WorldWideScience

Sample records for high alpha dynamics

  1. A Study of Optimization of Alpha-Beta-Gamma-Eta Filter for Tracking a High Dynamic Target

    Directory of Open Access Journals (Sweden)

    Tae-Gweon Jeong

    2017-03-01

    Full Text Available The tracking filter plays a key role in accurate estimation and prediction of maneuvering vessel’s position and velocity. Different methods are used for tracking. However, the most commonly used method is the Kalman filter and its modifications. The Alpha-Beta-Gamma filter is one of the special cases of the general solution pro-vided by the Kalman filter. It is a third order filter that computes the smoothed estimates of position, velocity and acceleration for the nth observation, and also predicts the next position and velocity. Although found to track a maneuvering target with a good accuracy than the constant velocity, Alpha-Beta filter, the Alpha-Beta-Gamma filter does not perform impressively under high maneuvers such as when the target is undergoing changing accelerations. This study, therefore, aims to track a highly maneuvering target experiencing jerky motions due to changing accelerations. The Alpha-Beta-Gamma filter is extended to include the fourth state that is, constant jerk to correct the sudden change of acceleration in order to improve the filter’s performance. Results obtained from simulations of the input model of the target dynamics under consideration indicate an improvement in performance of the jerky model, Alpha-Beta-Gamma-Eta, algorithm as compared to the constant acceleration model, Alpha-Beta-Gamma in terms of error reduction and stability of the filter during target maneuver.

  2. Self-assembling, dynamic alphaPNAs

    DEFF Research Database (Denmark)

    Nielsen, Peter E

    2009-01-01

    In the recent report published in Science, Ghadiri and coworkers describe dynamic tPNAs, alphaPNA derivatives with a nucleobase attached via a thioester bond that are a step forward toward self-repairing and replicating molecules.......In the recent report published in Science, Ghadiri and coworkers describe dynamic tPNAs, alphaPNA derivatives with a nucleobase attached via a thioester bond that are a step forward toward self-repairing and replicating molecules....

  3. Dynamical Screening Effect on $\\alpha$-$\\alpha$ Resonant Scattering and Thermal Nuclear Scattering Rate

    CERN Document Server

    Yao, Xiaojun; Müller, Berndt

    2016-01-01

    We study the dynamical screening effect in the QED plasma on the $\\alpha$-$\\alpha$ scattering at the $^8$Be resonance. Dynamical screening leads to an imaginary part of the potential which results in a thermal width for the resonance and dominates over the previously considered static screening effect. As a result, both the resonance energy and width increase with the plasma temperature. Furthermore, dynamical screening can have a huge impact on the $\\alpha$-$\\alpha$ thermal nuclear scattering rate. For example, when the temperature is around $10$ keV, the rate is suppressed by a factor of about $900$. We expect similar thermal suppressions of nuclear reaction rates to occur in nuclear reactions dominated by an above threshold resonance with a thermal energy. Dynamical screening effects on nuclear reactions can be relevant to cosmology and astrophysics.

  4. Mapping the Dynamics of a Giant Ly-alpha Halo at z=4.1 with MUSE: The Energetics of a Large Scale AGN-Driven Outflow around a Massive, High-Redshift Galaxy

    CERN Document Server

    Swinbank, Mark; Smail, Ian; De Breuck, Carlos; Bacon, Roland; Contini, Thierry; Richard, Johan; Rottgering, Huub; Urritia, Tanya; Venemans, Bram

    2015-01-01

    We present deep MUSE integral-field unit (IFU) spectroscopic observations of the giant (~150 x 80 kpc) Ly-alpha halo around the z=4.1 radio galaxy TNJ J1338-1942. This 9-hr observation maps the two-dimensional kinematics of the Ly-alpha emission across the halo. We identify two HI absorbers which are seen against the Ly-alpha emission, both of which cover the full 150 x 80 kpc extent of the halo and so have covering fractions ~1. The stronger and more blue-shifted absorber (dv~1200 km/s) has dynamics that mirror that of the underlying halo emission and we suggest that this high column material (n(HI) ~ 10^19.4 /cm^2), which is also seen in CIV absorption, represents an out-flowing shell that has been driven by the AGN (or star formation) within the galaxy. The weaker (n(HI)~10^14 /cm^2) and less blue shifted (dv~500 km/s) absorber most likely represents material in the cavity between the out-flowing shell and the Ly-alpha halo. We estimate that the mass in the shell must be of order 10^10 Msol -- a significan...

  5. Dynamical quenching with non-local alpha and downward pumping

    CERN Document Server

    Brandenburg, A; Käpylä, P J

    2014-01-01

    In light of new results, the one-dimensional mean-field dynamo model of Brandenburg & Kapyla (2007) with dynamical quenching and a nonlocal Babcock-Leighton alpha effect is re-examined for the solar dynamo. We extend the one-dimensional model to include the effects of turbulent downward pumping (Kitchatinov & Olemskoy 2011), and to combine dynamical quenching with shear. We use both the conventional dynamical quenching model of Kleeorin & Ruzmaikin (1982) and the alternate one of Hubbard & Brandenburg (2011), and confirm that with varying levels of non-locality in the alpha effect, and possibly shear as well, the saturation field strength can be independent of the magnetic Reynolds number.

  6. The Dynamical Masses, Densities, and Star Formation Scaling Relations of Lyman Alpha Galaxies

    CERN Document Server

    Rhoads, James E; Finkelstein, Steven L; Fynbo, Johan P U; McLinden, Emily M; Richardson, Mark L A; Tilvi, Vithal S

    2013-01-01

    We present the first dynamical mass measurements for Lyman alpha galaxies at high redshift, based on velocity dispersion measurements from rest-frame optical emission lines and size measurements from HST imaging, for a sample of nine galaxies drawn from four surveys. These measurements enable us to study the nature of Lyman alpha galaxies in the context of galaxy scaling relations. The resulting dynamical masses range from 1e9 to 1e10 solar masses. We also fit stellar population models to our sample, and use them to plot the Lyman alpha sample on a stellar mass vs. line width relation. Overall, the Lyman alpha galaxies follow well the scaling relation established by observing star forming galaxies at lower redshift (and without regard for Lyman alpha emission), though in 1/3 of the Lyman alpha galaxies, lower-mass fits are also acceptable. In all cases, the dynamical masses agree with established stellarmass-linewidth relation. Using the dynamical masses as an upper limit on gas mass, we show that Lyman alpha...

  7. Dynamic spatiotemporal variability of alpha-BOLD relationships during the resting-state and task-evoked responses.

    Science.gov (United States)

    Mayhew, S D; Bagshaw, A P

    2017-07-15

    Accurate characterization of the spatiotemporal relationship between two of the most prominent neuroimaging measures of neuronal activity, the 8-13Hz, occipito-parietal EEG alpha oscillation and the BOLD fMRI signal, must encompass the intrinsically dynamic nature of both alpha power and brain function. Here, during the eyes-open resting state, we use a 16s sliding-window analysis and demonstrate that the mean spatial network of dynamic alpha-BOLD correlations is highly comparable to the static network calculated over six minutes. However, alpha-BOLD correlations showed substantial spatiotemporal variability within-subjects and passed through many different configurations such that the static network was fully represented in only ~10% of 16s epochs, with visual and parietal regions (coherent on average) often opposingly correlated with each other or with alpha. We find that the common assumption of static-alpha BOLD correlations greatly oversimplifies temporal variation in brain network dynamics. Fluctuations in alpha-BOLD coupling significantly depended upon the instantaneous amplitude of alpha power, and primary and lateral visual areas were most strongly negatively correlated with alpha during different alpha power states, possibly suggesting the action of multiple alpha mechanisms. Dynamic alpha-BOLD correlations could not be explained by eye-blinks/movements, head motion or non-neuronal physiological variability. Individual's mean alpha power and frequency were found to contribute to between-subject variability in alpha-BOLD correlations. Additionally, application to a visual stimulation dataset showed that dynamic alpha-BOLD correlations provided functional information pertaining to the brain's response to stimulation by exhibiting spatiotemporal fluctuations related to variability in the trial-by-trial BOLD response magnitude. Significantly weaker visual alpha-BOLD correlations were found both preceding and following small amplitude BOLD response trials

  8. Bias in Dynamic Monte Carlo Alpha Calculations

    Energy Technology Data Exchange (ETDEWEB)

    Sweezy, Jeremy Ed [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Nolen, Steven Douglas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Adams, Terry R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Trahan, Travis John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-02-06

    A 1/N bias in the estimate of the neutron time-constant (commonly denoted as α) has been seen in dynamic neutronic calculations performed with MCATK. In this paper we show that the bias is most likely caused by taking the logarithm of a stochastic quantity. We also investigate the known bias due to the particle population control method used in MCATK. We conclude that this bias due to the particle population control method is negligible compared to other sources of bias.

  9. A dynamical $\\alpha$-cluster model of $^{16}$O

    CERN Document Server

    Halcrow, C J; Manton, N S

    2016-01-01

    We calculate the low-lying spectrum of the $^{16}$O nucleus using an $\\alpha$-cluster model which includes the important tetrahedral and square configurations. Our approach is motivated by the dynamics of $\\alpha$-particle scattering in the Skyrme model. We are able to replicate the large energy splitting that is observed between states of identical spin but opposite parities, as well as introduce states that were previously not found in other cluster models, such as a $0^-$ state. We also provide a novel interpretation of the first excited state of $^{16}$O and make predictions for the energies of $6^-$ states that have yet to be observed experimentally.

  10. Mapping High-Velocity H-alpha and Lyman-alpha Emission from Supernova 1987A

    Science.gov (United States)

    France, Kevin; McCray, Richard; Fransson, Claes; Larsson, Josefin; Frank, Kari A.; Burrows, David N.; Challis, Peter; Kirshner, Robert P.; Chevalier, Roger A.; Garnavich, Peter; Heng, Kevin; Lawrence, Stephen S.; Lundqvist, Peter; Smith, Nathan; Sonneborn, George

    2015-01-01

    We present new Hubble Space Telescope images of high-velocity H-alpha and Lyman-alpha emission in the outer debris of SN 1987A. The H-alpha images are dominated by emission from hydrogen atoms crossing the reverse shock. For the first time we observe emission from the reverse shock surface well above and below the equatorial ring, suggesting a bipolar or conical structure perpendicular to the ring plane. Using the H-alpha imaging, we measure the mass flux of hydrogen atoms crossing the reverse shock front, in the velocity intervals (-7,500 < V(sub obs) < -2,800 km/s) and (1,000 < V(sub obs) < 7,500 km/s), ?M(sub H) = 1.2 × 10(exp -3) M/ y. We also present the first Lyman-alpha imaging of the whole remnant and new Chandra X-ray observations. Comparing the spatial distribution of the Lyman-alpha and X-ray emission, we observe that the majority of the high-velocity Lyman-alpha emission originates interior to the equatorial ring. The observed Lyman-alpha/H-alpha photon ratio, R(L-alpha/H-alpha) approx. = 17, is significantly higher than the theoretically predicted ratio of approx. = 5 for neutral atoms crossing the reverse shock front. We attribute this excess to Lyman-alpha emission produced by X-ray heating of the outer debris. The spatial orientation of the Lyman-alpha and X-ray emission suggests that X-ray heating of the outer debris is the dominant Lyman-alpha production mechanism in SN 1987A at this phase in its evolution.

  11. High precision $^{89}$Y($\\alpha$,$\\alpha$)$^{89}$Y scattering at low energies

    CERN Document Server

    Kiss, G G; \\, Zs; Fülöp,; Galaviz, D; Gyürky, Gy; Elekes, Z; Somorjai, E; Kretschmer, A; Sonnabend, K; Zilges, A; Avrigeanu, M

    2010-01-01

    Elastic scattering cross sections of the $^{89}$Y($\\alpha$,$\\alpha$)$^{89}$Y reaction have been measured at energies E$_{c.m.}$ = 15.51 and 18.63 MeV. The high precision data for the semi-magic $N = 50$ nucleus $^{89}$Y are used to derive a local potential and to evaluate the predictions of global and regional $\\alpha$-nucleus potentials. The variation of the elastic alpha scattering cross sections along the $N = 50$ isotonic chain is investigated by a study of the ratios of angular distributions for $^{89}$Y($\\alpha$,$\\alpha$)$^{89}$Y and $^{92}$Mo($\\alpha$,$\\alpha$)$^{92}$Mo at E$_{c.m.} \\approx$ 15.51 and 18.63 MeV. This ratio is a very sensitive probe at energies close to the Coulomb barrier, where scattering data alone is usually not enough to characterize the different potentials. Furthermore, $\\alpha$-cluster states in $^{93}$Nb = $^{89}$Y $\\otimes$ $\\alpha$ are investigated.

  12. Mapping High-velocity H-alpha and Lyman-alpha Emission from Supernova 1987A

    OpenAIRE

    France, Kevin; McCray, Richard; Fransson, Claes; Larsson, Josefin; Frank, Kari A.; Burrows, David N.; Challis, Peter; Kirshner, Robert P.; Chevalier, Roger A.; Garnavich, Peter; Heng, Kevin; Lawrence, Stephen S.; Lundqvist, Peter; Smith, Nathan; Sonneborn, George

    2015-01-01

    We present new {\\it Hubble Space Telescope} images of high-velocity H-$\\alpha$ and Lyman-$\\alpha$ emission in the outer debris of SN~1987A. The H-$\\alpha$ images are dominated by emission from hydrogen atoms crossing the reverse shock. For the first time we observe emission from the reverse shock surface well above and below the equatorial ring, suggesting a bipolar or conical structure perpendicular to the ring plane. Using the H$\\alpha$ imaging, we measure the mass flux of hydrogen atoms cr...

  13. High collection efficiency CVD diamond alpha detectors

    Energy Technology Data Exchange (ETDEWEB)

    Bergonzo, P.; Foulon, F.; Marshall, R.D.; Jany, C.; Brambilla, A. [CEA/Saclay, Gif-sur-Yvette (France); McKeag, R.D.; Jackman, R.B. [University College London (United Kingdom). Electronic and Electrical Engineering Dept.

    1998-06-01

    Advances in Chemical Vapor Deposited (CVD) diamond have enabled the routine use of this material for sensor device fabrication, allowing exploitation of its unique combination of physical properties (low temperature susceptibility (> 500 C), high resistance to radiation damage (> 100 Mrad) and to corrosive media). A consequence of CVD diamond growth on silicon is the formation of polycrystalline films which has a profound influence on the physical and electronic properties with respect to those measured on monocrystalline diamond. The authors report the optimization of physical and geometrical device parameters for radiation detection in the counting mode. Sandwich and co-planar electrode geometries are tested and their performances evaluated with regard to the nature of the field profile and drift distances inherent in such devices. The carrier drift length before trapping was measured under alpha particles and values as high as 40% of the overall film thickness are reported. Further, by optimizing the device geometry, they show that a gain in collection efficiency, defined as the induced charge divided by the deposited charge within the material, can be achieved even though lower bias values are used.

  14. High enthalpy gas dynamics

    CERN Document Server

    Rathakrishnan, Ethirajan

    2014-01-01

    This is an introductory level textbook which explains the elements of high temperature and high-speed gas dynamics. written in a clear and easy to follow style, the author covers all the latest developments in the field including basic thermodynamic principles, compressible flow regimes and waves propagation in one volume covers theoretical modeling of High Enthalpy Flows, with particular focus on problems in internal and external gas-dynamic flows, of interest in the fields of rockets propulsion and hypersonic aerodynamics High enthalpy gas dynamics is a compulsory course for aerospace engine

  15. Non-slow-roll dynamics in $\\alpha-$attractors

    CERN Document Server

    Kumar, K Sravan; Moniz, Paulo Vargas; Das, Suratna

    2015-01-01

    In this paper we consider the $\\alpha-$attractor model and study inflation under a generalization of slow-roll dynamics. We follow the recently proposed Gong \\& Sasaki approach \\cite{Gong:2015ypa} of assuming $N=N\\left(\\phi\\right)$. We relax the requirement of inflaton potential flatness and consider a sufficiently steep one to support 60-efoldings. We find that this type of inflationary scenario predicts an attractor at $n_{s}\\approx0.967$ and $r\\approx5.5\\times10^{-4}$ which are very close to the predictions of the first chaotic inflationary model in supergravity (Goncharov-Linde model) \\cite{Goncharov:1983mw}. We show that even with non-slow-roll dynamics, the $\\alpha-$attractor model is compatible with any value of $r<0.1$. In addition, we emphasize that in this particular inflationary scenario, the standard consistency relation $\\left(r\\simeq-8n_{t}\\right)$ is significantly violated and we find an attractor for tensor tilt at $n_{t}\\approx-0.034$ as $r\\rightarrow0$. Any prominent detection of the ...

  16. Mapping of barley alpha-amylases and outer subsite mutants reveals dynamic high-affinity subsites and barriers in the long substrate binding cleft

    DEFF Research Database (Denmark)

    Kandra, L.; Abou Hachem, Maher; Gyemant, G.;

    2006-01-01

    as binding barriers. Barley a-amylase I mutants Y105A and T212Y at subsite -6 and +4 resulted in release or anchoring of bound substrate, thus modifying the affinities of other high-affinity subsites (-2 and +2) and barriers. The double mutant Y105A-T212Y displayed a hybrid subsite affinity profile...

  17. Proceedings, High-Precision $\\alpha_s$ Measurements from LHC to FCC-ee

    Energy Technology Data Exchange (ETDEWEB)

    d' Enterria, David [CERN; Skands, Peter Z. [Monash U.

    2015-01-01

    This document provides a writeup of all contributions to the workshop on "High precision measurements of $\\alpha_s$: From LHC to FCC-ee" held at CERN, Oct. 12--13, 2015. The workshop explored in depth the latest developments on the determination of the QCD coupling $\\alpha_s$ from 15 methods where high precision measurements are (or will be) available. Those include low-energy observables: (i) lattice QCD, (ii) pion decay factor, (iii) quarkonia and (iv) $\\tau$ decays, (v) soft parton-to-hadron fragmentation functions, as well as high-energy observables: (vi) global fits of parton distribution functions, (vii) hard parton-to-hadron fragmentation functions, (viii) jets in $e^\\pm$p DIS and $\\gamma$-p photoproduction, (ix) photon structure function in $\\gamma$-$\\gamma$, (x) event shapes and (xi) jet cross sections in $e^+e^-$ collisions, (xii) W boson and (xiii) Z boson decays, and (xiv) jets and (xv) top-quark cross sections in proton-(anti)proton collisions. The current status of the theoretical and experimental uncertainties associated to each extraction method, the improvements expected from LHC data in the coming years, and future perspectives achievable in $e^+e^-$ collisions at the Future Circular Collider (FCC-ee) with $\\cal{O}$(1--100 ab$^{-1}$) integrated luminosities yielding 10$^{12}$ Z bosons and jets, and 10$^{8}$ W bosons and $\\tau$ leptons, are thoroughly reviewed. The current uncertainty of the (preliminary) 2015 strong coupling world-average value, $\\alpha_s(m_Z)$ = 0.1177 $\\pm$ 0.0013, is about 1\\%. Some participants believed this may be reduced by a factor of three in the near future by including novel high-precision observables, although this opinion was not universally shared. At the FCC-ee facility, a factor of ten reduction in the $\\alpha_s$ uncertainty should be possible, mostly thanks to the huge Z and W data samples available.

  18. Anti-pp,. cap alpha cap alpha. and p. cap alpha. elastic scattering at high energies and Chou-Yang conjecture

    Energy Technology Data Exchange (ETDEWEB)

    Saleem, M.; Fazal-e-Aleem; Rifique, M.

    1987-03-01

    The recent experimental measurements for anti-pp and ..cap alpha cap alpha.. elastic scattering at high energies have shown that the Chou-Yang conjecture regarding the relationship between the electromagnetic and the hadronic form factor of a particle is only an approximation. A new ansatz has been proposed to obtain hadronic form factors of proton and the ..cap alpha..-particle. These form factors have been used to explain the various characteristics of anti-pp, ..cap alpha cap alpha.. and p..cap alpha.. elastic scattering at high energies.

  19. Workshop on High-precision $\\alpha_s$ measurements from LHC to FCC-ee

    CERN Document Server

    S. Alekhin; d'Enterria, David; A. Banfi; S. Bethke; J. Blümlein; K.G. Chetyrkin; D. d’Enterria; G. Dissertori; X. Garcia i Tormo; A. H. Hoang; M. Klasen; T. Klijnsma; S. Kluth; J.-L. Kneur; B.A. Kniehl; D. W. Kolodrubetz; J. Kühn; P. Mackenzie; B. Malaescu; V. Mateu; L. Mihaila; S. Moch; K. Mönig; R. Pérez-Ramos; A. Pich; J. Pires; K. Rabbertz; G. P. Salam; F. Sannino; J. Soto i Riera; M. Srebre; I. W. Stewart

    2015-01-01

    This document provides a writeup of all contributions to the workshop on "High precision measurements of $\\alpha_s$: From LHC to FCC-ee" held at CERN, Oct. 12--13, 2015. The workshop explored in depth the latest developments on the determination of the QCD coupling $\\alpha_s$ from 15 methods where high precision measurements are (or will be) available. Those include low-energy observables: (i) lattice QCD, (ii) pion decay factor, (iii) quarkonia and (iv) $\\tau$ decays, (v) soft parton-to-hadron fragmentation functions, as well as high-energy observables: (vi) global fits of parton distribution functions, (vii) hard parton-to-hadron fragmentation functions, (viii) jets in $e^\\pm$p DIS and $\\gamma$-p photoproduction, (ix) photon structure function in $\\gamma$-$\\gamma$, (x) event shapes and (xi) jet cross sections in $e^+e^-$ collisions, (xii) W boson and (xiii) Z boson decays, and (xiv) jets and (xv) top-quark cross sections in proton-(anti)proton collisions. The current status of the theoretical and experiment...

  20. Accretion disk dynamics: {\\alpha}-viscosity in self-similar self-gravitating models

    CERN Document Server

    Kubsch, Marcus; Duschl, W J

    2016-01-01

    Aims: We investigate the suitability of {\\alpha}-viscosity in self-similar models for self-gravitating disks with a focus on active galactic nuclei (AGN) disks. Methods: We use a self-similar approach to simplify the partial differential equations arising from the evolution equation, which are then solved using numerical standard procedures. Results: We find a self-similar solution for the dynamical evolution of self-gravitating {\\alpha}-disks and derive the significant quantities. In the Keplerian part of the disk our model is consistent with standard stationary {\\alpha}-disk theory, and self-consistent throughout the self-gravitating regime. Positive accretion rates throughout the disk demand a high degree of self-gravitation. Combined with the temporal decline of the accretion rate and its low amount, the model prohibits the growth of large central masses. Conclusions: {\\alpha}-viscosity cannot account for the evolution of the whole mass spectrum of super-massive black holes (SMBH) in AGN. However, conside...

  1. Acute toxicity of high doses of the glycoalkaloids, alpha-solanine and alpha-chaconine, in the Syrian Golden hamster

    DEFF Research Database (Denmark)

    Langkilde, Søren; Schrøder, Malene; Stewart, Derek

    2008-01-01

    Sprouted, stressed, or spoiled potato tubers have reportedly led to human acute intoxication, coma, and death when consumed in high amounts. These effects have been attributed to glycoalkaloids (GAs), primarily alpha-solanine and alpha-chaconine, naturally present in all potatoes. The level of GAs...... in potato tubers has previously been shown to increase substantially as a result of improper handling and postharvest storage. A short-term study was performed to investigate the dose-response profile of alpha-solanine and alpha-chaconine alone or in combination, administered daily by oral gavage to Syrian...... Golden hamsters. Daily doses of 100 mg of alpha-solanine [kg body weight (BW)](-1) induced death in two of four hamsters within 4 days, when administered by gavage to female Syrian hamsters. Doses of 100 mg of alpha-chaconine alone or alpha-solanine and alpha-chaconine combined in a ratio of 1...

  2. Dynamical stability of the alpha and theta phases of alumina

    DEFF Research Database (Denmark)

    Lodziana, Zbigniew; Parlinski, K.

    2003-01-01

    Using density functional calculations the phonon dispersion relations, phonon density of states, and free energy of theta and alpha phases of alumina are investigated. The temperature dependence of the free energy indicates that entropy contributes to the destabilization of the alpha phase...

  3. Preliminary experiments: High-energy alpha PIXE in archaeometry

    Energy Technology Data Exchange (ETDEWEB)

    Dupuis, Thomas, E-mail: T.Dupuis@ulg.ac.b [Centre Europeen d' Archeometrie, Atomique et Spectroscopie, Universite de Liege, Sart Tilman B15, B-4000 Liege (Belgium); Institut de Physique Nucleaire, Atomique et Spectroscopie, Universite de Liege, Sart Tilman B15, B-4000 Liege (Belgium); Chene, G.; Mathis, F. [Centre Europeen d' Archeometrie, Atomique et Spectroscopie, Universite de Liege, Sart Tilman B15, B-4000 Liege (Belgium); Institut de Physique Nucleaire, Atomique et Spectroscopie, Universite de Liege, Sart Tilman B15, B-4000 Liege (Belgium); Marchal, A.; Philippe, M.; Garnir, H.-P. [Institut de Physique Nucleaire, Atomique et Spectroscopie, Universite de Liege, Sart Tilman B15, B-4000 Liege (Belgium); Strivay, D. [Centre Europeen d' Archeometrie, Atomique et Spectroscopie, Universite de Liege, Sart Tilman B15, B-4000 Liege (Belgium); Institut de Physique Nucleaire, Atomique et Spectroscopie, Universite de Liege, Sart Tilman B15, B-4000 Liege (Belgium)

    2010-06-15

    This paper describes the work realized at the 'Centre Europeen d'Archeometrie' to highlight the utility of high-energy alpha PIXE in the particular field of archaeometry and to introduce the developments done and to be done to complete the knowledge of high-energy alpha PIXE. It starts with the comparison of the yield and the noise background between several alpha particle beams and the comparison between alpha particle and proton beams on different thick and thin references. After, this paper depicts the developments done at the 'Institut de Physique Nucleaire, Atomique et Spectroscopie' to perform such high-energy experiments, first on standards and later on cultural heritage objects. Moreover, it introduces the problematics of such beams for the quantification in PIXE by the intermediary of the knowledge of the ionization and X-ray production cross-sections and also the developments done to answer to this serious lack in the databases.

  4. Highly sensitive bolometers for rare alpha decay studies

    Directory of Open Access Journals (Sweden)

    Gironi L.

    2014-03-01

    Full Text Available High resolution detectors able to identify background events are very appealing in the study of rare nuclear processes. Scintillating bolometers featuring simultaneous read-out of heat and scintillation signals, can effectively address this problem thanks to the possibility to discriminate different ionizing particles and achieve background free experiments. With this technique it has already been possible to measure rare alpha decays never observed before or improve by orders of magnitude the existing limits.

  5. Lattice dynamics of {alpha} boron and of boron carbide; Proprietes vibrationnelles du bore {alpha} et du carbure de bore

    Energy Technology Data Exchange (ETDEWEB)

    Vast, N

    1999-07-01

    The atomic structure and the lattice dynamics of {alpha} boron and of B{sub 4}C boron carbide have been studied by Density Functional Theory (D.F.T.) and Density Functional Perturbation Theory (D.F.P.T.). The bulk moduli of the unit-cell and of the icosahedron have been investigated, and the equation of state at zero temperature has been determined. In {alpha} boron, Raman diffusion and infrared absorption have been studied under pressure, and the theoretical and experimental Grueneisen coefficients have been compared. In boron carbide, inspection of the theoretical and experimental vibrational spectra has led to the determination of the atomic structure of B{sub 4}C. Finally, the effects of isotopic disorder have been modeled by an exact method beyond the mean-field approximation, and the effects onto the Raman lines has been investigated. The method has been applied to isotopic alloys of diamond and germanium. (author)

  6. The Ly$\\alpha$ emission from high-$z$ galaxies hosting strong Damped Ly$\\alpha$ systems

    CERN Document Server

    Joshi, Ravi; Noterdaeme, Pasquier; Petitjean, Patrick

    2016-01-01

    We study the average Ly$\\alpha$ emission associated with high-$z$ strong (log $N$(H I) $\\ge$ 21) damped Ly$\\alpha$ systems (DLAs). We report Ly$\\alpha$ luminosities ($L_{\\rm Ly\\alpha}$) for the full as well as various sub-samples based on $N$(H I), $z$, $(r-i)$ colours of QSOs and rest equivalent width of Si II$\\lambda$1526 line (i.e., $W_{1526}$). For the full sample, we find $L_{\\rm Ly\\alpha}$$< 10^{41} (3\\sigma)\\ \\rm erg\\ s^{-1}$ with a $2.8\\sigma$ level detection of Ly$\\alpha$ emission in the red part of the DLA trough. The $L_{\\rm Ly\\alpha}$ is found to be higher for systems with higher $W_{1526}$ with its peak, detected at $\\geq 3\\sigma$, redshifted by about 300-400 $\\rm km\\ s^{-1}$ with respect to the systemic absorption redshift, as seen in Lyman Break Galaxies (LBGs) and Ly$\\alpha$ emitters. A clear signature of a double-hump Ly$\\alpha$ profile is seen when we consider $W_{1526} \\ge 0.4$ \\AA\\ and $(r-i) < 0.05$. Based on the known correlation between metallicity and $W_{1526}$, we interpret our...

  7. DFT Molecular Dynamics (DFTMD) Simulations of Carbohydrates: I. COSMO Solvated Alpha-maltose

    Science.gov (United States)

    Density functional molecular dynamics (DFTMD) is carried out on low-energy conformations of alpha-maltose. Finite temperature molecular dynamics trajectories are generated with forces obtained from B3LYP/6-31+G* electronic structure calculations. The implicit solvent method COSMO is applied to sim...

  8. Molecular dynamics simulations from putative transition states of alpha-spectrin SH3 domain

    NARCIS (Netherlands)

    Periole, Xavier; Vendruscolo, Michele; Mark, Alan E.

    2007-01-01

    A series of molecular dynamics simulations in explicit solvent were started from nine structural models of the transition state of the SH3 domain of alpha-spectrin, which were generated by Lindorff Larsen et al. (Nat Struct Mol Biol 2004;11:443-449) using molecular dynamics simulations in which expe

  9. High maltose-producing. cap alpha. -amylase of Penicillium expansum

    Energy Technology Data Exchange (ETDEWEB)

    Doyle, E.M.; Kelly, C.T.; Fogarty, W.M.

    1989-05-01

    An ..cap alpha..-amylase capable of producing exceptionally high levels of maltose (74%) from starch has been identified from a strain of Penicillium expansum. The enzyme is produced extracellularly and was purified to homogeneity by starch adsorption and Sephadex gel filtration chromatography. P. expansum ..cap alpha..-amylase has a pH optimum of 4.5 and is stable in the pH range of 3.6-6.0. Other properties include a temperature optimum of 60/sup 0/C, a molecular weight of 69 000 and and isoelectrtic point of 3.9. The most outstanding feature of the P. expansum enzyme is its ability to yield 14% more maltose and 17.1% less maltotriose than a currently used commercial enzyme. This may be partly explained by the greater affinity of this new enzyme for maltotriose (K/sub m/=0.76 mM) relative to the commercial enzyme, Fungamyl (K/sub m/=2.9 mM). The enzyme reported here is unique among fungal ..cap alpha..-amylases in being able to produce such high levels of maltose and its physicochemical properties suggest that it has potential for commercial development.

  10. Alpha-clustered hypernuclei and chiral SU(3) dynamics

    CERN Document Server

    Hiyama, Emiko; Kaiser, Norbert; Weise, Wolfram

    2013-01-01

    Light hypernuclei with an $\\alpha$ cluster substructure of the core nucleus are studied using an accurate cluster approach (the Hyper-THSR wave function) in combination with a density-dependent $\\Lambda$ hyperon-nuclear interaction derived from chiral SU(3) effective field theory. This interaction includes important two-pion exchange processes involving $\\Sigma N$ intermediate states and associated three-body mechanisms as well as effective mass and surface terms arising in a derivative expansion of the in-medium $\\Lambda$ self-energy. Applications and calculated results are presented and discussed for $_\\Lambda^9$Be and $^{13}_\\Lambda$C. Furthermore, the result of the lightest $\\alpha$ clustered hypernucleus, $^5_{\\Lambda}$He using realistic $ab initio$ four nucleon density is shown.

  11. Acute toxicity of high doses of the glycoalkaloids, alpha-solanine and alpha-chaconine, in the Syrian Golden hamster.

    Science.gov (United States)

    Langkilde, Søren; Schrøder, Malene; Stewart, Derek; Meyer, Otto; Conner, Sean; Davies, Howard; Poulsen, Morten

    2008-09-24

    Sprouted, stressed, or spoiled potato tubers have reportedly led to human acute intoxication, coma, and death when consumed in high amounts. These effects have been attributed to glycoalkaloids (GAs), primarily alpha-solanine and alpha-chaconine, naturally present in all potatoes. The level of GAs in potato tubers has previously been shown to increase substantially as a result of improper handling and postharvest storage. A short-term study was performed to investigate the dose-response profile of alpha-solanine and alpha-chaconine alone or in combination, administered daily by oral gavage to Syrian Golden hamsters. Daily doses of 100 mg of alpha-solanine [kg body weight (BW)] (-1) induced death in two of four hamsters within 4 days, when administered by gavage to female Syrian hamsters. Doses of 100 mg of alpha-chaconine alone or alpha-solanine and alpha-chaconine combined in a ratio of 1:2.5, in doses of 75 or 100 mg (kg BW) (-1), induced death in one of four hamsters within the same period. Animals dosed with alpha-solanine alone or in combination with alpha-chaconine suffered from fluid-filled and dilated small intestines. The GA administration had no effect on acetyl cholinesterase (AChE) or butyryl cholinesterase (BuChE) activity in plasma or brain. Liquid chromatography-mass spectrometry-based metabolomics showed that there was a specific accumulation of alpha-chaconine in the liver tissues. In addition, metabolomics gave direct evidence of glycolytic metabolism of the GA with the beta 1, beta 2, and gamma-GAs detected in the urine and, to a lesser extent, the feces. Doses from 75 mg (kg BW) (-1) of alpha-chaconine, alpha-solanine, or the two compounds combined were potentially lethal within 4-5 days in the Syrian Golden hamster. However, the cause of death in these studies could not be established. No synergistic effects of alpha-solanine combined with alpha-chaconine were evident.

  12. Elastic properties of {alpha}-iron at high temperatures by high-pressure neutron scattering

    Energy Technology Data Exchange (ETDEWEB)

    Klotz, S; Cornelius, A L; Philippe, J [IMPMC, Universite P and M Curie, 4 Place Jussieu, C115, 75252 Paris (France); Straessle, Th; Pomjakushin, V, E-mail: Stefan.Klotz@impmc.upmc.fr [Laboratory for Neutron Scattering, Paul Scherrer Institut, 5232 Villigen PSI (Switzerland)

    2011-02-09

    We present high pressure-high temperature neutron diffraction data of {alpha}-iron in the 0-8 GPa and 300-550 K range. We find the isochors of {alpha}-iron strictly parallel to those of {epsilon}-iron, except at high P/T when the {alpha}-{gamma}-{epsilon} triple point to the non-magnetic {gamma}- and {epsilon}-phases is approached. This gives evidence for magnetoelastic effects in {alpha}-iron at high P/T. The measurements have been made possible by the use of a cell which enables neutron diffraction by external heating in the 0-10 GPa range and to at least 550 K. The technique should have numerous applications in research on condensed matter using neutrons.

  13. Hot working of high purity Fe-C alloys in the {alpha}-range

    Energy Technology Data Exchange (ETDEWEB)

    Montheillet, F; Le Coze, J, E-mail: montheil@emse.f [Ecole des Mines (SMS), CNRS UMR 5146, 158 cours Fauriel, 42023 Saint-Etienne Cedex 2 (France)

    2010-07-01

    The influence of carbon in solid solution on the stress-strain curves of {alpha}-iron was investigated using model alloys prepared from high purity iron. Uniaxial compression tests were carried out within the ferritic domain at temperatures between 700 and 880 {sup 0}C. Oscillating stress-strain curves observed at high temperatures and low strain rates indicate that discontinuous dynamic recrystallization takes place. The macroscopic strain rate sensitivities m and apparent activation energies Q associated with the flow stress are not significantly modified by carbon additions. By contrast, the 'mesoscopic' parameters h and r associated with strain hardening and dynamic recovery, respectively, are strongly dependent on the carbon content. Finally, an estimation of the grain boundary mobilities during dynamic recrystallization was carried out from the above rheological data.

  14. Mutagenesis of p38alpha MAP Kinase Establishes Key Roles of Phe169 in Function and Structural Dynamics and Reveals a Novel DFG-OUT State

    Energy Technology Data Exchange (ETDEWEB)

    Bukhtiyarova,M.; Karpusas, M.; Northrup, K.; Namboodiri, H.; Springman, E.

    2007-01-01

    In order to study the role of Phe169 in p38{alpha} MAP kinase structure and function, wild-type p38{alpha} and five p38{alpha} DFG motif mutants were examined in vitro for phosphorylation by MKK6, kinase activity toward ATF2 substrate, thermal stability, and X-ray crystal structure. All six p38{alpha} variants were efficiently phosphorylated by MKK6. However, only one activated p38{alpha} mutant (F169Y) possessed measurable kinase activity (1% compared to wild-type). The loss of kinase activity among the DFG mutants may result from an inability to correctly position Asp168 in the activated form of p38{alpha}. Two mutations significantly increased the thermal stability of p38{alpha} (F169A {Delta}T{sub m} = 1.3 {sup o}C and D168G {Delta}T{sub m} = 3.8 {sup o}C), and two mutations significantly decreased the stability of p38{alpha} (F169R {Delta}T{sub m} = -3.2 {sup o}C and F169G {Delta}T{sub m} = -4.7 {sup o}C). Interestingly, X-ray crystal structures of two thermally destabilized p38{alpha}-F169R and p38{alpha}-F169G mutants revealed a DFG-OUT conformation in the absence of an inhibitor molecule. This DFG-OUT conformation, termed {alpha}-DFG-OUT, is different from the ones previously identified in p38{alpha} crystal structures with bound inhibitors and postulated from high-temperature molecular dynamics simulations. Taken together, these results indicate that Phe169 is optimized for p38{alpha} functional activity and structural dynamics, rather than for structural stability. The {alpha}-DFG-OUT conformation observed for p38{alpha}-F169R and p38{alpha}-F169G may represent a naturally occurring intermediate state of p38{alpha} that provides access for binding of allosteric inhibitors. A model of the local forces driving the DFG IN-OUT transition in p38{alpha} is proposed.

  15. {alpha}-Glycine under high pressures: a Raman scattering study

    Energy Technology Data Exchange (ETDEWEB)

    Murli, Chitra; Sharma, S.M.Surinder M.; Karmakar, S.; Sikka, S.K

    2003-11-01

    High-pressure behaviour of {alpha}-glycine has been investigated up to {approx}23 GPa using Raman scattering technique. The experimental results show slope change in the CO{sub 2} bending, NH{sub 3} torsional and NH{sub 3} rocking modes around 3 GPa and are interpreted in terms of change in the nature of an N-H...O-C intra-layer hydrogen bond at this pressure. Several other spectral features seem to arise from pressure-induced variations in the inter-molecular coupling.

  16. Infrared optical properties of $\\alpha$ quartz by molecular dynamics simulations

    CERN Document Server

    Gangemi, Fabrizio; Carati, Andrea; Maiocchi, Alberto; Galgani, Luigi

    2016-01-01

    This paper is concerned with theoretical estimates of the refractive--index curves for quartz, obtained by the Kubo formul\\ae\\ in the classical approximation, through MD simulations for the motions of the ions. Two objectives are considered. The first one is to understand the role of nonlinearities in situations where they are very large, as at the $\\alpha$--$\\beta$ structural phase transition. We show that on the one hand they don't play an essential role in connection with the form of the spectra in the infrared. On the other hand they play an essential role in introducing a chaoticity which involves a definite normal mode. This might explain why that mode is Raman active in the $\\alpha$ phase, but not in the $\\beta$ phase. The second objective concerns whether it is possible in a microscopic model to obtain normal mode frequencies, or peak frequencies in the optical spectra, that are in good agreement with the experimental data for quartz. Notwithstanding a lot of effort, we were unable to find results agr...

  17. High dynamic range subjective testing

    Science.gov (United States)

    Allan, Brahim; Nilsson, Mike

    2016-09-01

    This paper describes of a set of subjective tests that the authors have carried out to assess the end user perception of video encoded with High Dynamic Range technology when viewed in a typical home environment. Viewers scored individual single clips of content, presented in High Definition (HD) and Ultra High Definition (UHD), in Standard Dynamic Range (SDR), and in High Dynamic Range (HDR) using both the Perceptual Quantizer (PQ) and Hybrid Log Gamma (HLG) transfer characteristics, and presented in SDR as the backwards compatible rendering of the HLG representation. The quality of SDR HD was improved by approximately equal amounts by either increasing the dynamic range or increasing the resolution to UHD. A further smaller increase in quality was observed in the Mean Opinion Scores of the viewers by increasing both the dynamic range and the resolution, but this was not quite statistically significant.

  18. Secure High Dynamic Range Images

    OpenAIRE

    Med Amine Touil; Noureddine Ellouze

    2016-01-01

    In this paper, a tone mapping algorithm is proposed to produce LDR (Limited Dynamic Range) images from HDR (High Dynamic Range) images. In the approach, non-linear functions are applied to compress the dynamic range of HDR images. Security tools will be then applied to the resulting LDR images and their effectiveness will be tested on the reconstructed HDR images. Three specific examples of security tools are described in more details: integrity verification using hash function to compute loc...

  19. Stereoscopic High Dynamic Range Video

    OpenAIRE

    Rüfenacht, Dominic

    2011-01-01

    Stereoscopic video content is usually being created by using two or more cameras which are recording the same scene. Traditionally, those cameras have the exact same intrinsic camera parameters. In this project, the exposure times of the cameras differ, allowing to record different parts of the dynamic range of the scene. Image processing techniques are then used to enhance the dynamic range of the captured data. A pipeline for the recording, processing, and displaying of high dynamic range (...

  20. Cerebral PET glucose hypometabolism in subjects with mild cognitive impairment and higher EEG high-alpha/low-alpha frequency power ratio.

    Science.gov (United States)

    Moretti, Davide Vito; Pievani, Michela; Pini, Lorenzo; Guerra, Ugo Paolo; Paghera, Barbara; Frisoni, Giovanni Battista

    2017-10-01

    In Alzheimer's disease (AD) research, both 2-deoxy-2-((18)F)fluoro-D-glucose (FDG) positron emission tomography (PET) and electroencephalography (EEG) are reliable investigational modalities. The aim of this study was to investigate the associations between EEG High-alpha/Low-alpha (H-alpha/L-alpha) power ratio and cortical glucose metabolism. A total of 23 subjects with mild cognitive impairment (MCI) underwent FDG-PET and EEG examinations. H-alpha/L-alpha power ratio was computed for each subject and 2 groups were obtained based on the increase of the power ratio. The subjects with higher H-alpha/L-alpha power ratio showed a decrease in glucose metabolism in the hub brain areas previously identified as typically affected by AD pathology. In subjects with higher H-alpha/L-alpha ratio and lower metabolism, a "double alpha peak" was identified in the EEG spectrum and a U-shaped correlation between glucose metabolism and increase of H-alpha/L-alpha power ratio has been found. Moreover, in this group, a conversion rate of 62.5% at 24 months was detected, significantly different from the chance percentage expected. The neurophysiological meaning of the interplay between alpha oscillations and glucose metabolism and the possible interest of the H-alpha/L-alpha power ratio as a clinical biomarker in AD have been discussed. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. CHARACTERIZATION OF A NEW BACILLUS-STEAROTHERMOPHILUS ISOLATE - A HIGHLY THERMOSTABLE ALPHA-AMYLASE-PRODUCING STRAIN

    NARCIS (Netherlands)

    WIND, RD; BUITELAAR, RM; EGGINK, G; HUIZING, HJ; DIJKHUIZEN, L

    1994-01-01

    A novel strain of Bacillus stearothermophilus was isolated from samples of a potato-processing industry. Compared to known alpha-amylases from other B. stearothermophilus strains, the isolate was found to produce a highly thermostable alpha-amylase. The half-time of inactivation of this alpha-amylas

  2. Secure High Dynamic Range Images

    Directory of Open Access Journals (Sweden)

    Med Amine Touil

    2016-04-01

    Full Text Available In this paper, a tone mapping algorithm is proposed to produce LDR (Limited Dynamic Range images from HDR (High Dynamic Range images. In the approach, non-linear functions are applied to compress the dynamic range of HDR images. Security tools will be then applied to the resulting LDR images and their effectiveness will be tested on the reconstructed HDR images. Three specific examples of security tools are described in more details: integrity verification using hash function to compute local digital signatures, encryption for confidentiality, and scrambling technique.

  3. Non-linear Flight Dynamics at High Angles of Attack

    DEFF Research Database (Denmark)

    Granasy, P.; Sørensen, C.B.; Mosekilde, Erik

    1998-01-01

    The methods of nonlinear dynamics are applied to the longitudinal motion of a vectored thrust aircraft, in particular the behavior at high angles of attack. Our model contains analytic nonlinear aerodynamical coefficients based on NASA windtunnel experiments on the F-18 high-alpha research vehicle...... (HARV). When the aircraft is forced with small thrust deflections whilst in poststall equilibrium, chaotic motion is observed at certain frequencies. At other frequencies, several limiting states coexist....

  4. Viral dynamics and pharmacokinetics of peginterferon alpha-2a and peginterferon alpha-2b in naive patients with chronic hepatitis c: a randomized, controlled study.

    Science.gov (United States)

    Bruno, Raffaele; Sacchi, Paolo; Ciappina, Valentina; Zochetti, Cristina; Patruno, Savino; Maiocchi, Laura; Filice, Gaetano

    2004-08-01

    The two available pegylated interferon formulations, peginterferon alpha-2a and peginterferon alpha-2b, have different pharmacokinetic profiles; as a result they may have differing abilities to suppress the hepatitis C virus. A recently reported study by Formann and colleagues assessing early viral kinetics among 20 patients receiving peginterferon alpha-2b either once or twice weekly suggests that once-weekly administration of peginterferon alpha-2b is not sufficient for continuous exposure to interferon over 160 h. Twice-weekly administration is recommended to avoid increases in viral load as interferon levels decline prior to the end of the one-week dosing period. The objective of this study was to compare viral dynamics and pharmacokinetics between peginterferon alpha-2a and peginterferon alpha-2b in interferon-naive chronic hepatitis C patients. Patients were randomized to receive peginterferon alpha-2a 180 microg (n=10) or peginterferon alpha-2b 1.0 microg/kg (n=12) once weekly. Serum peginterferon concentrations were measured at baseline, 24, 48, 120 and 168h. Hepatitis C virus (HCV) RNA was measured at baseline, 24, 48, 120 and 168 h during week 1 and then at 4 and 12 weeks. Peginterferon alpha-2b achieved maximal serum levels at 24 h, and then decreased rapidly. Of the 12 patients who received peginterferon alpha-2b, no drug was detectable in seven (58%) patients at 120 h and in 11 (92%) at 168 h. In contrast, peginterferon alpha-2a concentrations increased continuously over time, reaching maximal serum levels from 48 to 168 h. Drug was detectable in all 10 patients at 168 h. At weeks 1 and 4 no significant difference was observed in mean HCV RNA between the groups. However, at week 12, mean HCV RNA was significantly lower in the peginterferon alpha-2a group versus the peginterferon alpha-2b group (2.8126 vs 3.8726; P<0.01). The differences in mean HCV RNA values at 12 weeks may be related to the different absorption and distribution profiles of the two

  5. Monte Carlo studies of folding, dynamics, and stability in alpha-helices.

    Science.gov (United States)

    Shental-Bechor, Dalit; Kirca, Safak; Ben-Tal, Nir; Haliloglu, Turkan

    2005-04-01

    Folding simulations of polyalanine peptides were carried out using an off-lattice Monte Carlo simulation technique. The peptide was represented as a chain of residues, each of which contains two interaction sites: one corresponding to the C(alpha) atom and the other to the side chain. A statistical potential was used to describe the interaction between these sites. The preferred conformations of the peptide chain on the energy surface, starting from several initial conditions, were searched by perturbations on its generalized coordinates with the Metropolis criterion. We observed that, at low temperatures, the effective energy was low and the helix content high. The calculated helix propagation (s) and nucleation (sigma) parameters of the Zimm-Bragg model were in reasonable agreement with the empirical data. Exploration of the energy surface of the alanine-based peptides (AAQAA)(3) and AAAAA(AAARA)(3)A demonstrated that their behavior is similar to that of polyalanine, in regard to their effective energy, helix content, and the temperature-dependence of their helicity. In contrast, stable secondary structures were not observed for (Gly)(20) at similar temperatures, which is consistent with the nonfolder nature of this peptide. The fluctuations in the slowest dynamics mode, which describe the elastic behavior of the chain, showed that as the temperature decreases, the polyalanine peptides become stiffer and retain conformations with higher helix content. Clustering of conformations during the folding phase implied that polyalanine folds into a helix through fewer numbers of intermediate conformations as the temperature decreases.

  6. Dynamic equilibrium unfolding pathway of human tumor necrosis factor-alpha induced by guanidine hydrochloride.

    Science.gov (United States)

    Kim, Y R; Hahn, J S; Hong, H; Jeong, W; Song, N W; Shin, H C; Kim, D

    1999-01-11

    The dynamic equilibrium unfolding pathway of human tumor necrosis factor-alpha (TNF-alpha) during denaturation at different guanidine hydrochloride (GdnHCl) concentrations (0-4.2 M) was investigated by steady-state fluorescence spectroscopy, potassium iodide (KI) fluorescence quenching, far-UV circular dichroism (CD), picosecond time-resolved fluorescence lifetime, and anisotropy decay measurements. We utilized the intrinsic fluorescence of Trp-28 and Trp-114 to characterize the conformational changes involved in the equilibrium unfolding pathway. The detailed unfolding pathway under equilibrium conditions was discussed with respect to motional dynamics and partially folded structures. At 0-0.9 M [GdnHCl], the rotational correlation times of 22-25 ns were obtained from fluorescence anisotropy decay measurements and assigned to those of trimeric states by hydrodynamic calculation. In this range, the solvent accessibility of Trp residues increased with increasing [GdnHCl], suggesting the slight expansion of the trimeric structure. At 1.2-2.1 M [GdnHCl], the enhanced solvent accessibility and the rotational degree of freedom of Trp residues were observed, implying the loosening of the internal structure. In this [GdnHCl] region, TNF-alpha was thought to be in soluble aggregates having distinct conformational characteristics from a native (N) or fully unfolded state (U). At 4.2 M [GdnHCl], TNF-alpha unfolded to a U-state. From these results, the equilibrium unfolding pathway of TNF-alpha, trimeric and all beta-sheet protein, could not be viewed from the simple two state model (N-->U).

  7. Oligosaccharides from the 3-linked 2-sulfated alpha-L-fucan and alpha-L-galactan show similar conformations but different dynamics.

    Science.gov (United States)

    Queiroz, Ismael N L; Vilela-Silva, Ana-Cristina E S; Pomin, Vitor H

    2016-11-01

    Here we have performed an nuclear magnetic resonance-based study on the ring and chain conformations as well as dynamics of oligosaccharides generated by acid hydrolysis on two structurally related glycans, a 3-linked 2-sulfated alpha-L-galactan and a 3-linked 2-sulfated alpha-L-fucan. Results derived from scalar couplings have confirmed the (1)C4 chair configuration to both alpha-L-fucose and alpha-L-galactose, and a similar solution 3D structure for the oligosaccharide chains of both sulfated glycans as seen on the basis of NOE patterns. Measurements of spin-relaxation rates have suggested, however, a slight difference dynamical property to these glycans. The fucose-based oligosaccharides showed an enhanced dynamical property if compared to the galactose-based oligosaccharides of same anomericity, sugar configuration, glycosidic bond and sulfation type. This distinction solely on the dynamical aspect has been driven therefore by the different sugar composition of the two studied sulfated glycans. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  8. High-statistics measurement of the {beta} -delayed {alpha} spectrum of {sup 20}Na

    Energy Technology Data Exchange (ETDEWEB)

    Laursen, K.L.; Fynbo, H.O.U.; Riisager, K. [Aarhus University, Department of Physics and Astronomy, Aarhus (Denmark); Kirsebom, O.S. [Aarhus University, Department of Physics and Astronomy, Aarhus (Denmark); TRIUMF, Vancouver, BC (Canada); Jokinen, A.; Saastamoinen, A.; Aeystoe, J. [University of Jyvaeskylae, Department of Physics, Jyvaeskylae (Finland); Madurga, M. [Instituto de Estructura de la Materia, CSIC, Madrid (Spain); Department of Physics and Astronomy, University of Tennessee, Knoxville, TN (United States); Tengblad, O. [Instituto de Estructura de la Materia, CSIC, Madrid (Spain)

    2013-06-15

    A measurement of the {sup 20}Na {beta} -delayed alpha spectrum with a high-granularity setup has allowed the decay scheme to be revised on several points. Three new transitions of low intensity are found at low {alpha} -particle energy. An R-matrix fit of the complete spectrum gives an improved description of the decay and indicates feeding to the broad 2{sup +} {alpha} -cluster state close to 9MeV. (orig.)

  9. Jet Production in ep Collisions at High $Q^2$ and Determination of $\\alpha_s$

    CERN Document Server

    Aaron, FD; Alimujiang, K; Andreev, V; Antunovic, B; Asmone, A; Backovic, S; Baghdasaryan, A; Barrelet, E; Bartel, W; Begzsuren, K; Belousov, A; Bizot, J C; Boudry, V; Bozovic-Jelisavcic, I; Bracinik, J; Brandt, G; Brinkmann, M; Brisson, V; Bruncko, D; Bunyatyan, A; Buschhorn, G; Bystritskaya, L; Campbell, A J; Cantun Avila, K B; Cassol-Brunner, F; Cerny, K; Cerny, V; Chekelian, V; Cholewa, A; Contreras, J G; Coughlan, J A; Cozzika, G; Cvach, J; Dainton, J B; Daum, K; Deak, M; de Boer, Y; Delcourt, B; Del Degan, M; Delvax, J; De Roeck, A; De Wolf, E A; Diaconu, C; Dodonov, V; Dossanov, A; Dubak, A; Eckerlin, G; Efremenko, V; Egli, S; Eliseev, A; Elsen, E; Falkiewicz, A; Faulkner, P J W; Favart, L; Fedotov, A; Felst, R; Feltesse, J; Ferencei, J; Fischer, D -J; Fleischer, M; Fomenko, A; Gabathuler, E; Gayler, J; Ghazaryan, Samvel; Glazov, A; Glushkov, I; Goerlich, L; Gogitidze, N; Gouzevitch, M; Grab, C; Greenshaw, T; Grell, B R; Grindhammer, G; Habib, S; Haidt, D; Helebrant, C; Henderson, R C W; Hennekemper, E; Henschel, H; Herbst, M; Herrera, G; Hildebrandt, M; Hiller, K H; Hoffmann, D; Horisberger, R; Hreus, T; Jacquet, M; Janssen, M E; Janssen, X; Jemanov, V; Jonsson, L; Jung, Andreas Werner; Jung, H; Kapichine, M; Katzy, J; Kenyon, I R; Kiesling, C; Klein, M; Kleinwort, C; Kluge, T; Knutsson, A; Kogler, R; Korbel, V; Kostka, P; Kraemer, M; Krastev, K; Kretzschmar, J; Kropivnitskaya, A; Kruger, K; Kutak, K; Landon, M P J; Lange, W; Lastovicka-Medin, G; Laycock, P; Lebedev, A; Leibenguth, G; Lendermann, V; Levonian, S; Li, G; Lipka, K; Liptaj, A; List, B; List, J; Loktionova, N; Lopez-Fernandez, R; Lubimov, V; Lytkin, L; Makankine, A; Malinovski, E; Marage, P; Marti, Ll; Martyn, H -U; Maxfield, S J; Mehta, A; Meyer, A B; Meyer, H; Meyer, H; Meyer, J; Michels, V; Mikocki, S; Milcewicz-Mika, I; Moreau, F; Morozov, A; Morris, J V; Mozer, Matthias Ulrich; Mudrinic, M; Muller, K; Murin, P; Naroska, B; Naumann, Th; Newman, P R; Niebuhr, C; Nikiforov, A; Nowak, G; Nowak, K; Nozicka, M; Olivier, B; Olsson, J E; Osman, S; Ozerov, D; Palichik, V; Panagoulias, I; Pandurovic, M; Papadopoulou, Th; Pascaud, C; Patel, G D; Pejchal, O; Perez, E; Petrukhin, A; Picuric, I; Piec, S; Pitzl, D; Placakyte, R; Pokorny, B; Polifka, R; Povh, B; Preda, T; Radescu, V; Rahmat, A J; Raicevic, N; Raspiareza, A; Ravdandorj, T; Reimer, P; Rizvi, E; Robmann, P; Roland, B; Roosen, R; Rostovtsev, A; Rotaru, M; Ruiz Tabasco, J E; Rurikova, Z; Rusakov, S; Salek, D; Sankey, D P C; Sauter, M; Sauvan, E; Schmitt, S; Schmitz, C; Schoeffel, L; Schoning, A; Schultz-Coulon, H -C; Sefkow, F; Shaw-West, R N; Sheviakov, I; Shtarkov, L N; Shushkevich, S; Sloan, T; Smiljanic, Ivan; Soloviev, Y; Sopicki, P; South, D; Spaskov, V; Specka, Arnd E; Staykova, Z; Steder, M; Stella, B; Stoicea, G; Straumann, U; Sunar, D; Sykora, T; Tchoulakov, V; Thompson, G; Thompson, P D; Toll, T; Tomasz, F; Tran, T H; Traynor, D; Trinh, T N; Truol, P; Tsakov, I; Tseepeldorj, B; Turnau, J; Urban, K; Valkarova, A; Vallee, C; Van Mechelen, P; Vargas Trevino, A; Vazdik, Y; Vinokurova, S; Volchinski, V; von den Driesch, M; Wegener, D; Wissing, Ch; Wunsch, E; Zacek, J; Zalesak, J; Zhang, Z; Zhokin, A; Zimmermann, T; Zohrabyan, H; Zomer, F; Zus, R

    2010-01-01

    The production of jets is studied in deep-inelastic ep scattering at large negative four momentum transfer squared 150alpha_s(M_Z) = 0.1168 +/-0.0007 (exp.) +0.0046/-0.0030 (th.) +/-0.0016(pdf).

  10. CHARACTERIZATION OF A NEW BACILLUS-STEAROTHERMOPHILUS ISOLATE - A HIGHLY THERMOSTABLE ALPHA-AMYLASE-PRODUCING STRAIN

    NARCIS (Netherlands)

    WIND, RD; BUITELAAR, RM; EGGINK, G; HUIZING, HJ; DIJKHUIZEN, L

    A novel strain of Bacillus stearothermophilus was isolated from samples of a potato-processing industry. Compared to known alpha-amylases from other B. stearothermophilus strains, the isolate was found to produce a highly thermostable alpha-amylase. The half-time of inactivation of this

  11. Integrin alphaVbeta6 is a high-affinity receptor for coxsackievirus A9.

    Science.gov (United States)

    Heikkilä, Outi; Susi, Petri; Stanway, Glyn; Hyypiä, Timo

    2009-01-01

    Coxsackievirus A9 (CAV9), a member of the genus Enterovirus in the family Picornaviridae, possesses an integrin-binding arginine-glycine-aspartic acid (RGD) motif in the C terminus of VP1 capsid protein. CAV9 has been shown to utilize integrins alphaVbeta3 and alphaVbeta6 as primary receptors for cell attachment. While CAV9 RGD-mutants (RGE and RGDdel) are capable of infecting rhabdomyosarcoma (RD) cell line, they grow very poorly in an epithelial lung carcinoma cell line (A549). In this study, the relationships between CAV9 infectivity in A549 and RD cells, receptor expression and integrin binding were analysed. A549 cells were shown to express both integrins alphaVbeta3 and alphaVbeta6, whereas alphaVbeta6 expression was not detected on the RD cells. Native CAV9 but not RGE and RGDdel mutants bound efficiently to immobilized alphaVbeta3 and alphaVbeta6. Adhesion of CAV9 but not RGE/RGDdel to A549 cells was also significantly higher than to RD cells. In contrast, no affinity or adhesion of bacterially produced VP1 proteins to the integrins or to the cells was detected. Function-blocking antibodies against alphaV-integrins blocked CAV9 but not CAV9-RGDdel infectivity, indicating that the viruses use different internalization routes; this may explain the differential infection kinetics of CAV9 and RGDdel. In an affinity assay, soluble alphaVbeta6, but not alphaVbeta3, bound to immobilized CAV9. Similarly, only soluble alphaVbeta6 blocked virus infectivity. These data suggest that CAV9 binding to alphaVbeta6 is a high-affinity interaction, which may indicate its importance in clinical infections; this remains to be determined.

  12. Hydrogen embrittlement on {alpha}-iron in high alkaline environment

    Energy Technology Data Exchange (ETDEWEB)

    Hu, R.; Habashi, M.; Galland, J. [Ecole Central Paris, Chatenay-Malabry (France)

    1994-12-31

    The partial pressure of hydrogen in concrete`s pore is very low. This hydrogen is due to the chemical reaction between the silica fumes and the alkaline solutions filling the concrete`s pore. Silica fumes are added in the concrete to increase its compression resistance. If the hydrogen pressure is low, the risk of hydrogen embrittlement is also low. However, for constructional works destined to endure more than 50 years, is this risk negligible? To answer this question, the authors have studied the hydrogen embrittlement on {alpha}-iron in alkaline solutions, in the pH range 9.5 to 13.3, presenting the liquids found in the concrete`s pores after different aging, periods. Cathodic charging has been performed for low current densities in the range 0.25 to 90 A/m{sup 2} simulating several partial pressures of hydrogen on the {alpha}-iron surface with and without EDTA inhibitor. The deformation rate was 2.5{times}10{sup {minus}5} s{sup {minus}1}. Finally {alpha}-iron samples and tensile specimens have been immersed in a mixture of silica fumes and an alkaline solution at pH 13.3 in an autoclave during 1,000 hours with the aim to measure the outgassed quantity of hydrogen under vacuum at 600C and to measure also the hydrogen embrittlement. The main conclusions of this study are as following: (1) Hydrogen embrittlement is promoted by oxide Fe{sub 3}O{sub 4} film rupture and/or hydroxide Fe(OH){sub 2}. This mechanism is efficient for current densities equivalent to a cathodic potential lower or equal to {minus}1V/NHE. (2) Silica fumes in contact with a solution of pH 13.3 provoke hydrogen release and its diffusion into the {alpha}-iron, but this quantity is not enough to embrittle it.

  13. Magnetic dynamics of small alpha-Fe2O3 and NiO particles

    DEFF Research Database (Denmark)

    Lefmann, K.; Bødker, Franz; Hansen, Mikkel Fougt;

    1999-01-01

    We have studied the magnetic dynamics in nanocrystalline samples of alpha-Fe2O3 (hematite) and NiO by inelastic neutron scattering. By measuring around the structural and the antiferromagnetic reflections, we have probed uniform and staggered magnetic oscillations, respectively. In the hematite...... as a sign of superparamagnetic relaxation. Studies of the antiferromagnetic signal from NiO also show evidence of collective magnetic excitations, but with a higher energy of the precession state than for hematite. The inelastic signal at the structural reflection of NiO presents evidence for uniform...

  14. Glauber dynamics in high dimensions

    CERN Document Server

    Morris, Robert

    2008-01-01

    We study Glauber dynamics on Z^d, which is a dynamic version of the celebrated Ising model of ferromagnetism. Spins are initially chosen according to a Bernoulli distribution with density p, and then the states are continuously (and randomly) updated according to the majority rule. This corresponds to the sudden quenching of a ferromagnetic system at high temperature with an external field, to one at zero temperature with no external field. Define p_c(Z^d) to be the infimum over those p \\ge 1/2 such that the system fixates with probability 1. It is a folklore conjecture that p_c(Z^d) = 1/2 for every d \\ge 2. We prove that p_c(Z^d) \\to 1/2 as d \\to \\infty.

  15. Lithium abundances in high- and low-alpha halo stars

    DEFF Research Database (Denmark)

    Nissen, P. E.; Schuster, W. J.

    2012-01-01

    A previous study of F and G main-sequence stars in the solar neighborhood has revealed the existence of two distinct halo populations with a clear separation in [alpha /Fe] for the metallicity range -1.4 < [Fe/H] < -0.7. The kinematics of the stars and models of galaxy formation suggest that the ......A previous study of F and G main-sequence stars in the solar neighborhood has revealed the existence of two distinct halo populations with a clear separation in [alpha /Fe] for the metallicity range -1.4 ... is well fitted by a relation A(Li) = a0 + a1 M + a2 Z + a3 M Z, where a0, a1, a2, and a3 are constants. Extrapolating this relation to Z = 0 leads to A(Li)= 2.58 ± 0.08 close to the primordial Li abundance predicted from standard Big Bang nucleosynthesis calculations and the WMAP baryon density. A...

  16. High contrast Kr gas jet K alpha x-ray source for high energy density physics experiments.

    Science.gov (United States)

    Kugland, N L; Neumayer, P; Döppner, T; Chung, H-K; Constantin, C G; Girard, F; Glenzer, S H; Kemp, A; Niemann, C

    2008-10-01

    A high contrast 12.6 keV Kr K alpha source has been demonstrated on the petawatt-class Titan laser facility using strongly clustering Kr gas jet targets. The contrast ratio (K alpha to continuum) is 65, with a competitive ultrashort pulse laser to x-ray conversion efficiency of 10(-5). Filtered shadowgraphy indicates that the Kr K alpha and K beta x rays are emitted from a roughly 1x2 mm(2) emission volume, making this source suitable for area backlighting and scattering. Spectral calculations indicate a typical bulk electron temperature of 50-70 eV (i.e., mean ionization state 13-16), based on the observed ratio of K alpha to K beta. Kr gas jets provide a debris-free high energy K alpha source for time-resolved diagnosis of dense matter.

  17. Discovering an Accessible Enzyme: Salivary [alpha]-Amylase--"Prima Digestio Fit in Ore"--A Didactic Approach for High School Students

    Science.gov (United States)

    Marini, Isabella

    2005-01-01

    Human salivary [alpha]-amylase is used in this experimental approach to introduce biology high school students to the concept of enzyme activity in a dynamic way. Through a series of five easy, rapid, and inexpensive laboratory experiments students learn what the activity of an enzyme consists of: first in a qualitative then in a semi-quantitative…

  18. Estimated environmental loads of alpha-amylase from transgenic high-amylase maize

    Energy Technology Data Exchange (ETDEWEB)

    Wolt, Jeffrey D. [Department of Agronomy, Iowa State University, Ames, IA 50011 (United States); Biosafety Institute for Genetically Modified Agricultural Products, 164 Seed Science, Iowa State University, Ames, IA 50011 (United States); Karaman, Sule [Biosafety Institute for Genetically Modified Agricultural Products, 164 Seed Science, Iowa State University, Ames, IA 50011 (United States)

    2007-11-15

    Environmental exposure of plants bioengineered to improve efficiencies of biofuel production is an important consideration for their adoption. High-amylase maize genetically engineered to produce thermostable alpha-amylase in seed endosperm is currently in development, and its successful adoption will entail >1000 km{sup 2} of annual production in the USA. Environmental exposure of thermostable amylase will occur in production fields from preharvest and harvest dropped grain, with minor additional contributions from stover and root biomass. Mass loadings of thermostable alpha-amylase are projected to be 16 kg km{sup -2} and represent a potential source of increased alpha-amylase activity in receiving soils. An understanding of the degradation, persistence, accumulation, and activity of thermostable alpha-amylase introduced from transgenic high-amylase maize will be necessary in order to effectively manage transgenic crop systems intended or biofeedstock production. (author)

  19. Dynamic study of (De)sodiation in alpha-MnO2 nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Yifei [Michigan Technological Univ., Houghton, MI (United States); Argonne National Lab. (ANL), Argonne, IL (United States); Ma, Lu [Argonne National Lab. (ANL), Argonne, IL (United States); He, Kun [Michigan Technological Univ., Houghton, MI (United States); Shandong Univ., Jinan (China); Yao, Wentao [Michigan Technological Univ., Houghton, MI (United States); Nie, Anmin [Univ. of Illinois, Chicago, IL (United States); Bi, Xuanxuan [Argonne National Lab. (ANL), Argonne, IL (United States); Amine, Khalil [Argonne National Lab. (ANL), Argonne, IL (United States); Wu, Tianpin [Argonne National Lab. (ANL), Argonne, IL (United States); Lu, Jun [Argonne National Lab. (ANL), Argonne, IL (United States); Shahbazian-Yassr, Reza [Michigan Technological Univ., Houghton, MI (United States); Univ. of Illinois, Chicago, IL (United States)

    2016-01-01

    In this report, the electrochemical sodiation and desodiation in single crystalline alpha-MnO2 nanowires are studied dynamically at both single particle level using in situ transmission electron microscopy (TEM) and bulk level using in situ synchrotron X-ray. The TEM results suggest that the first sodiation process starts with tunnel-based Na+ intercalation, experiences the formation of Na0.5MnO2 as a result of tunnel degradation, and ends with the Mn2O3 phase. The inserted Na+ can be partially extracted out of the sodiated products, and the following cycles are dominated by the reversible conversion reaction between Na0.5MnO2 and Mn2O3. The Mn valence evolution inside a cycling coin using alpha-MnO2 nanowire electrode also exhibits partially reversible characteristic, agreeing well with the in situ TEM analysis. The sodiation is compared with lithiation in the same alpha-MnO2 nanowires. Both Na+ and Li+ interact with the tunneled structure via a similar tunnel -driven intercalation mechanism before Mn4+ is reduced to Mn3.5+. For the following deep insertion, the tunnels survive up. to LiMnO2 (Mn3+) during lithiation, while the sodiation proceeds via a different mechanism that involves obvious phase transition and fast tunnel degradation after Mn's valence is below 3.5+. The difference in charge carrier insertion mechanisms can be ascribed to the strong interaction between the tunnel frame and inserted Na+ possessing a larger ionic size than inserted Li+.

