures and proactively trying to analyze and position themselves ahead of the competition, often regional rather than national, for the…

  11. Logotherapy and positive psychology

    Directory of Open Access Journals (Sweden)

    Oscar R. Oro

    2015-09-01

    Full Text Available Psychology omitted to approach, during almost a century, the positive aspects from persons, like creativity, humor, optimism, hope, forgiveness, life meaning, and happiness. These themes are approached by Positive Psychology, with Seligman like the principal exponent. Psychology was dedicated to explore the negative aspects from human beings improving human health. Nevertheless, this pathogenic model could not prevent mental disease. Concepts of Positive Psychology have a solid antecedent in Víktor Frankl ́s studies, which is the Logotherapy founder. This allows incorporating another perspective to approach positive aspects, from a philosophical and anthropological focus. Although the ways adopted by Frank and Seligman are different, both considered main aspects of human existence. Nevertheless, they investigated in different countries (from Europe and EE.UU.; in different circumstances (concentration camps, deaths, tortures; vs. academic context; in different historical periods and different social contexts (a country that lost the war and other that gave freedom to Europeans. In this work is used the concept life sense as the focus in professional formation and psychotherapy approach. 

  12. Positioning Theory in Paradigms

    Institute of Scientific and Technical Information of China (English)

    FU Xiao-qiu

    2015-01-01

    This article discusses the importance of theory and paradigm to a researcher. It starts from introducing and analyzing the definition of the two terms, by using the theories in the field of intercultural communication as examples. To a good researcher, he needs not only clarifying the paradigm his research is positioned, but also integrating the theories in his paradigm.

  13. A Position Paper.

    Science.gov (United States)

    Hixson, Richard A.

    This position paper covers possible problems of collective bargaining. (1) The two sides should not bring prejudgments of good or bad to the negotiating table. (2) Neither side should exaggerate its strength or minimize its weakness. (3) Neither side should confuse intransigence with firmness. (4) The composition of each team must be carefully…

  14. POSITIVE TO THE END

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    After serving at the United Nations (UN) for some 45 years, Secretary General Kofi Annan will leave his position at the end of the year. In a recent written interview with Beijing Review, the world's top diplomat discusses some past and present achievements of the UN, and hopes for the future.

  15. Positive reinforcement for viruses.

    Science.gov (United States)

    Vigant, Frederic; Jung, Michael; Lee, Benhur

    2010-10-29

    Virus-cell membrane fusion requires a critical transition from positive to negative membrane curvature. St. Vincent et al. (2010), in PNAS, designed a class of antivirals that targets this transition. These rigid amphipathic fusion inhibitors are active against an array of enveloped viruses.

  16. Sensitizing properties of proteins

    DEFF Research Database (Denmark)

    Poulsen, Lars K.; Ladics, Gregory S; McClain, Scott

    2014-01-01

    The scope of allergy risk is diverse considering the myriad ways in which protein allergenicity is affected by physiochemical characteristics of proteins. The complexity created by the matrices of foods and the variability of the human immune system add additional challenges to understanding...... the relationship between sensitization potential and allergy disease. To address these and other issues, an April 2012 international symposium was held in Prague, Czech Republic, to review and discuss the state-of-the-science of sensitizing properties of protein allergens. The symposium, organized by the Protein...... Allergenicity Technical Committee of the International Life Sciences Institute's Health and Environmental Sciences Institute, featured presentations on current methods, test systems, research trends, and unanswered questions in the field of protein sensitization. A diverse group of over 70 interdisciplinary...

  17. Sensitivity of Complex Networks

    CERN Document Server

    Angulo, Marco Tulio; Liu, Yang-Yu; Barabási, Albert-László

    2016-01-01

    The sensitivity (i.e. dynamic response) of complex networked systems has not been well understood, making difficult to predict whether new macroscopic dynamic behavior will emerge even if we know exactly how individual nodes behave and how they are coupled. Here we build a framework to quantify the sensitivity of complex networked system of coupled dynamic units. We characterize necessary and sufficient conditions for the emergence of new macroscopic dynamic behavior in the thermodynamic limit. We prove that these conditions are satisfied only for architectures with power-law degree distributions. Surprisingly, we find that highly connected nodes (i.e. hubs) only dominate the sensitivity of the network up to certain critical frequency.

  18. Highly Sensitive Optical Receivers

    CERN Document Server

    Schneider, Kerstin

    2006-01-01

    Highly Sensitive Optical Receivers primarily treats the circuit design of optical receivers with external photodiodes. Continuous-mode and burst-mode receivers are compared. The monograph first summarizes the basics of III/V photodetectors, transistor and noise models, bit-error rate, sensitivity and analog circuit design, thus enabling readers to understand the circuits described in the main part of the book. In order to cover the topic comprehensively, detailed descriptions of receivers for optical data communication in general and, in particular, optical burst-mode receivers in deep-sub-µm CMOS are presented. Numerous detailed and elaborate illustrations facilitate better understanding.

  19. Sensitivity analysis of SPURR

    Energy Technology Data Exchange (ETDEWEB)

    Witholder, R.E.

    1980-04-01

    The Solar Energy Research Institute has conducted a limited sensitivity analysis on a System for Projecting the Utilization of Renewable Resources (SPURR). The study utilized the Domestic Policy Review scenario for SPURR agricultural and industrial process heat and utility market sectors. This sensitivity analysis determines whether variations in solar system capital cost, operation and maintenance cost, and fuel cost (biomass only) correlate with intuitive expectations. The results of this effort contribute to a much larger issue: validation of SPURR. Such a study has practical applications for engineering improvements in solar technologies and is useful as a planning tool in the R and D allocation process.

  20. Position Ring System using Anger Type Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Joel S. Karp, principal investigator

    2004-12-14

    The overall objective of our project was to develop PET scanners and imaging techniques that achieve high performance and excellent image quality. Our approach was based upon 3-D imaging (no septa) with position-sensitive Anger-logic detectors, whereby the encoding ratio of resolution elements to number of photo-multiplier tube channels is very high. This design led to a series of PET systems that emphasized cost-effectiveness and practicality in a clinical environment.

  1. Disrupting sensitization of TRPV4.

    Science.gov (United States)

    Mack, Konrad; Fischer, Michael J M

    2017-03-31

    TRPV4 ion channels have a broad expression profile and were shown to contribute to enhanced pain sensation in inflammation. Directly blocking TRPV4 might run the risk of interfering with normal physiology, and has prompted to explore the interaction with the scaffolding protein AKAP79, an approach successfully used for TRPV1 channels. HEK293t cells express AKAP79, additional transfection did not sensitize human TRPV4. Application of trypsin facilitated responses to TRPV4 agonist GSK1016790A. Using a specific protease-activated receptor 2 agonist, involvement of an A-kinase anchoring protein in TRPV4 activation was demonstrated by inhibition with AKAP inhibitor peptide Ht31. TRPV4 has substantial sequence similarity to TRPV1 in the range interacting with AKAP79. A synthetic peptide resembling these amino acids and extended by a positive region for transmembrane uptake was tested. Sensitization of TRPV4 responses could be reduced after exposure to this 771-781::TAT peptide but not by a scrambled control peptide. This validates the concept of targeting the interaction between TRPV4 and AKAP79 and controlling increased TRPV4 activity.

  2. Gluten sensitivity and neurological manifestations

    Directory of Open Access Journals (Sweden)

    Agostino Berio

    2015-12-01

    Full Text Available The authors report on six cases of gluten-sensitivity, also defined non-celiac gluten sensitivity, characterized by abdominal features (diarrhea, bloating, pain, genetic positivity for predisposition to celiac disease (DQB1* 02 in all cases; DQA1*05 in three; DQA1*02 in two, DQB1*03 in two, negative anti-t-Transglutaminase antibodies, normal mucosa on biopsy in four cases, type 1 of Marsh in one case. The subjects presented frequent central nervous system (CNS symptoms: headache in three patients, somnolence in one, electroencephalogram aspecific alterations in three (in two of them with previous seizures, leptomeningeal cyst in one, intracranial calcification in one, cerebral gliosis in two. After a gluten-free diet, all intestinal and clinical CNS features remitted, but re-appeared after gluten reintroduction. On the basis of the neurological signs, the authors stress the relevance of immune innate system in the pathogenesis of these cases with possible subsequent evolution on immune adaptive system involvement.

  3. Pressure pain sensitivity

    DEFF Research Database (Denmark)

    Bergmann, Natasha; Ballegaard, Søren; Holmager, Pernille

    2013-01-01

    to induce hyperalgesia.The aim of the present study was to evaluate hyperalgesia by pressure pain sensitivity (PPS) in patients with IHD, and compare PPS to questionnaires measuring depressive symptoms, reduced psychological wellbeing, and QOL as markers of stress. Design. A cross-sectional study of 361...

  4. Sensitive hydrogen leak detector

    Science.gov (United States)

    Myneni, Ganapati Rao

    1999-01-01

    A sensitive hydrogen leak detector system using passivation of a stainless steel vacuum chamber for low hydrogen outgassing, a high compression ratio vacuum system, a getter operating at 77.5 K and a residual gas analyzer as a quantitative hydrogen sensor.

  5. UNITEC SENS-IT

    Science.gov (United States)

    The UniTec Sens-It is a small gas-sensing device that can measure volatile organic compounds (VOCs). This sensor is used to measure VOCs in applications such as urban air quality, roadside pollution, and (solid waste) landfill monitoring. This operating procedure explains what yo...

  6. Fundamental Physics Microgravity Sensitivity

    Science.gov (United States)

    Israelsson, Ulf

    1998-01-01

    An introduction followed by a brief discussion about the sensitivity to microgravity environment disturbances for some recent and planned experiments in microgravity fundamental physics will be presented. In particular, correlation between gravity disturbances and the quality of science data sets measured by the Confined Helium Experiment (CHEX) during ground testing and during the November 1997 USMP-4 flight will be described.

  7. Sexuality Sensitive Schooling

    Science.gov (United States)

    McCaughtry, Nate; Dillon, Suzanna; Jones, Elizabeth; Smigell, Sara

    2005-01-01

    American schools, especially their physical education and sport programs, provide some of the most hostile social geographies in all of society for gay youth. With the aim of transforming schools toward more democratic and sexuality sensitive institutions, this paper reviews the literature on sexuality and education. In the review, three themes,…

  8. High-Sensitivity Spectrophotometry.

    Science.gov (United States)

    Harris, T. D.

    1982-01-01

    Selected high-sensitivity spectrophotometric methods are examined, and comparisons are made of their relative strengths and weaknesses and the circumstances for which each can best be applied. Methods include long path cells, noise reduction, laser intracavity absorption, thermocouple calorimetry, photoacoustic methods, and thermo-optical methods.…

  9. Multiple Chemical Sensitivity

    DEFF Research Database (Denmark)

    Junge, Anne Gram

    Et voksende antal mennesker i Danmark oplever at være overfølsomme over for dufte og kemikalier. Imidlertid er den tilskrevne diagnose Multiple Chemical Sensitivity (MCS) ikke medicinsk anerkendt i Danmark pga. mangel på organiske og patofysiologisk basis for symptomerne. Dette speciale bygger på...

  10. Enlargements of positive sets

    CERN Document Server

    Bot, Radu Ioan

    2008-01-01

    In this paper we introduce the notion of enlargement of a positive set in SSD spaces. To a maximally positive set $A$ we associate a family of enlargements $\\E(A)$ and characterize the smallest and biggest element in this family with respect to the inclusion relation. We also emphasize the existence of a bijection between the subfamily of closed enlargements of $\\E(A)$ and the family of so-called representative functions of $A$. We show that the extremal elements of the latter family are two functions recently introduced and studied by Stephen Simons. In this way we extend to SSD spaces some former results given for monotone and maximally monotone sets in Banach spaces.

  11. Benign paroxysmal positional vertigo

    Directory of Open Access Journals (Sweden)

    Guo Xiang-Dong

    2011-01-01

    Full Text Available Benign paroxysmal positional vertigo (BPPV is a common clinical disorder characterized by brief recurrent spells of vertigo often brought about by certain head position changes as may occur with looking up, turning over in bed, or straightening up after bending over. It is important to understand BPPV not only because it may avert expensive and often unnecessary testing, but also because treatment is rapid, easy, and effective in >90% of cases. The diagnosis of BPPV can be made based on the history and examination. Patients usually report episodes of spinning evoked by certain movements, such as lying back or getting out of bed, turning in bed, looking up, or straightening after bending over. At present, the generally accepted recurrence rate of BPPV after successful treatment is 40%-50% at 5 years of average follow-up. There does appear to be a subset of individuals prone to multiple recurrences.

