Science.gov

Sample records for continuous position sensitive

  1. Reconstruction-free sensitive wavefront sensor based on continuous position sensitive detectors.

    PubMed

    Godin, Thomas; Fromager, Michael; Cagniot, Emmanuel; Brunel, Marc; Aït-Ameur, Kamel

    2013-12-01

    We propose a new device that is able to perform highly sensitive wavefront measurements based on the use of continuous position sensitive detectors and without resorting to any reconstruction process. We demonstrate experimentally its ability to measure small wavefront distortions through the characterization of pump-induced refractive index changes in laser material. In addition, it is shown using computer-generated holograms that this device can detect phase discontinuities as well as improve the quality of sharp phase variations measurements. Results are compared to reference Shack-Hartmann measurements, and dramatic enhancements are obtained.

  2. CONTINUOUSLY SENSITIVE BUBBLE CHAMBER

    DOEpatents

    Good, R.H.

    1959-08-18

    A radiation detector of the bubble chamber class is described which is continuously sensitive and which does not require the complex pressure cycling equipment characteristic of prior forms of the chamber. The radiation sensitive element is a gas-saturated liquid and means are provided for establishing a thermal gradient across a region of the liquid. The gradient has a temperature range including both the saturation temperature of the liquid and more elevated temperatures. Thus a supersaturated zone is created in which ionizing radiations may give rise to visible gas bubbles indicative of the passage of the radiation through the liquid. Additional means are provided for replenishing the supply of gas-saturated liquid to maintaincontinuous sensitivity.

  3. Position Sensitive Microcalorimeters

    NASA Technical Reports Server (NTRS)

    Sadleir, J. E.; Hammock, C.; Figueroa-Feliciano, E.; Stahle, C. K.; Bandler, S.; Saab, T.; Lindeman, M.; Porter, F. S.; Chervenak, J.; Brown, G.

    2004-01-01

    A Position Sensitive Transition-Edge Sensor (PoST) is a microcalorimeter device capable of one-dimensional imaging spectroscopy. The device consists of two Transition-Edge Sensors (TESs) connected to the ends of a long X-ray absorbing strip. The energy of a photon hitting the absorber and the position of the absorption event along the strip is measured from the response in the two sensors by analyzing the relative signal sizes, pulse rise times, and the sum of the pulses measured at each sensor, We report on the recent PoST effort at Goddard for applications to large field of view, high-energy- resolution, X-ray astrophysics.

  4. 32 CFR 154.13 - Sensitive positions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... be categorized, with respect to security sensitivity, as either nonsensitive, noncritical-sensitive... shall designate each position within their jurisdiction as to its security sensitivity and...

  5. 32 CFR 154.13 - Sensitive positions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... be categorized, with respect to security sensitivity, as either nonsensitive, noncritical-sensitive... shall designate each position within their jurisdiction as to its security sensitivity and...

  6. 32 CFR 154.13 - Sensitive positions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... be categorized, with respect to security sensitivity, as either nonsensitive, noncritical-sensitive... shall designate each position within their jurisdiction as to its security sensitivity and...

  7. Positive Behavior Support: Sustainability and Continuous Regeneration

    ERIC Educational Resources Information Center

    McIntosh, Kent; Turri, Mary G.

    2014-01-01

    Because of its widespread adoption and implementation (in over 13,000 schools in the US; Center on Positive Behavioral Interventions and Supports, 2010), there has been increasing attention to how School-wide Positive Behavior Support (SWPBS) systems can be sustained. Sustained implementation can be defined as "continued use of an…

  8. Position sensitive solid state detectors

    NASA Astrophysics Data System (ADS)

    Schnatterly, S. E.; Husk, D.

    1986-05-01

    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.

  9. Increasing Sensitivity In Continuous-Flow Electrophoresis

    NASA Technical Reports Server (NTRS)

    Sharnez, Rizwan; Sammons, David W.

    1994-01-01

    Sensitivity of continuous-flow electrophoresis (CFE) chamber increased by introducing lateral gradients in concentration of buffer solution and thickness of chamber. Such gradients, with resulting enhanced separation, achieved in CFE chamber with wedge-shaped cross section and collateral flow. Enables improved separations of homogeneous components of mixtures of variety of biologically important substances.

  10. Continuous positive airway pressure therapy: new generations.

    PubMed

    Garvey, John F; McNicholas, Walter T

    2010-02-01

    Continuous positive airway pressure (CPAP) is the treatment of choice for obstructive sleep apnoea syndrome (OSAS). However, CPAP is not tolerated by all patients with OSAS and alternative modes of pressure delivery have been developed to overcome pressure intolerance, thereby improving patient comfort and adherence. Auto-adjustable positive airway pressure (APAP) devices may be utilised for the long-term management of OSAS and may also assist in the initial diagnosis of OSAS and titration of conventional CPAP therapy. Newer modalities such as C-Flex and A-Flex also show promise as treatment options in the future. However, the evidence supporting the use of these alternative modalities remains scant, in particular with regard to long-term cardiovascular outcomes. In addition, not all APAP devices use the same technological algorithms and data supporting individual APAP devices cannot be extrapolated to support all. Further studies are required to validate the roles of APAP, C-Flex and A-Flex. In the interim, standard CPAP therapy should continue as the mainstay of OSAS management. PMID:20308751

  11. Position Sensitive Detection System for Charged Particles

    SciTech Connect

    Coello, E. A.; Favela, F.; Curiel, Q.; Chavez, E; Huerta, A.; Varela, A.; Shapira, Dan

    2012-01-01

    The position sensitive detection system presented in this work employs the Anger logic algorithm to determine the position of the light spark produced by the passage of charged particles on a 170 x 170 x 10 mm3 scintillator material (PILOT-U). The detection system consists of a matrix of nine photomultipliers, covering a fraction of the back area of the scintillators. Tests made with a non-collimated alpha particle source together with a Monte Carlo simulation that reproduces the data, suggest an intrinsic position resolution of up to 6 mm is achieved.

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

    PubMed

    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. PMID:24307743

  13. Large area position sensitive β-detector

    NASA Astrophysics Data System (ADS)

    Vaintraub, S.; Hass, M.; Edri, H.; Morali, N.; Segal, T.

    2015-03-01

    A new conceptual design of a large area electron detector, which is position and energy sensitive, was developed. This detector is designed for beta decay energies up to 4 MeV, but in principle can be re-designed for higher energies. The detector incorporates one large plastic scintillator and, in general, a limited number of photomultipliers (7 presently). The current setup was designed and constructed after an extensive Geant4 simulation study. By comparison of a single hit light distribution between the various photomultipliers to a pre-measured accurate position-response map, the anticipated position resolution is around 5 mm. The first benchmark experiments have been conducted in order to calibrate and confirm the position resolution of the detector. The new method, results of the first test experiments and comparison to simulations are presented.

  14. False-Positive Stress Echocardiograms: A Continuing Challenge

    PubMed Central

    Qamruddin, Salima

    2016-01-01

    Background: Stress echocardiography is an integral test in the cardiac diagnostic laboratory and has high sensitivity and specificity. Despite the excellent specificity of stress echocardiography, we continue to see a subset of patients with false-positive tests (defined as <50% diameter stenosis on subsequent coronary angiography). These false-positive findings present a management challenge because it remains unclear if and how to treat these patients. Methods: This article reviews relevant clinical studies and their outcomes. Results: Studies suggest that a group of patients develops a hypertensive response to exercise and therefore may have false-positive stress echocardiography. Hence, superior blood pressure control prior to stress echocardiography may prevent some false-positive tests. In addition, a subset of patients has microvascular abnormalities, vasomotor changes, endothelial dysfunction, and/or small vessel coronary disease that can lead to false-positive stress echocardiography. Conclusion: The evidence is insufficient to state that a false-positive stress echocardiography in the absence of obstructive coronary artery disease portends a poor outcome, but considerable evidence shows that some of these patients have microvascular abnormalities and endothelial dysfunction and consequently may benefit from aggressive medical management and further testing. PMID:27660577

  15. False-Positive Stress Echocardiograms: A Continuing Challenge

    PubMed Central

    Qamruddin, Salima

    2016-01-01

    Background: Stress echocardiography is an integral test in the cardiac diagnostic laboratory and has high sensitivity and specificity. Despite the excellent specificity of stress echocardiography, we continue to see a subset of patients with false-positive tests (defined as <50% diameter stenosis on subsequent coronary angiography). These false-positive findings present a management challenge because it remains unclear if and how to treat these patients. Methods: This article reviews relevant clinical studies and their outcomes. Results: Studies suggest that a group of patients develops a hypertensive response to exercise and therefore may have false-positive stress echocardiography. Hence, superior blood pressure control prior to stress echocardiography may prevent some false-positive tests. In addition, a subset of patients has microvascular abnormalities, vasomotor changes, endothelial dysfunction, and/or small vessel coronary disease that can lead to false-positive stress echocardiography. Conclusion: The evidence is insufficient to state that a false-positive stress echocardiography in the absence of obstructive coronary artery disease portends a poor outcome, but considerable evidence shows that some of these patients have microvascular abnormalities and endothelial dysfunction and consequently may benefit from aggressive medical management and further testing.

  16. Continuous psychophysics: Target-tracking to measure visual sensitivity

    PubMed Central

    Bonnen, Kathryn; Burge, Johannes; Yates, Jacob; Pillow, Jonathan; Cormack, Lawrence K.

    2015-01-01

    We introduce a novel framework for estimating visual sensitivity using a continuous target-tracking task in concert with a dynamic internal model of human visual performance. Observers used a mouse cursor to track the center of a two-dimensional Gaussian luminance blob as it moved in a random walk in a field of dynamic additive Gaussian luminance noise. To estimate visual sensitivity, we fit a Kalman filter model to the human tracking data under the assumption that humans behave as Bayesian ideal observers. Such observers optimally combine prior information with noisy observations to produce an estimate of target position at each time step. We found that estimates of human sensory noise obtained from the Kalman filter fit were highly correlated with traditional psychophysical measures of human sensitivity (R2 > 97%). Because each frame of the tracking task is effectively a “minitrial,” this technique reduces the amount of time required to assess sensitivity compared with traditional psychophysics. Furthermore, because the task is fast, easy, and fun, it could be used to assess children, certain clinical patients, and other populations that may get impatient with traditional psychophysics. Importantly, the modeling framework provides estimates of decision variable variance that are directly comparable with those obtained from traditional psychophysics. Further, we show that easily computed summary statistics of the tracking data can also accurately predict relative sensitivity (i.e., traditional sensitivity to within a scale factor). PMID:25795437

  17. High speed curved position sensitive detector

    DOEpatents

    Hendricks, Robert W.; Wilson, Jack W.

    1989-01-01

    A high speed curved position sensitive porportional counter detector for use in x-ray diffraction, the detection of 5-20 keV photons and the like. The detector employs a planar anode assembly of a plurality of parallel metallic wires. This anode assembly is supported between two cathode planes, with at least one of these cathode planes having a serpentine resistive path in the form of a meander having legs generally perpendicular to the anode wires. This meander is produced by special microelectronic fabrication techniques whereby the meander "wire" fans outwardly at the cathode ends to produce the curved aspect of the detector, and the legs of the meander are small in cross-section and very closely spaced whereby a spatial resolution of about 50 .mu.m can be achieved. All of the other performance characteristics are about as good or better than conventional position sensitive proportional counter type detectors. Count rates of up to 40,000 counts per second with 0.5 .mu.s shaping time constants are achieved.

  18. Two-dimensional position sensitive radiation detectors

    DOEpatents

    Mihalczo, John T.

    1994-01-01

    Nuclear reaction detectors capable of position sensitivity with submillimeter resolution in two dimensions are each provided by placing arrays of scintillation or wave length shifting optical fibers formed of a plurality of such optical fibers in a side-by-side relationship in X and Y directions with a layer of nuclear reactive material operatively associated with surface regions of the optical fiber arrays. Each nuclear reaction occurring in the layer of nuclear reactive material produces energetic particles for simultaneously providing a light pulse in a single optical fiber in the X oriented array and in a single optical fiber in the Y oriented array. These pulses of light are transmitted to a signal producing circuit for providing signals indicative of the X-Y coordinates of each nuclear event.

  19. Two-dimensional position sensitive radiation detectors

    DOEpatents

    Mihalczo, J.T.

    1994-02-22

    Nuclear reaction detectors capable of position sensitivity with submillimeter resolution in two dimensions are each provided by placing arrays of scintillation or wavelength shifting optical fibers formed of a plurality of such optical fibers in a side-by-side relationship in X and Y directions with a layer of nuclear reactive material operatively associated with surface regions of the optical fiber arrays. Each nuclear reaction occurring in the layer of nuclear reactive material produces energetic particles for simultaneously providing a light pulse in a single optical fiber in the X oriented array and in a single optical fiber in the Y oriented array. These pulses of light are transmitted to a signal producing circuit for providing signals indicative of the X-Y coordinates of each nuclear event. 6 figures.

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

    NASA Technical Reports Server (NTRS)

    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.

  1. Particle tracking with scintillating fibers and position sensitive photomultipliers

    SciTech Connect

    C.F. Perdrisat; R. Pourang; D. Koechner; D. Raine, III; B. Kross; S. Majewski; A. Weisenberger; R. Wojcik; K. Zorn; V. Punjabi; A. Day

    1991-11-01

    The use of position-sensitive phototubes in conjunction with scintillating plastic fibers for a particle tracking application in a future focal plane polarimeter (FPP) in the hadron arm of the hall A HRS 2 facility at the Continuous Electron Beam Accelerator Facility (CEBAF). Current results indicate that the design parameters of the FPP in the hadron arm of the double spectrometer facility HRS2 can be met with a design which couples round or square fibers 3 mm in size to Hamamatsu R4135 phototubes. Position resolutions {sigma}x or {sigma}y on the order of 0.6 mm are obtained in the phototubes. Detector structures with staggered double fiber layers lead to overall resolution of {sigma}=1 mm, and detection efficiencies close to 1. The characteristic speed of these detectors makes them particularly appropriate for the high rates which are expected with the 200-{micro}A continuous wave beam at CEBAF.

  2. SCALE Continuous-Energy Eigenvalue Sensitivity Coefficient Calculations

    DOE PAGESBeta

    Perfetti, Christopher M.; Rearden, Bradley T.; Martin, William R.

    2016-02-25

    Sensitivity coefficients describe the fractional change in a system response that is induced by changes to system parameters and nuclear data. The Tools for Sensitivity and UNcertainty Analysis Methodology Implementation (TSUNAMI) code within the SCALE code system makes use of eigenvalue sensitivity coefficients for an extensive number of criticality safety applications, including quantifying the data-induced uncertainty in the eigenvalue of critical systems, assessing the neutronic similarity between different critical systems, and guiding nuclear data adjustment studies. The need to model geometrically complex systems with improved fidelity and the desire to extend TSUNAMI analysis to advanced applications has motivated the developmentmore » of a methodology for calculating sensitivity coefficients in continuous-energy (CE) Monte Carlo applications. The Contributon-Linked eigenvalue sensitivity/Uncertainty estimation via Tracklength importance CHaracterization (CLUTCH) and Iterated Fission Probability (IFP) eigenvalue sensitivity methods were recently implemented in the CE-KENO framework of the SCALE code system to enable TSUNAMI-3D to perform eigenvalue sensitivity calculations using continuous-energy Monte Carlo methods. This work provides a detailed description of the theory behind the CLUTCH method and describes in detail its implementation. This work explores the improvements in eigenvalue sensitivity coefficient accuracy that can be gained through the use of continuous-energy sensitivity methods and also compares several sensitivity methods in terms of computational efficiency and memory requirements.« less

  3. The continuity of the output entropy of positive maps

    SciTech Connect

    Shirokov, Maxim E

    2011-10-31

    Global and local continuity conditions for the output von Neumann entropy for positive maps between Banach spaces of trace-class operators in separable Hilbert spaces are obtained. Special attention is paid to completely positive maps: infinite dimensional quantum channels and operations. It is shown that as a result of some specific properties of the von Neumann entropy (as a function on the set of density operators) several results on the output entropy of positive maps can be obtained, which cannot be derived from the general properties of entropy type functions. In particular, it is proved that global continuity of the output entropy of a positive map follows from its finiteness. A characterization of positive linear maps preserving continuity of the entropy (in the following sense: continuity of the entropy on an arbitrary subset of input operators implies continuity of the output entropy on this subset) is obtained. A connection between the local continuity properties of two completely positive complementary maps is considered. Bibliography: 21 titles.

  4. 32 CFR 154.13 - Sensitive positions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) Development or approval of war plans, plans or particulars of future major or special operations of war, or critical and extremely important items of war. (D) Investigative and certain investigative support duties...) Noncritical-sensitive. (A) Access to Secret or Confidential information. (B) Security police/provost...

  5. 32 CFR 154.13 - Sensitive positions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) Development or approval of war plans, plans or particulars of future major or special operations of war, or critical and extremely important items of war. (D) Investigative and certain investigative support duties...) Noncritical-sensitive. (A) Access to Secret or Confidential information. (B) Security police/provost...

  6. Intergenerational continuity in economic hardship, parental positivity, and positive parenting: The association with child behavior.

    PubMed

    Jeon, Shinyoung; Neppl, Tricia K

    2016-02-01

    The current study examined intergenerational continuity in economic hardship, parental positivity, and positive parenting across generations based on both the family stress model (FSM) and the family resilience framework. The study included 220 generation 1 (G1) parents, their target youth (generation 2: G2) who participated from adolescence through adulthood, and the target's child (generation 3: G3). Assessments included observational and self-report measures. Results indicated that G1 economic hardship negatively influenced both G1 positivity and G1 positive parenting. Similarly, G2 economic hardship was negatively related to both G2 positivity and G2 positive parenting, which in turn was associated with G3 positive behavior to G2. For both G1 and G2, parental positivity mediated the association between economic hardship and positive parenting. G2 economic hardship was indirectly related to G3 positive behavior through G2 parental positivity and positive parenting. An important finding is that the intergenerational continuity of economic hardship, positivity, and positive parenting were transmitted from G1 to G2. Results suggest that even in times of economic adversity, parental positivity and positive parenting were transmitted from G1 parents to their G2 youth during adulthood. Such continuity seems to influence the positive behavior of the G3 children.

  7. Neutron position-sensitive scintillation detector

    DOEpatents

    Strauss, Michael G.; Brenner, Raul

    1984-01-01

    A device is provided for mapping one- and two-dimensional distributions of neutron-positions in a scintillation detector. The device consists of a lithium glass scintillator coupled by an air gap and a light coupler to an array of photomultipliers. The air gap concentrates light flashes from the scintillator, whereas the light coupler disperses this concentrated light to a predetermined fraction of the photomultiplier tube array.

  8. Position sensitivity in gallium arsenide radiation detectors

    SciTech Connect

    Harper, R.; Hilko, R.A.

    1994-12-31

    For several years, the authors have studied the electrical output of GaAs detectors in response to MeV protons. Beams from the Los Alamos National Laboratory`s tandem Van de Graaff, bunched into pulses of about 0.7-ns width, have been used to drive detectors into the current mode, and fast electronics have enabled characterization of the impulse response shapes and the absolute sensitivities. Recently, the authors extended this line of investigation to measure output-charge spectra in response to low-current beams, in which the count rate was low and pulses due to individual ionizing particles were analyzed. The first part of the work was the measurement of spectra of the output charge of the detectors when bombarded by a beam of MeV-energy protons, which was collimated to a diameter of 0.1 mm. The GaAs detector was mounted on a microadjustable stage just behind the collimator, so that the site of irradiation on the detector could be varied. Output pulses originating from the impacts of individual protons were preamplified with charge-sensitive Lecroy 2004 preamplifiers, shaped with Lecroy 2011 amplifiers, and analyzed with a Lecroy 3500 multichannel analyzer. The second part was the measurement of the time response of the detector to a 0.1 mm-collimated bunched proton beam. The proton bunch width was less than 1 ns, during which time many protons struck the detector, driving it into the current mode where individual proton impacts are unresolved. A possible detector design is suggested by the results. In the past, GaAs time response has been improved by doping or radiation damaging, which introduces traps. The tails can be eliminated, but at the cost of a factor of a thousand in main peak sensitivity. It now appears that by masking off the region of the detector near the negative electrode, the tails can be eliminated with only a factor of about ten loss in peak gain.

  9. 43 CFR 422.11 - Position sensitivity and investigations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 1 2011-10-01 2011-10-01 false Position sensitivity and investigations. 422.11 Section 422.11 Public Lands: Interior Regulations Relating to Public Lands BUREAU OF... Requirements § 422.11 Position sensitivity and investigations. Each law enforcement contract or...

  10. 43 CFR 422.11 - Position sensitivity and investigations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Position sensitivity and investigations. 422.11 Section 422.11 Public Lands: Interior Regulations Relating to Public Lands BUREAU OF... Requirements § 422.11 Position sensitivity and investigations. Each law enforcement contract or...

  11. 43 CFR 422.11 - Position sensitivity and investigations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 1 2012-10-01 2011-10-01 true Position sensitivity and investigations. 422.11 Section 422.11 Public Lands: Interior Regulations Relating to Public Lands BUREAU OF... Requirements § 422.11 Position sensitivity and investigations. Each law enforcement contract or...

  12. 43 CFR 422.11 - Position sensitivity and investigations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 1 2014-10-01 2014-10-01 false Position sensitivity and investigations. 422.11 Section 422.11 Public Lands: Interior Regulations Relating to Public Lands BUREAU OF... Requirements § 422.11 Position sensitivity and investigations. Each law enforcement contract or...

  13. 43 CFR 422.11 - Position sensitivity and investigations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 1 2013-10-01 2013-10-01 false Position sensitivity and investigations. 422.11 Section 422.11 Public Lands: Interior Regulations Relating to Public Lands BUREAU OF... Requirements § 422.11 Position sensitivity and investigations. Each law enforcement contract or...

  14. Continuous Morse-Smale flows with three equilibrium positions

    NASA Astrophysics Data System (ADS)

    Zhuzhoma, E. V.; Medvedev, V. S.

    2016-05-01

    Continuous Morse-Smale flows on closed manifolds whose nonwandering set consists of three equilibrium positions are considered. Necessary and sufficient conditions for topological equivalence of such flows are obtained and the topological structure of the underlying manifolds is described. Bibliography: 36 titles.

  15. Sensitivity limits of continuous wave cavity ring-down spectroscopy.

    PubMed

    Huang, Haifeng; Lehmann, Kevin K

    2013-12-19

    An optimized nonlinear least-squares fit algorithm for data processing in cavity ring-down spectroscopy (CRDS) is discussed, which improves the calculation efficiency substantially over using a general purpose fitting package. Theoretical absorption sensitivity limits for both the detector noise and the shot noise limited situations are derived and compared with experimental results. The effect of limiting the bandwidth of detection system on ring-down signal is discussed and compared with real ring-down data. The optimal trigger level and fitting interval are obtained for continuous wave cavity ring-down spectroscopy (cw-CRDS) in both the detector noise and shot noise limits, with the resulting sensitivity in units of cm(-1) per (Hz(1/2)) derived. Interestingly, it is found that the optimized shot noise limited sensitivity in cw-CRDS method is, in principle, comparable with the ultimate sensitivity of noise-immune cavity-enhanced optical heterodyne molecular spectroscopy (NICE-OHMS). PMID:23978273

  16. Single photon emission imaging by position sensitive PMT

    NASA Astrophysics Data System (ADS)

    Pani, R.; Pellegrini, R.; Soluri, A.; De Vincentis, G.; Scafè, R.; Pergola, A.

    1998-02-01

    Position Sensitive Photo Multiplier Tube (PSPMT) represents a strong technological improvement for Nuclear Medicine imaging. Over the last 10 years Hamamatsu has developed a number of PSPMTs with different shapes and sizes, from 1 in. square up to more recent prototype of 8 in. diameter. The position is continuously detected by centroid method and spatial resolution represents its statistical uncertainty. By coupling PSPMTs to scintillating arrays it was possible to push PMTs near their intrinsic limit. A number of scintillating crystals arranged in a matrix were tested such as: YAP : Ce, NaI(Tl), CsI(Tl) and CsI(Na) with different pixel size (from 0.3×0.3 mm 2 to 2×2 mm 2) with overall dimension from 4×4 cm 2 up to 11 cm diameter. A number of applications in Nuclear Medicine were performed, such as miniature gamma cameras for radiopharmaceutical investigations on little animals where sub-millimeter spatial resolution values were carried out. More recently, the first prototype of dedicated gamma camera for scintimammography has been developed for small cancer detection in the breast.

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

    NASA Astrophysics Data System (ADS)

    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.

  18. GPS and odometer data fusion for outdoor robots continuous positioning

    NASA Astrophysics Data System (ADS)

    Pozo-Ruz, Ana; Garcia-Perez, Lia; Garcia-Alegre, Maria C.; Guinea, Domingo; Ribeiro, Angela; Sandoval, Francisco

    2002-02-01

    Present work describes an approximation to obtain the best estimation of the position of the outdoor robot ROJO, a low cost lawnmower to perform unmanned precision agriculture task such are the spraying of pesticides in horticulture. For continuous location of ROJO, two redundant sensors have been installed onboard: a DGPS submetric precision model and an odometric system. DGPS system will allow an absolute positioning of the vehicle in the field, but GPS failures in the reception of the signals due to obstacles and electrical and meteorological disturbance, lead us to the integration of the odometric system. Thus, a robust odometer based upon magnetic strip sensors has been designed and integrated in the vehicle. These sensors continuosly deliver the position of the vehicle relative to its initial position, complementing the DGPS blindness periods. They give an approximated location of the vehicle in the field that can be in turn conveniently updated and corrected by the DGPS. Thus, to provided the best estimation, a fusion algorithm has been proposed and proved, wherein the best estimation is calculated as the maximum value of the join probability function obtained from both position estimation of the onboard sensors. Some results are presented to show the performance of the proposed sensor fusion technique.

  19. Management of obstructive sleep apnea by continuous positive airway pressure.

    PubMed

    Weaver, Terri E; Sawyer, Amy

    2009-11-01

    Obstructive sleep apnea (OSA) is a common problem, with 9% to 28% of women and 24% to 26% of males having apneic events at a treatable level, making this syndrome a serious public health issue. This article describes the outcomes associated with continuous positive airway pressure treatment, significance of the issue of poor adherence in OSA, discusses evidence regarding the optimal duration of nightly use, describes the nature and predictors of nonadherence, and reviews interventions that have been tested to increase nightly use and suggests management strategies.

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

    NASA Astrophysics Data System (ADS)

    Vandebrouck, M.; Lemasson, A.; Rejmund, M.; Fremont, G.; Pancin, J.; Navin, A.; Michelagnoli, C.; Goupil, J.; Spitaels, C.; Jacquot, B.

    2016-03-01

    The characteristics and performance of a Dual Position Sensitive Multi-Wire Proportional Counter (DPS-MWPC) used to measure the scattering angle, the 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) μm for the scattering angle and the interaction point at the target respectively. The subsequent improvement of the Doppler correction of the energy of the γ-rays, detected in the γ-ray tracking array AGATA in coincidence with isotopically identified ions in VAMOS++, is also discussed.

  1. Self-Balancing Position-Sensitive Detector (SBPSD)

    PubMed Central

    Porrazzo, Ryan; Lydecker, Leigh; Gattu, Suhasini; Bakhru, Hassaram; Tokranova, Natalya; Castracane, James

    2015-01-01

    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 technology, are inexpensive and provide a real-time, analog signal output corresponding to the position of the light spot. An innovative type of optical position sensor was developed using two back-to-back connected photodiodes. These so called self-balancing position-sensitive detectors (SBPSDs) eliminate the need for external readout circuitry entirely. Fabricated prototype devices demonstrate linear, symmetric coordinate characteristics and a spatial resolution of 200 μm for a 74 mm device. PSDs are commercially available only up to a length of 37 mm. Prototype devices were fabricated with various lengths up to 100 mm and can be scaled down to any size below that. PMID:26205266

  2. Self-Balancing Position-Sensitive Detector (SBPSD).

    PubMed

    Porrazzo, Ryan; Lydecker, Leigh; Gattu, Suhasini; Bakhru, Hassaram; Tokranova, Natalya; Castracane, James

    2015-01-01

    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 technology, are inexpensive and provide a real-time, analog signal output corresponding to the position of the light spot. An innovative type of optical position sensor was developed using two back-to-back connected photodiodes. These so called self-balancing position-sensitive detectors (SBPSDs) eliminate the need for external readout circuitry entirely. Fabricated prototype devices demonstrate linear, symmetric coordinate characteristics and a spatial resolution of 200 μm for a 74 mm device. PSDs are commercially available only up to a length of 37 mm. Prototype devices were fabricated with various lengths up to 100 mm and can be scaled down to any size below that.

  3. [Continuous positive airways pressure treatment for obstructive sleep apnoea].

    PubMed

    Antone, E; Gilbert, M; Bironneau, V; Meurice, J C

    2015-04-01

    Continuous positive airway pressure (CPAP) still remains the most frequently used and the most efficient treatment for obstructive sleep apnea syndrome. However, its efficiency is conditioned by healthcare quality depending on many factors such as medical specificities of the patients as well as the severity of sleep-related breathing disorders. In order to optimize CPAP efficiency, it is necessary to be aware of the functional abilities of the different devices, and to perform a close monitoring of the patients, particularly during the first weeks of treatment, by maximally using the data provided by the CPAP apparatus. Some questions remain unsolved, such as the impact of nasal CPAP on glucose metabolism or cardiovascular prognosis. Furthermore, the strategy of CPAP use should be improved according to future results of studies dedicated to the interest of home telemonitoring and taking into account the validated mode of CPAP initiation. PMID:25823935

  4. Continuing Education Workshops in Bioinformatics Positively Impact Research and Careers

    PubMed Central

    Brazas, Michelle D.; Ouellette, B. F. Francis

    2016-01-01

    Bioinformatics.ca has been hosting continuing education programs in introductory and advanced bioinformatics topics in Canada since 1999 and has trained more than 2,000 participants to date. These workshops have been adapted over the years to keep pace with advances in both science and technology as well as the changing landscape in available learning modalities and the bioinformatics training needs of our audience. Post-workshop surveys have been a mandatory component of each workshop and are used to ensure appropriate adjustments are made to workshops to maximize learning. However, neither bioinformatics.ca nor others offering similar training programs have explored the long-term impact of bioinformatics continuing education training. Bioinformatics.ca recently initiated a look back on the impact its workshops have had on the career trajectories, research outcomes, publications, and collaborations of its participants. Using an anonymous online survey, bioinformatics.ca analyzed responses from those surveyed and discovered its workshops have had a positive impact on collaborations, research, publications, and career progression. PMID:27281025

  5. Development of a novel position-sensitive microchannel plate detector

    NASA Astrophysics Data System (ADS)

    Wiggins, Blake; Siwal, Davinder; Desouza, Romualdo

    2015-10-01

    Position sensitive microchannel plate (MCP) detectors which measure the position of an incident electron, ion, or photon, are useful in imaging applications. Recently, a novel detector, which utilizes an induced approach to provide position sensitivity, has been developed. In the prototype detector, using only the zero-crossing point of the inherently bipolar signals, a position resolution of 466 μm (FWHM) has been achieved. Implementing a differential readout may improve on this resolution. To realize this differential approach, a better understanding of the dependence of the induced signal shape on the position of the electron cloud is required. To characterize the dependence of the induced signal shape on position a resistive anode (RA) has been incorporated into the detector. The RA will allow determination of the centroid of the electron cloud. Factors impacting the position resolution obtained with the RA will be discussed and the achieved position resolution of 157 μm (FWHM) will be presented. Supported by the US DOE NNSA under Award No. DE-NA0002012.

  6. Control system design for a continuous positive airway pressure ventilator

    PubMed Central

    2012-01-01

    Continuous Positive Airway Pressure (CPAP) ventilation remains a mainstay treatment for obstructive sleep apnea syndrome (OSAS). Good pressure stability and pressure reduction during exhalation are of major importance to ensure clinical efficacy and comfort of CPAP therapy. In this study an experimental CPAP ventilator was constructed using an application-specific CPAP blower/motor assembly and a microprocessor. To minimize pressure variations caused by spontaneous breathing as well as the uncomfortable feeling of exhaling against positive pressure, we developed a composite control approach including the feed forward compensator and feedback proportional-integral-derivative (PID) compensator to regulate the pressure delivered to OSAS patients. The Ziegler and Nichols method was used to tune PID controller parameters. And then we used a gas flow analyzer (VT PLUS HF) to test pressure curves, flow curves and pressure-volume loops for the proposed CPAP ventilator. The results showed that it met technical criteria for sleep apnea breathing therapy equipment. Finally, the study made a quantitative comparison of pressure stability between the experimental CPAP ventilator and commercially available CPAP devices. PMID:22296604

  7. Position sensitive radioactivity detection for gas and liquid chromatography

    DOEpatents

    Cochran, Joseph L.; McCarthy, John F.; Palumbo, Anthony V.; Phelps, Tommy J.

    2001-01-01

    A method and apparatus are provided for the position sensitive detection of radioactivity in a fluid stream, particularly in the effluent fluid stream from a gas or liquid chromatographic instrument. The invention represents a significant advance in efficiency and cost reduction compared with current efforts.

  8. Position sensitivity of the first SmartPET HPGe detector

    NASA Astrophysics Data System (ADS)

    Cooper, R. J.; Turk, G.; Boston, A. J.; Boston, H. C.; Cresswell, J. R.; Mather, A. R.; Nolan, P. J.; Hall, C. J.; Lazarus, I.; Simpson, J.; Berry, A.; Beveridge, T.; Gillam, J.; Lewis, R. A.

    2007-04-01

    In this paper we discuss the Smart Positron Emission Tomography (PET) imaging system being developed by the University of Liverpool in conjunction with CCLRC Daresbury Laboratory. We describe the motivation for the development of a semiconductor-based PET system and the advantages it will offer over current tomographs. Details of the detectors and associated electronics are discussed and results of high precision scans are presented. Analysis of this scan data has facilitated full characterization of the detector response function and calibration of the three-dimensional position sensitivity. This work presents the analysis of the depth sensitivity of the detector.

  9. Strategies for the prevention of continuous positive airway pressure failure.

    PubMed

    Sahni, Rakesh; Schiaratura, Maria; Polin, Richard A

    2016-06-01

    Progress in neonatal intensive care is closely linked to improvements in the management of respiratory failure in preterm infants. Current modalities of respiratory support range from the more benign continuous positive airway pressure (CPAP) to various modes of mechanical ventilation. Data from recent randomized control trials suggest that the use of nasal (n)CPAP as the initial mode of respiratory support in critically ill very low birth weight infants is associated with a lower incidence of chronic lung disease. The practice of early initiation of nasal-prong CPAP in all spontaneously breathing infants at Columbia University has resulted in very low rates of chronic lung disease for decades. Many institutions have attempted to replicate the practices and results at Columbia University. However, success rates with nCPAP are highly variable, which may in part be attributable to how well it is utilized. With recent renewed interest in non-invasive respiratory support, particularly bubble nCPAP, it is essential to evaluate strategies for the prevention of CPAP failure. This review discusses strategies that address these issues and shares the practical aspects for replicating success with bubble nCPAP. In addition, it reviews desirable features, major components, and physiological consequences of various bubble CPAP systems along with clinical experience of CPAP use. PMID:26936186

  10. Use of nasal continuous positive airway pressure during neonatal transfers

    PubMed Central

    Bomont, R K; Cheema, I U

    2006-01-01

    Objective To review all cases in which nasal continuous positive airway pressure (CPAP) was used as a means of respiratory support during land based ambulance transfers by a regional neonatal transport service. Design Retrospective study based on review of transport records. Results A total of 1175 transfer requests were received over the 21 month period. The infant in 163 of these cases was receiving nasal CPAP. Ninety two referrals were accepted by the doctor/nurse practitioner led team. Of these, 84 were transported while receiving nasal CPAP. Intervention during transport was required in three of these cases. Fifty five referrals were accepted by the nurse led team. Of these, 16 were transported while receiving nasal CPAP. Intervention was required in two cases. Conclusion There is a small but significant demand for transferring infants who are receiving nasal CPAP. Nasal CPAP appears to be a safe method of respiratory support for a carefully selected group of infants during land based ambulance transfers. PMID:16204357

  11. A position sensitive microchannel photomultiplier for ultraviolet space astronomy

    NASA Technical Reports Server (NTRS)

    Lampton, M.; Siegmund, O. H. W.; Bixler, J.; Bowyer, S.

    1986-01-01

    The 25-mm microchannel-plate, position-sensitive UV astronomy photomultiplier tube presented is intended for the EOM-1 Spacelab Mission's FAUST payload and conducts wide-field imaging surveys in the VUV over the 1400-1800-A range. The sealed detector encompasses a CsI photocathode deposited on the inner surface of a MgF2 window, a stack of microchannel plates, and a wedge-and-strip two-dimensional position-sensing anode. Since the wedge-and-strip principle requires only three anode signals, flight electronics can be reduced to three charge amplifiers and three analog-to-digital converters.

  12. Development of a fast position-sensitive laser beam detector

    SciTech Connect

    Chavez, Isaac; Huang Rongxin; Henderson, Kevin; Florin, Ernst-Ludwig; Raizen, Mark G.

    2008-10-15

    We report the development of a fast position-sensitive laser beam detector. The detector uses a fiber-optic bundle that spatially splits the incident beam, followed by a fast balanced photodetector. The detector is applied to the study of Brownian motion of particles on fast time scales with 1 A spatial resolution. Future applications include the study of molecule motors, protein folding, as well as cellular processes.

  13. A novel method for assessing position-sensitive detector performance

    SciTech Connect

    Clinthorne, N.H.; Rogers, W.L.; Shao, L.; Hero, A.O. III; Koral, K.F.

    1989-02-01

    A marked point process model of a position-sensitive detector is developed which includes the effects of detector efficiency, spatial response, energy response, and source statistics. The average mutual information between the incident distribution of ..gamma.. rays and the detector response is derived and used as a performance index for detector optimization. A brief example is presented which uses this figure-of-merit for optimization of light guide dimensions for a modular scintillation camera.

  14. Two-dimensional position sensitive ionization chamber with GEM

    NASA Astrophysics Data System (ADS)

    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.

  15. Development of the Position Sensitive Ionization Chamber for ANASEN

    NASA Astrophysics Data System (ADS)

    Gardiner, Hannah; Blackmon, Jeff; Deibel, Catherine; Gardiner, Emily; Lai, Jianping; Lauer, Amber; Linhardt, Laura; Macon, Kevin; Rasco, Charlie; Baby, Lagy; Koshchiy, Yevegn; Rogachev, Grigory; Santiago-Gonzales, Daniel; Wiedenhoever, Ingo; Bardayan, Dan; Matos, Milan

    2013-10-01

    The Array for Nuclear Astrophysics Studies with Exotic Nuclei (ANASEN) is a charged-particle detector array developed for reaction studies using radioactive ion beams to help improve understanding of the nuclear reactions important in stellar explosions. A gas-filled ionization chamber with two position-sensitive anode wire grid planes read out in 32 channels, and 12 alternating anode/cathode planes was developed and tested for use with ANASEN to identify the kinematic trajectory and atomic number of recoiling heavy ions by their relative energy loss. The position sensitive grids are arranged perpendicularly to each other in order to determine the x-y position of each ion with better than 4 mm resolution. This ionization chamber was tested using a stable beam of 12C at FSU. We report on the performance of this test experiment and plans for measurements with radioactive ion beams at FSU. Two other versions of the detector have been constructed and are now in place at the National Superconducting Cyclotron Laboratory and at the ATLAS accelerator facility at Argonne National Laboratory.

  16. Michrochannel plate for position sensitive alpha particle detection

    SciTech Connect

    Paul Hurley and James Tinsley

    2007-08-31

    This paper will describe the use of a microchannel plate (MCP) as the associated particle detector on a sealed tube neutron generator. The generator produces neutrons and associated alpha particles for use as a probe to locate and identify hidden explosives in associated particle imaging (API). The MCP measures the position in two dimensions and precise timing of the incident alpha particle, information which is then used to calculate the emission time and direction of the corresponding neutron. The MCP replaces the position-sensitive photomultipler tube (PSPMT) which, until recently, had been the only detector available for measuring position and timing for alpha particles in neutron generator applications. Where the PSPMT uses charge division for generating position information, a process that requires a first order correction to each pulse, the MCP uses delay-line timing, which requires no correction. The result is a device with an order of magnitude improvement in both position resolution and timing compared to the PSPMT. Hardware and software development and the measurements made to characterize the MCP for API applications are described.

  17. Canadian Penning Trap Mass Measurements using a Position Sensitive MCP

    NASA Astrophysics Data System (ADS)

    Kuta, Trenton; Aprahamian, Ani; Marley, Scott; Nystrom, Andrew; Clark, Jason; Perez Galvan, Adrian; Hirsh, Tsviki; Savard, Guy; Orford, Rodney; Morgan, Graeme

    2015-10-01

    The primary focus of the Canadian Penning Trap (CPT) located at Argonne National Lab is to determine the masses of various isotopes produced in the spontaneous fission of Californium. Currently, the CPT is operating in conjunction with CARIBU at the ATLAS facility in an attempt to measure neutron-rich nuclei produced by a 1.5 Curie source of Californium 252. The masses of nuclei produced in fission is accomplished by measuring the cyclotron frequency of the isotopes circling within the trap. This frequency is determined by a position sensitive MCP, which records the relative position of the isotope in the trap at different times. Using these position changes over time in connection with a center spot, angles between these positions are calculated and used to determine the frequency. Most of the work currently being conducted on the CPT is focused on the precision of these frequency measurements. The use of traps has revolutionized the measurements of nuclear masses to very high precision. The optimization methods employed here include focusing the beam in order to reduce the spread on the position of the isotope as well as the tuning of the MR-ToF, a mass separator that is intended on removing contaminants in the beam. This work was supported by the nuclear Grant PHY-1419765 for the University of Notre Dame.

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

    NASA Technical Reports Server (NTRS)

    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.

  19. Positioning Continuing Education Computer Programs for the Corporate Market.

    ERIC Educational Resources Information Center

    Tilney, Ceil

    1993-01-01

    Summarizes the findings of the market assessment phase of Bellevue Community College's evaluation of its continuing education computer training program. Indicates that marketing efforts must stress program quality and software training to help overcome strong antiacademic client sentiment. (MGB)

  20. Position-Sensitive Nuclear Spectroscopy with Pixel Detectors

    SciTech Connect

    Granja, Carlos; Vykydal, Zdenek; Jakubek, Jan; Pospisil, Stanislav

    2007-10-26

    State-of-the-art hybrid semiconductor pixel detectors such as Medipix2 are suitable for energy- and position-sensitive nuclear spectroscopy. In addition to excellent energy- and spatial-resolution, these devices can operate in spectroscopic, single-quantum counting and/or on-line tracking mode. A devoted compact USB-readout interface provides functionality and ease of operation. The compact and versatile Medipix2/USB radiation camera provides visualization, vacuum and room-temperature operation as a real-time portable active nuclear emulsion.

  1. Emulation workbench for position sensitive gaseous scintillation detectors

    NASA Astrophysics Data System (ADS)

    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.

  2. Optimal landing position in reading isolated words and continuous text.

    PubMed

    Vitu, F; O'Regan, J K; Mittau, M

    1990-06-01

    During isolated-word reading, within-word eye-movement tactics (i.e., whether the eye makes one or more fixations on the word) depend strongly on the eye's first fixation position in the word; there exists an optimal landing position where the probability of having to refixate the word is much smaller than when the eye first fixates other parts of the word. The present experiment was designed to test whether the optimal landing position effect still exists during text reading, and to compare the nature and strength of the effect with the effect found for isolated words. The results confirmed the existence of an optimal landing position in both reading conditions, but the effect for words in texts was weaker than it was for isolated words, probably because of the presence of factors such as reading rhythm and linguistic context. However, the effect still existed in text reading; within-word tactics during text reading are dependent on the eye's initial landing position in words. Moreover, individual fixation durations were dependent on within-word tactics. Thus, the initial landing position in words must be taken into account if one wishes to understand eye-movement behavior during text reading. Further results concerned the effects of word length and word frequency in both reading conditions.

  3. Recent advances and future perspectives of position sensitive PMT

    NASA Astrophysics Data System (ADS)

    Pani, R.; Pellegrini, R.; Cinti, M. N.; Mattioli, M.; Trotta, C.; Montani, L.; Iurlaro, G.; Trotta, G.; D'Addio, L.; Ridolfi, S.; De Vincentis, G.; Weinberg, I. N.

    2004-01-01

    In recent years there has been a growing interest in developing compact gamma cameras to improve gamma ray imaging for application in nuclear medicine as well as in astrophysics, radiation physics and high energy physics. The gamma cameras based on position sensitive photomultipliers could be the best chance to obtain a realistic and low cost compact gamma camera. Since 1985 the development of position sensitive photo multiplier tubes (PSPMT) has shown the highest rate in technological advancement achieving very compact size (25 × 25 × 20 mm 3) by a novel charge multiplication system. The PSPMT shows the same advantages of a standard gamma camera with the additional possibility to utilize scintillation arrays with pixel dimension less than 1 mm, thus achieving sub-millimeter spatial resolution values. The last technological advance is a PSPMT with Flat Panel structure, named H8500. Its dimension is 50 × 50 mm 2 with a narrow peripheral dead zone to place closely different modules achieving large detection areas. In this paper the technological development of different PSPMT generations is reviewed and some measurements of the first Flat Panel PMT prototype are presented and compared with ones from previous generation. Flat Panel PMT could be the best trade-off between compactness, large detection areas, effective area (packing density) and imaging performance.

  4. Positioning a University Outreach Center: Strategies for Support and Continuation.

    ERIC Educational Resources Information Center

    Skivington, Kristen D.

    1998-01-01

    Argues that a strong case can be made for supporting outreach as a value-added function in a university. Specific strategies for positioning outreach within the university by developing a power base are outlined. The case of the University of Michigan-Flint is offered as an example of this approach. Seven lessons learned in the process are noted.…

  5. Position sensitive detection of neutrons in high radiation background field

    SciTech Connect

    Vavrik, D.; Jakubek, J.; Pospisil, S.; Vacik, J.

    2014-01-15

    We present the development of a high-resolution position sensitive device for detection of slow neutrons in the environment of extremely high γ and e{sup −} radiation background. We make use of a planar silicon pixelated (pixel size: 55 × 55 μm{sup 2}) spectroscopic Timepix detector adapted for neutron detection utilizing very thin {sup 10}B converter placed onto detector surface. We demonstrate that electromagnetic radiation background can be discriminated from the neutron signal utilizing the fact that each particle type produces characteristic ionization tracks in the pixelated detector. Particular tracks can be distinguished by their 2D shape (in the detector plane) and spectroscopic response using single event analysis. A Cd sheet served as thermal neutron stopper as well as intensive source of gamma rays and energetic electrons. Highly efficient discrimination was successful even at very low neutron to electromagnetic background ratio about 10{sup −4}.

  6. ASIC for High Rate 3D Position Sensitive Detectors

    SciTech Connect

    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. Development of a SCALE Tool for Continuous-Energy Eigenvalue Sensitivity Coefficient Calculations

    NASA Astrophysics Data System (ADS)

    Perfetti, Christopher M.; Rearden, Bradley T.

    2014-06-01

    Two methods for calculating eigenvalue sensitivity coefficients in continuous-energy Monte Carlo applications were implemented in the KENO code within the SCALE code package. The methods were used to calculate sensitivity coefficients for several criticality safety problems and produced sensitivity coefficients that agreed well with both reference sensitivities and multigroup TSUNAMI-3D sensitivity coefficients. The newly developed CLUTCH method was observed to produce sensitivity coefficients with high figures of merit and low memory requirements, and both continuous-energy sensitivity methods met or exceeded the accuracy of the multigroup TSUNAMI-3D calculations.

  8. Development of a SCALE Tool for Continuous-Energy Eigenvalue Sensitivity Coefficient Calculations

    SciTech Connect

    Perfetti, Christopher M; Rearden, Bradley T

    2013-01-01

    Two methods for calculating eigenvalue sensitivity coefficients in continuous-energy Monte Carlo applications were implemented in the KENO code within the SCALE code package. The methods were used to calculate sensitivity coefficients for several criticality safety problems and produced sensitivity coefficients that agreed well with both reference sensitivities and multigroup TSUNAMI-3D sensitivity coefficients. The newly developed CLUTCH method was observed to produce sensitivity coefficients with high figures of merit and low memory requirements, and both continuous-energy sensitivity methods met or exceeded the accuracy of the multigroup TSUNAMI-3D calculations.

  9. Continuous-energy eigenvalue sensitivity coefficient calculations in TSUNAMI-3D

    SciTech Connect

    Perfetti, C. M.; Rearden, B. T.

    2013-07-01

    Two methods for calculating eigenvalue sensitivity coefficients in continuous-energy Monte Carlo applications were implemented in the KENO code within the SCALE code package. The methods were used to calculate sensitivity coefficients for several test problems and produced sensitivity coefficients that agreed well with both reference sensitivities and multigroup TSUNAMI-3D sensitivity coefficients. The newly developed CLUTCH method was observed to produce sensitivity coefficients with high figures of merit and a low memory footprint, and both continuous-energy sensitivity methods met or exceeded the accuracy of the multigroup TSUNAMI-3D calculations. (authors)

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

    SciTech Connect

    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.

  11. Pulsed neutron imaging using 2-dimensional position sensitive detectors

    NASA Astrophysics Data System (ADS)

    Kiyanagi, Y.; Kamiyama, T.; Kino, K.; Sato, H.; Sato, S.; Uno, S.

    2014-07-01

    2-dimensional position sensitive detectors are used for pulsed neutron imaging and at each pixel of the detector a time of flight spectrum is recorded. Therefore, a transmission spectrum through the object has wavelength dependent structure reflecting the neutron total cross section. For such measurements, the detectors are required to have ability to store neutron events as a function of the flight time as well as to have good spatial resolution. Furthermore, high counting rate is also required at the high intensity neutron sources like J-PARC neutron source in Japan. We have developed several types of detectors with different characteristics; two counting type detectors for high counting rate with coarse spatial resolution and one camera type detector for high spatial resolution. One of counting type detectors is a pixel type. The highest counting rate is about 28 MHz. Better spatial resolution is obtained by a GEM detector. Effective area is 10 × 10 cm2, pixel size is 0.8 mm. The maximum counting rate is 3.65 MHz. To get higher spatial resolution we are now developing the camera type detector system using a neutron image intensifier, which have image integration function as a function of time of flight. We have succeeded to obtain time dependent images in this camera system. By using these detectors we performed transmission measurements for obtaining the crystallographic information and elemental distribution images.

  12. High resolution, position sensitive detector for energetic particle beams

    NASA Astrophysics Data System (ADS)

    Marsh, E. P.; Strathman, M. D.; Reed, D. A.; Morse, D. H.; Pontau, A. E.; Odom, R. W.

    1993-05-01

    The performance and design of an imaging position sensitive, particle beam detector will be presented. The detector is minimally invasive, operates over a wide dynamic range (> 10 10), and exhibits high spatial resolution. The secondary electrons produced when a particle beam passes through a thin foil are imaged using stigmatic ion optics onto a two-dimensional imaging detector. Due to the low scattering cross section of the 6 nm carbon foil the detector is a minimal perturbation on the primary beam. A prototype detector with an image resolution of approximately 5 μm for a field of view of 1 mm has been reported [R.W. Odom, M.D. Strathman, S.E. Buttrill, Jr., and S.M. Bauman, Nucl. Instr. and Meth. B44 (1990) 465]. A higher resolution detector for imaging small beams (< 50 μm) with an image resolution of better than 0.5 μm has since been developed and its design is presented.

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

    NASA Astrophysics Data System (ADS)

    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.

  14. High-sensitivity, high-speed continuous imaging system

    DOEpatents

    Watson, Scott A; Bender, III, Howard A

    2014-11-18

    A continuous imaging system for recording low levels of light typically extending over small distances with high-frame rates and with a large number of frames is described. Photodiode pixels disposed in an array having a chosen geometry, each pixel having a dedicated amplifier, analog-to-digital convertor, and memory, provide parallel operation of the system. When combined with a plurality of scintillators responsive to a selected source of radiation, in a scintillator array, the light from each scintillator being directed to a single corresponding photodiode in close proximity or lens-coupled thereto, embodiments of the present imaging system may provide images of x-ray, gamma ray, proton, and neutron sources with high efficiency.

  15. 78 FR 42982 - Submission for Review: Information Collection; Questionnaire for Non-Sensitive Positions (SF 85)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-18

    ... MANAGEMENT Submission for Review: Information Collection; Questionnaire for Non-Sensitive Positions (SF 85...), Office of Management and Budget (OMB) Control No. 3206-NEW, for Questionnaire for Non-Sensitive Positions...@opm.gov . SUPPLEMENTARY INFORMATION: The Questionnaire for Non-Sensitive Positions, SF 85, housed in...

  16. Modeling and Implementation of Multi-Position Non-Continuous Rotation Gyroscope North Finder

    PubMed Central

    Luo, Jun; Wang, Zhiqian; Shen, Chengwu; Kuijper, Arjan; Wen, Zhuoman; Liu, Shaojin

    2016-01-01

    Even when the Global Positioning System (GPS) signal is blocked, a rate gyroscope (gyro) north finder is capable of providing the required azimuth reference information to a certain extent. In order to measure the azimuth between the observer and the north direction very accurately, we propose a multi-position non-continuous rotation gyro north finding scheme. Our new generalized mathematical model analyzes the elements that affect the azimuth measurement precision and can thus provide high precision azimuth reference information. Based on the gyro’s principle of detecting a projection of the earth rotation rate on its sensitive axis and the proposed north finding scheme, we are able to deduct an accurate mathematical model of the gyro outputs against azimuth with the gyro and shaft misalignments. Combining the gyro outputs model and the theory of propagation of uncertainty, some approaches to optimize north finding are provided, including reducing the gyro bias error, constraining the gyro random error, increasing the number of rotation points, improving rotation angle measurement precision, decreasing the gyro and the shaft misalignment angles. According them, a north finder setup is built and the azimuth uncertainty of 18” is obtained. This paper provides systematic theory for analyzing the details of the gyro north finder scheme from simulation to implementation. The proposed theory can guide both applied researchers in academia and advanced practitioners in industry for designing high precision robust north finder based on different types of rate gyroscopes. PMID:27657067

  17. Development of Continuous-Energy Eigenvalue Sensitivity Coefficient Calculation Methods in the Shift Monte Carlo Code

    SciTech Connect

    Perfetti, Christopher M; Martin, William R; Rearden, Bradley T; Williams, Mark L

    2012-01-01

    Three methods for calculating continuous-energy eigenvalue sensitivity coefficients were developed and implemented into the SHIFT Monte Carlo code within the Scale code package. The methods were used for several simple test problems and were evaluated in terms of speed, accuracy, efficiency, and memory requirements. A promising new method for calculating eigenvalue sensitivity coefficients, known as the CLUTCH method, was developed and produced accurate sensitivity coefficients with figures of merit that were several orders of magnitude larger than those from existing methods.

  18. Influence of body position on the displacement of nasal prongs in preterm newborns receiving continuous positive airway pressure

    PubMed Central

    Brunherotti, Marisa Afonso Andrade; Martinez, Francisco Eulógio

    2015-01-01

    Abstract Objective: To evaluate the influence of body position on the displacement of nasal prongs in preterm infants. Methods: This prospective, randomized, crossover study enrolled infants born at a mean gestational age of 29.7±2 weeks, birth weight of 1353±280g and 2.9±2.2 days of life, submitted to continuous positive airway pressure by nasal prongs. The main outcome was the number of times that the nasal prongs were displaced following infant positioning in the following body positions: prone, right lateral, left lateral, and supine, according to a pre-established random order. Moreover, cardiorespiratory variables (respiratory rate, heart rate, and oxygen saturation) were evaluated for each body position. Data for each position were collected every 10 min, over a period of 60 min. An occurrence was defined when the nasal prongs were displaced from the nostrils after 3 min in the desired position, requiring intervention of the examiner. Results: Among the 16 studied infants, the occurrence of nasal prong displacement was only observed in the prone position (9 infants - 56.2%) and in the left lateral position (2 infants - 12.5%). The number of times that the prongs were displaced was 11 in the prone position (7 within the first 10min) and 2 in the left lateral position (1 within the first 10min). No clinically significant changes were observed in the cardiorespiratory variables. Conclusions: Maintenance of the nasal prongs to provide adequate noninvasive respiratory support was harder in the prone position. PMID:26116326

  19. Adherence to Continuous Positive Airway Pressure in Existing Users: Self-Efficacy Enhances the Association between Continuous Positive Airway Pressure and Adherence

    PubMed Central

    Dzierzewski, Joseph M.; Wallace, Douglas M.; Wohlgemuth, William K.

    2016-01-01

    Study Objectives: Obstructive sleep apnea-hypopnea syndrome (OSAHS) is a common sleep disorder associated with a myriad of sequelae. OSAHS is effectively treated with continuous positive airway pressure (CPAP) therapy. However, fewer than 50% of patients are compliant with their CPAP therapy prescriptions. The current study sought to explore an integrated, biopsychological approach to CPAP adherence among experienced CPAP users. Methods: We performed a retrospective, cross-sectional analysis of a cohort of veterans with a diagnosis of OSAHS (n = 191) who were prescribed CPAP therapy and returned for adherence download at the Miami VA Sleep Clinic. The relationships between biomedical characteristics (e.g., CPAP pressure, self-reported sleepiness, and change in sleep efficiency) and psychological factors (e.g., self-efficacy beliefs and psychological diagnoses) and objectively measured CPAP use were examined to determine whether psychological factors moderated the relationships between biomedical characteristics and CPAP adherence. Results: Hierarchical regression analyses predicting CPAP adherence (adjusting for time since CPAP prescription, age, education, prescribed CPAP pressure, daytime sleepiness, changes in sleep efficiency with CPAP, and psychiatric conditions) revealed the following: (1) CPAP self-efficacy and CPAP pressure were positively related to adherence, and (2) CPAP self-efficacy moderates the relationship between CPAP pressure and CPAP adherence. Conclusions: There was no relationship between CPAP pressure and adherence in individuals with low self-efficacy beliefs. However, for individuals with high self-efficacy beliefs, there was a significant positive relationship between CPAP pressure and adherence. Self-efficacy beliefs appear to be a prime target for focused interventions aimed at improving CPAP adherence among those individuals with higher pressure prescriptions. Citation: Dzierzewski JM, Wallace DM, Wohlgemuth WK. Adherence to continuous

  20. CONTINUOUS-ENERGY MONTE CARLO METHODS FOR CALCULATING GENERALIZED RESPONSE SENSITIVITIES USING TSUNAMI-3D

    SciTech Connect

    Perfetti, Christopher M; Rearden, Bradley T

    2014-01-01

    This work introduces a new approach for calculating sensitivity coefficients for generalized neutronic responses to nuclear data uncertainties using continuous-energy Monte Carlo methods. The approach presented in this paper, known as the GEAR-MC method, allows for the calculation of generalized sensitivity coefficients for multiple responses in a single Monte Carlo calculation with no nuclear data perturbations or knowledge of nuclear covariance data. The theory behind the GEAR-MC method is presented here, and proof of principle is demonstrated by using the GEAR-MC method to calculate sensitivity coefficients for responses in several 3D, continuous-energy Monte Carlo applications.

  1. Three-dimensional, position-sensitive radiation detection

    DOEpatents

    He, Zhong; Zhang, Feng

    2010-04-06

    Disclosed herein is a method of determining a characteristic of radiation detected by a radiation detector via a multiple-pixel event having a plurality of radiation interactions. The method includes determining a cathode-to-anode signal ratio for a selected interaction of the plurality of radiation interactions based on electron drift time data for the selected interaction, and determining the radiation characteristic for the multiple-pixel event based on both the cathode-to-anode signal ratio and the electron drift time data. In some embodiments, the method further includes determining a correction factor for the radiation characteristic based on an interaction depth of the plurality of radiation interactions, a lateral distance between the selected interaction and a further interaction of the plurality of radiation interactions, and the lateral positioning of the plurality of radiation interactions.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    SciTech Connect

    Not Available

    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.

  4. Use of SCALE Continuous-Energy Monte Carlo Tools for Eigenvalue Sensitivity Coefficient Calculations

    SciTech Connect

    Perfetti, Christopher M; Rearden, Bradley T

    2013-01-01

    The TSUNAMI code within the SCALE code system makes use of eigenvalue sensitivity coefficients for an extensive number of criticality safety applications, such as quantifying the data-induced uncertainty in the eigenvalue of critical systems, assessing the neutronic similarity between different critical systems, and guiding nuclear data adjustment studies. The need to model geometrically complex systems with improved fidelity and the desire to extend TSUNAMI analysis to advanced applications has motivated the development of a methodology for calculating sensitivity coefficients in continuous-energy (CE) Monte Carlo applications. The CLUTCH and Iterated Fission Probability (IFP) eigenvalue sensitivity methods were recently implemented in the CE KENO framework to generate the capability for TSUNAMI-3D to perform eigenvalue sensitivity calculations in continuous-energy applications. This work explores the improvements in accuracy that can be gained in eigenvalue and eigenvalue sensitivity calculations through the use of the SCALE CE KENO and CE TSUNAMI continuous-energy Monte Carlo tools as compared to multigroup tools. The CE KENO and CE TSUNAMI tools were used to analyze two difficult models of critical benchmarks, and produced eigenvalue and eigenvalue sensitivity coefficient results that showed a marked improvement in accuracy. The CLUTCH sensitivity method in particular excelled in terms of efficiency and computational memory requirements.

  5. Methodology, verification, and performance of the continuous-energy nuclear data sensitivity capability in MCNP6

    SciTech Connect

    Kiedrowski, B. C.; Brown, F. B.

    2013-07-01

    A continuous-energy sensitivity coefficient capability has been introduced into MCNP6. The methods for generating energy-resolved and energy-integrated sensitivity profiles are discussed. Results from the verification exercises that were performed are given, and these show that MCNP6 compares favorably with analytic solutions, direct density perturbations, and comparisons to TSUNAMI-3D and MONK. Run-time and memory requirements are assessed for typical applications, and these are shown to be reasonable with modern computing resources. (authors)

  6. Use of Biphasic Continuous Positive Airway Pressure in Premature Infant with Cleft Lip–Cleft Palate

    PubMed Central

    George, Lovya; Jain, Sunil K.

    2015-01-01

    Preterm infants (PIs) often require respiratory support due to surfactant deficiency. Early weaning from mechanical ventilation to noninvasive respiratory support decreases ventilation-associated irreversible lung damage. This wean is particularly challenging in PIs with cleft lip and cleft palate due to anatomical difficulties encountered in maintaining an adequate seal for positive pressure ventilation. PI with a cleft lip and palate often fail noninvasive respiratory support and require continued intubation and mechanical ventilation. We are presenting the first case report of a PI with cleft lip and palate who was managed by biphasic nasal continuous positive airway pressure. PMID:26495158

  7. Development of continuous-energy eigenvalue sensitivity coefficient calculation methods in the shift Monte Carlo Code

    SciTech Connect

    Perfetti, C.; Martin, W.; Rearden, B.; Williams, M.

    2012-07-01

    Three methods for calculating continuous-energy eigenvalue sensitivity coefficients were developed and implemented into the Shift Monte Carlo code within the SCALE code package. The methods were used for two small-scale test problems and were evaluated in terms of speed, accuracy, efficiency, and memory requirements. A promising new method for calculating eigenvalue sensitivity coefficients, known as the CLUTCH method, was developed and produced accurate sensitivity coefficients with figures of merit that were several orders of magnitude larger than those from existing methods. (authors)

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

    PubMed Central

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

    2014-01-01

    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 mm3 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

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

    PubMed

    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

  10. Absolute continuity for operator valued completely positive maps on C*-algebras

    SciTech Connect

    Gheondea, Aurelian; Kavruk, Ali Samil

    2009-02-15

    Motivated by applicability to quantum operations, quantum information, and quantum probability, we investigate the notion of absolute continuity for operator valued completely positive maps on C*-algebras, previously introduced by Parthasarathy [in Athens Conference on Applied Probability and Time Series Analysis I (Springer-Verlag, Berlin, 1996), pp. 34-54]. We obtain an intrinsic definition of absolute continuity, we show that the Lebesgue decomposition defined by Parthasarathy is the maximal one among all other Lebesgue-type decompositions and that this maximal Lebesgue decomposition does not depend on the jointly dominating completely positive map, we obtain more flexible formulas for calculating the maximal Lebesgue decomposition, and we point out the nonuniqueness of the Lebesgue decomposition as well as a sufficient condition for uniqueness. In addition, we consider Radon-Nikodym derivatives for absolutely continuous completely positive maps that, in general, are unbounded positive self-adjoint operators affiliated to a certain von Neumann algebra, and we obtain a spectral approximation by bounded Radon-Nikodym derivatives. An application to the existence of the infimum of two completely positive maps is indicated, and formulas in terms of Choi's matrices for the Lebesgue decomposition of completely positive maps in matrix algebras are obtained.