  20. Preliminary Molecular Dynamic Simulations of the Estrogen Receptor Alpha Ligand Binding Domain from Antagonist to Apo

    Directory of Open Access Journals (Sweden)

    Adrian E. Roitberg

    2008-06-01

    Full Text Available Estrogen receptors (ER are known as nuclear receptors. They exist in the cytoplasm of human cells and serves as a DNA binding transcription factor that regulates gene expression. However the estrogen receptor also has additional functions independent of DNA binding. The human estrogen receptor comes in two forms, alpha and beta. This work focuses on the alpha form of the estrogen receptor. The ERα is found in breast cancer cells, ovarian stroma cells, endometrium, and the hypothalamus. It has been suggested that exposure to DDE, a metabolite of DDT, and other pesticides causes conformational changes in the estrogen receptor. Before examining these factors, this work examines the protein unfolding from the antagonist form found in the 3ERT PDB crystal structure. The 3ERT PDB crystal structure has the estrogen receptor bound to the cancer drug 4-hydroxytamoxifen. The 4-hydroxytamoxifen ligand was extracted before the simulation, resulting in new conformational freedom due to absence of van der Waals contacts between the ligand and the receptor. The conformational changes that result expose the binding clef of the co peptide beside Helix 12 of the receptor forming an apo conformation. Two key conformations in the loops at either end of the H12 are produced resulting in the antagonist to apo conformation transformation. The results were produced over a 42ns Molecular Dynamics simulation using the AMBER FF99SB force field.

  1. High speed high dynamic range high accuracy measurement system

    Energy Technology Data Exchange (ETDEWEB)

    Deibele, Craig E.; Curry, Douglas E.; Dickson, Richard W.; Xie, Zaipeng

    2016-11-29

    A measuring system includes an input that emulates a bandpass filter with no signal reflections. A directional coupler connected to the input passes the filtered input to electrically isolated measuring circuits. Each of the measuring circuits includes an amplifier that amplifies the signal through logarithmic functions. The output of the measuring system is an accurate high dynamic range measurement.

  2. High-Alpha Research Vehicle (HARV) longitudinal controller: Design, analyses, and simulation resultss

    Science.gov (United States)

    Ostroff, Aaron J.; Hoffler, Keith D.; Proffitt, Melissa S.; Brown, Philip W.; Phillips, Michael R.; Rivers, Robert A.; Messina, Michael D.; Carzoo, Susan W.; Bacon, Barton J.; Foster, John F.

    1994-01-01

    This paper describes the design, analysis, and nonlinear simulation results (batch and piloted) for a longitudinal controller which is scheduled to be flight-tested on the High-Alpha Research Vehicle (HARV). The HARV is an F-18 airplane modified for and equipped with multi-axis thrust vectoring. The paper includes a description of the facilities, a detailed review of the feedback controller design, linear analysis results of the feedback controller, a description of the feed-forward controller design, nonlinear batch simulation results, and piloted simulation results. Batch simulation results include maximum pitch stick agility responses, angle of attack alpha captures, and alpha regulation for full lateral stick rolls at several alpha's. Piloted simulation results include task descriptions for several types of maneuvers, task guidelines, the corresponding Cooper-Harper ratings from three test pilots, and some pilot comments. The ratings show that desirable criteria are achieved for almost all of the piloted simulation tasks.

  3. High-performance liquid chromatographic determination of alpha-tocopherol in macroalgae.

    Science.gov (United States)

    Sánchez-Machado, D I; López-Hernández, J; Paseiro-Losada, P

    2002-11-08

    A high-performance liquid chromatographic (HPLC) method for the microscale determination of alpha-tocopherol in macroalgae is reported. The method includes microscale saponification and extraction with n-hexane. The presence of alpha-tocopherol in macroalgae samples was confirmed by HPLC-MS. Alpha-tocopherol levels as determined in samples by HPLC with UV and fluorescence detection did not differ significantly; however, fluorescence detection has a higher sensitivity (detection limit 10.4 ng/ml, vs. 104 ng/ml with UV detection), as well as good precision (relative standard deviation 1.81%) and recovery (94.3%). Fluorescence detection is also faster. We used this method to determine the alpha-tocopherol contents of four commercial macroalgae products from northwest Spain as part of nutritional studies in dehydrated Himanthalia elongata and Laminaria ochroleuca, and also in canned Himanthalia elongata and Saccorhiza polychides.

  4. Imidazenil: a low efficacy agonist at alpha1- but high efficacy at alpha5-GABAA receptors fail to show anticonvulsant cross tolerance to diazepam or zolpidem.

    Science.gov (United States)

    Auta, James; Impagnatiello, Francesco; Kadriu, Bashkim; Guidotti, Alessandro; Costa, Erminio

    2008-08-01

    Whereas advances in the molecular biology of GABA(A) receptor complex using knock-out and knock-in mice have been valuable in unveiling the structure, composition, receptor assembly, and several functions of different GABA(A) receptor subtypes, the mechanism(s) underlying benzodiazepine (BZ) tolerance and withdrawal remain poorly understood. Studies using specific GABA(A) receptor subunit knock-in mice suggest that tolerance to sedative action of diazepam requires long-term activation of alpha1 and alpha5 GABA(A) receptor subunits. We investigated the role of long-term activation of these GABA(A) receptor subunits during anticonvulsant tolerance using high affinity and high intrinsic efficacy ligands for GABA(A) receptors expressing the alpha5 subunit (imidazenil) or alpha1 subunit (zolpidem), and a non-selective BZ recognition site ligand (diazepam). We report here that long-term activation of GABA(A) receptors by zolpidem and diazepam but not by imidazenil elicits anticonvulsant tolerance. Although anticonvulsant cross-tolerance occurs between diazepam and zolpidem, there is no cross-tolerance between imidazenil and diazepam or zolpidem. Furthermore, diazepam or zolpidem long-term treatment decreased the expression of mRNA encoding the alpha1 GABA(A) receptor subunit in prefrontal cortex by 43% and 20% respectively. In addition, diazepam but not zolpidem long-term treatment produced a 30% increase in the expression of the alpha5 GABA(A) receptor subunit mRNA in prefrontal cortex. In contrast, imidazenil which is devoid of anticonvulsant tolerance does not elicit significant changes in the expression of alpha1 or alpha5 GABA(A) receptor subunit. These findings suggest that long-term activation of GABA(A) receptors containing the alpha1 or other subunits but not the alpha5 receptor subunit is essential for the induction of anticonvulsant tolerance.

  5. Nuclear reactions induced by high-energy alpha particles

    Science.gov (United States)

    Shen, B. S. P.

    1974-01-01

    Experimental and theoretical studies of nuclear reactions induced by high energy protons and heavier ions are included. Fundamental data needed in the shielding, dosimetry, and radiobiology of high energy particles produced by accelerators were generated, along with data on cosmic ray interaction with matter. The mechanism of high energy nucleon-nucleus reactions is also examined, especially for light target nuclei of mass number comparable to that of biological tissue.

  6. Use of Molecular Dynamics Data in Biochemistry Courses: An Amphipathy Scale to Determine Protein [alpha]-Helix Transmembrane Segments

    Science.gov (United States)

    Mazze, Fernanda M.; Fuzo, Carlos A.; Degreve, Leo; Ciancaglini, Pietro

    2008-01-01

    The aim of this manuscript is to explain the application of an amphipathy scale obtained from molecular dynamics simulations and to demonstrate how it can be useful in the protein structure field. It is shown that this scale is easy to be used with the advantage of revealing domains of transmembrane [alpha]-helix of proteins without the need of…

  7. Use of Molecular Dynamics Data in Biochemistry Courses: An Amphipathy Scale to Determine Protein [alpha]-Helix Transmembrane Segments

    Science.gov (United States)

    Mazze, Fernanda M.; Fuzo, Carlos A.; Degreve, Leo; Ciancaglini, Pietro

    2008-01-01

    The aim of this manuscript is to explain the application of an amphipathy scale obtained from molecular dynamics simulations and to demonstrate how it can be useful in the protein structure field. It is shown that this scale is easy to be used with the advantage of revealing domains of transmembrane [alpha]-helix of proteins without the need of…

  8. DMPD: What is disrupting IFN-alpha's antiviral activity? [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 15283983 What is disrupting IFN-alpha's antiviral activity? Mbow ML, Sarisky RT. Tr...ends Biotechnol. 2004 Aug;22(8):395-9. (.png) (.svg) (.html) (.csml) Show What is disrupting IFN-alpha's ant...iviral activity? PubmedID 15283983 Title What is disrupting IFN-alpha's antiviral activity? Authors Mbow ML,

  9. High Specific Power Multiple-Cylinder Free-Piston Alpha Stirling Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA seeks highly efficient, long life solar dynamic power conversion systems. The requirements for these missions emphasize low mass and high conversion...

  10. High-performance liquid chromatographic determination of the glycoalkaloids alpha-solanine and alpha-chaconine in 12 commercial varieties of Mexican potato.

    Science.gov (United States)

    Sotelo, A; Serrano, B

    2000-06-01

    The glycoalkaloid content in 12 commercial varieties of Mexican potatoes was measured by HPLC in both the peel and the flesh of the potato. The principal glycoalkaloids alpha-solanine and alpha-chaconine were present in higher concentration in the peel than in the flesh of all varieties. The main alkaloid in the peel of the potatoes was alpha-chaconine and comprised about 65-71% of the total glycoalkaloids. The high concentration of alpha-chaconine in peel, which is more toxic than alpha-solanine, gives more protection to the tuber against predators. The total alkaloids in the peel of Alpha, Juanita, Michoacan, Norteña, Rosita, and Tollocan varieties were higher than the limit recommended for food safety. However, the peel represents less than 10% of the total tuber in most of the varieties. The total alkaloids contained in the peel of Atzimba, Lopez, Marciana, Montsama, Murca, and Puebla was lower than the limits recommended for food safety. The glycoalkaloid content in the boiled peeled potatoes was less than 9 mg/100 g but in Alpha, Montsama, and Puebla varieties, both glycoalkaloids were absent. According to the results, the consumption of the 12 commercial varieties of Mexican potatoes does not represent any danger to human health.

  11. Development of a high resolution alpha spectrometer using a magnetic calorimeter

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, W.S. [Center for Underground Physics, Institute for Basic Science (IBS), Daejeon 305-811 (Korea, Republic of); Korea Research Institute of Standards and Science (KRISS), Daejeon 305-340 (Korea, Republic of); Korea University of Science and Technology (UST), Daejeon 305-350 (Korea, Republic of); Kang, C.S. [Center for Underground Physics, Institute for Basic Science (IBS), Daejeon 305-811 (Korea, Republic of); Korea Research Institute of Standards and Science (KRISS), Daejeon 305-340 (Korea, Republic of); Kim, S.R., E-mail: yhkim@kriss.re.kr [Center for Underground Physics, Institute for Basic Science (IBS), Daejeon 305-811 (Korea, Republic of); Korea Research Institute of Standards and Science (KRISS), Daejeon 305-340 (Korea, Republic of); Kim, G.B. [Center for Underground Physics, Institute for Basic Science (IBS), Daejeon 305-811 (Korea, Republic of); Lee, H.J. [Center for Underground Physics, Institute for Basic Science (IBS), Daejeon 305-811 (Korea, Republic of); Korea Research Institute of Standards and Science (KRISS), Daejeon 305-340 (Korea, Republic of); Lee, M.K.; Lee, J.H. [Korea Research Institute of Standards and Science (KRISS), Daejeon 305-340 (Korea, Republic of); So, J.H. [Center for Underground Physics, Institute for Basic Science (IBS), Daejeon 305-811 (Korea, Republic of); Korea Research Institute of Standards and Science (KRISS), Daejeon 305-340 (Korea, Republic of); Kim, Y.H. [Center for Underground Physics, Institute for Basic Science (IBS), Daejeon 305-811 (Korea, Republic of); Korea Research Institute of Standards and Science (KRISS), Daejeon 305-340 (Korea, Republic of); Korea University of Science and Technology (UST), Daejeon 305-350 (Korea, Republic of)

    2015-06-01

    We have developed a high resolution alpha spectrometer with a magnetic calorimeter. The operating principle of the detector is the calorimetric measurement of the temperature increase from particle absorption in a gold foil absorber at milli-Kelvin temperatures. A magnetic calorimeter made of gold doped with erbium on a superconducting meander pickup coil was used to accurately measure the temperature change, thereby acting as an ultra-sensitive thermometer. The detector demonstrated 1.2 keV FWHM equivalent resolution in alpha particle detection with an {sup 241}Am source. Many peaks were observed in the low-energy region from the absorption of low-energy X-rays, gamma rays, and conversion electrons. An energy resolution of 400 eV FWHM was achieved for 60 keV gamma rays that were measured with the alpha particles. Possible applications of such high resolution detectors are discussed.

  12. The Atmospheric Dynamics of Alpha Tau (K5 III) -- Clues to Understanding the Magnetic Dynamo

    Science.gov (United States)

    Carpenter Kenneth G.

    2008-01-01

    Using HST/GHRS, HST/STIS and FUSE archival data for (alpha) Tau and the CHIANTI spectroscopic code, we have derived line shifts, volumetric emission measures, and plasma density estimates, and calculated filling factors for a number of UV lines forming between 10,000 K and 300,000 K in the outer atmosphere of this red giant star. The data suggest the presence of low-temperature extended regions and high-temperature compact regions, associated with magnetically open and closed structures in the stellar atmosphere, respectively. The signatures of UV lines from Alpha Tau can be consistently understood via a model of upward-traveling Alfven waves in a gravitationally stratified atmosphere. These wakes cause non-thermal broadening in UV lines due to unresolved wave motions and downward plasma motions in compact magnetic loops heated by resonant .4lf\\en wave heating. We discuss implications of this interpretation for understanding the nature of magnetic dynamos operating in late-type giants.

  13. Variations in resting frontal alpha asymmetry between high- and low-neuroticism females across the menstrual cycle.

    Science.gov (United States)

    Huang, Yamei; Zhou, Renlai; Cui, Hong; Wu, Mengying; Wang, Qingguo; Zhao, Yan; Liu, Yanfeng

    2015-02-01

    Resting frontal alpha asymmetry measures the relative activation intensity across the left and right frontal regions that represent emotional experience. Here, the focus is on levels of alpha asymmetry between high- and low-neuroticism females across the menstrual cycle. Resting alpha asymmetry in healthy females who scored high or low on neuroticism was assessed during the menstrual phase, the late follicular phase, and the midlate luteal phase. High-neuroticism females exhibited lower relative left prefrontal activity than did low-neuroticism females during the midlate luteal phase, as indexed by alpha1 and alphaTotal asymmetry scores at the prefrontal electrode positions (FP1/2 ). EEG results demonstrate that the resting frontal alpha asymmetry of high- and low-neuroticism females was moderated by the menstrual cycle, and high-neuroticism females should pay particular attention to their emotional experience during the midlate luteal phase.

  14. High dynamic range images for enhancing low dynamic range content

    OpenAIRE

    Banterle, Francesco; Dellepiane, Matteo; Scopigno, Roberto

    2011-01-01

    This poster presents a practical system for enhancing the quality of Low Dynamic Range (LDR) videos using High Dynamic Range (HDR) background images. Our technique relies on the assumption that the HDR information is static in the video footage. This assumption can be valid in many scenarios where moving subjects are the main focus of the footage and do not have to interact with moving light sources or highly reflective objects. Another valid scenario is teleconferencing via webcams, where th...

  15. Lyman {\\alpha} radiative transfer in the high-redshift, dusty Universe

    CERN Document Server

    Laursen, Peter

    2010-01-01

    The significance of the Ly{\\alpha} emission line as a probe of the high-redshift Universe has long been established. Originating mainly in the vicinity of young, massive stars and in association with accretion of large bulks of matter, it is ideal for detecting young galaxies, the fundamental building blocks of our Universe. Since many different processes shape the spectrum and the spatial distribution of the Ly{\\alpha} photons in various ways, a multitude of physical properties of galaxies can be unveiled. However, this also makes the interpretation of Ly{\\alpha} observations notoriously difficult. Because Ly{\\alpha} is a resonant line, it scatters on neutral hydrogen, having its path length from the source to our telescopes vastly increased, and taking it through regions of unknown physical conditions. In this work, a numerical code capable of calculating realistically the radiative transfer of Ly{\\alpha} is presented. The code is capable of performing the radiative transfer in an arbitrary and adaptively r...

  16. Structural Origins of Nitroxide Side Chain Dynamics on Membrane Protein [alpha]-Helical Sites

    Energy Technology Data Exchange (ETDEWEB)

    Kroncke, Brett M.; Horanyi, Peter S.; Columbus, Linda (UV)

    2010-12-07

    Understanding the structure and dynamics of membrane proteins in their native, hydrophobic environment is important to understanding how these proteins function. EPR spectroscopy in combination with site-directed spin labeling (SDSL) can measure dynamics and structure of membrane proteins in their native lipid environment; however, until now the dynamics measured have been qualitative due to limited knowledge of the nitroxide spin label's intramolecular motion in the hydrophobic environment. Although several studies have elucidated the structural origins of EPR line shapes of water-soluble proteins, EPR spectra of nitroxide spin-labeled proteins in detergents or lipids have characteristic differences from their water-soluble counterparts, suggesting significant differences in the underlying molecular motion of the spin label between the two environments. To elucidate these differences, membrane-exposed {alpha}-helical sites of the leucine transporter, LeuT, from Aquifex aeolicus, were investigated using X-ray crystallography, mutational analysis, nitroxide side chain derivatives, and spectral simulations in order to obtain a motional model of the nitroxide. For each crystal structure, the nitroxide ring of a disulfide-linked spin label side chain (R1) is resolved and makes contacts with hydrophobic residues on the protein surface. The spin label at site I204 on LeuT makes a nontraditional hydrogen bond with the ortho-hydrogen on its nearest neighbor F208, whereas the spin label at site F177 makes multiple van der Waals contacts with a hydrophobic pocket formed with an adjacent helix. These results coupled with the spectral effect of mutating the i {+-} 3, 4 residues suggest that the spin label has a greater affinity for its local protein environment in the low dielectric than on a water-soluble protein surface. The simulations of the EPR spectra presented here suggest the spin label oscillates about the terminal bond nearest the ring while maintaining weak

  17. Condensation-Enhanced Self-Assembly as a Route to High Surface Area alpha-Aluminas

    NARCIS (Netherlands)

    Perez, Lidia Lopez; Zarubina, Valeriya; Heeres, Hero Jan; Melian-Cabrera, Ignacio

    2013-01-01

    High surface area nanosized alpha-alumina has been obtained by thermally treating a sol-gel-derived mesophase at 1200 degrees C; the mesophase was synthesized by a sol-gel route involving evaporation induced self-assembly (EISA) of a hydrolyzed gel from Al-tri-sec-butoxide in s-BuOH in the presence

  18. Condensation-Enhanced Self-Assembly as a Route to High Surface Area alpha-Aluminas

    NARCIS (Netherlands)

    Perez, Lidia Lopez; Zarubina, Valeriya; Heeres, Hero Jan; Melian-Cabrera, Ignacio

    2013-01-01

    High surface area nanosized alpha-alumina has been obtained by thermally treating a sol-gel-derived mesophase at 1200 degrees C; the mesophase was synthesized by a sol-gel route involving evaporation induced self-assembly (EISA) of a hydrolyzed gel from Al-tri-sec-butoxide in s-BuOH in the presence

  19. Alpha clustering in $^{28}$Si probed through the identification of high-lying $0^+$ states

    CERN Document Server

    Adsley, P; Cseh, J; Dimitriova, S S; Brummer, J W; Li, K C W; Marin-Lambarri, D J; Lukyanov, K; Kheswa, N Y; Neveling, R; Papka, P; Pellegri, L; Pesudo, V; Pool, L C; Riczu, G; Smit, F D; van Zyl, J J; Zemlyanaya, E

    2016-01-01

    Aspects of nuclear structure in alpha-conjugate nuclei have long been associated with alpha clustering, including the existence of superdeformed bands. In this paper, an alpha-particle inelastic scattering experiment investigating the location of $0^+$ states in $^{28}$Si is reported in an attempt to locate possible cluster states. The results are compared to a semi-microscopic model which shows good agreement with the data, and supports the assignment of a newly discovered $0^+$ state as the band-head of a previously observed superdeformed band in $^{28}$Si

  20. Weather in stellar atmosphere: the dynamics of mercury clouds in alpha Andromedae

    CERN Document Server

    Kochukhov, Oleg; Gulliver, Austin F; Piskunov, Nikolai

    2007-01-01

    The formation of long-lasting structures at the surfaces of stars is commonly ascribed to the action of strong magnetic fields. This paradigm is supported by observations of evolving cool spots in the Sun and active late-type stars, and stationary chemical spots in the early-type magnetic stars. However, results of our seven-year monitoring of mercury spots in non-magnetic early-type star alpha Andromedae show that the picture of magnetically-driven structure formation is fundamentally incomplete. Using an indirect stellar surface mapping technique, we construct a series of 2-D images of starspots and discover a secular evolution of the mercury cloud cover in this star. This remarkable structure formation process, observed for the first time in any star, is plausibly attributed to a non-equilibrium, dynamical evolution of the heavy-element clouds created by atomic diffusion and may have the same underlying physics as the weather patterns on terrestrial and giant planets.

  1. Electron transfer across {alpha}-helical peptides: Potential influence of molecular dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Mandal, Himadri S. [Department of Chemistry, University of Saskatchewan, 110 Science Place, Saskatoon, Saskatchewan, S7N 5C9 (Canada); Kraatz, Heinz-Bernhard [Department of Chemistry, University of Saskatchewan, 110 Science Place, Saskatoon, Saskatchewan, S7N 5C9 (Canada)], E-mail: kraatz@skyway.usask.ca

    2006-07-11

    Three hydrophobic leucine-rich peptides Fc18L, Ac18L and 18LAc were prepared. These peptides are equipped with a cystein sulfhydryl group which enables the formation of thin films on gold surfaces. Using these peptides, two types of films of {alpha}-helical peptides have been prepared, in which the redox-active peptide Fc18L is diluted by Ac18L (SAM1) or by a mixture of Ac18L and 18LAc (SAM2). In SAM1, the dipole moments of the peptides are aligned in the same direction, whereas in SAM2, they are opposite. Reflection absorption infrared spectroscopy (RAIRS) revealed that the peptides are more vertically oriented in SAM2 compared to those in SAM1. The interaction among the macroscopic helix dipoles gives tighter packing of the peptides in SAM2. Importantly, the electron transfer properties in the two films are significantly different, which is rationalized by differences in the molecular dynamics of the two films.

  2. Alpha-fetoprotein is dynamically expressed in rat pancreas during development.

    Science.gov (United States)

    Liu, Lijie; Guo, Jing; Yuan, Li; Cheng, Mei; Cao, Lihua; Shi, Hui; Tong, Hui; Wang, Ning; De, Wei

    2007-10-01

    To identify proteins involved in pancreatic development, we used a differential proteomics approach by comparing pancreatic extracts from four biologically significant stages of development: embryonic day (E) 15.5, E18.5, postnatal (P) days 0 and adult. By two-dimensional gel electrophoresis (2D-E) and MALDI-TOF MS (Matrix Assisted Laser Desorption/Ionization Time-Of-Flight Mass Spectrometry) following database searching and protein annotation, 15 proteins were identified as being differently expressed in the pancreas between the four phases. The expression pattern and the localization of alpha-fetoprotein (AFP), one of significant changed proteins observed, were further determined. Four isoforms of AFP (72 kDa, 60 kDa, 48 kDa and 37 kDa) were found by Western blotting in the pancreas tested, most of them showed a stronger signal in E18.5 followed by a steady decrease and only a 60-kDa isoform was detected in the adult pancreas. Immunolocalization for AFP revealed that a positive reactivity was detectable at E15.5 pancreas, became stronger in the cytoplasm of mesenchyme cells at E18.5, and declined after birth to a nearly undetectable level in adults. The dynamic expression of AFP in rat pancreas from different stages indicates that AFP might be involved in some aspects of pancreatic development.

  3. High Risk Alpha Papillomavirus Oncogenes Impair the Homologous Recombination Pathway.

    Science.gov (United States)

    Wallace, Nicholas A; Khanal, Sujita; Robinson, Kristin L; Wendel, Sebastian O; Messer, Joshua J; Galloway, Denise A

    2017-08-02

    Persistent high risk genus α human papillomavirus (HPV) infections cause nearly every cervical carcinoma and a subset of tumors in the oropharyngeal tract. During the decades required for HPV-associated tumorigenesis, the cellular genome becomes significantly destabilized. Our analysis of cervical tumors from 4 separate data sets found a significant upregulation of the homologous recombination (HR) pathway genes. The increased abundance of HR proteins can be replicated in primary cells by expression of the two HPV oncogenes (E6 and E7) required for HPV-associated transformation. HPV E6 and E7 also enhanced the ability of HR proteins to form repair foci, yet both E6 and E7 reduce the ability of the HR pathway to complete double strand break (DSB) repair by about 50%. The HPV oncogenes hinder HR by allowing the process to begin at points in the cell cycle when the lack of a sister chromatid to serve as a homologous template prevents completion of the repair. Further, HPV E6 attenuates repair by causing RAD51 to be mislocalized away from both transient and persistent DSBs, while HPV E7 is only capable of impairing RAD51 localization to transient lesions. Finally, we show that the inability to robustly repair DSBs causes some of these lesions to be more persistent, a phenotype that correlates with increased integration of episomal DNA. Together these data support our hypothesis that HPV oncogenes contribute to the genomic instability observed in HPV-associated malignancies by attenuating the repair of damaged DNA.IMPORTANCE: This work expands the understanding of HPV biology, establishing a direct role for both HPV E6 and E7 in the destabilization of the host genome by blocking the homologous repair of DSBs. To our knowledge, this is the first time that both viral oncogenes were shown to disrupt this DSB repair pathway. We show that HPV E6 and E7 allow HR to initiate at an inappropriate part of the cell cycle. The mislocalization of RAD51 away from DSBs in cells

  4. High-dynamic-range water window ptychography

    CERN Document Server

    Rose, Max; Senkbeil, Tobias; von Gundlach, Andreas R; Stuhr, Susan; Rumancev, Christoph; Besedin, Ilya; Skopintsev, Petr; Viefhaus, Jens; Rosenhahn, Axel; Vartanyants, Ivan A

    2016-01-01

    Ptychographic imaging with soft X-rays, especially in the water window energy range, suffers from limited detector dynamic range that directly influences the maximum spatial resolution achievable. High-dynamic-range data can be obtained by multiple exposures. By this approach we have increased the dynamic range of a ptychographic data set by a factor of 76 and obtained diffraction signal till the corners of the detector. The real space half period resolution was improved from 50 nm for the single exposure data to 18 nm for the high-dynamic-range data.

  5. High spatial resolution optical imaging of the multiple T Tauri system LkH{\\alpha} 262/LkH{\\alpha} 263

    CERN Document Server

    Velasco, S; Oscoz, A; Mackay, C; Labadie, L; Garrido, A Pérez; Crass, J; Díaz-Sánchez, A; Femenía, B; González-Escalera, V; King, D L; López, R L; Puga, M; Rodríguez-Ramos, L F; Zuther, J

    2016-01-01

    We report high spatial resolution i' band imaging of the multiple T Tauri system LkH$\\alpha$ 262/LkH$\\alpha$ 263 obtained during the first commissioning period of the Adaptive Optics Lucky Imager (AOLI) at the 4.2 m William Herschel Telescope, using its Lucky Imaging mode. AOLI images have provided photometry for each of the two components LkH$\\alpha$ 263 A and B (0.41 arcsec separation) and marginal evidence for an unresolved binary or a disc in LkH$\\alpha$ 262. The AOLI data combined with previously available and newly obtained optical and infrared imaging show that the three components of LkH$\\alpha$ 263 are co-moving, that there is orbital motion in the AB pair, and, remarkably, that LkH$\\alpha$ 262-263 is a common proper motion system with less than 1 mas/yr relative motion. We argue that this is a likely five-component gravitationally bounded system. According to BT-settl models the mass of each of the five components is close to 0.4 M$_{\\odot}$ and the age is in the range 1-2 Myr. The presence of discs...

  6. Dynamical analysis of highly excited molecular spectra

    Energy Technology Data Exchange (ETDEWEB)

    Kellman, M.E. [Univ. of Oregon, Eugene (United States)

    1993-12-01

    The goal of this program is new methods for analysis of spectra and dynamics of highly excited vibrational states of molecules. In these systems, strong mode coupling and anharmonicity give rise to complicated classical dynamics, and make the simple normal modes analysis unsatisfactory. New methods of spectral analysis, pattern recognition, and assignment are sought using techniques of nonlinear dynamics including bifurcation theory, phase space classification, and quantization of phase space structures. The emphasis is chaotic systems and systems with many degrees of freedom.

  7. Alpha reactivity to first names differs in subjects with high and low dream recall frequency

    Directory of Open Access Journals (Sweden)

    Perrine Marie RUBY

    2013-08-01

    Full Text Available Studies in cognitive psychology showed that personality (openness to experience, thin boundaries, absorption, creativity, nocturnal awakenings, and attitude toward dreams are significantly related to dream recall frequency (DRF. These results suggest the possibility of neurophysiological trait differences between subjects with high and low DRF. To test this hypothesis we compared sleep characteristics and alpha reactivity to sounds in subjects with high and low DRF using polysomnographic recordings and electroencephalography (EEG. We acquired EEG from 21 channels in 36 healthy subjects while they were presented with a passive auditory oddball paradigm (frequent standard tones, rare deviant tones and very rare first names during wakefulness and sleep (intensity, 50 dB above the subject’s hearing level. Subjects were selected as High-recallers (HR, DRF = 4.4 ± 1.1 dream recalls per week and Low-recallers (LR, DRF = 0.25 ± 0.1 using a questionnaire and an interview on sleep and dream habits. Despite the disturbing setup, the subjects’ quality of sleep was generally preserved. First names induced a more sustained decrease in alpha activity in HR than in LR at Pz (1000-1200ms during wakefulness, but no group difference was found in REM sleep. The current dominant hypothesis proposes that alpha rhythms would be involved in the active inhibition of the brain regions not involved in the ongoing brain operation. According to this hypothesis, a more sustained alpha decrease in HR would reflect a longer release of inhibition, suggesting a deeper processing of complex sounds than in LR during wakefulness. A possibility to explain the absence of group difference during sleep is that increase in alpha power in HR may have resulted in awakenings. Our results support this hypothesis since HR experienced more intra sleep wakefulness than LR (30 ± 4 vs 14 ± 4 min. As a whole our results support the hypothesis of neurophysiological trait differences in

  8. Alpha reactivity to first names differs in subjects with high and low dream recall frequency.

    Science.gov (United States)

    Ruby, Perrine; Blochet, Camille; Eichenlaub, Jean-Baptiste; Bertrand, Olivier; Morlet, Dominique; Bidet-Caulet, Aurélie

    2013-01-01

    Studies in cognitive psychology showed that personality (openness to experience, thin boundaries, absorption), creativity, nocturnal awakenings, and attitude toward dreams are significantly related to dream recall frequency (DRF). These results suggest the possibility of neurophysiological trait differences between subjects with high and low DRF. To test this hypothesis we compared sleep characteristics and alpha reactivity to sounds in subjects with high and low DRF using polysomnographic recordings and electroencephalography (EEG). We acquired EEG from 21 channels in 36 healthy subjects while they were presented with a passive auditory oddball paradigm (frequent standard tones, rare deviant tones and very rare first names) during wakefulness and sleep (intensity, 50 dB above the subject's hearing level). Subjects were selected as High-recallers (HR, DRF = 4.42 ± 0.25 SEM, dream recalls per week) and Low-recallers (LR, DRF = 0.25 ± 0.02) using a questionnaire and an interview on sleep and dream habits. Despite the disturbing setup, the subjects' quality of sleep was generally preserved. First names induced a more sustained decrease in alpha activity in HR than in LR at Pz (1000-1200 ms) during wakefulness, but no group difference was found in REM sleep. The current dominant hypothesis proposes that alpha rhythms would be involved in the active inhibition of the brain regions not involved in the ongoing brain operation. According to this hypothesis, a more sustained alpha decrease in HR would reflect a longer release of inhibition, suggesting a deeper processing of complex sounds than in LR during wakefulness. A possibility to explain the absence of group difference during sleep is that increase in alpha power in HR may have resulted in awakenings. Our results support this hypothesis since HR experienced more intra sleep wakefulness than LR (30 ± 4 vs. 14 ± 4 min). As a whole our results support the hypothesis of neurophysiological trait differences in high and

  9. Alpha reactivity to first names differs in subjects with high and low dream recall frequency

    Science.gov (United States)

    Ruby, Perrine; Blochet, Camille; Eichenlaub, Jean-Baptiste; Bertrand, Olivier; Morlet, Dominique; Bidet-Caulet, Aurélie

    2013-01-01

    Studies in cognitive psychology showed that personality (openness to experience, thin boundaries, absorption), creativity, nocturnal awakenings, and attitude toward dreams are significantly related to dream recall frequency (DRF). These results suggest the possibility of neurophysiological trait differences between subjects with high and low DRF. To test this hypothesis we compared sleep characteristics and alpha reactivity to sounds in subjects with high and low DRF using polysomnographic recordings and electroencephalography (EEG). We acquired EEG from 21 channels in 36 healthy subjects while they were presented with a passive auditory oddball paradigm (frequent standard tones, rare deviant tones and very rare first names) during wakefulness and sleep (intensity, 50 dB above the subject's hearing level). Subjects were selected as High-recallers (HR, DRF = 4.42 ± 0.25 SEM, dream recalls per week) and Low-recallers (LR, DRF = 0.25 ± 0.02) using a questionnaire and an interview on sleep and dream habits. Despite the disturbing setup, the subjects' quality of sleep was generally preserved. First names induced a more sustained decrease in alpha activity in HR than in LR at Pz (1000–1200 ms) during wakefulness, but no group difference was found in REM sleep. The current dominant hypothesis proposes that alpha rhythms would be involved in the active inhibition of the brain regions not involved in the ongoing brain operation. According to this hypothesis, a more sustained alpha decrease in HR would reflect a longer release of inhibition, suggesting a deeper processing of complex sounds than in LR during wakefulness. A possibility to explain the absence of group difference during sleep is that increase in alpha power in HR may have resulted in awakenings. Our results support this hypothesis since HR experienced more intra sleep wakefulness than LR (30 ± 4 vs. 14 ± 4 min). As a whole our results support the hypothesis of neurophysiological trait differences in high

  10. Lyman alpha emission in starbursts: implications for galaxies at high redshift

    CERN Document Server

    Mas-Hesse, J M; Tenorio-Tagle, G; Leitherer, C; Terlevich, R J; Terlevich, E

    2003-01-01

    We present the results of a high resolution UV 2-D spectroscopic survey of star forming galaxies observed with HST-STIS. Our main aim was to map the Lyman alpha profiles to learn about the gas kinematics and its relation with the escape of Lyman alpha photons and to detect extended Lyman alpha emission due to scattering in gaseous halos. We have combined our data with previously obtained UV spectroscopy on other three star-forming galaxies. We find that the P-Cygni profile is spatially extended, smooth and spans several kiloparsecs covering a region much larger than the starburst itself. We propose a scenario whereby an expanding super-shell is generated by the interaction of the combined stellar winds and supernova ejecta from the young starbursts, with an extended low density halo. The variety of observed Lyman alpha profiles both in our sample and in high redshift starbursts is explained as phases in the time evolution of the super-shell expanding into the disk and halo of the host galaxy. The observed sha...

  11. Alpha reactivity to first names differs in subjects with high and low dream recall frequency

    OpenAIRE

    Perrine Marie RUBY; Camille eBlochet; Jean-Baptiste eEichenlaub; Olivier eBertrand; Dominique eMorlet; Aurélie eBidet-Caulet

    2013-01-01

    Studies in cognitive psychology showed that personality (openness to experience, thin boundaries, absorption), creativity, nocturnal awakenings, and attitude toward dreams are significantly related to dream recall frequency (DRF). These results suggest the possibility of neurophysiological trait differences between subjects with high and low DRF. To test this hypothesis we compared sleep characteristics and alpha reactivity to sounds in subjects with high and low DRF using polysomnographic re...

  12. The Appearance of Spicules in High Resolution Observations of Ca II H and H-alpha

    CERN Document Server

    Pereira, Tiago M D; Carlsson, Mats

    2016-01-01

    Solar spicules are chromospheric fibrils that appear everywhere on the Sun, yet their origin is not understood. Using high resolution observations of spicules obtained with the Swedish 1-m Solar Telescope we aim to understand how spicules appear in filtergrams and Dopplergrams, how they compare in Ca II H and H-alpha, and what can make them appear and disappear. We find spicules display a rich and detailed spatial structure, and show a distribution of transverse velocities that when aligned with the line of sight can make them appear at different H-alpha wing positions. They become more abundant at positions closer to the line core, reflecting a distribution of Doppler shifts and widths. In H-alpha width maps they stand out as bright features both on disk and off-limb, reflecting their large Doppler motions and possibly higher temperatures than in the typical H-alpha formation region. Spicule lifetimes measured from narrowband images at only a few positions will be an underestimate because Doppler shifts can ...

  13. Revisit of alpha-chitin crystal structure using high resolution X-ray diffraction data.

    Science.gov (United States)

    Sikorski, Pawel; Hori, Ritsuko; Wada, Masahisa

    2009-05-11

    High resolution synchrotron X-ray fiber diffraction data recorded from crab tendon chitin have been used to describe the crystal structure of alpha-chitin. Crystal structures at 100 and 300 K have been solved using restrained crystallographic refinement against diffraction intensities measured from the fiber diffraction patterns. The unit cell contains two polymer chains in a 2(1) helix conformation and in the antiparallel orientation. The best agreement between predicated and observed X-ray diffraction intensities is obtained for a model that includes two distinctive conformations of C6-O6 hydroxymethl group. Those conformations are different from what is proposed in the generally accepted alpha-chitin crystal structure (J. Mol. Biol. 1978, 120, 167-181). Based on refined positions of the O6 atoms, a network of hydrogen bonds involving O6 is proposed. This network of hydrogen bonds can explain the main features of the polarized FTIR spectra of alpha-chitin and sheds some light on the origin of splitting of the amide I band observed on alpha-chitin IR spectra.

  14. High redshift galaxies and the Lyman-alpha forest in a CDM universe

    CERN Document Server

    Croft, R A C; Springel, V; Westover, M; White, M; Croft, Rupert A.C.; Hernquist, Lars; Springel, Volker; Westover, Michael; White, Martin

    2002-01-01

    We use a cosmological hydrodynamic simulation of a cold dark matter universe to investigate theoretically the relationship between high redshift galaxies and the Lyman=alpha forest at redshift z=3. Galaxies in the simulation are surrounded by halos of hot gas, which nevertheless contain enough neutral hydrogen to cause a Ly-alpha flux decrement, its strength increasing with galaxy mass. A comparison with recent observational data by Adelberger et. al on the Ly-alpha forest around galaxies reveals that actual galaxies may have systematically less Ly-alpha absorption within 1 Mpc of them than our simulated galaxies. In order to investigate this possibility, we add several simple prescriptions for galaxy feedback on the IGM to the evolved simulation. These include the effect of photoionizing background radiation coming from galactic sources, galactic winds whose only effect is to deposit thermal energy into the IGM, and another, kinetic model for winds, which are assumed to evacuate cavities in the IGM around ga...

  15. Alpha-ray spectrometry at high temperature by using a compound semiconductor detector.

    Science.gov (United States)

    Ha, Jang Ho; Kim, Han Soo

    2013-11-01

    The use of conventional radiation detectors in harsh environments is limited by radiation damage to detector materials and by temperature constraints. We fabricated a wide-band gap semiconductor radiation detector based on silicon carbide. All the detector components were considered for an application in a high temperature environment like a nuclear reactor core. The radiation response, especially to alpha particles, was measured using an (241)Am source at variable operating voltages at room temperature in the air. The temperature on detector was controlled from 30°C to 250°C. The alpha-particle spectra were measured at zero bias operation. Even though the detector is operated at high temperature, the energy resolution as a function of temperature is almost constant within 3.5% deviation.

  16. Alpha-Fetoprotein Detection of Hepatocellular Carcinoma Leads to a Standardized Analysis of Dynamic AFP to Improve Screening Based Detection.

    Science.gov (United States)

    Bird, Thomas G; Dimitropoulou, Polyxeni; Turner, Rebecca M; Jenks, Sara J; Cusack, Pearce; Hey, Shiying; Blunsum, Andrew; Kelly, Sarah; Sturgeon, Catharine; Hayes, Peter C; Bird, Sheila M

    2016-01-01

    Detection of hepatocellular carcinoma (HCC) through screening can improve outcomes. However, HCC surveillance remains costly, cumbersome and suboptimal. We tested whether and how serum Alpha-Fetoprotein (AFP) should be used in HCC surveillance. Record linkage, dedicated pathways for management and AFP data-storage identified i) consecutive highly characterised cases of HCC diagnosed in 2009-14 and ii) a cohort of ongoing HCC-free patients undergoing regular HCC surveillance from 2009. These two well-defined Scottish patient cohorts enabled us to test the utility of AFP surveillance. Of 304 cases of HCC diagnosed over 6 years, 42% (129) were identified by a dedicated HCC surveillance programme. Of these 129, 47% (61) had a detectable lesion first identified by screening ultrasound (US) but 38% (49) were prompted by elevated AFP. Despite pre-HCC diagnosis AFP >20kU/L being associated with poor outcome, 'AFP-detected' tumours were offered potentially curative management as frequently as 'US-detected' HCCs; and had comparable survival. Linearity of serial log10-transformed AFPs in HCC cases and in the screening 'HCC-free' cohort (n = 1509) provided indicators of high-risk AFP behaviour in HCC cases. An algorithm was devised in static mode, then tested dynamically. A case/control series in hepatitis C related disease demonstrated highly significant detection (pAFP in HCC surveillance. We show proof-of-principle that an automated and further refine-able algorithmic interpretation of AFP can identify patients at higher risk of HCC. This approach could provide a cost-effective, user-friendly and much needed addition to US surveillance.

  17. High-level expression of the native barley alpha-amylase/subtilisin inhibitor in Pichia pastoris

    DEFF Research Database (Denmark)

    Micheelsen, Pernille Ollendorff; Ostergaard, Peter Rahbek; Lange, Lene

    2008-01-01

    An expression system for high-level expression of the native Hordeum vulgare alpha-amylase/subtilisin inhibitor (BASI) has been developed in Pichia pastoris, using the methanol inducible alcohol oxidase 1 (AOX1) promoter. To optimize expression, two codon-optimized coding regions have been design...... and characterized by Edman degradation, liquid chromatography mass spectrometry and insoluble blue starch assay, and was shown to possess the same characteristics as wild-type protein purified from barley grains....

  18. Alpha Blockers

    Science.gov (United States)

    ... positive side, alpha blockers might decrease low-density lipoprotein (LDL) cholesterol (the "bad" cholesterol). Alpha blockers can ... PreventionTreatmentofHighBloodPressure/Types-of-Blood-Pressure-Medications_UCM_303247_Article.jsp. Accessed June 4, 2016. Kaplan NM, et ...

  19. Rapid, automated, parallel quantitative immunoassays using highly integrated microfluidics and AlphaLISA

    Science.gov (United States)

    TakYu, Zeta; Guan, Huijiao; Ki Cheung, Mei; McHugh, Walker M.; Cornell, Timothy T.; Shanley, Thomas P.; Kurabayashi, Katsuo; Fu, Jianping

    2015-06-01

    Immunoassays represent one of the most popular analytical methods for detection and quantification of biomolecules. However, conventional immunoassays such as ELISA and flow cytometry, even though providing high sensitivity and specificity and multiplexing capability, can be labor-intensive and prone to human error, making them unsuitable for standardized clinical diagnoses. Using a commercialized no-wash, homogeneous immunoassay technology (‘AlphaLISA’) in conjunction with integrated microfluidics, herein we developed a microfluidic immunoassay chip capable of rapid, automated, parallel immunoassays of microliter quantities of samples. Operation of the microfluidic immunoassay chip entailed rapid mixing and conjugation of AlphaLISA components with target analytes before quantitative imaging for analyte detections in up to eight samples simultaneously. Aspects such as fluid handling and operation, surface passivation, imaging uniformity, and detection sensitivity of the microfluidic immunoassay chip using AlphaLISA were investigated. The microfluidic immunoassay chip could detect one target analyte simultaneously for up to eight samples in 45 min with a limit of detection down to 10 pg mL-1. The microfluidic immunoassay chip was further utilized for functional immunophenotyping to examine cytokine secretion from human immune cells stimulated ex vivo. Together, the microfluidic immunoassay chip provides a promising high-throughput, high-content platform for rapid, automated, parallel quantitative immunosensing applications.

  20. Ly\\alpha\\ emission line reconstruction for high-$z$ QSOs

    CERN Document Server

    Greig, Bradley; McGreer, Ian D; Gallerani, Simona; Haiman, Zoltán

    2016-01-01

    We introduce an intrinsic Ly\\alpha\\ emission line profile reconstruction method for high-$z$ quasars (QSOs). This approach utilises a covariance matrix of emission line properties obtained from a large, moderate-$z$ ($2 \\leq z \\leq 2.5$), high signal to noise (S/N > 15) sample of BOSS QSOs. For each QSO, we complete a Monte Carlo Markov Chain fitting of the continuum and emission line properties and perform a visual quality assessment to construct a large database of robustly fit spectra. With this dataset, we construct a covariance matrix to describe the correlations between the high ionisation emission lines Ly\\alpha, C IV, Si IV + O IV] and C III], and find it to be well approximated by an $N$-dimensional Gaussian distribution. This covariance matrix characterises the correlations between the line width, peak height and velocity offset from systemic while also allowing for the existence of broad and narrow line components for Ly\\alpha\\ and C IV. We illustrate how this covariance matrix allows us to statist...

  1. INTERACTION BETWEEN THE ADH AND ALPHA-GPDH LOCI IN DROSOPHILA-MELANOGASTER - ADULT SURVIVAL AT HIGH-TEMPERATURE

    NARCIS (Netherlands)

    OUDMAN, L; VANDELDEN, W; KAMPING, A; BIJLSMA, R

    1992-01-01

    The role of high temperature resistance in the world-wide cline of Adh and alpha-Gpdh allele frequencies of Drosophila melanogaster was investigated. Experimental strains were used with different combinations of Adh and alpha-Gpdh alleles but with similar genetic background. The survival time of adu

  2. CLINICAL-EXPERIENCE WITH HIGH-DOSE TUMOR-NECROSIS-FACTOR-ALPHA IN REGIONAL THERAPY OF ADVANCED MELANOMA

    NARCIS (Netherlands)

    LEJEUNE, F; LIENARD, D; EGGERMONT, A; KOOPS, HS; KROON, B; GERAIN, J; ROSENKAIMER, F; SCHMITZ, P

    1994-01-01

    Isolated perfusion of the limbs (ILP) allows the delivery of high dose rTNF alpha in a closed system with acceptable side-effects. A protocol with a triple-drug regimen was based on the reported synergism of rTNF alpha with chemotherapy, with interferon-gamma, and with hyperthermia. In melanoma-in-t

  3. Universal primers suitable to assess population dynamics reveal apparent mutually exclusive transcription of the Babesia bovis ves1alpha gene.

    Science.gov (United States)

    Zupańska, Agata K; Drummond, Paul B; Swetnam, Daniele M; Al-Khedery, Basima; Allred, David R

    2009-07-01

    Babesia bovis is an intraerythrocytic hemoparasite of widespread distribution, which adversely affects livestock production in many regions of the world. This parasite establishes persistent infections of long duration, at least in part through rapid antigenic variation of the VESA1 protein on the infected-erythrocyte surface. To understand the dynamics of in vivo antigenic variation among the parasite population it is necessary to have sensitive and broadly applicable tools enabling monitoring of variation events in parasite antigen genes. To address this need for B. bovis, "universal" primers for the polymerase chain reaction have been designed for the ves1alpha gene, spanning from exon 2 to near the 3' end of cysteine-lysine-rich domain (CKRD) sequences in exon 3. These primers robustly amplified this segment, with minimal bias, from essentially the entire repertoire of full-length ves1alpha sequences in the B. bovis Mexico isolate genome, and are equivalently present in other isolates. On purified genomic DNA, this primer set can achieve a sensitivity of 10 genome equivalents or less. When applied to the amplification of cDNA derived from the B. bovis C9.1 clonal line evidence consistent with mutually exclusive transcription of the ves1alpha gene was obtained, concomitant with detection of numerous mutational events among members of the parasite population. These characteristics of the primers will facilitate the application of polymerase chain reaction-based methodologies to the study of B. bovis population and antigenic switching dynamics.

  4. Effect of alpha-Q-value on reaction dynamics at ≈ 4-7 AMeV

    Directory of Open Access Journals (Sweden)

    Bhowmik R.K.

    2012-02-01

    Full Text Available This paper deals with the dependence of incomplete fusion reaction dynamics on various entrance channel parameters, specially, the alpha-Q-value effect. The excitation functions for several radio-nuclides formed in 13C+159Tb interactions at ≈ 4-7 AMeV have been measured using activation technique followed by γ-spectroscopy. The experimentally measured excitation functions have been analyzed in the framework of statistical model code PACE4. A sizeable contribution of incomplete fusion has been delineated in the production of α-emitting channels in reference to the Monte Carlo simulation based statistical model code PACE4. For better insights into the onset and strength of incomplete fusion, the incomplete fusion strength function has been deduced as a function of various entrance channel parameters. A significant amount of incomplete fusion contribution has been observed at slightly above barrier energies, and found to increase smoothly with incident projectile energy. Present results have also been compared with the results obtained in the interactions of 16O and 12C with same target 159Tb, to probe the dependence of incomplete fusion on projectile, specially, on the binding energy & alpha-Q-value. The present work in light of previous data hints that instead of binding energy, the alpha-Q-value of the projectile is a parameter which influences the in-complete fusion reaction dynamics.

  5. Measurement of dijet production in neutral current deep inelastic scattering at high Q**2 and determination of alpha_s

    CERN Document Server

    Breitweg, J; Abramowicz, H; Adamczyk, L; Adamus, M; Aghuzumtsyan, G; Ahn, S H; Amelung, C; Antonioli, P; Antonov, A; Arneodo, M; Badgett, W F; Bailey, D C; Bailey, D S; Bamberger, Andreas; Barakbaev, A N; Barbagli, G; Barbi, M S; Bari, G; Barreiro, F; Barret, O; Bashkirov, V; Basile, M; Bauerdick, L A T; Bednarek, B; Behrens, U; Bell, M; Bellagamba, L; Benen, A; Bertolin, A; Bienlein, J K; Bodmann, B; Bokel, C; Boogert, S; Boos, E G; Borras, K; Boscherini, D; Botje, M; Brock, I; Brook, N H; Brugnera, R; Bruni, A; Bruni, G; Brümmer, N; Bussey, Peter J; Butterworth, J M; Bylsma, B; Caldwell, A; Capua, M; Cara Romeo, G; Carli, T; Carlin, R; Cartiglia, N; Chapin, D; Chekanov, S; Chiochia, V; Chwastowski, J; Ciborowski, J; Ciesielski, R; Cifarelli, Luisa; Cindolo, F; Cirio, R; Cloth, P; Coboken, K; Coldewey, C; Cole, J E; Contin, A; Cooper-Sarkar, A M; Coppola, N; Cormack, C; Corradi, M; Corriveau, F; Costa, M; Crittenden, James Arthur; Cross, R; D'Agostini, Giulio; Dagan, S; Dal Corso, F; Danilov, P; Dannheim, D; De Pasquale, S; De Wolf, E; Del Peso, J; Dementiev, R K; Deppe, O; Derrick, Malcolm; Desler, K; Devenish, R C E; Dolgoshein, B A; Doyle, A T; Drews, G; Durkin, L S; Dusini, S; Eisenberg, Y; Eisenhardt, S; Engelen, J; Epperson, D E; Ermolov, P F; Eskreys, Andrzej; Fagerstroem, C P; Ferrero, M I; Figiel, J; Filges, D; Foster, B; Foudas, C; Fox-Murphy, A; Fricke, U; Fusayasu, T; Gabareen, A; Gadaj, T; Galea, R; Gallo, E; García, G; Garfagnini, A; Geiser, A; Gendner, N; Gialas, I; Gilmore, J; Ginsburg, C M; Giusti, P; Gladilin, L K; Gladkov, D; Glasman, C; Göbel, F; Goers, S; Golubkov, Yu A; Goncalo, R; González, O; Graciani, R; Grijpink, S; Grosse-Knetter, J; Grzelak, G; Gwenlan, C; Göttlicher, P; Haas, T; Hain, W; Hamatsu, R; Hart, J C; Hartmann, H; Hartner, G F; Hayes, M E; Heaphy, E A; Heath, G P; Heath, H F; Hebbel, K; Heinloth, K; Heusch, C A; Hilger, E; Hillert, S; Hirose, T; Hochman, D; Holm, U; Iacobucci, G; Iannotti, L; Inuzuka, M; Irrgang, P; Ishii, T; Jakob, H P; Jelen, K; Jeoung, H Y; Jones, T W; Kananov, S; Kappes, A; Karshon, U; Katkov, I I; Katz, U F; Kcira, D; Kerger, R; Khein, L A; Kim, C L; Kim, J Y; Kind, O; Kisielewska, D; Kitamura, S; Klimek, K H; Koch, W; Koffeman, E; Kohno, T; Kooijman, P M; Koop, T; Korotkova, N A; Korzhavina, I A; Kotanski, Andrzej; Kowal, A M; Kowalski, H; Kowalski, T; Krakauer, D A; Kreisel, A; Kuze, M; Kuzmin, V A; Kötz, U; Labarga, L; Labes, H; Lane, J B; Lee, J H; Lee, S B; Lee, S W; Levi, G; Levman, G M; Levy, A; Lim, H; Lim, I T; Limentani, S; Ling, T Y; Liu, W; Liu, X; Lohrmann, E; Long, K R; Longhin, A; López-Duran-Viani, A; Lukina, O Yu; Lupi, A; Löhr, B; Ma, K J; MacDonald, N; Magill, S; Mankel, R; Margotti, A; Marini, G; Markun, P; Martens, J; Martin, J F; Martínez, M; Maselli, S; Massam, Thomas; Mastroberardino, A; Matsushita, T; Matsuzawa, K; Mattingly, M C K; Mattingly, S E K; McCance, G J; McCubbin, N A; Mellado, B; Meyer, A; Milite, M; Miller, D B; Mirea, A; Monaco, V; Moritz, M; Musgrave, B; Nagano, K; Nania, R; Nigro, A; Nishimura, T; Notz, D; Nowak, R J; Oh, B Y; Okrasinski, J R; Olkiewicz, K; Pac, M Y; Padhi, S; Paganis, S; Palmonari, F; Parenti, A; Park, I H; Park, S K; Paul, E; Pavel, N; Pawlak, J M; Pawlak, R; Pelfer, P G; Pellegrino, A; Peroni, C; Pesci, A; Petrucci, M C; Pokrovskiy, N S; Polini, A; Posocco, M; Proskuryakov, A S; Przybycien, M B; Raach, H; Rautenberg, J; Redondo, I; Reeder, D D; Repond, J; Robins, S A; Rodrigues, E; Rohde, M; Rulikowska-Zarebska, E; Ruske, O; Ruspa, M; Sabetfakhri, A; Sacchi, R; Sadrozinski, H F W; Salehi, H; Sampson, S; Sartorelli, G; Saull, P R B; Savin, A A; Saxon, D H; Schagen, S; Schioppa, M; Schlenstedt, S; Schmidke, W B; Schneekloth, U; Schnurbusch, H; Sciulli, F; Scott, J; Seiden, A; Selonke, F; Shah, T P; Shcheglova, L M; Sinclair, L E; Skillicorn, Ian O; Smalska, B; Smith, W H; Solano, A; Solomin, A N; Son, D; Sosnovtsev, V V; Staiano, A; Stairs, D G; Stanco, L; Stanek, R; Stifutkin, A; Stonjek, S; Stopa, P; Straub, P B; Suchkov, S; Susinno, G; Suszycki, L; Sutton, M R; Szuba, D; Tandler, J; Tapper, A D; Tapper, R J; Tassi, E; Terron, J; Tiecke, H G; Tokushuku, K; Toothacker, W S; Tsurugai, T; Tuning, N; Turcato, M; Tymieniecka, T; Umemori, K; Vaiciulis, A W; Van Sighem, A; Vázquez, M E; Velthuis, J J; Vlasov, N N; Voss, K C; Vossebeld, Joost Herman; Walczak, R; Walker, R; Waugh, R; Weber, A; West, B J; Whitmore, J J; Wichmann, R; Wick, K; Wieber, H; Wiggers, L; Wildschek, T; Williams, D C; Wing, M; Wodarczyk, M; Wolf, G; Wollmer, U; Wróblewski, A K; Wölfle, S; Yamada, S; Yamashita, T; Yamazaki, Y; Yildirim, A; Yoshida, R; Youngman, C; Zakrzewski, J A; Zawiejski, L; Zeuner, W; Zhautykov, B O; Zichichi, A; Ziegler, A; Zotkin, S A

    2001-01-01

    Dijet production has been studied in neutral current deep inelastic e+p scattering for 470 < Q**2 < 20000 GeV**2 with the ZEUS detector at HERA using an integrated luminosity of 38.4 pb**{-1}. Dijet differential cross sections are presented in a kinematic region where both theoretical and experimental uncertainties are small. Next-to-leading-order (NLO) QCD calculations describe the measured differential cross sections well. A QCD analysis of the measured dijet fraction as a function of Q**2 allows both a precise determination of alpha_s(M_Z) and a test of the energy-scale dependence of the strong coupling constant. A detailed analysis provides a realistic estimate of the uncertainties of the NLO QCD cross sections arising from the parton distribution functions of the proton. The value of alpha_s(M_Z), as determined from the QCD fit, is alpha_s(M_Z) = 0.1166 +- 0.0019 (stat.) {+ 0.0024}_{- 0.0033} (exp.)} {+ 0.0057}_{- 0.0044} (th.).

  6. High dynamic GPS receiver validation demonstration

    Science.gov (United States)

    Hurd, W. J.; Statman, J. I.; Vilnrotter, V. A.

    1985-01-01

    The Validation Demonstration establishes that the high dynamic Global Positioning System (GPS) receiver concept developed at JPL meets the dynamic tracking requirements for range instrumentation of missiles and drones. It was demonstrated that the receiver can track the pseudorange and pseudorange rate of vehicles with acceleration in excess of 100 g and jerk in excess of 100 g/s, dynamics ten times more severe than specified for conventional High Dynamic GPS receivers. These results and analytic extensions to a complete system configuration establish that all range instrumentation requirements can be met. The receiver can be implemented in the 100 cu in volume required by all missiles and drones, and is ideally suited for transdigitizer or translator applications.

  7. Guest editorial : high dynamic range imaging

    OpenAIRE

    Santos, Luís Paulo; Debattista, Kurt

    2013-01-01

    High Dynamic Range (HDR) imagery is a step-change in imaging technology that is not limited to the 8-bits per pixel for each color channel that traditional or low-dynamic range digital images have been constrained to. These restrictions have meant that the current and relatively novel imaging technologies including stereoscopic, HD and ultraHD imaging do not provide an accurate representation of the lighting available in a real world environment. HDR technology has enabled the capture, sto...

  8. High-harmonic generation in alpha-quartz by the electron-hole recombination

    CERN Document Server

    Otobe, T

    2016-01-01

    The first-principle calculation for the high-harmonic generation (HHG) in an alpha-quartz employing the time-dependent density-functional theory is reported. The photon energy is set to 1.55 eV, and the cutoff energy of the plateau region is found to be limited at the 19th harmonics (30 eV). The laser intensity dependence of HHG efficiency at the cutoff energy region is consistent with that of the hole density in the lowest-lying valence band. Numerical results indicate that the electron-hole recombination plays a crucial role in HHG in alpha-quartz. It is found that the 200 attosecond pulse train is generated utilizing HHG around the plateau cutoff energy.

  9. Development of scintillator plates with high energy resolution for alpha particles made of GPS scintillator grains

    Science.gov (United States)

    Shimaoka, Takehiro; Kaneko, Junichi H.; Izaki, Kenji; Tsubota, Youichi; Higuchi, Mikio; Nishiyama, Shusuke

    2014-01-01

    A scintillator plate with high energy resolution was developed to produce an alpha particle monitor used in nuclear fuel reprocessing plants and mixed plutonium-uranium oxide (MOX) fuel plants. Grains of a Gd2Si2O7 (GPS) scintillator of several 10 to 550 μm were fixed on a glass substrate and were then mechanically polished. By increasing the size of scintillator grains and removing fine powders, the collected light yield and energy resolution for alpha particles were drastically improved. Energy resolution of 9.3% was achieved using average grain size of 91 μm. Furthermore, the ratios between counts in a peak and total counts were improved by more than 60% by the further increase of grain size and adoption of mechanically polished surfaces on both sides. Beta and gamma ray influences were suppressed sufficiently by the thin 100 μm scintillator plates.

  10. Radiation electromagnetic effect in germanium crystals under high-energy. cap alpha. -particle irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kikoin, I.K.; Babichenko, V.S.; Kikoin, L.I.; Lazarev, S.D.; Rzhanov, A.E.; Filippov, V.I.

    1984-05-01

    Results of experimental investigation into radiation electromagnetic effect (REM) in samples of germanium crystals under approximately 40 MeV ..cap alpha..-particle irradiation in a cyclotron are presented. A high level of excitation, volumetric character of generation of non-equilibrium carriers and formation of defects as well as the form of their spatial distribution are shown to result in some peculiarities of the EMF of the REM effect on the particle flux, fluence and sample parameters. Agreement of theoretical calculations, conducted with account of specificity of ..cap alpha..-particle interaction with a crystal, and experimental data is obtained. It is revealed that the REM effect can be applied in obtaining data on spatial distribution of non-equilibrium carrier concentrations along the particle trajectory in the crystal.

  11. Radiation-electromagnetic effect in germanium crystals irradiated with high-energy. cap alpha. particles

    Energy Technology Data Exchange (ETDEWEB)

    Kikoin, I.K.; Babichenko, V.S.; Kikoin, L.I.; Lazarev, S.D.; Rzhanov, A.E.; Filippov, V.I.

    1984-05-01

    An experimental investigation was made of the radiation-electromagnetic effect in germanium crystals irradiated in a cyclotron with ..cap alpha.. particles of energies up to 40 MeV. The high excitation rate, the bulk nature of generation of nonequilibrium carriers and defects, and their spatial distributions gave rise to several special features in the dependence of the emf due to the radiation-electromagnetic effect on the particle flux, fluence, and parameters of samples. Theoretical calculations carried out allowing for the specific nature of the interaction of ..cap alpha.. particles with crystals agreed well with the experimental results. The radiation-electromagnetic effect could be used to obtain information on the nature of the spatial distribution of the density of nonequilibrium carriers along the trajectory of a particle in a crystal.

  12. Dynamics of a Highly Flexible Protein

    DEFF Research Database (Denmark)

    Andersen, Lisbeth

    Protein dynamics are important for protein function. Especially, dynamics plays an important role in ligand-binding where the induced fit and conformational selection binding mechanisms represent the extremes in a continuum of dynamic mechanisms. The difference between the mechanisms lies...... in the sequence of events; either the protein changes it conformation after initial binding of the ligand (induced fit) or before binding of the ligand (conformational selection). The nuclear co-activator binding domain (NCBD) interacts with many different binding partners to control gene transcription. High...... malleability are the subject of this defense. Using nuclear magnetic resonance (NMR) spectroscopy, the dynamics of NCBD have been investigated on timescales ranging from picoseconds to milliseconds using relaxation dispersion experiments, residual dipolar couplings and methyl group deuterium relaxation. From...

  13. Fluctuations in the High-Redshift Lyman-Werner and Lyman-alpha Radiation Backgrounds

    CERN Document Server

    Holzbauer, Lauren N

    2011-01-01

    We use a new method to model fluctuations of the Lyman-Werner (LW) and Lyman-alpha radiation backgrounds at high redshift. At these early epochs the backgrounds are symptoms of a universe newly lit with its first stars. LW photons (11.5-13.6 eV) are of particular interest because they dissociate molecular hydrogen, the primary coolant in the first minihalos. By using a variation of the halo model, we efficiently generate power spectra for any choice of radiation background. We find that the LW power spectrum typically traces the matter power spectrum at large scales but turns over at the scale corresponding to the effective `horizon' of LW photons (~100 comoving Mpc), unless the sources are extremely rare. The series of horizons that characterize the Lyman-alpha flux profile shape the fluctuations of that background in a similar fashion, though those imprints are washed out once one considers fluctuations in the brightness temperature of the 21-cm signal. The Lyman-alpha background strongly affects the redshi...

  14. Determination of alpha-solanine and alpha-chaconine in potatoes by high-performance thin-layer chromatography/densitometry.

    Science.gov (United States)

    Bodart, P; Kabengera, C; Noirfalise, A; Hubert, P; Angenot, L

    2000-01-01

    A high-performance thin-layer chromatographic (HPTLC) method was used to determine the glycoalkaloids alpha-solanine and alpha-chaconine in potatoes. Alpha-solanine and alpha-chaconine are extracted from dehydrated potatoes with boiling methanol-acetic acid (95 + 5, v/v). The analytes are separated on a Silica Gel 60 F254 HPTLC plate by a saturated mixture of dichloromethane-methanol-water-concentrated ammonium hydroxide (70 + 30 + 4 + 0.4, v/v), which is used for vertical development of the plate up to a distance of 85 mm. For visualization, the plate is dipped 3 times into a modified Carr-Price reagent, 20% (w/v) antimony(III) chloride in acetic acid-dichloromethane (1 + 3, v/v), and subsequently heated on a hot plate at 105 degrees C for 5 min. The glycoalkaloids all appear as red chromatographic zones on a colorless background. Densitometric quantification is performed at 507 nm by reflectance scanning. After determination of the appropriate response function, the proposed method was validated. Good results with respect to linearity, accuracy, and precision were obtained in the concentration range studied.

  15. Dynamics of Gauge Fields at High Temperature

    NARCIS (Netherlands)

    Nauta, B.J.

    2000-01-01

    An effective description of dynamical Bose fields is provided by the classical (high-temperature) limit of thermal field theory. The main subject of this thesis is to improve the ensuing classical field theory, that is, to include the dominant quantum corrections and to add counter terms for the Ray

  16. Shadow Attenuation With High Dynamic Range Images

    Science.gov (United States)

    Shadow often interferes with accurate image analysis. To mitigate shadow effects in near-earth imagery (2 m above ground level), we created high dynamic range (HDR) nadir images and used them to measure grassland ground cover. HDR composites were created by merging three differentially-exposed image...

  17. Dynamics of Gauge Fields at High Temperature

    NARCIS (Netherlands)

    Nauta, B.J.

    2000-01-01

    An effective description of dynamical Bose fields is provided by the classical (high-temperature) limit of thermal field theory. The main subject of this thesis is to improve the ensuing classical field theory, that is, to include the dominant quantum corrections and to add counter terms for the Ray

  18. IUE high resolution spectrophotometry of H Ly alpha emission from the local interstellar medium

    Science.gov (United States)

    Clarke, J. T.; Bowyer, S.; Fahr, H. J.; Lay, G.

    1984-01-01

    IUE high dispersion spectra of resonantly scattered solar Ly alpha emission from H moving into the solar system with the local interstellar wind are reported which are based on observations conducted in April 1981 and April 1983. A heliocentric velocity of -29 + or - 5 km/s has been observed from the ISW component along with a surface brightness which has decreased from about 1000 to 800 Rayleighs over the two-year interval. A preliminary derivation of the velocity of the ISM at large distances from the sun yields a value of 25.6 + or - 5 km/s.

  19. Alpha Channeling with High-field Launch of Lower Hybrid Waves

    CERN Document Server

    Ochs, Ian E; Fisch, Nathaniel J

    2015-01-01

    Although lower hybrid waves are effective at driving currents in present-day tokamaks, they are expected to interact strongly with high-energy particles in extrapolating to reactors. In the presence of a radial alpha particle birth gradient, this interaction can take the form of wave amplification rather than damping. While it is known that this amplification more easily occurs when launching from the tokamak high-field side, the extent of this amplification has not been made quantitative. Here, by tracing rays launched from the high- field-side of a tokamak, the required radial gradients to achieve amplification are calculated for a temperature and density regime consistent with a hot-ion-mode fusion reactor. These simulations, while valid only in the linear regime of wave amplification, nonetheless illustrate the possibilities for wave amplification using high-field launch of the lower hybrid wave.

  20. Identification of a novel, alpha2-fucosylation-dependent uptake system in highly proliferative cells.

    Science.gov (United States)

    Aldi, Silvia; Capone, Antonietta; Giovampaola, Cinzia Della; Ermini, Leonardo; Pianigiani, Elisa; Mariotti, Giancarlo; Rosati, Floriana

    2015-02-01

    In this paper we describe a new structure present in highly proliferative cells and absent in cells with normal growth potential. We used cultured bovine venular endothelial cells (CVEC) as examples of high proliferation, and dermal fibroblasts of a primary culture as examples of normal proliferation. The structure, consisting of tubules radiating from the nuclear region to the tips of cell protrusions, was revealed by its strong positivity to the fucose-binding lectin from Lotus (LTL) that prefers glycans with alpha-1,2-linked fucose. Another fucose-binding lectin that prefers glycans with alpha-1,6-linked fucose was instead found to localize glycans exclusively in Golgi complexes. LTL binding sites were also found at the surface of CVEC in a restricted region close to the nucleus. The role of alpha-1,2-linked fucose in forming or maintaining the tubules was confirmed by the fact that down-regulation of the fucosyltransferases FUT1 and FUT2 resulted in disappearance of the tubular structure. LTL also proved able to penetrate the cells through the tubular structures up to the nuclear region and to inhibit proliferation. Endostatin was also found to massively penetrate the cells in the tubular structures in control cells but not in FUT1/2 depleted cells. In cells of a first passage primary culture of dermal fibroblasts the tubular LTL-positive structure was absent as well as the LTL-positive sites at the external surface, and both fucose-binding lectins were found to exclusively localize glycans in Golgi complexes. Tubules were again found progressively in fibroblasts derived from repeated passages, where faster growing cells predominate. Disappearance of LTL-positivity in Golgi complexes paralleled appearance of LTL-positive tubules. The role of Golgi complexes in forming the tubules is discussed.