  12. Mapping your competitive position.

    Science.gov (United States)

    D'Aveni, Richard A

    2007-11-01

    A price-benefit positioning map helps you see, through your customers' eyes, how your product compares with all its competitors in a market. You can draw such a map quickly and objectively, without having to resort to costly, time-consuming consumer surveys or subjective estimates of the excellence of your product and the shortcomings of all the others. Creating a positioning map involves three steps: First, define your market to include everything your customers might consider to be your product's competitors or substitutes. Second, track the price your customers actually pay (wholesale or retail? bundled or unbundled?) and identify what your customers see as your offering's primary benefit. This is done through regression analysis, determining which of the product's attributes (as described objectively by rating services, government agencies, R&D departments, and the like) explains most of the variance in its price. Third, draw the map by plotting on a graph the position of every product in the market you've selected according to its price and its level of primary benefit, and draw a line that runs through the middle of the points. What you get is a picture of the competitive landscape of your market, where all the products above the line command a price premium owing to some secondary benefit customers value, and all those below the line are positioned to earn market share through lower prices and reduced secondary benefits. Using examples as varied as Harley-Davidson motorcycles, Motorola cell phones, and the New York restaurant market, Tuck professor D'Aveni demonstrates some of the many ways the maps can be used: to locate unoccupied or less-crowded spaces in highly competitive markets, for instance, or to identify opportunities created through changes in the relationship between the primary benefit and prices. The maps even allow companies to anticipate--and counter-- rivals' strategies. R eprint RO711G

  13. Review of HRP Positions

    Energy Technology Data Exchange (ETDEWEB)

    Center for Reliability Studies

    2007-01-01

    The Department of Energy (DOE) Human Reliability Program (HRP), published as 10 CFR Part 712, is currently being reviewed and revised to address concerns identified during its implementation. Although these ''page changes'' primarily incorporate clarification of terms and language, the following discussion relates to broadening the definition of positions that require HRP certification that is found in {section}712.10.

  14. Thought Positions in Sculpture

    OpenAIRE

    2015-01-01

    Thought Positions in Sculpture presents ten contemporary artists who have encountered the archive through the stories of their own art practice. The physical exhibition at Huddersfield Art Gallery refers to existing works of art from Leeds Museums and Galleries Sculpture Collection, archival material from the Henry Moore Institute, digitised archival material from the Tate Gallery, audio material from the British Library and other archival sites, some of which are inventions by the artist the...

  15. Matching Through Position Auctions

    OpenAIRE

    Terence Johnson

    2009-01-01

    This paper studies how an intermediary should design two-sided matching markets when agents are privately informed about their quality as a partner and can make payments to the intermediary. Using a mechanism design approach, I derive sufficient conditions for assortative matching to be profit- or welfare-maximizing, and then show how to implement the optimal match and payments through two-sided position auctions. This sharpens our understanding of intermediated matching markets by clarifying...

  16. Positional information, in bits.

    Science.gov (United States)

    Dubuis, Julien O; Tkacik, Gasper; Wieschaus, Eric F; Gregor, Thomas; Bialek, William

    2013-10-08

    Cells in a developing embryo have no direct way of "measuring" their physical position. Through a variety of processes, however, the expression levels of multiple genes come to be correlated with position, and these expression levels thus form a code for "positional information." We show how to measure this information, in bits, using the gap genes in the Drosophila embryo as an example. Individual genes carry nearly two bits of information, twice as much as would be expected if the expression patterns consisted only of on/off domains separated by sharp boundaries. Taken together, four gap genes carry enough information to define a cell's location with an error bar of ~1 along the anterior/posterior axis of the embryo. This precision is nearly enough for each cell to have a unique identity, which is the maximum information the system can use, and is nearly constant along the length of the embryo. We argue that this constancy is a signature of optimality in the transmission of information from primary morphogen inputs to the output of the gap gene network.

  17. Quantum Positioning System

    CERN Document Server

    Bahder, T B

    2004-01-01

    A quantum positioning system (QPS) is proposed that can provide a user with all four of his space-time coordinates. The user must carry a corner cube reflector, a good clock, and have a two-way classical channel of communication with the origin of the reference frame. Four pairs of entangled photons (biphotons) are sent through four interferometers: three interferometers are used to determine the user's spatial position, and an additional interferometer is used to synchronize the user's clock to coordinate time in the reference frame. The spatial positioning part of the QPS is similar to a classical time-of-arrival (TOA) system, however, a classical TOA system (such as GPS) must have synchronized clocks that keep coordinate time and therefore the clocks must have long-term stability, whereas in the QPS only a photon coincidence counter is needed and the clocks need only have short-term stability. Several scenarios are considered for a QPS: one is a terrestrial system and another is a space-based-system compos...

  18. The incentive sensitization theory of addiction: some current issues

    OpenAIRE

    Robinson, Terry E.; Berridge, Kent C

    2008-01-01

    We present a brief overview of the incentive sensitization theory of addiction. This posits that addiction is caused primarily by drug-induced sensitization in the brain mesocorticolimbic systems that attribute incentive salience to reward-associated stimuli. If rendered hypersensitive, these systems cause pathological incentive motivation (‘wanting’) for drugs. We address some current questions including: what is the role of learning in incentive sensitization and addiction? Does incentive s...

  19. LGBTQ relationally based positive psychology: An inclusive and systemic framework.

    Science.gov (United States)

    Domínguez, Daniela G; Bobele, Monte; Coppock, Jacqueline; Peña, Ezequiel

    2015-05-01

    Positive psychologists have contributed to our understandings of how positive emotions and flexible cognition enhance resiliency. However, positive psychologists' research has been slow to address the relational resources and interactions that help nonheterosexual families overcome adversity. Addressing overlooked lesbian, gay, bisexual, transgender, or queer (LGBTQ) and systemic factors in positive psychology, this article draws on family resilience literature and LGBTQ literature to theorize a systemic positive psychology framework for working with nonheterosexual families. We developed the LGBTQ relationally based positive psychology framework that integrates positive psychology's strengths-based perspective with the systemic orientation of Walsh's (1996) family resilience framework along with the cultural considerations proposed by LGBTQ family literature. We theorize that the LGBTQ relationally based positive psychology framework takes into consideration the sociopolitical adversities impacting nonheterosexual families and sensitizes positive psychologists, including those working in organized care settings, to the systemic interactions of same-sex loving relationships. (c) 2015 APA, all rights reserved).

  20. Position from gravity

    Science.gov (United States)

    Mather, R. S.

    1973-01-01

    Procedures for obtaining position from surface gravity observations are reviewed and their relevance assessed in the context of the application of modern geodetic techniques to programs of Earth and ocean physics. Solutions based on the use of surface layer techniques, the discrete value approach, and the development from Green's theorem are stated in summary, the latter being extended to order e cubed in the height anomaly. The representation of the surface gravity field which is required in order that this accuracy may be achieved is discussed. Interim techniques which could be used in the absence of such a representation are also outlined.

  1. Density Sensitive Hashing

    CERN Document Server

    Lin, Yue; Li, Cheng

    2012-01-01

    Nearest neighbors search is a fundamental problem in various research fields like machine learning, data mining and pattern recognition. Recently, hashing-based approaches, e.g., Locality Sensitive Hashing (LSH), are proved to be effective for scalable high dimensional nearest neighbors search. Many hashing algorithms found their theoretic root in random projection. Since these algorithms generate the hash tables (projections) randomly, a large number of hash tables (i.e., long codewords) are required in order to achieve both high precision and recall. To address this limitation, we propose a novel hashing algorithm called {\\em Density Sensitive Hashing} (DSH) in this paper. DSH can be regarded as an extension of LSH. By exploring the geometric structure of the data, DSH avoids the purely random projections selection and uses those projective functions which best agree with the distribution of the data. Extensive experimental results on real-world data sets have shown that the proposed method achieves better ...

  2. Culturally sensitive assessment.

    Science.gov (United States)

    Edwards, C P; Kumru, A

    1999-04-01

    Issues of cultural interaction and culturally sensitive assessment and treatment of young children have become prominent in recent years for mental health professionals, for reasons having to do with changing demographics, public values, and professional vision. "Culture" refers to the sociocultural adaptation of design for living shared by people as members of a community. Mental health professionals who work with culturally diverse populations need to become culturally self-aware and find abstract and experiential ways to build a useful body of professional knowledge concerning childrearing and discipline practices, health and illness beliefs, communication styles, and expectations about family or professional relations or other group interactions. They also need to learn how to work effectively in intercultural teams, use families as partners and resources, train and work with interpreters, and select and use formal and nonformal assessment procedures in appropriate, culturally sensitive ways.

  3. COLOR- SENSITIZED SOLAR ELEMENTS

    Directory of Open Access Journals (Sweden)

    Gish R. A.

    2016-05-01

    Full Text Available Photovoltaic devices are a promising solution to the energy crisis, because they generate electricity directly from sunlight, without producing CO2. While color-sensitized batteries are the most studied element, mainly due to its low cost and high efficiency solar energy conversion into electricity. Until recently, the color-sensitized solar cells performance was less than 1%, however, the use of titanium dioxide as the anode material have greatly raised their efficiency. The advantages of titanium dioxide is primarily in the low cost, but its use provides high light capture efficiency, with external quantum efficiency (efficiency incident photon - charge, usually in the range of 60-90% using nanocrystal forms in comparison with

  4. Solving tooth sensitivity.

    Science.gov (United States)

    Miller, Michael B

    2010-01-01

    Solving tooth sensitivity requires both you and the patients to be resilient and to understand that if one approach doesn't work, you can try another one that is non-invasive or, at worst, minimally invasive. Much like the clinician who posted the original question, I strongly believe that it is our responsibility to convince patients that jumping to a radical solution could be totally unnecessary--and expensive-- and still might not solve the problem.

  5. Integrated Sensitivity Analysis Workflow

    Energy Technology Data Exchange (ETDEWEB)

    Friedman-Hill, Ernest J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hoffman, Edward L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Gibson, Marcus J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Clay, Robert L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-08-01

    Sensitivity analysis is a crucial element of rigorous engineering analysis, but performing such an analysis on a complex model is difficult and time consuming. The mission of the DART Workbench team at Sandia National Laboratories is to lower the barriers to adoption of advanced analysis tools through software integration. The integrated environment guides the engineer in the use of these integrated tools and greatly reduces the cycle time for engineering analysis.

  6. Analysis of modern positioning systems, used for dynamic positioning purposes

    OpenAIRE

    2016-01-01

    This article contains the detailed analysis of the modern position systems used for dynamic positioning basing on their expediency perspective. The accuracy issue related to determining vessel’s positions using dynamic positioning has been contemplated. The analysis included not only advantages but disadvantages of each determining position system as well summarizing the results for further consideration and possible application purposes. The accuracy of ship’s positioning using the dynamic p...

  7. Contact sensitivity in palmar hyperkeratotic dermatitis

    Directory of Open Access Journals (Sweden)

    Minocha Y

    1993-01-01

    Full Text Available 230 patients presenting with palmar hyperkeratotic dermatitis were investigated by patch tests against various antigens depending upon occupation of the patients. Contact sensitivity was detected in 130 patients comprising of housewives (55, businessmen (20, farmers (15, teachers / clerks / students (13, doctors and nurses (9, factory workers and labourers (8, massons (7 and motor mechanics (3. Vegetables were found to be the most common agents followed by detergents and metals predominantly affecting housewives. Among the vegetables, garlic and onion were the most potent sensitizers whereas nickel was a common sensitizer among metals. Occupational factors were seen to have some influence in relation to the causative agents as indicated by higher positivity of vegetables in housewives; detergents, metals, rubber, leather, plastics in businessmen, teachers, clerks and students; fertilizers or animal foods in farmers; drugs in doctors and nurses and chromium and cobalt in massons.

  8. Contact sensitivity and bioavailability of chlorocresol

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner; Carlsen, L; Egsgaard, Helge

    1985-01-01

    % of the chlorocresol in aqueous suspension permeated the skin in contrast to 34% and 35% of the chlorocresol in olive oil/acetone (4/1) and propylene glycol, respectively. In spite of the same amount of chlorocresol absorption from the 2 latter preparations, they showed a significant difference in sensitizing capacity......Chlorocresol sensitization from 5 topical preparations was determined in guinea pigs using the cumulative contact enhancement test. Chlorocresol 5% in olive oil/acetone (4/1), and 5% in aqueous suspension stabilized with carbomer 941 were more sensitizing (55% and 60% of the animals positive...... (from each preparation) that remained in the bandage material and the patch test skin site was determined by combined gas chromatography-mass spectrometry using an isotopic dilution technique. From 0.2% to 1.6% of the applied doses remained at the patch test skin sites as free chlorocresol. 75...

  9. Contact Sensitivity and Bioavailability of Chlorocresol

    DEFF Research Database (Denmark)

    Egsgaard, Helge; Larsen, Elfinn; Carlsen, Lars

    1985-01-01

    % of the chlorocresol in aqueous suspension permeated the skin in contrast to 34% and 35% of the chlorocresol in olive oil/acetone (4/1) and propylene glycol, respectively. In spite of the same amount of chlorocresol absorption from the 2 latter preparations, they showed a significant difference in sensitizing capacity......Chlorocresol sensitization from 5 topical preparations was determined in guinea pigs using the cumulative contact enhancement test. Chlorocresol 5% in olive oil/acetone (4/1), and 5% in aqueous suspension stabilized with carbomer 941 were more sensitizing (55% and 60% of the animals positive...... (from each preparation) that remained in the bandage material and the patch test skin site was determined by combined gas chromatography-mass spectrometry using an isotopic dilution technique. From 0.2% to 1.6% of the applied doses remained at the patch test skin sites as free chlorocresol. 75...