  11. Human sensitivity to the magnitude and probability of a continuous causal relation in a video game.

    PubMed

    Young, Michael E; Cole, James J

    2012-01-01

    Continuous causation, in which incremental changes in one variable cause incremental changes in another, has received little attention in the causal judgment literature. A video game was adapted for the study of continuous causality in order to examine the novel cues to causality that are present in these paradigms. The spatial proximity of an object to an "enemy detector" produced auditory responses as a function of the object's proximity. Participants' behavior was a function of the range of the effect's auditory sensitivity and the moment-to-moment likelihood of detection. This new paradigm provides a rich platform for examining the cues to causation encountered in the learning of continuous causal relations.

  12. Motivational Interviewing (MINT) Improves Continuous Positive Airway Pressure (CPAP) Acceptance and Adherence: A Randomized Controlled Trial

    ERIC Educational Resources Information Center

    Olsen, Sara; Smith, Simon S.; Oei, Tian P. S.; Douglas, James

    2012-01-01

    Objective: Adherence to continuous positive airway pressure (CPAP) therapy for obstructive sleep apnoea (OSA) is poor. We assessed the effectiveness of a motivational interviewing intervention (motivational interview nurse therapy [MINT]) in addition to best practice standard care to improve acceptance and adherence to CPAP therapy in people with…

  13. The effect of positive reinforcement on hourly compliance in nasal continuous positive airway pressure users with obstructive sleep apnea.

    PubMed

    Fletcher, E C; Luckett, R A

    1991-05-01

    Previous reports have described compliance with nasal continuous positive airway pressure (nCPAP) for the treatment of obstructive sleep apnea (OSA) only in terms of the number of patients able to use it beyond their initial trial night or those continuing after some home use. Because of a possible difference between the level of compliance (mean number of hours of use per 24 h) needed for symptomatic relief of OSA versus cardiovascular improvement, the level of hourly compliance in chronic nCPAP users may be important. The first part of this study prospectively examines compliance in a stable population of OSA patients already using nCPAP for 6 months to 2 yr. The second part is a prospective randomized, crossover study examining the effect of weekly (three times) then monthly (twice) positive reinforcement on hourly compliance of new nCPAP users for 3 months versus no reinforcement for 3 months. Positive reinforcement consisted of telephone discussions with the patients about the severity or complications of OSA, benefits of nCPAP, and suggestions about minimizing side effects. Using self-assessment scales, each patient reported the perceived level of improvement from the untreated to the treated condition and the prevalence and severity of side effects from the nCPAP therapy. The level of compliance in stable, chronic nCPAP users with OSA was 6.1 +/- 2.2 h/24 h (n = 9). For the new nCPAP users during the nonreinforced period, the mean compliance was 6.0 +/- 2.8 h/24 h; that during the reinforcement period was 6.0 +/- 2.7 h/24 h (NS). There was no significant correlation between perceived improvement in OSA symptoms or between the perceived side effects of nCPAP versus hourly compliance.(ABSTRACT TRUNCATED AT 250 WORDS)

  14. Continuous Indoor Positioning Fusing WiFi, Smartphone Sensors and Landmarks.

    PubMed

    Deng, Zhi-An; Wang, Guofeng; Qin, Danyang; Na, Zhenyu; Cui, Yang; Chen, Juan

    2016-01-01

    To exploit the complementary strengths of WiFi positioning, pedestrian dead reckoning (PDR), and landmarks, we propose a novel fusion approach based on an extended Kalman filter (EKF). For WiFi positioning, unlike previous fusion approaches setting measurement noise parameters empirically, we deploy a kernel density estimation-based model to adaptively measure the related measurement noise statistics. Furthermore, a trusted area of WiFi positioning defined by fusion results of previous step and WiFi signal outlier detection are exploited to reduce computational cost and improve WiFi positioning accuracy. For PDR, we integrate a gyroscope, an accelerometer, and a magnetometer to determine the user heading based on another EKF model. To reduce accumulation error of PDR and enable continuous indoor positioning, not only the positioning results but also the heading estimations are recalibrated by indoor landmarks. Experimental results in a realistic indoor environment show that the proposed fusion approach achieves substantial positioning accuracy improvement than individual positioning approaches including PDR and WiFi positioning. PMID:27608019

  15. Continuous Indoor Positioning Fusing WiFi, Smartphone Sensors and Landmarks

    PubMed Central

    Deng, Zhi-An; Wang, Guofeng; Qin, Danyang; Na, Zhenyu; Cui, Yang; Chen, Juan

    2016-01-01

    To exploit the complementary strengths of WiFi positioning, pedestrian dead reckoning (PDR), and landmarks, we propose a novel fusion approach based on an extended Kalman filter (EKF). For WiFi positioning, unlike previous fusion approaches setting measurement noise parameters empirically, we deploy a kernel density estimation-based model to adaptively measure the related measurement noise statistics. Furthermore, a trusted area of WiFi positioning defined by fusion results of previous step and WiFi signal outlier detection are exploited to reduce computational cost and improve WiFi positioning accuracy. For PDR, we integrate a gyroscope, an accelerometer, and a magnetometer to determine the user heading based on another EKF model. To reduce accumulation error of PDR and enable continuous indoor positioning, not only the positioning results but also the heading estimations are recalibrated by indoor landmarks. Experimental results in a realistic indoor environment show that the proposed fusion approach achieves substantial positioning accuracy improvement than individual positioning approaches including PDR and WiFi positioning. PMID:27608019

  16. Continuous Indoor Positioning Fusing WiFi, Smartphone Sensors and Landmarks.

    PubMed

    Deng, Zhi-An; Wang, Guofeng; Qin, Danyang; Na, Zhenyu; Cui, Yang; Chen, Juan

    2016-09-05

    To exploit the complementary strengths of WiFi positioning, pedestrian dead reckoning (PDR), and landmarks, we propose a novel fusion approach based on an extended Kalman filter (EKF). For WiFi positioning, unlike previous fusion approaches setting measurement noise parameters empirically, we deploy a kernel density estimation-based model to adaptively measure the related measurement noise statistics. Furthermore, a trusted area of WiFi positioning defined by fusion results of previous step and WiFi signal outlier detection are exploited to reduce computational cost and improve WiFi positioning accuracy. For PDR, we integrate a gyroscope, an accelerometer, and a magnetometer to determine the user heading based on another EKF model. To reduce accumulation error of PDR and enable continuous indoor positioning, not only the positioning results but also the heading estimations are recalibrated by indoor landmarks. Experimental results in a realistic indoor environment show that the proposed fusion approach achieves substantial positioning accuracy improvement than individual positioning approaches including PDR and WiFi positioning.

  17. A comparative study of continuous positive airway pressure (CPAP) and intermittent positive pressure ventilation (IPPV) in patients with flail chest

    PubMed Central

    Gunduz, M; Unlugenc, H; Ozalevli, M; Inanoglu, K; Akman, H

    2005-01-01

    Introduction: The role of non-invasive positive pressure ventilation delivered through a face mask in patients with flail chest is uncertain. We conducted a prospective, randomised study of continuous positive airway pressure (CPAP) given via a face mask to spontaneously breathing patients compared with intermittent positive pressure ventilation (IPPV) with endotracheal intubation (ETI) in 52 patients with flail chest who required mechanical ventilation. Method: The 52 mechanically ventilated patients were randomly divided into two treatment groups: the ET group (n = 27) received mechanical ventilation with ETI, whereas patients in the CPAP group (n = 25) received CPAP via a face mask with patient controlled analgesia (PCA). Major complications, arterial blood gas levels, length of intensive care unit (ICU) stay and ICU survival rate were recorded. Results: Nosocomial infection was diagnosed in 10 of 21 patients in the ET group, but only in 4 of 22 in the CPAP group (p = 0.001). Mean PO2 was significantly higher in the ET group in the first 2 days (p<0.05). There were no significant differences in length of ICU stay between groups. Twenty CPAP patients survived, but only 14 of 21 intubated patients who received IPPV (p<0.01). Conclusion: Non-invasive CPAP with PCA led to lower mortality and a lower nosocomial infection rate, but similar oxygenation and length of ICU stay. The study supports the application of CPAP at least as a first line of treatment for flail chest caused by blunt thoracic trauma. PMID:15843697

  18. Theoretical Noise Analysis on a Position-sensitive Metallic Magnetic Calorimeter

    NASA Technical Reports Server (NTRS)

    Smith, Stephen J.

    2007-01-01

    We report on the theoretical noise analysis for a position-sensitive Metallic Magnetic Calorimeter (MMC), consisting of MMC read-out at both ends of a large X-ray absorber. Such devices are under consideration as alternatives to other cryogenic technologies for future X-ray astronomy missions. We use a finite-element model (FEM) to numerically calculate the signal and noise response at the detector outputs and investigate the correlations between the noise measured at each MMC coupled by the absorber. We then calculate, using the optimal filter concept, the theoretical energy and position resolution across the detector and discuss the trade-offs involved in optimizing the detector design for energy resolution, position resolution and count rate. The results show, theoretically, the position-sensitive MMC concept offers impressive spectral and spatial resolving capabilities compared to pixel arrays and similar position-sensitive cryogenic technologies using Transition Edge Sensor (TES) read-out.

  19. K-Eigenvalue sensitivities of secondary distributions of continuous-energy data

    SciTech Connect

    Kiedrowski, B. C.; Brown, F. B.

    2013-07-01

    MCNP6 has the capability to produce energy-resolved sensitivity profiles for secondary distributions (fission {Chi} and scattering laws). Computing both unconstrained and constrained profiles are possible. Verification is performed with analytic test problems and a comparison to TSUNAMI-3D, and the comparisons show MCNP6 calculates correct or consistent results. Continuous-energy calculations are performed for three fast critical experiments: Jezebel, Flattop, and copper-reflected Zeus. The sensitivities to the secondary distributions (integrated over chosen energy ranges) are of similar magnitude to those of many of the cross sections, demonstrating the possibility that integral experiments are useful for assessing the fidelity of these data as well. (authors)

  20. Effect of positive and negative defocus on contrast sensitivity in myopes and non-myopes.

    PubMed

    Radhakrishnan, Hema; Pardhan, Shahina; Calver, Richard I; O'Leary, Daniel J

    2004-01-01

    This study investigated the effect of lens induced defocus on the contrast sensitivity function in myopes and non-myopes. Contrast sensitivity for up to 20 spatial frequencies ranging from 1 to 20 c/deg was measured with vertical sine wave gratings under cycloplegia at different levels of positive and negative defocus in myopes and non-myopes. In non-myopes the reduction in contrast sensitivity increased in a systematic fashion as the amount of defocus increased. This reduction was similar for positive and negative lenses of the same power (p = 0.474). Myopes showed a contrast sensitivity loss that was significantly greater with positive defocus compared to negative defocus (p = 0.001). The magnitude of the contrast sensitivity loss was also dependent on the spatial frequency tested for both positive and negative defocus. There was significantly greater contrast sensitivity loss in non-myopes than in myopes at low-medium spatial frequencies (1-8 c/deg) with negative defocus. Latent accommodation was ruled out as a contributor to this difference in myopes and non-myopes. In another experiment, ocular aberrations were measured under cycloplegia using a Shack-Hartmann aberrometer. Modulation transfer functions were calculated using the second order term for defocus as well as the fourth order Zernike term for spherical aberration. The theoretical maximal contrast sensitivity based on aberration data predicted the measured asymmetry in contrast sensitivity to positive and negative defocus that was observed in myopic subjects. The observed asymmetry in contrast sensitivity with positive and negative defocus in myopes may be linked to the altered accommodative response observed in this group.

  1. Ant colony optimization algorithm for continuous domains based on position distribution model of ant colony foraging.

    PubMed

    Liu, Liqiang; Dai, Yuntao; Gao, Jinyu

    2014-01-01

    Ant colony optimization algorithm for continuous domains is a major research direction for ant colony optimization algorithm. In this paper, we propose a distribution model of ant colony foraging, through analysis of the relationship between the position distribution and food source in the process of ant colony foraging. We design a continuous domain optimization algorithm based on the model and give the form of solution for the algorithm, the distribution model of pheromone, the update rules of ant colony position, and the processing method of constraint condition. Algorithm performance against a set of test trials was unconstrained optimization test functions and a set of optimization test functions, and test results of other algorithms are compared and analyzed to verify the correctness and effectiveness of the proposed algorithm. PMID:24955402

  2. Ant Colony Optimization Algorithm for Continuous Domains Based on Position Distribution Model of Ant Colony Foraging

    PubMed Central

    Liu, Liqiang; Dai, Yuntao

    2014-01-01

    Ant colony optimization algorithm for continuous domains is a major research direction for ant colony optimization algorithm. In this paper, we propose a distribution model of ant colony foraging, through analysis of the relationship between the position distribution and food source in the process of ant colony foraging. We design a continuous domain optimization algorithm based on the model and give the form of solution for the algorithm, the distribution model of pheromone, the update rules of ant colony position, and the processing method of constraint condition. Algorithm performance against a set of test trials was unconstrained optimization test functions and a set of optimization test functions, and test results of other algorithms are compared and analyzed to verify the correctness and effectiveness of the proposed algorithm. PMID:24955402

  3. Sensitivity analysis and parameter identification of nonlinear hybrid systems for glycerol transport mechanisms in continuous culture.

    PubMed

    Gao, Kuikui; Zhang, Xu; Feng, Enmin; Xiu, Zhilong

    2014-04-21

    In this paper, we establish a modified fourteen-dimensional nonlinear hybrid dynamic system with genetic regulation to describe the microbial continuous culture, in which we consider that there are three possible ways for glycerol to pass the cell's membrane and one way for 1,3-PD (passive diffusion and active transport). Then we discuss the existence, uniqueness, continuous dependence of solutions and the compactness of the solution set. We construct a global sensitivity analysis approach to reduce the number of kinetic parameters. In order to infer the most reasonable transport mechanism of glycerol, we propose a parameter identification model aiming at identifying the parameter with higher sensitivity and transport of glycerol, which takes the robustness index of the intracellular substance together with the relative error between the experimental data and the computational values of the extracellular substance as a performance index. Finally, a parallel algorithm is applied to find the optimal transport of glycerol and parameters. PMID:24406809

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

    NASA Technical Reports Server (NTRS)

    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

  5. Continued Sensitivity of Plasmodium falciparum to Artemisinin in Guyana, With Absence of Kelch Propeller Domain Mutant Alleles

    PubMed Central

    Rahman, Reyaud; Martin, Maria Jesus Sanchez; Persaud, Shamdeo; Ceron, Nicolas; Kellman, Dwayne; Musset, Lise; Carter, Keith H.; Ringwald, Pascal

    2016-01-01

    Because of concerns about possible emergence of artemisinin resistance strains of Plasmodium falciparum in mining areas of the interior of Guyana, a 7-day artesunate trial was conducted from March to December 2014. The day-3 parasite clearance rate, the efficacy of artesunate at day 28, and polymorphism of Kelch 13 (PfK13)—the marker of artemisinin resistance—were assessed. The study confirmed the continued sensitivity of P falciparum to artemisinin. A 7-day course of artesunate was 100% efficacious with only 2% (95% confidence interval, .1%–10.9%) of enrolled subjects positive at day 3. All day-0 parasite samples were wild type. Continued resistance monitoring is nevertheless recommended, given the widespread availability and uncontrolled use of artemisinin drugs in mining areas of Guyana. PMID:27704030

  6. A position sensitive time of flight detector for heavy ion ERD

    NASA Astrophysics Data System (ADS)

    Eschbaumer, S.; Bergmaier, A.; Dollinger, G.

    2016-03-01

    A new 2D position sensitive time of flight detector for heavy ion ERD has been developed. The detector features separate time and position measurement in a straight geometry. An electrostatic lens focuses the secondary electrons ejected from a carbon foil onto a channel plate stack maintaining the position information despite the electron momentum distribution. For position readout a 2D Backgammon anode is used. A position resolution of <0.6 mm (FWHM) and a time resolution of 96 ps (FWHM) is demonstrated.

  7. DETECTORS AND EXPERIMENTAL METHODS: New test and analysis of position-sensitive-silicon-detector

    NASA Astrophysics Data System (ADS)

    Feng, Lang; Ge, Yu-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.

  8. Effects of rider position on continuous wave Doppler responses to maximal cycle ergometry.

    PubMed

    Franke, W D; Betz, C B; Humphrey, R H

    1994-03-01

    Using 10 well-trained (VO2peak = 60.6 ml kg-1min-1) college age cyclists and continuous wave Doppler echocardiography, peak acceleration (PkA) and velocity (PkV) of blood flow in the ascending aorta, and the stroke velocity integral (SVI) were assessed to determine if rider position influenced the central haemodynamic responses to graded maximal cycle ergometry. Cyclist position was determined by hand placement on the uprights (UPRI) or drops (DROP) of conventional handlebars or using aerodynamic handlebars (AHB). All subjects consistently achieved a peak workload of 300 W. The Doppler variables did not differ significantly between rider positions at each stage of the maximal exercise tests but did change in response to increasing workloads. PkA was significantly (P < 0.05) greater at workloads > or = 240 W versus < or = 120 W. PkV increased significantly (P < 0.05) up to 180 W and then reached a plateau. SVI increased to a workload of 120 W and then progressively declined, becoming significantly (P < 0.05) less at 300 W. For each stage, neither submaximal VO2, VI nor heart rate (HR) differed significantly between each trial. These results suggest that rider position does not affect the physiological response to maximal bicycle ergometry as responses to each position are similar. PMID:8044492

  9. Linear motor drive system for continuous-path closed-loop position control of an object

    DOEpatents

    Barkman, William E.

    1980-01-01

    A precision numerical controlled servo-positioning system is provided for continuous closed-loop position control of a machine slide or platform driven by a linear-induction motor. The system utilizes filtered velocity feedback to provide system stability required to operate with a system gain of 100 inches/minute/0.001 inch of following error. The filtered velocity feedback signal is derived from the position output signals of a laser interferometer utilized to monitor the movement of the slide. Air-bearing slides mounted to a stable support are utilized to minimize friction and small irregularities in the slideway which would tend to introduce positioning errors. A microprocessor is programmed to read command and feedback information and converts this information into the system following error signal. This error signal is summed with the negative filtered velocity feedback signal at the input of a servo amplifier whose output serves as the drive power signal to the linear motor position control coil.

  10. Effects of rider position on continuous wave Doppler responses to maximal cycle ergometry.

    PubMed Central

    Franke, W D; Betz, C B; Humphrey, R H

    1994-01-01

    Using 10 well-trained (VO2peak = 60.6 ml kg-1min-1) college age cyclists and continuous wave Doppler echocardiography, peak acceleration (PkA) and velocity (PkV) of blood flow in the ascending aorta, and the stroke velocity integral (SVI) were assessed to determine if rider position influenced the central haemodynamic responses to graded maximal cycle ergometry. Cyclist position was determined by hand placement on the uprights (UPRI) or drops (DROP) of conventional handlebars or using aerodynamic handlebars (AHB). All subjects consistently achieved a peak workload of 300 W. The Doppler variables did not differ significantly between rider positions at each stage of the maximal exercise tests but did change in response to increasing workloads. PkA was significantly (P < 0.05) greater at workloads > or = 240 W versus < or = 120 W. PkV increased significantly (P < 0.05) up to 180 W and then reached a plateau. SVI increased to a workload of 120 W and then progressively declined, becoming significantly (P < 0.05) less at 300 W. For each stage, neither submaximal VO2, VI nor heart rate (HR) differed significantly between each trial. These results suggest that rider position does not affect the physiological response to maximal bicycle ergometry as responses to each position are similar. PMID:8044492

  11. A Beta-Particle Hodoscope Constructed Using Scintillating Optical Fibers and Position Sensitive Photomultiplier Tubes

    SciTech Connect

    Orrell, John L.; Aalseth, Craig E.; Day, Anthony R.; Fast, Jim; Hossbach, Todd W.; Lidey, Lance S.; Ripplinger, Mike D.; Schrom, Brian T.

    2006-09-19

    A hodoscopic detector was constructed using a position-sensitive plastic scintillator active area to determine the location of beta-active micron-sized particulates on air filters. The ability to locate beta active particulates on airsample filters is a tool for environmental monitoring of anthropogenic production of radioactive material. A robust, field-deployable instrument can provide localization of radioactive particulate with position resolution of a few millimeters. The detector employs a novel configuration of scintillating plastic elements usually employed at much higher charged particle energies. A filter is placed on this element for assay. The detector is intended to be sensitive to activity greater than 1 Bq. The physical design, position reconstruction method, and expected detector sensitivity are reported.

  12. Spectral comparison of continuous Global Positioning System and strainmeter measurements of crustal deformation

    NASA Technical Reports Server (NTRS)

    Tralli, David M.

    1991-01-01

    Temporal power spectral density models of noise in continuous crustal deformation measurements obtained with the Global Positioning System (GPS) and high-quality strainmeters are compared. The crossover frequency at which GPS measurement noise is less than that of strainmeters is determined. Assuming GPS precision of 0.1 to 1 cm in horizontal components for baselines up to 100 km in length, local deformation monitoring with GPS may be preferable to strainmeters for observations of short-term deformation in under 6 months of continuous (at least daily) measurements. Short-period tropospheric path delays and multipath effects, which may obscure GPS-determined strain signals in local network measurements, also are discussed.

  13. Bubble continuous positive airway pressure in a human immunodeficiency virus-infected infant

    PubMed Central

    McCollum, E. D.; Smith, A.; Golitko, C. L.

    2014-01-01

    SUMMARY World Health Organization-classified very severe pneumonia due to Pneumocystis jirovecii infection is recognized as a life-threatening condition in human immunodeficiency virus (HIV) infected infants. We recount the use of nasal bubble continuous positive airway pressure (BCPAP) in an HIV-infected African infant with very severe pneumonia and treatment failure due to suspected infection with P. jirovecii. We also examine the potential implications of BCPAP use in resource-poor settings with a high case index of acute respiratory failure due to HIV-related pneumonia, but limited access to mechanical ventilation. PMID:21396221

  14. Management of severe obstructive sleep apnea using mandibular advancement devices with auto continuous positive airway pressures

    PubMed Central

    Upadhyay, Rashmi; Dubey, Abhishek; Kant, Surya; Singh, Balendra Pratap

    2015-01-01

    The use of continuous positive airway pressures (CPAP) is considered standard treatment of moderate to severe obstructive sleep apnea (OSA). Treatment of the disease poses a great challenge not only for its diagnostic purpose but also for its treatment part. In about 29-83% of the patients, treatment is difficult because of non-compliance resulting due to high pressures, air leaks and other related issues. In such situations, alternative methods of treatment need to be looked for so as to ascertain better management. Mandibular advancement devices along with CPAP may show better treatment outcome in specific situations. PMID:25814802

  15. Residual Daytime Sleepiness in Obstructive Sleep Apnea After Continuous Positive Airway Pressure Optimization: Causes and Management.

    PubMed

    Chapman, Julia L; Serinel, Yasmina; Marshall, Nathaniel S; Grunstein, Ronald R

    2016-09-01

    Excessive daytime sleepiness (EDS) is common in obstructive sleep apnea (OSA), but it is also common in the general population. When sleepiness remains after continuous positive airway pressure (CPAP) treatment of OSA, comorbid conditions or permanent brain injury before CPAP therapy may be the cause of the residual sleepiness. There is currently no broad approach to treating residual EDS in patients with OSA. Individual assessment must be made of comorbid conditions and medications, and of lifestyle factors that may be contributing to the sleepiness. Modafinil and armodafinil are the only pharmacologic agents indicated for residual sleepiness in these patients. PMID:27542881

  16. Single-point position and transition defects in continuous time quantum walks

    PubMed Central

    Li, Z. J.; Wang, J. B.

    2015-01-01

    We present a detailed analysis of continuous time quantum walks (CTQW) with both position and transition defects defined at a single point in the line. Analytical solutions of both traveling waves and bound states are obtained, which provide valuable insight into the dynamics of CTQW. The number of bound states is found to be critically dependent on the defect parameters, and the localized probability peaks can be readily obtained by projecting the state vector of CTQW on to these bound states. The interference between two bound states are also observed in the case of a transition defect. The spreading of CTQW probability over the line can be finely tuned by varying the position and transition defect parameters, offering the possibility of precision quantum control of the system. PMID:26323855

  17. Development and characterisation of a silicon PIN diode array based highly sensitive portable continuous radon monitor.

    PubMed

    Ashokkumar, P; Sahoo, B K; Raman, Anand; Mayya, Y S

    2014-03-01

    This paper discusses the development and characterisation of a portable and highly sensitive continuous radon monitor (CRM) based on an array of in-house developed silicon PIN diode detectors. The development of this system was initiated in view of the limitations of the available similar radon measurement systems with regards to low sensitivity. The system utilises a hemispherical metal chamber (1 L capacity) for active air sampling. A quantitative estimation of radon concentration is carried out through alpha spectroscopy of electro-deposited (222)Rn decay products on the detector surface. The system was successfully tested and characterised in laboratory conditions. The characterisation experiments included optimisation of sensitivity, calibration with respect to linearity and a study of the influence of humidity on its performance. The novel PIN diode array design yields a high sensitivity of 1.76 ± 0.003 counts h(-1)/(Bq m(-3)) at a relative humidity level of 10% in the sampled air, which is more than two times as high as that reported for similar commercial systems. This instrument displayed a minimum detectable activity level of 0.80 Bq m(-3). PMID:24334292

  18. Continuous and Discrete Space Particle Filters for Predictions in Acoustic Positioning

    NASA Astrophysics Data System (ADS)

    Bauer, Will; Kim, Surrey; Kouritzin, Michael A.

    2002-12-01

    Predicting the future state of a random dynamic signal based on corrupted, distorted, and partial observations is vital for proper real-time control of a system that includes time delay. Motivated by problems from Acoustic Positioning Research Inc., we consider the continual automated illumination of an object moving within a bounded domain, which requires object location prediction due to inherent mechanical and physical time lags associated with robotic lighting. Quality computational predictions demand high fidelity models for the coupled moving object signal and observation equipment pair. In our current problem, the signal represents the vector position, orientation, and velocity of a stage performer. Acoustic observations are formed by timing ultrasonic waves traveling from four perimeter speakers to a microphone attached to the performer. The goal is to schedule lighting movements that are coordinated with the performer by anticipating his/her future position based upon these observations using filtering theory. Particle system based methods have experienced rapid development and have become an essential technique of contemporary filtering strategies. Hitherto, researchers have largely focused on continuous state particle filters, ranging from traditional weighted particle filters to adaptive refining particle filters, readily able to perform path-space estimation and prediction. Herein, we compare the performance of a state-of-the-art refining particle filter to that of a novel discrete-space particle filter on the acoustic positioning problem. By discrete space particle filter we mean a Markov chain that counts particles in discretized cells of the signal state space in order to form an approximated unnormalized distribution of the signal state. For both filters mentioned above, we will examine issues like the mean time to localize a signal, the fidelity of filter estimates at various signal to noise ratios, computational costs, and the effect of signal

  19. Sensitivities of five alpha continuous air monitors for detection of airborne sup 239 Pu

    SciTech Connect

    McIsaac, C.V.; Amaro, C.R.

    1992-07-01

    Results of measurements of the sensitivities of five alpha continuous air monitors (CAMs) for detection of airborne {sup 239}Pu are presented. Four commercially available alpha CAMs (Kurz model 8311, Merlin Gerin Edgar, RADeCO model 452, and Victoreen model 758) and a prototype alpha CAM currently in use at Argonne National Laboratory- West (ANL-W) were tested sampling natural ambient air and laboratory-generated atmospheres laden with either blank dust or dust containing nCi/g concentrations of {sup 239}Pu. Cumulative alpha spectra were stored at 30 or 60 minute intervals during each sampling and were subsequently analyzed using three different commonly used alpha spectrum analysis algorithms. The effect of airborne dust concentration and sample filter porosity on detector resolution and sensitivity for airborne {sup 239}Pu are described.

  20. Sensitivities of five alpha continuous air monitors for detection of airborne {sup 239}Pu

    SciTech Connect

    McIsaac, C.V.; Amaro, C.R.

    1992-07-01

    Results of measurements of the sensitivities of five alpha continuous air monitors (CAMs) for detection of airborne {sup 239}Pu are presented. Four commercially available alpha CAMs (Kurz model 8311, Merlin Gerin Edgar, RADeCO model 452, and Victoreen model 758) and a prototype alpha CAM currently in use at Argonne National Laboratory- West (ANL-W) were tested sampling natural ambient air and laboratory-generated atmospheres laden with either blank dust or dust containing nCi/g concentrations of {sup 239}Pu. Cumulative alpha spectra were stored at 30 or 60 minute intervals during each sampling and were subsequently analyzed using three different commonly used alpha spectrum analysis algorithms. The effect of airborne dust concentration and sample filter porosity on detector resolution and sensitivity for airborne {sup 239}Pu are described.

  1. Sensitization to petrolatum: an unusual cause of false-positive drug patch-tests.

    PubMed

    Ulrich, G; Schmutz, J L; Trechot, Ph; Commun, N; Barbaud, A

    2004-09-01

    We report on an unexpected sensitization to petrolatum diagnosed with the occurrence of multiple nonrelevant and false-positive drug patch-tests performed while investigating a patient suffering from many cutaneous adverse drug reactions. All the positive drug patch-tests were prepared with GILBERT vaseline. This petrolatum reaction is positive as it was tested with five other brands of petrolatums a few months later. As the same petrolatums, but from different batches were tested, patch-tests with GILBERT petrolatum were doubtful, while other petrolatums were positive. White petrolatum is a mixture of semisolid hydrocarbons of the methane series. The sensitizing impurities of petrolatum are polycyclic aromatic hydrocarbons, e.g. phenanthrene derivatives. The purity of petrolatum depends on both the petroleum stock and on the production and packaging methods. Even if rare, contact sensitization to petrolatum can disturb the interpretation of drug patch-tests. It is necessary in the interpretation of drug patch-tests to test both in petrolatum and other vehicles and with all the different petrolatums used in preparing the material for drug patch-tests. So, it is essential to advise the patients sensitized to petrolatum to remove all the topical drugs, such as all the cosmetics, which contain petrolatum in their formulation.

  2. Face Inversion Disproportionately Disrupts Sensitivity to Vertical over Horizontal Changes in Eye Position

    ERIC Educational Resources Information Center

    Crookes, Kate; Hayward, William G.

    2012-01-01

    Presenting a face inverted (upside down) disrupts perceptual sensitivity to the spacing between the features. Recently, it has been shown that this disruption is greater for vertical than horizontal changes in eye position. One explanation for this effect proposed that inversion disrupts the processing of long-range (e.g., eye-to-mouth distance)…

  3. Sensitivity to Social Contingency and Positive Emotion in 2-Month-Olds

    ERIC Educational Resources Information Center

    Soussignan, Robert; Nadel, Jacqueline; Canet, Pierre; Gerardin, Priscille

    2006-01-01

    This study was aimed at sorting out conflicting results in the literature concerning 2-month-olds' sensitivity to interpersonal contingency, and investigated the potential role of infants' positive emotion in contingency detection. Infants were randomly assigned to an experimental group (EG) that was presented an uninterrupted live-replay-live…

  4. 3D position estimation using an artificial neural network for a continuous scintillator PET detector

    NASA Astrophysics Data System (ADS)

    Wang, Y.; Zhu, W.; Cheng, X.; Li, D.

    2013-03-01

    Continuous crystal based PET detectors have features of simple design, low cost, good energy resolution and high detection efficiency. Through single-end readout of scintillation light, direct three-dimensional (3D) position estimation could be another advantage that the continuous crystal detector would have. In this paper, we propose to use artificial neural networks to simultaneously estimate the plane coordinate and DOI coordinate of incident γ photons with detected scintillation light. Using our experimental setup with an ‘8 + 8’ simplified signal readout scheme, the training data of perpendicular irradiation on the front surface and one side surface are obtained, and the plane (x, y) networks and DOI networks are trained and evaluated. The test results show that the artificial neural network for DOI estimation is as effective as for plane estimation. The performance of both estimators is presented by resolution and bias. Without bias correction, the resolution of the plane estimator is on average better than 2 mm and that of the DOI estimator is about 2 mm over the whole area of the detector. With bias correction, the resolution at the edge area for plane estimation or at the end of the block away from the readout PMT for DOI estimation becomes worse, as we expect. The comprehensive performance of the 3D positioning by a neural network is accessed by the experimental test data of oblique irradiations. To show the combined effect of the 3D positioning over the whole area of the detector, the 2D flood images of oblique irradiation are presented with and without bias correction.

  5. Impact of Treatment with Continuous Positive Airway Pressure (CPAP) on Weight in Obstructive Sleep Apnea

    PubMed Central

    Quan, Stuart F.; Budhiraja, Rohit; Clarke, Denise P.; Goodwin, James L.; Gottlieb, Daniel J.; Nichols, Deborah A.; Simon, Richard D.; Smith, Terry W.; Walsh, James K.; Kushida, Clete A.

    2013-01-01

    Study Objective: To determine the impact of continuous positive airway pressure (CPAP) on weight change in persons with obstructive sleep apnea (OSA). Design, Setting, and Participants: The Apnea Positive Pressure Long-term Efficacy Study (APPLES) was a 6-month, randomized, double-blinded sham-controlled multicenter clinical trial conducted at 5 sites in the United States. Of 1,105 participants with an apnea hypopnea index ≥ 10 events/ hour initially randomized, 812 had body weight measured at baseline and after 6 months of study. Intervention: CPAP or Sham CPAP. Measurements: Body weight, height, hours of CPAP or Sham CPAP use, Epworth Sleepiness Scale score. Results: Participants randomized to CPAP gained 0.35 ± 5.01 kg, whereas those on Sham CPAP lost 0.70 ± 4.03 kg (mean ± SD, p = 0.001). Amount of weight gain with CPAP was related to hours of device adherence, with each hour per night of use predicting a 0.42 kg increase in weight. This association was not noted in the Sham CPAP group. CPAP participants who used their device ≥ 4 h per night on ≥ 70% of nights gained the most weight over 6 months in comparison to non-adherent CPAP participants (1.0 ± 5.3 vs. -0.3 ± 5.0 kg, p = 0.014). Conclusions: OSA patients using CPAP may gain a modest amount of weight with the greatest weight gain found in those most compliant with CPAP. Commentary: A commentary on this article appears in this issue on page 995. Citation: Quan SF; Budhiraja R; Clarke DP; Goodwin JL; Gottlieb DJ; Nichols DA; Simon RD; Smith TW; Walsh JK; Kushida CA. Impact of treatment with continuous positive airway pressure (CPAP) on weight in obstructive sleep apnea. J Clin Sleep Med 2013;9(10):989-993. PMID:24127141

  6. Sensitivity of the ice-divide position in Greenland to climate change

    SciTech Connect

    Anandakrishnan, S.; Alley, R.B.; Waddington, E.D. |

    1994-03-01

    Model calculations of depth-age relations for deep ice cores in central Greenland are sensitive to stability of the ice-divide position. In addition, the folding of layers observed in the deep ice could be instigated by divide migration changing the velocity and particle paths of ice flow. We use simple steady-state calculations to show that lateral divide migration of between 10 km and 50 km and elevation change of approximately 100 m is likely on glacial-interglacial time scales, enough to affect model dating. The ice-divide location appears to be most sensitive to the position of the ice-sheet margins. By contrast, the ice-divide elevation is most sensitive to the accumulation rate, the temperature profile, and the ice-stiffness profile.

  7. A New Animal Model of Obstructive Sleep Apnea Responding to Continuous Positive Airway Pressure

    PubMed Central

    Neuzeret, Pierre-Charles; Gormand, Frédéric; Reix, Philippe; Parrot, Sandrine; Sastre, Jean-Pierre; Buda, Colette; Guidon, Gérard; Sakai, Kazuya; Lin, Jian-Sheng

    2011-01-01

    Study Objectives: An improved animal model of obstructive sleep apnea (OSA) is needed for the development of effective pharmacotherapies. In humans, flexion of the neck and a supine position, two main pathogenic factors during human sleep, are associated with substantially greater OSA severity. We postulated that these two factors might generate OSA in animals. Design: We developed a restraining device for conditioning to investigate the effect of the combination of 2 body positions—prone (P) or supine (S)—and 2 head positions—with the neck flexed at right angles to the body (90°) or in extension in line with the body (180°)—during sleep in 6 cats. Polysomnography was performed twice on each cat in each of the 4 sleeping positions—P180, S180, P90, or S90. The effect of continuous positive airway pressure (CPAP) treatment was then investigated in 2 cats under the most pathogenic condition. Setting: NA. Patients or Participants: NA. Interventions: NA. Measurements and Results: Positions P180 and, S90 resulted, respectively, in the lowest and highest apnea-hypopnea index (AHI) (3 ± 1 vs 25 ± 2, P < 0.001), while P90 (18 ± 3, P < 0.001) and S180 (13 ± 5, P < 0.01) gave intermediate values. In position S90, an increase in slow wave sleep stage 1 (28% ± 3% vs 22% ± 3%, P < 0.05) and a decrease in REM sleep (10% ± 2% vs 18% ± 2%, P < 0.001) were also observed. CPAP resulted in a reduction in the AHI (8 ± 1 vs 27 ± 3, P < 0.01), with the added benefit of sleep consolidation. Conclusion: By mimicking human pathogenic sleep conditions, we have developed a new reversible animal model of OSA. Citation: Neuzeret PC; Gormand F; Reix P; Parrot S; Sastre JP; Buda C; Guidon G; Sakai K; Lin JS. A new animal model of obstructive sleep apnea responding to continuous positive airway pressure. SLEEP 2011;34(4):541-548. PMID:21461333

  8. Automatic detection of position and depth of potential UXO using continuous wavelet transforms

    NASA Astrophysics Data System (ADS)

    Billings, Stephen D.; Herrmann, Felix J.

    2003-09-01

    Inversion algorithms for UXO discrimination using magnetometery have recently been used to achieve very low False Alarm Rates, with 100% recovery of detected ordnance. When there are many UXO and/or when the UXO are at significantly different depths, manual estimation of the initial position and scale for each item, is a laborious and time-consuming process. In this paper, we utilize the multi-resolution properties of wavelets to automatically estimate both the position and scale of dipole peaks. The Automated Wavelet Detection (AWD) algorithm that we develop consists of four-stages: (i) maxima and minima in the data are followed across multiple scales as we zoom with a continuous wavelet transform; (ii) the decay of the amplitude of each peak with scale is used to estimate the depth to source; (iii) adjacent maxima and minima of comparable depth are joined together to form dipole anomalies; and (iv) the relative positions and amplitudes of the extrema, along with their depths, are used to estimate a dipole model. We demonstrate the application of the AWD algorithm to three datasets with different characteristics. In each case, the method rapidly located the majority of dipole anomalies and produced accurate estimates of dipole parameters.

  9. Positioning Continuing Education: Boundaries and Intersections between the Domains Continuing Education, Knowledge Translation, Patient Safety and Quality Improvement

    ERIC Educational Resources Information Center

    Kitto, Simon; Bell, Mary; Peller, Jennifer; Sargeant, Joan; Etchells, Edward; Reeves, Scott; Silver, Ivan

    2013-01-01

    Public and professional concern about health care quality, safety and efficiency is growing. Continuing education, knowledge translation, patient safety and quality improvement have made concerted efforts to address these issues. However, a coordinated and integrated effort across these domains is lacking. This article explores and discusses the…

  10. Early Bubble Continuous Positive Airway Pressure: Investigating Interprofessional Best Practices for the NICU Team.

    PubMed

    Casey, Jessica L; Newberry, Desi; Jnah, Amy

    2016-01-01

    Premature neonates delivered <32 completed weeks gestation are unprepared to handle the physiologic demands of extrauterine life. Within the respiratory system, alveolar instability and collapse can cause decreased functional residual capacity, impaired oxygenation, and hypoxemia leading to respiratory distress syndrome. Supportive measures are indicated immediately after birth to establish physiologic stability including bubble continuous positive airway pressure (CPAP) or endotracheal intubation and mechanical ventilation. CPAP is a noninvasive, gentle mode of ventilation that can mitigate the effects of lung immaturity, but prolonged use can increase the risk for nasal breakdown. Strategies to mitigate this risk must be infused as best practices in the NICU environment. The purpose of this article is to propose an evidence-based best practice care bundle for the early initiation of CPAP in the delivery room and associated skin barrier protection strategies for premature neonates <32 weeks gestation and weighing <1,500 g. PMID:27194606

  11. Gender Differences in Obstructive Sleep Apnea and Treatment Response to Continuous Positive Airway Pressure

    PubMed Central

    Ye, Lichuan; Pien, Grace W.; Ratcliffe, Sarah J.; Weaver, Terri E.

    2009-01-01

    Objectives: Whether gender differences exist in clinical manifestations of obstructive sleep apnea (OSA) and whether women's responses to continuous positive airway pressure (CPAP) are similar to those of men are critical areas of exploration in sleep disordered breathing. This exploratory analysis addressed these questions by examining gender differences over a wide range of clinical outcomes at baseline and in response to CPAP in participants with severe OSA. Methods: Data from 152 men and 24 women who participated in a multicenter CPAP effectiveness study were analyzed. Gender differences in functional status (functional outcomes of sleep questionnaire, sickness impact profile), daytime sleepiness (epworth sleepiness scale, multiple sleep latency test), mood disturbance (profile of mood states), apnea symptoms (multivariable apnea prediction index), and neurobehavioral performance (psychomotor vigilance task) were examined. Treatment response was examined by the change in each outcome from baseline to 3 months after treatment. Results: Despite similar age, body mass index, and apnea-hypopnea index, women reported significantly lower functional status, more subjective daytime sleepiness, higher frequency of apnea symptoms, more mood disturbance, and poorer neurobehavioral performance compared to men at baseline. CPAP treatment significantly improved functional status and relieved symptoms for both genders. The magnitude of improvement in each clinical outcome did not vary by gender. Conclusions: Women with OSA showed greater impairment in daytime functioning and symptoms than men. Both genders benefit from CPAP treatment. Adequately powered studies considering possible referral and response bias are necessary to examine gender differences in OSA clinical manifestations and response to CPAP treatment. Citation: Ye L; Pien GW; Ratcliffe SJ; Weaver TE. Gender Differences in Obstructive Sleep Apnea and Treatment Response to Continuous Positive Airway Pressure. J Clin

  12. Safety and effectiveness of bubble continuous positive airway pressure in preterm neonates with respiratory distress

    PubMed Central

    Mathai, S.S.; Rajeev, A.; Adhikari, K.M.

    2014-01-01

    Background Studies on Bubble Continuous Positive Airway Pressure (B-CPAP) as respiratory support for neonates are few. The aim of our study was to determine the efficacy and safety of B-CPAP in preterm neonates requiring respiratory support. Methods A prospective observation study was done on 50 preterm babies requiring respiratory support for mild to moderate respiratory distress. Support was given with short, nasal cannulae. Surfactant was administered when indicated. Monitoring was done clinically, with pulse oximeter, radiologically and with blood gases. Staff members were also asked their views. Follow-up was done for 3 months. Results The mean gestational age was 32.46 (+3.23) weeks and mean birth weight 1454.4 (+487.42) g. Respiratory Distress Syndrome was the commonest indication (30/50). The mean maximum pressure was 6.04 cm H2O and mean maximum FiO2 was 72.16%. Mean maximum paO2, paCO2 and mean minimum paCO2 were 92.93 mm Hg (+16.97), 52.36 mm Hg (+ 7.78) and 36.46 mm Hg (+ 4.95) respectively. Early initiation resulted in lesser duration of support. Failure rate was 30%. Apnoea, >1 dose surfactant and late initiation had a statistically higher incidence of failure. Main complications were skin abrasions (30%), feed intolerance (26%) and gastric distension (26%). Survival rate was 94%. 68% of staff felt that it was as easy to use and 88% felt it was more reliable than standard CPAP. Conclusions Bubble Continuous Positive Airway Pressure is safe, efficacious and easy to use in preterm neonates with mild to moderate respiratory distress. PMID:25382905

  13. Position-sensitive detectors of the detector group at Jülich

    NASA Astrophysics Data System (ADS)

    Engels, R.; Clemens, U.; Kemmerling, G.; Nöldgen, H.; Schelten, J.

    2009-06-01

    The detector group of the Central Institute of Electronics at the Forschungszentrum Jülich GmbH was founded in 1968. First developments aimed at a detector system with a position-sensitive BF 3 proportional counter for small-angle neutron scattering, which was later used at a beamline of the research reactor FRJ2. At the end of the 1970s first measurements were carried out with photomultiplier (PM)-based detector systems linked with a LiI crystal from Harshaw. Based on this experience we started with the spectrum of position-sensitive neutron scintillation detectors, which have been developed and designed in our institute during the last three decades comprising several high-resolution linear and two-dimensional detectors. The general design of those detectors is based on a modified Anger principle using an array of PMs and a 1 mm 6Li glass scintillator. The sensitive detector area varies on the type of the PMs used and is related to the spatial resolution of the detector type. The neutron sensitivity at 1 Å is about 65% and the remaining gamma sensitivity is less than 10 -4 with a maximum count rate up to 500 kHz depending on the used detector system.

  14. 2 Dimensional position sensitive XAFS by using in-house X-ray spectrometer

    NASA Astrophysics Data System (ADS)

    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.

  15. Position sensitive x-ray spectrophotometer using microwave kinetic inductance detectors

    SciTech Connect

    Mazin, Benjamin A.; Bumble, Bruce; Day, Peter K.; Eckart, Megan E.; Golwala, Sunil; Zmuidzinas, Jonas; Harrison, Fiona A.

    2006-11-27

    The surface impedance of a superconductor changes when energy is absorbed and Cooper pairs are broken to produce single electron (quasiparticle) excitations. This change may be sensitively measured using a thin-film resonant circuit called a microwave kinetic inductance detector (MKID). The practical application of MKIDs for photon detection requires a method of efficiently coupling the photon energy to the MKID. The authors present results on position sensitive x-ray detectors made by using two aluminum MKIDs on either side of a tantalum photon absorber strip. Diffusion constants, recombination times, and energy resolution are reported. MKIDs can easily be scaled into large arrays.

  16. Polarization-sensitive optical coherence tomography using continuous polarization modulation with arbitrary phase modulation amplitude

    NASA Astrophysics Data System (ADS)

    Lu, Zenghai; Kasaragod, Deepa K.; Matcher, Stephen J.

    2012-03-01

    We demonstrate theoretically and experimentally that the phase retardance and relative optic-axis orientation of a sample can be calculated without prior knowledge of the actual value of the phase modulation amplitude when using a polarization-sensitive optical coherence tomography system based on continuous polarization modulation (CPM-PS-OCT). We also demonstrate that the sample Jones matrix can be calculated at any values of the phase modulation amplitude in a reasonable range depending on the system effective signal-to-noise ratio. This has fundamental importance for the development of clinical systems by simplifying the polarization modulator drive instrumentation and eliminating its calibration procedure. This was validated on measurements of a three-quarter waveplate and an equine tendon sample by a fiber-based swept-source CPM-PS-OCT system.

  17. A multiplex readout method for position sensitive boron coated straw neutron detector

    NASA Astrophysics Data System (ADS)

    Yu, Hao; Gong, Hui; Li, Jianmin; Wang, Yongqiang; Wang, Xuewu; Li, Yuanjing; Kang, Kejun

    2015-10-01

    A 1 m×1 m boron coated straw neutron detector is expected to be used to build the small-angle neutron scattering (SANS) instrument of the Compact Pulsed Hadron Source (CPHS) in Tsinghua University. A multiplex readout method based on summing circuits in columns and rows is studied for this large area position sensitive detector. In this method, the outputs of charge sensitive preamplifiers are combined by columns and rows at two ends of the detector, and then the shaped signals are sampled by flash ADCs. With the position reconstructed algorithm implemented in FPGA which analyzes the charge division and column and row number of signals, the 3-D position information of neutron events can be obtained. The position resolution and counting rate performance of this method are analyzed, and the comparison to the delay-line readout method is also given. With the multiplex readout method, the scale of readout electronics can be greatly reduced and a good position resolution can be reached. A readout electronics system for a detector module which consists 4 × 10 straw tubes is designed based on this method, and the test with neutron beam shows an average 3-D spatial resolution of 4 × 4 × 6.8mm3.

  18. Compensation of optode sensitivity and position errors in diffuse optical tomography using the approximation error approach.

    PubMed

    Mozumder, Meghdoot; Tarvainen, Tanja; Arridge, Simon R; Kaipio, Jari; Kolehmainen, Ville

    2013-01-01

    Diffuse optical tomography is highly sensitive to measurement and modeling errors. Errors in the source and detector coupling and positions can cause significant artifacts in the reconstructed images. Recently the approximation error theory has been proposed to handle modeling errors. In this article, we investigate the feasibility of the approximation error approach to compensate for modeling errors due to inaccurately known optode locations and coupling coefficients. The approach is evaluated with simulations. The results show that the approximation error method can be used to recover from artifacts in reconstructed images due to optode coupling and position errors.

  19. Evaluation of a Compton scattering camera using 3-D position sensitive CdZnTe detectors

    NASA Astrophysics Data System (ADS)

    Du, Y. F.; He, Z.; Knoll, G. F.; Wehe, D. K.; Li, W.

    2001-01-01

    A CZT Compton Camera (CCC) is being built using two three-dimensional (3-D) position-sensitive CZT detectors. Expected system performance was analyzed by analytical and Monte Carlo approaches. Based on the measurement of detector energy and position resolution, the expected angular resolution is ˜3° and ˜2° for a ±30° FOV for 511 keV and 1 MeV γ-rays, respectively. The intrinsic efficiency for a point source 10 cm from the first detector surface ranges from 1.5×10 -4 to 8.8×10 -6 for 500 keV-3 MeV.

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

    SciTech Connect

    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.

  1. Spectroscopy of highly-ionized atoms using position-sensitive detection

    NASA Astrophysics Data System (ADS)

    Kukla, K. W.; Livingston, A. E.; Serpa, F. G.; Zacarias, A. S.; Berry, H. G.; Dunford, R. W.; Kanter, E.; Cheng, S.; Suleiman, J.; Curtis, L. J.; Träbert, E.

    1993-06-01

    We report new results of atomic structure and atomic lifetime measurements in highly-ionized few electron atoms obtained using position-sensitive detection of extreme ultraviolet emission from excited fast ions. Data is presented from experiments run at the Notre Dame Tandem Accelerator and at the Argonne ATLAS facility using beam-foil spectroscopy with a photon-counting position-sensitive imaging detector. The results include excited state lifetimes in Si XI and Si XII involving both resonance transitions and Rydberg transitions, spectra of high-ionized He-like, Li-like, and Be-like nickel including comparisons of electron capture and excitation processes for charge selected beams and spectra and lifetimes in highly-charged bromine ions for both allowed and forbidden transitions.

  2. Using Berrys phase for position-sensitive acoustical and stress detection

    NASA Astrophysics Data System (ADS)

    Kuzyk, Mark G.

    2002-10-01

    Berry showed that a quantum system, upon an excursion around a closed path in phase space, can lead to a geometric phase. The polarization state of light in a fiber is a classical analog that is called the Pancharantnam phase. While most experiments have focused on esoteric issues, I show that, in theory, Berrys phase (or Pancharantnams phase) can be used to make a position-sensitive acoustical or stress sensor. 2002 Optical Society of America

  3. Exposure to an inflammatory challenge enhances neural sensitivity to negative and positive social feedback.

    PubMed

    Muscatell, Keely A; Moieni, Mona; Inagaki, Tristen K; Dutcher, Janine M; Jevtic, Ivana; Breen, Elizabeth C; Irwin, Michael R; Eisenberger, Naomi I

    2016-10-01

    Inflammation, part of the body's innate immune response, can lead to "sickness behaviors," as well as alterations in social and affective experiences. Elevated levels of pro-inflammatory cytokines have been associated with increased neural sensitivity to social rejection and social threat, but also decreased neural sensitivity to rewards. However, recent evidence suggests that inflammation may actually enhance sensitivity to certain social rewards, such as those that signal support and care. Despite a growing interest in how inflammation influences neural reactivity to positive and negative social experiences, no known studies have investigated these processes in the same participants, using a similar task. To examine this issue, 107 participants were randomly assigned to receive either placebo or low-dose endotoxin, which safely triggers an inflammatory response. When levels of pro-inflammatory cytokines were at their peak, participants were scanned using fMRI while they received positive, negative, and neutral feedback from an "evaluator" (actually a confederate) about how they came across in an audio-recorded interview. In response to negative feedback (vs. neutral), participants in the endotoxin condition showed heightened neural activity in a number of threat-related neural regions (i.e., bilateral amygdala, dorsal anterior cingulate cortex) and a key mentalizing-related region (i.e., dorsomedial PFC), compared to placebo participants. Interestingly, when receiving positive feedback (vs. neutral), endotoxin (vs. placebo) led to greater neural activity in the ventral striatum and ventromedial PFC, regions often implicated in processing reward, as well as greater activity in dorsomedial PFC. Together, these results reveal that individuals exposed to an inflammatory challenge are more "neurally sensitive" to both negative and positive social feedback, suggesting that inflammation may lead to a greater vigilance for both social threats and social rewards.

  4. Sensitivity of regional forest carbon budgets to continuous and stochastic climate change pressures

    NASA Astrophysics Data System (ADS)

    Sulman, B. N.; Desai, A. R.; Scheller, R. M.

    2010-12-01

    Climate change is expected to impact forest-atmosphere carbon budgets through three processes: 1. Increased disturbance rates, including fires, mortality due to pest outbreaks, and severe storms 2. Changes in patterns of inter-annual variability, related to increased incidence of severe droughts and defoliating insect outbreaks 3. Continuous changes in forest productivity and respiration, related to increases in mean temperature, growing season length, and CO2 fertilization While the importance of these climate change effects in future regional carbon budgets has been established, quantitative characterization of the relative sensitivity of forested landscapes to these different types of pressures is needed. We present a model- and- data-based approach to understanding the sensitivity of forested landscapes to climate change pressures. Eddy-covariance and biometric measurements from forests in the northern United States were used to constrain two forest landscape models. The first, LandNEP, uses a prescribed functional form for the evolution of net ecosystem productivity (NEP) over the age of a forested grid cell, which is reset following a disturbance event. This model was used for investigating the basic statistical properties of a simple landscape’s responses to climate change pressures. The second model, LANDIS-II, includes different tree species and models forest biomass accumulation and succession, allowing us to investigate the effects of more complex forest processes such as species change and carbon pool accumulation on landscape responses to climate change effects. We tested the sensitivity of forested landscapes to these three types of climate change pressures by applying ensemble perturbations of random disturbance rates, distribution functions of inter-annual variability, and maximum potential carbon uptake rates, in the two models. We find that landscape-scale net carbon exchange responds linearly to continuous changes in potential carbon uptake and

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

    NASA Technical Reports Server (NTRS)

    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.

  6. Positive words or negative words: whose valence strength are we more sensitive to?

    PubMed

    Yang, Jiemin; Zeng, Jing; Meng, Xianxin; Zhu, Liping; Yuan, Jiajin; Li, Hong; Yusoff, Nasir

    2013-10-01

    The present study investigates the human brains' sensitivity to the valence strength of emotionally positive and negative chinese words. Event-Related Potentials were recorded, in two different experimental sessions, for Highly Positive (HP), Mildly Positive (MP) and neutral (NP) words and for Highly Negative (HN), Mildly Negative (MN) and neutral (NN) words, while subjects were required to count the number of words, irrespective of word meanings. The results showed a significant emotion effect in brain potentials for both HP and MP words, and the emotion effect occurred faster for HP words than MP words: HP words elicited more negative deflections than NP words in N2 (250-350 ms) and P3 (350-500 ms) amplitudes, while MP words elicited a significant emotion effect in P3, but not in N2, amplitudes. By contrast, HN words elicited larger amplitudes than NN words in N2 but not in P3 amplitudes, whereas MN words produced no significant emotion effect across N2 and P3 components. Moreover, the size of emotion-neutral differences in P3 amplitudes was significantly larger for MP compared to MN words. Thus, the human brain is reactive to both highly and mildly positive words, and this reactivity increased with the positive valence strength of the words. Conversely, the brain is less reactive to the valence of negative relative to positive words. These results suggest that human brains are equipped with increased sensitivity to the valence strength of positive compared to negative words, a type of emotional stimuli that are well known for reduced arousal.

  7. An Indoor Continuous Positioning Algorithm on the Move by Fusing Sensors and Wi-Fi on Smartphones.

    PubMed

    Li, Huaiyu; Chen, Xiuwan; Jing, Guifei; Wang, Yuan; Cao, Yanfeng; Li, Fei; Zhang, Xinlong; Xiao, Han

    2015-12-11

    Wi-Fi indoor positioning algorithms experience large positioning error and low stability when continuously positioning terminals that are on the move. This paper proposes a novel indoor continuous positioning algorithm that is on the move, fusing sensors and Wi-Fi on smartphones. The main innovative points include an improved Wi-Fi positioning algorithm and a novel positioning fusion algorithm named the Trust Chain Positioning Fusion (TCPF) algorithm. The improved Wi-Fi positioning algorithm was designed based on the properties of Wi-Fi signals on the move, which are found in a novel "quasi-dynamic" Wi-Fi signal experiment. The TCPF algorithm is proposed to realize the "process-level" fusion of Wi-Fi and Pedestrians Dead Reckoning (PDR) positioning, including three parts: trusted point determination, trust state and positioning fusion algorithm. An experiment is carried out for verification in a typical indoor environment, and the average positioning error on the move is 1.36 m, a decrease of 28.8% compared to an existing algorithm. The results show that the proposed algorithm can effectively reduce the influence caused by the unstable Wi-Fi signals, and improve the accuracy and stability of indoor continuous positioning on the move.

  8. An Indoor Continuous Positioning Algorithm on the Move by Fusing Sensors and Wi-Fi on Smartphones.

    PubMed

    Li, Huaiyu; Chen, Xiuwan; Jing, Guifei; Wang, Yuan; Cao, Yanfeng; Li, Fei; Zhang, Xinlong; Xiao, Han

    2015-01-01

    Wi-Fi indoor positioning algorithms experience large positioning error and low stability when continuously positioning terminals that are on the move. This paper proposes a novel indoor continuous positioning algorithm that is on the move, fusing sensors and Wi-Fi on smartphones. The main innovative points include an improved Wi-Fi positioning algorithm and a novel positioning fusion algorithm named the Trust Chain Positioning Fusion (TCPF) algorithm. The improved Wi-Fi positioning algorithm was designed based on the properties of Wi-Fi signals on the move, which are found in a novel "quasi-dynamic" Wi-Fi signal experiment. The TCPF algorithm is proposed to realize the "process-level" fusion of Wi-Fi and Pedestrians Dead Reckoning (PDR) positioning, including three parts: trusted point determination, trust state and positioning fusion algorithm. An experiment is carried out for verification in a typical indoor environment, and the average positioning error on the move is 1.36 m, a decrease of 28.8% compared to an existing algorithm. The results show that the proposed algorithm can effectively reduce the influence caused by the unstable Wi-Fi signals, and improve the accuracy and stability of indoor continuous positioning on the move. PMID:26690447

  9. An Indoor Continuous Positioning Algorithm on the Move by Fusing Sensors and Wi-Fi on Smartphones

    PubMed Central

    Li, Huaiyu; Chen, Xiuwan; Jing, Guifei; Wang, Yuan; Cao, Yanfeng; Li, Fei; Zhang, Xinlong; Xiao, Han

    2015-01-01

    Wi-Fi indoor positioning algorithms experience large positioning error and low stability when continuously positioning terminals that are on the move. This paper proposes a novel indoor continuous positioning algorithm that is on the move, fusing sensors and Wi-Fi on smartphones. The main innovative points include an improved Wi-Fi positioning algorithm and a novel positioning fusion algorithm named the Trust Chain Positioning Fusion (TCPF) algorithm. The improved Wi-Fi positioning algorithm was designed based on the properties of Wi-Fi signals on the move, which are found in a novel “quasi-dynamic” Wi-Fi signal experiment. The TCPF algorithm is proposed to realize the “process-level” fusion of Wi-Fi and Pedestrians Dead Reckoning (PDR) positioning, including three parts: trusted point determination, trust state and positioning fusion algorithm. An experiment is carried out for verification in a typical indoor environment, and the average positioning error on the move is 1.36 m, a decrease of 28.8% compared to an existing algorithm. The results show that the proposed algorithm can effectively reduce the influence caused by the unstable Wi-Fi signals, and improve the accuracy and stability of indoor continuous positioning on the move. PMID:26690447

  10. Continuous and Delayed Photohemolysis Sensitized With Methylene Blue and Iron Oxide Nanoparticles (Fe3O4)

    NASA Astrophysics Data System (ADS)

    AL-Akhras, M.-Ali; Aljarrah, Khaled; Albiss, Borhan; Alhaji Bala, Abba

    2015-10-01

    This research present the sensitization of methylene blue (MB), as a potential photodynamic therapy photo sensitizer which showed phototoxicity for many tumor cells in vitro incorporated with iron oxide nanoparticles (Fe3O4, IO-NP), which offer magnificent interaction both inside and outside the surface of biomolecules together with red blood cells (RBC's) with significant change in hemolysis process. The study investigated the sensitization of continuous photohemolysis (CPH) for MB and MB with IO-NP, delayed photohemolysis (DPH) at different irradiation temperature (Tirr). The photohemolysis rate for CPH at room temperature has a power dependence of 0.39 ± 0.05 with relative of steepness of 1.25 ± 0.02 and for different concentration of MB and power dependent of 0.15 ± 0.03 with relative steepness of 1.34 ± 0.01 for different MB and IO-NP. Logistic and Gompertz functions were applied as appropriate mathematical models to fit the collected experimental data for CPH and DPH respectively, and to calculate fractional photohemolysis rate with minimum errors. The Logistic function parameter; α, the hemolysis rate, increases with increasing concentrations of MB and decreases with increasing IO-NP concentrations in the presence of 6 μg/ml of MB. The parameter β the time required to reduce the maximum number of RBCs to one half of its value, decreases with increasing MB concentration and increases with increasing IO-NP concentrations in the presence of 6 pg/ml of MB. In DPH at different Tirr, the Gompertz parameter; a, fractional hemolysis ratio, is independent of temperature in both case MB and MB plus IO-NP, while the parameter; b, rate of fractional hemolysis change, increases with increasing Tirr, in both case MB and MB plus IO-NP. The apparent activation energy of colloid-osmotic hemolysis is 9.47±0.01 Kcal/mol with relative steepness of 1.31 ± 0.05 for different MB and 6.06±0.03 Kcal/mol with relative steepness of 1.41 ± 0.09 for MB with iron oxide. Our

  11. Reversibility of albuminuria and continuous positive airway pressure compliance in patients of obstructive sleep apnea syndrome.

    PubMed

    Chen, Ning-Hung; Chou, Yu-Ting; Lee, Pei-Hsien; Lin, Shih-Wei; Chuang, Li-Pang; Lin, Yu-Sheng; Yang, Cheng-Ta

    2016-06-01

    A positive correlation between albuminuria and severity of obstructive sleep apnea syndrome (OSAS) has been demonstrated, as indexed by urine albumin-to-creatinine ratios (UACRs). However, the effect of continuous positive airway pressure (CPAP) treatment on albuminuria in OSAS patients has not been established.Sixty subjects, with apnea-hypopnea indices >15 events per hour and no other diagnoses associated with albuminuria, underwent overnight polysomnography for sleep apnea and were examined for UACR at baseline and after 6 months of CPAP therapy. CPAP compliance rates were also recorded.Significant improvement in UACR was found in OSAS patients with good compliance to CPAP treatment after 6 months of therapy (baseline vs 6-month follow-up, 32.0 ± 9.5 vs 19.2 ± 6.5 mg/g, respectively, P = 0.007), whereas slight worsening in UACRs was noted in patients with poor compliance to CPAP treatment (baseline vs 6-month follow-up, respectively, 16.7 ± 4.4 vs 19.1 ± 6.3 mg/g, respectively, P = 0.39). Change in UACR was significant between poor compliance versus good compliance groups (2.4 ± 2.7 vs -12.8 ± 4.4 mg/g, respectively, t = 2.9, P = 0.005). A significant correlation between improvement in UACR and CPAP compliance rates was also noted (Spearman's correlation coefficient: -0.37, P = 0.007). Baseline UACR, good CPAP compliance, and body mass index were independent predictors of changes in UACR.Adequate CPAP treatment improves albuminuria in OSAS patients. In addition to monitoring CPAP adherence and subjective sleepiness, UACR may offer an objective physiological index of CPAP therapeutic effectiveness. PMID:27368036

  12. Reversibility of albuminuria and continuous positive airway pressure compliance in patients of obstructive sleep apnea syndrome

    PubMed Central

    Chen, Ning-Hung; Chou, Yu-Ting; Lee, Pei-Hsien; Lin, Shih-Wei; Chuang, Li-Pang; Lin, Yu-Sheng; Yang, Cheng-Ta

    2016-01-01

    Abstract A positive correlation between albuminuria and severity of obstructive sleep apnea syndrome (OSAS) has been demonstrated, as indexed by urine albumin-to-creatinine ratios (UACRs). However, the effect of continuous positive airway pressure (CPAP) treatment on albuminuria in OSAS patients has not been established. Sixty subjects, with apnea-hypopnea indices >15 events per hour and no other diagnoses associated with albuminuria, underwent overnight polysomnography for sleep apnea and were examined for UACR at baseline and after 6 months of CPAP therapy. CPAP compliance rates were also recorded. Significant improvement in UACR was found in OSAS patients with good compliance to CPAP treatment after 6 months of therapy (baseline vs 6-month follow-up, 32.0 ± 9.5 vs 19.2 ± 6.5 mg/g, respectively, P = 0.007), whereas slight worsening in UACRs was noted in patients with poor compliance to CPAP treatment (baseline vs 6-month follow-up, respectively, 16.7 ± 4.4 vs 19.1 ± 6.3 mg/g, respectively, P = 0.39). Change in UACR was significant between poor compliance versus good compliance groups (2.4 ± 2.7 vs −12.8 ± 4.4 mg/g, respectively, t = 2.9, P = 0.005). A significant correlation between improvement in UACR and CPAP compliance rates was also noted (Spearman's correlation coefficient: −0.37, P = 0.007). Baseline UACR, good CPAP compliance, and body mass index were independent predictors of changes in UACR. Adequate CPAP treatment improves albuminuria in OSAS patients. In addition to monitoring CPAP adherence and subjective sleepiness, UACR may offer an objective physiological index of CPAP therapeutic effectiveness. PMID:27368036

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

    PubMed

    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.