  1. FIRST SPECTROSCOPIC EVIDENCE FOR HIGH IONIZATION STATE AND LOW OXYGEN ABUNDANCE IN Ly{alpha} EMITTERS ,

    Energy Technology Data Exchange (ETDEWEB)

    Nakajima, Kimihiko; Shimasaku, Kazuhiro; Hashimoto, Takuya; Ono, Yoshiaki [Department of Astronomy, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Ouchi, Masami [Kavli Institute for the Physics and Mathematics of the Universe (WPI), University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8583 (Japan); Lee, Janice C., E-mail: nakajima@astron.s.u-tokyo.ac.jp [Space Telescope Science Institute, Baltimore, MD 21218 (United States)

    2013-05-20

    We present results from Keck/NIRSPEC and Magellan/MMIRS follow-up spectroscopy of Ly{alpha} emitters (LAEs) at z = 2.2 identified in our Subaru narrowband survey. We successfully detect H{alpha} emission from seven LAEs, and perform a detailed analysis of six LAEs free from active galactic nucleus activity, two out of which, CDFS-3865 and COSMOS-30679, have [O II] and [O III] line detections. They are the first [O II]-detected LAEs at high-z, and their [O III]/[O II] ratios and R23-indices provide the first simultaneous determinations of ionization parameter and oxygen abundance for LAEs. CDFS-3865 has a very high ionization parameter (q{sub ion}=2.5{sup +1.7}{sub -0.8} Multiplication-Sign 10{sup 8} cm s{sup -1}) and a low oxygen abundance (12+ log (O/H)=7.84{sup +0.24}{sub -0.25}) in contrast with moderate values of other high-z galaxies such as Lyman break galaxies (LBGs). COSMOS-30679 also possesses a relatively high ionization parameter (q{sub ion}=8{sup +10}{sub -4} Multiplication-Sign 10{sup 7} cm s{sup -1}) and a low oxygen abundance (12+ log (O/H)=8.18{sup +0.28}{sub -0.28}). Both LAEs appear to fall below the mass-metallicity relation of z {approx} 2 LBGs. Similarly, a low metallicity of 12 + log (O/H) < 8.4 is independently indicated for typical LAEs from a composite spectrum and the [N II]/H{alpha} index. Such high ionization parameters and low oxygen abundances can be found in local star-forming galaxies, but this extreme local population occupies only {approx}0.06% of the Sloan Digital Sky Survey spectroscopic galaxy sample with a number density {approx}100 times smaller than that of LAEs. With their high ionization parameters and low oxygen abundances, LAEs would represent an early stage of galaxy formation dominated by massive stars in compact star-forming regions. High-q{sub ion} galaxies like LAEs would produce ionizing photons efficiently with a high escape fraction achieved by density-bounded H II regions, which would significantly contribute to

  2. Modeling of intensified high dynamic star tracker.

    Science.gov (United States)

    Yan, Jinyun; Jiang, Jie; Zhang, Guangjun

    2017-01-23

    An intensified high dynamic star tracker (IHDST) is a photoelectric instrument and stably outputs three-axis attitude for a spacecraft at very high angular velocity. The IHDST uses an image intensifier to multiply the incident starlight. Thus, high sensitivity of the star detection is achieved under short exposure time such that extremely high dynamic performance is achieved. The IHDST differs from a traditional star tracker in terms of the imaging process. Therefore, we establish a quantum transfer model of IHDST based on stochastic process theory. By this model, the probability distribution of the output quantum number is obtained accurately. Then, we introduce two-dimensional Lorentz functions to describe the spatial spreading process of the IHDST. Considering the interaction of these two processes, a complete star imaging model of IHDST is provided. Using this model, the centroiding accuracy of the IHDST is analyzed in detail. Accordingly, a working parameter optimizing strategy is developed for high centroiding accuracy and improved dynamic performance. Finally, the laboratory tests and the night sky experiment support the conclusions.

  3. The spin temperature of high-redshift damped Lyman-$\\alpha$ systems

    CERN Document Server

    Kanekar, N; Smette, A; Ellison, S L; Ryan-Weber, E V; Momjian, E; Briggs, F H; Lane, W M; Chengalur, J N; Delafosse, T; Grave, J; Jacobsen, D; de Bruyn, A G

    2013-01-01

    We report results from a programme aimed at investigating the temperature of neutral gas in high-redshift damped Lyman-$\\alpha$ absorbers (DLAs). This involved (1) HI 21cm absorption studies of a large DLA sample, (2) VLBI studies to measure the low-frequency quasar core fractions, and (3) optical/ultraviolet spectroscopy to determine DLA metallicities and velocity widths. Including literature data, our sample consists of 37 DLAs with estimates of the spin temperature $T_s$ and the covering factor. We find a strong $4\\sigma$) difference between the $T_s$ distributions in high-z (z>2.4) and low-z (z1 sub-sample. Since z>1 DLAs have angular diameter distances comparable to or larger than those of the background quasars, they have similar efficiency in covering the quasars. Low covering factors in high-z DLAs thus cannot account for the observed redshift evolution in spin temperatures. (Abstract abridged.)

  4. Cosmochemistry, cosmology and fundamental constants: High-resolution spectroscopy of damped Lyman-alpha systems

    CERN Document Server

    Quast, R; Smette, A; Garcet, O; Ledoux, C; López, S; Wisotzki, L

    2004-01-01

    Spectroscopy of QSO absorption lines provides essential observational input for the study of nucleosynthesis and chemical evolution of galaxies at high redshift. But new observations may indicate that present chemical abundance data are biased due to deficient spectral resolution and unknown selection effects: Recent high-resolution spectra reveal the hitherto unperceived chemical nonuniformity of molecular hydrogen-bearing damped Lyman-alpha (DLA) systems, and the novel H/ESO DLA survey produces compelling evidence for faint QSOs being attenuated by dust. We present a revised analysis of the molecular hydrogen-bearing DLA complex toward HE 0515-4414 showing nonuniform differential depletion of chemical elements onto dust grains, and introduce to the H/ESO DLA survey and its implications. Conclusively, we aim at starting an unbiased chemical abundance database established on high-resolution spectroscopic observations. New data to probe the temperature-redshift relation predicted by standard cosmology and to t...

  5. Enhanced trigger for the NIFFTE fissionTPC in presence of high-rate alpha backgrounds

    Science.gov (United States)

    Bundgaard, Jeremy; Niffte Collaboration

    2015-10-01

    Nuclear physics and nuclear energy communities call for new, high precision measurements to improve existing fission models and design next generation reactors. The Neutron Induced Fission Fragment Tracking experiment (NIFFTE) has developed the fission Time Projection Chamber (fissionTPC) to measure neutron induced fission with unrivaled precision. The fissionTPC is annually deployed to the Weapons Neutron Research facility at Los Alamos Neutron Science Center where it operates with a neutron beam passing axially through the drift volume, irradiating heavy actinide targets to induce fission. The fissionTPC was developed at the Lawrence Livermore National Laboratory's TPC lab, where it measures spontaneous fission from radioactive sources to characterize detector response, improve performance, and evolve the design. To measure 244Cm, we've developed a fission trigger to reduce the data rate from alpha tracks while maintaining a high fission detection efficiency. In beam, alphas from 239Pu are a large background when detecting fission fragments; implementing the fission trigger will greatly reduce this background. The implementation of the cathode fission trigger in the fissionTPC will be presented along with a detailed study of its efficiency.

  6. Highly turbulent solutions of the Lagrangian-averaged Navier-Stokes alpha model and their large-eddy-simulation potential.

    Science.gov (United States)

    Pietarila Graham, Jonathan; Holm, Darryl D; Mininni, Pablo D; Pouquet, Annick

    2007-11-01

    spectrum for large alpha. These small-scale features, however, do not preclude the LANS alpha model from reproducing correctly the intermittency properties of the high-Reynolds-number flow.

  7. Taming Dynamical Complexity and Managing High Technology

    Institute of Scientific and Technical Information of China (English)

    FANGJin-qing; CHENGuan-rong; ZHAOGeng

    2003-01-01

    Variability is one of the most important features of complexity m complex networks anu systems,which usually depends sensitively on small perturbations. Various possible competing behaviours in a system may provide great flexibility in regulating or taming dynamical complexity, through which the designer may be able to better select and manage a desired behaviour for a specific application. In many high-tech fields, how to regulate or manage complexity is a very important but challenge issue.

  8. Improved High Dynamic Range Image Reproduction Method

    Directory of Open Access Journals (Sweden)

    András Rövid

    2007-10-01

    Full Text Available High dynamic range (HDR of illumination may cause serious distortions andother problems in viewing and further processing of digital images. This paper describes anew algorithm for HDR image creation based on merging images taken with differentexposure time. There are many fields, in which HDR images can be used advantageously,with the help of them the accuracy, reliability and many other features of the certain imageprocessing methods can be improved.

  9. ALPHN: A computer program for calculating ([alpha], n) neutron production in canisters of high-level waste

    Energy Technology Data Exchange (ETDEWEB)

    Salmon, R.; Hermann, O.W.

    1992-10-01

    The rate of neutron production from ([alpha], n) reactions in canisters of immobilized high-level waste containing borosilicate glass or glass-ceramic compositions is significant and must be considered when estimating neutron shielding requirements. The personal computer program ALPHA calculates the ([alpha], n) neutron production rate of a canister of vitrified high-level waste. The user supplies the chemical composition of the glass or glass-ceramic and the curies of the alpha-emitting actinides present. The output of the program gives the ([alpha], n) neutron production of each actinide in neutrons per second and the total for the canister. The ([alpha], n) neutron production rates are source terms only; that is, they are production rates within the glass and do not take into account the shielding effect of the glass. For a given glass composition, the user can calculate up to eight cases simultaneously; these cases are based on the same glass composition but contain different quantities of actinides per canister. In a typical application, these cases might represent the same canister of vitrified high-level waste at eight different decay times. Run time for a typical problem containing 20 chemical species, 24 actinides, and 8 decay times was 35 s on an IBM AT personal computer. Results of an example based on an expected canister composition at the Defense Waste Processing Facility are shown.

  10. ALPHN: A computer program for calculating ({alpha}, n) neutron production in canisters of high-level waste

    Energy Technology Data Exchange (ETDEWEB)

    Salmon, R.; Hermann, O.W.

    1992-10-01

    The rate of neutron production from ({alpha}, n) reactions in canisters of immobilized high-level waste containing borosilicate glass or glass-ceramic compositions is significant and must be considered when estimating neutron shielding requirements. The personal computer program ALPHA calculates the ({alpha}, n) neutron production rate of a canister of vitrified high-level waste. The user supplies the chemical composition of the glass or glass-ceramic and the curies of the alpha-emitting actinides present. The output of the program gives the ({alpha}, n) neutron production of each actinide in neutrons per second and the total for the canister. The ({alpha}, n) neutron production rates are source terms only; that is, they are production rates within the glass and do not take into account the shielding effect of the glass. For a given glass composition, the user can calculate up to eight cases simultaneously; these cases are based on the same glass composition but contain different quantities of actinides per canister. In a typical application, these cases might represent the same canister of vitrified high-level waste at eight different decay times. Run time for a typical problem containing 20 chemical species, 24 actinides, and 8 decay times was 35 s on an IBM AT personal computer. Results of an example based on an expected canister composition at the Defense Waste Processing Facility are shown.

  11. A search for H$\\alpha$ emission in high-metallicity damped Lyman-$\\alpha$ systems at $z \\sim 2.4$

    CERN Document Server

    Wang, Wei-Hao; Prochaska, J Xavier

    2015-01-01

    We report on a sensitive search for redshifted H$\\alpha$ line-emission from three high-metallicity damped Ly$\\alpha$ absorbers (DLAs) at $z \\approx 2.4$ with the Near-infrared Integral Field Spectrometer (NIFS) on the Gemini-North telescope, assisted by the ALTtitude conjugate Adaptive optics for the InfraRed (ALTAIR) system with a laser guide star. Within the NIFS field-of-view, $\\approx 3.22" \\times 2.92"$ corresponding to $\\approx 25$ kpc $ \\times 23$ kpc at $z=2.4$, we detect no statistically significant line-emission at the expected redshifted H$\\alpha$ wavelengths. The measured root-mean-square noise fluctuations in $0.4"$ apertures are $1-3\\times10^{-18}$ erg s$^{-1}$ cm$^{-2}$. Our analysis of simulated, compact, line-emitting sources yields stringent limits on the star-formation rates (SFRs) of the three DLAs, $< 2.2$~M$_{\\odot}$ yr$^{-1}$ ($3\\sigma$) for two absorbers, and $< 11$~M$_{\\odot}$ yr$^{-1}$ ($3\\sigma$) for the third, at all impact parameters within $\\approx 12.5$~kpc to the quasar s...

  12. Study of a sealed high gas pressure THGEM detector and response of Alpha particle spectra

    CERN Document Server

    Zhang, Yu-Ning; Liu, Hong-Bang; Xie, Yi-Gang; Lyu, Xiao-Rui; Chen, Shi; Huang, Wen-Qian; Hong, Dao-Jin; Zheng, Yang-Heng

    2016-01-01

    A sealed high gas pressure detector working in pure argon is assembled. It consists of a 5 cm $\\times$ 5 cm PCB THGEM (THick Gaseous Electron Multipliers). The detector structure and experimental setup are described. The performances under high pressure of 2 atm mainly consist in selecting optimal voltages for ionization region and induction region. The dependence of the shape of Alpha particle spectra measured with relative gas gain on gas pressure (1.3 $\\sim$ 2.0 atm) has been studied. The 8 groups of relative gas gain versus working voltage of THGEM expressed by weighting filed $E/P$ are normalized, being consistent with theory. The results show that the air tightness of the chamber is good measured by a sensitive barometer and checked with gas gain. The experimental results are compared with Monte Carlo simulation on energy deposition without gas gain involved.

  13. Alpha-constrained QSE Nucleosynthesis in High-entropy and Fast-expanding Material

    CERN Document Server

    Fujibayashi, Sho; Sekiguchi, Yuichiro

    2016-01-01

    We investigate the nucleosynthesis process in high-entropy ($s/k_{\\rm B}\\gtrsim100$) and very fast-expanding ($\\tau_{\\rm exp}\\sim10^{-3}\\ {\\rm s}$) materials. In such a material with the electron fraction near 0.5, an interesting nucleosynthesis process occurs. In this process, the abundance distribution of heavy-nuclei of $A>100$ achieve quasi-statistical equilibrium (QSE) at high temperature and the abundances are frozen at the end of the nucleosynthesis. We explain this abundance distribution using the "alpha-constrained QSE" abundances formulated in this paper. We demonstrate that this nucleosynthesis would occur in neutrino-driven winds from massive proto-neutron stars in hypernovae, where $A\\sim140$ $p$-nuclei are synthesized.

  14. High field magnetization processes in single crystals of alpha-Tb{sub 2}S{sub 3} and alpha-Dy{sub 2}S{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Ebisu, S; Omote, H; Nagata, S [Department of Materials Science and Engineering, Muroran Institute of Technology, 27-1 Mizumoto-cho, Muroran, Hokkaido 050-8585 (Japan); Koyama, K, E-mail: ebisu@mmm.muroran-it.ac.j [HFLSM, Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan)

    2009-03-01

    Rare earth sesquisulfides alpha-Tb{sub 2}S{sub 3} and alpha-Dy{sub 2}S{sub 3} possess orthorhombic crystal structure having two independent rare earth sites. High field magnetization processes for single crystals of these compounds have been investigated up to mu{sub o}H = 18 T. Some step-like transitions have been observed in both compounds. The magnetization of alpha-Tb{sub 2}S{sub 3} single crystal under the field along the 6-axis at T = 1.4 K shows a steep increase of about 4.5 mu{sub B}, which corresponds to a half of full saturation moment of free Tb{sup 3+}, at mu{sub o}H = 2.2 T. It is considered that the reorientation of Tb{sup 3+} moments on only one Tb site into a ferromagnetic arrangement occurs. When the magnetic field is perpendicular to the b-axis, one-step transition at mu{sub o}H = 0.7 T for H||c and two-step transitions at 0.7 and 1.2 T for H||a are observed. As for alpha-Dy{sub 2}S{sub 3}, the magnetization curve at T = 1.5 K shows two-step transitions at 1.3 and 1.6 T (H||b), three or four dull steps (H||a or c). The total height of two steps in the M-H curve for H||b corresponds to a half of full Dy{sup 3+} moment.

  15. Elemental Abundances in Two High Column Density Damped Lyman Alpha Systems at z < 1.5

    CERN Document Server

    Rao, S M; Howk, J C; Wolfe, A M; Rao, Sandhya M.; Prochaska, Jason X.; Wolfe, Arthur M.

    2004-01-01

    We present Keck/HIRES abundance measurements and metal-line kinematic profiles of the damped Lyman alpha systems (DLAs) towards the quasars Q0933+733 (z_abs=1.479) and Q0948+433 (z_abs=1.233). These two DLAs have among the five highest HI column densities at any redshift: N(HI)=4.2E21 cm^{-2}. The metal-line data, presented here for the first time, reveal that these DLAs are noteworthy for several other reasons as well. 1) The Q0933+733 DLA exhibits simple kinematic structure with unusually narrow velocity widths as measured from its unsaturated metal lines (delta v=16 km/s). At 2.6% solar, it has the second lowest metallicity at z -1) and a significant alpha-enhancement. The strong metal lines of this DLA have made possible the detection of TiII1910, CoII2012, and MgI2026. 3) We find that the relative gas-phase abundances of both DLAs follow the general trend seen at high redshift, e.g., enhanced Zn/Fe and Si/Fe, and sub-solar Mn/Fe, indicating that there is little evolution in the nucleosynthetic patterns o...

  16. Quantitative and selective polymerase chain reaction analysis of highly similar human alpha-class glutathione transferases.

    Science.gov (United States)

    Larsson, Emilia; Mannervik, Bengt; Raffalli-Mathieu, Françoise

    2011-05-01

    Alpha-class glutathione transferases (GSTs) found expressed in human tissues constitute a family of four homologous enzymes with contrasting enzyme activities. In particular, GST A3-3 has been shown to contribute to the biosynthesis of steroid hormones in human cells and is selectively expressed in steroidogenic tissues. The more ubiquitous GST A1-1, GST A2-2, and GST A4-4 appear to be primarily involved in detoxification processes and are expressed at higher levels than GST A3-3. We are interested in studying the cell and tissue expression of the GST A3-3 gene, yet the existence of highly expressed sequence-similar homologs and of several splice variants is a serious challenge for the specific detection of unique transcript species. We found that published polymerase chain reaction (PCR) primers for GST A3-3 lack the specificity required for reliable quantitative analysis. Therefore, we designed quantitative PCR (qPCR) primers with greatly increased discrimination power for the human GSTA3 full-length transcript. The improved primers allow accurate discrimination between GST A3-3 and the other alpha-class GSTs and so are of great value to studies of the expression of the GSTA3 gene. The novel primers were used to quantify GSTA3 transcripts in human embryonic liver and steroidogenic cell lines.

  17. Optimisation study of {alpha}-cyclotron production of At-211/Po-211g for high-LET metabolic radiotherapy purposes

    Energy Technology Data Exchange (ETDEWEB)

    Groppi, F. [Universita degli Studi di Milano and INFN-Milano, LASA, Radiochemistry Laboratory, via F.lli Cervi 201, I-20090 Segrate, Milan (Italy)]. E-mail: flavia.groppi@mi.infn.it; Bonardi, M.L. [Universita degli Studi di Milano and INFN-Milano, LASA, Radiochemistry Laboratory, via F.lli Cervi 201, I-20090 Segrate, Milan (Italy); Birattari, C. [Universita degli Studi di Milano and INFN-Milano, LASA, Radiochemistry Laboratory, via F.lli Cervi 201, I-20090 Segrate, Milan (Italy); Menapace, E. [ENEA, Division for Advanced Physics Technologies, via Don Fiammelli 2, I-40128 Bologna (Italy); Abbas, K. [Institute for Health and Consumer Protection, IHCP, JRC-Ispra, via E. Fermi, I-21020 Varese (Italy); Holzwarth, U. [Institute for Health and Consumer Protection, IHCP, JRC-Ispra, via E. Fermi, I-21020 Varese (Italy); Alfarano, A. [Universita degli Studi di Milano and INFN-Milano, LASA, Radiochemistry Laboratory, via F.lli Cervi 201, I-20090 Segrate, Milan (Italy); Institute for Health and Consumer Protection, IHCP, JRC-Ispra, via E. Fermi, I-21020 Varese (Italy); Morzenti, S. [Universita degli Studi di Milano and INFN-Milano, LASA, Radiochemistry Laboratory, via F.lli Cervi 201, I-20090 Segrate, Milan (Italy); Zona, C. [Universita degli Studi di Milano and INFN-Milano, LASA, Radiochemistry Laboratory, via F.lli Cervi 201, I-20090 Segrate, Milan (Italy); Alfassi, Z.B. [Department of Nuclear Engineering, Ben Gurion University of Negev, Beer-Sheva, Il-84105 (Israel)

    2005-12-01

    The production of no-carrier-added (NCA) {alpha}-emitter {sup 211}At/{sup 211g}Po radionuclides for high-LET targeted radiotherapy and immunoradiotherapy, through the {sup 209}Bi({alpha},2n) reaction, together with the required wet radiochemistry and radioanalytical quality controls carried out at LASA is described, through dedicated irradiation experiments at the MC-40 cyclotron of JRC-Ispra. The amount of both the {gamma}-emitter {sup 210}At and its long half-lived {alpha}-emitting daughter {sup 210}Po is optimised and minimised by appropriate choice of energy and energy loss of {alpha} particle beam. The measured excitation functions for production of the main radioisotopic impurity {sup 210}At{yields}{sup 210}Po are compared with theoretical predictions from model calculations performed at ENEA.

  18. Dissociation between PGC-1alpha and GLUT-4 expression in skeletal muscle of rats fed a high-fat diet.

    Science.gov (United States)

    Higashida, Kazuhiko; Higuchi, Mitsuru; Terada, Shin

    2009-12-01

    It has recently been reported that a 4-wk high-fat diet gradually increases skeletal muscle peroxisome proliferator activated receptor (PPAR) gamma coactivator-1alpha (PGC-1alpha) protein content, which has been suggested to regulate GLUT-4 gene transcription. However, it has not been reported that a high-fat diet enhances GLUT-4 mRNA expression and protein content in skeletal muscle, suggesting that an increase in PGC-1alpha protein content is not sufficient to induce muscle GLUT-4 biogenesis in a high-fat fed animal. Therefore, we first evaluated the relationship between PGC-1alpha and GLUT-4 expression in skeletal muscle of rats fed a high-fat diet for 4 wk. The PGC-1alpha protein content in rat epitrochlearis muscle significantly increased by twofold after the 4-wk high-fat diet feeding. However, the high-fat diet had no effect on GLUT-4 protein content and induced a 30% decrease in GLUT-4 mRNA expression in rat skeletal muscle (p<0.05). To clarify the mechanism by which a high-fat diet downregulates GLUT-4 mRNA expression, we next examined the effect of PPARdelta activation, which is known to occur in response to a high-fat diet, on GLUT-4 mRNA expression in L6 myotubes. Incubation with 500 nM GW501516 (PPARdelta activator) for 24 h significantly decreased GLUT-4 mRNA in L6 myotubes. Taken together, these findings suggest that a high-fat diet downregulates GLUT-4 mRNA, possibly through the activation of PPARdelta, despite an increase in PGC-1alpha protein content in rat skeletal muscle, and that a posttranscriptional regulatory mechanism maintains GLUT-4 protein content in skeletal muscle of rats fed a high-fat diet.

  19. Special Form Testing of Sealed Source Encapsulation for High-Alpha-Activity Actinide Materials

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, Oscar A [ORNL

    2016-01-01

    In the United States all transportation of radioactive material is regulated by the U.S. Department of Transportation (DOT). Beginning in 2008 a new type of sealed-source encapsulation package was developed and tested by Oak Ridge National Laboratory (ORNL). These packages contain high-alpha-activity actinides and are regulated and transported in accordance with the requirements for DOT Class 7 hazardous material. The DOT provides specific regulations pertaining to special form encapsulation designs. The special form designation indicates that the encapsulated radioactive contents have a very low probability of dispersion even when subjected to significant structural events. The special form designs have been shown to simplify the delivery, transport, acceptance, and receipt processes. It is intended for these sealed-source encapsulations to be shipped to various facilities making it very advantageous for them to be certified as special form. To this end, DOT Certificates of Competent Authority (CoCAs) have been sought for the design suitable for containing high-alpha-activity actinide materials. This design consists of the high-alpha-activity material encapsulated within a triangular zirconia canister, referred to as a ZipCan, tile that is then enclosed by a spherical shell. The spherical shell design, with ZipCan tile inside, was tested for compliance with the special form regulations found in 49 CFR 173.469. The spherical enclosure was subjected to 9-m impact, 1 m percussion, and 10-minute thermal tests at the Packaging Evaluation Facility located at the National Transportation Research Center in Knoxville, TN USA and operated by ORNL. Before and after each test, the test units were subjected to a helium leak check and a bubble test. The ZipCan tiles and core were also subjected to the tests required for ISO 2919:2012(E), including a Class IV impact test and heat test and subsequently subjected to helium leakage rate tests [49 CFR 173.469(a)(4)(i)]. The impact

  20. On the alpha --> beta transition of carbon-coated highly oriented PVDF ultrathin film induced by melt recrystallization.

    Science.gov (United States)

    Wang, Jijun; Li, Huihui; Liu, Jichun; Duan, Yongxin; Jiang, Shidong; Yan, Shouke

    2003-02-12

    Poly(vinylidene fluoride) (PVDF) is one of the polymers which exhibit pronounced polymorphic crystalline forms, depending on crystallization conditions. Four different crystalline modifications, i.e., alpha, beta, gamma, and delta, have been reported so far. Among them, even though the alpha-form is the most common one, the beta-phase is the one that has attracted the widest interest due to its extensive piezo- and pyroelectric applications. During the past few decades, a substantial amount of work has been done in attempts to characterize these crystal modifications and transformations among them. It was well documented that the alpha-form PVDF can be easily obtained through melt crystallization of the PVDF at atmospheric pressure. Its beta-counterpart can, however, only be directly obtained by growth from solution, molecular epitaxy on the surface of potassium bromide, melt crystallization at high pressures, or by applying with a strong electric field. Transformation from its alpha-phase to beta-phase has been achieved by mechanical deformation, while the retransformation could be conducted through melt recrystallization at atmospheric pressure. In the present work, the recrystallization behavior of carbon-coated melt-drawn oriented PVDF ultrathin films at atmospheric pressure was studied by means of transmission electron microscopy and electron diffraction. The results indicate that through vacuum evaporating a thin carbon layer on the surface of highly oriented alpha-PVDF ultrathin film, not only has its high orientation been preserved after a complete melting and recrystallization process, but an alpha --> beta transition of PVDF has also been achieved through melt recrystallization at atmospheric pressure. This technique can be successfully used for preparing highly oriented beta-PVDF ultrathin films, especially patterned microstructures of PVDF with its highly oriented polar beta-phase and nonoriented nonpolar alpha-phase.

  1. The Nucleotide Capture Region of Alpha Hemolysin: Insights into Nanopore Design for DNA Sequencing from Molecular Dynamics Simulations

    Science.gov (United States)

    Manara, Richard M. A.; Tomasio, Susana; Khalid, Syma

    2015-01-01

    Nanopore technology for DNA sequencing is constantly being refined and improved. In strand sequencing a single strand of DNA is fed through a nanopore and subsequent fluctuations in the current are measured. A major hurdle is that the DNA is translocated through the pore at a rate that is too fast for the current measurement systems. An alternative approach is “exonuclease sequencing”, in which an exonuclease is attached to the nanopore that is able to process the strand, cleaving off one base at a time. The bases then flow through the nanopore and the current is measured. This method has the advantage of potentially solving the translocation rate problem, as the speed is controlled by the exonuclease. Here we consider the practical details of exonuclease attachment to the protein alpha hemolysin. We employ molecular dynamics simulations to determine the ideal (a) distance from alpha-hemolysin, and (b) the orientation of the monophosphate nucleotides upon release from the exonuclease such that they will enter the protein. Our results indicate an almost linear decrease in the probability of entry into the protein with increasing distance of nucleotide release. The nucleotide orientation is less significant for entry into the protein.

  2. The Nucleotide Capture Region of Alpha Hemolysin: Insights into Nanopore Design for DNA Sequencing from Molecular Dynamics Simulations.

    Science.gov (United States)

    Manara, Richard M A; Tomasio, Susana; Khalid, Syma

    2015-01-27

    Nanopore technology for DNA sequencing is constantly being refined and improved. In strand sequencing a single strand of DNA is fed through a nanopore and subsequent fluctuations in the current are measured. A major hurdle is that the DNA is translocated through the pore at a rate that is too fast for the current measurement systems. An alternative approach is "exonuclease sequencing", in which an exonuclease is attached to the nanopore that is able to process the strand, cleaving off one base at a time. The bases then flow through the nanopore and the current is measured. This method has the advantage of potentially solving the translocation rate problem, as the speed is controlled by the exonuclease. Here we consider the practical details of exonuclease attachment to the protein alpha hemolysin. We employ molecular dynamics simulations to determine the ideal (a) distance from alpha-hemolysin, and (b) the orientation of the monophosphate nucleotides upon release from the exonuclease such that they will enter the protein. Our results indicate an almost linear decrease in the probability of entry into the protein with increasing distance of nucleotide release. The nucleotide orientation is less significant for entry into the protein.

  3. Comparison of structure and dynamics of micelle-bound human alpha-synuclein and Parkinson disease variants.

    Science.gov (United States)

    Ulmer, Tobias S; Bax, Ad

    2005-12-30

    Three point mutations (A30P, E46K, and A53T) as well as gene triplication genetically link the 140-residue protein alpha-synuclein (aS) to the development of Parkinson disease. Here, the structure and dynamics of micelle-bound aS(A30P) and aS(A53T) are described and compared with wild-type aS, in addition to describing the aS-micelle interaction. A53T is sensed only by directly adjacent residues and leaves the backbone structure and dynamics indistinguishable from the wild type. A30P interrupts one helix turn (Val26-Ala29) and destabilizes the preceding one. A shift in helix register following A30P disturbs the canonical succession of polar and hydrophobic residues for at least two turns. The shortened helix-N adopts a slightly higher helical content and is less bent, indicating that strain was present in the micelle-bound helix. In the vicinity of the A30P-induced perturbations, the underlying micelle environment has rearranged, but nevertheless all aS variants maintain similar interrelationships with the micelle. Moreover, aS-micelle immersion correlates well with fast and slow aS backbone dynamics, allowing a rare insight into protein-micelle interplay.

  4. Role of deformation twins in static recrystallization kinetics of high-purity alpha titanium

    Science.gov (United States)

    Won, Jong Woo; Lee, Taekyung; Hong, Seong-Gu; Lee, Yongmoon; Lee, Jeong Hun; Lee, Chong Soo

    2016-11-01

    The importance of deformation twins in static recrystallization kinetics of high-purity alpha titanium was investigated by carrying out thermal annealing tests of deformed materials in combination with electron-backscatterdiffraction- based microstructural analysis. Prior to thermal annealing, the material was compressed to a true strain of 0.22 along three directions to introduce different twinning characteristics. Our results showed that deformation twins substantially promoted the static recrystallization process by deepening the microstructural inhomogeneity induced by the formation of twin boundaries and twinning-induced crystallographic lattice reorientation. Twin morphology was also observed to be important because it influenced the extent of microstructural inhomogeneity. Intersecting twin morphology, caused by the activation of multiple twin variants, was more effective than parallel twin morphology, caused by the activation of a single twin variant (or a twin variant pair), because it gave rise to more twin boundaries, more twin boundary junctions (intersections, triple junctions, etc.), and greater in-grain crystallographic orientation spread.

  5. Ionization and scintillation response of high-pressure xenon gas to alpha particles

    CERN Document Server

    Álvarez, V; Cárcel, S; Cebrián, S; Cervera, A; Conde, C A N; Dafni, T; Díaz, J; Egorov, M; Esteve, R; Evtoukhovitch, P; Fernandes, L M P; Ferrario, P; Ferreira, A L; Freitas, E D C; Gehman, V M; Gil, A; Goldschmidt, A; Gómez, H; Gómez-Cadenas, J J; González-Díaz, D; Gutiérrez, R M; Hauptman, J; Morata, J A Hernando; Herrera, D C; Irastorza, I G; Jinete, M A; Labarga, L; Laing, A; Liubarsky, I; Lopes, J A M; Lorca, D; Losada, M; Luzón, G; Marí, A; Martín-Albo, J; Miller, T; Moiseenko, A; Monrabal, F; Monteiro, C M B; Mora, F J; Moutinho, L M; Vidal, J Muñoz; da Luz, H Natal; Navarro, G; Nebot, M; Nygren, D; Oliveira, C A B; Palma, R; Pérez, J; Aparicio, J L Pérez; Renner, J; Ripoll, L; Rodríguez, A; Rodríguez, J; Santos, F P; Santos, J M F dos; Segui, L; Serra, L; Shuman, D; Simón, A; Sofka, C; Sorel, M; Toledo, J F; Tomás, A; Torrent, J; Tsamalaidze, Z; Vázquez, D; Veloso, J F C A; Webb, R; White, J T; Yahlali, N

    2012-01-01

    High-pressure xenon gas is an attractive detection medium for a variety of applications in fundamental and applied physics. In this paper we study the transport properties of ionization electrons, and the mechanism of electron-ion recombination, in xenon gas at 10 bar pressure. For this purpose, we use a source of alpha particles in the NEXT-DEMO time projection chamber, the large scale prototype of the NEXT-100 neutrinoless double beta decay experiment, in three different drift electric field configurations. Our electron drift velocity and longitudinal diffusion results are similar to expectations based on available electron scattering cross sections on pure xenon, favoring low-diffusion models. In addition, two types of measurements addressing the connection between the ionization and scintillation yields were performed. On the one hand we observe, for the first time in xenon gas, large event-by-event correlated fluctuations between the ionization and scintillation signals, similarly to what has already bee...

  6. Treatment with interferon-alpha delays disease in swine infected with a highly virulent CSFV strain.

    Science.gov (United States)

    Fernandez-Sainz, I; Ramanathan, P; O'Donnell, V; Diaz-San Segundo, F; Velazquez-Salinas, L; Sturza, D F; Zhu, J; de los Santos, T; Borca, M V

    2015-09-01

    Interferon-alpha (IFNα) can effectively inhibit or abort a viral infection within the host. It has been reported that IFN induction and production is hindered during classical swine fever virus (CSFV) infection. Most of those studies have been performed in vitro, making it difficult to elucidate the actual role of IFNs during CSFV infection in swine. Here, we report the effect of IFNα treatment (delivered by a replication defective recombinant human adenovirus type 5, Ad5) in swine experimentally infected with highly virulent CSFV strain Brescia. Treatment with two different subtypes of IFNα delayed the appearance of CSF-related clinical signs and virus replication although it did not prevent lethal disease. This is the first report describing the effect of IFNα treatment during CSFV infection in swine. Published by Elsevier Inc.

  7. Influence of thermal barrier effect of grain boundaries on bulk cascades in alpha-zirconium revealed by molecular dynamics simulation

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Yanan; Lai, Wensheng, E-mail: wslai@tsinghua.edu.cn

    2016-03-15

    The effect of grain boundaries (GBs) on bulk cascades in nano-structured alpha-zirconium has been studied by molecular dynamics (MD) simulations. It turns out that the existence of GBs increases the defect productivity in grains, suggesting that the GBs may act as a thermal barrier and postpone the annihilation of defects within grains. Moreover, it is found that the thermal barrier effect of GBs facilitates the shift of symmetric tilt GBs to the grain with higher temperature, and the smaller the tilt angle is, the easier the boundary shift will be. Thus, the influence of GBs on radiation damage in the nano-structured materials comes from the competition between damage increase in grains and defect annihilation at GBs.

  8. Photonic crystal fiber-based immunosensor for high-performance detection of alpha fetoprotein.

    Science.gov (United States)

    Liu, Xiaoxia; Song, Xingda; Dong, Zhiyong; Meng, Xiaoting; Chen, Yiping; Yang, Li

    2017-05-15

    We have developed a sensitive photonic crystal fiber (PCF)-based immunosensor for detection of alpha fetoprotein (AFP). The unique PCF possesses a morphology characterized by numerous pore structures and a large surface area-to-volume ratio, which can be used as an immune-reaction carrier to improve the sensitivity and reaction speed of AFP detection. The PCF-based immunosensor possesses a low limit of detection of 0.1ng/mL, which is five times lower than that of the capillary-based sensor and 35 times lower than that of the traditional enzyme-linked immunosorbent assay. The wide linear dynamic range of 0.1-150ng/mL makes the developed immunosensor suitable for clinical practice. The proposed method was successfully applied to AFP detection in a clinical serum sample with acceptable precision. It is indicated that the present PCF-based immunosensor could be used as an attractive analytical platform for sensitive and specific detection of cancer biomarkers.

  9. Determination of alpha-Tocopherol (vitamin E) in irradiated garlic by high performance liquid chromatography (HPLC); Determinacao de alpha-tocoferol em alho irradiado utilizando cromatografia liquida de alta frequencia (CLAE)

    Energy Technology Data Exchange (ETDEWEB)

    Rios, Magda Dias Goncalves; Penteado, Marilene de Vuono Camargo [Sao Paulo Univ., SP (Brazil). Faculdade de Ciencias Farmaceuticas. Dept. de Alimentos e Nutricao Experimental]. E-mail: riosmagda@hotmail.com

    2003-02-01

    The effects of {sup 60}Co ionizing radiations in doses of 0, 75, 100, 150, 200 and 250Gy on garlic, upon the {alpha}-tocopherol concentration were studied. The {alpha}-tocopherol contents were established by high performance liquid chromatography (HPLC), after direct hexane extraction from the garlic samples. The {alpha}-tocopherol was determined through normal phase column, and mobile phase was composed by hexane: iso-propyl alcohol (99:01 v/v), with 2mL/min flow rate and fluorescence detector. It is statistically shown that an irradiation dose of up to 150 Gy does not affect the garlic {alpha}-tocopherol content. (author)

  10. High theta and low alpha powers may be indicative of BCI-illiteracy in motor imagery.

    Directory of Open Access Journals (Sweden)

    Minkyu Ahn

    Full Text Available In most brain computer interface (BCI systems, some target users have significant difficulty in using BCI systems. Such target users are called 'BCI-illiterate'. This phenomenon has been poorly investigated, and a clear understanding of the BCI-illiteracy mechanism or a solution to this problem has not been reported to date. In this study, we sought to demonstrate the neurophysiological differences between two groups (literate, illiterate with a total of 52 subjects. We investigated recordings under non-task related state (NTS which is collected during subject is relaxed with eyes open. We found that high theta and low alpha waves were noticeable in the BCI-illiterate relative to the BCI-literate people. Furthermore, these high theta and low alpha wave patterns were preserved across different mental states, such as NTS, resting before motor imagery (MI, and MI states, even though the spatial distribution of both BCI-illiterate and BCI-literate groups did not differ. From these findings, an effective strategy for pre-screening subjects for BCI illiteracy has been determined, and a performance factor that reflects potential user performance has been proposed using a simple combination of band powers. Our proposed performance factor gave an r = 0.59 (r(2 = 0.34 in a correlation analysis with BCI performance and yielded as much as r = 0.70 (r(2 = 0.50 when seven outliers were rejected during the evaluation of whole data (N = 61, including BCI competition datasets (N = 9. These findings may be directly applicable to online BCI systems.

  11. A High Fraction of Ly-alpha-Emitters Among Galaxies with Extreme Emission Line Ratios at z ~ 2

    CERN Document Server

    Erb, Dawn K; Steidel, Charles C; Strom, Allison L; Rudie, Gwen C; Trainor, Ryan F; Shapley, Alice E; Reddy, Naveen A

    2016-01-01

    Star-forming galaxies form a sequence in the [OIII]/H-beta vs. [NII]/H-alpha diagnostic diagram, with low metallicity, highly ionized galaxies falling in the upper left corner. Drawing from a large sample of UV-selected star-forming galaxies at z~2 with rest-frame optical nebular emission line measurements from Keck-MOSFIRE, we select the extreme ~5% of the galaxies lying in this upper left corner, requiring log([NII]/H-alpha) = 0.75. These cuts identify galaxies with 12 + log(O/H) 20 A. We compare the equivalent width distribution of a sample of 522 UV-selected galaxies at 2.0alpha equivalent width -1 (-4) A, and only 9% of these galaxies qualify as LAEs. The extreme galaxies typically have lower attenuation at Ly-alpha than those in the comparison sample, and have ~50% lower median oxygen abundances. Both factors are likely to facilitate the escape of Ly-alpha: in less dusty galaxies Ly-alpha photons are l...

  12. Dynamics of High-Resolution Networks

    DEFF Research Database (Denmark)

    Sekara, Vedran

    NETWORKS are everywhere. From the smallest confines of the cells within our bodies to the webs of social relations across the globe. Networks are not static, they constantly change, adapt, and evolve to suit new conditions. In order to understand the fundamental laws that govern networks we need...... the unprecedented amounts of information collected by mobile phones to gain detailed insight into the dynamics of social systems. This dissertation presents an unparalleled data collection campaign, collecting highly detailed traces for approximately 1000 people over the course of multiple years. The availability...

  13. High dynamic range imaging sensors and architectures

    CERN Document Server

    Darmont, Arnaud

    2013-01-01

    Illumination is a crucial element in many applications, matching the luminance of the scene with the operational range of a camera. When luminance cannot be adequately controlled, a high dynamic range (HDR) imaging system may be necessary. These systems are being increasingly used in automotive on-board systems, road traffic monitoring, and other industrial, security, and military applications. This book provides readers with an intermediate discussion of HDR image sensors and techniques for industrial and non-industrial applications. It describes various sensor and pixel architectures capable

  14. Excitation and Ionisation dynamics in high-frequency plasmas

    Science.gov (United States)

    O'Connell, D.

    2008-07-01

    excitation and sustainment of the discharge. As the pressure decreases the discharge operates in so-called 'alpha-mode' where the sheath expansion is responsible for discharge sustainment. Decreasing the pressure towards the limit of operation (below 1 Pa) the discharge operates in a regime where kinetic effects dominate plasma sustainment. Wave particle interactions resulting from the flux of highly energetic electrons interacting with thermal bulk electrons give rise to a series of oscillations in the electron excitation phase space at the sheath edge. This instability is responsible for a significant energy deposit in the plasma when so-called 'ohmic heating' is no longer efficient. In addition to this an interesting electron acceleration mechanism occurs during the sheath collapse. The large sheath width, due to low plasma densities at the lower pressure, and electron inertia allows the build up of a local electric field accelerating electrons towards the electrode. Multi-frequency plasmas, provide additional process control for technological applications, and through investigating the excitation dynamics in such discharges the limitations of functional separation is observed. Non-linear frequency coupling is observed in plasma boundary sheaths governed by two frequencies simultaneously. In an alpha-operated discharge the sheath edge velocity governs the excitation and ionisation within the plasma, and it will be shown that this is determined by the time varying sheath width. The nature of the coupling effects strongly depends on the ratio of the applied voltages. Under technologically relevant conditions (low frequency voltage >> high frequency voltage) interesting phenomena depending on the phase relation of the voltages are also observed and will be discussed.

  15. Molecular dynamics study of the solvation of an alpha-helical transmembrane peptide by DMSO

    NARCIS (Netherlands)

    Duarte, A.M.; Mierlo, van C.P.M.; Hemminga, M.A.

    2008-01-01

    10-ns molecular dynamics study of the solvation of a hydrophobic transmembrane helical peptide in dimethyl sulfoxide (DMSO) is presented. The objective is to analyze how this aprotic polar solvent is able to solvate three groups of amino acid residues (i.e., polar, apolar, and charged) that are loca

  16. Molecular dynamics study of the solvation of an alpha-helical transmembrane peptide by DMSO

    NARCIS (Netherlands)

    Duarte, A.M.; Mierlo, van C.P.M.; Hemminga, M.A.

    2008-01-01

    10-ns molecular dynamics study of the solvation of a hydrophobic transmembrane helical peptide in dimethyl sulfoxide (DMSO) is presented. The objective is to analyze how this aprotic polar solvent is able to solvate three groups of amino acid residues (i.e., polar, apolar, and charged) that are loca

  17. Inside-Out Regulation of ICAM-1 Dynamics in TNF-alpha-Activated Endothelium

    NARCIS (Netherlands)

    van Buul, J.D.; van Rijssel, J.; van Alphen, F.P.J.; Hoogenboezem, M.; Tol, S.; Hoeben, K.A.; van Marle, J.; Mul, E.P.J.; Hordijk, P.L.

    2010-01-01

    Background: During transendothelial migration, leukocytes use adhesion molecules, such as ICAM-1, to adhere to the endothelium. ICAM-1 is a dynamic molecule that is localized in the apical membrane of the endothelium and clusters upon binding to leukocytes. However, not much is known about the regul

  18. Quantitative digital image analysis of chromogenic assays for high throughput screening of alpha-amylase mutant libraries.

    Science.gov (United States)

    Shankar, Manoharan; Priyadharshini, Ramachandran; Gunasekaran, Paramasamy

    2009-08-01

    An image analysis-based method for high throughput screening of an alpha-amylase mutant library using chromogenic assays was developed. Assays were performed in microplates and high resolution images of the assay plates were read using the Virtual Microplate Reader (VMR) script to quantify the concentration of the chromogen. This method is fast and sensitive in quantifying 0.025-0.3 mg starch/ml as well as 0.05-0.75 mg glucose/ml. It was also an effective screening method for improved alpha-amylase activity with a coefficient of variance of 18%.

  19. X-ray resonant photoexcitation: line widths and energies of K{\\alpha} transitions in highly charged Fe ions

    CERN Document Server

    Rudolph, J K; Epp, S W; Steinbrügge, R; Beilmann, C; Brown, G V; Eberle, S; Graf, A; Harman, Z; Hell, N; Leutenegger, M; Müller, A; Schlage, K; Wille, H -C; Yavas, H; Ullrich, J; López-Urrutia, J R Crespo

    2013-01-01

    Photoabsorption by and fluorescence of the K{\\alpha} transitions in highly charged iron ions are essential mechanisms for X-ray radiation transfer in astrophysical environments. We study photoabsorption due to the main K{\\alpha} transitions in highly charged iron ions from heliumlike to fluorinelike (Fe 24+...17+) using monochromatic X-rays around 6.6 keV at the PETRA III synchrotron photon source. Natural linewidths were determined with hitherto unattained accuracy. The observed transitions are of particular interest for the understanding of photoexcited plasmas found in X-ray binaries and active galactic nuclei.

  20. B56alpha/protein phosphatase 2A inhibits adipose lipolysis in high-fat diet-induced obese mice.

    Science.gov (United States)

    Kinney, Brice P; Qiao, Liping; Levaugh, Justin M; Shao, Jianhua

    2010-08-01

    Lipolysis and lipogenesis are two opposite processes that control lipid storage in adipocytes. Impaired adipose lipolysis has been observed in both obese human subjects and animal models. This study investigated the mechanisms underlying impaired adipose lipolysis in a high-fat diet-induced obese (DIO) mouse model. DIO models were created using male C57BL/6 mice. Our results show that beta3 adrenergic receptor-specific agonist BRL37344 induced adipose lipolysis was significantly blunted in DIO mice. The levels of Ser660 phosphorylation of hormone-sensitive lipase (HSL) were significantly decreased in the epididymal fat of DIO mice. However, protein levels of HSL, adipose triglyceride lipase and its coactivator comparative gene identification-58 were similar between DIO and control mice. It is known that upon lipolytic hormone stimulation, protein kinase A phosphorylates HSL Ser660 and activates HSL, whereas protein phosphatase 2A (PP2A) dephosphorylates and inactivates HSL. Interestingly, our study shows that high-fat feeding did not alter epididymal fat cAMP and protein kinase A protein levels but significantly increased the expression of the alpha-isoform of PP2A regulatory subunit B' (B56alpha). To study the role of B56alpha in obesity-associated lipolytic defect, B56alpha was overexpressed or knocked down by adenovirus-mediated gene transduction in cultured 3T3-L1CARDelta1 adipocytes. Overexpression of B56alpha significantly decreased HSL Ser660 phosphorylation. In contrast, knocking down B56alpha increased hormone-stimulated HSL activation and lipolysis in mature 3T3-L1CARDelta1 adipocytes. These results strongly suggest that elevated B56alpha/PP2A inhibits HSL and lipolysis in white adipose tissue of DIO mice.

  1. Highly efficient ytterbium triflate catalyzed Michael additions of alpha-nitroesters in water

    NARCIS (Netherlands)

    Keller, E; Feringa, B.L.

    Michael additions of alpha-nitroesters with enones and alpha,beta-unsaturated aldehydes result in quantitative conversions to the corresponding 1,4-adducts by performing the reactions in water in the presence of ytterbium triflate as water-tolerant Lewis acid.

  2. Highly efficient ytterbium triflate catalyzed Michael additions of alpha-nitroesters in water

    NARCIS (Netherlands)

    Keller, E; Feringa, B.L.

    1997-01-01

    Michael additions of alpha-nitroesters with enones and alpha,beta-unsaturated aldehydes result in quantitative conversions to the corresponding 1,4-adducts by performing the reactions in water in the presence of ytterbium triflate as water-tolerant Lewis acid.

  3. Enabling low cost biopharmaceuticals: high level interferon alpha-2b production in Trichoderma reesei.

    Science.gov (United States)

    Landowski, Christopher P; Mustalahti, Eero; Wahl, Ramon; Croute, Laurence; Sivasiddarthan, Dhinakaran; Westerholm-Parvinen, Ann; Sommer, Benjamin; Ostermeier, Christian; Helk, Bernhard; Saarinen, Juhani; Saloheimo, Markku

    2016-06-10

    The filamentous fungus Trichoderma reesei has tremendous capability to secrete over 100 g/L of proteins and therefore it would make an excellent host system for production of high levels of therapeutic proteins at low cost. We have developed T. reesei strains suitable for production of therapeutic proteins by reducing the secreted protease activity. Protease activity has been the major hindrance to achieving high production levels. We have constructed a series of interferon alpha-2b (IFNα-2b) production strains with 9 protease deletions to gain knowledge for further strain development. We have identified two protease deletions that dramatically improved the production levels. Deletion of the subtilisin protease slp7 and the metalloprotease amp2 has enabled production levels of IFNα-2b up to 2.1 and 2.4 g/L, respectively. With addition of soybean trypsin protease inhibitor the level of production improved to 4.5 g/L, with an additional 1.8 g/L still bound to the secretion carrier protein. High levels of IFNα-2b were produced using T. reesei strains with reduced protease secretion. Further strain development can be done to improve the production system by reducing protease activity and improving carrier protein cleavage.

  4. High-Throughput Screening Methodology to Identify Alpha-Synuclein Aggregation Inhibitors.

    Science.gov (United States)

    Pujols, Jordi; Peña-Díaz, Samuel; Conde-Giménez, María; Pinheiro, Francisca; Navarro, Susanna; Sancho, Javier; Ventura, Salvador

    2017-03-02

    An increasing number of neurodegenerative diseases are being found to be associated with the abnormal accumulation of aggregated proteins in the brain. In Parkinson's disease, this process involves the aggregation of alpha-synuclein (α-syn) into intraneuronal inclusions. Thus, compounds that inhibit α-syn aggregation represent a promising therapeutic strategy as disease-modifying agents for neurodegeneration. The formation of α-syn amyloid aggregates can be reproduced in vitro by incubation of the recombinant protein. However, the in vitro aggregation of α-syn is exceedingly slow and highly irreproducible, therefore precluding fast high throughput anti-aggregation drug screening. Here, we present a simple and easy-to-implement in-plate method for screening large chemical libraries in the search for α-syn aggregation modulators. It allows us to monitor aggregation kinetics with high reproducibility, while being faster and requiring lower protein amounts than conventional aggregation assays. We illustrate how the approach enables the identification of strong aggregation inhibitors in a library of more than 14,000 compounds.

  5. An 80-kpc Lyman-alpha halo around a high redshift type-2 QSO

    CERN Document Server

    Smith, Daniel J B; Simpson, Chris; Martinez-Sansigre, Alejo

    2008-01-01

    We announce the discovery of an extended emission line region associated with a high redshift type-2 QSO. The halo, which was discovered in our new wide-field narrow-band survey, resides at z = 2.85 in the Spitzer First Look Survey region and is extended over ~80 kpc. Deep VLBI observations imply that approximately 50 per cent of the radio emission is extended on scales > 200pc. The inferred AGN luminosity is sufficient to ionize the extended halo, and the optical emission is consistent with being triggered coevally with the radio source. The Lyman-alpha halo is as luminous as those found around high redshift radio galaxies, however the active nucleus is several orders of magnitude less luminous at radio wavelengths than those FRIIs more commonly associated with extended emission line regions. AMS05 appears to be a high-redshift analogue to the radio-quiet quasar E1821+643 which is core dominated but which also exhibits extended FRI-like structure and contains an optically powerful AGN. We also find evidence ...

  6. Simulations of alpha parameters in a TFTR DT supershot with high fusion power

    Energy Technology Data Exchange (ETDEWEB)

    Budny, R.V.; Bell, M.G.; Janos, A.C. [and others

    1995-07-01

    A TFTR supershot with a plasma current of 2.5 MA, neutral beam heating power of 33.7 MW, and a peak DT fusion power of 7.5 MW is studied using the TRANSP plasma analysis code. Simulations of alpha parameters such as the alpha heating, pressure, and distributions in energy and v{sub parallel}/v are given. The effects of toroidal ripple and mixing of the fast alpha particles during the sawteeth observed after the neutral beam injection phase are modeled. The distributions of alpha particles on the outer midplane are peaked near forward and backward v{sub parallel}/v. Ripple losses deplete the distributions in the vicinity of v{sub parallel}/v {approximately}{minus}0.4. Sawtooth mixing of fast alpha particles is computed to reduce their central density and broaden their width in energy.

  7. Dynamic shear deformation in high purity Fe

    Energy Technology Data Exchange (ETDEWEB)

    Cerreta, Ellen K [Los Alamos National Laboratory; Bingert, John F [Los Alamos National Laboratory; Trujillo, Carl P [Los Alamos National Laboratory; Lopez, Mike F [Los Alamos National Laboratory; Gray, George T [Los Alamos National Laboratory

    2009-01-01

    The forced shear test specimen, first developed by Meyer et al. [Meyer L. et al., Critical Adiabatic Shear Strength of Low Alloyed Steel Under Compressive Loading, Metallurgical Applications of Shock Wave and High Strain Rate Phenomena (Marcel Decker, 1986), 657; Hartmann K. et al., Metallurgical Effects on Impact Loaded Materials, Shock Waves and High Strain rate Phenomena in Metals (Plenum, 1981), 325-337.], has been utilized in a number of studies. While the geometry of this specimen does not allow for the microstructure to exactly define the location of shear band formation and the overall mechanical response of a specimen is highly sensitive to the geometry utilized, the forced shear specimen is useful for characterizing the influence of parameters such as strain rate, temperature, strain, and load on the microstructural evolution within a shear band. Additionally, many studies have utilized this geometry to advance the understanding of shear band development. In this study, by varying the geometry, specifically the ratio of the inner hole to the outer hat diameter, the dynamic shear localization response of high purity Fe was examined. Post mortem characterization was performed to quantify the width of the localizations and examine the microstructural and textural evolution of shear deformation in a bcc metal. Increased instability in mechanical response is strongly linked with development of enhanced intergranular misorientations, high angle boundaries, and classical shear textures characterized through orientation distribution functions.

  8. [Characteristics of cortical activity in persons with high and low verbal creativity: analysis of alpha1,2 rhythms].

    Science.gov (United States)

    Razumnikova, O M; Tarasova, I V; Vol'f, N V

    2009-01-01

    Creativity-related changes in alpha power in low-frequency (8-10 Hz) and high-frequency (10-13 Hz) bands were studied in university students having regard to generation of original ideas during performance of two verbal tasks. A high-creative group enrolled 16 subjects asked to generate original words--associates to the triads of verbal stimuli and 14 subjects who were asked to compose a sentence using triads of nouns from remote semantic categories. Low-creative groups included 22 and 13 individuals, respectively. In low-frequency band, highly creative subjects showed a higher level of alpha power than low creative individuals. In the high-frequency band, task-related alpha2 power desynchronization was different in these groups: high-creative individuals had higher power score than low-creative mostly in the anterior and parietal cortical areas. These data and a factor structure of alpha rhythm indices may be evidence of different strategies of information selection in highly and low creative persons.

  9. Total alpha-globin gene cluster deletion has high frequency in Filipinos

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, J.A.; Haruyama, A.Z.; Chu, B.M. [Kapiolani Medical Center, Honolulu, HI (United States)] [and others

    1994-09-01

    Most {alpha}-thalassemias [Thal] are due to large deletions. In Southeast Asians, the (--{sup SEA}) double {alpha}-globin gene deletion is common, 3 (--{sup Tot}) total {alpha}-globin cluster deletions are known: Filipino (--{sup Fil}), Thai (--{sup Thai}), and Chinese (--{sup Chin}). In a Hawaii Thal project, provisional diagnosis of {alpha}-Thal-1 heterozygotes was based on microcytosis, normal isoelectric focusing, and no iron deficiency. One in 10 unselected Filipinos was an {alpha}-Thal-1 heterozygote, 2/3 of these had a (--{sup Tot}) deletion: a {var_sigma}-cDNA probe consistently showed fainter intensity of the constant 5.5 kb {var_sigma}{sub 2} BamHI band, with no heterzygosity for {var_sigma}-globin region polymorphisms; {alpha}-cDNA or {var_sigma}-cDNA probes showed no BamHI or BglII bands diagnostic of the (--{sup SEA}) deletion; bands for the (-{alpha}) {alpha}-Thal-2 single {alpha}-globin deletions were only seen in Hb H cases. A reliable monoclonal anti-{var_sigma}-peptide antibody test for the (--{sup SEA}) deletion was always negative in (--{sup Tot}) samples. Southern digests with the Lo probe, a gift from D. Higgs of Oxford Univ., confirmed that 49 of 50 (--{sup Tot}) chromosomes in Filipinos were (--{sup Fil}). Of 20 {alpha}-Thal-1 hydrops born to Filipinos, 11 were (--{sup Fil}/--{sup SEA}) compound heterozygotes; 9 were (--{sup SEA}/--{sup SEA}) homozygotes, but none was a (--{sup Fil}/--{sup Fil}).

  10. The TF1-ATPase and ATPase activities of assembled alpha 3 beta 3 gamma, alpha 3 beta 3 gamma delta, and alpha 3 beta 3 gamma epsilon complexes are stimulated by low and inhibited by high concentrations of rhodamine 6G whereas the dye only inhibits the alpha 3 beta 3, and alpha 3 beta 3 delta complexes.

    Science.gov (United States)

    Paik, S R; Yokoyama, K; Yoshida, M; Ohta, T; Kagawa, Y; Allison, W S

    1993-12-01

    The ATPase activity of the F1-ATPase from the thermophilic bacterium PS3 is stimulated at concentrations of rhodamine 6G up to about 10 microM where 70% stimulation is observed at 36 degrees C. Half maximal stimulation is observed at about 3 microM dye. At rhodamine 6G concentrations greater than 10 microM, ATPase activity declines with 50% inhibition observed at about 75 microM dye. The ATPase activities of the alpha 3 beta 3 gamma and alpha 3 beta 3 gamma delta complexes assembled from isolated subunits of TF1 expressed in E. coli deleted of the unc operon respond to increasing concentrations of rhodamine 6G nearly identically to the response of TF1. In contrast, the ATPase activities of the alpha 3 beta 3 and alpha 3 beta 3 delta complexes are only inhibited by rhodamine 6G with 50% inhibition observed, respectively, at 35 and 75 microM dye at 36 degrees C. The ATPase activity of TF1 is stimulated up to 4-fold by the neutral detergent, LDAO. In the presence of stimulating concentrations of LDAO, the ATPase activity of TF1 is no longer stimulated by rhodamine 6G, but rather, it is inhibited with 50% inhibition observed at about 30 microM dye at 30 degrees C. One interpretation of these results is that binding of rhodamine 6G to a high-affinity site on TF1 stimulates ATPase activity and unmasks a low-affinity, inhibitory site for the dye which is also exposed by LDAO.

  11. The Sizes of Diffuse Ly$\\alpha$ Nebulae around Star-Forming Galaxies at High Redshift

    CERN Document Server

    Xue, Rui; Dey, Arjun; Reddy, Naveen; Hong, Sungryong; Prescott, Moire K M; Inami, Hanae; Jannuzi, Buell T; Gonzalez, Anthony H

    2016-01-01

    We report the detection of diffuse Ly$\\alpha$ emission, or Lyman alpha halos (LAHs), around star-forming galaxies at $z\\approx3.78$ and $2.66$ in the NOAO Deep Wide-Field Survey Bo\\"otes field. Our samples consist of a total of $\\approx$1,400 galaxies, within two separate regions containing spectroscopically confirmed galaxy overdensities. They provide a unique opportunity to investigate how the LAH characteristics vary with host galaxy large-scale environment and physical properties. We stack Ly$\\alpha$ images of different samples defined by these properties and measure their median LAH sizes by decomposing the stacked Ly$\\alpha$ radial profile into a compact galaxy-like and an extended halo-like component. We find that the exponential scalelength of LAHs depends on UV continuum and Ly$\\alpha$ luminosities, but not on Ly$\\alpha$ equivalent widths or galaxy overdensity parameters. The full samples, which are dominated by low UV-continuum luminosity Ly$\\alpha$ emitters ($M_{\\rm UV} \\gtrsim -21$), exhibit LAH s...

  12. NMR analysis of G-protein betagamma subunit complexes reveals a dynamic G(alpha)-Gbetagamma subunit interface and multiple protein recognition modes.

    Science.gov (United States)

    Smrcka, Alan V; Kichik, Nessim; Tarragó, Teresa; Burroughs, Michael; Park, Min-Sun; Itoga, Nathan K; Stern, Harry A; Willardson, Barry M; Giralt, Ernest

    2010-01-12

    G-protein betagamma (Gbetagamma) subunits interact with a wide range of molecular partners including: G(alpha) subunits, effectors, peptides, and small molecule inhibitors. The molecular mechanisms underlying the ability to accommodate this wide range of structurally distinct binding partners are not well understood. To uncover the role of protein flexibility and alterations in protein conformation in molecular recognition by Gbetagamma, a method for site-specific (15)N-labeling of Gbeta-Trp residue backbone and indole amines in insect cells was developed. Transverse Relaxation Optimized Spectroscopy-Heteronuclear Single-Quantum Coherence Nuclear Magnetic Resonance (TROSY-HSQC NMR) analysis of (15)N-Trp Gbetagamma identified well-dispersed signals for the individual Trp residue side chain and amide positions. Surprisingly, a wide range of signal intensities was observed in the spectrum, likely representing a range of backbone and side chain mobilities. The signal for GbetaW99 indole was very intense, suggesting a high level of mobility on the protein surface and molecular dynamics simulations indicate that GbetaW99 is highly mobile on the nanosecond timescale in comparison with other Gbeta tryptophans. Binding of peptides and phosducin dramatically altered the mobility of GbetaW99 and GbetaW332 in the binding site and the chemical shifts at sites distant from the direct binding surface in distinct ways. In contrast, binding of G(alpha)(i1)-GDP to Gbetagamma had relatively little effect on the spectrum and, most surprisingly, did not significantly alter Trp mobility at the subunit interface. This suggests the inactive heterotrimer in solution adopts a conformation with an open subunit interface a large percentage of the time. Overall, these data show that Gbetagamma subunits explore a range of conformations that can be exploited during molecular recognition by diverse binding partners.

  13. [Diversity and dynamics of a high sub-Andean forest from Northern Andes, Colombia].

    Science.gov (United States)

    Restrepo, Jesús Oswaldo Velásquez; Maniguaje, Nancy Lorena; Duque, Alvaro Javier

    2012-06-01

    The sub-Andean forests are characterized by a high biodiversity, but little is known about their natural dynamics. In order to generate new information, this study assessed two permanent plots of one hectare each, in the Northern Andean area of the Western Cordillera, Colombia. Methodology included the evaluation of diversity patterns, above ground biomass (AGB) dynamics, and mortality and recruitment rates. Besides, we used the Fisher's Alpha index to calculate species diversity. Forest dynamics and AGB were evaluated in both plots by means of three censuses carried out within a nine years period. In total, we found 1 664 individuals with diameter at breast height (DBH)> or =10cm belonging to 222 species, 113 genera and 60 families. Mean species richness was of 156 species/ha and a mean Fisher's Alpha index of 56.2/ha. The mortality rate was 0.88% and recruitment was 1.16%, which did not allow to lay any external effect of global warming or climate change on individual forest dynamics. However, the mean AGB was 243.44+/-9.82t/ha, with an annual average increase of 2.9t/ha, a higher value than the one reported in other studies of high sub-Andean forests, which suggests that equilibrium in terms of the AGB have not yet been reached. Besides, according to field observations, a recovery process, from a disturbance that occurred in the past, might be on his way.

  14. High dynamic, low volume GPS receiver

    Science.gov (United States)

    Hurd, W. J.

    1983-01-01

    A new GPS receiver concept and design are presented to meet the high dynamic and low volume requirements for range applications in missiles and drones. The receiver has the potential to satisfy all range requirements with one basic receiver, which has significant potential economic benefit over the alternate approach of using a family of receivers, each tailored for specific applications. The main new concept is to use approximate maximum likelihood estimates of pseudo range and range-rate, rather than tracking with carrier phase locked loops and code delay locked loops. Preliminary analysis indicates that receivers accelerating at 50 g or more can track with position errors due to acceleration of approximately 0.2 m/g, or 10 m at 50 g. Implementation is almost entirely digital to meet the low volume requirements.

  15. Loss of inhibin alpha uncouples oocyte-granulosa dynamics and disrupts postnatal folliculogenesis

    Science.gov (United States)

    Myers, Michelle; Middlebrook, Brooke S.; Matzuk, Martin M.; Pangas, Stephanie A.

    2009-01-01

    Targeted disruption of the inhibin α gene (Inha−/−) in mice results in an ovarian phenotype of granulosa cell tumors that renders the animals infertile. Little is known about the reproductive defects prior to tumor development. Here, we report novel data on early follicle dynamics in Inha−/− mice, which demonstrate that inhibin α has important consequences upon follicle development. Morphological changes in both germ and somatic cells were evident in postnatal day 12 ovaries, with Inha−/− mice exhibiting numerous multilayered follicles that were far more advanced than those observed in age-matched controls. These changes were accompanied by alterations in follicle dynamics such that Inha−/− ovaries had fewer follicles in the resting pool and more committed in the growth phase. Absence of inhibin α resulted in advanced follicular maturation as marked by premature loss of anti-Müllerian hormone (AMH) in secondary follicles. Additionally, gene expression analysis revealed changes in factors known to be vital for oocyte and follicle development. Together, these data provide key evidence to suggest that regulation of the inhibin/activin system is essential for early folliculogenesis in the prepubertal mouse ovary. PMID:19666016

  16. Influence of Mn-dopant on the properties of {alpha}-FeOOH particles precipitated in highly alkaline media

    Energy Technology Data Exchange (ETDEWEB)

    Krehula, Stjepko [Division of Materials Chemistry, Ruder Boskovic Institute, P.O. Box 180, HR-10002 Zagreb (Croatia); Music, Svetozar [Division of Materials Chemistry, Ruder Boskovic Institute, P.O. Box 180, HR-10002 Zagreb (Croatia)]. E-mail: music@irb.hr

    2006-12-21

    The effects of Mn-dopant on the formation of solid solutions {alpha}-(Fe, Mn)OOH in dependence on the initial concentration ratio r = [Mn]/([Mn] + [Fe]), as well as on the size and morphology of the corresponding particles were investigated using Moessbauer and FT-IR spectroscopies, high-resolution scanning electron microscopy (FE SEM) and an energy dispersive X-ray analyser (EDS). The value of the hyperfine magnetic field of 34.9 T, as recorded for the reference {alpha}-FeOOH sample at RT, decreased linearly up to 21.4 T for sample with r = 0.1667. Only a paramagnetic doublet at RT was recorded for sample with r = 0.2308, a ferrite phase was additionally found for r = 0.3333. Fe-OH bending IR bands, {delta} {sub OH} and {gamma} {sub OH}, were influenced by the Mn-substitution as manifested through their gradual shifts. FE SEM micrographs showed a great elongation of the starting acicular particles along the c-axis with an increase in Mn-doping. For r = 0.1667 and 0.2308 star-shaped and dendritic twin {alpha}-(Fe, Mn)OOH particles were observed. The length of these {alpha}-(Fe, Mn)OOH particles decreased, whereas their width increased. The {alpha}-Fe{sub 2}O{sub 3} phase was not detected in any of the samples prepared.

  17. Dynamic transport and localization of alpha-synuclein in primary hippocampal neurons

    Directory of Open Access Journals (Sweden)

    Woods Wendy S

    2010-02-01

    Full Text Available Abstract Background Alpha-synuclein is a presynaptic protein with a proposed role in neurotransmission and dopamine homeostasis. Abnormal accumulation of α-synuclein aggregates in dopaminergic neurons of the substantia nigra is diagnostic of sporadic Parkinson's disease, and mutations in the protein are linked to early onset forms of the disease. The folded conformation of the protein varies depending upon its environment and other factors that are poorly understood. When bound to phospholipid membranes, α-synuclein adopts a helical conformation that mediates specific interactions with other proteins. Results To investigate the role of the helical domain in transport and localization of α-synuclein, eGFP-tagged constructs were transfected into rat primary hippocampal neurons at 7 DIV. A series of constructs were analyzed in which each individual exon was deleted, for comparison to previous studies of lipid affinity and α-helix content. A53T and A30P substitutions, representing Parkinson's disease-associated variants, were analyzed as well. Single exon deletions within the lipid-binding N-terminal domain of α-synuclein (exons 2, 3, and 4 partially disrupted its presynaptic localization at 17-21 DIV, resulting in increased diffuse labeling of axons. Similar results were obtained for A30P, which exhibits decreased lipid binding, but not A53T. To examine whether differences in presynaptic enrichment were related to deficiencies in transport velocity, transport was visualized via live cell microscopy. Tagged α-synuclein migrated at a rate of 1.85 ± 0.09 μm/s, consistent with previous reports, and single exon deletion mutants migrated at similar rates, as did A30P. Deletion of the entire N-terminal lipid-binding domain (Δ234GFP did not significantly alter rates of particle movement, but decreased the number of moving particles. Only the A53TGFP mutant exhibited a significant decrease in transport velocity as compared to ASGFP. Conclusions

  18. High Speed Dynamics in Brittle Materials

    Science.gov (United States)

    Hiermaier, Stefan

    2015-06-01

    Brittle Materials under High Speed and Shock loading provide a continuous challenge in experimental physics, analysis and numerical modelling, and consequently for engineering design. The dependence of damage and fracture processes on material-inherent length and time scales, the influence of defects, rate-dependent material properties and inertia effects on different scales make their understanding a true multi-scale problem. In addition, it is not uncommon that materials show a transition from ductile to brittle behavior when the loading rate is increased. A particular case is spallation, a brittle tensile failure induced by the interaction of stress waves leading to a sudden change from compressive to tensile loading states that can be invoked in various materials. This contribution highlights typical phenomena occurring when brittle materials are exposed to high loading rates in applications such as blast and impact on protective structures, or meteorite impact on geological materials. A short review on experimental methods that are used for dynamic characterization of brittle materials will be given. A close interaction of experimental analysis and numerical simulation has turned out to be very helpful in analyzing experimental results. For this purpose, adequate numerical methods are required. Cohesive zone models are one possible method for the analysis of brittle failure as long as some degree of tension is present. Their recent successful application for meso-mechanical simulations of concrete in Hopkinson-type spallation tests provides new insight into the dynamic failure process. Failure under compressive loading is a particular challenge for numerical simulations as it involves crushing of material which in turn influences stress states in other parts of a structure. On a continuum scale, it can be modeled using more or less complex plasticity models combined with failure surfaces, as will be demonstrated for ceramics. Models which take microstructural

  19. Maltose effects on barley malt diastatic power enzyme activity and thermostability at high isothermal mashing temperature: II. Alpha-amylase

    Science.gov (United States)

    Maltose, the primary product of starch degradation during mashing, has the potential as a compatible solute to affect the activity of and increase the thermostability of barley malt alpha-amylase activity at high temperatures used in mashing and temperatures above those normally used in mashing. To ...