  10. SENSITIVITY OF DARCY'S LAW TO DISCONTINUITIES

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The authors investigate the sensitivity of hydrostatic pressure of flows through porous mediawith respect to the position of the soil layers. Indeed, these induce discontinuities of the porositypressure u and it leads to the computation of the derivative of u with respect to changes inThe analysis relies on a mixed formulation of the problem. Preliminary numerical simu-lations are given to illustrate the theory. An application to a simple inverse problem is also given.

  11. Metallic positive expulsion diaphragms

    Science.gov (United States)

    Gleich, D.

    1972-01-01

    High-cycle life ring-reinforced hemispherical type positive expulsion diaphragm performance was demonstrated by room temperature fluid expulsion tests of 13" diameter, 8 mil thick stainless steel configurations. A maximum of eleven (11) leak-free, fluid expulsions were achieved by a 25 deg cone angle diaphragm hoop-reinforced with .110-inch cross-sectional diameter wires. This represents a 70% improvement in diaphragm reversal cycle life compared to results previously obtained. The reversal tests confirmed analytic predictions for diaphragm cycle life increases due to increasing values of diaphragm cone angle, radius to thickness ratio and material strain to necking capacity. Practical fabrication techniques were demonstrated for forming close-tolerance, thin corrugated shells and for obtaining closely controlled reinforcing ring stiffness required to maximize diaphragm cycle life. A non-destructive inspection technique for monitoring large local shell bending strains was developed.

  12. Algorithms for Global Positioning

    DEFF Research Database (Denmark)

    Borre, Kai; Strang, Gilbert

    The emergence of satellite technology has changed the lives of millions of people. In particular, GPS has brought an unprecedented level of accuracy to the field of geodesy. This text is a guide to the algorithms and mathematical principles that account for the success of GPS technology and repla......The emergence of satellite technology has changed the lives of millions of people. In particular, GPS has brought an unprecedented level of accuracy to the field of geodesy. This text is a guide to the algorithms and mathematical principles that account for the success of GPS technology....... At the heart of the matter are the positioning algorithms on which GPS technology relies, the discussion of which will affirm the mathematical contents of the previous chapters. Numerous ready-to-use MATLAB codes are included for the reader. This comprehensive guide will be invaluable for engineers...

  13. Inductive Position Sensor

    Science.gov (United States)

    Youngquist, Robert C. (Inventor); Simmons, Stephen M. (Inventor)

    2015-01-01

    An inductive position sensor uses three parallel inductors, each of which has an axial core that is an independent magnetic structure. A first support couples first and second inductors and separate them by a fixed distance. A second support coupled to a third inductor disposed between the first and second inductors. The first support and second support are configured for relative movement as distance changes from the third inductor to each of the first and second inductors. An oscillating current is supplied to the first and second inductors. A device measures a phase component of a source voltage generating the oscillating current and a phase component of voltage induced in the third inductor when the oscillating current is supplied to the first and second inductors such that the phase component of the voltage induced overlaps the phase component of the source voltage.

  14. Position paper on mesotherapy

    Directory of Open Access Journals (Sweden)

    Rashmi Sarkar

    2011-01-01

    Full Text Available Mesotherapy is a controversial cosmetic procedure which has received publicity among the lay people, in the internet and in the media. It refers to minimally invasive techniques which consist of the use of intra- or subcutaneous injections containing liquid mixture of compounds (pharmaceutical and homeopathic medications, plant extracts, vitamins and other ingredients to treat local medical and cosmetic conditions. This position paper has examined the available evidence and finds that acceptable scientific evidence for its effectiveness and safety is lacking. IADVL taskforce, therefore would like to state that the use of this technique remains controversial at present. Further research and well-designed controlled scientific studies are required to substantiate the claims of benefit of this mode of therapy.

  15. Galileo positioning technology

    CERN Document Server

    Lohan, Elena; Sand, Stephan; Hurskainen, Heikki

    2015-01-01

    This book covers multi-band Galileo receivers (especially E1-E5 bands of Galileo) and addresses all receiver building blocks, from the antenna and front end, through details of the baseband receiver processing blocks, up to the navigation processing, including the Galileo message structure and Position, Velocity, Time (PVT) computation. Moreover, hybridization solutions with communications systems for improved localization are discussed and an open-source GNSS receiver platform (available for download) developed at Tampere University of Technology (TUT) is addressed in detail. • Takes a holistic approach to GALILEO and related systems, such as EGNOS and hybrid solutions on mobile phones; • Provides an invaluable reference to Binary Offset Carrier modulations and related families, which are some of the trademarks of GALILEO; • Includes a detailed survey of GALILEO receiver research in Europe and existing software-defined radio (SDR) GALILEO receiver implementations; • Addresses the multiple challen...

  16. Hiding Sensitive Association Rules without Altering the Support of Sensitive Item(s)

    CERN Document Server

    Jain, Dhyanendra

    2012-01-01

    Association rule mining is an important data-mining technique that finds interesting association among a large set of data items. Since it may disclose patterns and various kinds of sensitive knowledge that are difficult to find otherwise, it may pose a threat to the privacy of discovered confidential information. Such information is to be protected against unauthorized access. Many strategies had been proposed to hide the information. Some use distributed databases over several sites, data perturbation, clustering, and data distortion techniques. Hiding sensitive rules problem, and still not sufficiently investigated, is the requirement to balance the confidentiality of the disclosed data with the legitimate needs of the user. The proposed approach uses the data distortion technique where the position of the sensitive items is altered but its support is never changed. The size of the database remains the same. It uses the idea of representative rules to prune the rules first and then hides the sensitive rule...

  17. Sensitivity Data File Formats

    Energy Technology Data Exchange (ETDEWEB)

    Rearden, Bradley T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-04-01

    The format of the TSUNAMI-A sensitivity data file produced by SAMS for cases with deterministic transport solutions is given in Table 6.3.A.1. The occurrence of each entry in the data file is followed by an identification of the data contained on each line of the file and the FORTRAN edit descriptor denoting the format of each line. A brief description of each line is also presented. A sample of the TSUNAMI-A data file for the Flattop-25 sample problem is provided in Figure 6.3.A.1. Here, only two profiles out of the 130 computed are shown.

  18. Dye sensitized solar cells.

    Science.gov (United States)

    Wei, Di

    2010-03-16

    Dye sensitized solar cell (DSSC) is the only solar cell that can offer both the flexibility and transparency. Its efficiency is comparable to amorphous silicon solar cells but with a much lower cost. This review not only covers the fundamentals of DSSC but also the related cutting-edge research and its development for industrial applications. Most recent research topics on DSSC, for example, applications of nanostructured TiO(2), ZnO electrodes, ionic liquid electrolytes, carbon nanotubes, graphene and solid state DSSC have all been included and discussed.

  19. Dye Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Di Wei

    2010-03-01

    Full Text Available Dye sensitized solar cell (DSSC is the only solar cell that can offer both the flexibility and transparency. Its efficiency is comparable to amorphous silicon solar cells but with a much lower cost. This review not only covers the fundamentals of DSSC but also the related cutting-edge research and its development for industrial applications. Most recent research topics on DSSC, for example, applications of nanostructured TiO2, ZnO electrodes, ionic liquid electrolytes, carbon nanotubes, graphene and solid state DSSC have all been included and discussed.

  20. Context Sensitive Health Informatics

    DEFF Research Database (Denmark)

    Healthcare information technologies are now routinely deployed in a variety of healthcare contexts. These contexts differ widely, but the smooth integration of IT systems is crucial, so the design, implementation, and evaluation of safe, effective, efficient and easy to adopt health informatics...... involves careful consideration of both human and organizational factors. This book presents the proceedings of the Context Sensitive Health Informatics (CSHI) conference, held in Copenhagen, Denmark, in August 2013. The theme of this year’s conference is human and sociotechnical approaches. The Human...

  1. Context Sensitive Health Informatics

    DEFF Research Database (Denmark)

    2013-01-01

    Context is a key consideration when designing and evaluating health information technology (HIT) and cannot be overstated. Unintended consequences are common post HIT implementation and even well designed technology may not achieve desired outcomes because of contextual issues. While context should...... be considered in the design and evaluation of health information systems (HISs) there is a shortcoming of empirical research on contextual aspects of HIT. This conference integrates the sociotechnical and Human-Centered-Design (HCD) approaches and showcases current research on context sensitive health...

  2. Radiation sensitive devices and systems for detection of radioactive materials and related methods

    Science.gov (United States)

    Kotter, Dale K

    2014-12-02

    Radiation sensitive devices include a substrate comprising a radiation sensitive material and a plurality of resonance elements coupled to the substrate. Each resonance element is configured to resonate responsive to non-ionizing incident radiation. Systems for detecting radiation from a special nuclear material include a radiation sensitive device and a sensor located remotely from the radiation sensitive device and configured to measure an output signal from the radiation sensitive device. In such systems, the radiation sensitive device includes a radiation sensitive material and a plurality of resonance elements positioned on the radiation sensitive material. Methods for detecting a presence of a special nuclear material include positioning a radiation sensitive device in a location where special nuclear materials are to be detected and remotely interrogating the radiation sensitive device with a sensor.

  3. Contact sensitivity to lichens and compositae in Frullania dermatitis.

    Science.gov (United States)

    Gonçalo, S

    1987-02-01

    48 patients with allergic contact dermatitis from Frullania were patch tested with a lichen mix, compositae and lichen acids. 27 were sensitive to Frullania and lichens. Parmelia caperata and Parmelia reticulata were positive in all, and in a descending order of positivity: Pseudovernia furfuracea, Evernia prunastri, Usnea spp, Ramalina lusitanica. d-Usnic and evernic acids and atranorin were the main responsible allergens.

  4. Relationship of condylar position to disc position and morphology

    Energy Technology Data Exchange (ETDEWEB)

    Incesu, L.; Taskaya-Yilmaz, N. E-mail: nergizy@omu.edu.tr; Oeguetcen-Toller, M.; Uzun, E

    2004-09-01

    Introduction/objective: The purpose of this study was to assess whether condylar position, as depicted by magnetic resonance imaging, was an indicator of disc morphology and position. Methods and material: One hundred and twenty two TMJs of 61 patients with temporomandibular joint disorder were examined. Condylar position, disc deformity and degree of anterior disc displacement were evaluated by using magnetic resonance imaging. Results and discussion: Posterior condyle position was found to be the main feature of temporomandibular joints with slight and moderate anterior disc displacement. No statistical significance was found between the condylar position, and reducing and nonreducing disc positions. On the other hand, superior disc position was found to be statistically significant for centric condylar position. Conclusion: It was concluded that posterior condyle position could indicate anterior disc displacement whereas there was no relation between the position of condyle and the disc deformity.

  5. A TOF-PET prototype with position sensitive PMT readout%A TOF-PET prototype with position sensitive PMT readout

    Institute of Scientific and Technical Information of China (English)

    陈金达; 臧永东; 王建松; 孙志宇; 郭忠言; 徐瑚珊; 胡正国; 陈若富; 唐彬; 岳珂; 余玉洪; 章学恒; 孔洁

    2011-01-01

    A prototype of time-of-flight positron emission computed tomography (TOF-PET) has been developed for acquiring the coincident detection of 511 keV γ-rays produced from positron annihilation. It consists of two 80.5 minx80.5 mm LYSO scintillator arrays (co

  6. Surveillance Metrics Sensitivity Study

    Energy Technology Data Exchange (ETDEWEB)

    Bierbaum, R; Hamada, M; Robertson, A

    2011-11-01

    In September of 2009, a Tri-Lab team was formed to develop a set of metrics relating to the NNSA nuclear weapon surveillance program. The purpose of the metrics was to develop a more quantitative and/or qualitative metric(s) describing the results of realized or non-realized surveillance activities on our confidence in reporting reliability and assessing the stockpile. As a part of this effort, a statistical sub-team investigated various techniques and developed a complementary set of statistical metrics that could serve as a foundation for characterizing aspects of meeting the surveillance program objectives. The metrics are a combination of tolerance limit calculations and power calculations, intending to answer level-of-confidence type questions with respect to the ability to detect certain undesirable behaviors (catastrophic defects, margin insufficiency defects, and deviations from a model). Note that the metrics are not intended to gauge product performance but instead the adequacy of surveillance. This report gives a short description of four metrics types that were explored and the results of a sensitivity study conducted to investigate their behavior for various inputs. The results of the sensitivity study can be used to set the risk parameters that specify the level of stockpile problem that the surveillance program should be addressing.

  7. Density sensitive hashing.

    Science.gov (United States)

    Jin, Zhongming; Li, Cheng; Lin, Yue; Cai, Deng

    2014-08-01

    Nearest neighbor search is a fundamental problem in various research fields like machine learning, data mining and pattern recognition. Recently, hashing-based approaches, for example, locality sensitive hashing (LSH), are proved to be effective for scalable high dimensional nearest neighbor search. Many hashing algorithms found their theoretic root in random projection. Since these algorithms generate the hash tables (projections) randomly, a large number of hash tables (i.e., long codewords) are required in order to achieve both high precision and recall. To address this limitation, we propose a novel hashing algorithm called density sensitive hashing (DSH) in this paper. DSH can be regarded as an extension of LSH. By exploring the geometric structure of the data, DSH avoids the purely random projections selection and uses those projective functions which best agree with the distribution of the data. Extensive experimental results on real-world data sets have shown that the proposed method achieves better performance compared to the state-of-the-art hashing approaches.