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

    PubMed Central

    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

  15. Otic Barotrauma Resulting from Continuous Positive Airway Pressure: Case Report and Literature Review

    PubMed Central

    McCormick, Justin P.; Hildrew, Douglas M.; Lawlor, Claire M.; Guittard, Jesse A.; Worley, N. Knight

    2016-01-01

    Background: Obstructive sleep apnea (OSA) is a growing problem affecting millions of people in the United States. The prevalence of OSA has risen drastically in the past few decades concurrently with the increasing prevalence of obesity. Subsequently, there has been an ever-increasing rise in the use of continuous positive airway pressure (CPAP) devices. While using CPAP devices may lead to many adverse effects, the majority of these effects are described as relatively benign. Case Report: We describe the detailed clinical course and outcome for a patient with otic barotrauma as a result of excessive self-titration of CPAP therapy in an in-home setting. We also discuss the pathophysiology of otic barotrauma and present a review of current literature on the topic. Conclusion: While the benefits of CPAP are clear, we must take into account the rare but possible effects on ear structure and function. Many studies describe an increase in middle ear pressure with the use of CPAP, but few describe the effects of this increased pressure on the middle ear, such as the otic barotrauma described in this case. Given the increased prevalence of OSA, it is important to understand the risks associated with CPAP therapy. PMID:27303224

  16. Continuous Positive Airway Pressure Treatment: Effect on Serum Lipids in Patients with Obstructive Sleep Apnoea

    PubMed Central

    Michailidis, Vassileios; Steiropoulos, Paschalis; Nena, Evangelia; Papanas, Nikolaos; Maltezos, Efstratios; Bouros, Demosthenes

    2011-01-01

    Obstructive Sleep Apnoea (OSA) is a common disorder in adults. Its hallmark is repetitive episodes of partial or complete obstruction of the upper airway during sleep associated with increasing respiratory efforts. This leads to oxyhaemoglobin desaturation, sleep fragmentation, and daytime symptoms, mainly excessive sleepiness. Accumulating evidence suggests that intermittent hypoxia and oxyhaemoglobin desaturation may, irrespective of obesity, lead to elevation of serum lipids even in non-dyslipidaemic OSA patients. Continuous Positive Airway Pressure (CPAP) is the treatment of choice for OSA, since it eliminates upper airway collapse during sleep and improves sleep fragmentation, daytime symptoms and quality of life. Moreover, it has been proposed that the amelioration of breathing disturbances during sleep can improve several markers of the lipid profile, such as total cholesterol, triglycerides, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol as well as apolipoproteins A, B and C. Indeed, some studies have reported improvements in these parameters especially in CPAP adherent patients. However, other studies failed to confirm this beneficial effect. The present article reviews the issue whether CPAP treatment exerts a beneficial effect on lipids. PMID:22216063

  17. Continuous positive airway pressure treatment: effect on serum lipids in patients with obstructive sleep apnoea.

    PubMed

    Michailidis, Vassileios; Steiropoulos, Paschalis; Nena, Evangelia; Papanas, Nikolaos; Maltezos, Efstratios; Bouros, Demosthenes

    2011-01-01

    Obstructive Sleep Apnoea (OSA) is a common disorder in adults. Its hallmark is repetitive episodes of partial or complete obstruction of the upper airway during sleep associated with increasing respiratory efforts. This leads to oxyhaemoglobin desaturation, sleep fragmentation, and daytime symptoms, mainly excessive sleepiness. Accumulating evidence suggests that intermittent hypoxia and oxyhaemoglobin desaturation may, irrespective of obesity, lead to elevation of serum lipids even in non-dyslipidaemic OSA patients. Continuous Positive Airway Pressure (CPAP) is the treatment of choice for OSA, since it eliminates upper airway collapse during sleep and improves sleep fragmentation, daytime symptoms and quality of life. Moreover, it has been proposed that the amelioration of breathing disturbances during sleep can improve several markers of the lipid profile, such as total cholesterol, triglycerides, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol as well as apolipoproteins A, B and C. Indeed, some studies have reported improvements in these parameters especially in CPAP adherent patients. However, other studies failed to confirm this beneficial effect. The present article reviews the issue whether CPAP treatment exerts a beneficial effect on lipids. PMID:22216063

  18. Continuous positive airway pressure increases heart rate variability in heart failure patients with obstructive sleep apnoea.

    PubMed

    Gilman, Matthew P; Floras, John S; Usui, Kengo; Kaneko, Yasuyuki; Leung, Richard S T; Bradley, T Douglas

    2008-02-01

    Patients with heart failure or OSA (obstructive sleep apnoea) have reduced HF-HRV (high-frequency heart rate variability), indicating reduced cardiac vagal modulation, a marker of poor prognosis. CPAP (continuous positive airway pressure) abolishes OSA in patients with heart failure, but effects on daytime HF-HRV have not been determined. We hypothesized that, in patients with heart failure, treatment of coexisting OSA by CPAP would increase morning HF-HRV. In 19 patients with heart failure (left ventricular ejection fraction <45%) and OSA (>/=20 apnoeas and hypopnoeas/h of sleep), HF-HRV was quantified before and 1 month after randomization to a control or CPAP-treated group. In the control group (n=7), there were no changes in HF-HRV over the 1 month study during wakefulness in the morning. In the CPAP-treated group (n=12) HF-HRV increased significantly during wakefulness in the morning [from 2.43+/-0.55 to 2.82+/-0.50 log(ms(2)/Hz); P=0.002] due to an increase in transfer function between changes in lung volume and changes in HF-HRV (92.37+/-96.03 to 219.07+/-177.14 ms/l; P=0.01). In conclusion, treatment of coexisting OSA by nocturnal CPAP in patients with heart failure increases HF-HRV during morning wakefulness, indicating improved vagal modulation of heart rate. This may contribute to improved prognosis.

  19. Is continuous positive airway pressure necessarily an everyday therapy in patients with obstructive sleep apnoea?

    PubMed

    Rossi, Valentina A; Schwarz, Esther I; Bloch, Konrad E; Stradling, John R; Kohler, Malcolm

    2014-05-01

    There are limited data on the evolution of obstructive sleep apnoea (OSA) during continuous positive airway pressure (CPAP) therapy and whether this treatment is required every night. 125 OSA patients with an original oxygen desaturation index (ODI) >10 events per hour, established on CPAP, were asked to withdraw CPAP for four nights and performed ambulatory nocturnal pulse oximetry on the fourth night of CPAP withdrawal. An ODI >10 events per hour during pulse oximetry was considered to indicate persistent OSA. Patients not experiencing recurrence of OSA underwent repeat ambulatory pulse oximetry after a further 2-week period off CPAP. In 71% of the patients, OSA recurred after four nights of CPAP withdrawal (group 1); thus, OSA did not recur in 29% (group 2). 55% of group 2 had an ODI >10 events per hour after 2 weeks off CPAP; thus, 45% remained without a recurrence. In multivariate analysis, higher original ODI, longer duration of CPAP therapy, current smoking status and larger neck circumference were independently associated with a higher ODI after four nights of CPAP withdrawal (all p<0.05). Following CPAP withdrawal, a third of CPAP-treated patients do not experience significant recurrence of oxygen desaturations after 4 days and ∼10% do not after 2 weeks. Thus, a significant proportion of patients may be able to stop CPAP for short periods.

  20. Adherence to Continuous Positive Airway Pressure Treatment for Obstructive Sleep Apnea: Implications for Future Interventions

    PubMed Central

    Weaver, Terri E.; Sawyer, Amy M.

    2010-01-01

    Adherence to continuous positive airway pressure (CPAP) treatment for obstructive sleep apnea (OSA) is a critical problem with adherence rates ranging from 30–60%. Poor adherence to CPAP is widely recognized as a significant limiting factor in treating OSA, reducing the overall effectiveness of the treatment and leaving many OSA patients at heightened risk for comorbid conditions, impaired function and quality of life. The extant literature examining adherence to CPAP provides critical insight to measuring adherence outcomes, defining optimal adherence levels, and predicting CPAP adherence. This research has revealed salient factors that are associated with or predict CPAP adherence and may guide the development of interventions to promote CPAP adherence. Over the past 10 years, intervention studies to promote CPAP adherence have incorporated a multitude of strategies including education, support, cognitive behavioral approaches, and mixed strategies. This review of the current state of science of CPAP adherence will (1) synthesize the extant literature with regard to measuring, defining, and predicting CPAP adherence, (2) review published intervention studies aimed at promoting CPAP adherence, and (3) suggest directions for future empiric study of adherence to CPAP that will have implications for translational science. Our current understanding of CPAP adherence suggests that adherence is a multi-factorial, complex clinical problem that requires similarly designed approaches to effectively address poor CPAP adherence in the OSA population. PMID:20308750

  1. Do turbines with servo-controlled speed improve continuous positive airway pressure generation?

    PubMed

    Lofaso, F; Heyer, L; Leroy, A; Lorino, H; Harf, A; Isabey, D

    1994-11-01

    Nasal continuous positive airway pressure (CPAP) devices with a servo-mechanism to control pressure have recently been developed. We evaluated six such devices and three conventional systems in terms of effectiveness in maintaining constant pressure. Machines were tested with pressure levels of 5, 10 and 15 cmH2O. Dynamic behaviour was evaluated: 1) by calculating the imposed work of breathing during simulated breath generated by a sinusoidal pump; and 2) by following the fall in pressure after a transient flow of 1 l.s-1. Quasi-static behaviour was evaluated by simulating a predetermined air leak. Under dynamic conditions, work of breathing was lowest with one conventional nasal CPAP device and three servo-controlled nasal CPAP devices; whereas, the highest levels of work of breathing were recorded with two servo-controlled nasal CPAP devices. The pressure-time response to a transient flow yielded similar results, with a significant inverse correlation between pressure values observed after 300 ms and imposed work of breathing during simulated breathing (r = -0.91). Under quasi-static conditions, microprocessor servo-controlled devices exhibited the best performance. These results suggest that microprocessor servo-controlled nasal CPAP devices are not always the best systems for maintaining constant airway pressure in dynamic situations. However, they are more effective in ensuring maintenance of the desired pressure in the event of an air leak at the mask. PMID:7875284

  2. Increased airway reactivity in a neonatal mouse model of Continuous Positive Airway Pressure (CPAP)

    PubMed Central

    Mayer, Catherine A.; Martin, Richard J.; MacFarlane, Peter M.

    2015-01-01

    Background Continuous positive airway pressure (CPAP) is a primary form of respiratory support used in the intensive care of preterm infants, but its long-term effects on airway (AW) function are unknown. Methods We developed a neonatal mouse model of CPAP treatment to determine whether it modifies later AW reactivity. Un-anesthetized spontaneously breathing mice were fitted with a mask to deliver CPAP (6cmH2O, 3hrs/day) for 7 consecutive days starting at postnatal day 1. Airway reactivity to methacholine was assessed using the in vitro living lung slice preparation. Results One week of CPAP increased AW responsiveness to methacholine in male, but not female mice, compared to untreated control animals. The AW hyper-reactivity of male mice persisted for 2 weeks (at P21) after CPAP treatment ended. 4 days of CPAP, however, did not significantly increase AW reactivity. Females also exhibited AW hyper-reactivity at P21, suggesting a delayed response to early (7 days) CPAP treatment. The effects of 7 days of CPAP on hyper-reactivity to methacholine were unique to smaller AWs whereas larger ones were relatively unaffected. Conclusion These data may be important to our understanding of the potential long-term consequences of neonatal CPAP therapy used in the intensive care of preterm infants. PMID:25950451

  3. A neural network simulating human reach-grasp coordination by continuous updating of vector positioning commands.

    PubMed

    Ulloa, Antonio; Bullock, Daniel

    2003-10-01

    We developed a neural network model to simulate temporal coordination of human reaching and grasping under variable initial grip apertures and perturbations of object size and object location/orientation. The proposed model computes reach-grasp trajectories by continuously updating vector positioning commands. The model hypotheses are (1) hand/wrist transport, grip aperture, and hand orientation control modules are coupled by a gating signal that fosters synchronous completion of the three sub-goals. (2) Coupling from transport and orientation velocities to aperture control causes maximum grip apertures that scale with these velocities and exceed object size. (3) Part of the aperture trajectory is attributable to an aperture-reducing passive biomechanical effect that is stronger for larger apertures. (4) Discrepancies between internal representations of targets partially inhibit the gating signal, leading to movement time increases that compensate for perturbations. Simulations of the model replicate key features of human reach-grasp kinematics observed under three experimental protocols. Our results indicate that no precomputation of component movement times is necessary for online temporal coordination of the components of reaching and grasping.

  4. Nasal airway responses to nasal continuous positive airway pressure breathing: An in-vivo pilot study.

    PubMed

    White, David E; Bartley, Jim; Shakeel, Muhammad; Nates, Roy J; Hankin, Robin K S

    2016-06-14

    The nasal cycle, through variation in nasal airflow partitioning, allows the upper airway to accommodate the contrasting demands of air conditioning and removal of entrapped air contaminants. The purpose of this study was to investigate the influence of nasal continuous positive airway pressure (nCPAP) breathing has on both nasal airflow partitioning and nasal geometry. Using a custom-made nasal mask, twenty healthy participants had the airflow in each naris measured during normal nasal breathing followed by nCPAP breathing. Eight participants also underwent magnetic resonance imaging (MRI) of the nasal region during spontaneous nasal breathing, and then nCPAP breathing over a range of air pressures. During nCPAP breathing, a simultaneous reduction in airflow through the patent airway together with a corresponding increase in airway flow within the congested nasal airway were observed in sixteen of the twenty participants. Nasal airflow resistance is inversely proportional to airway cross-sectional area. MRI data analysis during nCPAP breathing confirmed airway cross-sectional area reduced along the patent airway while the congested airway experienced an increase in this parameter. During awake breathing, nCPAP disturbs the normal inter-nasal airflow partitioning. This could partially explain the adverse nasal drying symptoms frequently reported by many users of this therapy. PMID:27173595

  5. Bubble Continuous Positive Airway Pressure Enhances Lung Volume and Gas Exchange in Preterm Lambs

    PubMed Central

    Pillow, J. Jane; Hillman, Noah; Moss, Timothy J. M.; Polglase, Graeme; Bold, Geoff; Beaumont, Chris; Ikegami, Machiko; Jobe, Alan H.

    2007-01-01

    Rationale: The technique used to provide continuous positive airway pressure (CPAP) to the newborn may influence lung function and breathing efficiency. Objectives: To compare differences in gas exchange physiology and lung injury resulting from treatment of respiratory distress with either bubble or constant pressure CPAP and to determine if the applied flow influences short-term outcomes. Methods: Lambs (133 d gestation; term is 150 d) born via cesarean section were weighed, intubated, and treated with CPAP for 3 hours. Two groups were treated with 8 L/minute applied flow using the bubble (n = 12) or the constant pressure (n = 12) technique. A third group (n = 10) received the bubble method with 12 L/minute bias flow. Measurements at study completion included arterial blood gases, oxygraphy, capnography, tidal flow, multiple breath washout, lung mechanics, static pressure–volume curves, and bronchoalveolar lavage fluid protein. Measurements and Main Results: Birth weight and arterial gas variables at 15 minutes were comparable. Flow (8 or 12 L/min) did not influence the 3-hour outcomes in the bubble group. Bubble technique was associated with a higher pH, PaO2, oxygen uptake, and area under the flow–volume curve, and a decreased alveolar protein, respiratory quotient, PaCO2, and ventilation inhomogeneity compared with the constant pressure group. Conclusions: Compared with constant pressure technique, bubble CPAP promotes enhanced airway patency during treatment of acute postnatal respiratory disease in preterm lambs and may offer protection against lung injury. PMID:17431223

  6. Exposure to an Inflammatory Challenge Enhances Neural Sensitivity to Negative and Positive Social Feedback

    PubMed Central

    Muscatell, Keely A.; Moieni, Mona; Inagaki, Tristen K.; Dutcher, Janine M.; Jevtic, Ivana; Breen, Elizabeth C.; Irwin, Michael R.; Eisenberger, Naomi I.

    2016-01-01

    Inflammation, part of the body’s innate immune response, can lead to “sickness behaviors,” as well as alterations in social and affective experiences. Elevated levels of pro-inflammatory cytokines have been associated with increased neural sensitivity to social rejection and social threat, but also decreased neural sensitivity to rewards. However, recent evidence suggests that inflammation may actually enhance sensitivity to certain social rewards, such as those that signal support and care. Despite a growing interest in how inflammation influences neural reactivity to positive and negative social experiences, no known studies have investigated these processes in the same participants, using a similar task. To examine this issue, 107 participants were randomly assigned to receive either placebo or low-dose endotoxin, which safely triggers an inflammatory response. When levels of pro-inflammatory cytokines were at their peak, participants were scanned using fMRI while they received positive, negative, and neutral feedback from an “evaluator” (actually a confederate) about how they came across in an audio-recorded interview. In response to negative feedback (vs. neutral), participants in the endotoxin condition showed heightened neural activity in a number of threat-related neural regions (i.e., bilateral amygdala, dorsal anterior cingulate cortex) and a key mentalizing-related region (i.e., dorsomedial PFC), compared to placebo participants. Interestingly, when receiving positive feedback (vs. neutral), endotoxin led to greater neural activity in the ventral striatum and ventromedial PFC, regions often implicated in processing reward, compared to placebo. Together, these results reveal that individuals exposed to an inflammatory challenge are more “neurally sensitive” to both negative and positive social feedback, suggesting that inflammation may lead to a greater vigilance for both social threats and social rewards. PMID:27032568

  7. Development of arrays of position-sensitive microcalorimeters for Constellation-X

    NASA Technical Reports Server (NTRS)

    Smith, S. J.; Bandler, S. R.; Brekosky, R. P.; Brown, A.-D.; Chervenak, J. A.; Eckart, M. E.; Finkbeiner, F. M.; Iyomoto, N.; Kelley, R. L.; Kolbourne, C. A.; Porter, F. S.; Figueroa-Feliciano, E.

    2008-01-01

    We are developing arrays of position-sensitive transition-edge sensor (POST) X-ray detectors for future astronomy missions such as NASA's Constellation-X. The POST consists of multiple absorbers thermally coupled to one or more transition-edge sensor (TES). Each absorber element has a different thermal coupling to the TES. This results in a distribution of different pulse shapes and enables position discrimination between the absorber elements. POST'S are motivated by the desire to achieve the largest possible focal plane area with the fewest number of readout channels and are ideally suited to increasing the Constellation-X focal plane area, without comprising on spatial sampling. Optimizing the performance of POST'S requires careful design of key parameters such as the thermal conductances between the absorbers, TES and the heat sink. as well as the absorber heat capacities. Using recently developed signal processing algorithms we have investigated the trade-off between position-sensitivity, energy resolution and pulse decay time. based on different device design parameters for PoST's. Our new generation of PoST's utilize technology successfully developed on high resolution (approximately 2.5eV) single pixels arrays of Mo/Au TESs. also under development for Constellation-X. This includes noise mitigation features on the TES and low resistivity electroplated absorbers. We report on the first experimental results from these new one and two-channel PoST"s, consisting of all Au and composite Au/Bi absorbers, which are designed to achieve an energy resolution of < 10 eV. coupled with count-rates of 100's per pixel per second and position sensitivity over the energy range 0.3-10 keV.

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

    NASA Astrophysics Data System (ADS)

    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.

  9. Sensitivity to abscisic acid modulates positive interactions between Arabidopsis thaliana individuals.

    PubMed

    Zhang, Hao; Shen, Zhuxia; Wang, Genxuan; Dai, Xinfeng; Huang, Qiaoqiao; Zheng, Kefeng

    2010-03-01

    The ability of abscisic acid (ABA) to modulate positive interactions between Arabidopsis thaliana individuals under salinity stress was investigated using abi1-1 (insensitive to ABA), era1-2 (hypersensitive to ABA) mutant and wild type plants. The results showed that sensitivity to ABA affects relative interaction intensity (RII) between Arabidopsis thaliana individuals. The neighbor removal experiments also confirmed the role of phenotypic responses in linking plant-plant interactions and sensitivity to ABA. For abi1-1 mutants, the absolute value differences between neighbor removal and control of stem length, root length, leaf area, leaf thickness, flower density, above biomass/belowground biomass (A/U), photosynthetic rate, stomatal conductance, leaf water content and water-use efficiency were smaller than those of the wild type, while for era1-2 mutants, these absolute value differences were larger than those of the wild type. Thus, it is suggested that positive interactions between Arabidopsis thaliana individuals are at least partly modulated by different sensitivity to ABA through different physiological and phenotypic plasticity. PMID:20377695

  10. Mammography outcomes in a practice setting by age: prognostic factors, sensitivity, and positive biopsy rate.

    PubMed

    Linver, M N; Paster, S B

    1997-01-01

    The separate unplanned analysis of women ages 40-49 in population-based randomized controlled trials has resulted in demonstration of statistically significant breast cancer mortality reduction due to screening mammography in only two of the individual trials, and in all such trials only through meta-analysis. Therefore, many researchers have utilized the surrogate endpoints of tumor size and axillary lymph node status to evaluate screening efficacy. For the present study, these endpoints were evaluated in an audit of 854 screen-detected cancers found in 147,125 mammographic examinations performed in women over 40 between 1988 and 1994 in a community practice setting. The concerns that mammography in the 40-49 group has a lower sensitivity and higher biopsy rate were also addressed. Median invasive tumor size and lymph node positivity were found to be equally small (1.0-1.1 cm and 13.5-12.2%, respectively), and the sensitivity and overall biopsy rate were found to be constant over all ages 40 and above. Positive biopsy rate (PBR) varied directly with increasing age, paralleling the measured cancer detection rate in each decade, with no abrupt change at age 50. We conclude that modern mammography in a community practice setting can successfully detect breast cancers with favorable prognostic factors and achieve constant sensitivity and acceptable PBRs in all women over 40. Our data also suggest that many of the large differences seen by inappropriately dividing data at age 50 decrease or disappear when analysis is performed by decade.

  11. Assessment of baroreflex sensitivity by continuous noninvasive monitoring of peripheral and central aortic pressure.

    PubMed

    Kouchaki, Zahra; Butlin, Mark; Qasem, Ahmed; Avolio, Alberto P

    2014-01-01

    Noninvasive assessment of baroreceptor sensitivity (BRS) facilitates clinical investigation of autonomic function. The spontaneous sequence method estimates BRS using the continuous measurement of arterial pressure in the finger. Since the baroreceptors are centrally located (aortic arch, carotid arteries), this study assessed the use of a continuous aortic pressure signal derived from the peripheral pressure pulse to compute the BRS from changes in systolic pressure (SBP) and pulse interval (PI). BRS computed from central aortic (cBRS) and peripheral pressure (pBRS) was calculated in 12 healthy subjects (25-62 years, 7 females). The difference between pBRS and cBRS was calculated for four levels of pulse lags between changes in SBP and PI. For each lag and for the pooled data for all lags, cBRS was significantly correlated with pBRS (r(2)=0.82). The within subject difference ranged from -41.2% to 59.2%. This difference was not related to age, gender of hemodynamic parameters (systolic or diastolic pressure, heart rate, aortic pulse wave velocity). However 18.2% of the variance was due to the difference in the number of spontaneous pulse sequences used to determine values of cBRS and pBRS. The differences between pBRS and cBRS are in the range of values of BRS as those found, in other studies, to discriminate between patient groups with different levels of autonomic function. Findings of this study suggest that, given the heart rate dependent amplification of the arterial pressure pulse between the central aorta and the peripheral limbs, BRS determined from central aortic pressure derived from the peripheral pulse may provide an improved method for noninvasive assessment of baroreceptor function.

  12. Continuous positive airway pressure for bronchiolitis in a general paediatric ward; a feasibility study

    PubMed Central

    2014-01-01

    Background Continuous positive airway pressure (CPAP) is commonly used to relieve respiratory distress in infants with bronchiolitis, but has mostly been studied in an intensive care setting. Our prime aim was to evaluate the feasibility of CPAP for infants with bronchiolitis in a general paediatric ward, and secondary to assess capillary PCO2 (cPCO2) levels before and during treatment. Methods From May 1st 2008 to April 30th 2012, infants with bronchiolitis at Stavanger University Hospital were treated with CPAP in a general paediatric ward, but could be referred to an intensive care unit (ICU) when needed, according to in-house guidelines. Levels of cPCO2 were prospectively registered before the start of CPAP and at approximately 4, 12, 24 and 48 hours of treatment as long as CPAP was given. We had a continuous updating program for the nurses and physicians caring for the infants with CPAP. The study was population based. Results 672 infants (3.4%) were hospitalized with bronchiolitis. CPAP was initiated in 53 infants (0.3%; 7.9% of infants with bronchiolitis), and was well tolerated in all but three infants. 46 infants were included in the study, the majority of these (n = 33) were treated in the general ward only. These infants had lower cPCO2 before treatment (8.0; 7.7, 8.6)(median; quartiles) than those treated at the ICU (n = 13) (9.3;8.5, 9.9) (p < 0.001). The level of cPCO2 was significantly reduced after 4 h in both groups; 1.1 kPa (paediatric ward) (p < 0.001) and 1.3 kPa (ICU) (p = 0.002). Two infants on the ICU did not respond to CPAP (increasing cPCO2 and severe apnoe) and were given mechanical ventilation, otherwise no side effects were observed in either group treated with CPAP. Conclusion Treatment with CPAP for infants with bronchiolitis may be feasible in a general paediatric ward, providing sufficient staffing and training, and the possibility of referral to an ICU when needed. PMID:24886569

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

    PubMed

    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.

  14. An improved method of energy calibration for position-sensitive silicon detectors

    NASA Astrophysics Data System (ADS)

    Sun, Ming-Dao; Huang, Tian-Heng; Liu, Zhong; Ding, Bing; Yang, Hua-Bin; Zhang, Zhi-Yuan; Wang, Jian-Guo; Ma, Long; Yu, Lin; Wang, Yong-Sheng; Gan, Zai-Guo; Xiao-Hong, Zhou

    2016-04-01

    Energy calibration of resistive charge division-based position-sensitive silicon detectors is achieved by parabolic fitting in the traditional method, where the systematic variations of vertex and curvature of the parabola with energy must be considered. In this paper we extend the traditional method in order to correct the fitting function, simplify the procedure of calibration and improve the experimental data quality. Instead of a parabolic function as used in the traditional method, a new function describing the relation of position and energy is introduced. The energy resolution of the 8.088 MeV α decay of 213Rn is determined to be about 87 keV (FWHM), which is better than the result of the traditional method, 104 keV (FWHM). The improved method can be applied to the energy calibration of resistive charge division-based position-sensitive silicon detectors with various performances. Supported by ‘100 Person Project’ of the Chinese Academy of Sciences and the National Natural Science Foundation of China (11405224 and 11435014)

  15. Skin sensitization, false positives and false negatives: experience with guinea pig assays.

    PubMed

    Basketter, David A; Kimber, Ian

    2010-07-01

    The advent of the local lymph node assay (LLNA), and efforts to develop in vitro alternatives for the identification of skin sensitizing chemicals has focused attention on the issue of false positive and false negative results. In essence, the question becomes 'what is the gold standard?' In this context, attention has focused primarily on the LLNA as this is now the preferred assay for skin sensitization testing. However, for many years prior to introduction of the LLNA, the guinea pig maximization test and the occluded patch test of Buehler were the methods of choice. In order to encourage a more informed dialogue about the relative performance, accuracy and applicability of the LLNA and guinea pig tests, we have here considered the extent to which guinea pig methods were themselves subject to false positives and negative results. We describe and discuss here well-characterized examples of instances where both false negatives (including abietic acid and eugenol) or false positives (including vanillin and sulfanilic acid) have been recorded in guinea pig tests. These and other examples are discussed with particular reference to the fabrication of a gold standard dataset that is required for the validation of in vitro alternatives.

  16. Exploring the spatial resolution of position-sensitive microchannel plate detectors

    NASA Astrophysics Data System (ADS)

    Wiggins, Blake; Siwal, Davinder; Desouza, Romualdo

    2016-03-01

    High amplification and excellent timing make microchannel plate (MCP) detectors excellent devices for detection of photons, electrons, and ions. In addition to providing sub-nanosecond time resolution MCP detectors can also provide spatial resolution, thus making them useful in imaging applications. Use of a resistive anode (RA) is a routinely used approach to make an MCP position-sensitive. The spatial resolution of the RA associated with detection of a single incident electron was determined. Factors impacting the spatial resolution obtained with the RA will be discussed and the achieved spatial resolution of 64 μm (FWHM) will be presented. Recently, a novel approach has been developed to provide position-sensitivity for an MCP detector. In this approach, namely the induced signal approach, the position of the incident particle is determined by sensing the electron cloud emanating from a MCP stack. By utilizing the zero-crossing point of the inherently bipolar signals, a spatial resolution of 466 μm (FWHM) has been achieved. Work to improve the spatial resolution of the induced signal approach further will be presented. Supported by the US DOE NNSA under Award No. DE-NA0002012.

  17. A fast neuronal signal-sensitive continuous-wave near-infrared imaging system

    NASA Astrophysics Data System (ADS)

    Zhang, Zhongxing; Sun, Bailei; Gong, Hui; Zhang, Lei; Sun, Jinyan; Wang, Bangde; Luo, Qingming

    2012-09-01

    We have developed a continuous-wave near-infrared imaging system to measure fast neuronal signals. We used a simultaneous sampling method with a separate high-speed analog-to-digital converter for each input channel, which provides a much larger point sample in a digital lock-in algorithm, higher temporal resolution, and lower crosstalk among detected channels. Without any analog filter, digital lock-in detection with a large point sample suppresses noise excellently, making the system less complex and offering better flexibility. In addition, using a custom-made collimator, more photons can reach the brain tissue due to the smaller divergence angle. Performance analysis shows high detection sensitivity (on the order of 0.1 pW) and high temporal resolution (˜50 Hz, 48 channels). Simulation experiments show that intensity changes on the order of 0.01% can be resolved by our instrument when averaging over approximately 500 stimuli. In vivo experiments over the motor cortex show that our instrument can detect fast neuronal signals in the human brain.

  18. Biological basis for increased sensitivity to radiation therapy in HPV-positive head and neck cancers.

    PubMed

    Bol, V; Grégoire, V

    2014-01-01

    Although development of head and neck squamous cell carcinomas (HNSCCs) is commonly linked to the consumption of tobacco and alcohol, a link between human papillomavirus (HPV) infection and a subgroup of head and neck cancers has been established. These HPV-positive tumors represent a distinct biological entity with overexpression of viral oncoproteins E6 and E7. It has been shown in several clinical studies that HPV-positive HNSCCs have a more favorable outcome and greater response to radiotherapy. The reason for improved prognosis of HPV-related HNSCC remains speculative, but it could be owned to multiple factors. One hypothesis is that HPV-positive cells are intrinsically more sensitive to standard therapies and thus respond better to treatment. Another possibility is that HPV-positive tumors uniquely express viral proteins that induce an immune response during therapy that helps clear tumors and prevents recurrence. Here, we will review current evidence for the biological basis of increased radiosensitivity in HPV-positive HNSCC.

  19. High-speed measurement of rotational anisotropy nonlinear optical harmonic generation using position-sensitive detection.

    PubMed

    Harter, J W; Niu, L; Woss, A J; Hsieh, D

    2015-10-15

    We present a method of performing high-speed rotational anisotropy nonlinear optical harmonic generation experiments at rotational frequencies of several hertz by projecting the harmonic light reflected at different angles from a sample onto a stationary position-sensitive detector. The high rotational speed of the technique, 10(3) to 10(4) times larger than existing methods, permits precise measurements of the crystallographic and electronic symmetries of samples by averaging over low frequency laser-power, beam-pointing, and pulse-width fluctuations. We demonstrate the sensitivity of our technique by resolving the bulk fourfold rotational symmetry of GaAs about its [001] axis using second-harmonic generation. PMID:26469591

  20. Biomarkers of oxidative stress following continuous positive airway pressure withdrawal: data from two randomised trials.

    PubMed

    Stradling, John R; Schwarz, Esther I; Schlatzer, Christian; Manuel, Ari R; Lee, Regent; Antoniades, Charalambos; Kohler, Malcolm

    2015-10-01

    There is conflicting evidence whether intermittent hypoxia in obstructive sleep apnoea (OSA) influences oxidative stress. We hypothesised that withdrawal of continuous positive airway pressure (CPAP) from patients with OSA would raise markers of oxidative stress.59 patients with CPAP-treated moderate-to-severe OSA (oxygen desaturation index (ODI) >20 events·h(-1)) were randomised 1:1 to either stay on CPAP (n=30) or change to sham CPAP (n=29) for 2 weeks. Using samples from two similar studies at two sites, we measured early morning blood malondialdehyde (MDA, a primary outcome in one study and a secondary outcome in the other), lipid hydroperoxides, total antioxidant capacity, superoxide generation from mononuclear cells and urinary F2-isoprostane. We also measured superoxide dismutase as a marker of hypoxic preconditioning. "Treatment" effects (sham CPAP versus CPAP) were calculated via linear regression.Sham CPAP provoked moderate-to-severe OSA (mean ODI 46 events·h(-1)), but blood markers of oxidative stress did not change significantly (MDA "treatment" effect (95% CI) -0.02 (-0.23 to +0.19) μmol·L(-1)). Urinary F2-isoprostane fell significantly by ~30% (-0.26 (-0.42 to -0.10) ng·mL(-1)) and superoxide dismutase increased similarly (+0.17 (+0.02 to +0.30) ng·mL(-1)).We found no direct evidence of increased oxidative stress in patients experiencing a return of their moderate-to-severe OSA. The fall in urinary F2-isoprostane and rise in superoxide dismutase implies that hypoxic preconditioning may have reduced oxidative stress.

  1. High Flow Nasal Cannula as a Method for Rapid Weaning From Nasal Continuous Positive Airway Pressure

    PubMed Central

    Badiee, Zohreh; Eshghi, Alireza; Mohammadizadeh, Majid

    2015-01-01

    Background: To compare two methods of weaning premature infants from nasal continuous positive airway pressure (NCPAP). Methods: Between March and November 2012, 88 preterm infants who were stable on NCPAP of 5 cmH2O with FIO2 <30% for a minimum of 6 h were randomly allocated to one of two groups. The high flow nasal cannula (HFNC) group received HFNC with flow of 2 L/min and FIO2 = 0.3 and then stepwise reduction of FIO2 and then flow. The non-HFNC group was maintained on NCPAP of 5 cmH2O and gradual reduction of oxygen until they were on FIO2 = 0.21 for 6 h, and we had weaned them directly from NCPAP (with pressure of 5 cmH2O) to room air. Results: No significant differences were found between 2 study groups with regards to gestational age, birth weight, Apgar score at 1 and 5 min after birth, patent ductus arteriosus and use of xanthines. The mean duration of oxygen therapy after randomization was significantly lower in HFNC group compared to non-HFNC group (20.6 ± 16.8 h vs. 49.6 ± 25.3 h, P < 0.001). Also, the mean length of hospital stay was significantly lower in HFNC group compared to non-HFNC group (11.3 ± 7.8 days vs. 14.8 ± 8.6 days, P = 0.04). The rate of successful weaning was not statistically different between two groups. Conclusions: Weaning from NCPAP to HFNC could decrease the duration of oxygen therapy and length of hospitalization in preterm infants. PMID:25949783

  2. Application of continuous positive airway pressure in the delivery room: a multicenter randomized clinical trial

    PubMed Central

    Gonçalves-Ferri, W.A.; Martinez, F.E.; Caldas, J.P.S.; Marba, S.T.M.; Fekete, S.; Rugolo, L.; Tanuri, C.; Leone, C.; Sancho, G.A.; Almeida, M.F.B.; Guinsburg, R.

    2014-01-01

    This study evaluated whether the use of continuous positive airway pressure (CPAP) in the delivery room alters the need for mechanical ventilation and surfactant during the first 5 days of life and modifies the incidence of respiratory morbidity and mortality during the hospital stay. The study was a multicenter randomized clinical trial conducted in five public university hospitals in Brazil, from June 2008 to December 2009. Participants were 197 infants with birth weight of 1000-1500 g and without major birth defects. They were treated according to the guidelines of the American Academy of Pediatrics (APP). Infants not intubated or extubated less than 15 min after birth were randomized for two treatments, routine or CPAP, and were followed until hospital discharge. The routine (n=99) and CPAP (n=98) infants studied presented no statistically significant differences regarding birth characteristics, complications during the prenatal period, the need for mechanical ventilation during the first 5 days of life (19.2 vs 23.4%, P=0.50), use of surfactant (18.2 vs 17.3% P=0.92), or respiratory morbidity and mortality until discharge. The CPAP group required a greater number of doses of surfactant (1.5 vs 1.0, P=0.02). When CPAP was applied to the routine group, it was installed within a median time of 30 min. We found that CPAP applied less than 15 min after birth was not able to reduce the need for ventilator support and was associated with a higher number of doses of surfactant when compared to CPAP applied as clinically indicated within a median time of 30 min. PMID:24554040

  3. Obstructive sleep apnoea in the elderly: role of continuous positive airway pressure treatment.

    PubMed

    Martínez-García, Miguel Ángel; Chiner, Eusebi; Hernández, Luis; Cortes, Jose Pascual; Catalán, Pablo; Ponce, Silvia; Diaz, Jose Ramón; Pastor, Ester; Vigil, Laura; Carmona, Carmen; Montserrat, Josep Maria; Aizpuru, Felipe; Lloberes, Patricia; Mayos, Mercedes; Selma, Maria José; Cifuentes, Jose Fernando; Muñoz, Alvaro

    2015-07-01

    Almost all the information about the effect of continuous positive airway pressure (CPAP) in patients with obstructive sleep apnoea (OSA) comes from clinical trials involving only middle-aged patients. The objective of this study was to assess the effect of CPAP treatment in elderly patients with severe OSA on clinical, quality-of-life and neurocognitive spheres. We performed an open-label, randomised, multicentre clinical trial in a consecutive clinical cohort of 224 elderly (≥70 years old) patients with confirmed severe OSA (apnoea-hypopnea index ≥30) randomised to receive CPAP (n=115) or no CPAP (n=109) for 3 months. A sleep study was performed by either full polysomnography or respiratory polygraphy. CPAP titration was performed by an autoCPAP device. The primary endpoint was quality of life (Quebec Sleep Questionnaire) and secondary endpoints included sleep-related symptoms, presence of anxiety/depression, office-based blood pressure and some neurocognitive tests. The mean±sd age was 75.5±3.9 years. The CPAP group achieved a greater improvement in all quality-of-life domains (p<0.001; effect size: 0.41-0.98), sleep-related symptoms (p<0.001; effect size 0.31-0.91) as well as anxiety (p=0.016; effect size 0.51) and depression (p<0.001; effect size: 0.28) indexes and some neurocognitive tests (digit symbol test (p=0.047; effect size: 0.20) and Trail Making Test A (p=0.029; effect size: 0.44)) in an intention-to-treat analysis. In conclusion, CPAP treatment resulted in an improvement in quality of life, sleep-related symptoms, anxiety and depression indexes and some neurocognitive aspects in elderly people with severe OSA.

  4. Obstructive sleep apnea syndrome, continuous positive airway pressure and treatment of hypertension.

    PubMed

    Floras, John S

    2015-09-15

    Obstructive sleep apnea (OSA), present in ~15% of the general population, increases the risks of stroke, heart failure, and premature death. Importantly, individuals with cardiovascular disease have a higher prevalence yet they often have few symptoms to alert clinicians to its presence. OSA with an apnea-hypopnea index (AHI) ≥15 events/hour is present in ≥30% of patients with primary hypertension and in up to 80% of those with drug resistant hypertension, suggesting that the neural, hormonal, inflammatory and vascular cascades triggered by OSA may elevate blood pressure chronically. The purpose of this review is to summarize: (1) the epidemiology of OSA and its relation to cardiovascular risk; (2) potential mechanisms by which OSA could promote conditions known to increase the risk of hypertension or contribute to its development and progression; (3) evidence for and against a pro-hypertensive effect of OSA; and, (4) the impact of treatment with continuous positive airway pressure (CPAP) on blood pressure and blood pressure-related morbidities. The prevailing view that the effect of treatment on blood pressure is modest arises from the inability of most contemporary technology to measure accurately the true impact of CPAP on OSA-entrained surges in nocturnal blood pressure. Moreover the exclusive focus on blood pressure, as if this is the principal determinant of cardiovascular event rates in this population, is naïve. The capacity to reduce cardiovascular risk by treating OSA with CPAP likely transcends a simple blood pressure effect; formal testing of this hypothesis will require adequately powered randomized clinical trials.

  5. Improvement in exercise endurance in patients with chronic airflow limitation using continuous positive airway pressure.

    PubMed

    O'Donnell, D E; Sanii, R; Younes, M

    1988-12-01

    To cope with the increased ventilatory demands of exercise, patients with severe expiratory flow limitation adopt strategies that ultimately place greater demands on their inspiratory muscles. Increased inspiratory muscle work may contribute to dyspnea causation and exercise limitation in such patients even before their ventilatory ceiling is attained. In this setting, continuous positive airway pressure (CPAP) should, by favorably affecting inspiratory muscle function and respiratory sensation, improve exercise performance. Six patients with chronic airflow limitation (CAL) (FEV1 +/- SD = 35 +/- 12% predicted) undertook constant-load, submaximal, cycle exercise at 50% of their predetermined maximal oxygen consumption: CPAP of 4 to 5 cm H2O was delivered during one exercise session and bracketed by one or two unassisted control sessions. In four patients, CPAP-assisted (4 to 5 cm H2O) exercise was bracketed by two unassisted control exercise sessions; two remaining patients undertook CPAP-assisted exercise and one unassisted control session. CPAP resulted in a significant increase in exercise endurance time (TLIM) (by 48%: CPAP TLIM (mean +/- SE) = 8.82 +/- 1.90 min; averaged control TLIM = 5.98 +/- 1.23 min (p less than 0.01). CPAP effectively ameliorated exertional dyspnea in the majority of patients; selected dyspnea ratings (Borg scale) during control (final minute) and CPAP at isotime, at comparable levels of ventilation, were (mean +/- SD) 7.83 +/- 2.25 and 5.5 +/- 2.2, respectively (p less than 0.025). Breathing frequency fell significantly during CPAP application (at isotime) by 17% (p less than 0.02); other steady-state ventilatory variables and end-expiratory lung volumes were not significantly different during CPAP and control.(ABSTRACT TRUNCATED AT 250 WORDS)

  6. [CD11b-positive cells expression in rectal mucosa from ovalbumin sensitized and challenged rabbits].

    PubMed

    Bassan, Norberto; Vinuesa, Miguel; Roma, Stella

    2005-01-01

    Rabbit MAC-1 receptor, homologue to human CD11b is present in macrophages. The aim of the study was to determine quantitative and distributive modifications of CD11b-positive cells that participate in immune response at rectal mucosa, in an animal model of mucosal immunity. New Zealand rabbits were divided into three groups. G1: control; G2: ovalbumin (OVA) sensitized; G3: OVA-senstitized and rectal challenged. Animals were subcutaneously sensitized twice with 70 microg OVA and 30 ml aluminium hydroxide in 2 ml saline solution. Rectal challenge was developed with a solution of 50 mg OVA in 5 ml saline solution. Sensitized groups (G2 and G3) showed a positive PCA (Passive Cutaneous Anaphylaxis) at 1/160 fold dilutions. In G3 we observed a patchy mucosal edema, lymphangiectasis and eosinophil leucocyte infiltration. Cells were counted as the number of cells per high power field. G1: 9.64 (SE 0.22); G2: 18.10 (SE 0.09) and G3: 23.60 (SE 0.29). (G2 vs G1 p < 0.001; G3 vs G1 p < 0.001; G3 vs G2 p < 0.001). We conclude that there is a close relationship between the food antigen OVA penetration (after challenge) and the increase of CD11b positive cells in rectal mucosa. This fact could be due to the cellular influx to the inflammatory site by the action of chemotactic factors released after challenge.

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

    NASA Astrophysics Data System (ADS)

    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. Fast neutron spectrometry and dosimetry using a spherical moderator with position-sensitive detectors.

    PubMed

    Li, Taosheng; Yang, Lianzhen; Ma, Jizeng; Fang, Dong

    2007-01-01

    A neutron spectrometry and dosimetry measurement system has been developed based on a different design of the divided regions for a sphere, with three position-sensitive counters. The characteristics of the measurement system have been investigated in the reference radiation fields of Am-Be and (252)Cf sources. When realistic input spectra are used for the unfolding, the overall deviations of the calculated results for four dosimetric quantities are less than +/-10%. The results of other input spectra are also discussed in this report.

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

    PubMed

    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.

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

    PubMed Central

    Graham, Rebecca A.; Weems, Carl F.

    2014-01-01

    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 others 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 parent 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. PMID:25301177

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

    NASA Astrophysics Data System (ADS)

    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

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

    NASA Astrophysics Data System (ADS)

    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).

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

    NASA Astrophysics Data System (ADS)

    Singh, Prashant Kumar; Kakolee, K. F.; Jeong, T. W.; Ter-Avetisyan, Sargis

    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.

  14. Resonant inelastic hard x-ray scattering with diced analyzer crystals and position-sensitive detectors

    SciTech Connect

    Huotari, S.; Albergamo, F.; Vanko, Gy.; Verbeni, R.; Monaco, G.

    2006-05-15

    A novel design of a high-resolution spectrometer is proposed for emission spectroscopy and resonant inelastic hard x-ray scattering applications. The spectrometer is based on a Rowland circle geometry with a diced analyzer crystal and a position-sensitive detector. The individual flat crystallites of the diced analyzer introduce a well-defined linear position-energy relationship within the analyzer focus. This effect can be exploited to measure emission spectra with an unprecedented resolution. For demonstration, a spectrometer was constructed using a diced Si(553) analyzer working at the Cu K edge with an intrinsic resolution of 60 meV. With the proposed design, spectrometers operating at the K edges of 3d transition metals can have intrinsic resolutions below 100 meV even with analyzer crystals not working in Bragg-backscattering conditions.

  15. The Development of Cavity Ringdown Spectroscopy as a Sensitive Continuous Emission Monitor for Metals

    SciTech Connect

    Miller, George P.

    1999-06-01

    The aim of this study is to evaluate cavity ringdown spectroscopy (CRDS) as an ultra-sensitive technique for trace analysis of metals. Potential applications of CRDS meeting the Department of Energy needs include: Mercury Continuous Emission Monitor Multi-Metal Emissions Monitor Radionuclide Detector and Monitor CRDS is based upon the measurement of the rate of light absorption in a closed optical cavity. A laser pulse is injected into a stable optical cavity through one of the cavity mirrors. This light pulse is trapped between the mirror surfaces and decays exponentially over time at a rate determined by the round trip losses within the cavity. When used for trace analysis, the primary loss mechanisms governing the decay time are mirror reflectivity losses, atomic absorption from the sample, and Rayleigh scattering from air in the cavity. The decay time is given by t= d c 1- R ( )+ als + bd [ ] (1) where d is the cavity length, R is the reflectivity of the cavity mirrors, a is the familiar Beer's Law absorption coefficient of a sample in the cavity, ls is the length of the optical path through the sample (i.e., approximately the graphite furnace length), b is the wavelength-dependent Rayleigh scattering attenuation coefficient, and c is the speed of light. Thus, variations in a caused by changes in the sample concentration are reflected in the ringdown time. As the sample concentration increases (i.e., a increases), the ringdown time decreases yielding an absolute measurement for a. With the use of suitable mirrors, it is possible to achieve thousands of passes through the sample resulting in a significant increase in sensitivity. An additional benefit is that it is not subject to collisional quenching, the branching of fluorescence emission into multiple transitions, and the ability to detect only a fraction of the fluorescence photons that occur in laser-excited atomic fluorescence (LEAFS). One other advantage of the ringdown technique is the ability to use

  16. Cost-effectiveness of Out-of-Hospital Continuous Positive Airway Pressure for Acute Respiratory Failure

    PubMed Central

    Thokala, Praveen; Goodacre, Steve; Ward, Matt; Penn-Ashman, Jerry; Perkins, Gavin D.

    2015-01-01

    Study objective We determine the cost-effectiveness of out-of-hospital continuous positive airway pressure (CPAP) compared with standard care for adults presenting to emergency medical services with acute respiratory failure. Methods We developed an economic model using a United Kingdom health care system perspective to compare the costs and health outcomes of out-of-hospital CPAP to standard care (inhospital noninvasive ventilation) when applied to a hypothetical cohort of patients with acute respiratory failure. The model assigned each patient a probability of intubation or death, depending on the patient’s characteristics and whether he or she had out-of-hospital CPAP or standard care. The patients who survived accrued lifetime quality-adjusted life-years (QALYs) and health care costs according to their age and sex. Costs were accrued through intervention and hospital treatment costs, which depended on patient outcomes. All results were converted into US dollars, using the Organisation for Economic Co-operation and Development purchasing power parities rates. Results Out-of-hospital CPAP was more effective than standard care but was also more expensive, with an incremental cost-effectiveness ratio of £20,514 per QALY ($29,720/QALY) and a 49.5% probability of being cost-effective at the £20,000 per QALY ($29,000/QALY) threshold. The probability of out-of-hospital CPAP’s being cost-effective at the £20,000 per QALY ($29,000/QALY) threshold depended on the incidence of eligible patients and varied from 35.4% when a low estimate of incidence was used to 93.8% with a high estimate. Variation in the incidence of eligible patients also had a marked influence on the expected value of sample information for a future randomized trial. Conclusion The cost-effectiveness of out-of-hospital CPAP is uncertain. The incidence of patients eligible for out-of-hospital CPAP appears to be the key determinant of cost-effectiveness. PMID:25737210

  17. Effect of Nasal Obstruction on Continuous Positive Airway Pressure Treatment: Computational Fluid Dynamics Analyses

    PubMed Central

    Wakayama, Tadashi; Suzuki, Masaaki; Tanuma, Tadashi

    2016-01-01

    Objective Nasal obstruction is a common problem in continuous positive airway pressure (CPAP) therapy for obstructive sleep apnea and limits treatment compliance. The purpose of this study is to model the effects of nasal obstruction on airflow parameters under CPAP using computational fluid dynamics (CFD), and to clarify quantitatively the relation between airflow velocity and pressure loss coefficient in subjects with and without nasal obstruction. Methods We conducted an observational cross-sectional study of 16 Japanese adult subjects, of whom 9 had nasal obstruction and 7 did not (control group). Three-dimensional reconstructed models of the nasal cavity and nasopharynx with a CPAP mask fitted to the nostrils were created from each subject’s CT scans. The digital models were meshed with tetrahedral cells and stereolithography formats were created. CPAP airflow simulations were conducted using CFD software. Airflow streamlines and velocity contours in the nasal cavities and nasopharynx were compared between groups. Simulation models were confirmed to agree with actual measurements of nasal flow rate and with pressure and flow rate in the CPAP machine. Results Under 10 cmH2O CPAP, average maximum airflow velocity during inspiration was 17.6 ± 5.6 m/s in the nasal obstruction group but only 11.8 ± 1.4 m/s in the control group. The average pressure drop in the nasopharynx relative to inlet static pressure was 2.44 ± 1.41 cmH2O in the nasal obstruction group but only 1.17 ± 0.29 cmH2O in the control group. The nasal obstruction and control groups were clearly separated by a velocity threshold of 13.5 m/s, and pressure loss coefficient threshold of approximately 10.0. In contrast, there was no significant difference in expiratory pressure in the nasopharynx between the groups. Conclusion This is the first CFD analysis of the effect of nasal obstruction on CPAP treatment. A strong correlation between the inspiratory pressure loss coefficient and maximum airflow

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

    NASA Astrophysics Data System (ADS)

    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.

  19. The Development of Cavity Ringdown Spectroscopy as a Sensitive Continuous Emission Monitor for Metals

    SciTech Connect

    Miller, George P.

    2000-06-01

    The aim of this study is to evaluate cavity ringdown spectroscopy (CRDS) as an ultrasensitive technique for trace analysis of metals. Potential applications of CRDS to meet stated Department of Energy needs include: Mercury Continuous Emission Monitor Multi-Metal Emissions Monitor Radionuclide Detector and Monitor A full description of the technique can be found in Ref. 1. Briefly, CRDS is based upon the measurement of the rate of light absorption in a closed optical cavity. PMT Cavity Mirror Sample Cavity Mirror Laser Pulse A laser pulse is injected into a stable optical cavity through one of the cavity mirrors. This light pulse is trapped between the mirror surfaces and decays exponentially over time at a rate determined by the round trip losses within the cavity. When used for trace analysis, the primary loss mechanisms governing the decay time are mirror reflectivity losses, atomic absorption from the sample, and Rayleigh scattering from air in the cavity. The decay time is given by t = d c 1- R ( ) +als + bd [ ] (1) where d is the cavity length, R is the reflectivity of the cavity mirrors, a is the familiar Beer's Law absorption coefficient of a sample in the cavity, ls is the length of the optical path through the sample (i.e., approximately the graphite furnace length), b is the wavelength-dependent Rayleigh scattering attenuation coefficient, and c is the speed of light. Thus, variations in a caused by changes in the sample concentration are reflected in the ringdown time. As the sample concentration increases (i.e., a increases), the ringdown time decreases yielding an absolute measurement for a. With the use of suitable mirrors, it is possible to achieve thousands of passes through the sample. This results in an effective path length reaching into the kilometers and a corresponding increase in sensitivity. An additional benefit is that it is not subject to collisional 2 quenching and the branching that occur in techniques such as laser-excited atomic

  20. Evidence for the sensitivity of a Great Basin terminal lake to storm track position

    NASA Astrophysics Data System (ADS)

    Hatchett, B.; Boyle, D. P.; Garner, C.; Kaplan, M. L.; Bassett, S.

    2014-12-01

    Arid, closed basin watersheds can serve as indicators of regional climate change. In this work we test the hypothesis that surface elevations of Walker Lake, a Great Basin terminal lake, are sensitive to storm track positions. To do so, we use historical climate records, numerically dated paleolakeshore elevations, global reanalysis products and a semi-distributed water balance model. Precipitation and temperature values from calculated wet and dry periods between 1920-2011 were used as input to the model. Storm track climatologies were developed using reanalysis products. Our results demonstrate that a strong relationship exists between historic wet and dry periods and storm track positions. Under the assumption of a stationary climate using these historic wet and dry climates with the model, we simulated lake levels that are consistent with recorded high and lowstands occurring during Heinrich Stadial 1, the Younger Dryas, the Medieval Climate Anomaly and the Little Ice Age. These findings provide direct support for the storm track migration hypothesis. The nonlinear relationship between changes in precipitation and runoff appears to play a critical role in determining why terminal lakes are particularly responsive to changes in storm track positions.

  1. Parameter correction method for dual position-sensitive-detector-based unit.

    PubMed

    Mao, Shuai; Hu, Pengcheng; Ding, XueMei; Tan, JiuBin

    2016-05-20

    A dual position-sensitive-detector (PSD)-based unit can be used for angular measurements of a multi-degree-of-freedom measurement system and a laser interferometry-based sensing and tracking system. In order to ensure the precision of incident beam direction measurement for a PSD-based unit, model and autoreflection alignment methods for correction of PSD-based unit parameters are proposed. Experimental results demonstrate the deviations between the angular measurements obtained using a dual PSD-based unit and an autocollimator varied by 70″, 20″, and 1″ for three runs of the autoreflection alignment method, respectively, and the model method deviations all varied by 1″ in the 1000″ measurement range for three runs. It is therefore concluded that the model method is more reliable than the autoreflection alignment method for ensuring the accuracy of a dual PSD-based unit. PMID:27411134

  2. Development of a Position Sensitive Heavy Ion Detector for Nuclear Astrophysics

    NASA Astrophysics Data System (ADS)

    Need, Emily; Blackmon, J. C.; Deibel, C. M.; Lai, J.; Lindhart, L. E.; Macon, K. T.; Matos, M.; Rasco, B. C.; Rogachev, G.; Wiedenhover, I.

    2012-10-01

    The Array for Nuclear Astrophysics Studies with Exotic Nuclei (ANASEN) is a charged-particle detector array used to study reactions with radioactive beams at FSU and the NSCL. One of the main goals is to improve our understanding of nuclear reactions important in stellar explosions. One important component of ANASEN is a heavy ion detector located downstream of the target that is used to identify the atomic number of heavy ions based upon their energy loss through the gas-filled chamber. We have developed a new version of this detector with major design changes to improve data collection and allow much greater selectivity for the reactions of interest. These changes include anodes based on custom printed circuit boards that provide position sensitivity, larger grids to provide greater acceptance, and a change in wire spacing on the grids to improve transmission. We will present the new design and results from initial tests.

  3. Intensity-sensitive and position-resolving cavity for heavy-ion storage rings

    NASA Astrophysics Data System (ADS)

    Chen, X.; Sanjari, M. S.; Hülsmann, P.; Litvinov, Yu. A.; Nolden, F.; Piotrowski, J.; Steck, M.; Stöhlker, Th.; Walker, P. M.

    2016-08-01

    A heavy-ion storage ring can be adapted for use as an isochronous mass spectrometer if the ion velocity matches the transition energy of the ring. Due to the variety of stored ion species, the isochronous condition cannot be fulfilled for all the ions. In order to eliminate the measurement uncertainty stemming from the velocity spread, an intensity-sensitive and position-resolving cavity is proposed. In this paper we first briefly discuss the correction method for the anisochronism effect in the measurement with the cavity. Then we introduce a novel design, which is operated in the monopole mode and offset from the central beam orbit to one side. The geometrical parameters were optimized by analytic and numerical means in accordance with the beam dynamics of the future collector ring at FAIR. Afterwards, the electromagnetic properties of scaled prototypes were measured on a test bench. The results were in good agreement with the predictions.

  4. Parameter correction method for dual position-sensitive-detector-based unit.

    PubMed

    Mao, Shuai; Hu, Pengcheng; Ding, XueMei; Tan, JiuBin

    2016-05-20

    A dual position-sensitive-detector (PSD)-based unit can be used for angular measurements of a multi-degree-of-freedom measurement system and a laser interferometry-based sensing and tracking system. In order to ensure the precision of incident beam direction measurement for a PSD-based unit, model and autoreflection alignment methods for correction of PSD-based unit parameters are proposed. Experimental results demonstrate the deviations between the angular measurements obtained using a dual PSD-based unit and an autocollimator varied by 70″, 20″, and 1″ for three runs of the autoreflection alignment method, respectively, and the model method deviations all varied by 1″ in the 1000″ measurement range for three runs. It is therefore concluded that the model method is more reliable than the autoreflection alignment method for ensuring the accuracy of a dual PSD-based unit.

  5. Measuring Relative-Story Displacement and Local Inclination Angle Using Multiple Position-Sensitive Detectors

    PubMed Central

    Matsuya, Iwao; Katamura, Ryuta; Sato, Maya; Iba, Miroku; Kondo, Hideaki; Kanekawa, Kiyoshi; Takahashi, Motoichi; Hatada, Tomohiko; Nitta, Yoshihiro; Tanii, Takashi; Shoji, Shuichi; Nishitani, Akira; Ohdomari, Iwao

    2010-01-01

    We propose a novel sensor system for monitoring the structural health of a building. The system optically measures the relative-story displacement during earthquakes for detecting any deformations of building elements. The sensor unit is composed of three position sensitive detectors (PSDs) and lenses capable of measuring the relative-story displacement precisely, even if the PSD unit was inclined in response to the seismic vibration. For verification, laboratory tests were carried out using an Xθ-stage and a shaking table. The static experiment verified that the sensor could measure the local inclination angle as well as the lateral displacement. The dynamic experiment revealed that the accuracy of the sensor was 150 μm in the relative-displacement measurement and 100 μrad in the inclination angle measurement. These results indicate that the proposed sensor system has sufficient accuracy for the measurement of relative-story displacement in response to the seismic vibration. PMID:22163434

  6. 3D scanning characteristics of an amorphous silicon position sensitive detector array system.

    PubMed

    Contreras, Javier; Gomes, Luis; Filonovich, Sergej; Correia, Nuno; Fortunato, Elvira; Martins, Rodrigo; Ferreira, Isabel

    2012-02-13

    The 3D scanning electro-optical characteristics of a data acquisition prototype system integrating a 32 linear array of 1D amorphous silicon position sensitive detectors (PSD) were analyzed. The system was mounted on a platform for imaging 3D objects using the triangulation principle with a sheet-of-light laser. New obtained results reveal a minimum possible gap or simulated defect detection of approximately 350 μm. Furthermore, a first study of the angle for 3D scanning was also performed, allowing for a broad range of angles to be used in the process. The relationship between the scanning angle of the incident light onto the object and the image displacement distance on the sensor was determined for the first time in this system setup. Rendering of 3D object profiles was performed at a significantly higher number of frames than in the past and was possible for an incident light angle range of 15 ° to 85 °.

  7. Position sensitive detectors for the proposed AXAF imaging optical/UV monitor (AXIOM)

    NASA Astrophysics Data System (ADS)

    Allington-Smith, J. R.; Mason, I. M.; Schwarz, H. E.; Culhane, J. L.

    1985-02-01

    A description is given of the imaging detectors of the AXIOM instrument proposed for NASA's Advanced X-ray Astrophysics Facility (AXAF). The instrument is aligned with the X-ray telescope and consists of a diffraction limited, 30-cm aperture, telescope with redundant position sensitive detectors at the focus. This allows simultaneous imaging at optical and near UV wavelengths of the X-ray target objects. The proposed detectors cover a field of view of 8.5 x 8.5 sq arcmin with a resolution of 1 arcsec (= 50 microns FWHM). The quantum efficiency peaks at 30 percent and exceeds 10 percent over the wavelength range 125 to 540 nm. The detector design consists of a bi-alkali photocathode on a UV-transmitting window, proximity focussed onto a microchannel plate intensifier with a wedge and strip readout system, and is optimized for high count rates both from point sources and from the sky background.

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

    NASA Astrophysics Data System (ADS)

    Wei, Wanchun; Broussard, L. J.; 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.; Ortiz, Jose D.; Pattie, R. W.; Ramsey, J. C.; Saunders, A.; Seestrom, S. J.; Sharapov, E. I.; Sjue, S. K.; Wexler, J.; Womack, T. L.; Young, A. R.; Zeck, B. A.; Wang, Zhehui

    2016-09-01

    Position-sensitive detection of ultracold neutrons (UCNs) is demonstrated using an imaging charge-coupled device (CCD) camera. A spatial resolution less than 15 μm has been achieved, which is equivalent to a UCN energy resolution below 2 pico-electron-volts through the relation δE =m0 gδx. Here, the symbols δE, δx, m0 and g are the energy resolution, the spatial resolution, the neutron rest mass and the gravitational acceleration, respectively. A multilayer surface convertor described previously is used to capture UCNs and then emits visible light for CCD imaging. Particle identification and noise rejection are discussed through the use of light intensity profile analysis. This method allows different types of UCN spectroscopy and other applications.

  9. Imaging of β particle sources used in medical applications with position sensitive Silicon sensors

    NASA Astrophysics Data System (ADS)

    Caccia, M.; Alemi, M.; Bianchi, C.; Bulgheroni, A.; Cappellini, C.; Conte, L.; Kucewicz, W.; Prest, M.; Vallazza, E.; Sampietro, C.

    2004-06-01

    Real-time dosimetry is a critical issue in most radiotherapy applications. Silicon Ultra fast Cameras for electron and gamma sources In Medical Applications (Nucl. Phys. B 125 (2003) 133) is an EC project addressing the development of an imaging device for extended radioactive sources based on monolithic and hybrid-position-sensitive silicon sensors. Large-area Silicon strip detectors read out by low noise charge integrating chips were used to characterize a 90Sr intravascular brachytherapy source in terms of dose-depth curves in a tissue equivalent material and homogeneity of the activity. The results obtained with the Silicon sensor were compared to measurements with standard certified systems and are reported in the paper.