  20. High circulating levels of tumor necrosis factor-alpha in centenarians are not associated with increased production in T lymphocytes

    DEFF Research Database (Denmark)

    Sandmand, Marie; Bruunsgaard, Helle; Kemp, Kåre

    2003-01-01

    BACKGROUND: Aging is characterized by increased inflammatory activity reflected by increased plasma levels of proinflammatory cytokines, concomitant with an altered cytokine profile of T lymphocytes. High plasma levels of tumor necrosis factor (TNF)-alpha are strongly associated with morbidity an...

  1. Projectile breakup dynamics for {sup 6}Li+{sup 59}Co: Kinematical analysis of {alpha}-d coincidences

    Energy Technology Data Exchange (ETDEWEB)

    Souza, F.A.; Carlin, N.; Liguori Neto, R.; Siqueira-Mello, C.; Moura, M.M. de; Munhoz, M.G.; Oliveira, R.A.N.; Santo, M.G. del; Suaide, A.A.P.; Szanto, E.M.; Szanto de Toledo, A. [Instituto de Fisica - Universidade de Sao Paulo, Departamento de Fisica Nuclear, Sao Paulo, SP (Brazil); Beck, C. [CNRS-IN2P3 and Universite Louis Pasteur, Institut Pluridisciplinaire Hubert Curien, UMR 7178, Strasbourg (France); Keeley, N. [The Andrzej Soltan Institute for Nuclear Studies, Department of Nuclear Reactions, Warsaw (Poland); Diaz-Torres, A. [University of Surrey, Department of Physics, Faculty of Engineering and Physical Sciences, Guildford (United Kingdom)

    2010-05-15

    A study of the kinematics of the {alpha} -d coincidences in the {sup 6}Li+{sup 59}Co system at a bombarding energy of E{sub lab}=29.6 MeV is presented. With exclusive measurements performed over different angular intervals it is possible to identify the respective contributions of the sequential and direct projectile breakup components. The angular distributions of both breakup components are fairly well described by the Continuum-Discretized Coupled-Channels framework (CDCC). Furthermore, a careful analysis of these processes using a semiclassical approach provides information on both their lifetime and their distance of occurrence with respect to the target. Breakup to the low-lying (near-threshold) continuum is delayed, and happens at large internuclear distances. This suggests that the influence of the projectile breakup on the complete fusion process can be related essentially to the direct breakup to the {sup 6}Li high-lying continuum spectrum. (orig.)

  2. Dynamic behaviour and shock-induced martensite transformation in near-beta Ti-5553 alloy under high strain rate loading

    Directory of Open Access Journals (Sweden)

    Wang Lin

    2015-01-01

    Full Text Available Ti-5553 alloy is a near-beta titanium alloy with high strength and high fracture toughness. In this paper, the dynamic behaviour and shock-induced martensite phase transformation of Ti-5553 alloy with alpha/beta phases were investigated. Split Hopkinson Pressure Bar was employed to investigate the dynamic properties. Microstructure evolutions were characterized by Scanning Electronic Microscopy and Transmission Electron Microscope. The experimental results have demonstrated that Ti-5553 alloy with alpha/beta phases exhibits various strain rate hardening effects, both failure through adiabatic shear band. Ti-5553 alloy with Widmannstatten microstructure exhibit more obvious strain rate hardening effect, lower critical strain rate for ASB nucleation, compared with the alloy with Bimodal microstructures. Under dynamic compression, shock-induced beta to alpha” martensite transformation occurs.

  3. Inside-out regulation of ICAM-1 dynamics in TNF-alpha-activated endothelium.

    Directory of Open Access Journals (Sweden)

    Jaap D van Buul

    Full Text Available BACKGROUND: During transendothelial migration, leukocytes use adhesion molecules, such as ICAM-1, to adhere to the endothelium. ICAM-1 is a dynamic molecule that is localized in the apical membrane of the endothelium and clusters upon binding to leukocytes. However, not much is known about the regulation of ICAM-1 clustering and whether membrane dynamics are linked to the ability of ICAM-1 to cluster and bind leukocyte integrins. Therefore, we studied the dynamics of endothelial ICAM-1 under non-clustered and clustered conditions. PRINCIPAL FINDINGS: Detailed scanning electron and fluorescent microscopy showed that the apical surface of endothelial cells constitutively forms small filopodia-like protrusions that are positive for ICAM-1 and freely move within the lateral plane of the membrane. Clustering of ICAM-1, using anti-ICAM-1 antibody-coated beads, efficiently and rapidly recruits ICAM-1. Using fluorescence recovery after photo-bleaching (FRAP, we found that clustering increased the immobile fraction of ICAM-1, compared to non-clustered ICAM-1. This shift required the intracellular portion of ICAM-1. Moreover, biochemical assays showed that ICAM-1 clustering recruited beta-actin and filamin. Cytochalasin B, which interferes with actin polymerization, delayed the clustering of ICAM-1. In addition, we could show that cytochalasin B decreased the immobile fraction of clustered ICAM-1-GFP, but had no effect on non-clustered ICAM-1. Also, the motor protein myosin-II is recruited to ICAM-1 adhesion sites and its inhibition increased the immobile fraction of both non-clustered and clustered ICAM-1. Finally, blocking Rac1 activation, the formation of lipid rafts, myosin-II activity or actin polymerization, but not Src, reduced the adhesive function of ICAM-1, tested under physiological flow conditions. CONCLUSIONS: Together, these findings indicate that ICAM-1 clustering is regulated in an inside-out fashion through the actin cytoskeleton. Overall

  4. Ultra-fast Measurements of Optically Induced Lattice Dynamics in LuMnO3 Using Aluminum K-alpha X-Ray Diffraction.

    Science.gov (United States)

    Workman, J.; Wark, J. S.

    2005-10-01

    An experiment to study the structural dynamics at the ultra-fast time scale in optically-pumped samples is presented. Measurements of lattice dynamics in LuMnO3 are presented and compared to calculations using dynamical diffraction theory modified for hexagonal crystal structure. Ultra-fast x-ray emission is used to measure Bragg peak shifts using diffraction and compared to calculations. Results are presented for optical pump energy densities of 8 and 20-mJ/cm^2. The experiment uses ˜150 mJ of a 100fs Ti:Sapphire laser to excite K-alpha x-ray emission in an aluminum wire with ˜1-2% split off for the material pump. The x-ray emission is relayed using a spherical Quartz crystal to the sample target. Plans for experiments using Cu K-alpha emission to probe Fe samples will also be described.

  5. High Specific Power Multiple-Cylinder Alpha Free-Piston Stirling Engine Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed effort will result in a design of a 30 kWe dual opposed alpha free-piston Stirling engine power conversion system for space applications, and provide...

  6. Stability of helium bubbles in alpha-iron: A molecular dynamics study

    Energy Technology Data Exchange (ETDEWEB)

    Lucas, G. [Ecole Polytechnique Federale de Lausanne (EPFL), Centre de Recherche en Physique des Plasmas, Association Euratom-Confederation Suisse, CH 5332 Villigen PSI (Switzerland)], E-mail: guillaume.lucas@psi.ch; Schaeublin, R. [Ecole Polytechnique Federale de Lausanne (EPFL), Centre de Recherche en Physique des Plasmas, Association Euratom-Confederation Suisse, CH 5332 Villigen PSI (Switzerland)

    2009-04-30

    Molecular dynamics simulations were performed to estimate the dissociation energies of helium interstitials, vacancies and self-interstitial atoms from small helium-vacancy clusters. Several sets of empirical potentials have been tested and compared with available ab initio calculations in order to provide the best combination of potentials to study the stability of small helium bubbles. The behavior of the cluster seems to be better described using Ackland potential for the Fe-Fe interactions and Juslin potential for the Fe-He interactions. From the calculations, it appears that the dissociation energies mainly depend on the helium-to-vacancy ratio rather than the cluster size. The helium/vacancy crossover slightly varies with increasing number of vacancies, but the crossover defining the loop-punching regime decreases strongly with increasing cluster sizes.

  7. Alpha Eigenvalue Estimation from Dynamic Monte Carlo Calculation for Subcritical Systems

    Energy Technology Data Exchange (ETDEWEB)

    Shaukat, Nadeem; Shim, Hyung Jin; Jang, Sang Hoon [Seoul National University, Seoul (Korea, Republic of)

    2016-05-15

    The dynamic Monte Carlo (DMC) method has been used in the TART code for the α eigenvalue calculations. A unique method has been equipped to measure the α in time-stepwise Monte Carlo simulations. For off-critical systems, the neutron population is allowed to change exponentially over a period of time. The neutron population is uniformly combed to return it to the neutron population started with at the beginning of time boundary. In this study, the conventional dynamic Monte Carlo method has been implemented in the McCARD. There is an exponential change of neutron population at the end of each time boundary for off-critical systems. In order to control this exponential change at the end of each time boundary, a conventional time cut-off controlling population strategy is included in the DMC module implemented in the McCARD. the conventional combing method to control the neutron population for off-critical systems is implemented. Instead of considering the cycles, the simulation is divided in time intervals. At the end of each time interval, neutron population control is applied on the banked neutrons. Randomly selected neutrons are discarded, until the size of neutron population matches the initial neutron histories at the beginning of time simulation. The prompt neutron decay constant α is estimated from DMC algorithm for subcritical systems. The effectiveness of the results is examined for two-group infinite homogeneous problems with varying the k-value. From the comparisons with the analytical solutions, it is observed that the results are quite comparable with each other for each k-value.

  8. Tip-alpha (hp0596 gene product) is a highly immunogenic Helicobacter pylori protein involved in colonization of mouse gastric mucosa.

    Science.gov (United States)

    Godlewska, Renata; Pawlowski, Marcin; Dzwonek, Artur; Mikula, Michal; Ostrowski, Jerzy; Drela, Nadzieja; Jagusztyn-Krynicka, Elzbieta K

    2008-03-01

    A product of the Helicobacter pylori hp0596 gene (Tip-alpha) is a highly immunogenic homodimeric protein, unique for this bacterium. Cell fractionation experiments indicate that Tip-alpha is anchored to the inner membrane. In contrast, the three-dimensional model of the protein suggests that Tip-alpha is soluble or, at least, largely exposed to the solvent. hp0596 gene knockout resulted in a significant decrease in the level of H. pylori colonization as measured by real-time PCR assay. In addition, the Tip-alpha recombinant protein was determined to stimulate macrophage to produce IL-1alpha and TNF-alpha. Both results imply that Tip-alpha is rather loosely connected to the inner membrane and potentially released during infection.

  9. Comparative study between the effect of the peroxisome proliferator activated receptor-alpha ligands fenofibrate and n-3 polyunsaturated fatty acids on activation of 5'-AMP-activated protein kinase-alpha1 in high-fat fed rats.

    Science.gov (United States)

    Motawi, Tarek M Kamal; Hashem, Reem M; Rashed, Laila A; El-Razek, Sabry M Abd

    2009-10-01

    Obesity is a risk factor for type 2 diabetes mellitus. It results from an energy imbalance in which energy intake exceeds energy expenditure. The cellular fuel gauge 5'-AMP-activated protein kinase (AMPK) is a heterotrimeric protein consisting of one catalytic subunit (alpha) and two non-catalytic subunits (beta and gamma), and approximately equal levels of alpha1 and alpha2 complexes are present in the liver. AMPK regulates metabolic pathways in response to metabolic stress and in particular ATP depletion to switch on energy-producing catabolic pathways such as beta-oxidation of fatty acids and switch off energy-depleting processes such as synthesis of fatty acid and cholesterol. A high-fat diet alters AMPK-alpha1 gene expression in the liver and skeletal muscle of rats and results in body weight gain and hyperglycaemia. The aim of this study was to investigate and compare the potential effects of peroxisome proliferator-activated receptor (PPAR)-alpha agonists fenofibrate and n-3 polyunsaturated fatty acids (PUFAs) in modulation of AMPK-alpha1 activity in liver and skeletal muscle of high-fat diet fed rats. Reverse transcription-polymerase chain reaction was used for determination of AMPK-alpha1 in liver and soleus muscle and both PPAR-alpha and CPT-1 in hepatic tissues. Serum, total cholesterol, triacylglycerol, fatty acid and fasting blood glucose were determined colorimetrically. Both PPAR-alpha agonists, fenofibrate and n-3 PUFA, increased the mRNA expression of AMPK-alpha1 activity in liver and skeletal muscle of obese diabetic rats. Fenofibrate was superior in its activation of hepatic mRNA expression of AMPK-alpha 1 to exert more lipolytic effect and body weight reduction, as estimated through the decrease of triacylglycerol output and serum levels of fatty acid on the one hand and the increase in CPT-1 mRNA expression, the key enzyme in beta-oxidation of fatty acid, on the other hand. n-3 PUFA activated AMPK-alpha1 mRNA expression in skeletal muscle much

  10. Synthesis of high-quality crystalline {alpha}-MoO{sub 3} nanobelts

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Xiaofei; Tang, Hua; Song, Haojie; Cao, Kesheng [School of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013 (China); Zhang, Rongxian [School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013 (China)

    2011-04-15

    High-quality crystalline MoO{sub 3} nanobelts were successfully fabricated with a facile hydrothermal route by using common and inexpensive NaCl as a capping agent. The products are thoroughly characterized by the combination of different techniques. The results indicate that as-prepared MoO{sub 3} nanobelts have an orthorhombic crystal structure ({alpha}-MoO{sub 3}) with growth preferential in the [001] direction, the size of the obtained MoO{sub 3} nanobelts ranges from 200 nm to 300 nm in width and micrometers in length. The effects of the amount of NaCl on the morphology and size of the resultant MoO{sub 3} were also investigated, it is clearly shown that the presence of appropriate amount of NaCl plays a crucial role in controlling the size and morphology of the obtained MoO{sub 3}. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  11. Human rhinovirus VPg uridylylation AlphaScreen for high-throughput screening.

    Science.gov (United States)

    Gingras, Rock; Mekhssian, Kevork; Fenwick, Craig; White, Peter W; Thibeault, Diane

    2014-02-01

    As an obligate step for picornaviruses to replicate their genome, the small viral peptide VPg must first be specifically conjugated with uridine nucleotides at a conserved tyrosine hydroxyl group. The resulting VPg-pUpU serves as the primer for genome replication. The uridylylation reaction requires the coordinated activity of many components, including the viral polymerase, a conserved internal RNA stem loop structure, and additional viral proteins. Formation of this complex and the resulting conjugation reaction catalyzed by the polymerase, offers a number of biochemical targets for inhibition of an essential process in the viral life cycle. Therefore, an assay recapitulating uridylylation would provide multiple opportunities for discovering potential antiviral agents. Our goal was to identify inhibitors of human rhinovirus (HRV) VPg uridylylation, which might ultimately be useful to reduce or prevent HRV-induced lower airway immunologic inflammatory responses, a major cause of asthma and chronic obstructive pulmonary disease exacerbations. We have reconstituted the complex uridylylation reaction in an AlphaScreen suitable for high-throughput screening, in which a rabbit polyclonal antiserum specific for uridylylated VPg serves as a key reagent. Assay results were validated by quantitative mass spectrometric detection of uridylylation.

  12. Measurement of natural radioactivity in chemical fertilizer and agricultural soil: evidence of high alpha activity.

    Science.gov (United States)

    Ghosh, Dipak; Deb, Argha; Bera, Sukumar; Sengupta, Rosalima; Patra, Kanchan Kumar

    2008-02-01

    People are exposed to ionizing radiation from the radionuclides that are present in different types of natural sources, of which phosphate fertilizer is one of the most important sources. Radionuclides in phosphate fertilizer belonging to 232Th and 238U series as well as radioisotope of potassium (40K) are the major contributors of outdoor terrestrial natural radiation. The study of alpha activity in fertilizers, which is the first ever in West Bengal, has been performed in order to determine the effect of the use of phosphate fertilizers on human health. The data have been compared with the alpha activity of different types of chemical fertilizers. The measurement of alpha activity in surface soil samples collected from the cultivated land was also performed. The sampling sites were randomly selected in the cultivated land in the Midnapore district, which is the largest district in West Bengal. The phosphate fertilizer is widely used for large agricultural production, mainly potatoes. The alpha activities have been measured using solid-state nuclear track detectors (SSNTD), a very sensitive detector for alpha particles. The results show that alpha activity of those fertilizer and soil samples varies from 141 Bq/kg to 2,589 Bq/kg and from 109 Bq/kg to 660 Bq/kg, respectively. These results were used to estimate environmental radiation exposure on human health contributed by the direct application of fertilizers.

  13. Extended Lyman alpha haloes around individual high-redshift galaxies revealed by MUSE

    CERN Document Server

    Wisotzki, L; Blaizot, J; Brinchmann, J; Herenz, E C; Schaye, J; Bouché, N; Cantalupo, S; Contini, T; Carollo, C M; Caruana, J; Courbot, J -B; Emsellem, E; Kamann, S; Kerutt, J; Leclercq, F; Lilly, S J; Patrício, V; Sandin, C; Steinmetz, M; Straka, L A; Urrutia, T; Verhamme, A; Weilbacher, P M; Wendt, M

    2015-01-01

    We report the detection of extended Ly alpha emission around individual star-forming galaxies at redshifts z = 3-6 in an ultradeep exposure of the Hubble Deep Field South obtained with MUSE on the ESO-VLT. The data reach a limiting surface brightness (1sigma) of ~1 x 10^-19 erg s^-1 cm^-2 arcsec^-2 in azimuthally averaged radial profiles, an order of magnitude improvement over previous narrowband imaging. Our sample consists of 26 spectroscopically confirmed Ly alpha-emitting, but mostly continuum-faint (m_AB >~ 27) galaxies. In most objects the Ly alpha emission is considerably more extended than the UV continuum light. While 5 of the faintest galaxies in the sample show no significantly detected Ly alpha haloes, the derived upper limits suggest that this is just due to insufficient S/N. Ly alpha haloes therefore appear to be (nearly) ubiquitous even for low-mass (~10^8-10^9 M_sun) star-forming galaxies at z>3. We decompose the Ly alpha emission of each object into a compact `continuum-like' and an extended ...

  14. Phase space trajectories and Lyapunov exponents in the dynamics of an alpha-helical protein lattice with intra- and inter-spine interactions

    Energy Technology Data Exchange (ETDEWEB)

    Angelin Jeba, K.; Latha, M. M., E-mail: lathaisaac@yahoo.com [Department of Physics, Women' s Christian College, Nagercoil 629 001 (India); Jain, Sudhir R. [Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

    2015-11-15

    The nonlinear dynamics of intra- and inter-spine interaction models of alpha-helical proteins is investigated by proposing a Hamiltonian using the first quantized operators. Hamilton's equations of motion are derived, and the dynamics is studied by constructing the trajectories and phase space plots in both cases. The phase space plots display a chaotic behaviour in the dynamics, which opens questions about the relationship between the chaos and exciton-exciton and exciton-phonon interactions. This is verified by plotting the Lyapunov characteristic exponent curves.

  15. Phase space trajectories and Lyapunov exponents in the dynamics of an alpha-helical protein lattice with intra- and inter-spine interactions.

    Science.gov (United States)

    Angelin Jeba, K; Latha, M M; Jain, Sudhir R

    2015-11-01

    The nonlinear dynamics of intra- and inter-spine interaction models of alpha-helical proteins is investigated by proposing a Hamiltonian using the first quantized operators. Hamilton's equations of motion are derived, and the dynamics is studied by constructing the trajectories and phase space plots in both cases. The phase space plots display a chaotic behaviour in the dynamics, which opens questions about the relationship between the chaos and exciton-exciton and exciton-phonon interactions. This is verified by plotting the Lyapunov characteristic exponent curves.

  16. Molecular dynamics in high electric fields

    Science.gov (United States)

    Apostol, M.; Cune, L. C.

    2016-06-01

    Molecular rotation spectra, generated by the coupling of the molecular electric-dipole moments to an external time-dependent electric field, are discussed in a few particular conditions which can be of some experimental interest. First, the spherical-pendulum molecular model is reviewed, with the aim of introducing an approximate method which consists in the separation of the azimuthal and zenithal motions. Second, rotation spectra are considered in the presence of a static electric field. Two particular cases are analyzed, corresponding to strong and weak fields. In both cases the classical motion of the dipoles consists of rotations and vibrations about equilibrium positions; this motion may exhibit parametric resonances. For strong fields a large macroscopic electric polarization may appear. This situation may be relevant for polar matter (like pyroelectrics, ferroelectrics), or for heavy impurities embedded in a polar solid. The dipolar interaction is analyzed in polar condensed matter, where it is shown that new polarization modes appear for a spontaneous macroscopic electric polarization (these modes are tentatively called "dipolons"); one of the polarization modes is related to parametric resonances. The extension of these considerations to magnetic dipoles is briefly discussed. The treatment is extended to strong electric fields which oscillate with a high frequency, as those provided by high-power lasers. It is shown that the effect of such fields on molecular dynamics is governed by a much weaker, effective, renormalized, static electric field.

  17. Study of lattice thermal conductivity of alpha-zirconium by molecular dynamics simulation

    Institute of Scientific and Technical Information of China (English)

    Wu Tian-Yu; Lai Wen-Sheng; Fu Bao-Qin

    2013-01-01

    The non-equilibrium molecular dynamics method is adapted to calculate the phonon thermal conductivity of alphazirconium.By exchanging velocities of atoms in different regions,the stable heat flux and the temperature gradient are established to calculate the thermal conductivity.The phonon thermal conductivities under different conditions,such as different heat exchange frequencies,different temperatures,different crystallographic orientations,and crossing grain boundary (GB),are studied in detail with considering the finite size effect.It turns out that the phonon thermal conductivity decreases with the increase of temperature,and displays anisotropies along different crystallographic orientations.The phonon thermal conductivity in [0001] direction (close-packed plane) is largest,while the values in other two directions of [2(1)(1)0] and [01 (1)0] are relatively close.In the region near GB,there is a sharp temperature drop,and the phonon thermal conductivity is about one-tenth of that of the single crystal at 550 K,suggesting that the GB may act as a thermal barrier in the crystal.

  18. Homology modeling and molecular dynamics study on Schwanniomyces occidentalis alpha-amylase.

    Science.gov (United States)

    Sefidbakht, Yahya; Ranaei Siadat, Omid; Taheri, Fatemeh

    2017-02-01

    With consumers growing increasingly aware of environmental issues, industries find enzymes as a reasonable alternative over physical conditions and chemical catalysts. Amylases are important hydrolase enzymes, which have been widely used in variety of industrial process such as pharmaceutical, food, and fermentation industries. Among amylases α-Amylase is in maximum demand due to its wide range of applications. The homology modeling study on Schwanniomyces occidentalis amylase (AMY1, UniProt identifier number: P19269) was performed by Modeller using Aspergillus oryzae (6TAA) as the template. The resulting structure was analyzed for validity and subjected to 14 ns of molecular dynamics (MD) simulation trough GROMACS. The validity of obtained model may represent that utilized OPLS force field is suitable for calcium-containing enzymes. DSSP secondary structure and contact map analysis represent the conservation of domain A TIM barrel feature together with calcium ion coordination sphere. Investigating the covariance matrix followed by principle component analyses for the first five eigenvectors of both trajectories indicate a little more flexibility for AMY1 structure. The electrostatic calculation for the final structures shows similar isoelectric point and superimposed buffering zone in the 5-8 pH range.

  19. H$\\alpha$ and EUV observations of a partial CME

    CERN Document Server

    Christian, Damian J; Antolin, Patrick; Mathioudakis, Mihalis

    2015-01-01

    We have obtained H$\\alpha$ high spatial and time resolution observations of the upper solar chromosphere and supplemented these with multi-wavelength observations from the Solar Dynamic Observatory (SDO) and the {\\it Hinode} ExtremeUltraviolet Imaging Spectrometer (EIS). The H$\\alpha$ observations were conducted on 11 February 2012 with the Hydrogen-Alpha Rapid Dynamics Camera (HARDcam) instrument at the National Solar Observatory's Dunn Solar Telescope. Our H$\\alpha$ observations found large downflows of chromospheric material returning from coronal heights following a failed prominence eruption. We have detected several large condensations ("blobs") returning to the solar surface at velocities of $\\approx$200 km s$^{-1}$ in both H$\\alpha$ and several SDO AIA band passes. The average derived size of these "blobs" in H$\\alpha$ is 500 by 3000 km$^2$ in the directions perpendicular and parallel to the direction of travel, respectively. A comparison of our "blob" widths to those found from coronal rain, indicate...

  20. H-alpha spectra of dynamic chromospheric processes in five well-observed X-ray flares

    Science.gov (United States)

    Canfield, Richard C.; Penn, Matthew J.; Wulser, Jean-Pierre; Kiplinger, Alan L.

    1990-01-01

    Simultaneous H-alpha and hard X-ray (HXR) spectra were obtained for five solar flares to determine the relationship of H-alpha profiles and the nonthermal part of the flare represented by the hard X-ray burst. All five flares exhibited impulsive-phase redshifted H-alpha in emission, which was temporarily and spatially associated with intense HXR emission and broad impulsive-phase H-alpha wings. A few small regions within two flares showed a blueshifted H-alpha emission which appeared only early in the impulsive phase and was temporally correlated with the HXR emission but not with broad H-alpha wings. Finally, there were both redshifted and blueshifted absorption spectra with properties fully consistent with those known for erupting and untwisting filaments.

  1. Molecular dynamics simulation of displacement cascades in iron-alpha; Cascades de deplacements atomiques dans le FER-alpha simulation par dynamique moleculaire

    Energy Technology Data Exchange (ETDEWEB)

    Vascon, R

    1997-12-31

    Radiation damage by neutrons or ions in bcc iron has been investigated by molecular dynamics simulations using an embedded atom type many-body potential (EAM). Displacement cascades with energies of 1 to 30 keV were generated in the microcanonical system where the number of atoms (up to 1.5 million) is chosen high enough to compensate the fact that the dissipation of energy is not taken into account in our model. The defect number at the end of cascade lifetime was found to be 60 percent of the NRT standard value. This tendency is in good agreement with experimental data. However, compared with other simulations in iron, we found significant differences in the defect production and distribution. The comparison with results obtained form simulations of cascades in other metals, leads on the one hand to a higher value of the defect number in bcc iron than in fcc metals like copper or nickel, and on the other hand to a ratio, between the number of replacements and the number of defects, lower in iron ( 100). We observed the transient melting of the core of the cascade during simulations. We showed that a higher value of the initial iron crystal temperature, as the mass difference between the components of an artificial binary alloy Fe-X(X=Al,Sb,Au,U) both produce a `cascade effect`: a decrease of the number of defects and an increase of the number of replacements. We also showed up the quasi-channeling of some atoms in high energy cascades. They are at the origin of sub-cascades formation; as a result they induce an opposite effect to the `cascade effect`. (author). 286 refs.

  2. Insights from molecular dynamics simulations: structural basis for the V567D mutation-induced instability of zebrafish alpha-dystroglycan and comparison with the murine model.

    Directory of Open Access Journals (Sweden)

    Davide Pirolli

    Full Text Available A missense amino acid mutation of valine to aspartic acid in 567 position of alpha-dystroglycan (DG, identified in dag1-mutated zebrafish, results in a reduced transcription and a complete absence of the protein. Lacking experimental structural data for zebrafish DG domains, the detailed mechanism for the observed mutation-induced destabilization of the DG complex and membrane damage, remained unclear. With the aim to contribute to a better clarification of the structure-function relationships featuring the DG complex, three-dimensional structural models of wild-type and mutant (V567D C-terminal domain of alpha-DG from zebrafish were constructed by a template-based modelling approach. We then ran extensive molecular dynamics (MD simulations to reveal the structural and dynamic properties of the C-terminal domain and to evaluate the effect of the single mutation on alpha-DG stability. A comparative study has been also carried out on our previously generated model of murine alpha-DG C-terminal domain including the I591D mutation, which is topologically equivalent to the V567D mutation found in zebrafish. Trajectories from MD simulations were analyzed in detail, revealing extensive structural disorder involving multiple beta-strands in the mutated variant of the zebrafish protein whereas local effects have been detected in the murine protein. A biochemical analysis of the murine alpha-DG mutant I591D confirmed a pronounced instability of the protein. Taken together, the computational and biochemical analysis suggest that the V567D/I591D mutation, belonging to the G beta-strand, plays a key role in inducing a destabilization of the alpha-DG C-terminal Ig-like domain that could possibly affect and propagate to the entire DG complex. The structural features herein identified may be of crucial help to understand the molecular basis of primary dystroglycanopathies.

  3. Basal cell carcinoma is associated with high TNF-alpha release but nor with TNF-alpha polymorphism at position--308

    DEFF Research Database (Denmark)

    Skov, Lone; Allen, Michael H; Bang, Bo

    2003-01-01

    The mechanisms underlying induction of UVB-induced immunosuppression are not fully understood, but tumor necrosis factor alpha (TNF-alpha) is suggested to play a central role. A single base pair polymorphism at position --308 in the promoter region of the TNF-alpha gene associated with an enhance...... with increased TNF-alpha production and BCC and necessary.......The mechanisms underlying induction of UVB-induced immunosuppression are not fully understood, but tumor necrosis factor alpha (TNF-alpha) is suggested to play a central role. A single base pair polymorphism at position --308 in the promoter region of the TNF-alpha gene associated with an enhanced...... secretion of TNF-alpha has been identified in humans. We have therefore investigated the association of the --308 polymorphism with the risk of basal cell carcinoma (BCC) in humans. The frequency of TNF G and TNF A alleles among Caucasian patients with a previous BCC (n=191) and health adults (n-107) were...

  4. Shape recovery using high dynamic range images

    Institute of Scientific and Technical Information of China (English)

    Zheng Zuoyong; Ma Lizhuang; Li Zhong

    2008-01-01

    An effective method for object shape recovery using HDRIs (high dynamic range images) is proposed. The radiance values of each point on the reference sphere and target object are firstly calculated, thus the set of candidate normals of each target point are found by comparing its radiance to that of each reference sphere point. In single-image shape recovery, a smoothness operation is applied to the target normals to obtain a stable and reasonable result; while in photometric stereo, radiance vectors of reference and target objects formed due to illuminations under different light source directions are directly compared to get the most suitable target normals. Finally, the height values can be recovered from the resulting normal field. Because diffuse and specular reflection are handled in an unified framework with radiance, our approach eliminates the limitation presented in most recovery strategies, i.e., only Lambertian model can be used. The experiment results from the real and synthesized images show the performance of our approach.

  5. Cryogenic microcalorimeter system for ultra-high resolution alpha-particle spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Rabin, Michael W [Los Alamos National Laboratory; Hoover, Andrew S [Los Alamos National Laboratory; Bacrania, Mnesh K [Los Alamos National Laboratory; Croce, Mark P [Los Alamos National Laboratory; Hoteling, N J [Los Alamos National Laboratory; Lamont, S P [Los Alamos National Laboratory; Plionis, A A [Los Alamos National Laboratory; Dry, D E [Los Alamos National Laboratory; Ullom, J N [NIST; Bennett, D A [NIST; Horansky, R [NIST; Kotsubo, V [NIST; Cantor, R [STAR CRYOELECTRONICS

    2009-01-01

    Microcalorimeters have been shown to yield unsurpassed energy resolution for alpha spectrometry, up to 1.06 keV FWHM at 5.3 MeV. These detectors use a superconducting transition-edge sensor (TES) to measure the temperature change in an absorber from energy deposited by an interacting alpha particle. Our system has four independent detectors mounted inside a liquid nitrogen/liquid helium cryostat. An adiabatic demagnetization refrigerator (ADR) cools the detector stage to its operating temperature of 80 mK. Temperature regulation with {approx}15 uK peak-to-peak variation is achieved by PID control of the ADR. The detectors are voltage-biased, and the current signal is amplified by a commercial SQUID readout system and digitized for further analysis, This paper will discuss design and operation of our microcalorimeter alpha spectrometer, and will show recent results.

  6. A high plasma concentration of TNF-alpha is associated with dementia in centenarians

    DEFF Research Database (Denmark)

    Bruunsgaard, H.; Andersen-Ranberg, K.; Jeune, B.;

    1999-01-01

    Background Inflammatory mechanisms and immune activation have been hypothesized to play a role in the pathogenesis of age-associated diseases such as dementia and atherosclerosis. The purpose of this study was to evaluate the plasma concentration of tumor necrosis factor (TNF)-alpha in a large...... cohort of centenarians and to look for its possible associations with cognitive function, atherosclerosis, and general health status. Furthermore, we investigated whether the concentration of TNF-alpha was correlated with the blood concentration of leucocyte subsets or the plasma concentrations...... of interleukin (IL)-6, soluble TNF receptor II (sTNFR-II) (75 kDa) and C-reactive protein (CRP). Methods. Plasma TNF-alpha was measured by ELISA in 126 centenarians, 45 subjects aged 81 years, 23 subjects aged 55-65 years, and 38 subjects aged 18-30 years. Atherosclerosis was evaluated by the ankle...

  7. Range of Medium and High Energy Protons and Alpha Particles in NaI Scintillator

    Directory of Open Access Journals (Sweden)

    Onder Kabadayi

    2004-01-01

    Full Text Available We have calculated the range of proton and alpha particle in NaI scintillator which is a commonly used substance in scintillation detector manufacturing. The stopping power of proton and alpha particle in NaI is calculated first by using the theoretical treatment of Montenegro et al.[1]. The range calculation has been performed by using a technique that we developed in the earlier works[2,3]. We compared the results with Monte Carlo simulation program SRIM2003 and PRAL[4]. The obtained results are in satisfactory agreement with the literature."

  8. High specific activity N-Acetyl-3{sup H}-{alpha}-Aspartyl- L-Glutamic at micro mole scale; Sintesis de N-Acetil-3{sup H}- {alpha} -Aspartil-Glutamico a escala de Micromoles

    Energy Technology Data Exchange (ETDEWEB)

    Suarez, C.

    1984-07-01

    High specific activity N-Acetyl-3{sup H}- {alpha} -Aspartyl-I-Glutamic acid at micro mole scale in prepared acetylating L- {alpha} -Aspartyl-L-glutamic with 3{sup H}-acetic anhydride in re distilled toluene. The product le purified through cationic and anionic columns. The radiochemical purity as determined by thin-layer chromatography is greater then 99% at the time preparation. (Author) 5 refs.

  9. Research on high dynamic range information capture of GEO camera

    Science.gov (United States)

    Huang, Sijie; Chen, Fansheng; Gong, Xueyi

    2014-07-01

    A high dynamic range imaging method of GEO staring imaging is proposed based on radiance simulation of GEO remote sensing targets and analysis of foreign and domestic remote sensing payload characteristics. Due to the high temporal resolution of GEO staring imaging, multiple exposure method is used and image sequences are captured with different integration times; Then a high dynamic range image is obtained after fusion with the contrast of neighborhood pixel values being the weighting factor. Finally experiments are done in lab with visible plane array 2048*2048 imaging system for verifying multiple exposure test. It can be proved that using multiple exposure capture fusion method can obtain an 11 bit high dynamic range image. The essence of the method is that it sacrifices time resolution in exchange for high dynamic range, which overcomes the defect of small dynamic range of single exposure and is of practical significance in terms of GEO high dynamic range information capture.

  10. [Determination of alpha-arbutin, beta-arbutin and niacinamide in cosmetics by high performance liquid chromatography].

    Science.gov (United States)

    Cheng, Peng; Chen, Meilan; Zhu, Yan

    2010-01-01

    A high performance liquid chromatography (HPLC) method for the determination of two optical isomers of arbutin (alpha-arbutin and beta-arbutin) and niacinamide in cosmetics was developed. The samples were extracted by the mixture of salt water and chloroform (2:1, v/v). The separation was performed on an ODS-BP column (200 mm x 4.6 mm, 5 microm, Elite) with methanol-water (10:90, v/v) as the mobile phase at a flow rate of 0.5 mL/min and 25 degrees C. The detection wavelength was set at 220 nm and the sample injection volume was 20 microL. There were good linear relationships between the mass concentration and the peak areas of alpha-arbutin, beta-arbutin and niacinamide in the ranges of 0.07-50, 0.06-50 and 0.05-50 mg/L, respectively. The relative standard deviations (RSDs, n = 7) of alpha-arbutin, beta-arbutin and niacinamide were 1.65%, 1.73% and 1.33%, respectively. The proposed method has been applied for the determination of alpha-arbutin, beta-arbutin and niacinamide in cosmetics with recoveries of 91.7%-109.6%. This method is rapid, simple and suitable for the detection of whitening ingredients in cosmetic.

  11. Development of a high-speed H-alpha camera system for the observation of rapid fluctuations in solar flares

    Science.gov (United States)

    Kiplinger, Alan L.; Dennis, Brian R.; Orwig, Larry E.; Chen, P. C.

    1988-01-01

    A solid-state digital camera was developed for obtaining H alpha images of solar flares with 0.1 s time resolution. Beginning in the summer of 1988, this system will be operated in conjunction with SMM's hard X-ray burst spectrometer (HXRBS). Important electron time-of-flight effects that are crucial for determining the flare energy release processes should be detectable with these combined H alpha and hard X-ray observations. Charge-injection device (CID) cameras provide 128 x 128 pixel images simultaneously in the H alpha blue wing, line center, and red wing, or other wavelength of interest. The data recording system employs a microprocessor-controlled, electronic interface between each camera and a digital processor board that encodes the data into a serial bitstream for continuous recording by a standard video cassette recorder. Only a small fraction of the data will be permanently archived through utilization of a direct memory access interface onto a VAX-750 computer. In addition to correlations with hard X-ray data, observations from the high speed H alpha camera will also be correlated and optical and microwave data and data from future MAX 1991 campaigns. Whether the recorded optical flashes are simultaneous with X-ray peaks to within 0.1 s, are delayed by tenths of seconds or are even undetectable, the results will have implications on the validity of both thermal and nonthermal models of hard X-ray production.

  12. Dynamics of a Highly Flexible Protein

    DEFF Research Database (Denmark)

    Andersen, Lisbeth

    Protein dynamics are important for protein function. Especially, dynamics plays an important role in ligand-binding where the induced fit and conformational selection binding mechanisms represent the extremes in a continuum of dynamic mechanisms. The difference between the mechanisms lies......-resolution structures of NCBD in complex with four binding partners are currently known and while three of them are practically identical and resemble the major conformation in the unbound ensemble, one shows NCBD adopting an alternative and markedly different conformation. The mechanisms underlying this conformational...

  13. Alpha Thalassemia

    Science.gov (United States)

    Alpha Thalassemia Physicians often mistake alpha thalassemia trait for iron deficiency anemia and incorrectly prescribe iron supplements that have no effect 1 on the anemia. αα αα Normal alpha ...

  14. PURIFICATION AND CHARACTERIZATION OF A HIGHLY THERMOSTABLE ALPHA-L-ARABINOFURANOSIDASE FROM GEOBACILLUS CALDOXYLOLYTICUS TK4

    Science.gov (United States)

    The gene encoding an alpha-L-arabinofuranosidase from Geobacillus caldoxylolyticus TK4, AbfATK4, was isolated, cloned, and sequenced. The deduced protein had a molecular mass of about 58 kDa, and analysis of its amino acid sequence revealed significant homology and conservation of different catalyt...

  15. A deep search for 21-cm absorption in high redshift damped Lyman-alpha systems

    NARCIS (Netherlands)

    Kanekar, N; Chengalur, JN

    2003-01-01

    We present deep GMRT 21-cm absorption spectra of 10 damped Lyman-alpha systems (DLAs), of which 8 are at redshifts zgreater than or similar to1.3. HI absorption was detected in only one DLA, the z=0.5318 absorber toward PKS 1629+12. This absorber has been identified with a luminous spiral galaxy; th

  16. Lyman alpha emitting galaxies at high redshift: Direct detection of young galaxies in a young universe

    Science.gov (United States)

    Dawson, Steven Arthur

    Alpha (LALA) survey. We conclude that if there is evolution in the Lya luminosity function over these epochs, its significance is below the statistical uncertainty of these data. This result supports the conclusion from several smaller samples of high-redshift Lya---emitters that the intergalactic medium remains largely reionized from the local universe out to z [approximate] 6.5. However, it is somewhat at odds with the pronounced drop in the cosmic star formation rate density recently measured between z ~ 3 and z ~ 6 in Lyman-break galaxies, and therefore potentially sheds light on the relationship between the two populations. (Abstract shortened by UMI.)

  17. Recurrence plot analysis of spatially extended high-dimensional dynamics

    Science.gov (United States)

    Marwan, Norbert; Foerster, Saskia; Kurths, Jürgen

    2015-04-01

    Recurrence plot based measures of complexity are capable tools for characterizing complex dynamics. We show the potential of selected recurrence plot measures for the investigation of spatially extended high-dimensional dynamics by applying them to data from the Lorenz96 model. The recurrence plot based measures are able to qualitatively characterize typical dynamical properties such as chaotic or periodic dynamics. Moreover, we demonstrate its power by analyzing satellite image time series of vegetation cover with contrasting dynamics as a spatially extended and potentially high-dimensional example from the real world.

  18. Analysing spatially extended high-dimensional dynamics by recurrence plots

    Science.gov (United States)

    Marwan, Norbert; Foerster, Saskia; Kurths, Jürgen

    2016-04-01

    Recurrence plot based measures of complexity are capable tools for characterizing complex dynamics. We show the potential of selected recurrence plot measures for the investigation of even high-dimensional dynamics. We apply this method on spatially extended chaos, such as derived from the Lorenz96 model and show that the recurrence plot based measures can qualitatively characterize typical dynamical properties such as chaotic or periodic dynamics. Moreover, we demonstrate its power by analyzing satellite image time series of vegetation cover with contrasting dynamics as a spatially extended and potentially high-dimensional example from the real world.

  19. Immobilization of a thermostable alpha-amylase by covalent binding to an alginate matrix increases high temperature usability.

    Science.gov (United States)

    Tee, Boon L; Kaletunç, Gönül

    2009-01-01

    Thermostable alpha-amylase was covalently bound to calcium alginate matrix to be used for starch hydrolysis at liquefaction temperature of 95 degrees C. 1-ethyl-3-(3-dimethylamino-propyl) carbodiimide hydrochloride (EDAC) was used as crosslinker. EDAC reacts with the carboxylate groups on the calcium alginate matrix and the amine groups of the enzyme. Ethylenediamine tetraacetic acid (EDTA) treatment was applied to increase the number of available carboxylate groups on the calcium alginate matrix for EDAC binding. After the immobilization was completed, the beads were treated with 0.1 M calcium chloride solution to reinstate the bead mechanical strength. Enzyme loading efficiency, activity, and reusability of the immobilized alpha-amylase were investigated. Covalently bound thermostable alpha-amylase to calcium alginate produced a total of 53 g of starch degradation/mg of bound protein after seven consecutive starch hydrolysis cycles of 10 min each at 95 degrees C in a stirred batch reactor. The free and covalently bound alpha-amylase had maximum activity at pH 5.5 and 6.0, respectively. The Michaelis-Menten constant (K(m)) of the immobilized enzyme (0.98 mg/mL) was 2.5 times greater than that of the free enzyme (0.40 mg/mL). The maximum reaction rate (V(max)) of immobilized and free enzyme were determined to be 10.4-mg starch degraded/mL min mg bound protein and 25.7-mg starch degraded/mL min mg protein, respectively. The high cumulative activity and seven successive reuses obtained at liquefaction temperature make the covalently bound thermostable alpha-amylase to calcium alginate matrix, a promising candidate for use in industrial starch hydrolysis process.

  20. Analysing spatially extended high-dimensional dynamics by recurrence plots

    Energy Technology Data Exchange (ETDEWEB)

    Marwan, Norbert, E-mail: marwan@pik-potsdam.de [Potsdam Institute for Climate Impact Research, 14412 Potsdam (Germany); Kurths, Jürgen [Potsdam Institute for Climate Impact Research, 14412 Potsdam (Germany); Humboldt Universität zu Berlin, Institut für Physik (Germany); Nizhny Novgorod State University, Department of Control Theory, Nizhny Novgorod (Russian Federation); Foerster, Saskia [GFZ German Research Centre for Geosciences, Section 1.4 Remote Sensing, Telegrafenberg, 14473 Potsdam (Germany)

    2015-05-08

    Recurrence plot based measures of complexity are capable tools for characterizing complex dynamics. In this letter we show the potential of selected recurrence plot measures for the investigation of even high-dimensional dynamics. We apply this method on spatially extended chaos, such as derived from the Lorenz96 model and show that the recurrence plot based measures can qualitatively characterize typical dynamical properties such as chaotic or periodic dynamics. Moreover, we demonstrate its power by analysing satellite image time series of vegetation cover with contrasting dynamics as a spatially extended and potentially high-dimensional example from the real world. - Highlights: • We use recurrence plots for analysing partially extended dynamics. • We investigate the high-dimensional chaos of the Lorenz96 model. • The approach distinguishes different spatio-temporal dynamics. • We use the method for studying vegetation cover time series.

  1. Biosensor analysis of dynamics of interleukin 5 receptor subunit beta(c) interaction with IL5:IL5R(alpha) complexes.

    Science.gov (United States)

    Scibek, Jeffery J; Evergren, Emma; Zahn, Stefan; Canziani, Gabriela A; Van Ryk, Donald; Chaiken, Irwin M

    2002-08-15

    To gain insight into IL5 receptor subunit recruitment mechanism, and in particular the experimentally elusive pathway for assembly of signaling subunit beta(c), we constructed a soluble beta(c) ectodomain (s(beta)(c)) and developed an optical biosensor assay to measure its binding kinetics. Functionally active s(beta)(c) was anchored via a C-terminal His tag to immobilized anti-His monoclonal antibodies on the sensor surface. Using this surface, we quantitated for the first time direct binding of s(beta)(c) to IL5R(alpha) complexed to either wild-type or single-chain IL5. Binding was much weaker if at all with either R(alpha) or IL5 alone. Kinetic evaluation revealed a moderate affinity (0.2-1 microM) and relatively fast off rate for the s(beta)(c) interaction with IL5:R(alpha) complexes. The data support a model in which beta(c) recruitment occurs with preformed IL5:R(alpha) complex. Dissociation kinetics analysis suggests that the IL5-alpha-beta(c) complex is relatively short-lived. Overall, this study solidifies a model of sequential recruitment of receptor subunits by IL5, provides a novel biosensor binding assay of beta(c) recruitment dynamics, and sets the stage for more advanced characterization of the roles of structural elements within R(alpha), beta(c), and cytokines of the IL5/IL3/GM-CSF family in receptor recruitment and activation.

  2. Experimental Study of Two-Alpha Emission from High-Lying Excited States of 17'18^Ne

    Institute of Scientific and Technical Information of China (English)

    徐新星; 林承键; 贾会明; 杨峰; 贾飞; 吴振东; 张世涛; 刘祖华; 张焕乔; 徐瑚珊; 孙志宇; 王建松; 胡正国; 王猛; 陈若富; 张雪荧; 李琛; 雷祥国; 徐治国; 肖国青

    2012-01-01

    The experiments of two-alpha emission from 17,18^Ne excited levels were performed at the HIRFL-RIBLL facility of the Institute of Modern Physics, Lanzhou. The beams of 17^Ne at the energy of 49.9 MeV/u and lSNe at 51.8 MeV/u bombarded a 197Au target to populate excited states of 17,18^Ne via Coulomb excitation. Complete kinematics measurements were achieved by the detectors of a silicon strip and CsI+PIN array. The experimental results combined with simple MC simulations show the characteristic of sequential two-alpha emission via 140 excited states for lSNe. The results of two-alpha emission from 17^Ne are preliminary and need further analyses.

  3. X-ray and optical crystallographic parameters investigations of high frequency induction melted Al-(alpha-Al(2)O(3)) alloys.

    Science.gov (United States)

    Bourbia, A; Draissia, M; Bedboudi, H; Boulkhessaim, S; Debili, M Y

    2010-01-01

    This article deals with the microstructural strengthening mechanisms of aluminium by means of hard alpha-Al(2)O(3) alumina fine particles. A broad of understanding views covering materials preparations, elaboration process, characterization techniques and associated microstructural characteristic parameters measurements is given. In order to investigate the microstructural characteristic parameters and the mechanical strengthening mechanisms of pure aluminium by hard fine particles, a set of Al-(alpha-Al(2)O(3)) alloys samples were made under vacuum by high fusion temperature melting, the high frequency (HF) process, and rapidly solidified under ambient temperature from a mixture of cold-compacted high-pure fine Al and alpha-Al(2)O(3) powders. The as-solidified Al-(alpha-Al(2)O(3)) alloys were characterized by means of X-ray diffraction (XRD) analyses, optical microscopy observations and Vickers microhardness tests in both brut and heat-treated states. It was found that the as-solidified HF Al-(alpha-Al(2)O(3)) alloys with compositions below 4 wt.% (alpha-Al(2)O(3)) are single-phase microstructures of the solid solution FCC Al phase and over two-phase microstructures of the solid solution FCC Al and the Rhombohedral alpha-Al(2)O(3) phases. The optical micrographs reveal the presence of a grain size refinement in these alloys. Vickers microhardness of the as-solidified Al-(alpha-Al(2)O(3)) is increased by means of pure fine alpha-Al(2)O(3) alumina particles. These combined effects of strengthening and grain size refinement observed in the as-solidified Al-(alpha-Al(2)O(3)) alloys are essentially due to a strengthening of Al by the alpha-Al(2)O(3) alumina particles insertion in the (HF) melted and rapidly solidified alloys.

  4. Alpha slow-moving high-density-lipoprotein subfraction in serum of a patient with radiation enteritis and peritoneal carcinosis

    Energy Technology Data Exchange (ETDEWEB)

    Peynet, J.; Legrand, A.; Messing, B.; Thuillier, F.; Rousselet, F.

    1989-04-01

    An alpha slow-moving high-density-lipoprotein (HDL) subfraction was seen in a patient presenting with radiation enteritis and peritoneal carcinosis, who was given long-term cyclic parenteral nutrition. This subfraction, observed in addition to normal HDL, was precipitated with low-density lipoproteins (LDL) and very-low-density lipoproteins (VLDL) by sodium phosphotungstate-magnesium chloride. The patient's serum lipoproteins were analyzed after fractionation by density gradient ultracentrifugation. The alpha slow-moving HDL floated in the ultracentrifugation subfractions with densities ranging from 1.028 to 1.084 kg/L, and their main apolipoproteins included apolipoprotein E in addition to apolipoprotein A-I. These HDL were larger than HDL2. The pathogenesis of this unusual HDL subfraction is hypothesized.

  5. Quantum Dot-Induced Phase Stabilization of ..alpha..-CsPbI3 Perovskite for High-Efficiency Photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Swarnkar, Abhishek; Marshall, Ashley R.; Sanehira, Erin M.; Chernomordik, Boris D.; Moore, David T.; Christians, Jeffrey A.; Chakrabarti, Tamoghna; Luther, Joseph M.

    2016-10-07

    We show nanoscale phase stabilization of CsPbI3 quantum dots (QDs) to low temperatures that can be used as the active component of efficient optoelectronic devices. CsPbI3 is an all-inorganic analog to the hybrid organic cation halide perovskites, but the cubic phase of bulk CsPbI3 (..alpha..-CsPbI3) -- the variant with desirable band gap -- is only stable at high temperatures. We describe the formation of ..alpha..-CsPbI3 QD films that are phase-stable for months in ambient air. The films exhibit long-range electronic transport and were used to fabricate colloidal perovskite QD photovoltaic cells with an open-circuit voltage of 1.23 volts and efficiency of 10.77%. These devices also function as light-emitting diodes with low turn-on voltage and tunable emission.

  6. High Fidelity Adiabatic Quantum Computation via Dynamical Decoupling

    CERN Document Server

    Quiroz, Gregory

    2012-01-01

    We introduce high-order dynamical decoupling strategies for open system adiabatic quantum computation. Our numerical results demonstrate that a judicious choice of high-order dynamical decoupling method, in conjunction with an encoding which allows computation to proceed alongside decoupling, can dramatically enhance the fidelity of adiabatic quantum computation in spite of decoherence.

  7. Probing high-redshift galaxies with Ly$\\alpha$ intensity mapping

    CERN Document Server

    Comaschi, P

    2015-01-01

    We present a study of the cosmological Ly$\\alpha$ emission signal at $z > 4$. Our goal is to predict the power spectrum of the spatial fluctuations that could be observed by an intensity mapping survey. The model uses the latest data from the HST legacy fields and the abundance matching technique to associate UV emission and dust properties with the halos, computing the emission from the interstellar medium (ISM) of galaxies and the intergalactic medium (IGM), including the effects of reionization, self-consistently. The Ly$\\alpha$ intensity from the diffuse IGM emission is 1.3 (2.0) times more intense than the ISM emission at $z = 4(7)$; both components are fair tracers of the star-forming galaxy distribution. However the power spectrum is dominated by ISM emission on small scales ($k > 0.01 h{\\rm Mpc}^{-1}$) with shot noise being significant only above $k = 1 h{\\rm Mpc}^{-1}$. At very lange scales ($k < 0.01h{\\rm Mpc}^{-1}$) diffuse IGM emission becomes important. The comoving Ly$\\alpha$ luminosity densi...

  8. RAYLEIGH-TAYLOR STRENGTH EXPERIMENTS OF THE PRESSURE-INDUCED alpha->epsilon->alpha' PHASE TRANSITION IN IRON

    Energy Technology Data Exchange (ETDEWEB)

    Belof, J L; Cavallo, R M; Olson, R T; King, R S; Gray, G T; Holtkamp, D B; Chen, S R; Rudd, R E; Barton, N R; Arsenlis, A; Remington, B A; Park, H; Prisbrey, S T; Vitello, P A; Bazan, G; Mikaelian, K O; Comley, A J; Maddox, B R; May, M J

    2011-08-10

    We present here the first dynamic Rayleigh-Taylor (RT) strength measurement of a material undergoing solid-solid phase transition. Iron is quasi-isentropically driven across the pressure-induced bcc ({alpha}-Fe) {yields} hcp ({var_epsilon}-Fe) phase transition and the dynamic strength of the {alpha}, {var_epsilon} and reverted {alpha}{prime} phases have been determined via proton radiography of the resulting Rayleigh-Taylor unstable interface between the iron target and high-explosive products. Simultaneous velocimetry measurements of the iron free surface yield the phase transition dynamics and, in conjunction with detailed hydrodynamic simulations, allow for determination of the strength of the distinct phases of iron. Forward analysis of the experiment via hydrodynamic simulations reveals significant strength enhancement of the dynamically-generated {var_epsilon}-Fe and reverted {alpha}{prime}-Fe, comparable in magnitude to the strength of austenitic stainless steels.

  9. HIGH DYNAMIC-RANGE HIGH SPEED LINAC CURRENT MEASUREMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Deibele, Craig Edmond [ORNL; Curry, Douglas E [ORNL; Dickson, Richard W [ORNL

    2012-01-01

    It is desired to measure the linac current of a charged particle beam with a consistent accuracy over a dynamic range of over 120 dB. Conventional current transformers suffer from droop, can be susceptible to electromagnetic interference (EMI), and can be bandwidth limited. A novel detector and electronics were designed to maximize dynamic range of about 120 dB and measure rise-times on the order of 10 nanoseconds.

  10. High Performance Interactive System Dynamics Visualization

    Energy Technology Data Exchange (ETDEWEB)

    Bush, Brian W [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Brunhart-Lupo, Nicholas J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Gruchalla, Kenny M [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Duckworth, Jonathan C [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-09-14

    This brochure describes a system dynamics simulation (SD) framework that supports an end-to-end analysis workflow that is optimized for deployment on ESIF facilities(Peregrine and the Insight Center). It includes (I) parallel and distributed simulation of SD models, (ii) real-time 3D visualization of running simulations, and (iii) comprehensive database-oriented persistence of simulation metadata, inputs, and outputs.

  11. High Performance Interactive System Dynamics Visualization

    Energy Technology Data Exchange (ETDEWEB)

    Bush, Brian W [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Brunhart-Lupo, Nicholas J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Gruchalla, Kenny M [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Duckworth, Jonathan C [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-09-14

    This presentation describes a system dynamics simulation (SD) framework that supports an end-to-end analysis workflow that is optimized for deployment on ESIF facilities(Peregrine and the Insight Center). It includes (I) parallel and distributed simulation of SD models, (ii) real-time 3D visualization of running simulations, and (iii) comprehensive database-oriented persistence of simulation metadata, inputs, and outputs.

  12. High Dynamic Range Digital Imaging of Spacecraft

    Science.gov (United States)

    Karr, Brian A.; Chalmers, Alan; Debattista, Kurt

    2014-01-01

    The ability to capture engineering imagery with a wide degree of dynamic range during rocket launches is critical for post launch processing and analysis [USC03, NNC86]. Rocket launches often present an extreme range of lightness, particularly during night launches. Night launches present a two-fold problem: capturing detail of the vehicle and scene that is masked by darkness, while also capturing detail in the engine plume.

  13. Direct chemical synthesis of 1 alpha,25-dihydroxy(26,27-3H) vitamin D3 with high specific activity: its use in receptor studies

    Energy Technology Data Exchange (ETDEWEB)

    Napoli, J.L.; Mellon, W.S.; Fivizzani, M.A.; Schnoes, H.K.; DeLuca, H.F.

    1980-05-01

    The first direct chemical synthesis of radiolabeled 1 alpha, 25-dihydroxyvitamin D3 is reported. Unlike all previous syntheses, the new approach does not rely on enzymatic 1 alpha-hydroxylation of radiolabeled precursors. Rather, isotope is introduced in the last synthetic step by reaction of (3H) -methylmagnesium bromide with methyl 1 alpha-hydroxy-26,27-dinorvitamin D3-25-carboxylate to give 1 alpha,25-dihydroxy-(26,27-3H) vitamin D3 with a specific activity of 160 Ci/mmol. Mass spectroscopy confirmed that the radiohormone consists of a single isomer with six tritium atoms bound to carbons 26 and 27. Synthetically produced 1 alpha,25-dihydroxy (26,27-3H) vitamin D3 is indistinguishable from 1 alpha,25-dihydroxy-(26,27-3H) vitamin D3 obtained from the enzymatic 1 alpha-hydroxylation of 25-hydroxy(26,27-3H) vitamin D3 (160 Ci/mmol) by high-pressure liquid chromatography analysis and in the competitive binding assay using chick intestinal cytosol as the receptor source. Equilibrium dissociation constant measurements with the high specific activity radiohormone indicate a Kd of 8.2 x 10(-11) M for the chick intestinal cytosol 1 alpha,25-dihydroxyvitamin D3 receptor--a value considerably lower than the constants in the range of (1-5) x 10(-9) M previously reported.

  14. Redesign of a Variable-Gain Output Feedback Longitudinal Controller Flown on the High-Alpha Research Vehicle (HARV)

    Science.gov (United States)

    Ostroff, Aaron J.

    1998-01-01

    This paper describes a redesigned longitudinal controller that flew on the High-Alpha Research Vehicle (HARV) during calendar years (CY) 1995 and 1996. Linear models are developed for both the modified controller and a baseline controller that was flown in CY 1994. The modified controller was developed with three gain sets for flight evaluation, and several linear analysis results are shown comparing the gain sets. A Neal-Smith flying qualities analysis shows that performance for the low- and medium-gain sets is near the level 1 boundary, depending upon the bandwidth assumed, whereas the high-gain set indicates a sensitivity problem. A newly developed high-alpha Bode envelope criterion indicates that the control system gains may be slightly high, even for the low-gain set. A large motion-base simulator in the United Kingdom was used to evaluate the various controllers. Desired performance, which appeared to be satisfactory for flight, was generally met with both the low- and medium-gain sets. Both the high-gain set and the baseline controller were very sensitive, and it was easy to generate pilot-induced oscillation (PIO) in some of the target-tracking maneuvers. Flight target-tracking results varied from level 1 to level 3 and from no sensitivity to PIO. These results were related to pilot technique and whether actuator rate saturation was encountered.

  15. A New Population of High Redshift, Dusty Lyman-Alpha Emitters and Blobs Discovered by WISE

    CERN Document Server

    Bridge, Carrie R; Borys, Colin J K; Petty, Sara; Benford, Dominic; Eisenhardt, Peter; Farrah, Duncan; Griffith, Roger L; Jarrett, Tom; Stanford, S Adam; Stern, Daniel; Tsai, Chao-Wei; Wright, Edward L; Wu, Jingwen

    2012-01-01

    We report a new technique to select 1.610^{13-14}L_sun) and warm colors, typically larger than submillimeter-selected galaxies (SMGs) and dust-obscured galaxies (DOGs). These traits are commonly associated with the dust being energized by intense AGN activity. We hypothesize that the combination of spatially extended Lyman-alpha, large amounts of warm IR-luminous dust, and rarity (implying a short-lived phase) can be explained if the galaxies are undergoing strong `feedback' transforming them from an extreme dusty starburst to a QSO.

  16. High Serum Interleukin-10 and Tumor Necrosis Factor Alpha Levels in Chronic Paracoccidioidomycosis

    Science.gov (United States)

    Fornari, M. C.; Bava, A. J.; Guereño, M. T.; Berardi, V. E.; Silaf, M. R.; Negroni, R.; Diez, R. A.

    2001-01-01

    In patients with chronic paracoccidioidomycosis (n = 10), levels of tumor necrosis factor alpha, interleukin-10, and interleukin-2 in serum, measured by enzyme-linked immunosorbent assay (in picograms per milliliter, as mean ± standard error of the mean), were higher than in normal controls (n = 8): 186 ± 40 versus 40 ± 7 (P < 0.05), 203 ± 95 versus 20 ± 8 (P = 0.001), and 96.3 ± 78.57 versus 1.19 ± 1.19 (P = 0.045), respectively. Gamma interferon and interleukin-4 levels were similar in patients and controls. PMID:11527826

  17. Abundances in Damped Lyman-$\\alpha$ Systems and Chemical Evolution of High Redshift Galaxies

    CERN Document Server

    Lü, L; Barlow, T A; Lu, Limin; Sargent, Wallace L.W.; Barlow, Thomas A.

    1997-01-01

    Recent abundance measurements in damped Lyman-alpha galaxies, supplemented with unpublished Keck observations, are discussed. The metallicity distribution with cosmic time is examined for clues about the degree of enrichment, the onset of initial star formation, and the nature of the galxies. The relative abundances of the elements are compared with the abundnce pattern in Galactic halo stars and in the Sun, taking into account of the effects of dust depletion, in order to gain insight into the stellar processes and the time scales by which the enrichment occurred.

  18. Highly Potent, Water Soluble Benzimidazole Antagonist for Activated (alpha)4(beta)1 Integrin

    Energy Technology Data Exchange (ETDEWEB)

    Carpenter, R D; Andrei, M; Lau, E Y; Lightstone, F C; Liu, R; Lam, K S; Kurth, M J

    2007-08-29

    The cell surface receptor {alpha}{sub 4}{beta}{sub 1} integrin, activated constitutively in lymphoma, can be targeted with the bisaryl urea peptidomimetic antagonist 1 (LLP2A). However, concerns on its preliminary pharmacokinetic (PK) profile provided an impetus to change the pharmacophore from a bisaryl urea to a 2-arylaminobenzimidazole moiety resulting in improved solubility while maintaining picomolar potency [5 (KLCA4); IC{sub 50} = 305 pM]. With exceptional solubility, this finding has potential for improving PK to help diagnose and treat lymphomas.

  19. Effects of a high-pressure treatment on the wheat alpha-amylase inhibitor and its relationship to elimination of allergenicity

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, S [Food Science Center, Niigata University, Ikarashi, Niigata, 950-2181 (Japan); Takanohashi, K; Nishiumi, T [Graduate School of Science and Technology, Niigata University, Ikarashi, Niigata, 950-2181 (Japan); Hara, T [Department of Applied Biological Chemistry, Faculty of Agriculture, Niigata University, Ikarashi, Niigata, 950-2181 (Japan); Odani, S [Department of Living Science and Technology, Faculty of Education and Human Science, Ikarashi, Niigata, 950-2181 (Japan); Suzuki, A, E-mail: shuyama@agr.niigata-u.ac.j [Department of Health and Nutrition, Faculty of Medical Science for Health, Teikyo Heisei University, Ikebukuro, Tokyo, 170-0013 (Japan)

    2010-03-01

    In this study, the effects of high-pressure treatment on structure and allergeincity of alpha amylase inhibitor (a-AI) were investigated. The pressure-induced structural changes of {alpha}-AI were estimated by fluorescence spectra and by fourth derivative UV-spectroscopy for probed tyrosine residues and by circular dichroism (CD) spectroscopy. The changes in the tertiary structure detected by fluorescence spectra and by fourth derivative UV-spectroscopy under high pressure were indicated at over 300 MPa. Measurements of CD spectroscopy suggested that the effects of a high-pressure treatment on changes in the secondary structure of {alpha}-AI were little. From our results, pressure-induced changes of the {alpha}-AI structure were not apparent. On the other hands, the IgE-specific binding activities of pressurized {alpha}-AI to sera from allergic patients against wheat, which is estimated by observations of dot-blotting, were decreased by high-pressure treatment. It is known that the pressure-induced elimination of allergenicity is related to the tertiary structural changes of allergen molecules. This study are suspected that the epitopes of {alpha}-AI do not contain tyrosine residues, and thus the decrease of IgE-specific binding activities is probably caused by the tertiary structural changes of these parts of {alpha}-AI.

  20. Giant Dipole Resonance as a Fingerprint of $\\alpha$ Clustering Configurations in $^{12}$C and $^{16}$O

    CERN Document Server

    He, W B; Cao, X G; Cai, X Z; Zhang, G Q

    2014-01-01

    It is studied how the $\\alpha$ cluster degrees of freedom, such as $\\alpha$ clustering configurations close to the $\\alpha$ decay threshold in $^{12}$C and $^{16}$O, including the linear chain, triangle, square, kite, and tetrahedron, affect nuclear collective vibrations with a microscopic dynamical approach, which can describe properties of nuclear ground states well across the nuclide chart and reproduce the standard giant dipole resonance (GDR) of $^{16}$O quite nicely. It is found that the GDR spectrum is highly fragmented into several apparent peaks due to the $\\alpha$ structure. The different $\\alpha$ cluster configurations in $^{12}$C and $^{16}$O have corresponding characteristic spectra of GDR. The number and centroid energies of peaks in the GDR spectra can be reasonably explained by the geometrical and dynamical symmetries of $\\alpha$ clustering configurations. Therefore, the GDR can be regarded as a very effective probe to diagnose the different $\\alpha$ cluster configurations in light nuclei.

  1. Molecular Dynamics of Materials Possessing High Energy Content.

    Science.gov (United States)

    1988-01-26

    I -RI90 634 MOLECULAR DYNAMICS OF MATERIALS POSSESSING HIGH ENERGY 1/1 r CONTENTCU) COLUMBIA UNIV MENd YORK N J TURRO 26 JAN GO I RFOSR-TR-88-0168...Bolling Air Force Base, D.C. 2 61102F_ 2303 I B2 11 T,TL.E (Inciuoe Security Classification) Molecular Dynamics of Materials Possessing High Energy...York 10027 (212) 280-2175 TITLE: MOLECULAR DYNAMICS OF MATERIALS POSSESSING HIGH ENERGY CONTENT .. 0 0 88 2 ... "" ’% ,i u , . .. .. ....... ŝ" ;! ,i

  2. Overlay Share Mesh for Interactive Group Communication with High Dynamic

    Institute of Scientific and Technical Information of China (English)

    WU Yan-hua; CAI Yun-ze; XU Xiao-ming

    2007-01-01

    An overlay share mesh infrastructure is presented for high dynamic group communication systems, such as distributed interactive simulation (DIS) and distributed virtual environments (DVE). Overlay share mesh infrastructure can own better adapting ability for high dynamic group than tradition multi-tree multicast infrastructure by sharing links among different groups. The mechanism of overlay share mesh based on area of interest (AOI) was discussed in detail in this paper. A large number of simulation experiments were done and the permance of mesh infrastructure was studied. Experiments results proved that overlay mesh infrastructure owns better adaptability than traditional multi-tree infrastructure for high dynamic group communication systems.

  3. Inference in High-dimensional Dynamic Panel Data Models

    DEFF Research Database (Denmark)

    Kock, Anders Bredahl; Tang, Haihan

    We establish oracle inequalities for a version of the Lasso in high-dimensional fixed effects dynamic panel data models. The inequalities are valid for the coefficients of the dynamic and exogenous regressors. Separate oracle inequalities are derived for the fixed effects. Next, we show how one can...

  4. Is a malleable protein necessarily highly dynamic?

    DEFF Research Database (Denmark)

    Kjærgaard, Magnus; Poulsen, Flemming Martin; Teilum, Kaare

    2012-01-01

    core of NCBD in the ligand-free state and in a well-folded complex with the ligand activator for thyroid hormone and retinoid receptors using multiple NMR methods including methyl chemical shifts, coupling constants, and methyl order parameters. From all NMR measures, the aliphatic side chains...... in the hydrophobic core are slightly more dynamic in the free protein than in the complex, but have mobility comparable to the hydrophobic cores of average folded proteins. Urea titration monitored by NMR reveals that all parts of the protein, including the side-chain packing in the hydrophobic core, denatures...... in a single cooperative process. The molten globule characteristics of NCBD are thus restricted to a slowly fluctuating tertiary structure. Consequently, the conformational plasticity of the protein is most likely related to its low overall stability rather than an intrinsically flexible protein structure...

  5. Highly polarized emission in spin resolved photoelectron spectroscopy of alpha-Fe(001)/GaAs(001)

    Energy Technology Data Exchange (ETDEWEB)

    Tobin, James; Yu, Sung Woo; Morton, Simon; Waddill, George; Thompson, Jamie; Neal, James; Spangenberg, Matthais; Shen, T.H.

    2009-05-19

    Highly spin-polarized sources of electrons, Integrated into device design, remain of great interest to the spintronic and magneto-electronic device community Here, the growth of Fe upon GaAs(001) has been studied with photoelectron spectroscopy (PES), including Spin Resolved PES. Despite evidence of atomic level disorder such as intermixing, an over-layer with the spectroscopic signature of alpha-Fe(001), with a bcc real space ordering, Is obtained The results will be discussed in light of the possibility of using such films as a spin-polarized source in device applications.