  8. Camera sensitivity study

    Science.gov (United States)

    Schlueter, Jonathan; Murphey, Yi L.; Miller, John W. V.; Shridhar, Malayappan; Luo, Yun; Khairallah, Farid

    2004-12-01

    As the cost/performance Ratio of vision systems improves with time, new classes of applications become feasible. One such area, automotive applications, is currently being investigated. Applications include occupant detection, collision avoidance and lane tracking. Interest in occupant detection has been spurred by federal automotive safety rules in response to injuries and fatalities caused by deployment of occupant-side air bags. In principle, a vision system could control airbag deployment to prevent this type of mishap. Employing vision technology here, however, presents a variety of challenges, which include controlling costs, inability to control illumination, developing and training a reliable classification system and loss of performance due to production variations due to manufacturing tolerances and customer options. This paper describes the measures that have been developed to evaluate the sensitivity of an occupant detection system to these types of variations. Two procedures are described for evaluating how sensitive the classifier is to camera variations. The first procedure is based on classification accuracy while the second evaluates feature differences.

  9. Gathering positive experience

    CERN Multimedia

    2009-01-01

    Last Monday, the new CERN Machine Advisory Committee (CMAC) met for the first time, and we had good news to tell its members. Over the weekend, injection tests for both LHC beams were successfully carried out. In other words, we’ve had beam in the LHC for the first time since September 2008. That’s a good feeling, but it’s no reason for complacency. There’s still a long way to go before first physics at the new energy frontier. As the Bulletin has reported over recent weeks, we’re gathering a lot of positive experience with the new quench detection and protection system (QPS), which is already allowing us to monitor the LHC far better than we were able to in the past. So far, the QPS for three of the LHC’s eight sectors has been put through its paces, and we’ve also power tested those sectors to 2000 amperes, the equivalent of around 1.2 TeV per beam. The next step is to slowly increase the current to 4000 amperes, and...

  10. Systematic review: noncoeliac gluten sensitivity.

    Science.gov (United States)

    Molina-Infante, J; Santolaria, S; Sanders, D S; Fernández-Bañares, F

    2015-05-01

    Noncoeliac gluten sensitivity (NCGS) is a controversial emerging disorder. Despite reported symptoms related to the ingestion of gluten, NCGS remains a diagnosis based on the exclusion of coeliac disease, given the absence of reliable biomarkers. To evaluate the prevalence, diagnostic exclusion of coeliac disease and the efficacy of a gluten-free diet (GFD) for NCGS patients. A PubMed search was performed up to December 2014. According to consensus diagnostic criteria, NCGS was defined as self-reported gluten intolerance, negative coeliac serology and absence of villous atrophy. Studies evaluating the impact of a GFD on patients with irritable bowel syndrome (IBS) were also included. Prevalence rates of NCGS (0.5-13%) differed widely. Seventeen studies, including 1561 patients (26 children), met the inclusion criteria for NCGS. HLA haplotypes could not be linked to histology [normal or lymphocytic enteritis (LE)] in 1123 NCGS patients. HLADQ2/DQ8 haplotypes were present in 44% of NCGS patients. After advanced diagnostic techniques in 189 NCGS patients combining LE and HLADQ2/DQ8 haplotypes, 39 (20%) were reclassified as coeliac disease. There was a higher than expected family history of coeliac disease and autoimmune disorders in NCGS patients. A GFD resulted in variable results for variable, but significantly improved stool frequency in HLADQ2 positive diarrhoea-predominant IBS patients. Prevalence rates for NCGS are extremely variable. A subset of NCGS patients might belong in the so-called 'coeliac-lite' disease. The benefit of a GFD for NCGS patients is currently controversial. HLADQ2 positive diarrhoea-type IBS patients might gain symptom improvement from a GFD. © 2015 John Wiley & Sons Ltd.

  11. Exposing Position Uncertainty in Middleware

    DEFF Research Database (Denmark)

    Langdal, Jakob; Kjærgaard, Mikkel Baun; Toftkjær, Thomas;

    2010-01-01

    Traditionally, the goal for positioning middleware is to provide developers with seamless position transparency, i.e., providing a connection between the application domain and the positioning sensors while hiding the complexity of the positioning technologies in use. A key part of the hidden com...

  12. Sensitivity and specificity of leukocyte count in feces as a predictor of stool culture positivity for S amonella or Shigella Sensibilidad y especificidad del recuento de leucocitos en las materias fecales para predecir la presencia de Salmonella o Shigella en pacientes con enfermedad diarreica aguda

    Directory of Open Access Journals (Sweden)

    John Jairo Zuleta Tobón

    2008-01-01

    Full Text Available

    In most studies of fecal leukocyte counts as predictors of the result of stool cultures the sensitivity and specificity were not determined.

    Objective: to evaluate fecal leukocyte counts as a predictor of the presence of Salmonella and Shigella.

    Design: a descriptive, cross section study was carried out in 905 stool cultures at a university hospital in Medellín, Colombia. Results for Salmonella and Shigella were taken as the gold standard to evaluate the sensitivity and specificity of fecal leukocyte counts.

    Results: sensitivity and specificity, according to the level of the count, were, respectively: 1-5 leukocytes: 89.2% and 57.1%; 6-10 leukocytes: 86.2% and 52.8%;11-20 leukocytes: 77.7% and 62.7%; 21-30 leukocytes: 63.9% and 76.3%; 31-50 leukocytes: 45.2% and 85.5%; more than 50 leukocytes: 28.3% and 90.9%. The area under the curve was 0.7699 (CI 95%: 0.7275-0.8123.

    Conclusions: sensitivity

  13. Culture-sensitive psychotraumatology

    Science.gov (United States)

    Schnyder, Ulrich; Bryant, Richard A.; Ehlers, Anke; Foa, Edna B.; Hasan, Aram; Mwiti, Gladys; Kristensen, Christian H.; Neuner, Frank; Oe, Misari; Yule, William

    2016-01-01

    Background Although there is some evidence of the posttraumatic stress disorder (PTSD) construct's cross cultural validity, trauma-related disorders may vary across cultures, and the same may be true for treatments that address such conditions. Experienced therapists tailor psychotherapy to each patient's particular situation, to the nature of the patient's psychopathology, to the stage of therapy, and so on. In addition, culture-sensitive psychotherapists try to understand how culture enhances the meaning of their patient's life history, the cultural components of their illness and help-seeking behaviors, as well as their expectations with regard to treatment. We cannot take for granted that all treatment-seeking trauma survivors speak our language or share our cultural values. Therefore, we need to increase our cultural competencies. Methods The authors of this article are clinicians and/or researchers from across the globe, working with trauma survivors in various settings. Each author focused on one or more specific cultural aspects of working with trauma survivors and highlighted the following aspects. Results As a result of culture-specific individual and collective meanings linked to trauma and trauma-related disorders survivors may be exposed to (self-)stigma in the aftermath of trauma. Patients who are reluctant to talk about their traumatic experiences may instead be willing to write or use other ways of accessing the painful memories such as drawing. In other cultures, community and family cohesion are crucial elements of recovery. While awareness of culture-specific aspects is important, we also need to beware of premature cultural stereotyping. When disseminating empirically supported psychotherapies for PTSD across cultures, a number of additional challenges need to be taken into account: many low and middle income countries have very limited resources available and suffer from a poor health infrastructure. Conclusions In summary, culture-sensitive

  14. Diamond dosimetry: Outcomes of the CANDIDO and CONRAD INFN projects

    Energy Technology Data Exchange (ETDEWEB)

    Bucciolini, M. [Dipartimento di Fisiopatologia dell' Universita and INFN, Florence (Italy)]. E-mail: marta@dfc.unifi.it; Borchi, E. [Dipartimento di Energetica dell' Universita and INFN, Florence (Italy); Bruzzi, M. [Dipartimento di Energetica dell' Universita and INFN, Florence (Italy); Casati, M. [Dipartimento di Fisiopatologia dell' Universita and INFN, Florence (Italy); Cirrone, P. [Laboratori Nazionali del SUD, INFN, Catania (Italy); Cuttone, G. [Laboratori Nazionali del SUD, INFN, Catania (Italy); De Angelis, C. [Dipartimento di Tecnologie e Salute, Istituto Superiore di Sanita and INFN, Rome (Italy); Lovik, I. [Dipartimento di Fisiopatologia dell' Universita and INFN, Florence (Italy); Onori, S. [Dipartimento di Tecnologie e Salute, Istituto Superiore di Sanita and INFN, Rome (Italy); Raffaele, L. [Laboratori Nazionali del SUD, INFN, Catania (Italy); Sciortino, S. [Dipartimento di Energetica dell' Universita and INFN, Florence (Italy)

    2005-10-21

    This paper reviews the main results of the study, carried out in the framework of the Italian National Institute of Nuclear Physics (INFN, Istituto Nazionale di Fisica Nucleare) projects, namely CANDIDO and CONRAD, on natural and synthetic diamond-based dosimeters for clinical radiotherapy. Characteristics of diamond such as radiation hardness, high sensitivity, tissue equivalence, etc., make this material interesting for dosimetry applications. For some years, natural diamonds have been commercially available for on-line radiotherapy dosimetry. Nevertheless, recent developments in the 'Chemical Vapour Deposition' (CVD) technique have addressed the attention on synthetic samples that potentially could be grown at low cost and with features suitable for dosimetric use. Several samples, differently grown and with different electrical contacts, have been compared by measuring their current response during irradiation with high-energy photon, electron and proton beams. Properties of dosimetric interest such as linearity, pre-irradiation dose, dose rate dependence, stability and rise time have been investigated. The results obtained so far within the INFN collaboration demonstrate the suitability of natural diamond detectors for many radiotherapy applications and the great potential of CVD diamond-based devices even though, at present, the commercial natural diamond dosimeters have a better behaviour with respect to the synthetic samples. Further efforts have to be made mainly to improve the dynamic of response and performance stability.

  15. Diamond dosimetry: Outcomes of the CANDIDO and CONRAD INFN projects

    Science.gov (United States)

    Bucciolini, M.; Borchi, E.; Bruzzi, M.; Casati, M.; Cirrone, P.; Cuttone, G.; De Angelis, C.; Lovik, I.; Onori, S.; Raffaele, L.; Sciortino, S.

    2005-10-01

    This paper reviews the main results of the study, carried out in the framework of the Italian National Institute of Nuclear Physics (INFN, Istituto Nazionale di Fisica Nucleare) projects, namely CANDIDO and CONRAD, on natural and synthetic diamond-based dosimeters for clinical radiotherapy. Characteristics of diamond such as radiation hardness, high sensitivity, tissue equivalence, etc., make this material interesting for dosimetry applications. For some years, natural diamonds have been commercially available for on-line radiotherapy dosimetry. Nevertheless, recent developments in the "Chemical Vapour Deposition" (CVD) technique have addressed the attention on synthetic samples that potentially could be grown at low cost and with features suitable for dosimetric use. Several samples, differently grown and with different electrical contacts, have been compared by measuring their current response during irradiation with high-energy photon, electron and proton beams. Properties of dosimetric interest such as linearity, pre-irradiation dose, dose rate dependence, stability and rise time have been investigated. The results obtained so far within the INFN collaboration demonstrate the suitability of natural diamond detectors for many radiotherapy applications and the great potential of CVD diamond-based devices even though, at present, the commercial natural diamond dosimeters have a better behaviour with respect to the synthetic samples. Further efforts have to be made mainly to improve the dynamic of response and performance stability.

  16. Secure positioning in wireless networks

    DEFF Research Database (Denmark)

    Capkun, Srdjan; Hubaux, Jean-Pierre

    2006-01-01

    So far, the problem of positioning in wireless networks has been studied mainly in a non-adversarial settings. In this work, we analyze the resistance of positioning techniques to position and distance spoofing attacks. We propose a mechanism for secure positioning of wireless devices, that we call...... Verifiable Multilateration. We then show how this mechanism can be used to secure positioning in sensor networks. We analyze our system through simulations....

  17. Moderating effects of sensitivity to punishment and sensitivity to reward on associations between marijuana effect expectancies and use.

    Science.gov (United States)

    Simons, Jeffrey S; Arens, Ashley M

    2007-09-01

    The study examined associations between sensitivity to reward (SR), sensitivity to punishment (SP), positive and negative expectancies, and marijuana use in a college sample (N = 809). Marijuana users (n = 227) reported lower SP and greater SR than nonusers. SR attenuated the association between SP and the probability of marijuana use. SP attenuated the association between positive expectancies and the probability of marijuana use as well as the frequency of use among users. SP potentiated the association between negative expectancies and use. The results indicate that SP and SR have interactive effects and that SP moderates the strength of positive and negative cues for risk behavior.