  10. Imprinted Numbers: Newborn Chicks' Sensitivity to Number vs. Continuous Extent of Objects They Have Been Reared with

    ERIC Educational Resources Information Center

    Rugani, Rosa; Regolin, Lucia; Vallortigara, Giorgio

    2010-01-01

    Newborn chicks were tested for their sensitivity to number vs. continuous physical extent of artificial objects they had been reared with soon after hatching. Because of the imprinting process, such objects were treated by chicks as social companions. We found that when the objects were similar, chicks faced with choices between 1 vs. 2 or 2 vs. 3…

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

    NASA Astrophysics Data System (ADS)

    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

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

    NASA Astrophysics Data System (ADS)

    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.

  13. Fourier synthesis image reconstruction by use of one-dimensional position-sensitive detectors.

    PubMed

    Kotoku, Jun'ichi; Makishima, Kazuo; Okada, Yuu; Negoro, Hitoshi; Terada, Yukikatsu; Kaneda, Hidehiro; Oda, Minoru

    2003-07-10

    An improvement of Fourier synthesis optics for hard x-ray imaging is described, and the basic performance of the new optics is confirmed through numerical simulations. The original concept of the Fourier synthesis imager utilizes nonposition-sensitive hard x-ray detectors coupled to individual bigrid modulation collimators. The improved concept employs a one-dimensional position-sensitive detector (such as a CdTe strip detector) instead of the second grid layer of each bigrid modulation collimator. This improves the imaging performance in several respects over the original design. One performance improvement is a two-fold increase in the average transmission, from 1/4 to 1/2. The second merit is that both the sine and cosine components can be derived from a single grid-detector module, and hence the number of imaging modules can be halved. Furthermore, it provides information along the depth direction simultaneously. This in turn enables a three-dimensional imaging hard x-ray microscope for medical diagnostics, incorporating radioactive tracers. A conceptual design of such a microscope is presented, designed to provide a field of view of 4 mm and a spatial resolution of 400 microm.

  14. Position sensitivity of graphene field effect transistors to X-rays

    SciTech Connect

    Cazalas, Edward Moore, Michael E.; Jovanovic, Igor; Sarker, Biddut K.; Childres, Isaac; Chen, Yong P.

    2015-06-01

    Device architectures that incorporate graphene to realize detection of electromagnetic radiation typically utilize the direct absorbance of radiation by graphene. This limits their effective area to the size of the graphene and their applicability to lower-energy, less penetrating forms of radiation. In contrast, graphene-based transistor architectures that utilize the field effect as the detection mechanism can be sensitive to interactions of radiation not only with graphene but also with the surrounding substrate. Here, we report the study of the position sensitivity and response of a graphene-based field effect transistor (GFET) to penetrating, well-collimated radiation (micro-beam X-rays), producing ionization in the substrate primarily away from graphene. It is found that responsivity and response speed are strongly dependent on the X-ray beam distance from graphene and the gate voltage applied to the GFET. To develop an understanding of the spatially dependent response, a model is developed that incorporates the volumetric charge generation, transport, and recombination. The model is in good agreement with the observed spatial response characteristics of the GFET and predicts a greater response potential of the GFET to radiation interacting near its surface. The study undertaken provides the necessary insight into the volumetric nature of the GFET response, essential for development of GFET-based detectors for more penetrating forms of ionizing radiation.

  15. Positive Affect Relevant to Epistemic Curiosity to Reflect Continuance Intention to Join a Hands-On Making Contest

    ERIC Educational Resources Information Center

    Hong, Jon-Chao; Hwang, Ming-Yueh; Szeto, Elson; Tai, Kai-Hsin; Tsai, Chi-Ruei

    2016-01-01

    Hands-on making (e.g., "Maker") has become prevalent in current educational settings. To understand the role that students' epistemic curiosity plays in hands-on making contests, this study explored its correlation to students' positive affect and continuance intention to participate in a hands-on making contest called…

  16. Method of nonlinear correction of two-dimensional position sensitive detector

    NASA Astrophysics Data System (ADS)

    Mo, Changtao; Wang, Ming; Zhang, Guoyu

    2007-12-01

    The position sensitive detector (PSD) is photo-electronic sensor which can detect the position of a light spot incident on its surface. Many types of non-contact dynamic displacement monitoring instruments could be constructed using PSD. How to overcome the influence of non-linearity action is the most important problem to improve measuring precision and reliability of the instrument. The output characteristic of PSD is analyzed. It is found that the output response of sensor is non-linear when the measuring range is large. In this paper we propose a method for correcting non-linearity of PSD sensor based on high precision linearization sub-block integration neural network interpolation. By using conjugate gradient algorithm of neural network which have characteristic to approach arbitrary nonlinear function, the nonlinear mapping between detecting the voltage of sensor and the outputting results are obtained by training neural network under different nonlinear condition. Experiment results indicate that not only the influence of non-linearity is eliminated effectively, but also the output of nerve network is linear.

  17. Performance of BF{sub 3} Filled Position Sensitive Neutron Detector

    SciTech Connect

    Desai, Shraddha S.; Devan, Shylaja; Krishna, P. S. R.

    2011-07-15

    {sup 3}He filled position sensitive detectors (PSD)s developed in-house are successfully used for neutron scattering studies at Dhruva. However recent global scarcity of {sup 3}He has made it essential to find an alternative. It is very difficult to meet performance capabilities of {sup 3}He for neutron detection in any of the alternate materials. Among various alternatives, BF{sub 3} gas can be one. We have recently put an effort to evaluate performance of BF{sub 3} based PSD. For that a PSD filled with BF{sub 3} gas at 0.8 bar pressure is fabricated and characterized. Performances of the same with Pu-Be source and at Hi-Q Diffractometer, Dhruva are reported in this paper. Diffraction spectra from standard samples Fe and Si at wavelength 0.783 A were recorded. It is found that while position resolution of the BF{sub 3} filled PSD is comparable but the efficiency is 20 times less than that of a {sup 3}He(12 bar) filled PSD.

  18. Higher sensitivity of human auditory nerve fibers to positive electrical currents.

    PubMed

    Macherey, Olivier; Carlyon, Robert P; van Wieringen, Astrid; Deeks, John M; Wouters, Jan

    2008-06-01

    Most contemporary cochlear implants (CIs) stimulate the auditory nerve with trains of amplitude-modulated, symmetric biphasic pulses. Although both polarities of a pulse can depolarize the nerve fibers and generate action potentials, it remains unknown which of the two (positive or negative) phases has the stronger effect. Understanding the effects of pulse polarity will help to optimize the stimulation protocols and to deliver the most relevant information to the implant listeners. Animal experiments have shown that cathodic (negative) current flows are more effective than anodic (positive) ones in eliciting neural responses, and this finding has motivated the development of novel speech-processing algorithms. In this study, we show electrophysiologically and psychophysically that the human auditory system exhibits the opposite pattern, being more sensitive to anodic stimulation. We measured electrically evoked compound action potentials in CI listeners for phase-separated pulses, allowing us to tease out the responses to each of the two opposite-polarity phases. At an equal stimulus level, the anodic phase yielded the larger response. Furthermore, a measure of psychophysical masking patterns revealed that this polarity difference was still present at higher levels of the auditory system and was therefore not solely due to antidromic propagation of the neural response. This finding may relate to a particular orientation of the nerve fibers relative to the electrode or to a substantial degeneration and demyelination of the peripheral processes. Potential applications to improve CI speech-processing strategies are discussed.

  19. Position-sensitive proportional counter with low-resistance metal-wire anode

    DOEpatents

    Kopp, Manfred K.

    1980-01-01

    A position-sensitive proportional counter circuit is provided which allows the use of a conventional (low-resistance, metal-wire anode) proportional counter for spatial resolution of an ionizing event along the anode of the counter. A pair of specially designed active-capacitance preamplifiers are used to terminate the anode ends wherein the anode is treated as an RC line. The preamplifiers act as stabilized active capacitance loads and each is composed of a series-feedback, low-noise amplifier, a unity-gain, shunt-feedback amplifier whose output is connected through a feedback capacitor to the series-feedback amplifier input. The stabilized capacitance loading of the anode allows distributed RC-line position encoding and subsequent time difference decoding by sensing the difference in rise times of pulses at the anode ends where the difference is primarily in response to the distributed capacitance along the anode. This allows the use of lower resistance wire anodes for spatial radiation detection which simplifies the counter construction and handling of the anodes, and stabilizes the anode resistivity at high count rates (>10.sup.6 counts/sec).

  20. Position-sensitive change in the transition metal L-edge fine structures

    SciTech Connect

    Gulec, Ahmet; Phillips, Patrick J.; Klie, Robert F.

    2015-10-05

    Studying the structure and composition of solid-state materials on the atomic scale has become nearly routine in transmission electron microscopy with the development of novel electron optics and electron sources. In particular, with spatial resolutions better than 0.1 nm and energy resolution smaller than 100 meV, the stoichiometry, bonding, and coordination can now be examined on similar scales. Aberration-corrected scanning transmission electron microscopy and electron energy-loss spectroscopy (EELS) have played a crucial role in identifying charge ordering, valence, and as spin state transitions in transition metal perovskite oxides. In this letter, we investigate the effects of ever-decreasing electron-probe sizes on the measured near-edge fine-structure of the transition metal core-loss edge using EELS. We find that for certain transition metal perovskites, the position of the electron probe with respect to the atomic column is crucial in determining the correct valence state. Several reasons for the observed position-sensitive EELS fine-structure are discussed.

  1. Control system to reduce the effects of friction in drive trains of continuous-path-positioning systems. [Patent application

    DOEpatents

    Green, W.L.

    1980-12-01

    An improved continuous-path-positioning servo-control system is provided for reducing the effects of friction arising at very low cutting speeds in the drive trains of numerically controlled cutting machines, and the like. The improvement comprises a feed forward network for altering the gain of the servo-control loop at low positioning velocities to prevent stick-slip movement of the cutting tool holder being positioned by the control system. The feed forward network shunts conventional lag-compensators in the control loop, or loops, so that the error signal used for positioning varies linearly when the value is small, but being limited for larger values. Thus, at higher positioning speeds there is little effect of the added component upon the control being achieved.

  2. A Simple Capacitive Charge-Division Readout for Position-Sensitive Solid-State Photomultiplier Arrays

    PubMed Central

    Du, Junwei; Schmall, Jeffrey P.; Yang, Yongfeng; Di, Kun; Dokhale, Purushottam A.; Shah, Kanai S.; Cherry, Simon R.

    2014-01-01

    A capacitive charge-division readout method for reading out a 2 × 2 array of 5 mm × 5 mm position-sensitive solid-state photomultipliers (PS-SSPM) was designed and evaluated. Using this analog multiplexing method, the 20 signals (16 position, 4 timing) from the PS-SSPM array are reduced to 5 signals (4 position, 1 timing), allowing the PS-SSPM array to be treated as an individual large-area PS-SSPM module. A global positioning approach can now be used, instead of individual positioning for each PS-SSPM in the array, ensuring that the entire light signal is utilized. The signal-to-noise ratio (SNR) and flood histogram quality at different bias voltages (27.5 V to 32.0 V at 0.5 V intervals) and a fixed temperature of 0 °C were evaluated by coupling a 6 × 6 array of 1.3 mm × 1.3 mm × 20 mm polished LSO crystals to the center of the PS-SSPM array. The timing resolution was measured at a fixed bias voltage of 31.0 V and a fixed temperature of 0 °C. All the measurements were evaluated and compared using capacitors with different values and tolerances. Capacitor values ranged from 0.051 nf to 10 nf, and the capacitance tolerance ranged from 1% to 20%. The results show that better performance was achieved using capacitors with smaller values and better capacitance tolerance. Using 0.2 nf capacitors, the SNR, energy resolution and timing resolution were 24.3, 18.2% and 8.8 ns at a bias voltage 31.0 V, respectively. The flood histogram quality was also evaluated by using a 10 × 10 array of 1 mm × 1 mm × 10 mm polished LSO crystals and a 10 × 10 array of 0.7 mm × 0.7 mm × 20 mm unpolished LSO crystals to determine the smallest crystal size resolvable. These studies showed that the high spatial resolution of the PS-SSPM was preserved allowing for 0.7 mm crystals to be identified. These results show that the capacitive charge-division analog signal processing method can significantly reduce the number of electronic channels, from 20 to 5, while retaining the

  3. New Data Collection Subsystem for Powder Neutron Diffractometer with Position Sensitive Detectors

    NASA Astrophysics Data System (ADS)

    Drab, Martin; Kalvoda, Ladislav; Vratislav, Stanislav; Dlouha, Maja

    2012-02-01

    Project INDECS (Integrated Neutron Diffraction Experiment Control System) is a newly developed software system created for the purpose of data acquisition from, and controlling of the upgraded version of the KSN-2 powder neutron diffractometer equipped with Position Sensitive Detectors. The KSN-2 neutron diffractometer (belonging to LND, DSSE, FNSPE, CTU in Prague, CZ, placed at the NRI, Řež near Prague, CZ) was recently upgraded with the possibility to contain up to three parallel linear PSDs which can be mounted on the detector arm instead of the original single counter detector. That was the motivation for the project INDECS to be started. For the actual data acquisition and initial data analysis of the raw sampled signals within the project INDECS a special modular structure called the PSD Acquisition Path (or PSDAP) was designed. Raw sampled signals from either end of the PSD are taken as the main input to the subsystem. The signals are then split into multiple events, analyzed for the position of the obtained events on the PSD, and a histogram of the diffraction events is created as the main output of this subsystem. Moreover, the PSDAP is capable of storing the raw signals either before event splitting or after, so that later the whole process of acquisition can be replayed in software, perhaps with different settings of the processing parameters or perhaps even algorithms. It can also be switched into a mode where under special conditions a correction curve specific for the given PSD can be constructed and later in normal operation it can be used to do the corrections of detected event positions to enhance the results on that particular PSD. This whole subsystem then acts as a single modular command unit (External Execution Module or EEM) within the entire system of project INDECS.

  4. Recodifications of Academic Positions and Reiterations of Desire: Change but Continuity in Gendered Subjectivities

    ERIC Educational Resources Information Center

    Lapping, Claudia

    2006-01-01

    This article argues that the analysis of changes in the social position of women needs to distinguish between levels of social practice and psychic subjectification. The argument draws on Lacan's conception of the relationship between subjectivity, desire and sexual difference to describe gendered aspects of subjectivity embedded within the…

  5. Time-resolved luminescence biosensor for continuous activity detection of protein acetylation-related enzymes based on DNA-sensitized terbium(III) probes.

    PubMed

    Han, Yitao; Li, Hao; Hu, Yufang; Li, Pei; Wang, Huixia; Nie, Zhou; Yao, Shouzhuo

    2015-09-15

    Protein acetylation of histone is an essential post-translational modification (PTM) mechanism in epigenetic gene regulation, and its status is reversibly controlled by histone acetyltransferases (HATs) and histone deacetylases (HDACs). Herein, we have developed a sensitive and label-free time-resolved luminescence (TRL) biosensor for continuous detection of enzymatic activity of HATs and HDACs, respectively, based on acetylation-mediated peptide/DNA interaction and Tb(3+)/DNA luminescent probes. Using guanine (G)-rich DNA-sensitized Tb(3+) luminescence as the output signal, the polycationic substrate peptides interact with DNA with high affinity and subsequently replace Tb(3+), eliminating the luminescent signal. HAT-catalyzed acetylation remarkably reduces the positive charge of the peptides and diminishes the peptide/DNA interaction, resulting in the signal on detection via recovery of DNA-sensitized Tb(3+) luminescence. With this TRL sensor, HAT (p300) can be sensitively detected with a wide linear range from 0.2 to 100 nM and a low detection limit of 0.05 nM. The proposed sensor was further used to continuously monitor the HAT activity in real time. Additionally, the TRL biosensor was successfully applied to evaluating HAT inhibition by two specific inhibitors, anacardic acid and C464, and satisfactory Z'-factors above 0.73 were obtained. Moreover, this sensor is feasible to continuously monitor the HDAC (Sirt1)-catalyzed deacetylation with a linear range from 0.5 to 500 nM and a detection limit of 0.5 nM. The proposed sensor is a convenient, sensitive, and mix-and-read assay, presenting a promising platform for protein acetylation-targeted epigenetic research and drug discovery.

  6. Development of a generalized perturbation theory method for sensitivity analysis using continuous-energy Monte Carlo methods

    DOE PAGESBeta

    Perfetti, Christopher M.; Rearden, Bradley T.

    2016-03-01

    The sensitivity and uncertainty analysis tools of the ORNL SCALE nuclear modeling and simulation code system that have been developed over the last decade have proven indispensable for numerous application and design studies for nuclear criticality safety and reactor physics. SCALE contains tools for analyzing the uncertainty in the eigenvalue of critical systems, but cannot quantify uncertainty in important neutronic parameters such as multigroup cross sections, fuel fission rates, activation rates, and neutron fluence rates with realistic three-dimensional Monte Carlo simulations. A more complete understanding of the sources of uncertainty in these design-limiting parameters could lead to improvements in processmore » optimization, reactor safety, and help inform regulators when setting operational safety margins. A novel approach for calculating eigenvalue sensitivity coefficients, known as the CLUTCH method, was recently explored as academic research and has been found to accurately and rapidly calculate sensitivity coefficients in criticality safety applications. The work presented here describes a new method, known as the GEAR-MC method, which extends the CLUTCH theory for calculating eigenvalue sensitivity coefficients to enable sensitivity coefficient calculations and uncertainty analysis for a generalized set of neutronic responses using high-fidelity continuous-energy Monte Carlo calculations. Here, several criticality safety systems were examined to demonstrate proof of principle for the GEAR-MC method, and GEAR-MC was seen to produce response sensitivity coefficients that agreed well with reference direct perturbation sensitivity coefficients.« less

  7. Parametric stability of continuous shafts, connected to mechanisms with position-dependent inertia

    NASA Astrophysics Data System (ADS)

    Turhan, O.; Koser, K.

    2004-10-01

    Stability of the parametrically excited torsional vibrations of shafts connected to mechanisms with position-dependent inertia is studied via a version of Bolotin's method. The shafts are considered to be torsionally elastic, distributed parameter systems and discretized through a finite element scheme. The mechanisms are modelled by a linearized Eksergian equation of motion. A general method of analysis is described and applied to examples with slider-crank and Scotch-yoke mechanisms.

  8. COUPP - a search for dark matter with a continuously sensitive bubble chamber

    SciTech Connect

    Collar, Juan,; Crum, Keith; Mishra, Smriti; Nakazawa, Dante; Odom, Brian; Rasmussen, Julia; Riley, Nathan; Szydagis, Matthew; Behnke, Ed; Levine, Ilan; Vander Werf, Nate; Cooper, Peter; Crisler, Mike; Hu, Martin; Ramberg, Erik; Sonnenschein, Andrew; Tschirhart, Robert; /Fermilab

    2007-01-01

    We propose to construct and operate a 60-kg room temperature CF{sub 3}I bubble chamber as a prototype dark matter (WIMP) detector. Operating in weakly-superheated mode, the chamber will be sensitive to WIMP induced nuclear recoils above 10 keV, while rejecting background electron recoils at a level approaching 10{sup 10}. We would first commission and operate this chamber in the MINOS near detector hall with the goal to demonstrate stable operation and measure internal contamination and any other backgrounds. This chamber, or an improved version, would then be relocated to an appropriate deep underground site such as the Soudan Mine. This detector will have unique sensitivity to spin-dependent WIMP-nucleon couplings, and even in this early stage of development will attain competitive sensitivity to spin-independent couplings.

  9. Sensitivity of MJO propagation to a robust positive Indian Ocean dipole event in the superparameterized CAM

    NASA Astrophysics Data System (ADS)

    Benedict, James J.; Pritchard, Michael S.; Collins, William D.

    2015-12-01

    The superparameterized Community Atmosphere Model (SPCAM) is used to investigate the impact and geographic sensitivity of positive Indian Ocean Dipole (+IOD) sea-surface temperatures (SSTs) on Madden-Julian oscillation (MJO) propagation. The goal is to clarify potentially appreciable +IOD effects on MJO dynamics detected in prior studies by using a global model with explicit convection representation. Prescribed climatological October SSTs and variants of the SST distribution from October 2006, a +IOD event, force the model. Modest MJO convection weakening over the Maritime Continent occurs when either climatological SSTs, or +IOD SST anomalies restricted to the Indian Ocean, are applied. However, severe MJO weakening occurs when either +IOD SST anomalies are applied globally or restricted to the equatorial Pacific. MJO disruption is associated with time-mean changes in the zonal wind profile and lower moist static energy (MSE) in subsiding air masses imported from the Subtropics by Rossby-like gyres. On intraseasonal scales, MJO disruption arises from significantly smaller MSE accumulation, weaker meridional advective moistening, and overactive submonthly eddies that mix drier subtropical air into the path of MJO convection. These results (1) demonstrate that SPCAM reproduces observed time-mean and intraseasonal changes during +IOD episodes, (2) reaffirm the role that submonthly eddies play in MJO propagation and show that such multiscale interactions are sensitive to interannual SST states, and (3) suggest that boreal fall +IOD SSTs local to the Indian Ocean have a significantly smaller impact on Maritime Continent MJO propagation compared to contemporaneous Pacific SST anomalies which, for October 2006, resemble El Niño-like conditions.

  10. Imatinib sensitizes endometrial cancer cells to cisplatin by targeting CD117-positive growth-competent cells.

    PubMed

    Zhang, Xiuzhi; Kyo, Satoru; Nakamura, Mitsuhiro; Mizumoto, Yasunari; Maida, Yoshiko; Bono, Yukiko; Takakura, Masahiro; Fujiwara, Hiroshi

    2014-04-01

    The use of molecular target therapy has not been established for endometrial cancer. The present study investigated the potential therapeutic strategy of targeting CD117-positive cancer cells as a novel molecular target therapy. FACS-sorted CD117(+) cells isolated from endometrial cancer cell lines (Ishikawa or MFE280 cells) exhibited higher proliferative capacity in vitro and colony forming activity on soft agar, and decreased sensitivity to cisplatin, compared to CD117(-) cells. Immunohistochemical analyses with surgical specimens of endometrial cancers showed that high CD117 expression was tightly linked to advanced FIGO stages, myometrial invasion and histological grade, and was significantly associated with poor overall survival and relapse-free survival (Kaplan-Meier analysis; p<0.001, log-rank test). The Cox-regression hazard model identified high CD117 expression to be an independent prognostic factor for survival (p<0.05). In vitro assay confirmed that stem cell factor (SCF), a ligand of CD117, was produced specifically in CD117(+) cells of endometrial cancer, and the colony-forming activity were abrogated by adding anti-SCF antibody, indicating an SCF-dependent growth property. Imatinib was confirmed to selectively target CD117(+) cells in vitro, and synergistically enhanced the anti-tumor effect of low dose cisplatin in vivo, which showed only modest effects when used as a single use. These findings suggest that CD117 can be a marker of aggressive behavior of cells as well as an independent prognostic marker in endometrial cancer. Targeting of the SCF/CD117 axis by imatinib sensitized endometrial cancer cells to cisplatin, proposing a novel therapeutic strategy for this tumor type. PMID:24333732

  11. Continuous wavelength tunable laser source with optimum positioning of pivot axis for grating

    DOEpatents

    Pushkarsky, Michael; Amone, David F.

    2010-06-08

    A laser source (10) for generating a continuously wavelength tunable light (12) includes a gain media (16), an optical output coupler (36F), a cavity collimator (38A), a diffraction grating (30), a grating beam (54), and a beam attacher (56). The diffraction grating (30) is spaced apart from the cavity collimator (38A) and the grating (30) cooperates with the optical output coupler (36F) to define an external cavity (32). The grating (30) includes a grating face surface (42A) that is in a grating plane (42B). The beam attacher (56) retains the grating beam (54) and allows the grating beam (54) and the grating (30) to effectively pivot about a pivot axis (33) that is located approximately at an intersection of a pivot plane (50) and the grating plane (42B). As provided herein, the diffraction grating (30) can be pivoted about the unique pivot axis (33) to move the diffraction grating (30) relative to the gain media (16) to continuously tune the lasing frequency of the external cavity (32) and the wavelength of the output light (12) so that the output light (12) is mode hop free.

  12. Multiple Chemical Sensitivity and the Workplace: Current Position and Need for an Occupational Health Surveillance Protocol

    PubMed Central

    Martini, A.; Iavicoli, S.; Corso, L.

    2013-01-01

    Multiple chemical sensitivity, commonly known as environmental illness, is a chronic disease in which exposure to low levels of chemicals causes correlated symptoms of varying intensity. With the continuous introduction of new substances, people with MCS suffer significant limitations to their living environment and frequently to their workplace. This paper describes the current situation as regards MCS and the critical points in its case definition, which is still not generally agreed upon; this makes it difficult to recognize with certainty, especially, its precise relationship with work. Other problems arise in relation to the occupational physician's role in diagnosing and managing the worker with the disorder, the question of low levels of exposure to chemicals, and the best measures possible to prevent it. A diagnostic “route” is proposed, useful as a reference for the occupational physician who is often called in first to identify cases suspected of having this disease and to manage MCS workers. Work-related problems for people with MCS depend not only on occupational exposure but also on the incompatibility between their illness and their work. More occupational physicians need to be “sensitive” to MCS, so that these workers are recognized promptly, the work is adapted as necessary, and preventive measures are promoted in the workplace. PMID:23844274

  13. A collision history-based approach to Sensitivity/Perturbation calculations in the continuous energy Monte Carlo code SERPENT

    SciTech Connect

    Giuseppe Palmiotti

    2015-05-01

    In this work, the implementation of a collision history-based approach to sensitivity/perturbation calculations in the Monte Carlo code SERPENT is discussed. The proposed methods allow the calculation of the eects of nuclear data perturbation on several response functions: the eective multiplication factor, reaction rate ratios and bilinear ratios (e.g., eective kinetics parameters). SERPENT results are compared to ERANOS and TSUNAMI Generalized Perturbation Theory calculations for two fast metallic systems and for a PWR pin-cell benchmark. New methods for the calculation of sensitivities to angular scattering distributions are also presented, which adopts fully continuous (in energy and angle) Monte Carlo estimators.

  14. Betabox: a beta particle imaging system based on a position sensitive avalanche photodiode

    NASA Astrophysics Data System (ADS)

    Dooraghi, A. A.; Vu, N. T.; Silverman, R. W.; Farrell, R.; Shah, K. S.; Wang, J.; Heath, J. R.; Chatziioannou, A. F.

    2013-06-01

    A beta camera has been developed that allows planar imaging of the spatial and temporal distribution of beta particles using a 14 × 14 mm2 position sensitive avalanche photodiode (PSAPD). This camera system, which we call Betabox, can be directly coupled to microfluidic chips designed for cell incubation or other biological applications. Betabox allows for imaging the cellular uptake of molecular imaging probes labeled with charged particle emitters such as 18F inside these chips. In this work, we investigate the quantitative imaging capabilities of Betabox for 18F beta particles, in terms of background rate, efficiency, spatial resolution, and count rate. Measurements of background and spatial resolution are considered both at room temperature (21 °C ± 1 °C) and at an elevated operating temperature (37 °C ± 1 °C), as is often required for biological assays. The background rate measured with a 4 keV energy cutoff is below 2 cph mm-2 at both 21 and 37 °C. The absolute efficiency of Betabox for the detection of 18F positron sources in contact with a PSAPD with the surface passivated from ambient light and damage is 46% ± 1%. The lower detection limit is estimated using the Rose Criterion to be 0.2 cps mm-2 for 1 min acquisitions and a 62 × 62 µm2 pixel size. The upper detection limit is approximately 21 000 cps. The spatial resolution at both 21 and 37 °C ranges from 0.4 mm FWHM at the center of the field of view (FOV), and degrades to 1 mm at a distance of 5 mm away from center yielding a useful FOV of approximately 10 × 10 mm2. We also investigate the effects on spatial resolution and sensitivity that result from the use of a polymer based microfluidic chip. For these studies we place varying layers of low-density polyethylene (LDPE) between the detector and the source and find that the spatial resolution degrades by ˜180 µm for every 100 µm of LDPE film. Sensitivity is reduced by half with the inclusion of ˜200 µm of additional LDPE film. Lastly

  15. Betabox: a beta particle imaging system based on a position sensitive avalanche photodiode

    PubMed Central

    Dooraghi, AA; Vu, NT; Silverman, RW; Farrell, R; Shah, KS; Wang, J; Heath, JR; Chatziioannou, AF

    2013-01-01

    A beta camera has been developed that allows planar imaging of the spatial and temporal distribution of beta particles using a 14 × 14 mm2 position sensitive avalanche photodiode (PSAPD). This camera system, which we call Betabox, can be directly coupled to microfluidic chips designed for cell incubation or other biological applications. Betabox allows for imaging the cellular uptake of molecular imaging probes labeled with charged particle emitters such as 18F inside these chips. In this work, we investigate the quantitative imaging capabilities of Betabox for 18F beta particles, in terms of background rate, efficiency, spatial resolution, and count rate. Measurements of background and spatial resolution are considered both at room temperature (21 °C ± 1 °C) and at an elevated operating temperature (37 °C ± 1 °C), as is often required for biological assays. The background rate measured with a 4 keV energy cutoff is below 2 cph mm−2 at both 21 and 37 °C. The absolute efficiency of Betabox for the detection of 18F positron sources in contact with a PSAPD with the surface passivated from ambient light and damage is 46% ± 1%. The lower detection limit is estimated using the Rose Criterion to be 0.2 cps mm−2 for 1 min acquisitions and a 62 × 62 µm2 pixel size. The upper detection limit is approximately 21 000 cps. The spatial resolution at both 21 and 37 °C ranges from 0.4 mm FWHM at the center of the field of view (FOV), and degrades to 1 mm at a distance of 5 mm away from center yielding a useful FOV of approximately 10 × 10 mm2. We also investigate the effects on spatial resolution and sensitivity that result from the use of a polymer based microfluidic chip. For these studies we place varying layers of low-density polyethylene (LDPE) between the detector and the source and find that the spatial resolution degrades by ~180 µm for every 100 µm of LDPE film. Sensitivity is reduced by half with the inclusion of ~200 µm of additional LDPE film

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

    PubMed

    Shuai, Binbin; Xia, Li; Liu, Deming

    2012-11-01

    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. PMID:23187403

  17. 75 FR 17124 - Pressure Sensitive Plastic Tape from Italy: Notice of Continuation of Antidumping Duty Finding

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-05

    ... Act of 1930, as amended (the Act). See Initiation of Five-Year Sunset Review, 74 FR 20286 (May 1, 2009... Review, 74 FR 40811 (August 13, 2009) (Final Results).\\1\\ \\1\\ On October 26, 2009, the Department placed... Sensitive Plastic Tape from Italy; Determination, 75 FR 14628 (March 26, 2010). Scope of the Finding...

  18. Potential of sulfasalazine as a therapeutic sensitizer for CD44 splice variant 9-positive urogenital cancer.

    PubMed

    Takayama, Tatsuya; Kubo, Taro; Morikawa, Ai; Morita, Tatsuo; Nagano, Osamu; Saya, Hideyuki

    2016-05-01

    Cancer stem-like cells (CSCs) with high expression of CD44 splice variant (CD44v) have an enhanced capacity for intracellular reduced glutathione synthesis and defense against reactive oxygen species, resulting in resistance to various therapeutic stresses. Sulfasalazine (SSZ), a drug used in the treatment of rheumatoid arthritis (RA), inhibits glutamate-cystine transport, and suppressed CD44v-dependent tumor growth and increased sensitivity to cytotoxic drugs in an in vivo study. Here, we present two cases of CD44v9-positive urogenital cancer with concomitant treatment with SSZ for RA. Patient 1 was a 62-year-old man who had received SSZ for RA beginning 2 months before the diagnosis of urinary bladder cancer. Although he had multiple metastases to the bladder, abdominal, left cervical and left axillary lymph nodes, and brain, complete response with multidisciplinary therapy was maintained for more than 2 years. Patient 2 was a 74-year-old man with castration-resistant prostate cancer who was diagnosed with RA during chemotherapy and a gradual increase in prostate-specific antigen (PSA) level. When SSZ was added, his PSA value (ng/mL) decreased from 12.93 to 5.58 in only 2 weeks and then quickly rebounded, whereas levels of neuron-specific enolase, a neuroendocrine differentiator and CSC marker, remained almost unchanged. We therefore speculate that SSZ treatment may represent a new adjuvant treatment option for patients with CD44v9-positive urogenital cancer. PMID:27044355

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

    NASA Technical Reports Server (NTRS)

    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.

  20. Reciprocal space mapping of epitaxial materials using position-sensitive x-ray detection

    SciTech Connect

    Lee, S.R.; Doyle, B.L.; Drummond, T.J.; Medernach, J.W.; Schneider, R.P. Jr.

    1994-10-01

    Reciprocal space mapping can be efficiently carried out using a position-sensitive x-ray detector (PSD) coupled to a traditional double-axis diffractometer. The PSD offers parallel measurement of the total scattering angle of all diffracted x-rays during a single rocking-curve scan. As a result, a two-dimensional reciprocal space map can be made in a very short time similar to that of a one-dimensional rocking-curve scan. Fast, efficient reciprocal space mapping offers numerous routine advantages to the x-ray diffraction analyst. Some of these advantages are the explicit differentiation of lattice strain from crystal orientation effects in strain-relaxed heteroepitaxial layers; the nondestructive characterization of the size, shape and orientation of nanocrystalline domains in ordered-alloy epilayers; and the ability to measure the average size and shape of voids in porous epilayers. Here, the PSD-based diffractometer is described, and specific examples clearly illustrating the advantages of complete reciprocal space analysis are presented.

  1. Characterization of two resistive anode encoder position sensitive detectors for use in ion microscopy

    NASA Astrophysics Data System (ADS)

    Brigham, Robert H.; Bleiler, Roger J.; McNitt, Paul J.; Reed, David A.; Fleming, Ronald H.

    1993-02-01

    Both the standard resistive anode encoder (RAE) position sensitive ion detector and a new faster version have been adapted for use with CAMECA IMS-3f/4f imaging secondary-ion mass spectroscopy instruments. Each detector includes a dual microchannel plate image intensifier mounted in front of a resistive anode. The conversion efficiencies of the standard and fast detectors are 60% and 55%, respectively. The high count rates attainable with the fast detector require high strip-current microchannel plates for optimum performance. The mass bias of these detectors is proportional to (mass)1/2 and can be compensated by adjustment of detector supply voltage. The response across the active area of these detectors is uniform to within 3% with the greatest deviations occurring at the periphery. Distortion and pixel-to-pixel bias are negligible with the standard RAE, but noticeable in the prototype of the fast RAE. Software has been developed that corrects pixel-to-pixel bias. The dead times of the standard and fast RAE systems are 4.3±0.1 μs and 330±2 ns which limit practical count rates to about 40 000 and 600 000 Hz, respectively. For many applications, the higher ion arrival rates and dynamic range of the fast RAE imaging system more than compensate for the increased pixel-to-pixel bias and distortion and the small decrease in conversion efficiency.

  2. Mathematical modelling and study of the encoding readout scheme for position sensitive detectors

    NASA Astrophysics Data System (ADS)

    Yue, Xiaoguang; Zeng, Ming; Zeng, Zhi; Wang, Yi; Wang, Xuewu; Zhao, Ziran; Cheng, Jianping; Kang, Kejun

    2016-04-01

    Encoding readout methods based on different schemes have been successfully developed and tested with different types of position-sensitive detectors with strip-readout structures. However, how to construct an encoding scheme in a more general and systematic way is still under study. In this paper, we present a graph model for the encoding scheme. With this model, encoding schemes can be studied in a more systematic way. It is shown that by using an encoding readout method, a maximum of n (n - 1)/2 + 1 strips can be processed with n channels if n is odd, while a maximum of n (n - 2)/2 + 2 strips can be processed with n channels if n is even. Furthermore, based on the model, the encoding scheme construction problem can be translated into a problem in graph theory, the aim of which is to construct an Eulerian trail such that the length of the shortest subcycle is as long as possible. A more general approach to constructing the encoding scheme is found by solving the associated mathematical problem. In addition, an encoding scheme prototype has been constructed, and verified with MRPC detectors.

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

    SciTech Connect

    Arnold, C. W.; Tovesson, F.; 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.

    2014-07-09

    A position-sensitive, high-resolution time-of-flight detector for fission fragments has been developed. The SPectrometer for Ion DEtermination 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 α-particles from 229Th and its decay chain and α-particles and spontaneous fission fragments from 252Cf. Each detector module is comprised of 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 were measured with 250 ps resolution FWHM. Computed particle velocities are accurate to within 0.06 mm/ns corresponding to a precision of 0.5%. As a result, an ionization chamber capable of 400 keV energy resolution coupled with the velocity measurements described here will pave the way for modestly efficient measurements of light fission fragments with unit mass resolution.

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

    DOE PAGESBeta

    Arnold, C. W.; Tovesson, F.; Meierbachtol, K.; Bredeweg, T.; Jandel, M.; Jorgenson, H. J.; Laptev, A.; Rusev, G.; Shields, D. W.; White, M.; et al

    2014-07-09

    A position-sensitive, high-resolution time-of-flight detector for fission fragments has been developed. The SPectrometer for Ion DEtermination 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 α-particles from 229Th and its decay chain and α-particles and spontaneous fission fragments from 252Cf. Each detector module is comprised of 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. Flightmore » times were measured with 250 ps resolution FWHM. Computed particle velocities are accurate to within 0.06 mm/ns corresponding to a precision of 0.5%. As a result, an ionization chamber capable of 400 keV energy resolution coupled with the velocity measurements described here will pave the way for modestly efficient measurements of light fission fragments with unit mass resolution.« less

  5. ROSAT Position Sensitive Proportional Counter spectra of six Seyfert 1 galaxies

    NASA Technical Reports Server (NTRS)

    Turner, T. J.; George, I. M.; Mushotzky, R. F.

    1993-01-01

    We present the results from ROSAT Position Sensitive Proportional Counter observations of six Seyfert 1 galaxies in the soft (0.1-2.0 keV) X-ray band. The sources (Mrk 335, ESO 198-G24, ESO 141-G55, Mrk 509, NGC 7469, and MCG-2-58-22) were chosen to have low absorbing column densities along the line of sight. As expected, it is found that all the sources possess significantly steeper spectra below about 1 keV than observed at higher X-ray energies. Assuming a simple absorbed power-law spectral model, the mean (photon) spectral index for the sample is Gamma = 2.38 +/- 0.25, compared to the canonical 1.7 typically observed in the 2-10 keV band. Furthermore, we find strong evidence for soft X-ray spectral features in half the sources. In NGC 7469 and ESO 198-G24, we find that the addition of a narrow emission line or an absorption edge to the underlying continuum is a significant improvement to the parameterization of the spectra. Mrk 335 also shows evidence for spectral complexity, but from these data it is not possible to unambiguously distinguish between an absorption edge and a steepening of the spectrum at low energies. We examine these results in the light of the accuracy of the PSPC spectral calibration.

  6. High-resolution and high-intensity neutron diffractometer with linear position-sensitive detector

    NASA Astrophysics Data System (ADS)

    Lee, Chang-Hee; Moon, Myung-Kook; Em, V. T.; Choi, Young-Nam; Oh, Hwa-Suk; Nam, Uk-Won

    2003-08-01

    The characteristics of a neutron diffractometer using a 3He one-dimensional position-sensitive detector (PSD) with delay line readout, a 200 (length) × 100 (height) mm 2 active window and 2.5 mm spatial resolution have been studied and compared with those of the High-Resolution Powder Diffractometer (HRPD) of KAERI with 32 3He conventional tube (∅50 mm) detectors and Soller collimators (10') before detectors. For the sample to PSD distance R=1200 mm, the PSD subtends 8° angle of 2 θ and provides the resolution and the peak-to-background ratio close to that for HRPD. Time for scanning (with the same statistics) of a 0-160° interval is about 1.6 times longer and the multi-PSD system providing efficiency about 10 times higher than HRPD is proposed. Because of the small angle subtended by the PSD, the parasitic peaks from the sample environment are eliminated and operation without an oscillating radial collimator is possible. Additionally, the proposed diffractometer has an advantage for small samples.

  7. High sensitivity detection of NO2 employing cavity ringdown spectroscopy and an external cavity continuously tunable quantum cascade laser.

    PubMed

    Rao, Gottipaty N; Karpf, Andreas

    2010-09-10

    A trace gas sensor for the detection of nitrogen dioxide based on cavity ringdown spectroscopy (CRDS) and a continuous wave external cavity tunable quantum cascade laser operating at room temperature has been designed, and its features and performance characteristics are reported. By measuring the ringdown times of the cavity at different concentrations of NO(2), we report a sensitivity of 1.2 ppb for the detection of NO(2) in Zero Air.

  8. Whole-body magnetic resonance imaging featuring moving table continuous data acquisition with high-precision position feedback.

    PubMed

    Zenge, Michael O; Ladd, Mark E; Vogt, Florian M; Brauck, Katja; Barkhausen, Joerg; Quick, Harald H

    2005-09-01

    A novel setup for whole-body MR imaging with moving table continuous data acquisition has been developed and evaluated. The setup features a manually positioned moving table platform with integrated phased-array surface radiofrequency coils. A high-precision laser position sensor was integrated into the system to provide real-time positional data that were used to compensate for nonlinear manual table translation. This setup enables continuous 2D and 3D whole-body data acquisition during table movement with surface coil image quality. The concept has been successfully evaluated with whole-body steady-state free precession (TrueFISP) anatomic imaging in five healthy volunteers. Seamless coronal and sagittal slices of continually acquired whole-body data during table movement were accurately reconstructed. The proposed strategy is potentially useful for a variety of applications, including whole-body metastasis screening, whole-body MR angiography, large field-of-view imaging in short bore systems, and for moving table applications during MR-guided interventions.

  9. A Monte Carlo simulation comparing hydrocarbons as stopping gases for position sensitive neutron detectors

    NASA Astrophysics Data System (ADS)

    Doumas, A.; Smith, G. C.

    2009-12-01

    Various neutron detectors are being developed for the next generation user facilities, which incorporate new as well as existing approaches for the detection of thermal neutrons. Improvements in neutron detector efficiency, detector size and position resolution have occurred over the last three decades and further advances are expected in the next ten years. Since gas detectors are expected to continue in a key role for future thermal neutron experiments, it is advantageous to review some of the criteria for the choice of proton/triton stopping gases for gas-based detectors. Monte Carlo simulations, using the group of programs "Stopping and Range of Ions in Matter", have been run to determine key performance characteristics for neutron detectors which utilize the reaction 3He(n,p)t. This paper will focus on investigating the use of three common hydrocarbons and CF 4 as stopping gases for thermal neutron detectors. A discussion of these gases will include their behavior in terms of proton and triton range, ion distribution and straggle.

  10. Improvement of sensitivity in continuous wave near infra-red spectroscopy systems by using silicon photomultipliers.

    PubMed

    Pagano, Roberto; Libertino, Sebania; Sanfilippo, Delfo; Fallica, Giorgio; Lombardo, Salvatore

    2016-04-01

    We experimentally analyze the signal-to-noise ratio of continuous wave (CW) near infrared spectroscopy (NIRS) reflectance systems based on light emitting diodes and silicon photomultipliers for high performance low cost NIRS biomedical systems. We show that under suitable experimental conditions such systems exhibit a high SNR, which allows an SDS of 7 cm, to our knowledge the largest ever demonstrated in a CW-NIRs system. PMID:27486551

  11. Improvement of sensitivity in continuous wave near infra-red spectroscopy systems by using silicon photomultipliers

    PubMed Central

    Pagano, Roberto; Libertino, Sebania; Sanfilippo, Delfo; Fallica, Giorgio; Lombardo, Salvatore

    2016-01-01

    We experimentally analyze the signal-to-noise ratio of continuous wave (CW) near infrared spectroscopy (NIRS) reflectance systems based on light emitting diodes and silicon photomultipliers for high performance low cost NIRS biomedical systems. We show that under suitable experimental conditions such systems exhibit a high SNR, which allows an SDS of 7 cm, to our knowledge the largest ever demonstrated in a CW-NIRs system. PMID:27486551

  12. Acute Effects of Continuous Positive Air way Pressure on Pulse Pressure in Chronic Heart Failure

    PubMed Central

    Quintão, Mônica; Chermont, Sérgio; Marchese, Luana; Brandão, Lúcia; Bernardez, Sabrina Pereira; Mesquita, Evandro Tinoco; Rocha, Nazareth de Novaes; Nóbrega, Antônio Claudio L.

    2014-01-01

    Background Patients with heart failure (HF) have left ventricular dysfunction and reduced mean arterial pressure (MAP). Increased adrenergic drive causes vasoconstriction and vessel resistance maintaining MAP, while increasing peripheral vascular resistance and conduit vessel stiffness. Increased pulse pressure (PP) reflects a complex interaction of the heart with the arterial and venous systems. Increased PP is an important risk marker in patients with chronic HF (CHF). Non-invasive ventilation (NIV) has been used for acute decompensated HF, to improve congestion and ventilation through both respiratory and hemodynamic effects. However, none of these studies have reported the effect of NIV on PP. Objective The objective of this study was to determine the acute effects of NIV with CPAP on PP in outpatients with CHF. Methods Following a double-blind, randomized, cross-over, and placebo-controlled protocol, twenty three patients with CHF (17 males; 60 ± 11 years; BMI 29 ± 5 kg/cm2, NYHA class II, III) underwent CPAP via nasal mask for 30 min in a recumbent position. Mask pressure was 6 cmH2O, whereas placebo was fixed at 0-1 cmH2O. PP and other non invasive hemodynamics variables were assessed before, during and after placebo and CPAP mode. Results CPAP decreased resting heart rate (Pre: 72 ± 9; vs. Post 5 min: 67 ± 10 bpm; p < 0.01) and MAP (CPAP: 87 ± 11; vs. control 96 ± 11 mmHg; p < 0.05 post 5 min). CPAP decreased PP (CPAP: 47 ± 20 pre to 38 ± 19 mmHg post; vs. control: 42 ± 12 mmHg, pre to 41 ± 18 post p < 0.05 post 5 min). Conclusion NIV with CPAP decreased pulse pressure in patients with stable CHF. Future clinical trials should investigate whether this effect is associated with improved clinical outcome. PMID:24676373

  13. Progress in Bathymetric Surveys: Combining High Precision Positioning in Real Time with a Continuous Vertical Datum in Remote Areas

    NASA Astrophysics Data System (ADS)

    Lévesque, S.; Robin, C. M. I.; MacLeod, K.; Fadaie, K.

    2014-12-01

    For most of its bathymetric survey activities, the Canadian Hydrographic Service (CHS) requires high precision, three dimensional positioning. As part of a pilot project, one of its launches was equipped with a GNSS receiver processing a high precision correction service in real time (HP-GPS*C) via the internet using satellite telecommunication. This service was provided by Natural Resources Canada/Canadian Geodetic Survey (NRCan/CGS). The bathymetric data from a survey in eastern Hudson Bay performed by CHS in Fall 2013 was post -processed using different standard methods. This resulted in high precision positions that were compared with positions corrected with the real-time precise point positioning (PPP) service (HP-GPS*C) from NRCan/CGS. CHS bathymetric surveys must be referred to chart datum, the hydrographical vertical datum defined for use on nautical charts. In the Canadian north, another limitation to high precision bathymetric work is the availability of tide observations and/or predictions. The territory is vast and tide data is limited in space and in time while predicted tides are not always accurate. This makes reductions of bathymetric soundings to Chart datum difficult. To address this problem, CHS and NRCan/CGS have collaborated to produce a Continuous Vertical Datum for Canadian Waters (CVDCW), which incorporates data from NRCan's geoid model, tide gauge and GPS data, satellite altimetry, and ocean models. Thus high precision positioning provides ellipsoidal heights for the bathymetric depths, and the CVDCW allows to correct these ellipsoidal heights to chart datum. Comparisons of the bathymetry from the pilot survey corrected for tide data versus the bathymetry referred to its ellipsoidal height corrected to chart datum with the CVDCW are given to demonstrate the relative changes to the depths. This also illustrates the advantage of a continuous vertical datum with its potential to be combined with real-time high precision positioning.

  14. Pedunculopontine tegmental nucleus lesions impair probabilistic reversal learning by reducing sensitivity to positive reward feedback.

    PubMed

    Syed, Anam; Baker, Phillip M; Ragozzino, Michael E

    2016-05-01

    Recent findings indicate that pedunculopontine tegmental nucleus (PPTg) neurons encode reward-related information that is context-dependent. This information is critical for behavioral flexibility when reward outcomes change signaling a shift in response patterns should occur. The present experiment investigated whether NMDA lesions of the PPTg affects the acquisition and/or reversal learning of a spatial discrimination using probabilistic reinforcement. Male Long-Evans rats received a bilateral infusion of NMDA (30nmoles/side) or saline into the PPTg. Subsequently, rats were tested in a spatial discrimination test using a probabilistic learning procedure. One spatial location was rewarded with an 80% probability and the other spatial location rewarded with a 20% probability. After reaching acquisition criterion of 10 consecutive correct trials, the spatial location - reward contingencies were reversed in the following test session. Bilateral and unilateral PPTg-lesioned rats acquired the spatial discrimination test comparable to that as sham controls. In contrast, bilateral PPTg lesions, but not unilateral PPTg lesions, impaired reversal learning. The reversal learning deficit occurred because of increased regressions to the previously 'correct' spatial location after initially selecting the new, 'correct' choice. PPTg lesions also reduced the frequency of win-stay behavior early in the reversal learning session, but did not modify the frequency of lose-shift behavior during reversal learning. The present results suggest that the PPTg contributes to behavioral flexibility under conditions in which outcomes are uncertain, e.g. probabilistic reinforcement, by facilitating sensitivity to positive reward outcomes that allows the reliable execution of a new choice pattern. PMID:26976089

  15. Toward increased concentration sensitivity for continuous wave EPR investigations of spin-labeled biological macromolecules at high fields

    NASA Astrophysics Data System (ADS)

    Song, Likai; Liu, Zhanglong; Kaur, Pavanjeet; Esquiaqui, Jackie M.; Hunter, Robert I.; Hill, Stephen; Smith, Graham M.; Fanucci, Gail E.

    2016-04-01

    High-field, high-frequency electron paramagnetic resonance (EPR) spectroscopy at W-(∼94 GHz) and D-band (∼140 GHz) is important for investigating the conformational dynamics of flexible biological macromolecules because this frequency range has increased spectral sensitivity to nitroxide motion over the 100 ps to 2 ns regime. However, low concentration sensitivity remains a roadblock for studying aqueous samples at high magnetic fields. Here, we examine the sensitivity of a non-resonant thin-layer cylindrical sample holder, coupled to a quasi-optical induction-mode W-band EPR spectrometer (HiPER), for continuous wave (CW) EPR analyses of: (i) the aqueous nitroxide standard, TEMPO; (ii) the unstructured to α-helical transition of a model IDP protein; and (iii) the base-stacking transition in a kink-turn motif of a large 232 nt RNA. For sample volumes of ∼50 μL, concentration sensitivities of 2-20 μM were achieved, representing a ∼10-fold enhancement compared to a cylindrical TE011 resonator on a commercial Bruker W-band spectrometer. These results therefore highlight the sensitivity of the thin-layer sample holders employed in HiPER for spin-labeling studies of biological macromolecules at high fields, where applications can extend to other systems that are facilitated by the modest sample volumes and ease of sample loading and geometry.

  16. Toward increased concentration sensitivity for continuous wave EPR investigations of spin-labeled biological macromolecules at high fields.

    PubMed

    Song, Likai; Liu, Zhanglong; Kaur, Pavanjeet; Esquiaqui, Jackie M; Hunter, Robert I; Hill, Stephen; Smith, Graham M; Fanucci, Gail E

    2016-04-01

    High-field, high-frequency electron paramagnetic resonance (EPR) spectroscopy at W-(∼94 GHz) and D-band (∼140 GHz) is important for investigating the conformational dynamics of flexible biological macromolecules because this frequency range has increased spectral sensitivity to nitroxide motion over the 100 ps to 2 ns regime. However, low concentration sensitivity remains a roadblock for studying aqueous samples at high magnetic fields. Here, we examine the sensitivity of a non-resonant thin-layer cylindrical sample holder, coupled to a quasi-optical induction-mode W-band EPR spectrometer (HiPER), for continuous wave (CW) EPR analyses of: (i) the aqueous nitroxide standard, TEMPO; (ii) the unstructured to α-helical transition of a model IDP protein; and (iii) the base-stacking transition in a kink-turn motif of a large 232 nt RNA. For sample volumes of ∼50 μL, concentration sensitivities of 2-20 μM were achieved, representing a ∼10-fold enhancement compared to a cylindrical TE011 resonator on a commercial Bruker W-band spectrometer. These results therefore highlight the sensitivity of the thin-layer sample holders employed in HiPER for spin-labeling studies of biological macromolecules at high fields, where applications can extend to other systems that are facilitated by the modest sample volumes and ease of sample loading and geometry.

  17. Young children's developing sensitivity to discourse continuity as a cue for inferring reference.

    PubMed

    Horowitz, Alexandra C; Frank, Michael C

    2015-01-01

    Children encounter many opportunities for word learning where a novel word (e.g., "chinchilla") coincides in time with the presence of its referent (e.g., a parent pointing at a fuzzy rodent). These two ingredients are not always paired simultaneously, but they sometimes still occur in succession within a discourse. We investigated children's ability to apply their knowledge of discourse structure to infer the referent of a novel word in the absence of social cues such as pointing and eye gaze. In Experiment 1A, we introduced 2- to 6-year-old children and adults to two novel toys and described each using two sentences. We embedded the introduction of a novel label ("Have you seen a toma before?") between the two sentences about one of the toys, with no cues implying the label's referent other than its position in the discourse. Children older than 3 years and adults were more likely to attribute the label to the toy whose descriptions surrounded the naming event. In Experiment 1B, we tested whether participants made their selections based on temporal associations-choosing the toy that was described closest in time to the naming event-rather than inferences about discourse. Participants heard the novel label introduced after the two descriptions of a toy rather than embedded between them. Both children and adults responded close to chance in this experiment, indicating that temporal proximity alone did not guide their selections. Together, these results suggest that children can use discourse position to make inferences about reference in word learning situations.

  18. N-Ethylmaleimide Sensitive Factor (NSF) Inhibition Prevents Vascular Instability following Gram-Positive Pulmonary Challenge

    PubMed Central

    Lee, Ji Young; Linge, Helena M.; Ochani, Kanta; Lin, Ke; Miller, Edmund J.

    2016-01-01

    Background The Acute Respiratory Distress Syndrome (ARDS), remains a significant source of morbidity and mortality in critically ill patients. Pneumonia and sepsis are leading causes of ARDS, the pathophysiology of which includes increased pulmonary microvascular permeability and hemodynamic instability resulting in organ dysfunction. We hypothesized that N-ethylmaleimide sensitive factor (NSF) regulates exocytosis of inflammatory mediators, such as Angiopoietin-2 (Ang-2), and cytoskeletal stability by modulating myosin light chain (MLC) phosphorylation. Therefore, we challenged pulmonary cells, in vivo and in vitro, with Gram Positive bacterial cell wall components, lipoteichoic acid (LTA), and peptidoglycan (PGN) and examined the effects of NSF inhibition. Methods Mice were pre-treated with an inhibitor of NSF, TAT-NSF700 (to prevent Ang-2 release). After 30min, LTA and PGN (or saline alone) were instilled intratracheally. Pulse oximetry was assessed in awake mice prior to, and 6 hour post instillation. Post mortem, tissues were collected for studies of inflammation and Ang-2. In vitro, pulmonary endothelial cells were assessed for their responses to LTA and PGN. Results Pulmonary challenge induced signs of airspace and systemic inflammation such as changes in neutrophil counts and protein concentration in bronchoalveolar lavage fluid and tissue Ang-2 concentration, and decreased physiological parameters including oxygen saturation and pulse distention. TAT-NSF700 pre-treatment reduced LTA-PGN induced changes in lung tissue Ang-2, oxygen saturation and pulse distention. In vitro, LTA-PGN induced a rapid (<2 min) release of Ang-2, which was significantly attenuated by TAT-NSF700 or anti TLR2 antibody. Furthermore, TAT-NSF700 reduced LTA-PGN-induced MLC phosphorylation at low concentrations of 1–10 nM. Conclusions TAT-NSF700 decreased Ang-2 release, improved oxygen saturation and pulse distention following pulmonary challenge by inhibiting MLC phosphorylation, an

  19. Sci—Thur PM: Imaging — 01: Position-sensitive noise characteristics in multi-pinhole cardiac SPECT imaging

    SciTech Connect

    Cuddy-Walsh, SG; Wells, RG

    2014-08-15

    Myocardial perfusion imaging (MPI) with Single Photon Emission Computed Tomography (SPECT) is invaluable in the diagnosis and management of heart disease. It provides essential information on myocardial blood flow and ischemia. Multi-pinhole dedicated cardiac-SPECT cameras offer improved count sensitivity, and spatial and energy resolutions over parallel-hole camera designs however variable sensitivity across the field-of-view (FOV) can lead to position-dependent noise variations. Since MPI evaluates differences in the signal-to-noise ratio, noise variations in the camera could significantly impact the sensitivity of the test for ischemia. We evaluated the noise characteristics of GE Healthcare's Discovery NM530c camera with a goal of optimizing the accuracy of our patient assessment and thereby improving outcomes. Theoretical sensitivity maps of the camera FOV, including attenuation effects, were estimated analytically based on the distance and angle between the spatial position of a given voxel and each pinhole. The standard deviation in counts, σ was inferred for each voxel position from the square root of the sensitivity mapped at that position. Noise was measured experimentally from repeated (N=16) acquisitions of a uniform spherical Tc-99m-water phantom. The mean (μ) and standard deviation (σ) were calculated for each voxel position in the reconstructed FOV. Noise increased ∼2.1× across a 12 cm sphere. A correlation of 0.53 is seen when experimental noise is compared with theory suggesting that ∼53% of the noise is attributed to the combined effects of attenuation and the multi-pinhole geometry. Further investigations are warranted to determine the clinical impact of the position-dependent noise variation.

  20. Shot noise statistics and information theory of sensitivity limits in frequency-modulated continuous-wave ladar.

    PubMed

    Barber, Zeb W; Dahl, Jason R; Sharpe, Tia L; Erkmen, Baris I

    2013-07-01

    A theoretical analysis and experimental verification of the sensitivity limits of frequency-modulated continuous-wave (FMCW) ladar in the limit of a strong local oscillator is presented. The single-photon sensitivity of coherent heterodyne detection in this shot-noise dominated limit is verified to extend to linearly chirped waveforms. An information theoretic analysis is presented to estimate the information efficiency of received photons for the task of locating the range to single and multiple targets. It is found that the optimum receive signal level is proportional to the logarithm of the number of resolvable range locations and the maximum theoretical photon information efficiency for FMCW ranging with coherent fields is log(e)≈1.44 bits per received photon. PMID:24323147

  1. Established vascular effects of continuous positive airway pressure therapy in patients with obstructive sleep apnoea—an update

    PubMed Central

    Wons, Annette Marie

    2015-01-01

    The aim of this review was to summarize the current data from randomised controlled trials (RCTs) on vascular effects of continuous positive airway pressure (CPAP) therapy in patients with obstructive sleep apnoea (OSA). There is good evidence from RCTs that CPAP lowers blood pressure (BP) to a clinically significant amount. The effect seems to be dependent on the hours of nightly CPAP usage. Data from RCTs have also proven a beneficial effect of CPAP on measures of vascular function such as endothelial function and arterial stiffness. However, there is still a lack of evidence from RCTs proving that CPAP reduces vascular events and mortality. PMID:26101649

  2. Continuous positive airway pressure with pressure support ventilation is effective in treating acute-onset bilateral recurrent laryngeal nerve palsy.

    PubMed

    Leung, Yiuka; Fikry, Karim; Shah, Bhavika; Madapu, Manokanth; Gaz, Randall D; Leffert, Lisa R; Jiang, Yandong

    2015-06-01

    Acute bilateral recurrent laryngeal nerve injury leading to acute vocal cord paralysis (VCP) is a serious complication of head and neck surgery, often requiring emergent surgical intervention. Although well documented, its presentation may be sudden and unexpected, occurring despite lack of obvious intraoperative nerve injury. There is limited literature on airway management strategies for patients with acute bilateral VCP before attaining a secure airway. We report a case of acute VCP that was successfully treated with continuous positive airway pressure via facemask ventilation. This effective temporizing strategy allowed clinicians to plan and prepare for tracheostomy, minimizing potential complications.

  3. Established vascular effects of continuous positive airway pressure therapy in patients with obstructive sleep apnoea-an update.

    PubMed

    Wons, Annette Marie; Kohler, Malcolm

    2015-05-01

    The aim of this review was to summarize the current data from randomised controlled trials (RCTs) on vascular effects of continuous positive airway pressure (CPAP) therapy in patients with obstructive sleep apnoea (OSA). There is good evidence from RCTs that CPAP lowers blood pressure (BP) to a clinically significant amount. The effect seems to be dependent on the hours of nightly CPAP usage. Data from RCTs have also proven a beneficial effect of CPAP on measures of vascular function such as endothelial function and arterial stiffness. However, there is still a lack of evidence from RCTs proving that CPAP reduces vascular events and mortality. PMID:26101649

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

    NASA Astrophysics Data System (ADS)

    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

  5. Sensitivity to the Positional Information of Morphemes inside Chinese Compound Words and Its Relationship with Word Reading

    ERIC Educational Resources Information Center

    Liu, Duo; Chung, Kevin Kien Hoa; Zhang, Yimin; Lu, Zheng

    2014-01-01

    The purpose of the present study was to investigate developmental differences in lexical processing and sensitivity to the positional information of constituent morphemes with reference to Chinese word-reading ability. One hundred mainland Chinese children (50 second graders and 50 third graders) and 22 high school students were tested with a…

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

    NASA Technical Reports Server (NTRS)

    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.

  7. Positioning system for single or multi-axis sensitive instrument calibration and calibration system for use therewith

    NASA Technical Reports Server (NTRS)

    Finley, Tom D. (Inventor); Parker, Peter A. (Inventor)

    2008-01-01

    A positioning and calibration system are provided for use in calibrating a single or multi axis sensitive instrument, such as an inclinometer. The positioning system includes a positioner that defines six planes of tangential contact. A mounting region within the six planes is adapted to have an inclinometer coupled thereto. The positioning system also includes means for defining first and second flat surfaces that are approximately perpendicular to one another with the first surface adapted to be oriented relative to a local or induced reference field of interest to the instrument being calibrated, such as a gravitational vector. The positioner is positioned such that one of its six planes tangentially rests on the first flat surface and another of its six planes tangentially contacts the second flat surface. A calibration system is formed when the positioning system is used with a data collector and processor.

  8. Continuous Monitoring and Intrafraction Target Position Correction During Treatment Improves Target Coverage for Patients Undergoing SBRT Prostate Therapy

    SciTech Connect

    Lovelock, D. Michael; Messineo, Alessandra P.; Cox, Brett W.; Kollmeier, Marisa A.; Zelefsky, Michael J.

    2015-03-01

    Purpose: To compare the potential benefits of continuous monitoring of prostate position and intervention (CMI) using 2-mm displacement thresholds during stereotactic body radiation therapy (SBRT) treatment to those of a conventional image-guided procedure involving single localization prior to treatment. Methods and Materials: Eighty-nine patients accrued to a prostate SBRT dose escalation protocol were implanted with radiofrequency transponder beacons. The planning target volume (PTV) margin was 5 mm in all directions, except for 3 mm in the posterior direction. The prostate was kept within 2 mm of its planned position by the therapists halting dose delivery and, if necessary, correcting the couch position. We computed the number, type, and time required for interventions and where the prostate would have been during dose delivery had there been, instead, a single image-guided setup procedure prior to each treatment. Distributions of prostate displacements were computed as a function of time. Results: After the initial setup, 1.7 interventions per fraction were required, with a concomitant increase in time for dose delivery of approximately 65 seconds. Small systematic drifts in prostate position in the posterior and inferior directions were observed in the study patients. Without CMI, intrafractional motion would have resulted in approximately 10% of patients having a delivered dose that did not meet our clinical coverage requirement, that is, a PTV D95 of >90%. The posterior PTV margin required for 95% of the dose to be delivered with the target positioned within the PTV was computed as a function of time. The margin necessary was found to increase by 2 mm every 5 minutes, starting from the time of the imaging procedure. Conclusions: CMI using a tight 2-mm displacement threshold was not only feasible but was found to deliver superior PTV coverage compared with the conventional image-guided procedure in the SBRT setting.

  9. The blink reflex magnitude is continuously adjusted according to both current and predicted stimulus position with respect to the face.