  6. GAS PHASE MOLECULAR DYNAMICS: HIGH-RESOLUTION SPECTROSCOPIC PROBES OF CHEMICAL DYNAMICS.

    Energy Technology Data Exchange (ETDEWEB)

    HALL, G.E.

    2006-05-30

    This research is carried out as part of the Gas Phase Molecular Dynamics group program in the Chemistry Department at Brookhaven National Laboratory. High-resolution spectroscopic tools are developed and applied to problems in chemical dynamics. Recent topics have included the state-resolved studies of collision-induced electronic energy transfer, dynamics of barrierless unimolecular reactions, and the kinetics and spectroscopy of transient species.

  7. Lyman-alpha radiation hydrodynamics of galactic winds before cosmic reionization

    CERN Document Server

    Smith, Aaron; Loeb, Abraham

    2016-01-01

    The dynamical impact of Lyman-alpha (Ly{\\alpha}) radiation pressure on galaxy formation depends on the rate and duration of momentum transfer between Ly{\\alpha} photons and neutral hydrogen gas. Although photon trapping has the potential to multiply the effective force, ionizing radiation from stellar sources may relieve the Ly{\\alpha} pressure before appreciably affecting the kinematics of the host galaxy or efficiently coupling Ly{\\alpha} photons to the outflow. We present self-consistent Ly{\\alpha} radiation-hydrodynamics simulations of high-$z$ galaxy environments by coupling the Cosmic Ly{\\alpha} Transfer code (COLT) with spherically symmetric Lagrangian frame hydrodynamics. The accurate but computationally expensive Monte-Carlo radiative transfer calculations are feasible under the one-dimensional approximation. In certain cases Ly{\\alpha} feedback significantly enhances the velocity of the shell of gas expanding around a central source. Radiative feedback alone is capable of ejecting baryons into the i...

  8. Design Of High Performance CMOS Dynamic Latch Comparator

    Directory of Open Access Journals (Sweden)

    G.Saroja

    2016-10-01

    Full Text Available High performance analog to digital converters (ADC, memory sense amplifiers, and Radio Frequency identification applications, data receivers with less area and power efficient designs has attracted a broad range of dynamic comparators. This paper presents an ameliorate design for a dynamic latch based comparator in attaining high performance. The comparators accuracyis mainly defined by two factors they are speed and power consumption. The latch based comparator has two different stages encompassing of a dynamic differential input gain stage and an output latch.The output node in the differential gain stage of proposed comparator requires lesser time to regain higher charge potential. The proposed comparator hasbeen designed and simulated using 130nm CMOS 1P2M technology by using mentor graphics tools with a supply voltage of 1V. Proposed dynamic latch comparator iscompared with existing conventional dynamic latch comparator and with other comparators and the results are discussed in detail.

  9. Mivazerol, a novel compound with high specificity for alpha 2 adrenergic receptors: binding studies on different human and rat membrane preparations.

    Science.gov (United States)

    Noyer, M; de Laveleye, F; Vauquelin, G; Gobert, J; Wülfert, E

    1994-03-01

    Mivazerol, 3-[1(H-imidazol-4-yl)methyl]-2-hydroxybenzamide hydrochloride, a new potential anti-ischemic drug designed by UCB S.A. Pharma Sector, has been studied in binding experiments on adrenergic, dopaminergic, serotoninergic, muscarinic and idazoxan binding sites. Our results indicate that this compound displays high affinity and marked specificity for alpha 2 adrenoceptors. Mivazerol displaced the binding of the alpha 2 adrenoceptor antagonist [3H]RX 821002 to the alpha 2A adrenoceptors in human frontal cortex membranes with an apparent Ki value of 37 nM. The competition curve was shallow (nH = 0.55), suggesting that this compound acts as an alpha 2 adrenergic agonist. Mivazerol was also a potent competitor for [3H]RX 821002 binding to human platelet membranes (containing alpha 2A adrenoceptors) and rat kidney membranes (75% of the alpha 2 adrenoceptors of the alpha 2B subtype), indicating that this compound is not alpha 2 adrenoceptor subtype selective. Equilibrium dissociation constants for alpha 1 adrenoceptors (displacement of [3H]prazosin) and 5-HT1A receptors (displacement of [3H]rauwolscine) were respectively about 120 times (Ki = 4.4 microM) and 14 times (Ki = 530 nM) higher than that for the alpha 2 adrenoceptors. Equilibrium dissociation constants were approximately 1000 times higher for all other receptors tested in this study; namely beta 1 and beta 2 adrenoceptors, D1- and D2-dopamine receptors, M1-, M2- and M3-muscarinic receptors, 5-HT2 receptors and non-adrenergic idazoxan binding sites.

  10. Dynamic High-Pressure Behavior of Hierarchical Heterogeneous Geological Materials

    Science.gov (United States)

    2016-04-01

    pressure -density Hugoniot plots for simulations using the ‘mix 5’ option, as will be presented later. The volume weighted option for mixed cells (refered...AFRL-AFOSR-VA-TR-2016-0150 Dynamic High- Pressure Behavior of Geological Materials Naresh Thadhani GEORGIA TECH RESEARCH CORPORATION Final Report 04...31-12-2015 4.  TITLE AND SUBTITLE Dynamic High- Pressure Behavior of Hierarchical Heterogeneous Geological Materials 5a.  CONTRACT NUMBER 5b.  GRANT

  11. Imaging with high Dynamic using an Ionization Chamber

    OpenAIRE

    Menk, Ralf-Hendrik; Amenitsch, Heinz; Arfelli, Fulvia; Bernstorff, Sigrid; Besch, Hans Juergen; Voltolina, Francesco

    2010-01-01

    In this work a combination of an ionization chamber with one-dimensional spatial resolution and a MicroCAT structure will be presented. The combination between gas gain operations and integrating front-end electronics yields a dynamic range as high as eight to nine orders of magnitude. Therefore this device is well suitable for medical imaging or applications such as small angle x-ray scattering, where the requirements on the dynamic of the detector are exceptional high. Basically the describ...

  12. Dynamic retention of Ero1alpha and Ero1beta in the endoplasmic reticulum by interactions with PDI and ERp44.

    Science.gov (United States)

    Otsu, Mieko; Bertoli, Gloria; Fagioli, Claudio; Guerini-Rocco, Elena; Nerini-Molteni, Silvia; Ruffato, Elena; Sitia, Roberto

    2006-01-01

    Disulfide bonds are formed in the endoplasmic reticulum (ER) by sequential interchange reactions: Ero1alpha and Ero1beta transfer oxidative equivalents to protein disulfide isomerase (PDI), which in turn oxidizes cargo proteins. Neither Ero1alpha nor Ero1beta contains known ER localization motif(s), raising the question of how they are retained in this organelle. Here the authors show that, unlike endogenous molecules, overexpressed Ero1alpha and Ero1beta are secreted by HeLa transfectants, suggesting saturation of their normal retention mechanism(s). Co-expression of either PDI or ERp44 prevents Ero1 secretion in a KDEL/RDEL dependent way. Covalent interactions between ERp44 and Ero1 are essential for retention. In contrast, a mutant PDI lacking the four cysteines in the two active sites still inhibits secretion, albeit less efficiently. PDI and ERp44 compete for Ero1 binding. PDI also prevents Ero1 aggregation and dimerization, thus chaperoning its own oxidase. This dynamic retention mechanism of Ero1 may be important for fine-tuning the regulation of ER redox homeostasis and quality control.

  13. Development of thin foil Faraday collector as a lost alpha particle diagnostic for high yield D-T tokamak fusion plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Van Belle, P.; Jarvis, O.N.; Sadler, G.J. [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking; Cecil, F.E. [Colorado School of Mines, Golden, CO (United States)

    1994-07-01

    Alpha particle confinement is necessary for ignition of a D-T tokamak fusion plasma and for first wall protection. Due to high radiation backgrounds and temperatures, scintillators and semiconductor detectors may not be used to study alpha particles which are lost to the first wall during the D-T programs on JET and ITER. An alternative method of charged particle spectrometry capable of operation in these harsh environments, is proposed: it consists of thin foils of electrically isolated conductors with the flux of alpha particles determined by the positive current flowing from the foils. 2 refs., 3 figs.

  14. Large-amplitude jumps and non-Gaussian dynamics in highly concentrated hard sphere fluids.

    Science.gov (United States)

    Saltzman, Erica J; Schweizer, Kenneth S

    2008-05-01

    Our microscopic stochastic nonlinear Langevin equation theory of activated dynamics has been employed to study the real-space van Hove function of dense hard sphere fluids and suspensions. At very short times, the van Hove function is a narrow Gaussian. At sufficiently high volume fractions, such that the entropic barrier to relaxation is greater than the thermal energy, its functional form evolves with time to include a rapidly decaying component at small displacements and a long-range exponential tail. The "jump" or decay length scale associated with the tail increases with time (or particle root-mean-square displacement) at fixed volume fraction, and with volume fraction at the mean alpha relaxation time. The jump length at the alpha relaxation time is predicted to be proportional to a measure of the decoupling of self-diffusion and structural relaxation. At long times corresponding to mean displacements of order a particle diameter, the volume fraction dependence of the decay length disappears. A good superposition of the exponential tail feature based on the jump length as a scaling variable is predicted at high volume fractions. Overall, the theoretical results are in good accord with recent simulations and experiments. The basic aspects of the theory are also compared with a classic jump model and a dynamically facilitated continuous time random-walk model. Decoupling of the time scales of different parts of the relaxation process predicted by the theory is qualitatively similar to facilitated dynamics models based on the concept of persistence and exchange times if the elementary event is assumed to be associated with transport on a length scale significantly smaller than the particle size.

  15. High frequency dynamics in centrifugal compressors

    NARCIS (Netherlands)

    Twerda, A.; Meulendijks, D.; Smeulers, J.P.M.; Handel, R. van den; Lier, L.J. van

    2008-01-01

    Problems with centrifugal compressors relating to high frequency, i.e. Blade passing frequency (BPF) are increasing. Pulsations and vibrations generated in centrifugal compressors can lead to nuisance, due to strong tonal noise, and even breakdown. In several cases the root cause of a failure or a

  16. High frequency dynamics in centrifugal compressors

    NARCIS (Netherlands)

    Twerda, A.; Meulendijks, D.; Smeulers, J.P.M.; Handel, R. van den; Lier, L.J. van

    2008-01-01

    Problems with centrifugal compressors relating to high frequency, i.e. Blade passing frequency (BPF) are increasing. Pulsations and vibrations generated in centrifugal compressors can lead to nuisance, due to strong tonal noise, and even breakdown. In several cases the root cause of a failure or a n

  17. Purification, enzymatic characterization, and nucleotide sequence of a high-isoelectric-point alpha-glucosidase from barley malt

    DEFF Research Database (Denmark)

    Frandsen, T P; Lok, F; Mirgorodskaya, E;

    2000-01-01

    High-isoelectric-point (pI) alpha-glucosidase was purified 7, 300-fold from an extract of barley (Hordeum vulgare) malt by ammonium sulfate fractionation, ion-exchange, and butyl-Sepharose chromatography. The enzyme had high activity toward maltose (k(cat) = 25 s(-1)), with an optimum at pH 4...... in the transition state complex. Mass spectrometry of tryptic fragments assigned the 92-kD protein to a barley cDNA (GenBank accession no. U22450) that appears to encode an alpha-glucosidase. A corresponding sequence (HvAgl97; GenBank accession no. AF118226) was isolated from a genomic phage library using a c......DNA fragment from a barley cDNA library. HvAgl97 encodes a putative 96.6-kD protein of 879 amino acids with 93.8% identity to the protein deduced from U22450. The sequence contains two active site motifs of glycoside hydrolase family 31. Three introns of 86 to 4,286 bp interrupt the coding region. The four...

  18. Mindfulness-based cognitive therapy (MBCT), cognitive style, and the temporal dynamics of frontal EEG alpha asymmetry in recurrently depressed patients.

    Science.gov (United States)

    Keune, Philipp M; Bostanov, Vladimir; Hautzinger, Martin; Kotchoubey, Boris

    2011-12-01

    Mindfulness-based cognitive therapy (MBCT), a meditation-based maintenance therapy, reduces the relapse risk in individuals suffering from major depressive disorder (MDD). However, only a few studies investigated the psychophysiological mechanisms underlying this protective effect. We examined effects of MBCT on trait rumination and mindfulness, as indicators of global cognitive style, as well as on residual depressive symptoms in a group of recurrently depressed patients (n=78) in remission. Additionally, alpha asymmetry in resting-state electroencephalogram (EEG) was assessed. Alpha asymmetry has been found to be predictive of affective style and a pattern indicative of stronger relative right-hemispheric anterior cortical activity may represent a trait marker for the vulnerability to develop MDD. In line with previous findings, residual depressive symptoms and trait rumination decreased, whereas trait mindfulness increased following MBCT, while no such changes took place in a wait-list control group. Mean values of alpha asymmetry, on the other hand, remained unaffected by training, and shifted systematically toward a pattern indicative of stronger relative right-hemispheric anterior cortical activity in the whole sample. These findings provide further support for the protective effect of MBCT. In the examined patients who were at an extremely high risk for relapse, however, this effect did not manifest itself on a neurophysiological level in terms of alpha asymmetry, where a shift, putatively indicative of increased vulnerability, was observed.

  19. Unexpected high digestion rate of cooked starch by the Ct-Maltase-Glucoamylase small intestine mucosal alpha-glucosidase subunit

    Science.gov (United States)

    For starch digestion to glucose, two luminal alpha-amylases and four gut mucosal alpha-glucosidase subunits are employed. The aim of this research was to investigate, for the first time, direct digestion capability of individual mucosal alpha-glucosidases on cooked (gelatinized) starch. Gelatinized ...

  20. High-precision (p,t) reaction measurement to determine Ne-18(alpha,p)Na-21 reaction rates

    NARCIS (Netherlands)

    Matic, A.; van den Berg, A. M.; Harakeh, M. N.; Wörtche, H. J.; Berg, G. P. A.; Couder, M.; Fisker, J. L.; Goerres, J.; LeBlanc, P.; O'Brien, S.; Wiescher, M.; Fujita, K.; Hatanaka, K.; Sakemi, Y.; Shimizu, Y.; Tameshige, Y.; Tamii, A.; Yosoi, M.; Adachi, T.; Fujita, Y.; Shimbara, Y.; Fujita, H.; Wakasa, T.; Hess, P. O.; Brown, B. A.; Schatz, H.

    2009-01-01

    x-ray bursts are identified as thermonuclear explosions in the outer atmosphere of accreting neutron stars. The thermonuclear runaway is fueled by the alpha p process that describes a sequence of (alpha,p) reactions triggered by the Ne-18(alpha,p)Na-21 breakout reaction from the hot CNO cycles. We

  1. Lyman Alpha Control

    CERN Document Server

    Nielsen, Daniel Stefaniak

    2015-01-01

    This document gives an overview of how to operate the Lyman Alpha Control application written in LabVIEW along with things to watch out for. Overview of the LabVIEW code itself as well as the physical wiring of and connections from/to the NI PCI-6229 DAQ box is also included. The Lyman Alpha Control application is the interface between the ALPHA sequencer and the HighFinesse Wavelength Meter as well as the Lyman Alpha laser setup. The application measures the wavelength of the output light from the Lyman Alpha cavity through the Wavelength Meter. The application can use the Wavelength Meter’s PID capabilities to stabilize the Lyman Alpha laser output as well as switch between up to three frequencies.

  2. New Highly Dynamic Approach for Thrust Vector Control

    Science.gov (United States)

    Hecht, M.; Ettl, J.; Grothe, D.; Hrbud, I.

    2015-09-01

    For a new launcher system a thrust vector control system is needed. This launch vehicle system consists of two rockets which are namely the VS-50 (two-stage suborbital vehicle) and the VLM-1 (three-stage microsatellite launch vehicle). VLM-1 and VS-50 are developed in a cooperation between the German Aerospace Center (DLR) and the Brazilian Aeronautics and Space Institute (IAE). To keep these two rockets on its trajectory during flight a highly dynamic thrust vector control system is required. For the purpose of developing such a highly dynamic thrust vector control system a master thesis was written by the author. The development includes all mechanical constructions as well as control algorithms and electronics design. Moreover an optimization of control algorithms was made to increase the dynamic capabilities of the thrust vector control system. The composition of the right components plus the sophisticated control algorithm make the thrust vector control system highly dynamic.

  3. Low Dynamic Range Solutions to the High Dynamic Range Imaging Problem

    Institute of Scientific and Technical Information of China (English)

    Shanmuganathan RAMAN; Subhasis CHAUDHURI

    2010-01-01

    While capturing a real world scene using a common digital camera,due to limitations of the sensar dynamic range,we will not be able to capture the entire dynamic range of the soene.This problem is evident while capturing a picture of a scene which has both brightly and poorly illumninated regions.High Dynamic Range (HDR) imaging aims to recover the entire dynamic range of the scene by compositing multi-exposure images.Tone reproduction is required for displaying HDR images as the corresponding Low Dynamic Range(LDR) images on common displays.This paper discusses novel approaches to reconstruct LDR images directly from multi-exposure images.It is assumed that there is no knowledge of camera response function and other caraera settings.At last,it is explained how this task can be achieved effectively for static and dynamic scenes.

  4. Biophysical Modeling of Alpha Rhythms During Halothane-Induced Unconsciousness.

    Science.gov (United States)

    Vijayan, Sujith; Ching, ShiNung; Purdon, Patrick L; Brown, Emery N; Kopell, Nancy J

    2013-01-01

    During the induction of general anesthesia there is a shift in power from the posterior regions of the brain to the frontal cortices; this shift in power is called anteriorization. For many anesthetics, a prominent feature of anteriorization is a shift specifically in the alpha band (8-13 Hz) from posterior to frontal cortices. Here we present a biophysical computational model that describes thalamocortical circuit-level dynamics underlying anteriorization of the alpha rhythm in the case of halothane. Halothane potentiates GABAA and increases potassium leak conductances. According to our model, an increase in potassium leak conductances hyperpolarizes and silences the high-threshold thalamocortical (HTC) cells, a specialized subset of thalamocortical cells that fire at the alpha frequency at relatively depolarized membrane potentials (>-60 mV) and are thought to be the generators of quiet awake occipital alpha. At the same time the potentiation of GABAA imposes an alpha time scale on both the cortical and the thalamic component of the frontal portion of our model. The alpha activity in the frontal component is further strengthened by reciprocal thalamocortical feedback. Thus, we argue that the dual molecular targets of halothane induce the anteriorization of the alpha rhythm by increasing potassium leak conductances, which abolishes occipital alpha, and by potentiating GABAA, which induces frontal alpha. These results provide a computational modeling formulation for studying highly detailed biophysical mechanisms of anesthetic action in silico.

  5. Cerebral artery alpha-1 AR subtypes: high altitude long-term acclimatization responses.

    Directory of Open Access Journals (Sweden)

    Ravi Goyal

    Full Text Available In response to hypoxia and other stress, the sympathetic (adrenergic nervous system regulates arterial contractility and blood flow, partly through differential activities of the alpha1 (α1 - adrenergic receptor (AR subtypes (α1A-, α1B-, and α1D-AR. Thus, we tested the hypothesis that with acclimatization to long-term hypoxia (LTH, contractility of middle cerebral arteries (MCA is regulated by changes in expression and activation of the specific α1-AR subtypes. We conducted experiments in MCA from adult normoxic sheep maintained near sea level (300 m and those exposed to LTH (110 days at 3801 m. Following acclimatization to LTH, ovine MCA showed a 20% reduction (n = 5; P<0.05 in the maximum tension achieved by 10-5 M phenylephrine (PHE. LTH-acclimatized cerebral arteries also demonstrated a statistically significant (P<0.05 inhibition of PHE-induced contractility in the presence of specific α1-AR subtype antagonists. Importantly, compared to normoxic vessels, there was significantly greater (P<0.05 α1B-AR subtype mRNA and protein levels in LTH acclimatized MCA. Also, our results demonstrate that extracellular regulated kinase 1 and 2 (ERK1/2-mediated negative feedback regulation of PHE-induced contractility is modulated by α1B-AR subtype. Overall, in ovine MCA, LTH produces profound effects on α1-AR subtype expression and function.

  6. High Dynamic Performance Nonlinear Source Emulator

    DEFF Research Database (Denmark)

    Nguyen-Duy, Khiem; Knott, Arnold; Andersen, Michael A. E.

    2016-01-01

    As research and development of renewable and clean energy based systems is advancing rapidly, the nonlinear source emulator (NSE) is becoming very essential for testing of maximum power point trackers or downstream converters. Renewable and clean energy sources play important roles in both...... terrestrial and nonterrestrial applications. However, most existing NSEs have only been concerned with simulating energy sources in terrestrial applications, which may not be fast enough for testing of nonterrestrial applications. In this paper, a high-bandwidth NSE is developed that is able to simulate...... change in the input source but also to a load step between nominal and open circuit. Moreover, all of these operation modes have a very fast settling time of only 10 μs, which is hundreds of times faster than that of existing works. This attribute allows for higher speed and a more efficient maximum...

  7. Dynamical Instabilities in High-Obliquity Systems

    CERN Document Server

    Tamayo, Daniel; Hamilton, Douglas P; Nicholson, Philip D

    2012-01-01

    High-inclination circumplanetary orbits that are gravitationally perturbed by the central star can undergo Kozai oscillations---large-amplitude, coupled variations in the orbital eccentricity and inclination. We first study how this effect is modified by incorporating perturbations from the planetary oblateness. Tremaine et al. (2009) found that, for planets with obliquities > 68.875 degrees, orbits in the equilibrium local Laplace plane are unstable to eccentricity perturbations over a finite radial range, and execute large-amplitude chaotic oscillations in eccentricity and inclination. In the hope of making that treatment more easily understandable, we analyze the problem using orbital elements, confirming this threshold obliquity. Furthermore, we find that orbits inclined to the Laplace plane will be unstable over a broader radial range, and that such orbits can go unstable for obliquities less than 68.875 degrees. Finally, we analyze the added effects of radiation pressure, which are important for dust gr...

  8. High magnetic shear gain in a liquid sodium stable couette flow experiment A prelude to an alpha - omega dynamo

    Energy Technology Data Exchange (ETDEWEB)

    Colgate, Stirling [Los Alamos National Laboratory; Li, Jui [Los Alamos National Laboratory; Finn, John [Los Alamos National Laboratory; Pariev, Vladimir [Los Alamos National Laboratory; Beckley, Howard [NM INSTIT. OF MINING AND TECH; Si, Jiahe [NM INSTIT. OF MINING AND TECH.; Martinic, Joe [NM INSTIT. OF MINING AND TECH.; Westpfahl, David [NM INSTIT. OF TECH.; Slutz, James [NM INSTIT. OF MINING AND TECH.; Westrom, Zeb [NM INSTIT. OF TECH.; Klein, Brianna [NM INSTIT. OF MINING AND TECH.

    2010-11-08

    The {Omega}-phase of the liquid sodium {alpha}-{Omega} dynamo experiment at NMIMT in cooperation with LANL has successfully demonstrated the production of a high toroidal field, B{sub {phi}} {approx_equal} 8 x B{sub r} from the radial component of an applied poloidal magnetic field, B{sub r}. This enhanced toroidal field is produced by rotational shear in stable Couette Row within liquid sodium at Rm {approx_equal} 120. The small turbulence in stable Taylor-Couette Row is caused by Ekman Row where ({delta}v/v){sup 2} {approx} 10{sup -3}. This high {Omega}-gain in low turbulence flow contrasts with a smaller {Omega}-gain in higher turbulence, Helmholtz-unstable shear flows. This result supports the ansatz that large scale astrophysical magnetic fields are created within semi-coherent large scale motions in which turbulence plays a diffusive role that enables magnetic flux linkage.

  9. High Magnetic Shear Gain in a Liquid Sodium Stable Couette Flow Experiment; A Prelude to an alpha-Omega Dynamo

    CERN Document Server

    Colgate, Stirling A; Pariev, Vladimir; Finn, John; Beckley, Howard; Si, Jiahe; Martinic, Joe; Westpfahl, David; Slutz, James; Westrom, Cebastian; Klein, Brianna; Schendel, Paul; Scharle, Cletus; McKinney, Travis; Ginanni, Rocky; Bentley, Ian; Mickey, Timothy

    2010-01-01

    The $\\Omega$-phase of the liquid sodium $\\alpha$-$\\Omega$ dynamo experiment at NMIMT in cooperation with LANL has successfully demonstrated the production of a high toroidal field, $B_{\\phi} \\simeq 8\\times B_r$ from the radial component of an applied poloidal magnetic field, $B_r$. This enhanced toroidal field is produced by rotational shear in stable Couette flow within liquid sodium at $Rm \\simeq 120$. The small turbulence in stable Taylor-Couette flow is caused by Ekman flow where $ (\\delta v/v)^2 \\sim 10^{-3} $. This high $\\Omega$-gain in low turbulence flow contrasts with a smaller $\\Omega$-gain in higher turbulence, Helmholtz-unstable shear flows. This result supports the ansatz that large scale astrophysical magnetic fields are created within semi-coherent large scale motions in which turbulence plays only a smaller diffusive role that enables magnetic flux linkage.

  10. A cosmic web filament revealed in Lyman-alpha emission around a luminous high-redshift quasar

    CERN Document Server

    Cantalupo, Sebastiano; Prochaska, J Xavier; Hennawi, Joseph F; Madau, Piero

    2014-01-01

    Simulations of structure formation in the Universe predict that galaxies are embedded in a "cosmic web", where the majority of baryons reside as rarefied and highly ionized gas. This material has been studied for decades in absorption against background sources, but the sparseness of these inherently one-dimensional probes preclude direct constraints on the three-dimensional morphology of the underlying web. Here we report observations of a cosmic web filament in Lyman-alpha emission, discovered during a survey for cosmic gas fluorescently "illuminated" by bright quasars at z=2.3. With a projected size of approximately 460 physical kpc, the Lyman-alpha emission surrounding the radio-quiet quasar UM287 extends well beyond the virial radius of any plausible associated dark matter halo. The estimated cold gas mass of the nebula from the observed emission is at least ten times larger than what is typically found by cosmological simulations, suggesting that a population of intergalactic gas clumps with sub-kpc siz...

  11. The most metal-poor damped Lyman alpha systems: An insight into dwarf galaxies at high redshift

    CERN Document Server

    Cooke, Ryan; Jorgenson, Regina A

    2014-01-01

    In this paper, we analyze the kinematics, chemistry, and physical properties of a sample of the most metal-poor damped Lyman alpha systems (DLAs), to uncover their links to modern-day galaxies. We present evidence that the DLA population as a whole exhibits a `knee' in the relative abundances of the alpha-capture and Fe-peak elements when the metallicity is [Fe/H] ~ -2.0. In this respect, the chemical evolution of DLAs is clearly different from that experienced by Milky Way halo stars, but resembles that of dwarf spheroidal galaxies in the Local Group. We also find a close correspondence between the kinematics of Local Group dwarf galaxies and of high redshift metal-poor DLAs, which further strengthens this connection. On the basis of such similarities, we propose that the most metal-poor DLAs provide us with a unique opportunity to directly study the dwarf galaxy population more than ten billion years in the past, at a time when many dwarf galaxies were forming the bulk of their stars. To this end, we have m...

  12. A detector module with highly efficient surface-alpha event rejection operated in CRESST-II Phase 2

    Energy Technology Data Exchange (ETDEWEB)

    Strauss, R. [Max-Planck-Institut fuer Physik, Munich (Germany); Technische Universitaet Muenchen, Physik-Department, Garching (Germany); Angloher, G.; Ferreiro, N.; Hauff, D.; Kiefer, M.; Petricca, F.; Proebst, F.; Reindl, F.; Seidel, W.; Stodolsky, L.; Tanzke, A.; Wuestrich, M. [Max-Planck-Institut fuer Physik, Munich (Germany); Bento, A. [Universidade de Coimbra, CIUC, Departamento de Fisica, Coimbra (Portugal); Bucci, C.; Canonica, L.; Gorla, P.; Schaeffner, K. [Laboratori Nazionali del Gran Sasso, INFN, Assergi (Italy); Erb, A. [Technische Universitaet Muenchen, Physik-Department, Garching (Germany); Walther-Meissner-Institut fuer Tieftemperaturforschung, Garching (Germany); Feilitzsch, F. von; Guetlein, A.; Lanfranchi, J.C.; Muenster, A.; Potzel, W.; Roth, S.; Schoenert, S.; Stanger, M.; Ulrich, A.; Wawoczny, S.; Willers, M.; Zoeller, A. [Technische Universitaet Muenchen, Physik-Department, Garching (Germany); Jochum, J.; Loebell, J.; Rottler, K.; Sailer, C.; Scholl, S.; Strandhagen, C.; Uffinger, M.; Usherov, I. [Eberhard-Karls-Universitaet Tuebingen, Physikalisches Institut, Tuebingen (Germany); Kluck, H. [Institut fuer Hochenergiephysik der Oesterreichischen Akademie der Wissenschaften, Wien (Austria); Vienna University of Technology, Atominstitut, Wien (Austria); Kraus, H. [University of Oxford, Department of Physics, Oxford (United Kingdom); Schieck, J. [Institut fuer Hochenergiephysik der Oesterreichischen Akademie der Wissenschaften, Wien (Austria); Sivers, M. von [Technische Universitaet Muenchen, Physik-Department, Garching (Germany); University of Bern, Albert Einstein Center for Fundamental Physics, Bern (Switzerland)

    2015-08-15

    The cryogenic dark matter experiment CRESSTII aims at the direct detection of WIMPs via elastic scattering off nuclei in scintillating CaWO{sub 4} crystals. We present a new, highly improved, detector design installed in the current run of CRESST-II Phase 2 with an efficient active rejection of surface-alpha backgrounds. Using CaWO{sub 4} sticks instead of metal clamps to hold the target crystal, a detector housing with fully-scintillating inner surface could be realized. The presented detector (TUM40) provides an excellent threshold of ∝0.60 keV and a resolution of σ ∼ 0.090 keV (at 2.60 keV).With significantly reduced background levels, TUM40 sets stringent limits on the spin-independent WIMP nucleon scattering cross section and probes a new region of parameter space for WIMP masses below 3GeV/c{sup 2}. In this paper, we discuss the novel detector design and the surface-alpha event rejection in detail. (orig.)

  13. A detector module with highly efficient surface-alpha event rejection operated in CRESST-II Phase 2

    CERN Document Server

    Strauss, R; Bento, A; Bucci, C; Canonica, L; Erb, A; Feilitzsch, F v; Ferreiro, N; Gorla, P; Gütlein, A; Hauff, D; Jochum, J; Kiefer, M; Kluck, H; Kraus, H; Lanfranchi, J -C; Loebell, J; Münster, A; Petricca, F; Potzel, W; Pröbst, F; Reindl, F; Roth, S; Rottler, K; Sailer, C; Schäffner, K; Schieck, J; Scholl, S; Schönert, S; Seidel, W; Sivers, M v; Stanger, M; Stodolsky, L; Strandhagen, C; Tanzke, A; Uffinger, M; Ulrich, A; Usherov, I; Wawoczny, S; Willers, M; Wüstrich, M; Zöller, A

    2014-01-01

    The cryogenic dark matter experiment CRESST-II aims at the direct detection of WIMPs via elastic scattering off nuclei in scintillating CaWO$_4$ crystals. We present a new, highly improved, detector design installed in the current run of CRESST-II Phase 2 with an efficient active rejection of surface-alpha backgrounds. Using CaWO$_4$ sticks to hold the target crystal a detector housing with fully-scintillating inner surface could be realized. The presented detector (TUM40) provides an excellent threshold of ${\\sim}\\,0.60\\,$keV and a resolution of $\\sigma\\,{\\approx}\\,0.090\\,$keV (at 2.60$\\,$keV). With significantly reduced background levels, TUM40 sets stringent limits on the spin-independent WIMP-nucleon scattering cross section and probes a new region of parameter space for WIMP masses below 3$\\,$GeV/c$^2$. In this paper, we discuss the novel detector design and the surface-alpha event rejection in detail.

  14. Oxygen Escape from Venus During High Dynamic Pressure ICMEs

    Science.gov (United States)

    McEnulty, Tess; Luhmann, J. G.; Brain, D. A.; Fedorov, A.; Jian, L. K.; Russell, C. T.; Zhang, T.; Möstl, C.; Futaana, Y.; de Pater, I.

    2013-10-01

    Previous studies using data from Pioneer Venus suggested that oxygen ion escape flux may be enhanced by orders of magnitude during Interplanetary Coronal Mass Ejections. However, this large enhancement has been ambiguous in Venus Express ion data - with some analyses showing no flux enhancement or a small enhancement (within 2 times undisturbed cases). One possible explanation is that high escape flux may be due to high dynamic pressure in the solar wind, and the dynamic pressure has been lower during the VEX time period. So, we focus on ICMEs with the largest dynamic pressure and with VEX sampling of the escaping ions during the sheath of the ICMEs (during which the highest dynamic pressures in the solar wind occur). We will show the characteristics of these large events measured by VEX, and compare them to the largest ICMEs measured by PVO. We will then discuss estimates of the oxygen ion escape flux during these events.

  15. Understanding the dynamical structure of pulsating stars: The center-of-mass velocity and the Baade-Wesselink projection factor of the beta-Cephei star alpha-Lupi

    CERN Document Server

    Nardetto, N; Fokin, A; Chapellier, E; Pietrzynski, G; Gieren, W; Graczyk, D; Mourard, D

    2013-01-01

    High-resolution spectroscopy of pulsating stars is a powerful tool to study the dynamical structure of their atmosphere. Lines asymmetry is used to derive the center-of-mass velocity of the star, while a direct measurement of the atmospheric velocity gradient helps determine the projection factor used in the Baade-Wesselink method of distance determination. We aim at deriving the center-of-mass velocity and the projection factor of the beta-Cephei star alpha-Lup. We present HARPS high spectral resolution observations of alpha-Lup. We calculate the first-moment radial velocities and fit the spectral line profiles by a bi-Gaussian to derive line asymmetries. Correlations between the gamma-velocity and the gamma-asymmetry (defined as the average values of the radial velocity and line asymmetry curves respectively) are used to derive the center-of-mass velocity of the star. By combining our spectroscopic determination of the atmospheric velocity gradient with a hydrodynamical modelof the photosphere of the star, ...

  16. Anomalous dynamic behaviour of optically trapped high aspect ratio nanowires

    CERN Document Server

    Toe, Wen Jun; Angstmann, Christopher; Gao, Qiang; Tan, Hark Hoe; Jagadish, Chennupati; Henry, Bruce; Reece, Peter J

    2015-01-01

    We investigate the dynamics of high aspect ratio nanowires trapped axially in a single gradient force optical tweezers. A power spectrum analysis of the Brownian dynamics reveals a broad spectral resonance of the order of a kHz with peak properties that are strongly dependent on the input trapping power. Modelling of the dynamical equations of motion of the trapped nanowire that incorporate non-conservative effects through asymmetric coupling between translational and rotational degrees of freedom provides excellent agreement with the experimental observations. An associated observation of persistent cyclical motion around the equilibrium trapping position using winding analysis provides further evidence for the influence of non-conservative forces.

  17. High speed railway track dynamics models, algorithms and applications

    CERN Document Server

    Lei, Xiaoyan

    2017-01-01

    This book systematically summarizes the latest research findings on high-speed railway track dynamics, made by the author and his research team over the past decade. It explores cutting-edge issues concerning the basic theory of high-speed railways, covering the dynamic theories, models, algorithms and engineering applications of the high-speed train and track coupling system. Presenting original concepts, systematic theories and advanced algorithms, the book places great emphasis on the precision and completeness of its content. The chapters are interrelated yet largely self-contained, allowing readers to either read through the book as a whole or focus on specific topics. It also combines theories with practice to effectively introduce readers to the latest research findings and developments in high-speed railway track dynamics. It offers a valuable resource for researchers, postgraduates and engineers in the fields of civil engineering, transportation, highway & railway engineering.

  18. Large Scale, High Resolution, Mantle Dynamics Modeling

    Science.gov (United States)

    Geenen, T.; Berg, A. V.; Spakman, W.

    2007-12-01

    To model the geodynamic evolution of plate convergence, subduction and collision and to allow for a connection to various types of observational data, geophysical, geodetical and geological, we developed a 4D (space-time) numerical mantle convection code. The model is based on a spherical 3D Eulerian fem model, with quadratic elements, on top of which we constructed a 3D Lagrangian particle in cell(PIC) method. We use the PIC method to transport material properties and to incorporate a viscoelastic rheology. Since capturing small scale processes associated with localization phenomena require a high resolution, we spend a considerable effort on implementing solvers suitable to solve for models with over 100 million degrees of freedom. We implemented Additive Schwartz type ILU based methods in combination with a Krylov solver, GMRES. However we found that for problems with over 500 thousend degrees of freedom the convergence of the solver degraded severely. This observation is known from the literature [Saad, 2003] and results from the local character of the ILU preconditioner resulting in a poor approximation of the inverse of A for large A. The size of A for which ILU is no longer usable depends on the condition of A and on the amount of fill in allowed for the ILU preconditioner. We found that for our problems with over 5×105 degrees of freedom convergence became to slow to solve the system within an acceptable amount of walltime, one minute, even when allowing for considerable amount of fill in. We also implemented MUMPS and found good scaling results for problems up to 107 degrees of freedom for up to 32 CPU¡¯s. For problems with over 100 million degrees of freedom we implemented Algebraic Multigrid type methods (AMG) from the ML library [Sala, 2006]. Since multigrid methods are most effective for single parameter problems, we rebuild our model to use the SIMPLE method in the Stokes solver [Patankar, 1980]. We present scaling results from these solvers for 3D

  19. Dynamical symmetry breaking with hypercolour and high colour representations

    Energy Technology Data Exchange (ETDEWEB)

    Zoupanos, G.

    1985-03-01

    A model is presented in which the electroweak gauge group is spontaneously broken according to a dynamical scenario based on the existence of high colour representations. An unattractive feature of this scenario was the necessity to introduce elementary Higgs fields in order to obtain the spontaneous symmetry breaking of part of the theory. In the present model, this breaking can also be understood dynamically with the introduction of hypercolour interactions.

  20. IMPACT OF TONE MAPPING IN HIGH DYNAMIC RANGE IMAGE COMPRESSION

    OpenAIRE

    Narwaria, Manish; Perreira Da Silva, Matthieu; Le Callet, Patrick; Pépion, Romuald

    2014-01-01

    International audience; Tone mapping or range reduction is often used in High Dynamic Range (HDR) visual signal compression to take advantage of the existing image/video coding architectures. Thus, it is important to study the impact of tone mapping on the visual quality of decompressed HDR visual signals. To our knowledge, most of the existing studies focus only on the quality loss in the resultant low dynamic range (LDR) signal (obtained via tone mapping) and typically employ LDR displays f...

  1. Wetting dynamics at high values of contact line speed

    OpenAIRE

    Пономарев, К. О.; Феоктистов, Дмитрий Владимирович; Орлова, Евгения Георгиевна

    2015-01-01

    Experimental results analyses of dynamic contact angle change under the conditions of substrate wetting by distilled water at high values of the contact line speed was conducted. Three spreading modes for copper substrates with different roughness were selected: drop formation, spreading and equilibrium contact angle formation. Peculiarity of droplet spreading on superhydrophobic surface is found. It consists in a monotonic increase of the advancing dynamic contact angle. The effect of the dr...

  2. A high dynamic range readout unit for a calorimeter

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yun-Long; WU Jian; CHANG Jin; LI Bing; FENG Chang-Qing; LI Xian-Li; WANG Xiao-Lian; XU Zi-Zong; GUO Jian-Hua; CAI Ming-Sheng; HU Yi-Ming

    2012-01-01

    A high dynamic range readout system,consisting of a multi-dynode readout PMT and a VA32 chip,is presented.An LED system is set up to calibrate the relative gains between the dynodes,and the ADC counts per MIPs from dynode 7 are determined under cosmic-ray calibration.A dynamic range from 0.5 MIPs to 1 × 105 MIPs is achieved.

  3. Laser assisted {alpha} decay

    Energy Technology Data Exchange (ETDEWEB)

    Castaneda Cortes, Hector Mauricio

    2012-02-01

    Excited or short-lived nuclei often decay by emitting alpha particles that are assumed to be preformed inside the nucleus and confined in the nuclear potential well. In this picture, {alpha} decay refers to the tunneling of the alpha particle through the potential barrier. In this thesis we investigate for the first time how strong laser fields can assist the tunneling of the alpha particle and thus influence the nuclear decay. Generally speaking, laser-assisted {alpha} decay can be described as laser-assisted tunneling of a quasistationary state, i.e, a slowly decaying state. Our theoretical treatment is developed starting from the complex trajectory formulation of the well-known strong-field approximation used to describe laser-induced ionization. We extend this formulation and develop a method to treat the decay of quasistationary states. The effect of both static and optical and X-ray monochromatic fields on the lifetimes and {alpha}-particle emission spectra are investigated for a number of {alpha}-emitting nuclei. We find that even at strong intensities, the laser-induced acceleration of the {alpha} decay is negligible, ranging from a relative modification in the decay rate of 10{sup -3} for static fields of electric field strengths of 10{sup 15} V/m, to 10{sup -8} for strong optical fields with intensities of 10{sup 22} W/cm{sup 2}, and to 10{sup -6} for strong X-ray fields with laser intensities around 10{sup 24} W/cm{sup 2}. However, the effect of the external field is visible in the spectrum of emitted alpha particles, leading in the case of optical fields even to rescattering phenomena for intensities approaching 6 x 10{sup 22} W/cm{sup 2}. The dynamics of the alpha particle in laser fields of intensities below the rescattering limit is investigated.

  4. Consistency of spherical, gravity-dominated dynamics with quasar high-ionization emission-line profiles

    Science.gov (United States)

    Kallman, T. R.; Wilkes, B. J.; Krolik, J. H.; Green, Richard

    1993-01-01

    Line profile data are used to test a simple kinematic model - spherically symmetric gravitational free fall - in which the number of free parameters is limited by requiring physical self-consistency. The predictions of this model are fitted to high-resolution spectra of the stronger rest-frame UV emission lines in 12 quasars with z of about 2. It is found that if all the lines are radiated predominantly from the illuminated faces of the emission-line clouds, the profiles of Ly-alpha, N V 1240 A, and C IV 1549 A can be simultaneously well fitted with very similar parameters for all 12 quasars. It is concluded that spherically symmetric gravitational free fall does not correctly describe the dynamics of quasar broad emission-line regions.

  5. Design of a mixer for the thrust-vectoring system on the high-alpha research vehicle

    Science.gov (United States)

    Pahle, Joseph W.; Bundick, W. Thomas; Yeager, Jessie C.; Beissner, Fred L., Jr.

    1996-01-01

    One of the advanced control concepts being investigated on the High-Alpha Research Vehicle (HARV) is multi-axis thrust vectoring using an experimental thrust-vectoring (TV) system consisting of three hydraulically actuated vanes per engine. A mixer is used to translate the pitch-, roll-, and yaw-TV commands into the appropriate TV-vane commands for distribution to the vane actuators. A computer-aided optimization process was developed to perform the inversion of the thrust-vectoring effectiveness data for use by the mixer in performing this command translation. Using this process a new mixer was designed for the HARV and evaluated in simulation and flight. An important element of the Mixer is the priority logic, which determines priority among the pitch-, roll-, and yaw-TV commands.

  6. High statistics determination of the strong coupling constant in Taylor scheme and its OPE Wilson coefficient from lattice QCD with a dynamical charm

    CERN Document Server

    Blossier, B; Brinet, M; De Soto, F; Morenas, V; Pène, O; Petrov, K; Rodríguez-Quintero, J

    2014-01-01

    This paper reports on the determination of $\\alpha_S$ from lattice simulations with 2+1+1 twisted-mass dynamical flavours {\\it via} the computation of the ghost-gluon coupling renormalized in the MOM Taylor scheme. A high-statistics sample of gauge configurations, used to evaluate the coupling from ghost and gluon propagators, allows for the appropriate update of previous results, now performing an improved analysis of data with reduced statistical errors and the systematical uncertainties under a better control.

  7. Gas-Phase Molecular Dynamics: High Resolution Spectroscopy and Collision Dynamics of Transient Species

    Energy Technology Data Exchange (ETDEWEB)

    Hall,G.E.; Sears, T.J.

    2009-04-03

    This research is carried out as part of the Gas-Phase Molecular Dynamics program in the Chemistry Department at Brookhaven National Laboratory. High-resolution spectroscopy, augmented by theoretical and computational methods, is used to investigate the structure and collision dynamics of chemical intermediates in the elementary gas-phase reactions involved in combustion chemistry. Applications and methods development are equally important experimental components of this work.

  8. High-field spin dynamics of antiferromagnetic quantum spin chains

    DEFF Research Database (Denmark)

    Enderle, M.; Regnault, L.P.; Broholm, C.;

    2000-01-01

    The characteristic internal order of macroscopic quantum ground states in one-dimensional spin systems is usually not directly accessible, but reflected in the spin dynamics and the field dependence of the magnetic excitations. In high magnetic fields quantum phase transitions are expected. We...... present recent work on the high-field spin dynamics of the S = I antiferromagnetic Heisenberg chains NENP (Haldane ground state) and CsNiCl3 (quasi-1D HAF close to the quantum critical point), the uniform S = 1/2 chain CTS, and the spin-Peierls system CuGeO3. (C) 2000 Elsevier Science B,V. All rights...

  9. Advanced High Dynamic Range Imaging Theory and Practice

    CERN Document Server

    Banterle, Francesco

    2011-01-01

    Imaging techniques seek to simulate the array of light that reaches our eyes to provide the illusion of sensing scenes directly. Both photography and computer graphics deal with the generation of images. Both disciplines have to cope with the high dynamic range in the energy of visible light that human eyes can sense. Traditionally photography and computer graphics took different approaches to the high dynamic range problem. Work over the last ten years though has unified these disciplines and created powerful new tools for the creation of complex, compelling and realistic images. This book pr

  10. The determination of $\\alpha_s$ by the ALPHA collaboration

    CERN Document Server

    Bruno, Mattia

    2016-01-01

    We review the ALPHA collaboration strategy for obtaining the QCD coupling at high scale. In the three-flavor effective theory it avoids the use of perturbation theory at $\\alpha > 0.2$ and at the same time has the physical scales small compared to the cutoff $1/a$ in all stages of the computation. The result $\\Lambda_\\overline{MS}^{(3)}=332(14)$~MeV is translated to $\\alpha_\\overline{MS}(m_Z)=0.1179(10)(2)$ by use of (high order) perturbative relations between the effective theory couplings at the charm and beauty quark "thresholds". The error of this perturbative step is discussed and estimated as $0.0002$.

  11. LaaA, a novel high-active alkalophilic alpha-amylase from deep-sea bacterium Luteimonas abyssi XH031(T).

    Science.gov (United States)

    Song, Qinghao; Wang, Yan; Yin, Chong; Zhang, Xiao-Hua

    2016-08-01

    Alpha-amylase is a kind of broadly used industrial enzymes, most of which have been exploited from terrestrial organism. Comparatively, alpha-amylase from marine environment was largely undeveloped. In this study, a novel alkalophilic alpha-amylase with high activity, Luteimonas abyssi alpha-amylase (LaaA), was cloned from deep-sea bacterium L. abyssi XH031(T) and expressed in Escherichia coli BL21. The gene has a length of 1428bp and encodes 475 amino acids with a 35-residue signal peptide. The specific activity of LaaA reached 8881U/mg at the optimum pH 9.0, which is obvious higher than other reported alpha-amylase. This enzyme can remain active at pH levels ranging from 6.0 to 11.0 and temperatures below 45°C, retaining high activity even at low temperatures (almost 38% residual activity at 10°C). In addition, 1mM Na(+), K(+), and Mn(2+) enhanced the activity of LaaA. To investigate the function of potential active sites, R227G, D229K, E256Q/H, H327V and D328V mutants were generated, and the results suggested that Arg227, Asp229, Glu256 and Asp328 were total conserved and essential for the activity of alpha-amylase LaaA. This study shows that the alpha-amylase LaaA is an alkali-tolerant and high-active amylase with strong potential for use in detergent industry. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. A highly sensitive biosensor for tumor maker alpha fetoprotein based on poly(ethylene glycol) doped conducting polymer PEDOT.

    Science.gov (United States)

    Cui, Min; Song, Zhiling; Wu, Yumin; Guo, Bing; Fan, Xiaojian; Luo, Xiliang

    2016-05-15

    Biocompatible polymers, such as poly(ethylene glycol) (PEG), are of great significance in the development of bio-interfaces and biosensors, as they possess excellent biocompatibility and are easy for modification. A novel highly biocompatible polymer composite was synthesized herein through electrochemical polymerization of the conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) and a PEG derivative, 4-arm PEG terminated with thiol groups. The electrodeposited conducting polymer composite of PEG doped PEDOT (PEDOT/PEG) exhibited flake-like nanostructure, large surface area and outstanding stability. In order to further immobilize antibodies, gold nanoparticles (AuNPs) were introduced to the PEDOT/PEG composite surface through their unique interaction with the thiol groups. AuNPs modified PEDOT/PEG provided a desirable support for the immobilization of various biomolecules such as antibodies for alpha fetoprotein (AFP), a vital tumor biomarker for liver cancer. The fabricated AFP biosensor demonstrated favorable selectivity, high sensitivity, and ultralow detection limit. Furthermore, owing to the presence of PEG polymers that are highly hydrophilic, such AuNPs/PEDOT/PEG based AFP biosensor also exhibited good anti-fouling ability, and it was capable of assaying target AFP in 10% (V/V) human serum samples, indicating highly feasible potential for clinical diagnosis.

  13. HB Hillingdon [alpha46(CE4)Phe-->Val (alpha1 Or alpha2)]: a new alpha chain hemoglobin variant.

    Science.gov (United States)

    Babb, Anna; Solaiman, Susannah; Green, Brian N; Mantio, Debbie; Patel, Ketan

    2009-01-01

    Routine antenatal hemoglobinopathy screening detected a new alpha chain variant that eluted with Hb A(2) on cation exchange high performance liquid chromatography (HPLC) in a lady of Sri Lankan origin who had normal hematological indices. The mutation was identified by electrospray ionization mass spectrometry (ESI-MS) as alpha46(CE4)Phe-->Val, inferring that the variant was due to a single base change at codon 46 (TTC>GTC) of the alpha1- or alpha2-globin genes.

  14. Real-time high dynamic range laser scanning microscopy

    Science.gov (United States)

    Vinegoni, C.; Leon Swisher, C.; Fumene Feruglio, P.; Giedt, R. J.; Rousso, D. L.; Stapleton, S.; Weissleder, R.

    2016-04-01

    In conventional confocal/multiphoton fluorescence microscopy, images are typically acquired under ideal settings and after extensive optimization of parameters for a given structure or feature, often resulting in information loss from other image attributes. To overcome the problem of selective data display, we developed a new method that extends the imaging dynamic range in optical microscopy and improves the signal-to-noise ratio. Here we demonstrate how real-time and sequential high dynamic range microscopy facilitates automated three-dimensional neural segmentation. We address reconstruction and segmentation performance on samples with different size, anatomy and complexity. Finally, in vivo real-time high dynamic range imaging is also demonstrated, making the technique particularly relevant for longitudinal imaging in the presence of physiological motion and/or for quantification of in vivo fast tracer kinetics during functional imaging.

  15. Real-time high dynamic range laser scanning microscopy.

    Science.gov (United States)

    Vinegoni, C; Leon Swisher, C; Fumene Feruglio, P; Giedt, R J; Rousso, D L; Stapleton, S; Weissleder, R

    2016-04-01

    In conventional confocal/multiphoton fluorescence microscopy, images are typically acquired under ideal settings and after extensive optimization of parameters for a given structure or feature, often resulting in information loss from other image attributes. To overcome the problem of selective data display, we developed a new method that extends the imaging dynamic range in optical microscopy and improves the signal-to-noise ratio. Here we demonstrate how real-time and sequential high dynamic range microscopy facilitates automated three-dimensional neural segmentation. We address reconstruction and segmentation performance on samples with different size, anatomy and complexity. Finally, in vivo real-time high dynamic range imaging is also demonstrated, making the technique particularly relevant for longitudinal imaging in the presence of physiological motion and/or for quantification of in vivo fast tracer kinetics during functional imaging.

  16. Geophysical analysis of the Alpha-Mendeleev ridge complex: Characterization of the High Arctic Large Igneous Province

    Science.gov (United States)

    Oakey, G. N.; Saltus, R. W.

    2016-11-01

    The Alpha-Mendeleev ridge complex is a first-order physiographic and geological feature of the Arctic Amerasia Basin. High amplitude "chaotic" magnetic anomalies (the High Arctic Magnetic High Domain or HAMH) are associated with the complex and extend beyond the bathymetric high beneath the sediment cover of the adjacent Canada and Makarov-Podvodnikov basins. Residual marine Bouguer gravity anomalies over the ridge complex have low amplitudes implying that the structure has minimal lateral density variability. A closed pseudogravity (magnetic potential) contour around the ridge complex quantifies the aerial extent of the HAMH at 1.3 × 106 km2. We present 2D gravity/magnetic models for transects across the Alpha Ridge portion of the complex constrained with recently acquired seismic reflection and refraction data. The crustal structure is modeled with a simple three-layer geometry. Large induced and remanent magnetization components were required to fit the observed magnetic anomalies. Density values for the models were based on available seismic refraction P-wave velocities. The 3000 kg/m3 lower crustal layer is interpreted as a composite of the original crustal protolith and deep (ultramafic) plutonic intrusions related to a plume sourced (High Arctic) LIP. The 2900 kg/m3 mid-crustal and 2600 kg/m3 upper-crustal layers are interpreted as the combined effect of sills, dikes, and flows. Volumetric estimates of the volcanic composition include (at least) 6 × 106 km3 for the mid- and upper-crust and between 13 × 106 and 17 × 106 km3 within the lower crust - for a total of 20 × 106 km3. We compare the magnetic structure, pseudogravity, and volumetric estimates for the HAMH portion of the HALIP with global large igneous province analogs and discuss implications for Arctic tectonics. Our results show that the closest analog to the HAMH/HALIP is the Kerguelen Plateau, which is considered a continental plateau intensively modified by plume-related volcanism.

  17. Computational model of thalamo-cortical networks: dynamical control of alpha rhythms in relation to focal attention.

    Science.gov (United States)

    Suffczynski, P; Kalitzin, S; Pfurtscheller, G; Lopes da Silva, F H

    2001-12-01

    EEG/MEG rhythmic activities such as alpha rhythms, of the visual or of the somato-sensory cortex, are commonly modulated as subjects perform certain tasks or react to specific stimuli. In general, these activities change depending on extrinsic or intrinsic events. A decrease of the amplitude of alpha rhythmic activity occurring after a given event, which manifests as a decrease of a spectral peak, is called event-related desynchronization (ERD), whereas the inverse is called event-related synchronization (ERS), since it is assumed that the power of a spectral peak is related to the degree of synchrony of the underlying oscillating neuronal populations. An intriguing observation in this respect [Pfurtscheller and Neuper, Neurosci. Lett. 174 (1994) 93-96] was that ERD of alpha rhythms recorded over the central areas was accompanied by ERS, within the same frequency band, recorded over neighboring areas. In case the event was a hand movement, ERD was recorded over the scalp overlying the hand cortical area, whereas ERS was concomitantly recorded over the midline, whereas if the movement was of the foot the opposite was found. We called this phenomenon 'focal ERD/surround ERS'. The question of how this phenomenon may be generated was approached by means of a computational model of thalamo-cortical networks, that incorporates basic properties of neurons and synaptic interactions. These simulation studies revealed that this antagonistic ERD/ERS phenomenon depends on the functional interaction between the populations of thalamo-cortical cells (TCR) and reticular nucleus cells (RE) and on how this interaction is modulated by cholinergic inputs. An essential feature of this interaction is the existence of cross-talk between different sectors of RE that correspond to distinct sensory modules (e.g. hand, foot). These observations led us to formulate the hypothesis that this basic neurophysiological mechanism can account for the general observation that enhanced attention

  18. High Resolution Spectropolarimetry of the H-alpha Line: Obscured Stars and Absorptive Polarization

    CERN Document Server

    Harrington, D M

    2008-01-01

    The near-star environment around obscured stars is very dynamic. Many classes of stars show evidence for winds, disks, inflows and outflows with many phenomena occurring simultaneously. These processes are involved in stellar evolution, star and planet formation, and influence the formation and habitability of planets around host stars. Even for the nearest stars, this region will not be imaged even after the completion of the next generation of telescopes. Other methods for measuring the physical properties of circumstellar material must be developed. The polarization of light across spectral lines is a signature that contains information about the circumstellar material on these small spatial scales. We used the HiVIS (R=13000 to 50000) and ESPaDOnS (R=68000) spectropolarimeters to monitor several classes of stars on over a hundred nights of observing from 2004-2008. In 10/30 classical Be stars, the traditional broad depolarization morphology is reproduced, but with some additional absorptive effects in 4 o...

  19. Dynamic evolution of the alpha (α) and beta (β) keratins has accompanied integument diversification and the adaptation of birds into novel lifestyles

    DEFF Research Database (Denmark)

    Greenwold, Matthew J.; Bao, Weier; Jarvis, Erich D.

    2014-01-01

    BACKGROUND: Vertebrate skin appendages are constructed of keratins produced by multigene families. Alpha (α) keratins are found in all vertebrates, while beta (β) keratins are found exclusively in reptiles and birds. We have studied the molecular evolution of these gene families in the genomes...... of 48 phylogenetically diverse birds and their expression in the scales and feathers of the chicken. RESULTS: We found that the total number of α-keratins is lower in birds than mammals and non-avian reptiles, yet two α-keratin genes (KRT42 and KRT75) have expanded in birds. The β-keratins, however......, demonstrate a dynamic evolution associated with avian lifestyle. The avian specific feather β-keratins comprise a large majority of the total number of β-keratins, but independently derived lineages of aquatic and predatory birds have smaller proportions of feather β-keratin genes and larger proportions...

  20. Study of the inclusion of the (R)- and (S)-camphor enantiomers in alpha-cyclodextrin by X-ray crystallography and molecular dynamics.

    Science.gov (United States)

    Kokkinou, Areti; Tsorteki, Frantzeska; Karpusas, Michael; Papakyriakou, Athanasios; Bethanis, Kostas; Mentzafos, Dimitris

    2010-05-27

    The inclusion of (R)- and (S)-camphor compounds in alpha-cyclodextrin has been studied by X-ray crystallography. The crystal structures of the complexes reveal that one guest molecule is accommodated inside the cavity formed by a head-to-head cyclodextrin dimer. In the crystal lattice, the dimers form layers which are successively shifted by half a dimer. In both (R)- and (S)-cases, the camphor molecule exhibits disorder and occupies three major sites with orientations that can be described as either 'polar' or 'equatorial'. Molecular dynamics simulations performed for the observed complexes indicate that although the carbonyl oxygen of both (R)- and (S)-camphor switches between different hydrogen bonding partners, it maintains the observed mode of 'polar' or 'equatorial' alignment.

  1. Parallel Beam Dynamics Code Development for High Intensity Cyclotron

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>1 Parallel PIC algorithm Self field solver is the key part of a high intensity beam dynamic PIC code which usually adopts the P-M (Particle-Mesh) method to solve the space charge. The P-M method is composed of four major

  2. Veiling Glare and Perceived Black in High Dynamic Range Displays

    NARCIS (Netherlands)

    Murdoch, M.J.; Heynderickx, I.E.J.

    2012-01-01

    A perceptual experiment was conducted to measure the visibility of black-level differences in the proximity of a bright glare source. In a controlled viewing environment, visual difference thresholds were adaptively measured using dark, shadow-detail images shown on a high dynamic range liquid crys

  3. Regulation of hepatic branched-chain alpha-keto acid dehydrogenase complex in rats fed a high-fat diet

    Science.gov (United States)

    Objective: Branched-chain alpha-keto acid dehydrogenase complex (BCKDC) regulates branched-chain amino acid (BCAA) metabolism at the level of branched chain alpha-ketoacid (BCKA) catabolism. It has been demonstrated that the activity of hepatic BCKDC is markedly decreased in type 2 diabetic animal...

  4. High dynamic range (HDR) virtual bronchoscopy rendering for video tracking

    Science.gov (United States)

    Popa, Teo; Choi, Jae

    2007-03-01

    In this paper, we present the design and implementation of a new rendering method based on high dynamic range (HDR) lighting and exposure control. This rendering method is applied to create video images for a 3D virtual bronchoscopy system. One of the main optical parameters of a bronchoscope's camera is the sensor exposure. The exposure adjustment is needed since the dynamic range of most digital video cameras is narrower than the high dynamic range of real scenes. The dynamic range of a camera is defined as the ratio of the brightest point of an image to the darkest point of the same image where details are present. In a video camera exposure is controlled by shutter speed and the lens aperture. To create the virtual bronchoscopic images, we first rendered a raw image in absolute units (luminance); then, we simulated exposure by mapping the computed values to the values appropriate for video-acquired images using a tone mapping operator. We generated several images with HDR and others with low dynamic range (LDR), and then compared their quality by applying them to a 2D/3D video-based tracking system. We conclude that images with HDR are closer to real bronchoscopy images than those with LDR, and thus, that HDR lighting can improve the accuracy of image-based tracking.

  5. High temperature gas dynamics an introduction for physicists and engineers

    CERN Document Server

    Bose, Tarit K

    2014-01-01

    High Temperature Gas Dynamics is a primer for scientists, engineers, and students who would like to have a basic understanding of the physics and the behavior of high-temperature gases. It is a valuable tool for astrophysicists as well. The first chapters treat the basic principles of quantum and statistical mechanics and how to derive thermophysical properties from them. Special topics are included that are rarely found in other textbooks, such as the thermophysical and transport properties of multi-temperature gases and a novel method to compute radiative transfer. Furthermore, collision processes between different particles are discussed. Separate chapters deal with the production of high-temperature gases and with electrical emission in plasmas, as well as related diagnostic techniques.This new edition adds over 100 pages and includes the following updates: several sections on radiative properties of high temperature gases and various radiation models, a section on shocks in magneto-gas-dynamics, a sectio...

  6. Sc and neutron-capture abundances in Galactic low- and high-alpha field halo stars

    DEFF Research Database (Denmark)

    Fishlock, Cherie K.; Yong, D.; Karakas, Amanda I.

    2017-01-01

    We determine relative abundance ratios for the neutron-capture elements Zr, La, Ce, Nd and Eu for a sample of 27 Galactic dwarf stars with -1.5 <[Fe/H] <-0.8. We also measure the iron-peak element Sc. These stars separate into three populations (low-and high-a halo and thick-disc stars) based on ...

  7. Treatment with interferon-alpha delays disease in swine infected with a highly virulent CSFV strain

    Science.gov (United States)

    Classical swine fever (CSF) is an economically significant, highly contagious swine disease. The etiological agent, CSF virus (CSFV), is an enveloped virus with a positive-sense, single-stranded RNA genome, classified as a member of the genus Pestivirus within the family Flaviviridae (Becher et al.,...

  8. High-ion absorption in the proximate damped Lyman-alpha system toward Q0841+129

    CERN Document Server

    Fox, Andrew J; Petitjean, Patrick; Srianand, Raghunathan; Guimarães, Rodney

    2011-01-01

    We present VLT/UVES spectroscopy of the quasar Q0841+129, whose spectrum shows a proximate damped Lyman-alpha (PDLA) absorber at z=2.47621 and a proximate sub-DLA at z=2.50620, both lying close in redshift to the QSO itself at z_em=2.49510+/-0.00003. This fortuitous arrangement, with the sub-DLA acting as a filter that hardens the QSO's ionizing radiation field, allows us to model the ionization level in the foreground PDLA, and provides an interesting case-study on the origin of the high-ion absorption lines Si IV, C IV, and O VI in DLAs. The high ions in the PDLA show at least five components spanning a total velocity extent of ~160 km/s, whereas the low ions exist predominantly in a single component spanning just 30 km/s. We examine various models for the origin of the high ions. Both photoionization and turbulent mixing layer models are fairly successful at reproducing the observed ionic ratios after correcting for the non-solar relative abundance pattern, though neither model can explain all five compone...

  9. Elongated fibrillar structure of a streptococcal adhesin assembled by the high-affinity association of [alpha]- and PPII-helices

    Energy Technology Data Exchange (ETDEWEB)

    Larson, Matthew R.; Rajashankar, Kanagalaghatta R.; Patel, Manisha H.; Robinette, Rebekah A.; Crowley, Paula J.; Michalek, Suzanne; Brady, L. Jeannine; Deivanayagam, Champion (Cornell); (UAB); (Florida)

    2010-08-18

    Streptococcus mutans antigen I/II (AgI/II) is a cell surface-localized protein adhesin that interacts with salivary components within the salivary pellicle. AgI/II contributes to virulence and has been studied as an immunological and structural target, but a fundamental understanding of its underlying architecture has been lacking. Here we report a high-resolution (1.8 {angstrom}) crystal structure of the A{sub 3}VP{sub 1} fragment of S. mutans AgI/II that demonstrates a unique fibrillar form (155 {angstrom}) through the interaction of two noncontiguous regions in the primary sequence. The A{sub 3} repeat of the alanine-rich domain adopts an extended {alpha}-helix that intertwines with the P{sub 1} repeat polyproline type II (PPII) helix to form a highly extended stalk-like structure heretofore unseen in prokaryotic or eukaryotic protein structures. Velocity sedimentation studies indicate that full-length AgI/II that contains three A/P repeats extends over 50 nanometers in length. Isothermal titration calorimetry revealed that the high-affinity association between the A{sub 3} and P{sub 1} helices is enthalpically driven. Two distinct binding sites on AgI/II to the host receptor salivary agglutinin (SAG) were identified by surface plasmon resonance (SPR). The current crystal structure reveals that AgI/II family proteins are extended fibrillar structures with the number of alanine- and proline-rich repeats determining their length.

  10. Highly excited and exotic meson spectrum from dynamical lattice QCD

    Energy Technology Data Exchange (ETDEWEB)

    Jozef Dudek, Robert Edwards, David Richards, Christopher Thomas

    2009-12-01

    Using a new quark-field construction algorithm and a large variational basis of operators, we extract a highly excited isovector meson spectrum on dynamical anisotropic lattices. We show how carefully constructed operators can be used to identify the continuum spin of extracted states. This method allows us to extract, with confidence, excited states, states of high spin and states with exotic quantum numbers, including, for the first time, spin-four states.

  11. Cellular adaptive response of distal renal tubular cells to high-oxalate environment highlights surface alpha-enolase as the enhancer of calcium oxalate monohydrate crystal adhesion.

    Science.gov (United States)

    Kanlaya, Rattiyaporn; Fong-Ngern, Kedsarin; Thongboonkerd, Visith

    2013-03-27

    Hyperoxaluria is one of etiologic factors of calcium oxalate kidney stone disease. However, response of renal tubular cells to high-oxalate environment remained largely unknown. We applied a gel-based proteomics approach to characterize changes in cellular proteome of MDCK cells induced by 10mM sodium oxalate. A total of 14 proteins were detected as differentially expressed proteins. The oxalate-induced up-regulation of alpha-enolase in whole cell lysate was confirmed by 2-D Western blot analysis. Interaction network analysis revealed that cellular adaptive response under high-oxalate condition involved stress response, energy production, metabolism and transcriptional regulation. Down-regulation of RhoA, which was predicted to be associated with the identified proteins, was confirmed by immunoblotting. In addition, the up-regulation of alpha-enolase on apical surface of renal tubular epithelial cells was also confirmed by immunoblotting of the isolated apical membranes and immunofluorescence study. Interestingly, blockage of alpha-enolase expressed on the cell surface by antibody neutralization significantly reduced the number of calcium oxalate monohydrate (COM) crystals adhered on the cells. These results strongly suggest that surface alpha-enolase plays an important role as the enhancer of COM crystal binding. The increase of alpha-enolase expressed on the cell surface may aggravate kidney stone formation in patients with hyperoxaluria. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. Context-aware Authorization in Highly Dynamic Environments

    CERN Document Server

    Tigli, Jean-Yves; Rey, Gaetan; Hourdin, Vincent; Riveill, Michel

    2011-01-01

    Highly dynamic computing environments, like ubiquitous and pervasive computing environments, require frequent adaptation of applications. Context is a key to adapt suiting user needs. On the other hand, standard access control trusts users once they have authenticated, despite the fact that they may reach unauthorized contexts. We analyse how taking into account dynamic information like context in the authorization subsystem can improve security, and how this new access control applies to interaction patterns, like messaging or eventing. We experiment and validate our approach using context as an authorization factor for eventing in Web service for device (like UPnP or DPWS), in smart home security.

  13. Context-aware Authorization in Highly Dynamic Environments

    Directory of Open Access Journals (Sweden)

    Vincent Hourdin

    2009-09-01

    Full Text Available Highly dynamic computing environments, like ubiquitous and pervasive computing environments, require frequent adaptation of applications. Context is a key to adapt suiting user needs. On the other hand, standard access control trusts users once they have authenticated, despite the fact that they may reach unauthorized contexts. We analyse how taking into account dynamic information like context in the authorization subsystem can improve security, and how this new access control applies to interaction patterns, like messaging or eventing. We experiment and validate our approach using context as an authorization factor for eventing in Web service for device (like UPnP or DPWS, in smart home security.

  14. Characterizing the dynamics of alpha-synuclein oligomers using hydrogen/deuterium exchange monitored by mass spectrometry

    DEFF Research Database (Denmark)

    Mysling, Simon; Betzer, Cristine; Jensen, Poul H;

    2013-01-01

    hydrogen/deuterium exchange monitored by mass spectrometry (HDX-MS), we have analyzed the structural dynamics of soluble αSN oligomers. The analyzed oligomers were metastable, slowly dissociating to monomers over a period of 21 days, after excess monomer had been removed. The C-terminal region of α......-shielded structure. The protected regions were interspersed by two somewhat more dynamic regions (residues 18-38 and 55-70). In the oligomeric state, the isotopic exchange pattern of the region of residues 35-95 of αSN corresponded well with previous nuclear magnetic resonance and electron paramagnetic resonance...