  18. Disgust sensitivity and anorexia nervosa

    DEFF Research Database (Denmark)

    Nielsen, Ruth Aharoni; Hertz, Marianne M

    2012-01-01

    Previous studies found inconsistent differences in disgust sensitivity between patients with a variety of eating disorders and normal controls.......Previous studies found inconsistent differences in disgust sensitivity between patients with a variety of eating disorders and normal controls....

  19. Extraversion and taste sensitivity.

    Science.gov (United States)

    Zverev, Yuriy; Mipando, Mwapatsa

    2008-03-01

    The rationale for investigating the gustatory reactivity as influenced by personality dimensions was suggested by some prior findings of an association between extraversion and acuity in other sensory systems. Detection thresholds for sweet, salty, and bitter qualities of taste were measured in 60 young healthy male and female volunteers using a two-alternative forced-choice technique. Personality of the responders was assessed using the Eysenck Personality Inventory. Multivariate analysis of variance failed to demonstrate a statistically significant interaction between an extraversion-introversion score, neuroticism score, smoking, gender and age. The only reliable negative association was found between the body mass index (BMI) and taste sensitivity (Roy's largest root = 0.05, F(7436.5) = 8.34, P = 0.003). Possible reasons for lack of differences between introverts and extraverts in the values of taste detection thresholds were discussed.

  20. Context Sensitive Health Informatics

    DEFF Research Database (Denmark)

    Healthcare information technologies are now routinely deployed in a variety of healthcare contexts. These contexts differ widely, but the smooth integration of IT systems is crucial, so the design, implementation, and evaluation of safe, effective, efficient and easy to adopt health informatics...... involves careful consideration of both human and organizational factors. This book presents the proceedings of the Context Sensitive Health Informatics (CSHI) conference, held in Copenhagen, Denmark, in August 2013. The theme of this year’s conference is human and sociotechnical approaches. The Human......: patients and IT; usability test and evaluation; work tasks and related contexts; human factors and simulation; and context and systems design, and outline theories and models for studying contextual issues and insights related to how health information technologies can be better designed to accommodate...

  1. Multiple Chemical Sensitivity

    DEFF Research Database (Denmark)

    Dantoft, Thomas Meinertz

    Multiple chemical sensitivity (MCS) is a chronic disorder characterized by reports of symptoms from various organ systems attributed by the individuals to exposure to common odors and airborne chemicals in doses far below those known to induce toxic effects. There exists a general lack of knowledge...... controls at baseline, immediately after and four hours after a controlled chemical (n-butanol) exposure, in an exposure chamber previously verified to induce symptom elicitation in MCS subjects. In manuscript III, mucosal lining fluid samples were collected and levels of 19 cytokines and chemokines were...... quantified and compared between MCS subjects and healthy controls. The investigation did not identify any group associated differences in mediator levels, either at baseline or upon the exposure session. However, time dependent changes were identified for four of the 19 mediators, with decreasing mediator...

  2. Neonatal sensitization to latex.

    Science.gov (United States)

    Worth, J

    2000-05-01

    Babies born in delivery rooms of hospitals are exposed to latex through skin and mucous membrane contact with prepowdered latex gloves worn by midwives and doctors, and through the inhalation of latex-bound starch powder in the air of the delivery room. This paper examines the hypothesis that they are at risk for latex sensitization, and that part of the sharp increase of childhood asthma, eczema and anaphylaxis in the past 30-40 years may be linked. These possibilities seem hitherto unsuspected. In over 700 papers on latex allergy no mention of neonatal exposure to latex has been found. Even obstetric papers discussing the risks for an atopic mother (atopy - a tendency to develop allergies) do not seem to anticipate any risk for the baby, who might also be atopic. Latex allergy is primarily regarded as an occupational hazard. This paper suggests that it is a hazard for every baby handled by latex gloves at birth. Copyright 2000 Harcourt Publishers Ltd.

  3. SOX sensitivity study

    Energy Technology Data Exchange (ETDEWEB)

    Martyn, Johann [Johannes Gutenberg-Universitaet, Mainz (Germany); Collaboration: BOREXINO-Collaboration

    2016-07-01

    To this day most experimental results on neutrino oscillations can be explained in the standard three neutrino model. There are however a few experiments that show anomalous behaviour at a very short baselines. These anomalies can hypothetically be explained with the existence of one or additional more light neutrino states that do not take part in weak interactions and are thus called sterile. Although the anomalies only give a hint that such sterile neutrinos could exist the prospect for physics beyond the standard model is a major motivation to investigate the neutrino oscillations in new very short baseline experiments. The SOX (Short distance Oscillations in BoreXino) experiment will use the Borexino detector and a {sup 144}Ce source to search for sterile neutrinos via the occurance of an oscillation pattern at a baseline of several meters. This talk examines the impact of the Borexino detector systematics on the experimental sensitivity of SOX.

  4. Culture-sensitive psychotraumatology

    Directory of Open Access Journals (Sweden)

    Ulrich Schnyder

    2016-07-01

    Full Text Available Background: Although there is some evidence of the posttraumatic stress disorder (PTSD construct's cross cultural validity, trauma-related disorders may vary across cultures, and the same may be true for treatments that address such conditions. Experienced therapists tailor psychotherapy to each patient's particular situation, to the nature of the patient's psychopathology, to the stage of therapy, and so on. In addition, culture-sensitive psychotherapists try to understand how culture enhances the meaning of their patient's life history, the cultural components of their illness and help-seeking behaviors, as well as their expectations with regard to treatment. We cannot take for granted that all treatment-seeking trauma survivors speak our language or share our cultural values. Therefore, we need to increase our cultural competencies. Methods: The authors of this article are clinicians and/or researchers from across the globe, working with trauma survivors in various settings. Each author focused on one or more specific cultural aspects of working with trauma survivors and highlighted the following aspects. Results: As a result of culture-specific individual and collective meanings linked to trauma and trauma-related disorders survivors may be exposed to (self-stigma in the aftermath of trauma. Patients who are reluctant to talk about their traumatic experiences may instead be willing to write or use other ways of accessing the painful memories such as drawing. In other cultures, community and family cohesion are crucial elements of recovery. While awareness of culture-specific aspects is important, we also need to beware of premature cultural stereotyping. When disseminating empirically supported psychotherapies for PTSD across cultures, a number of additional challenges need to be taken into account: many low and middle income countries have very limited resources available and suffer from a poor health infrastructure. Conclusions: In summary

  5. Reducing pawing in horses using positive reinforcement.

    Science.gov (United States)

    Fox, Adam E; Belding, Devon L

    2015-12-01

    Aversive control is a common method to reduce undesirable behavior in horses. However, it often results in unintended negative side effects, including potential abuse of the animal. Procedures based on positive reinforcement, such as differential reinforcement of other behavior (DRO), may reduce undesirable behaviors with fewer negative consequences. The current study used DRO schedules to reduce pawing using a multiple baseline design across 3 horses. Results indicated that DRO schedules were effective at reducing pawing. However, individual differences in sensitivity to DRO and reinforcer efficacy may be important considerations.

  6. How to minimise the health risks to athletes who compete in weight-sensitive sports review and position statement on behalf of the Ad Hoc Research Working Group on Body Composition, Health and Performance, under the auspices of the IOC Medical Commission.

    Science.gov (United States)

    Sundgot-Borgen, Jorunn; Meyer, Nanna L; Lohman, Timothy G; Ackland, Timothy R; Maughan, Ronald J; Stewart, Arthur D; Müller, Wolfram

    2013-11-01

    A focus on low body weight and body fat content, combined with regulations in some weight-sensitive sports, are considered risk factors for extreme dieting, eating disorders (EDs) and related health consequences among athletes. At present there are, from a health perspective, no generally accepted optimum values for body weight or percentage of fat mass in different sports and there is no 'gold standard' method for body composition assessment in athletes. On the basis of health considerations as well as performance, medical support teams should know how to approach elite athletes who seek to achieve an unrealistic body composition and how to prevent restrictive eating practices from developing into an ED. In addition, these teams must know when to raise the alarm and how to advice athletes who are affected by extreme dieting or clinical EDs. However, there is no consensus on when athletes struggling with extreme dieting or EDs should be referred for specialist medical treatment or removed from competition. Based on the present review, we conclude that there is a need for (1) sport-specific and gender-specific preventive programmes, (2) criteria for raising alarm and 'does not start' (DNS) for athletes with EDs and (3) modifications to the regulations in some sports. Further, the key areas for research identified include the development of standard methods for body composition assessment in elite athletes; screening measures for EDs among athletes; development and testing of prevention programmes; investigating the short and long-term effects of extreme dieting; and EDs on health and performance.

  7. Disgust sensitivity and psychopathological symptoms in non-clinical children.

    Science.gov (United States)

    Muris, Peter; van der Heiden, Simone; Rassin, Eric

    2008-06-01

    There is clear evidence in the adult literature that disgust sensitivity is implicated in various psychopathological syndromes. The current study examined the link between disgust sensitivity and psychopathological symptoms in youths. In a sample of non-clinical children aged 9-13 years, disgust sensitivity was assessed by two self-report questionnaires (i.e., the Disgust Scale and the Disgust Sensitivity Questionnaire) and a behavioural test. Furthermore, children completed scales for measuring the personality trait of neuroticism and various types of psychopathological symptoms. Results showed that disgust measures had sufficient to good convergent validity. Further, significant positive correlations were found between disgust sensitivity and symptoms of specific phobias (i.e., spider phobia, blood-injection phobia, small-animal phobia), social phobia, agoraphobia, obsessive-compulsive disorder (OCD), and eating problems, and these links were not attenuated when controlling for neuroticism. The possible role of disgust sensitivity in the aetiology of child psychopathology is discussed.

  8. The relations between secrecy, rejection sensitivity and autonomy-connectedness.

    Science.gov (United States)

    Wismeijer, Andreas A J; Van Assen, Marcel A L M; Bekker, Marrie H J

    2014-01-01

    The aim of this study was to examine the effects of two attachment-related variables on secrecy: rejection sensitivity and autonomy-connectedness. We hypothesized that rejection sensitivity is positively associated with secrecy, and autonomy-connectedness negatively with rejection sensitivity and secrecy. These hypotheses were generally corroborated in a sample of 303 university students. Moreover, we found that autonomy-connectedness at least partly explained the association between rejection sensitivity and secrecy. Self-awareness was negatively related to secrecy, suggesting that being aware of what one needs and thinks and being able to realize one's needs in social interactions reduce the tendency to keep secrets. In addition, interesting gender effects were found suggesting that men have a higher tendency to have secrets than women after controlling for the effects of autonomy-connectedness and rejection sensitivity. Our findings deepen the insight into possible reasons behind established associations between rejection sensitivity and secrecy, and may have clinical implications.

  9. 78 FR 7251 - Rulemaking Concerning the Standards for Designating Positions in the Competitive Service as...

    Science.gov (United States)

    2013-01-31

    ... Standards for Designating Positions in the Competitive Service as National Security Sensitive and Related... 25, 2013 Rulemaking Concerning the Standards for Designating Positions in the Competitive Service as National Security Sensitive and Related Matters Memorandum for the Director of National Intelligence...

  10. HIV-Positive-to-HIV-Positive Liver Transplantation

    OpenAIRE

    Calmy, Alexandra; van Delden, Christian; Giostra, Emiliano; Junet, C; Rubbia Brandt, L; Yerly, S; Chave, J-P; Samer, Caroline Flora; Elkrief, Laure; Vionnet, J; Berney, Thierry

    2016-01-01

    Most countries exclude human immunodeficiency virus (HIV)-positive patients from organ donation because of concerns regarding donor-derived HIV transmission. The Swiss Federal Act on Transplantation has allowed organ transplantation between HIV-positive donors and recipients since 2007. We report the successful liver transplantation from an HIV-positive donor to an HIV-positive recipient. Both donor and recipient had been treated for many years with antiretroviral therapy and harbored multidr...

  11. Robust Solar Position Sensor for Tracking Systems

    DEFF Research Database (Denmark)

    Ritchie, Ewen; Argeseanu, Alin; Leban, Krisztina Monika

    2009-01-01

    The paper proposes a new solar position sensor used in tracking system control. The main advantages of the new solution are the robustness and the economical aspect. Positioning accuracy of the tracking system that uses the new sensor is better than 1°. The new sensor uses the ancient principle...... of the solar clock. The sensitive elements are eight ordinary photo-resistors. It is important to note that all the sensors are not selected simultaneously. It is not necessary for sensor operating characteristics to be quasi-identical because the sensor principle is based on extreme operating duty measurement...... (bright or dark). In addition, the proposed solar sensor significantly simplifies the operation of the tracking control device....

  12. False Position, Double False Position and Cramer's Rule

    Science.gov (United States)

    Boman, Eugene

    2009-01-01

    We state and prove the methods of False Position (Regula Falsa) and Double False Position (Regula Duorum Falsorum). The history of both is traced from ancient Egypt and China through the work of Fibonacci, ending with a connection between Double False Position and Cramer's Rule.

  13. Videofluoroscopic Investigation of Body Position on Articulatory Positioning

    Science.gov (United States)

    Bae, Youkyung; Perry, Jamie L.; Kuehn, David P.