    PubMed

    Wallwork, Sarah B; Talbot, Kerwin; Camfferman, Danny; Moseley, G L; Iannetti, G D

    2016-08-01

    The magnitude of the hand-blink reflex (HBR), a subcortical defensive reflex elicited by the electrical stimulation of the median nerve, is increased when the stimulated hand is close to the face ('far-near effect'). This enhancement occurs through a cortico-bulbar facilitation of the polysynaptic medullary pathways subserving the reflex. Here, in two experiments, we investigated the temporal characteristics of this facilitation, and its adjustment during voluntary movement of the stimulated hand. Given that individuals navigate in a fast changing environment, one would expect the cortico-bulbar modulation of this response to adjust rapidly, and as a function of the predicted spatial position of external threats. We observed two main results. First, the HBR modulation occurs without a temporal delay between when the hand has reached the stimulation position and when the stimulus happens (Experiments 1 and 2). Second, the voluntary movement of the hand interacts with the 'far-near effect': stimuli delivered when the hand is far from the face elicit an enhanced HBR if the hand is being moved towards the face, whereas stimuli delivered when the hand is near the face elicit an enhanced HBR regardless of the direction of the hand movement (Experiment 2). These results indicate that the top-down modulation of this subcortical defensive reflex occurs continuously, and takes into account both the current and the predicted position of potential threats with respect to the body. The continuous control of the excitability of subcortical reflex circuits ensures appropriate adjustment of defensive responses in a rapidly-changing sensory environment. PMID:27236372

  10. Early Surfactant Therapy With Nasal Continuous Positive Airway Pressure or Continued Mechanical Ventilation in Very Low Birth Weight Neonates With Respiratory Distress Syndrome

    PubMed Central

    Najafian, Bita; Fakhraie, Seyed Hasan; Afjeh, Seyed Abulfazl; Kazemian, Mohammad; Shohrati, Majid; Saburi, Amin

    2014-01-01

    Background: Various strategies have been suggested for the treatment of respiratory distress syndrome (RDS). Objectives: The aim of this study was to compare the efficacies of two common methods of RDS management among neonates with low birth weight. Patients and Methods: A cohort study was conducted on 98 neonates with definite diagnosis of RDS during 2008-2009. The neonates were divided into two groups by a blinded supervisor using simple randomization (odd and even numbers). Forty-five cases in the first group were treated with intubation, surfactant therapy, extubation (INSURE method) followed by nasal continuous positive airway pressure (N.CPAP) and 53 cases in the second group underwent intubation, surfactant therapy followed by mechanical ventilation (MV). Results: Five (11.1%) cases in the first group and 23 (43%) cases in the second group expired during the study. The rates of MV dependency among cases with INSURE failure and cases in the MV group were 37% and 83%, respectively (P < 0.001). Birth weight (BW) (P = 0.017), presence of retinopathy of prematurity (P = 0.022), C/S delivery (P = 0.029) and presence of lung bleeding (P = 0.010) could significantly predict mortality in the second group, although only BW (P = 0.029) had a significant impact on the mortality rate in the first group. Moreover, BW was significantly related to the success rate in the first group (P = 0.001). Conclusions: Our findings demonstrated that INSURE plus NCPAP was more effective than the routine method (permanent intubation after surfactant prescription). In addition, the lower rates of mortality, MV dependency, duration of hospitalization, and complications were observed in cases treated with the INSURE method compared to the routine one. PMID:24910785

  11. Impact of Randomization, Clinic Visits, and Medical and Psychiatric Cormorbidities on Continuous Positive Airway Pressure Adherence in Obstructive Sleep Apnea

    PubMed Central

    Budhiraja, Rohit; Kushida, Clete A.; Nichols, Deborah A.; Walsh, James K.; Simon, Richard D.; Gottlieb, Daniel J.; Quan, Stuart F.

    2016-01-01

    Study Objectives: To evaluate factors associated with continuous positive airway pressure (CPAP) adherence in patients with obstructive sleep apnea (OSA) in the Apnea Positive Pressure Long-term Efficacy Study (APPLES) cohort. Methods: The data from a prospective 6-mo multicenter randomized controlled trial with 558 subjects randomized to active CPAP and 547 to sham CPAP were analyzed to assess adherence to CPAP during first 2 mo (early period) and during months 5-6 (late period). Results: Participants randomized to active CPAP had higher hours of nightly adherence compared to the sham CPAP group at both 2 (4.9 ± 2.0 h versus 4.07 ± 2.14 h, p < 0.001) and 6 mo (4.70 ± 2.08 h versus 3.41 ± 2.19 h, p < 0.001). Those assigned to sham CPAP were more likely to correctly identify their treatment group (70.0% versus 55.2%, p < 0.001). Irrespective of treatment group assignment, those who believed they were receiving active CPAP had higher hours of adherence than those who thought they were in the sham CPAP group at both 2 mo (4.91 ± 2.01 versus 4.17 ± 2.17, p < 0.001) and 6 mo (4.65 ± 2.10 versus 3.65 ± 2.22, p < 0.001). Among those randomized to active CPAP, older age was significantly related to CPAP use > 4 h per night. Presence of cardiovascular disorders was associated with higher hours of CPAP use, whereas presence of anxiety was associated with a trend toward lower hours of CPAP use. Presence of nasal congestion was associated with a decrease in mean daily CPAP use between the early and the late adherence period. The adherence during the week prior to a clinic visit was higher than the average adherence during the 2-mo period prior to the visit. Conclusions: Randomization to active therapy, belief that one is in the active treatment group, older age, and possibly presence of cardiovascular disorders are positively linked to CPAP adherence. Nasal congestion and anxiety are negatively associated with CPAP adherence. CPAP nightly usage increases as clinic

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

    NASA Astrophysics Data System (ADS)

    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.

  13. Off-axis digital holographic particle positioning based on polarization-sensitive wavefront curvature estimation.

    PubMed

    Öhman, Johan; Sjödahl, Mikael

    2016-09-20

    Poor axial resolution in holographic particle imaging applications makes particle positioning in 3D space more complex since the positions are not directly obtained. In this paper we estimate the axial position of micrometer particles by finding the location where the wavefront curvature from the scattered light becomes zero. By recording scattered light at 90° using off-axis holography, the complex amplitude of the light is obtained. By reconstruction of the imaged scene, a complex valued volume is produced. From this volume, phase gradients are calculated for each particle and used to estimate the wavefront curvature. From simulations it is found that the wavefront curvature became zero at the true axial position of the particle. We applied this metric to track an axial translation experimentally using a telecentric off-axis holographic imaging system with a lateral magnification of M=1.33. A silicon cube with molded particles inside was used as sample. Holographic recordings are performed both before and after a 100 μm axial translation. From the estimated positions, it was found that the mean displacement of particles between recordings was 105.0 μm with a standard deviation of 25.3 μm. PMID:27661575

  14. Music training and empathy positively impact adults’ sensitivity to infant distress

    PubMed Central

    Parsons, Christine E.; Young, Katherine S.; Jegindø, Else-Marie E.; Vuust, Peter; Stein, Alan; Kringelbach, Morten L.

    2014-01-01

    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. This task required that participants discriminate between pitch differences and interpret these as differences in infant distress. 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. PMID:25566122

  15. Music training and empathy positively impact adults' sensitivity to infant distress.

    PubMed

    Parsons, Christine E; Young, Katherine S; Jegindø, Else-Marie E; Vuust, Peter; Stein, Alan; Kringelbach, Morten L

    2014-01-01

    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. This task required that participants discriminate between pitch differences and interpret these as differences in infant distress. 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. PMID:25566122

  16. Effects of 12 Months Continuous Positive Airway Pressure on Sympathetic Activity Related Brainstem Function and Structure in Obstructive Sleep Apnea.

    PubMed

    Henderson, Luke A; Fatouleh, Rania H; Lundblad, Linda C; McKenzie, David K; Macefield, Vaughan G

    2016-01-01

    Muscle sympathetic nerve activity (MSNA) is greatly elevated in patients with obstructive sleep apnea (OSA) during normoxic daytime wakefulness. Increased MSNA is a precursor to hypertension and elevated cardiovascular morbidity and mortality. However, the mechanisms underlying the high MSNA in OSA are not well understood. In this study we used concurrent microneurography and magnetic resonance imaging to explore MSNA-related brainstem activity changes and anatomical changes in 15 control and 15 OSA subjects before and after 6 and 12 months of continuous positive airway pressure (CPAP) treatment. We found that following 6 and 12 months of CPAP treatment, resting MSNA levels were significantly reduced in individuals with OSA. Furthermore, this MSNA reduction was associated with restoration of MSNA-related brainstem activity and structural changes in the medullary raphe, rostral ventrolateral medulla, dorsolateral pons, and ventral midbrain. This restoration occurred after 6 months of CPAP treatment and was maintained following 12 months CPAP. These findings show that continual CPAP treatment is an effective long-term treatment for elevated MSNA likely due to its effects on restoring brainstem structure and function. PMID:27013952

  17. Effects of 12 Months Continuous Positive Airway Pressure on Sympathetic Activity Related Brainstem Function and Structure in Obstructive Sleep Apnea

    PubMed Central

    Henderson, Luke A.; Fatouleh, Rania H.; Lundblad, Linda C.; McKenzie, David K.; Macefield, Vaughan G.

    2016-01-01

    Muscle sympathetic nerve activity (MSNA) is greatly elevated in patients with obstructive sleep apnea (OSA) during normoxic daytime wakefulness. Increased MSNA is a precursor to hypertension and elevated cardiovascular morbidity and mortality. However, the mechanisms underlying the high MSNA in OSA are not well understood. In this study we used concurrent microneurography and magnetic resonance imaging to explore MSNA-related brainstem activity changes and anatomical changes in 15 control and 15 OSA subjects before and after 6 and 12 months of continuous positive airway pressure (CPAP) treatment. We found that following 6 and 12 months of CPAP treatment, resting MSNA levels were significantly reduced in individuals with OSA. Furthermore, this MSNA reduction was associated with restoration of MSNA-related brainstem activity and structural changes in the medullary raphe, rostral ventrolateral medulla, dorsolateral pons, and ventral midbrain. This restoration occurred after 6 months of CPAP treatment and was maintained following 12 months CPAP. These findings show that continual CPAP treatment is an effective long-term treatment for elevated MSNA likely due to its effects on restoring brainstem structure and function. PMID:27013952

  18. Evaluation of a Compton scattering camera using 3D position-sensitive CdZnTe detectors

    NASA Astrophysics Data System (ADS)

    Du, Yanfeng; He, Zhong; Knoll, Glenn F.; Wehe, David K.; Li, Weiqi

    1999-10-01

    A CZT Compton Camera (CCC) is being built using two 3D position sensitive CZT detectors. Expected system performance was analyzed by analytical and Monte Carlo approaches. Based on the measurement of detector energy and position resolution, the expected angular resolution is approximately 3 degree and approximately 2 degrees for a +/- 30 degrees FOV for 511 keV and 1 MeV (gamma) -rays, respectively. The intrinsic efficiency for a point source 10 cm from the first detector surface ranges from 1.5 X 10-4 to 8.8 X 10-6 for 500 keV to 3 MeV.

  19. Polarization-sensitive optical coherence tomography measurements with different phase modulation amplitude when using continuous polarization modulation

    NASA Astrophysics Data System (ADS)

    Lu, Zenghai; Kasaragod, Deepa K.; Matcher, Stephen J.

    2012-01-01

    We demonstrate theoretically and experimentally that the phase retardance and relative optic-axis orientation of a sample can be calculated without prior knowledge of the actual value of the phase modulation amplitude when using a polarization-sensitive optical coherence tomography system based on continuous polarization modulation (CPM-PS-OCT). We also demonstrate that the sample Jones matrix can be calculated at any values of the phase modulation amplitude in a reasonable range depending on the system effective signal-to-noise ratio. This has fundamental importance for the development of clinical systems by simplifying the polarization modulator drive instrumentation and eliminating its calibration procedure. This was validated on measurements of a three-quarter waveplate and an equine tendon sample by a fiber-based swept-source CPM-PS-OCT system.

  20. Study of position reconstruction of a LaBr3:Ce continuous scintillation crystal for medical applications

    NASA Astrophysics Data System (ADS)

    Fabbri, A.; Sacco, D.; Bennati, P.; Baroncelli, A.; Galasso, M.; Cinti, M. N.; Pellegrini, R.; Pani, R.; Cencelli, V. O.

    2013-12-01

    Many modern molecular imaging techniques, based on radiopharmaceuticals, can take advantage of sophisticated devices but are still based on the scintillation detector mechanism proposed by Anger. These devices can perform with millimeter spatial resolution and high detection efficiency, but the final performance is strongly affected by the algorithm used for the scintillation position detection. In this work, a detailed comparison of the effect on the imaging performances of three new position detection algorithms, in terms of spatial resolution, detection linearity and useful Field of View is performed on a prototype gamma detector. The detector, built by the authors, is based on a continuous LaBr3:Ce scintillation crystal coupled to an Hamamatsu MA-PMT H8500 and a single anode readout electronics. The experimental data are obtained scanning the detector surface with a Tc99m collimated source (0.4 mm phi) at 1.5 mm step. The overall imaging performances of the device are also tested by mean of a bar phantom. We conclude that the Anger-like algorithms give a 50% uFoV with a 1.30 mm ±0.05 mm spatial resolution while the proposed algorithms give a 80% uFoV and 1.10 mm ±0.06 mm spatial resolution.

  1. Sensitivity of N170 and late positive components to social categorization and emotional valence.

    PubMed

    Montalan, B; Caharel, S; Personnaz, B; Le Dantec, C; Germain, R; Bernard, C; Lalonde, R; Rebaï, M

    2008-10-01

    Previous experiments have shown that categorization of people into two distinct fictive groups has an impact on cognitive processes. The main objective of the present study was to examine whether this mere categorization improves information processing speed and alters early and late onset ERPs during a social judgment task. In a group membership situation, in-group evaluation enhanced information processing speed and occipito-temporal N170 amplitudes, associated with orthographic processing, compared to out-group evaluation, more so for positive than negative attributes. Moreover, negative adjectives elicited larger N170 amplitudes and faster information processing speed than positive adjectives. In contrast, positive adjectives in a non-membership context enhanced a late positive component in prefrontal regions. These results reflect the existence of a motivational top-down influence due to social categorization in early perceptual stages of word processing. These findings are also in accord with the existence of two distinct systems of evaluation, the first implicating an automatic processing represented in occipito-temporal neocortex and the other a more controlled processing represented in PFC. PMID:18691559

  2. Sensitive low-pressure relief valve has positive seating against leakage

    NASA Technical Reports Server (NTRS)

    1964-01-01

    A pilot-operated relief valve which provides positive seating against leakage in cryogenic systems is described. The principal advantage is that the pilot poppet is unaffected by variations in control pressures in the pilot cavity, and results in a more accurate sensing of inlet pressure conditions.

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

    ERIC Educational Resources Information Center

    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.…

  4. Positive selection of T cells: rescue from programmed cell death and differentiation require continual engagement of the T cell receptor

    PubMed Central

    1995-01-01

    Positive selection of T cells is a complex developmental process generating long-lived, functionally mature CD4+CD8- and CD4-CD8+ cells from short-lived, immature CD4+CD8+ precursors. The process is initiated in the thymus by interaction of the alpha beta TCR with molecules encoded by the MHC, occurs without cell division, and involves rescue from programmed cell death (PCD), as well as induction of differentiation and maturation of selected precursors. It is unclear whether development of small, positively selected CD4+CD8+ thymocytes (characterized by up-regulated levels of TCR and CD69 molecules) depends on further interactions with MHC molecules and, if so, whether such interactions are required for survival, for maturation, or for both. The involvement of the TCR and/or CD4/CD8 coreceptors in transmitting additional signals is also unknown. We have examined these questions by analyzing survival and differentiation of early (CD4+CD8+TCRhi) and later (CD4-CD8+TCRhi) postselection stages of thymocytes from normal and bcl-2 transgenic mice expressing transgenic, class I MHC-restricted TCR, upon intrathymic transfer into recipients that lacked ligands either for both the TCR and CD8 coreceptor, or for the TCR only. The results provide direct evidence that induction of differentiation of CD4+CD8+ thymocytes by recognition of MHC molecules does not rescue them from PCD and is insufficient to activate the entire maturation program. Both processes require continual engagement of the TCR by positively selecting MHC molecules that, at least in the case of class I MHC-restricted CD4-CD8+ T cells, cannot be substituted by the engagement of coreceptor alone. PMID:7759993

  5. A high-speed high-sensitivity acoustic cell for in-line continuous monitoring of MOCVD precursor gases

    NASA Astrophysics Data System (ADS)

    Wajid, A.; Gogol, C.; Hurd, C.; Hetzel, M.; Spina, A.; Lum, R.; McDonald, M.; Capik, R. J.

    1997-01-01

    We describe a continuous wave resonant acoustic sensor that has been optimized as a very sensitive in-line monitor for measuring the composition of precursor gases used in MOCVD processes. The precursor/carrier gas mixtures flow through a compact stainless steel acoustic chamber that is isolated from the acoustic transducers by a set of metallic diaphragms. The sensor has been successfully operated at supply line pressures from atmosphere down to 50 Torr with gas flow rates of up to 1600 sccm. The accuracy of the speed of sound measurement for hydrogen gas is better than 0.005%, even in a high noise and low pressure environment. Hydrogen, as well as nitrogen or argon carrier gases, are accommodated within the instrument's 1-5 kHz working frequency range. The instrument's sensitivity and stability are demonstrated with the laboratory data. Measurements of the dynamic response characteristics of the metalorganic bubbler lines at low pressure are also be presented. Application of the cell is general, encompassing any of the metalorganic and hydride materials typically used in MOCVD processes.

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

    PubMed

    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. PMID:27451643

  7. A position-sensitive germanium detector for gamma-ray astronomy

    NASA Technical Reports Server (NTRS)

    Varnell, L. S.; Ling, J. C.; Mahoney, W. A.; Jacobson, A. S.; Pehl, R. H.; Goulding, F. S.; Landis, D. A.; Luke, P. N.; Madden, N. W.

    1984-01-01

    The critical problem in high-resolution cosmic gamma-ray spectroscopy in the energy range from 0.02 to 10 MeV is the limited spectral sensitivity of the detectors used. This results from the small effective area of the detectors and the high background noise due to induced radioactivity and scattering in the detectors' high-energy particle environment. The effective area can be increased by increasing the number of detectors, but this becomes prohibitive because of the size and expense of the resulting instrument. We have taken a new approach: a segmented large-volume germanium gamma-ray detector which can effectively discriminate against internal background yet maintain the high spectral resolution and efficiency of conventional coaxial Ge detectors. To verify this concept, a planar detector divided into two segments has been fabricated and laboratory measurements agree well with Monte Carlo calculations. A large coaxial detector which will be divided into five segments is being built using the techniques developed for the planar detector. Monte Carlo calculations show that the sensitivity (minimum detectable flux) of the segmented coaxial detector is a factor of 2-3 better than conventional detectors because of the reduction in the internal background.

  8. Position sensitive photon detectors for nuclear physics, particle physics and healthcare applications

    NASA Astrophysics Data System (ADS)

    Seitz, B.

    2012-01-01

    Modern experiments in hadronic physics require detector systems capable of identifying and reconstructing all final-state particles and their momentum vectors. Imaging Cherenkov counters (RICH and DIRC) are frequently employed in nuclear and particle physics experiments. These detectors require high-rate, single-photon capable light detection system with sufficient granularity and position resolution. Several candidate systems are available, ranging from multi-anode photomultiplier tubes to micro-channel plate systems to silicon photomultipliers. Each of these detection solutions has particular advantages and disadvantages. Detailed studies of rate dependence, cross-talk, time-resolution and position resolution for a range of available photon detection solutions are presented. These properties make these photon detection systems ideal for radionuclide imaging applications. Cherenkov radiation can also be used for medical imaging applications. Two different applications using the Cherenkov effect for radionuclide imaging will be reviewed.

  9. Wedge-and-strip anodes for centroid-finding position-sensitive photon and particle detectors

    NASA Technical Reports Server (NTRS)

    Martin, C.; Jelinsky, P.; Lampton, M.; Malina, R. F.

    1981-01-01

    The paper examines geometries employing position-dependent charge partitioning to obtain a two-dimensional position signal from each detected photon or particle. Requiring three or four anode electrodes and signal paths, images have little distortion and resolution is not limited by thermal noise. An analysis of the geometrical image nonlinearity between event centroid location and the charge partition ratios is presented. In addition, fabrication and testing of two wedge-and-strip anode systems are discussed. Images obtained with EUV radiation and microchannel plates verify the predicted performance, with further resolution improvements achieved by adopting low noise signal circuitry. Also discussed are the designs of practical X-ray, EUV, and charged particle image systems.

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

    SciTech Connect

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

    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.

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

    PubMed Central

    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

    2010-01-01

    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. PMID:20709959

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

    PubMed

    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. PMID:20709959

  15. Treatment of obstructive sleep apnea with nasal continuous positive airway pressure. Patient compliance, perception of benefits, and side effects.

    PubMed

    Hoffstein, V; Viner, S; Mateika, S; Conway, J

    1992-04-01

    Obstructive sleep apnea is a chronic disease whose treatment may require long-term nightly use of relatively cumbersome and expensive breathing equipment that provides continuous positive airway pressure (CPAP) via nasal mask. Compliance with this treatment may be influenced not only by the objective improvement in sleep apnea but also by the patient's subjective perception of the benefit, bed mate or family support, side effects, and cost. The last factor may not be important in Ontario, where 75% of the cost is paid by the Ministry of Health. The goal of this study was to analyze the factors that may influence patient acceptance of nasal CPAP. This was done by tabulating the responses to a detailed questionnaire mailed to 148 patients with obstructive sleep apnea (OSA). There were 96 replies. We were able to contact by telephone an additional 42 patients. The results showed that 105 patients continued to use CPAP at a mean follow-up time of 17 +/- 11 months, some for as long as 6 yr. The majority of patients (81%) perceived CPAP as an effective treatment of the disorder, 5% were unsure, and 14% believed that CPAP was ineffective, despite the resolution of sleep apnea on polysomnography. Subjective improvement reported by the patients was also observed by the family members in 83% of the patients. The most common complaint, voiced by 46% of the patients, was nocturnal awakenings. Nasal problems, such as dryness, congestion, and sneezing, were the second most frequent complaint present in 44% of the responders.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1554212

  16. Efficacy of Home Single-Channel Nasal Pressure for Recommending Continuous Positive Airway Pressure Treatment in Sleep Apnea

    PubMed Central

    Masa, Juan F.; Duran-Cantolla, Joaquin; Capote, Francisco; Cabello, Marta; Abad, Jorge; Garcia-Rio, Francisco; Ferrer, Antoni; Fortuna, Ana M.; Gonzalez-Mangado, Nicolas; de la Peña, Monica; Aizpuru, Felipe; Barbe, Ferran; Montserrat, Jose M.; Larrateguy, Luis D.; de Castro, Jorge Rey; Garcia-Ledesma, Estefania; Corral, Jaime; Martin-Vicente, Maria J.; Martinez-Null, Cristina; Egea, Carlos; Cancelo, Laura; García-Díaz, Emilio; Carmona-Bernal, Carmen; Sánchez-Armengol, Ángeles; Mayos, Merche; Miralda, Rosa M; Troncoso, Maria F.; Gonzalez, Monica; Martinez-Martinez, Marian; Cantalejo, Olga; Piérola, Javier; Vigil, Laura; Embid, Cristina; del Mar Centelles, Mireia; Prieto, Teresa Ramírez; Rojo, Blas; Lores, Vanesa

    2015-01-01

    Introduction: Unlike other prevalent diseases, obstructive sleep apnea (OSA) has no simple tool for diagnosis and therapeutic decision-making in primary healthcare. Home single-channel nasal pressure (HNP) may be an alternative to polysomnography for diagnosis but its use in therapeutic decisions has yet to be explored. Objectives: To ascertain whether an automatically scored HNP apnea-hypopnea index (AHI), used alone to recommend continuous positive airway pressure (CPAP) treatment, agrees with decisions made by a specialist using polysomnography and several clinical variables. Methods: Patients referred by primary care physicians for OSA suspicion underwent randomized polysomnography and HNP. We analyzed the total sample and both more and less symptomatic subgroups for Bland and Altman plots to explore AHI agreement; receiver operating characteristic curves to establish area under the curve (AUC) measurements for CPAP recommendation; and therapeutic decision efficacy for several HNP AHI cutoff points. Results: Of the 787 randomized patients, 35 (4%) were lost, 378 (48%) formed the more symptomatic and 374 (48%) the less symptomatic subgroups. AHI bias and agreement limits were 5.8 ± 39.6 for the total sample, 5.3 ± 38.7 for the more symptomatic, and 6 ± 40.2 for the less symptomatic subgroups. The AUC were 0.826 for the total sample, 0.903 for the more symptomatic, and 0.772 for the less symptomatic subgroups. In the more symptomatic subgroup, 70% of patients could be correctly treated with CPAP. Conclusion: Automatic home single-channel nasal pressure scoring can correctly recommend CPAP treatment in most of more symptomatic patients with OSA suspicion. Our results suggest that this device may be an interesting tool in initial OSA management for primary care physicians, although future studies in a primary care setting are necessary. Clinical Trials Information: Clinicaltrial.gov identifier: NCT01347398. Citation: Masa JF, Duran-Cantolla J, Capote F, Cabello

  17. Position sensitive detectors for synchrotron radiation studies: the tortoise and the hare?

    NASA Astrophysics Data System (ADS)

    Lewis, Rob

    2003-11-01

    The huge gulf between the high photon fluxes available from synchrotrons and the capabilities of detectors to measure the resulting photon, electron or ion signals is well known. Whilst accelerator technology continues to advance at a rapid pace, it is detector performance which represents the limiting factor for many synchrotron experiments. In some cases there are still single channel counting detectors based on 40-year-old designs operational on synchrotron beamlines. The dream of many researchers is a detector which is able to simultaneously image and perform spectroscopy at the required data rates. A solution is the massive integration of parallel electronics into detectors on a pixel by pixel basis. These ideas have been in gestation for very many years awaiting sufficient funding, nevertheless, several prototypes are now at the testing stage. The current status of these and other detector developments targeted at synchrotron science are briefly reviewed.

  18. Position effect variegation and viability are both sensitive to dosage of constitutive heterochromatin in Drosophila.

    PubMed

    Berloco, Maria; Palumbo, Gioacchino; Piacentini, Lucia; Pimpinelli, Sergio; Fanti, Laura

    2014-09-01

    The dosage effect of Y-chromosome heterochromatin on suppression of position effect variegation (PEV) has long been well-known in Drosophila. The phenotypic effects of increasing the overall dosage of Y heterochromatin have also been demonstrated; hyperploidy of the Y chromosome produces male sterility and many somatic defects including variegation and abnormal legs and wings. This work addresses whether the suppression of position effect variegation (PEV) is a general feature of the heterochromatin (independent of the chromosome of origin) and whether a hyperdosage of heterochromatin can affect viability. The results show that the suppression of PEV is a general feature of any type of constitutive heterochromatin and that the intensity of suppression depends on its amount instead of some mappable factor on it. We also describe a clear dosage effect of Y heterochromatin on the viability of otherwise wild-type embryos and the modification of that effect by a specific gene mutation. Together, our results indicate that the correct balance between heterochromatin and euchromatin is essential for the normal genome expression and that this balance is genetically controlled.

  19. Valproic Acid Increases CD133 Positive Cells that Show Low Sensitivity to Cytostatics in Neuroblastoma

    PubMed Central

    Khalil, Mohamed Ashraf; Hraběta, Jan; Groh, Tomáš; Procházka, Pavel; Doktorová, Helena; Eckschlager, Tomáš

    2016-01-01

    Valproic acid (VPA) is a well-known antiepileptic drug that exhibits antitumor activities through its action as a histone deacetylase inhibitor. CD133 is considered to be a cancer stem cell marker in several tumors including neuroblastoma. CD133 transcription is strictly regulated by epigenetic modifications. We evaluated the epigenetic effects of treatment with 1mM VPA and its influence on the expression of CD133 in four human neuroblastoma cell lines. Chemoresistance and cell cycle of CD133+ and CD133− populations were examined by flow cytometry. We performed bisulfite conversion followed by methylation-sensitive high resolution melting analysis to assess the methylation status of CD133 promoters P1 and P3. Our results revealed that VPA induced CD133 expression that was associated with increased acetylation of histones H3 and H4. On treatment with VPA and cytostatics, CD133+ cells were mainly detected in the S and G2/M phases of the cell cycle and they showed less activated caspase-3 compared to CD133− cells. UKF-NB-3 neuroblastoma cells which express CD133 displayed higher colony and neurosphere formation capacities when treated with VPA, unlike IMR-32 which lacks for CD133 protein. Induction of CD133 in UKF-NB-3 was associated with increased expression of phosphorylated Akt and pluripotency transcription factors Nanog, Oct-4 and Sox2. VPA did not induce CD133 expression in cell lines with methylated P1 and P3 promoters, where the CD133 protein was not detected. Applying the demethylating agent 5-aza-2’-deoxycytidine to the cell lines with methylated promoters resulted in CD133 re-expression that was associated with a drop in P1 and P3 methylation level. In conclusion, CD133 expression in neuroblastoma can be regulated by histone acetylation and/or methylation of its CpG promoters. VPA can induce CD133+ cells which display high proliferation potential and low sensitivity to cytostatics in neuroblastoma. These results give new insight into the possible

  20. Valproic Acid Increases CD133 Positive Cells that Show Low Sensitivity to Cytostatics in Neuroblastoma.

    PubMed

    Khalil, Mohamed Ashraf; Hraběta, Jan; Groh, Tomáš; Procházka, Pavel; Doktorová, Helena; Eckschlager, Tomáš

    2016-01-01

    Valproic acid (VPA) is a well-known antiepileptic drug that exhibits antitumor activities through its action as a histone deacetylase inhibitor. CD133 is considered to be a cancer stem cell marker in several tumors including neuroblastoma. CD133 transcription is strictly regulated by epigenetic modifications. We evaluated the epigenetic effects of treatment with 1mM VPA and its influence on the expression of CD133 in four human neuroblastoma cell lines. Chemoresistance and cell cycle of CD133+ and CD133- populations were examined by flow cytometry. We performed bisulfite conversion followed by methylation-sensitive high resolution melting analysis to assess the methylation status of CD133 promoters P1 and P3. Our results revealed that VPA induced CD133 expression that was associated with increased acetylation of histones H3 and H4. On treatment with VPA and cytostatics, CD133+ cells were mainly detected in the S and G2/M phases of the cell cycle and they showed less activated caspase-3 compared to CD133- cells. UKF-NB-3 neuroblastoma cells which express CD133 displayed higher colony and neurosphere formation capacities when treated with VPA, unlike IMR-32 which lacks for CD133 protein. Induction of CD133 in UKF-NB-3 was associated with increased expression of phosphorylated Akt and pluripotency transcription factors Nanog, Oct-4 and Sox2. VPA did not induce CD133 expression in cell lines with methylated P1 and P3 promoters, where the CD133 protein was not detected. Applying the demethylating agent 5-aza-2'-deoxycytidine to the cell lines with methylated promoters resulted in CD133 re-expression that was associated with a drop in P1 and P3 methylation level. In conclusion, CD133 expression in neuroblastoma can be regulated by histone acetylation and/or methylation of its CpG promoters. VPA can induce CD133+ cells which display high proliferation potential and low sensitivity to cytostatics in neuroblastoma. These results give new insight into the possible

  1. Valproic Acid Increases CD133 Positive Cells that Show Low Sensitivity to Cytostatics in Neuroblastoma.

    PubMed

    Khalil, Mohamed Ashraf; Hraběta, Jan; Groh, Tomáš; Procházka, Pavel; Doktorová, Helena; Eckschlager, Tomáš

    2016-01-01

    Valproic acid (VPA) is a well-known antiepileptic drug that exhibits antitumor activities through its action as a histone deacetylase inhibitor. CD133 is considered to be a cancer stem cell marker in several tumors including neuroblastoma. CD133 transcription is strictly regulated by epigenetic modifications. We evaluated the epigenetic effects of treatment with 1mM VPA and its influence on the expression of CD133 in four human neuroblastoma cell lines. Chemoresistance and cell cycle of CD133+ and CD133- populations were examined by flow cytometry. We performed bisulfite conversion followed by methylation-sensitive high resolution melting analysis to assess the methylation status of CD133 promoters P1 and P3. Our results revealed that VPA induced CD133 expression that was associated with increased acetylation of histones H3 and H4. On treatment with VPA and cytostatics, CD133+ cells were mainly detected in the S and G2/M phases of the cell cycle and they showed less activated caspase-3 compared to CD133- cells. UKF-NB-3 neuroblastoma cells which express CD133 displayed higher colony and neurosphere formation capacities when treated with VPA, unlike IMR-32 which lacks for CD133 protein. Induction of CD133 in UKF-NB-3 was associated with increased expression of phosphorylated Akt and pluripotency transcription factors Nanog, Oct-4 and Sox2. VPA did not induce CD133 expression in cell lines with methylated P1 and P3 promoters, where the CD133 protein was not detected. Applying the demethylating agent 5-aza-2'-deoxycytidine to the cell lines with methylated promoters resulted in CD133 re-expression that was associated with a drop in P1 and P3 methylation level. In conclusion, CD133 expression in neuroblastoma can be regulated by histone acetylation and/or methylation of its CpG promoters. VPA can induce CD133+ cells which display high proliferation potential and low sensitivity to cytostatics in neuroblastoma. These results give new insight into the possible

  2. Enhancing the sensitivity of a micro-diaphragm resonating sensor by effectively positioning the mass on the membrane

    PubMed Central

    Kim, Jinsik; Kim, Hye Jin; Cho, EunAe; Shin, Hyun-Joon; Park, Jung Ho; Hwang, Kyo Seon

    2015-01-01

    The detection of biomarkers in the liquid phase using mechanical sensors is difficult because of noise caused by the liquid. To reduce and verify the side effects of liquid loading, we performed calculations and experiments to determine the shift in resonant frequency according to the loading conditions. A 2-μm-thick piezoelectric rectangular micro-diaphragm with a 500 × 500 μm membrane was used. These dimensions were determined such that there would be an analogous resonant frequency shift ratio in both (1, 1) and (2, 2) modes. By calculating and measuring the resonant frequency, we verified that the resonant frequency of the sensor would change only through contact with the liquid, even the resonant frequency change by only liquid much higher than the changes caused by the nanoparticles. The real signal constituted only 0.017% of the initial resonant frequency. To enhance the sensitivity by reducing the unexpected surface stress in the liquid, the liquid was dropped onto the surface of the micro-diaphragm. This resulted in an improvement of more than 10 times the sensitivity in both modes. In addition, by controlling the position in the micro-diaphragm resonating sensor, more sensitive positions with large displacements were determined according to each mode. PMID:26594022

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

    DOEpatents

    Kurtz, David S.; Ruud, Clay O.

    1998-01-01

    A method and apparatus for x-ray measurement of certain properties of a solid material. 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.

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

    DOEpatents

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

    1998-07-21

    A method and apparatus are disclosed for x-ray measurement of certain properties of a solid material. 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. Large angle solid state position sensitive x-ray detector system

    DOEpatents

    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.

  6. Questionnaire for sensitive positions (QSP) version 4.0 -- Users guide document

    SciTech Connect

    Hausel, J.M.

    1996-05-21

    The US Government does background investigations and reinvestigations to establish that applicants are eligible for required security clearance. The QSP system is an automated Paradox application developed by Boeing in 1988 and used by DOE-RL for data collection, retention, and printing by facsimile of the Standard Form 86 containing a person`s data needed to conduct an investigation. In March 1991 the QSP form was revised by the Office of Personnel Management (OPM). The QSP system was modified and enhanced to QSP version 3.0 and released for use in 1992. Copies of QSP version 3.0 were provided to approximately 20 other sites when requested. In February 1995 the OPM approved the new Standard Form 86 ``Questionnaire for National Security Positions.`` The QSP system was modified and upgraded to QSP version 4.0 to agree with the revised form.

  7. [Determination of sensitivity of biofilm-positive forms of microorganisms to antibiotics].

    PubMed

    Holá, Veronika; Růzicka, Filip; Tejkalová, Renata; Votava, Miroslav

    2004-10-01

    Nosocomial infections caused by biofilm-positive microorganisms are a serious therapeutic problem. In the biofilm, microorganisms are protected against adverse effects of the external environment, including the action of antibiotics. It is well known that the values of minimum inhibitory concentrations (MIC) determined for planktonic forms do not correspond to the actual concentrations of antibiotics necessary for the eradication of bacteria in a biofilm. The purpose of the study was to propose a method of determining minimum biofilm inhibitory concentrations (MBIC) and minimum biofilm eradication concentrations (MBEC) and to compare these values with MIC values. Biofilm-positive strains of Staphylococcus epidermidis were cultured so as to form a biofilm layer on polystyrene pegs. The biofilm on the pegs was then exposed to the action of antibiotics and after 18 hours we determined the minimum biofilm inhibitory concentration (MBIC). The evaluation of minimum biofilm eradication concentrations was done colorimetrically from the metabolic activity of surviving cells. MBIC and MBEC values were many times higher than MIC values. We selected such a duration of the biofilms cultivation on the pegs of the plate, which ensured that the number of bacterial cells corresponded to standard MIC assessment. The MBEC values established in our study indicate that the currently used concentrations of tested antibiotics cannot be used in monotherapy for an efficacious eradication of a biofilm. The MBEC determination is a far more laborious and time-consuming method than the determination of MIC, but the use of plates with pegs facilitates the handling of biofilms. The advantage of our method is the possibility of standardization of the size of the inoculum and thus of the whole MBEC assessment.

  8. Nocturnal nasal continuous positive airway pressure in patients with chronic obstructive pulmonary disease. Influence on waking respiratory muscle function.

    PubMed

    Mezzanotte, W S; Tangel, D J; Fox, A M; Ballard, R D; White, D P

    1994-10-01

    Patients with COPD often have reduced inspiratory muscle strength and endurance as well as poor exercise tolerance. Increased inspiratory work during sleep (probably due to increased upper airway resistance) may further strain these compromised respiratory muscles in COPD patients. We hypothesized that nasal continuous positive airway pressure (CPAP) might reduce respiratory work during sleep in COPD patients and thereby improve waking inspiratory muscle function. To test this hypothesis, eight male COPD patients were treated with sustained nocturnal nasal CPAP. Inspiratory muscle strength (maximum inspiratory pressure) and endurance (sustained inspiratory pressure) as well as clinical performance (12-min walk) were assessed before and after therapy. We observed that compared with matched controls, COPD patients treated with nocturnal nasal CPAP had significant and substantial improvement in inspiratory muscle strength and endurance as well as functional ability as assessed by the 12-min walk. In addition, CPAP did not significantly alter sleep quality or oxygenation in the patients studied. We conclude that nocturnal nasal CPAP improves inspiratory muscle performance during wakefulness in COPD patients, which is very likely a product of the reduced work of breathing during sleep while these individuals received CPAP.

  9. Continuous positive airway pressure therapy reduces oxidative stress markers and blood pressure in sleep apnea-hypopnea syndrome patients.

    PubMed

    Murri, Mora; García-Delgado, Regina; Alcázar-Ramírez, José; Fernández de Rota, Luis; Fernández-Ramos, Ana; Cardona, Fernando; Tinahones, Francisco J

    2011-12-01

    Sleep apnea-hypopnea syndrome (SAHS) is characterized by recurrent episodes of hypoxia/reoxygenation, which seems to promote oxidative stress. SAHS patients experience increases in hypertension, obesity and insulin resistance (IR). The purpose was to evaluate in SAHS patients the effects of 1 month of treatment with continuous positive airway pressure (CPAP) on oxidative stress and the association between oxidative stress and insulin resistance and blood pressure (BP). Twenty-six SAHS patients requiring CPAP were enrolled. Measurements were recorded before and 1 month after treatment. Cellular oxidative stress parameters were notably decreased after CPAP. Intracellular glutathione and mitochondrial membrane potential increased significantly. Also, total antioxidant capacity and most of the plasma antioxidant activities increased significantly. Significant decreases were seen in BP. Negative correlations were observed between SAHS severity and markers of protection against oxidative stress. BP correlated with oxidative stress markers. In conclusion, we observed an obvious improvement in oxidative stress and found that it was accompanied by an evident decrease in BP with no modification in IR. Consequently, we believe that the decrease in oxidative stress after 1 month of CPAP treatment in these patients is not contributing much to IR genesis, though it could be related to the hypertension etiology.

  10. Heart rate variability in non-apneic snorers and controls before and after continuous positive airway pressure

    PubMed Central

    Gates, Gregory J; Mateika, Susan E; Mateika, Jason H

    2005-01-01

    Background We hypothesized that sympathetic nervous system activity (SNSA) is increased and parasympathetic nervous system activity (PNSA) is decreased during non-rapid eye movement (NREM) sleep in non-apneic, otherwise healthy, snoring individuals compared to control. Moreover, we hypothesized that these alterations in snoring individuals would be more evident during non-snoring than snoring when compared to control. Methods To test these hypotheses, heart rate variability was used to measure PNSA and SNSA in 11 normotensive non-apneic snorers and 12 control subjects before and 7-days after adapting to nasal continuous positive airway pressure (nCPAP). Results Our results showed that SNSA was increased and PNSA was decreased in non-apneic snorers during NREM compared to control. However, these changes were only evident during the study in which snoring was eliminated with nCPAP. Conversely, during periods of snoring SNSA and PNSA were similar to measures obtained from the control group. Additionally, within the control group, SNSA and PNSA did not vary before and after nCPAP application. Conclusion Our findings suggest that long-lasting alterations in autonomic function may exist in snoring subjects that are otherwise healthy. Moreover, we speculate that because of competing inputs (i.e. inhibitory versus excitatory inputs) to the autonomic nervous system during snoring, the full impact of snoring on autonomic function is most evident during non-snoring periods. PMID:16048652

  11. Long-term effects of nasal continuous positive airway pressure on vasodilatory endothelial function in obstructive sleep apnea syndrome.

    PubMed

    Duchna, Hans-W; Orth, Maritta; Schultze-Werninghaus, Gerhard; Guilleminault, Christian; Stoohs, Riccardo A

    2005-09-01

    Obstructive sleep apnea syndrome (OSAS) is associated with a dysfunction of vascular endothelial cells. The aim of this study was to investigate long-term improvement of endothelial dysfunction in OSAS with nasal continuous positive airway pressure (nCPAP) treatment. We investigated endothelium-dependent and endothelium-independent vasodilatory function in patients with OSAS using the hand vein compliance technique. Dose-response curves to endothelium-dependent vasodilator bradykinin were obtained in 16 subjects with OSAS before and after 6 months of nCPAP therapy and in 12 control subjects without OSAS. Maximum dilation (Emax) to bradykinin, being impaired in all OSAS patients, was completely restored with nCPAP. Mean Emax to bradykinin rose from 54.9+/-18.5 to 108.2+/-28.7% with 164.4+/-90.0 nights of nCPAP therapy (p<0.0001; Emax healthy controls, 94.8+/-9.5%). At treatment follow-up, endothelium-dependent vasodilatory capacity was not significantly different in nCPAP-treated OSAS patients vs healthy controls. Mean vasodilation with endothelium independently acting nitroglycerin was not altered initially and did not change with nCPAP therapy indicating that nCPAP restored endothelial cell function and not unspecific, endothelium-independent factors. These results suggest that regular nocturnal nCPAP treatment leads to a sustained restoration of OSAS-induced impaired endothelium-dependent nitric oxide-mediated vasodilation, suggesting an improvement of systemic endothelial dysfunction in patients studied.

  12. Long-term effects of nocturnal continuous positive airway pressure therapy in patients with resistant hypertension and obstructive sleep apnea.

    PubMed

    Frenţ, Ştefan M; Tudorache, Voicu M; Ardelean, Carmen; Mihăicuţă, Stefan

    2014-01-01

    Obstructive sleep apnea (OSA) is often linked to high blood pressure and has a particularly high prevalence in patients with resistant hypertension. The effect of continuous positive airway pressure (CPAP) therapy on blood pressure (BP) values has been evaluated in several short-term clinical trials with conflicting results. Our aim was to investigate the role of long-term CPAP treatment in achieving BP control in patients who associate OSA and resistant hypertension. We have included in the study 33 patients with resistant hypertension, diagnosed with OSA in our sleep lab. Data was collected initially and after a mean follow-up period of 4 years. Patients were divided into 2 groups according to the use of CPAP therapy. Patients under CPAP therapy (n = 12) exhibited a higher reduction in both systolic and diastolic pressure and BP control was achieved in 75% of cases, while patients without CPAP treatment (n = 21) remained with refractory hypertension in proportion of 90.5%. A de-escalation of antihypertensive drug regimen by discontinuation of 1 or more drugs was observed in 41.6% (n = 5) of patients from CPAP group and in the other 33.4% (n = 4) the medication remained unchanged, but BP control was reached. Using a direct logistic regression model for examining the impact of different confounders on the probability of diagnosis of resistant hypertension at follow-up, the only statistically significant predictor found was the lack of CPAP usage. PMID:25665364

  13. Randomized comparison of oxygen mask treatment vs. nasal continuous positive airway pressure in dengue shock syndrome with acute respiratory failure.

    PubMed

    Cam, B V; Tuan, D T; Fonsmark, L; Poulsen, A; Tien, N M; Tuan, H M; Heegaard, E D

    2002-12-01

    Dengue hemorrhagic fever (DHF) is caused by dengue virus. Patients with DHF grade 3-4, termed Dengue Shock Syndrome (DSS), may develop acute respiratory failure after initial fluid resuscitation. Previously, these patients were treated with oxygen on a nasal cannula, or if necessary with tracheal intubation and mechanical ventilation. In the present prospective randomized study, we compared the effectiveness of oxygen treatment administered by a face mask vs. nasal continuous positive airway pressure (NCPAP). Morbidity, mortality, and supportive treatment was evaluated. Thirty-seven patients with DSS complicated by respiratory failure were enrolled. On admission and after 30 min of treatment, clinical and paraclinical data were obtained. Chest X-ray revealed pleural effusion in 92 per cent and showed interstitial oedema in 33 per cent. After 30 min of treatment the respiratory rate decreased significantly in the NCPAP group (p < 0.05), while SaO2 and PaO2 increased in both groups (p < 0.01). However, subsequently a significant difference of unresponsiveness to treatment between the oxygen mask group and the NCPAP group (13/19 vs. 4/18,p < 0.01) was noted. Complications of NCPAP or oxygen mask treatment were not documented. We conclude that NCPAP is useful in improving the management of acute respiratory failure in children with DHF/DSS in dengue-endemic areas.

  14. Dorsal Striatal D2-Like Receptor Availability Co-varies with Sensitivity to Positive Reinforcement during Discrimination Learning

    PubMed Central

    Groman, S.M.; Lee, B.; London, E.D.; Mandelkern, M.; James, A.S.; Feiler, K.; Rivera, R.; Dahlbom, M.; Sossi, V.; Vandervoort, E.; Jentsch, J.D.

    2011-01-01

    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 D2-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 D2-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. D2-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. D2-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. PMID:21593313

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

    PubMed

    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.

  16. Sensitivity of Allelic Divergence to Genomic Position: Lessons from the Drosophila tan Gene

    PubMed Central

    John, Alisha V.; Sramkoski, Lisa L.; Walker, Elizabeth A.; Cooley, Arielle M.; Wittkopp, Patricia J.

    2016-01-01

    To identify genetic variants underlying changes in phenotypes within and between species, researchers often utilize transgenic animals to compare the function of alleles in different genetic backgrounds. In Drosophila, targeted integration mediated by the ΦC31 integrase allows activity of alternative alleles to be compared at the same genomic location. By using the same insertion site for each transgene, position effects are generally assumed to be controlled for because both alleles are surrounded by the same genomic context. Here, we test this assumption by comparing the activity of tan alleles from two Drosophila species, D. americana and D. novamexicana, at five different genomic locations in D. melanogaster. We found that the relative effects of these alleles varied among insertion sites, with no difference in activity observed between them at two sites. One of these sites simply silenced both transgenes, but the other allowed expression of both alleles that was sufficient to rescue a mutant phenotype yet failed to reveal the functional differences between the two alleles. These results suggest that more than one insertion site should be used when comparing the activity of transgenes because failing to do so could cause functional differences between alleles to go undetected. PMID:27449514

  17. Directed searches for continuous gravitational waves from binary systems: Parameter-space metrics and optimal Scorpius X-1 sensitivity

    NASA Astrophysics Data System (ADS)

    Leaci, Paola; Prix, Reinhard

    2015-05-01

    We derive simple analytic expressions for the (coherent and semicoherent) phase metrics of continuous-wave sources in low-eccentricity binary systems for the two regimes of long and short segments compared to the orbital period. The resulting expressions correct and extend previous results found in the literature. We present results of extensive Monte Carlo studies comparing metric mismatch predictions against the measured loss of detection statistics for binary parameter offsets. The agreement is generally found to be within ˜10 %- 30 % . For an application of the metric template expressions, we estimate the optimal achievable sensitivity of an Einstein@Home directed search for Scorpius X-1, under the assumption of sufficiently small spin wandering. We find that such a search, using data from the upcoming advanced detectors, would be able to beat the torque-balance level [R. V. Wagoner, Astrophys. J. 278, 345 (1984); L. Bildsten, Astrophys. J. 501, L89 (1998).] up to a frequency of ˜500 - 600 Hz , if orbital eccentricity is well constrained, and up to a frequency of ˜160 - 200 Hz for more conservative assumptions about the uncertainty on orbital eccentricity.

  18. A zero dead-time multi-particle time and position sensitive detector based on correlation between brightness and amplitude.

    PubMed

    Urbain, X; Bech, D; Van Roy, J-P; Géléoc, M; Weber, S J; Huetz, A; Picard, Y J

    2015-02-01

    A new multi-particle time and position sensitive detector using only a set of microchannel plates, a waveform digitizer, a phosphor screen, and a CMOS camera is described. The assignment of the timing information, as taken from the microchannel plates by fast digitizing, to the positions, as recorded by the camera, is based on the COrrelation between the BRightness of the phosphor screen spots, defined as their integrated intensity and the Amplitude of the electrical signals (COBRA). Tests performed by observing the dissociation of HeH, the fragmentation of H3 into two or three fragments, and the photo-double-ionization of Xenon atoms are presented, which illustrate the performances of the COBRA detection scheme. PMID:25725834

  19. A zero dead-time multi-particle time and position sensitive detector based on correlation between brightness and amplitude.

    PubMed

    Urbain, X; Bech, D; Van Roy, J-P; Géléoc, M; Weber, S J; Huetz, A; Picard, Y J

    2015-02-01

    A new multi-particle time and position sensitive detector using only a set of microchannel plates, a waveform digitizer, a phosphor screen, and a CMOS camera is described. The assignment of the timing information, as taken from the microchannel plates by fast digitizing, to the positions, as recorded by the camera, is based on the COrrelation between the BRightness of the phosphor screen spots, defined as their integrated intensity and the Amplitude of the electrical signals (COBRA). Tests performed by observing the dissociation of HeH, the fragmentation of H3 into two or three fragments, and the photo-double-ionization of Xenon atoms are presented, which illustrate the performances of the COBRA detection scheme.

  20. Rapid and sensitive quantification of levoglucosan in aerosols by high-performance anion-exchange chromatography with positive electrospray ionization mass spectrometry (HPAEC-positive ESI-MS)

    NASA Astrophysics Data System (ADS)

    Asakawa, Daichi; Furuichi, Yuko; Yamamoto, Atsushi; Oku, Yuichiro; Funasaka, Kunihiro

    2015-12-01

    A convenient quantification method for underivatized levoglucosan, which is a tracer for biomass burning influenced particulate matter (PM), has been established using high-performance anion-exchange chromatography (HPAEC) coupled to positive electrospray ionization mass spectrometry ((+)ESI-MS). Levoglucosan was chromatographically separated from its isomers (mannosan and galactosan) and detected selectively with positive ESI-MS. Limits of detection and quantification for this method were 0.40 and 1.3 ng mL-1, respectively. A comparison of simultaneous measurements by this method and conventional derivatization gas chromatography/mass spectrometry showed a good linearity with a slope of 1.008 and a determination coefficient of 0.9932. The developed method was applied to ambient suspended particulate matter hourly collected by continuous particulate monitors at 10 stations. The hourly concentration of levoglucosan during August 9-11, 2011, was 1.7-918 ng m-3 and its distribution indicated the transportation of biomass burning aerosols of a forest fire. This is the first report of horizontal distribution of the hourly levoglucosan concentration in Japan.

  1. Randomized Controlled Trial Comparing Flexible and Continuous Positive Airway Pressure Delivery: Effects on Compliance, Objective and Subjective Sleepiness and Vigilance

    PubMed Central

    Bakker, Jessie; Campbell, Angela; Neill, Alister

    2010-01-01

    Study Objectives: Positive airway pressure (PAP) treatment for obstructive sleep apnea (OSA) can be limited by suboptimal compliance. C-Flex technology (Philips Respironics, PA, USA) reduces pressure during expiration, aiming to improve comfort and therefore compliance. This may be of particular relevance to patients requiring high pressures. Many studies thus far have suffered from design limitations and small sample sizes. This study aimed to compare compliance with C-Flex and CPAP, as well as analyzing objective and subjective sleepiness and vigilance. Design: Three-month, double-blinded, parallel-arm randomized controlled trial. Setting: A university-based sleep laboratory. Patients: 76 consecutive patients with severe OSA (mean ± SD AHI 60.2 ± 32.9 events/hour, ESS 13.6 ± 4.5/24, BMI 35.6 ± 7.8 kg/m2), without significant cardiac, respiratory, psychiatric, or sleep comorbidities. Interventions: Patients were randomized to C-Flex (dip level 2) or CPAP. Measurements and Results: Patients underwent titration with C-Flex/CPAP (mean pressure 11.6 cm H2O). Modified maintenance of wakefulness tests (mod-MWT), psychomotor vigilance tasks (PVT) and questionnaires were administered at baseline and after one and 3 months. Median compliance was 5.51 and 5.89 h/ night in the C-Flex and CPAP groups respectively (P = 0.82). There were no significant differences between groups in terms of PVT reaction time, subjective sleepiness, sleep quality, health-related quality of life, or treatment comfort. There was no significant difference between the groups regarding the change in mod-MWT sleep latency values. Conclusions: In patients with severe OSA both CPAP and C-Flex resulted in substantial improvements in sleepiness, vigilance, and quality of life. The use of C-Flex did not result in greater compliance, and neither treatment appeared superior. Citation: Bakker J; Campbell A; Neill A. Randomized controlled trial comparing flexible and continuous positive airway pressure

  2. Sensitivity of Solvation Environment to Oxidation State and Position in the Early Actinide Period.

    PubMed

    Clark, Aurora E; Samuels, Alex; Wisuri, Katy; Landstrom, Sarah; Saul, Tessa

    2015-07-01

    The aqueous solvation of U-Pu in the III-VI oxidation states has been examined using density functional theory and hydrated cluster models of the form An(H2O)30(4+/3+) and AnO2(H2O)30(2+/+) embedded within a polarizable continuum model to approximate the effect of bulk water. The structural features are compared to available data from extended X-ray absorption fine structure. Then, using a multiple-scattering approach, the X-ray absorption near-edge spectra (XANES) have been simulated and compared to experiment. These structural data are complemented by a detailed thermodynamic analysis using a recently benchmarked protocol. The structural, spectroscopic, and thermodynamic information has been used to assign the primary solvation environments in water, with an emphasis upon understanding how oxidation state and position in the period modifies the hydration number and equilibrium between different solvation shell environments. Tetravalent U is proposed to exist in equilibrium between the 8- and 9-coordinate species. Moving to the right of the period, Np(IV) and Pu(IV) exist solely as the octa-aquo species. Reduction to the trivalent ions leads to thermodynamic favorability for this solvation environment, whose features reproduce the XANES spectra. The actinyl dications (AnO2(2+)) of U and Np have a preferred environment in the equatorial plane consisting of 5 solvating waters; however, changes to the ionic radius and electronic structure at Pu leads to an equilibrium between the 4- and 5-coordinate species for PuO2(2+). Reduction of the dications to form the monocations generally leads to a preference for the 4-coordinate primary solvation shell, with an equilibrium existing for uranyl, while the neptunyl and plutonyl species exist solely as AnO2(H2O)4(+). These data provide accurate thermodynamic information for several rare species and the combined thermodynamic, structural, and spectroscopic approach reveals trends in hydration behavior across actinide oxidation

  3. TRPV1 expression level in isolectin B₄-positive neurons contributes to mouse strain difference in cutaneous thermal nociceptive sensitivity.

    PubMed

    Ono, Kentaro; Ye, Yi; Viet, Chi T; Dang, Dongmin; Schmidt, Brian L

    2015-05-01

    Differential thermal nociception across inbred mouse strains has genetic determinants. Thermal nociception is largely attributed to the heat/capsaicin receptor transient receptor potential vanilloid 1 (TRPV1); however, the contribution of this channel to the genetics of thermal nociception has not been revealed. In this study we compared TRPV1 expression levels and electrophysiological properties in primary sensory neurons and thermal nociceptive behaviors between two (C57BL/6 and BALB/c) inbred mouse strains. Using immunofluorescence and patch-clamp physiology methods, we demonstrated that TRPV1 expression was significantly higher in isolectin B4 (IB4)-positive trigeminal sensory neurons of C57BL/6 relative to BALB/c; the expression in IB4-negative neurons was similar between the strains. Furthermore, using electrophysiological cell classification (current signature method), we showed differences between the two strains in capsaicin sensitivity in IB4-positive neuronal cell types 2 and 13, which were previously reported as skin nociceptors. Otherwise electrophysiological membrane properties of the classified cell types were similar in the two mouse strains. In publicly available nocifensive behavior data and our own behavior data from the using the two mouse strains, C57BL/6 exhibited higher sensitivity to heat stimulation than BALB/c, independent of sex and anatomical location of thermal testing (the tail, hind paw, and whisker pad). The TRPV1-selective antagonist JNJ-17203212 inhibited thermal nociception in both strains; however, removing IB4-positive trigeminal sensory neurons with IB4-conjugated saporin inhibited thermal nociception on the whisker pad in C57BL/6 but not in BALB/c. These results suggest that TRPV1 expression levels in IB4-positive type 2 and 13 neurons contributed to differential thermal nociception in skin of C57BL/6 compared with BALB/c.

  4. A randomised control study comparing the Infant Flow Driver with nasal continuous positive airway pressure in preterm infants

    PubMed Central

    Mazzella, M; Bellini, C; Calevo, M; Campone, F; Massocco, D; Mezzano, P; Zullino, E; Scopesi, F; Arioni, C; Bonacci, W; Serra, G

    2001-01-01

    OBJECTIVE—To compare the effectiveness of the Infant Flow Driver (IFD) with single prong nasal continuous positive airway pressure (nCPAP) in preterm neonates affected by respiratory distress syndrome.
DESIGN—Randomised controlled study.
PATIENTS—Between September 1997 and March 1999, 36 preterm infants who were eligible for CPAP treatment were randomly selected for either nCPAP or IFD and studied prospectively for changes in oxygen requirement and/or respiratory rate. The requirement for mechanical ventilation, complications of treatment, and effects on mid-term outcome were also evaluated.
RESULTS—Use of the IFD had a significantly beneficial effect on both oxygen requirement and respiratory rate (p < 0.0001) when compared with nCPAP. Moreover, O2 requirement and respiratory rate were significantly decreased by four hours (p < 0.001 and p < 0.03 respectively). The probability of remaining supplementary oxygen free over the first 48 hours of treatment was significantly higher in patients treated with the IFD than with nCPAP (p < 0.02). IFD treated patients had a higher success (weaning) rate (94% v 72%) and shorter duration of treatment (49.3 (31) v 56 (29.7) hours respectively; mean (SD)), although the difference was not significant.
CONCLUSIONS—IFD appears to be a feasible device for managing respiratory distress syndrome in preterm infants, and benefits may be had with regard to oxygen requirement and respiratory rate when compared with nCPAP. The trend towards reduced requirement for mechanical ventilation, shorter clinical recovery time, and shorter duration of treatment requires further evaluation in a multicentre randomised clinical trial.

 PMID:11517199

  5. Effect of Continuous Positive Airway Pressure on Airway Inflammation and Oxidative Stress in Patients with Obstructive Sleep Apnea

    PubMed Central

    Tichanon, Promsrisuk; Sopida, Santamit; Orapin, Pasurivong; Watchara, Boonsawat; Banjamas, Intarapoka

    2016-01-01

    Background. Airway inflammation and oxidative stress may be linked in obstructive sleep apnea (OSA) patients. We determined the effectiveness of continuous positive airway pressure (CPAP) therapy in reducing fractional exhaled nitric oxide (FeNO) and malondialdehyde (MDA) levels in OSA patients. Methods. Thirteen patients with OSA and 13 normal controls were recruited. FeNO and MDA levels were measured in the controls and in OSA patients before and after three months of CPAP therapy. Results. FeNO and MDA levels were higher in the patients compared to the age and gender matched controls (FeNO: 25.9 ± 5.0 versus 17.5 ± 5.9 ppb, P < 0.001; MDA: 14.6 ± 7.8 versus 2.1 ± 0.3 μmol/L, P < 0.001). FeNO and MDA levels were lower post-CPAP compared to pre-CPAP (FeNO: 25.9 ± 5.0 versus 17.0 ± 2.3 ppb, P < 0.001; MDA: 14.6 ± 7.8 versus 10.0 ± 6.4 μmol/L, P < 0.01). Apnea-hypopnea index (15.9 ± 6.6 versus 4.1 ± 2.1/h, P < 0.001) and mean arterial pressure (P < 0.01) decreased following CPAP treatment. Daytime mean SpO2 (P < 0.05) increased. Conclusion. Our study demonstrates that CPAP therapy yields clinical benefits by reducing upper airway inflammation and oxidative stress in OSA patients. PMID:27445526

  6. Effect of Continuous Positive Airway Pressure on Airway Inflammation and Oxidative Stress in Patients with Obstructive Sleep Apnea.

    PubMed

    Tichanon, Promsrisuk; Wilaiwan, Khrisanapant; Sopida, Santamit; Orapin, Pasurivong; Watchara, Boonsawat; Banjamas, Intarapoka

    2016-01-01

    Background. Airway inflammation and oxidative stress may be linked in obstructive sleep apnea (OSA) patients. We determined the effectiveness of continuous positive airway pressure (CPAP) therapy in reducing fractional exhaled nitric oxide (FeNO) and malondialdehyde (MDA) levels in OSA patients. Methods. Thirteen patients with OSA and 13 normal controls were recruited. FeNO and MDA levels were measured in the controls and in OSA patients before and after three months of CPAP therapy. Results. FeNO and MDA levels were higher in the patients compared to the age and gender matched controls (FeNO: 25.9 ± 5.0 versus 17.5 ± 5.9 ppb, P < 0.001; MDA: 14.6 ± 7.8 versus 2.1 ± 0.3 μmol/L, P < 0.001). FeNO and MDA levels were lower post-CPAP compared to pre-CPAP (FeNO: 25.9 ± 5.0 versus 17.0 ± 2.3 ppb, P < 0.001; MDA: 14.6 ± 7.8 versus 10.0 ± 6.4 μmol/L, P < 0.01). Apnea-hypopnea index (15.9 ± 6.6 versus 4.1 ± 2.1/h, P < 0.001) and mean arterial pressure (P < 0.01) decreased following CPAP treatment. Daytime mean SpO2 (P < 0.05) increased. Conclusion. Our study demonstrates that CPAP therapy yields clinical benefits by reducing upper airway inflammation and oxidative stress in OSA patients.

  7. Lung clearance in children with Duchenne muscular dystrophy or spinal muscular atrophy with and without CPAP (continuous positive airway pressure).