  15. High resolution, large dynamic range field map estimation

    Science.gov (United States)

    Dagher, Joseph; Reese, Timothy; Bilgin, Ali

    2013-01-01

    Purpose We present a theory and a corresponding method to compute high resolution field maps over a large dynamic range. Theory and Methods We derive a closed-form expression for the error in the field map value when computed from two echoes. We formulate an optimization problem to choose three echo times which result in a pair of maximally distinct error distributions. We use standard field mapping sequences at the prescribed echo times. We then design a corresponding estimation algorithm which takes advantage of the optimized echo times to disambiguate the field offset value. Results We validate our method using high resolution images of a phantom at 7T. The resulting field maps demonstrate robust mapping over both a large dynamic range, and in low SNR regions. We also present high resolution offset maps in vivo using both, GRE and MEGE sequences. Even though the proposed echo time spacings are larger than the well known phase aliasing cutoff, the resulting field maps exhibit a large dynamic range without the use of phase unwrapping or spatial regularization techniques. Conclusion We demonstrate a novel 3-echo field map estimation method which overcomes the traditional noise-dynamic range trade-off. PMID:23401245

  16. Were progenitors of local L* galaxies Lyman-alpha emitters at high redshift?

    CERN Document Server

    Yajima, Hidenobu; Zhu, Qirong; Abel, Tom; Gronwall, Caryl; Ciardullo, Robin

    2011-01-01

    The Lya emission has been observed from galaxies over a redshift span z ~ 0 - 8.6. However, the link between high-redshift Lya emitters (LAEs) and local galaxies is largely unknown. Here, we investigate the Lya properties of progenitors of a local L^{*} galaxy by combining cosmological hydrodynamic simulations with three-dimensional radiative transfer calculations using the new ART^2 code. We find that the modeled galaxies are Lya bright in redshift z= 0 - 10. In particular, the Lya luminosities of some massive progenitors at z ~ 2 - 6 are close to the observed characteristic L_{Lya}^{*} of LAEs in that redshift range. Both Lya photon escape fraction and line equivalent width increase with redshift. The Lya escape fraction correlates with a number of physical properties of the galaxy, such as mass, SFR and metallicity. We find a "viewing-angle scatter" in which the photon escape depends strongly on the galaxy morphology and orientation. Moreover, we find that high-redshift LAEs show blue-shifted Lya line prof...

  17. The numerical dynamic for highly nonlinear partial differential equations

    Science.gov (United States)

    Lafon, A.; Yee, H. C.

    1992-01-01

    Problems associated with the numerical computation of highly nonlinear equations in computational fluid dynamics are set forth and analyzed in terms of the potential ranges of spurious behaviors. A reaction-convection equation with a nonlinear source term is employed to evaluate the effects related to spatial and temporal discretizations. The discretization of the source term is described according to several methods, and the various techniques are shown to have a significant effect on the stability of the spurious solutions. Traditional linearized stability analyses cannot provide the level of confidence required for accurate fluid dynamics computations, and the incorporation of nonlinear analysis is proposed. Nonlinear analysis based on nonlinear dynamical systems complements the conventional linear approach and is valuable in the analysis of hypersonic aerodynamics and combustion phenomena.

  18. Development of HEROICs: High-Sensitivity, High-Dynamic Range Detector Systems for Ultraviolet Astronomy Project

    Data.gov (United States)

    National Aeronautics and Space Administration — "We propose a four-year program for the fabrication and characterization of high dynamic range, low background photon counting detectors that will support the next...

  19. High-Latitude Ionospheric Dynamics During Conditions of Northward IMF

    Science.gov (United States)

    Sharber, J. R.

    1996-01-01

    In order to better understand the physical processes operating during conditions of northward interplanetary magnetic field (IMF), in situ measurements from the Dynamics Explorer-2 (low altitude) polar satellite and simultaneous observations from the auroral imager on the Dynamics Explorer-1 (high altitude) satellite were used to investigate the relationships between optical emissions, particle precipitation, and convective flows in the high-latitude ionosphere. Field aligned current and convective flow patterns during IMF north include polar cap arcs, the theta aurora or transpolar arc, and the 'horse-collar' aurora. The initial part of the study concentrated on the electrodynamics of auroral features in the horse-collar aurora, a contracted but thickened emission region in which the dawn and dusk portions can spread to very high latitudes, while the latter part focused on the evolution of one type of IMF north auroral pattern to another, specifically the quiet-time horse-collar pattern to a theta aurora.

  20. Multi-dimensional modulations of alpha and gamma cortical dynamics following mindfulness-based cognitive therapy in Major Depressive Disorder

    NARCIS (Netherlands)

    Schoenberg, P.L.; Speckens, A.E.M.

    2015-01-01

    To illuminate candidate neural working mechanisms of Mindfulness-Based Cognitive Therapy (MBCT) in the treatment of recurrent depressive disorder, parallel to the potential interplays between modulations in electro-cortical dynamics and depressive symptom severity and self-compassionate experience.

  1. Imaging with high Dynamic using an Ionization Chamber

    CERN Document Server

    Menk, Ralf-Hendrik; Arfelli, Fulvia; Bernstorff, Sigrid; Besch, Hans Juergen; Voltolina, Francesco

    2010-01-01

    In this work a combination of an ionization chamber with one-dimensional spatial resolution and a MicroCAT structure will be presented. The combination between gas gain operations and integrating front-end electronics yields a dynamic range as high as eight to nine orders of magnitude. Therefore this device is well suitable for medical imaging or applications such as small angle x-ray scattering, where the requirements on the dynamic of the detector are exceptional high. Basically the described detector is an ionization chamber adapted to fan beam geometry with an active area of 192 cm and a pitch of the anode strips of 150 micrometer. In the vertical direction beams as high as 10 mm can be accepted. Every read-out strip is connected to an analogue integrating electronics channel realized in a custom made VLSI chip. A MicroCAT structure utilized as a shielding grid enables frame rates as high as 10kHz. The high dynamic range observed stems from the fact that the MicroCAT enables active electron amplification ...

  2. The protective effect of alpha lipoic acid on Schwann cells exposed to constant or intermittent high glucose.

    Science.gov (United States)

    Sun, Lian-Qing; Chen, Ying-Ying; Wang, Xuan; Li, Xiao-Jin; Xue, Bing; Qu, Ling; Zhang, Ting-Ting; Mu, Yi-Ming; Lu, Ju-Ming

    2012-10-01

    Diabetic peripheral neuropathy (DPN) is one of the most common and costly microvascular complications of diabetes, and no effective therapy exists. Previous studies have demonstrated that oxidative stress may be the unifying factor for the damaging effect of hyperglycemia. The aim of this study was to examine the impact of treatment with Alpha lipoic acid (ALA) on the intermittent high glucose (IHG) or high glucose (HG)-induced oxidative stress-induced mitochondrial pathway activation and Schwann cells (SCs) apoptosis in vitro. Our results suggested that IHG and HG induced SCs apoptosis in both caspase-dependent and caspase-independent pathways related to oxidative stress. More importantly, the cytotoxic effect of IHG was significantly more potent than that of HG. Treatment with ALA inhibited the IHG and HG-induced oxidative stress and apoptosis in SCs. Furthermore, treatment with ALA down-regulated the Bax expression and the release of cytochrome c and AIF translocation, but up-regulated the Bcl-2 expression in SCs. Treatment with ALA attenuated the activation of caspase-3 and caspase-9 and minimized the cleavage of PARP in SCs. These findings suggest that variability in glycemic control could be more deleterious than a constant HG and ALA antagonized the IHG-induced oxidative stress, activation of mitochondrial pathway and apoptosis in SCs.

  3. Probing the Circumgalactic Medium at High-Redshift Using Composite BOSS Spectra of Strong Lyman-alpha Forest Absorbers

    CERN Document Server

    Pieri, Matthew M; Frank, Stephan; Crighton, Neil; Weinberg, David H; Lee, Khee-Gan; Noterdaeme, Pasquier; Bailey, Stephen J; Busca, Nicolas; Ge, Jian; Kirkby, David; Lundgren, Britt; Mathur, Smita; Paris, Isabelle; Palanque-Delabrouille, Nathalie; Petitjean, Patrick; Rich, James; Ross, Nicholas P; Schneider, Donald P; York, Donald G

    2013-01-01

    We present composite spectra constructed from a sample of 242,150 Lyman-alpha (Lya) forest absorbers at redshifts 2.4high-resolution spectra show that our three strongest absorption bins would probe circumgalactic regions (projected separation < 300 proper kpc and |Delta v| < 300km/s) in about 60% of cases for very high signal-to-noise ratio. Within this subset, weakening Lya absorption is associated with decreasing purity of circumgalactic selection once BOSS noise is included. Our weaker two Lya absorption samples are dominated by the intergalactic medium. We present composite spectra of these samples and a...

  4. High-throughput hydrolysis of starch during permeation across {alpha}-amylase-immobilized porous hollow-fiber membranes

    Energy Technology Data Exchange (ETDEWEB)

    Miura, Suguru; Kubota, Noboru; Kawakita, Hidetaka; Saito, Kyoichi E-mail: marukyo@xtal.tf.chiba-u.ac.jp; Sugita, Kazuyuki; Watanabe, Kohei; Sugo, Takanobu

    2002-02-01

    Two kinds of supporting porous membranes, ethanolamine (EA) and phenol (Ph) fibers, for immobilization of {alpha}-amylase were prepared by radiation-induced graft polymerization of an epoxy-group-containing monomer, glycidyl methacrylate, onto a porous hollow-fiber membrane, and subsequent ring-opening with EA and Ph, respectively. An {alpha}-amylase solution was forced to permeate radially outward through the pores of the EA and Ph fibers. {alpha}-Amylase was captured at a density of 0.15 and 6.6 g/L of the membrane by the graft chain containing 2-hydroxyethylamino and phenyl groups, respectively. A permeation pressure of 0.10 MPa provided a space velocity of 780 and 1500 h{sup -1} for the {alpha}-amylase-immobilized EA and Ph fibers, respectively. Quantitative hydrolysis of starch during permeation of a 20 g/L starch solution in the buffer across the {alpha}-amylase-immobilized Ph fiber was attained up to a space velocity of about 2000 h{sup -1}; this was achieved because of negligible diffusional mass-transfer resistance of the starch to the {alpha}-amylase due to convective flow/ whereas an enzyme reaction-controlled system was observed for the {alpha}-amylase-immobilized EA fiber.

  5. High resolution photoelectron spectroscopy and femtosecond intramolecular dynamics using supersonic molecular beams

    Energy Technology Data Exchange (ETDEWEB)

    Niu, B.

    1992-09-01

    High resolution He I[alpha] photoelectron spectroscopy of formaldehyde and ketene and their deuterated compounds, are reported. The combination of a (H2CO) double-pass high-resolution electron-energy analyzer and effective rotational cooling of the sample by supersonic expansion enable the spectroscopy of these molecular cations. The vibrational autocorrelation functions are calculated from the high-resolution photoelectron spectra, shedding light on the ultrafast intramolecular dynamics of the molecular cations. This study reveals much more vibrational structural detail in the first electronic excited state of H2CO cations. The first electronic excited state of H2CO cations may have nonplanar equilibrium geometry. Strong isotope effects on vibronic (vibrational) coupling are observed in the second electronic excited state of H2CO. Vibrational autocorrelation functions are calculated for all four observed electronic states of H2CO. The correlation function of the first electronic excited state of H2CO shows a slow decay rate on the femtosecond time scale. The ultrafast decay of the H2CO cations in the third electronic excited state implies that dissociation and intramolecular processes are the main decay pathways. The present spectra of the ground states of ketene cations have more fine structure than before. The AIEs of the first and fifth excited states are determined unambiguously more accurately. The doublet-like fine structures present in the lint excited state of ketene implies the excitation of a soft'' mode not observed before. The vibrational autocorrelation functions are calculated for 4 of the 6 observed electronic states. The dynamics of the ground states of the cations are characterized by a wave packet oscillating with small amplitude around the minimum on the upper PES. The decay dynamics of the first and the fifth excited states of ketene are characterized by ultra-fast intramolecular processes like predissociation.

  6. High resolution photoelectron spectroscopy and femtosecond intramolecular dynamics using supersonic molecular beams

    Energy Technology Data Exchange (ETDEWEB)

    Niu, B.

    1992-09-01

    High resolution He I{alpha} photoelectron spectroscopy of formaldehyde and ketene and their deuterated compounds, are reported. The combination of a (H2CO) double-pass high-resolution electron-energy analyzer and effective rotational cooling of the sample by supersonic expansion enable the spectroscopy of these molecular cations. The vibrational autocorrelation functions are calculated from the high-resolution photoelectron spectra, shedding light on the ultrafast intramolecular dynamics of the molecular cations. This study reveals much more vibrational structural detail in the first electronic excited state of H2CO cations. The first electronic excited state of H2CO cations may have nonplanar equilibrium geometry. Strong isotope effects on vibronic (vibrational) coupling are observed in the second electronic excited state of H2CO. Vibrational autocorrelation functions are calculated for all four observed electronic states of H2CO. The correlation function of the first electronic excited state of H2CO shows a slow decay rate on the femtosecond time scale. The ultrafast decay of the H2CO cations in the third electronic excited state implies that dissociation and intramolecular processes are the main decay pathways. The present spectra of the ground states of ketene cations have more fine structure than before. The AIEs of the first and fifth excited states are determined unambiguously more accurately. The doublet-like fine structures present in the lint excited state of ketene implies the excitation of a ``soft`` mode not observed before. The vibrational autocorrelation functions are calculated for 4 of the 6 observed electronic states. The dynamics of the ground states of the cations are characterized by a wave packet oscillating with small amplitude around the minimum on the upper PES. The decay dynamics of the first and the fifth excited states of ketene are characterized by ultra-fast intramolecular processes like predissociation.

  7. K(alpha) x-ray emission characterization of 100 Hz, 15 mJ femtosecond laser system with high contrast ratio.

    Science.gov (United States)

    Fourmaux, S; Serbanescu, C; Kincaid, R E; Krol, A; Kieffer, J C

    2008-12-12

    We report K(alpha) x-ray production with a high energy (110 mJ per pulse at 800 nm before compression/15 mJ at 400 nm after compression), high repetition rate (100 Hz), and high pulse contrast (better than 10(-9) at 400 nm) laser system. To develop laser-based x-ray sources for biomedical imaging requires to use high-energy and high-power ultra-fast laser system where compression is achieved under vacuum. Using this type of laser system, we demonstrate long-term stability of the x-ray yield, conversion efficiency higher than 1.5 x 10(-5) with a Mo target, and the x-ray spot size close to the optical focal spot. This high-repetition K(alpha) x-ray source can be very useful for x-ray phase-contrast imaging.

  8. Alpha fetoprotein

    Science.gov (United States)

    Fetal alpha globulin; AFP ... Greater than normal levels of AFP may be due to: Cancer in testes , ovaries, biliary (liver secretion) tract, stomach, or pancreas Cirrhosis of the liver Liver cancer ...

  9. Alpha-tocopherol inhibits pore formation in the oxidized bilayers

    CERN Document Server

    Boonnoy, Phansiri; Wong-ekkabut, Jirasak

    2016-01-01

    In biological membranes, alpha-tocopherols ({\\alpha}-toc; vitamin E) protect polyunsaturated lipids from free radicals. Although the interactions of {\\alpha}-toc with non-oxidized lipid bilayers have been studied, their on oxidized bilayers remain unknown. In this study, atomistic molecular dynamics (MD) simulations of oxidized lipid bilayers were performed with varying concentrations of {\\alpha}-toc. Bilayers with 1-palmitoyl-2-lauroyl-sn-glycero-3-phosphocholine (PLPC) lipids and its aldehyde derivatives at 1:1 ratio were studied. Our simulations show that oxidized lipids self-assemble into aggregates with a water pore rapidly developing across the lipid bilayer. The free energy of transporting an {\\alpha}-toc molecule in a lipid bilayer suggests that {\\alpha}-tocs can passively adsorb into the bilayer. When {\\alpha}-toc molecules were present at low concentrations in bilayers containing oxidized lipids, the formation of water pores was slowed down. At high {\\alpha}-toc concentra-tions, no pores were observ...

  10. RADIANCE DOMAIN COMPOSITING FOR HIGH DYNAMIC RANGE IMAGING

    Directory of Open Access Journals (Sweden)

    M.R. Renu

    2013-02-01

    Full Text Available High dynamic range imaging aims at creating an image with a range of intensity variations larger than the range supported by a camera sensor. Most commonly used methods combine multiple exposure low dynamic range (LDR images, to obtain the high dynamic range (HDR image. Available methods typically neglect the noise term while finding appropriate weighting functions to estimate the camera response function as well as the radiance map. We look at the HDR imaging problem in a denoising frame work and aim at reconstructing a low noise radiance map from noisy low dynamic range images, which is tone mapped to get the LDR equivalent of the HDR image. We propose a maximum aposteriori probability (MAP based reconstruction of the HDR image using Gibb’s prior to model the radiance map, with total variation (TV as the prior to avoid unnecessary smoothing of the radiance field. To make the computation with TV prior efficient, we extend the majorize-minimize method of upper bounding the total variation by a quadratic function to our case which has a nonlinear term arising from the camera response function. A theoretical justification for doing radiance domain denoising as opposed to image domain denoising is also provided.

  11. Pretreatment with high-fat enteral nutrition reduces ondotoxin and tumor necrosis factor-alpha and preserves gut barrier function early after hemorrhagic shock

    NARCIS (Netherlands)

    Luyer, M.D.; Buurman, W.A.; Hadfoune, M.; Jacobs, J.A.; Konstantinov, S.R.; Dejong, C.H.; Greve, J.W.

    2004-01-01

    Gram-negative sepsis is a potentially fatal clinical syndrome characterized by a proinflammatory response (tumor necrosis factor-alpha) to bacterial (endo)toxins and gut barrier function loss. Recently, we found that high-fat enteral nutrition protects against late bacterial translocation in a model

  12. High-performance towards removal of toxic hexavalent chromium from aqueous solution using graphene oxide-alpha cyclodextrin-polypyrrole nanocomposites

    CSIR Research Space (South Africa)

    Chauke, VP

    2015-07-01

    Full Text Available Graphene oxide (GO) was functionalized with alpha cyclodextrin (aCD) through a covalent bond to form GO-aCD nanocomposites (NC). GO-aCD NC was further modified with polypyrrole (PPY) to afford an advanced GO-aCD-PPY NC for the removal of highly...

  13. Pretreatment with high-fat enteral nutrition reduces ondotoxin and tumor necrosis factor-alpha and preserves gut barrier function early after hemorrhagic shock

    NARCIS (Netherlands)

    Luyer, M.D.; Buurman, W.A.; Hadfoune, M.; Jacobs, J.A.; Konstantinov, S.R.; Dejong, C.H.; Greve, J.W.

    2004-01-01

    Gram-negative sepsis is a potentially fatal clinical syndrome characterized by a proinflammatory response (tumor necrosis factor-alpha) to bacterial (endo)toxins and gut barrier function loss. Recently, we found that high-fat enteral nutrition protects against late bacterial translocation in a model

  14. Unique Physically Anchored Cryptographic Theoretical Calculation of the Fine-Structure Constant {\\alpha} Matching both the g/2 and Interferometric High-Precision Measurements

    CERN Document Server

    Rhodes, Charles Kirkham

    2010-01-01

    The fine-structure constant {\\alpha}, the dimensionless number that represents the strength of electromagnetic coupling in the limit of sufficiently low energy interactions, is the crucial fundamental physical parameter that governs a nearly limitless range of phenomena involving the interaction of radiation with materials. Ideally, the apparatus of physical theory should be competent to provide a calculational procedure that yields a quantitatively correct value for {\\alpha} and the physical basis for its computation. This study presents the first demonstration of an observationally anchored theoretical procedure that predicts a unique value for {\\alpha} that stands in full agreement with the best (~370 ppt) high-precision experimental determinations. In a directly connected cryptographic computation, the method that gives these results also yields the magnitude of the cosmological constant {\\Omega}{\\Lambda} in conformance with the observational data and the condition of perfect flatness ({\\Omega}{\\Lambda} +...

  15. F-18 high alpha research vehicle surface pressures - Initial in-flight results and correlation with flow visualization and wind-tunnel data

    Science.gov (United States)

    Fisher, David F.; Banks, Daniel W.; Richwine, David M.

    1990-01-01

    Flight tests with the NASA F-18 high-alpha research vehicle (HARV) have yielded pressure distributions at angles of attack from 10 to 50 deg, at Mach 0.23 to 0.6, at five fuselage forebody stations and three on the leading-edge extensions (LEXs). Correlations are made between these data and both previously obtained HARV flow visualizations and wind tunnel model test results. The general trend is one in which the forebody's maximum suction pressure peaks increase in magnitude, after their first appearance at alpha of about 19 deg, with increasing alpha. LEX pressure-distribution trends involve the inward progression of the maximum suction peaks, an increase in the magnitude of the maximum pressure peaks up to pressure core breakdown, and the decrease and general flattening of the pressure distribution beyond the LEX primary vortex breakdown.

  16. Characterization of nanostructured alpha-Fe2O3-SnO2 solid solutions prepared by high energy ball milling

    DEFF Research Database (Denmark)

    Jiang, Jianzhong; Lin, R.; Mørup, Steen

    1998-01-01

    Solid solutions of SnO2 in alpha-Fe2O3 with SnO2 contents up to 20+-4 mol% have been prepared by mechanical alloying of alpha-Fe2O3 and SnO2 powder blends. X-ray diffraction and Mossbauer spectroscopy investigations show that the mechanical milling results in alloying on an atomic scale...... and that true solid solution formation occurs. We suggest that the high defect concentration and the chemical enthalpy of Fe3+ -O2- -Sn4+ interfaces between nanostructured alpha-Fe2O3 and SnO2 regions may serve as a driving force for the formation of a solid solution in the immiscible ceramic system....

  17. Characterization of nanostructured alpha-Fe2O3-SnO2 solid solutions prepared by high energy ball milling

    DEFF Research Database (Denmark)

    Jiang, Jianzhong; Lin, R.; Mørup, Steen

    1998-01-01

    Solid solutions of SnO2 in alpha-Fe2O3 with SnO2 contents up to 20+-4 mol% have been prepared by mechanical alloying of alpha-Fe2O3 and SnO2 powder blends. X-ray diffraction and Mossbauer spectroscopy investigations show that the mechanical milling results in alloying on an atomic scale...... and that true solid solution formation occurs. We suggest that the high defect concentration and the chemical enthalpy of Fe3+ -O2- -Sn4+ interfaces between nanostructured alpha-Fe2O3 and SnO2 regions may serve as a driving force for the formation of a solid solution in the immiscible ceramic system....

  18. Role of quenching on alpha/beta separation in liquid scintillation counting for several high capacity cocktails

    Energy Technology Data Exchange (ETDEWEB)

    Pujol, L.; Sanchez-Cabeza, J.-A. [Universidad Autonoma de Barcelona (Spain). Facultad de Ciencias

    1997-04-01

    The optimization of alpha/beta separation in liquid scintillation using pulse shape analysis is convenient for the simultaneous determination of alpha and beta emitters in natural water and other samples. In this work, alpha/beta separation was studied for different scintillant/vial combinations and it was observed that both the optimum pulse shape discrimination level and the total interference value (that is, the summed relative interference between alpha and beta spectra) were dependent on the sample quenching and independent of the scintillant/vial combination. These results provide a simple method for modifying the counting configuration, such as a change in the cocktail, vial or sample characteristics, without the need to perform exhaustive parameter optimizations. Also, it was observed that, for our counting conditions, the combination of Ultima Gold AB scintillation cocktail with Zinsser low diffusion vials presented the lowest total interference, namely 0.94 {+-} 0.28%, which is insignificant for the counting of environmental samples. (Author).

  19. Simulation of transition dynamics to high confinement in fusion plasmas

    DEFF Research Database (Denmark)

    Nielsen, Anders Henry; Xu, G. S.; Madsen, Jens;

    2015-01-01

    The transition dynamics from the low (L) to the high (H) confinement mode in magnetically confined plasmas is investigated using a first-principles four-field fluid model. Numerical results are in agreement with measurements from the Experimental Advanced Superconducting Tokamak - EAST. Particula......The transition dynamics from the low (L) to the high (H) confinement mode in magnetically confined plasmas is investigated using a first-principles four-field fluid model. Numerical results are in agreement with measurements from the Experimental Advanced Superconducting Tokamak - EAST....... Particularly, the slow transition with an intermediate dithering phase is well reproduced at proper parameters. The model recovers the power threshold for the L-H transition as well as the decrease in power threshold switching from single to double null configuration observed experimentally. The results...

  20. Runaway electron dynamics in tokamak plasmas with high impurity content

    Science.gov (United States)

    Martín-Solís, J. R.; Loarte, A.; Lehnen, M.

    2015-09-01

    The dynamics of high energy runaway electrons is analyzed for plasmas with high impurity content. It is shown that modified collision terms are required in order to account for the collisions of the relativistic runaway electrons with partially stripped impurity ions, including the effect of the collisions with free and bound electrons, as well as the scattering by the full nuclear and the electron-shielded ion charge. The effect of the impurities on the avalanche runaway growth rate is discussed. The results are applied, for illustration, to the interpretation of the runaway electron behavior during disruptions, where large amounts of impurities are expected, particularly during disruption mitigation by massive gas injection. The consequences for the electron synchrotron radiation losses and the resulting runaway electron dynamics are also analyzed.

  1. In-Vivo High Dynamic Range Vector Flow Imaging

    DEFF Research Database (Denmark)

    Villagómez Hoyos, Carlos Armando; Stuart, Matthias Bo; Jensen, Jørgen Arendt

    2015-01-01

    Current vector flow systems are limited in their detectable range of blood flow velocities. Previous work on phantoms has shown that the velocity range can be extended using synthetic aperture directional beamforming combined with an adaptive multi-lag approach. This paper presents a first invivo...... example with a high dynamic velocity range. Velocities with an order of magnitude apart are detected on the femoral artery of a 41 years old healthy individual. Three distinct heart cycles are captured during a 3 secs acquisition. The estimated vector velocities are compared against each other within...... in-vivo and provide quantitative results in a high dynamic velocity range. Providing velocity measurements during the whole cardiac cycle for both arteries and veins...

  2. High dose androgen therapy in male pseudohermaphroditism due to 5 alpha-reductase deficiency and disorders of the androgen receptor.

    OpenAIRE

    Price, P; Wass, J. A.; Griffin, J E; Leshin, M; Savage, M O; Large, D. M.; Bu'Lock, D E; Anderson, D. C.; Wilson, J. D.; Besser, G M

    1984-01-01

    We describe the clinical and biochemical features of six men with male pseudohermaphroditism due to androgen resistance. Each of the subjects had male-gender behavior but incomplete virilization. The underlying defects in androgen metabolism were defined by studies of the 5 alpha-reductase enzyme and the androgen receptor in fibroblasts cultured from biopsies of genital skin. Four of the six have 5 alpha-reductase deficiency, and two have defects of the androgen receptor (the Reifenstein synd...

  3. Highly effective recognition of carbohydrates by phenanthroline-based receptors: alpha- versus beta-anomer binding preference.

    Science.gov (United States)

    Mazik, Monika; Hartmann, Andrè; Jones, Peter G

    2009-09-14

    (1)H NMR spectroscopic titrations in competitive and non-competitive media, as well as binding studies in two-phase systems, such as phase transfer of sugars from aqueous into organic solvents and dissolution of solid carbohydrates in apolar media revealed both highly effective recognition of neutral carbohydrates and interesting binding preferences of an acyclic phenanthroline-based receptor 1. Compared to the previously described acyclic receptors, compound 1 displays significantly higher binding affinities, the rare capability to extract sugars from water into non-polar organic solutions and alpha- versus beta-anomer binding preference in the recognition of glycosides, which differs from those observed for other receptor systems. X-ray crystallographic investigations revealed the presence of water molecules in the binding pocket of 1 that are engaged in the formation of hydrogen-bonding motifs similar to those suggested by molecular modelling for the sugar OH groups in the receptor-sugar complexes. The molecular modelling calculations, synthesis, crystal structure and binding properties of 1 are described and compared with those of the previously described receptors.

  4. Lyman-alpha forest-CMB cross-correlation and the search for the ionized baryons at high redshift

    CERN Document Server

    Croft, R A C; Hernquist, L; Croft, Rupert A.C.; Hernquist, Lars

    2005-01-01

    The intergalactic neutral hydrogen which is responsible for the Lyman alpha forest of quasar absorption is a tracer of much larger amounts of ionised hydrogen. The ionised component has yet to be detected directly, but is expected to scatter CMB photons via the Sunyaev-Zel'dovich (SZ) effect. We use hydrodynamic simulations of a LambdaCDM universe to create mock quasar spectra and CMB sky maps. We find that the high-z Lya forest gas causes temperature fluctuations of the order of 1 muK rms in the CMB on arcmin scales. The kinetic and thermal SZ effects have a similar magnitude at z=3, with the thermal effect becoming relatively weaker as expected at higher z. The CMB signal associated with lines of sight having HI column densities > 10^18 cm^-2 is only marginally stronger than that for lower column densities. The strong dependence of rms temperature fluctuation on mean Lya absorbed flux, however, suggests that the CMB signal effectively arises in lower density material. We investigate the use of the cross-cor...

  5. Determination of alpha-methyldopa in human plasma by validated high-performance liquid chromatography with fluorescence detection.

    Science.gov (United States)

    Róna, K; Ary, K; Gachályi, B; Klebovich, I

    1996-04-12

    A sensitive reversed-phase gradient elution high-performance liquid chromatographic method with fluorescence detection has been developed for the determination of alpha-methyldopa (AMD) in human plasma. Separation of the investigated compound and the 3,4-dihydroxyphenylalanine (DOPA) internal standard was achieved on a Nucleosil 7 C18 column with a 5 mM heptanesulphonic acid sodium salt containing 0.05 M potassium dihydrogenphosphate (pH 3.2)-acetonitrile mobile phase. The composition of the mobile phase was changed according to a linear gradient time program. Detection was performed at 270 nm fluorimetric excitation and 320 nm emission. The compounds were isolated from plasma by Bond-Elut C18 solid-phase extraction. The limit of quantitation was found to be 10 ng/ml plasma. The assay was validated with respect to accuracy, precision and system suitability. All validated parameters were found to be within the 20% required limits. On the basis of the sensitivity, linearity and validation parameters the developed analytical method was found to be suitable for application in a bioequivalency study.

  6. Escape of about five per cent of Lyman-alpha photons from high-redshift star-forming galaxies.

    Science.gov (United States)

    Hayes, Matthew; Ostlin, Göran; Schaerer, Daniel; Mas-Hesse, J Miguel; Leitherer, Claus; Atek, Hakim; Kunth, Daniel; Verhamme, Anne; de Barros, Stéphane; Melinder, Jens

    2010-03-25

    The Lyman-alpha (Lyalpha) emission line is the primary observational signature of star-forming galaxies at the highest redshifts, and has enabled the compilation of large samples of galaxies with which to study cosmic evolution. The resonant nature of the line, however, means that Lyalpha photons scatter in the neutral interstellar medium of their host galaxies, and their sensitivity to absorption by interstellar dust may therefore be greatly enhanced. This implies that the Lyalpha luminosity may be significantly reduced, or even completely suppressed. Hitherto, no unbiased empirical test of the escaping fraction (f(esc)) of Lyalpha photons has been performed at high redshifts. Here we report that the average f(esc) from star-forming galaxies at redshift z = 2.2 is just 5 per cent by performing a blind narrowband survey in Lyalpha and Halpha. This implies that numerous conclusions based on Lyalpha-selected samples will require upwards revision by an order of magnitude and we provide a benchmark for this revision. We demonstrate that almost 90 per cent of star-forming galaxies emit insufficient Lyalpha to be detected by standard selection criteria. Both samples show an anti-correlation of f(esc) with dust content, and we show that Lyalpha- and Halpha-selection recovers populations that differ substantially in dust content and f(esc).

  7. Dynamic aperture studies for the LHC high luminosity lattice

    Energy Technology Data Exchange (ETDEWEB)

    Maria, R. de [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Giovannozzi, M. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); McIntosh, E. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Nosochkov, Y. M. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Cai, Y. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Wang, M. -H. [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-07-14

    Since quite some time, dynamic aperture studies have been undertaken with the aim of specifying the required field quality of the new magnets that will be installed in the LHC ring in the framework of the high-luminosity upgrade. In this paper the latest results concerning the specification work will be presented, taking into account both injection and collision energies and the field quality contribution from all the magnets in the newly designed interaction regions.

  8. Nike Black Brant V high altitude dynamic instability characteristics

    Science.gov (United States)

    Montag, W. H.; Walker, L. L., Jr.

    1979-01-01

    Flight experience on the Nike Black Brant V has demonstrated the existence of plume induced flow separation over the fins and aft body of the Black Brant V motor. Modelling of the forces associated with this phenomenon as well as analysis of the resultant vehicle coning motion and its effect on the velocity vector heading are presented. A summary of Nike Black Brant V flight experience with high altitude dynamic instability is included.

  9. Nike Black Brant V high altitude dynamic instability characteristics

    Science.gov (United States)

    Montag, W. H.; Walker, L. L., Jr.

    1979-01-01

    Flight experience on the Nike Black Brant V has demonstrated the existence of plume induced flow separation over the fins and aft body of the Black Brant V motor. Modelling of the forces associated with this phenomenon as well as analysis of the resultant vehicle coning motion and its effect on the velocity vector heading are presented. A summary of Nike Black Brant V flight experience with high altitude dynamic instability is included.

  10. High-pressure polymorphic transformation of rutile to alpha-PbO2-type TiO2 at {011}R twin boundaries.

    Science.gov (United States)

    Meng, D W; Wu, X L; Sun, F; Huang, L W; Liu, F; Han, Y J; Zheng, J P; Meng, X; Mason, R

    2008-01-01

    The presence of nano-scale lamellae of the alpha-PbO2-type polymorph of TiO2 sandwiched between twinned rutile inclusions in jadeite has been confirmed by electron diffraction and high-resolution transmission electron microscopy, backed up by image simulation techniques, from ultrahigh-pressure jadeite quartzite at Shuanghe in the Dabie Mountains, China. The crystal structure is orthorhombic with lattice parameters a=4.58 A, b=5.42 A, c=5.02 A and space group Pbcn. A three-dimensional structural model has been constructed for the rutile to alpha-PbO2-type TiO2 phase transformation based on high-resolution electron microscopic images. Computer image simulation and structural model analysis reveal that rutile {011}R twin interface is a basic structural unit of alpha-PbO2-type TiO2. Nucleation of alpha-PbO2-type TiO2 lamellae 1-2 nm thick is caused by the displacement of one half of the titanium cations within the {011}R twin slab. This displacement reduces the Ti-O-Ti distance and is favored by high pressure.

  11. Dynamics in serum of the inflammatory markers serum amyloid A (SAA), haptoglobin, fibrinogen and alpha2-globulins during induced noninfectious arthritis in the horse.

    Science.gov (United States)

    Hultén, C; Grönlund, U; Hirvonen, J; Tulamo, R-M; Suominen, M M; Marhaug, G; Forsberg, M

    2002-11-01

    Despite the importance of noninfectious joint diseases in equine medicine, little is known about the acute phase response which may be elicited if the local inflammatory process of noninfectious arthritis is sufficiently strong, Therefore the aim of this study was to monitor the systemic inflammatory response during experimentally-induced noninfectious arthritis by studying the dynamics in serum of the acute phase proteins serum amyloid A (SAA), haptoglobin, fibrinogen and alpha2-globulins. Twenty-four Standardbred horses, age 3-7 years, found healthy on thorough clinical, radiological, haematological and serum biochemical examination, were injected aseptically into the right midcarpal joint with amphotericin B. Blood samples were drawn before induction of arthritis (0 h), and at 8, 16, 24, 36 and 48 h postinduction and then on Days 3, 4, 5 and 15 postinduction. All horses developed lameness with joint effusion and joint heat as well as increased respiratory rate, heart rate and body temperature. The lameness started to decline after 24-36 h and, in most animals, systemic signs disappeared on Day 2 postinjection. The concentration of the acute phase proteins increased following induction of arthritis. The SAA concentrations were higher than baseline concentrations from 16 h postinduction and were maximal at 36-48 h (227 times baseline concentration). The haptoglobin concentrations were higher than baseline concentrations from 24 h and were maximal at 48-96 h (1.14 times baseline concentration). The maximal concentrations of fibrinogen were seen between 36-72 h postinjection and increased on average 0.87 times from baseline concentrations. The fibrinogen concentrations were higher than baseline concentrations from 24 h postinjection. Alpha2-globulins concentrations showed a minor increase and increased 0.55 times from baseline concentrations. The markers had returned to baseline concentrations by Day 15. Our results demonstrate that amphotericin B-induced arthritis

  12. Structural and dynamic study of the tetramerization region of non-erythroid alpha-spectrin: a frayed helix revealed by site-directed spin labeling electron paramagnetic resonance.

    Science.gov (United States)

    Li, Qufei; Fung, L W-M

    2009-01-13

    The N-terminal region of alpha-spectrin is responsible for its association with beta-spectrin in a heterodimer, forming functional tetramers. Non-erythroid alpha-spectrin (alphaII-spectrin) has a significantly higher association affinity for beta-spectrin than the homologous erythroid alpha-spectrin (alphaI-spectrin). We have previously determined the solution structure of the N-terminal region of alphaI-spectrin by NMR methods, but currently no structural information is available for alphaII-spectrin. We have used cysteine scanning, spin labeling electron paramagnetic resonance (EPR), and isothermal titration calorimetry (ITC) methods to study the tetramerization region of alphaII-spectrin. EPR data clearly show that, in alphaII-spectrin, the first nine N-terminal residues were unstructured, followed by an irregular helix (helix C'), frayed at the N-terminal end, but rigid at the C-terminal end, which merges into the putative triple-helical structural domain. The region corresponding to the important unstructured junction region linking helix C' to the first structural domain in alphaI-spectrin was clearly structured. On the basis of the published model for aligning helices A', B', and C', important interactions among residues in helix C' of alphaI- and alphaII-spectrin and helices A' and B' of betaI- and betaII-spectrin are identified, suggesting similar coiled coil helical bundling for spectrin I and II in forming tetramers. The differences in affinity are likely due to the differences in the conformation of the junction regions. Equilibrium dissociation constants of spin-labeled alphaII and betaI complexes from ITC measurements indicate that residues 15, 19, 37, and 40 are functionally important residues in alphaII-spectrin. Interestingly, all four corresponding homologous residues in alphaI-spectrin (residues 24, 28, 46, and 49) have been reported to be clinically significant residues involved in hematological diseases.

  13. Long-term dynamics of high mass ratio multiples

    Science.gov (United States)

    Li, Gongjie

    This thesis presents a series of studies on the dynamics of high mass ratio multiples, with applications to planetary systems orbiting stars and stellar systems orbiting supermassive black holes (SMBHs). Almost two thousand exoplanetary systems have recently been discovered, and their configurations gave rise to new puzzles to planetary formation theories. We studied the dynamics of planetary systems aiming to understand how the configuration of planetary system is sculptured and to probe the origin of planetary systems. First, we discussed hierarchical three-body dynamics, which can be applied to planets that are orbiting a star while perturbed by a planet or a star that is farther away. The perturbation from the farther object can flip the planetary orbits and produce counter orbiting hot Jupiters, which cannot be formed in the classical planetary formation theory. In addition, we have studied the scatter encounter of planetary systems in clusters, which produce eccentric and inclined planets. Moreover, we investigated the obliquity variation of planets, which can be applied to exoplanetary systems. The obliquity variation is important to the habitability of the exoplanets. The long term dynamics is also important to stellar systems orbiting SMBHs. SMBHs are common in the center of galaxies and lead to rich dynamical interactions with nearby stars. At the same time, dynamical features of the nearby stars reveal important properties of the SMBHs. The aforementioned hierarchical three-body dynamics can be applied to stars near SMBH binaries, which are natural consequences of galaxy mergers. We found that the distribution of stars surrounding one of the SMBHs results in a shape of torus due to the perturbation from the other SMBH, and the dynamical interactions contribute to an enhancement of tidal disruption rates, which can help identify the SMBH binaries. In addition, we investigated the heating of stars near SMBHs, where the heating of stars due to gravitational

  14. Large dynamic range diagnostics for high current electron LINACs

    Energy Technology Data Exchange (ETDEWEB)

    Evtushenko, Pavel [JLAB

    2013-11-01

    The Jefferson Lab FEL driver accelerator - Energy Recovery Linac has provided a beam with average current of up to 9 mA and beam energy of 135 MeV. The high power beam operations have allowed developing and testing methods and approaches required to set up and tune such a facility simultaneously for the high beam power and high beam quality required for high performance FEL operations. In this contribution we briefly review this experience and outline problems that are specific to high current - high power non-equilibrium linac beams. While the original strategy for beam diagnostics and tuning have proven to be quite successful, some shortcomings and unresolved issues were also observed. The most important issues are the non-equilibrium (non-Gaussian) nature of the linac beam and the presence of small intensity - large amplitude fraction of the beam a.k.a. beam halo. Thus we also present a list of the possible beam halo sources and discuss possible mitigations means. We argue that for proper understanding and management of the beam halo large dynamic range (>10{sup 6}) transverse and longitudinal beam diagnostics can be used. We also present results of transverse beam profile measurements with the dynamic range approaching 10{sup 5} and demonstrate the effect the increased dynamic range has on the beam characterization, i.e., emittance and Twiss parameters measurements. We also discuss near future work planned in this field and where the JLab FEL facility will be used for beam tests of the developed of new diagnostics.

  15. Large dynamic range diagnostics for high current electron LINACs

    Energy Technology Data Exchange (ETDEWEB)

    Evtushenko, P., E-mail: Pavel.Evtushenko@jlab.org [Thomas Jefferson National Accelerator Facility 12000 Jefferson Avenue, Newport News, VA 23606 (United States)

    2013-11-07

    The Jefferson Lab FEL driver accelerator - Energy Recovery Linac has provided a beam with average current of up to 9 mA and beam energy of 135 MeV. The high power beam operations have allowed developing and testing methods and approaches required to set up and tune such a facility simultaneously for the high beam power and high beam quality required for high performance FEL operations. In this contribution we briefly review this experience and outline problems that are specific to high current - high power non-equilibrium linac beams. While the original strategy for beam diagnostics and tuning have proven to be quite successful, some shortcomings and unresolved issues were also observed. The most important issues are the non-equilibrium (non-Gaussian) nature of the linac beam and the presence of small intensity - large amplitude fraction of the beam a.k.a. beam halo. Thus we also present a list of the possible beam halo sources and discuss possible mitigations means. We argue that for proper understanding and management of the beam halo large dynamic range (>10{sup 6}) transverse and longitudinal beam diagnostics can be used. We also present results of transverse beam profile measurements with the dynamic range approaching 10{sup 5} and demonstrate the effect the increased dynamic range has on the beam characterization, i.e., emittance and Twiss parameters measurements. We also discuss near future work planned in this field and where the JLab FEL facility will be used for beam tests of the developed of new diagnostics.

  16. High Dynamic Range Processing for Magnetic Resonance Imaging

    Science.gov (United States)

    Sukerkar, Preeti A.; Meade, Thomas J.

    2013-01-01

    Purpose To minimize feature loss in T1- and T2-weighted MRI by merging multiple MR images acquired at different TR and TE to generate an image with increased dynamic range. Materials and Methods High Dynamic Range (HDR) processing techniques from the field of photography were applied to a series of acquired MR images. Specifically, a method to parameterize the algorithm for MRI data was developed and tested. T1- and T2-weighted images of a number of contrast agent phantoms and a live mouse were acquired with varying TR and TE parameters. The images were computationally merged to produce HDR-MR images. All acquisitions were performed on a 7.05 T Bruker PharmaScan with a multi-echo spin echo pulse sequence. Results HDR-MRI delineated bright and dark features that were either saturated or indistinguishable from background in standard T1- and T2-weighted MRI. The increased dynamic range preserved intensity gradation over a larger range of T1 and T2 in phantoms and revealed more anatomical features in vivo. Conclusions We have developed and tested a method to apply HDR processing to MR images. The increased dynamic range of HDR-MR images as compared to standard T1- and T2-weighted images minimizes feature loss caused by magnetization recovery or low SNR. PMID:24250788

  17. High dynamic range processing for magnetic resonance imaging.

    Directory of Open Access Journals (Sweden)

    Andy H Hung

    Full Text Available To minimize feature loss in T1- and T2-weighted MRI by merging multiple MR images acquired at different TR and TE to generate an image with increased dynamic range.High Dynamic Range (HDR processing techniques from the field of photography were applied to a series of acquired MR images. Specifically, a method to parameterize the algorithm for MRI data was developed and tested. T1- and T2-weighted images of a number of contrast agent phantoms and a live mouse were acquired with varying TR and TE parameters. The images were computationally merged to produce HDR-MR images. All acquisitions were performed on a 7.05 T Bruker PharmaScan with a multi-echo spin echo pulse sequence.HDR-MRI delineated bright and dark features that were either saturated or indistinguishable from background in standard T1- and T2-weighted MRI. The increased dynamic range preserved intensity gradation over a larger range of T1 and T2 in phantoms and revealed more anatomical features in vivo.We have developed and tested a method to apply HDR processing to MR images. The increased dynamic range of HDR-MR images as compared to standard T1- and T2-weighted images minimizes feature loss caused by magnetization recovery or low SNR.

  18. Hemoglobin A2 values in sickle cell disease patients quantified by high performance liquid chromatography and the influence of alpha thalassemia

    Science.gov (United States)

    da Fonseca, Silvana Fahel; Amorim, Tatiana; Purificação, Antônio; Gonçalves, Marilda; Boa-Sorte, Ney

    2015-01-01

    Background In sickle cell disease, the quantification of Hb A2 is important for the differential diagnosis between sickle cell anemia (Hb SS) and Hb S/β0-thalassemia. Objective To determine Hb A2 levels as quantified by high performance liquid chromatography in patients with sickle cell anemia (Hb SS) and with the SC hemoglobinopathy, with or without concomitant alpha thalassemia. Methods This is a retrospective study of 242 children aged between two and six years with diagnoses of Hb SS or Hb SC. The hemoglobin was evaluated using high performance liquid chromatography and alpha thalassemia [3.7 kb deletion (−α3.7)] was detected by polymerase chain reaction. Patients were classified as homozygous (−α3.7/−α3.7), heterozygous (−α3.7/α), or homozygous wild-type. Analysis of variance was used to compare the mean Hb A2 values between the alpha thalassemia groups. Results The mean (± standard deviation) Hb A2 concentrations in the Hb SS group (n = 135) was 3.68 ± 0.65%. The mean values for individuals with Hb SS and heterozygous (n = 28) or homozygous for alpha thalassemia (n = 3) were 3.98 ± 0.64% and 4.73 ± 0.25%, respectively. The mean Hb A2 of all the Hb SC patients (n = 107) was 4.01 ± 0.507 with 4.29 ± 0.41% and 4.91 ± 0.22% in individuals heterozygous (n = 23) and homozygous for alpha thalassemia (n = 7), respectively. All patients homozygous for alpha thalassemia had Hb A2 levels above 3.5%. However, Hb A2 values above 5.2% were seen in patients with Hb SS and Hb SC, independently of alpha thalassemia. Conclusion Hb A2 levels are elevated in patients with Hb S or Hb C, and are directly influenced by the alpha thalassemia genotypes. PMID:26408362

  19. High Dynamic Range Imaging by Perceptual Logarithmic Exposure Merging

    Directory of Open Access Journals (Sweden)

    Florea Corneliu

    2015-12-01

    Full Text Available In this paper we emphasize a similarity between the logarithmic type image processing (LTIP model and the Naka–Rushton model of the human visual system (HVS. LTIP is a derivation of logarithmic image processing (LIP, which further replaces the logarithmic function with a ratio of polynomial functions. Based on this similarity, we show that it is possible to present a unifying framework for the high dynamic range (HDR imaging problem, namely, that performing exposure merging under the LTIP model is equivalent to standard irradiance map fusion. The resulting HDR algorithm is shown to provide high quality in both subjective and objective evaluations.

  20. High dynamic range real-time 3D shape measurement.

    Science.gov (United States)

    Jiang, Chufan; Bell, Tyler; Zhang, Song

    2016-04-04

    This paper proposes a method that can measure high-contrast surfaces in real-time without changing camera exposures. We propose to use 180-degree phase-shifted (or inverted) fringe patterns to complement regular fringe patterns. If not all of the regular patterns are saturated, inverted fringe patterns are used in lieu of original saturated patterns for phase retrieval, and if all of the regular fringe patterns are saturated, both the original and inverted fringe patterns are all used for phase computation to reduce phase error. Experimental results demonstrate that three-dimensional (3D) shape measurement can be achieved in real time by adopting the proposed high dynamic range method.

  1. High Dynamic Range Image Based on Multiple Exposure Time Synthetization

    Directory of Open Access Journals (Sweden)

    Yoshifumi Shimodaira

    2007-03-01

    Full Text Available High dynamic range of illumination may cause serious distortions and otherproblems in viewing and further processing of digital images. In this paper a new tonereproduction preprocessing algorithm is introduced which may help in developing hardly ornon-viewable features and content of the images. The method is based on the synthetizationof multiple exposure images from which the dense part, i.e. regions having the maximumlevel of detail are included in the output image. The resulted high quality HDR image makeseasier the information extraction and effectively supports the further processing of theimage.

  2. Algorithmic approach to high-throughput molecular screening for alpha interferon-resistant genotypes in hepatitis C patients.

    Science.gov (United States)

    Sreevatsan, S; Bookout, J B; Ringpis, F M; Pottathil, M R; Marshall, D J; De Arruda, M; Murvine, C; Fors, L; Pottathil, R M; Barathur, R R

    1998-07-01

    This study was designed to analyze the feasibility and validity of using Cleavase Fragment Length Polymorphism (CFLP) analysis as an alternative to DNA sequencing for high-throughput screening of hepatitis C virus (HCV) genotypes in a high-volume molecular pathology laboratory setting. By using a 244-bp amplicon from the 5' untranslated region of the HCV genome, 61 clinical samples received for HCV reverse transcription-PCR (RT-PCR) were genotyped by this method. The genotype frequencies assigned by the CFLP method were 44.3% for type 1a, 26.2% for 1b, 13.1% for type 2b, and 5% type 3a. The results obtained by nucleotide sequence analysis provided 100% concordance with those obtained by CFLP analysis at the major genotype level, with resolvable differences as to subtype designations for five samples. CFLP analysis-derived HCV genotype frequencies also concurred with the national estimates (N. N. Zein et al., Ann. Intern. Med. 125:634-639, 1996). Reanalysis of 42 of these samples in parallel in a different research laboratory reproduced the CFLP fingerprints for 100% of the samples. Similarly, the major subtype designations for 19 samples subjected to different incubation temperature-time conditions were also 100% reproducible. Comparative cost analysis for genotyping of HCV by line probe assay, CFLP analysis, and automated DNA sequencing indicated that the average cost per amplicon was lowest for CFLP analysis, at $20 (direct costs). On the basis of these findings we propose that CFLP analysis is a robust, sensitive, specific, and an economical method for large-scale screening of HCV-infected patients for alpha interferon-resistant HCV genotypes. The paper describes an algorithm that uses as a reflex test the RT-PCR-based qualitative screening of samples for HCV detection and also addresses genotypes that are ambiguous.

  3. Entrapment of alpha1-acid glycoprotein in high-performance affinity columns for drug-protein binding studies.

    Science.gov (United States)

    Bi, Cong; Jackson, Abby; Vargas-Badilla, John; Li, Rong; Rada, Giana; Anguizola, Jeanethe; Pfaunmiller, Erika; Hage, David S

    2016-05-15

    A slurry-based method was developed for the entrapment of alpha1-acid glycoprotein (AGP) for use in high-performance affinity chromatography to study drug interactions with this serum protein. Entrapment was achieved based on the physical containment of AGP in hydrazide-activated porous silica supports and by using mildly oxidized glycogen as a capping agent. The conditions needed for this process were examined and optimized. When this type of AGP column was used in binding studies, the association equilibrium constant (Ka) measured by frontal analysis at pH 7.4 and 37°C for carbamazepine with AGP was found to be 1.0 (±0.5)×10(5)M(-1), which agreed with a previously reported value of 1.0 (±0.1)×10(5)M(-1). Binding studies based on zonal elution were conducted for several other drugs with such columns, giving equilibrium constants that were consistent with literature values. An entrapped AGP column was also used in combination with a column containing entrapped HSA in a screening assay format to compare the binding of various drugs to AGP and HSA. These results also agreed with previous data that have been reported in literature for both of these proteins. The same entrapment method could be extended to other proteins and to the investigation of additional types of drug-protein interactions. Potential applications include the rapid quantitative analysis of biological interactions and the high-throughput screening of drug candidates for their binding to a given protein.

  4. Alpha particle spectroscopy — A useful tool for the investigation of spent nuclear fuel from high temperature gas-cooled reactors

    Science.gov (United States)

    Helmbold, M.

    1984-06-01

    For more than a decade, alpha particle spectrometry of spent nuclear fuel has been used at the Kernforschungsanlage Jülich (KFA) in the field of research for the German high temperature reactor (HTR). Techniques used for the preparation of samples for alpha spectrometry have included deposition from aqueous solutions of spent fuel, annealing of fuel particles in an oven and the evaporation of fuel material by a laser beam. The resulting sources are very thin but of low activity and the alpha spectrometry data obtained from them must be evaluated with sophisticated computer codes to achieve the required accuracy. Measurements have been made on high and low enriched uranium fuel and on a variety of parameters relevant to the fuel cycle. In this paper the source preparation and data evaluation techniques will be discussed together with the results obtained to data, i.e. production of alpha active actinide isotopes, correlations between actinide isotopes and fission products, build up and transmutation of actinides during burn-up of HTR fuel, diffusion coefficients of actinides for fuel particle kernels and coating materials. All these KFA results have helped to establish the basis for the design, licensing and operation of HTR power plants, including reprocessing and waste management.

  5. Stable high-copy-number integration of Aspergillus oryzae alpha-AMYLASE cDNA in an industrial baker's yeast strain.

    Science.gov (United States)

    Nieto, A; Prieto, J A; Sanz, P

    1999-01-01

    The Aspergillus oryzae alpha-amylase cDNA was placed under the control of the Saccharomyces cerevisiae actin promoter (pACT1) and introduced into the ribosomal DNA locus of an industrial baker's yeast strain. To obtain a strain eligible for commercial use, we constructed an integrative cassette lacking bacterial DNA sequences but containing the alpha-amylase cDNA and ribosomal DNA sequences to target the integration to this locus. High-copy-number integrants were obtained including a defective TRP1d promoter in the integrative cassette. We selected one transformant, Rib-AMY (CECT10872), in which the multi-integrated sequences were stable even after 200 generations of growth in nonselective medium. This transformant also expressed and secreted high levels of alpha-amylase. Bread made with this strain had a higher volume, lower density, and softer crumbs than bread made with a control strain. The Rib-AMY transformant also was useful in retarding bread firming. This new strain fulfills all the requirements for commercial utilization and should reduce or eliminate the requirement for addition of exogenous alpha-amylase to the flour, reducing allergenic work-related symptoms due to this enzyme.

  6. Development of a Novel Nonradiometric Assay for Nucleic Acid Binding to TDP-43 Suitable for High-Throughput Screening Using AlphaScreen® Technology

    OpenAIRE

    Cassel, Joel A.; Blass, Benjamin E.; Reitz, Allen B.; Pawlyk, Aaron C.

    2010-01-01

    TAR DNA binding protein 43 (TDP-43) is a nucleic acid binding protein that is associated with the pathology of cystic fibrosis and neurodegenerative diseases such as amyotrophic lateral sclerosis and frontotemporal lobar dementia. We have developed a robust, quantitative, nonradiometric high-throughput assay measuring oligonucleotide binding to TDP-43 using AlphaScreen® technology. Biotinylated single-stranded TAR DNA (bt-TAR-32) and 6 TG repeats (bt-TG6) bound with high affinity to TDP-43, w...

  7. Dynamics of High-Speed Precision Geared Rotor Systems

    Directory of Open Access Journals (Sweden)

    Lim Teik C.

    2014-07-01

    Full Text Available Gears are one of the most widely applied precision machine elements in power transmission systems employed in automotive, aerospace, marine, rail and industrial applications because of their reliability, precision, efficiency and versatility. Fundamentally, gears provide a very practical mechanism to transmit motion and mechanical power between two rotating shafts. However, their performance and accuracy are often hampered by tooth failure, vibrations and whine noise. This is most acute in high-speed, high power density geared rotor systems, which is the primary scope of this paper. The present study focuses on the development of a gear pair mathematical model for use to analyze the dynamics of power transmission systems. The theory includes the gear mesh representation derived from results of the quasi-static tooth contact analysis. This proposed gear mesh theory comprising of transmission error, mesh point, mesh stiffness and line-of-action nonlinear, time-varying parameters can be easily incorporated into a variety of transmission system models ranging from the lumped parameter type to detailed finite element representation. The gear dynamic analysis performed led to the discovery of the out-of-phase gear pair torsion modes that are responsible for much of the mechanical problems seen in gearing applications. The paper concludes with a discussion on effectual design approaches to minimize the influence of gear dynamics and to mitigate gear failure in practical power transmission systems.

  8. A gas-tight Cu K alpha x-ray transparent reaction chamber for high-temperature x-ray diffraction analyses of halide gas/solid reactions.

    Science.gov (United States)

    Shian, Samuel; Sandhage, Kenneth H

    2009-11-01

    An externally heated, x-ray transparent reaction chamber has been developed to enable the dynamic high temperature x-ray diffraction (HTXRD) analysis of a gas/solid [TiF(4)(g)/SiO(2)(s)] reaction involving a halide gas reactant formed at elevated temperatures (up to 350 degrees C) from a condensed source (TiF(4) powder) sealed within the chamber. The reaction chamber possessed x-ray transparent windows comprised of a thin (13 microm) internal layer of Al foil and a thicker (125 microm) external Kapton film. After sealing the SiO(2) specimens (diatom frustules or Stober spheres) above TiF(4) powder within the reaction chamber, the chamber was heated to a temperature in the range of 160-350 degrees C to allow for internal generation of TiF(4)(g). The TiF(4)(g) underwent a metathetic reaction with the SiO(2) specimen to yield a TiOF(2)(s) product. HTXRD analysis, using Cu K alpha x rays passed through the Kapton/Al windows of the chamber, was used to track the extent of SiO(2) consumption and/or TiOF(2) formation with time. The Al foil inner layer of the windows protected the Kapton film from chemical attack by TiF(4)(g), whereas the thicker, more transparent Kapton film provided the mechanical strength needed to contain this gas. By selecting an appropriate combination of x-ray transparent materials to endow such composite windows with the required thermal, chemical, and mechanical performance, this inexpensive reaction chamber design may be applied to the HTXRD analyses of a variety of gas/solid reactions.

  9. Gas-Phase Molecular Dynamics: High Resolution Spectroscopy and Collision Dynamics of Transient Species

    Energy Technology Data Exchange (ETDEWEB)

    Hall, G.E.

    2011-05-31

    This research is carried out as part of the Gas-Phase Molecular Dynamics program in the Chemistry Department at Brookhaven National Laboratory. Chemical intermediates in the elementary gas-phase reactions involved in combustion chemistry are investigated by high resolution spectroscopic tools. Production, reaction, and energy transfer processes are investigated by transient, double resonance, polarization and saturation spectroscopies, with an emphasis on technique development and connection with theory, as well as specific molecular properties.

  10. Vortex dynamics and shear layer instability in high intensity cyclotrons

    CERN Document Server

    Cerfon, Antoine J

    2016-01-01

    We show that the space charge dynamics of high intensity beams in the plane perpendicular to the magnetic field in cyclotrons is described by the two-dimensional Euler equations for an incompressible fluid. This analogy with fluid dynamics gives a unified and intuitive framework to explain the beam spiraling and beam break up behavior observed in experiments and in simulations. In particular, we demonstrate that beam break up is the result of a classical instability occurring in fluids subject to a sheared flow. We give scaling laws for the instability and predict the nonlinear evolution of beams subject to it. Our work suggests that cyclotrons may be uniquely suited for the experimental study of shear layers and vortex distributions that are not achievable in Penning-Malmberg traps.

  11. Dynamical Structures of High-Frequency Financial Data

    CERN Document Server

    Kim, K; Kim, S Y; Kim, Y; Yoon, S M; Chang, Ki-Ho; Kim, Kyungsik; Kim, Soo Yong; Kim, Yup; Yoon, Seong-Min

    2005-01-01

    We study the dynamical behavior of high-frequency data from the Korean Stock Price Index (KOSPI) using the movement of returns in Korean financial markets. The dynamical behavior for a binarized series of our models is not completely random. The conditional probability is numerically estimated from a return series of KOSPI tick data. Non-trivial probability structures can be constituted from binary time series of autoregressive (AR), logit, and probit models, for which the Akaike Information Criterion shows a minimum value at the 15th order. From our results, we find that the value of the correct match ratio for the AR model is slightly larger than the findings of other models.

  12. The Dynamic Behaviour of Gears with High Transmission Ratio

    Directory of Open Access Journals (Sweden)

    Ivana Atanasovska

    2012-06-01

    Full Text Available This paper describes the dynamic behaviour of helical gears with new standpoint for calculation of influence variables: mesh teeth stiffness, contact lines lengths and load distribution during mesh period. Nonlinear contact Finite Element Analysis and the new iteration procedure are used for calculation of meshed teeth deformations, stiffness and contact loads. The normal load distribution calculated with this procedure is used for evaluation of nonlinear dynamic analytical model of helical gears motion. Described investigation is especially important for gear pairs with high value of transmission ratio, often used in large transport machines. The presented models and results can be used for helical gears modeling when standard procedures don’t cover the requirements.

  13. Toxicity of combined treatment of adjuvant irradiation and interferon alpha2b in high-risk melanoma patients.

    Science.gov (United States)

    Conill, Carlos; Jorcano, Sandra; Domingo-Domènech, Josep; Marruecos, Jordi; Vilella, Ramón; Malvehy, Josep; Puig, Susana; Sánchez, Marcelo; Gallego, Rosa; Castel, Teresa

    2007-10-01

    Surgically resected stage III melanoma patients commonly receive adjuvant therapy with interferon (IFN) alpha2b. For those patients with high-risk features of draining node recurrence, radiation therapy can also be considered as a treatment option. The purpose of this retrospective study was to assess the efficacy and radiation-related toxicity of this combined therapy. Eighteen patients receiving adjuvant IFNalpha2b therapy during radiation therapy, or within 1 month of its completion, were reviewed retrospectively and analysed for outcome. Radiation was delivered at 600 cGy dose per fraction, in 16 out of 18 patients, twice a week, and at 200 cGy dose per fraction in two patients five times a week. Total radiation dose and number of fractions were as follows: 30 Gy/5 fr (n=8), 36 Gy/6 fr (n=8) and 50 Gy/25 fr (n=2). The percentage of disease-free patients, with no local recurrence, at 3 years was 88%. In 10 patients, IFNalpha2b was administered concurrently with radiotherapy; in three, within 30 days before or after radiation; and in five, more than 30 days after radiation. All the patients experienced acute skin reactions, grade I on the Radiation Therapy Oncology Group (RTOG) scale. Late radiation-related toxicity was seen in one patient with grade III (RTOG) skin reaction and two with grade IV (RTOG) radiation-induced myelitis. Concurrent use of adjuvant radiotherapy and IFNalpha2b might enhance radiation-induced toxicity, and special care should be taken when the spinal cord is included in the radiation field.

  14. $\\alpha_s$ review (2016)

    CERN Document Server

    d'Enterria, David

    2016-01-01

    The current world-average of the strong coupling at the Z pole mass, $\\alpha_s(m^2_{Z}) = 0.1181 \\pm 0.0013$, is obtained from a comparison of perturbative QCD calculations computed, at least, at next-to-next-to-leading-order accuracy, to a set of 6 groups of experimental observables: (i) lattice QCD "data", (ii) $\\tau$ hadronic decays, (iii) proton structure functions, (iv) event shapes and jet rates in $e^+e^-$ collisions, (v) Z boson hadronic decays, and (vi) top-quark cross sections in p-p collisions. In addition, at least 8 other $\\alpha_s$ extractions, usually with a lower level of theoretical and/or experimental precision today, have been proposed: pion, $\\Upsilon$, W hadronic decays; soft and hard fragmentation functions; jets cross sections in pp, e-p and $\\gamma$-p collisions; and photon F$_2$ structure function in $\\gamma\\,\\gamma$ collisions. These 14 $\\alpha_s$ determinations are reviewed, and the perspectives of reduction of their present uncertainties are discussed.

  15. Dynamic Stability Analysis Using High-Order Interpolation

    Directory of Open Access Journals (Sweden)

    Juarez-Toledo C.

    2012-10-01

    Full Text Available A non-linear model with robust precision for transient stability analysis in multimachine power systems is proposed. The proposed formulation uses the interpolation of Lagrange and Newton's Divided Difference. The High-Order Interpolation technique developed can be used for evaluation of the critical conditions of the dynamic system.The technique is applied to a 5-area 45-machine model of the Mexican interconnected system. As a particular case, this paper shows the application of the High-Order procedure for identifying the slow-frequency mode for a critical contingency. Numerical examples illustrate the method and demonstrate the ability of the High-Order technique to isolate and extract temporal modal behavior.

  16. Simulation studies of high-latitude magnetospheric boundary dynamics

    Institute of Scientific and Technical Information of China (English)

    PU; Zuyin; SHI; Quanqi; XIAO; Chijie; FU; Suiyan; ZHANG; Hu

    2004-01-01

    Magnetic reconnection at the high-latitude magnetopause is studied using 2.5-dimensional Hail-MHD simulation. Concentric flow vortices and magnetic islands appear when both Hall effect and sheared flow are considered. Plasma mixing across the magnetopause occurs in the presence of the flow vortices. Reconnected structure generated in the vicinity of the subsolar point changes its geometry with increasing flow shear while moving to high latitudes. In the presence of flow shear, with the Hail-MHD reconnection a higher reconnection rate than with the traditional MHD is obtained. The out-of-plane components of flow and magnetic field produced by the Hall current are redistributed under the action of the flow shear, which makes the plasma transport across the boundaries more complicated. The simulation results provide some help in understanding the dynamic processes at the high latitude magnetopause.

  17. X-ray production cross-sections measurements for high-energy alpha particle beams: New dedicated set-up and first results with aluminum

    Energy Technology Data Exchange (ETDEWEB)

    Dupuis, T., E-mail: T.Dupuis@ulg.ac.be [Centre Europeen d' Archeometrie, Atomique et Spectroscopie, Universite de Liege, Sart Tilman B15, B-4000 Liege (Belgium); Institut de Physique Nucleaire, Atomique et Spectroscopie, Universite de Liege, Sart Tilman B15, B-4000 Liege (Belgium); Chene, G., E-mail: Gregoire.Chene@ulg.ac.be [Centre Europeen d' Archeometrie, Atomique et Spectroscopie, Universite de Liege, Sart Tilman B15, B-4000 Liege (Belgium); Institut de Physique Nucleaire, Atomique et Spectroscopie, Universite de Liege, Sart Tilman B15, B-4000 Liege (Belgium); Mathis, F., E-mail: Francois.Mathis@ulg.ac.be [Centre Europeen d' Archeometrie, Atomique et Spectroscopie, Universite de Liege, Sart Tilman B15, B-4000 Liege (Belgium); Institut de Physique Nucleaire, Atomique et Spectroscopie, Universite de Liege, Sart Tilman B15, B-4000 Liege (Belgium); and others

    2011-12-15

    The 'IPNAS' laboratory, in collaboration with the 'Centre Europeen d'Archeometrie' is partly focused on material analysis by means of IBA techniques: PIXE, PIGE and RBS. A new transport beam line has been developed at our CGR-520 MeV cyclotron to analyze Cultural Heritage objects using these techniques. This facility allows us to produce proton and alpha particle beams with energies up to 20 MeV. A vacuum chamber dedicated to X-ray production and Non-Rutherford cross-section measurements has been recently constructed. After determination of the chamber's geometry for X-ray detection using thin foils of several elements (11 Less-Than-Or-Slanted-Equal-To Z Less-Than-Or-Slanted-Equal-To 82) and 3 MeV proton beams, the measurement of the X-ray production cross-sections in the 6-12 MeV energy range has started using alpha particle beams on light element targets. These experiments contribute to the filling a serious lack of experimental values for alpha particles of this particular energy range in databases. The recent decision to focus our work on the alpha particle interaction with light elements was taken because of the high interest of the low Z elements in the field of archaeometry.

  18. Examination of the suitability of alpha-tocopherol as a stabilizer for ultra-high molecular weight polyethylene used for articulating surfaces in joint endoprostheses.

    Science.gov (United States)

    Wolf, C; Krivec, T; Blassnig, J; Lederer, K; Schneider, W

    2002-02-01

    The lifetime of articulating surfaces in joint endoprostheses made of ultra-high molecular weight polyethylene (UHMW-PE), especially of UHMW-PE-cups of hip-endoprostheses, is usually limited to 10-15 years due to material failure as a result of oxidation of the UHMW-PE in vivo. In this study the suitability of the natural antioxidant alpha-tocopherol (vitamin E) as a stabilizer for UHMW-PE in these applications was investigated. Specimens with 0.1%, 0.2%, 0.4% and 0.8% w/w alpha-tocopherol as well as unstabilized samples were sintered and sterilized with gamma-rays at 25 kGy in accordance with standard processing methods of cups for total hip-endoprostheses. These specimens were aged in pure oxygen at 70 degrees C and 5 bar as well as in aqueous H2O2 at 50 degrees C. The degree of oxidation was observed by means of FTIR-spectroscopy, DSC analysis and mechanical testing. The FTIR-measurements showed that alpha-tocopherol can prolong the lifetime of UHMW-PE in an oxidative environment by a factor of more than 2.5. In the mechanical tests no embrittlement could be observed with the stabilized samples. A comparison with the standard antioxidant system Irganox 1010/Irgafos 168 (Ciba-Geigy, Switzerland) was carried out and revealed that alpha-tocopherol can even exceed the stabilization effect of this widely-used antioxidant system.

  19. X-ray production cross-sections measurements for high-energy alpha particle beams: New dedicated set-up and first results with aluminum

    Science.gov (United States)

    Dupuis, T.; Chêne, G.; Mathis, F.; Marchal, A.; Garnir, H.-P.; Strivay, D.

    2011-12-01

    The "IPNAS" laboratory, in collaboration with the "Centre Européen d'Archéométrie" is partly focused on material analysis by means of IBA techniques: PIXE, PIGE and RBS. A new transport beam line has been developed at our CGR-520 MeV cyclotron to analyze Cultural Heritage objects using these techniques. This facility allows us to produce proton and alpha particle beams with energies up to 20 MeV. A vacuum chamber dedicated to X-ray production and Non-Rutherford cross-section measurements has been recently constructed. After determination of the chamber's geometry for X-ray detection using thin foils of several elements (11 ⩽ Z ⩽ 82) and 3 MeV proton beams, the measurement of the X-ray production cross-sections in the 6-12 MeV energy range has started using alpha particle beams on light element targets. These experiments contribute to the filling a serious lack of experimental values for alpha particles of this particular energy range in databases. The recent decision to focus our work on the alpha particle interaction with light elements was taken because of the high interest of the low Z elements in the field of archaeometry.