    2014-01-01

    Purpose: To quantitatively examine the effects of body position on the positioning of the epiglottis, tongue, and velum at rest and during speech. Method: Videofluoroscopic data were obtained from 12 healthy adults in the supine and upright positions at rest and during speech while the participants produced 12 VCV sequences. The effects of body…

  14. Positive Psychology and Positive Education: Old Wine in New Bottles?

    Science.gov (United States)

    Kristjansson, Kristjan

    2012-01-01

    The recently fashionable theories of positive psychology have educational ramifications at virtually every level of engagement, culminating in the model of positive education. In this critical review, I scrutinize positive education as a potential theory in educational psychology. Special attention is given to conceptual controversies and…

  15. Positive Psychology and Positive Education: Old Wine in New Bottles?

    Science.gov (United States)

    Kristjansson, Kristjan

    2012-01-01

    The recently fashionable theories of positive psychology have educational ramifications at virtually every level of engagement, culminating in the model of positive education. In this critical review, I scrutinize positive education as a potential theory in educational psychology. Special attention is given to conceptual controversies and…

  16. Positional nystagmus showing neutral points.

    Science.gov (United States)

    Hiruma, Kiyoshi; Numata, Tsutomu

    2004-01-01

    We encountered patients who had their static direction-changing positional nystagmus canceled at about 20-30 degrees yaw head rotation from the supine position. This nystagmus was also canceled when the head was rotated 180 degrees from this position. We call these head positions neutral points. At the neutral points, the cupula of the horizontal semicircular canal of the affected ear is positioned vertical to the gravitational plane and no deflection of the cupula occurs. The positional nystagmus observed (except the neutral points) was thought to occur due to a "heavy cupula" or "light cupula", which may be determined by the specific gravity of its endolymph.

  17. Multiple antibiotic sensitivity in a pediatric population.

    Science.gov (United States)

    Kamada, M M; Twarog, F; Leung, D Y

    1991-01-01

    Multiple antibiotic sensitivity (MAS), a common but complex clinical problem, has not been reviewed in the pediatric population. We evaluated 120 children with a history of MAS. The offending antibiotics were beta lactam (186 adverse reactions), sulfonamide (86 adverse reactions), macrolide (32 adverse reactions), erythromycin/sulfisoxazole (26 adverse reactions), aminoglycoside (2 adverse reactions), and tetracycline (2 adverse reactions). Urticaria occurred in 183 reactions, followed by polymorphous rash (n = 71), angioedema (n = 19), erythema multiform (n = 9), bronchospasm (n = 8), arthralgia (n = 7), serum sickness (n = 4), and laryngeal edema (n = 3), the mean age for the first reaction was 3 years (range 1 month to 13 years). Adverse reaction to three classes of antibiotics were noted in 22 patients, and two patients were noted to have adverse reactions to four or more antibiotic classes. Skin tests (ST) were performed in 98 children using penicillin G, a commercial benzyl penicilloyl polylysine, a minor determinant mixture, and a beta lactam analog. Positive ST were noted in 26% (31/120) of the MAS patients. Children with a history of MAS are likely to have true IgE-mediated reactions as documented by positive immediate hypersensitivity reactions to penicillin and/or its minor determinants. Therefore, MAS patients should be carefully evaluated for antibiotic sensitivity and not be assumed to have sensitivity to drug formulation as a basis for MAS.

  18. Device for monitoring the position of a drilling ship in relation to the underwater well head

    Energy Technology Data Exchange (ETDEWEB)

    Kurbanov, A.O.; Bagirov, M.D.

    1981-05-07

    A device is suggested for monitoring the position of a drilling ship in relation to the underwater well head containing a winch, two sensitive elements arranged in two mutually perpendicular planes through which a cable is passed, two sensors attached to the sensitive elements. In order to improve the accuracy of monitoring the position of the drilling ship, the sensitive elements are made in the form of two semirings installed with the possibility of rotation.

  19. Robot Position Sensor Fault Tolerance

    Science.gov (United States)

    Aldridge, Hal A.

    1997-01-01

    Robot systems in critical applications, such as those in space and nuclear environments, must be able to operate during component failure to complete important tasks. One failure mode that has received little attention is the failure of joint position sensors. Current fault tolerant designs require the addition of directly redundant position sensors which can affect joint design. A new method is proposed that utilizes analytical redundancy to allow for continued operation during joint position sensor failure. Joint torque sensors are used with a virtual passive torque controller to make the robot joint stable without position feedback and improve position tracking performance in the presence of unknown link dynamics and end-effector loading. Two Cartesian accelerometer based methods are proposed to determine the position of the joint. The joint specific position determination method utilizes two triaxial accelerometers attached to the link driven by the joint with the failed position sensor. The joint specific method is not computationally complex and the position error is bounded. The system wide position determination method utilizes accelerometers distributed on different robot links and the end-effector to determine the position of sets of multiple joints. The system wide method requires fewer accelerometers than the joint specific method to make all joint position sensors fault tolerant but is more computationally complex and has lower convergence properties. Experiments were conducted on a laboratory manipulator. Both position determination methods were shown to track the actual position satisfactorily. A controller using the position determination methods and the virtual passive torque controller was able to servo the joints to a desired position during position sensor failure.

  20. Benign Paroxysmal Positional Vertigo (BPPV)

    Science.gov (United States)

    ... Rated Nonprofit! Volunteer. Donate. Review. Benign Paroxysmal Positional Vertigo (BPPV) BPPV is the most common vestibular disorder. Benign ... al. Diagnosis and management of benign paroxysmal positional vertigo (BPPV). CMAJ. 2003 169(7):681-693. Nuti D, ...

  1. On some positive definite functions

    OpenAIRE

    Bhatia, Rajendra; Jain, Tanvi

    2014-01-01

    We study the function $(1 - \\|x\\|)\\slash (1 - \\|x\\|^r),$ and its reciprocal, on the Euclidean space $\\mathbb{R}^n,$ with respect to properties like being positive definite, conditionally positive definite, and infinitely divisible.

  2. Diffuse loss of sensitivity in early glaucoma.

    Science.gov (United States)

    Henson, D B; Artes, P H; Chauhan, B C

    1999-12-01

    To establish whether there is significant diffuse loss of sensitivity in a population of patients with early glaucoma. The differential light sensitivities at the 10 most sensitive locations from within the central 24 degrees of program 30-2 of the Humphrey Field Analyzer (Humphrey Instruments, San Leandro, CA) were compared in 38 pairs of age-matched subjects, one of each pair with early primary open-angle glaucoma (POAG) and the other with normal eyes. All subjects had had experience with automated perimetry and had clear media, visual acuity of 20/25 or better, and one or fewer false-positive or false-negative responses to catch trials. The mean difference in age between the subjects with glaucoma and normal subjects was 29 days (P = 0.44, maximum 1.42 years). The mean paired difference in pupil size was 0.16 mm (P = 0.26), and visual acuity was higher in the glaucoma-affected subjects (P = 0.044). The 10 highest sensitivity measurements in the POAG-affected subjects were found to be lower by a median of between 1.0 and 2.0 dB than those in the normal pair members (0.0001pupil size and media opacity.

  3. Spectral Conditions for Positive Maps

    Science.gov (United States)

    Chruściński, Dariusz; Kossakowski, Andrzej

    2009-09-01

    We provide partial classification of positive linear maps in matrix algebras which is based on a family of spectral conditions. This construction generalizes the celebrated Choi example of a map which is positive but not completely positive. It is shown how the spectral conditions enable one to construct linear maps on tensor products of matrix algebras which are positive but only on a convex subset of separable elements. Such maps provide basic tools to study quantum entanglement in multipartite systems.

  4. False positive reduction for lung nodule CAD

    Science.gov (United States)

    Zhao, Luyin; Boroczky, Lilla; Drysdale, Jeremy; Agnihotri, Lalitha; Lee, Michael C.

    2007-03-01

    Computer-aided detection (CAD) algorithms 'automatically' identify lung nodules on thoracic multi-slice CT scans (MSCT) thereby providing physicians with a computer-generated 'second opinion'. While CAD systems can achieve high sensitivity, their limited specificity has hindered clinical acceptance. To overcome this problem, we propose a false positive reduction (FPR) system based on image processing and machine learning to reduce the number of false positive lung nodules identified by CAD algorithms and thereby improve system specificity. To discriminate between true and false nodules, twenty-three 3D features were calculated from each candidate nodule's volume of interest (VOI). A genetic algorithm (GA) and support vector machine (SVM) were then used to select an optimal subset of features from this pool of candidate features. Using this feature subset, we trained an SVM classifier to eliminate as many false positives as possible while retaining all the true nodules. To overcome the imbalanced nature of typical datasets (significantly more false positives than true positives), an intelligent data selection algorithm was designed and integrated into the machine learning framework, thus further improving the FPR rate. Three independent datasets were used to train and validate the system. Using two datasets for training and the third for validation, we achieved a 59.4% FPR rate while removing one true nodule on the validation datasets. In a second experiment, 75% of the cases were randomly selected from each of the three datasets and the remaining cases were used for validation. A similar FPR rate and true positive retention rate was achieved. Additional experiments showed that the GA feature selection process integrated with the proposed data selection algorithm outperforms the one without it by 5%-10% FPR rate. The methods proposed can be also applied to other application areas, such as computer-aided diagnosis of lung nodules.

  5. Fuzzy Logic Indoor Positioning System

    Directory of Open Access Journals (Sweden)

    Roberto García Sánz

    2008-12-01

    Full Text Available The GPS system is not valid for positioning indoors, thus positioning systems are designed using Wi-Fi technology that allows location of a device inside buildings. The use of fuzzy logic is argued by the failure to find positioning systems based on this technology, which seeks toobserve how their use in this field

  6. Introducing Positive Psychology to SLA

    Science.gov (United States)

    MacIntyre, Peter D.; Mercer, Sarah

    2014-01-01

    Positive psychology is a rapidly expanding subfield in psychology that has important implications for the field of second language acquisition (SLA). This paper introduces positive psychology to the study of language by describing its key tenets. The potential contributions of positive psychology are contextualized with reference to prior work,…

  7. Positive Psychology and Outdoor Education

    Science.gov (United States)

    Berman, Dene S.; Davis-Berman, Jennifer

    2005-01-01

    A relatively new movement in psychology, positive psychology, has many implications for the field of outdoor education. Positive psychology has the goal of fostering excellence through the understanding and enhancement of factors that lead to growth. It embraces the view that growth occurs when positive factors are present, as opposed to the…

  8. Identificação microbiológica e sensibilidade in vitro de Candida isoladas da cavidade oral de indivíduos HIV positivos Microbiological identification and in vitro sensitivity of Candida isolates from the oral cavity of HIV-positive individuals

    Directory of Open Access Journals (Sweden)

    Márcia Arias Wingeter

    2007-06-01

    Full Text Available A candidíase orofaríngea é a infecção fúngica mais comum entre os pacientes infectados pelo vírus da imunodeficiência humana e seu tratamento é realizado com antifúngicos tópicos ou sistêmicos, que são indicados empiricamente com base em dados clínicos. O objetivo deste estudo foi determinar a freqüência de leveduras em lavados bucais de indivíduos HIV positivos, comparando os resultados entre pacientes com diferentes condições de imunodeficiência e verificar o perfil de susceptibilidade das espécies isoladas frente aos antifúngicos visando avaliar se as opções de tratamento utilizadas na prática clínica atingem a maioria das espécies identificadas. Leveduras foram isoladas em 58% das amostras de lavado bucal coletadas e Candida albicans foi a espécie mais (93% freqüente. Resistência ou susceptibilidade dose dependente, frente aos antifúngicos testados foi registrada em aproximadamente 17% das amostras. A importante variabilidade de resposta sugere limitações quanto à eficácia das terapias instituídas empiricamente.Oropharyngeal candidiasis is the most common fungal infection among patients infected with the human immunodeficiency virus. It can be treated with either systemic or topical antifungal agents, which are indicated empirically on the basis of clinical data. The objective of this study was to determine the frequency of yeast in mouthwashes from HIV-positive patients, compare the results between patients presenting different states of immunodeficiency, and investigate the susceptibility profile of the species isolated in relation to antifungal agents, with the aim of evaluating whether the treatments used in clinical practice are able to reach the majority of the species identified. Yeasts were isolated from 58% of the mouthwash samples collected. Candida albicans was the most (93% frequent species. Resistance or dose-dependent susceptibility in relation to the antifungal agent tested was registered in

  9. Reliability Sensitivity Analysis for Location Scale Family

    Institute of Scientific and Technical Information of China (English)

    洪东跑; 张海瑞

    2011-01-01

    Many products always operate under various complex environment conditions. To describe the dynamic influence of environment factors on their reliability, a method of reliability sensitivity analysis is proposed. In this method, the location parameter is assumed as a function of relevant environment variables while the scale parameter is assumed as an un- known positive constant. Then, the location parameter function is constructed by using the method of radial basis function. Using the varied environment test data, the log-likelihood function is transformed to a generalized linear expression by de- scribing the indicator as Poisson variable. With the generalized linear model, the maximum likelihood estimations of the model coefficients are obtained. With the reliability model, the reliability sensitivity is obtained. An instance analysis shows that the method is feasible to analyze the dynamic variety characters of reliability along with environment factors and is straightforward for engineering application.