    PubMed

    Klefbeck, B; Svartengren, K; Camner, P; Philipson, K; Svartengren, M; Sejersen, T; Mattsson, E

    2001-09-01

    Bronchiolar clearance was studied in 7 boys in the age range of 8 to 17 years, 6 with Duchenne muscular dystrophy (DMD) and 1 with spinal muscular atrophy type II (SMA-II). These boys had healthy lungs but a severely reduced muscular strength (wheelchair dependent). In 6 of the boys, clearance was studied twice, at one occasion as a control and at the other occasion following treatment with continuous positive airway pressure (CPAP). A control group of healthy adults was used. In the clearance examinations, 6-microm Teflon particles, labeled with III In was inhaled extremely slowly, 0.05 L/s. This gives a deposition mainly in the bronchioles. Lung retention was measured after 0,24,48, and 72 hours. A model for deposition of particles in the adult lung was scaled down to represent the children in this study. Deposition in various airway generations was calculated to be similar in children and adults. Also the measured retentions were similar in the boys and the adults. In the clearance experiments during CPAP treatment, there was a significantly lower retention after 72 hours (but not after 24 and 48 hours) than in the control experiments. Theresults indicate that a severe reduction of muscular strength, and thereby a reduction of mechanical movement of the lung, does not affect clearance from large and small airways. However, some effect of clearance from small airways cannot be excluded due to the short measuring period. The small but significant effect of the CPAP treatment might have potential clinical importance and suggest that bronchiolar clearance can be affected by some form of mechanical force. PMID:11558965

  8. EGFR kinase domain mutation positive lung cancers are sensitive to intrapleural perfusion with hyperthermic chemotherapy (IPHC) complete treatment

    PubMed Central

    Zhang, Hongjuan; Zhan, Cheng; Ke, Ji; Xue, Zhiqiang; Zhang, Aiqun; Xu, Kaifeng; Shen, Zhirong; Yu, Lei; Chen, Liang

    2016-01-01

    Lung cancer is the global leading cause of cancer-related deaths. A significant portion of lung cancer patients harbor kinase domain mutations in the epidermal growth factor receptor (EGFR). While EGFR tyrosine kinase inhibitors (TKI) effectively shrink tumors harboring mutant EGFR, clinical efficacy is limited by the development of TKI resistance. Effective alternatives are desperately needed in clinic for treating EGFR kinase domain mutation positive lung cancer. In our clinic in treating M1a lung cancer patients through intrapleural perfusion with hyperthermic chemotherapy (IPHC) followed by cycles of systemic chemotherapy (we termed this procedure IPHC complete treatment, IPHC-CT), we found dramatic tumor shrinkage in mutant EGFR-positive patients. We further confirmed the sensitivity of EGFR mutation-positive lung cancer cell lines derived from patients to HC (hyperthermic chemotherapy) treatment. We found that hyperthermia promoted accumulation of cisplatin in lung cancer cells. Hyperthermia and cisplatin synergistically downregulated the EGFR protein level, leading to quenching of signal from EGFR and induction of apoptosis. Our work therefore showed IPHC-CT is an effective treatment for EGFR kinase domain mutation positive lung cancer patients. PMID:26654941

  9. Positive lusitropic effect and diminished myofibrillar sensitivity to calcium produced by cAMP on toad (Bufo arenarum Hensel) ventricle.

    PubMed

    Vila Petroff, M; Vittone, L; Mundiña, C; Chiappe de Cingolani, G; Alicia, M

    1992-01-01

    In intact ventricular strips from toad heart, we studied the relaxant or positive lusitropic effect of different interventions known to increase intracellular cAMP levels. Isoproterenol increased developed tension (DT), maximal rate of contraction (+T), and maximal velocity of relaxation (-T). From 10(-8) to 10(-4)M isoproterenol, -T increased proportionally more than +T being the ratio +T/-T significantly decreased. A single dose of isoproterenol (3 x 10(-8)M) increased cAMP levels from 0.174 +/- 0.022 to 0.329 +/- 0.039 pmoles/mg ww (P < 0.05), increased contractility by 69 +/- 13% and decreased +T/-T by 18.5 +/- 4.55%. Administration of 10(-3)M of dibutyryl cyclic AMP (dcAMP) significantly increased DT and +T and decreased the ratio +T/-T. Similar effects were obtained with milrinone, a specific cAMP phosphodiesterase inhibitor. Papaverine, a non selective phosphodiesterase inhibitor, failed to increase +T but significantly increased -T. In chemically skinned ventricular trabeculae, calcium sensitivity of the myofibrils was significantly increased by 10(-5)M of the phosphodiesterase inhibitor 3-isobutyl-1-methyl-xanthine (IBMX). 10(-3)M dcAMP failed to affect calcium sensitivity of chemically skinned ventricular trabeculae when given alone, but produced a decrease in calcium sensitivity of the myofibrils in the presence of 10(-5)M of either IBMX or papaverine. The results would indicate that the relaxant effect of isoproterenol is mediated in toad ventricle by an increase in intracellular cAMP levels. They furthermore suggest that a decrease in myofilament sensitivity to calcium may be a mechanism by which cAMP produces its relaxant effect.

  10. The importance of administration of early surfactant and nasal continuous positive airway pressure in newborns with respiratory distress syndrome

    PubMed Central

    Ceylan, Abdullah; Gezer, Suat; Demir, Nihat; Tuncer, Oğuz; Peker, Erdal; Kırımi, Ercan

    2014-01-01

    Aim: Mechanical ventilation is an invasive method and causes to important problems in the respiratory tract and lung parenchyma. The objective of our study was to investigate if administration of early surfactant and nasal continuous positive airway pressure (nCPAP) was superior to delayed surfactant administration and mechanical ventilation. Material and Methods: The study was conducted in the Van 100th Year University, Medical Faculty Hospital, Neonatal Intensive Care Unit. One hundred and nine infants with respiratory distrss syndrome (RDS) with a gestational age of 32 weeks and/or below were included in the study. Surfactant was given to 61 infants in the delivery room or intensive care unit and subsequently nCPAP was administered. Surfactant was administered in 48 infants in the control group and mechanical ventilation was inititated subsequently. Informed consent was obtained from the relatives of all patients and ethics committee approval was also obtained (Approval number: 03.02.2011/15). Results: There was no statistically significant difference between the two groups in terms of gestational age, birth weight, gender, height and head circumference measurements (p>0.05). The mean hospitalization time in the patients in the study group was 24.4±17.8 days, whereas the mean time of nCPAP was 28.4 (4–120) hours. In the study group, intracranial hemorrhage was found with a rate of 27.85%, bronchopulmonary dysplasia was found with a rate of 4.91%, pneumothorax was found with a rate of 3.27%, necrotizing enterocolitis was found with a rate of 3.27%, patent ductus arteriosus was found with a rate of 16.39, sepsis was found with a rate of 22.95% and retinopathy of prematurity was found with a rate of 1.63%. No statistically significant difference was found between the study and control groups in terms of the rates of complications. During the follow-up period, 17 (27.86%) patients were lost. The length of stay on mechanical ventilation in the study group was

  11. Cost-effectiveness of continuous positive airway pressure therapy in patients with obstructive sleep apnea-hypopnea in British Columbia

    PubMed Central

    Tan, MCY; Ayas, NT; Mulgrew, A; Cortes, L; FitzGerald, JM; Fleetham, JA; Schulzer, M; Ryan, CF; Ghaeli, R; Cooperx, P; Marra, CA

    2008-01-01

    BACKGROUND: Obstructive sleep apnea-hypopnea (OSAH) is a common disorder characterized by recurrent collapse of the upper airway during sleep. Patients experience a reduced quality of life and an increased risk of motor vehicle crashes (MVCs). Continuous positive airway pressure (CPAP), which is the first-line therapy for OSAH, improves sleepiness, vigilance and quality of life. OBJECTIVE: To assess the cost-effectiveness of CPAP therapy versus no treatment for OSAH patients who are drivers. METHODS: A Markov decision analytical model with a five-year time horizon was used. The study population consisted of male and female patients, between 30 and 59 years of age, who were newly diagnosed with moderate to severe OSAH. The model evaluated the cost-effectiveness of CPAP therapy in reducing rates of MVCs and improving quality of life. Utility values were obtained from previously published studies. Rates of MVCs under the CPAP and no CPAP scenarios were calculated from Insurance Corporation of British Columbia data and a systematic review of published studies. MVCs, equipment and physician costs were obtained from the British Columbia Medical Association, published cost-of-illness studies and the price lists of established vendors of CPAP equipment in British Columbia. Findings were examined from the perspectives of a third-party payer and society. RESULTS: From the third-party payer perspective, CPAP therapy was more effective but more costly than no CPAP (incremental cost-effectiveness ratio [ICER] of $3,626 per quality-adjusted life year). From the societal perspective, the ICER was similar ($2,979 per quality-adjusted life year). The ICER was most dependent on preference elicitation method used to obtain utility values, varying almost sixfold under alternative assumptions from the base-case analysis. CONCLUSION: After considering costs and impact on quality of life, as well as the risk of MVCs in individuals with OSAH, CPAP therapy for OSAH patients is a highly

  12. Erectile Dysfunction and Sexual Hormone Levels in Men With Obstructive Sleep Apnea: Efficacy of Continuous Positive Airway Pressure.

    PubMed

    Zhang, Xiao-Bin; Lin, Qi-Chang; Zeng, Hui-Qing; Jiang, Xing-Tang; Chen, Bo; Chen, Xiao

    2016-01-01

    In this study, the prevalence of erectile dysfunction (ED) and serum sexual hormone levels were evaluated in men with obstructive sleep apnea (OSA). In these patients, the efficacy of continuous positive airway pressure (CPAP) was determined. The 207 men (mean age 44.0 ± 11.1 years) enrolled in the study were stratified within four groups based on their apnea-hypopnea index score: simple snoring (n = 32), mild OSA (n = 29), moderate OSA (n = 38), and severe OSA (n = 108). The International Index of Erectile Dysfunction-5 (IIEF-5) score was obtained from each patient, and blood samples for the analysis of sexual hormones (prolactin, luteotropin, follicle-stimulating hormone, estradiol, progestin, and testosterone) were drawn in the morning after polysomnography. The IIEF-5 test and serum sexual hormone measurements were repeated after 3 months of CPAP treatment in 53 men with severe OSA. The prevalence of ED was 60.6 % in OSA patients overall and 72.2 % in those with severe OSA. Compared with the simple snoring group, patients with severe OSA had significantly lower testosterone levels (14.06 ± 5.62 vs. 17.02 ± 4.68, p = .018) and lower IIEF-5 scores (16.33 ± 6.50 vs. 24.09 ± 1.94, p = .001). The differences in the other sexual hormones between groups were not significant. After 3 months of CPAP treatment, there were no significant changes in sexual hormone levels, but the IIEF-5 score had improved significantly (18.21 ± 4.05 vs. 19.21 ± 3.86, p = .001). Severe OSA patients have low testosterone concentration and high ED prevalence. IIEF-5 scores increased significantly after CPAP treatment, but there was no effect on serum testosterone levels.

  13. Sustainable use of continuous positive airway pressure in extremely preterm infants during the first week after delivery

    PubMed Central

    Booth, C; Premkumar, M H; Yannoulis, A; Thomson, M; Harrison, M; Edwards, A D

    2006-01-01

    Background Early use of nasal continuous positive airway pressure (nCPAP) may reduce lung damage, but it is not clear how many extremely preterm infants can be cared for without mechanical ventilation on the first days after delivery. Objectives To describe our experience of nCPAP in infants born at <27 weeks' gestation and to determine the chance of reintubation of this group of extremely preterm infants. Methods A retrospective, observational study examined the period from November 2002 to October 2003, when efforts were made to extubate infants to nCPAP at the earliest opportunity. Data were collected on all infants born at <27 weeks' and gestation admitted to The Neonatal Intensive Care Unit, Queen Charlotte's and Chelsea Hospital, London, UK. The chance of an individual infant requiring reintubation within 48 h of delivery was estimated, calculating the predictive probability using a Bayesian approach, and oxygen requirements at 36 weeks' postmenstrual age were examined. Results 60 infants, 34 inborn and 26 ex utero transfers, were admitted; 7 infants admitted 24 h after birth were excluded and 5 died within 48 h. The mean birth weight was 788 g and the gestational age was 25.3 weeks. Extubation was attempted on day 1 in 21 of 52 infants on ventilators and was successful in 14; and on day 2 in 14 of 35 and successful in 10 of infants extubated within 48 h of delivery survived to discharge. 5 of 23 infants on mechanical ventilation at 48 h of age were on air at 36 weeks postmenstrual age, and 12 of 26 of those were on nCPAP at 48 h of age. The probability of an individual baby remaining on nCPAP was 66% (95% CI 46% to 86%) on day 1 and 80% (95% CI 60% to 99%) on day 2. The smallest infant to be successfully extubated was 660 g and the youngest gestational age was 23.8 weeks. Conclusions Extremely preterm infants can be extubated to nCPAP soon after delivery, with a reasonable probability of not requiring immediate reintubation. PMID

  14. Continuous Positive Airway Pressure for Motion Management in Stereotactic Body Radiation Therapy to the Lung: A Controlled Pilot Study

    SciTech Connect

    Goldstein, Jeffrey D.; Lawrence, Yaacov R.; Appel, Sarit; Landau, Efrat; Ben-David, Merav A.; Rabin, Tatiana; Benayun, Maoz; Dubinski, Sergey; Weizman, Noam; Alezra, Dror; Gnessin, Hila; Goldstein, Adam M.; Baidun, Khader; Segel, Michael J.; Peled, Nir; Symon, Zvi

    2015-10-01

    Objective: To determine the effect of continuous positive airway pressure (CPAP) on tumor motion, lung volume, and dose to critical organs in patients receiving stereotactic body radiation therapy (SBRT) for lung tumors. Methods and Materials: After institutional review board approval in December 2013, patients with primary or secondary lung tumors referred for SBRT underwent 4-dimensional computed tomographic simulation twice: with free breathing and with CPAP. Tumor excursion was calculated by subtracting the vector of the greatest dimension of the gross tumor volume (GTV) from the internal target volume (ITV). Volumetric and dosimetric determinations were compared with the Wilcoxon signed-rank test. CPAP was used during treatment if judged beneficial. Results: CPAP was tolerated well in 10 of the 11 patients enrolled. Ten patients with 18 lesions were evaluated. The use of CPAP decreased tumor excursion by 0.5 ± 0.8 cm, 0.4 ± 0.7 cm, and 0.6 ± 0.8 cm in the superior–inferior, right–left, and anterior–posterior planes, respectively (P≤.02). Relative to free breathing, the mean ITV reduction was 27% (95% confidence interval [CI] 16%-39%, P<.001). CPAP significantly augmented lung volume, with a mean absolute increase of 915 ± 432 cm{sup 3} and a relative increase of 32% (95% CI 21%-42%, P=.003), contributing to a 22% relative reduction (95% CI 13%-32%, P=.001) in mean lung dose. The use of CPAP was also associated with a relative reduction in mean heart dose by 29% (95% CI 23%-36%, P=.001). Conclusion: In this pilot study, CPAP significantly reduced lung tumor motion compared with free breathing. The smaller ITV, the planning target volume (PTV), and the increase in total lung volume associated with CPAP contributed to a reduction in lung and heart dose. CPAP was well tolerated, reproducible, and simple to implement in the treatment room and should be evaluated further as a novel strategy for motion management in radiation therapy.

  15. Randomised controlled cross-over comparison of continuous positive airway pressure through the Hamilton Galileo ventilator with a Dräger CF 800 device.

    PubMed

    Sutton, P J; Perkins, C L; Giles, S P; McAuley, D F; Gao, F

    2005-01-01

    In this controlled, randomised cross-over trial on 26 intensive care patients, we compared the effects on haemodynamic and respiratory profiles of continuous positive airway pressure delivered through the Hamilton Galileo ventilator or a Drager CF 800 device. We also compared the nursing time saved using the two approaches when weaning patients from mechanical ventilation. We did not find significant differences in haemodynamics, respiratory rate, physiological dead space, oxygen saturation and carbon dioxide production between the continuous positive airway pressure generated by the Galileo and Drager machines. However, there was a 10-fold reduction in nursing time using the Galileo ventilator compared with the Drager generator. We conclude that continuous positive airway pressure delivered through the Galileo ventilator is as efficient as a Drager device but consumes less nursing time.

  16. Sealed position sensitive hard X-ray detector having large drift region for all sky camera with high angular resolution

    NASA Technical Reports Server (NTRS)

    Gorenstein, P.; Perlman, D.; Parsignault, D.; Burns, R.

    1979-01-01

    A sealed position sensitive proportional counter filled with two atmospheres of 95% xenon and 5% methane, and containing a drift region of 24 atm cm, has operated in a stable manner for many months. The detector contains G-10 frames to support the anode and cathode wires. The detector was sealed successfully by a combination of vacuum baking the G-10 frames at 150 C for two weeks followed by assembly into the detector in an environment of dry nitrogen, and the use of passive internal getters. The counter is intended for use with a circumferential cylindrical collimator. Together they provide a very broad field of view detection system with the ability to locate cosmic hard X-ray and soft gamma ray sources to an angular precision of a minute of arc. A set of instruments based on this principle have been proposed for satellites to detect and precisely locate cosmic gamma ray bursts.

  17. Simulated Performance of Algorithms for the Localization of Radioactive Sources from a Position Sensitive Radiation Detecting System (COCAE)

    SciTech Connect

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

    2011-12-13

    Simulation studies are presented regarding the performance of algorithms that localize point-like radioactive sources detected by a position sensitive portable radiation instrument (COCAE). The source direction is estimated by using the List Mode Maximum Likelihood Expectation Maximization (LM-ML-EM) imaging algorithm. Furthermore, the source-to-detector distance is evaluated by three different algorithms based on the photo-peak count information of each detecting layer, the quality of the reconstructed source image, and the triangulation method. These algorithms have been tested on a large number of simulated photons over a wide energy range (from 200 keV to 2 MeV) emitted by point-like radioactive sources located at different orientations and source-to-detector distances.

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

    NASA Astrophysics Data System (ADS)

    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.

  19. Handy Compton camera using 3D position-sensitive scintillators coupled with large-area monolithic MPPC arrays

    NASA Astrophysics Data System (ADS)

    Kataoka, J.; Kishimoto, A.; Nishiyama, T.; Fujita, T.; Takeuchi, K.; Kato, T.; Nakamori, T.; Ohsuka, S.; Nakamura, S.; Hirayanagi, M.; Adachi, S.; Uchiyama, T.; Yamamoto, K.

    2013-12-01

    The release of radioactive isotopes (mainly 137Cs, 134Cs and 131I) from the crippled Fukushima Daiichi Nuclear Plant remains a serious problem in Japan. To help identify radiation hotspots and ensure effective decontamination operation, we are developing a novel Compton camera weighting only 1 kg and measuring just ∼10 cm2 in size. Despite its compactness, the camera realizes a wide 180° field of vision with a sensitivity about 50 times superior to other cameras being tested in Fukushima. We expect that a hotspot producing a 5 μSv/h dose at a distance of 3 m can be imaged every 10 s, with angular resolution better than 10° (FWHM). The 3D position-sensitive scintillators and thin monolithic MPPC arrays are the key technologies developed here. By measuring the pulse-height ratio of MPPC-arrays coupled at both ends of a Ce:GAGG scintillator block, the depth of interaction (DOI) is obtained for incident gamma rays as well as the usual 2D positions, with accuracy better than 2 mm. By using two identical 10 mm cubic Ce:GAGG scintillators as a scatterer and an absorber, we confirmed that the 3D configuration works well as a high-resolution gamma camera, and also works as spectrometer achieving typical energy resolution of 9.8% (FWHM) for 662 keV gamma rays. We present the current status of the prototype camera (weighting 1.5 kg and measuring 8.5×14×16 cm3 in size) being fabricated by Hamamatsu Photonics K.K. Although the camera still operates in non-DOI mode, angular resolution as high as 14° (FWHM) was achieved with an integration time of 30 s for the assumed hotspot described above.

  20. Comprehensive simulation of the response of a silicon strip detector for position-sensitive measurements of X-rays

    NASA Astrophysics Data System (ADS)

    Wiącek, P.; Dąbrowski, W.

    2005-10-01

    The paper describes a comprehensive simulation method to evaluate X-ray imaging response of a silicon strip detector with particular emphasis on the charge-sharing effects. The simulation steps include: generation of the initial charge distribution in the detector volume, transport of generated charge in the detector volume, calculation of charges induced in the readout strips, discrimination of noisy electronic signals, and finally determination of the count efficiency vs. photon position as a function of the discrimination threshold. The developed simulation tools are useful for optimising the designs and operating parameters of silicon strip detectors used as 1-D position sensitive devices in experimental techniques like X-ray powder diffraction, X-ray high-resolution diffraction and small angle X-ray scattering, using laboratory X-ray sources. The response of the detector as a function of the detector bias and discrimination threshold has been investigated for two measurement configurations: irradiation from the strip-side and from the back-side.

  1. Positive selection of a duplicated UV-sensitive visual pigment coincides with wing pigment evolution in Heliconius butterflies

    PubMed Central

    Briscoe, Adriana D.; Bybee, Seth M.; Bernard, Gary D.; Yuan, Furong; Sison-Mangus, Marilou P.; Reed, Robert D.; Warren, Andrew D.; Llorente-Bousquets, Jorge; Chiao, Chuan-Chin

    2010-01-01

    The butterfly Heliconius erato can see from the UV to the red part of the light spectrum with color vision proven from 440 to 640 nm. Its eye is known to contain three visual pigments, rhodopsins, produced by an 11-cis-3-hydroxyretinal chromophore together with long wavelength (LWRh), blue (BRh) and UV (UVRh1) opsins. We now find that H. erato has a second UV opsin mRNA (UVRh2)—a previously undescribed duplication of this gene among Lepidoptera. To investigate its evolutionary origin, we screened eye cDNAs from 14 butterfly species in the subfamily Heliconiinae and found both copies only among Heliconius. Phylogeny-based tests of selection indicate positive selection of UVRh2 following duplication, and some of the positively selected sites correspond to vertebrate visual pigment spectral tuning residues. Epi-microspectrophotometry reveals two UV-absorbing rhodopsins in the H. erato eye with λmax = 355 nm and 398 nm. Along with the additional UV opsin, Heliconius have also evolved 3-hydroxy-DL-kynurenine (3-OHK)-based yellow wing pigments not found in close relatives. Visual models of how butterflies perceive wing color variation indicate this has resulted in an expansion of the number of distinguishable yellow colors on Heliconius wings. Functional diversification of the UV-sensitive visual pigments may help explain why the yellow wing pigments of Heliconius are so colorful in the UV range compared to the yellow pigments of close relatives lacking the UV opsin duplicate. PMID:20133601

  2. The residual stress instrument with optimized Si(2 2 0) monochromator and position-sensitive detector at HANARO

    NASA Astrophysics Data System (ADS)

    Lee, Chang-Hee; Moon, Myung-Kook; Em, Vyacheslav T.; Choi, Young-Hyun; Cheon, Jong-Kyu; Nam, Uk-Won; Kong, Kyung-Nam

    2005-06-01

    An upgraded residual stress instrument at the HANARO reactor of the KAERI is described. A horizontally focusing bent perfect crystal Si(2 2 0) monochromator (instead of a mosaic vertical focusing Ge monochromator) is installed in a drum with a tunable (2 θM=0-60°) take-off angle/wavelength. A specially designed position-sensitive detector (60% efficiency for λ=1.8 A) with 200 mm (instead of 100 mm) high-active area is used. There are no Soller type collimators in the instrument. The minimum possible monochromator to sample distance, L=2 m, and sample to detector distance, L=1.2 m, were found to be optimal. The new PSD and bent Si(2 2 0) 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(2 2 0) 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 56 mm length of path.

  3. Health effects of obstructive sleep apnoea and the effectiveness of continuous positive airways pressure: a systematic review of the research evidence.

    PubMed Central

    Wright, J.; Johns, R.; Watt, I.; Melville, A.; Sheldon, T.

    1997-01-01

    OBJECTIVE: To examine the research evidence for the health consequences of obstructive sleep apnoea and the effectiveness of continuous positive airways pressure. DESIGN: A systematic review of published research, studies being identified by searching Medline (1966-96), Embase (1974-96), and CINAHL (Cumulative Index to Nursing and Allied Health Literature) (1982-95); scanning citations; and consulting experts. Studies in all languages were considered which either investigated the association between obstructive sleep apnoea in adults and key health outcomes or evaluated the effectiveness of treatment of obstructive sleep apnoea with continuous positive airways pressure in adults. MAIN OUTCOME MEASURES: Mortality, systematic hypertension, cardiac arrhythmias, ischaemic heart disease, left ventricular hypertrophy, pulmonary hypertension, stroke, vehicle accidents, measures of daytime sleepiness, and quality of life. RESULTS: 54 epidemiological studies examined the association between sleep apnoea and health related outcomes. Most were poorly designed and only weak or contradictory evidence was found of an association with cardiac arrhythmias, ischaemic heart disease, cardiac failure, systemic or pulmonary hypertension, and stroke. Evidence of a link with sleepiness and road traffic accidents was stronger but inconclusive. Only one small randomised controlled trial evaluated continuous positive airways pressure. Five non-randomised controlled trials and 38 uncontrolled trials were identified. Small changes in objectively measured daytime sleepiness were consistently found, but improvements in morbidity, mortality, and quality of life indicators were not adequately assessed. CONCLUSIONS: The relevance of sleep apnoea to public health has been exaggerated. The effectiveness of continuous positive airways pressure in improving health outcomes has been poorly evaluated. There is enough evidence suggesting benefit in reducing daytime sleepiness in some patients to warrant

  4. A CdTe position sensitive detector for a hard X- and gamma-ray wide field camera

    SciTech Connect

    Caroli, E.; Cesare, G. de; Donati, A.; Dusi, W.; Landini, G.; Stephen, J.B.; Perotti, F.

    1998-12-31

    An important region of the electromagnetic spectrum for astrophysics is the hard X- and gamma ray band between 10 keV and a few MeV, where several processes occur in a wide variety of objects and with different spatial distribution and time scales. In order to fulfill the observational requirements in this energy range and taking into account the opportunities given by small/medium size missions (e.g., on the ISS), the authors have proposed a compact, wide field camera based on a thick (1 cm) position sensitive CdTe detector (PSD). The detector is made of an array of 128x96 CdTe microspectrometers with a pixel size of 2x2 mm{sup 2}. The basic element of the PSD is the linear module that is an independent detection unit with 32 CdTe crystals and monolithic front-electronics (ASIC) supported by a thin (300 {micro}m) ceramic layer. The expected performance of the PSD over the operative energy range and some of the required ASIC functionality are presented and discussed.

  5. A simple technique to increase the linearity and field-of-view in position sensitive photomultiplier tubes

    SciTech Connect

    Clancy, R.L.; Thompson, C.J.; Robar, J.L.; Bergman, A.M.

    1996-12-31

    Crossed anode wire position sensitive photomultiplier tubes (PS-PMTs) detect the location of a light source and provide the X and Y axis coordinates of the event. These coordinates are typically generated using Anger logic, where a resistor chain divides the current flow into two signals for each coordinate (X{sup +}, X{sup -} & Y{sup +}, Y{sup -}). In the standard readout, identical resistor values are used across the entire resistor chain. While this arrangement provides a linear readout in the central portion of the photomultiplier face, the readout is non-linear and sometimes even double valued near the edges of the PS-PMT due to the truncation of the charge beyond the last anode wire. To counter this effect, we have increased the value of the resistance near the ends of each resistor chain in order to compensate for the charge lost beyond the anode wires. Measurements were made using a Hamamatsu R-3941 PS-PMT coupled to a pixellated BGO matrix of cut crystals with a 2mm pitch in each direction. After changing the end resistors, the usable field-of-view increased by 39%. This simple modification should enhance the operation of PS-PMTs in applications such as positron emission mammography, and small animal PET imaging.

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

    SciTech Connect

    Bolotnikov, Aleksey E.; James, Ralph B.; Cui, Y.; De Geronimo, G.; Vernon, E.; Camarda, G. S.; Hossain, A.; Yang, G.; Indusi, J.; Boyer, Brian

    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.

  7. Reciprocal-Space Analysis of Compositional Modulation in Short-Period Superlattices Using Position-Sensitive X-Ray Detection

    SciTech Connect

    Ahrenkiel, S.P.; Follstaedt, D.M.; Lee, S.R.; Millunchick, J.M.; Norman, A.G.; Reno, J.L.; Twesten, R.D.

    1998-11-10

    Epitaxial growth of AlAs-InAs short-period superlattices on (001) InP can lead to heterostructures exhibiting strong, quasi-periodic, lateral modulation of the alloy composition; transverse satellites arise in reciprocal space as a signature of the compositional modulation. Using an x-ray diffractometer equipped with a position-sensitive x-ray detector, we demonstrate reciprocal-space mapping of these satellites as an efficient, nondestructive means for detecting and characterizing the occurrence of compositional modulation. Systematic variations in the compositional modulation due to the structural design and the growth conditions of the short-period superlattice are characterized by routine mapping of the lateral satellites. Spontaneous compositional modulation occurs along the growth front during molecular-beam epitaxy of (AlAs) (InAs)n short-period superlattices. The modulation is quasi-periodic and forms a lateral superlattice superimposed on the intended SPS structure. Corresponding transverse satellites arise about each reciprocal lattice point, and x-ray diffraction can be routinely used to map their local reciprocal-space structure. The integrated intensity, spacing, orientation, and shape of these satellites provide a reliable means for nondestructively detecting and characterizing the compositional modulation in short-period superlattices. The analytical efficiency afforded by the use of a PSD has enabled detailed study of systematic vacations in compositional modulation as a function of the average composition, the period, and the growth rate of the short- period superlattice

  8. Charge integrating type position-sensitive proportional chamber for time-resolved measurements using intense X-ray sources

    NASA Astrophysics Data System (ADS)

    Mochiki, Koh-ichi; Hasegawa, Ken-ichi

    1985-02-01

    A position-sensitive detecting system for time-resolved diffraction measurements with very intensive X-ray sources has been developed. It consists of a charge integrating type gas-filled detector, multichannel analog multiplexers, a signal processor and a memory (120 ch.×128 phases×24 bits). The detector is 120 mm long in effective length by 10 mm×10 mm in cross section with a single anode of 20 μm diameter. One of the cathode planes consists of 120 cathode strips with a pitch of 1 mm. The spatial resolution is equal to the pitch under a certain detector current limit. The gas gain is adjustable to an appropriate value according to the X-ray intensity range of interest. For experiments with 8 keV X-ray sources, maximum absorption rates of 9×10 7 photons/s·mm with low applied voltage and minimum absorption rates of about 3 photons/s·mm with high applied voltage can be achieved. This system was applied to a time-resolved X-ray diffraction study on frog muscle using a synchrotron radiation source at the Photon Factory and we could collect diffraction patterns with a time resolution of 10 ms and only 10 stimulations.

  9. Continuous Positive Airway Pressure Therapy for Obstructive Sleep Apnea: Maximizing Adherence Including Using Novel Information Technology-based Systems.

    PubMed

    Hevener, Bretton; Hevener, William

    2016-09-01

    Sleep apnea is a form of sleep-disordered breathing that is associated with an increase in disease comorbidities, mortality risks, health care costs, and traffic accidents. Sleep apnea is most commonly treated with positive airway pressure (PAP). PAP can be difficult for patients to tolerate. This leads to initial and long-term noncompliance. Most insurance companies require compliance with PAP treatment to cover ongoing reimbursements for the device and related disposable supplies. Therefore, there are both clinical and financial incentives to a sleep apneic patient's compliance with PAP therapy. PMID:27542878

  10. Continuous Positive Airway Pressure Therapy for Obstructive Sleep Apnea: Maximizing Adherence Including Using Novel Information Technology-based Systems.

    PubMed

    Hevener, Bretton; Hevener, William

    2016-09-01

    Sleep apnea is a form of sleep-disordered breathing that is associated with an increase in disease comorbidities, mortality risks, health care costs, and traffic accidents. Sleep apnea is most commonly treated with positive airway pressure (PAP). PAP can be difficult for patients to tolerate. This leads to initial and long-term noncompliance. Most insurance companies require compliance with PAP treatment to cover ongoing reimbursements for the device and related disposable supplies. Therefore, there are both clinical and financial incentives to a sleep apneic patient's compliance with PAP therapy.

  11. Continuation of trastuzumab beyond disease progression in HER2-positive metastatic gastric cancer: the MD Anderson experience

    PubMed Central

    Fahmawi, Yazan; Dahbour, Ibrahim; Tabash, Aziz; Rogers, Jane E.; Mares, Jeannette Elizabeth; Blum, Mariela A.; Estrella, Jeannelyn; Matamoros, Aurelio; Sagebiel, Tara; Devine, Catherine E.; Badgwell, Brian D.; Lin, Quan D.; Das, Prajnan; Ajani, Jaffer A.

    2016-01-01

    Background Despite the wide spread use of trastuzumab in human epidermal growth factor receptor 2 (HER2) overexpressing metastatic gastric cancer patients, its optimal duration of administration beyond first-line disease progression is unknown. In HER2 overexpressing metastatic breast cancer, trastuzumab continuation beyond first-line disease progression has shown improvement in time to progression (TTP) without an increased risk of treatment related toxicity. Methods HER2-overexpressing metastatic gastric cancer patients were identified from our database between January 2010 and December 2014. We retrospectively reviewed the medical records of 43 patients who received trastuzumab in combination with chemotherapy as first-line and continued trastuzumab beyond disease progression. Results Forty-three cases were identified, 27 males (62.8%), median age of the patients was 58 years. Thirty-five (81.4%) presented with stage 4 as their initial presentation. Eighty one percent had 3+ HER2 overexpression by immunohistochemistry (IHC) and 18% had 2+ HER2 overexpression confirmed by fluorescence in situ hybridization (FISH). Thirteen (52%) were moderately differentiated, 16 (37.1%) were poorly differentiated. The most common sites of metastasis were liver 35 (81.4%) and lung 14 (32.5%). The most commonly used first-line regimen was oxaliplatin, 5-fluorouracil (5-FU), and trastuzumab in 22 (51.1%) patients. Twenty-five (58.1%) patients received irinotecan, 5-FU and trastuzumab in the second-line. Progression-free survival (PFS) was 5 months (95% CI: 4.01–5.99 months). Five patients are still alive and excluded from calculating the median overall survival (OS) which was 11 months (range, 5–53 months) for the remaining 20 subjects of this second-line group. Trastuzumab was not discontinued due to side effects in any of the study population. Conclusions In conclusion, this retrospective analysis suggests that continuation of trastuzumab beyond disease progression in

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

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

    2016-01-01

    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. PMID:27634110

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

    PubMed Central

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

    2016-01-01

    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. PMID:27634110

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

    PubMed

    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.

  16. Early continuous white noise exposure alters auditory spatial sensitivity and expression of GAD65 and GABAA receptor subunits in rat auditory cortex.

    PubMed

    Xu, Jinghong; Yu, Liping; Cai, Rui; Zhang, Jiping; Sun, Xinde

    2010-04-01

    Sensory experiences have important roles in the functional development of the mammalian auditory cortex. Here, we show how early continuous noise rearing influences spatial sensitivity in the rat primary auditory cortex (A1) and its underlying mechanisms. By rearing infant rat pups under conditions of continuous, moderate level white noise, we found that noise rearing markedly attenuated the spatial sensitivity of A1 neurons. Compared with rats reared under normal conditions, spike counts of A1 neurons were more poorly modulated by changes in stimulus location, and their preferred locations were distributed over a larger area. We further show that early continuous noise rearing induced significant decreases in glutamic acid decarboxylase 65 and gamma-aminobutyric acid (GABA)(A) receptor alpha1 subunit expression, and an increase in GABA(A) receptor alpha3 expression, which indicates a returned to the juvenile form of GABA(A) receptor, with no effect on the expression of N-methyl-D-aspartate receptors. These observations indicate that noise rearing has powerful adverse effects on the maturation of cortical GABAergic inhibition, which might be responsible for the reduced spatial sensitivity. PMID:19620619

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

    PubMed

    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.

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

    NASA Astrophysics Data System (ADS)

    Hanu, A. R.; Prestwich, W. V.; Byun, S. H.

    2015-04-01

    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 1.8×106 Hz without any loses and will report a maximum event rate of 6.11×105 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.

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

    PubMed

    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. PMID:25283165

  20. Fast x-ray scattering measurements on molten alumina using a 120{degree} curved position sensitive detector.

    SciTech Connect

    Hennet, L.; Thiaudiere, D.; Gailhanou, M.; Landron, C.; Coutures, J.-P.; Price, D. L.; C.R.M.H.T.; LURE; Univ. de Perpignan

    2002-01-01

    Fast x-ray scattering measurements on molten alumina were performed on the H10 beam line at the DCI Synchrotron of LURE (Orsay, France). A high-temperature chamber with a levitation device was coupled with the four-circle goniometer of the beam line. A 100 W CO{sub 2} laser was used to melt the sample and the temperature was measured using an optical pyrometer operating at 0.85 {mu}m. Usually, measurements of the total structure factor S(Q) on molten materials are performed using a fixed detector scanned over an angular range. In this work, in order to reduce the total scan duration, x-ray scattered intensities were measured with a 120{sup o} position sensitive detector (INEL CPS120). We performed several measurements with different acquisition times varying from 10 s to 5 min. In 5 min it was possible to obtain a good determination of S(Q) with a usable signal up to the Q range limit (13 Angstroms{sup -1}). The intensity was comparable with a 1 h measurement with a NaI (Tl) scintillator scanned over the 120 2{theta} range. On reducing the counting time the statistics are degraded and the data are noisier, especially in the high Q region. Nevertheless, even with 10 s, the S(Q) data remain usable and give good results. Performing the Fourier transformation of S(Q), we obtain similar reliable pair-correlation functions with both 5 min and 10 s acquisition times.

  1. How does serum brain natriuretic peptide level change under nasal continuous positive airway pressure in obstructive sleep apnea-hypopnea syndrome?

    PubMed Central

    Msaad, Sameh; Marrakchi, Rim; Grati, Malek; Gargouri, Rahma; Kammoun, Samy; Jammoussi, Kamel; Yangui, Ilhem

    2016-01-01

    Background Obstructive sleep apnea-hypopnea syndrome (OSAHS) is associated with cardiovascular morbidity and mortality, which can be improved by using continuous positive airway pressure (CPAP) therapy. However, the pathophysiological links between the two kinds of disease and the mechanism of the CPAP effect remain incompletely understood. We aimed to inquire into the myocardial involvement in this relationship. We suggested that serum brain natriuretic peptide (BNP) is sensitive enough to detect myocardial stress caused by OSAHS. Design and methods Sixty-four subjects without cardiovascular disease (21 controls, 24 normotensive OSAHS patients, and 19 hypertensive OSAHS patients) were analyzed for serum BNP at baseline and serially over 6 months. CPAP was applied to 23 patients with severe OSAHS. Results At baseline, the serum BNP levels were significantly higher (p=0.0001) in the OSAHS group (22.3±14.79 pg/ml) than in the control group (9.2±6.75 pg/ml). Increased serum BNP levels were significantly associated with mean transcutaneous oxygen saturation (SpO2) (p<0.0001), minimal SpO2 (p=0.002), oxygen desaturation index (p=0.001), and total sleep time spent with SpO2 lower than 90% (p=0.002). All patients with elevated BNP levels (≥37 pg/ml) had moderate or severe OSAHS (11/43 OSAHS patients). The more severe the OSAHS, the higher the BNP levels were. However, only the difference between severe and mild OSAHS was statistically significant (p=0.029). Hypertensive OSAHS patients had the highest baseline BNP levels (27.7±16.74 pg/ml). They were significantly higher (p=0.001) than in normotensive OSAHS patients (18±11.72 pg/ml) (p=0.039) and the controls (9.2±6.75 pg/ml). As compared with baseline, treatment with CPAP significantly decreased BNP levels in both hypertensive and normotensive OSAHS patients (respectively, from 36±16.10 to 29.7±14.29 pg/ml, p<0.001, and from 20±10.09 to 16±8.98 pg/ml, p<0.001). In contrast, the BNP levels slightly increased in

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

    NASA Astrophysics Data System (ADS)

    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

  3. [Continuous positive airway pressure and high-frequency independent lung ventilation in patients with chronic obstructive lung diseases].

    PubMed

    Fedorova, E A; Vyzhigina, M A; Gal'perin, Iu S; Zhukova, S G; Titov, V A; Godin, A V

    2004-01-01

    The original hypoxemia, hypercapnia, high pulmonary hypertension, high resistance of microcirculation vessels, right volumetric ventricular overload, persistent sub-edema of pulmonary intersticium as well as disparity of ventilation and perfusion between both lungs are the main problems in patients with chronic obstructive disease of the lungs (CODL). Such patients are, as a rule, intolerant to the independent lung collaboration or artificial single-stage ventilation (ASV). Patients with respiratory insufficiency, stages 2 and 3, and with a pronounced impaired type of ventilation have originally a deranged blood gas composition, like hypoxemia or hypercapnia. The application of volume-controllable bi-pulmonary ASV in such patients maintains an adequate gas exchange hemodynamics. However, ASV is accompanied by a significantly reduced gas-exchange function of the single ventilated lung and by essentially worsened intrapulmonary hemodynamics. Therefore, what is needed is to use alternative methods of independent lung ventilation in order to eliminate the gas-exchange impairments and to enable surgical interventions at thoracic organs in such patients (who are intolerant to ASV). A choice of a method and means of oxygen supply to the independent lung is of great importance. The possibility to avoid a high pressure in the airways, while maintaining, simultaneously, an adequate gas exchange, makes the method related with maintaining a constant positive pressure in the airways (CPPA) a priority one in case of CODL patients. The use of constant high-frequency ventilation in the independent lung in patients with obstructive pulmonary lesions does not improve the gas exchange or hemodynamics. Simultaneously, a growing total pulmonary resistance and an increasing pressure in the pulmonary artery are observed. Consequently, the discussed method must not be used for the ventilation support of the independent lung in patients with the obstructive type of the impaired external

  4. Young women's attitudes toward continuous use of oral contraceptives: the effect of priming positive attitudes toward menstruation on women's willingness to suppress menstruation.

    PubMed

    Rose, Jennifer Gorman; Chrisler, Joan C; Couture, Samantha

    2008-08-01

    The present study investigated American women's attitudes toward menstrual suppression and the effect of priming attitudes toward menstruation on women's willingness to suppress menstruation. One hundred college women randomly were assigned to either a positive priming group or a negative priming group. The positive priming group first completed the menstrual joy questionnaire (MJQ) followed by a willingness to suppress menstruation (WSM) questionnaire, the beliefs and attitudes toward menstruation (BATM) questionnaire, the menstrual distress questionnaire (MDQ), and a demographic questionnaire. The negative priming group completed, in the following order: the MDQ, WSM, BATM, MJQ, and demographics. Priming affected women's reports of positive cycle-related changes on the MDQ, but not women's willingness to suppress menstruation. Higher scores on the MJQ, positive attitudes toward menstrual suppression, and previous oral contraceptive (OC) use were predictors of women's willingness to suppress menstruation. Women's primary source of information about menstrual suppression was "media," and their primary concern was "safety." Thus, researchers should continue to investigate the long-term effects of continuous OC use and to analyze information about menstrual suppression in the popular press.

  5. Continuous-output terminal-shock-position sensor for mixed-compression inlets evaluated in wind tunnel tests of YF-12 aircraft inlet

    NASA Technical Reports Server (NTRS)

    Dustin, M. O.; Cole, G. L.; Neiner, G. H.

    1974-01-01

    An electronic sensor was built to measure the position of the terminal shock in a supersonic inlet. The sensor uses several static-pressure taps in the inlet wall. The sensor output is continuously proportional to shock position. When the sensor was installed in a YF-12 aircraft flight inlet during wind tunnel tests, it indicated shock position within + or - 5 percent of the total distance covered by the static-pressure-tap region. The maximum error caused by an angle of attack change of 4 deg was less than 25 percent. In the region of normal inlet operation, the angle of attack error is negligible. Frequency-response tests show the amplitude ratio is constant out to 60 Hz, and decreases to about 50 percent at 100 Hz, with a phase lag of 50 deg.

  6. Predictors of Long-Term Adherence to Continuous Positive Airway Pressure Therapy in Patients with Obstructive Sleep Apnea and Cardiovascular Disease in the SAVE Study

    PubMed Central

    Chai-Coetzer, Ching Li; Luo, Yuan-Ming; Antic, Nick A.; Zhang, Xi-Long; Chen, Bao-Yuan; He, Quan-Ying; Heeley, Emma; Huang, Shao-Guang; Anderson, Craig; Zhong, Nan-Shan; McEvoy, R. Doug

    2013-01-01

    Study Objectives: To determine the clinical variables that best predict long- term continuous positive airway pressure (CPAP) adherence among patients with cardiovascular disease who have obstructive sleep apnea (OSA). Design: 12-mo prospective within-trial observational study. Setting: Centers in China, Australia, and New Zealand participating in the Sleep Apnea cardioVascular Endpoints (SAVE) study. Patients: There were 275 patients age 45-70 y with cardiovascular disease (i.e., previously documented transient ischemic attack, stroke, or coronary artery disease) and OSA (4% oxygen desaturation index (ODI) > 12) who were randomized into the CPAP arm of the SAVE trial prior to July 1, 2010. Methods: Age, sex, country of residence, type of cardiovascular disease, baseline ODI, severity of sleepiness, and Hospital Anxiety and Depression Scale (HADS) scores plus CPAP side effects and adherence at 1 mo were entered in univariate analyses in an attempt to identify factors predictive of CPAP adherence at 12 mo. Variables with P < 0.2 were then included in a multivariate analysis using a linear mixed model with sites as a random effect and 12-mo CPAP use as the dependent outcome variable. Measurements and Results: CPAP adherence at 1, 6, and 12 mo was (mean ± standard deviation) 4.4 ± 2.0, 3.8 ± 2.3, and 3.3 ± 2.4 h/night, respectively. CPAP use at 1 mo (effect estimate ± standard error, 0.65 ± 0.07 per h increase, P < 0.001) and side effects at 1 mo (-0.24 ± 0.092 per additional side effect, P = 0.009) were the only independent predictors of 12- mo CPAP adherence. Conclusion: Continuous positive airway pressure use in patients with coexisting cardiovascular disease and moderate to severe obstructive sleep apnea decreases significantly over 12 months. This decline can be predicted by early patient experiences with continuous positive airway pressure (i.e., adherence and side effects at 1 month), raising the possibility that intensive early interventions could

  7. Lymphoblastoid Cell lines: a Continuous in Vitro Source of Cells to Study Carcinogen Sensitivity and DNA Repair.

    PubMed

    Hussain, Tabish; Mulherkar, Rita

    2012-01-01

    Obtaining a continuous source of normal cells or DNA from a single individual has always been a rate limiting step in biomedical research. Availability of Lymphoblastoid cell lines (LCLs) as a surrogate for isolated or cryopreserved peripheral blood lymphocytes has substantially accelerated the process of biological investigations. LCLs can be established by in vitro infection of resting B cells from peripheral blood with Epstein Barr Virus (EBV) resulting in a continuous source, bearing negligible genetic and phenotypic alterations. Being a spontaneous replicating source, LCLs fulfil the requirement of constant supply of starting material for variety of assays, sparing the need of re-sampling. There is a reason to believe that LCLs are in close resemblance with the parent lymphocytes based on the ample supporting observations from a variety of studies showing significant level of correlation at molecular and functional level. LCLs, which carry the complete set of germ line genetic material, have been instrumental in general as a source of biomolecules and a system to carry out various immunological and epidemiological studies. Furthermore, in recent times their utility for analysing the whole human genome has extensively been documented. This proves the usefulness of LCLs in various genetic and functional studies. There are a few contradictory reports that have questioned the employment of LCLs as parent surrogate. Regardless of some inherent limitations LCLs are increasingly being considered as an important resource for genetic and functional research.

  8. Use of a Continuous Wave Laser and Pockels Cell for Sensitive High-Resolution Collinear Resonance Ionization Spectroscopy

    NASA Astrophysics Data System (ADS)

    de Groote, R. P.; Budinčević, I.; Billowes, J.; Bissell, M. L.; Cocolios, T. E.; Farooq-Smith, G. J.; Fedosseev, V. N.; Flanagan, K. T.; Franchoo, S.; Garcia Ruiz, R. F.; Heylen, H.; Li, R.; Lynch, K. M.; Marsh, B. A.; Neyens, G.; Rossel, R. E.; Rothe, S.; Stroke, H. H.; Wendt, K. D. A.; Wilkins, S. G.; Yang, X.

    2015-09-01

    New technical developments have led to a 2 orders of magnitude improvement of the resolution of the collinear resonance ionization spectroscopy (CRIS) experiment at ISOLDE, CERN, without sacrificing the high efficiency of the CRIS technique. Experimental linewidths of 20(1) MHz were obtained on radioactive beams of francium, allowing us for the first time to determine the electric quadrupole moment of the short lived [t1 /2=22.0 (5 ) ms ] 219Fr Qs=-1.21 (2 ) eb , which would not have been possible without the advantages offered by the new method. This method relies on a continuous-wave laser and an external Pockels cell to produce narrow-band light pulses, required to reach the high resolution in two-step resonance ionization. Exotic nuclei produced at rates of a few hundred ions/s can now be studied with high resolution, allowing detailed studies of the anchor points for nuclear theories.

  9. Use of a Continuous Wave Laser and Pockels Cell for Sensitive High-Resolution Collinear Resonance Ionization Spectroscopy.

    PubMed

    de Groote, R P; Budinčević, I; Billowes, J; Bissell, M L; Cocolios, T E; Farooq-Smith, G J; Fedosseev, V N; Flanagan, K T; Franchoo, S; Garcia Ruiz, R F; Heylen, H; Li, R; Lynch, K M; Marsh, B A; Neyens, G; Rossel, R E; Rothe, S; Stroke, H H; Wendt, K D A; Wilkins, S G; Yang, X

    2015-09-25

    New technical developments have led to a 2 orders of magnitude improvement of the resolution of the collinear resonance ionization spectroscopy (CRIS) experiment at ISOLDE, CERN, without sacrificing the high efficiency of the CRIS technique. Experimental linewidths of 20(1) MHz were obtained on radioactive beams of francium, allowing us for the first time to determine the electric quadrupole moment of the short lived [t_{1/2}=22.0(5) ms] ^{219}Fr Q_{s}=-1.21(2) eb, which would not have been possible without the advantages offered by the new method. This method relies on a continuous-wave laser and an external Pockels cell to produce narrow-band light pulses, required to reach the high resolution in two-step resonance ionization. Exotic nuclei produced at rates of a few hundred ions/s can now be studied with high resolution, allowing detailed studies of the anchor points for nuclear theories. PMID:26451548

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

    NASA Astrophysics Data System (ADS)

    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

  11. Continued Development Of A Sensitive Mid-IR Cavity Ring-Down Spectrometer Using A Quantum Cascade Laser

    NASA Astrophysics Data System (ADS)

    Brumfield, Brian E.; Stewart, Jacob T.; McCall, Benjamin, J.

    2010-11-01

    Since its initial discovery in 1985, it has been postulated that buckminsterfullerene (C60) should be present in space. Over the past 25 years there has been indirect evidence for the presence of extrasolar C60. This indirect evidence comes from the analysis of micrometeorite impact craters from a satellite called the Long Duration Exposure Facility (LDEF). Also, studies of the isotopic ratio of Ar found encapsulated in C60 from extinction impact event sediemnts provides indirect evidence for extrasolar source of fullerenes. This past summer emission from C60 in the young planetary nebula Tc1 provided the first direct evidence of C60 in space. This was quickly followed by detection of emission from gas phase C60 pumped by ultraviolet radiation in the reflection nebulae NGC2023 and NGC7023. While these studies have confirmed the presence of C60 in space, it is difficult to use emission to estimate the column density and temperature of the gas phase C60. In the case of emission via UV pumping, the presence of C60 in the gas phase could extend beyond the region of high UV ux. For these reasons, it would be beneficial to search for a C60 absorption signal in the mid-IR. We are developing a sensitive mid-infrared cavity ringdown spectrometer for acquiring a cold gas phase spectrum of buckminsterfullerene (C60) ~8.5 μm. A high-resolution absorption spectrum of this vibrational band would aid in astronomical searches for a C60 absorption signal. Recently, a significant number of experimental improvements have enhanced both the sensitivity and the resolution of the instrument. The addition of a Fresnel quarter wave rhomb and a wire grid polarizer have mitigated the impact of optical cavity back-reflection on the laser stability and enabled mode-hop free tunability. Finer laser current control has allowed for the collection of spectra with a frequency step resolution of 2 MHz. We have tested the spectrometer by re-scanning &nu8 band of methylene bromide in a slit nozzle

  12. Lock-in-photon-counting-based highly-sensitive and large-dynamic imaging system for continuous-wave diffuse optical tomography.

    PubMed

    Chen, Weiting; Wang, Xin; Wang, Bingyuan; Wang, Yihan; Zhang, Yanqi; Zhao, Huijuan; Gao, Feng

    2016-02-01

    We implemented a novel lock-in photon-counting detection architecture that combines the ultra-high sensitivity of the photon-counting detection and the measurement parallelism of the lock-in technique. Based on this technique, a dual-wavelength simultaneous measurement continuous wave diffuse optical tomography system was developed with a configuration of 16 sources and 16 detectors that works in a tandem serial-to-parallel fashion. Methodology validation and performance assessment of the system were conducted using phantom experiments that demonstrate excellent measurement linearity, moderate-term system stability, robustness to noise and negligible inter-wavelength crosstalk. 2-D imaging experiments further validate high sensitivity of the lock-in photon-counting methodology as well as high reliability of the proposed system. The advanced detection principle can be adapted to achieving a fully parallelized instrumentation for the extended applications. PMID:26977358

  13. Lock-in-photon-counting-based highly-sensitive and large-dynamic imaging system for continuous-wave diffuse optical tomography

    PubMed Central

    Chen, Weiting; Wang, Xin; Wang, Bingyuan; Wang, Yihan; Zhang, Yanqi; Zhao, Huijuan; Gao, Feng

    2016-01-01

    We implemented a novel lock-in photon-counting detection architecture that combines the ultra-high sensitivity of the photon-counting detection and the measurement parallelism of the lock-in technique. Based on this technique, a dual-wavelength simultaneous measurement continuous wave diffuse optical tomography system was developed with a configuration of 16 sources and 16 detectors that works in a tandem serial-to-parallel fashion. Methodology validation and performance assessment of the system were conducted using phantom experiments that demonstrate excellent measurement linearity, moderate-term system stability, robustness to noise and negligible inter-wavelength crosstalk. 2-D imaging experiments further validate high sensitivity of the lock-in photon-counting methodology as well as high reliability of the proposed system. The advanced detection principle can be adapted to achieving a fully parallelized instrumentation for the extended applications. PMID:26977358

  14. 'I thought I was just going to teach': stories of new nurse academics on transitioning from sessional teaching to continuing academic positions.

    PubMed

    McDermid, Fiona; Peters, Kath; Daly, John; Jackson, Debra

    2013-08-01

    Currently many nursing faculties and schools employ high numbers of sessional teachers to meet the demands of teaching. Sessional teachers are a source for future continuing academic staff; however, there is little exploration on the experiences of sessional teachers as they transition into the full-time nurse academic role. A qualitative study of 14 registered nurse participants used a story-telling approach to explore the experiences of sessional teachers as they transitioned into full-time and continuing academic roles. Findings revealed that participants had only a very limited understanding of the requirements of the academic role when appointed to it. Thematic analysis revealed two major themes. These were: 'Uncertainty: Dealing with role expectation' and 'Mitigating lack of confidence'. The implications of this paper contributes to and enhances knowledge of the transition experiences of sessional teachers and provides new evidence to suggest that adequate support processes are essential for sessional staff transitioning into permanent, full-time academic positions.

  15. Genetic Evidence for Restricted Dispersal along Continuous Altitudinal Gradients in a Climate Change-Sensitive Mammal: The American Pika

    PubMed Central

    Henry, Philippe; Sim, Zijian; Russello, Michael A.

    2012-01-01

    plasticity in order to survive predicted climate changes, although additional studies are required to investigate the evolutionary potential of this climate change sensitive species. PMID:22720034

  16. Genetic evidence for restricted dispersal along continuous altitudinal gradients in a climate change-sensitive mammal: the American Pika.

    PubMed

    Henry, Philippe; Sim, Zijian; Russello, Michael A

    2012-01-01

    plasticity in order to survive predicted climate changes, although additional studies are required to investigate the evolutionary potential of this climate change sensitive species.

  17. Impact of variation in the BDNF gene on social stress sensitivity and the buffering impact of positive emotions: replication and extension of a gene-environment interaction.

    PubMed

    van Winkel, Mark; Peeters, Frenk; van Winkel, Ruud; Kenis, Gunter; Collip, Dina; Geschwind, Nicole; Jacobs, Nele; Derom, Catherine; Thiery, Evert; van Os, Jim; Myin-Germeys, Inez; Wichers, Marieke

    2014-06-01

    A previous study reported that social stress sensitivity is moderated by the brain-derived-neurotrophic-factor(Val66Met) (BDNF rs6265) genotype. Additionally, positive emotions partially neutralize this moderating effect. The current study aimed to: (i) replicate in a new independent sample of subjects with residual depressive symptoms the moderating effect of BDNF(Val66Met) genotype on social stress sensitivity, (ii) replicate the neutralizing impact of positive emotions, (iii) extend these analyses to other variations in the BDNF gene in the new independent sample and the original sample of non-depressed individuals. Previous findings were replicated in an experience sampling method (ESM) study. Negative Affect (NA) responses to social stress were stronger in "Val/Met" carriers of BDNF(Val66Met) compared to "Val/Val" carriers. Positive emotions neutralized the moderating effect of BDNF(Val66Met) genotype on social stress sensitivity in a dose-response fashion. Finally, two of four additional BDNF SNPs (rs11030101, rs2049046) showed similar moderating effects on social stress-sensitivity across both samples. The neutralizing effect of positive emotions on the moderating effects of these two additional SNPs was found in one sample. In conclusion, ESM has important advantages in gene-environment (GxE) research and may attribute to more consistent findings in future GxE research. This study shows how the impact of BDNF genetic variation on depressive symptoms may be explained by its impact on subtle daily life responses to social stress. Further, it shows that the generation of positive affect (PA) can buffer social stress sensitivity and partially undo the genetic susceptibility.

  18. Effectiveness of applying continuous positive airway pressure in a patient with paradoxical vocal fold movement after endotracheal extubation: a case report

    PubMed Central

    Song, Keu La Me; Ko, Dong Chan; Pin, Jung Woo; Ryu, Kyong Ho; Kim, Hyun Soo

    2016-01-01

    Paradoxical vocal fold movement (PVFM) is an uncommon upper airway disorder defined as paradoxical adduction of the vocal folds during inspiration. The etiology and treatment of PVFM are unclear. The physician should manage this condition because of the possibility of near complete airway obstruction in severe case of PVFM. We report a case of successful airway management in a patient with PVFM by applying continuous positive airway pressure (CPAP). In this case, PVFM was detected after removing an endotracheal tube from a 67-year-old male who underwent excision of a laryngeal mass. The patient recovered without complications in 1 day with support by CPAP. PMID:26885309

  19. Application of continuous normal-lognormal bivariate density functions in a sensitivity analysis of municipal solid waste landfill.

    PubMed

    Petrovic, Igor; Hip, Ivan; Fredlund, Murray D

    2016-09-01

    The variability of untreated municipal solid waste (MSW) shear strength parameters, namely cohesion and shear friction angle, with respect to waste stability problems, is of primary concern due to the strong heterogeneity of MSW. A large number of municipal solid waste (MSW) shear strength parameters (friction angle and cohesion) were collected from published literature and analyzed. The basic statistical analysis has shown that the central tendency of both shear strength parameters fits reasonably well within the ranges of recommended values proposed by different authors. In addition, it was established that the correlation between shear friction angle and cohesion is not strong but it still remained significant. Through use of a distribution fitting method it was found that the shear friction angle could be adjusted to a normal probability density function while cohesion follows the log-normal density function. The continuous normal-lognormal bivariate density function was therefore selected as an adequate model to ascertain rational boundary values ("confidence interval") for MSW shear strength parameters. It was concluded that a curve with a 70% confidence level generates a "confidence interval" within the reasonable limits. With respect to the decomposition stage of the waste material, three different ranges of appropriate shear strength parameters were indicated. Defined parameters were then used as input parameters for an Alternative Point Estimated Method (APEM) stability analysis on a real case scenario of the Jakusevec landfill. The Jakusevec landfill is the disposal site of the capital of Croatia - Zagreb. The analysis shows that in the case of a dry landfill the most significant factor influencing the safety factor was the shear friction angle of old, decomposed waste material, while in the case of a landfill with significant leachate level the most significant factor influencing the safety factor was the cohesion of old, decomposed waste material. The

  20. Application of continuous normal-lognormal bivariate density functions in a sensitivity analysis of municipal solid waste landfill.

    PubMed

    Petrovic, Igor; Hip, Ivan; Fredlund, Murray D

    2016-09-01

    The variability of untreated municipal solid waste (MSW) shear strength parameters, namely cohesion and shear friction angle, with respect to waste stability problems, is of primary concern due to the strong heterogeneity of MSW. A large number of municipal solid waste (MSW) shear strength parameters (friction angle and cohesion) were collected from published literature and analyzed. The basic statistical analysis has shown that the central tendency of both shear strength parameters fits reasonably well within the ranges of recommended values proposed by different authors. In addition, it was established that the correlation between shear friction angle and cohesion is not strong but it still remained significant. Through use of a distribution fitting method it was found that the shear friction angle could be adjusted to a normal probability density function while cohesion follows the log-normal density function. The continuous normal-lognormal bivariate density function was therefore selected as an adequate model to ascertain rational boundary values ("confidence interval") for MSW shear strength parameters. It was concluded that a curve with a 70% confidence level generates a "confidence interval" within the reasonable limits. With respect to the decomposition stage of the waste material, three different ranges of appropriate shear strength parameters were indicated. Defined parameters were then used as input parameters for an Alternative Point Estimated Method (APEM) stability analysis on a real case scenario of the Jakusevec landfill. The Jakusevec landfill is the disposal site of the capital of Croatia - Zagreb. The analysis shows that in the case of a dry landfill the most significant factor influencing the safety factor was the shear friction angle of old, decomposed waste material, while in the case of a landfill with significant leachate level the most significant factor influencing the safety factor was the cohesion of old, decomposed waste material. The

  1. Integration and evaluation of a position sensor with continuous read-out for use with the Environmental Measurement-While-Drilling Gamma Ray Spectrometer system

    SciTech Connect

    Normann, R.A.; Lockwood, G.J.; Williams, C.V.; Selph, M.M.

    1998-02-01

    The Environmental Measurement-While-Drilling-Gamma Ray Spectrometer (EMWD-GRS) system represents an innovative blend of new and existing technology that provides real-time environmental and drill bit data during drilling operations. The EMWD-GRS technology was demonstrated at Savannah River Site (SRS) F-Area Retention Basin. The EMWD-GRS technology demonstration consisted of continuously monitoring for gamma-radiation-producing contamination while drilling two horizontal boreholes below the backfilled waste retention basin. These boreholes passed near previously sampled locations where concentrations of contaminant levels of cesium had been measured. Contaminant levels continuously recorded by the EMWD-GRS system during drilling were compared to contaminant levels previously determined through quantitative laboratory analysis of soil samples. The results show general agreement between the soil sampling and EMWD-GRS techniques for Cs-137. The EMWD-GRS system has been improved by the integration of an orientation sensor package for position sensing (PS) (EMWD-GRS/PS). This added feature gives the capability of calculating position, which is tied directly to EMWD-GRS sensor data obtained while drilling. The EMWD-GRS/PS system is described and the results of the field tests are presented.

  2. Extraction of a series of novel damage sensitive features derived from the continuous wavelet transform of input and output acceleration measurements

    NASA Astrophysics Data System (ADS)

    Balafas, Konstantinos; Kiremidjian, Anne S.

    2014-03-01

    This paper proposes a series of novel Damage Sensitive Features for earthquake damage estimation. The features take into account input (ground motion) and output acceleration (structure response) measurements. The Continuous Wavelet Transform is applied to both acceleration signals in order to obtain both time domain and frequency domain resolution. An algorithm that has been proposed for Maximum Entropy Deconvolution is applied to the Continuous Wavelet Transforms in order to obtain a matrix that relates the output wavelet coefficients to the input ones. The Damage Sensitive Features are then derived through statistical processing of the resulting matrix. This algorithm has been applied on data acquired from shake table tests where the structures were subjected to progressive damage. The proposed features are compared to response quantities that are indicative of damage (such as the hysteretic energy dissipated) and show high correlation with the extent of damage. The data utilized has not been pre-processed, illustrating the robustness of the algorithm against sensor noise. The proposed algorithm has several advantages: Minimal input and knowledge of the structure is required. More information on the structure's state is extracted through use of both the input and output signals than when only output signal is considered. Only two acceleration measurements are required to obtain a damage forecast utilizing primarily the strong motion recordings, resulting in easier sensor deployment. The use of strong motion recordings allows for information delivery immediately after an earthquake without additional data collection.

  3. Stress sensitivity mediates the relationship between traumatic life events and attenuated positive psychotic symptoms differentially by gender in a college population sample.

    PubMed

    Gibson, Lauren E; Anglin, Deidre M; Klugman, Joshua T; Reeves, Lauren E; Fineberg, Anna M; Maxwell, Seth D; Kerns, Connor M; Ellman, Lauren M

    2014-06-01

    The purpose of this study was to investigate whether stress sensitivity mediates the relationship between traumatic life events and total attenuated positive psychotic symptoms, as well as the relationship between traumatic life events and endorsement of 8 or more attenuated positive psychotic symptoms as distressing (a threshold that has been associated with higher risk for psychosis in clinical groups). Participants (n = 671, aged 17-35, 29% male) were college students who were administered the Prodromal Questionnaire, the Perceived Stress Scale and the Life Events Checklist. Bootstrapping results indicated that stress sensitivity significantly mediated the relationships between traumatic life events and the number of attenuated positive psychotic symptoms endorsed and between traumatic life events and those who endorsed 8 or more distressing attenuated positive psychotic symptoms. Stratified gender analyses indicated the findings were specific to females. Results suggest that stress sensitivity may represent a specific vulnerability factor for risk of attenuated psychotic symptoms in those previously exposed to traumatic life events and that this liability appears stronger in females.