  20. Water and polymer dynamics in highly crosslinked polyamide membranes

    Science.gov (United States)

    Frieberg, Bradley; Chan, Edwin; Tyagi, Madhu; Stafford, Christopher; Soles, Christopher

    Highly crosslinked polyamides for reverse osmosis are the state-of-the-art active material in membranes for desalination. The thin film composite membrane structure that is used commercially has been empirically designed to selectively allow the passage of water molecules and minimize the passage of solutes such as salt. However, due to the large roughness and variability of the polyamide layer, there is a limited understanding of the structure-property relationship for these materials as well as the transport mechanism. To better understand the water transport mechanism we measure the water and polymer dynamics of polyamide membranes using quasi-elastic neutron scattering (QENS). By hydrating the membrane with deuterated water, we are able to isolate the dynamics of the hydrogenated membrane on the pico- and nanosecond time scales. By subsequently hydrating the membranes with hydrogenated water, the QENS measurements on the same times scales reveal information about both the translational and rotational dynamics of water confined within the polyamide membrane. Further understanding of the water diffusion mechanism will establish design rules in which the performance of future membrane materials can be improved.

  1. Dynamic recrystallization behavior and kinetics of high strength steel

    Institute of Scientific and Technical Information of China (English)

    吴光亮; 周超洋; 刘新彬

    2016-01-01

    The dynamic recrystallization behavior of high strength steel during hot deformation was investigated. The hot compression test was conducted in the temperature range of 950−1150 °C under strain rates of 0.1, 1 and 5 s−1. It is observed that dynamic recrystallization (DRX) is the main flow softening mechanism and the flow stress increases with decreasing temperature and increasing strain rate. The relationship between material constants (Q, n, α and lnA) and strain is identified by the sixth order polynomial fit. The constitutive model is developed to predict the flow stress of the material incorporating the strain softening effect and verified. Moreover, the critical characteristics of DRX are extracted from the stress−strain curves under different deformation conditions by linear regression. The dynamic recrystallization volume fraction decreases with increasing strain rate at a constant temperature or decreasing deformation temperature under a constant strain rate. The kinetics of DRX increases with increasing deformation temperature or strain rate.

  2. Dynamical evolution of high velocity clouds in the intergalactic medium

    CERN Document Server

    Konz, C; Birk, G T

    2002-01-01

    HI observations of high-velocity clouds (HVCs) indicate, that they are interacting with their ambient medium. Even clouds located in the very outer Galactic halo or the intergalactic space seem to interact with their ambient medium. In this paper, we investigate the dynamical evolution of high velocity neutral gas clouds moving through a hot magnetized ambient plasma by means of two-dimensional magnetohydrodynamic plasma-neutral gas simulations. This situation is representative for the fast moving dense neutral gas cloudlets in the Magellanic Stream as well as for high velocity clouds in general. The question on the dynamical and thermal stabilization of a cold dense neutral cloud in a hot thin ambient halo plasma is numerically investigated. The simulations show the formation of a comet-like head-tail structure combined with a magnetic barrier of increased field strength which exerts a stabilizing pressure on the cloud and hinders hot plasma from diffusing into the cloud. The simulations can explain both the...

  3. H$_{\\alpha}$ line as an indicator of envelope presence around the Cepheid Polaris Aa ($\\alpha~ UMi$)

    CERN Document Server

    Usenko, I A; Klochkova, V G; Tavolzhanskaya, N S

    2015-01-01

    We present the results of the radial velocity ($RV$) measurements of metallic lines as well as H$_{\\alpha}$ (H$_{\\beta}$) obtained in 55 high-resolution spectra of the Cepheid $\\alpha$ UMi (Polaris Aa) in 1994-2010. While the $RV$ amplitudes of these lines are roughly equal, their mean $RV$ begin to differ essentially with growth of the Polaris Aa pulsational activity. This difference is accompanied by the H$_{\\alpha}$ line core asymmetries on the red side mainly (so-called knife-like profiles) and reaches 8-12 km/s in 2003 with a subsequent decrease to 1.5-2 km/s. We interpret a so unusual behaviour of the H$_{\\alpha}$ line core as dynamical changes in the envelope around Polaris Aa.

  4. Simulation of transition dynamics to high confinement in fusion plasmas

    CERN Document Server

    Nielsen, A H; Madsen, J; Naulin, V; Rasmussen, J Juul; Wan, B N

    2014-01-01

    The transition dynamics from the low (L) to the high (H) confinement mode in magnetically confined plasmas is investigated using a first-principles four-field fluid model. Numerical results are in close agreement with measurements from the Experimental Advanced Superconducting Tokamak - EAST. Particularly, the slow transition with an intermediate dithering phase is well reproduced by the numerical solutions. Additionally, the model reproduces the experimentally determined L-H transition power threshold scaling that the ion power threshold increases with increasing particle density. The results hold promise for developing predictive models of the transition, essential for understanding and optimizing future fusion power reactors.

  5. High Speed Optical Tomography System for Imaging Dynamic Transparent Media

    Science.gov (United States)

    McMackin, Lenore; Hugo, Ronald J.; Pierson, R. E.; Truman, C. R.

    1997-11-01

    We describe the design and operation of a high speed optical tomography system for measuring two-dimensional images of a dynamic phase object at a rate of 5 kHz. Data from a set of eight Hartmann wavefront sensors is back-projected to produce phase images showing the details of the inner structure of a heated air flow. The tomographic reconstructions have a spatial resolution of approximately 2.0 mm and can measure temperature variations across the flow with an accuracy of about 0.7 C. Series of animated reconstructions at different downstream locations illustrate the development of flow structure and the effect of acoustic flow forcing.

  6. Adaptive Process Management in Highly Dynamic and Pervasive Scenarios

    CERN Document Server

    de Leoni, Massimiliano

    2009-01-01

    Process Management Systems (PMSs) are currently more and more used as a supporting tool for cooperative processes in pervasive and highly dynamic situations, such as emergency situations, pervasive healthcare or domotics/home automation. But in all such situations, designed processes can be easily invalidated since the execution environment may change continuously due to frequent unforeseeable events. This paper aims at illustrating the theoretical framework and the concrete implementation of SmartPM, a PMS that features a set of sound and complete techniques to automatically cope with unplanned exceptions. PMS SmartPM is based on a general framework which adopts the Situation Calculus and Indigolog.

  7. High Dynamic Range Electric Field Sensor for Electromagnetic Pulse Detection

    CERN Document Server

    Lin, Che-Yun; Lee, Beom Suk; Zhang, Xingyu; Chen, Ray T

    2014-01-01

    We design a high dynamic range electric field sensor based on domain inverted electro-optic (E-O) polymer Y-fed directional coupler for electromagnetic wave detection. This electrode-less, all optical, wideband electrical field sensor is fabricated using standard processing for E-O polymer photonic devices. Experimental results demonstrate effective detection of electric field from 16.7V/m to 750KV/m at a frequency of 1GHz, and spurious free measurement range of 70dB.

  8. Generation of high-dynamic range image from digital photo

    Science.gov (United States)

    Wang, Ying; Potemin, Igor S.; Zhdanov, Dmitry D.; Wang, Xu-yang; Cheng, Han

    2016-10-01

    A number of the modern applications such as medical imaging, remote sensing satellites imaging, virtual prototyping etc use the High Dynamic Range Image (HDRI). Generally to obtain HDRI from ordinary digital image the camera is calibrated. The article proposes the camera calibration method based on the clear sky as the standard light source and takes sky luminance from CIE sky model for the corresponding geographical coordinates and time. The article considers base algorithms for getting real luminance values from ordinary digital image and corresponding programmed implementation of the algorithms. Moreover, examples of HDRI reconstructed from ordinary images illustrate the article.

  9. Note: A high dynamic range, linear response transimpedance amplifier.

    Science.gov (United States)

    Eckel, S; Sushkov, A O; Lamoreaux, S K

    2012-02-01

    We have built a high dynamic range (nine decade) transimpedance amplifier with a linear response. The amplifier uses junction-gate field effect transistors (JFETs) to switch between three different resistors in the feedback of a low input bias current operational amplifier. This allows for the creation of multiple outputs, each with a linear response and a different transimpedance gain. The overall bandwidth of the transimpedance amplifier is set by the bandwidth of the most sensitive range. For our application, we demonstrate a three-stage amplifier with transimpedance gains of approximately 10(9)Ω, 3 × 10(7)Ω, and 10(4)Ω with a bandwidth of 100 Hz.

  10. Adaptive Process Management in Highly Dynamic and Pervasive Scenarios

    Directory of Open Access Journals (Sweden)

    Massimiliano de Leoni

    2009-06-01

    Full Text Available Process Management Systems (PMSs are currently more and more used as a supporting tool for cooperative processes in pervasive and highly dynamic situations, such as emergency situations, pervasive healthcare or domotics/home automation. But in all such situations, designed processes can be easily invalidated since the execution environment may change continuously due to frequent unforeseeable events. This paper aims at illustrating the theoretical framework and the concrete implementation of SmartPM, a PMS that features a set of sound and complete techniques to automatically cope with unplanned exceptions. PMS SmartPM is based on a general framework which adopts the Situation Calculus and Indigolog.

  11. Tolerance and antiviral effects of high-dose interferon-alpha B/D in patients with chronic hepatitis B

    NARCIS (Netherlands)

    Rasch, MC; Schellekens, H; van Dijck, CMM; Haagsma, EB; Michielsen, PP; van Buuren, AHJAM; Stotter, H; van Hattum, J

    1998-01-01

    A novel recombinant interferon-alpha B/D hybrid was applied to assess tolerability, antiviral effect, and biological activity in chronic hepatitis B. The study was designed as an open nonrandomized trial. Treatment comprised a two-week run-in phase with 16 MU three times a week followed by 14 weeks

  12. The RINGS Survey: High-Resolution H-alpha Velocity Fields of Nearby Spiral Galaxies with the SALT Fabry-Perot

    CERN Document Server

    Mitchell, Carl J; Williams, T B; Spekkens, Kristine; Lee-Waddell, K; de Naray, Rachel Kuzio

    2015-01-01

    We have obtained high-spatial-resolution spectrophotometric data on several nearby spiral galaxies with the Southern African Large Telescope (SALT) Fabry-P\\'erot interferometer on the Robert Stobie Spectrograph (RSS) as a part of the RSS Imaging spectroscopy Nearby Galaxy Survey (RINGS). We have successfully reduced two tracks of Fabry-P\\'erot data for the galaxy NGC 2280 to produce a velocity field of the H-alpha line of excited hydrogen. We have modeled these data with the DiskFit modeling software and found these models to be in excellent agreement both with previous measurements in the literature and with our lower-resolution HI velocity field of the same galaxy. Despite this good agreement, small regions exist where the difference between the H-alpha and HI velocities is larger than would be expected from typical dispersions. We investigate these regions of high velocity difference and offer possible explanations for their existence.

  13. High-performance liquid chromatographic separation of carminic acid, alpha- and beta-bixin, and alpha- and beta-norbixin, and the determination of carminic acid in foods.

    Science.gov (United States)

    Lancaster, F E; Lawrence, J F

    1996-05-03

    During a study of natural food colours, a simple and reliable high-performance liquid chromatography system was developed for use with cochineal and annato. An isocratic mobile phase, consisting of methanol and 6% aqueous acetic acid, resolved bixin and norbixin, while a gradient system was used to separate carminic acid and the annato compounds. The carminic acid contents of cochineal extract, carmine and carmine hydrosoluble were determined using an isocratic mobile phase (40:60, v/v). The detection limit for carminic acid in the various products was approximately 100 ng/g. Carminic acid was determined quantitatively in fruit beverages, yogurt and candies. It was demonstrated that, because of decomposition, carminic acid was not suitable for use in candies when manufacturing temperatures above 100 degrees C were required. Most membrane filters are not suitable for use with cochineal solutions, but a cellulose membrane filter did not adsorb carminic acid and was used successfully to remove impurities from water-based cochineal products and food extracts containing carminic acid.

  14. A K-alpha x-ray source using high energy and high repetition rate laser system for phase contrast imaging

    OpenAIRE

    Serbanescu, Cristina; Fourmaux, Sylvain; Kieffer, Jean-Claude; Kincaid, Russell; Krol, Andrzej

    2009-01-01

    K-alpha x-ray sources from laser produced plasmas provide completely new possibilities for x-ray phase-contrast imaging applications. By tightly focusing intense femtosecond laser pulses onto a solid target K-alpha x-ray pulses are generated through the interaction of energetic electrons created in the plasma with the bulk target. In this paper, we present a continuous and efficient Mo K-alpha x-ray source produced by a femtosecond laser system operating at 100 Hz repetition rate with maximum...

  15. Hydrological Dynamics In High Mountain Catchment Areas of Central Norway

    Science.gov (United States)

    Löffler, Jörg; Rößler, Ole

    Large-scaled landscape structure is regarded as a mosaic of ecotopes where process dynamics of water and energy fluxes are analysed due to its effects on ecosystem functioning. The investigations have been carried out in the continental most Vågå/Oppland high mountains in central Norway since 1994 (LÖFFLER &WUNDRAM 1999, 2000, 2001). Additionally, comparable investigations started in 2000 dealing with the oceanic high mountain landscapes on same latitudes (LÖFFLER et al. 2001). The theoretical and methodological framework of the project is given by the Landscape-Ecological Complex Analysis (MOSIMANN 1984, 1985) and its variations due to technical and principle methodical challenges in this high mountain landscape (KÖHLER et al. 1994, LÖFFLER 1998). The aim of the project is to characterize high mountain ecosystem structure, functioning and dynamics within small catchment areas, that are chosen in two different altitudinal belts each in the eastern continental and the western oceanic region of central Norway. In the frame of this research project hydrological and meteorological measurements on ground water, percolation and soil moisture dynamics as well as on evaporation, air humidity and air-, surface- and soil-temperatures have been conducted. On the basis of large-scaled landscape-ecological mappings (LÖFFLER 1997) one basic meteorological station and several major data logger run stations have been installed in representative sites of each two catchment areas in the low and mid alpine belts of the investigation regions ( JUNGet al. 1997, LÖFFLER &WUNDRAM 1997). Moreover, spatial differentiations of groundwater level, soil moisture and temperature profiles have been investigated by means of hand held measurements at different times of the day, during different climatic situations and different seasons. Daily and annual air-, surface- and soil-temperature dynamics are demonstrated by means of thermoisopleth-diagrams for different types of ecotopes of the

  16. Routing in Highly Dynamic Ad Hoc Networks: Issues and Challenges

    Directory of Open Access Journals (Sweden)

    Varun G Menon

    2016-04-01

    Full Text Available The aim of this research paper is to analyze the various issues and challenges involved in routing of data packets in highly mobile ad hoc networks. Routing in ad hoc networks has always been a challenging and tough task due to the dynamic topology and error prone wireless channel. There are a number of issues like lack of centralized control, constantly moving nodes etc that has to be considered while routing a data packet from the source to the destination in the ad hoc network. Routing of data packets becomes much more difficult with increased mobility of nodes. This paper analyses the various issues in routing of data packets from the source to the destination node and also lists down the parameters that has to be considered while designing and selecting a routing protocol for highly mobile ad hoc networks.

  17. Dynamic Strengthening During High Velocity Shear Experiments with Siliceous Rocks

    Science.gov (United States)

    Liao, Z.; Chang, J. C.; Boneh, Y.; Chen, X.; Reches, Z.

    2011-12-01

    It is generally accepted that dynamic-weakening is essential for earthquake instability, and many experimental works have documented this weakening. Recent observations revealed also opposite trends of dynamic-strengthening in experiments (Reches & Lockner, 2010). We present here our experimental results of this dynamic-strengthening and discuss possible implications to earthquake behavior. We ran hundreds of experiments on experimental faults made of siliceous rock including granite, syenite, diorite, and quartzite. The experimental fault is comprised of two solid cylindrical blocks with a raised-ring contact of 7 cm diameter and 1 cm width. We recognized general, three regimes of strength-velocity relations: (I) Dynamic weakening (drop of 20-60% of static strength) as slip velocity increased from ~0.0003 m/s (lowest experimental velocity) to a critical velocity, Vc=0.008-0.16 m/s; (II) Abrupt transition to dynamic strengthening regime during which the fault strength almost regains its static strength; and (III) Quasi-constant strength with further possible drops as velocity approaches ~1 m/s. The critical velocity depends on the sample lithology: Vc is ~0.06 m/s for granite, ~0.008 m/s for syenite, ~0.01 m/s for diorite, and ~0.16 m/s for quartzite. The strengthening stage is associated with temperature increase, wear-rate increase, and the occurrence of intense, high frequency stick-slip events (Reches & Lockner, 2010). Sammis et al., (this meeting) attributed this strengthening to dehydration of the thin water layer that covers the gouge particles as the temperature increases. On the other hand, we note that tens of experiments with dolomite samples (non-siliceous), which were deformed under similar conditions, did not exhibit the velocity strengthening (unpublished). Based on the analyses by Andrews (2004, 2005), we speculate that velocity strengthening may bound the slip velocity. The numerical models of Andrews show that the slip velocity along a slip

  18. High affinity of anti-GBM antibodies from Goodpasture and transplanted Alport patients to alpha3(IV)NC1 collagen.

    Science.gov (United States)

    Rutgers, A; Meyers, K E; Canziani, G; Kalluri, R; Lin, J; Madaio, M P

    2000-07-01

    Anti-glomerular basement membrane (anti-GBM) antibody-mediated diseases are characterized by rapidly progressive glomerulonephritis (RPGN) that often results in irreversible loss of renal function and renal failure. Although many factors contribute to the fulminant nature and treatment resistance of this disease, we questioned whether high affinity autoantibody-alpha3(IV) collagen interactions lead to persistent antibody deposition, thereby perpetuating inflammation. To address this hypothesis, the binding kinetics of human anti-GBM antibodies (Ab) to alpha3(IV)NC1 were evaluated using an optical biosensor interaction analysis. Polyclonal anti-GBM Abs were purified by alpha3(IV)NC1 affinity chromatography from the sera of patients with anti-GBM AB-mediated diseases, including individuals with Goodpasture syndrome (GS), idiopathic RPGN (N = 7), and Alport syndrome (AL) following kidney transplantation (N = 4). The affinity-binding characteristics of the autoantibodies were determined using a biosensor analysis system, with immobilized bovine alpha3(IV)NC1 dimers. All of the autoantibody preparations bound to alpha3(IV)NC1, whereas none bound to alpha1(IV)NC1 (control). Purified, normal serum IgG did not bind to either antigen. Estimated dissociation constants (Kd) for the purified autoantibodies were 1.39E-04 +/- 7.30E-05 s-l (GS) and 8. 90E-05 +/- 2.80E-05 s-l (AL). Their estimated association constants (Ka) were 2.67E+04 +/- 1.8E+04 (M-ls-l) and 2.76E+04 +/- 1. 70E+04(M-ls-l) for GS and AL patients, respectively. By comparison with other Ab interactions, these Abs demonstrated high affinity, with relatively high on (binding) rates and slow off (dissociation) rates. The results suggest that anti-GBM Abs bind rapidly and remain tightly bound to the GBM in vivo. This property likely contributes to both the fulminant nature of this disease and its resistance to therapy, because persistent glomerular Ab deposition has the potential to produce continuous inflammation

  19. High-Resolution Force Balance Analyses of Tidewater Glacier Dynamics

    Science.gov (United States)

    Enderlin, E. M.; Hamilton, G. S.; O'Neel, S.

    2015-12-01

    Changes in glacier velocity, thickness, and terminus position have been used to infer the dynamic response of tidewater glaciers to environmental perturbations, yet few analyses have attempted to quantify the associated variations in the glacier force balance. Where repeat high-resolution ice thickness and velocity estimates are available, force balance time series can be constructed to investigate the redistribution of driving and resistive forces associated with changes in terminus position. Comparative force balance analyses may, therefore, help us understand the variable dynamic response observed for glaciers in close proximity to each other. Here we construct force balance time series for Helheim Glacier, SE Greenland, and Columbia Glacier, SE Alaska, to investigate differences in dynamic sensitivity to terminus position change. The analysis relies on in situ and remotely sensed observations of ice thickness, velocity, and terminus position. Ice thickness time series are obtained from stereo satellite image-derived surface elevation and continuity-derived bed elevations that are constrained by airborne radar observations. Surface velocity time series are obtained from interferometric synthetic aperture radar (InSAR) observations. Approximately daily terminus positions are from a combination of satellite images and terrestrial time-lapse photographs. Helheim and Columbia glaciers are two of the best-studied Arctic tidewater glaciers with comprehensive high-resolution observational time series, yet we find that bed elevation uncertainties and poorly-constrained stress-coupling length estimates still hinder the analysis of spatial and temporal force balance variations. Here we use a new observationally-based method to estimate the stress-coupling length which successfully reduces noise in the derived force balance but preserves spatial variations that can be over-smoothed when estimating the stress-coupling length as a scalar function of the ice thickness

  20. Dynamics and sensitivity analysis of high-frequency conduction block

    Science.gov (United States)

    Ackermann, D. Michael; Bhadra, Niloy; Gerges, Meana; Thomas, Peter J.

    2011-10-01

    The local delivery of extracellular high-frequency stimulation (HFS) has been shown to be a fast acting and quickly reversible method of blocking neural conduction and is currently being pursued for several clinical indications. However, the mechanism for this type of nerve block remains unclear. In this study, we investigate two hypotheses: (1) depolarizing currents promote conduction block via inactivation of sodium channels and (2) the gating dynamics of the fast sodium channel are the primary determinate of minimal blocking frequency. Hypothesis 1 was investigated using a combined modeling and experimental study to investigate the effect of depolarizing and hyperpolarizing currents on high-frequency block. The results of the modeling study show that both depolarizing and hyperpolarizing currents play an important role in conduction block and that the conductance to each of three ionic currents increases relative to resting values during HFS. However, depolarizing currents were found to promote the blocking effect, and hyperpolarizing currents were found to diminish the blocking effect. Inward sodium currents were larger than the sum of the outward currents, resulting in a net depolarization of the nodal membrane. Our experimental results support these findings and closely match results from the equivalent modeling scenario: intra-peritoneal administration of the persistent sodium channel blocker ranolazine resulted in an increase in the amplitude of HFS required to produce conduction block in rats, confirming that depolarizing currents promote the conduction block phenomenon. Hypothesis 2 was investigated using a spectral analysis of the channel gating variables in a single-fiber axon model. The results of this study suggested a relationship between the dynamical properties of specific ion channel gating elements and the contributions of corresponding conductances to block onset. Specifically, we show that the dynamics of the fast sodium inactivation gate are

  1. Manufacturing of {alpha}-Al{sub 2}O{sub 3} with high specific surface using urban waste and materials from uranium extractive metallurgy

    Energy Technology Data Exchange (ETDEWEB)

    Pascual Cosp, J.; Ramirez del Valle, A.J. [Dpto. Ingenieria Civil de Materiales y Fabricacion. E. T. S. I. I. Campus de El Ejido, s/n, Univ. de Malaga (Spain); Galiano Serrano, J.C. [Dpto. Ingenieria Civil de Materiales y Fabricacion. E. T. S. I. I. Campus de El Ejido, s/n, Univ. de Malaga (Spain); Unidad Asociada ' ' Lab. de Materiales y Superficies' ' Inst. de Ciencia de Materiales, UNSE-SCIC-Univ. de Malaga (Spain); Cordero Alcantara, T. [Dpto. Ingenieria Civil de Materiales y Fabricacion. E. T. S. I. I. Campus de El Ejido, s/n, Univ. de Malaga (Spain); Dpto. Ingenieria Quimica. E. T. S. I. I. Campus de El Ejido, s/n, Univ. de Malaga (Spain); Balek, V.; Cerny, Z.; Casensky, B. [Dpto. Ingenieria Civil de Materiales y Fabricacion. E. T. S. I. I. Campus de El Ejido, s/n, Univ. de Malaga (Spain); Charles Univ., Prague (Czech Republic)

    2004-07-01

    This work shows a comparative study of different methods to obtain {alpha}-Al{sub 2}O{sub 3} with high specific surface by chemical way using different precipitation methods. The efficacy of each method is studied with regard to material surface, establishing a correlation with the type of initial waste. If we can obtain supports with high crystallographical and dimensional stability and high specific surface, it's a very important contribution to catalytic process who need elevated temperatures. The use of waste supposes the capacity of manufacturing materials with a low cost and a option to give solutions for various environmental problems. (orig.)

  2. A K-alpha x-ray source using high energy and high repetition rate laser system for phase contrast imaging.

    Science.gov (United States)

    Serbanescu, Cristina; Fourmaux, Sylvain; Kieffer, Jean-Claude; Kincaid, Russell; Krol, Andrzej

    2009-01-01

    K-alpha x-ray sources from laser produced plasmas provide completely new possibilities for x-ray phase-contrast imaging applications. By tightly focusing intense femtosecond laser pulses onto a solid target K-alpha x-ray pulses are generated through the interaction of energetic electrons created in the plasma with the bulk target. In this paper, we present a continuous and efficient Mo K-alpha x-ray source produced by a femtosecond laser system operating at 100 Hz repetition rate with maximum pulse energy of 110 mJ before compression. The source has an x-ray conversion efficiency of greater than 10(-5) into K-alpha line emission. In preparation for phase contrast imaging applications, the size of the resultant K-alpha x-ray emission spot has been also characterized. The source exhibits sufficient spatial coherence to observe phase contrast. We observe a relatively small broadening of the K-alpha source size compared to the size of the laser beam itself. Detailed characterization of the source including the x-ray spectrum and the x-ray average yield along with phase contrast images of test objects will be presented.

  3. Molecular dynamics of water at high temperatures and pressures

    Science.gov (United States)

    Brodholt, John; Wood, Bernard

    1990-09-01

    There are currently no precise P-V-T data for water at pressures above 8.9 kbars and temperatures above 900°C. Many petrological processes in the lower crust and upper mantle take place under more extreme conditions, however and petrologists commonly rely on empirical equations of state such as the modified Redlich-Kwong equation (MRK) to extrapolate the low pressure data. In this study we have taken an alternative approach and attempted to simulate the P-V-T properties of water using molecular dynamics. The TIP4P intermolecular potential for H 2O ( JORGENSEN et al., 1983) has had considerable success predicting the properties of water at low temperatures and pressures up to 10 kbar ( MADURA et al., 1988). We have extended its application by making molecular dynamics (MD) simulations at a density of 1.0 g/cc from 300 to 2300 K and 0.5 to 40 kbars. The results agree with the P-V-T data of BURNHAM et al. (1969) (up to 10 kbars) with an average error of under 2%. This is a much better concordance than is obtained with any of the currently used versions of MRK. At 300 kbars and 2000 K the MD simulations predict densities within 8% of those obtained in the shock wave experiments of KORMER (1968). This is a very good agreement given the fact that water ionizes to some extent at high pressures ( MITCHELL and NELLIS, 1982) and we have made no provisions for this effect. We conclude that molecular dynamics simulations provide the possibility of estimating P-V-T properties in the upper mantle P-T regime with very good accuracy.

  4. Towards robust dynamical decoupling and high fidelity adiabatic quantum computation

    Science.gov (United States)

    Quiroz, Gregory

    Quantum computation (QC) relies on the ability to implement high-fidelity quantum gate operations and successfully preserve quantum state coherence. One of the most challenging obstacles for reliable QC is overcoming the inevitable interaction between a quantum system and its environment. Unwanted interactions result in decoherence processes that cause quantum states to deviate from a desired evolution, consequently leading to computational errors and loss of coherence. Dynamical decoupling (DD) is one such method, which seeks to attenuate the effects of decoherence by applying strong and expeditious control pulses solely to the system. Provided the pulses are applied over a time duration sufficiently shorter than the correlation time associated with the environment dynamics, DD effectively averages out undesirable interactions and preserves quantum states with a low probability of error, or fidelity loss. In this study various aspects of this approach are studied from sequence construction to applications of DD to protecting QC. First, a comprehensive examination of the error suppression properties of a near-optimal DD approach is given to understand the relationship between error suppression capabilities and the number of required DD control pulses in the case of ideal, instantaneous pulses. While such considerations are instructive for examining DD efficiency, i.e., performance vs the number of control pulses, high-fidelity DD in realizable systems is difficult to achieve due to intrinsic pulse imperfections which further contribute to decoherence. As a second consideration, it is shown how one can overcome this hurdle and achieve robustness and recover high-fidelity DD in the presence of faulty control pulses using Genetic Algorithm optimization and sequence symmetrization. Thirdly, to illustrate the implementation of DD in conjunction with QC, the utilization of DD and quantum error correction codes (QECCs) as a protection method for adiabatic quantum

  5. Quantum molecular dynamics simulations of beryllium at high pressures

    Science.gov (United States)

    Desjarlais, Michael; Knudson, Marcus

    2008-03-01

    The phase boundaries and high pressure melt properties of beryllium have been the subject of several recent experimental and theoretical studies. The interest is motivated in part by the use of beryllium as an ablator material in inertial confinement fusion capsule designs. In this work, the high pressure melt curve, Hugoniot crossings, sound speeds, and phase boundaries of beryllium are explored with DFT based quantum molecular dynamics calculations. The entropy differences between the various phases of beryllium are extracted in the vicinity of the melt curve and agree favorably with earlier theoretical work on normal melting. High velocity flyer plate experiments with beryllium targets on Sandia's Z machine have generated high quality data for the Hugoniot, bulk sound speeds, and longitudinal sound speeds. This data provides a tight constraint on the pressure for the onset of shock melting of beryllium and intriguing information on the solid phase prior to melt. The results of the QMD calculations and the experimental results will be compared, and implications for the HCP and BCC phase boundaries of beryllium will be presented.

  6. Relativistic nuclear recoil corrections to the energy levels of hydrogen-like and high Z lithium like atoms in all orders in $\\alpha$Z

    CERN Document Server

    Artemiev, A N; Yerokhin, V A

    1995-01-01

    The relativistic nuclear recoil corrections to the energy levels of low-laying states of hydrogen-like and high Z lithium-like atoms in all orders in \\alpha Z are calculated. The calculations are carried out using the B-spline method for the Dirac equation. For low Z the results of the calculation are in good agreement with the \\alpha Z -expansion results. It is found that the nuclear recoil contribution, additional to the Salpeter's one, to the Lamb shift (n=2) of hydrogen is -1.32(6)\\,kHz. The total nuclear recoil correction to the energy of the (1s)^{2}2p_{\\frac{1}{2}}-(1s)^{2}2s transition in lithium-like uranium constitutes -0.07\\,eV and is largely made up of QED contributions.

  7. Evaluation of Alternate Materials and Methods for Strontium and Alpha Removal from Savannah River Site High-Level Waste Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Hobbs, D.T.

    2000-11-07

    A literature survey indicated a number of alternate materials and methods for the removal of strontium and alpha-emitting radionuclides (actinides). We evaluated the use of alternate materials versus proposed flowsheets for salt processing at the Savannah River Site (SRS). From this evaluation we recommend the following materials for further testing to determine the rate and extent of removal. We do not recommend testing of liquid/liquid extraction and polymer filtration methods at this time.

  8. Disentangling seasonal bacterioplankton population dynamics by high-frequency sampling.

    Science.gov (United States)

    Lindh, Markus V; Sjöstedt, Johanna; Andersson, Anders F; Baltar, Federico; Hugerth, Luisa W; Lundin, Daniel; Muthusamy, Saraladevi; Legrand, Catherine; Pinhassi, Jarone

    2015-07-01

    Multiyear comparisons of bacterioplankton succession reveal that environmental conditions drive community shifts with repeatable patterns between years. However, corresponding insight into bacterioplankton dynamics at a temporal resolution relevant for detailed examination of variation and characteristics of specific populations within years is essentially lacking. During 1 year, we collected 46 samples in the Baltic Sea for assessing bacterial community composition by 16S rRNA gene pyrosequencing (nearly twice weekly during productive season). Beta-diversity analysis showed distinct clustering of samples, attributable to seemingly synchronous temporal transitions among populations (populations defined by 97% 16S rRNA gene sequence identity). A wide spectrum of bacterioplankton dynamics was evident, where divergent temporal patterns resulted both from pronounced differences in relative abundance and presence/absence of populations. Rates of change in relative abundance calculated for individual populations ranged from 0.23 to 1.79 day(-1) . Populations that were persistently dominant, transiently abundant or generally rare were found in several major bacterial groups, implying evolution has favoured a similar variety of life strategies within these groups. These findings suggest that high temporal resolution sampling allows constraining the timescales and frequencies at which distinct populations transition between being abundant or rare, thus potentially providing clues about physical, chemical or biological forcing on bacterioplankton community structure.

  9. Computational Fluid Dynamics Analysis of High Injection Pressure Blended Biodiesel

    Science.gov (United States)

    Khalid, Amir; Jaat, Norrizam; Faisal Hushim, Mohd; Manshoor, Bukhari; Zaman, Izzuddin; Sapit, Azwan; Razali, Azahari

    2017-08-01

    Biodiesel have great potential for substitution with petrol fuel for the purpose of achieving clean energy production and emission reduction. Among the methods that can control the combustion properties, controlling of the fuel injection conditions is one of the successful methods. The purpose of this study is to investigate the effect of high injection pressure of biodiesel blends on spray characteristics using Computational Fluid Dynamics (CFD). Injection pressure was observed at 220 MPa, 250 MPa and 280 MPa. The ambient temperature was kept held at 1050 K and ambient pressure 8 MPa in order to simulate the effect of boost pressure or turbo charger during combustion process. Computational Fluid Dynamics were used to investigate the spray characteristics of biodiesel blends such as spray penetration length, spray angle and mixture formation of fuel-air mixing. The results shows that increases of injection pressure, wider spray angle is produced by biodiesel blends and diesel fuel. The injection pressure strongly affects the mixture formation, characteristics of fuel spray, longer spray penetration length thus promotes the fuel and air mixing.

  10. Bubble cloud dynamics in a high-pressure spherical resonator

    Science.gov (United States)

    Anderson, Phillip Andrew

    A bubble cloud is a population of bubbles confined to a region within a fluid. Bubble clouds play a large role in a variety of naturally occurring phenomena and man-made applications (e.g., ocean noise, cavitation damage, sonoluminescence, ultrasonic cleaning, drug delivery, lithotripsy). It is important, therefore, to understand the behavior of bubble clouds so that their effects may be enhanced or diminished as desired. This work explores and characterizes the properties of bubble clouds nucleated inside a high-pressure spherical acoustic resonator, in connection with recent interest in acoustic inertial confinement fusion (acoustic ICF). A laser system was developed to repeatably nucleate a cloud of bubbles inside the resonator. The resulting events were then observed, primarily with schlieren imaging methods. Preliminary studies of the bubble cloud dynamics showed the sensitivity of the initial cloud to nucleation parameters including the phase of nucleation, the laser energy, and the acoustic power. After many acoustic cycles, some bubble clouds are observed to evolve into a tight cluster. The formation of these clusters correlates with initial bubble distributions which have a large cloud interaction parameter, β. Cluster dynamics are seen to be largely driven by reconverging shock waves from previous collapses reflected from the resonator's interior surface. Initial expansion of the cluster boundary is on the order of 8 mm/µs and the maximum radius approaches 3 mm. Shock pressures are estimated to be > 10 GPa at a radius of 100 µm using weak shock theory.

  11. Delocalization of Electrons in Strong Insulators at High Dynamic Pressures

    Directory of Open Access Journals (Sweden)

    William J. Nellis

    2011-06-01

    Full Text Available Systematics of material responses to shock flows at high dynamic pressures are discussed. Dissipation in shock flows drives structural and electronic transitions or crossovers, such as used to synthesize metallic liquid hydrogen and most probably Al2O3 metallic glass. The term “metal” here means electrical conduction in a degenerate system, which occurs by band overlap in degenerate condensed matter, rather than by thermal ionization in a non-degenerate plasma. Since H2 and probably disordered Al2O3 become poor metals with minimum metallic conductivity (MMC virtually all insulators with intermediate strengths do so as well under dynamic compression. That is, the magnitude of strength determines the split between thermal energy and disorder, which determines material response. These crossovers occur via a transition from insulators with electrons localized in chemical bonds to poor metals with electron energy bands. For example, radial extents of outermost electrons of Al and O atoms are 7 a0 and 4 a0, respectively, much greater than 1.7 a0 needed for onset of hybridization at 300 GPa. All such insulators are Mott insulators, provided the term “correlated electrons” includes chemical bonds.

  12. Pupil dilation dynamics track attention to high-level information.

    Directory of Open Access Journals (Sweden)

    Olivia E Kang

    Full Text Available It has long been thought that the eyes index the inner workings of the mind. Consistent with this intuition, empirical research has demonstrated that pupils dilate as a consequence of attentional effort. Recently, Smallwood et al. (2011 demonstrated that pupil dilations not only provide an index of overall attentional effort, but are time-locked to stimulus changes during attention (but not during mind-wandering. This finding suggests that pupil dilations afford a dynamic readout of conscious information processing. However, because stimulus onsets in their study involved shifts in luminance as well as information, they could not determine whether this coupling of stimulus and pupillary dynamics reflected attention to low-level (luminance or high-level (information changes. Here, we replicated the methodology and findings of Smallwood et al. (2011 while controlling for luminance changes. When presented with isoluminant digit sequences, participants' pupillary dilations were synchronized with stimulus onsets when attending, but not when mind-wandering. This replicates Smallwood et al. (2011 and clarifies their finding by demonstrating that stimulus-pupil coupling reflects online cognitive processing beyond sensory gain.

  13. Alpha Models for 3D Eulerian mean fluid circulation

    Energy Technology Data Exchange (ETDEWEB)

    Holm, D.D. [Los Alamos National Laboratory, Los Alamos, NM (United States). Center for Nonlinear Studies and Theoretical Division

    1999-12-01

    The study provides the known analytical properties of the alpha models, including an outline of their derivation and the associated assumptions, their simplification for the case of constant dispersion length (alpha) and their conservation properties. Interpretations of nonlinear dynamics of viscous alpha models are also showed and the differences one might expect from the dynamics of the Navier-Stokes equations are indicated.

  14. Beam manipulation techniques, nonlinear beam dynamics, and space charge effect in high energy high power accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S. Y.

    2014-04-07

    We had carried out a design of an ultimate storage ring with beam emittance less than 10 picometer for the feasibility of coherent light source at X-ray wavelength. The accelerator has an inherent small dynamic aperture. We study method to improve the dynamic aperture and collective instability for an ultimate storage ring. Beam measurement and accelerator modeling are an integral part of accelerator physics. We develop the independent component analysis (ICA) and the orbit response matrix method for improving accelerator reliability and performance. In collaboration with scientists in National Laboratories, we also carry out experimental and theoretical studies on beam dynamics. Our proposed research topics are relevant to nuclear and particle physics using high brightness particle and photon beams.

  15. High performance computation on beam dynamics problems in high intensity compact cyclotrons

    Institute of Scientific and Technical Information of China (English)

    ADELMANN; Andreas

    2011-01-01

    This paper presents the research progress in the beam dynamics problems for future high intensity compact cyclotrons by utilizing the state-of-the-art high performance computation technology. A "Start-to-Stop" model, which includes both the interaction of the internal particles of a single bunch and the mutual interaction of neighboring multiple bunches in the radial direction, is established for compact cyclotrons with multi-turn extraction. This model is then implemented in OPAL-CYCL, which is a 3D object-oriented parallel code for large scale particle simulations in cyclotrons. In addition, to meet the running requirement of parallel computation, we have constructed a small scale HPC cluster system and tested its performance. Finally, the high intensity beam dynamics problems in the 100 MeV compact cyclotron, which is being constructed at CIAE, are studied using this code and some conclusions are drawn.

  16. Conservation of the S10-spc-alpha locus within otherwise highly plastic genomes provides phylogenetic insight into the genus Leptospira.

    Science.gov (United States)

    Victoria, Berta; Ahmed, Ahmed; Zuerner, Richard L; Ahmed, Niyaz; Bulach, Dieter M; Quinteiro, Javier; Hartskeerl, Rudy A

    2008-07-16

    S10-spc-alpha is a 17.5 kb cluster of 32 genes encoding ribosomal proteins. This locus has an unusual composition and organization in Leptospira interrogans. We demonstrate the highly conserved nature of this region among diverse Leptospira and show its utility as a phylogenetically informative region. Comparative analyses were performed by PCR using primer sets covering the whole locus. Correctly sized fragments were obtained by PCR from all L. interrogans strains tested for each primer set indicating that this locus is well conserved in this species. Few differences were detected in amplification profiles between different pathogenic species, indicating that the S10-spc-alpha locus is conserved among pathogenic Leptospira. In contrast, PCR analysis of this locus using DNA from saprophytic Leptospira species and species with an intermediate pathogenic capacity generated varied results. Sequence alignment of the S10-spc-alpha locus from two pathogenic species, L. interrogans and L. borgpetersenii, with the corresponding locus from the saprophyte L. biflexa serovar Patoc showed that genetic organization of this locus is well conserved within Leptospira. Multilocus sequence typing (MLST) of four conserved regions resulted in the construction of well-defined phylogenetic trees that help resolve questions about the interrelationships of pathogenic Leptospira. Based on the results of secY sequence analysis, we found that reliable species identification of pathogenic Leptospira is possible by comparative analysis of a 245 bp region commonly used as a target for diagnostic PCR for leptospirosis. Comparative analysis of Leptospira strains revealed that strain H6 previously classified as L. inadai actually belongs to the pathogenic species L. interrogans and that L. meyeri strain ICF phylogenetically co-localized with the pathogenic clusters. These findings demonstrate that the S10-spc-alpha locus is highly conserved throughout the genus and may be more useful in comparing

  17. Dynamic distributions of tumor necrosis factor-alpha and its receptors in the red nucleus of rats with spared nerve injury.

    Science.gov (United States)

    Wang, Jing; Ding, Cui-Ping; Yu, Jing; Zeng, Xiao-Yan; Han, Shui-Ping; Wang, Jun-Yang

    2016-08-01

    Previous studies have demonstrated that tumor necrosis factor-alpha (TNF-α) in the red nucleus (RN) plays a facilitated role in the development of neuropathic pain, and its effect is transmitted through TNF-α receptor (TNFR) subtypes 1 and 2. Here, the dynamic distributions of TNF-α and TNFRs in the RN of rats with spared nerve injury (SNI) were investigated. Western blot analysis and immunofluorescence staining indicated that TNF-α was hardly expressed in the RN of normal rats but significantly increased at 1 week and peaked at 2 weeks after SNI. Neurons and oligodendrocytes showed TNF-α expression at both 1 week and 2 weeks after SNI, while astrocytes and microglia produced TNF-α later than neurons and oligodendrocytes starting at 2 weeks after SNI. TNFR1 was constitutively expressed in the RN of normal rats and significantly enhanced at 2 weeks but not 1 week after SNI; it was mainly localized in neurons, oligodendrocytes and microglia. Astrocytes were not immunopositive for TNFR1 under normal conditions and at 1 week after injury, but small amounts of astrocytes showed TNFR1 expression at 2 weeks after SNI. A low level of TNFR2 was expressed in the RN of normal rats, but it was significantly increased at 1 week and 2 weeks after SNI and localized in neurons and all three types of glia. These findings suggest that neurons and three types of glia in the RN all contribute to TNF-α production and participate in the initiation and/or maintenance of neuropathic pain induced by SNI. TNF-α exerts its effects in different types of cells maybe through different receptors, TNFR1 and/or TNFR2, in the different stages of neuropathic pain.

  18. High-harmonic generation enhanced by dynamical electron correlation

    CERN Document Server

    Tikhomirov, Iliya; Ishikawa, Kenichi L

    2016-01-01

    We theoretically study multielectron effects in high-harmonic generation (HHG), using all-electron first-principles simulations for a one-dimensional (1D) model atom. In addition to usual plateau and cutoff (from a cation in the present case, since the neutral is immediately ionized), we find a prominent resonance peak far above the plateau and a second plateau extended beyond the first cutoff. These features originate from the dication response enhanced by orders of magnitude due to the action of the Coulomb force from the rescattering electron, and, hence, are a clear manifestation of electron correlation. Although the present simulations are done in 1D, the physical mechanism underlying the dramatic enhancement is expected to hold also for three-dimensional real systems. This will provide new possibilities to explore dynamical electron correlation in intense laser fields using HHG, which is usually considered to be of single-electron nature in most cases.

  19. Biodegradation dynamics of high catechol concentrations by Aspergillus awamori.

    Science.gov (United States)

    Stanchev, Veselin; Stoilova, Ivanka; Krastanov, Albert

    2008-06-15

    The biodegradation process of high catechol concentrations by Aspergillus awamori was investigated. The values of the kinetic constants for a model of specific growth rate at different initial conditions were determined. At 1.0 g/L catechol concentration, the biodegradation process proceeded in the conditions of substrate limitation. At higher catechol concentrations (2.0 and 3.0 g/L) a presence of substrate inhibition was established. The dynamics of the specific catechol degradation rate was studied and the values of catechol and biomass concentrations, maximizing the specific catechol degradation rate, were estimated analytically. The specified ratio catechol/biomass could serve as a starting base for determination of the initial conditions for a batch process, for specifying the moment of feeding for a fed-batch process, and for monitoring and control of a continuous process by the aim of time-optimal control.

  20. Color Sensitivity Multiple Exposure Fusion using High Dynamic Range Image

    Directory of Open Access Journals (Sweden)

    Varsha Borole

    2014-02-01

    Full Text Available In this paper, we present a high dynamic range imaging (HDRI method using a capturing camera image using normally exposure, over exposure and under exposure. We make three different images from a multiple input image using local histogram stretching. Because the proposed method generated three histogram-stretched images from a multiple input image, ghost artifacts that are the result of the relative motion between the camera and objects during exposure time, are inherently removed. Therefore, the proposed method can be applied to a consumer compact camera to provide the ghost artifacts free HDRI. Experiments with several sets of test images with different exposures show that the proposed method gives a better performance than existing methods in terms of visual results and computation time.

  1. High resolution dynamical mapping of social interactions with active RFID

    CERN Document Server

    Barrat, Alain; Colizza, Vittoria; Pinton, Jean-Francois; Broeck, Wouter Van den; Vespignani, Alessandro

    2008-01-01

    In this paper we present an experimental framework to gather data on face-to-face social interactions between individuals, with a high spatial and temporal resolution. We use active Radio Frequency Identification (RFID) devices that assess contacts with one another by exchanging low-power radio packets. When individuals wear the beacons as a badge, a persistent radio contact between the RFID devices can be used as a proxy for a social interaction between individuals. We present the results of a pilot study %recently performed during a conference, and a subsequent preliminary data analysis, that provides an assessment of our method and highlights its versatility and applicability in many areas concerned with human dynamics.

  2. Applications of Asymptotic Sampling on High Dimensional Structural Dynamic Problems

    DEFF Research Database (Denmark)

    Sichani, Mahdi Teimouri; Nielsen, Søren R.K.; Bucher, Christian

    2011-01-01

    is minimized. Next, the method is applied on different cases of linear and nonlinear systems with a large number of random variables representing the dynamic excitation. The results show that asymptotic sampling is capable of providing good approximations of low failure probability events for very high......The paper represents application of the asymptotic sampling on various structural models subjected to random excitations. A detailed study on the effect of different distributions of the so-called support points is performed. This study shows that the distribution of the support points has...... considerable effect on the final estimations of the method, in particular on the coefficient of variation of the estimated failure probability. Based on these observations, a simple optimization algorithm is proposed which distributes the support points so that the coefficient of variation of the method...

  3. Applications of Asymptotic Sampling on High Dimensional Structural Dynamic Problems

    DEFF Research Database (Denmark)

    Sichani, Mahdi Teimouri; Nielsen, Søren R.K.; Bucher, Christian

    2011-01-01

    is minimized. Next, the method is applied on different cases of linear and nonlinear systems with a large number of random variables representing the dynamic excitation. The results show that asymptotic sampling is capable of providing good approximations of low failure probability events for very high......The paper represents application of the asymptotic sampling on various structural models subjected to random excitations. A detailed study on the effect of different distributions of the so-called support points is performed. This study shows that the distribution of the support points has...... considerable effect on the final estimations of the method, in particular on the coefficient of variation of the estimated failure probability. Based on these observations, a simple optimization algorithm is proposed which distributes the support points so that the coefficient of variation of the method...

  4. Stage III-IV Uterine Prolapse Risk Factors: Sacrouterine Ligaments High Estrogen Receptor Alpha and Collagen III Expression and Low Elastin Expression

    Directory of Open Access Journals (Sweden)

    I Wayan Megadhana

    2016-08-01

    Full Text Available Background: Uterine prolapse is common, non-life-threatening, but has a negative impact on women psychosocial and economic life. Damage to levator ani muscle is the early onset of uterine prolapse, while the damage of sacrouterine ligaments aggravates the stage. The strength of sacrouterine ligament depends on tissue cellularity, the formation of collagen I/III ratio, and the decreased expression of elastin. The lower the ratio of collagen I/III, the higher the risk of stage III-IV uterine prolapse. The ratio of collagen I/III formation is allegedly influencing through the expression of estrogen receptor alpha, by increasing collagen III synthesis and decreasing the degradation. Objective: We aimed to investigate whether high estrogen receptor alpha and collagen III expression, and the low elastin expression in the sacrouterine ligaments were stage III-IV uterine prolapse risk factors. Method: In March to August 2014, a non-matching case control study was conducted in 3 hospitals in Denpasar, and the materials were processed in the Faculty of Veterinary Medicine Laboratory of Udayana University. The case was uterine prolapse stage III-IV, the control was the non-uterine prolapse. We collected 1.5 cm residual sacrouterine ligaments from the edge of the cervix fixed with 10% buffered formalin from patients who underwent a total hysterectomy. They were examined immunohistochemically to identify estrogen receptor alpha expression, collagen III, and elastin. Results: Our sample was 44, divided equally between the case and control group. Compared to the control, in the case group, the proportion was significantly higher for the high estrogen receptor alpha expression (OR=5.71, 95%CI 1.56-20.93, p=0.007, high collagen III (OR=6.50, 95% CI 1.64- 25.76, p=0.005, and low elastin (OR=5.40, 95%CI 1.37-21.26, p=0.012. Conclusion: the high expression of estrogen receptor alpha and collagen III and low expressions of elastin in sacrouterine ligaments served as

  5. Alpha particle emitters in medicine

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, D.R.

    1989-09-01

    Radiation-induced cancer of bone, liver and lung has been a prominent harmful side-effect of medical applications of alpha emitters. In recent years, however, the potential use of antibodies labeled with alpha emitting radionuclides against cancer has seemed promising because alpha particles are highly effective in cell killing. High dose rates at high LET, effectiveness under hypoxic conditions, and minimal expectancy of repair are additional advantages of alpha emitters over antibodies labeled with beta emitting radionuclides for cancer therapy. Cyclotron-produced astatine-211 ({sup 211}At) and natural bismuth-212 ({sup 212}Bi) have been proposed and are under extensive study in the United States and Europe. Radium-223 ({sup 223}Ra) also has favorable properties as a potential alpha emitting label, including a short-lived daughter chain with four alpha emissions. The radiation dosimetry of internal alpha emitters is complex due to nonuniformly distributed sources, short particle tracks, and high relative specific ionization. The variations in dose at the cellular level may be extreme. Alpha-particle radiation dosimetry, therefore, must involve analysis of statistical energy deposition probabilities for cellular level targets. It must also account fully for nonuniform distributions of sources in tissues, source-target geometries, and particle-track physics. 18 refs., 4 figs.

  6. High-speed imaging of dynamic shock wave reflection phenomena

    CSIR Research Space (South Africa)

    Naidoo, K

    2010-09-01

    Full Text Available Dynamic shock wave reflection generated by a rapidly pitching wedge in a steady supersonic free stream has been studied with numerical simulation previously. An experimental facility was developed for the investigation of these dynamic phenomena...

  7. Hexamethylenetetramine directed synthesis and properties of a new family of alpha-nickel hydroxide organic-inorganic hybrid materials with high chemical stability.

    Science.gov (United States)

    Liu, Bian-Hua; Yu, Shu-Hong; Chen, Shao-Feng; Wu, Chun-Yan

    2006-03-09

    A new family of organic-inorganic hybrid material of alpha-nickel hydroxide formulated as Ni(OH)2-x(An-)x/n-(C6H12N4)y.zH2O (A=Cl-, CH3COO-, SO4(2-), NO3-; x=0.05-0.18, y=0.09-0.11, z=0.36-0.43) with high stability and adjustable interlayer spacing ranging from 7.21 to 15.12 A has been successfully prepared by a simple hydrothermal method. The effects of various anions and hexamethylenetetramine (HMT) on the d values of alpha-nickel hydroxide have been systematically investigated. This family of hybrid materials is of such high stability that they can stand more than 40 days in 6 M KOH. The product with a formula Ni(OH)1.95(C6H12N4)0.11(Cl-)0.05(H2O)0.36 has a high surface area of about 299.26 m2/g and an average pore diameter of about 45.1 A. The coercivity (Hc) value is ca. 2000 Oe for the sample with a d spacing of 13.14 A. Moreover, the prepared alpha-Ni(OH)2 in our experiment is of high stability in strong alkali solution. Such high stability could be derived from strong chelating interactions between the Ni ions and HMT molecules with the interlayers. This high chemical stability could make this material more suitable for the applications.

  8. Production of enzymatically active recombinant full-length barley high pI alpha-glucosidase of glycoside family 31 by high cell-density fermentation of Pichia pastoris and affinity purification

    DEFF Research Database (Denmark)

    Næsted, Henrik; Kramhøft, Birte; Lok, F.

    2006-01-01

    Recombinant barley high pI alpha-glucosidase was produced by high cell-density fermentation of Pichia pastoris expressing the cloned full-length gene. The gene was amplified from a genomic clone and exons (coding regions) were assembled by overlap PCR. The resulting cDNA was expressed under contr...... nM x s(-1), and 85 s(-1) using maltose as substrate. This work presents the first production of fully active recombinant alpha-glucosidase of glycoside hydrolase family 31 from higher plants. (c) 2005 Elsevier Inc. All rights reserved.......Recombinant barley high pI alpha-glucosidase was produced by high cell-density fermentation of Pichia pastoris expressing the cloned full-length gene. The gene was amplified from a genomic clone and exons (coding regions) were assembled by overlap PCR. The resulting cDNA was expressed under control...... of the alcohol oxidase 1 promoter using methanol induction of P. pastoris fermentation in a Biostat B 5 L reactor. Forty-two milligrams a-glucosidase was purified from 3.5 L culture in four steps applying an N-terminal hexa-histidine tag. The apparent molecular mass of the recombinant alpha-glucosidase was 100 k...

  9. High Precision Sunphotometer using Wide Dynamic Range (WDR) Camera Tracking

    Science.gov (United States)

    Liss, J.; Dunagan, S. E.; Johnson, R. R.; Chang, C. S.; LeBlanc, S. E.; Shinozuka, Y.; Redemann, J.; Flynn, C. J.; Segal-Rosenhaimer, M.; Pistone, K.; Kacenelenbogen, M. S.; Fahey, L.

    2016-12-01

    High Precision Sunphotometer using Wide Dynamic Range (WDR) Camera TrackingThe NASA Ames Sun-photometer-Satellite Group, DOE, PNNL Atmospheric Sciences and Global Change Division, and NASA Goddard's AERONET (AErosol RObotic NETwork) team recently collaborated on the development of a new airborne sunphotometry instrument that provides information on gases and aerosols extending far beyond what can be derived from discrete-channel direct-beam measurements, while preserving or enhancing many of the desirable AATS features (e.g., compactness, versatility, automation, reliability). The enhanced instrument combines the sun-tracking ability of the current 14-Channel NASA Ames AATS-14 with the sky-scanning ability of the ground-based AERONET Sun/sky photometers, while extending both AATS-14 and AERONET capabilities by providing full spectral information from the UV (350 nm) to the SWIR (1,700 nm). Strengths of this measurement approach include many more wavelengths (isolated from gas absorption features) that may be used to characterize aerosols and detailed (oversampled) measurements of the absorption features of specific gas constituents. The Sky Scanning Sun Tracking Airborne Radiometer (3STAR) replicates the radiometer functionality of the AATS-14 instrument but incorporates modern COTS technologies for all instruments subsystems. A 19-channel radiometer bundle design is borrowed from a commercial water column radiance instrument manufactured by Biospherical Instruments of San Diego California (ref, Morrow and Hooker)) and developed using NASA funds under the Small Business Innovative Research (SBIR) program. The 3STAR design also incorporates the latest in robotic motor technology embodied in Rotary actuators from Oriental motor Corp. having better than 15 arc seconds of positioning accuracy. Control system was designed, tested and simulated using a Hybrid-Dynamical modeling methodology. The design also replaces the classic quadrant detector tracking sensor with a

  10. Enzyme-synthesized highly branched maltodextrins have slow glucose generation at the mucosal alpha-glucosidase level and are slowly digestible "in vivo"

    Science.gov (United States)

    For digestion of starch in humans, alpha-amylase first hydrolyzes starch molecules to produce alpha-limit dextrins, followed by complete hydrolysis to glucose by the mucosal alpha-glucosidases in the small intestine. It is known that alpha-1,6 linkages in starch are hydrolyzed at a lower rate than a...

  11. New fabrication techniques for high dynamic range tunneling sensors

    Science.gov (United States)

    Chang, David T.; Stratton, Fred P.; Kubena, Randall L.; Vickers-Kirby, Deborah J.; Joyce, Richard J.; Schimert, Thomas R.; Gooch, Roland W.

    2000-08-01

    We have developed high dynamic range (105-106 g's) tunneling accelerometers1,2 that may be ideal for smart munitions applications by employing both surface and bulk micromachining processing techniques. The highly miniaturized surface-micromachined devices can be manufactured at very low cost and integrated on chip with the control electronics. Bulk-micromachined devices with Si as the cantilever material should have reduced long-term bias drift as well as better stability at higher temperatures. Fully integrated sensors may provide advantages in minimizing microphonics for high-g applications. Previously, we described initial test results using electrostatic forces generated by a self-test electrode located under a Au cantilever3. In this paper, we describe more recent testing of Ni and Au cantilever devices on a shaker table using a novel, low input voltage (5 V) servo controller on both printed wiring board and surface-mount control circuitry. In addition, we report our initial test results for devices packaged using a low-temperature wafer-level vacuum packaging technique for low-cost manufacturing.

  12. High-Precision Computation: Mathematical Physics and Dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, D. H.; Barrio, R.; Borwein, J. M.

    2010-04-01

    At the present time, IEEE 64-bit oating-point arithmetic is suficiently accurate for most scientic applications. However, for a rapidly growing body of important scientic computing applications, a higher level of numeric precision is required. Such calculations are facilitated by high-precision software packages that include high-level language translation modules to minimize the conversion e ort. This pa- per presents a survey of recent applications of these techniques and provides someanalysis of their numerical requirements. These applications include supernova simulations, climate modeling, planetary orbit calculations, Coulomb n-body atomic systems, studies of the one structure constant, scattering amplitudes of quarks, glu- ons and bosons, nonlinear oscillator theory, experimental mathematics, evaluation of orthogonal polynomials, numerical integration of ODEs, computation of periodic orbits, studies of the splitting of separatrices, detection of strange nonchaotic at- tractors, Ising theory, quantum held theory, and discrete dynamical systems. We conclude that high-precision arithmetic facilities are now an indispensable compo- nent of a modern large-scale scientic computing environment.

  13. Electromagnetic effects on dynamics of high-beta filamentary structures

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Wonjae; Krasheninnikov, Sergei I., E-mail: skrash@mae.ucsd.edu [University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093 (United States); Umansky, Maxim V. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States); Angus, J. R. [Naval Research Laboratory, 4555 Overlook Avenue, Washington, DC 20375 (United States)

    2015-01-15

    The impacts of the electromagnetic effects on blob dynamics are considered. Electromagnetic BOUT++ simulations on seeded high-beta blobs demonstrate that inhomogeneity of magnetic curvature or plasma pressure along the filament leads to bending of the blob filaments and the magnetic field lines due to increased propagation time of plasma current (Alfvén time). The bending motion can enhance heat exchange between the plasma facing materials and the inner scrape-off layer (SOL) region. The effects of sheath boundary conditions on the part of the blob away from the boundary are also diminished by the increased Alfvén time. Using linear analysis and BOUT++ simulations, it is found that electromagnetic effects in high temperature and high density plasmas reduce the growth rate of resistive drift wave instability when resistivity drops below a certain value. The blobs temperature decreases in the course of its motion through the SOL and so the blob can switch from the electromagnetic to the electrostatic regime where resistive drift waves become important again.

  14. Molecular Dynamics Simulations on High-Performance Reconfigurable Computing Systems.

    Science.gov (United States)

    Chiu, Matt; Herbordt, Martin C

    2010-11-01

    The acceleration of molecular dynamics (MD) simulations using high-performance reconfigurable computing (HPRC) has been much studied. Given the intense competition from multicore and GPUs, there is now a question whether MD on HPRC can be competitive. We concentrate here on the MD kernel computation: determining the short-range force between particle pairs. In one part of the study, we systematically explore the design space of the force pipeline with respect to arithmetic algorithm, arithmetic mode, precision, and various other optimizations. We examine simplifications and find that some have little effect on simulation quality. In the other part, we present the first FPGA study of the filtering of particle pairs with nearly zero mutual force, a standard optimization in MD codes. There are several innovations, including a novel partitioning of the particle space, and new methods for filtering and mapping work onto the pipelines. As a consequence, highly efficient filtering can be implemented with only a small fraction of the FPGA's resources. Overall, we find that, for an Altera Stratix-III EP3ES260, 8 force pipelines running at nearly 200 MHz can fit on the FPGA, and that they can perform at 95% efficiency. This results in an 80-fold per core speed-up for the short-range force, which is likely to make FPGAs highly competitive for MD.

  15. Dynamically supported geoid highs over hotspots: Observation and theory

    Science.gov (United States)

    Richards, M. A.; Hager, B. H.; Sleep, N. H.

    1986-01-01

    Hotspots are associated with long wavelength geoid highs, an association that is even stronger when the geoid highs associated with subduction zones are removed. These associations are quantified by expanding the hotspot distribution in spherical harmonics and calculating correlation coefficients as a function of harmonic degree. The hotspot distribution spectrum is essentially white, with peaks at degrees 2 and 6. It is correlated positively with the slab residual geoid for degrees 2 to 6, with low seismic velocity in the lower mantle at degree 2, and with low seismic velocity in the upper mantle at degree 6. A variety of fluid mechanical models were tested for hotspots, including lithospheric delamination and hot plumes, by calculating their predicted dynamic geoid responses and comparing them to the observations. These models include the effects of temperature dependent rheology. The preferred hotspot model, based on observations of the geoid and seismic tomography, has plumes preferentially occurring in regions of large scale background temperature highs in a mantle with substantial viscosity increase with depth, although other models are possible.

  16. Dynamically supported geoid highs over hotspots - Observation and theory

    Science.gov (United States)

    Richards, Mark A.; Hager, Bradford H.; Sleep, Norman H.

    1988-01-01

    Hotspots are associated with long wavelength geoid highs, an association that is even stronger when the geoid highs associated with subduction zones are removed. These associations are quantified by expanding the hotspot distribution in spherical harmonics and calculating correlation coefficients as a function of harmonic degree. The hotspot distribution spectrum is essentially white, with peaks at degrees 2 and 6. It is correlated positively with the slab residual geoid for degrees 2 to 6, with low seismic velocity in the lower mantle at degree 2, and with low seismic velocity in the upper mantle at degree 6. A variety of fluid mechanical models were tested for hotspots, including lithospheric delamination and hot plumes, by calculating their predicted dynamic geoid responses and comparing them to the observations. These models include the effects of temperature dependent rheology. The preferred hotspot model, based on observations of the geoid and seismic tomography, has plumes preferentially occurring in regions of large scale background temperature highs in a mantle with substantial viscosity increase with depth, although other models are possible.

  17. High-Performance Java Codes for Computational Fluid Dynamics

    Science.gov (United States)

    Riley, Christopher; Chatterjee, Siddhartha; Biswas, Rupak; Biegel, Bryan (Technical Monitor)

    2001-01-01

    The computational science community is reluctant to write large-scale computationally -intensive applications in Java due to concerns over Java's poor performance, despite the claimed software engineering advantages of its object-oriented features. Naive Java implementations of numerical algorithms can perform poorly compared to corresponding Fortran or C implementations. To achieve high performance, Java applications must be designed with good performance as a primary goal. This paper presents the object-oriented design and implementation of two real-world applications from the field of Computational Fluid Dynamics (CFD): a finite-volume fluid flow solver (LAURA, from NASA Langley Research Center), and an unstructured mesh adaptation algorithm (2D_TAG, from NASA Ames Research Center). This work builds on our previous experience with the design of high-performance numerical libraries in Java. We examine the performance of the applications using the currently available Java infrastructure and show that the Java version of the flow solver LAURA performs almost within a factor of 2 of the original procedural version. Our Java version of the mesh adaptation algorithm 2D_TAG performs within a factor of 1.5 of its original procedural version on certain platforms. Our results demonstrate that object-oriented software design principles are not necessarily inimical to high performance.

  18. Dynamic High-Temperature Characterization of an Iridium Alloy in Compression at High Strain Rates

    Energy Technology Data Exchange (ETDEWEB)

    Song, Bo [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Experimental Environment Simulation Dept.; Nelson, Kevin [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Mechanics of Materials Dept.; Lipinski, Ronald J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Advanced Nuclear Fuel Cycle Technology Dept.; Bignell, John L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Structural and Thermal Analysis Dept.; Ulrich, G. B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Radioisotope Power Systems Program; George, E. P. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Radioisotope Power Systems Program

    2014-06-01

    Iridium alloys have superior strength and ductility at elevated temperatures, making them useful as structural materials for certain high-temperature applications. However, experimental data on their high-temperature high-strain-rate performance are needed for understanding high-speed impacts in severe elevated-temperature environments. Kolsky bars (also called split Hopkinson bars) have been extensively employed for high-strain-rate characterization of materials at room temperature, but it has been challenging to adapt them for the measurement of dynamic properties at high temperatures. Current high-temperature Kolsky compression bar techniques are not capable of obtaining satisfactory high-temperature high-strain-rate stress-strain response of thin iridium specimens investigated in this study. We analyzed the difficulties encountered in high-temperature Kolsky compression bar testing of thin iridium alloy specimens. Appropriate modifications were made to the current high-temperature Kolsky compression bar technique to obtain reliable compressive stress-strain response of an iridium alloy at high strain rates (300 – 10000 s-1) and temperatures (750°C and 1030°C). Uncertainties in such high-temperature high-strain-rate experiments on thin iridium specimens were also analyzed. The compressive stress-strain response of the iridium alloy showed significant sensitivity to strain rate and temperature.

  19. Novel Logarithmic Active Pixel Sensor with High Dynamic Range and High Output Swing

    Institute of Scientific and Technical Information of China (English)

    FU Xian-song; YAO Su-ying; YUAN Yi-dong; XU Jiang-tao; DING Ke; YAN Kun-shan

    2008-01-01

    The logarithmic response complementary metal oxide semiconductor(CMOS) image sensor provides a wide dynamic range, but its drawback is the lack of simple fixed pattern noise(FPN) cancellation scheme. Designed is a novel logarithmic active pixel sensor(APS) with high dynamic range and high output swing. Firstly, the operation principle of mixed-model APS is introduced. The pixel can work in three operation modes by choosing the proper control signals. Then, FPN sources of logarithmic APS are analyzed, and double-sampled technique is implemented to reduce FPN. Finally, according to the simulation results, layout is designed and has passed design rule check(DRC), electronic rule check(ERC) and layout versus schematic(LVS) verifications, and the post-simulation results are basically in agreement with the simulation results. Dynamic range of the new logarithmic APS can reach about 140 dB; and the output swing is about 750 mV. Results show that by using double sampled technique, most FPN is eliminated and the dynamic range is enhanced.

  20. Small angle X-ray scattering of wheat seed-storage proteins: alpha-, gamma- and omega-gliadins and the high molecular weight (HMW) subunits of glutenin.

    Science.gov (United States)

    Thomson, N H; Miles, M J; Popineau, Y; Harries, J; Shewry, P; Tatham, A S

    1999-03-19

    Small angle X-ray scattering in solution was performed on seed-storage proteins from wheat. Three different groups of gliadins (alpha-, gamma- and omega-) and a high molecular weight (HMW) subunit of glutenin (1Bx20) were studied to determine molecular size parameters. All the gliadins could be modelled as prolate ellipsoids with extended conformations. The HMW subunit existed as a highly extended rod-like particle in solution with a length of about 69 nm and a diameter of about 6.4 nm. Specific aggregation effects were observed which may reflect mechanisms of self-assembly that contribute to the unique viscoelastic properties of wheat dough.

  1. A model for the generic alpha relaxation in viscous liquids

    DEFF Research Database (Denmark)

    Dyre, Jeppe

    2005-01-01

    . Rev. Lett., 86 (2001) 1271]. Assuming that long-wavelength fluctuations dominate the dynamics, a model for the dielectric alpha relaxation based on the simplest coupling between the density and dipole density fields is proposed here. The model, which is solved in second-order perturbation theory......Dielectric measurements on molecular liquids just above the glass transition indicate that alpha relaxation is characterized by a generic high-frequency loss varying as one over square root of frequency, whereas deviations from this come from one or more low-lying beta processes [Olsen et al., Phys...

  2. Spectroscopy of z ~ 7 candidate galaxies: Using Lyman-alpha to constrain the neutral fraction of hydrogen in the high-redshift universe

    CERN Document Server

    Caruana, Joseph; Wilkins, Stephen M; Stanway, Elizabeth R; Lorenzoni, Silvio; Jarvis, Matt J; Elbert, Holly

    2013-01-01

    Following our previous spectroscopic observations of $z>7$ galaxies with Gemini/GNIRS and VLT/XSHOOTER, which targeted a total of 8 objects, we present here our results from a deeper and larger VLT/FORS2 spectroscopic sample of Wide Field Camera 3 selected $z>7$ candidate galaxies. With our FORS2 setup we cover the 737-1070nm wavelength range, enabling a search for Lyman-$\\alpha$ in the redshift range spanning 5.06 - 7.80. We target 22 $z$-band dropouts and find no evidence of Lyman-$\\alpha$ emission. The upper limits on Lyman-$\\alpha$ flux and the broad-band magnitudes are used to constrain the rest-frame Equivalent Widths for this line emission. We analyse our FORS2 observations in combination with our previous GNIRS and XSHOOTER observations, and suggest that a simple model where the fraction of high rest-frame Equivalent Width emitters follows the trend seen at $z=3-6.5$ is inconsistent with our non-detections at $z\\sim7.8$ at the 96\\% confidence level. This may indicate that a significant neutral HI frac...

  3. Water Temperature Dynamics in High Arctic River Basins

    Science.gov (United States)

    Blaen, P. J.; Hannah, D. M.; Brown, L. E.; Milner, A. M.