  10. Nonceliac gluten sensitivity.

    Science.gov (United States)

    Fasano, Alessio; Sapone, Anna; Zevallos, Victor; Schuppan, Detlef

    2015-05-01

    During the past decade there has been an impressive increase in popularity of the gluten-free diet (GFD)-now the most trendy alimentary habit in the United States and other countries. According to recent surveys, as many as 100 million Americans will consume gluten-free products within a year. Operating under the concept that the GFD benefits only individuals with celiac disease, health care professionals have struggled to separate the wheat from the chaff; there are claims that eliminating gluten from the diet increases health and helps with weight loss, or even that gluten can be harmful to every human being. However, apart from unfounded trends, a disorder related to ingestion of gluten or gluten-containing cereals, namely nonceliac gluten sensitivity (NCGS), has resurfaced in the literature, fueling a debate on the appropriateness of the GFD for people without celiac disease. Although there is clearly a fad component to the popularity of the GFD, there is also undisputable and increasing evidence for NCGS. However, we require a better understanding of the clinical presentation of NCGS, as well as its pathogenesis, epidemiology, management, and role in conditions such as irritable bowel syndrome, chronic fatigue, and autoimmunity. Before we can begin to identify and manage NCGS, there must be agreement on the nomenclature and definition of the disorder based on proper peer-reviewed scientific information. We review the most recent findings on NCGS and outline directions to dissipate some of the confusion related to this disorder. Copyright © 2015 AGA Institute. Published by Elsevier Inc. All rights reserved.

  11. Navicular bone position determined by positional MRI: a reproducibility study

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, Philip; Nybing, Janus D. [Copenhagen University Hospital Frederiksberg and Bispebjerg, Department of Radiology, Frederiksberg (Denmark); Johannsen, Finn E.; Stallknecht, Sandra E. [Copenhagen University Hospital Bispebjerg, Institute of Sports Medicine Copenhagen, Copenhagen, NV (Denmark); Hangaard, Stine; Hansen, Bjarke B. [Copenhagen University Hospital Frederiksberg, Parker Institute, Department of Rheumatology, Frederiksberg (Denmark); Boesen, Mikael [Copenhagen University Hospital Frederiksberg and Bispebjerg, Department of Radiology, Frederiksberg (Denmark); Copenhagen University Hospital Frederiksberg, Parker Institute, Department of Rheumatology, Frederiksberg (Denmark)

    2016-02-15

    To examine intraobserver, interobserver and between-day reproducibility of positional MRI for evaluation of navicular bone height (NVH) and medial navicular position (MNP). Positional MRI (pMRI) of the foot was performed on ten healthy participants (0.25 T G-scanner). Scanning was performed in supine and standing position, respectively. Two radiologists evaluated the images in a blinded manner. Reliability and agreement were assessed by calculation of intraclass correlation coefficient (ICC) and 95 % limits of agreement as a percentage of the mean (LOA%). Intraobserver and interobserver reliability was ''substantial'' in both supine and standing position (ICC 0.86-0.98) and showed good agreement (LOA% 4.9-14.7 %). Between-day reliability of navicular height and medial navicular position in standing position remained substantial (ICC 0.85-0.92) with adequate agreement (LOA% 8.3-19.8 %). In supine position between-day reliability was ''moderate'' for NVH (ICC 0.72) and ''slight'' for MNP (ICC 0.39). Agreement remained adequate between-days for MNP in supine position (LOA% 17.7 %), but it was less than adequate for NVH in supine position (LOA% 24.2 %). Navicular height and medial navicular position can be measured by pMRI in a very reproducible manner within and between observers. Increased measurement variation is observed between-days in supine position, which may be due to small positional differences or other unknown biomechanical factors. (orig.)

  12. The Kepler False Positive Table

    Science.gov (United States)

    Bryson, Steve; Kepler False Positive Working Group

    2015-01-01

    The Kepler Space Telescope has detected thousands of candidate exoplanets by observing transit signals in a sample of more than 190,000 stars. Many of these transit signals are false positives, defined as a transit-like signal that is not due to a planet orbiting the target star (or a bound companion if the target is a multiple-star system). Astrophysical causes of false positives include background eclipsing binaries, planetary transits not associated with the target star, and non-planetary eclipses of the target star by stellar companions. The fraction of Kepler planet candidates that are false positives ranges from about 10% at high Galactic latitudes to 40% at low Galactic latitudes. Creating a high-reliability planet candidate catalog for statistical studies such as occurrence rate calculations requires removing clearly identified false positives.The Kepler Object of Interest (KOI) catalog at the NExScI NASA Exoplanet Archive flags false positives, and will soon provide a high-level classification of false positives, but lacks detailed description of why a KOI was determined to be a false positive. The Kepler False Positive Working Group (FPWG) examines each false positive in detail to certify that it is correctly identified as a false positive, and determines the primary reason(s) a KOI is classified as a false positive. The work of the FPWG will be published as the Kepler False Positive Table, hosted at the NExScI NASA Exoplanet Archive.The Kepler False Positive Table provides detailed information on the evidence for background binaries, transits caused by stellar companions, and false alarms. In addition to providing insight into the Kepler false positive population, the false positive table gives information about the background binary population and other areas of astrophysical interest. Because a planet around a star not associated with the target star is considered a false positive, the false positive table likely contains further planet candidates

  13. Pathophysiological Study of Sensitive Skin.

    Science.gov (United States)

    Buhé, Virginie; Vié, Katell; Guéré, Christelle; Natalizio, Audrey; Lhéritier, Céline; Le Gall-Ianotto, Christelle; Huet, Flavien; Talagas, Matthieu; Lebonvallet, Nicolas; Marcorelles, Pascale; Carré, Jean-Luc; Misery, Laurent

    2016-03-01

    Sensitive skin is a clinical syndrome characterized by the occurrence of unpleasant sensations, such as pruritus, burning or pain, in response to various factors, including skincare products, water, cold, heat, or other physical and/or chemical factors. Although these symptoms suggest inflammation and the activation of peripheral innervation, the pathophysiogeny of sensitive skin remains unknown. We systematically analysed cutaneous biopsies from 50 healthy women with non-sensitive or sensitive skin and demonstrated that the intraepidermal nerve fibre density, especially that of peptidergic C-fibres, was lower in the sensitive skin group. These fibres are involved in pain, itching and temperature perception, and their degeneration may promote allodynia and similar symptoms. These results suggest that the pathophysiology of skin sensitivity resembles that of neuropathic pruritus within the context of small fibre neuropathy, and that environmental factors may alter skin innervation.

  14. Sensitivity of ring growth and carbon allocation to climatic variation vary within ponderosa pine trees.

    Science.gov (United States)

    Kerhoulas, Lucy P; Kane, Jeffrey M

    2012-01-01

    Most dendrochronological studies focus on cores sampled from standard positions (main stem, breast height), yet vertical gradients in hydraulic constraints and priorities for carbon allocation may contribute to different growth sensitivities with position. Using cores taken from five positions (coarse roots, breast height, base of live crown, mid-crown branch and treetop), we investigated how radial growth sensitivity to climate over the period of 1895-2008 varies by position within 36 large ponderosa pines (Pinus ponderosa Dougl.) in northern Arizona. The climate parameters investigated were Palmer Drought Severity Index, water year and monsoon precipitation, maximum annual temperature, minimum annual temperature and average annual temperature. For each study tree, we generated Pearson correlation coefficients between ring width indices from each position and six climate parameters. We also investigated whether the number of missing rings differed among positions and bole heights. We found that tree density did not significantly influence climatic sensitivity to any of the climate parameters investigated at any of the sample positions. Results from three types of analyses suggest that climatic sensitivity of tree growth varied with position height: (i) correlations of radial growth and climate variables consistently increased with height; (ii) model strength based on Akaike's information criterion increased with height, where treetop growth consistently had the highest sensitivity and coarse roots the lowest sensitivity to each climatic parameter; and (iii) the correlation between bole ring width indices decreased with distance between positions. We speculate that increased sensitivity to climate at higher positions is related to hydraulic limitation because higher positions experience greater xylem tensions due to gravitational effects that render these positions more sensitive to climatic stresses. The low sensitivity of root growth to all climatic variables

  15. Epicutaneous sensitization with protein antigen

    Directory of Open Access Journals (Sweden)

    I-Lin Liu

    2012-12-01

    Full Text Available In the past few decades there has been a progressive understanding that epicutaneous sensitization with protein antigen is an important sensitization route in patients with atopic dermatitis. A murine protein-patch model has been established, and an abundance of data has been obtained from experiments using this model. This review discusses the characteristics of epicutaneous sensitization with protein antigen, the induced immune responses, the underlying mechanisms, and the therapeutic potential.

  16. Detecting Positioning Errors and Estimating Correct Positions by Moving Window.

    Science.gov (United States)

    Song, Ha Yoon; Lee, Jun Seok

    2015-01-01

    In recent times, improvements in smart mobile devices have led to new functionalities related to their embedded positioning abilities. Many related applications that use positioning data have been introduced and are widely being used. However, the positioning data acquired by such devices are prone to erroneous values caused by environmental factors. In this research, a detection algorithm is implemented to detect erroneous data over a continuous positioning data set with several options. Our algorithm is based on a moving window for speed values derived by consecutive positioning data. Both the moving average of the speed and standard deviation in a moving window compose a moving significant interval at a given time, which is utilized to detect erroneous positioning data along with other parameters by checking the newly obtained speed value. In order to fulfill the designated operation, we need to examine the physical parameters and also determine the parameters for the moving windows. Along with the detection of erroneous speed data, estimations of correct positioning are presented. The proposed algorithm first estimates the speed, and then the correct positions. In addition, it removes the effect of errors on the moving window statistics in order to maintain accuracy. Experimental verifications based on our algorithm are presented in various ways. We hope that our approach can help other researchers with regard to positioning applications and human mobility research.

  17. A wideband sensitive holographic photopolymer

    Institute of Scientific and Technical Information of China (English)

    Mingju Huang; Sulian Wang; Airong Wang; Qiaoxia Gong; Fuxi Gan

    2005-01-01

    A novel wideband sensitive dry holographic photopolymer sensitized by rose bengal (RB) and methylene blue (MB) is fabricated, the holographic storage characteristics of which are investigated under different exposure wavelengths. The result shows that the sensitive spectral band exceeds 200 nm in visible light range, the maximum diffraction efficiency under different exposure wavelengths is more than 40% and decreases with the decrease of exposure wavelength, the exposure sensitivity is not change with the exposure wavelength.This photopolymer is appropriate for wavelength multiplexing or multi-wavelength recording in digital holographic storage.

  18. Pathophysiological Study of Sensitive Skin

    National Research Council Canada - National Science Library

    Buhé, Virginie; Vié, Katell; Guéré, Christelle; Natalizio, Audrey; Lhéritier, Céline; Le Gall-Ianotto, Christelle; Huet, Flavien; Talagas, Matthieu; Lebonvallet, Nicolas; Marcorelles, Pascale; Carré, Jean-Luc; Misery, Laurent

    2016-01-01

    Sensitive skin is a clinical syndrome characterized by the occurrence of unpleasant sensations, such as pruritus, burning or pain, in response to various factors, including skincare products, water...

  19. Infrared sensing based sensitive skin

    Institute of Scientific and Technical Information of China (English)

    CAO Zheng-cai; FU Yi-li; WANG Shu-guo; JIN Bao

    2006-01-01

    Developed robotics sensitive skin is a modularized, flexible, mini-type array of infrared sensors with data processing capabilities, which can be used to cover the body of a robot. Depending on the infrared sensors and periphery processing circuit, robotics sensitive skin can in real-time provide existence and distance information about obstacles for robots within sensory areas. The methodology of designing sensitive skin and the algorithm of a mass of IR data fusion are presented. The experimental results show that the multi-joint robot with this sensitive skin can work autonomously in an unknown environment.

  20. Dye Sensitized Solar Cell, DSSC

    Directory of Open Access Journals (Sweden)

    Pongsatorn Amornpitoksuk

    2003-07-01

    Full Text Available A dye sensitized solar cell is a new type of solar cell. The operating system of this solar cell type is similar to plant’s photosynthesis process. The sensitizer is available for absorption light and transfer electrons to nanocrystalline metal oxide semiconductor. The ruthenium(II complexes with polypyridyl ligands are usually used as the sensitizers in solar cell. At the present time, the complex of [Ru(2,2',2'’-(COOH3- terpy(NCS3] is the most efficient sensitizer. The total photon to current conversion efficiency was approximately 10% at AM = 1.5.