  4. Effects of Armodafinil on Simulated Driving and Self-Report Measures in Obstructive Sleep Apnea Patients prior to Treatment with Continuous Positive Airway Pressure

    PubMed Central

    Kay, Gary G.; Feldman, Neil

    2013-01-01

    Study Objectives: Obstructive sleep apnea (OSA) has been associated with an increased risk of motor vehicle crashes. This driving risk can be reduced (≥ 50%) by treatment with continuous positive airway pressure (CPAP). However residual excessive daytime sleepiness (EDS) can persist for some patients who regularly use CPAP. The current study was designed to assess the effect of armodafinil on simulated driving performance and subsequent CPAP treatment compliance in newly diagnosed OSA patients with EDS during a 2-week “waiting period” prior to initiation of CPAP. Methods: Sixty-nine newly diagnosed OSA patients, awaiting CPAP therapy, were randomized (1:1) to placebo or armodafinil (150 mg/day) treatment. Simulated driving tests and self-report measures were completed at baseline, after 2 weeks of drug treatment, and following 6 weeks of CPAP treatment. CPAP compliance was evaluated at the end of 6 weeks of CPAP. Results: Compared to placebo, armodafinil improved simulated driving safety performance in OSA patients awaiting CPAP therapy (p = 0.03). Improvement was seen in lane position deviation (p = 0.002) and number of lane excursions (p = 0.02). Improvement was also observed on measures of sleepiness using the Epworth Sleepiness Scale (ESS) and sleep related quality of life. Following 6 weeks of CPAP, there was also significant improvement observed on multiple measures of simulated driving performance. CPAP compliance did not differ between armodafinil-treated and placebo-treated patients (p = 0.80). Conclusions: Armodafinil was found to improve simulated driving performance in OSA patients with EDS prior to initiation of CPAP. Treatment with armodafinil showed no effect on subsequent CPAP compliance. Citation: Kay GG; Feldman N. Effects of armodafinil on simulated driving and self-report measures in obstructive sleep apnea patients prior to treatment with continuous positive airway pressure. J Clin Sleep Med 2013;9(5):445-454. PMID:23674935

  5. Positive but variable sensitivity of August surface ozone to large-scale warming in the southeast United States

    NASA Astrophysics Data System (ADS)

    Fu, Tzung-May; Zheng, Yiqi; Paulot, Fabien; Mao, Jingqiu; Yantosca, Robert M.

    2015-05-01

    Surface ozone, a major air pollutant toxic to humans and damaging to ecosystems, is produced by the oxidation of volatile organic compounds in the presence of nitrogen oxides (NOx = NO + NO2) and sunlight. Climate warming may affect future surface ozone levels even in the absence of anthropogenic emission changes, but the direction of ozone change due to climate warming remains uncertain over the southeast US and other polluted forested areas. Here we use observations and simulations to diagnose the sensitivity of August surface ozone to large-scale temperature variations in the southeast US during 1988-2011. We show that the enhanced biogenic emissions and the accelerated photochemical reaction rates associated with warmer temperatures both act to increase surface ozone. However, the sensitivity of surface ozone to large-scale warming is highly variable on interannual and interdecadal timescales owing to variation in regional ozone advection. Our results have important implications for the prediction and management of future ozone air quality.

  6. Evaluation of effect of continuous positive airway pressure during cardiopulmonary bypass on cardiac de-airing after open heart surgery in randomized clinical trial

    PubMed Central

    Mansour, Mojtaba; Massodnia, Nasim; Mirdehghan, Abolghasem; Bigdelian, Hamid; Massoumi, Gholamreza; Alavi, Zeinab Rafieipour

    2014-01-01

    Background: Cardiac and pulmonary veins de-airing are of the most important steps during open heart surgery. This study evaluates the effect of continuous positive airway pressure (CPAP) on air trapping in pulmonary veins and on quality of de-airing procedure. Materials and Methods: This randomized prospective double blind clinical trial conducted on 40 patients. In the control group: During cardiopulmonary bypass (CPB), the ventilator was turned off and adjustable pressure limit (APL) valve was placed in SPONT position. In CPAP group: During CPB, after turning the ventilator off, the flow of oxygen flow was maintained at the rate of 0.5 L/min and the APL valve was placed in MAN position on 20 mbar. During cardiopulmonary bypass (CPB) weaning, the patients were observed for air bubbles in left atrium by using transesophageal echocardiography. Results: The mean de-airing time after the start of mechanical ventilation in CPAP group (n = 20) was significantly lower than the control group (n = 20) (P = 0.0001). The mean time of the left atrium air bubbles occupation as mild (P = 0.004), moderate (P = 0.0001) and severe (P = 0.015) grading was significantly lower in CPAP group. Conclusions: By CPAP at 20 mbar during CPB in open heart surgery, de-airing process can be down in better quality and in significantly shorter time. PMID:24949307

  7. Integration and Evaluation of a Position Sensor with Continuous Read-Out for use with the Environmental Measurement-While-Drilling Gamma Ray Spectrometer System

    SciTech Connect

    Lockwood, G.J.; Normann, R.A.; Selph, M.M.; Williams, C.V.

    1999-02-22

    The Environmental Measurement-While-Drilling-Gamma Ray Spectrometer (EMWD-GRS) system represents an innovative blend of new and existing technology that provides real-time environmental and drill bit data during drilling operations. The EMWD-GRS technology was demonstrated at Savannah River Site (SRS) F-Area Retention Basin. The EMWD-GRS technology demonstration consisted of continuously monitoring for gamma-radiation-producing contamination while drilling two horizontal boreholes below the backfilled waste retention basin. These boreholes passed near previously sampled locations where concentrations of contaminant levels of cesium had been measured. Contaminant levels continuously recorded by the EMWD-GRS system during drilling were compared to contaminant levels previously determined through quantitative laboratory analysis of soil samples. The demonstration of the EMWD-GRS was a complete success. The results show general agreement between the soil sampling and EMWD-GRS techniques for CS-137. It was recognized that the EMWD-GRS tool would better satisfy our customers' needs if the instrument location could be continuously monitored. During the demonstration at SRS, an electromagnetic beacon with a walkover monitor (Subsite{reg_sign}) was used to measure bit location at depth. To use a beacon locator drilling must be stopped, thus it is normally only used when a new section of pipe was added. The location of contamination could only be estimated based on the position of the EMED-GRS package and the distance between locator beacon readings. A continuous location system that would allow us to know the location of each spectrum as it is obtained is needed.

  8. Effects of Detector Thickness on Geometric Sensitivity and Event Positioning Errors in the Rectangular PET/X Scanner

    PubMed Central

    MacDonald, Lawrence R.; Hunter, William C. J.; Kinahan, Paul E.; Miyaoka, Robert S.

    2015-01-01

    We used simulations to investigate the relationship between sensitivity and spatial resolution as a function of crystal thickness in a rectangular PET scanner intended for quantitative assessment of breast cancers. The system had two 20 × 15-cm2 and two 10 × 15-cm2 flat detectors forming a box, with the larger detectors separated by 4 or 8 cm. Depth-of-interaction (DOI) resolution was modeled as a function of crystal thickness based on prior measurements. Spatial resolution was evaluated independent of image reconstruction by deriving and validating a surrogate metric from list-mode data (dFWHM). When increasing crystal thickness from 5 to 40 mm, and without using DOI information, the dFWHM for a centered point source increased from 0.72 to 1.6 mm. Including DOI information improved dFWHM by 12% and 27% for 5- and 40-mm-thick crystals, respectively. For a point source in the corner of the FOV, use of DOI information improved dFWHM by 20% (5-mm crystal) and 44% (40-mm crystal). Sensitivity was 7.7% for 10-mm-thick crystals (8-cm object). Increasing crystal thickness on the smaller side detectors from 10 to 20 mm (keeping 10-mm crystals on the larger detectors) boosted sensitivity by 24% (relative) and degraded dFWHM by only ~3%/8% with/without DOI information. The benefits of measuring DOI must be evaluated in terms of the intended clinical task of assessing tracer uptake in small lesions. Increasing crystal thickness on the smaller side detectors provides substantial sensitivity increase with minimal accompanying loss in resolution. PMID:26160982

  9. Over-the-Counter Relief From Pains and Pleasures Alike: Acetaminophen Blunts Evaluation Sensitivity to Both Negative and Positive Stimuli.

    PubMed

    Durso, Geoffrey R O; Luttrell, Andrew; Way, Baldwin M

    2015-06-01

    Acetaminophen, an effective and popular over-the-counter pain reliever (e.g., the active ingredient in Tylenol), has recently been shown to blunt individuals' reactivity to a range of negative stimuli in addition to physical pain. Because accumulating research has shown that individuals' reactivity to both negative and positive stimuli can be influenced by a single factor (an idea known as differential susceptibility), we conducted two experiments testing whether acetaminophen blunted individuals' evaluations of and emotional reactions to both negative and positive images from the International Affective Picture System. Participants who took acetaminophen evaluated unpleasant stimuli less negatively and pleasant stimuli less positively, compared with participants who took a placebo. Participants in the acetaminophen condition also rated both negative and positive stimuli as less emotionally arousing than did participants in the placebo condition (Studies 1 and 2), whereas nonevaluative ratings (extent of color saturation in each image; Study 2) were not affected by drug condition. These findings suggest that acetaminophen has a general blunting effect on individuals' evaluative and emotional processing, irrespective of negative or positive valence. PMID:25862546

  10. Over-the-Counter Relief From Pains and Pleasures Alike: Acetaminophen Blunts Evaluation Sensitivity to Both Negative and Positive Stimuli

    PubMed Central

    Durso, Geoffrey R. O.; Luttrell, Andrew; Way, Baldwin M.

    2015-01-01

    Acetaminophen, an effective and popular over-the-counter pain reliever (e.g., the active ingredient in Tylenol), has recently been shown to blunt individuals’ reactivity to a range of negative stimuli in addition to physical pain. Because accumulating research has shown that individuals’ reactivity to both negative and positive stimuli can be influenced by a single factor (an idea known as differential susceptibility), we conducted two experiments testing whether acetaminophen blunted individuals’ evaluations of and emotional reactions to both negative and positive images from the International Affective Picture System. Participants who took acetaminophen evaluated unpleasant stimuli less negatively and pleasant stimuli less positively, compared with participants who took a placebo. Participants in the acetaminophen condition also rated both negative and positive stimuli as less emotionally arousing than did participants in the placebo condition (Studies 1 and 2), whereas nonevaluative ratings (extent of color saturation in each image; Study 2) were not affected by drug condition. These findings suggest that acetaminophen has a general blunting effect on individuals’ evaluative and emotional processing, irrespective of negative or positive valence. PMID:25862546

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

    PubMed

    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). PMID:17645997

  12. The Development of Sensitivity to Sublexical Orthographic Constraints: An Investigation of Positional Frequency and Consistency Using a Wordlikeness Choice Task

    ERIC Educational Resources Information Center

    O'Brien, Beth A.

    2014-01-01

    The developmental sequence of the types of orthographic knowledge that children acquire early in reading development is unclear. Following findings of skilled reading, the orthographic constraints of positional frequency and feedback consistency were explored with a wordlikeness judgement task for grades 1-3 English-speaking children. The data…

  13. Withdrawal of Continuous Positive Airway Pressure Therapy after Malar Advancement and Le Fort II Distraction in a Case of Apert Syndrome with Obstructive Sleep Apnea

    PubMed Central

    Onda, Nobuto; Chiba, Shintaro; Moriwaki, Hiroto; Sawai, Rika; Yoshigoe, Akira; Watanabe, Subaru; Ando, Yuji; Uchida, Ryo; Miyawaki, Takeshi; Wada, Kota

    2015-01-01

    Apert syndrome is a congenital syndrome characterized by craniosynostosis and craniofacial dysostosis, among other features, and is reported to cause obstructive sleep apnea (OSA) because of upper airway narrowing associated with midfacial dysplasia. We recently encountered a case involving a patient with Apert syndrome complicated by OSA who began to receive continuous positive airway pressure (CPAP) therapy at the age of 4. OSA resolved after maxillofacial surgery performed at the age of 11, and CPAP was eventually withdrawn. In pediatric patients with maxillofacial dysplasia complicated by OSA, a long-term treatment plan including CPAP in addition to maxillofacial plastic and reconstructive surgery should be considered in view of the effects of OSA on growth. PMID:26473084

  14. Does the use of primary continuous positive airway pressure reduce the need for intubation and mechanical ventilation in infants ≤32 weeks’ gestation?

    PubMed Central

    Yee, Wendy H; Scotland, Jeanne; Pham, Yung; Finch, Robert

    2011-01-01

    BACKGROUND: Ventilator-induced lung injury is a recognized risk factor for bronchopulmonary dysplasia. OBJECTIVE: To determine whether primary continuous positive airway pressure (CPAP), defined as CPAP without previous endotracheal intubation for any indication, can reduce the need for intubation and mechanical ventilation in infants born at ≤32 weeks’ gestational age. METHODS: The literature was reviewed using the methodology for systematic reviews for the Consensus on Resuscitation Science adapted from the American Heart Association’s International Liaison Committee on Resuscitation. RESULTS: Fourteen studies were reviewed. Eleven studies provided varying degrees of supportive evidence (level of evidence 3 to 4) that the use of primary CPAP can reduce the need for intubation and mechanical ventilation. CONCLUSION: The use of CPAP as a primary intervention and mode of respiratory support is an option for infants ≤32 weeks’ gestation, but avoidance of intubation and mechanical ventilation is more likely in mature infants >27 weeks’ gestation. PMID:23204903

  15. A Comparison of Different Success Definitions in Non-Continuous Positive Airway Pressure Treatment for Obstructive Sleep Apnea Using Cardiopulmonary Coupling

    PubMed Central

    Lee, Woo Hyun; Hong, Seung-No; Kim, Hong Joong; Rhee, Chae-Seo; Lee, Chul Hee; Yoon, In-Young; Kim, Jeong-Whun

    2016-01-01

    Study Objectives: The definition and the criteria for the successful treatment of obstructive sleep apnea vary, depending on the study. This study aimed to compare different success criteria of non-continuous positive airway pressure (non-CPAP) treatment for obstructive sleep apnea in terms of sleep quality by using cardiopulmonary coupling. Methods: We included 98 patients who had been treated with sleep surgery or with a mandibular advancement device at our sleep clinic from January 2011 to March 2013. The success and failure groups were divided by 6 criteria that have been used in the literature. The validity of each of the 6 criteria was evaluated by cardiopulmonary coupling-based sleep quality. Results: The parameters of cardiopulmonary coupling indicated that sleep quality improved with non-CPAP treatment: low-frequency coupling decreased from 57.4% ± 17.7% to 46.9% ± 16.5%, whereas high-frequency coupling increased from 30.2% ± 17.1% to 37.4% ± 16.7%. In multiple regression analysis, only the criterion of a reduction in the apnea-hypopnea index greater than 50% was significantly associated with sleep quality improvement (p = 0.016; 95% confidence interval, 1.008–1.076 in the high-frequency coupling increment; p = 0.001; 95% confidence interval, 1.025–1.099 in the low-frequency coupling decrement). Conclusions: Cardiopulmonary coupling analysis showed that a reduction in the apnea-hypopnea index of more than 50% might be the optimal criterion to determine the success or failure of non-CPAP treatment in terms of sleep quality. Citation: Lee WH, Hong SN, Kim HJ, Rhee CS, Lee CH, Yoon IY, Kim JW. A comparison of different success definitions in non-continuous positive airway pressure treatment for obstructive sleep apnea using cardiopulmonary coupling. J Clin Sleep Med 2016;12(1):35–41. PMID:26235153

  16. [Differences in antibiotic sensitivity in biofilm-positive and biofilm-negative strains of Staphylococcus epidermidis isolated from blood cultures].

    PubMed

    Holá, V; Růzicka, F; Votava, M

    2004-01-01

    The adhering capability and biofilm growth facilitate staphylococcal colonization of surfaces of damaged tissues and foreign bodies. Biofilm-forming bacteria are more resistant to immune system activities, mechanical effects of blood flow and other adverse effects, e.g. those due to antibiotics. Minimal inhibitory concentrations (MICs) were compared for two groups of Staphylococcus epidermidis strains isolated from blood cultures. Group 1 included biofilm positive strains whose biofilm-forming potential was revealed by both phenotypic and genotypic methods. Group 2 included strains without biofilm-forming potential. The comparison of MICs for selected antibiotics showed higher resistance of biofilm positive compared to biofilm negative strains. The difference was evident particularly for oxacillin, tetracycline, co-trimoxazole and gentamicin.

  17. IsoDOT Detects Differential RNA-isoform Expression/Usage with respect to a Categorical or Continuous Covariate with High Sensitivity and Specificity

    PubMed Central

    Sun, Wei; Liu, Yufeng; Crowley, James J.; Chen, Ting-Hued; Zhou, Hua; Chu, Haitao; Huang, Shunping; Kuan, Pei-Fen; Li, Yuan; Miller, Darla R.; Shaw, Ginger D.; Wu, Yichao; Zhabotynsky, Vasyl; McMillan, Leonard; Zou, Fei; Sullivan, Patrick F.; de Villena, Fernando Pardo-Manuel

    2015-01-01

    We have developed a statistical method named IsoDOT to assess differential isoform expression (DIE) and differential isoform usage (DIU) using RNA-seq data. Here isoform usage refers to relative isoform expression given the total expression of the corresponding gene. IsoDOT performs two tasks that cannot be accomplished by existing methods: to test DIE/DIU with respect to a continuous covariate, and to test DIE/DIU for one case versus one control. The latter task is not an uncommon situation in practice, e.g., comparing the paternal and maternal alleles of one individual or comparing tumor and normal samples of one cancer patient. Simulation studies demonstrate the high sensitivity and specificity of IsoDOT. We apply IsoDOT to study the effects of haloperidol treatment on the mouse transcriptome and identify a group of genes whose isoform usages respond to haloperidol treatment. PMID:26617424

  18. The effect of short-term withdrawal from continuous positive airway pressure therapy on sympathetic activity and markers of vascular inflammation in subjects with obstructive sleep apnoea.

    PubMed

    Phillips, Craig L; Yang, Qiao; Williams, Andrew; Roth, Michael; Yee, Brendon J; Hedner, Jan A; Berend, Norbert; Grunstein, Ronald R

    2007-06-01

    Obstructive sleep apnoea (OSA) is commonly associated with cardiovascular disease and sympathetic activation. However, it is unclear whether this association is independent of obesity and to what extent treatment with nasal continuous positive airway pressure (CPAP) alleviates the vascular inflammation that underpins cardiovascular disease. We therefore evaluated whether short-term withdrawal from CPAP therapy in subjects with moderate-severe OSA would result in increased levels of sympathetic activity and circulating inflammatory cytokines independent of weight. Vascular inflammatory markers (hsCRP, hsIL-6 and hsTNF-alpha) were assessed in 20 subjects after one and seven nights of withdrawal from CPAP together with the hypoxia-responsive angiogenic marker VEGF and urinary catecholamines. Compared with baseline on CPAP, withdrawal from therapy resulted in an immediate return of OSA with an increase in RDI to 26.7 +/- 5.2 and 39.0 +/- 5.9 events per hour after one and seven nights without CPAP, respectively (both P < 0.0001). This was accompanied by a concomitant rise in daytime urinary noradrenaline (P < 0.0001) after seven nights CPAP withdrawal that was positively associated with the severity of hypoxaemia. In contrast, withdrawal from CPAP therapy was not accompanied by any change in measured cytokines or VEGF (all P > 0.1). In conclusion, 1 week of CPAP withdrawal was associated with a return of OSA and a marked increase in sympathetic activity without a concomitant elevation of vascular inflammatory markers.

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

    SciTech Connect

    Lupone, S.; Damoy, S.; Husseen, A.; Briand, N.; Debiossac, M.; Tall, S.; Roncin, P.

    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.

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

    PubMed

    Shi, Haitao; Chen, Yinhua; Qian, Yongqiang; Chan, Zhulong

    2015-01-01

    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. PMID:26539205

  1. Sensitivity of Fermi level position at Ga-polar, N-polar, and nonpolar m-plane GaN surfaces to vacuum and air ambient

    NASA Astrophysics Data System (ADS)

    Janicki, Łukasz; Ramírez-López, Manolo; Misiewicz, Jan; Cywiński, Grzegorz; Boćkowski, Michał; Muzioł, Grzegorz; Chèze, Caroline; Sawicka, Marta; Skierbiszewski, Czesław; Kudrawiec, Robert

    2016-05-01

    Ga-polar, N-polar, and nonpolar m-plane GaN UN+ structures have been examined in air and vacuum ambient by contactless electroreflectance (CER). This technique is very sensitive to the surface electric field that varies with the Fermi level position at the surface. For UN+ GaN structures [i.e., GaN (undoped)/GaN (n-type)/substrate], a homogeneous built-in electric field is expected in the undoped GaN layer that is manifested by Franz-Keldysh oscillation (FKO) in CER spectra. A clear change in FKO has been observed in CER spectra for N-polar and nonpolar m-plane structures when changing from air to vacuum ambient. This means that those surfaces are very sensitive to ambient atmosphere. In contrast to that, only a small change in FKO can be seen in the Ga-polar structure. This clearly shows that the ambient sensitivity of the Fermi level position at the GaN surface varies with the crystallographic orientation and is very high for N-polar and nonpolar m-plane surfaces. This feature of the N-polar and nonpolar m-plane surfaces can be very important for GaN-based devices grown on these crystallographic orientations and can be utilized in some of the devices, e.g., sensors.

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

    PubMed

    Shi, Haitao; Chen, Yinhua; Qian, Yongqiang; Chan, Zhulong

    2015-01-01

    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.

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

    PubMed Central

    Shi, Haitao; Chen, Yinhua; Qian, Yongqiang; Chan, Zhulong

    2015-01-01

    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. PMID:26539205

  4. Sensitivity analysis of the position of the intervertebral centres of reaction in upright standing--a musculoskeletal model investigation of the lumbar spine.

    PubMed

    Zander, Thomas; Dreischarf, Marcel; Schmidt, Hendrik

    2016-03-01

    The loads between adjacent vertebrae can be generalised as a single spatial force acting at the intervertebral centre of reaction. The exact position in vivo is unknown. However, in rigid body musculoskeletal models that simulate upright standing, the position is generally assumed to be located at the discs' centres of rotation. The influence of the antero-posterior position of the centre of reaction on muscle activity and joint loads remains unknown. Thus, by using an inverse dynamic model, we varied the position of the centre of reaction at L4/L5 (i), simultaneously at all lumbar levels (ii), and by optimisation at all lumbar levels (iii). Variation of the centres of reaction can considerably influence the activities of lumbar muscles and the joint forces between vertebrae. The optimisation of the position of the centre of reaction reduced the maximum lumbar muscle activity and axial joint forces at L4/L5 from 17.5% to 1.5% of the muscle strength and from 490 N to 390 N, respectively. Thus, when studying individual postures, such as for therapeutic or preventive evaluations, potential differences between the centre of reaction and the centre of rotation might influence the study results. These differences could be taken into account by sensitivity analyses.

  5. Pressure-Relief Features of Fixed and Autotitrating Continuous Positive Airway Pressure May Impair Their Efficacy: Evaluation with a Respiratory Bench Model

    PubMed Central

    Zhu, Kaixian; Aouf, Sami; Roisman, Gabriel; Escourrou, Pierre

    2016-01-01

    Study Objectives: Pressure-relief features are aimed at improving the patient's comfort during continuous positive airway pressure (CPAP) treatment for obstructive sleep apnea. The objective of this study was to determine the effect of these therapy features on fixed CPAP and autotitrating CPAP (APAP) treatment efficacy. Methods: Seven pressure-relief features applied by three CPAP devices were included in our study (Remstar Auto: C-Flex 3, C-Flex+ 3, A-Flex 3, P-Flex; AirSense 10: EPR 3; Prisma 20A: SoftPAP 2 and 3). In fixed CPAP, the devices were subjected to a 10-min bench-simulated obstructive apnea sequence (initial apnea-hypopnea index, AHI = 60/h) with and without pressure-relief features. In APAP, the sequence was lengthened to 4.2 h (initial AHI = 58.6/h). The residual AHI and mean/median pressure were compared with and without pressure-relief features. Results: Compared to conventional CPAP, where pressure was adjusted to be just sufficient to control the simulated obstructive events, C-Flex+ 3, P-Flex, and EPR 3 failed to normalize the breathing flow and did not reduce the AHI. The mean pressures with the three features, respectively, were 1.8, 2.6, and 2.6 cmH2O lower than the conventional CPAP. Compared to conventional APAP, similar levels of control were observed with pressure-relief features, apart from P-Flex where the delivered mean pressure was lower and residual AHI greater. The device-reported mean/median pressures in APAP with A-Flex 3, P-Flex, EPR 3, and SoftPAP 3 were higher than that measured on the bench. Conclusions: Pressure-relief features may attenuate CPAP efficacy if not adjusted for at the time of their introduction. In clinical practice, efficacy can be ensured by increasing the therapeutic pressure delivered by fixed CPAP or by enabling the pressure-relief features prior to initial pressure titration. Device-reported pressures in APAP devices with pressure relief activated may overstate delivered pressures. Citation: Zhu K, Aouf S

  6. The Effect of Nasal Surgery on Continuous Positive Airway Pressure Device Use and Therapeutic Treatment Pressures: A Systematic Review and Meta-Analysis

    PubMed Central

    Camacho, Macario; Riaz, Muhammad; Capasso, Robson; Ruoff, Chad M.; Guilleminault, Christian; Kushida, Clete A.; Certal, Victor

    2015-01-01

    Background: The relationship between nasal surgery and its effect on continuous positive airway pressure (CPAP) device therapeutic treatment pressures and CPAP device use has not been previously systematically examined. Study Objectives: To conduct a systematic review and meta-analysis evaluating the effect of isolated nasal surgery on therapeutic CPAP device pressures and use in adults with obstructive sleep apnea. Methods: MEDLINE, Scopus, Web of Science, and The Cochrane Library were searched through July 15, 2014. The MOOSE consensus statement and PRISMA statement were followed. Results: Eighteen studies (279 patients) reported CPAP data after isolated nasal surgery. Seven studies (82 patients) reported preoperative and postoperative mean therapeutic CPAP device pressures and standard deviations, which reduced from 11.6 ± 2.2 to 9.5 ± 2.0 centimeters of water pressure (cwp) after nasal surgery. Pooled random effects analysis demonstrated a statistically significant pressure reduction, with a mean difference of −2.66 cwp (95% confidence intervals, −3.65 to −1.67); P < 0.00001. Eleven studies (153 patients) described subjective, self-reported data for CPAP use; and a subgroup analysis demonstrated that 89.1% (57 of 64 patients) who were not using CPAP prior to nasal surgery subsequently accepted, adhered to, or tolerated it after nasal surgery. Objective, device meter-based hours of use increased in 33 patients from 3.0 ± 3.1 to 5.5 ± 2.0 h in the short term (< 6 mo of follow-up). Conclusion: Isolated nasal surgery in patients with obstructive sleep apnea and nasal obstruction reduces therapeutic CPAP device pressures and the currently published literature's objective and subjective data consistently suggest that it also increases CPAP use in select patients. Citation: Camacho M, Riaz M, Capasso R, Ruoff CM, Guilleminault C, Kushida CA, Certal V. The effect of nasal surgery on continuous positive airway pressure device use and therapeutic treatment

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

    PubMed Central

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

    2015-01-01

    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/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. PMID:26655816

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

    PubMed Central

    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

  9. Sensitive detection of miRNA by using hybridization chain reaction coupled with positively charged gold nanoparticles.

    PubMed

    Miao, Xiangmin; Ning, Xue; Li, Zongbing; Cheng, Zhiyuan

    2016-01-01

    Positively charged gold nanoparticles (+)AuNPs can adsorb onto the negatively charged surface of single-stranded DNA (ssDNA) or double-stranded DNA (dsDNA). Herein, long-range dsDNA polymers could form based on the hybridization chain reaction (HCR) of two hairpin probes (H1 and H2) by using miRNA-21 as an initiator. (+)AuNPs could adsorb onto the negatively charged surface of such long-range dsDNA polymers based on the electrostatic adsorption, which directly resulted in the precipitation of (+)AuNPs and the decrease of (+)AuNPs absorption spectra. Under optimal conditions, miRNA-21 detection could be realized in the range of 20 pM-10 nM with a detection limit of 6.8 pM. In addition, (+)AuNPs used here are much more stable than commonly used negatively charged gold nanoparticles ((-)AuNPs) in mixed solution that contained salt, protein or other metal ions. Importantly, the assay could realize the detection of miRNA in human serum samples. PMID:27576601

  10. Sensitive detection of miRNA by using hybridization chain reaction coupled with positively charged gold nanoparticles

    PubMed Central

    Miao, Xiangmin; Ning, Xue; Li, Zongbing; Cheng, Zhiyuan

    2016-01-01

    Positively charged gold nanoparticles (+)AuNPs can adsorb onto the negatively charged surface of single-stranded DNA (ssDNA) or double-stranded DNA (dsDNA). Herein, long-range dsDNA polymers could form based on the hybridization chain reaction (HCR) of two hairpin probes (H1 and H2) by using miRNA-21 as an initiator. (+)AuNPs could adsorb onto the negatively charged surface of such long-range dsDNA polymers based on the electrostatic adsorption, which directly resulted in the precipitation of (+)AuNPs and the decrease of (+)AuNPs absorption spectra. Under optimal conditions, miRNA-21 detection could be realized in the range of 20 pM-10 nM with a detection limit of 6.8 pM. In addition, (+)AuNPs used here are much more stable than commonly used negatively charged gold nanoparticles ((−)AuNPs) in mixed solution that contained salt, protein or other metal ions. Importantly, the assay could realize the detection of miRNA in human serum samples. PMID:27576601

  11. The anti-malarial chloroquine overcomes primary resistance and restores sensitivity to trastuzumab in HER2-positive breast cancer.

    PubMed

    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

  12. Effectiveness of flow inflating device in providing Continuous Positive Airway Pressure for critically ill children in limited-resource settings: A prospective observational study

    PubMed Central

    Anitha, G. Fatima Shirly; Velmurugan, Lakshmi; Sangareddi, Shanthi; Nedunchelian, Krishnamurthy; Selvaraj, Vinoth

    2016-01-01

    Background and Aims: Noninvasive ventilation (NIV) is an emerging popular concept, which includes bi-level positive airway pressure or continuous positive airway pressure (CPAP). In settings with scarce resources for NIV machines, CPAP can be provided through various indigenous means and one such mode is flow inflating device - Jackson-Rees circuit (JR)/Bain circuit. The study analyses the epidemiology, various clinical indications, predictors of CPAP failure, and stresses the usefulness of flow inflating device as an indigenous way of providing CPAP. Methods: A prospective observational study was undertaken in the critical care unit of a Government Tertiary Care Hospital, from November 2013 to September 2014. All children who required CPAP in the age group 1 month to 12 years of both sexes were included in this study. They were started on indigenous CPAP through flow inflating device on clinical grounds based on the pediatric assessment triangle, and the duration and outcome were analyzed. Results: This study population included 214 children. CPAP through flow inflating device was successful in 89.7% of cases, of which bronchiolitis accounted for 98.3%. A prolonged duration of CPAP support of >96 h was required in pneumonia. CPAP failure was noted in 10.3% of cases, the major risk factors being children <1 year and pneumonia with septic shock. Conclusion: We conclude that flow inflating devices - JR/Bain circuit are effective as an indigenous CPAP in limited resource settings. Despite its benefits, CPAP is not a substitute for invasive ventilation, as when the need for intubation arises timely intervention is needed.

  13. Effectiveness of flow inflating device in providing Continuous Positive Airway Pressure for critically ill children in limited-resource settings: A prospective observational study

    PubMed Central

    Anitha, G. Fatima Shirly; Velmurugan, Lakshmi; Sangareddi, Shanthi; Nedunchelian, Krishnamurthy; Selvaraj, Vinoth

    2016-01-01

    Background and Aims: Noninvasive ventilation (NIV) is an emerging popular concept, which includes bi-level positive airway pressure or continuous positive airway pressure (CPAP). In settings with scarce resources for NIV machines, CPAP can be provided through various indigenous means and one such mode is flow inflating device - Jackson-Rees circuit (JR)/Bain circuit. The study analyses the epidemiology, various clinical indications, predictors of CPAP failure, and stresses the usefulness of flow inflating device as an indigenous way of providing CPAP. Methods: A prospective observational study was undertaken in the critical care unit of a Government Tertiary Care Hospital, from November 2013 to September 2014. All children who required CPAP in the age group 1 month to 12 years of both sexes were included in this study. They were started on indigenous CPAP through flow inflating device on clinical grounds based on the pediatric assessment triangle, and the duration and outcome were analyzed. Results: This study population included 214 children. CPAP through flow inflating device was successful in 89.7% of cases, of which bronchiolitis accounted for 98.3%. A prolonged duration of CPAP support of >96 h was required in pneumonia. CPAP failure was noted in 10.3% of cases, the major risk factors being children <1 year and pneumonia with septic shock. Conclusion: We conclude that flow inflating devices - JR/Bain circuit are effective as an indigenous CPAP in limited resource settings. Despite its benefits, CPAP is not a substitute for invasive ventilation, as when the need for intubation arises timely intervention is needed. PMID:27630454

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

    SciTech Connect

    Liu, Juntao; Mao, Zhangfan; Huang, Jie; Xie, Songping; Liu, Tianshu; Mao, Zhifu

    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

  15. Improved sensitivity by use of gas chromatography-positive chemical ionization triple quadrupole mass spectrometry for the analysis of drug related substances.

    PubMed

    Van Gansbeke, Wim; Polet, Michael; Hooghe, Fiona; Devos, Christophe; Van Eenoo, Peter

    2015-09-15

    In 2013, the World Anti-Doping Agency (WADA) drastically lowered the minimum required performance levels (MRPLs) of most doping substances, demanding a substantial increase in sensitivity of the existing methods. For a number of compounds, conventional electron impact ionization gas chromatography tandem mass spectrometry (GC-EI-MS/MS) is often no longer sufficient to reach these MRPLs and new strategies are required. In this study, the capabilities of positive ion chemical ionization (PICI) GC-MS/MS are investigated for a wide range of drug related compounds of various classes by injection of silylated reference standards. Ammonia as PICI reagent gas had superior characteristics for GC-MS/MS purposes than methane. Compared to GC-EI-MS/MS, PICI (with ammonia as reagent gas) provided more selective ion transitions and consequently, increased sensitivity by an average factor of 50. The maximum increase (by factor of 500-1000) was observed in the analysis of stimulants, namely chlorprenaline, furfenorex and phentermine. In total, improved sensitivity was obtained for 113 out of 120 compounds. A new GC-PICI-MS/MS method has been developed and evaluated for the detection of a wide variety of exogenous doping substances and the quantification of endogenous steroids in urine in compliance with the required MRPLs established by WADA in 2013. The method consists of a hydrolysis and extraction step, followed by derivatization and subsequent 1μL pulsed splitless injection on GC-PICI-MS/MS (16min run). The increased sensitivity allows the set up of a balanced screening method that meets the requirements for both quantitative and qualitative compounds: sufficient capacity and resolution in combination with high sensitivity and short analysis time. This resulted in calibration curves with a wide linear range (e.g., 48-9600ng/mL for androsterone and etiochanolone; all r(2)>0.99) without compromising the requirements for the qualitative compounds.

  16. Improved sensitivity by use of gas chromatography-positive chemical ionization triple quadrupole mass spectrometry for the analysis of drug related substances.

    PubMed

    Van Gansbeke, Wim; Polet, Michael; Hooghe, Fiona; Devos, Christophe; Van Eenoo, Peter

    2015-09-15

    In 2013, the World Anti-Doping Agency (WADA) drastically lowered the minimum required performance levels (MRPLs) of most doping substances, demanding a substantial increase in sensitivity of the existing methods. For a number of compounds, conventional electron impact ionization gas chromatography tandem mass spectrometry (GC-EI-MS/MS) is often no longer sufficient to reach these MRPLs and new strategies are required. In this study, the capabilities of positive ion chemical ionization (PICI) GC-MS/MS are investigated for a wide range of drug related compounds of various classes by injection of silylated reference standards. Ammonia as PICI reagent gas had superior characteristics for GC-MS/MS purposes than methane. Compared to GC-EI-MS/MS, PICI (with ammonia as reagent gas) provided more selective ion transitions and consequently, increased sensitivity by an average factor of 50. The maximum increase (by factor of 500-1000) was observed in the analysis of stimulants, namely chlorprenaline, furfenorex and phentermine. In total, improved sensitivity was obtained for 113 out of 120 compounds. A new GC-PICI-MS/MS method has been developed and evaluated for the detection of a wide variety of exogenous doping substances and the quantification of endogenous steroids in urine in compliance with the required MRPLs established by WADA in 2013. The method consists of a hydrolysis and extraction step, followed by derivatization and subsequent 1μL pulsed splitless injection on GC-PICI-MS/MS (16min run). The increased sensitivity allows the set up of a balanced screening method that meets the requirements for both quantitative and qualitative compounds: sufficient capacity and resolution in combination with high sensitivity and short analysis time. This resulted in calibration curves with a wide linear range (e.g., 48-9600ng/mL for androsterone and etiochanolone; all r(2)>0.99) without compromising the requirements for the qualitative compounds. PMID:26296082

  17. Industry leading satellite based GNSS (Global Navigation Satellite System) positioning and monitoring solutions with real-time CORS (Continuously Operating Reference Station) networks

    NASA Astrophysics Data System (ADS)

    Janousek, Martin

    2010-05-01

    Real-Time CORS (Continuously Operating Reference Station Networks) today are typically GNSS networks for positioning and monitoring purposes. Real-Time networks can consist of a few stations for a local network up to nation- or continental wide networks with several hundred CORS stations. Such networks use wide area modeling of GNSS error sources including ionospheric, tropospheric and satellite orbit correction parameters to produce highest precision and efficiency method of positioning using GNSS. In 1998 Trimble Navigation Ltd. introduced a method of surveying with a non-physical or computed base station, called VRS (Virtual Reference Station). It is the most widely supported method of producing a network solution for precise carrier phase positioning in the industry. Surveying historically required one base as the fixed point of reference, and one or multiple rovers using that point of reference to compute their location by processing a vector result, either in real-time or in a postprocessed sense. Real-time survey is often referred to as RTK, short for real-time kinematic, and as the name suggests the results are in real time and you can move. The power of VRS is in the ability to compute a real-time wide-area solution to the factors that cause single base methods to degrade with distance. Namely, ionospheric and tropospheric modeling, and satellite orbit corrections. This is achieved by the reference network of CORS. A wide scattering of CORS across a state, typically 50-70km in mid-latitudes, creates a ground based sampling which significantly reduces the distance dependent errors that accumulate in the single base-rover relationship described early. Furthermore, GNSS networks can be used for real-time monitoring purposes at various distance range. Trimble Integrity Manager software provides a suite of motion engines designed to detect and quantify any movement in a range of scales from slow, creeping movement like subsidence, through sudden events such as

  18. Impact of obstructive sleep apnea treatment by continuous positive airway pressure on cardiometabolic biomarkers: a systematic review from sham CPAP randomized controlled trials.

    PubMed

    Jullian-Desayes, Ingrid; Joyeux-Faure, Marie; Tamisier, Renaud; Launois, Sandrine; Borel, Anne-Laure; Levy, Patrick; Pepin, Jean-Louis

    2015-06-01

    Reducing cardiometabolic risk may represent an important target for effective obstructive sleep apnea (OSA) treatment. The impact of continuous positive airway pressure (CPAP), the first line therapy of OSA, on metabolic or inflammatory markers is still debated. A systematic literature search using several databases was performed. We provide a systematic analysis of randomized studies comparing therapeutic versus sham CPAP intervention and also include studies using a CPAP withdrawal design. We addressed the impact of CPAP on the following cardiometabolic biomarkers: 1) plasma and urine catecholamines and their metabolites that reflect sympathetic activity; 2) insulin resistance and lipid metabolism biomarkers; 3) oxidative stress, systemic and vascular inflammation biomarkers; 4) liver enzymes highlighting the association between OSA and nonalcoholic fatty liver disease (NAFLD); 5) coagulation biomarkers. The impact of CPAP on sympathetic activity is robust across studies and occurs rapidly. In contrast to sympathetic activity, the well-designed studies included in this review failed to demonstrate that CPAP alters metabolic or inflammatory markers in OSA. CPAP did not change glucose, lipids, insulin resistance levels or the ratio of patients with metabolic syndrome. In unselected OSA patients, it is not realistic to expect a clinically relevant decrease in cardiometabolic biomarkers with CPAP therapy.

  19. Effect of chronic continuous positive airway pressure (CPAP) therapy on upper airway size in patients with sleep apnoea/hypopnoea syndrome.

    PubMed Central

    Mortimore, I. L.; Kochhar, P.; Douglas, N. J.

    1996-01-01

    BACKGROUND: There is evidence to suggest that chronic continuous positive airway pressure (CPAP) therapy may produce reversible changes in upper airway morphology and function in patients with sleep apnoea/hypopnoea. This study was designed to examine the effect of chronic CPAP therapy on upper airway calibre. METHODS: Twenty four men with the sleep apnoea/hypopnoea syndrome (mean (SE) apnoea/hypopnoea index 37 (5)) underwent lateral cephalometry with measurement of posterior airway space performed before and at least three months after initiation of CPAP therapy. RESULTS: There was no weight change between the two assessments and mean CPAP use was 4.8 (0.4) hours per night. Posterior airway space (PAS) was measured in erect and supine postures. PAS supine increased with CPAP therapy from a mean (SE) of 11.8 (0.8) mm to 13.4 (0.8) mm, but PAS erect did not. Correlation of the change in PAS (dPAS) before and after CPAP therapy showed an increase with increasing CPAP compliance measured as machine run time both for dPAS supine (r = 0.68) and dPAS erect (r = 0.47). CONCLUSIONS: Patients with the sleep apnoea/hypopnoea syndrome regularly using CPAP for more than four hours per night all showed an increase in dPAS supine. The use of chronic CPAP increases PAS supine probably by a reduction in upper airway oedema, and the change in size is dependent on CPAP use. PMID:8711654

  20. A High-Value, Low-Cost Bubble Continuous Positive Airway Pressure System for Low-Resource Settings: Technical Assessment and Initial Case Reports

    PubMed Central

    Brown, Jocelyn; Machen, Heather; Kawaza, Kondwani; Mwanza, Zondiwe; Iniguez, Suzanne; Lang, Hans; Gest, Alfred; Kennedy, Neil; Miros, Robert; Richards-Kortum, Rebecca; Molyneux, Elizabeth; Oden, Maria

    2013-01-01

    Acute respiratory infections are the leading cause of global child mortality. In the developing world, nasal oxygen therapy is often the only treatment option for babies who are suffering from respiratory distress. Without the added pressure of bubble Continuous Positive Airway Pressure (bCPAP) which helps maintain alveoli open, babies struggle to breathe and can suffer serious complications, and frequently death. A stand-alone bCPAP device can cost $6,000, too expensive for most developing world hospitals. Here, we describe the design and technical evaluation of a new, rugged bCPAP system that can be made in small volume for a cost-of-goods of approximately $350. Moreover, because of its simple design—consumer-grade pumps, medical tubing, and regulators—it requires only the simple replacement of a <$1 diaphragm approximately every 2 years for maintenance. The low-cost bCPAP device delivers pressure and flow equivalent to those of a reference bCPAP system used in the developed world. We describe the initial clinical cases of a child with bronchiolitis and a neonate with respiratory distress who were treated successfully with the new bCPAP device. PMID:23372661

  1. Nurse-led intensive interventions improve adherence to continuous positive airway pressure therapy and quality of life in obstructive sleep apnea patients

    PubMed Central

    Chen, Xiaofen; Chen, Weiting; Hu, Weijie; Huang, Kui; Huang, Jing; Zhou, Yu

    2015-01-01

    Background Continuous positive airway pressure (CPAP) is widely recommended for the treatment of sleep apnea/hypopnea syndrome (SAHS), but its usage by patients is very low. The aim of this study was to assess intensive educational programs and nursing support for the improvement of CPAP use and outcomes in SAHS patients. Methods Eighty new SAHS patients were randomized to receive nurse-led intensive interventions or usual support at hospital and home. The main outcome measure was CPAP use; changes in sleeping, symptoms, mood, and quality of life were also assessed after 12 months of treatment. Results All outcome measures were improved after treatment in both groups. However, patients receiving intensive support with significantly higher CPAP use (higher daily CPAP usage by 2.2 hours/day) had greater improvements in SAHS symptoms and mood (P<0.05). The intervention group further showed an improvement in the Short Form-36 domains of mental and physical health (P<0.05). Conclusion The CPAP usage and quality of life can be significantly improved by nurse-led intensive program in obstructive sleep apnea patients. PMID:26648703

  2. Cheyne-Stokes respiration in congestive heart failure: continuous positive airway pressure of 5-8 cm H2O for 1 year in five cases.

    PubMed

    Yasuma, Fumihiko

    2005-01-01

    Five adult patients with congestive heart failure (CHF) due to dilated cardiomyopathy complicated by Cheyne-Stokes respiration/central sleep apnea (CSR/CSA) were treated with continuous positive airway pressure (CPAP) with an initial pressure of 5 cm H2O. Four patients were followed up for 12 months with CPAP of 5 cm H2O. The rest, a 93-year-old patient, was followed up for 30 months, and the CPAP was reset at 8 cm H2O due to worsened cardiac function after 6 months and it was reset at 6 cm H2O due to dryness of the nose after 23 months. For all the patients with nightly CPAP use for 6.0+/-1.4 h per day for a year, frequency of CSR/CSA was significantly reduced after 3 and 12 months with CPAP (p<0.05). Moreover, their symptoms, cardiac function and sleep quality were significantly improved after 3 months (p<0.05), and were maintained above the pre-CPAP levels after 12 months, except for the oldest patient whose cardiac function tended to deteriorate. The results suggest that CSR/CSA in CHF can be treated with CPAP set at a lower pressure than the conventional method, and that CPAP at 5-8 cm H2O is often effective in eliminating CSR/CSA, improving sleep quality, and presumably maintaining cardiac function.

  3. Early versus delayed initiation of nasal continuous positive airway pressure for treatment of respiratory distress syndrome in premature newborns: A randomized clinical trial

    PubMed Central

    Badiee, Zohreh; Naseri, Fatemeh; Sadeghnia, Alireza

    2013-01-01

    Background: This prospective study was performed to identify whether the early use of nasal continuous positive airway pressure (n CPAP) would reduce the rate of endotracheal intubation, mechanical ventilation and surfactant administration. Materials and Methods: This study was conducted from June 2009 to September 2010 in the Shahid Beheshti University Hospital, Isfahan-Iran. A total of 72 preterm infants with 25-30 weeks gestation who needed respiratory support at 5 min after birth entered the study. Infants were randomly assigned to the very early CPAP (initiated 5 min after birth) or to the late CPAP (initiated 30 min after birth) treatment groups. The primary outcomes were need for intubation and mechanical ventilation during the first 48 h after birth and secondary outcomes were death, pneumothorax, intraventricular hemorrhage, duration of mechanical ventilation and bronchopulmonary dysplasia. Results: There were no significant differences between the two groups with regard to mortality rate, bronchopulmonary dysplasia and patent ductus arteriosus. The need for surfactant administration was significantly reduced in the early CPAP group (P = 0.04). Infants in the early CPAP group less frequently required intubation and mechanical ventilation. Conclusions: Early n CPAP is more effective than late n CPAP for the treatment of respiratory distress syndrome. In addition, the early use of n CPAP would reduce the need for some invasive procedures such as intubation and mechanical ventilation. PMID:23930249

  4. Impact of the type of mask on the effectiveness of and adherence to continuous positive airway pressure treatment for obstructive sleep apnea*

    PubMed Central

    de Andrade, Rafaela Garcia Santos; Piccin, Vivien Schmeling; Nascimento, Juliana Araújo; Viana, Fernanda Madeiro Leite; Genta, Pedro Rodrigues; Lorenzi-Filho, Geraldo

    2014-01-01

    Continuous positive airway pressure (CPAP) is the gold standard for the treatment of obstructive sleep apnea (OSA). Although CPAP was originally applied with a nasal mask, various interfaces are currently available. This study reviews theoretical concepts and questions the premise that all types of interfaces produce similar results. We revised the evidence in the literature about the impact that the type of CPAP interface has on the effectiveness of and adherence to OSA treatment. We searched the PubMed database using the search terms "CPAP", "mask", and "obstructive sleep apnea". Although we identified 91 studies, only 12 described the impact of the type of CPAP interface on treatment effectiveness (n = 6) or adherence (n = 6). Despite conflicting results, we found no consistent evidence that nasal pillows and oral masks alter OSA treatment effectiveness or adherence. In contrast, most studies showed that oronasal masks are less effective and are more often associated with lower adherence and higher CPAP abandonment than are nasal masks. We concluded that oronasal masks can compromise CPAP OSA treatment adherence and effectiveness. Further studies are needed in order to understand the exact mechanisms involved in this effect. PMID:25610507

  5. Practice Parameters for the Use of Autotitrating Continuous Positive Airway Pressure Devices for Titrating Pressures and Treating Adult Patients with Obstructive Sleep Apnea Syndrome: An Update for 2007

    PubMed Central

    Morgenthaler, Timothy I.; Aurora, R. Nisha; Brown, Terry; Zak, Rochelle; Alessi, Cathy; Boehlecke, Brian; Chesson, Andrew L.; Friedman, Leah; Kapur, Vishesh; Maganti, Rama; Owens, Judith; Pancer, Jeffrey; Swick, Todd J.

    2008-01-01

    These practice parameters are an update of the previously published recommendations regarding the use of autotitrating positive airway pressure (APAP) devices for titrating pressures and treating adult patients with obstructive sleep apnea syndrome. Continuous positive airway pressure (CPAP) at an effective setting verified by attended polysomnography is a standard treatment for obstructive sleep apnea (OSA). APAP devices change the treatment pressure based on feedback from various patient measures such as airflow, pressure fluctuations, or measures of airway resistance. These devices may aid in the pressure titration process, address possible changes in pressure requirements throughout a given night and from night to night, aid in treatment of OSA when attended CPAP titration has not or cannot be accomplished, or improve patient comfort. A task force of the Standards of Practice Committee of the American Academy of Sleep Medicine has reviewed the literature published since the 2002 practice parameter on the use of APAP. Current recommendations follow: (1) APAP devices are not recommended to diagnose OSA; (2) patients with congestive heart failure, patients with significant lung disease such as chronic obstructive pulmonary disease; patients expected to have nocturnal arterial oxyhemoglobin desaturation due to conditions other than OSA (e.g., obesity hypoventilation syndrome); patients who do not snore (either naturally or as a result of palate surgery); and patients who have central sleep apnea syndromes are not currently candidates for APAP titration or treatment; (3) APAP devices are not currently recommended for split-night titration; (4) certain APAP devices may be used during attended titration with polysomnography to identify a single pressure for use with standard CPAP for treatment of moderate to severe OSA; (5) certain APAP devices may be initiated and used in the self-adjusting mode for unattended treatment of patients with moderate to severe OSA without

  6. A BGO/GSO position sensitive block detector for a high resolution positron emission tomography with depth of interaction detection capability

    SciTech Connect

    Yamamoto, S.

    1996-12-31

    We developed a position sensitive block detector with depth of interaction detection capability for positron emission tomography (PET). The detector consists of 6 x 8 array of GSO scintillators, 6 x 8 array of BGO scintillators and two dual photomultiplier tubes (PMT). The GSO scintillators are optically coupled to front surface of the BGO scintillators. The position of 6 x 8 scintillators are determined by the Anger principle and depth of interaction position is determined by using the pulse shape analysis of GSOs and BGOs. Performance of the block detector was measured. Position distribution of the developed BGO/GSO block detector was little distorted. However the separation of the spots was still enough to distinguish the scintillators in transaxial and axial directions. Since pulse shape distribution using a developed simple pulse shape analyzer had two peaks, it is possible to separate the GSOs and BGOs for depth of interaction detection. With these results, a high resolution PET with depth of interaction detection capability will be possible using the developed BGO/GSO block detectors.

  7. Aerosol characteristics in Phimai, Thailand determined by continuous observation with a polarization sensitive Mie-Raman lidar and a sky radiometer

    NASA Astrophysics Data System (ADS)

    Sugimoto, Nobuo; Shimizu, Atsushi; Nishizawa, Tomoaki; Matsui, Ichiro; Jin, Yoshitaka; Khatri, Pradeep; Irie, Hitoshi; Takamura, Tamio; Aoki, Kazuma; Thana, Boossarasiri

    2015-06-01

    Distributions and optical characteristics of aerosols were continuously observed with a polarization-sensitive (532 nm), Mie-scattering (532 and 1064 nm) and Raman-scattering (607 nm) lidar and a sky radiometer in Phimai, Thailand. Polarization lidar measurements indicated that high concentration plumes of spherical aerosols considered as biomass burning smoke were often observed in the dry season. Plumes of non-spherical aerosols considered as long-range transported soil dust from Africa, the Middle East, or Northeast Asia were occasionally observed. Furthermore, low-concentration non-spherical aerosols were almost always observed in the atmospheric mixing layer. Extinction coefficient profiles of spherical aerosols and non-spherical dust exhibited different diurnal variations, and spherical aerosols including smoke were distributed in higher altitudes in the mixing layer and residual layer. The difference can be explained by hygroscopic growth of smoke particles and buoyancy of the smoke. Analysis of seasonal variations of optical properties derived from the Raman lidar and the sky radiometer confirmed that the lidar ratio, aerosol optical depth, and Angstrom exponent were higher in the dry season (October-May) and lower in the wet season (June-September). The single scattering albedo was lower in the dry season. These seasonal variations are explained by frequent biomass burning in the dry season consistent with previous studies in Southeast Asian region. At the same time, the present work confirmed that soil dust was a major aerosol component in Phimai, Thailand.

  8. A transformer of molecular beacon for sensitive and real-time detection of phosphatases with effective inhibition of the false positive signals.

    PubMed

    Zhang, Chen; Su, Xin; Liang, Yuan; Zhu, Xiaocui; Song, Chen; Zhao, Meiping

    2011-10-15

    Molecular beacons (MBs) have shown great potential in measurement of enzyme activities. However, currently available methods for monitoring of phosphatases only use MBs as a signal reporter. Extra substrates for the phosphatases are needed to hybridize to the MB either as a primer or as a template. Moreover, few MB-based methods have been used to detect enzyme activities in real biological samples due to insufficient sensitivity or false positive interference signals caused by nonspecific nucleases. In this work, a novel type of fluorescent probe was designed and synthesized for monitoring of phosphatases by integrating the DNA substrate and the signaling structures into a single molecule. Such a new design not only significantly simplified the probing system and greatly enhanced the sensitivity, but also offered a practical way to guard against the false-positive signal problems in the application to real samples. The unique design of the assay format should be widely applicable to many other enzymatic assays using oligonucleotide fluorescent probes.

  9. 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.

    PubMed

    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. PMID

  10. Positive or negative allosteric modulation of metabotropic glutamate receptor 5 (mGluR5) does not alter expression of behavioral sensitization to methamphetamine.

    PubMed

    Kufahl, Peter R; Nemirovsky, Natali E; Watterson, Lucas R; Zautra, Nicholas; Olive, M Foster

    2013-01-01

    We investigated the role of metabotropic glutamate receptor type 5 (mGluR5) in methamphetamine-induced behavioral sensitization. The mGluR5 positive allosteric modulator (3-cyano-N-(1,3-diphenyl-1H-pyrazol-5-yl) benzamide (CDPPB) and negative allosteric modulator fenobam were tested in separate experiments. Sprague-Dawley rats were repeatedly injected with 1 mg/kg methamphetamine or saline, and then given a locomotor challenge test using a dose of 0.5 mg/kg methamphetamine. Prior to the challenge test session, rats were injected with CDPPB, fenobam, or a vehicle.  Doses from previous studies showed reduced drug-conditioned behavior; however in this study neither CDPPB nor fenobam pretreatment resulted in an altered expression of behavioral sensitization, indicating a lack of mGluR5 involvement in sensitized methamphetamine-induced locomotion. Additionally, the high dose (30 mg/kg) of fenobam resulted in decreased methamphetamine-induced locomotion in rats regardless of drug exposure history, which suggests evidence of nonspecific behavioral inhibition.

  11. Continuous positive airway pressure and ventilation are more effective with a nasal mask than a full face mask in unconscious subjects: a randomized controlled trial

    PubMed Central

    2013-01-01

    Introduction Upper airway obstruction (UAO) is a major problem in unconscious subjects, making full face mask ventilation difficult. The mechanism of UAO in unconscious subjects shares many similarities with that of obstructive sleep apnea (OSA), especially the hypotonic upper airway seen during rapid eye movement sleep. Continuous positive airway pressure (CPAP) via nasal mask is more effective at maintaining airway patency than a full face mask in patients with OSA. We hypothesized that CPAP via nasal mask and ventilation (nCPAP) would be more effective than full face mask CPAP and ventilation (FmCPAP) for unconscious subjects, and we tested our hypothesis during induction of general anesthesia for elective surgery. Methods In total, 73 adult subjects requiring general anesthesia were randomly assigned to one of four groups: nCPAP P0, nCPAP P5, FmCPAP P0, and FmCPAP P5, where P0 and P5 represent positive end-expiratory pressure (PEEP) 0 and 5 cm H2O applied prior to induction. After apnea, ventilation was initiated with pressure control ventilation at a peak inspiratory pressure over PEEP (PIP/PEEP) of 20/0, then 20/5, and finally 20/10 cm H2O, each applied for 1 min. At each pressure setting, expired tidal volume (Vte) was calculated by using a plethysmograph device. Results The rate of effective tidal volume (Vte > estimated anatomical dead space) was higher (87.9% vs. 21.9%; P<0.01) and the median Vte was larger (6.9 vs. 0 mL/kg; P<0.01) with nCPAP than with FmCPAP. Application of CPAP prior to induction of general anesthesia did not affect Vte in either approach (nCPAP pre- vs. post-; 7.9 vs. 5.8 mL/kg, P = 0.07) (FmCPAP pre- vs. post-; 0 vs. 0 mL/kg, P = 0.11). Conclusions nCPAP produced more effective tidal volume than FmCPAP in unconscious subjects. Trial registration ClinicalTrials.gov identifier: NCT01524614. PMID:24365207

  12. Effects of continuous positive airway pressure treatment on clinic and ambulatory blood pressures in patients with obstructive sleep apnea and resistant hypertension: a randomized controlled trial.

    PubMed

    Muxfeldt, Elizabeth S; Margallo, Victor; Costa, Leonardo M S; Guimarães, Gleison; Cavalcante, Aline H; Azevedo, João C M; de Souza, Fabio; Cardoso, Claudia R L; Salles, Gil F

    2015-04-01

    The effect of continuous positive airway pressure (CPAP) on blood pressures (BPs) in patients with resistant hypertension and obstructive sleep apnea is not established. We aimed to evaluate it in a randomized controlled clinical trial, with blinded assessment of outcomes. Four hundred thirty-four resistant hypertensive patients were screened and 117 patients with moderate/severe obstructive sleep apnea, defined by an apnea-hypopnea index ≥15 per hour, were randomized to 6-month CPAP treatment (57 patients) or no therapy (60 patients), while maintaining antihypertensive treatment. Clinic and 24-hour ambulatory BPs were obtained before and after 6-month treatment. Primary outcomes were changes in clinic and ambulatory BPs and in nocturnal BP fall patterns. Intention-to-treat and per-protocol (limited to those with uncontrolled ambulatory BPs) analyses were performed. Patients had mean (SD) 24-hour BP of 129(16)/75(12) mm Hg, and 59% had uncontrolled ambulatory BPs. Mean apnea-hypopnea index was 41 per hour and 58.5% had severe obstructive sleep apnea. On intention-to-treat analysis, there was no significant difference in any BP change, neither in nocturnal BP fall, between CPAP and control groups. The best effect of CPAP was on night-time systolic blood pressure in per-protocol analysis, with greater reduction of 4.7 mm Hg (95% confidence interval, -11.3 to +3.1 mm Hg; P=0.24) and an increase in nocturnal BP fall of 2.2% (95% confidence interval, -1.6% to +5.8%; P=0.25), in comparison with control group. In conclusion, CPAP treatment had no significant effect on clinic and ambulatory BPs in patients with resistant hypertension and moderate/severe obstructive sleep apnea, although a beneficial effect on night-time systolic blood pressure and on nocturnal BP fall might exist in patients with uncontrolled ambulatory BP levels.

  13. Continuous positive airway pressure treatment for obstructive sleep apnoea reduces resting heart rate but does not affect dysrhythmias: a randomised controlled trial.

    PubMed

    Craig, Sonya; Pepperell, Justin C T; Kohler, Malcolm; Crosthwaite, Nicky; Davies, Robert J O; Stradling, John R

    2009-09-01

    Obstructive sleep apnoea (OSA) is associated with cardiovascular morbidity and may precipitate cardiac dysrhythmias. Uncontrolled reports suggest that continuous positive airway pressure (CPAP) may reduce dysrhythmia frequency and resting heart rate. We undertook a randomised controlled trial of therapeutic CPAP and compared with a subtherapeutic control which included an exploration of changes in dysrhythmia frequency and heart rate. Values are expressed as mean (SD). Eighty-three men [49.5 (9.6) years] with moderate-severe OSA [Oxygen Desaturation Index, 41.2 (24.3) dips per hour] underwent 3-channel 24-h electrocardiograms during normal daily activities, before and after 1 month of therapeutic (n = 43) or subtherapeutic (n = 40) CPAP. Recordings were manually analysed for mean heart rate, pauses, bradycardias, supraventricular and ventricular dysrhythmias. The two groups were well matched for age, body mass index, OSA severity, cardiovascular risk factors and history. Supraventricular ectopics and ventricular ectopics were frequently found in 95.2% and 85.5% of patients, respectively. Less common were sinus pauses (42.2%), episodes of bradycardia (12%) and ventricular tachycardias (4.8%). Compared with subtherapeutic control, CPAP reduced mean 24-h heart rate from 83.0 (11.5) to 79.7 (9.8) (P < 0.002) in the CPAP group compared with a non-significant rise (P = 0.18) from 79.0 (10.4) to 79.9 (10.4) in the subtherapeutic group; this was also the case for the day period analysed separately. There was no significant change in the frequencies of dysrhythmias after CPAP. Four weeks of CPAP therapy reduces mean 24-h heart rate possibly due to reduced sympathetic activation but did not result in a significant decrease in dysrhythmia frequency.

  14. The Effects of Massage with Coconut and Sunflower Oils on Oxygen Saturation of Premature Infants with Respiratory Distress Syndrome Treated With Nasal Continuous Positive Airway Pressure

    PubMed Central

    Valizadeh, Sousan; Hosseini, Mohammad Bagher; Asghari Jafarabadi, Mohammad; Ajoodanian, Najmeh

    2012-01-01

    Introduction: Nowadays particular emphasis is placed on the developmental aspects of premature infants care. Massage therapy is one of the best-known methods of caring. Due to the minimal touch policy in neonatal intensive care units (NICUs), massaging is not usually performed on premature infants. However, there is not sufficient evidence to support the claim that newborn infants with complex medical conditions should not be massaged. This study aimed to determine the effects of massage with coconut and sunflower oils on oxygen saturation of infants with respiratory distress syndrome (RDS) treated with nasal continuous positive airway pressure (NCPAP). Methods: This was a randomized controlled trial on 90 newborns who were admitted to Alzahra Hospital (Tabriz, Iran). The infants were divided into control and massage therapy groups (massage with coconut and sunflower oils). Data was collected using a hospital documentation form. A 15-minute daily massage was performed for 3 days. Respiratory rate (RR), fraction of inspired oxygen (FiO2) and oxygen saturation were measured 5 minutes before the massage, 3 times during the massage, and 5 minutes after the massage. The collected data was analyzed using a mixed model. Results: In comparison to coconut oil and control groups, mean oxygen saturation of sunflower oil group was improved. In addition, the coconut massage group showed lower oxygen saturation than the control group but was all values were within the normal range. Although massage decreased oxygen saturation, there was no need to increase FiO2. Conclusion: Massage therapy can provide developmental care for infants treated with NCPAP. PMID:25276695

  15. Effects of continuous positive airway pressure on blood pressure in patients with resistant hypertension and obstructive sleep apnea: a meta-analysis

    PubMed Central

    Iftikhar, Imran H.; Valentine, Christopher W.; Bittencourt, Lia R.A.; Cohen, Debbie L.; Fedson, Annette C.; Gíslason, Thorarinn; Penzel, Thomas; Phillips, Craig L.; Yu-sheng, Lin; Pack, Allan I.; Magalang, Ulysses J.