    2012-04-01

    Despite the high sensitivity of polar regions to climate change, and the strong influence of temperature upon ecosystem processes, contemporary understanding of water temperature dynamics in Arctic river systems is limited. This research gap is addressed by exploring high-resolution water column thermal regimes for glacier-fed and non-glacial rivers at eight sites across Svalbard during the 2010 melt season. Mean water column temperatures in glacier-fed rivers (0.3 - 3.2 °C) were the lowest and most thermally-stable near the glacier terminus but increased downstream (0.7 - 2.3 °C km-1). Non-glacial rivers, where discharge was sourced primarily from snowmelt, were warmer (mean 2.9 - 5.7 °C) and more variable, indicating increased water residence times in shallow alluvial zones with increased potential for atmospheric influence. Mean summer water temperature and the magnitude of daily thermal variation were similar to those of Alaskan rivers but low at all sites when compared to alpine glacierized environments at lower latitudes. Thermal regimes were strongly correlated (pgeomorphological features (e.g. channel morphology). These results provide insight into the potential changes in high-latitude river systems in the context of projected warming in polar regions. We hypothesise warmer and more variable temperature regimes may prevail in future as the proportion of bulk discharge sourced from glacial meltwater declines and rivers undergo a progressive shift towards snow- and groundwater sources. Importantly, such changes could have implications for species diversity and abundance in benthic communities and influence rates of ecosystem functioning in high-latitude aquatic systems.

  4. A High-Resolution Sensor Network for Monitoring Glacier Dynamics

    Science.gov (United States)

    Edwards, S.; Murray, T.; O'Farrell, T.; Rutt, I. C.; Loskot, P.; Martin, I.; Selmes, N.; Aspey, R.; James, T.; Bevan, S. L.; Baugé, T.

    2013-12-01

    Changes in Greenland and Antarctic ice sheets due to ice flow/ice-berg calving are a major uncertainty affecting sea-level rise forecasts. Latterly GNSS (Global Navigation Satellite Systems) have been employed extensively to monitor such glacier dynamics. Until recently however, the favoured methodology has been to deploy sensors onto the glacier surface, collect data for a period of time, then retrieve and download the sensors. This approach works well in less dynamic environments where the risk of sensor loss is low. In more extreme environments e.g. approaching the glacial calving front, the risk of sensor loss and hence data loss increases dramatically. In order to provide glaciologists with new insights into flow dynamics and calving processes we have developed a novel sensor network to increase the robustness of data capture. We present details of the technological requirements for an in-situ Zigbee wireless streaming network infrastructure supporting instantaneous data acquisition from high resolution GNSS sensors thereby increasing data capture robustness. The data obtained offers new opportunities to investigate the interdependence of mass flow, uplift, velocity and geometry and the network architecture has been specifically designed for deployment by helicopter close to the calving front to yield unprecedented detailed information. Following successful field trials of a pilot three node network during 2012, a larger 20 node network was deployed on the fast-flowing Helheim glacier, south-east Greenland over the summer months of 2013. The utilisation of dual wireless transceivers in each glacier node, multiple frequencies and four ';collector' stations located on the valley sides creates overlapping networks providing enhanced capacity, diversity and redundancy of data 'back-haul', even close to ';floor' RSSI (Received Signal Strength Indication) levels around -100 dBm. Data loss through radio packet collisions within sub-networks are avoided through the

  5. A novel high throughput screening assay for binding affinities of perfluoroalkyl iodide for estrogen receptor alpha and beta isoforms.

    Science.gov (United States)

    Song, Wenting; Zhao, Lixia; Sun, Zhendong; Yang, Xiaoxi; Zhou, Qunfang; Jiang, Guibin

    2017-12-01

    Contaminants of emerging concern are continuously increasing, which makes it important to develop high throughput screening techniques for the evaluation of their potential biological effects, especially endocrine disrupting effects, which would directly influence the population dynamics in environment. A novel competitive binding assay based on enzyme fragmentation complementation technology was established to screen the binding affinities of emerging chemicals for estrogen receptor (ER) α or β isoforms. Exogenous compounds could compete with the fragment (ED-ES) of genetically engineered β-galactosidase enzyme (β-gal) for the binding to ERα or β, thus quantitatively altering the formation of enzymatically active β-gal and the hydrolysis of luminescent substrate. According to the monitoring of luminescence curves and the optimization of ERα or β concentrations, it was found that luminescent signals were sustainably emitted for 9h, and 40nM ERα or β in the system would lead to the most sensitive luminescence response. Using 17β-estrodiol (E2) and genistein as the representative estrogenic hormones, their binding affinities for ERα and β were evaluated. The results were consistent with those determined by traditional methods, which confirmed the reliability of this competitive binding assay based on β-gal. Four polyfluorinated iodine alkanes (PFIs) with specific structural characteristics in iodine substitution and carbon chain length were screened, and the results showed diverse binding affinities and different preferences of these chemicals to ERα or β isoforms. The binding affinities of PFIs for ERα were consistent with the result from MVLN transcriptional reporter assay. Overall, the competitive binding assay presented in this study provided a promising alternative to high throughput screening of emerging chemicals with estrogenic effects, which would be important in explanation of their potential toxicological effects and human exposure risks

  6. Application of nonlinear dynamic techniques to high pressure plasma jets

    Science.gov (United States)

    Ghorui, S.; Das, A. K.

    2010-02-01

    Arcs and arc plasmas have been known and used for welding, cutting, chemical synthesis and multitude of other industrial applications for more than hundred years. Though a copious source of heat, light and active species, plasma arc is inherently unstable, turbulent and difficult to control. During recent years, primarily driven by the need of new and energy efficient materials processing, various research groups around the world have been studying new and innovative ways of looking at the issues related to arc dynamics, arc stabilization, species non equilibrium, flow and heat transfer in a stabilized arc plasma device. In this context, experimental determination of nature of arc instabilities using tools of non-linear dynamics, theoretical model formulation, prediction of instability behavior under given operating conditions and possible control methods for the observed instabilities in arcs are reviewed. Space selective probing of the zones inside arc plasma devices without disturbing the system is probably the best way to identify the originating zone of instabilities inside such devices. Existence of extremely high temperature and inaccessibility to direct experimentations due to mechanical obstructions make this task extremely difficult. Probing instabilities in otherwise inaccessible inner regions of the torches, using binary gas mixture as plasma gas is a novel technique that primarily rests on a process known as demixing in arcs. Once a binary gas mixture enters the constricted plasma column, the demixing process sets in causing spatial variations for each of the constituent gases depending on the diffusion coefficients and the gradient of the existing temperature field. By varying concentrations of the constituent gases in the feeding line, it is possible to obtain spatial variations of the plasma composition in a desired manner, enabling spatial probing of the associated zones. Detailed compositional description of different zones inside the torch may be

  7. High frame-rate neutron radiography of dynamic events

    Energy Technology Data Exchange (ETDEWEB)

    Bossi, R.H.; Robinson, A.H.; Barton, J.P.

    1981-11-20

    A system has been developed to perform neutron radiographic analysis of dynamic events having a duration of several milliseconds. The system has been operated in the range of 2000 to 10,000 frames/second. Synchronization has provided high-speed-motion neutron radiographs for evaluation of the firing cycle of 7.62 mm munition rounds within a steel rifle barrel. The system has also been used to demonstrate the ability to produce neutron radiographic movies of two-phase flow. The equipment uses the Oregon State University TRIGA reactor capable of pulsing to 3000 MW peak power, a neutron beam collimator, a scintillator neutron conversion screen coupled to an image intensifier, and a 16 mm high speed movie camera. The peak neutron flux incident at the object position is approximately 4 x 10/sup 11/ n/cm/sup 2/s with a pulse, full width at half maximum, of 9 ms. Special studies have been performed on the scintillator conversion screens and on the effects of statistical limitations on the image quality. Modulation transfer function analysis has been used to assist in the evaluation of the system performance.

  8. Quantitative high dynamic range beam profiling for fluorescence microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, T. J., E-mail: t.j.mitchell@dur.ac.uk; Saunter, C. D.; O’Nions, W.; Girkin, J. M.; Love, G. D. [Centre for Advanced Instrumentation and Biophysical Sciences Institute, Department of Physics, Durham University, Durham DH1 3LE (United Kingdom)

    2014-10-15

    Modern developmental biology relies on optically sectioning fluorescence microscope techniques to produce non-destructive in vivo images of developing specimens at high resolution in three dimensions. As optimal performance of these techniques is reliant on the three-dimensional (3D) intensity profile of the illumination employed, the ability to directly record and analyze these profiles is of great use to the fluorescence microscopist or instrument builder. Though excitation beam profiles can be measured indirectly using a sample of fluorescent beads and recording the emission along the microscope detection path, we demonstrate an alternative approach where a miniature camera sensor is used directly within the illumination beam. Measurements taken using our approach are solely concerned with the illumination optics as the detection optics are not involved. We present a miniature beam profiling device and high dynamic range flux reconstruction algorithm that together are capable of accurately reproducing quantitative 3D flux maps over a large focal volume. Performance of this beam profiling system is verified within an optical test bench and demonstrated for fluorescence microscopy by profiling the low NA illumination beam of a single plane illumination microscope. The generality and success of this approach showcases a widely flexible beam amplitude diagnostic tool for use within the life sciences.

  9. Using inorganic POSS-modified laponite clay to support a nickel {alpha}-diimine catalyst for in situ formation of high performance polyethylene nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    He Fuan; Zhang Liming [Laboratory for Polymer Composite and Functional Materials, Institute of Optoelectronic and Functional Composite Materials, School of Chemistry and Chemical Engineering, Sun Yat-Sen (Zhongshan) University, Guangzhou 510275 (China)

    2006-12-28

    A new strategy was developed for in situ formation of polyethylene nanocomposites, in which synthetic laponite clay was first modified by octaaminopropyl polyhedral oligometric silsesquioxane (OapPOSS) and then used to support a nickel {alpha}-diimine late-transition-metal catalyst for ethylene polymerization. The resulting polyethylene nanocomposites were investigated with respect to their structure and properties by x-ray diffraction analysis (XRD), transmission electron microscopy (TEM), nuclear magnetic resonance (NMR), dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA). It was found that the layered silicates could be exfoliated effectively in the polyethylene matrix. In comparison with pure polyethylene, the polyethylene in the nanocomposites has a lower branching degree. The combination of OapPOSS with the laponite clay particles results in a remarkable increase in storage modulus and thermal decomposition temperature.

  10. High-density lipoprotein proteome dynamics in human endotoxemia

    Directory of Open Access Journals (Sweden)

    Stroes Erik SG

    2011-06-01

    Full Text Available Abstract Background A large variety of proteins involved in inflammation, coagulation, lipid-oxidation and lipid metabolism have been associated with high-density lipoprotein (HDL and it is anticipated that changes in the HDL proteome have implications for the multiple functions of HDL. Here, SELDI-TOF mass spectrometry (MS was used to study the dynamic changes of HDL protein composition in a human experimental low-dose endotoxemia model. Ten healthy men with low HDL cholesterol (0.7+/-0.1 mmol/L and 10 men with high HDL cholesterol levels (1.9+/-0.4 mmol/L were challenged with endotoxin (LPS intravenously (1 ng/kg bodyweight. We previously showed that subjects with low HDL cholesterol are more susceptible to an inflammatory challenge. The current study tested the hypothesis that this discrepancy may be related to differences in the HDL proteome. Results Plasma drawn at 7 time-points over a 24 hour time period after LPS challenge was used for direct capture of HDL using antibodies against apolipoprotein A-I followed by subsequent SELDI-TOF MS profiling. Upon LPS administration, profound changes in 21 markers (adjusted p-value Conclusions This study shows that the semi-quantitative differences in the HDL proteome as assessed by SELDI-TOF MS cannot explain why subjects with low HDL cholesterol are more susceptible to a challenge with LPS than those with high HDL cholesterol. Instead the results indicate that hierarchical clustering could be useful to predict HDL functionality in acute phase responses towards LPS.

  11. Fractional {sup 13}C enrichment of isolated carbons using [1-{sup 13}C]- or [2-{sup 13}C]-glucose facilitates the accurate measurement of dynamics at backbone C{sup {alpha}} and side-chain methyl positions in proteins

    Energy Technology Data Exchange (ETDEWEB)

    Lundstroem, Patrik [University of Toronto, Departments of Medical Genetics and Chemistry (Canada); Teilum, Kaare; Carstensen, Tommy [Lund University, Department of Biophysical Chemistry (Sweden); Bezsonova, Irina [University of Toronto, Department of Chemistry (Canada); Wiesner, Silke [University of Toronto, Department of Biochemistry (Canada); Hansen, D. Flemming [University of Toronto, Departments of Medical Genetics and Chemistry (Canada); Religa, Tomasz L. [Medical Research Council Centre for Protein Engineering (United Kingdom); Akke, Mikael [Lund University, Department of Biophysical Chemistry (Sweden); Kay, Lewis E. [University of Toronto, Departments of Medical Genetics and Chemistry (Canada)], E-mail: kay@pound.med.utoronto.ca

    2007-07-15

    A simple labeling approach is presented based on protein expression in [1-{sup 13}C]- or [2-{sup 13}C]-glucose containing media that produces molecules enriched at methyl carbon positions or backbone C{sup {alpha}} sites, respectively. All of the methyl groups, with the exception of Thr and Ile({delta}1) are produced with isolated {sup 13}C spins (i.e., no {sup 13}C-{sup 13}C one bond couplings), facilitating studies of dynamics through the use of spin-spin relaxation experiments without artifacts introduced by evolution due to large homonuclear scalar couplings. Carbon-{alpha} sites are labeled without concomitant labeling at C{sup {beta}} positions for 17 of the common 20 amino acids and there are no cases for which {sup 13}C{sup {alpha}}-{sup 13}CO spin pairs are observed. A large number of probes are thus available for the study of protein dynamics with the results obtained complimenting those from more traditional backbone {sup 15}N studies. The utility of the labeling is established by recording {sup 13}C R{sub 1{rho}} and CPMG-based experiments on a number of different protein systems.

  12. Synthesis, morphology and microstructure of pomegranate-like hematite ({alpha}-Fe{sub 2}O{sub 3}) superstructure with high coercivity

    Energy Technology Data Exchange (ETDEWEB)

    Tadic, Marin, E-mail: marint@vinca.rs [Condensed Matter Physics Laboratory, Vinca Institute, University of Belgrade, P.O. Box 522, 11001 Belgrade (Serbia); Citakovic, Nada [Military Academy, Generala Pavla Jurisica Sturma 33, University of Belgrade, 11000 Belgrade (Serbia); Panjan, Matjaz [Jozef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia); Stanojevic, Boban [Vinca Institute of Nuclear Sciences, P.O. Box 522, 11001 Belgrade, University of Belgrade (Serbia); Markovic, Dragana [Condensed Matter Physics Laboratory, Vinca Institute, University of Belgrade, P.O. Box 522, 11001 Belgrade (Serbia); Jovanovic, Dorde [Center for Solid State Physics and New Materials, Institute of Physics, University of Belgrade, Pregrevica 118, 11080 Belgrade (Serbia); Spasojevic, Vojislav [Condensed Matter Physics Laboratory, Vinca Institute, University of Belgrade, P.O. Box 522, 11001 Belgrade (Serbia)

    2012-12-05

    Highlights: Black-Right-Pointing-Pointer We found superior magnetic properties of the hematite ({alpha}-Fe{sub 2}O{sub 3}). Black-Right-Pointing-Pointer TEM and HRTEM images show a pomegranate-like superstructure. Black-Right-Pointing-Pointer Magnetic measurements display high coercivity H{sub C} = 4350 Oe at the room temperature. - Abstract: We found novel and superior magnetic properties of the hematite ({alpha}-Fe{sub 2}O{sub 3}) that originate from an internal microstructure of particles and strong inter-particle interactions between nanocrystal sub-units. The hematite particles were synthesized by thermal decomposition of iron (III) nitrate without any template or surfactant. The purity, size, crystallinity, morphology, microstructure and magnetic features of the as-prepared particles were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), Raman spectroscopy (RS) and SQUID magnetometry. An XRD study reveals a pure phase of {alpha}-Fe{sub 2}O{sub 3} whereas TEM shows {alpha}-Fe{sub 2}O{sub 3} spheres with a diameter of about 150 nm. RS also shows high quality and purity of the sample. Moreover, TEM and HRTEM images show a pomegranate-like superstructure and evidence that the spherical particles are composed of individual well-crystallized nanoparticle sub-units (self-assembled nanoparticles) with a size of about 20 nm. Magnetic measurements display hysteretic behavior at the room temperature with remanent magnetization M{sub r} = 0.731 emu/g, saturation magnetization M{sub S} = 6.83 emu/g and coercivity H{sub C} = 4350 Oe, as well as the Morin transition at T{sub M} = 261 K. These results and comparison with those in the literature reveal that the sample has extremely high coercivity. The magnetic properties of the sample are discussed in relation to morphology, internal microstructure, surface

  13. Dynamic properties of ionospheric plasma turbulence driven by high-power high-frequency radiowaves

    Science.gov (United States)

    Grach, S. M.; Sergeev, E. N.; Mishin, E. V.; Shindin, A. V.

    2017-02-01

    A review is given of the current state-of-the-art of experimental studies and the theoretical understanding of nonlinear phenomena that occur in the ionospheric F-layer irradiated by high-power high-frequency ground-based transmitters. The main focus is on the dynamic features of high-frequency turbulence (plasma waves) and low-frequency turbulence (density irregularities of various scales) that have been studied in experiments at the Sura and HAARP heating facilities operated in temporal and frequency regimes specially designed with consideration of the characteristic properties of nonlinear processes in the perturbed ionosphere using modern radio receivers and optical instruments. Experimental results are compared with theoretical turbulence models for a magnetized collisional plasma in a high-frequency electromagnetic field, allowing the identification of the processes responsible for the observed features of artificial ionospheric turbulence.

  14. OTDM Networking for Short Range High-Capacity Highly Dynamic Networks

    DEFF Research Database (Denmark)

    Medhin, Ashenafi Kiros

    This PhD thesis aims at investigating the possibility of designing energy-efficient high-capacity (up to Tbit/s) optical network scenarios, leveraging on the effect of collective switching of many bits simultaneously, as is inherent in high bit rate serial optical data signals. The focus...... is on short range highly dynamic networks, catering to data center needs. The investigation concerns optical network scenarios, and experimental implementations of high bit rate serial data packet generation and reception, scalable optical packet labeling, simple optical label extraction and stable ultra......-fast optical packet switching, with the constraint that there must be potential energy savings, which is also evaluated. A survey of the current trends in data centers is given and state-of-the-art research approaches are mentioned. Optical time-division multiplexing is proposed and demonstrated to generate...

  15. A high-dynamic range transimpedance amplifier with compression

    Science.gov (United States)

    Mičušík, D.; Zimmermann, H.

    2007-02-01

    This paper presents a transimpedance amplifier (TIA) with the logarithmic compression of the input current signal. The presented TIA has two regions of operation: a linear one for small input current signals and a compression one for high input currents, that could otherwise saturate the TIA. The measured -3dB bandwidth in the linear region of operation is 102MHz. The measured maximum input current overdrive is 20.5mA. However, the maximum of the monotonic compression is approx. 8mA. Using the compression technique we could achieve low rms equivalent input noise current (~20.2nA) within the measured bandwidth and with approx. 2pF capacitance at the input. Thus the dynamic range at the input of the TIA is approx. 120dB considering the maximal current overdrive. The proposed TIA represents the input stage of a optical receiver with integrated differential 50Ω output driver. The optical receiver occupies approx. 1.24mm2 in 0.35 μm SiGe BiCMOS technology and consumes 78mA from 5V supply.

  16. Dynamic Epigenetic Control of Highly Conserved Noncoding Elements

    KAUST Repository

    Seridi, Loqmane

    2014-10-07

    Background Many noncoding genomic loci have remained constant over long evolutionary periods, suggesting that they are exposed to strong selective pressures. The molecular functions of these elements have been partially elucidated, but the fundamental reason for their extreme conservation is still unknown. Results To gain new insights into the extreme selection of highly conserved noncoding elements (HCNEs), we used a systematic analysis of multi-omic data to study the epigenetic regulation of such elements during the development of Drosophila melanogaster. At the sequence level, HCNEs are GC-rich and have a characteristic oligomeric composition. They have higher levels of stable nucleosome occupancy than their flanking regions, and lower levels of mononucleosomes and H3.3, suggesting that these regions reside in compact chromatin. Furthermore, these regions showed remarkable modulations in histone modification and the expression levels of adjacent genes during development. Although HCNEs are primarily initiated late in replication, about 10% were related to early replication origins. Finally, HCNEs showed strong enrichment within lamina-associated domains. Conclusion HCNEs have distinct and protective sequence properties, undergo dynamic epigenetic regulation, and appear to be associated with the structural components of the chromatin, replication origins, and nuclear matrix. These observations indicate that such elements are likely to have essential cellular functions, and offer insights into their epigenetic properties.

  17. High Temperature Dynamic Pressure Measurements Using Silicon Carbide Pressure Sensors

    Science.gov (United States)

    Okojie, Robert S.; Meredith, Roger D.; Chang, Clarence T.; Savrun, Ender

    2014-01-01

    Un-cooled, MEMS-based silicon carbide (SiC) static pressure sensors were used for the first time to measure pressure perturbations at temperatures as high as 600 C during laboratory characterization, and subsequently evaluated in a combustor rig operated under various engine conditions to extract the frequencies that are associated with thermoacoustic instabilities. One SiC sensor was placed directly in the flow stream of the combustor rig while a benchmark commercial water-cooled piezoceramic dynamic pressure transducer was co-located axially but kept some distance away from the hot flow stream. In the combustor rig test, the SiC sensor detected thermoacoustic instabilities across a range of engine operating conditions, amplitude magnitude as low as 0.5 psi at 585 C, in good agreement with the benchmark piezoceramic sensor. The SiC sensor experienced low signal to noise ratio at higher temperature, primarily due to the fact that it was a static sensor with low sensitivity.

  18. High Dynamic Range Beam Imaging with Two Simultaneously Sampling CCDs

    Energy Technology Data Exchange (ETDEWEB)

    Evtushenko, Pavel [JLAB; Douglas, David R. [JLAB; Legg, Robert A. [JLAB; Tennant, Christopher D. [JLAB

    2013-05-01

    Transverse beam profile measurement with sufficiently high dynamic range (HDR) is a key diagnostic to measure the beam halo, understand its sources and evolution. In this contribution we describe our initial experience with the HDR imaging of the electron beam at the JLab FEL. On contrary to HDR measurements made with wire scanners in counting mode, which provide only two or three 1D projections of transverse beam distribution, imaging allows to measure the distribution itself. That is especially important for non-equilibrium beams in the LINACs. The measurements were made by means of simultaneous imaging with two CCD sensors with different exposure time. Two images are combined then numerically in to one HDR image. The system works as an online tool providing HDR images at 4 Hz. An optically polished YAG:Ce crystal with the thickness of 100 {micro}m was used for the measurements. When tested with a laser beam images with the DR of about 10{sup 5} were obtained. With the electron beam the DR was somewhat smaller due to the limitations in the time structure of the tune-up beam macro pulse.

  19. High Dynamic Range Beam Imaging with Two Simultaneously Sampling CCDs

    Energy Technology Data Exchange (ETDEWEB)

    Evtushenko, Pavel E. [JLAB; Douglas, David R. [JLAB

    2013-06-01

    Transverse beam profile measurement with sufficiently high dynamic range (HDR) is a key diagnostic to measure the beam halo, understand its sources and evolution. In this contribution we describe our initial experience with the HDR imaging of the electron beam at the JLab FEL. On contrary to HDR measurements made with wire scanners in counting mode, which provide only two or three 1D projections of transverse beam distribution, imaging allows to measure the distribution itself. That is especially important for non-equilibrium beams in the LINACs. The measurements were made by means of simultaneous imaging with two CCD sensors with different exposure time. Two images are combined then numerically in to one HDR image. The system works as an online tool providing HDR images at 4 Hz. An optically polished YAG:Ce crystal with the thickness of 100 {micro}m was used for the measurements. When tested with a laser beam images with the DR of about 10{sup 5} were obtained. With the electron beam the DR was somewhat smaller due to the limitations in the time structure of the tune-up beam macro pulse.

  20. Advances to Dynamic Mechanical Analysis: High Frequencies and Environmental Applications

    Science.gov (United States)

    Foreman, Jonathon

    2002-03-01

    In dynamic mechanical analysis (DMA) the sample is deformed and released sinusoidally providing information about the modulus and damping behaviors with respect to temperature, time, oscillation frequency and amplitude of motion. It offers exceptional sensitivity to glass transitions and secondary relaxations. Recent developments have increased the frequency range up to 1000 Hz, which allow properties measurements under actual end-use conditions. Furthermore high frequencies enhance the ability to determine the kinetics of viscoelastic relaxations. Another recent development allows DMA measurements while samples are immersed in fluids or enveloped in gases. Most significant is the ability to alter the furnace control parameters to account for the thermal properties of the environment used. This configuration allows temperature-controlled measurements (both heating and isothermal profiles) on a wide range of sample shapes and sizes. Environmental DMA is easier to interpret than standard DMA (in air or inert gas) on preconditioned samples because such samples often lose the conditioning solvent or gas during the measurement. easy.com/dma_apps.asp>Examples will show real-time property changes from the interaction of unconditioned materials with conditioning environments and experiments on pre-conditioned materials that are heated while immersed in conditioning environments. -------------------------------------------------------------

  1. Interferon-alpha induced Raynaud's syndrome.

    Science.gov (United States)

    Kruit, W H; Eggermont, A M; Stoter, G

    2000-11-01

    The cytokine interferon-alpha (IFN-alpha) is increasingly prescribed for a number of indications, especially viral hepatitis and several malignancies. Two patients are described who developed Raynaud's syndrome during treatment with IFN-alpha as adjuvant therapy for high-risk melanoma. With a review of the available literature the symptomatology, possible pathophysiologic mechanisms and treatment options are discussed.

  2. Proteinaceous alpha-araylase inhibitors

    DEFF Research Database (Denmark)

    Svensson, Birte; Fukuda, Kenji; Nielsen, P.K.

    2004-01-01

    Proteins that inhibit alpha-amylases have been isolated from plants and microorganisms. These inhibitors can have natural roles in the control of endogenous a-amylase activity or in defence against pathogens and pests; certain inhibitors are reported to be antinutritional factors. The alpha-amylase...... inhibitors belong to seven different protein structural families, most of which also contain evolutionary related proteins without inhibitory activity. Two families include bifunctional inhibitors acting both on alpha-amylases and proteases. High-resolution structures are available of target alpha-amylases...... in complex with inhibitors from five families. These structures indicate major diversity but also some similarity in the structural basis of alpha-amylase inhibition. Mutational analysis of the mechanism of inhibition was performed in a few cases and various protein engineering and biotechnological...

  3. Dynamics of alpha-globin locus chromatin structure and gene expression during erythroid differentiation of human CD34(+) cells in culture.

    Science.gov (United States)

    Mahajan, Milind C; Karmakar, Subhradip; Newburger, Peter E; Krause, Diane S; Weissman, Sherman M

    2009-10-01

    The aim of the present study has been to establish serum-free culture conditions for ex vivo expansion and differentiation of human CD34(+) cells into erythroid lineage and to study the chromatin structure, gene expression, and transcription factor recruitment at the alpha-globin locus in the developing erythron. A basal Iscove's modified Dulbecco's medium cell culture medium with 1% bovine serum albumin as a serum replacement and a combination of cytokines and growth factors was used for expansion and differentiation of the CD34(+) cells. Expression patterns of the alpha- and beta-like genes at various stages of erythropoiesis was studied by reverse transcriptase quantitative polymerase chain reaction analysis, profile of key erythroid transcription factors was investigated by Western blotting, and the chromatin structure and transcription factor recruitment at the alpha-globin locus was investigated by chromatin immunoprecipitation quantitative polymerase chain reaction analysis. Human CD34(+) cells in the serum-free medium undergo near synchronous erythroid differentiation to yield large amount of cells at different differentiation stages. We observe distinct patterns of the histone modifications and transcription factor binding at the alpha-globin locus during erythroid differentiation of CD34(+) cells. Nuclear factor erythroid-derived 2 (NF-E2) was present at upstream activator sites even before addition of erythropoietin (EPO), while bound GATA-1 was only detectable after EPO treatment. After 7 days of EPO treatment, H3K4Me2 modification uniformly increases throughout the alpha-globin locus. Acetylation at H3K9 and binding of Pol II, NF-E2, and GATA-1 were restricted to certain hypersensitive sites of the enhancer and theta gene, and were conspicuously low at the alpha-like globin promoters. Rearrangement of the insulator binding factor CTCF took place at and around the alpha-globin locus as CD34(+) cells differentiated into erythroid pathway. Our results

  4. Serine protease espP subtype alpha, but not beta or gamma, of Shiga toxin-producing Escherichia coli is associated with highly pathogenic serogroups.

    Science.gov (United States)

    Khan, Abdul Basit; Naim, Asma; Orth, Dorothea; Grif, Katharina; Mohsin, Mashkoor; Prager, Rita; Dierich, Manfred P; Würzner, Reinhard

    2009-04-01

    Besides Shiga toxins (Stx), Stx-producing Escherichia coli (STEC) harbour several other putative virulence factors, including the serine protease EspP. We have investigated 214 STEC strains from Austria belonging to 61 different serotypes from humans, animals, and food for the presence of this serine protease gene and have determined the espP subtypes and their association with clinical outcome. espP was detected in 121 (57%) out of 214 strains. Sixty-five of 68 strains (96%) of non-sorbitol-fermenting (NSF) O157:H7/NM (NM, non-motile) were positive for espP, while none of 8 SF E. coli O157:NM isolates contained this gene. All 9 strains of serotype O145:NM and 17 of 21 strains (81%) of serotype O26:H11/NM were positive for espP. Nineteen STEC serogroups including O103 and O111 serogroups--considered to be highly pathogenic--were completely negative for espP. Only 5 of 12 strains isolated from patients suffering from haemolytic uraemic syndrome (HUS) were espP-positive (all serogroup NSF O157) as well as 28 of 39 strains from patients with bloody diarrhoea, 40 of 63 strains from patients with non-bloody diarrhoea, and 15 of 19 strains from asymptomatic patients. In O157:H7/NM, O26:H11/NM, and O145:NM only espP subtype alpha was found, whereas in most of the other non-O157 serogroups, subtypes beta and gamma were found. Subtype delta was not detected in our strain collection. Regarding the espP subtypes, only subtype alpha, but not beta and gamma, were found in HUS patients. Moreover, we could demonstrate that espP, and in particular subtype alpha, is associated with highly pathogenic serogroups.

  5. Semi-preparative separation of {alpha} and {beta}-amyrin by high performance liquid chromatographic; Separacao semipreparativa de {alpha} e {beta}-amirina por cromatografia liquida de alta eficiencia

    Energy Technology Data Exchange (ETDEWEB)

    Dias, Marluce Oliveira; Hamerski, Lidilhone; Pinto, Angelo C., E-mail: hamerski_1@hotmail.co [Universidade Federal do Rio de Janeiro (IQ/UFRJ), RJ (Brazil). Inst. de Quimica

    2011-07-01

    The resin obtained from species of the genus Protium (Burseraceae) is formed mostly of pentacyclic triterpenes: {alpha}-amyrin and {beta}-amyrin. The separation and purification of these triterpenes were optimized in three steps. (author)

  6. Case Study - Alpha

    Directory of Open Access Journals (Sweden)

    Stephen Leybourne

    2016-11-01

    Full Text Available This case study was developed from an actual scenario by Dr. Steve Leybourne of Boston University.  The case documents the historical evolution of an organization, and has been used successfully in courses dealing with organizational and cultural change, and the utilization of ‘soft skills’ in project-based management. This is a short case, ideal for classroom use and discussion.  The issues are easily accessible to students, and there is a single wide ranging question that allows for the inclusion of many issues surrounding strategic decision-making, and behavioural and cultural change. Alpha was one of the earlier companies in the USA to invest in large, edge-of-town superstores, with plentiful free vehicle parking, selling food and related household products. Alpha was created in the 1950s as a subsidiary of a major publicly quoted retail group.  It started business by opening a string of very large discount stores in converted industrial and warehouse premises in the south of the United States. In the early days shoppers were offered a limited range of very competitively priced products. When Alpha went public in 1981 it was the fourth largest food retailer in the US, selling an ever-widening range of food and non-food products.  Its success continued to be based on high volume, low margins and good value for money, under the slogan of ‘Alpha Price.’

  7. Dipole oscillation modes in $\\alpha$-clustering light nuclei

    CERN Document Server

    He, W B; Cao, X G; Cai, X Z; Zhang, G Q

    2016-01-01

    The alpha cluster states are discussed in an extended quantum molecular dynamics (EQMD) model frame. Different alpha cluster structures are studied in details, such as $^8$Be two-alpha cluster structure, $^{12}$C triangle structure, $^{12}$C chain structure, $^{16}$O chain structure, $^{16}$O kite structure, and $^{16}$O square structure. The properties like width of wave packets for different alpha clusters, momentum distribution, and the binding energy among alpha clusters are studied. It is also discussed how the $\\alpha$ cluster degree of freedom affects nuclear collective vibrations. The different $\\alpha$ cluster configurations in $^{12}$C and $^{16}$O have corresponding characteristic spectra of GDR and the coherence of different alpha clusters's dipole oscillation are described in details. The number and centroid energies of peaks in the GDR spectra can be reasonably explained by the geometrical and dynamical symmetries of $\\alpha$-clustering configurations. The GDR can be regarded as a very effective...

  8. Lucid dreaming and alpha activity: a preliminary report.

    Science.gov (United States)

    Ogilvie, R D; Hunt, H T; Tyson, P D; Lucescu, M L; Jeakins, D B

    1982-12-01

    10 good dream recallers spent 2 nights in the sleep lab during which they were awakened 4 times per night from REM sleep, twice during their highest alpha activity in REM, and twice during low REM alpha. 5 were given alpha feedback training prior to sleep onset. Arousals from high alpha REM sleep yielded significantly higher lucidity ratings. Alpha feedback had no effect upon lucidity or REM alpha levels. Similarities between lucid dreams and meditative phenomena are discussed.

  9. Analog computation through high-dimensional physical chaotic neuro-dynamics

    Science.gov (United States)

    Horio, Yoshihiko; Aihara, Kazuyuki

    2008-07-01

    Conventional von Neumann computers have difficulty in solving complex and ill-posed real-world problems. However, living organisms often face such problems in real life, and must quickly obtain suitable solutions through physical, dynamical, and collective computations involving vast assemblies of neurons. These highly parallel computations through high-dimensional dynamics (computation through dynamics) are completely different from the numerical computations on von Neumann computers (computation through algorithms). In this paper, we explore a novel computational mechanism with high-dimensional physical chaotic neuro-dynamics. We physically constructed two hardware prototypes using analog chaotic-neuron integrated circuits. These systems combine analog computations with chaotic neuro-dynamics and digital computation through algorithms. We used quadratic assignment problems (QAPs) as benchmarks. The first prototype utilizes an analog chaotic neural network with 800-dimensional dynamics. An external algorithm constructs a solution for a QAP using the internal dynamics of the network. In the second system, 300-dimensional analog chaotic neuro-dynamics drive a tabu-search algorithm. We demonstrate experimentally that both systems efficiently solve QAPs through physical chaotic dynamics. We also qualitatively analyze the underlying mechanism of the highly parallel and collective analog computations by observing global and local dynamics. Furthermore, we introduce spatial and temporal mutual information to quantitatively evaluate the system dynamics. The experimental results confirm the validity and efficiency of the proposed computational paradigm with the physical analog chaotic neuro-dynamics.

  10. The influence of molecular weight, crosslinking and counterface roughness on TNF-alpha production by macrophages in response to ultra high molecular weight polyethylene particles.

    Science.gov (United States)

    Ingram, Joanne Helen; Stone, Martin; Fisher, John; Ingham, Eileen

    2004-08-01

    The response of murine macrophages to clinically relevant polyethylene wear particles generated from different polyethylenes at various time points and volumetric doses in vitro was evaluated. Clinically relevant ultra high molecular weight polyethylene (UHMWPE) wear debris was generated in vitro in a lubricant of RPMI 1640 supplemented with 25% (v/v) foetal calf serum using a multi-directional pin-on-plate wear rig under sterile conditions. Wear debris was cultured with C3H murine peritoneal macrophages at various particle volume (microm(3)): cell number ratios. The secretion of TNF-alpha was determined by ELISA. Initially the effect of molecular weight of UHMWPE was considered. Higher molecular weight GUR415HP was shown to have a lower wear rate than the lower molecular weight GUR1120, however a greater volume of the wear debris produced by the high molecular weight GUR415HP was in the 0.1-1.0 microm size range. Wear debris from GUR415HP produced significant levels of TNF-alpha at a concentration of 1 microm(3)/cell while at least 10 microm(3)/cell of GUR1120 wear debris per cell was needed to produce significant levels of TNF-alpha. Secondly the effects of crosslinking GUR1050 was examined when worn against a scratched counterface. The wear rate of the material was shown to decrease as the level of crosslinking increased. However the materials crosslinked with 5 and 10 Mrad of gamma irradiation produced higher percentages of 0.1-1.0 microm size wear particles than the non-crosslinked material. While the crosslinked material was able to stimulate cells to produce significantly elevated TNF-alpha levels at a particle concentration of just 0.1 microm(3)/cell only concentrations of 10 microm(3)/cell and above of the non-crosslinked wear debris were stimulatory. When the counterface was changed from scratched to smooth the wear rate for all three GUR1050 materials was further reduced. For the first time nanometre size wear particles were observed from polyethylene

  11. [Dynamics of tumour necrosis factor-alpha and clinical signs of osteoarthrosis during the treatment with alflutop in combination with peloid applications under conditions of health resort].

    Science.gov (United States)

    Maganev, V A; Davletshin, R A; Davletshina, G K; Iapparov, G S

    2011-01-01

    The objective of the present work was to develop indications for the combined treatment of patients presenting with osteoarthrosis including the use of peloid applications and intramuscular injections of alflutop. The study was based at Yakty-Kul' health resort and included 94 patients at the age from 40 to 59 years. The proposed method was shown to have beneficial effect on the patients' clinical conditions. In addition, the treatment caused a decrease in the level of tumour necrosis factor-alpha (TNF-alpha) that turned out to be related to the articular index.

  12. Features of the gas discharge in the narrow gap micro-pattern gas detectors (MPGD) at a high level of alpha-particles background

    CERN Document Server

    Razin, V I

    2010-01-01

    In given article preliminary results of the research of the electron multiplication in MPGD are presented at a high level of alpha-particles background. This work has expanded borders of understanding of the streamer mode nature. It is seen as a complex from electrostatic and electromagnetic interactions which begin with appearance of the precursor in plasma state. In an inter-electrode gap the plasma oscillations occur, accompanied by longitudinal elastic waves of ionization, which can reach the cathode surface with induced negative charge. With the release of this charge due to previously established conducting channel there is a strong current pulse, accompanied by the emission due to recombination of positive and negative ions and a thin cord or streamer derive. In the aim of the MPGD protection from the spark breakdown at a high level of the alpha-particle background the next gas composition from a buffer, cooling and electronegative components are offered: 70% He +28% CF4 +2% SF6.

  13. Dynamics of a high speed impeller - Analysis and experimental verification

    Science.gov (United States)

    Straub, F. K.; Ngo, H.; Silverthorn, L. J.; Ruopsa, J. A.

    1993-04-01

    Centrifugal compressors are used on numerous aircraft as an efficient and lightweight source of air. The impeller is the key compressor component, both from an aerodynamic and structural dynamics point of view. The present paper investigates the structural dynamics of the blades of a particular impeller, using analytical and experimental methods. Correlation of results show good agreement. The analytical model is then used for design studies to improve the fatigue life of the impeller blades.

  14. Role of glycine residues highly conserved in the S2-S3 linkers of domains I and II of voltage-gated calcium channel alpha(1) subunits.

    Science.gov (United States)

    Teng, Jinfeng; Iida, Kazuko; Ito, Masanori; Izumi-Nakaseko, Hiroko; Kojima, Itaru; Adachi-Akahane, Satomi; Iida, Hidetoshi

    2010-05-01

    The pore-forming component of voltage-gated calcium channels, alpha(1) subunit, contains four structurally conserved domains (I-IV), each of which contains six transmembrane segments (S1-S6). We have shown previously that a Gly residue in the S2-S3 linker of domain III is completely conserved from yeasts to humans and important for channel activity. The Gly residues in the S2-S3 linkers of domains I and II, which correspond positionally to the Gly in the S2-S3 linker of domain III, are also highly conserved. Here, we investigated the role of the Gly residues in the S2-S3 linkers of domains I and II of Ca(v)1.2. Each of the Gly residues was replaced with Glu or Gln to produce mutant Ca(v)1.2s; G182E, G182Q, G579E, G579Q, and the resulting mutants were transfected into BHK6 cells. Whole-cell patch-clamp recordings showed that current-voltage relationships of the four mutants were the same as those of wild-type Ca(v)1.2. However, G182E and G182Q showed significantly smaller current densities because of mislocalization of the mutant proteins, suggesting that Gly(182) in domain I is involved in the membrane trafficking or surface expression of alpha(1) subunit. On the other hand, G579E showed a slower voltage-dependent current inactivation (VDI) compared to Ca(v)1.2, although G579Q showed a normal VDI, implying that Gly(579) in domain II is involved in the regulation of VDI and that the incorporation of a negative charge alters the VDI kinetics. Our findings indicate that the two conserved Gly residues are important for alpha(1) subunit to become functional.

  15. Veal Calves Produce Less Antibodies against C. Perfringens Alpha Toxin Compared to Beef Calves

    Directory of Open Access Journals (Sweden)

    Bonnie R. Valgaeren

    2015-07-01

    Full Text Available Enterotoxaemia is a disease with a high associated mortality rate, affecting beef and veal calves worldwide, caused by C. perfringens alpha toxin and perfringolysin. A longitudinal study was conducted to determine the dynamics of antibodies against these toxins in 528 calves on 4 beef and 15 veal farms. The second study aimed to determine the effect of solid feed intake on the production of antibodies against alpha toxin and perfringolysin. The control group only received milk replacer, whereas in the test group solid feed was provided. Maternal antibodies for alpha toxin were present in 45% of the veal calves and 66% of the beef calves. In beef calves a fluent transition from maternal to active immunity was observed for alpha toxin, whereas almost no veal calves developed active immunity. Perfringolysin antibodies significantly declined both in veal and beef calves. In the second study all calves were seropositive for alpha toxin throughout the experiment and solid feed intake did not alter the dynamics of alpha and perfringolysin antibodies. In conclusion, the present study showed that veal calves on a traditional milk replacer diet had significantly lower alpha toxin antibodies compared to beef calves in the risk period for enterotoxaemia, whereas no differences were noticed for perfringolysin.

  16. Substructure method in high-speed monorail dynamic problems

    Science.gov (United States)

    Ivanchenko, I. I.

    2008-12-01

    The study of actions of high-speed moving loads on bridges and elevated tracks remains a topical problem for transport. In the present study, we propose a new method for moving load analysis of elevated tracks (monorail structures or bridges), which permits studying the interaction between two strained objects consisting of rod systems and rigid bodies with viscoelastic links; one of these objects is the moving load (monorail rolling stock), and the other is the carrying structure (monorail elevated track or bridge). The methods for moving load analysis of structures were developed in numerous papers [1-15]. At the first stage, when solving the problem about a beam under the action of the simplest moving load such as a moving weight, two fundamental methods can be used; the same methods are realized for other structures and loads. The first method is based on the use of a generalized coordinate in the expansion of the deflection in the natural shapes of the beam, and the problem is reduced to solving a system of ordinary differential equations with variable coefficients [1-3]. In the second method, after the "beam-weight" system is decomposed, just as in the problem with the weight impact on the beam [4], solving the problem is reduced to solving an integral equation for the dynamic weight reaction [6, 7]. In [1-3], an increase in the number of retained forms leads to an increase in the order of the system of equations; in [6, 7], difficulties arise when solving the integral equations related to the conditional stability of the step procedures. The method proposed in [9, 14] for beams and rod systems combines the above approaches and eliminates their drawbacks, because it permits retaining any necessary number of shapes in the deflection expansion and has a resolving system of equations with an unconditionally stable integration scheme and with a minimum number of unknowns, just as in the method of integral equations [6, 7]. This method is further developed for

  17. Lyman-alpha radiation hydrodynamics of galactic winds before cosmic reionization

    Science.gov (United States)

    Smith, Aaron; Bromm, Volker; Loeb, Abraham

    2017-01-01

    Radiation from the first stars and galaxies initiated the dramatic phase transition marking an end to the cosmic dark ages. The emission and absorption signatures from the Lyman-alpha transition of neutral hydrogen have been indispensable in extending the observational frontier for high-redshift galaxies into the epoch of reionization. Lyman-alpha radiative transfer provides clues about the processes leading to Lyman-alpha escape from individual galaxies and the subsequent transmission through the intergalactic medium. Cosmological simulations incorporating Lyman-alpha radiative transfer enhance our understanding of fundamental physics by supplying the inferred spectra and feedback on the gas. We discuss the dynamical impact of Lyman-alpha radiation pressure on galaxy formation throughout cosmic reionization with the first fully coupled Lyman-alpha radiation-hydrodynamics simulations. We self-consistently follow the chemistry, cooling, self-gravity, and ionizing radiation in protogalaxies and find that Lyman-alpha radiation pressure turns out to be dynamically important in several spherically symmetric simulations. As a case in point we apply our model to the COSMOS redshift 7 (CR7) galaxy at z = 6.6, which exhibits a +160 km/s velocity offset between the Lyman-alpha and HeII line peaks. We find that a massive black hole with a nonthermal Compton-thick spectrum is able to reproduce the observed Lyman-alpha signatures as a result of higher photon trapping and longer potential lifetime. We conclude with a general discussion of Lyman-alpha radiation in the first galaxies by considering simulations that cover the expected range of halo and source properties.

  18. Impairment of mitochondria dynamics by human A53T alpha-synuclein and rescue by NAP (davunetide) in a cell model for Parkinson's disease

    NARCIS (Netherlands)

    Q. Melo, T.; van Zomeren, K. C.; Ferrari, M F R; Boddeke, H. W. G. M.; Copray, J. C. V. M.

    The formation of oligomers and aggregates of overexpressed or mutant alpha-synuclein play a role in the degeneration of dopaminergic neurons in Parkinson's disease by causing dysfunction of mitochondria, reflected in their disturbed mobility and production of ROS. The mode of action and mechanisms

  19. Very High Efficiency, Miniaturized, Long-Lived Alpha Particle Power Source Using Diamond Devices for Extreme Space Environments

    Science.gov (United States)

    Kolawa, Elizabeth A. (Inventor); Patel, Jagdishbhai U. (Inventor); Fleurial, Jean-Pierre (Inventor)

    2004-01-01

    A power source that converts a-particle energy into electricity by coulomb collision in doped diamond films is described. Alpha particle decay from curium-244 creates electron-hole pairs by free- ing electrons and holes inside the crystal lattice in N- and P-doped diamond films. Ohmic contacts provide electrical connection to an electronic device. Due to the built-in electric field at the rectifying junction across the hT- and P-doped diamond films, the free electrons are constrained to traveling in generally one direction. This one direction then supplies electrons in a manner similar to that of a battery. The radioactive curium layer may be disposed on diamond films for even distribution of a-particle radiation. The resulting power source may be mounted on a diamond substrate that serves to insulate structures below the diamond substrate from a-particle emission. Additional insulation or isolation may be provided in order to prevent damage from a-particle collision. N-doped silicon may be used instead of N-doped diamond.

  20. Glycation promoted by dynamic high pressure microfluidisation pretreatment revealed by high resolution mass spectrometry.

    Science.gov (United States)

    Huang, Xiaoqin; Tu, Zongcai; Wang, Hui; Zhang, Qiuting; Hu, Yueming; Zhang, Lan; Niu, Peipei; Shi, Yan; Xiao, Hui

    2013-12-01

    The effect of dynamic high pressure microfluidisation (DHPM) pretreatment on the glycation of bovine serum albumin (BSA) was investigated. A detailed glycation map was obtained from high resolution mass spectrometry. Without DHPM pretreatment, only 7 glycation sites were identified, whereas the numbers were increased to 10, 11 and 11 when BSA-glucose was pretreated with DHPM at 50, 100 and 200 MPa, respectively, suggesting that DHPM pretreatment can significantly promote the Maillard reaction. Average degree of substitution per peptide molecule BSA (DSP) was used to further evaluate the glycation level under various DHPM conditions. All the DHPM pretreated samples exhibited elevated glycation level compared to the un-pretreated sample. With 100 MPa DHPM pretreatment, the protein showed the most significantly enhanced glycation extent. In addition, our results suggest that Maillard-type glycation followed by mass spectrometry analysis can be used to study the conformational changes when proteins are disturbed by external forces.

  1. Alpha heating in toroidal devices

    Energy Technology Data Exchange (ETDEWEB)

    Miley, G.H.

    1978-01-01

    Ignition (or near-ignition) by alpha heating is a key objective for the achievement of economic fusion reactors. While good confinement of high-energy alphas appears possible in larger reactors, near-term tokamak-type ignition experiments as well as some concepts for small reactors (e.g., the Field-Reversed Mirror or FRM) potentially face marginal situations. Consequently, there is a strong motivation to develop methods to evaluate alpha losses and heating profiles in some detail. Such studies for a TFTR-size tokamak and for a small FRM are described here.

  2. Analysis of transistor and snubber turn-off dynamics in high-frequency high-voltage high-power converters

    Science.gov (United States)

    Wilson, P. M.; Wilson, T. G.; Owen, H. A., Jr.

    1982-01-01

    Dc to dc converters which operate reliably and efficiently at switching frequencies high enough to effect substantial reductions in the size and weight of converter energy storage elements are studied. A two winding current or voltage stepup (buck boost) dc-to-dc converter power stage submodule designed to operate in the 2.5-kW range, with an input voltage range of 110 to 180 V dc, and an output voltage of 250 V dc is emphasized. In order to assess the limitations of present day component and circuit technologies, a design goal switching frequency of 10 kHz was maintained. The converter design requirements represent a unique combination of high frequency, high voltage, and high power operation. The turn off dynamics of the primary circuit power switching transistor and its associated turn off snubber circuitry are investigated.

  3. Analysis of transistor and snubber turn-off dynamics in high-frequency high-voltage high-power converters

    Science.gov (United States)

    Wilson, P. M.; Wilson, T. G.; Owen, H. A., Jr.

    Dc to dc converters which operate reliably and efficiently at switching frequencies high enough to effect substantial reductions in the size and weight of converter energy storage elements are studied. A two winding current or voltage stepup (buck boost) dc-to-dc converter power stage submodule designed to operate in the 2.5-kW range, with an input voltage range of 110 to 180 V dc, and an output voltage of 250 V dc is emphasized. In order to assess the limitations of present day component and circuit technologies, a design goal switching frequency of 10 kHz was maintained. The converter design requirements represent a unique combination of high frequency, high voltage, and high power operation. The turn off dynamics of the primary circuit power switching transistor and its associated turn off snubber circuitry are investigated.

  4. F-18 high alpha research vehicle surface pressures: Initial in-flight results and correlation with flow visualization and wind-tunnel data

    Science.gov (United States)

    Fisher, David F.; Banks, Daniel W.; Richwine, David M.

    1990-01-01

    Pressure distributions measured on the forebody and the leading-edge extensions (LEX's) of the NASA F-18 high alpha research vehicle (HARV) were reported at 10 and 50 degree angles of attack and at Mach 0.20 to 0.60. The results were correlated with HARV flow visualization and 6-percent scale F-18 wind-tunnel-model test results. The general trend in the data from the forebody was for the maximum suction pressure peaks to first appear at an angle of attack (alpha) of approximately 19 degrees and increase in magnitude with angle of attack. The LEX pressure distribution general trend was the inward progression and increase in magnitude of the maximum suction peaks up to vortex core breakdown and then the decrease and general flattening of the pressure distribution beyond that. No significant effect of Mach number was noted for the forebody results. However, a substantial compressibility effect on the LEX's resulted in a significant reduction in vortex-induced suction pressure as Mach number increased. The forebody primary and the LEX secondary vortex separation lines, from surface flow visualization, correlated well with the end of pressure recovery, leeward and windward, respectively, of maximum suction pressure peaks. The flight to wind-tunnel correlations were generally good with some exceptions.

  5. High sensitivity boron quantification in bulk silicon using the {sup 11}B(p,{alpha}{sub 0}){sup 8}Be nuclear reaction

    Energy Technology Data Exchange (ETDEWEB)

    Moro, Marcos V.; Silva, Tiago F. da; Added, Nemitala; Rizutto, Marcia A.; Tabacniks, Manfredo H. [Instituto de Fisica da Universidade de Sao Paulo, C.P. 66318, 05315-970 Sao Paulo, SP (Brazil); Neira, John B.; Neto, Joao B. F. [Institute of Research Tecnology, Cidade Universitaria, SP, 05508-091 (Brazil)

    2013-05-06

    There is a great need to quantify sub-ppm levels of boron in bulk silicon. There are several methods to analyze B in Si: Nuclear Reaction Analysis using the {sup 11}B(p,{alpha}{sub 0}){sup 8}Be reaction exhibits a quantification limit of some hundreds ppm of B in Si. Heavy Ion Elastic Recoil Detection Analysis offers a detection limit of 5 to 10 at. ppm. Secondary Ion Mass Spectrometry is the method of choice of the semiconductor industry for the analysis of B in Si. This work verifies the use of NRA to quantify B in Si, and the corresponding detection limits. Proton beam with 1.6 up to 2.6 MeV was used to obtain the cross-section of the {sup 11}B(p,{alpha}{sub 0}){sup 8}Be nuclear reaction at 170 Degree-Sign scattering angle. The results show good agreementwith literature indicating that the quantification of boron in silicon can be achieved at 100 ppm level (high sensitivity) at LAMFI-IFUSP with about 16% uncertainty. Increasing the detection solid angle and the collected beam charge, can reduce the detection limit to less than 100 ppm meeting present technological needs.

  6. Alpha-linolenic acid intake prevents endothelial dysfunction in high-fat diet-fed streptozotocin rats and underlying mechanisms.

    Science.gov (United States)

    Zhang, Wei; Fu, Fang; Tie, Ru; Liang, Xiangyan; Tian, Fei; Xing, Wenjuan; Li, Jia; Ji, Lele; Xing, Jinliang; Sun, Xin; Zhang, Haifeng

    2013-11-01

    Hintergrund: Die endotheliale Dysfunktion ist ein wichtiger Faktor in der Pathogenenese von diabetes- assoziierten Gefäßkomplikationen. Alpha-Linolensäure (ALA) kann die flußvermittelte Dilatation der diabetischen Arterie vier Stunden postprandial erhöhen. Es ist aber weitgehend unklar, ob eine chronische ALA Supplementierung eine endotheliale Dysfunktion verhüten kann. Material und Methoden: Streptozotozin (HFD-STZ) Ratten unter hochdosierter Fettdiät (HFD-STZ) stellen ein Tiermodell für den Typ 2 Diabetes (T2DM) dar. Altersgleiche normale und HFD-STZ Ratten bekamen randomisiert eine normale Diät oder ALA (500 mg/kg pro Tag). Nach 5 Wochen wurde die endotheliale Dysfunktion gemessen. Ergebnisse: Diabetes verursachte eine signifikante endotheliale Dysfunktion (maximale Vasorelaxation auf Azetylcholin) in aortalen Segmenten. ALA Aufnahme milderte die endotheliale Dysfunktion. Superoxide Produktion and Peroxynitrite (ONOO-) Bildung waren unter ALA Supplementierung in den diabetischen Gefäßsegmenten vermindert. Bemerkenswerterweise verstärkte die ALA Aufnahme eNOS, hemmte aber die iNOS Aktivität in diabetischen Gefäßen. Darüber hinaus steigerte ALA die Aufnahme der eNOS Phosphorylation signifikant. Andererseits waren gp91phox und iNOS Überexpression moderat bei ALA Aufnahme reduziert. Schlussfolgerungen: ALA wirkt präventiv auf eine diabetes-induzierte endotheliale Dysfunktion, indem es die eNOS Aktivität verstärkt und den oxidativen/nitrativen Stress durch Hemmung der iNOS und NADPH Oxidase Expression und ONOO-Production mildert.

  7. Regio-selective detection of dynamic structure of transmembrane alpha-helices as revealed from (13)C NMR spectra of [3-13C]Ala-labeled bacteriorhodopsin in the presence of Mn2+ ion.

    Science.gov (United States)

    Tuzi, S; Hasegawa, J; Kawaminami, R; Naito, A; Saitô, H

    2001-07-01

    13C Nuclear magnetic resonance (NMR) spectra of [3-(13)C]Ala-labeled bacteriorhodopsin (bR) were edited to give rise to regio-selective signals from hydrophobic transmembrane alpha-helices by using NMR relaxation reagent, Mn(2+) ion. As a result of selective suppression of (13)C NMR signals from the surfaces in the presence of Mn(2+) ions, several (13)C NMR signals of Ala residues in the transmembrane alpha-helices were identified on the basis of site-directed mutagenesis without overlaps from (13)C NMR signals of residues located near the bilayer surfaces. The upper bound of the interatomic distances between (13)C nucleus in bR and Mn(2+) ions bound to the hydrophilic surface to cause suppressed peaks by the presence of Mn(2+) ion was estimated as 8.7 A to result in the signal broadening to 100 Hz and consistent with the data based on experimental finding. The Ala C(beta) (13)C NMR peaks corresponding to Ala-51, Ala-53, Ala-81, Ala-84, and Ala-215 located around the extracellular half of the proton channel and Ala-184 located at the kink in the helix F were successfully identified on the basis of (13)C NMR spectra of bR in the presence of Mn(2+) ion and site-directed replacement of Ala by Gly or Val. Utilizing these peaks as probes to observe local structure in the transmembrane alpha-helices, dynamic conformation of the extracellular half of bR at ambient temperature was examined, and the local structures of Ala-215 and 184 were compared with those elucidated at low temperature. Conformational changes in the transmembrane alpha-helices induced in D85N and E204Q and its long-range transmission from the proton release site to the site around the Schiff base in E204Q were also examined.

  8. A model for plasticity kinetics and its role in simulating the dynamic behavior of Fe at high strain rates

    Energy Technology Data Exchange (ETDEWEB)

    Colvin, J D; Minich, R W; Kalantar, D H

    2007-03-29

    The recent diagnostic capability of the Omega laser to study solid-solid phase transitions at pressures greater than 10 GPa and at strain rates exceeding 10{sup 7} s{sup -1} has also provided valuable information on the dynamic elastic-plastic behavior of materials. We have found, for example, that plasticity kinetics modifies the effective loading and thermodynamic paths of the material. In this paper we derive a kinetics equation for the time-dependent plastic response of the material to dynamic loading, and describe the model's implementation in a radiation-hydrodynamics computer code. This model for plasticity kinetics incorporates the Gilman model for dislocation multiplication and saturation. We discuss the application of this model to the simulation of experimental velocity interferometry data for experiments on Omega in which Fe was shock compressed to pressures beyond the {alpha}-to-{var_epsilon} phase transition pressure. The kinetics model is shown to fit the data reasonably well in this high strain rate regime and further allows quantification of the relative contributions of dislocation multiplication and drag. The sensitivity of the observed signatures to the kinetics model parameters is presented.

  9. Dynamic weakening by nanoscale smoothing during high velocity fault slip

    Science.gov (United States)

    Chen, X.; Madden, A. S.; Bickmore, B. R.; Reches, Z.

    2012-12-01

    the roughest, and the roughness of profiles parallel-and normal-to striations in-between. A systematic change of the PSD slope, beta, was observed. The un-sheared profiles have steep PSD curves, with beta = 2.3 ± 0.1, and profiles measured normal to the striations are smoother, but with similar slope. Profiles parallel to the striations are even smoother and with beta = 1.4 ± 0.4, indicating distinct roughness anisotropy. The RMS roughness was calculated along 1 micron segments either slip-parallel or slip-normal from the profile data. The relation between the AFM friction coefficients and the RMS indicate that at length scales of 0.01-10 microns, friction coefficients strongly correlate with roughness. We noted that surfaces with RMS > 0.1 micron, have FC approaching the "universal" friction coefficient of 0.6-0.85 (Byerlee law). We propose that fault smoothing under high velocity is an effective driving mechanism for dynamic weakening and earthquake instability.

  10. THz Generation Using Fluxon Dynamics in High Temperature Superconductors

    DEFF Research Database (Denmark)

    Pedersen, Niels Falsig; Madsen, S.

    2009-01-01

    We consider THz emission due to fluxon dynamics in a stack of inductively coupled long Josephson junctions connected electrically to a resonant cavity. By comparing to experiments on Josephson junction parametric amplifiers we consider the role of a negative resistance in connection with THz emis...

  11. Shaper Design in CMOS for High Dynamic Range

    Energy Technology Data Exchange (ETDEWEB)

    De Geronimo G.; Li S.

    2011-10-12

    We start with an analysis of the configurations commonly adopted to implement linear shapers. We show that, once the ENC from the charge amplifier is defined, the dynamic range of the system is set by the voltage swing and the value of the capacitance realizing the poles. The configuration used to realize the poles has also an impact, and those configurations based on passive components in feedback are expected to offer a higher dynamic range than the ones that use both active and passive components, like scaling mirrors. Finally, we introduce the concept of delayed dissipative feedback (DDF), which consists of delaying the resistive feedbacks from the furthest available nodes along the shaping chain. We will show that, in order to implement semi-Gaussian shapers, a small capacitor in positive feedback is required. The DDF technique can overcome some of the limitations of the more classical configurations. For example, in a third order shaper a factor of two higher dynamic range can be obtained or, at equal dynamic range, about 25% of the capacitance is needed (i.e. about 30% of the area in practical cases).

  12. Hybrid Young interferometer for high resolution measurement of dynamic speckle using high birefringence liquid crystal

    Science.gov (United States)

    Bennis, N.; Holdynski, Z.; Merta, I.; Marc, P.; Kula, P.; Mazur, R.; Piecek, W.; Jaroszewicz, L. R.

    2015-08-01

    It is well known that the Young interference experiment is the fundamental setup to combine two beams and to construct the phase modulated light. Moreover, homodyne phase demodulator is based on signal decoding in back Fourier focal plane using bicell photodetector (B-PD). On the above base, we propose a novel experimental approach to the signals demodulation by using the optical interferometer which operates in homodyne mode, combined with liquid crystal spatial light modulators operating both phase as speckle modulator. Dynamic phase changes between the two beams can be controlled by monopixel liquid crystals cell placed in one branch of the interferometer. A phase modulation effect in a signal arm of interferometer is observed as a dynamic shift of the speckle pattern. Simple arithmetic combination of signals from B-PD placed in speckle pattern plane is only one necessary numerical manipulation to obtain exactly phase difference. Concept of signals demodulation in the Fourier focal plane can be only used for exactly defined geometrical (B-PD as well as Young interferometer) and physical parameters (polarization, wavelength). We optimize the setup geometry to obtain extremely high measurement resolution. In this paper we focus on the principles of operation of each part of the system as well as discussion their requirement in order to increase the signal to noise ratio.

  13. High Temperature Dynamic Hohlraums on the Pulsed Power Driver Z.

    Science.gov (United States)

    Nash, Thomas J.

    1998-11-01

    In the concept of the dynamic hohlraum an imploding z-pinch is optically thick to its own radiation. Radiation may be trapped inside the pinch to give a radiation temperature inside the pinch greater than that outside the pinch. The radiation is typically produced by colliding an outer z-pinch liner onto an inner liner. The collision generates a strongly radiating shock, and the radiation is trapped by the outer liner. As the implosion continues after the collision the radiation temperature may continue to increase due to ongoing PdV work done by the implosion. In principal the radiation temperature may increase to the point at which the outer liner burns through, becomes optically thin, and no longer traps the radiation. One application of the dynamic hohlraum is to drive an ICF pellet with the trapped radiation field. Members of the dynamic hohlraum team at Sandia National Labs have used the pulsed power driver Z (20 MA, 100 ns) to create a dynamic hohlraum with temperature linearly ramping from 100 to 180 eV over 5 ns. On this shot zp214 we imploded a nested tungsten wire array of 4 and 2 cm diameters with masses of 2 and 1 mg onto a 2.5 mg plastic annulus at 5 mm diameter. The current return can on this shot was slotted. We anticipate that the radiation temperature may be increased to over 200 eV by stabilizing the pinch with a solid current return can. A current return can with 9 slots imprints 9 filaments onto the imploding pinch. This degrades the optical trapping and the quality of the liner collision. A 1.6 mm diameter capsule situated inside this dynamic hohlraum of zp214 would see 50 kJ of radiation impinging on its surface before the pinch itself collapses to a 1.6 mm diameter. Dynamic hohlraum shots including pellets are scheduled to take place on Z in September of 1998. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin company, for the US-DOE under contract DE-AC04-94AL85000.

  14. PLE CATALYZED HYDROLYZES OF ALPHA-SUBSTITUTED ALPHA-HYDROXY ESTERS - THE INFLUENCE OF THE SUBSTITUENTS

    NARCIS (Netherlands)

    MOORLAG, H; KELLOGG, RM

    1991-01-01

    The enzymatic hydrolyses of a variety of alpha-substituted mandelic and lactic esters using pig liver esterase (PLE) have been investigated. High to moderate enantioselectivity was found for various alpha-substituted mandelic esters, whereas PLE showed low to no enantioselectivity for alpha-substitu

  15. High temperature phonon dispersion in graphene using classical molecular dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Anees, P., E-mail: anees@igcar.gov.in; Panigrahi, B. K. [Materials Physics Division, Indira Gandhi Centre for Atomic Research, Kalpakkam-603102 (India); Valsakumar, M. C., E-mail: anees@igcar.gov.in [School of Engineering Sciences and Technology, University of Hyderabad, Hyderabad-500046 (India)

    2014-04-24

    Phonon dispersion and phonon density of states of graphene are calculated using classical molecular dynamics simulations. In this method, the dynamical matrix is constructed based on linear response theory by computing the displacement of atoms during the simulations. The computed phonon dispersions show excellent agreement with experiments. The simulations are done in both NVT and NPT ensembles at 300 K and found that the LO/TO modes are getting hardened at the Γ point. The NPT ensemble simulations capture the anharmonicity of the crystal accurately and the hardening of LO/TO modes is more pronounced. We also found that at 300 K the C-C bond length reduces below the equilibrium value and the ZA bending mode frequency becomes imaginary close to Γ along K-Γ direction, which indicates instability of the flat 2D graphene sheets.

  16. Design Specification for a Thrust-Vectoring, Actuated-Nose-Strake Flight Control Law for the High-Alpha Research Vehicle

    Science.gov (United States)

    Bacon, Barton J.; Carzoo, Susan W.; Davidson, John B.; Hoffler, Keith D.; Lallman, Frederick J.; Messina, Michael D.; Murphy, Patrick C.; Ostroff, Aaron J.; Proffitt, Melissa S.; Yeager, Jessie C.; hide

    1996-01-01

    Specifications for a flight control law are delineated in sufficient detail to support coding the control law in flight software. This control law was designed for implementation and flight test on the High-Alpha Research Vehicle (HARV), which is an F/A-18 aircraft modified to include an experimental multi-axis thrust-vectoring system and actuated nose strakes for enhanced rolling (ANSER). The control law, known as the HARV ANSER Control Law, was designed to utilize a blend of conventional aerodynamic control effectors, thrust vectoring, and actuated nose strakes to provide increased agility and good handling qualities throughout the HARV flight envelope, including angles of attack up to 70 degrees.

  17. High plasma tumor necrosis factor (TNF)-alpha concentrations and a sepsis-like syndrome in patients undergoing hyperthermic isolated limb perfusion with recombinant TNF-alpha, interferon-gamma, and melphalan

    NARCIS (Netherlands)

    Zwaveling, JH; Maring, JK; Clarke, FL; vanGinkel, RJ; Limburg, PC; Hoekstra, HJ; Girbes, ARJ; Schraffordt Koops, H.

    1996-01-01

    Objectives: To describe the postoperative course of patients who underwent hyperthermic isolated limb perfusion with recombinant tumor necrosis factor (TNF)-alpha and melphalan after pretreat ment with recombinant interferon-gamma as treatment for recurrent melanoma, primary nonresectable soft-tissu

  18. Dynamic High-speed Knotting of a Rope by a Manipulator

    Directory of Open Access Journals (Sweden)

    Yuji Yamakawa

    2013-10-01

    Full Text Available In this paper we suggest an entirely new strategy for the dexterous manipulation of a linear flexible object, such as rope or a cable, with a high-speed manipulator. We deal with a flexible rope as one example of the linear flexible object. The strategy involves manipulating the object at high-speed. By moving the robot at high-speed, we can assume that the dynamic behaviour of the flexible rope can be obtained by performing algebraic calculations of the high- speed robot motion. Based on this assumption, we derive a dynamic deformation model of the flexible rope and confirm the validity of the proposed model. Then we perform a simulation of dynamic, high-speed knotting based on the proposed model. We also discuss the possibility of forming the knot based on a simple analysis model. Finally, we show experimental results demonstrating dynamic, high-speed knotting with a high-speed manipulator.

  19. [The correction action of Phosprenyl and Gamavit on the functional activity of mouse peritoneal macrophages in response to high doses of Staphylococcus aureus alpha-toxin].

    Science.gov (United States)

    Zaĭtseva, L G; Bekhalo, V A; Vasil'ev, I K; Godunov, R S; Kireeva, I V; Kozhevnikova, T N; Nagurskaia, E V; Narovlianskiĭ, A N; Ozherelkov, S V; Pronin, A V; Sanin, A V

    2005-01-01

    The study of the functional activity of peritoneal macrophages of BALB/c mice at different stages of the toxic action caused by S. aureus alpha-toxin (ST) was carried out. The analysis of the dynamics of toxic reaction revealed the main critical points of triggering necrotic processes: the first hour and day 2. One hour after the injection of large doses of ST a sharp increase in the process of antigen binding with its subsequent sharp decrease. Simultaneously, a decrease in the activity of the lysosomal enzymes cathepsin D and acidic phosphatase was established, which was indicative of the destabilization of both lysosomal and cellular macrophage membranes. The increase of oxygen metabolism on day 2, together with the release of lysosomal proteases into the extracellular area, correlated with the maximum death rate of mice and served as the main index of the development of necrosis. The prophylactic and therapeutic use of the preparations Gamavit and Phosprenyl revealed their antitoxic activity and capacityfor stimulating the level of natural body resistance.

  20. Highly accurate fiber transfer delay measurement with large dynamic range

    CERN Document Server

    Dong, J W; Gao, C; Guo, Y C; Wang, L J

    2015-01-01

    A novel and efficient method for fiber transfer delay measurement is demonstrated. Fiber transfer delay measurement in time domain is converted into the frequency measurement of the modulation signal in frequency domain, accompany with a coarse and easy ambiguity resolving process. This method achieves a sub-picosecond resolution, with an accuracy of 1 picosecond, and a large dynamic range up to 50 km as well as no measurement dead zone.