  1. Evolutionary game theory and multiple chemical sensitivity.

    Science.gov (United States)

    Newlin, D B

    1999-01-01

    Newlin's [Newlin D.B. Evolutionary game theory of tolerance and sensitization in substance abuse. Paper presented to the Research Society on Alcoholism, Hilton Head, SC, 1998] evolutionary game theory of addictive behavior specifies how evolutionarily stable strategies for survival and reproduction may lead to addiction. The game theory of multiple chemical sensitivity (MCS) assumes that: (1) the MCS patient responds to low-level toxicants as stressors or as direct threats to their survival and reproductive fitness, (2) this activates the cortico-mesolimbic dopamine system, (3) this system is a survival motivation center--not a 'reward center', (4) the subject emits a counter-response that is in the same direction as the naive response to the chemicals, (5) previously neutral stimuli associated with chemicals also trigger conditioned responses that mimic those to the chemicals, (6) these counter-responses further activate the dopaminergic survival motivation system, and (7) this produces a positive feedback loop that leads to strong neural sensitization in these structures and in behavior controlled by this system, despite a small initial response. Psychologically, the MCS patient with a sensitized cortico-mesolimbic dopamine system is behaving as though his/her survival is directly threatened by these chemicals. Non-MCS subjects have counter-responses opposite in direction to those of the chemicals and show tolerance. An autoshaping/sign-tracking model of this game is discussed. This evolutionary game makes several specific, testable predictions about differences between MCS subjects, non-MCS controls, and substance abusers in laboratory experiments, and between sensitized and nonsensitized animals.

  2. Sensitivity in the trajectory of long-range -particle

    Indian Academy of Sciences (India)

    P V Kunhikrishnan; A Rajan Nambiar; K P Santhosh

    2012-09-01

    The factors influencing the trajectory of long-range -particle in the cold ternary fission of 252Cf are discussed. The trajectory of the -particle is studied by considering the influence of the force on the -particle due to Coulomb and proximity potentials and is found to have sensitive dependence on the initial position and initial energy of the -particle. The sensitivity to initial conditions signifies the presence of deterministic chaos which is characterized by Lyapunov exponent (LE). The LE is calculated using Wolf’s algorithm and found positive which implies that the objectives of trajectory calculations are restricted.

  3. Positivity of the English language

    CERN Document Server

    Kloumann, Isabel M; Harris, Kameron Decker; Bliss, Catherine A; Dodds, Peter Sheridan

    2011-01-01

    Within the last million years, human language has emerged and evolved as a fundamental instrument of social communication and semiotic representation. People use language in part to convey emotional information, leading to the central and contingent questions: (1) What is the emotional spectrum of natural language? and (2) Are natural languages neutrally, positively, or negatively biased? Previous findings are mixed: suggestive evidence of a positive bias has been found in small samples of English words [1-3], framed as the Pollyanna Hypothesis [3] and Linguistic Positivity Bias [1], while the experimental elicitation of emotional words has instead found a strong negative bias [4]. Here, we report that the human-perceived positivity of over 10,000 of the most frequently used English words exhibits a clear positive bias. More deeply, we characterize and quantify distributions of word positivity for four large and distinct corpora, demonstrating that their form is surprisingly invariant with respect to frequenc...

  4. Positive parenting in ethnic minority families : challenges and outcomes

    NARCIS (Netherlands)

    Emmen, Rosalia Antonia Grada (Rosanneke)

    2014-01-01

    The overall goal of the current dissertation is to uncover predictors and outcomes of positive parenting in ethnic minority families. Chapter 2 provides an overview of commonly used observational instruments to measure sensitivity, showing the versatility and scientific importance of the construct.

  5. Fostering Resiliency in Students: Positive Action Strategies for Classroom Teachers.

    Science.gov (United States)

    Bruce, Mary Alice

    1995-01-01

    Describes research-supported positive action strategies for teachers that will help foster resiliency in their classrooms and promote the healthy development and social competence of all students. Strategies include brainstorming, creative problem solving, goal setting, critical thinking and reflection, sensitivity to social learning, and…

  6. Sensitivity analysis for a type of statically stable sailcrafts

    Institute of Scientific and Technical Information of China (English)

    Zheng-Xue Li; Jun-Feng Li; He-Xi Baoyin

    2012-01-01

    Two types of sensitivities are proposed for statically stable sailcrafts. One type is the sensitivities of solar-radiation-pressure force with respect to position of the center of mass,and the other type is the sensitivities of solar-radiation-pressure force with respect to attitude.The two types of sensitivities represent how the solar-radiationpressure force changes with the position of mass center and the attitude.Sailcrafts with larger sensitivities undergo larger error of the solar-radiation-pressure force,leading to larger orbit error,as demonstrated by simulation.Then as a case study,detailed formulas are derived to calculate the sensitivities for sailcrafts with four triangular sails.According to these formulas,in order to reduce both types of sensitivities,the angle between opposed sails should not be too large,and the center of mass should be as close to the axis of symmetry of the four sails as possible and as far away from the center of pressure of the sailcraft as possible.

  7. COMPANIES WITH MARKET POSITIONING BRANDS

    OpenAIRE

    Ruxandra Radoviciu; Filimon Stremtan

    2009-01-01

    Positioning a company on the market by the usage of brands is defined as the act ofdesigning the supply and its image on the market, so as to occupy a distinct place in the minds of theirtarget audience. The role of positioning in developing marketing strategy to differentiate products andservices involves the selection of attributes that are considered important for consumers. In order togain a strong position on the market the companies must perform a market analysis, an internalanalysis an...

  8. Vestibular reflexes and positional manoeuvres

    OpenAIRE

    Bronstein, A

    2003-01-01

    Dizziness and vertigo are some of the more frequently encountered symptoms in neurology clinics. In turn, one of the most common causes of vertigo is benign paroxysmal positional vertigo (BPPV), accounting for a quarter of all patients with dizziness and vertigo. Reviewing the value of the positional manoeuvres available is relevant, particularly in the light of the efficient treatments available for BPPV. In this article I will deal with positional manoeuvres first, and then with how vestibu...

  9. Position Auctions with Consumer Search

    OpenAIRE

    Susan Athey; Glenn Ellison

    2011-01-01

    This paper examines a model in which advertisers bid for "sponsored-link" positions on a search engine. The value advertisers derive from each position is endogenized as coming from sales to a population of consumers who make rational inferences about firm qualities and search optimally. Consumer search strategies, equilibrium bidding, and the welfare benefits of position auctions are analyzed. Implications for reserve prices and a number of other auction design questions are discussed.

  10. Position Command Shaping for Vibration Suppression Considering Target Position Correction

    Science.gov (United States)

    Yamamoto, Masafumi; Ito, Kazuaki; Iwasaki, Makoto; Matsui, Nobuyuki

    This paper presents a command shaping technique based on a minimum jerk control approach considering a target position correction during motion, for the fast and precise positioning in vibratory mechatronic systems. The positioning controller is designed by a 2-degrees-of-freedom control: a feedback compensator is synthesized by H∞ control design to ensure the robust stability, while a feedforward compensator suppresses the vibration in response based on a coprime factorization expression of the plant mechanism. The command shaping, on the other hand, eliminates the corresponding vibration components of the primary and secondary modes in the position command, where the continuity of jerk component in the command can be ensured against the target position correction. The effectiveness of the proposed shaping technique has been verified by experiments using a table drive system on machine stand.

  11. Metals Are Important Contact Sensitizers: An Experience from Lithuania

    Directory of Open Access Journals (Sweden)

    Kotryna Linauskienė

    2017-01-01

    Full Text Available Background. Metals are very frequent sensitizers causing contact allergy and allergic contact dermatitis worldwide; up-to-date data based on patch test results has proved useful for the identification of a problem. Objectives. In this retrospective study prevalence of contact allergy to metals (nickel, chromium, palladium, gold, cobalt, and titanium in Lithuania is analysed. Patients/Methods. Clinical and patch test data of 546 patients patch tested in 2014–2016, in Vilnius University Hospital Santariskiu Klinikos, was analysed and compared with previously published data. Results. Almost third of tested patients (29.56% were sensitized to nickel. Younger women were more often sensitized to nickel than older ones (36% versus 22.8%, p=0.0011. Women were significantly more often sensitized to nickel than men (33% versus 6.1%, p<0.0001. Younger patients were more often sensitized to cobalt (11.6% versus 5.7%, p=0.0183. Sensitization to cobalt was related to sensitization to nickel (p<0.0001. Face dermatitis and oral discomfort were related to gold allergy (28% versus 6.9% dermatitis of other parts, p<0.0001. Older patients were patch test positive to gold(I sodium thiosulfate statistically significantly more often than younger ones (44.44% versus 21.21%, p=0.0281. Conclusions. Nickel, gold, cobalt, and chromium are leading metal sensitizers in Lithuania. Cobalt sensitization is often accompanied by sensitization to nickel. Sensitivity rate to palladium and nickel indicates possible cross-reactivity. No sensitization to titanium was found.

  12. Noise sensitivity and sleep disturbance

    NARCIS (Netherlands)

    Laszlo, H.E.; Janssen, S.A.; Babisch, W.; Hansell, A.L.

    2012-01-01

    It has been shown that noise induced health effects are strongly related to non-acoustical factors such as noise sensitivity. It is a stable personality trait and it can be conceptualised as a causal pathway confounder and/or effect modifier between noise and health. Furthermore noise sensitivity pa

  13. NCLEX fairness and sensitivity review.

    Science.gov (United States)

    Wendt, Anne; Kenny, Lorraine; Riley, Michelle

    2009-01-01

    The National Council Licensing Examination is an examination that is used for the purpose of licensing registered nurses and practical/vocational nurses. To help ensure that the examination questions (items) are fair and unbiased, all items undergo a fairness and sensitivity review as part of the item development process. This article focuses on the fairness and sensitivity review.

  14. Sensitization to palladium in Europe

    NARCIS (Netherlands)

    Muris, J.; Goossens, A.; Gonçalo, M.; Bircher, A.J.; Giménez-Arnau, A.; Foti, C.; Bruze, M.; Andersen, K.E.; Rustemeyer, T.; Feilzer, A.J.; Kleverlaan, C.J.

    2015-01-01

    Background Recently, sodium tetrachloropalladate (Na2PdCl4) was found to be a more sensitive palladium patch test allergen than palladium dichloride (PdCl2). Objectives To determine the optimal test concentration of Na2PdCl4, to evaluate the prevalence of palladium sensitization with Na2PdCl4 and Pd

  15. High-Sensitivity Magnetization Measurements

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The three most common instruments for high-sensitivity magnetization measurements (the vibrating-sample magnetometer, the alternating gradient magnetometer, and the SQUID magne tometer) are described and their limiting sensitivities are discussed. The advantages and disad vantages of each are described. Magnetometers using micro-machined force detectors are briefly mentioned.

  16. Radiation Sensitization in Cancer Therapy.

    Science.gov (United States)

    Greenstock, Clive L.

    1981-01-01

    Discusses various aspects of radiation damage to biological material, including free radical mechanisms, radiation sensitization and protection, tumor hypoxia, mechanism of hypoxic cell radiosensitization, redox model for radiation modification, sensitizer probes of cellular radiation targets, pulse radiolysis studies of free radical kinetics,…

  17. Local Sensitivity and Diagnostic Tests

    NARCIS (Netherlands)

    Magnus, J.R.; Vasnev, A.L.

    2004-01-01

    In this paper we confront sensitivity analysis with diagnostic testing.Every model is misspecified, but a model is useful if the parameters of interest (the focus) are not sensitive to small perturbations in the underlying assumptions. The study of the e ect of these violations on the focus is calle

  18. Frequency Sensitivity in Nervous Systems

    Institute of Scientific and Technical Information of China (English)

    LIU Feng; WANG Wei

    2001-01-01

    We first demonstrate how to quantify the information conveyed in temporal firing patterns of neurons. We then show that neurons are more sensitive to signals with frequencies within the range of 20 - 70 Hz in weak signal detection. Such frequency sensitivity is characterized by both the output signal-to-noise ratio and the information measures.

  19. Beam position monitor for energy recovered linac beams

    Energy Technology Data Exchange (ETDEWEB)

    Powers, Thomas; Evtushenko, Pavel

    2017-06-06

    A method of determining the beam position in an energy recovered linac (ERL). The method makes use of in phase and quadrature (I/Q) demodulation techniques to separate the pickup signal generated by the electromagnetic fields generated by the first and second pass beam in the energy recovered linac. The method includes using analog or digital based I/Q demodulation techniques in order to measure the relative amplitude of the signals from a position sensitive beam pickup such as a button, strip line or microstripline beam position monitor.

  20. Novel planar binuclear zinc phthalocyanine sensitizer for dye-sensitized solar cells: Synthesis and spectral, electrochemical, and photovoltaic properties

    Science.gov (United States)

    Zhu, Baiqing; Zhang, Xuejun; Han, Mingliang; Deng, Pengfei; Li, Qiaoling

    2015-01-01

    A planar binuclear zinc phthalocyanine was newly synthesized for use in dye-sensitized solar cells, based on Schiff base and asymmetric amino zinc phthalocyanine. The novel compounds were characterized using FTIR, UV-Vis, 1H NMR, cyclic voltammetry and elemental analysis. From the reduction and oxidation behavior, it is proved that APC and bi-NPC have negative LUMO levels and positive HOMO levels, satisfying the energy gap rule, and can be employed as sensitizers for dye-sensitized solar cells (DSSCs) applications.