    2015-01-01

    Objective To systematically analyze the studies that have examined the effect of continuous positive airway pressure (CPAP) on blood pressure (BP) in patients with resistant hypertension and obstructive sleep apnea (OSA). Methods Design – meta-analysis of observational studies and randomized controlled trials (RCTs) indexed in PubMed and Ovid (All Journals@Ovid). participants: individuals with resistant hypertension and OSA; interventions – CPAP treatment. Results A total of six studies met the inclusion criteria for preintervention to postintervention analyses. The pooled estimates of mean changes after CPAP treatment for the ambulatory (24-h) SBP and DBP from six studies were −7.21 mmHg [95% confidence interval (CI): −9.04 to −5.38; P <0.001; I2 58%) and −4.99 mmHg (95% CI: −6.01 to −3.96; P <0.001; I2 31%), respectively. The pooled estimate of the ambulatory SBP and DBP from the four RCTs showed a mean net change of −6.74 mmHg [95% CI: −9.98 to −3.49; P <0.001; I2 61%] and −5.94 mmHg (95% CI: −9.40 to −2.47; P =0.001; I2 76%), respectively, in favor of the CPAP group. Conclusion The pooled estimate shows a favorable reduction of BP with CPAP treatment in patients with resistant hypertension and OSA. The effects sizes are larger than those previously reported in patients with OSA without resistant hypertension. PMID:25243523

  16. Management of Neonatal Respiratory Distress Syndrome Employing ACoRN Respiratory Sequence Protocol versus Early Nasal Continuous Positive Airway Pressure Protocol

    PubMed Central

    Niknafs, Pedram; Faghani, Asadallah; Afjeh, Seyed-Abolfazl; Moradinazer, Mehdi; Bahman-Bijari, Bahareh

    2014-01-01

    Objective: Respiratory distress syndrome (RDS) is a common cause of respiratory distress in premature infants. This study was designed to evaluate two different RDS treatment protocols by comparing the outcomes. Methods: This study was a double center cross sectional study performed from June to December 2012. During that period, 386 neonates with RDS were hospitalized and treated according to two different therapeutic protocols so-called Acute Care of at-Risk Newborns (ACoRN) respiratory sequence protocol (group I) and Early Nasal Continuous Positive Airway Pressure (E-NCPAP) protocol (group II). The variables and main outcomes of this study were gestational age, birth weight, bronchopulmonary dysplasia (BPD), pulmonary hemorrhage (PH), intraventricular hemorrhage (IVH), air leak and mortality rate (MR). Findings : Out of 386 infants, 202 infants were in group I (male 60.4%, female 39.6%, mean gestational age 316/7 weeks, mean birth weight=1688 grams) and group II included 184 infants (male 61.4%, female 38.6%, mean gestational age 32 weeks, mean birth weight 1787 grams), P= 0.07. The ratios of BPD of group I to group II and PH of group I to group two were not significant (P=0.63 and P=0.84, respectively). Air leak ratio in group I was higher than in group II (P=0.001). Although IVH ratio in group II was higher than in group I (P=0.01), grade III and IV IVH was higher in group I (30% vs. 4.6%). In case of MR, it was higher in group I than in group II (P=0.001). Conclusion: According to the findings the incidence of air leak, grade III and IV IVH and MR was less common in E-NCPAP protocol, so it may show the effectiveness of this protocol. The authors suggest that more researches are needed for more accurate results. PMID:25793046

  17. The impact of effective continuous positive airway pressure on homeostasis model assessment insulin resistance in non-diabetic patients with moderate to severe obstructive sleep apnea.

    PubMed

    Yang, Dan; Liu, Zhihong; Yang, Haixing

    2012-09-01

    Previous studies on the effects of continuous positive airway pressure (CPAP) on homeostasis model assessment insulin resistance (HOMA-IR) in obstructive sleep apnea patients have yielded conflicting results. Therefore, we conducted this meta-analysis to evaluate the impact of effective CPAP on HOMA-IR in non-diabetic patients with moderate to severe obstructive sleep apnea. We searched PubMed, HighWire Press, Ovid Medline (R), Cochrane library and EMBASE before December 2011 on original English language studies. The data on HOMA-IR and body mass index (BMI) were extracted from these studies. As compared with baseline values, 8 to 24 weeks of effective CPAP (>4 h/night) treatment significantly reduced HOMA-IR by an average of 0.75(95% CI, from -0.96 to -0.53; p < 0.001). However, in subjects with irregular CPAP (<4 h/night), this effect was not observed (-0.22; 95%CI, from -2.24 to 1.80; p = 0.83). There were no intervention-related changes in BMI in both regular and irregular CPAP. Our analysis showed that 8 to 24 weeks of effective CPAP could significantly improve HOMA-IR in non-diabetic patients with moderate to severe obstructive sleep apnea, while no significant changes in BMI were detected. Further large scale, randomized and controlled trials are needed to evaluate the longer treatment and its possible effects on weight control and cardiovascular disease.

  18. Evaluation of an integrated Fourier-transform spectrometer utilizing a lateral effect position sensitive detector with a multi-channel Fabry Perot interferometer

    NASA Astrophysics Data System (ADS)

    Andersson, H. A.; Manuilskiy, A.; Thungström, G.; Nilsson, H.-E.

    2008-04-01

    The basis of this paper is the evaluation of an integrated multi-channel Fourier-transform (FT) spectrometer based on a multi-channel wedge Fabry-Perot interferometer and a one-dimensional lateral effect position sensitive detector (PSD). The use of a PSD for an interferogram readout allows for a simple scanning mechanism with no requirement for any position reference. The use of a wedge-shaped interferometer makes it possible to integrate it directly onto the PSD surface, thus producing a very compact spectrometer. The capabilities of the spectrometer are demonstrated by absorption spectral measurements using a reference sample. In addition, spectral measurements on 532 nm DPSS and 632.8 nm He-Ne lasers are presented. The resolution of the spectrometer is approximately 5 nm. The evaluated spectrometer set-up can be used in applications where compact and low cost spectrometers are required, such as in process control and in education. Further, it is shown that there are deteriorations in very high accuracy position measurements, which are caused by changes in incident light intensity. A model describing the above-mentioned nonlinearities was developed based on analysing the equivalent circuit for PSDs and parameters such as leakage current and serial resistance. Additionally, a method is proposed to assist in the reduction of the nonlinearity caused by this effect.

  19. Development and applications of a new neutron single-crystal diffractometer based on a two-dimensional large-area curved position-sensitive detector

    PubMed Central

    Lee, Chang-Hee; Noda, Yukio; Ishikawa, Yoshihisa; Kim, Shin Ae; Moon, Myungkook; Kimura, Hiroyuki; Watanabe, Masashi; Dohi, Yuki

    2013-01-01

    A new single-crystal neutron diffractometer based on a large-area curved two-dimensional position-sensitive detector (C-2DPSD) has been developed. The diffractometer commissioning is almost complete, together with development of the measurement methodology and the raw data processing software package, the Reciprocal Analyzer, and the instrument is now ready to be launched for users. Position decoding of the C-2DPSD is via a delay-line readout method with an effective angular range of 110 × 54° in the horizontal and vertical directions, respectively, with a nominal radius of curvature of 530 mm. The diffractometer is equipped with a Ge(311) mosaic monochromator and two supermirror vacuum guide paths, one before and one after the monochromator position. The commissioning incorporates corrections and calibration of the instrument using an NaCl crystal, various applications such as crystallographic and magnetic structure measurements, a crystallinity check on large crystals, and a study on the composition or dopant content of a mixed crystal of (TmxYb1−x)Mn2O5. The installation of the diffractometer and the measurement method, the calibration procedure and results, the raw data treatment and visualization, and several applications using the large C-2DPSD-based diffractometer are reported. PMID:23682194

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

    NASA Astrophysics Data System (ADS)

    Vaquero, J. J.; Sánchez, J. J.; Udías, J. M.; Cal-González, J.; Desco, M.

    2013-02-01

    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.

  1. Performance and field tests of a handheld Compton camera using 3-D position-sensitive scintillators coupled to multi-pixel photon counter arrays

    NASA Astrophysics Data System (ADS)

    Kishimoto, A.; Kataoka, J.; Nishiyama, T.; Fujita, T.; Takeuchi, K.; Okochi, H.; Ogata, H.; Kuroshima, H.; Ohsuka, S.; Nakamura, S.; Hirayanagi, M.; Adachi, S.; Uchiyama, T.; Suzuki, H.

    2014-11-01

    After the nuclear disaster in Fukushima, radiation decontamination has become particularly urgent. To help identify radiation hotspots and ensure effective decontamination operation, we have developed a novel Compton camera based on Ce-doped Gd3Al2Ga3O12 scintillators and multi-pixel photon counter (MPPC) arrays. Even though its sensitivity is several times better than that of other cameras being tested in Fukushima, we introduce a depth-of-interaction (DOI) method to further improve the angular resolution. For gamma rays, the DOI information, in addition to 2-D position, is obtained by measuring the pulse-height ratio of the MPPC arrays coupled to ends of the scintillator. We present the detailed performance and results of various field tests conducted in Fukushima with the prototype 2-D and DOI Compton cameras. Moreover, we demonstrate stereo measurement of gamma rays that enables measurement of not only direction but also approximate distance to radioactive hotspots.

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

    NASA Astrophysics Data System (ADS)

    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.

  3. Determination of (235)U, (239)Pu, (240)Pu, and (241)Am in a nuclear bomb particle using a position-sensitive α-γ coincidence technique.

    PubMed

    Peräjärvi, Kari A; Ihantola, Sakari; Pöllänen, Roy C; Toivonen, Harri I; Turunen, Jani A

    2011-02-15

    A nuclear bomb particle containing 1.6 ng of Pu was investigated nondestructively with a position-sensitive α detector and a broad-energy HPGe γ-ray detector. An event-mode data acquisition system was used to record the data. α-γ coincidence counting was shown to be well suited to nondestructive isotope ratio determination. Because of the very small background, the 51.6 keV γ rays of (239)Pu and the 45.2 keV γ rays of (240)Pu were identified, which enabled isotopic ratio calculations. In the present work, the (239)Pu/((239)Pu+(240)Pu) atom ratio was determined to be 0.950 ± 0.010. The uncertainties were much smaller than in the previous more conventional nondestructive studies on this particle. Obtained results are also in good agreement with the data from the destructive mass spectrometric studies obtained previously by other investigators.

  4. Source apportionment of 1 h semi-continuous data during the 2005 Study of Organic Aerosols in Riverside (SOAR) using positive matrix factorization

    NASA Astrophysics Data System (ADS)

    Eatough, Delbert J.; Grover, Brett D.; Woolwine, Woods R.; Eatough, Norman L.; Long, Russell; Farber, Robert

    Positive matrix factorization (PMF2) was used to elucidate sources of fine particulate material (PM 2.5) for a study conducted during July and August 2005, in Riverside, CA. One-hour averaged semi-continuous measurements were made with a suite of instruments to provide PM 2.5 mass and chemical composition data. Total PM 2.5 mass concentrations (non-volatile plus semi-volatile) were measured with an R&P filter dynamic measurement system (FDMS TEOM) and a conventional TEOM monitor was used to measure non-volatile mass concentrations. PM 2.5 chemical species monitors included a dual-oven Sunset monitor to measure both non-volatile and semi-volatile carbonaceous material, an ion chromatographic-based monitor to measure sulfate and nitrate and an Anderson Aethalometer to measure black carbon (BC). Gas phase data including CO, NO 2, NO x and O 3 were also collected during the sampling period. In addition, single-particle measurements were made using aerosol time-of-flight mass spectrometry (ATOFMS). Twenty different single-particle types consistent with those observed in previous ATOFMS studies in Riverside were identified for the PMF2 analysis. Finally, time-of-flight aerosol mass spectrometry (ToF-AMS) provided data on markers of primary and secondary organic aerosol. Two distinct PMF2 analyses were performed. In analysis 1, all the data except for the ATOFMS and ToF-AMS data were used in an initial evaluation of sources at Riverside during the study. PMF2 was able to identify six factors from the data set corresponding to both primary and secondary sources, primarily from automobile emissions, diesel emissions, secondary nitrate formation, a secondary photochemical associated source, organic emissions and Basin transported pollutants. In analysis 2, the ATOFMS and ToF-AMS data were included in the analysis. In the second analysis, PMF2 was able to identify 16 factors with a variety of both primary and secondary factors being identified, corresponding to both primary

  5. Initial Treatment of Respiratory Distress Syndrome with Nasal Intermittent Mandatory Ventilation versus Nasal Continuous Positive Airway Pressure: A Randomized Controlled Trial

    PubMed Central

    Armanian, Amir-Mohammad; Badiee, Zohreh; Heidari, Ghobad; Feizi, Awat; Salehimehr, Nima

    2014-01-01

    Background: Neonatal respiratory distress syndrome (RDS) in premature infants who survived and its complications are a common problem. Due to high morbidity and mechanical ventilation (MV) nowadays researchers in interested minimizing MV. To determine, in very low birth weight (BW) preterm neonates with RDS, if initial treatment with nasal intermittent mandatory ventilation (early NIMV) compared with early nasal continuous positive airway pressure (early NCPAP) obtains more favorable outcomes in terms of the duration of treatment, and the need for endotracheal tube ventilation. Methods: In this single-center randomized control trial study, infants (BW ≤ 1500 g and/or gestational age ≤ 34 weeks) with respiratory distress were considered eligible. Forty-four infants were randomly assigned to receive early-NIMV and 54 comparable infants to early-NCPAP. Surfactants were given, when FIO2 requirement was of >30%. Primary outcomes were failure of noninvasive respiratory support, that is, the need for MV in the first 48 h of life and for the duration of noninvasive respiratory support in each group. Results: 98 infants were enrolled (44 in the NIMV and 54 in the NCPAP group). The Preventive power of MV of NIMV usage (95.5%) was not lower than the NCPAP (98.1%) strength (hazard ratio: 0.21 (95% confidence interval: 0.02-2.66); P: 0.23). The duration of noninvasive respiratory support in the NIMV group was significantly shorter than NCPAP (the median (range) was 24 (18.00-48.00) h versus 48.00 (22.00-120.00) h in NIMV versus NCPAP groups; P < 0.001). Similarly, the duration of dependency on oxygen was less, for NIMV (the median (range) was 96.00 (41.00-504.00) h versus144.00 (70.00-1130.00) h in NIMV versus NCPAP groups; P: 0.009). Interestingly, time to full enteral feeds and length of hospital stay were more favorable in the NIMV versus the NCPAP group. Conclusions: Initial treatment of RDS with NIMV was safe, and well tolerated. Furthermore, NIMV had excellent

  6. Discovery of Novel Cell Wall-Active Compounds Using PywaC, a Sensitive Reporter of Cell Wall Stress, in the Model Gram-Positive Bacterium Bacillus subtilis

    PubMed Central

    Czarny, T. L.; Perri, A. L.; French, S.

    2014-01-01

    The emergence of antibiotic resistance in recent years has radically reduced the clinical efficacy of many antibacterial treatments and now poses a significant threat to public health. One of the earliest studied well-validated targets for antimicrobial discovery is the bacterial cell wall. The essential nature of this pathway, its conservation among bacterial pathogens, and its absence in human biology have made cell wall synthesis an attractive pathway for new antibiotic drug discovery. Herein, we describe a highly sensitive screening methodology for identifying chemical agents that perturb cell wall synthesis, using the model of the Gram-positive bacterium Bacillus subtilis. We report on a cell-based pilot screen of 26,000 small molecules to look for cell wall-active chemicals in real time using an autonomous luminescence gene cluster driven by the promoter of ywaC, which encodes a guanosine tetra(penta)phosphate synthetase that is expressed under cell wall stress. The promoter-reporter system was generally much more sensitive than growth inhibition testing and responded almost exclusively to cell wall-active antibiotics. Follow-up testing of the compounds from the pilot screen with secondary assays to verify the mechanism of action led to the discovery of 9 novel cell wall-active compounds. PMID:24687489

  7. DNA double strand break repair defect and sensitivity to poly ADP-ribose polymerase (PARP) inhibition in human papillomavirus 16-positive head and neck squamous cell carcinoma

    PubMed Central

    Weaver, Alice N.; Cooper, Tiffiny S.; Rodriguez, Marcela; Trummell, Hoa Q.; Bonner, James A.; Rosenthal, Eben L.; Yang, Eddy S.

    2015-01-01

    Patients with human papillomavirus-positive (HPV+) head and neck squamous cell carcinomas (HNSCCs) have increased response to radio- and chemotherapy and improved overall survival, possibly due to an impaired DNA damage response. Here, we investigated the correlation between HPV status and repair of DNA damage in HNSCC cell lines. We also assessed in vitro and in vivo sensitivity to the PARP inhibitor veliparib (ABT-888) in HNSCC cell lines and an HPV+ patient xenograft. Repair of DNA double strand breaks (DSBs) was significantly delayed in HPV+ compared to HPV− HNSCCs, resulting in persistence of γH2AX foci. Although DNA repair activators 53BP1 and BRCA1 were functional in all HNSCCs, HPV+ cells showed downstream defects in both non-homologous end joining and homologous recombination repair. Specifically, HPV+ cells were deficient in protein recruitment and protein expression of DNA-Pk and BRCA2, key factors for non-homologous end joining and homologous recombination respectively. Importantly, the apparent DNA repair defect in HPV+ HNSCCs was associated with increased sensitivity to the PARP inhibitor veliparib, resulting in decreased cell survival in vitro and a 10–14 day tumor growth delay in vivo. These results support the testing of PARP inhibition in combination with DNA damaging agents as a novel therapeutic strategy for HPV+ HNSCC. PMID:26336991

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

    PubMed Central

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

    2012-01-01

    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. PMID:23223078

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

    PubMed

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

    2012-01-01

    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. PMID:23223078

  10. Continuous-wave operation at 2.1 microns of a diode-laser-pumped, Tm-sensitized Ho:Y3Al5O12 laser at 300 K

    NASA Technical Reports Server (NTRS)

    Fan, T. Y.; Huber, G.; Byer, R. L.; Mitzscherlich, P.

    1987-01-01

    Room-temperature operation of a continuous-wave Tm-sensitized Ho:YAG laser at 2.0974 microns has been achieved under diode-laser pumping at 781.5 nm. Observed thresholds are as low as 4.4 mW, with a slope efficiency of 19 percent with 0.5 percent output coupling.

  11. Keeping patient beds in a low position: an exploratory descriptive study to continuously monitor the height of patient beds in an adult acute surgical inpatient care setting.

    PubMed

    Tzeng, Huey-Ming; Prakash, Atul; Brehob, Mark; Devecsery, David Andrew; Anderson, Allison; Yin, Chang-Yi

    2012-06-01

    This descriptive study was intended to measure the percentage of the time that patient beds were kept in high position in an adult acute inpatient surgical unit with medical overflow in a community hospital in Michigan, United States. The percentage of the time was calculated for morning, evening, and night shifts. The results showed that overall, occupied beds were in a high position 5.6% of the time: 5.40% in the day shift, 6.88% in the evening shift, and 4.38% in the night shift. It is recognized that this study was unable to differentiate whether those times patient beds being kept in a high position were appropriate for an elevated bed height (e.g., staff were working with the patient). Further research is warranted. Falls committees may conduct high-bed prevalence surveys in a regular basis as a proxy to monitor staff members' behaviors in keeping beds in a high position.

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

    PubMed

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

    2015-07-01

    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.

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

    SciTech Connect

    Li, Luchuan; Lv, Bin; Chen, Bo; Guan, Ming; Sun, Yongfeng; Li, Haipeng; Zhang, Binbin; Ding, Changyuan; He, Shan; Zeng, Qingdong

    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.

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

    PubMed Central

    Di Trani, Livia; Bedini, Barbara; Donatelli, Isabella; Campitelli, Laura; Chiappini, Barbara; De Marco, Maria Alessandra; Delogu, Mauro; Buonavoglia, Canio; Vaccari, Gabriele

    2006-01-01

    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 the use of IPC to monitor

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

    PubMed

    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.

  16. Positive feedback loops for factor V and factor VII activation supply sensitivity to local surface tissue factor density during blood coagulation.

    PubMed

    Balandina, A N; Shibeko, A M; Kireev, D A; Novikova, A A; Shmirev, I I; Panteleev, M A; Ataullakhanov, F I

    2011-10-19

    Blood coagulation is triggered not only by surface tissue factor (TF) density but also by surface TF distribution. We investigated recognition of surface TF distribution patterns during blood coagulation and identified the underlying molecular mechanisms. For these investigations, we employed 1), an in vitro reaction-diffusion experimental model of coagulation; and 2), numerical simulations using a mathematical model of coagulation in a three-dimensional space. When TF was uniformly immobilized over the activating surface, the clotting initiation time in normal plasma increased from 4 min to >120 min, with a decrease in TF density from 100 to 0.7 pmol/m(2). In contrast, surface-immobilized fibroblasts initiated clotting within 3-7 min, independently of fibroblast quantity and despite a change in average surface TF density from 0.5 to 130 pmol/m(2). Experiments using factor V-, VII-, and VIII-deficient plasma and computer simulations demonstrated that different responses to these two TF distributions are caused by two positive feedback loops in the blood coagulation network: activation of the TF-VII complex by factor Xa, and activation of factor V by thrombin. This finding suggests a new role for these reactions: to supply sensitivity to local TF density during blood coagulation.

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

    NASA Astrophysics Data System (ADS)

    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.

  18. Time-Resolved Imaging of the MALDI Linear-TOF Ion Cloud: Direct Visualization and Exploitation of Ion Optical Phenomena Using a Position- and Time-Sensitive Detector

    NASA Astrophysics Data System (ADS)

    Ellis, Shane R.; Soltwisch, Jens; Heeren, Ron M. A.

    2014-05-01

    In this study, we describe the implementation of a position- and time-sensitive detection system (Timepix detector) to directly visualize the spatial distributions of the matrix-assisted laser desorption ionization ion cloud in a linear-time-of-flight (MALDI linear-ToF) as it is projected onto the detector surface. These time-resolved images allow direct visualization of m/z-dependent ion focusing effects that occur within the ion source of the instrument. The influence of key parameters, namely extraction voltage ( E V ), pulsed-ion extraction (PIE) delay, and even the matrix-dependent initial ion velocity was investigated and were found to alter the focusing properties of the ion-optical system. Under certain conditions where the spatial focal plane coincides with the detector plane, so-called x-y space focusing could be observed (i.e., the focusing of the ion cloud to a small, well-defined spot on the detector). Such conditions allow for the stigmatic ion imaging of intact proteins for the first time on a commercial linear ToF-MS system. In combination with the ion-optical magnification of the system (~100×), a spatial resolving power of 11-16 μm with a pixel size of 550 nm was recorded within a laser spot diameter of ~125 μm. This study demonstrates both the diagnostic and analytical advantages offered by the Timepix detector in ToF-MS.

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

    PubMed

    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.

  20. Sensitive monitoring of monoterpene metabolites in human urine using two-step derivatisation and positive chemical ionisation-tandem mass spectrometry.

    PubMed

    Schmidt, Lukas; Belov, Vladimir N; Göen, Thomas

    2013-09-01

    A gas chromatographic-positive chemical ionisation-tandem mass spectrometric (GC-PCI-MS/MS) method for the simultaneous determination of 10 oxidative metabolites of the monoterpenoid hydrocarbons α-pinene, (R)-limonene, and Δ(3)-carene ((+)-3-carene) in human urine was developed and tested for the monoterpene biomonitoring of the general population (n=36). The method involves enzymatic cleavage of the glucuronides followed by solid-supported liquid-liquid extraction and derivatisation using a two-step reaction with N,O-bis(trimethylsilyl)-trifluoroacetamide and N-(trimethylsilyl)imidazole. The method proved to be both sensitive and reliable with detection limits ranging from 0.1 to 0.3 μg L(-1). In contrast to the frequent and distinct quantities of (1S,2S,4R)-limonene-1,2-diol, the (1R,2R,4R)-stereoisomer could not be detected. The expected metabolite of (+)-3-carene, 3-caren-10-ol was not detected in any of the samples. All other metabolites were detected in almost all urine samples. The procedure enables for the first time the analysis of trace levels of a broad spectrum of mono- and bicyclic monoterpenoid metabolites (alcohols, diols, and carboxylic acids) in human urine. This analytical procedure is a powerful tool for population studies as well as for the discovery of human metabolism and toxicokinetics of monoterpenes. PMID:23953203

  1. SKIN SENSITIZATION AND ALLERGIC CONTACT DERMATITIS (BASIC COURSE): THE GLOBAL REGULATORY ENVIRONMENT - CONTINUING EDUCATION COURSE; 1 OF 4 SPEAKERS FOR AN SOT BASIC COURSE

    EPA Science Inventory

    New regulations have emerged in recent years giving guidance on how best to conduct skin sensitization testing on new chemical entities. For example, recently The Interagency Coordinating Committee on the Validation of Alternative Methods (ICCVAM) in the U.S. and the European Ce...

  2. Influence of temperature and bias voltage on the performance of a high resolution PET detector built with position sensitive avalanche photodiodes

    NASA Astrophysics Data System (ADS)

    Vandenbroucke, A.; McLaughlin, T. J.; Levin, C. S.

    2012-08-01

    We evaluate the performance of an 8 × 8 array of 0.9 × 0.9 × 1 mm3 cerium doped lutetium oxyothosilicate (LSO) crystals coupled to a position sensitive avalanche photodiode (PSAPD) as a function of bias voltage and temperature. We use this detector to develop a general methodology to optimize bias voltage, temperature, and gain for PET detectors using semiconductor photodetectors. This detector module will be used in a novel high resolution positron emission tomography (PET) camera dedicated to breast imaging under construction in our lab. Due to the tight packing of many PSAPDs in the system a thermal gradient is expected across the imaging heads. Data were collected for 11 PSAPD temperatures between 5°C and 40°C using a thermo-electric (Peltier) device. At each temperature the bias voltage was varied in steps of 5 V over a 50 V range. We present three methods to predict the optimal bias voltage at every temperature: one based on optimizing the coincidence time resolution, the others based on the relative change in PSAPD gain and leakage current due to the onset of hole multiplication. Optimal gain could also be predicted based on the quality of the flood histogram. At optimal bias voltage, the energy resolution degrades as (10.5±0.1)+((0.038±0.006)/ °C·T)%. Time resolution stays constant at 2.37±0.02 ns below 15°C. Above this temperature, time resolution deteriorates as (1.67±0.06)+((0.042±0.002)/°C·T)ns. Even at high temperatures, all 64 crystal position peaks in the flood histogram are still clearly visible. The width of the peaks in the flood histogram show a quadratic degradation with temperature: (2.6±0.1)·10-2+(1.6±0.2)·10-5/(°C)2·T2. We conclude that both the quality of the flood histogram as well as the coincidence time resolution are better parameters to estimate the optimal bias voltage, than energy resolution. Optimal bias voltage is found to be dependent on the value of k, the ratio between hole and electron multiplication. We

  3. Fine Tuning of CaV1.3 Ca2+ Channel Properties in Adult Inner Hair Cells Positioned in the Most Sensitive Region of the Gerbil Cochlea

    PubMed Central

    Zampini, Valeria; Johnson, Stuart L.; Franz, Christoph; Knipper, Marlies; Holley, Matthew C.; Magistretti, Jacopo; Russo, Giancarlo; Marcotti, Walter; Masetto, Sergio

    2014-01-01

    Hearing relies on faithful signal transmission by cochlear inner hair cells (IHCs) onto auditory fibres over a wide frequency and intensity range. Exocytosis at IHC ribbon synapses is triggered by Ca2+ inflow through CaV1.3 (L-type) Ca2+ channels. We investigated the macroscopic (whole-cell) and elementary (cell-attached) properties of Ca2+ currents in IHCs positioned at the middle turn (frequency ∼2 kHz) of the adult gerbil cochlea, which is their most sensitive hearing region. Using near physiological recordings conditions (body temperature and a Na+ based extracellular solution), we found that the macroscopic Ca2+ current activates and deactivates very rapidly (time constant below 1 ms) and inactivates slowly and only partially. Single-channel recordings showed an elementary conductance of 15 pS, a sub-ms latency to first opening, and a very low steady-state open probability (Po: 0.024 in response to 500-ms depolarizing steps at ∼−18 mV). The value of Po was significantly larger (0.06) in the first 40 ms of membrane depolarization, which corresponds to the time when most Ca2+ channel openings occurred clustered in bursts (mean burst duration: 19 ms). Both the Po and the mean burst duration were smaller than those previously reported in high-frequency basal IHCs. Finally, we found that middle turn IHCs are likely to express about 4 times more Ca2+ channels per ribbon than basal cells. We propose that middle-turn IHCs finely-tune CaV1.3 Ca2+ channel gating in order to provide reliable information upon timing and intensity of lower-frequency sounds. PMID:25409445

  4. Highly sensitive and selective analysis of urinary steroids by comprehensive two-dimensional gas chromatography combined with positive chemical ionization quadrupole mass spectrometry

    PubMed Central

    Zhang, Ying; Tobias, Herbert J.; Brenna, J. Thomas

    2014-01-01

    Comprehensive two dimensional gas chromatography (GC×GC) provides greater separation space than conventional GC. Because of fast peak elution, a time of flight mass spectrometer (TOFMS) is the usual structure-specific detector of choice. The quantitative capabilities of a novel GC×GC fast quadrupole MS were investigated with electron ionization (EI), and CH4 or NH3 positive chemical ionization (PCI) for analysis of endogenous urinary steroids targeted in anti-doping tests. Average precisions for steroid quantitative analysis from replicate urine extractions were 6% (RSD) for EI and 8% for PCI-NH3. The average limits of detection (LOD) calculated by quantification ions for 12 target steroids spiked into steroid-free urine matrix (SFUM) were 2.6 ng mL−1 for EI, 1.3 ng mL−1 for PCI-CH4, and 0.3 ng mL−1 for PCI-NH3, all in mass scanning mode. The measured limits of quantification (LOQ) with full mass scan GC×GC-qMS were comparable with the LOQ values measured by one-dimensional GC-MS in single ion monitoring (SIM) mode. PCI-NH3 yields fewer fragments and greater (pseudo)molecular ion abundances than EI or PCI-CH4. These data show a benchtop GC×GC-qMS system has the sensitivity, specificity, and resolution to analyze urinary steroids at normal urine concentrations, and that PCI-NH3, not currently available on most GC×GC-TOFMS instruments, is of particular value for generation of structure-specific ions. PMID:22606686

  5. SENSITIVITY OF NORMAL THEORY METHODS TO MODEL MISSPECIFICATION IN THE CALCULATION OF UPPER CONFIDENCE LIMITS ON THE RISK FUNCTION FOR CONTINUOUS RESPONSES. (R825385)

    EPA Science Inventory

    Normal theory procedures for calculating upper confidence limits (UCL) on the risk function for continuous responses work well when the data come from a normal distribution. However, if the data come from an alternative distribution, the application of the normal theory procedure...

  6. High-sensitivity C-reactive protein (hs-CRP) as a biomarker for trastuzumab-induced cardiotoxicity in HER2-positive early-stage breast cancer: a pilot study.

    PubMed

    Onitilo, Adedayo A; Engel, Jessica M; Stankowski, Rachel V; Liang, Hong; Berg, Richard L; Doi, Suhail A R

    2012-07-01

    Monitoring of left ventricular ejection fraction (LVEF) is the current standard for detection of trastuzumab-induced cardiotoxicity; however, time-to-diagnosis and cost of assessment are suboptimal in women with early-stage breast cancer. We assessed the utility of B-type natriuretic peptide (BNP), high-sensitivity C-reactive protein (hs-CRP), and cardiac troponin I (cTnI) as serum biomarkers for early detection of trastuzumab-induced cardiotoxicity. Fifty-four women with human epidermal growth factor receptor 2 (HER2)-positive early-stage breast cancer were prospectively enrolled, and the relationship between elevated serum BNP, hs-CRP, and cTnI levels and clinically significant decreases in LVEF was examined. LVEF was monitored at 3-4 month intervals during trastuzumab treatment. Laboratory testing for candidate biomarkers was repeated every 3 weeks with each cycle of trastuzumab. Trastuzumab-induced cardiotoxicity was defined as a decrease in LVEF of ≥15% or to a value below 50%. A clinically significant decrease in LVEF was observed in 28.6% of women. Abnormal hs-CRP (≥3 mg/L) predicted decreased LVEF with a sensitivity of 92.9% (95% CI 66.1-99.8) and specificity of 45.7% (95% CI 28.8-63.4), and subjects with normal hs-CRP levels (<3 mg/L) have 94.1% negative predictive 94.1% (95% CI 70.3-99.9) suggesting that normal hs-CRP levels may be associated with low future risk for decreased LVEF; however, no association with BNP or cTnI was observed. A false positive would have a relatively low associated cost in breast cancer patients undergoing adjuvant trastuzumab therapy and would indicate continuation of routine observation during treatment through traditional means. The maximum hs-CRP value was observed a median of 78 days prior to detection of cardiotoxicity by decreased LVEF, and those with normal levels were at lower risk for cardiotoxicity. Regular monitoring of hs-CRP holds promise as a biomarker for identifying women with early-stage breast cancer at

  7. Feeding, body weight, and sensitivity to non-ingestive reward stimuli during and after 12-day continuous central infusions of melanocortin receptor ligands.

    PubMed

    Cabeza de Vaca, S; Hao, J; Afroz, T; Krahne, L L; Carr, K D

    2005-11-01

    The brain melanocortin system mediates downstream effects of hypothalamic leptin and insulin signaling. Yet, there have been few studies of chronic intracerebroventricular (i.c.v.) melanocortin receptor (MCR) agonist or antagonist infusion. Although there is evidence of interaction between melanocortin and dopamine (DA) systems, effects of chronic MCR ligand infusion on behavioral sensitivity to non-ingestive reward stimuli have not been investigated. The objective of this study was to investigate effects of chronic i.c.v. infusion of the MCR agonist, MTII, and the MCR antagonist, SHU9119, on food intake, body weight, and sensitivity to rewarding lateral hypothalamic electrical stimulation (LHSS) and the reward-potentiating (i.e., threshold-lowering) effect of D-amphetamine. The MCR antagonist, SHU9119 (0.02 microg/h) produced sustained hyperphagia and weight gain during the 12-day infusion period, followed by compensatory hypophagia and an arrest of body weight gain during the 24-day post-infusion period. At no point during the experiment was sensitivity to LHSS or D-amphetamine (0.25mg/kg, i.p.) altered. The MCR agonist, MTII (0.02 microg/h) produced a brief hypophagia (3 days) followed by a return to control levels of daily intake, but with body weight remaining at a reduced level throughout the 12-day infusion period. This was followed by compensatory hyperphagia and weight gain during the 24-day post-infusion period. There was no change in sensitivity to non-ingestive reward stimuli during the infusion of MTII. However, sensitivity to D-amphetamine was increased during the 24-day post-infusion period. It therefore seems that changes in ingestive behavior that occur during chronic MCR ligand infusion may not affect the response to non-ingestive reward stimuli. However, it is possible that the drive to re-feed and restore body weight following MCR agonist treatment includes neuroadaptations that enhance the incentive effects of drug stimuli. PMID:15894406

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

    NASA Astrophysics Data System (ADS)

    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.

  9. Positioning Agility

    NASA Astrophysics Data System (ADS)

    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.

  10. Climate Sensitivity

    SciTech Connect

    Lindzen, Richard

    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.

  11. Sensitivity of the acid-base properties of clays to the methods of preparation and measurement. 2. Evidence from continuous potentiometric titrations.

    PubMed

    Duc, Myriam; Gaboriaud, Fabien; Thomas, Fabien

    2005-09-01

    The effects of experimental procedures on the acid-base consumption titration curves of montmorillonite suspension were studied using continuous potentiometric titration. For that purpose, the hysteresis amplitudes between the acid and base branches were found to be useful to systematically evaluate the impacts of storage conditions (wet or dried), the atmosphere in titration reactor, the solid-liquid ratio, the time interval between successive increments, and the ionic strength. In the case of storage conditions, the increase of the hysteresis was significantly higher for longer storage of clay in suspension and drying procedures compared to "fresh" clay suspension. The titration carried out under air demonstrated carbonate contamination that could only be cancelled by performing experiments under inert gas. Interestingly, the increase of the time intervals between successive increments of titrant strongly emphasized the amplitude of hysteresis, which could be correlated with the slow kinetic process specifically observed for acid addition in acid media. Thus, such kinetic behavior is probably associated with dissolution processes of clay particles. However, the resulting curves recorded at different ionic strengths under optimized conditions did not show the common intersection point required to define point of zero charge. Nevertheless, the ionic strength dependence of the point of zero net proton charge suggested that the point of zero charge of sodic montmorillonite could be estimated as lower than 5.

  12. Position sensor

    NASA Technical Reports Server (NTRS)

    Auer, Siegfried (Inventor)

    1988-01-01

    A radiant energy angle sensor is provided wherein the sensitive portion thereof comprises a pair of linear array detectors with each detector mounted normal to the other to provide X and Y channels and a pair of slits spaced from the pair of linear arrays with each of the slits positioned normal to its associated linear array. There is also provided electrical circuit means connected to the pair of linear array detectors and to separate X and Y axes outputs.

  13. IUdR polymers for combined continuous low-dose rate and high-dose rate sensitization of experimental human malignant gliomas.

    PubMed

    Yuan, X; Dillehay, L E; Williams, J R; Shastri, V R; Williams, J A

    2001-04-20

    .0 + 6.4 days (P < 0.05 vs. blank polymer + LDR + HDR). The polymeric IUdR delivery plus combined continuous LDR and HDR treatments results in growth delay and improved survival in animals bearing the MG xenografts. This treatment may hold promise for the treatment of human MGs.

  14. Climate Sensitivity

    NASA Astrophysics Data System (ADS)

    Hansen, J.

    2007-12-01

    Discussion of climate sensitivity requires careful definition of forcings, feedbacks and response times, indeed, foggy definitions have produced flawed assessments of climate sensitivity. The best information available on climate sensitivity comes from insightful interpretation of the Earth's history aided by quantitative information from climate models and understanding of climate processes. Climate sensitivity is a strong function of time scale, in part because of the nature of climate feedbacks. Unfortunately for humanity, the preponderance of feedbacks on the century time scale appears to be positive. The chief implication is the need for a sharp reversal in the trend of human-made climate forcing, if we are to avoid creating a planet that is dramatically different than the one on which civilization developed.

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

    PubMed

    Synowiec, Ewelina; Hoser, Grazyna; Wojcik, Katarzyna; Pawlowska, Elzbieta; Skorski, Tomasz; Błasiak, Janusz

    2015-08-05

    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.

  16. Structural basis for the in situ Ca2+ sensitization of cardiac troponin C by positive feedback from force-generating myosin cross-bridges

    PubMed Central

    Rieck, Daniel C.; Li, King-Lun; Ouyang, Yexin; Solaro, R. John; Dong, Wen-Ji

    2013-01-01

    The in situ structural coupling between the cardiac troponin (cTn) Ca2+-sensitive regulatory switch (CRS) and strong myosin cross-bridges was investigated using Förster resonance energy transfer (FRET). The double cysteine mutant cTnC(T13C/N51C) was fluorescently labeled with the FRET pair 5-(iodoacetamidoethyl)aminonaphthelene-1-sulfonic acid (IAEDENS) and N-(4-dimethylamino-3,5-dinitrophenyl)maleimide (DDPM) and then incorporated into detergent skinned left ventricular papillary fiber bundles. Ca2+ titrations of cTnC(T13C/N51C)AEDENS/DDPM-reconstituted fibers showed that the Ca2+-dependence of the opening of the N-domain of cTnC (N-cTnC) statistically matched the force–Ca2+ relationship. N-cTnC opening still occurred steeply during Ca2+ titrations in the presence of 1 mM vanadate, but the maximal extent of ensemble-averaged N-cTnC opening and the Ca2+-sensitivity of the CRS were significantly reduced. At nanomolar, resting Ca2+ levels, treatment with ADP•Mg in the absence of ATP caused a partial opening of N-cTnC. During subsequent Ca2+ titrations in the presence of ADP•Mg and absence of ATP, further N-cTnC opening was stimulated as the CRS responded to Ca2+ with increased Ca2+-sensitivity and reduced steepness. These findings supported our hypothesis here that strong cross-bridge interactions with the cardiac thin filament exert a Ca2+-sensitizing effect on the CRS by stabilizing the interaction between the exposed hydrophobic patch of N-cTnC and the switch region of cTnI. PMID:23896515

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

    PubMed Central

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

    2015-01-01

    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. PMID:26117541

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

    PubMed

    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.

  19. Semi-continuous ultrasonic sounding and changes of ultrasonic signal characteristics as a sensitive tool for the evaluation of ongoing microstructural changes of experimental mortar bars tested for their ASR potential.

    PubMed

    Lokajíček, T; Kuchařová, A; Petružálek, M; Šachlová, Š; Svitek, T; Přikryl, R

    2016-09-01

    Semi-continuous ultrasonic sounding of experimental mortar bars used in the accelerated alkali silica reactivity laboratory test (ASTM C1260) is proposed as a supplementary measurement technique providing data that are highly sensitive to minor changes in the microstructure of hardening/deteriorating concrete mixture. A newly designed, patent pending, heating chamber was constructed allowing ultrasonic sounding of mortar bars, stored in accelerating solution without necessity to remove the test specimens from the bath during the measurement. Subsequent automatic data analysis of recorded ultrasonic signals proved their high correlation to the measured length changes (expansion) and their high sensitivity to microstructural changes. The changes of P-wave velocity, and of the energy, amplitude, and frequency of ultrasonic signal, were in the range of 10-80%, compared to 0.51% change of the length. Results presented in this study thus show that ultrasonic sounding seems to be more sensitive to microstructural changes due to ongoing deterioration of concrete microstructure by alkali-silica reaction than the dimensional changes.

  20. Semi-continuous ultrasonic sounding and changes of ultrasonic signal characteristics as a sensitive tool for the evaluation of ongoing microstructural changes of experimental mortar bars tested for their ASR potential.

    PubMed

    Lokajíček, T; Kuchařová, A; Petružálek, M; Šachlová, Š; Svitek, T; Přikryl, R

    2016-09-01

    Semi-continuous ultrasonic sounding of experimental mortar bars used in the accelerated alkali silica reactivity laboratory test (ASTM C1260) is proposed as a supplementary measurement technique providing data that are highly sensitive to minor changes in the microstructure of hardening/deteriorating concrete mixture. A newly designed, patent pending, heating chamber was constructed allowing ultrasonic sounding of mortar bars, stored in accelerating solution without necessity to remove the test specimens from the bath during the measurement. Subsequent automatic data analysis of recorded ultrasonic signals proved their high correlation to the measured length changes (expansion) and their high sensitivity to microstructural changes. The changes of P-wave velocity, and of the energy, amplitude, and frequency of ultrasonic signal, were in the range of 10-80%, compared to 0.51% change of the length. Results presented in this study thus show that ultrasonic sounding seems to be more sensitive to microstructural changes due to ongoing deterioration of concrete microstructure by alkali-silica reaction than the dimensional changes. PMID:27268163

  1. Low-distortion resistive anodes for two-dimensional position-sensitive MCP systems. [Microchannel Plates for ion, electron and photon image sensing and conversion

    NASA Technical Reports Server (NTRS)

    Lampton, M.; Carlson, C. W.

    1979-01-01

    Microchannel plates (MCPs) are frequently used with resistive anodes to detect charged particles or photons and yield analog signals from which event positions can be decoded. The paper discusses a four-corner concave circular arc terminated resistive anode that permits theoretically distortionless encoding of Cartesian event positions into pulse charge ratios. The theory of the circular arc terminated anode is discussed along with anode design and performance. Electron beam images obtained by using such an anode are presented to confirm the usefulness of the approach.

  2. Expression of the Bacillus subtilis sacB gene leads to sucrose sensitivity in the gram-positive bacterium Corynebacterium glutamicum but not in Streptomyces lividans.

    PubMed Central

    Jäger, W; Schäfer, A; Pühler, A; Labes, G; Wohlleben, W

    1992-01-01

    The expression of the structural gene (sacB) encoding Bacillus subtilis levansucrase in two gram-positive soil bacteria, Corynebacterium glutamicum ATCC 13032 and Streptomyces lividans 1326, was investigated. sacB expression in the presence of sucrose is lethal to C. glutamicum but not to S. lividans. While S. lividans secretes levansucrase into the medium, we could show that the enzyme is retained by C. glutamicum cells. Our results imply that the sacB gene can be used as a positive selection system in coryneform bacteria. PMID:1644774

  3. Long-term effects of continuing adjuvant tamoxifen to 10 years versus stopping at 5 years after diagnosis of oestrogen receptor-positive breast cancer: ATLAS, a randomised trial

    PubMed Central

    Davies, Christina; Pan, Hongchao; Godwin, Jon; Gray, Richard; Arriagada, Rodrigo; Raina, Vinod; Abraham, Mirta; Alencar, Victor Hugo Medeiros; Badran, Atef; Bonfill, Xavier; Bradbury, Joan; Clarke, Michael; Collins, Rory; Davis, Susan R; Delmestri, Antonella; Forbes, John F; Haddad, Peiman; Hou, Ming-Feng; Inbar, Moshe; Khaled, Hussein; Kielanowska, Joanna; Kwan, Wing-Hong; Mathew, Beela S; Müller, Bettina; Nicolucci, Antonio; Peralta, Octavio; Pernas, Fany; Petruzelka, Lubos; Pienkowski, Tadeusz; Rajan, Balakrishnan; Rubach, Maryna T; Tort, Sera; Urrútia, Gerard; Valentini, Miriam; Wang, Yaochen; Peto, Richard

    2013-01-01

    Summary Background For women with oestrogen receptor (ER)-positive early breast cancer, treatment with tamoxifen for 5 years substantially reduces the breast cancer mortality rate throughout the first 15 years after diagnosis. We aimed to assess the further effects of continuing tamoxifen to 10 years instead of stopping at 5 years. Methods In the worldwide Adjuvant Tamoxifen: Longer Against Shorter (ATLAS) trial, 12 894 women with early breast cancer who had completed 5 years of treatment with tamoxifen were randomly allocated to continue tamoxifen to 10 years or stop at 5 years (open control). Allocation (1:1) was by central computer, using minimisation. After entry (between 1996 and 2005), yearly follow-up forms recorded any recurrence, second cancer, hospital admission, or death. We report effects on breast cancer outcomes among the 6846 women with ER-positive disease, and side-effects among all women (with positive, negative, or unknown ER status). Long-term follow-up still continues. This study is registered, number ISRCTN19652633. Findings Among women with ER-positive disease, allocation to continue tamoxifen reduced the risk of breast cancer recurrence (617 recurrences in 3428 women allocated to continue vs 711 in 3418 controls, p=0·002), reduced breast cancer mortality (331 deaths vs 397 deaths, p=0·01), and reduced overall mortality (639 deaths vs 722 deaths, p=0·01). The reductions in adverse breast cancer outcomes appeared to be less extreme before than after year 10 (recurrence rate ratio [RR] 0·90 [95% CI 0·79–1·02] during years 5–9 and 0·75 [0·62–0·90] in later years; breast cancer mortality RR 0·97 [0·79–1·18] during years 5–9 and 0·71 [0·58–0·88] in later years). The cumulative risk of recurrence during years 5–14 was 21·4% for women allocated to continue versus 25·1% for controls; breast cancer mortality during years 5–14 was 12·2% for women allocated to continue versus 15·0% for controls (absolute mortality

  4. Intracardiac Shunt—Use of the Hydrogen-Sensitive Catheter to Clarify False Positive Diagnosis of Left-to-Right Shunt

    PubMed Central

    Stoike, Roger; Kuzman, William J.

    1967-01-01

    The charts of 142 patients who had diagnostic right heart catheterization with conventional oximetry, oxygen content determinations and hydrogen electrode curve recording for left-to-right shunt were reviewed. A false positive diagnosis of surgical significance would have been made in nine patients if the hydrogen electrode had not been used. In addition, a diagnosis of left-to-right shunt could have been made at the wrong chamber level in three additional cases. PMID:18730066

  5. Observations related to the Salmonella EU layer baseline survey in the United Kingdom: follow-up of positive flocks and sensitivity issues

    PubMed Central

    CARRIQUE-MAS, J. J.; BRESLIN, M.; SNOW, L.; ARNOLD, M. E.; WALES, A.; McLAREN, I.; DAVIES, R. H.

    2008-01-01

    SUMMARY A follow-on study was carried out on 23 holdings identified as Salmonella positive in the 2004/2005 European Union (EU) baseline survey of Salmonella in laying hens. Eleven of 13 cage and 4/7 floor houses remained positive for Salmonella when the new flock was tested, and from 10/13 cage and 3/7 floor houses a Salmonella of the same serovar/phage type as found in the EU survey was isolated. There was a high correlation between the level of contamination in the houses at the time of the EU survey and in the follow-on flock. On seven occasions the house identified as positive in the EU survey was sampled after cleaning and disinfection but before a new flock was placed, and in all of them Salmonella could be isolated from the houses. The observed number of infected houses in infected holdings suggests that the holding-level prevalence in the United Kingdom would be about 21% higher than the results obtained in the EU survey. PMID:18177519

  6. Precision and sensitivity of the measurement of 15N enrichment in D-alanine from bacterial cell walls using positive/negative ion mass spectrometry

    NASA Technical Reports Server (NTRS)

    Tunlid, A.; Odham, G.; Findlay, R. H.; White, D. C.

    1985-01-01

    Sensitive detection of cellular components from specific groups of microbes can be utilized as 'signatures' in the examination of microbial consortia from soils, sediments or biofilms. Utilizing capillary gas chromatography/mass spectrometry and stereospecific derivatizing agents, D-alanine, a component localized in the prokaryotic (bacterial) cell wall, can be detected reproducibly. Enrichments of D-[15N]alanine determined in E. coli grown with [15N]ammonia can be determined with precision at 1.0 atom%. Chemical ionization with methane gas and the detection of negative ions (M - HF)- and (M - F or M + H - HF)- formed from the heptafluorobutyryl D-2 butanol ester of D-alanine allowed as little as 8 pg (90 fmol) to be detected reproducibly. This method can be utilized to define the metabolic activity in terms of 15N incorporation at the level of 10(3)-10(4) cells, as a function of the 15N-14N ratio.

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

    SciTech Connect

    Hernandez-Prieto, A.; Quintana, B.

    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)

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

    PubMed

    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.

  9. Metformin synergistically sensitizes FLT3-ITD-positive acute myeloid leukemia to sorafenib by promoting mTOR-mediated apoptosis and autophagy.

    PubMed

    Wang, Fangfang; Liu, Zuofeng; Zeng, Jisha; Zhu, Hongyan; Li, Jingjing; Cheng, Xiaomin; Jiang, Tao; Zhang, Li; Zhang, Chuanfen; Chen, Tie; Liu, Ting; Jia, Yongqian

    2015-12-01

    Mutations of Fms-like tyrosine kinase 3-internal tandem duplication (FLT3-ITD), accounting for approximately 30% of patients with acute myeloid leukemia (AML), results in poor therapeutic efficacy and short survival. Sorafenib, an oral multikinase inhibitor, can inhibit FLT3 and improve clinical outcome of FLT3 mutated leukemia. Our current studies have shown that, the antidiabetic drug metformin also exerts anti-leukemic effect by activating p-AMPK and synergistically sensitizes FLT3 mutated AML to sorafenib. Both agents suppress cell proliferation in a dose-dependent manner and induce apoptosis via cell cycle arrest, but does not obviously modulate autophagy marker, light chain 3 (LC3). Mechanistically, in the presence of metformin, the anticancer potential of sorafenib, accompanying with increased LC3 levels, is found to be synergistically enhanced with the remarkably reduced protein expression of the mTOR/p70S6K/4EBP1 pathway, while not appreciably altering cell cycle. Overall, these results show metformin in aid of sorafenib may represent a promising and attractive strategy for the treatment of FLT3-ITD mutated AML. PMID:26505133

  10. A novel acquired ALK F1245C mutation confers resistance to crizotinib in ALK-positive NSCLC but is sensitive to ceritinib.

    PubMed

    Kodityal, Sandeep; Elvin, Julia A; Squillace, Rachel; Agarwal, Nikita; Miller, Vincent A; Ali, Siraj M; Klempner, Samuel J; Ou, Sai-Hong Ignatius

    2016-02-01

    The emergence of acquired anaplastic lymphoma kinase (ALK) resistant mutations is a common molecular mechanism underpinning disease progression during crizotinib treatment of ALK-positive (ALK+) non-small cell lung cancer (NSCLC) patients. Identifying acquired resistance mutations in ALK is paramount for tailoring future therapy with second generation ALK inhibitors and beyond. Comprehensive genomic profiling using hybrid-capture next generation sequencing has been successful in identifying acquired ALK resistance mutations. Here we described the emergence of an ALK F1245C mutation in an advanced ALK+ NSCLC patient (EML4-ALK variant 3a/b) who developed slow disease progression after a durable response to crizotinib. The patient was eventually switched to ceritinib with on-going clinical response. This is the first patient report that ALK F1245C is an acquired resistance mutation to crizotinib that can be overcome by ceritinib. PMID:26775591

  11. Continuous Problem of Function Continuity

    ERIC Educational Resources Information Center

    Jayakody, Gaya; Zazkis, Rina

    2015-01-01

    We examine different definitions presented in textbooks and other mathematical sources for "continuity of a function at a point" and "continuous function" in the context of introductory level Calculus. We then identify problematic issues related to definitions of continuity and discontinuity: inconsistency and absence of…

  12. Claim and Continuous Improvement

    NASA Astrophysics Data System (ADS)

    Paulová, Iveta; Meravá, Miroslava

    2010-01-01

    The claim will always represent the kind of information that is annoying to recipients. Systematic work with claims has a positive value for the company. Addressing the complaint has a positive effect on continuous improvement. This paper was worked out with the support of VEGA No.1/0229/08 Perspectives of quality management development in coherence with requirements of Slovak republic market.

  13. 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.

    PubMed

    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. PMID:27155868

  14. 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.

    PubMed

    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.

  15. A Pilot Study on the Efficacy of Continuous Positive Airway Pressure on the Manifestations of Ménière's Disease in Patients with Concomitant Obstructive Sleep Apnea Syndrome

    PubMed Central

    Nakayama, Meiho; Masuda, Ayako; Ando, Kayoko Bhardwaj; Arima, Sachie; Kabaya, Kayoko; Inagaki, Akira; Nakamura, Yoshihisa; Suzuki, Motohiko; Brodie, Hilary; Diaz, Rodney C.; Murakami, Shingo

    2015-01-01

    Objective: To evaluate the effect of continuous positive airway pressure (CPAP) therapy on Ménière's disease patients with concomitant obstructive sleep apnea syndrome (OSAS), since recent reports suggest OSAS may cause dysfunction of the vestibular system. Study Design: Prospective study using CPAP administered to patients diagnosed with “Definite Ménière's disease” according to the guidelines of the American Academy of Otolaryngology— Head and Neck Surgery and combined with OSAS. Setting: University hospital. Methods: Twenty consecutive patients, 14 male and 6 female with active, unilateral, cochleovestibular Ménière's disease refractory to medical management who also had concurrent OSAS as defined by International Classification of Sleep Disorders, Second Edition were selected to undergo solitary CPAP therapy. Audiometric testing, caloric testing, and DHI survey were conducted before and after CPAP therapy and compared to assess effectiveness of CPAP therapy as utilized for treatment of Ménière's disease. Results: Although caloric testing did not show significant difference, audiometric testing and results of dizziness handicap inventory were significantly improved (p < 0.05) after CPAP therapy only, without standard treatment for Ménière's disease. Conclusions: Recent reports have suggested that OSAS may cause dysfunction of the vestibular system. We investigated whether standard therapy for OSAS would be of benefit in the management of vertigo and hearing loss in Ménière's disease patients. Our study cohort demonstrated significant improvement in both DHI and audiometric testing following solitary CPAP therapy for OSAS. Solitary CPAP therapy may become a new effective treatment strategy for Ménière's disease patients with OSAS, not just only for control of dizziness and vertigo but also for potential benefit of hearing. Citation: Nakayama M, Masuda A, Ando KB, Arima S, Kabaya K, Inagaki A, Nakamura Y, Suzuki M, Brodie H, Diaz RC, Murakami S

  16. Continuous Positive Airway Pressure Increases Pulsatile Growth Hormone Secretion and Circulating Insulin-like Growth Factor-1 in a Time-Dependent Manner in Men With Obstructive Sleep Apnea: A Randomized Sham-Controlled Study

    PubMed Central

    Hoyos, Camilla M.; Killick, Roo; Keenan, Daniel M.; Baxter, Robert C.; Veldhuis, Johannes D.; Liu, Peter Y.

    2014-01-01

    Study Objectives: To assess the time-dependent effect of continuous positive airway pressure (CPAP), on insulin-like growth factor-1 (IGF-1), IGF binding proteins (IGFBPs) and pulsatile growth hormone (GH) secretion. Design: A randomized, double-blind, sham-controlled, parallel group study. Participants: Sixty-five middle-aged men with moderate to severe obstructive sleep apnea. Intervention: Active (n = 34) or sham (n = 31) CPAP for 12 weeks, followed by 12 weeks of active CPAP (n = 65). Measurements and Results: Fasting morning IGF-1, IGFBP-3, and IGFBP-1 blood levels at 0, 6, 12, and 24 weeks. Overnight GH secretion was calculated by mathematical deconvolution of serial GH measurements from serum samples collected every 10 min (22:00-06:00) during simultaneous polysomnography in a subset of 18 men (active n = 11, sham n = 7) at week 12. Active, compared with sham, CPAP increased IGF-1 at 12 weeks (P = 0.006), but not at 6 weeks (P = 0.44). Changes in IGFBP-3 and IGFBP-1 were not different between groups at 6 or 12 weeks (all P ≥ 0.15). At week 24, there was a further increase in IGF-1 and a decrease in IGFBP-1 in the pooled group (P = 0.0001 and 0.046, respectively). In the subset, total (P = 0.001) and pulsatile (P = 0.002) GH secretion, mean GH concentration (P = 0.002), mass of GH secreted per pulse (P = 0.01) and pulse frequency (P = 0.04) were all higher after 12 weeks of CPAP compared with sham. Basal secretion, interpulse regularity, and GH regularity were not different between groups (all P > 0.11). Conclusions: Twelve weeks, but not 6 weeks, of CPAP increases IGF-1, with a further increase after 24 weeks. Total and pulsatile GH secretion, secretory burst mass and pulse frequency are also increased by 12 weeks. CPAP improves specific elements of the GH/IGF-1 axis in a time-dependent manner. Clinical Trials Registration: Australia New Zealand Clinical Trials Network, www.anzctr.org.au, number ACTRN12608000301369. Citation: Hoyos CM; Killick R; Keenan DM

  17. A pilot study investigating the effects of continuous positive airway pressure treatment and weight-loss surgery on autonomic activity in obese obstructive sleep apnea patients☆, ☆☆

    PubMed Central

    Bakker, Jessie P.; Campana, Lisa M.; Montesi, Sydney B.; Balachandran, Jayshankar; DeYoung, Pamela N.; Smales, Erik; Patel, Sanjay R.; Malhotra, Atul

    2015-01-01

    Background We have previously demonstrated that severity of obstructive sleep apnea (OSA) as measured by the apnea–hypopnea index (AHI) is a significant independent predictor of readily-computed time-domain metrics of short-term heart rate variability (HRV). Methods We aimed to assess time-domain HRV measured over 5-min while awake in a trial of obese subjects undergoing one of two OSA therapies: weight-loss surgery (n = 12, 2 males, median and interquartile range (IQR) for BMI 43.7 [42.0, 51.4] kg/m2, and AHI 18.1 [16.3, 67.5] events/h) or continuous positive airway pressure (CPAP) (n = 15, 11 males, median BMI 33.8 [31.3, 37.9] kg/m2, and AHI 36.5 [24.7, 77.3] events/h). Polysomnography was followed by electrocardiography during wakefulness; measurements were repeated at 6 and 12–18 months post-intervention. Results Despite similar measurements at baseline, subjects who underwent surgery exhibited greater improvement in short-term HRV than those who underwent CPAP (p = 0.04). Conclusions Our data suggest a possible divergence in autonomic function between the effects of weight loss resulting from bariatric surgery, and the amelioration of obstructive respiratory events resulting from CPAP treatment. Randomized studies are necessary before clinical recommendations can be made. PMID:24636793

  18. Chemical applicability domain of the Local Lymph Node Assay (LLNA) for skin sensitisation potency. Part 3. Apparent discrepancies between LLNA and GPMT sensitisation potential: False positives or differences in sensitivity?

    PubMed

    Roberts, David W; Schultz, Terry W; Api, Anne Marie

    2016-10-01

    The Local Lymph Node Assay (LLNA) is the gold standard regulatory toxicology test for skin sensitisation along with the guinea pig maximisation test (GPMT). Compared with the GPMT, LLNA uses fewer animals, it is quantitative, and it gives a numerical prediction of potency. However several concerns have been raised with this assay, mainly related to false positives and false negatives. Over the years, many authors, including the developers of the assay, have presented cases where there have been discrepancies between the GMPT and LLNA results. Several theories have been put forward for these discrepancies, the main one being the "over-sensitivity" of the GPMT. This paper analyses the data from a systematic study, published in three papers from 2008 to 2011, covering several classes of chemicals, in particular unsaturated fatty acids, sugar surfactants and ethoxylated alcohols, with many cases of chemicals testing positive in the LLNA being negative in the GPMT. Based on consideration of reaction chemistry and structural alerts, it is concluded that these discrepancies are not LLNA false positives, but can be rationalised in terms of the different protocols of the assays. PMID:27477089

  19. A multicentre, randomised controlled, non-inferiority trial, comparing high flow therapy with nasal continuous positive airway pressure as primary support for preterm infants with respiratory distress (the HIPSTER trial): study protocol

    PubMed Central

    Roberts, Calum T; Owen, Louise S; Manley, Brett J; Donath, Susan M; Davis, Peter G

    2015-01-01

    Introduction High flow (HF) therapy is an increasingly popular mode of non-invasive respiratory support for preterm infants. While there is now evidence to support the use of HF to reduce extubation failure, there have been no appropriately designed and powered studies to assess the use of HF as primary respiratory support soon after birth. Our hypothesis is that HF is non-inferior to the standard treatment—nasal continuous positive airway pressure (NCPAP)— as primary respiratory support for preterm infants. Methods and analysis The HIPSTER trial is an unblinded, international, multicentre, randomised, non-inferiority trial. Eligible infants are preterm infants of 28–36+6 weeks’ gestational age (GA) who require primary non-invasive respiratory support for respiratory distress in the first 24 h of life. Infants are randomised to treatment with either HF or NCPAP. The primary outcome is treatment failure within 72 h after randomisation, as determined by objective oxygenation, blood gas, and apnoea criteria, or the need for urgent intubation and mechanical ventilation. Secondary outcomes include the incidence of intubation, pneumothorax, bronchopulmonary dysplasia, nasal trauma, costs associated with hospital care and parental stress. With a specified non-inferiority margin of 10%, using a two-sided 95% CI and 90% power, the study requires 375 infants per group (total 750 infants). Ethics and dissemination Ethical approval has been granted by the relevant human research ethics committees at The Royal Women's Hospital (13/12), The Royal Children's Hospital (33144A), The Mercy Hospital for Women (R13/34), and the South-Eastern Norway Regional Health Authority (2013/1657). The trial is currently recruiting at 9 centres in Australia and Norway. The trial results will be published in peer-reviewed international journals, and presented at national and international conferences. Trial registration number Australian New Zealand Clinical Trials Registry ID: ACTRN

  20. An evaluation of the relative efficacy of an open airway, an oxygen reservoir and continuous positive airway pressure 5 cmH2O on the non-ventilated lung.

    PubMed

    Slimani, J; Russell, W J; Jurisevic, C

    2004-12-01

    The aim of this study, during one-lung ventilation, was to evaluate if oxygenation could be improved by use of a simple oxygen reservoir or application of 5 cmH2O continuous positive airway pressure (CPAP) to the non-ventilated lung compared with an open airway. Twenty-three patients with lung malignancy, undergoing thoracotomy requiring at least 60 minutes of one-lung ventilation before lung lobe excision, were studied. After routine induction and establishment of one-lung ventilation, the three treatments were applied in turn to the same patient in a sequence selected randomly. The first treatment was repeated as a fourth treatment and these results of the repeated treatment averaged to minimize the effect of slow changes. Arterial oxygenation was measured by an arterial blood gas 15 minutes after the application of each treatment. Twenty patients completed the study. Mean PaO2 (in mmHg) was 210.3 (SD 105.5) in the "OPEN" treatment, 186.0 (SD 109.2) in the "RESERVOIR" treatment, and 240.5 (SD 116.0) in the "CPAP" treatment. This overall difference was not quite significant (P = 0.058, paired ANOVA), but comparison of the pairs showed that there was a significant better oxygenation only with the CPAP compared to the reservoir treatments (t = 2.52, P = 0.021). While the effect on the surgical field was not apparent in most patients, in one patient surgery was impeded during CPAP. Our results show that the use of a reservoir does not give oxygenation better than an open tube, and is less effective than the use of CPAP 5 cmH2O on the non-ventilated lung during one-lung ventilation.